sensor technology: september 2014
DESCRIPTION
Smaller Than a Grain of Sand - mCube's Sensors Enable IoMTTRANSCRIPT
S E P T EMB E R 2 0 1 4
Interview with Ben LeePresident and CEO of mCube
Next-Gen Signal ConditionersLighter amp More Robust
Skintight TechnologyFlexible Sensors Collect Vitals
mCubersquos Sensors Enable IoMT
SmallerThan a
Grain Sand
of
22
SENSOR TECHNOLOGY
Unipolar Switch with Self DiagnosticsAllegro MicroSystems developed the A1160 a complete unipolar Hall-ef-fect switch that is unique with any other devices The device was released recently in January this year The A1160 features an integrated coil that surrounds the Hall sensing element and a built-in diagnostics During nor-mal operation the device functions as a typical unipolar switch (output turns on in the presence of south-pole magnetic field and turns off when the field is removed) but when the diagnostics pin is pulled high it enters diagnostics mode This patented feature allows current to pass through the integrated coils generating ~20 G of magnetic field
The proximity of the coils to the Hall sensing element allows the element to sense the field generated by the coil while ignoring external fields In diagnostics mode the device will output a PWM signal of 50 duty cycle when the device is properly sensing the internally generated magnetic fieldRead More
2-Wire EOL Programmable Hall Effect SwitchThe MLX92242 is a 2-wire EOL programmable hall-effect latchswitch featuring customer end-of-line programming and programmable per-manent magnet It has reverse supply voltage protection and integrated self-diagnostic functions activating dedicated safe-mode
The device integrates a voltage regulator Hall sensor with advanced offset cancellation system and a current sink-configured output driver all in a single package Based on a brand new platform the magnetic core is using an improved offset cancellation system allowing faster and more accurate processing while being temperature insensitive and stress independent In addition a programmable temperature coefficient is implemented to compensate the natural behavior of certain types of magnets becoming weaker with rise in temperatureRead More
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Sensor Signal Conditioners
Powerful and Flexible yet Easy to Use
By David Grice Applications Engineer Zentrum Mikrokelektronik (ZMDI) Dresden Germany
As demands increase for the number type and range of sensors in
almost every product category the difficulty of implementing them
increases proportionately This is especially true in the automotive
arena driven by efficiency safety and emission requirements
Existing sensor technologies are inadequate to meet many of these
new and more stringent requirements spurring the development
of a new class of sensors based on micro-electro-
mechanical systems (MEMS) These new sensors
are smaller lighter more robust less expensive
and consume less power but they also
produce electrical signals that
are smaller and more nonlinear
than their bulkier counterparts
Next-Generation SO MANY SENSORS SO LITTLE TIME
Non-contact measurement of
electrophysiological signals is of great
interest in healthcare settings with the
potential of reducing disposable costs
speeding up or simplifying measurement
techniques Monitoring long-term medical
conditions within the home or observing pilots
drivers soldiers and others in safety critical
situations is now possible without needing
skin contact Monitoring vehicle drivers for
health and alertness by detecting heart rate
and respiration or determining car occupancy
to adjust the ride handling and air bag
deployment with the varying size and location
of occupants is a vast potential market
Capacitive (insulated) electrodes can register
ECG signals without conductive contact to the
bodyndasheven through clothesndashand represent
an attractive alternative for a wide range of
new applications EPIC (Electric Potential
Integrated Circuit) is a completely new sensor
technology resulting from research at the
University of Sussex (UK) Novel ultra high
impedance EPIC sensors measure electric field
changes without requiring physical or resistive
contact This award winning patent-protected
sensor can rapidly measure electric potential
sources such as electrophysiological signals
or even spatial electric fields It therefore
has the ability to measure ECGs without
direct skin contact By adjusting the DSP and
amplification circuitry the sensors can be
tuned for detection at a distance as required
for differing automotive applications EPIC
sensor electrodes can be easily and discretely
incorporated inside car seat backs to acquire
the necessary biometric data
Signals measured on the human body always
include a large amount of noise the major
component of this being 50 or 60 Hz power
line noise capacitively-coupled to the body
from the surrounding electricity supply
Measurements such as ECG depend on being
able to extract the small electrophysiological
signals from the much larger noise signals
EPIC sensors can be used in ldquocontact moderdquo for
ECG measurement where the subject touches
both the capacitive electrode surface and
some metal at the system ground directly with
the skin This ground reference allows filtering
and differential amplification of signals from
two sensors to be effective in removing the
mains frequency noise leaving a high quality
ECG signal In non-contact ECG measurement
there is ndash by definition - no skin contact
and thus no direct connection can be made
between the subjectrsquos body and the system
ground Some other method of reducing
the power line noise is therefore required to
EPIC Sensors in
contact with clothing
Conductive fabric in contact
with clothing eg on chair seat
Output
EPICdemo box
Figure 1 Basic configuration for non-contact ECG
measurement including capacitively-oocupied
DR circuit
OP-AMP
+5V
-5V
Vout
Rf (27KΩ)
Ra(11KΩ)
Rb(11KΩ)
Rp (15MΩ)To conductive
fabric on chair
thus capacitively
coupled to body
Inputs from
outputs of
demo box
A
B
C(1nF)
Figure 2 DPL circuit Voltage gain is set by Rf Rp limits current fed back to the body (see text)
Operational amplifier output Vout = - (VA + VB) Rf 11K
enable the ECG signal to be extracted reliably
and accurately One such method utilizes an
approach very similar to the ldquoDriven Right Legrdquo
(DRL) system that is used for the same purpose
in conventional ECG measurement techniques
In conventional ECG the DRL signal is coupled
directly to the patientrsquos skin The DRL signal
reduces power line noise on the sensor signals
by feeding back an inverted average of the
signals from two sensors on to the patientrsquos
body In non-contact ECG the generated DRL
signal can be capacitively-coupled to the body
through clothing via a piece of conductive
material placed ndash for instance ndash on the seat
or back of a chair Capacitive coupling of DRL
signals is described by Lim et al1 and Lee et al2
SYSTEM DESIGN
An ECG system can therefore be built into a
chair a mattress or clothing for instance The
DRL circuit improves the sensor signalnoise
ratio enormously In the example in Figure 1
EPIC sensors are mounted on a chair back such
that the electrodes touch the clothing on the
subjectrsquos back when resting normally against
the back of the chair The generated DRL signal
is connected to a piece of conductive material
placed either on the seat of the chair or at
the bottom of the chair back contacting the
subjectrsquos clothing in the normal sitting position
Copper-coated nylon fabric is one possible
material suitable for the DRL coupling material
but other conductive materials may be equally
successful A thin non- conductive material
such as a cotton fabric may be used to cover
both the sensors and the DRL coupling fabric if
required for instance when building the sensors
into a seat Consideration must be given as
to how material will reduce the coupling
capacitance between the sensor and the
subject or add additional noise to the signals
through static charging effects
Figure 2 shows the design of the DRL circuit It
is a standard summing amplifier generating an
amplified and inverted signal that is the average
of the individual signals A and B
The optimum value for Rf will be dependent
on the type of sensors being used as well as
the clothing being worn by the subject being
measured It should be set to achieve maximum
noise reduction while ensuring circuit stability
A value of 27kohms is suggested as a suitable
starting point for EPIC sensors
SmallerThan a
Grain Sand
of
Analysts project that by
2020 there will be over
50 billion connected
devices in the now-nascent
Internet of Things (IoT) However
the technology that will enable the
IoT of the future may look a little
different than todayrsquosmdashin fact
you may not be able to see it at all
Many new mobile devices require
motion sensors in order to monitor
analyze and deliver real-time data
and analysis to improve the way
consumers interact with everyday
technology While traditional
sensor platforms require multichip
modules or stacked die within a
device mCube a new MEMS sensor
company is driving the emergence
of Sensor 30 which will lead the
development of the smallest
sensors to datemdashsmaller than a
grain of sand By EEWeb Contributing Writers
mCubersquos Sensors Enable IoMTInterview with Ben Lee President and CEO of mCube
to enable the kind of constant and complex data accumulation that the Biostamp promises
In the interim MC10 is partnering up with other medical and pharmaceutical companies to develop integrated sensor and monitoring products The company plans to become a certified medical-ready partner for companies who donrsquot have access to this unique and proprietary technology Even the US Army has begun working with MC10 on military-grade sensors that will add further safety features for troops in the field This funding from NIH grants Department of Defense grants as well as foundation grants will help the company get one step closer to realization of devices so flexible that users might forget theyrsquore wearing them
ldquoThe company has been bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devicesrdquo
Join the
DESIGNERS OF THINGS conference in San Francisco on
September 23 and 24
Dedicated to the explosive and exciting potential of Wearable
Tech 3D Printing and the Internet of Things the conference
provides the growing design and development community
around these technologies a meeting place to discuss and
showcase the newest products
Click here for more info
httpwwwdesignersofthingscomsanfranciscoscheduler
speakersheth-nirav-rav33310
TECH REPORTNext-Generation Sensor Signal ConditionersPowerful and Flexible yet Easy to Use
TECH REPORTNon-Contact ECG Measurement Possibilities with EPIC Sensors
INDUSTRY INTERVIEWmCubersquos Super Small SensorsBen Lee President and CEO of mCube
TECH REPORTSkintight Technology Flexible Sensors Collect Vitals
CONTENTS
3
The Biostamp a prototype from MC10 is a new kind of wearable device that will redefine ldquoformrdquo in ldquoform factorrdquo pg 26
44
SENSOR TECHNOLOGY
Sensor Signal Conditioners
Powerful and Flexible yet Easy to Use
By David Grice Applications Engineer Zentrum Mikrokelektronik (ZMDI) Dresden Germany
As demands increase for the number type and range of sensors in
almost every product category the difficulty of implementing them
increases proportionately This is especially true in the automotive
arena driven by efficiency safety and emission requirements
Existing sensor technologies are inadequate to meet many of these
new and more stringent requirements spurring the development
of a new class of sensors based on micro-electro-
mechanical systems (MEMS) These new sensors
are smaller lighter more robust less expensive
and consume less power but they also
produce electrical signals that
are smaller and more nonlinear
than their bulkier counterparts
Next-Generation SO MANY SENSORS SO LITTLE TIME
5
TECH REPORT
5
Sensor Signal Conditioners
Powerful and Flexible yet Easy to Use
By David Grice Applications Engineer Zentrum Mikrokelektronik (ZMDI) Dresden Germany
As demands increase for the number type and range of sensors in
almost every product category the difficulty of implementing them
increases proportionately This is especially true in the automotive
arena driven by efficiency safety and emission requirements
Existing sensor technologies are inadequate to meet many of these
new and more stringent requirements spurring the development
of a new class of sensors based on micro-electro-
mechanical systems (MEMS) These new sensors
are smaller lighter more robust less expensive
and consume less power but they also
produce electrical signals that
are smaller and more nonlinear
than their bulkier counterparts
Next-Generation SO MANY SENSORS SO LITTLE TIME
66
SENSOR TECHNOLOGY
As the quality of output from transducers declines to meet application demands system
requirements such as measurement range accuracy speed and power consumption continue to increase squeezing the performance of sensor signal conditioning (SSC) circuits from both ends and making the task of designing them exponentially more difficult
integrity level (ASIL) for automotive applications These requirements include detection and notification of faults due to open or short circuits out-of-range parameters aging sensors and excessive temperature Additionally the SSC must be able to monitor these faults while tolerant of shorts to ground or supply voltage supply overvoltage conditions or reverse battery connections
ldquoOne of the key features of next-generation SSCs
is flexibilityrdquoldquoA highly efficient and powerful
reduced-instruction-set computer coordinates numerous control and
computational tasksrdquo
NEXT GENERATION TO THE RESCUE
In the same way increasing demands have spurred a new class of sensors Zentrum Mikroelektronik (ZMDI) is developing and introducing the next generation of SSC products and technologies to the sensor marketplace This article describes some of the most important and beneficial new features of these new SSCs
FLEXIBILITY IS A BEAUTIFUL THING
One of the key features of next-generation SSCs is flexibility The types and combinations of physical quantities measured for products are growing rapidly and new SSCs must facilitate fast development of complex sensor modules with low component counts and a user interface that is easy to learn and use This requires a signal interface that is configurable for a wide range of signals and correction algorithms that are much more complex than second or third order polynomial curve fitting offered by previous generations of SSCs For example a single application might require the conditioning of two temperature inputs one being a diode and the other a thermocouple and two resistive pressure bridges with widely varying output levels each of which require linearization and calibration
Flexibility is not limited only to signal types and ranges however Another dimension of configurability is required for the sequence of signal processing tasks Typically some signals must be acquired at a much higher rate than others and the
quantization and correction algorithms must be reconfigured quickly from one measurement to another in a programmable fashion In addition to this sometimes it is necessary to perform math operations between signals like subtracting two pressure inputs to generate a differential pressure output The SSC must generate a user-programmable sequence that samples the inputs in a defined order and rate correct each signal according to a user-defined calibration algorithm and combine the conditioned outputs into an orderly stream of data
Finally flexibility must include the number and type of output signals and protocols Reliability safety weight and noise constraints are also driving the creation of innovative new output protocols like single-edge nibble transmission (SENT) for the automotive industry Next-generation SSCs must support new interfaces like SENT along with the traditional analog one-wire and serial interfaces such as I2Ctrade and SPI In fact the SENT interface is output only and requires an auxiliary interface like I2C to configure and calibrate the SSC
Another important feature for next-generation SSCs is the ability to perform self-testing and diagnostics to meet critical safety standards like the automotive safety
I2Ctrade is a trademark of NXP
7
TECH REPORT
7
As the quality of output from transducers declines to meet application demands system
requirements such as measurement range accuracy speed and power consumption continue to increase squeezing the performance of sensor signal conditioning (SSC) circuits from both ends and making the task of designing them exponentially more difficult
integrity level (ASIL) for automotive applications These requirements include detection and notification of faults due to open or short circuits out-of-range parameters aging sensors and excessive temperature Additionally the SSC must be able to monitor these faults while tolerant of shorts to ground or supply voltage supply overvoltage conditions or reverse battery connections
ldquoOne of the key features of next-generation SSCs
is flexibilityrdquoldquoA highly efficient and powerful
reduced-instruction-set computer coordinates numerous control and
computational tasksrdquo
NEXT GENERATION TO THE RESCUE
In the same way increasing demands have spurred a new class of sensors Zentrum Mikroelektronik (ZMDI) is developing and introducing the next generation of SSC products and technologies to the sensor marketplace This article describes some of the most important and beneficial new features of these new SSCs
FLEXIBILITY IS A BEAUTIFUL THING
One of the key features of next-generation SSCs is flexibility The types and combinations of physical quantities measured for products are growing rapidly and new SSCs must facilitate fast development of complex sensor modules with low component counts and a user interface that is easy to learn and use This requires a signal interface that is configurable for a wide range of signals and correction algorithms that are much more complex than second or third order polynomial curve fitting offered by previous generations of SSCs For example a single application might require the conditioning of two temperature inputs one being a diode and the other a thermocouple and two resistive pressure bridges with widely varying output levels each of which require linearization and calibration
Flexibility is not limited only to signal types and ranges however Another dimension of configurability is required for the sequence of signal processing tasks Typically some signals must be acquired at a much higher rate than others and the
quantization and correction algorithms must be reconfigured quickly from one measurement to another in a programmable fashion In addition to this sometimes it is necessary to perform math operations between signals like subtracting two pressure inputs to generate a differential pressure output The SSC must generate a user-programmable sequence that samples the inputs in a defined order and rate correct each signal according to a user-defined calibration algorithm and combine the conditioned outputs into an orderly stream of data
Finally flexibility must include the number and type of output signals and protocols Reliability safety weight and noise constraints are also driving the creation of innovative new output protocols like single-edge nibble transmission (SENT) for the automotive industry Next-generation SSCs must support new interfaces like SENT along with the traditional analog one-wire and serial interfaces such as I2Ctrade and SPI In fact the SENT interface is output only and requires an auxiliary interface like I2C to configure and calibrate the SSC
Another important feature for next-generation SSCs is the ability to perform self-testing and diagnostics to meet critical safety standards like the automotive safety
I2Ctrade is a trademark of NXP
88
SENSOR TECHNOLOGY
PUTTING IT ALL TOGETHER
Figure 1 shows the block diagram of a next-generation SSC In this particular case the SSC supports two temperature inputsmdashone resistive one diodemdashand two resistive bridge inputs The conditioning signal chain includes sensor check and common mode (SCCM) adjustment multiplexing (MUX) programmable gain (PGA) from 1 to 200 VV and an analog to digital converter (ADC) with adjustable sample rate and resolution from 12 to 18 bits
The SSC in figure 1 looks similar to other SSCs that are presently available but most of its potential and flexibility lies in the calibration microcontroller (CMC) A highly efficient and powerful reduced instruction set computer (RISC) coordinates the numerous control and computational tasks necessary to provide the tremendous amount of flexibility required for next-generation SSCs The controller also combines the multiple output data packets into a structured stream in a wide variety of formats that can be either analog or digital
The cycle of tasks performed by the RISC engine consists of three main types measurement tasks conditioning tasks and output tasks Measurement tasks include operations that select the MUX input and signal polarities the gain and offset of the signal path the speed and resolution of the quantizer and auxiliary tasks such as auto-zeroing gain stages The output values of all the main measurement tasks are stored in registers for processing by the conditioning tasks These tasks range from simple operations like shifting and synchronization to basic math functions such as add subtract multiply and divide to complex functions such as logarithms polynomial evaluation spline curve fitting and digital filtering Output tasks include synchronization of data streams formatting packetizing encoding error detection and safety features like redundancy or inversion
The SSC shown in figure 1 provides for up to 20 measurement tasks and 62 conditioning tasks enabling thousands
of different combinations of signal processing sequences for each of the four inputs The number of output tasks varies greatly depending on the type of output but for a complex protocol like SENT the number can be in the dozens
MAKING IT EASY
However it is also vitally important that the flexibility power and complexity of next-generation SSCs do not require a commensurate level of time and resources for system designers implementing them The example shown in figure 1 is a member of a product family that is preconfigured by the manufacturer for a specific application using firmware All of the measurement conditioning and output tasks are programmed so that the designer need only focus on determining gain resolution and calibration coefficients for the correction algorithm all of which are facilitated by software that is easy to use and
Figure 1 An example block diagram of a next-generation SSC from ZMDI
ldquoOne thing that should not be flexible in next-generation
SSCs is the user interfacerdquo
consistent across the product line Special use cases can be implemented easily in firmware by the manufacturer should the need arise but the standard factory configuration will cover the majority of designs Additional family members of the product line are optimized for different numbers and types of inputs and outputs and also preconfigured for the intended application use
Finally one thing that should not be flexible in next-generation SSCs is the user interface including the physical dimensions pin or pad locations and software user interface The product family exemplified in figure 1 has a standardized footprint pinout and software user interface to minimize the costs time and resources associated with board layout calibration and climbing the learning curve
9
TECH REPORT
9
PUTTING IT ALL TOGETHER
Figure 1 shows the block diagram of a next-generation SSC In this particular case the SSC supports two temperature inputsmdashone resistive one diodemdashand two resistive bridge inputs The conditioning signal chain includes sensor check and common mode (SCCM) adjustment multiplexing (MUX) programmable gain (PGA) from 1 to 200 VV and an analog to digital converter (ADC) with adjustable sample rate and resolution from 12 to 18 bits
The SSC in figure 1 looks similar to other SSCs that are presently available but most of its potential and flexibility lies in the calibration microcontroller (CMC) A highly efficient and powerful reduced instruction set computer (RISC) coordinates the numerous control and computational tasks necessary to provide the tremendous amount of flexibility required for next-generation SSCs The controller also combines the multiple output data packets into a structured stream in a wide variety of formats that can be either analog or digital
The cycle of tasks performed by the RISC engine consists of three main types measurement tasks conditioning tasks and output tasks Measurement tasks include operations that select the MUX input and signal polarities the gain and offset of the signal path the speed and resolution of the quantizer and auxiliary tasks such as auto-zeroing gain stages The output values of all the main measurement tasks are stored in registers for processing by the conditioning tasks These tasks range from simple operations like shifting and synchronization to basic math functions such as add subtract multiply and divide to complex functions such as logarithms polynomial evaluation spline curve fitting and digital filtering Output tasks include synchronization of data streams formatting packetizing encoding error detection and safety features like redundancy or inversion
The SSC shown in figure 1 provides for up to 20 measurement tasks and 62 conditioning tasks enabling thousands
of different combinations of signal processing sequences for each of the four inputs The number of output tasks varies greatly depending on the type of output but for a complex protocol like SENT the number can be in the dozens
MAKING IT EASY
However it is also vitally important that the flexibility power and complexity of next-generation SSCs do not require a commensurate level of time and resources for system designers implementing them The example shown in figure 1 is a member of a product family that is preconfigured by the manufacturer for a specific application using firmware All of the measurement conditioning and output tasks are programmed so that the designer need only focus on determining gain resolution and calibration coefficients for the correction algorithm all of which are facilitated by software that is easy to use and
Figure 1 An example block diagram of a next-generation SSC from ZMDI
ldquoOne thing that should not be flexible in next-generation
SSCs is the user interfacerdquo
consistent across the product line Special use cases can be implemented easily in firmware by the manufacturer should the need arise but the standard factory configuration will cover the majority of designs Additional family members of the product line are optimized for different numbers and types of inputs and outputs and also preconfigured for the intended application use
Finally one thing that should not be flexible in next-generation SSCs is the user interface including the physical dimensions pin or pad locations and software user interface The product family exemplified in figure 1 has a standardized footprint pinout and software user interface to minimize the costs time and resources associated with board layout calibration and climbing the learning curve
1212
SENSOR TECHNOLOGY
The human heartbeat is arguably the single most important (ldquolife-and-deathrdquo) diagnostic indicator Thus electrocardiograms (ECGs) are one of the most significant diagnostic methods in that
they monitor heart function ECGs are not only used in a clinical setting but are increasingly seen in personal health devices Traditionally ECG measurement conductive electrodes have been applied which are directly attached to the skin With the help of contact gel (wet or solid) to ensure that there is good electrical contact between the skin and the sensor direct resistive contact is made with the patient However conventional electrodes possess various disadvantages which are not conducive for long-term use in non-clinical settings In addition to being potentially messy metal allergies can cause skin irritations and as a single-use item they are quite expensive
Non-contact ECG measurementusing EPIC Sensors
Measuring electrocardiogram (ECG) signals without skin contact is now possible using novel Electric Potential Integrated Circuit (EPIC) sensors
By Alan Lowne CEO of Saelig Co Inc
13
TECH REPORT
13
The human heartbeat is arguably the single most important (ldquolife-and-deathrdquo) diagnostic indicator Thus electrocardiograms (ECGs) are one of the most significant diagnostic methods in that
they monitor heart function ECGs are not only used in a clinical setting but are increasingly seen in personal health devices Traditionally ECG measurement conductive electrodes have been applied which are directly attached to the skin With the help of contact gel (wet or solid) to ensure that there is good electrical contact between the skin and the sensor direct resistive contact is made with the patient However conventional electrodes possess various disadvantages which are not conducive for long-term use in non-clinical settings In addition to being potentially messy metal allergies can cause skin irritations and as a single-use item they are quite expensive
Non-contact ECG measurementusing EPIC Sensors
Measuring electrocardiogram (ECG) signals without skin contact is now possible using novel Electric Potential Integrated Circuit (EPIC) sensors
By Alan Lowne CEO of Saelig Co Inc
1414
SENSOR TECHNOLOGY
Non-contact measurement of electrophysiological signals is of great interest in healthcare settings with the potential of reducing disposable costs speeding up or simplifying measurement techniques Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact Monitoring vehicle drivers for health and alertness by detecting heart rate and respiration or determining car occupancy to adjust the ride handling and air bag deployment with the varying size and location of occupants is a vast potential market
Capacitive (insulated) electrodes can register ECG signals without conductive contact to the bodyndasheven through clothesndashand represent
an attractive alternative for a wide range of new applications EPIC (Electric Potential Integrated Circuit) is a completely new sensor technology resulting from research at the University of Sussex (UK) Novel ultra high impedance EPIC sensors measure electric field changes without requiring physical or resistive contact This award winning patent-protected sensor can rapidly measure electric potential sources such as electrophysiological signals or even spatial electric fields It therefore has the ability to measure ECGs without direct skin contact By adjusting the DSP and amplification circuitry the sensors can be tuned for detection at a distance as required for differing automotive applications EPIC sensor electrodes can be easily and discretely incorporated inside car seat backs to acquire the necessary biometric data
Signals measured on the human body always include a large amount of noise the major component of this being 50 or 60 Hz power line noise capacitively-coupled to the body from the surrounding electricity supply Measurements such as ECG depend on being able to extract the small electrophysiological signals from the much larger noise signals EPIC sensors can be used in ldquocontact moderdquo for ECG measurement where the subject touches both the capacitive electrode surface and some metal at the system ground directly with the skin This ground reference allows filtering and differential amplification of signals from two sensors to be effective in removing the mains frequency noise leaving a high quality ECG signal In non-contact ECG measurement there is ndash by definition - no skin contact and thus no direct connection can be made between the subjectrsquos body and the system ground Some other method of reducing the power line noise is therefore required to
EPIC Sensors incontact with clothing
Conductive fabric in contactwith clothing eg on chair seat
Output
EPICdemo box
Figure 1 Basic configuration for non-contact ECG measurement including capacitively-oocupied DR circuit
OP-AMP
+5V
-5V
Vout
Rf (27KΩ)
Ra(11KΩ)
Rb(11KΩ)
Rp (15MΩ) To conductive fabric on chair thus capacitively coupled to body
Inputs from outputs of demo box
A
BC
(1nF)
Figure 2 DPL circuit Voltage gain is set by Rf Rp limits current fed back to the body (see text)Operational amplifier output Vout = - (VA + VB) Rf 11K
enable the ECG signal to be extracted reliably and accurately One such method utilizes an approach very similar to the ldquoDriven Right Legrdquo (DRL) system that is used for the same purpose in conventional ECG measurement techniques In conventional ECG the DRL signal is coupled directly to the patientrsquos skin The DRL signal reduces power line noise on the sensor signals by feeding back an inverted average of the signals from two sensors on to the patientrsquos body In non-contact ECG the generated DRL signal can be capacitively-coupled to the body through clothing via a piece of conductive material placed ndash for instance ndash on the seat or back of a chair Capacitive coupling of DRL signals is described by Lim et al1 and Lee et al2
SYSTEM DESIGNAn ECG system can therefore be built into a chair a mattress or clothing for instance The DRL circuit improves the sensor signalnoise ratio enormously In the example in Figure 1 EPIC sensors are mounted on a chair back such that the electrodes touch the clothing on the subjectrsquos back when resting normally against the back of the chair The generated DRL signal is connected to a piece of conductive material
placed either on the seat of the chair or at the bottom of the chair back contacting the subjectrsquos clothing in the normal sitting position Copper-coated nylon fabric is one possible material suitable for the DRL coupling material but other conductive materials may be equally successful A thin non- conductive material such as a cotton fabric may be used to cover both the sensors and the DRL coupling fabric if required for instance when building the sensors into a seat Consideration must be given as to how material will reduce the coupling capacitance between the sensor and the subject or add additional noise to the signals through static charging effectsFigure 2 shows the design of the DRL circuit It is a standard summing amplifier generating an amplified and inverted signal that is the average of the individual signals A and B
The optimum value for Rf will be dependent on the type of sensors being used as well as the clothing being worn by the subject being measured It should be set to achieve maximum noise reduction while ensuring circuit stability A value of 27kohms is suggested as a suitable starting point for EPIC sensors
15
TECH REPORT
15
Non-contact measurement of electrophysiological signals is of great interest in healthcare settings with the potential of reducing disposable costs speeding up or simplifying measurement techniques Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact Monitoring vehicle drivers for health and alertness by detecting heart rate and respiration or determining car occupancy to adjust the ride handling and air bag deployment with the varying size and location of occupants is a vast potential market
Capacitive (insulated) electrodes can register ECG signals without conductive contact to the bodyndasheven through clothesndashand represent
an attractive alternative for a wide range of new applications EPIC (Electric Potential Integrated Circuit) is a completely new sensor technology resulting from research at the University of Sussex (UK) Novel ultra high impedance EPIC sensors measure electric field changes without requiring physical or resistive contact This award winning patent-protected sensor can rapidly measure electric potential sources such as electrophysiological signals or even spatial electric fields It therefore has the ability to measure ECGs without direct skin contact By adjusting the DSP and amplification circuitry the sensors can be tuned for detection at a distance as required for differing automotive applications EPIC sensor electrodes can be easily and discretely incorporated inside car seat backs to acquire the necessary biometric data
Signals measured on the human body always include a large amount of noise the major component of this being 50 or 60 Hz power line noise capacitively-coupled to the body from the surrounding electricity supply Measurements such as ECG depend on being able to extract the small electrophysiological signals from the much larger noise signals EPIC sensors can be used in ldquocontact moderdquo for ECG measurement where the subject touches both the capacitive electrode surface and some metal at the system ground directly with the skin This ground reference allows filtering and differential amplification of signals from two sensors to be effective in removing the mains frequency noise leaving a high quality ECG signal In non-contact ECG measurement there is ndash by definition - no skin contact and thus no direct connection can be made between the subjectrsquos body and the system ground Some other method of reducing the power line noise is therefore required to
EPIC Sensors incontact with clothing
Conductive fabric in contactwith clothing eg on chair seat
Output
EPICdemo box
Figure 1 Basic configuration for non-contact ECG measurement including capacitively-oocupied DR circuit
OP-AMP
+5V
-5V
Vout
Rf (27KΩ)
Ra(11KΩ)
Rb(11KΩ)
Rp (15MΩ) To conductive fabric on chair thus capacitively coupled to body
Inputs from outputs of demo box
A
BC
(1nF)
Figure 2 DPL circuit Voltage gain is set by Rf Rp limits current fed back to the body (see text)Operational amplifier output Vout = - (VA + VB) Rf 11K
enable the ECG signal to be extracted reliably and accurately One such method utilizes an approach very similar to the ldquoDriven Right Legrdquo (DRL) system that is used for the same purpose in conventional ECG measurement techniques In conventional ECG the DRL signal is coupled directly to the patientrsquos skin The DRL signal reduces power line noise on the sensor signals by feeding back an inverted average of the signals from two sensors on to the patientrsquos body In non-contact ECG the generated DRL signal can be capacitively-coupled to the body through clothing via a piece of conductive material placed ndash for instance ndash on the seat or back of a chair Capacitive coupling of DRL signals is described by Lim et al1 and Lee et al2
SYSTEM DESIGNAn ECG system can therefore be built into a chair a mattress or clothing for instance The DRL circuit improves the sensor signalnoise ratio enormously In the example in Figure 1 EPIC sensors are mounted on a chair back such that the electrodes touch the clothing on the subjectrsquos back when resting normally against the back of the chair The generated DRL signal is connected to a piece of conductive material
placed either on the seat of the chair or at the bottom of the chair back contacting the subjectrsquos clothing in the normal sitting position Copper-coated nylon fabric is one possible material suitable for the DRL coupling material but other conductive materials may be equally successful A thin non- conductive material such as a cotton fabric may be used to cover both the sensors and the DRL coupling fabric if required for instance when building the sensors into a seat Consideration must be given as to how material will reduce the coupling capacitance between the sensor and the subject or add additional noise to the signals through static charging effectsFigure 2 shows the design of the DRL circuit It is a standard summing amplifier generating an amplified and inverted signal that is the average of the individual signals A and B
The optimum value for Rf will be dependent on the type of sensors being used as well as the clothing being worn by the subject being measured It should be set to achieve maximum noise reduction while ensuring circuit stability A value of 27kohms is suggested as a suitable starting point for EPIC sensors
1616
SENSOR TECHNOLOGY
Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact
7660SwitchedCapacitorVoltage
Converter
1
2
3
4
8
7
6
5
OP-AMP
Rb(11K)
Ra(11K)
Rf (27KΩ)
Rp (15MΩ)DRLOutput
1nFVout
6Vbatterypack4xAA
+6V
-6V10microF
10microF
A
B
Figure 3 DRL circuit including battery power supply and voltage converter to provide -6v rail Inputs A and B are buffered outputs from the sensors and may be taken from the A and B outputs of the EPIC demo box Ground should be connected to the sensor 0V the shielding of the BNC A and B outputs on the demo box being a suitable connection point See figure 2 and the text for further comments on the DRL design
sensors and the DRL circuit into saturation Because the system contains some large impedances and hence has some very long RC time constants settling times of tens of seconds can be needed before a clean ECG signal is seen During this period the signal can either appear very noisy or be virtually flat depending on whether one or both sensors or the DRL circuit are ldquorailingrdquo The subject should sit still during this time and wait for the circuit to settle since continually adjusting position will only make matters worse Settling times can sometimes be reduced by turning off the power to the demo box for a few seconds
CLOTHINGGood results can be obtained with one or two layers of cotton material between the sensors and the skin Other materials including a wool-mix sweater and a polyester fleece in addition
to two layers of cotton material have been successful Examples are shown in Figures 6 and 7 If the key greatest interest is in the ldquoR-Rrdquo interval adjusting filter settings to reduce or re-center the signal bandwidth can give improved signal quality
STATICBecause there is no direct physical contact between the subject and any grounding point there is no path for any static build up to be discharged Under most circumstances static build-up does not present a problem butdepending on factors including clothing footwear flooring humidity levels in the air and so forth static build up can sometimes prevent the cardiac signal from being seen clearly Product design must take into account a discharge to the system ground to remove the static charge
Rp the protection resistor is included to limit the current that can be fed back to the human body This resistor is essential in ensuring that the subjectrsquos wellbeing is not endangered and must not be omitted
IMPLEMENTATIONThe demonstration of non-contact ECG is best performed using an EPIC demonstration kit Plessey part no PS25003 which includes the necessary drive circuitry and switchable 50Hz and 60Hz notch filters The inputs to the DRL circuit can be taken from the BNC outputs ldquoA amp Brdquo on the front of the demo box The DRL circuit will require its own bipolar power supply plusmn5V or plusmn6V is suggested A circuit design including a battery power supply is shown in Figure 3
Plesseyrsquos compact sensors (PS2520x) and disc sensors (PS25101) provide equally good results although for demonstration purposes disc sensors are simplest to fix to a chair to make contact with the occupantrsquos back Compact sensors are recommended when designing a custom-built system
EPIC sensors which are designed for contact electrophysiology sensing give excellent results in most cases Initial trials suggest that custom modifications to the sensor design (eg lower gain and higher input impedance) can offer increased sensitivity and the ability to detect weaker ECG signalsThe shape of the measured ECG trace ndash in terms of relative magnitudes of the P Q R S and T waves ndash will depend on the positioning of the sensors behind the subjectrsquos back If the desire is only to measure the ldquoR-Rrdquo interval to determine heart rate then the positioning of the sensors is not critical Placing one sensor either side of the spine separated by 6rdquo -10rdquo (15-25 cm) at approximately the same height as the heart is recommended as a starting point For applications where signals from other parts of the cardiac cycle are required the user should refer to texts on bio-electronic signals for guidance on sensor position
SETTLING TIMEWhen a subject first sits in the chair and leans against the EPIC sensors the changes in electric potential will normally send both the
17
TECH REPORT
17
Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact
7660SwitchedCapacitorVoltage
Converter
1
2
3
4
8
7
6
5
OP-AMP
Rb(11K)
Ra(11K)
Rf (27KΩ)
Rp (15MΩ)DRLOutput
1nFVout
6Vbatterypack4xAA
+6V
-6V10microF
10microF
A
B
Figure 3 DRL circuit including battery power supply and voltage converter to provide -6v rail Inputs A and B are buffered outputs from the sensors and may be taken from the A and B outputs of the EPIC demo box Ground should be connected to the sensor 0V the shielding of the BNC A and B outputs on the demo box being a suitable connection point See figure 2 and the text for further comments on the DRL design
sensors and the DRL circuit into saturation Because the system contains some large impedances and hence has some very long RC time constants settling times of tens of seconds can be needed before a clean ECG signal is seen During this period the signal can either appear very noisy or be virtually flat depending on whether one or both sensors or the DRL circuit are ldquorailingrdquo The subject should sit still during this time and wait for the circuit to settle since continually adjusting position will only make matters worse Settling times can sometimes be reduced by turning off the power to the demo box for a few seconds
CLOTHINGGood results can be obtained with one or two layers of cotton material between the sensors and the skin Other materials including a wool-mix sweater and a polyester fleece in addition
to two layers of cotton material have been successful Examples are shown in Figures 6 and 7 If the key greatest interest is in the ldquoR-Rrdquo interval adjusting filter settings to reduce or re-center the signal bandwidth can give improved signal quality
STATICBecause there is no direct physical contact between the subject and any grounding point there is no path for any static build up to be discharged Under most circumstances static build-up does not present a problem butdepending on factors including clothing footwear flooring humidity levels in the air and so forth static build up can sometimes prevent the cardiac signal from being seen clearly Product design must take into account a discharge to the system ground to remove the static charge
Rp the protection resistor is included to limit the current that can be fed back to the human body This resistor is essential in ensuring that the subjectrsquos wellbeing is not endangered and must not be omitted
IMPLEMENTATIONThe demonstration of non-contact ECG is best performed using an EPIC demonstration kit Plessey part no PS25003 which includes the necessary drive circuitry and switchable 50Hz and 60Hz notch filters The inputs to the DRL circuit can be taken from the BNC outputs ldquoA amp Brdquo on the front of the demo box The DRL circuit will require its own bipolar power supply plusmn5V or plusmn6V is suggested A circuit design including a battery power supply is shown in Figure 3
Plesseyrsquos compact sensors (PS2520x) and disc sensors (PS25101) provide equally good results although for demonstration purposes disc sensors are simplest to fix to a chair to make contact with the occupantrsquos back Compact sensors are recommended when designing a custom-built system
EPIC sensors which are designed for contact electrophysiology sensing give excellent results in most cases Initial trials suggest that custom modifications to the sensor design (eg lower gain and higher input impedance) can offer increased sensitivity and the ability to detect weaker ECG signalsThe shape of the measured ECG trace ndash in terms of relative magnitudes of the P Q R S and T waves ndash will depend on the positioning of the sensors behind the subjectrsquos back If the desire is only to measure the ldquoR-Rrdquo interval to determine heart rate then the positioning of the sensors is not critical Placing one sensor either side of the spine separated by 6rdquo -10rdquo (15-25 cm) at approximately the same height as the heart is recommended as a starting point For applications where signals from other parts of the cardiac cycle are required the user should refer to texts on bio-electronic signals for guidance on sensor position
SETTLING TIMEWhen a subject first sits in the chair and leans against the EPIC sensors the changes in electric potential will normally send both the
1818
SENSOR TECHNOLOGY
Figure 4 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit HP filter corner frequency is 50mHz LP filter in demo box has corner frequency of 30Hz
Figure 6 ECG signals measured from a subject wearing a wool-mix sweater over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 8-25Hz The heart rate can be easily extracted
Figure 5 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit Software filters limit the bandwidth to 8-25Hz
Figure 7 ECG signals measured from a subject wearing a polyester fleece over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 16-40Hz The heart rate can be easily extracted
CABLE SHIELDINGCareful shielding is necessary to reduce unwanted noise artifacts Grounding the shielding of the sensor cable via the connection between the outer casing of the sensor plugs and the metal surround of the socket on the control electronics is recommended
CONCLUSIONEPIC sensors can be used to measure ECG signals without physical skin contact While
sensors can be embedded in a chair or seat the techniques are equally applicable to sensors mounted on a mattress in clothing or in other situations There are many variables that will affect signal quality from the strength of cardiac signal generated by the individual being measured to clothing to the surrounding environment but the designs given here are a starting point in establishing an optimum system for a particular application infin
Find us at Booth 37310World Maker Faire New York
Figure 4 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit HP filter corner frequency is 50mHz LP filter in demo box has corner frequency of 30Hz
Figure 6 ECG signals measured from a subject wearing a wool-mix sweater over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 8-25Hz The heart rate can be easily extracted
Figure 5 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit Software filters limit the bandwidth to 8-25Hz
Figure 7 ECG signals measured from a subject wearing a polyester fleece over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 16-40Hz The heart rate can be easily extracted
CABLE SHIELDINGCareful shielding is necessary to reduce unwanted noise artifacts Grounding the shielding of the sensor cable via the connection between the outer casing of the sensor plugs and the metal surround of the socket on the control electronics is recommended
CONCLUSIONEPIC sensors can be used to measure ECG signals without physical skin contact While
sensors can be embedded in a chair or seat the techniques are equally applicable to sensors mounted on a mattress in clothing or in other situations There are many variables that will affect signal quality from the strength of cardiac signal generated by the individual being measured to clothing to the surrounding environment but the designs given here are a starting point in establishing an optimum system for a particular application infin
Find us at Booth 37310World Maker Faire New York
20
SENSOR TECHNOLOGY
SmallerThan a
Grain Sand
of
Analysts project that by
2020 there will be over
50 billion connected
devices in the now-nascent
Internet of Things (IoT) However
the technology that will enable the
IoT of the future may look a little
different than todayrsquosmdashin fact
you may not be able to see it at all
Many new mobile devices require
motion sensors in order to monitor
analyze and deliver real-time data
and analysis to improve the way
consumers interact with everyday
technology While traditional
sensor platforms require multichip
modules or stacked die within a
device mCube a new MEMS sensor
company is driving the emergence
of Sensor 30 which will lead the
development of the smallest
sensors to datemdashsmaller than a
grain of sand By EEWeb Contributing Writers
mCubersquos Sensors Enable IoMTInterview with Ben Lee President and CEO of mCube
INDUSTRY INTERVIEW
21
SmallerThan a
Grain Sand
of
Analysts project that by
2020 there will be over
50 billion connected
devices in the now-nascent
Internet of Things (IoT) However
the technology that will enable the
IoT of the future may look a little
different than todayrsquosmdashin fact
you may not be able to see it at all
Many new mobile devices require
motion sensors in order to monitor
analyze and deliver real-time data
and analysis to improve the way
consumers interact with everyday
technology While traditional
sensor platforms require multichip
modules or stacked die within a
device mCube a new MEMS sensor
company is driving the emergence
of Sensor 30 which will lead the
development of the smallest
sensors to datemdashsmaller than a
grain of sand By EEWeb Contributing Writers
mCubersquos Sensors Enable IoMTInterview with Ben Lee President and CEO of mCube
22
SENSOR TECHNOLOGY
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
INDUSTRY INTERVIEW
23
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
24
SENSOR TECHNOLOGY
Since sensors are so small and affordable donrsquot be surprised to find unique applications in the future Lee speculates that ldquofarmers might have sensor tags to monitor livestock for abnormal activity patterns of grazing potential illness and herd behaviorrdquo Commercial trucking might involve motion sensors connected to video cameras in rear-view mirrors to better assess the cause of an accident and driving conditions For shipping Lee describes ldquomotion sensors embedded directly onto packages to record jarring motions or accidents in order to determine when and how contents were damagedrdquo
As of 2014 mCubersquos complete intertial sensor portfolio contains an accelerometer magnetometer and its proprietary iGyrotrade gyroscope offering nine degrees of freedom (9DoF) Through reductions in cost power consumption and size mCubersquos sensor offerings make it possible to place them onto nearly any object or devicemdashin some cases without packaging ldquoWe aspire to put one or more MEMS motion sensors on anything that movesrdquo remarks Lee And with the IoMT taking shape and consumer expectations for connected moving devices becoming more concrete developers of new applications will turn to solutions like mCube to deliver truly cutting-edge connected devices
ldquoAt mCube we aspire to put one or more MEMS motion sensors on
anything that movesrdquo
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 15
Complete Inertial Motion Sensor Portfolio
Solutions for up to 9DoF (Degrees of Freedom)
Accelerometer
Magnetometer
iGyroTM
3DoF 3DoF
9DoF
2x2mm
3x3mm 3DoF 6DoF
14x14mm
3x3mm
3x3mm
2626
SENSOR TECHNOLOGY
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
27
TECH REPORT
27
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
2828
SENSOR TECHNOLOGY
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
29
TECH REPORT
29
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
3030
SENSOR TECHNOLOGY
to enable the kind of constant and complex data accumulation that the Biostamp promises
In the interim MC10 is partnering up with other medical and pharmaceutical companies to develop integrated sensor and monitoring products The company plans to become a certified medical-ready partner for companies who donrsquot have access to this unique and proprietary technology Even the US Army has begun working with MC10 on military-grade sensors that will add further safety features for troops in the field This funding from NIH grants Department of Defense grants as well as foundation grants will help the company get one step closer to realization of devices so flexible that users might forget theyrsquore wearing them
ldquoThe company has been bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devicesrdquo
Join the
DESIGNERS OF THINGS conference in San Francisco on
September 23 and 24
Dedicated to the explosive and exciting potential of Wearable
Tech 3D Printing and the Internet of Things the conference
provides the growing design and development community
around these technologies a meeting place to discuss and
showcase the newest products
Click here for more info
httpwwwdesignersofthingscomsanfranciscoscheduler
speakersheth-nirav-rav33310
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Sierra CircuitsA Complete PCB Resource
PLUS The Ground rdquo Myth in PrintedCircuits
ldquo
PCB Resin Reactor+
Ken BahlCEO of Sierra Circuits
Let There Be
How Cree reinvented the light bulb
LIGHT
David ElienVP of Marketing amp Business
Development Cree Inc
New LED Filament Tower
Cutting Edge Flatscreen Technologies
+
+
M o v i n g T o w a r d s
a Clean Energy
FUTUREmdash Hugo van Nispen COO of DNV KEMA
MCU Wars 32-bit MCU Comparison
Cutting Edge
SPICEModeling
Freescale and TI Embedded
Modules
ARMCortex
Programming
From Concept to
Reality Wolfgang Heinz-Fischer
Head of Marketing amp PR TQ-Group
Low-Power Design Techniques
TQ-Grouprsquos Comprehensive Design Process
+
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PowerDeveloper
Octobe r 20 13
Designing forDurability
View more EEWeb magazinesmdash Click Here
22
SENSOR TECHNOLOGY
Unipolar Switch with Self DiagnosticsAllegro MicroSystems developed the A1160 a complete unipolar Hall-ef-fect switch that is unique with any other devices The device was released recently in January this year The A1160 features an integrated coil that surrounds the Hall sensing element and a built-in diagnostics During nor-mal operation the device functions as a typical unipolar switch (output turns on in the presence of south-pole magnetic field and turns off when the field is removed) but when the diagnostics pin is pulled high it enters diagnostics mode This patented feature allows current to pass through the integrated coils generating ~20 G of magnetic field
The proximity of the coils to the Hall sensing element allows the element to sense the field generated by the coil while ignoring external fields In diagnostics mode the device will output a PWM signal of 50 duty cycle when the device is properly sensing the internally generated magnetic fieldRead More
2-Wire EOL Programmable Hall Effect SwitchThe MLX92242 is a 2-wire EOL programmable hall-effect latchswitch featuring customer end-of-line programming and programmable per-manent magnet It has reverse supply voltage protection and integrated self-diagnostic functions activating dedicated safe-mode
The device integrates a voltage regulator Hall sensor with advanced offset cancellation system and a current sink-configured output driver all in a single package Based on a brand new platform the magnetic core is using an improved offset cancellation system allowing faster and more accurate processing while being temperature insensitive and stress independent In addition a programmable temperature coefficient is implemented to compensate the natural behavior of certain types of magnets becoming weaker with rise in temperatureRead More
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3
4
12
20
26
Sensor Signal Conditioners
Powerful and Flexible yet Easy to Use
By David Grice Applications Engineer Zentrum Mikrokelektronik (ZMDI) Dresden Germany
As demands increase for the number type and range of sensors in
almost every product category the difficulty of implementing them
increases proportionately This is especially true in the automotive
arena driven by efficiency safety and emission requirements
Existing sensor technologies are inadequate to meet many of these
new and more stringent requirements spurring the development
of a new class of sensors based on micro-electro-
mechanical systems (MEMS) These new sensors
are smaller lighter more robust less expensive
and consume less power but they also
produce electrical signals that
are smaller and more nonlinear
than their bulkier counterparts
Next-Generation SO MANY SENSORS SO LITTLE TIME
Non-contact measurement of
electrophysiological signals is of great
interest in healthcare settings with the
potential of reducing disposable costs
speeding up or simplifying measurement
techniques Monitoring long-term medical
conditions within the home or observing pilots
drivers soldiers and others in safety critical
situations is now possible without needing
skin contact Monitoring vehicle drivers for
health and alertness by detecting heart rate
and respiration or determining car occupancy
to adjust the ride handling and air bag
deployment with the varying size and location
of occupants is a vast potential market
Capacitive (insulated) electrodes can register
ECG signals without conductive contact to the
bodyndasheven through clothesndashand represent
an attractive alternative for a wide range of
new applications EPIC (Electric Potential
Integrated Circuit) is a completely new sensor
technology resulting from research at the
University of Sussex (UK) Novel ultra high
impedance EPIC sensors measure electric field
changes without requiring physical or resistive
contact This award winning patent-protected
sensor can rapidly measure electric potential
sources such as electrophysiological signals
or even spatial electric fields It therefore
has the ability to measure ECGs without
direct skin contact By adjusting the DSP and
amplification circuitry the sensors can be
tuned for detection at a distance as required
for differing automotive applications EPIC
sensor electrodes can be easily and discretely
incorporated inside car seat backs to acquire
the necessary biometric data
Signals measured on the human body always
include a large amount of noise the major
component of this being 50 or 60 Hz power
line noise capacitively-coupled to the body
from the surrounding electricity supply
Measurements such as ECG depend on being
able to extract the small electrophysiological
signals from the much larger noise signals
EPIC sensors can be used in ldquocontact moderdquo for
ECG measurement where the subject touches
both the capacitive electrode surface and
some metal at the system ground directly with
the skin This ground reference allows filtering
and differential amplification of signals from
two sensors to be effective in removing the
mains frequency noise leaving a high quality
ECG signal In non-contact ECG measurement
there is ndash by definition - no skin contact
and thus no direct connection can be made
between the subjectrsquos body and the system
ground Some other method of reducing
the power line noise is therefore required to
EPIC Sensors in
contact with clothing
Conductive fabric in contact
with clothing eg on chair seat
Output
EPICdemo box
Figure 1 Basic configuration for non-contact ECG
measurement including capacitively-oocupied
DR circuit
OP-AMP
+5V
-5V
Vout
Rf (27KΩ)
Ra(11KΩ)
Rb(11KΩ)
Rp (15MΩ)To conductive
fabric on chair
thus capacitively
coupled to body
Inputs from
outputs of
demo box
A
B
C(1nF)
Figure 2 DPL circuit Voltage gain is set by Rf Rp limits current fed back to the body (see text)
Operational amplifier output Vout = - (VA + VB) Rf 11K
enable the ECG signal to be extracted reliably
and accurately One such method utilizes an
approach very similar to the ldquoDriven Right Legrdquo
(DRL) system that is used for the same purpose
in conventional ECG measurement techniques
In conventional ECG the DRL signal is coupled
directly to the patientrsquos skin The DRL signal
reduces power line noise on the sensor signals
by feeding back an inverted average of the
signals from two sensors on to the patientrsquos
body In non-contact ECG the generated DRL
signal can be capacitively-coupled to the body
through clothing via a piece of conductive
material placed ndash for instance ndash on the seat
or back of a chair Capacitive coupling of DRL
signals is described by Lim et al1 and Lee et al2
SYSTEM DESIGN
An ECG system can therefore be built into a
chair a mattress or clothing for instance The
DRL circuit improves the sensor signalnoise
ratio enormously In the example in Figure 1
EPIC sensors are mounted on a chair back such
that the electrodes touch the clothing on the
subjectrsquos back when resting normally against
the back of the chair The generated DRL signal
is connected to a piece of conductive material
placed either on the seat of the chair or at
the bottom of the chair back contacting the
subjectrsquos clothing in the normal sitting position
Copper-coated nylon fabric is one possible
material suitable for the DRL coupling material
but other conductive materials may be equally
successful A thin non- conductive material
such as a cotton fabric may be used to cover
both the sensors and the DRL coupling fabric if
required for instance when building the sensors
into a seat Consideration must be given as
to how material will reduce the coupling
capacitance between the sensor and the
subject or add additional noise to the signals
through static charging effects
Figure 2 shows the design of the DRL circuit It
is a standard summing amplifier generating an
amplified and inverted signal that is the average
of the individual signals A and B
The optimum value for Rf will be dependent
on the type of sensors being used as well as
the clothing being worn by the subject being
measured It should be set to achieve maximum
noise reduction while ensuring circuit stability
A value of 27kohms is suggested as a suitable
starting point for EPIC sensors
SmallerThan a
Grain Sand
of
Analysts project that by
2020 there will be over
50 billion connected
devices in the now-nascent
Internet of Things (IoT) However
the technology that will enable the
IoT of the future may look a little
different than todayrsquosmdashin fact
you may not be able to see it at all
Many new mobile devices require
motion sensors in order to monitor
analyze and deliver real-time data
and analysis to improve the way
consumers interact with everyday
technology While traditional
sensor platforms require multichip
modules or stacked die within a
device mCube a new MEMS sensor
company is driving the emergence
of Sensor 30 which will lead the
development of the smallest
sensors to datemdashsmaller than a
grain of sand By EEWeb Contributing Writers
mCubersquos Sensors Enable IoMTInterview with Ben Lee President and CEO of mCube
to enable the kind of constant and complex data accumulation that the Biostamp promises
In the interim MC10 is partnering up with other medical and pharmaceutical companies to develop integrated sensor and monitoring products The company plans to become a certified medical-ready partner for companies who donrsquot have access to this unique and proprietary technology Even the US Army has begun working with MC10 on military-grade sensors that will add further safety features for troops in the field This funding from NIH grants Department of Defense grants as well as foundation grants will help the company get one step closer to realization of devices so flexible that users might forget theyrsquore wearing them
ldquoThe company has been bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devicesrdquo
Join the
DESIGNERS OF THINGS conference in San Francisco on
September 23 and 24
Dedicated to the explosive and exciting potential of Wearable
Tech 3D Printing and the Internet of Things the conference
provides the growing design and development community
around these technologies a meeting place to discuss and
showcase the newest products
Click here for more info
httpwwwdesignersofthingscomsanfranciscoscheduler
speakersheth-nirav-rav33310
TECH REPORTNext-Generation Sensor Signal ConditionersPowerful and Flexible yet Easy to Use
TECH REPORTNon-Contact ECG Measurement Possibilities with EPIC Sensors
INDUSTRY INTERVIEWmCubersquos Super Small SensorsBen Lee President and CEO of mCube
TECH REPORTSkintight Technology Flexible Sensors Collect Vitals
CONTENTS
3
The Biostamp a prototype from MC10 is a new kind of wearable device that will redefine ldquoformrdquo in ldquoform factorrdquo pg 26
44
SENSOR TECHNOLOGY
Sensor Signal Conditioners
Powerful and Flexible yet Easy to Use
By David Grice Applications Engineer Zentrum Mikrokelektronik (ZMDI) Dresden Germany
As demands increase for the number type and range of sensors in
almost every product category the difficulty of implementing them
increases proportionately This is especially true in the automotive
arena driven by efficiency safety and emission requirements
Existing sensor technologies are inadequate to meet many of these
new and more stringent requirements spurring the development
of a new class of sensors based on micro-electro-
mechanical systems (MEMS) These new sensors
are smaller lighter more robust less expensive
and consume less power but they also
produce electrical signals that
are smaller and more nonlinear
than their bulkier counterparts
Next-Generation SO MANY SENSORS SO LITTLE TIME
5
TECH REPORT
5
Sensor Signal Conditioners
Powerful and Flexible yet Easy to Use
By David Grice Applications Engineer Zentrum Mikrokelektronik (ZMDI) Dresden Germany
As demands increase for the number type and range of sensors in
almost every product category the difficulty of implementing them
increases proportionately This is especially true in the automotive
arena driven by efficiency safety and emission requirements
Existing sensor technologies are inadequate to meet many of these
new and more stringent requirements spurring the development
of a new class of sensors based on micro-electro-
mechanical systems (MEMS) These new sensors
are smaller lighter more robust less expensive
and consume less power but they also
produce electrical signals that
are smaller and more nonlinear
than their bulkier counterparts
Next-Generation SO MANY SENSORS SO LITTLE TIME
66
SENSOR TECHNOLOGY
As the quality of output from transducers declines to meet application demands system
requirements such as measurement range accuracy speed and power consumption continue to increase squeezing the performance of sensor signal conditioning (SSC) circuits from both ends and making the task of designing them exponentially more difficult
integrity level (ASIL) for automotive applications These requirements include detection and notification of faults due to open or short circuits out-of-range parameters aging sensors and excessive temperature Additionally the SSC must be able to monitor these faults while tolerant of shorts to ground or supply voltage supply overvoltage conditions or reverse battery connections
ldquoOne of the key features of next-generation SSCs
is flexibilityrdquoldquoA highly efficient and powerful
reduced-instruction-set computer coordinates numerous control and
computational tasksrdquo
NEXT GENERATION TO THE RESCUE
In the same way increasing demands have spurred a new class of sensors Zentrum Mikroelektronik (ZMDI) is developing and introducing the next generation of SSC products and technologies to the sensor marketplace This article describes some of the most important and beneficial new features of these new SSCs
FLEXIBILITY IS A BEAUTIFUL THING
One of the key features of next-generation SSCs is flexibility The types and combinations of physical quantities measured for products are growing rapidly and new SSCs must facilitate fast development of complex sensor modules with low component counts and a user interface that is easy to learn and use This requires a signal interface that is configurable for a wide range of signals and correction algorithms that are much more complex than second or third order polynomial curve fitting offered by previous generations of SSCs For example a single application might require the conditioning of two temperature inputs one being a diode and the other a thermocouple and two resistive pressure bridges with widely varying output levels each of which require linearization and calibration
Flexibility is not limited only to signal types and ranges however Another dimension of configurability is required for the sequence of signal processing tasks Typically some signals must be acquired at a much higher rate than others and the
quantization and correction algorithms must be reconfigured quickly from one measurement to another in a programmable fashion In addition to this sometimes it is necessary to perform math operations between signals like subtracting two pressure inputs to generate a differential pressure output The SSC must generate a user-programmable sequence that samples the inputs in a defined order and rate correct each signal according to a user-defined calibration algorithm and combine the conditioned outputs into an orderly stream of data
Finally flexibility must include the number and type of output signals and protocols Reliability safety weight and noise constraints are also driving the creation of innovative new output protocols like single-edge nibble transmission (SENT) for the automotive industry Next-generation SSCs must support new interfaces like SENT along with the traditional analog one-wire and serial interfaces such as I2Ctrade and SPI In fact the SENT interface is output only and requires an auxiliary interface like I2C to configure and calibrate the SSC
Another important feature for next-generation SSCs is the ability to perform self-testing and diagnostics to meet critical safety standards like the automotive safety
I2Ctrade is a trademark of NXP
7
TECH REPORT
7
As the quality of output from transducers declines to meet application demands system
requirements such as measurement range accuracy speed and power consumption continue to increase squeezing the performance of sensor signal conditioning (SSC) circuits from both ends and making the task of designing them exponentially more difficult
integrity level (ASIL) for automotive applications These requirements include detection and notification of faults due to open or short circuits out-of-range parameters aging sensors and excessive temperature Additionally the SSC must be able to monitor these faults while tolerant of shorts to ground or supply voltage supply overvoltage conditions or reverse battery connections
ldquoOne of the key features of next-generation SSCs
is flexibilityrdquoldquoA highly efficient and powerful
reduced-instruction-set computer coordinates numerous control and
computational tasksrdquo
NEXT GENERATION TO THE RESCUE
In the same way increasing demands have spurred a new class of sensors Zentrum Mikroelektronik (ZMDI) is developing and introducing the next generation of SSC products and technologies to the sensor marketplace This article describes some of the most important and beneficial new features of these new SSCs
FLEXIBILITY IS A BEAUTIFUL THING
One of the key features of next-generation SSCs is flexibility The types and combinations of physical quantities measured for products are growing rapidly and new SSCs must facilitate fast development of complex sensor modules with low component counts and a user interface that is easy to learn and use This requires a signal interface that is configurable for a wide range of signals and correction algorithms that are much more complex than second or third order polynomial curve fitting offered by previous generations of SSCs For example a single application might require the conditioning of two temperature inputs one being a diode and the other a thermocouple and two resistive pressure bridges with widely varying output levels each of which require linearization and calibration
Flexibility is not limited only to signal types and ranges however Another dimension of configurability is required for the sequence of signal processing tasks Typically some signals must be acquired at a much higher rate than others and the
quantization and correction algorithms must be reconfigured quickly from one measurement to another in a programmable fashion In addition to this sometimes it is necessary to perform math operations between signals like subtracting two pressure inputs to generate a differential pressure output The SSC must generate a user-programmable sequence that samples the inputs in a defined order and rate correct each signal according to a user-defined calibration algorithm and combine the conditioned outputs into an orderly stream of data
Finally flexibility must include the number and type of output signals and protocols Reliability safety weight and noise constraints are also driving the creation of innovative new output protocols like single-edge nibble transmission (SENT) for the automotive industry Next-generation SSCs must support new interfaces like SENT along with the traditional analog one-wire and serial interfaces such as I2Ctrade and SPI In fact the SENT interface is output only and requires an auxiliary interface like I2C to configure and calibrate the SSC
Another important feature for next-generation SSCs is the ability to perform self-testing and diagnostics to meet critical safety standards like the automotive safety
I2Ctrade is a trademark of NXP
88
SENSOR TECHNOLOGY
PUTTING IT ALL TOGETHER
Figure 1 shows the block diagram of a next-generation SSC In this particular case the SSC supports two temperature inputsmdashone resistive one diodemdashand two resistive bridge inputs The conditioning signal chain includes sensor check and common mode (SCCM) adjustment multiplexing (MUX) programmable gain (PGA) from 1 to 200 VV and an analog to digital converter (ADC) with adjustable sample rate and resolution from 12 to 18 bits
The SSC in figure 1 looks similar to other SSCs that are presently available but most of its potential and flexibility lies in the calibration microcontroller (CMC) A highly efficient and powerful reduced instruction set computer (RISC) coordinates the numerous control and computational tasks necessary to provide the tremendous amount of flexibility required for next-generation SSCs The controller also combines the multiple output data packets into a structured stream in a wide variety of formats that can be either analog or digital
The cycle of tasks performed by the RISC engine consists of three main types measurement tasks conditioning tasks and output tasks Measurement tasks include operations that select the MUX input and signal polarities the gain and offset of the signal path the speed and resolution of the quantizer and auxiliary tasks such as auto-zeroing gain stages The output values of all the main measurement tasks are stored in registers for processing by the conditioning tasks These tasks range from simple operations like shifting and synchronization to basic math functions such as add subtract multiply and divide to complex functions such as logarithms polynomial evaluation spline curve fitting and digital filtering Output tasks include synchronization of data streams formatting packetizing encoding error detection and safety features like redundancy or inversion
The SSC shown in figure 1 provides for up to 20 measurement tasks and 62 conditioning tasks enabling thousands
of different combinations of signal processing sequences for each of the four inputs The number of output tasks varies greatly depending on the type of output but for a complex protocol like SENT the number can be in the dozens
MAKING IT EASY
However it is also vitally important that the flexibility power and complexity of next-generation SSCs do not require a commensurate level of time and resources for system designers implementing them The example shown in figure 1 is a member of a product family that is preconfigured by the manufacturer for a specific application using firmware All of the measurement conditioning and output tasks are programmed so that the designer need only focus on determining gain resolution and calibration coefficients for the correction algorithm all of which are facilitated by software that is easy to use and
Figure 1 An example block diagram of a next-generation SSC from ZMDI
ldquoOne thing that should not be flexible in next-generation
SSCs is the user interfacerdquo
consistent across the product line Special use cases can be implemented easily in firmware by the manufacturer should the need arise but the standard factory configuration will cover the majority of designs Additional family members of the product line are optimized for different numbers and types of inputs and outputs and also preconfigured for the intended application use
Finally one thing that should not be flexible in next-generation SSCs is the user interface including the physical dimensions pin or pad locations and software user interface The product family exemplified in figure 1 has a standardized footprint pinout and software user interface to minimize the costs time and resources associated with board layout calibration and climbing the learning curve
9
TECH REPORT
9
PUTTING IT ALL TOGETHER
Figure 1 shows the block diagram of a next-generation SSC In this particular case the SSC supports two temperature inputsmdashone resistive one diodemdashand two resistive bridge inputs The conditioning signal chain includes sensor check and common mode (SCCM) adjustment multiplexing (MUX) programmable gain (PGA) from 1 to 200 VV and an analog to digital converter (ADC) with adjustable sample rate and resolution from 12 to 18 bits
The SSC in figure 1 looks similar to other SSCs that are presently available but most of its potential and flexibility lies in the calibration microcontroller (CMC) A highly efficient and powerful reduced instruction set computer (RISC) coordinates the numerous control and computational tasks necessary to provide the tremendous amount of flexibility required for next-generation SSCs The controller also combines the multiple output data packets into a structured stream in a wide variety of formats that can be either analog or digital
The cycle of tasks performed by the RISC engine consists of three main types measurement tasks conditioning tasks and output tasks Measurement tasks include operations that select the MUX input and signal polarities the gain and offset of the signal path the speed and resolution of the quantizer and auxiliary tasks such as auto-zeroing gain stages The output values of all the main measurement tasks are stored in registers for processing by the conditioning tasks These tasks range from simple operations like shifting and synchronization to basic math functions such as add subtract multiply and divide to complex functions such as logarithms polynomial evaluation spline curve fitting and digital filtering Output tasks include synchronization of data streams formatting packetizing encoding error detection and safety features like redundancy or inversion
The SSC shown in figure 1 provides for up to 20 measurement tasks and 62 conditioning tasks enabling thousands
of different combinations of signal processing sequences for each of the four inputs The number of output tasks varies greatly depending on the type of output but for a complex protocol like SENT the number can be in the dozens
MAKING IT EASY
However it is also vitally important that the flexibility power and complexity of next-generation SSCs do not require a commensurate level of time and resources for system designers implementing them The example shown in figure 1 is a member of a product family that is preconfigured by the manufacturer for a specific application using firmware All of the measurement conditioning and output tasks are programmed so that the designer need only focus on determining gain resolution and calibration coefficients for the correction algorithm all of which are facilitated by software that is easy to use and
Figure 1 An example block diagram of a next-generation SSC from ZMDI
ldquoOne thing that should not be flexible in next-generation
SSCs is the user interfacerdquo
consistent across the product line Special use cases can be implemented easily in firmware by the manufacturer should the need arise but the standard factory configuration will cover the majority of designs Additional family members of the product line are optimized for different numbers and types of inputs and outputs and also preconfigured for the intended application use
Finally one thing that should not be flexible in next-generation SSCs is the user interface including the physical dimensions pin or pad locations and software user interface The product family exemplified in figure 1 has a standardized footprint pinout and software user interface to minimize the costs time and resources associated with board layout calibration and climbing the learning curve
1212
SENSOR TECHNOLOGY
The human heartbeat is arguably the single most important (ldquolife-and-deathrdquo) diagnostic indicator Thus electrocardiograms (ECGs) are one of the most significant diagnostic methods in that
they monitor heart function ECGs are not only used in a clinical setting but are increasingly seen in personal health devices Traditionally ECG measurement conductive electrodes have been applied which are directly attached to the skin With the help of contact gel (wet or solid) to ensure that there is good electrical contact between the skin and the sensor direct resistive contact is made with the patient However conventional electrodes possess various disadvantages which are not conducive for long-term use in non-clinical settings In addition to being potentially messy metal allergies can cause skin irritations and as a single-use item they are quite expensive
Non-contact ECG measurementusing EPIC Sensors
Measuring electrocardiogram (ECG) signals without skin contact is now possible using novel Electric Potential Integrated Circuit (EPIC) sensors
By Alan Lowne CEO of Saelig Co Inc
13
TECH REPORT
13
The human heartbeat is arguably the single most important (ldquolife-and-deathrdquo) diagnostic indicator Thus electrocardiograms (ECGs) are one of the most significant diagnostic methods in that
they monitor heart function ECGs are not only used in a clinical setting but are increasingly seen in personal health devices Traditionally ECG measurement conductive electrodes have been applied which are directly attached to the skin With the help of contact gel (wet or solid) to ensure that there is good electrical contact between the skin and the sensor direct resistive contact is made with the patient However conventional electrodes possess various disadvantages which are not conducive for long-term use in non-clinical settings In addition to being potentially messy metal allergies can cause skin irritations and as a single-use item they are quite expensive
Non-contact ECG measurementusing EPIC Sensors
Measuring electrocardiogram (ECG) signals without skin contact is now possible using novel Electric Potential Integrated Circuit (EPIC) sensors
By Alan Lowne CEO of Saelig Co Inc
1414
SENSOR TECHNOLOGY
Non-contact measurement of electrophysiological signals is of great interest in healthcare settings with the potential of reducing disposable costs speeding up or simplifying measurement techniques Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact Monitoring vehicle drivers for health and alertness by detecting heart rate and respiration or determining car occupancy to adjust the ride handling and air bag deployment with the varying size and location of occupants is a vast potential market
Capacitive (insulated) electrodes can register ECG signals without conductive contact to the bodyndasheven through clothesndashand represent
an attractive alternative for a wide range of new applications EPIC (Electric Potential Integrated Circuit) is a completely new sensor technology resulting from research at the University of Sussex (UK) Novel ultra high impedance EPIC sensors measure electric field changes without requiring physical or resistive contact This award winning patent-protected sensor can rapidly measure electric potential sources such as electrophysiological signals or even spatial electric fields It therefore has the ability to measure ECGs without direct skin contact By adjusting the DSP and amplification circuitry the sensors can be tuned for detection at a distance as required for differing automotive applications EPIC sensor electrodes can be easily and discretely incorporated inside car seat backs to acquire the necessary biometric data
Signals measured on the human body always include a large amount of noise the major component of this being 50 or 60 Hz power line noise capacitively-coupled to the body from the surrounding electricity supply Measurements such as ECG depend on being able to extract the small electrophysiological signals from the much larger noise signals EPIC sensors can be used in ldquocontact moderdquo for ECG measurement where the subject touches both the capacitive electrode surface and some metal at the system ground directly with the skin This ground reference allows filtering and differential amplification of signals from two sensors to be effective in removing the mains frequency noise leaving a high quality ECG signal In non-contact ECG measurement there is ndash by definition - no skin contact and thus no direct connection can be made between the subjectrsquos body and the system ground Some other method of reducing the power line noise is therefore required to
EPIC Sensors incontact with clothing
Conductive fabric in contactwith clothing eg on chair seat
Output
EPICdemo box
Figure 1 Basic configuration for non-contact ECG measurement including capacitively-oocupied DR circuit
OP-AMP
+5V
-5V
Vout
Rf (27KΩ)
Ra(11KΩ)
Rb(11KΩ)
Rp (15MΩ) To conductive fabric on chair thus capacitively coupled to body
Inputs from outputs of demo box
A
BC
(1nF)
Figure 2 DPL circuit Voltage gain is set by Rf Rp limits current fed back to the body (see text)Operational amplifier output Vout = - (VA + VB) Rf 11K
enable the ECG signal to be extracted reliably and accurately One such method utilizes an approach very similar to the ldquoDriven Right Legrdquo (DRL) system that is used for the same purpose in conventional ECG measurement techniques In conventional ECG the DRL signal is coupled directly to the patientrsquos skin The DRL signal reduces power line noise on the sensor signals by feeding back an inverted average of the signals from two sensors on to the patientrsquos body In non-contact ECG the generated DRL signal can be capacitively-coupled to the body through clothing via a piece of conductive material placed ndash for instance ndash on the seat or back of a chair Capacitive coupling of DRL signals is described by Lim et al1 and Lee et al2
SYSTEM DESIGNAn ECG system can therefore be built into a chair a mattress or clothing for instance The DRL circuit improves the sensor signalnoise ratio enormously In the example in Figure 1 EPIC sensors are mounted on a chair back such that the electrodes touch the clothing on the subjectrsquos back when resting normally against the back of the chair The generated DRL signal is connected to a piece of conductive material
placed either on the seat of the chair or at the bottom of the chair back contacting the subjectrsquos clothing in the normal sitting position Copper-coated nylon fabric is one possible material suitable for the DRL coupling material but other conductive materials may be equally successful A thin non- conductive material such as a cotton fabric may be used to cover both the sensors and the DRL coupling fabric if required for instance when building the sensors into a seat Consideration must be given as to how material will reduce the coupling capacitance between the sensor and the subject or add additional noise to the signals through static charging effectsFigure 2 shows the design of the DRL circuit It is a standard summing amplifier generating an amplified and inverted signal that is the average of the individual signals A and B
The optimum value for Rf will be dependent on the type of sensors being used as well as the clothing being worn by the subject being measured It should be set to achieve maximum noise reduction while ensuring circuit stability A value of 27kohms is suggested as a suitable starting point for EPIC sensors
15
TECH REPORT
15
Non-contact measurement of electrophysiological signals is of great interest in healthcare settings with the potential of reducing disposable costs speeding up or simplifying measurement techniques Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact Monitoring vehicle drivers for health and alertness by detecting heart rate and respiration or determining car occupancy to adjust the ride handling and air bag deployment with the varying size and location of occupants is a vast potential market
Capacitive (insulated) electrodes can register ECG signals without conductive contact to the bodyndasheven through clothesndashand represent
an attractive alternative for a wide range of new applications EPIC (Electric Potential Integrated Circuit) is a completely new sensor technology resulting from research at the University of Sussex (UK) Novel ultra high impedance EPIC sensors measure electric field changes without requiring physical or resistive contact This award winning patent-protected sensor can rapidly measure electric potential sources such as electrophysiological signals or even spatial electric fields It therefore has the ability to measure ECGs without direct skin contact By adjusting the DSP and amplification circuitry the sensors can be tuned for detection at a distance as required for differing automotive applications EPIC sensor electrodes can be easily and discretely incorporated inside car seat backs to acquire the necessary biometric data
Signals measured on the human body always include a large amount of noise the major component of this being 50 or 60 Hz power line noise capacitively-coupled to the body from the surrounding electricity supply Measurements such as ECG depend on being able to extract the small electrophysiological signals from the much larger noise signals EPIC sensors can be used in ldquocontact moderdquo for ECG measurement where the subject touches both the capacitive electrode surface and some metal at the system ground directly with the skin This ground reference allows filtering and differential amplification of signals from two sensors to be effective in removing the mains frequency noise leaving a high quality ECG signal In non-contact ECG measurement there is ndash by definition - no skin contact and thus no direct connection can be made between the subjectrsquos body and the system ground Some other method of reducing the power line noise is therefore required to
EPIC Sensors incontact with clothing
Conductive fabric in contactwith clothing eg on chair seat
Output
EPICdemo box
Figure 1 Basic configuration for non-contact ECG measurement including capacitively-oocupied DR circuit
OP-AMP
+5V
-5V
Vout
Rf (27KΩ)
Ra(11KΩ)
Rb(11KΩ)
Rp (15MΩ) To conductive fabric on chair thus capacitively coupled to body
Inputs from outputs of demo box
A
BC
(1nF)
Figure 2 DPL circuit Voltage gain is set by Rf Rp limits current fed back to the body (see text)Operational amplifier output Vout = - (VA + VB) Rf 11K
enable the ECG signal to be extracted reliably and accurately One such method utilizes an approach very similar to the ldquoDriven Right Legrdquo (DRL) system that is used for the same purpose in conventional ECG measurement techniques In conventional ECG the DRL signal is coupled directly to the patientrsquos skin The DRL signal reduces power line noise on the sensor signals by feeding back an inverted average of the signals from two sensors on to the patientrsquos body In non-contact ECG the generated DRL signal can be capacitively-coupled to the body through clothing via a piece of conductive material placed ndash for instance ndash on the seat or back of a chair Capacitive coupling of DRL signals is described by Lim et al1 and Lee et al2
SYSTEM DESIGNAn ECG system can therefore be built into a chair a mattress or clothing for instance The DRL circuit improves the sensor signalnoise ratio enormously In the example in Figure 1 EPIC sensors are mounted on a chair back such that the electrodes touch the clothing on the subjectrsquos back when resting normally against the back of the chair The generated DRL signal is connected to a piece of conductive material
placed either on the seat of the chair or at the bottom of the chair back contacting the subjectrsquos clothing in the normal sitting position Copper-coated nylon fabric is one possible material suitable for the DRL coupling material but other conductive materials may be equally successful A thin non- conductive material such as a cotton fabric may be used to cover both the sensors and the DRL coupling fabric if required for instance when building the sensors into a seat Consideration must be given as to how material will reduce the coupling capacitance between the sensor and the subject or add additional noise to the signals through static charging effectsFigure 2 shows the design of the DRL circuit It is a standard summing amplifier generating an amplified and inverted signal that is the average of the individual signals A and B
The optimum value for Rf will be dependent on the type of sensors being used as well as the clothing being worn by the subject being measured It should be set to achieve maximum noise reduction while ensuring circuit stability A value of 27kohms is suggested as a suitable starting point for EPIC sensors
1616
SENSOR TECHNOLOGY
Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact
7660SwitchedCapacitorVoltage
Converter
1
2
3
4
8
7
6
5
OP-AMP
Rb(11K)
Ra(11K)
Rf (27KΩ)
Rp (15MΩ)DRLOutput
1nFVout
6Vbatterypack4xAA
+6V
-6V10microF
10microF
A
B
Figure 3 DRL circuit including battery power supply and voltage converter to provide -6v rail Inputs A and B are buffered outputs from the sensors and may be taken from the A and B outputs of the EPIC demo box Ground should be connected to the sensor 0V the shielding of the BNC A and B outputs on the demo box being a suitable connection point See figure 2 and the text for further comments on the DRL design
sensors and the DRL circuit into saturation Because the system contains some large impedances and hence has some very long RC time constants settling times of tens of seconds can be needed before a clean ECG signal is seen During this period the signal can either appear very noisy or be virtually flat depending on whether one or both sensors or the DRL circuit are ldquorailingrdquo The subject should sit still during this time and wait for the circuit to settle since continually adjusting position will only make matters worse Settling times can sometimes be reduced by turning off the power to the demo box for a few seconds
CLOTHINGGood results can be obtained with one or two layers of cotton material between the sensors and the skin Other materials including a wool-mix sweater and a polyester fleece in addition
to two layers of cotton material have been successful Examples are shown in Figures 6 and 7 If the key greatest interest is in the ldquoR-Rrdquo interval adjusting filter settings to reduce or re-center the signal bandwidth can give improved signal quality
STATICBecause there is no direct physical contact between the subject and any grounding point there is no path for any static build up to be discharged Under most circumstances static build-up does not present a problem butdepending on factors including clothing footwear flooring humidity levels in the air and so forth static build up can sometimes prevent the cardiac signal from being seen clearly Product design must take into account a discharge to the system ground to remove the static charge
Rp the protection resistor is included to limit the current that can be fed back to the human body This resistor is essential in ensuring that the subjectrsquos wellbeing is not endangered and must not be omitted
IMPLEMENTATIONThe demonstration of non-contact ECG is best performed using an EPIC demonstration kit Plessey part no PS25003 which includes the necessary drive circuitry and switchable 50Hz and 60Hz notch filters The inputs to the DRL circuit can be taken from the BNC outputs ldquoA amp Brdquo on the front of the demo box The DRL circuit will require its own bipolar power supply plusmn5V or plusmn6V is suggested A circuit design including a battery power supply is shown in Figure 3
Plesseyrsquos compact sensors (PS2520x) and disc sensors (PS25101) provide equally good results although for demonstration purposes disc sensors are simplest to fix to a chair to make contact with the occupantrsquos back Compact sensors are recommended when designing a custom-built system
EPIC sensors which are designed for contact electrophysiology sensing give excellent results in most cases Initial trials suggest that custom modifications to the sensor design (eg lower gain and higher input impedance) can offer increased sensitivity and the ability to detect weaker ECG signalsThe shape of the measured ECG trace ndash in terms of relative magnitudes of the P Q R S and T waves ndash will depend on the positioning of the sensors behind the subjectrsquos back If the desire is only to measure the ldquoR-Rrdquo interval to determine heart rate then the positioning of the sensors is not critical Placing one sensor either side of the spine separated by 6rdquo -10rdquo (15-25 cm) at approximately the same height as the heart is recommended as a starting point For applications where signals from other parts of the cardiac cycle are required the user should refer to texts on bio-electronic signals for guidance on sensor position
SETTLING TIMEWhen a subject first sits in the chair and leans against the EPIC sensors the changes in electric potential will normally send both the
17
TECH REPORT
17
Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact
7660SwitchedCapacitorVoltage
Converter
1
2
3
4
8
7
6
5
OP-AMP
Rb(11K)
Ra(11K)
Rf (27KΩ)
Rp (15MΩ)DRLOutput
1nFVout
6Vbatterypack4xAA
+6V
-6V10microF
10microF
A
B
Figure 3 DRL circuit including battery power supply and voltage converter to provide -6v rail Inputs A and B are buffered outputs from the sensors and may be taken from the A and B outputs of the EPIC demo box Ground should be connected to the sensor 0V the shielding of the BNC A and B outputs on the demo box being a suitable connection point See figure 2 and the text for further comments on the DRL design
sensors and the DRL circuit into saturation Because the system contains some large impedances and hence has some very long RC time constants settling times of tens of seconds can be needed before a clean ECG signal is seen During this period the signal can either appear very noisy or be virtually flat depending on whether one or both sensors or the DRL circuit are ldquorailingrdquo The subject should sit still during this time and wait for the circuit to settle since continually adjusting position will only make matters worse Settling times can sometimes be reduced by turning off the power to the demo box for a few seconds
CLOTHINGGood results can be obtained with one or two layers of cotton material between the sensors and the skin Other materials including a wool-mix sweater and a polyester fleece in addition
to two layers of cotton material have been successful Examples are shown in Figures 6 and 7 If the key greatest interest is in the ldquoR-Rrdquo interval adjusting filter settings to reduce or re-center the signal bandwidth can give improved signal quality
STATICBecause there is no direct physical contact between the subject and any grounding point there is no path for any static build up to be discharged Under most circumstances static build-up does not present a problem butdepending on factors including clothing footwear flooring humidity levels in the air and so forth static build up can sometimes prevent the cardiac signal from being seen clearly Product design must take into account a discharge to the system ground to remove the static charge
Rp the protection resistor is included to limit the current that can be fed back to the human body This resistor is essential in ensuring that the subjectrsquos wellbeing is not endangered and must not be omitted
IMPLEMENTATIONThe demonstration of non-contact ECG is best performed using an EPIC demonstration kit Plessey part no PS25003 which includes the necessary drive circuitry and switchable 50Hz and 60Hz notch filters The inputs to the DRL circuit can be taken from the BNC outputs ldquoA amp Brdquo on the front of the demo box The DRL circuit will require its own bipolar power supply plusmn5V or plusmn6V is suggested A circuit design including a battery power supply is shown in Figure 3
Plesseyrsquos compact sensors (PS2520x) and disc sensors (PS25101) provide equally good results although for demonstration purposes disc sensors are simplest to fix to a chair to make contact with the occupantrsquos back Compact sensors are recommended when designing a custom-built system
EPIC sensors which are designed for contact electrophysiology sensing give excellent results in most cases Initial trials suggest that custom modifications to the sensor design (eg lower gain and higher input impedance) can offer increased sensitivity and the ability to detect weaker ECG signalsThe shape of the measured ECG trace ndash in terms of relative magnitudes of the P Q R S and T waves ndash will depend on the positioning of the sensors behind the subjectrsquos back If the desire is only to measure the ldquoR-Rrdquo interval to determine heart rate then the positioning of the sensors is not critical Placing one sensor either side of the spine separated by 6rdquo -10rdquo (15-25 cm) at approximately the same height as the heart is recommended as a starting point For applications where signals from other parts of the cardiac cycle are required the user should refer to texts on bio-electronic signals for guidance on sensor position
SETTLING TIMEWhen a subject first sits in the chair and leans against the EPIC sensors the changes in electric potential will normally send both the
1818
SENSOR TECHNOLOGY
Figure 4 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit HP filter corner frequency is 50mHz LP filter in demo box has corner frequency of 30Hz
Figure 6 ECG signals measured from a subject wearing a wool-mix sweater over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 8-25Hz The heart rate can be easily extracted
Figure 5 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit Software filters limit the bandwidth to 8-25Hz
Figure 7 ECG signals measured from a subject wearing a polyester fleece over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 16-40Hz The heart rate can be easily extracted
CABLE SHIELDINGCareful shielding is necessary to reduce unwanted noise artifacts Grounding the shielding of the sensor cable via the connection between the outer casing of the sensor plugs and the metal surround of the socket on the control electronics is recommended
CONCLUSIONEPIC sensors can be used to measure ECG signals without physical skin contact While
sensors can be embedded in a chair or seat the techniques are equally applicable to sensors mounted on a mattress in clothing or in other situations There are many variables that will affect signal quality from the strength of cardiac signal generated by the individual being measured to clothing to the surrounding environment but the designs given here are a starting point in establishing an optimum system for a particular application infin
Find us at Booth 37310World Maker Faire New York
Figure 4 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit HP filter corner frequency is 50mHz LP filter in demo box has corner frequency of 30Hz
Figure 6 ECG signals measured from a subject wearing a wool-mix sweater over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 8-25Hz The heart rate can be easily extracted
Figure 5 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit Software filters limit the bandwidth to 8-25Hz
Figure 7 ECG signals measured from a subject wearing a polyester fleece over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 16-40Hz The heart rate can be easily extracted
CABLE SHIELDINGCareful shielding is necessary to reduce unwanted noise artifacts Grounding the shielding of the sensor cable via the connection between the outer casing of the sensor plugs and the metal surround of the socket on the control electronics is recommended
CONCLUSIONEPIC sensors can be used to measure ECG signals without physical skin contact While
sensors can be embedded in a chair or seat the techniques are equally applicable to sensors mounted on a mattress in clothing or in other situations There are many variables that will affect signal quality from the strength of cardiac signal generated by the individual being measured to clothing to the surrounding environment but the designs given here are a starting point in establishing an optimum system for a particular application infin
Find us at Booth 37310World Maker Faire New York
20
SENSOR TECHNOLOGY
SmallerThan a
Grain Sand
of
Analysts project that by
2020 there will be over
50 billion connected
devices in the now-nascent
Internet of Things (IoT) However
the technology that will enable the
IoT of the future may look a little
different than todayrsquosmdashin fact
you may not be able to see it at all
Many new mobile devices require
motion sensors in order to monitor
analyze and deliver real-time data
and analysis to improve the way
consumers interact with everyday
technology While traditional
sensor platforms require multichip
modules or stacked die within a
device mCube a new MEMS sensor
company is driving the emergence
of Sensor 30 which will lead the
development of the smallest
sensors to datemdashsmaller than a
grain of sand By EEWeb Contributing Writers
mCubersquos Sensors Enable IoMTInterview with Ben Lee President and CEO of mCube
INDUSTRY INTERVIEW
21
SmallerThan a
Grain Sand
of
Analysts project that by
2020 there will be over
50 billion connected
devices in the now-nascent
Internet of Things (IoT) However
the technology that will enable the
IoT of the future may look a little
different than todayrsquosmdashin fact
you may not be able to see it at all
Many new mobile devices require
motion sensors in order to monitor
analyze and deliver real-time data
and analysis to improve the way
consumers interact with everyday
technology While traditional
sensor platforms require multichip
modules or stacked die within a
device mCube a new MEMS sensor
company is driving the emergence
of Sensor 30 which will lead the
development of the smallest
sensors to datemdashsmaller than a
grain of sand By EEWeb Contributing Writers
mCubersquos Sensors Enable IoMTInterview with Ben Lee President and CEO of mCube
22
SENSOR TECHNOLOGY
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
INDUSTRY INTERVIEW
23
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
24
SENSOR TECHNOLOGY
Since sensors are so small and affordable donrsquot be surprised to find unique applications in the future Lee speculates that ldquofarmers might have sensor tags to monitor livestock for abnormal activity patterns of grazing potential illness and herd behaviorrdquo Commercial trucking might involve motion sensors connected to video cameras in rear-view mirrors to better assess the cause of an accident and driving conditions For shipping Lee describes ldquomotion sensors embedded directly onto packages to record jarring motions or accidents in order to determine when and how contents were damagedrdquo
As of 2014 mCubersquos complete intertial sensor portfolio contains an accelerometer magnetometer and its proprietary iGyrotrade gyroscope offering nine degrees of freedom (9DoF) Through reductions in cost power consumption and size mCubersquos sensor offerings make it possible to place them onto nearly any object or devicemdashin some cases without packaging ldquoWe aspire to put one or more MEMS motion sensors on anything that movesrdquo remarks Lee And with the IoMT taking shape and consumer expectations for connected moving devices becoming more concrete developers of new applications will turn to solutions like mCube to deliver truly cutting-edge connected devices
ldquoAt mCube we aspire to put one or more MEMS motion sensors on
anything that movesrdquo
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 15
Complete Inertial Motion Sensor Portfolio
Solutions for up to 9DoF (Degrees of Freedom)
Accelerometer
Magnetometer
iGyroTM
3DoF 3DoF
9DoF
2x2mm
3x3mm 3DoF 6DoF
14x14mm
3x3mm
3x3mm
2626
SENSOR TECHNOLOGY
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
27
TECH REPORT
27
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
2828
SENSOR TECHNOLOGY
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
29
TECH REPORT
29
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
3030
SENSOR TECHNOLOGY
to enable the kind of constant and complex data accumulation that the Biostamp promises
In the interim MC10 is partnering up with other medical and pharmaceutical companies to develop integrated sensor and monitoring products The company plans to become a certified medical-ready partner for companies who donrsquot have access to this unique and proprietary technology Even the US Army has begun working with MC10 on military-grade sensors that will add further safety features for troops in the field This funding from NIH grants Department of Defense grants as well as foundation grants will help the company get one step closer to realization of devices so flexible that users might forget theyrsquore wearing them
ldquoThe company has been bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devicesrdquo
Join the
DESIGNERS OF THINGS conference in San Francisco on
September 23 and 24
Dedicated to the explosive and exciting potential of Wearable
Tech 3D Printing and the Internet of Things the conference
provides the growing design and development community
around these technologies a meeting place to discuss and
showcase the newest products
Click here for more info
httpwwwdesignersofthingscomsanfranciscoscheduler
speakersheth-nirav-rav33310
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Sierra CircuitsA Complete PCB Resource
PLUS The Ground rdquo Myth in PrintedCircuits
ldquo
PCB Resin Reactor+
Ken BahlCEO of Sierra Circuits
Let There Be
How Cree reinvented the light bulb
LIGHT
David ElienVP of Marketing amp Business
Development Cree Inc
New LED Filament Tower
Cutting Edge Flatscreen Technologies
+
+
M o v i n g T o w a r d s
a Clean Energy
FUTUREmdash Hugo van Nispen COO of DNV KEMA
MCU Wars 32-bit MCU Comparison
Cutting Edge
SPICEModeling
Freescale and TI Embedded
Modules
ARMCortex
Programming
From Concept to
Reality Wolfgang Heinz-Fischer
Head of Marketing amp PR TQ-Group
Low-Power Design Techniques
TQ-Grouprsquos Comprehensive Design Process
+
+
PowerDeveloper
Octobe r 20 13
Designing forDurability
View more EEWeb magazinesmdash Click Here
3
4
12
20
26
Sensor Signal Conditioners
Powerful and Flexible yet Easy to Use
By David Grice Applications Engineer Zentrum Mikrokelektronik (ZMDI) Dresden Germany
As demands increase for the number type and range of sensors in
almost every product category the difficulty of implementing them
increases proportionately This is especially true in the automotive
arena driven by efficiency safety and emission requirements
Existing sensor technologies are inadequate to meet many of these
new and more stringent requirements spurring the development
of a new class of sensors based on micro-electro-
mechanical systems (MEMS) These new sensors
are smaller lighter more robust less expensive
and consume less power but they also
produce electrical signals that
are smaller and more nonlinear
than their bulkier counterparts
Next-Generation SO MANY SENSORS SO LITTLE TIME
Non-contact measurement of
electrophysiological signals is of great
interest in healthcare settings with the
potential of reducing disposable costs
speeding up or simplifying measurement
techniques Monitoring long-term medical
conditions within the home or observing pilots
drivers soldiers and others in safety critical
situations is now possible without needing
skin contact Monitoring vehicle drivers for
health and alertness by detecting heart rate
and respiration or determining car occupancy
to adjust the ride handling and air bag
deployment with the varying size and location
of occupants is a vast potential market
Capacitive (insulated) electrodes can register
ECG signals without conductive contact to the
bodyndasheven through clothesndashand represent
an attractive alternative for a wide range of
new applications EPIC (Electric Potential
Integrated Circuit) is a completely new sensor
technology resulting from research at the
University of Sussex (UK) Novel ultra high
impedance EPIC sensors measure electric field
changes without requiring physical or resistive
contact This award winning patent-protected
sensor can rapidly measure electric potential
sources such as electrophysiological signals
or even spatial electric fields It therefore
has the ability to measure ECGs without
direct skin contact By adjusting the DSP and
amplification circuitry the sensors can be
tuned for detection at a distance as required
for differing automotive applications EPIC
sensor electrodes can be easily and discretely
incorporated inside car seat backs to acquire
the necessary biometric data
Signals measured on the human body always
include a large amount of noise the major
component of this being 50 or 60 Hz power
line noise capacitively-coupled to the body
from the surrounding electricity supply
Measurements such as ECG depend on being
able to extract the small electrophysiological
signals from the much larger noise signals
EPIC sensors can be used in ldquocontact moderdquo for
ECG measurement where the subject touches
both the capacitive electrode surface and
some metal at the system ground directly with
the skin This ground reference allows filtering
and differential amplification of signals from
two sensors to be effective in removing the
mains frequency noise leaving a high quality
ECG signal In non-contact ECG measurement
there is ndash by definition - no skin contact
and thus no direct connection can be made
between the subjectrsquos body and the system
ground Some other method of reducing
the power line noise is therefore required to
EPIC Sensors in
contact with clothing
Conductive fabric in contact
with clothing eg on chair seat
Output
EPICdemo box
Figure 1 Basic configuration for non-contact ECG
measurement including capacitively-oocupied
DR circuit
OP-AMP
+5V
-5V
Vout
Rf (27KΩ)
Ra(11KΩ)
Rb(11KΩ)
Rp (15MΩ)To conductive
fabric on chair
thus capacitively
coupled to body
Inputs from
outputs of
demo box
A
B
C(1nF)
Figure 2 DPL circuit Voltage gain is set by Rf Rp limits current fed back to the body (see text)
Operational amplifier output Vout = - (VA + VB) Rf 11K
enable the ECG signal to be extracted reliably
and accurately One such method utilizes an
approach very similar to the ldquoDriven Right Legrdquo
(DRL) system that is used for the same purpose
in conventional ECG measurement techniques
In conventional ECG the DRL signal is coupled
directly to the patientrsquos skin The DRL signal
reduces power line noise on the sensor signals
by feeding back an inverted average of the
signals from two sensors on to the patientrsquos
body In non-contact ECG the generated DRL
signal can be capacitively-coupled to the body
through clothing via a piece of conductive
material placed ndash for instance ndash on the seat
or back of a chair Capacitive coupling of DRL
signals is described by Lim et al1 and Lee et al2
SYSTEM DESIGN
An ECG system can therefore be built into a
chair a mattress or clothing for instance The
DRL circuit improves the sensor signalnoise
ratio enormously In the example in Figure 1
EPIC sensors are mounted on a chair back such
that the electrodes touch the clothing on the
subjectrsquos back when resting normally against
the back of the chair The generated DRL signal
is connected to a piece of conductive material
placed either on the seat of the chair or at
the bottom of the chair back contacting the
subjectrsquos clothing in the normal sitting position
Copper-coated nylon fabric is one possible
material suitable for the DRL coupling material
but other conductive materials may be equally
successful A thin non- conductive material
such as a cotton fabric may be used to cover
both the sensors and the DRL coupling fabric if
required for instance when building the sensors
into a seat Consideration must be given as
to how material will reduce the coupling
capacitance between the sensor and the
subject or add additional noise to the signals
through static charging effects
Figure 2 shows the design of the DRL circuit It
is a standard summing amplifier generating an
amplified and inverted signal that is the average
of the individual signals A and B
The optimum value for Rf will be dependent
on the type of sensors being used as well as
the clothing being worn by the subject being
measured It should be set to achieve maximum
noise reduction while ensuring circuit stability
A value of 27kohms is suggested as a suitable
starting point for EPIC sensors
SmallerThan a
Grain Sand
of
Analysts project that by
2020 there will be over
50 billion connected
devices in the now-nascent
Internet of Things (IoT) However
the technology that will enable the
IoT of the future may look a little
different than todayrsquosmdashin fact
you may not be able to see it at all
Many new mobile devices require
motion sensors in order to monitor
analyze and deliver real-time data
and analysis to improve the way
consumers interact with everyday
technology While traditional
sensor platforms require multichip
modules or stacked die within a
device mCube a new MEMS sensor
company is driving the emergence
of Sensor 30 which will lead the
development of the smallest
sensors to datemdashsmaller than a
grain of sand By EEWeb Contributing Writers
mCubersquos Sensors Enable IoMTInterview with Ben Lee President and CEO of mCube
to enable the kind of constant and complex data accumulation that the Biostamp promises
In the interim MC10 is partnering up with other medical and pharmaceutical companies to develop integrated sensor and monitoring products The company plans to become a certified medical-ready partner for companies who donrsquot have access to this unique and proprietary technology Even the US Army has begun working with MC10 on military-grade sensors that will add further safety features for troops in the field This funding from NIH grants Department of Defense grants as well as foundation grants will help the company get one step closer to realization of devices so flexible that users might forget theyrsquore wearing them
ldquoThe company has been bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devicesrdquo
Join the
DESIGNERS OF THINGS conference in San Francisco on
September 23 and 24
Dedicated to the explosive and exciting potential of Wearable
Tech 3D Printing and the Internet of Things the conference
provides the growing design and development community
around these technologies a meeting place to discuss and
showcase the newest products
Click here for more info
httpwwwdesignersofthingscomsanfranciscoscheduler
speakersheth-nirav-rav33310
TECH REPORTNext-Generation Sensor Signal ConditionersPowerful and Flexible yet Easy to Use
TECH REPORTNon-Contact ECG Measurement Possibilities with EPIC Sensors
INDUSTRY INTERVIEWmCubersquos Super Small SensorsBen Lee President and CEO of mCube
TECH REPORTSkintight Technology Flexible Sensors Collect Vitals
CONTENTS
3
The Biostamp a prototype from MC10 is a new kind of wearable device that will redefine ldquoformrdquo in ldquoform factorrdquo pg 26
44
SENSOR TECHNOLOGY
Sensor Signal Conditioners
Powerful and Flexible yet Easy to Use
By David Grice Applications Engineer Zentrum Mikrokelektronik (ZMDI) Dresden Germany
As demands increase for the number type and range of sensors in
almost every product category the difficulty of implementing them
increases proportionately This is especially true in the automotive
arena driven by efficiency safety and emission requirements
Existing sensor technologies are inadequate to meet many of these
new and more stringent requirements spurring the development
of a new class of sensors based on micro-electro-
mechanical systems (MEMS) These new sensors
are smaller lighter more robust less expensive
and consume less power but they also
produce electrical signals that
are smaller and more nonlinear
than their bulkier counterparts
Next-Generation SO MANY SENSORS SO LITTLE TIME
5
TECH REPORT
5
Sensor Signal Conditioners
Powerful and Flexible yet Easy to Use
By David Grice Applications Engineer Zentrum Mikrokelektronik (ZMDI) Dresden Germany
As demands increase for the number type and range of sensors in
almost every product category the difficulty of implementing them
increases proportionately This is especially true in the automotive
arena driven by efficiency safety and emission requirements
Existing sensor technologies are inadequate to meet many of these
new and more stringent requirements spurring the development
of a new class of sensors based on micro-electro-
mechanical systems (MEMS) These new sensors
are smaller lighter more robust less expensive
and consume less power but they also
produce electrical signals that
are smaller and more nonlinear
than their bulkier counterparts
Next-Generation SO MANY SENSORS SO LITTLE TIME
66
SENSOR TECHNOLOGY
As the quality of output from transducers declines to meet application demands system
requirements such as measurement range accuracy speed and power consumption continue to increase squeezing the performance of sensor signal conditioning (SSC) circuits from both ends and making the task of designing them exponentially more difficult
integrity level (ASIL) for automotive applications These requirements include detection and notification of faults due to open or short circuits out-of-range parameters aging sensors and excessive temperature Additionally the SSC must be able to monitor these faults while tolerant of shorts to ground or supply voltage supply overvoltage conditions or reverse battery connections
ldquoOne of the key features of next-generation SSCs
is flexibilityrdquoldquoA highly efficient and powerful
reduced-instruction-set computer coordinates numerous control and
computational tasksrdquo
NEXT GENERATION TO THE RESCUE
In the same way increasing demands have spurred a new class of sensors Zentrum Mikroelektronik (ZMDI) is developing and introducing the next generation of SSC products and technologies to the sensor marketplace This article describes some of the most important and beneficial new features of these new SSCs
FLEXIBILITY IS A BEAUTIFUL THING
One of the key features of next-generation SSCs is flexibility The types and combinations of physical quantities measured for products are growing rapidly and new SSCs must facilitate fast development of complex sensor modules with low component counts and a user interface that is easy to learn and use This requires a signal interface that is configurable for a wide range of signals and correction algorithms that are much more complex than second or third order polynomial curve fitting offered by previous generations of SSCs For example a single application might require the conditioning of two temperature inputs one being a diode and the other a thermocouple and two resistive pressure bridges with widely varying output levels each of which require linearization and calibration
Flexibility is not limited only to signal types and ranges however Another dimension of configurability is required for the sequence of signal processing tasks Typically some signals must be acquired at a much higher rate than others and the
quantization and correction algorithms must be reconfigured quickly from one measurement to another in a programmable fashion In addition to this sometimes it is necessary to perform math operations between signals like subtracting two pressure inputs to generate a differential pressure output The SSC must generate a user-programmable sequence that samples the inputs in a defined order and rate correct each signal according to a user-defined calibration algorithm and combine the conditioned outputs into an orderly stream of data
Finally flexibility must include the number and type of output signals and protocols Reliability safety weight and noise constraints are also driving the creation of innovative new output protocols like single-edge nibble transmission (SENT) for the automotive industry Next-generation SSCs must support new interfaces like SENT along with the traditional analog one-wire and serial interfaces such as I2Ctrade and SPI In fact the SENT interface is output only and requires an auxiliary interface like I2C to configure and calibrate the SSC
Another important feature for next-generation SSCs is the ability to perform self-testing and diagnostics to meet critical safety standards like the automotive safety
I2Ctrade is a trademark of NXP
7
TECH REPORT
7
As the quality of output from transducers declines to meet application demands system
requirements such as measurement range accuracy speed and power consumption continue to increase squeezing the performance of sensor signal conditioning (SSC) circuits from both ends and making the task of designing them exponentially more difficult
integrity level (ASIL) for automotive applications These requirements include detection and notification of faults due to open or short circuits out-of-range parameters aging sensors and excessive temperature Additionally the SSC must be able to monitor these faults while tolerant of shorts to ground or supply voltage supply overvoltage conditions or reverse battery connections
ldquoOne of the key features of next-generation SSCs
is flexibilityrdquoldquoA highly efficient and powerful
reduced-instruction-set computer coordinates numerous control and
computational tasksrdquo
NEXT GENERATION TO THE RESCUE
In the same way increasing demands have spurred a new class of sensors Zentrum Mikroelektronik (ZMDI) is developing and introducing the next generation of SSC products and technologies to the sensor marketplace This article describes some of the most important and beneficial new features of these new SSCs
FLEXIBILITY IS A BEAUTIFUL THING
One of the key features of next-generation SSCs is flexibility The types and combinations of physical quantities measured for products are growing rapidly and new SSCs must facilitate fast development of complex sensor modules with low component counts and a user interface that is easy to learn and use This requires a signal interface that is configurable for a wide range of signals and correction algorithms that are much more complex than second or third order polynomial curve fitting offered by previous generations of SSCs For example a single application might require the conditioning of two temperature inputs one being a diode and the other a thermocouple and two resistive pressure bridges with widely varying output levels each of which require linearization and calibration
Flexibility is not limited only to signal types and ranges however Another dimension of configurability is required for the sequence of signal processing tasks Typically some signals must be acquired at a much higher rate than others and the
quantization and correction algorithms must be reconfigured quickly from one measurement to another in a programmable fashion In addition to this sometimes it is necessary to perform math operations between signals like subtracting two pressure inputs to generate a differential pressure output The SSC must generate a user-programmable sequence that samples the inputs in a defined order and rate correct each signal according to a user-defined calibration algorithm and combine the conditioned outputs into an orderly stream of data
Finally flexibility must include the number and type of output signals and protocols Reliability safety weight and noise constraints are also driving the creation of innovative new output protocols like single-edge nibble transmission (SENT) for the automotive industry Next-generation SSCs must support new interfaces like SENT along with the traditional analog one-wire and serial interfaces such as I2Ctrade and SPI In fact the SENT interface is output only and requires an auxiliary interface like I2C to configure and calibrate the SSC
Another important feature for next-generation SSCs is the ability to perform self-testing and diagnostics to meet critical safety standards like the automotive safety
I2Ctrade is a trademark of NXP
88
SENSOR TECHNOLOGY
PUTTING IT ALL TOGETHER
Figure 1 shows the block diagram of a next-generation SSC In this particular case the SSC supports two temperature inputsmdashone resistive one diodemdashand two resistive bridge inputs The conditioning signal chain includes sensor check and common mode (SCCM) adjustment multiplexing (MUX) programmable gain (PGA) from 1 to 200 VV and an analog to digital converter (ADC) with adjustable sample rate and resolution from 12 to 18 bits
The SSC in figure 1 looks similar to other SSCs that are presently available but most of its potential and flexibility lies in the calibration microcontroller (CMC) A highly efficient and powerful reduced instruction set computer (RISC) coordinates the numerous control and computational tasks necessary to provide the tremendous amount of flexibility required for next-generation SSCs The controller also combines the multiple output data packets into a structured stream in a wide variety of formats that can be either analog or digital
The cycle of tasks performed by the RISC engine consists of three main types measurement tasks conditioning tasks and output tasks Measurement tasks include operations that select the MUX input and signal polarities the gain and offset of the signal path the speed and resolution of the quantizer and auxiliary tasks such as auto-zeroing gain stages The output values of all the main measurement tasks are stored in registers for processing by the conditioning tasks These tasks range from simple operations like shifting and synchronization to basic math functions such as add subtract multiply and divide to complex functions such as logarithms polynomial evaluation spline curve fitting and digital filtering Output tasks include synchronization of data streams formatting packetizing encoding error detection and safety features like redundancy or inversion
The SSC shown in figure 1 provides for up to 20 measurement tasks and 62 conditioning tasks enabling thousands
of different combinations of signal processing sequences for each of the four inputs The number of output tasks varies greatly depending on the type of output but for a complex protocol like SENT the number can be in the dozens
MAKING IT EASY
However it is also vitally important that the flexibility power and complexity of next-generation SSCs do not require a commensurate level of time and resources for system designers implementing them The example shown in figure 1 is a member of a product family that is preconfigured by the manufacturer for a specific application using firmware All of the measurement conditioning and output tasks are programmed so that the designer need only focus on determining gain resolution and calibration coefficients for the correction algorithm all of which are facilitated by software that is easy to use and
Figure 1 An example block diagram of a next-generation SSC from ZMDI
ldquoOne thing that should not be flexible in next-generation
SSCs is the user interfacerdquo
consistent across the product line Special use cases can be implemented easily in firmware by the manufacturer should the need arise but the standard factory configuration will cover the majority of designs Additional family members of the product line are optimized for different numbers and types of inputs and outputs and also preconfigured for the intended application use
Finally one thing that should not be flexible in next-generation SSCs is the user interface including the physical dimensions pin or pad locations and software user interface The product family exemplified in figure 1 has a standardized footprint pinout and software user interface to minimize the costs time and resources associated with board layout calibration and climbing the learning curve
9
TECH REPORT
9
PUTTING IT ALL TOGETHER
Figure 1 shows the block diagram of a next-generation SSC In this particular case the SSC supports two temperature inputsmdashone resistive one diodemdashand two resistive bridge inputs The conditioning signal chain includes sensor check and common mode (SCCM) adjustment multiplexing (MUX) programmable gain (PGA) from 1 to 200 VV and an analog to digital converter (ADC) with adjustable sample rate and resolution from 12 to 18 bits
The SSC in figure 1 looks similar to other SSCs that are presently available but most of its potential and flexibility lies in the calibration microcontroller (CMC) A highly efficient and powerful reduced instruction set computer (RISC) coordinates the numerous control and computational tasks necessary to provide the tremendous amount of flexibility required for next-generation SSCs The controller also combines the multiple output data packets into a structured stream in a wide variety of formats that can be either analog or digital
The cycle of tasks performed by the RISC engine consists of three main types measurement tasks conditioning tasks and output tasks Measurement tasks include operations that select the MUX input and signal polarities the gain and offset of the signal path the speed and resolution of the quantizer and auxiliary tasks such as auto-zeroing gain stages The output values of all the main measurement tasks are stored in registers for processing by the conditioning tasks These tasks range from simple operations like shifting and synchronization to basic math functions such as add subtract multiply and divide to complex functions such as logarithms polynomial evaluation spline curve fitting and digital filtering Output tasks include synchronization of data streams formatting packetizing encoding error detection and safety features like redundancy or inversion
The SSC shown in figure 1 provides for up to 20 measurement tasks and 62 conditioning tasks enabling thousands
of different combinations of signal processing sequences for each of the four inputs The number of output tasks varies greatly depending on the type of output but for a complex protocol like SENT the number can be in the dozens
MAKING IT EASY
However it is also vitally important that the flexibility power and complexity of next-generation SSCs do not require a commensurate level of time and resources for system designers implementing them The example shown in figure 1 is a member of a product family that is preconfigured by the manufacturer for a specific application using firmware All of the measurement conditioning and output tasks are programmed so that the designer need only focus on determining gain resolution and calibration coefficients for the correction algorithm all of which are facilitated by software that is easy to use and
Figure 1 An example block diagram of a next-generation SSC from ZMDI
ldquoOne thing that should not be flexible in next-generation
SSCs is the user interfacerdquo
consistent across the product line Special use cases can be implemented easily in firmware by the manufacturer should the need arise but the standard factory configuration will cover the majority of designs Additional family members of the product line are optimized for different numbers and types of inputs and outputs and also preconfigured for the intended application use
Finally one thing that should not be flexible in next-generation SSCs is the user interface including the physical dimensions pin or pad locations and software user interface The product family exemplified in figure 1 has a standardized footprint pinout and software user interface to minimize the costs time and resources associated with board layout calibration and climbing the learning curve
1212
SENSOR TECHNOLOGY
The human heartbeat is arguably the single most important (ldquolife-and-deathrdquo) diagnostic indicator Thus electrocardiograms (ECGs) are one of the most significant diagnostic methods in that
they monitor heart function ECGs are not only used in a clinical setting but are increasingly seen in personal health devices Traditionally ECG measurement conductive electrodes have been applied which are directly attached to the skin With the help of contact gel (wet or solid) to ensure that there is good electrical contact between the skin and the sensor direct resistive contact is made with the patient However conventional electrodes possess various disadvantages which are not conducive for long-term use in non-clinical settings In addition to being potentially messy metal allergies can cause skin irritations and as a single-use item they are quite expensive
Non-contact ECG measurementusing EPIC Sensors
Measuring electrocardiogram (ECG) signals without skin contact is now possible using novel Electric Potential Integrated Circuit (EPIC) sensors
By Alan Lowne CEO of Saelig Co Inc
13
TECH REPORT
13
The human heartbeat is arguably the single most important (ldquolife-and-deathrdquo) diagnostic indicator Thus electrocardiograms (ECGs) are one of the most significant diagnostic methods in that
they monitor heart function ECGs are not only used in a clinical setting but are increasingly seen in personal health devices Traditionally ECG measurement conductive electrodes have been applied which are directly attached to the skin With the help of contact gel (wet or solid) to ensure that there is good electrical contact between the skin and the sensor direct resistive contact is made with the patient However conventional electrodes possess various disadvantages which are not conducive for long-term use in non-clinical settings In addition to being potentially messy metal allergies can cause skin irritations and as a single-use item they are quite expensive
Non-contact ECG measurementusing EPIC Sensors
Measuring electrocardiogram (ECG) signals without skin contact is now possible using novel Electric Potential Integrated Circuit (EPIC) sensors
By Alan Lowne CEO of Saelig Co Inc
1414
SENSOR TECHNOLOGY
Non-contact measurement of electrophysiological signals is of great interest in healthcare settings with the potential of reducing disposable costs speeding up or simplifying measurement techniques Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact Monitoring vehicle drivers for health and alertness by detecting heart rate and respiration or determining car occupancy to adjust the ride handling and air bag deployment with the varying size and location of occupants is a vast potential market
Capacitive (insulated) electrodes can register ECG signals without conductive contact to the bodyndasheven through clothesndashand represent
an attractive alternative for a wide range of new applications EPIC (Electric Potential Integrated Circuit) is a completely new sensor technology resulting from research at the University of Sussex (UK) Novel ultra high impedance EPIC sensors measure electric field changes without requiring physical or resistive contact This award winning patent-protected sensor can rapidly measure electric potential sources such as electrophysiological signals or even spatial electric fields It therefore has the ability to measure ECGs without direct skin contact By adjusting the DSP and amplification circuitry the sensors can be tuned for detection at a distance as required for differing automotive applications EPIC sensor electrodes can be easily and discretely incorporated inside car seat backs to acquire the necessary biometric data
Signals measured on the human body always include a large amount of noise the major component of this being 50 or 60 Hz power line noise capacitively-coupled to the body from the surrounding electricity supply Measurements such as ECG depend on being able to extract the small electrophysiological signals from the much larger noise signals EPIC sensors can be used in ldquocontact moderdquo for ECG measurement where the subject touches both the capacitive electrode surface and some metal at the system ground directly with the skin This ground reference allows filtering and differential amplification of signals from two sensors to be effective in removing the mains frequency noise leaving a high quality ECG signal In non-contact ECG measurement there is ndash by definition - no skin contact and thus no direct connection can be made between the subjectrsquos body and the system ground Some other method of reducing the power line noise is therefore required to
EPIC Sensors incontact with clothing
Conductive fabric in contactwith clothing eg on chair seat
Output
EPICdemo box
Figure 1 Basic configuration for non-contact ECG measurement including capacitively-oocupied DR circuit
OP-AMP
+5V
-5V
Vout
Rf (27KΩ)
Ra(11KΩ)
Rb(11KΩ)
Rp (15MΩ) To conductive fabric on chair thus capacitively coupled to body
Inputs from outputs of demo box
A
BC
(1nF)
Figure 2 DPL circuit Voltage gain is set by Rf Rp limits current fed back to the body (see text)Operational amplifier output Vout = - (VA + VB) Rf 11K
enable the ECG signal to be extracted reliably and accurately One such method utilizes an approach very similar to the ldquoDriven Right Legrdquo (DRL) system that is used for the same purpose in conventional ECG measurement techniques In conventional ECG the DRL signal is coupled directly to the patientrsquos skin The DRL signal reduces power line noise on the sensor signals by feeding back an inverted average of the signals from two sensors on to the patientrsquos body In non-contact ECG the generated DRL signal can be capacitively-coupled to the body through clothing via a piece of conductive material placed ndash for instance ndash on the seat or back of a chair Capacitive coupling of DRL signals is described by Lim et al1 and Lee et al2
SYSTEM DESIGNAn ECG system can therefore be built into a chair a mattress or clothing for instance The DRL circuit improves the sensor signalnoise ratio enormously In the example in Figure 1 EPIC sensors are mounted on a chair back such that the electrodes touch the clothing on the subjectrsquos back when resting normally against the back of the chair The generated DRL signal is connected to a piece of conductive material
placed either on the seat of the chair or at the bottom of the chair back contacting the subjectrsquos clothing in the normal sitting position Copper-coated nylon fabric is one possible material suitable for the DRL coupling material but other conductive materials may be equally successful A thin non- conductive material such as a cotton fabric may be used to cover both the sensors and the DRL coupling fabric if required for instance when building the sensors into a seat Consideration must be given as to how material will reduce the coupling capacitance between the sensor and the subject or add additional noise to the signals through static charging effectsFigure 2 shows the design of the DRL circuit It is a standard summing amplifier generating an amplified and inverted signal that is the average of the individual signals A and B
The optimum value for Rf will be dependent on the type of sensors being used as well as the clothing being worn by the subject being measured It should be set to achieve maximum noise reduction while ensuring circuit stability A value of 27kohms is suggested as a suitable starting point for EPIC sensors
15
TECH REPORT
15
Non-contact measurement of electrophysiological signals is of great interest in healthcare settings with the potential of reducing disposable costs speeding up or simplifying measurement techniques Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact Monitoring vehicle drivers for health and alertness by detecting heart rate and respiration or determining car occupancy to adjust the ride handling and air bag deployment with the varying size and location of occupants is a vast potential market
Capacitive (insulated) electrodes can register ECG signals without conductive contact to the bodyndasheven through clothesndashand represent
an attractive alternative for a wide range of new applications EPIC (Electric Potential Integrated Circuit) is a completely new sensor technology resulting from research at the University of Sussex (UK) Novel ultra high impedance EPIC sensors measure electric field changes without requiring physical or resistive contact This award winning patent-protected sensor can rapidly measure electric potential sources such as electrophysiological signals or even spatial electric fields It therefore has the ability to measure ECGs without direct skin contact By adjusting the DSP and amplification circuitry the sensors can be tuned for detection at a distance as required for differing automotive applications EPIC sensor electrodes can be easily and discretely incorporated inside car seat backs to acquire the necessary biometric data
Signals measured on the human body always include a large amount of noise the major component of this being 50 or 60 Hz power line noise capacitively-coupled to the body from the surrounding electricity supply Measurements such as ECG depend on being able to extract the small electrophysiological signals from the much larger noise signals EPIC sensors can be used in ldquocontact moderdquo for ECG measurement where the subject touches both the capacitive electrode surface and some metal at the system ground directly with the skin This ground reference allows filtering and differential amplification of signals from two sensors to be effective in removing the mains frequency noise leaving a high quality ECG signal In non-contact ECG measurement there is ndash by definition - no skin contact and thus no direct connection can be made between the subjectrsquos body and the system ground Some other method of reducing the power line noise is therefore required to
EPIC Sensors incontact with clothing
Conductive fabric in contactwith clothing eg on chair seat
Output
EPICdemo box
Figure 1 Basic configuration for non-contact ECG measurement including capacitively-oocupied DR circuit
OP-AMP
+5V
-5V
Vout
Rf (27KΩ)
Ra(11KΩ)
Rb(11KΩ)
Rp (15MΩ) To conductive fabric on chair thus capacitively coupled to body
Inputs from outputs of demo box
A
BC
(1nF)
Figure 2 DPL circuit Voltage gain is set by Rf Rp limits current fed back to the body (see text)Operational amplifier output Vout = - (VA + VB) Rf 11K
enable the ECG signal to be extracted reliably and accurately One such method utilizes an approach very similar to the ldquoDriven Right Legrdquo (DRL) system that is used for the same purpose in conventional ECG measurement techniques In conventional ECG the DRL signal is coupled directly to the patientrsquos skin The DRL signal reduces power line noise on the sensor signals by feeding back an inverted average of the signals from two sensors on to the patientrsquos body In non-contact ECG the generated DRL signal can be capacitively-coupled to the body through clothing via a piece of conductive material placed ndash for instance ndash on the seat or back of a chair Capacitive coupling of DRL signals is described by Lim et al1 and Lee et al2
SYSTEM DESIGNAn ECG system can therefore be built into a chair a mattress or clothing for instance The DRL circuit improves the sensor signalnoise ratio enormously In the example in Figure 1 EPIC sensors are mounted on a chair back such that the electrodes touch the clothing on the subjectrsquos back when resting normally against the back of the chair The generated DRL signal is connected to a piece of conductive material
placed either on the seat of the chair or at the bottom of the chair back contacting the subjectrsquos clothing in the normal sitting position Copper-coated nylon fabric is one possible material suitable for the DRL coupling material but other conductive materials may be equally successful A thin non- conductive material such as a cotton fabric may be used to cover both the sensors and the DRL coupling fabric if required for instance when building the sensors into a seat Consideration must be given as to how material will reduce the coupling capacitance between the sensor and the subject or add additional noise to the signals through static charging effectsFigure 2 shows the design of the DRL circuit It is a standard summing amplifier generating an amplified and inverted signal that is the average of the individual signals A and B
The optimum value for Rf will be dependent on the type of sensors being used as well as the clothing being worn by the subject being measured It should be set to achieve maximum noise reduction while ensuring circuit stability A value of 27kohms is suggested as a suitable starting point for EPIC sensors
1616
SENSOR TECHNOLOGY
Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact
7660SwitchedCapacitorVoltage
Converter
1
2
3
4
8
7
6
5
OP-AMP
Rb(11K)
Ra(11K)
Rf (27KΩ)
Rp (15MΩ)DRLOutput
1nFVout
6Vbatterypack4xAA
+6V
-6V10microF
10microF
A
B
Figure 3 DRL circuit including battery power supply and voltage converter to provide -6v rail Inputs A and B are buffered outputs from the sensors and may be taken from the A and B outputs of the EPIC demo box Ground should be connected to the sensor 0V the shielding of the BNC A and B outputs on the demo box being a suitable connection point See figure 2 and the text for further comments on the DRL design
sensors and the DRL circuit into saturation Because the system contains some large impedances and hence has some very long RC time constants settling times of tens of seconds can be needed before a clean ECG signal is seen During this period the signal can either appear very noisy or be virtually flat depending on whether one or both sensors or the DRL circuit are ldquorailingrdquo The subject should sit still during this time and wait for the circuit to settle since continually adjusting position will only make matters worse Settling times can sometimes be reduced by turning off the power to the demo box for a few seconds
CLOTHINGGood results can be obtained with one or two layers of cotton material between the sensors and the skin Other materials including a wool-mix sweater and a polyester fleece in addition
to two layers of cotton material have been successful Examples are shown in Figures 6 and 7 If the key greatest interest is in the ldquoR-Rrdquo interval adjusting filter settings to reduce or re-center the signal bandwidth can give improved signal quality
STATICBecause there is no direct physical contact between the subject and any grounding point there is no path for any static build up to be discharged Under most circumstances static build-up does not present a problem butdepending on factors including clothing footwear flooring humidity levels in the air and so forth static build up can sometimes prevent the cardiac signal from being seen clearly Product design must take into account a discharge to the system ground to remove the static charge
Rp the protection resistor is included to limit the current that can be fed back to the human body This resistor is essential in ensuring that the subjectrsquos wellbeing is not endangered and must not be omitted
IMPLEMENTATIONThe demonstration of non-contact ECG is best performed using an EPIC demonstration kit Plessey part no PS25003 which includes the necessary drive circuitry and switchable 50Hz and 60Hz notch filters The inputs to the DRL circuit can be taken from the BNC outputs ldquoA amp Brdquo on the front of the demo box The DRL circuit will require its own bipolar power supply plusmn5V or plusmn6V is suggested A circuit design including a battery power supply is shown in Figure 3
Plesseyrsquos compact sensors (PS2520x) and disc sensors (PS25101) provide equally good results although for demonstration purposes disc sensors are simplest to fix to a chair to make contact with the occupantrsquos back Compact sensors are recommended when designing a custom-built system
EPIC sensors which are designed for contact electrophysiology sensing give excellent results in most cases Initial trials suggest that custom modifications to the sensor design (eg lower gain and higher input impedance) can offer increased sensitivity and the ability to detect weaker ECG signalsThe shape of the measured ECG trace ndash in terms of relative magnitudes of the P Q R S and T waves ndash will depend on the positioning of the sensors behind the subjectrsquos back If the desire is only to measure the ldquoR-Rrdquo interval to determine heart rate then the positioning of the sensors is not critical Placing one sensor either side of the spine separated by 6rdquo -10rdquo (15-25 cm) at approximately the same height as the heart is recommended as a starting point For applications where signals from other parts of the cardiac cycle are required the user should refer to texts on bio-electronic signals for guidance on sensor position
SETTLING TIMEWhen a subject first sits in the chair and leans against the EPIC sensors the changes in electric potential will normally send both the
17
TECH REPORT
17
Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact
7660SwitchedCapacitorVoltage
Converter
1
2
3
4
8
7
6
5
OP-AMP
Rb(11K)
Ra(11K)
Rf (27KΩ)
Rp (15MΩ)DRLOutput
1nFVout
6Vbatterypack4xAA
+6V
-6V10microF
10microF
A
B
Figure 3 DRL circuit including battery power supply and voltage converter to provide -6v rail Inputs A and B are buffered outputs from the sensors and may be taken from the A and B outputs of the EPIC demo box Ground should be connected to the sensor 0V the shielding of the BNC A and B outputs on the demo box being a suitable connection point See figure 2 and the text for further comments on the DRL design
sensors and the DRL circuit into saturation Because the system contains some large impedances and hence has some very long RC time constants settling times of tens of seconds can be needed before a clean ECG signal is seen During this period the signal can either appear very noisy or be virtually flat depending on whether one or both sensors or the DRL circuit are ldquorailingrdquo The subject should sit still during this time and wait for the circuit to settle since continually adjusting position will only make matters worse Settling times can sometimes be reduced by turning off the power to the demo box for a few seconds
CLOTHINGGood results can be obtained with one or two layers of cotton material between the sensors and the skin Other materials including a wool-mix sweater and a polyester fleece in addition
to two layers of cotton material have been successful Examples are shown in Figures 6 and 7 If the key greatest interest is in the ldquoR-Rrdquo interval adjusting filter settings to reduce or re-center the signal bandwidth can give improved signal quality
STATICBecause there is no direct physical contact between the subject and any grounding point there is no path for any static build up to be discharged Under most circumstances static build-up does not present a problem butdepending on factors including clothing footwear flooring humidity levels in the air and so forth static build up can sometimes prevent the cardiac signal from being seen clearly Product design must take into account a discharge to the system ground to remove the static charge
Rp the protection resistor is included to limit the current that can be fed back to the human body This resistor is essential in ensuring that the subjectrsquos wellbeing is not endangered and must not be omitted
IMPLEMENTATIONThe demonstration of non-contact ECG is best performed using an EPIC demonstration kit Plessey part no PS25003 which includes the necessary drive circuitry and switchable 50Hz and 60Hz notch filters The inputs to the DRL circuit can be taken from the BNC outputs ldquoA amp Brdquo on the front of the demo box The DRL circuit will require its own bipolar power supply plusmn5V or plusmn6V is suggested A circuit design including a battery power supply is shown in Figure 3
Plesseyrsquos compact sensors (PS2520x) and disc sensors (PS25101) provide equally good results although for demonstration purposes disc sensors are simplest to fix to a chair to make contact with the occupantrsquos back Compact sensors are recommended when designing a custom-built system
EPIC sensors which are designed for contact electrophysiology sensing give excellent results in most cases Initial trials suggest that custom modifications to the sensor design (eg lower gain and higher input impedance) can offer increased sensitivity and the ability to detect weaker ECG signalsThe shape of the measured ECG trace ndash in terms of relative magnitudes of the P Q R S and T waves ndash will depend on the positioning of the sensors behind the subjectrsquos back If the desire is only to measure the ldquoR-Rrdquo interval to determine heart rate then the positioning of the sensors is not critical Placing one sensor either side of the spine separated by 6rdquo -10rdquo (15-25 cm) at approximately the same height as the heart is recommended as a starting point For applications where signals from other parts of the cardiac cycle are required the user should refer to texts on bio-electronic signals for guidance on sensor position
SETTLING TIMEWhen a subject first sits in the chair and leans against the EPIC sensors the changes in electric potential will normally send both the
1818
SENSOR TECHNOLOGY
Figure 4 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit HP filter corner frequency is 50mHz LP filter in demo box has corner frequency of 30Hz
Figure 6 ECG signals measured from a subject wearing a wool-mix sweater over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 8-25Hz The heart rate can be easily extracted
Figure 5 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit Software filters limit the bandwidth to 8-25Hz
Figure 7 ECG signals measured from a subject wearing a polyester fleece over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 16-40Hz The heart rate can be easily extracted
CABLE SHIELDINGCareful shielding is necessary to reduce unwanted noise artifacts Grounding the shielding of the sensor cable via the connection between the outer casing of the sensor plugs and the metal surround of the socket on the control electronics is recommended
CONCLUSIONEPIC sensors can be used to measure ECG signals without physical skin contact While
sensors can be embedded in a chair or seat the techniques are equally applicable to sensors mounted on a mattress in clothing or in other situations There are many variables that will affect signal quality from the strength of cardiac signal generated by the individual being measured to clothing to the surrounding environment but the designs given here are a starting point in establishing an optimum system for a particular application infin
Find us at Booth 37310World Maker Faire New York
Figure 4 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit HP filter corner frequency is 50mHz LP filter in demo box has corner frequency of 30Hz
Figure 6 ECG signals measured from a subject wearing a wool-mix sweater over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 8-25Hz The heart rate can be easily extracted
Figure 5 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit Software filters limit the bandwidth to 8-25Hz
Figure 7 ECG signals measured from a subject wearing a polyester fleece over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 16-40Hz The heart rate can be easily extracted
CABLE SHIELDINGCareful shielding is necessary to reduce unwanted noise artifacts Grounding the shielding of the sensor cable via the connection between the outer casing of the sensor plugs and the metal surround of the socket on the control electronics is recommended
CONCLUSIONEPIC sensors can be used to measure ECG signals without physical skin contact While
sensors can be embedded in a chair or seat the techniques are equally applicable to sensors mounted on a mattress in clothing or in other situations There are many variables that will affect signal quality from the strength of cardiac signal generated by the individual being measured to clothing to the surrounding environment but the designs given here are a starting point in establishing an optimum system for a particular application infin
Find us at Booth 37310World Maker Faire New York
20
SENSOR TECHNOLOGY
SmallerThan a
Grain Sand
of
Analysts project that by
2020 there will be over
50 billion connected
devices in the now-nascent
Internet of Things (IoT) However
the technology that will enable the
IoT of the future may look a little
different than todayrsquosmdashin fact
you may not be able to see it at all
Many new mobile devices require
motion sensors in order to monitor
analyze and deliver real-time data
and analysis to improve the way
consumers interact with everyday
technology While traditional
sensor platforms require multichip
modules or stacked die within a
device mCube a new MEMS sensor
company is driving the emergence
of Sensor 30 which will lead the
development of the smallest
sensors to datemdashsmaller than a
grain of sand By EEWeb Contributing Writers
mCubersquos Sensors Enable IoMTInterview with Ben Lee President and CEO of mCube
INDUSTRY INTERVIEW
21
SmallerThan a
Grain Sand
of
Analysts project that by
2020 there will be over
50 billion connected
devices in the now-nascent
Internet of Things (IoT) However
the technology that will enable the
IoT of the future may look a little
different than todayrsquosmdashin fact
you may not be able to see it at all
Many new mobile devices require
motion sensors in order to monitor
analyze and deliver real-time data
and analysis to improve the way
consumers interact with everyday
technology While traditional
sensor platforms require multichip
modules or stacked die within a
device mCube a new MEMS sensor
company is driving the emergence
of Sensor 30 which will lead the
development of the smallest
sensors to datemdashsmaller than a
grain of sand By EEWeb Contributing Writers
mCubersquos Sensors Enable IoMTInterview with Ben Lee President and CEO of mCube
22
SENSOR TECHNOLOGY
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
INDUSTRY INTERVIEW
23
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
24
SENSOR TECHNOLOGY
Since sensors are so small and affordable donrsquot be surprised to find unique applications in the future Lee speculates that ldquofarmers might have sensor tags to monitor livestock for abnormal activity patterns of grazing potential illness and herd behaviorrdquo Commercial trucking might involve motion sensors connected to video cameras in rear-view mirrors to better assess the cause of an accident and driving conditions For shipping Lee describes ldquomotion sensors embedded directly onto packages to record jarring motions or accidents in order to determine when and how contents were damagedrdquo
As of 2014 mCubersquos complete intertial sensor portfolio contains an accelerometer magnetometer and its proprietary iGyrotrade gyroscope offering nine degrees of freedom (9DoF) Through reductions in cost power consumption and size mCubersquos sensor offerings make it possible to place them onto nearly any object or devicemdashin some cases without packaging ldquoWe aspire to put one or more MEMS motion sensors on anything that movesrdquo remarks Lee And with the IoMT taking shape and consumer expectations for connected moving devices becoming more concrete developers of new applications will turn to solutions like mCube to deliver truly cutting-edge connected devices
ldquoAt mCube we aspire to put one or more MEMS motion sensors on
anything that movesrdquo
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 15
Complete Inertial Motion Sensor Portfolio
Solutions for up to 9DoF (Degrees of Freedom)
Accelerometer
Magnetometer
iGyroTM
3DoF 3DoF
9DoF
2x2mm
3x3mm 3DoF 6DoF
14x14mm
3x3mm
3x3mm
2626
SENSOR TECHNOLOGY
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
27
TECH REPORT
27
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
2828
SENSOR TECHNOLOGY
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
29
TECH REPORT
29
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
3030
SENSOR TECHNOLOGY
to enable the kind of constant and complex data accumulation that the Biostamp promises
In the interim MC10 is partnering up with other medical and pharmaceutical companies to develop integrated sensor and monitoring products The company plans to become a certified medical-ready partner for companies who donrsquot have access to this unique and proprietary technology Even the US Army has begun working with MC10 on military-grade sensors that will add further safety features for troops in the field This funding from NIH grants Department of Defense grants as well as foundation grants will help the company get one step closer to realization of devices so flexible that users might forget theyrsquore wearing them
ldquoThe company has been bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devicesrdquo
Join the
DESIGNERS OF THINGS conference in San Francisco on
September 23 and 24
Dedicated to the explosive and exciting potential of Wearable
Tech 3D Printing and the Internet of Things the conference
provides the growing design and development community
around these technologies a meeting place to discuss and
showcase the newest products
Click here for more info
httpwwwdesignersofthingscomsanfranciscoscheduler
speakersheth-nirav-rav33310
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Sierra CircuitsA Complete PCB Resource
PLUS The Ground rdquo Myth in PrintedCircuits
ldquo
PCB Resin Reactor+
Ken BahlCEO of Sierra Circuits
Let There Be
How Cree reinvented the light bulb
LIGHT
David ElienVP of Marketing amp Business
Development Cree Inc
New LED Filament Tower
Cutting Edge Flatscreen Technologies
+
+
M o v i n g T o w a r d s
a Clean Energy
FUTUREmdash Hugo van Nispen COO of DNV KEMA
MCU Wars 32-bit MCU Comparison
Cutting Edge
SPICEModeling
Freescale and TI Embedded
Modules
ARMCortex
Programming
From Concept to
Reality Wolfgang Heinz-Fischer
Head of Marketing amp PR TQ-Group
Low-Power Design Techniques
TQ-Grouprsquos Comprehensive Design Process
+
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PowerDeveloper
Octobe r 20 13
Designing forDurability
View more EEWeb magazinesmdash Click Here
44
SENSOR TECHNOLOGY
Sensor Signal Conditioners
Powerful and Flexible yet Easy to Use
By David Grice Applications Engineer Zentrum Mikrokelektronik (ZMDI) Dresden Germany
As demands increase for the number type and range of sensors in
almost every product category the difficulty of implementing them
increases proportionately This is especially true in the automotive
arena driven by efficiency safety and emission requirements
Existing sensor technologies are inadequate to meet many of these
new and more stringent requirements spurring the development
of a new class of sensors based on micro-electro-
mechanical systems (MEMS) These new sensors
are smaller lighter more robust less expensive
and consume less power but they also
produce electrical signals that
are smaller and more nonlinear
than their bulkier counterparts
Next-Generation SO MANY SENSORS SO LITTLE TIME
5
TECH REPORT
5
Sensor Signal Conditioners
Powerful and Flexible yet Easy to Use
By David Grice Applications Engineer Zentrum Mikrokelektronik (ZMDI) Dresden Germany
As demands increase for the number type and range of sensors in
almost every product category the difficulty of implementing them
increases proportionately This is especially true in the automotive
arena driven by efficiency safety and emission requirements
Existing sensor technologies are inadequate to meet many of these
new and more stringent requirements spurring the development
of a new class of sensors based on micro-electro-
mechanical systems (MEMS) These new sensors
are smaller lighter more robust less expensive
and consume less power but they also
produce electrical signals that
are smaller and more nonlinear
than their bulkier counterparts
Next-Generation SO MANY SENSORS SO LITTLE TIME
66
SENSOR TECHNOLOGY
As the quality of output from transducers declines to meet application demands system
requirements such as measurement range accuracy speed and power consumption continue to increase squeezing the performance of sensor signal conditioning (SSC) circuits from both ends and making the task of designing them exponentially more difficult
integrity level (ASIL) for automotive applications These requirements include detection and notification of faults due to open or short circuits out-of-range parameters aging sensors and excessive temperature Additionally the SSC must be able to monitor these faults while tolerant of shorts to ground or supply voltage supply overvoltage conditions or reverse battery connections
ldquoOne of the key features of next-generation SSCs
is flexibilityrdquoldquoA highly efficient and powerful
reduced-instruction-set computer coordinates numerous control and
computational tasksrdquo
NEXT GENERATION TO THE RESCUE
In the same way increasing demands have spurred a new class of sensors Zentrum Mikroelektronik (ZMDI) is developing and introducing the next generation of SSC products and technologies to the sensor marketplace This article describes some of the most important and beneficial new features of these new SSCs
FLEXIBILITY IS A BEAUTIFUL THING
One of the key features of next-generation SSCs is flexibility The types and combinations of physical quantities measured for products are growing rapidly and new SSCs must facilitate fast development of complex sensor modules with low component counts and a user interface that is easy to learn and use This requires a signal interface that is configurable for a wide range of signals and correction algorithms that are much more complex than second or third order polynomial curve fitting offered by previous generations of SSCs For example a single application might require the conditioning of two temperature inputs one being a diode and the other a thermocouple and two resistive pressure bridges with widely varying output levels each of which require linearization and calibration
Flexibility is not limited only to signal types and ranges however Another dimension of configurability is required for the sequence of signal processing tasks Typically some signals must be acquired at a much higher rate than others and the
quantization and correction algorithms must be reconfigured quickly from one measurement to another in a programmable fashion In addition to this sometimes it is necessary to perform math operations between signals like subtracting two pressure inputs to generate a differential pressure output The SSC must generate a user-programmable sequence that samples the inputs in a defined order and rate correct each signal according to a user-defined calibration algorithm and combine the conditioned outputs into an orderly stream of data
Finally flexibility must include the number and type of output signals and protocols Reliability safety weight and noise constraints are also driving the creation of innovative new output protocols like single-edge nibble transmission (SENT) for the automotive industry Next-generation SSCs must support new interfaces like SENT along with the traditional analog one-wire and serial interfaces such as I2Ctrade and SPI In fact the SENT interface is output only and requires an auxiliary interface like I2C to configure and calibrate the SSC
Another important feature for next-generation SSCs is the ability to perform self-testing and diagnostics to meet critical safety standards like the automotive safety
I2Ctrade is a trademark of NXP
7
TECH REPORT
7
As the quality of output from transducers declines to meet application demands system
requirements such as measurement range accuracy speed and power consumption continue to increase squeezing the performance of sensor signal conditioning (SSC) circuits from both ends and making the task of designing them exponentially more difficult
integrity level (ASIL) for automotive applications These requirements include detection and notification of faults due to open or short circuits out-of-range parameters aging sensors and excessive temperature Additionally the SSC must be able to monitor these faults while tolerant of shorts to ground or supply voltage supply overvoltage conditions or reverse battery connections
ldquoOne of the key features of next-generation SSCs
is flexibilityrdquoldquoA highly efficient and powerful
reduced-instruction-set computer coordinates numerous control and
computational tasksrdquo
NEXT GENERATION TO THE RESCUE
In the same way increasing demands have spurred a new class of sensors Zentrum Mikroelektronik (ZMDI) is developing and introducing the next generation of SSC products and technologies to the sensor marketplace This article describes some of the most important and beneficial new features of these new SSCs
FLEXIBILITY IS A BEAUTIFUL THING
One of the key features of next-generation SSCs is flexibility The types and combinations of physical quantities measured for products are growing rapidly and new SSCs must facilitate fast development of complex sensor modules with low component counts and a user interface that is easy to learn and use This requires a signal interface that is configurable for a wide range of signals and correction algorithms that are much more complex than second or third order polynomial curve fitting offered by previous generations of SSCs For example a single application might require the conditioning of two temperature inputs one being a diode and the other a thermocouple and two resistive pressure bridges with widely varying output levels each of which require linearization and calibration
Flexibility is not limited only to signal types and ranges however Another dimension of configurability is required for the sequence of signal processing tasks Typically some signals must be acquired at a much higher rate than others and the
quantization and correction algorithms must be reconfigured quickly from one measurement to another in a programmable fashion In addition to this sometimes it is necessary to perform math operations between signals like subtracting two pressure inputs to generate a differential pressure output The SSC must generate a user-programmable sequence that samples the inputs in a defined order and rate correct each signal according to a user-defined calibration algorithm and combine the conditioned outputs into an orderly stream of data
Finally flexibility must include the number and type of output signals and protocols Reliability safety weight and noise constraints are also driving the creation of innovative new output protocols like single-edge nibble transmission (SENT) for the automotive industry Next-generation SSCs must support new interfaces like SENT along with the traditional analog one-wire and serial interfaces such as I2Ctrade and SPI In fact the SENT interface is output only and requires an auxiliary interface like I2C to configure and calibrate the SSC
Another important feature for next-generation SSCs is the ability to perform self-testing and diagnostics to meet critical safety standards like the automotive safety
I2Ctrade is a trademark of NXP
88
SENSOR TECHNOLOGY
PUTTING IT ALL TOGETHER
Figure 1 shows the block diagram of a next-generation SSC In this particular case the SSC supports two temperature inputsmdashone resistive one diodemdashand two resistive bridge inputs The conditioning signal chain includes sensor check and common mode (SCCM) adjustment multiplexing (MUX) programmable gain (PGA) from 1 to 200 VV and an analog to digital converter (ADC) with adjustable sample rate and resolution from 12 to 18 bits
The SSC in figure 1 looks similar to other SSCs that are presently available but most of its potential and flexibility lies in the calibration microcontroller (CMC) A highly efficient and powerful reduced instruction set computer (RISC) coordinates the numerous control and computational tasks necessary to provide the tremendous amount of flexibility required for next-generation SSCs The controller also combines the multiple output data packets into a structured stream in a wide variety of formats that can be either analog or digital
The cycle of tasks performed by the RISC engine consists of three main types measurement tasks conditioning tasks and output tasks Measurement tasks include operations that select the MUX input and signal polarities the gain and offset of the signal path the speed and resolution of the quantizer and auxiliary tasks such as auto-zeroing gain stages The output values of all the main measurement tasks are stored in registers for processing by the conditioning tasks These tasks range from simple operations like shifting and synchronization to basic math functions such as add subtract multiply and divide to complex functions such as logarithms polynomial evaluation spline curve fitting and digital filtering Output tasks include synchronization of data streams formatting packetizing encoding error detection and safety features like redundancy or inversion
The SSC shown in figure 1 provides for up to 20 measurement tasks and 62 conditioning tasks enabling thousands
of different combinations of signal processing sequences for each of the four inputs The number of output tasks varies greatly depending on the type of output but for a complex protocol like SENT the number can be in the dozens
MAKING IT EASY
However it is also vitally important that the flexibility power and complexity of next-generation SSCs do not require a commensurate level of time and resources for system designers implementing them The example shown in figure 1 is a member of a product family that is preconfigured by the manufacturer for a specific application using firmware All of the measurement conditioning and output tasks are programmed so that the designer need only focus on determining gain resolution and calibration coefficients for the correction algorithm all of which are facilitated by software that is easy to use and
Figure 1 An example block diagram of a next-generation SSC from ZMDI
ldquoOne thing that should not be flexible in next-generation
SSCs is the user interfacerdquo
consistent across the product line Special use cases can be implemented easily in firmware by the manufacturer should the need arise but the standard factory configuration will cover the majority of designs Additional family members of the product line are optimized for different numbers and types of inputs and outputs and also preconfigured for the intended application use
Finally one thing that should not be flexible in next-generation SSCs is the user interface including the physical dimensions pin or pad locations and software user interface The product family exemplified in figure 1 has a standardized footprint pinout and software user interface to minimize the costs time and resources associated with board layout calibration and climbing the learning curve
9
TECH REPORT
9
PUTTING IT ALL TOGETHER
Figure 1 shows the block diagram of a next-generation SSC In this particular case the SSC supports two temperature inputsmdashone resistive one diodemdashand two resistive bridge inputs The conditioning signal chain includes sensor check and common mode (SCCM) adjustment multiplexing (MUX) programmable gain (PGA) from 1 to 200 VV and an analog to digital converter (ADC) with adjustable sample rate and resolution from 12 to 18 bits
The SSC in figure 1 looks similar to other SSCs that are presently available but most of its potential and flexibility lies in the calibration microcontroller (CMC) A highly efficient and powerful reduced instruction set computer (RISC) coordinates the numerous control and computational tasks necessary to provide the tremendous amount of flexibility required for next-generation SSCs The controller also combines the multiple output data packets into a structured stream in a wide variety of formats that can be either analog or digital
The cycle of tasks performed by the RISC engine consists of three main types measurement tasks conditioning tasks and output tasks Measurement tasks include operations that select the MUX input and signal polarities the gain and offset of the signal path the speed and resolution of the quantizer and auxiliary tasks such as auto-zeroing gain stages The output values of all the main measurement tasks are stored in registers for processing by the conditioning tasks These tasks range from simple operations like shifting and synchronization to basic math functions such as add subtract multiply and divide to complex functions such as logarithms polynomial evaluation spline curve fitting and digital filtering Output tasks include synchronization of data streams formatting packetizing encoding error detection and safety features like redundancy or inversion
The SSC shown in figure 1 provides for up to 20 measurement tasks and 62 conditioning tasks enabling thousands
of different combinations of signal processing sequences for each of the four inputs The number of output tasks varies greatly depending on the type of output but for a complex protocol like SENT the number can be in the dozens
MAKING IT EASY
However it is also vitally important that the flexibility power and complexity of next-generation SSCs do not require a commensurate level of time and resources for system designers implementing them The example shown in figure 1 is a member of a product family that is preconfigured by the manufacturer for a specific application using firmware All of the measurement conditioning and output tasks are programmed so that the designer need only focus on determining gain resolution and calibration coefficients for the correction algorithm all of which are facilitated by software that is easy to use and
Figure 1 An example block diagram of a next-generation SSC from ZMDI
ldquoOne thing that should not be flexible in next-generation
SSCs is the user interfacerdquo
consistent across the product line Special use cases can be implemented easily in firmware by the manufacturer should the need arise but the standard factory configuration will cover the majority of designs Additional family members of the product line are optimized for different numbers and types of inputs and outputs and also preconfigured for the intended application use
Finally one thing that should not be flexible in next-generation SSCs is the user interface including the physical dimensions pin or pad locations and software user interface The product family exemplified in figure 1 has a standardized footprint pinout and software user interface to minimize the costs time and resources associated with board layout calibration and climbing the learning curve
1212
SENSOR TECHNOLOGY
The human heartbeat is arguably the single most important (ldquolife-and-deathrdquo) diagnostic indicator Thus electrocardiograms (ECGs) are one of the most significant diagnostic methods in that
they monitor heart function ECGs are not only used in a clinical setting but are increasingly seen in personal health devices Traditionally ECG measurement conductive electrodes have been applied which are directly attached to the skin With the help of contact gel (wet or solid) to ensure that there is good electrical contact between the skin and the sensor direct resistive contact is made with the patient However conventional electrodes possess various disadvantages which are not conducive for long-term use in non-clinical settings In addition to being potentially messy metal allergies can cause skin irritations and as a single-use item they are quite expensive
Non-contact ECG measurementusing EPIC Sensors
Measuring electrocardiogram (ECG) signals without skin contact is now possible using novel Electric Potential Integrated Circuit (EPIC) sensors
By Alan Lowne CEO of Saelig Co Inc
13
TECH REPORT
13
The human heartbeat is arguably the single most important (ldquolife-and-deathrdquo) diagnostic indicator Thus electrocardiograms (ECGs) are one of the most significant diagnostic methods in that
they monitor heart function ECGs are not only used in a clinical setting but are increasingly seen in personal health devices Traditionally ECG measurement conductive electrodes have been applied which are directly attached to the skin With the help of contact gel (wet or solid) to ensure that there is good electrical contact between the skin and the sensor direct resistive contact is made with the patient However conventional electrodes possess various disadvantages which are not conducive for long-term use in non-clinical settings In addition to being potentially messy metal allergies can cause skin irritations and as a single-use item they are quite expensive
Non-contact ECG measurementusing EPIC Sensors
Measuring electrocardiogram (ECG) signals without skin contact is now possible using novel Electric Potential Integrated Circuit (EPIC) sensors
By Alan Lowne CEO of Saelig Co Inc
1414
SENSOR TECHNOLOGY
Non-contact measurement of electrophysiological signals is of great interest in healthcare settings with the potential of reducing disposable costs speeding up or simplifying measurement techniques Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact Monitoring vehicle drivers for health and alertness by detecting heart rate and respiration or determining car occupancy to adjust the ride handling and air bag deployment with the varying size and location of occupants is a vast potential market
Capacitive (insulated) electrodes can register ECG signals without conductive contact to the bodyndasheven through clothesndashand represent
an attractive alternative for a wide range of new applications EPIC (Electric Potential Integrated Circuit) is a completely new sensor technology resulting from research at the University of Sussex (UK) Novel ultra high impedance EPIC sensors measure electric field changes without requiring physical or resistive contact This award winning patent-protected sensor can rapidly measure electric potential sources such as electrophysiological signals or even spatial electric fields It therefore has the ability to measure ECGs without direct skin contact By adjusting the DSP and amplification circuitry the sensors can be tuned for detection at a distance as required for differing automotive applications EPIC sensor electrodes can be easily and discretely incorporated inside car seat backs to acquire the necessary biometric data
Signals measured on the human body always include a large amount of noise the major component of this being 50 or 60 Hz power line noise capacitively-coupled to the body from the surrounding electricity supply Measurements such as ECG depend on being able to extract the small electrophysiological signals from the much larger noise signals EPIC sensors can be used in ldquocontact moderdquo for ECG measurement where the subject touches both the capacitive electrode surface and some metal at the system ground directly with the skin This ground reference allows filtering and differential amplification of signals from two sensors to be effective in removing the mains frequency noise leaving a high quality ECG signal In non-contact ECG measurement there is ndash by definition - no skin contact and thus no direct connection can be made between the subjectrsquos body and the system ground Some other method of reducing the power line noise is therefore required to
EPIC Sensors incontact with clothing
Conductive fabric in contactwith clothing eg on chair seat
Output
EPICdemo box
Figure 1 Basic configuration for non-contact ECG measurement including capacitively-oocupied DR circuit
OP-AMP
+5V
-5V
Vout
Rf (27KΩ)
Ra(11KΩ)
Rb(11KΩ)
Rp (15MΩ) To conductive fabric on chair thus capacitively coupled to body
Inputs from outputs of demo box
A
BC
(1nF)
Figure 2 DPL circuit Voltage gain is set by Rf Rp limits current fed back to the body (see text)Operational amplifier output Vout = - (VA + VB) Rf 11K
enable the ECG signal to be extracted reliably and accurately One such method utilizes an approach very similar to the ldquoDriven Right Legrdquo (DRL) system that is used for the same purpose in conventional ECG measurement techniques In conventional ECG the DRL signal is coupled directly to the patientrsquos skin The DRL signal reduces power line noise on the sensor signals by feeding back an inverted average of the signals from two sensors on to the patientrsquos body In non-contact ECG the generated DRL signal can be capacitively-coupled to the body through clothing via a piece of conductive material placed ndash for instance ndash on the seat or back of a chair Capacitive coupling of DRL signals is described by Lim et al1 and Lee et al2
SYSTEM DESIGNAn ECG system can therefore be built into a chair a mattress or clothing for instance The DRL circuit improves the sensor signalnoise ratio enormously In the example in Figure 1 EPIC sensors are mounted on a chair back such that the electrodes touch the clothing on the subjectrsquos back when resting normally against the back of the chair The generated DRL signal is connected to a piece of conductive material
placed either on the seat of the chair or at the bottom of the chair back contacting the subjectrsquos clothing in the normal sitting position Copper-coated nylon fabric is one possible material suitable for the DRL coupling material but other conductive materials may be equally successful A thin non- conductive material such as a cotton fabric may be used to cover both the sensors and the DRL coupling fabric if required for instance when building the sensors into a seat Consideration must be given as to how material will reduce the coupling capacitance between the sensor and the subject or add additional noise to the signals through static charging effectsFigure 2 shows the design of the DRL circuit It is a standard summing amplifier generating an amplified and inverted signal that is the average of the individual signals A and B
The optimum value for Rf will be dependent on the type of sensors being used as well as the clothing being worn by the subject being measured It should be set to achieve maximum noise reduction while ensuring circuit stability A value of 27kohms is suggested as a suitable starting point for EPIC sensors
15
TECH REPORT
15
Non-contact measurement of electrophysiological signals is of great interest in healthcare settings with the potential of reducing disposable costs speeding up or simplifying measurement techniques Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact Monitoring vehicle drivers for health and alertness by detecting heart rate and respiration or determining car occupancy to adjust the ride handling and air bag deployment with the varying size and location of occupants is a vast potential market
Capacitive (insulated) electrodes can register ECG signals without conductive contact to the bodyndasheven through clothesndashand represent
an attractive alternative for a wide range of new applications EPIC (Electric Potential Integrated Circuit) is a completely new sensor technology resulting from research at the University of Sussex (UK) Novel ultra high impedance EPIC sensors measure electric field changes without requiring physical or resistive contact This award winning patent-protected sensor can rapidly measure electric potential sources such as electrophysiological signals or even spatial electric fields It therefore has the ability to measure ECGs without direct skin contact By adjusting the DSP and amplification circuitry the sensors can be tuned for detection at a distance as required for differing automotive applications EPIC sensor electrodes can be easily and discretely incorporated inside car seat backs to acquire the necessary biometric data
Signals measured on the human body always include a large amount of noise the major component of this being 50 or 60 Hz power line noise capacitively-coupled to the body from the surrounding electricity supply Measurements such as ECG depend on being able to extract the small electrophysiological signals from the much larger noise signals EPIC sensors can be used in ldquocontact moderdquo for ECG measurement where the subject touches both the capacitive electrode surface and some metal at the system ground directly with the skin This ground reference allows filtering and differential amplification of signals from two sensors to be effective in removing the mains frequency noise leaving a high quality ECG signal In non-contact ECG measurement there is ndash by definition - no skin contact and thus no direct connection can be made between the subjectrsquos body and the system ground Some other method of reducing the power line noise is therefore required to
EPIC Sensors incontact with clothing
Conductive fabric in contactwith clothing eg on chair seat
Output
EPICdemo box
Figure 1 Basic configuration for non-contact ECG measurement including capacitively-oocupied DR circuit
OP-AMP
+5V
-5V
Vout
Rf (27KΩ)
Ra(11KΩ)
Rb(11KΩ)
Rp (15MΩ) To conductive fabric on chair thus capacitively coupled to body
Inputs from outputs of demo box
A
BC
(1nF)
Figure 2 DPL circuit Voltage gain is set by Rf Rp limits current fed back to the body (see text)Operational amplifier output Vout = - (VA + VB) Rf 11K
enable the ECG signal to be extracted reliably and accurately One such method utilizes an approach very similar to the ldquoDriven Right Legrdquo (DRL) system that is used for the same purpose in conventional ECG measurement techniques In conventional ECG the DRL signal is coupled directly to the patientrsquos skin The DRL signal reduces power line noise on the sensor signals by feeding back an inverted average of the signals from two sensors on to the patientrsquos body In non-contact ECG the generated DRL signal can be capacitively-coupled to the body through clothing via a piece of conductive material placed ndash for instance ndash on the seat or back of a chair Capacitive coupling of DRL signals is described by Lim et al1 and Lee et al2
SYSTEM DESIGNAn ECG system can therefore be built into a chair a mattress or clothing for instance The DRL circuit improves the sensor signalnoise ratio enormously In the example in Figure 1 EPIC sensors are mounted on a chair back such that the electrodes touch the clothing on the subjectrsquos back when resting normally against the back of the chair The generated DRL signal is connected to a piece of conductive material
placed either on the seat of the chair or at the bottom of the chair back contacting the subjectrsquos clothing in the normal sitting position Copper-coated nylon fabric is one possible material suitable for the DRL coupling material but other conductive materials may be equally successful A thin non- conductive material such as a cotton fabric may be used to cover both the sensors and the DRL coupling fabric if required for instance when building the sensors into a seat Consideration must be given as to how material will reduce the coupling capacitance between the sensor and the subject or add additional noise to the signals through static charging effectsFigure 2 shows the design of the DRL circuit It is a standard summing amplifier generating an amplified and inverted signal that is the average of the individual signals A and B
The optimum value for Rf will be dependent on the type of sensors being used as well as the clothing being worn by the subject being measured It should be set to achieve maximum noise reduction while ensuring circuit stability A value of 27kohms is suggested as a suitable starting point for EPIC sensors
1616
SENSOR TECHNOLOGY
Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact
7660SwitchedCapacitorVoltage
Converter
1
2
3
4
8
7
6
5
OP-AMP
Rb(11K)
Ra(11K)
Rf (27KΩ)
Rp (15MΩ)DRLOutput
1nFVout
6Vbatterypack4xAA
+6V
-6V10microF
10microF
A
B
Figure 3 DRL circuit including battery power supply and voltage converter to provide -6v rail Inputs A and B are buffered outputs from the sensors and may be taken from the A and B outputs of the EPIC demo box Ground should be connected to the sensor 0V the shielding of the BNC A and B outputs on the demo box being a suitable connection point See figure 2 and the text for further comments on the DRL design
sensors and the DRL circuit into saturation Because the system contains some large impedances and hence has some very long RC time constants settling times of tens of seconds can be needed before a clean ECG signal is seen During this period the signal can either appear very noisy or be virtually flat depending on whether one or both sensors or the DRL circuit are ldquorailingrdquo The subject should sit still during this time and wait for the circuit to settle since continually adjusting position will only make matters worse Settling times can sometimes be reduced by turning off the power to the demo box for a few seconds
CLOTHINGGood results can be obtained with one or two layers of cotton material between the sensors and the skin Other materials including a wool-mix sweater and a polyester fleece in addition
to two layers of cotton material have been successful Examples are shown in Figures 6 and 7 If the key greatest interest is in the ldquoR-Rrdquo interval adjusting filter settings to reduce or re-center the signal bandwidth can give improved signal quality
STATICBecause there is no direct physical contact between the subject and any grounding point there is no path for any static build up to be discharged Under most circumstances static build-up does not present a problem butdepending on factors including clothing footwear flooring humidity levels in the air and so forth static build up can sometimes prevent the cardiac signal from being seen clearly Product design must take into account a discharge to the system ground to remove the static charge
Rp the protection resistor is included to limit the current that can be fed back to the human body This resistor is essential in ensuring that the subjectrsquos wellbeing is not endangered and must not be omitted
IMPLEMENTATIONThe demonstration of non-contact ECG is best performed using an EPIC demonstration kit Plessey part no PS25003 which includes the necessary drive circuitry and switchable 50Hz and 60Hz notch filters The inputs to the DRL circuit can be taken from the BNC outputs ldquoA amp Brdquo on the front of the demo box The DRL circuit will require its own bipolar power supply plusmn5V or plusmn6V is suggested A circuit design including a battery power supply is shown in Figure 3
Plesseyrsquos compact sensors (PS2520x) and disc sensors (PS25101) provide equally good results although for demonstration purposes disc sensors are simplest to fix to a chair to make contact with the occupantrsquos back Compact sensors are recommended when designing a custom-built system
EPIC sensors which are designed for contact electrophysiology sensing give excellent results in most cases Initial trials suggest that custom modifications to the sensor design (eg lower gain and higher input impedance) can offer increased sensitivity and the ability to detect weaker ECG signalsThe shape of the measured ECG trace ndash in terms of relative magnitudes of the P Q R S and T waves ndash will depend on the positioning of the sensors behind the subjectrsquos back If the desire is only to measure the ldquoR-Rrdquo interval to determine heart rate then the positioning of the sensors is not critical Placing one sensor either side of the spine separated by 6rdquo -10rdquo (15-25 cm) at approximately the same height as the heart is recommended as a starting point For applications where signals from other parts of the cardiac cycle are required the user should refer to texts on bio-electronic signals for guidance on sensor position
SETTLING TIMEWhen a subject first sits in the chair and leans against the EPIC sensors the changes in electric potential will normally send both the
17
TECH REPORT
17
Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact
7660SwitchedCapacitorVoltage
Converter
1
2
3
4
8
7
6
5
OP-AMP
Rb(11K)
Ra(11K)
Rf (27KΩ)
Rp (15MΩ)DRLOutput
1nFVout
6Vbatterypack4xAA
+6V
-6V10microF
10microF
A
B
Figure 3 DRL circuit including battery power supply and voltage converter to provide -6v rail Inputs A and B are buffered outputs from the sensors and may be taken from the A and B outputs of the EPIC demo box Ground should be connected to the sensor 0V the shielding of the BNC A and B outputs on the demo box being a suitable connection point See figure 2 and the text for further comments on the DRL design
sensors and the DRL circuit into saturation Because the system contains some large impedances and hence has some very long RC time constants settling times of tens of seconds can be needed before a clean ECG signal is seen During this period the signal can either appear very noisy or be virtually flat depending on whether one or both sensors or the DRL circuit are ldquorailingrdquo The subject should sit still during this time and wait for the circuit to settle since continually adjusting position will only make matters worse Settling times can sometimes be reduced by turning off the power to the demo box for a few seconds
CLOTHINGGood results can be obtained with one or two layers of cotton material between the sensors and the skin Other materials including a wool-mix sweater and a polyester fleece in addition
to two layers of cotton material have been successful Examples are shown in Figures 6 and 7 If the key greatest interest is in the ldquoR-Rrdquo interval adjusting filter settings to reduce or re-center the signal bandwidth can give improved signal quality
STATICBecause there is no direct physical contact between the subject and any grounding point there is no path for any static build up to be discharged Under most circumstances static build-up does not present a problem butdepending on factors including clothing footwear flooring humidity levels in the air and so forth static build up can sometimes prevent the cardiac signal from being seen clearly Product design must take into account a discharge to the system ground to remove the static charge
Rp the protection resistor is included to limit the current that can be fed back to the human body This resistor is essential in ensuring that the subjectrsquos wellbeing is not endangered and must not be omitted
IMPLEMENTATIONThe demonstration of non-contact ECG is best performed using an EPIC demonstration kit Plessey part no PS25003 which includes the necessary drive circuitry and switchable 50Hz and 60Hz notch filters The inputs to the DRL circuit can be taken from the BNC outputs ldquoA amp Brdquo on the front of the demo box The DRL circuit will require its own bipolar power supply plusmn5V or plusmn6V is suggested A circuit design including a battery power supply is shown in Figure 3
Plesseyrsquos compact sensors (PS2520x) and disc sensors (PS25101) provide equally good results although for demonstration purposes disc sensors are simplest to fix to a chair to make contact with the occupantrsquos back Compact sensors are recommended when designing a custom-built system
EPIC sensors which are designed for contact electrophysiology sensing give excellent results in most cases Initial trials suggest that custom modifications to the sensor design (eg lower gain and higher input impedance) can offer increased sensitivity and the ability to detect weaker ECG signalsThe shape of the measured ECG trace ndash in terms of relative magnitudes of the P Q R S and T waves ndash will depend on the positioning of the sensors behind the subjectrsquos back If the desire is only to measure the ldquoR-Rrdquo interval to determine heart rate then the positioning of the sensors is not critical Placing one sensor either side of the spine separated by 6rdquo -10rdquo (15-25 cm) at approximately the same height as the heart is recommended as a starting point For applications where signals from other parts of the cardiac cycle are required the user should refer to texts on bio-electronic signals for guidance on sensor position
SETTLING TIMEWhen a subject first sits in the chair and leans against the EPIC sensors the changes in electric potential will normally send both the
1818
SENSOR TECHNOLOGY
Figure 4 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit HP filter corner frequency is 50mHz LP filter in demo box has corner frequency of 30Hz
Figure 6 ECG signals measured from a subject wearing a wool-mix sweater over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 8-25Hz The heart rate can be easily extracted
Figure 5 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit Software filters limit the bandwidth to 8-25Hz
Figure 7 ECG signals measured from a subject wearing a polyester fleece over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 16-40Hz The heart rate can be easily extracted
CABLE SHIELDINGCareful shielding is necessary to reduce unwanted noise artifacts Grounding the shielding of the sensor cable via the connection between the outer casing of the sensor plugs and the metal surround of the socket on the control electronics is recommended
CONCLUSIONEPIC sensors can be used to measure ECG signals without physical skin contact While
sensors can be embedded in a chair or seat the techniques are equally applicable to sensors mounted on a mattress in clothing or in other situations There are many variables that will affect signal quality from the strength of cardiac signal generated by the individual being measured to clothing to the surrounding environment but the designs given here are a starting point in establishing an optimum system for a particular application infin
Find us at Booth 37310World Maker Faire New York
Figure 4 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit HP filter corner frequency is 50mHz LP filter in demo box has corner frequency of 30Hz
Figure 6 ECG signals measured from a subject wearing a wool-mix sweater over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 8-25Hz The heart rate can be easily extracted
Figure 5 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit Software filters limit the bandwidth to 8-25Hz
Figure 7 ECG signals measured from a subject wearing a polyester fleece over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 16-40Hz The heart rate can be easily extracted
CABLE SHIELDINGCareful shielding is necessary to reduce unwanted noise artifacts Grounding the shielding of the sensor cable via the connection between the outer casing of the sensor plugs and the metal surround of the socket on the control electronics is recommended
CONCLUSIONEPIC sensors can be used to measure ECG signals without physical skin contact While
sensors can be embedded in a chair or seat the techniques are equally applicable to sensors mounted on a mattress in clothing or in other situations There are many variables that will affect signal quality from the strength of cardiac signal generated by the individual being measured to clothing to the surrounding environment but the designs given here are a starting point in establishing an optimum system for a particular application infin
Find us at Booth 37310World Maker Faire New York
20
SENSOR TECHNOLOGY
SmallerThan a
Grain Sand
of
Analysts project that by
2020 there will be over
50 billion connected
devices in the now-nascent
Internet of Things (IoT) However
the technology that will enable the
IoT of the future may look a little
different than todayrsquosmdashin fact
you may not be able to see it at all
Many new mobile devices require
motion sensors in order to monitor
analyze and deliver real-time data
and analysis to improve the way
consumers interact with everyday
technology While traditional
sensor platforms require multichip
modules or stacked die within a
device mCube a new MEMS sensor
company is driving the emergence
of Sensor 30 which will lead the
development of the smallest
sensors to datemdashsmaller than a
grain of sand By EEWeb Contributing Writers
mCubersquos Sensors Enable IoMTInterview with Ben Lee President and CEO of mCube
INDUSTRY INTERVIEW
21
SmallerThan a
Grain Sand
of
Analysts project that by
2020 there will be over
50 billion connected
devices in the now-nascent
Internet of Things (IoT) However
the technology that will enable the
IoT of the future may look a little
different than todayrsquosmdashin fact
you may not be able to see it at all
Many new mobile devices require
motion sensors in order to monitor
analyze and deliver real-time data
and analysis to improve the way
consumers interact with everyday
technology While traditional
sensor platforms require multichip
modules or stacked die within a
device mCube a new MEMS sensor
company is driving the emergence
of Sensor 30 which will lead the
development of the smallest
sensors to datemdashsmaller than a
grain of sand By EEWeb Contributing Writers
mCubersquos Sensors Enable IoMTInterview with Ben Lee President and CEO of mCube
22
SENSOR TECHNOLOGY
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
INDUSTRY INTERVIEW
23
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
24
SENSOR TECHNOLOGY
Since sensors are so small and affordable donrsquot be surprised to find unique applications in the future Lee speculates that ldquofarmers might have sensor tags to monitor livestock for abnormal activity patterns of grazing potential illness and herd behaviorrdquo Commercial trucking might involve motion sensors connected to video cameras in rear-view mirrors to better assess the cause of an accident and driving conditions For shipping Lee describes ldquomotion sensors embedded directly onto packages to record jarring motions or accidents in order to determine when and how contents were damagedrdquo
As of 2014 mCubersquos complete intertial sensor portfolio contains an accelerometer magnetometer and its proprietary iGyrotrade gyroscope offering nine degrees of freedom (9DoF) Through reductions in cost power consumption and size mCubersquos sensor offerings make it possible to place them onto nearly any object or devicemdashin some cases without packaging ldquoWe aspire to put one or more MEMS motion sensors on anything that movesrdquo remarks Lee And with the IoMT taking shape and consumer expectations for connected moving devices becoming more concrete developers of new applications will turn to solutions like mCube to deliver truly cutting-edge connected devices
ldquoAt mCube we aspire to put one or more MEMS motion sensors on
anything that movesrdquo
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 15
Complete Inertial Motion Sensor Portfolio
Solutions for up to 9DoF (Degrees of Freedom)
Accelerometer
Magnetometer
iGyroTM
3DoF 3DoF
9DoF
2x2mm
3x3mm 3DoF 6DoF
14x14mm
3x3mm
3x3mm
2626
SENSOR TECHNOLOGY
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
27
TECH REPORT
27
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
2828
SENSOR TECHNOLOGY
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
29
TECH REPORT
29
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
3030
SENSOR TECHNOLOGY
to enable the kind of constant and complex data accumulation that the Biostamp promises
In the interim MC10 is partnering up with other medical and pharmaceutical companies to develop integrated sensor and monitoring products The company plans to become a certified medical-ready partner for companies who donrsquot have access to this unique and proprietary technology Even the US Army has begun working with MC10 on military-grade sensors that will add further safety features for troops in the field This funding from NIH grants Department of Defense grants as well as foundation grants will help the company get one step closer to realization of devices so flexible that users might forget theyrsquore wearing them
ldquoThe company has been bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devicesrdquo
Join the
DESIGNERS OF THINGS conference in San Francisco on
September 23 and 24
Dedicated to the explosive and exciting potential of Wearable
Tech 3D Printing and the Internet of Things the conference
provides the growing design and development community
around these technologies a meeting place to discuss and
showcase the newest products
Click here for more info
httpwwwdesignersofthingscomsanfranciscoscheduler
speakersheth-nirav-rav33310
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Sierra CircuitsA Complete PCB Resource
PLUS The Ground rdquo Myth in PrintedCircuits
ldquo
PCB Resin Reactor+
Ken BahlCEO of Sierra Circuits
Let There Be
How Cree reinvented the light bulb
LIGHT
David ElienVP of Marketing amp Business
Development Cree Inc
New LED Filament Tower
Cutting Edge Flatscreen Technologies
+
+
M o v i n g T o w a r d s
a Clean Energy
FUTUREmdash Hugo van Nispen COO of DNV KEMA
MCU Wars 32-bit MCU Comparison
Cutting Edge
SPICEModeling
Freescale and TI Embedded
Modules
ARMCortex
Programming
From Concept to
Reality Wolfgang Heinz-Fischer
Head of Marketing amp PR TQ-Group
Low-Power Design Techniques
TQ-Grouprsquos Comprehensive Design Process
+
+
PowerDeveloper
Octobe r 20 13
Designing forDurability
View more EEWeb magazinesmdash Click Here
5
TECH REPORT
5
Sensor Signal Conditioners
Powerful and Flexible yet Easy to Use
By David Grice Applications Engineer Zentrum Mikrokelektronik (ZMDI) Dresden Germany
As demands increase for the number type and range of sensors in
almost every product category the difficulty of implementing them
increases proportionately This is especially true in the automotive
arena driven by efficiency safety and emission requirements
Existing sensor technologies are inadequate to meet many of these
new and more stringent requirements spurring the development
of a new class of sensors based on micro-electro-
mechanical systems (MEMS) These new sensors
are smaller lighter more robust less expensive
and consume less power but they also
produce electrical signals that
are smaller and more nonlinear
than their bulkier counterparts
Next-Generation SO MANY SENSORS SO LITTLE TIME
66
SENSOR TECHNOLOGY
As the quality of output from transducers declines to meet application demands system
requirements such as measurement range accuracy speed and power consumption continue to increase squeezing the performance of sensor signal conditioning (SSC) circuits from both ends and making the task of designing them exponentially more difficult
integrity level (ASIL) for automotive applications These requirements include detection and notification of faults due to open or short circuits out-of-range parameters aging sensors and excessive temperature Additionally the SSC must be able to monitor these faults while tolerant of shorts to ground or supply voltage supply overvoltage conditions or reverse battery connections
ldquoOne of the key features of next-generation SSCs
is flexibilityrdquoldquoA highly efficient and powerful
reduced-instruction-set computer coordinates numerous control and
computational tasksrdquo
NEXT GENERATION TO THE RESCUE
In the same way increasing demands have spurred a new class of sensors Zentrum Mikroelektronik (ZMDI) is developing and introducing the next generation of SSC products and technologies to the sensor marketplace This article describes some of the most important and beneficial new features of these new SSCs
FLEXIBILITY IS A BEAUTIFUL THING
One of the key features of next-generation SSCs is flexibility The types and combinations of physical quantities measured for products are growing rapidly and new SSCs must facilitate fast development of complex sensor modules with low component counts and a user interface that is easy to learn and use This requires a signal interface that is configurable for a wide range of signals and correction algorithms that are much more complex than second or third order polynomial curve fitting offered by previous generations of SSCs For example a single application might require the conditioning of two temperature inputs one being a diode and the other a thermocouple and two resistive pressure bridges with widely varying output levels each of which require linearization and calibration
Flexibility is not limited only to signal types and ranges however Another dimension of configurability is required for the sequence of signal processing tasks Typically some signals must be acquired at a much higher rate than others and the
quantization and correction algorithms must be reconfigured quickly from one measurement to another in a programmable fashion In addition to this sometimes it is necessary to perform math operations between signals like subtracting two pressure inputs to generate a differential pressure output The SSC must generate a user-programmable sequence that samples the inputs in a defined order and rate correct each signal according to a user-defined calibration algorithm and combine the conditioned outputs into an orderly stream of data
Finally flexibility must include the number and type of output signals and protocols Reliability safety weight and noise constraints are also driving the creation of innovative new output protocols like single-edge nibble transmission (SENT) for the automotive industry Next-generation SSCs must support new interfaces like SENT along with the traditional analog one-wire and serial interfaces such as I2Ctrade and SPI In fact the SENT interface is output only and requires an auxiliary interface like I2C to configure and calibrate the SSC
Another important feature for next-generation SSCs is the ability to perform self-testing and diagnostics to meet critical safety standards like the automotive safety
I2Ctrade is a trademark of NXP
7
TECH REPORT
7
As the quality of output from transducers declines to meet application demands system
requirements such as measurement range accuracy speed and power consumption continue to increase squeezing the performance of sensor signal conditioning (SSC) circuits from both ends and making the task of designing them exponentially more difficult
integrity level (ASIL) for automotive applications These requirements include detection and notification of faults due to open or short circuits out-of-range parameters aging sensors and excessive temperature Additionally the SSC must be able to monitor these faults while tolerant of shorts to ground or supply voltage supply overvoltage conditions or reverse battery connections
ldquoOne of the key features of next-generation SSCs
is flexibilityrdquoldquoA highly efficient and powerful
reduced-instruction-set computer coordinates numerous control and
computational tasksrdquo
NEXT GENERATION TO THE RESCUE
In the same way increasing demands have spurred a new class of sensors Zentrum Mikroelektronik (ZMDI) is developing and introducing the next generation of SSC products and technologies to the sensor marketplace This article describes some of the most important and beneficial new features of these new SSCs
FLEXIBILITY IS A BEAUTIFUL THING
One of the key features of next-generation SSCs is flexibility The types and combinations of physical quantities measured for products are growing rapidly and new SSCs must facilitate fast development of complex sensor modules with low component counts and a user interface that is easy to learn and use This requires a signal interface that is configurable for a wide range of signals and correction algorithms that are much more complex than second or third order polynomial curve fitting offered by previous generations of SSCs For example a single application might require the conditioning of two temperature inputs one being a diode and the other a thermocouple and two resistive pressure bridges with widely varying output levels each of which require linearization and calibration
Flexibility is not limited only to signal types and ranges however Another dimension of configurability is required for the sequence of signal processing tasks Typically some signals must be acquired at a much higher rate than others and the
quantization and correction algorithms must be reconfigured quickly from one measurement to another in a programmable fashion In addition to this sometimes it is necessary to perform math operations between signals like subtracting two pressure inputs to generate a differential pressure output The SSC must generate a user-programmable sequence that samples the inputs in a defined order and rate correct each signal according to a user-defined calibration algorithm and combine the conditioned outputs into an orderly stream of data
Finally flexibility must include the number and type of output signals and protocols Reliability safety weight and noise constraints are also driving the creation of innovative new output protocols like single-edge nibble transmission (SENT) for the automotive industry Next-generation SSCs must support new interfaces like SENT along with the traditional analog one-wire and serial interfaces such as I2Ctrade and SPI In fact the SENT interface is output only and requires an auxiliary interface like I2C to configure and calibrate the SSC
Another important feature for next-generation SSCs is the ability to perform self-testing and diagnostics to meet critical safety standards like the automotive safety
I2Ctrade is a trademark of NXP
88
SENSOR TECHNOLOGY
PUTTING IT ALL TOGETHER
Figure 1 shows the block diagram of a next-generation SSC In this particular case the SSC supports two temperature inputsmdashone resistive one diodemdashand two resistive bridge inputs The conditioning signal chain includes sensor check and common mode (SCCM) adjustment multiplexing (MUX) programmable gain (PGA) from 1 to 200 VV and an analog to digital converter (ADC) with adjustable sample rate and resolution from 12 to 18 bits
The SSC in figure 1 looks similar to other SSCs that are presently available but most of its potential and flexibility lies in the calibration microcontroller (CMC) A highly efficient and powerful reduced instruction set computer (RISC) coordinates the numerous control and computational tasks necessary to provide the tremendous amount of flexibility required for next-generation SSCs The controller also combines the multiple output data packets into a structured stream in a wide variety of formats that can be either analog or digital
The cycle of tasks performed by the RISC engine consists of three main types measurement tasks conditioning tasks and output tasks Measurement tasks include operations that select the MUX input and signal polarities the gain and offset of the signal path the speed and resolution of the quantizer and auxiliary tasks such as auto-zeroing gain stages The output values of all the main measurement tasks are stored in registers for processing by the conditioning tasks These tasks range from simple operations like shifting and synchronization to basic math functions such as add subtract multiply and divide to complex functions such as logarithms polynomial evaluation spline curve fitting and digital filtering Output tasks include synchronization of data streams formatting packetizing encoding error detection and safety features like redundancy or inversion
The SSC shown in figure 1 provides for up to 20 measurement tasks and 62 conditioning tasks enabling thousands
of different combinations of signal processing sequences for each of the four inputs The number of output tasks varies greatly depending on the type of output but for a complex protocol like SENT the number can be in the dozens
MAKING IT EASY
However it is also vitally important that the flexibility power and complexity of next-generation SSCs do not require a commensurate level of time and resources for system designers implementing them The example shown in figure 1 is a member of a product family that is preconfigured by the manufacturer for a specific application using firmware All of the measurement conditioning and output tasks are programmed so that the designer need only focus on determining gain resolution and calibration coefficients for the correction algorithm all of which are facilitated by software that is easy to use and
Figure 1 An example block diagram of a next-generation SSC from ZMDI
ldquoOne thing that should not be flexible in next-generation
SSCs is the user interfacerdquo
consistent across the product line Special use cases can be implemented easily in firmware by the manufacturer should the need arise but the standard factory configuration will cover the majority of designs Additional family members of the product line are optimized for different numbers and types of inputs and outputs and also preconfigured for the intended application use
Finally one thing that should not be flexible in next-generation SSCs is the user interface including the physical dimensions pin or pad locations and software user interface The product family exemplified in figure 1 has a standardized footprint pinout and software user interface to minimize the costs time and resources associated with board layout calibration and climbing the learning curve
9
TECH REPORT
9
PUTTING IT ALL TOGETHER
Figure 1 shows the block diagram of a next-generation SSC In this particular case the SSC supports two temperature inputsmdashone resistive one diodemdashand two resistive bridge inputs The conditioning signal chain includes sensor check and common mode (SCCM) adjustment multiplexing (MUX) programmable gain (PGA) from 1 to 200 VV and an analog to digital converter (ADC) with adjustable sample rate and resolution from 12 to 18 bits
The SSC in figure 1 looks similar to other SSCs that are presently available but most of its potential and flexibility lies in the calibration microcontroller (CMC) A highly efficient and powerful reduced instruction set computer (RISC) coordinates the numerous control and computational tasks necessary to provide the tremendous amount of flexibility required for next-generation SSCs The controller also combines the multiple output data packets into a structured stream in a wide variety of formats that can be either analog or digital
The cycle of tasks performed by the RISC engine consists of three main types measurement tasks conditioning tasks and output tasks Measurement tasks include operations that select the MUX input and signal polarities the gain and offset of the signal path the speed and resolution of the quantizer and auxiliary tasks such as auto-zeroing gain stages The output values of all the main measurement tasks are stored in registers for processing by the conditioning tasks These tasks range from simple operations like shifting and synchronization to basic math functions such as add subtract multiply and divide to complex functions such as logarithms polynomial evaluation spline curve fitting and digital filtering Output tasks include synchronization of data streams formatting packetizing encoding error detection and safety features like redundancy or inversion
The SSC shown in figure 1 provides for up to 20 measurement tasks and 62 conditioning tasks enabling thousands
of different combinations of signal processing sequences for each of the four inputs The number of output tasks varies greatly depending on the type of output but for a complex protocol like SENT the number can be in the dozens
MAKING IT EASY
However it is also vitally important that the flexibility power and complexity of next-generation SSCs do not require a commensurate level of time and resources for system designers implementing them The example shown in figure 1 is a member of a product family that is preconfigured by the manufacturer for a specific application using firmware All of the measurement conditioning and output tasks are programmed so that the designer need only focus on determining gain resolution and calibration coefficients for the correction algorithm all of which are facilitated by software that is easy to use and
Figure 1 An example block diagram of a next-generation SSC from ZMDI
ldquoOne thing that should not be flexible in next-generation
SSCs is the user interfacerdquo
consistent across the product line Special use cases can be implemented easily in firmware by the manufacturer should the need arise but the standard factory configuration will cover the majority of designs Additional family members of the product line are optimized for different numbers and types of inputs and outputs and also preconfigured for the intended application use
Finally one thing that should not be flexible in next-generation SSCs is the user interface including the physical dimensions pin or pad locations and software user interface The product family exemplified in figure 1 has a standardized footprint pinout and software user interface to minimize the costs time and resources associated with board layout calibration and climbing the learning curve
1212
SENSOR TECHNOLOGY
The human heartbeat is arguably the single most important (ldquolife-and-deathrdquo) diagnostic indicator Thus electrocardiograms (ECGs) are one of the most significant diagnostic methods in that
they monitor heart function ECGs are not only used in a clinical setting but are increasingly seen in personal health devices Traditionally ECG measurement conductive electrodes have been applied which are directly attached to the skin With the help of contact gel (wet or solid) to ensure that there is good electrical contact between the skin and the sensor direct resistive contact is made with the patient However conventional electrodes possess various disadvantages which are not conducive for long-term use in non-clinical settings In addition to being potentially messy metal allergies can cause skin irritations and as a single-use item they are quite expensive
Non-contact ECG measurementusing EPIC Sensors
Measuring electrocardiogram (ECG) signals without skin contact is now possible using novel Electric Potential Integrated Circuit (EPIC) sensors
By Alan Lowne CEO of Saelig Co Inc
13
TECH REPORT
13
The human heartbeat is arguably the single most important (ldquolife-and-deathrdquo) diagnostic indicator Thus electrocardiograms (ECGs) are one of the most significant diagnostic methods in that
they monitor heart function ECGs are not only used in a clinical setting but are increasingly seen in personal health devices Traditionally ECG measurement conductive electrodes have been applied which are directly attached to the skin With the help of contact gel (wet or solid) to ensure that there is good electrical contact between the skin and the sensor direct resistive contact is made with the patient However conventional electrodes possess various disadvantages which are not conducive for long-term use in non-clinical settings In addition to being potentially messy metal allergies can cause skin irritations and as a single-use item they are quite expensive
Non-contact ECG measurementusing EPIC Sensors
Measuring electrocardiogram (ECG) signals without skin contact is now possible using novel Electric Potential Integrated Circuit (EPIC) sensors
By Alan Lowne CEO of Saelig Co Inc
1414
SENSOR TECHNOLOGY
Non-contact measurement of electrophysiological signals is of great interest in healthcare settings with the potential of reducing disposable costs speeding up or simplifying measurement techniques Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact Monitoring vehicle drivers for health and alertness by detecting heart rate and respiration or determining car occupancy to adjust the ride handling and air bag deployment with the varying size and location of occupants is a vast potential market
Capacitive (insulated) electrodes can register ECG signals without conductive contact to the bodyndasheven through clothesndashand represent
an attractive alternative for a wide range of new applications EPIC (Electric Potential Integrated Circuit) is a completely new sensor technology resulting from research at the University of Sussex (UK) Novel ultra high impedance EPIC sensors measure electric field changes without requiring physical or resistive contact This award winning patent-protected sensor can rapidly measure electric potential sources such as electrophysiological signals or even spatial electric fields It therefore has the ability to measure ECGs without direct skin contact By adjusting the DSP and amplification circuitry the sensors can be tuned for detection at a distance as required for differing automotive applications EPIC sensor electrodes can be easily and discretely incorporated inside car seat backs to acquire the necessary biometric data
Signals measured on the human body always include a large amount of noise the major component of this being 50 or 60 Hz power line noise capacitively-coupled to the body from the surrounding electricity supply Measurements such as ECG depend on being able to extract the small electrophysiological signals from the much larger noise signals EPIC sensors can be used in ldquocontact moderdquo for ECG measurement where the subject touches both the capacitive electrode surface and some metal at the system ground directly with the skin This ground reference allows filtering and differential amplification of signals from two sensors to be effective in removing the mains frequency noise leaving a high quality ECG signal In non-contact ECG measurement there is ndash by definition - no skin contact and thus no direct connection can be made between the subjectrsquos body and the system ground Some other method of reducing the power line noise is therefore required to
EPIC Sensors incontact with clothing
Conductive fabric in contactwith clothing eg on chair seat
Output
EPICdemo box
Figure 1 Basic configuration for non-contact ECG measurement including capacitively-oocupied DR circuit
OP-AMP
+5V
-5V
Vout
Rf (27KΩ)
Ra(11KΩ)
Rb(11KΩ)
Rp (15MΩ) To conductive fabric on chair thus capacitively coupled to body
Inputs from outputs of demo box
A
BC
(1nF)
Figure 2 DPL circuit Voltage gain is set by Rf Rp limits current fed back to the body (see text)Operational amplifier output Vout = - (VA + VB) Rf 11K
enable the ECG signal to be extracted reliably and accurately One such method utilizes an approach very similar to the ldquoDriven Right Legrdquo (DRL) system that is used for the same purpose in conventional ECG measurement techniques In conventional ECG the DRL signal is coupled directly to the patientrsquos skin The DRL signal reduces power line noise on the sensor signals by feeding back an inverted average of the signals from two sensors on to the patientrsquos body In non-contact ECG the generated DRL signal can be capacitively-coupled to the body through clothing via a piece of conductive material placed ndash for instance ndash on the seat or back of a chair Capacitive coupling of DRL signals is described by Lim et al1 and Lee et al2
SYSTEM DESIGNAn ECG system can therefore be built into a chair a mattress or clothing for instance The DRL circuit improves the sensor signalnoise ratio enormously In the example in Figure 1 EPIC sensors are mounted on a chair back such that the electrodes touch the clothing on the subjectrsquos back when resting normally against the back of the chair The generated DRL signal is connected to a piece of conductive material
placed either on the seat of the chair or at the bottom of the chair back contacting the subjectrsquos clothing in the normal sitting position Copper-coated nylon fabric is one possible material suitable for the DRL coupling material but other conductive materials may be equally successful A thin non- conductive material such as a cotton fabric may be used to cover both the sensors and the DRL coupling fabric if required for instance when building the sensors into a seat Consideration must be given as to how material will reduce the coupling capacitance between the sensor and the subject or add additional noise to the signals through static charging effectsFigure 2 shows the design of the DRL circuit It is a standard summing amplifier generating an amplified and inverted signal that is the average of the individual signals A and B
The optimum value for Rf will be dependent on the type of sensors being used as well as the clothing being worn by the subject being measured It should be set to achieve maximum noise reduction while ensuring circuit stability A value of 27kohms is suggested as a suitable starting point for EPIC sensors
15
TECH REPORT
15
Non-contact measurement of electrophysiological signals is of great interest in healthcare settings with the potential of reducing disposable costs speeding up or simplifying measurement techniques Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact Monitoring vehicle drivers for health and alertness by detecting heart rate and respiration or determining car occupancy to adjust the ride handling and air bag deployment with the varying size and location of occupants is a vast potential market
Capacitive (insulated) electrodes can register ECG signals without conductive contact to the bodyndasheven through clothesndashand represent
an attractive alternative for a wide range of new applications EPIC (Electric Potential Integrated Circuit) is a completely new sensor technology resulting from research at the University of Sussex (UK) Novel ultra high impedance EPIC sensors measure electric field changes without requiring physical or resistive contact This award winning patent-protected sensor can rapidly measure electric potential sources such as electrophysiological signals or even spatial electric fields It therefore has the ability to measure ECGs without direct skin contact By adjusting the DSP and amplification circuitry the sensors can be tuned for detection at a distance as required for differing automotive applications EPIC sensor electrodes can be easily and discretely incorporated inside car seat backs to acquire the necessary biometric data
Signals measured on the human body always include a large amount of noise the major component of this being 50 or 60 Hz power line noise capacitively-coupled to the body from the surrounding electricity supply Measurements such as ECG depend on being able to extract the small electrophysiological signals from the much larger noise signals EPIC sensors can be used in ldquocontact moderdquo for ECG measurement where the subject touches both the capacitive electrode surface and some metal at the system ground directly with the skin This ground reference allows filtering and differential amplification of signals from two sensors to be effective in removing the mains frequency noise leaving a high quality ECG signal In non-contact ECG measurement there is ndash by definition - no skin contact and thus no direct connection can be made between the subjectrsquos body and the system ground Some other method of reducing the power line noise is therefore required to
EPIC Sensors incontact with clothing
Conductive fabric in contactwith clothing eg on chair seat
Output
EPICdemo box
Figure 1 Basic configuration for non-contact ECG measurement including capacitively-oocupied DR circuit
OP-AMP
+5V
-5V
Vout
Rf (27KΩ)
Ra(11KΩ)
Rb(11KΩ)
Rp (15MΩ) To conductive fabric on chair thus capacitively coupled to body
Inputs from outputs of demo box
A
BC
(1nF)
Figure 2 DPL circuit Voltage gain is set by Rf Rp limits current fed back to the body (see text)Operational amplifier output Vout = - (VA + VB) Rf 11K
enable the ECG signal to be extracted reliably and accurately One such method utilizes an approach very similar to the ldquoDriven Right Legrdquo (DRL) system that is used for the same purpose in conventional ECG measurement techniques In conventional ECG the DRL signal is coupled directly to the patientrsquos skin The DRL signal reduces power line noise on the sensor signals by feeding back an inverted average of the signals from two sensors on to the patientrsquos body In non-contact ECG the generated DRL signal can be capacitively-coupled to the body through clothing via a piece of conductive material placed ndash for instance ndash on the seat or back of a chair Capacitive coupling of DRL signals is described by Lim et al1 and Lee et al2
SYSTEM DESIGNAn ECG system can therefore be built into a chair a mattress or clothing for instance The DRL circuit improves the sensor signalnoise ratio enormously In the example in Figure 1 EPIC sensors are mounted on a chair back such that the electrodes touch the clothing on the subjectrsquos back when resting normally against the back of the chair The generated DRL signal is connected to a piece of conductive material
placed either on the seat of the chair or at the bottom of the chair back contacting the subjectrsquos clothing in the normal sitting position Copper-coated nylon fabric is one possible material suitable for the DRL coupling material but other conductive materials may be equally successful A thin non- conductive material such as a cotton fabric may be used to cover both the sensors and the DRL coupling fabric if required for instance when building the sensors into a seat Consideration must be given as to how material will reduce the coupling capacitance between the sensor and the subject or add additional noise to the signals through static charging effectsFigure 2 shows the design of the DRL circuit It is a standard summing amplifier generating an amplified and inverted signal that is the average of the individual signals A and B
The optimum value for Rf will be dependent on the type of sensors being used as well as the clothing being worn by the subject being measured It should be set to achieve maximum noise reduction while ensuring circuit stability A value of 27kohms is suggested as a suitable starting point for EPIC sensors
1616
SENSOR TECHNOLOGY
Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact
7660SwitchedCapacitorVoltage
Converter
1
2
3
4
8
7
6
5
OP-AMP
Rb(11K)
Ra(11K)
Rf (27KΩ)
Rp (15MΩ)DRLOutput
1nFVout
6Vbatterypack4xAA
+6V
-6V10microF
10microF
A
B
Figure 3 DRL circuit including battery power supply and voltage converter to provide -6v rail Inputs A and B are buffered outputs from the sensors and may be taken from the A and B outputs of the EPIC demo box Ground should be connected to the sensor 0V the shielding of the BNC A and B outputs on the demo box being a suitable connection point See figure 2 and the text for further comments on the DRL design
sensors and the DRL circuit into saturation Because the system contains some large impedances and hence has some very long RC time constants settling times of tens of seconds can be needed before a clean ECG signal is seen During this period the signal can either appear very noisy or be virtually flat depending on whether one or both sensors or the DRL circuit are ldquorailingrdquo The subject should sit still during this time and wait for the circuit to settle since continually adjusting position will only make matters worse Settling times can sometimes be reduced by turning off the power to the demo box for a few seconds
CLOTHINGGood results can be obtained with one or two layers of cotton material between the sensors and the skin Other materials including a wool-mix sweater and a polyester fleece in addition
to two layers of cotton material have been successful Examples are shown in Figures 6 and 7 If the key greatest interest is in the ldquoR-Rrdquo interval adjusting filter settings to reduce or re-center the signal bandwidth can give improved signal quality
STATICBecause there is no direct physical contact between the subject and any grounding point there is no path for any static build up to be discharged Under most circumstances static build-up does not present a problem butdepending on factors including clothing footwear flooring humidity levels in the air and so forth static build up can sometimes prevent the cardiac signal from being seen clearly Product design must take into account a discharge to the system ground to remove the static charge
Rp the protection resistor is included to limit the current that can be fed back to the human body This resistor is essential in ensuring that the subjectrsquos wellbeing is not endangered and must not be omitted
IMPLEMENTATIONThe demonstration of non-contact ECG is best performed using an EPIC demonstration kit Plessey part no PS25003 which includes the necessary drive circuitry and switchable 50Hz and 60Hz notch filters The inputs to the DRL circuit can be taken from the BNC outputs ldquoA amp Brdquo on the front of the demo box The DRL circuit will require its own bipolar power supply plusmn5V or plusmn6V is suggested A circuit design including a battery power supply is shown in Figure 3
Plesseyrsquos compact sensors (PS2520x) and disc sensors (PS25101) provide equally good results although for demonstration purposes disc sensors are simplest to fix to a chair to make contact with the occupantrsquos back Compact sensors are recommended when designing a custom-built system
EPIC sensors which are designed for contact electrophysiology sensing give excellent results in most cases Initial trials suggest that custom modifications to the sensor design (eg lower gain and higher input impedance) can offer increased sensitivity and the ability to detect weaker ECG signalsThe shape of the measured ECG trace ndash in terms of relative magnitudes of the P Q R S and T waves ndash will depend on the positioning of the sensors behind the subjectrsquos back If the desire is only to measure the ldquoR-Rrdquo interval to determine heart rate then the positioning of the sensors is not critical Placing one sensor either side of the spine separated by 6rdquo -10rdquo (15-25 cm) at approximately the same height as the heart is recommended as a starting point For applications where signals from other parts of the cardiac cycle are required the user should refer to texts on bio-electronic signals for guidance on sensor position
SETTLING TIMEWhen a subject first sits in the chair and leans against the EPIC sensors the changes in electric potential will normally send both the
17
TECH REPORT
17
Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact
7660SwitchedCapacitorVoltage
Converter
1
2
3
4
8
7
6
5
OP-AMP
Rb(11K)
Ra(11K)
Rf (27KΩ)
Rp (15MΩ)DRLOutput
1nFVout
6Vbatterypack4xAA
+6V
-6V10microF
10microF
A
B
Figure 3 DRL circuit including battery power supply and voltage converter to provide -6v rail Inputs A and B are buffered outputs from the sensors and may be taken from the A and B outputs of the EPIC demo box Ground should be connected to the sensor 0V the shielding of the BNC A and B outputs on the demo box being a suitable connection point See figure 2 and the text for further comments on the DRL design
sensors and the DRL circuit into saturation Because the system contains some large impedances and hence has some very long RC time constants settling times of tens of seconds can be needed before a clean ECG signal is seen During this period the signal can either appear very noisy or be virtually flat depending on whether one or both sensors or the DRL circuit are ldquorailingrdquo The subject should sit still during this time and wait for the circuit to settle since continually adjusting position will only make matters worse Settling times can sometimes be reduced by turning off the power to the demo box for a few seconds
CLOTHINGGood results can be obtained with one or two layers of cotton material between the sensors and the skin Other materials including a wool-mix sweater and a polyester fleece in addition
to two layers of cotton material have been successful Examples are shown in Figures 6 and 7 If the key greatest interest is in the ldquoR-Rrdquo interval adjusting filter settings to reduce or re-center the signal bandwidth can give improved signal quality
STATICBecause there is no direct physical contact between the subject and any grounding point there is no path for any static build up to be discharged Under most circumstances static build-up does not present a problem butdepending on factors including clothing footwear flooring humidity levels in the air and so forth static build up can sometimes prevent the cardiac signal from being seen clearly Product design must take into account a discharge to the system ground to remove the static charge
Rp the protection resistor is included to limit the current that can be fed back to the human body This resistor is essential in ensuring that the subjectrsquos wellbeing is not endangered and must not be omitted
IMPLEMENTATIONThe demonstration of non-contact ECG is best performed using an EPIC demonstration kit Plessey part no PS25003 which includes the necessary drive circuitry and switchable 50Hz and 60Hz notch filters The inputs to the DRL circuit can be taken from the BNC outputs ldquoA amp Brdquo on the front of the demo box The DRL circuit will require its own bipolar power supply plusmn5V or plusmn6V is suggested A circuit design including a battery power supply is shown in Figure 3
Plesseyrsquos compact sensors (PS2520x) and disc sensors (PS25101) provide equally good results although for demonstration purposes disc sensors are simplest to fix to a chair to make contact with the occupantrsquos back Compact sensors are recommended when designing a custom-built system
EPIC sensors which are designed for contact electrophysiology sensing give excellent results in most cases Initial trials suggest that custom modifications to the sensor design (eg lower gain and higher input impedance) can offer increased sensitivity and the ability to detect weaker ECG signalsThe shape of the measured ECG trace ndash in terms of relative magnitudes of the P Q R S and T waves ndash will depend on the positioning of the sensors behind the subjectrsquos back If the desire is only to measure the ldquoR-Rrdquo interval to determine heart rate then the positioning of the sensors is not critical Placing one sensor either side of the spine separated by 6rdquo -10rdquo (15-25 cm) at approximately the same height as the heart is recommended as a starting point For applications where signals from other parts of the cardiac cycle are required the user should refer to texts on bio-electronic signals for guidance on sensor position
SETTLING TIMEWhen a subject first sits in the chair and leans against the EPIC sensors the changes in electric potential will normally send both the
1818
SENSOR TECHNOLOGY
Figure 4 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit HP filter corner frequency is 50mHz LP filter in demo box has corner frequency of 30Hz
Figure 6 ECG signals measured from a subject wearing a wool-mix sweater over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 8-25Hz The heart rate can be easily extracted
Figure 5 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit Software filters limit the bandwidth to 8-25Hz
Figure 7 ECG signals measured from a subject wearing a polyester fleece over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 16-40Hz The heart rate can be easily extracted
CABLE SHIELDINGCareful shielding is necessary to reduce unwanted noise artifacts Grounding the shielding of the sensor cable via the connection between the outer casing of the sensor plugs and the metal surround of the socket on the control electronics is recommended
CONCLUSIONEPIC sensors can be used to measure ECG signals without physical skin contact While
sensors can be embedded in a chair or seat the techniques are equally applicable to sensors mounted on a mattress in clothing or in other situations There are many variables that will affect signal quality from the strength of cardiac signal generated by the individual being measured to clothing to the surrounding environment but the designs given here are a starting point in establishing an optimum system for a particular application infin
Find us at Booth 37310World Maker Faire New York
Figure 4 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit HP filter corner frequency is 50mHz LP filter in demo box has corner frequency of 30Hz
Figure 6 ECG signals measured from a subject wearing a wool-mix sweater over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 8-25Hz The heart rate can be easily extracted
Figure 5 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit Software filters limit the bandwidth to 8-25Hz
Figure 7 ECG signals measured from a subject wearing a polyester fleece over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 16-40Hz The heart rate can be easily extracted
CABLE SHIELDINGCareful shielding is necessary to reduce unwanted noise artifacts Grounding the shielding of the sensor cable via the connection between the outer casing of the sensor plugs and the metal surround of the socket on the control electronics is recommended
CONCLUSIONEPIC sensors can be used to measure ECG signals without physical skin contact While
sensors can be embedded in a chair or seat the techniques are equally applicable to sensors mounted on a mattress in clothing or in other situations There are many variables that will affect signal quality from the strength of cardiac signal generated by the individual being measured to clothing to the surrounding environment but the designs given here are a starting point in establishing an optimum system for a particular application infin
Find us at Booth 37310World Maker Faire New York
20
SENSOR TECHNOLOGY
SmallerThan a
Grain Sand
of
Analysts project that by
2020 there will be over
50 billion connected
devices in the now-nascent
Internet of Things (IoT) However
the technology that will enable the
IoT of the future may look a little
different than todayrsquosmdashin fact
you may not be able to see it at all
Many new mobile devices require
motion sensors in order to monitor
analyze and deliver real-time data
and analysis to improve the way
consumers interact with everyday
technology While traditional
sensor platforms require multichip
modules or stacked die within a
device mCube a new MEMS sensor
company is driving the emergence
of Sensor 30 which will lead the
development of the smallest
sensors to datemdashsmaller than a
grain of sand By EEWeb Contributing Writers
mCubersquos Sensors Enable IoMTInterview with Ben Lee President and CEO of mCube
INDUSTRY INTERVIEW
21
SmallerThan a
Grain Sand
of
Analysts project that by
2020 there will be over
50 billion connected
devices in the now-nascent
Internet of Things (IoT) However
the technology that will enable the
IoT of the future may look a little
different than todayrsquosmdashin fact
you may not be able to see it at all
Many new mobile devices require
motion sensors in order to monitor
analyze and deliver real-time data
and analysis to improve the way
consumers interact with everyday
technology While traditional
sensor platforms require multichip
modules or stacked die within a
device mCube a new MEMS sensor
company is driving the emergence
of Sensor 30 which will lead the
development of the smallest
sensors to datemdashsmaller than a
grain of sand By EEWeb Contributing Writers
mCubersquos Sensors Enable IoMTInterview with Ben Lee President and CEO of mCube
22
SENSOR TECHNOLOGY
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
INDUSTRY INTERVIEW
23
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
24
SENSOR TECHNOLOGY
Since sensors are so small and affordable donrsquot be surprised to find unique applications in the future Lee speculates that ldquofarmers might have sensor tags to monitor livestock for abnormal activity patterns of grazing potential illness and herd behaviorrdquo Commercial trucking might involve motion sensors connected to video cameras in rear-view mirrors to better assess the cause of an accident and driving conditions For shipping Lee describes ldquomotion sensors embedded directly onto packages to record jarring motions or accidents in order to determine when and how contents were damagedrdquo
As of 2014 mCubersquos complete intertial sensor portfolio contains an accelerometer magnetometer and its proprietary iGyrotrade gyroscope offering nine degrees of freedom (9DoF) Through reductions in cost power consumption and size mCubersquos sensor offerings make it possible to place them onto nearly any object or devicemdashin some cases without packaging ldquoWe aspire to put one or more MEMS motion sensors on anything that movesrdquo remarks Lee And with the IoMT taking shape and consumer expectations for connected moving devices becoming more concrete developers of new applications will turn to solutions like mCube to deliver truly cutting-edge connected devices
ldquoAt mCube we aspire to put one or more MEMS motion sensors on
anything that movesrdquo
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 15
Complete Inertial Motion Sensor Portfolio
Solutions for up to 9DoF (Degrees of Freedom)
Accelerometer
Magnetometer
iGyroTM
3DoF 3DoF
9DoF
2x2mm
3x3mm 3DoF 6DoF
14x14mm
3x3mm
3x3mm
2626
SENSOR TECHNOLOGY
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
27
TECH REPORT
27
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
2828
SENSOR TECHNOLOGY
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
29
TECH REPORT
29
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
3030
SENSOR TECHNOLOGY
to enable the kind of constant and complex data accumulation that the Biostamp promises
In the interim MC10 is partnering up with other medical and pharmaceutical companies to develop integrated sensor and monitoring products The company plans to become a certified medical-ready partner for companies who donrsquot have access to this unique and proprietary technology Even the US Army has begun working with MC10 on military-grade sensors that will add further safety features for troops in the field This funding from NIH grants Department of Defense grants as well as foundation grants will help the company get one step closer to realization of devices so flexible that users might forget theyrsquore wearing them
ldquoThe company has been bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devicesrdquo
Join the
DESIGNERS OF THINGS conference in San Francisco on
September 23 and 24
Dedicated to the explosive and exciting potential of Wearable
Tech 3D Printing and the Internet of Things the conference
provides the growing design and development community
around these technologies a meeting place to discuss and
showcase the newest products
Click here for more info
httpwwwdesignersofthingscomsanfranciscoscheduler
speakersheth-nirav-rav33310
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Sierra CircuitsA Complete PCB Resource
PLUS The Ground rdquo Myth in PrintedCircuits
ldquo
PCB Resin Reactor+
Ken BahlCEO of Sierra Circuits
Let There Be
How Cree reinvented the light bulb
LIGHT
David ElienVP of Marketing amp Business
Development Cree Inc
New LED Filament Tower
Cutting Edge Flatscreen Technologies
+
+
M o v i n g T o w a r d s
a Clean Energy
FUTUREmdash Hugo van Nispen COO of DNV KEMA
MCU Wars 32-bit MCU Comparison
Cutting Edge
SPICEModeling
Freescale and TI Embedded
Modules
ARMCortex
Programming
From Concept to
Reality Wolfgang Heinz-Fischer
Head of Marketing amp PR TQ-Group
Low-Power Design Techniques
TQ-Grouprsquos Comprehensive Design Process
+
+
PowerDeveloper
Octobe r 20 13
Designing forDurability
View more EEWeb magazinesmdash Click Here
66
SENSOR TECHNOLOGY
As the quality of output from transducers declines to meet application demands system
requirements such as measurement range accuracy speed and power consumption continue to increase squeezing the performance of sensor signal conditioning (SSC) circuits from both ends and making the task of designing them exponentially more difficult
integrity level (ASIL) for automotive applications These requirements include detection and notification of faults due to open or short circuits out-of-range parameters aging sensors and excessive temperature Additionally the SSC must be able to monitor these faults while tolerant of shorts to ground or supply voltage supply overvoltage conditions or reverse battery connections
ldquoOne of the key features of next-generation SSCs
is flexibilityrdquoldquoA highly efficient and powerful
reduced-instruction-set computer coordinates numerous control and
computational tasksrdquo
NEXT GENERATION TO THE RESCUE
In the same way increasing demands have spurred a new class of sensors Zentrum Mikroelektronik (ZMDI) is developing and introducing the next generation of SSC products and technologies to the sensor marketplace This article describes some of the most important and beneficial new features of these new SSCs
FLEXIBILITY IS A BEAUTIFUL THING
One of the key features of next-generation SSCs is flexibility The types and combinations of physical quantities measured for products are growing rapidly and new SSCs must facilitate fast development of complex sensor modules with low component counts and a user interface that is easy to learn and use This requires a signal interface that is configurable for a wide range of signals and correction algorithms that are much more complex than second or third order polynomial curve fitting offered by previous generations of SSCs For example a single application might require the conditioning of two temperature inputs one being a diode and the other a thermocouple and two resistive pressure bridges with widely varying output levels each of which require linearization and calibration
Flexibility is not limited only to signal types and ranges however Another dimension of configurability is required for the sequence of signal processing tasks Typically some signals must be acquired at a much higher rate than others and the
quantization and correction algorithms must be reconfigured quickly from one measurement to another in a programmable fashion In addition to this sometimes it is necessary to perform math operations between signals like subtracting two pressure inputs to generate a differential pressure output The SSC must generate a user-programmable sequence that samples the inputs in a defined order and rate correct each signal according to a user-defined calibration algorithm and combine the conditioned outputs into an orderly stream of data
Finally flexibility must include the number and type of output signals and protocols Reliability safety weight and noise constraints are also driving the creation of innovative new output protocols like single-edge nibble transmission (SENT) for the automotive industry Next-generation SSCs must support new interfaces like SENT along with the traditional analog one-wire and serial interfaces such as I2Ctrade and SPI In fact the SENT interface is output only and requires an auxiliary interface like I2C to configure and calibrate the SSC
Another important feature for next-generation SSCs is the ability to perform self-testing and diagnostics to meet critical safety standards like the automotive safety
I2Ctrade is a trademark of NXP
7
TECH REPORT
7
As the quality of output from transducers declines to meet application demands system
requirements such as measurement range accuracy speed and power consumption continue to increase squeezing the performance of sensor signal conditioning (SSC) circuits from both ends and making the task of designing them exponentially more difficult
integrity level (ASIL) for automotive applications These requirements include detection and notification of faults due to open or short circuits out-of-range parameters aging sensors and excessive temperature Additionally the SSC must be able to monitor these faults while tolerant of shorts to ground or supply voltage supply overvoltage conditions or reverse battery connections
ldquoOne of the key features of next-generation SSCs
is flexibilityrdquoldquoA highly efficient and powerful
reduced-instruction-set computer coordinates numerous control and
computational tasksrdquo
NEXT GENERATION TO THE RESCUE
In the same way increasing demands have spurred a new class of sensors Zentrum Mikroelektronik (ZMDI) is developing and introducing the next generation of SSC products and technologies to the sensor marketplace This article describes some of the most important and beneficial new features of these new SSCs
FLEXIBILITY IS A BEAUTIFUL THING
One of the key features of next-generation SSCs is flexibility The types and combinations of physical quantities measured for products are growing rapidly and new SSCs must facilitate fast development of complex sensor modules with low component counts and a user interface that is easy to learn and use This requires a signal interface that is configurable for a wide range of signals and correction algorithms that are much more complex than second or third order polynomial curve fitting offered by previous generations of SSCs For example a single application might require the conditioning of two temperature inputs one being a diode and the other a thermocouple and two resistive pressure bridges with widely varying output levels each of which require linearization and calibration
Flexibility is not limited only to signal types and ranges however Another dimension of configurability is required for the sequence of signal processing tasks Typically some signals must be acquired at a much higher rate than others and the
quantization and correction algorithms must be reconfigured quickly from one measurement to another in a programmable fashion In addition to this sometimes it is necessary to perform math operations between signals like subtracting two pressure inputs to generate a differential pressure output The SSC must generate a user-programmable sequence that samples the inputs in a defined order and rate correct each signal according to a user-defined calibration algorithm and combine the conditioned outputs into an orderly stream of data
Finally flexibility must include the number and type of output signals and protocols Reliability safety weight and noise constraints are also driving the creation of innovative new output protocols like single-edge nibble transmission (SENT) for the automotive industry Next-generation SSCs must support new interfaces like SENT along with the traditional analog one-wire and serial interfaces such as I2Ctrade and SPI In fact the SENT interface is output only and requires an auxiliary interface like I2C to configure and calibrate the SSC
Another important feature for next-generation SSCs is the ability to perform self-testing and diagnostics to meet critical safety standards like the automotive safety
I2Ctrade is a trademark of NXP
88
SENSOR TECHNOLOGY
PUTTING IT ALL TOGETHER
Figure 1 shows the block diagram of a next-generation SSC In this particular case the SSC supports two temperature inputsmdashone resistive one diodemdashand two resistive bridge inputs The conditioning signal chain includes sensor check and common mode (SCCM) adjustment multiplexing (MUX) programmable gain (PGA) from 1 to 200 VV and an analog to digital converter (ADC) with adjustable sample rate and resolution from 12 to 18 bits
The SSC in figure 1 looks similar to other SSCs that are presently available but most of its potential and flexibility lies in the calibration microcontroller (CMC) A highly efficient and powerful reduced instruction set computer (RISC) coordinates the numerous control and computational tasks necessary to provide the tremendous amount of flexibility required for next-generation SSCs The controller also combines the multiple output data packets into a structured stream in a wide variety of formats that can be either analog or digital
The cycle of tasks performed by the RISC engine consists of three main types measurement tasks conditioning tasks and output tasks Measurement tasks include operations that select the MUX input and signal polarities the gain and offset of the signal path the speed and resolution of the quantizer and auxiliary tasks such as auto-zeroing gain stages The output values of all the main measurement tasks are stored in registers for processing by the conditioning tasks These tasks range from simple operations like shifting and synchronization to basic math functions such as add subtract multiply and divide to complex functions such as logarithms polynomial evaluation spline curve fitting and digital filtering Output tasks include synchronization of data streams formatting packetizing encoding error detection and safety features like redundancy or inversion
The SSC shown in figure 1 provides for up to 20 measurement tasks and 62 conditioning tasks enabling thousands
of different combinations of signal processing sequences for each of the four inputs The number of output tasks varies greatly depending on the type of output but for a complex protocol like SENT the number can be in the dozens
MAKING IT EASY
However it is also vitally important that the flexibility power and complexity of next-generation SSCs do not require a commensurate level of time and resources for system designers implementing them The example shown in figure 1 is a member of a product family that is preconfigured by the manufacturer for a specific application using firmware All of the measurement conditioning and output tasks are programmed so that the designer need only focus on determining gain resolution and calibration coefficients for the correction algorithm all of which are facilitated by software that is easy to use and
Figure 1 An example block diagram of a next-generation SSC from ZMDI
ldquoOne thing that should not be flexible in next-generation
SSCs is the user interfacerdquo
consistent across the product line Special use cases can be implemented easily in firmware by the manufacturer should the need arise but the standard factory configuration will cover the majority of designs Additional family members of the product line are optimized for different numbers and types of inputs and outputs and also preconfigured for the intended application use
Finally one thing that should not be flexible in next-generation SSCs is the user interface including the physical dimensions pin or pad locations and software user interface The product family exemplified in figure 1 has a standardized footprint pinout and software user interface to minimize the costs time and resources associated with board layout calibration and climbing the learning curve
9
TECH REPORT
9
PUTTING IT ALL TOGETHER
Figure 1 shows the block diagram of a next-generation SSC In this particular case the SSC supports two temperature inputsmdashone resistive one diodemdashand two resistive bridge inputs The conditioning signal chain includes sensor check and common mode (SCCM) adjustment multiplexing (MUX) programmable gain (PGA) from 1 to 200 VV and an analog to digital converter (ADC) with adjustable sample rate and resolution from 12 to 18 bits
The SSC in figure 1 looks similar to other SSCs that are presently available but most of its potential and flexibility lies in the calibration microcontroller (CMC) A highly efficient and powerful reduced instruction set computer (RISC) coordinates the numerous control and computational tasks necessary to provide the tremendous amount of flexibility required for next-generation SSCs The controller also combines the multiple output data packets into a structured stream in a wide variety of formats that can be either analog or digital
The cycle of tasks performed by the RISC engine consists of three main types measurement tasks conditioning tasks and output tasks Measurement tasks include operations that select the MUX input and signal polarities the gain and offset of the signal path the speed and resolution of the quantizer and auxiliary tasks such as auto-zeroing gain stages The output values of all the main measurement tasks are stored in registers for processing by the conditioning tasks These tasks range from simple operations like shifting and synchronization to basic math functions such as add subtract multiply and divide to complex functions such as logarithms polynomial evaluation spline curve fitting and digital filtering Output tasks include synchronization of data streams formatting packetizing encoding error detection and safety features like redundancy or inversion
The SSC shown in figure 1 provides for up to 20 measurement tasks and 62 conditioning tasks enabling thousands
of different combinations of signal processing sequences for each of the four inputs The number of output tasks varies greatly depending on the type of output but for a complex protocol like SENT the number can be in the dozens
MAKING IT EASY
However it is also vitally important that the flexibility power and complexity of next-generation SSCs do not require a commensurate level of time and resources for system designers implementing them The example shown in figure 1 is a member of a product family that is preconfigured by the manufacturer for a specific application using firmware All of the measurement conditioning and output tasks are programmed so that the designer need only focus on determining gain resolution and calibration coefficients for the correction algorithm all of which are facilitated by software that is easy to use and
Figure 1 An example block diagram of a next-generation SSC from ZMDI
ldquoOne thing that should not be flexible in next-generation
SSCs is the user interfacerdquo
consistent across the product line Special use cases can be implemented easily in firmware by the manufacturer should the need arise but the standard factory configuration will cover the majority of designs Additional family members of the product line are optimized for different numbers and types of inputs and outputs and also preconfigured for the intended application use
Finally one thing that should not be flexible in next-generation SSCs is the user interface including the physical dimensions pin or pad locations and software user interface The product family exemplified in figure 1 has a standardized footprint pinout and software user interface to minimize the costs time and resources associated with board layout calibration and climbing the learning curve
1212
SENSOR TECHNOLOGY
The human heartbeat is arguably the single most important (ldquolife-and-deathrdquo) diagnostic indicator Thus electrocardiograms (ECGs) are one of the most significant diagnostic methods in that
they monitor heart function ECGs are not only used in a clinical setting but are increasingly seen in personal health devices Traditionally ECG measurement conductive electrodes have been applied which are directly attached to the skin With the help of contact gel (wet or solid) to ensure that there is good electrical contact between the skin and the sensor direct resistive contact is made with the patient However conventional electrodes possess various disadvantages which are not conducive for long-term use in non-clinical settings In addition to being potentially messy metal allergies can cause skin irritations and as a single-use item they are quite expensive
Non-contact ECG measurementusing EPIC Sensors
Measuring electrocardiogram (ECG) signals without skin contact is now possible using novel Electric Potential Integrated Circuit (EPIC) sensors
By Alan Lowne CEO of Saelig Co Inc
13
TECH REPORT
13
The human heartbeat is arguably the single most important (ldquolife-and-deathrdquo) diagnostic indicator Thus electrocardiograms (ECGs) are one of the most significant diagnostic methods in that
they monitor heart function ECGs are not only used in a clinical setting but are increasingly seen in personal health devices Traditionally ECG measurement conductive electrodes have been applied which are directly attached to the skin With the help of contact gel (wet or solid) to ensure that there is good electrical contact between the skin and the sensor direct resistive contact is made with the patient However conventional electrodes possess various disadvantages which are not conducive for long-term use in non-clinical settings In addition to being potentially messy metal allergies can cause skin irritations and as a single-use item they are quite expensive
Non-contact ECG measurementusing EPIC Sensors
Measuring electrocardiogram (ECG) signals without skin contact is now possible using novel Electric Potential Integrated Circuit (EPIC) sensors
By Alan Lowne CEO of Saelig Co Inc
1414
SENSOR TECHNOLOGY
Non-contact measurement of electrophysiological signals is of great interest in healthcare settings with the potential of reducing disposable costs speeding up or simplifying measurement techniques Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact Monitoring vehicle drivers for health and alertness by detecting heart rate and respiration or determining car occupancy to adjust the ride handling and air bag deployment with the varying size and location of occupants is a vast potential market
Capacitive (insulated) electrodes can register ECG signals without conductive contact to the bodyndasheven through clothesndashand represent
an attractive alternative for a wide range of new applications EPIC (Electric Potential Integrated Circuit) is a completely new sensor technology resulting from research at the University of Sussex (UK) Novel ultra high impedance EPIC sensors measure electric field changes without requiring physical or resistive contact This award winning patent-protected sensor can rapidly measure electric potential sources such as electrophysiological signals or even spatial electric fields It therefore has the ability to measure ECGs without direct skin contact By adjusting the DSP and amplification circuitry the sensors can be tuned for detection at a distance as required for differing automotive applications EPIC sensor electrodes can be easily and discretely incorporated inside car seat backs to acquire the necessary biometric data
Signals measured on the human body always include a large amount of noise the major component of this being 50 or 60 Hz power line noise capacitively-coupled to the body from the surrounding electricity supply Measurements such as ECG depend on being able to extract the small electrophysiological signals from the much larger noise signals EPIC sensors can be used in ldquocontact moderdquo for ECG measurement where the subject touches both the capacitive electrode surface and some metal at the system ground directly with the skin This ground reference allows filtering and differential amplification of signals from two sensors to be effective in removing the mains frequency noise leaving a high quality ECG signal In non-contact ECG measurement there is ndash by definition - no skin contact and thus no direct connection can be made between the subjectrsquos body and the system ground Some other method of reducing the power line noise is therefore required to
EPIC Sensors incontact with clothing
Conductive fabric in contactwith clothing eg on chair seat
Output
EPICdemo box
Figure 1 Basic configuration for non-contact ECG measurement including capacitively-oocupied DR circuit
OP-AMP
+5V
-5V
Vout
Rf (27KΩ)
Ra(11KΩ)
Rb(11KΩ)
Rp (15MΩ) To conductive fabric on chair thus capacitively coupled to body
Inputs from outputs of demo box
A
BC
(1nF)
Figure 2 DPL circuit Voltage gain is set by Rf Rp limits current fed back to the body (see text)Operational amplifier output Vout = - (VA + VB) Rf 11K
enable the ECG signal to be extracted reliably and accurately One such method utilizes an approach very similar to the ldquoDriven Right Legrdquo (DRL) system that is used for the same purpose in conventional ECG measurement techniques In conventional ECG the DRL signal is coupled directly to the patientrsquos skin The DRL signal reduces power line noise on the sensor signals by feeding back an inverted average of the signals from two sensors on to the patientrsquos body In non-contact ECG the generated DRL signal can be capacitively-coupled to the body through clothing via a piece of conductive material placed ndash for instance ndash on the seat or back of a chair Capacitive coupling of DRL signals is described by Lim et al1 and Lee et al2
SYSTEM DESIGNAn ECG system can therefore be built into a chair a mattress or clothing for instance The DRL circuit improves the sensor signalnoise ratio enormously In the example in Figure 1 EPIC sensors are mounted on a chair back such that the electrodes touch the clothing on the subjectrsquos back when resting normally against the back of the chair The generated DRL signal is connected to a piece of conductive material
placed either on the seat of the chair or at the bottom of the chair back contacting the subjectrsquos clothing in the normal sitting position Copper-coated nylon fabric is one possible material suitable for the DRL coupling material but other conductive materials may be equally successful A thin non- conductive material such as a cotton fabric may be used to cover both the sensors and the DRL coupling fabric if required for instance when building the sensors into a seat Consideration must be given as to how material will reduce the coupling capacitance between the sensor and the subject or add additional noise to the signals through static charging effectsFigure 2 shows the design of the DRL circuit It is a standard summing amplifier generating an amplified and inverted signal that is the average of the individual signals A and B
The optimum value for Rf will be dependent on the type of sensors being used as well as the clothing being worn by the subject being measured It should be set to achieve maximum noise reduction while ensuring circuit stability A value of 27kohms is suggested as a suitable starting point for EPIC sensors
15
TECH REPORT
15
Non-contact measurement of electrophysiological signals is of great interest in healthcare settings with the potential of reducing disposable costs speeding up or simplifying measurement techniques Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact Monitoring vehicle drivers for health and alertness by detecting heart rate and respiration or determining car occupancy to adjust the ride handling and air bag deployment with the varying size and location of occupants is a vast potential market
Capacitive (insulated) electrodes can register ECG signals without conductive contact to the bodyndasheven through clothesndashand represent
an attractive alternative for a wide range of new applications EPIC (Electric Potential Integrated Circuit) is a completely new sensor technology resulting from research at the University of Sussex (UK) Novel ultra high impedance EPIC sensors measure electric field changes without requiring physical or resistive contact This award winning patent-protected sensor can rapidly measure electric potential sources such as electrophysiological signals or even spatial electric fields It therefore has the ability to measure ECGs without direct skin contact By adjusting the DSP and amplification circuitry the sensors can be tuned for detection at a distance as required for differing automotive applications EPIC sensor electrodes can be easily and discretely incorporated inside car seat backs to acquire the necessary biometric data
Signals measured on the human body always include a large amount of noise the major component of this being 50 or 60 Hz power line noise capacitively-coupled to the body from the surrounding electricity supply Measurements such as ECG depend on being able to extract the small electrophysiological signals from the much larger noise signals EPIC sensors can be used in ldquocontact moderdquo for ECG measurement where the subject touches both the capacitive electrode surface and some metal at the system ground directly with the skin This ground reference allows filtering and differential amplification of signals from two sensors to be effective in removing the mains frequency noise leaving a high quality ECG signal In non-contact ECG measurement there is ndash by definition - no skin contact and thus no direct connection can be made between the subjectrsquos body and the system ground Some other method of reducing the power line noise is therefore required to
EPIC Sensors incontact with clothing
Conductive fabric in contactwith clothing eg on chair seat
Output
EPICdemo box
Figure 1 Basic configuration for non-contact ECG measurement including capacitively-oocupied DR circuit
OP-AMP
+5V
-5V
Vout
Rf (27KΩ)
Ra(11KΩ)
Rb(11KΩ)
Rp (15MΩ) To conductive fabric on chair thus capacitively coupled to body
Inputs from outputs of demo box
A
BC
(1nF)
Figure 2 DPL circuit Voltage gain is set by Rf Rp limits current fed back to the body (see text)Operational amplifier output Vout = - (VA + VB) Rf 11K
enable the ECG signal to be extracted reliably and accurately One such method utilizes an approach very similar to the ldquoDriven Right Legrdquo (DRL) system that is used for the same purpose in conventional ECG measurement techniques In conventional ECG the DRL signal is coupled directly to the patientrsquos skin The DRL signal reduces power line noise on the sensor signals by feeding back an inverted average of the signals from two sensors on to the patientrsquos body In non-contact ECG the generated DRL signal can be capacitively-coupled to the body through clothing via a piece of conductive material placed ndash for instance ndash on the seat or back of a chair Capacitive coupling of DRL signals is described by Lim et al1 and Lee et al2
SYSTEM DESIGNAn ECG system can therefore be built into a chair a mattress or clothing for instance The DRL circuit improves the sensor signalnoise ratio enormously In the example in Figure 1 EPIC sensors are mounted on a chair back such that the electrodes touch the clothing on the subjectrsquos back when resting normally against the back of the chair The generated DRL signal is connected to a piece of conductive material
placed either on the seat of the chair or at the bottom of the chair back contacting the subjectrsquos clothing in the normal sitting position Copper-coated nylon fabric is one possible material suitable for the DRL coupling material but other conductive materials may be equally successful A thin non- conductive material such as a cotton fabric may be used to cover both the sensors and the DRL coupling fabric if required for instance when building the sensors into a seat Consideration must be given as to how material will reduce the coupling capacitance between the sensor and the subject or add additional noise to the signals through static charging effectsFigure 2 shows the design of the DRL circuit It is a standard summing amplifier generating an amplified and inverted signal that is the average of the individual signals A and B
The optimum value for Rf will be dependent on the type of sensors being used as well as the clothing being worn by the subject being measured It should be set to achieve maximum noise reduction while ensuring circuit stability A value of 27kohms is suggested as a suitable starting point for EPIC sensors
1616
SENSOR TECHNOLOGY
Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact
7660SwitchedCapacitorVoltage
Converter
1
2
3
4
8
7
6
5
OP-AMP
Rb(11K)
Ra(11K)
Rf (27KΩ)
Rp (15MΩ)DRLOutput
1nFVout
6Vbatterypack4xAA
+6V
-6V10microF
10microF
A
B
Figure 3 DRL circuit including battery power supply and voltage converter to provide -6v rail Inputs A and B are buffered outputs from the sensors and may be taken from the A and B outputs of the EPIC demo box Ground should be connected to the sensor 0V the shielding of the BNC A and B outputs on the demo box being a suitable connection point See figure 2 and the text for further comments on the DRL design
sensors and the DRL circuit into saturation Because the system contains some large impedances and hence has some very long RC time constants settling times of tens of seconds can be needed before a clean ECG signal is seen During this period the signal can either appear very noisy or be virtually flat depending on whether one or both sensors or the DRL circuit are ldquorailingrdquo The subject should sit still during this time and wait for the circuit to settle since continually adjusting position will only make matters worse Settling times can sometimes be reduced by turning off the power to the demo box for a few seconds
CLOTHINGGood results can be obtained with one or two layers of cotton material between the sensors and the skin Other materials including a wool-mix sweater and a polyester fleece in addition
to two layers of cotton material have been successful Examples are shown in Figures 6 and 7 If the key greatest interest is in the ldquoR-Rrdquo interval adjusting filter settings to reduce or re-center the signal bandwidth can give improved signal quality
STATICBecause there is no direct physical contact between the subject and any grounding point there is no path for any static build up to be discharged Under most circumstances static build-up does not present a problem butdepending on factors including clothing footwear flooring humidity levels in the air and so forth static build up can sometimes prevent the cardiac signal from being seen clearly Product design must take into account a discharge to the system ground to remove the static charge
Rp the protection resistor is included to limit the current that can be fed back to the human body This resistor is essential in ensuring that the subjectrsquos wellbeing is not endangered and must not be omitted
IMPLEMENTATIONThe demonstration of non-contact ECG is best performed using an EPIC demonstration kit Plessey part no PS25003 which includes the necessary drive circuitry and switchable 50Hz and 60Hz notch filters The inputs to the DRL circuit can be taken from the BNC outputs ldquoA amp Brdquo on the front of the demo box The DRL circuit will require its own bipolar power supply plusmn5V or plusmn6V is suggested A circuit design including a battery power supply is shown in Figure 3
Plesseyrsquos compact sensors (PS2520x) and disc sensors (PS25101) provide equally good results although for demonstration purposes disc sensors are simplest to fix to a chair to make contact with the occupantrsquos back Compact sensors are recommended when designing a custom-built system
EPIC sensors which are designed for contact electrophysiology sensing give excellent results in most cases Initial trials suggest that custom modifications to the sensor design (eg lower gain and higher input impedance) can offer increased sensitivity and the ability to detect weaker ECG signalsThe shape of the measured ECG trace ndash in terms of relative magnitudes of the P Q R S and T waves ndash will depend on the positioning of the sensors behind the subjectrsquos back If the desire is only to measure the ldquoR-Rrdquo interval to determine heart rate then the positioning of the sensors is not critical Placing one sensor either side of the spine separated by 6rdquo -10rdquo (15-25 cm) at approximately the same height as the heart is recommended as a starting point For applications where signals from other parts of the cardiac cycle are required the user should refer to texts on bio-electronic signals for guidance on sensor position
SETTLING TIMEWhen a subject first sits in the chair and leans against the EPIC sensors the changes in electric potential will normally send both the
17
TECH REPORT
17
Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact
7660SwitchedCapacitorVoltage
Converter
1
2
3
4
8
7
6
5
OP-AMP
Rb(11K)
Ra(11K)
Rf (27KΩ)
Rp (15MΩ)DRLOutput
1nFVout
6Vbatterypack4xAA
+6V
-6V10microF
10microF
A
B
Figure 3 DRL circuit including battery power supply and voltage converter to provide -6v rail Inputs A and B are buffered outputs from the sensors and may be taken from the A and B outputs of the EPIC demo box Ground should be connected to the sensor 0V the shielding of the BNC A and B outputs on the demo box being a suitable connection point See figure 2 and the text for further comments on the DRL design
sensors and the DRL circuit into saturation Because the system contains some large impedances and hence has some very long RC time constants settling times of tens of seconds can be needed before a clean ECG signal is seen During this period the signal can either appear very noisy or be virtually flat depending on whether one or both sensors or the DRL circuit are ldquorailingrdquo The subject should sit still during this time and wait for the circuit to settle since continually adjusting position will only make matters worse Settling times can sometimes be reduced by turning off the power to the demo box for a few seconds
CLOTHINGGood results can be obtained with one or two layers of cotton material between the sensors and the skin Other materials including a wool-mix sweater and a polyester fleece in addition
to two layers of cotton material have been successful Examples are shown in Figures 6 and 7 If the key greatest interest is in the ldquoR-Rrdquo interval adjusting filter settings to reduce or re-center the signal bandwidth can give improved signal quality
STATICBecause there is no direct physical contact between the subject and any grounding point there is no path for any static build up to be discharged Under most circumstances static build-up does not present a problem butdepending on factors including clothing footwear flooring humidity levels in the air and so forth static build up can sometimes prevent the cardiac signal from being seen clearly Product design must take into account a discharge to the system ground to remove the static charge
Rp the protection resistor is included to limit the current that can be fed back to the human body This resistor is essential in ensuring that the subjectrsquos wellbeing is not endangered and must not be omitted
IMPLEMENTATIONThe demonstration of non-contact ECG is best performed using an EPIC demonstration kit Plessey part no PS25003 which includes the necessary drive circuitry and switchable 50Hz and 60Hz notch filters The inputs to the DRL circuit can be taken from the BNC outputs ldquoA amp Brdquo on the front of the demo box The DRL circuit will require its own bipolar power supply plusmn5V or plusmn6V is suggested A circuit design including a battery power supply is shown in Figure 3
Plesseyrsquos compact sensors (PS2520x) and disc sensors (PS25101) provide equally good results although for demonstration purposes disc sensors are simplest to fix to a chair to make contact with the occupantrsquos back Compact sensors are recommended when designing a custom-built system
EPIC sensors which are designed for contact electrophysiology sensing give excellent results in most cases Initial trials suggest that custom modifications to the sensor design (eg lower gain and higher input impedance) can offer increased sensitivity and the ability to detect weaker ECG signalsThe shape of the measured ECG trace ndash in terms of relative magnitudes of the P Q R S and T waves ndash will depend on the positioning of the sensors behind the subjectrsquos back If the desire is only to measure the ldquoR-Rrdquo interval to determine heart rate then the positioning of the sensors is not critical Placing one sensor either side of the spine separated by 6rdquo -10rdquo (15-25 cm) at approximately the same height as the heart is recommended as a starting point For applications where signals from other parts of the cardiac cycle are required the user should refer to texts on bio-electronic signals for guidance on sensor position
SETTLING TIMEWhen a subject first sits in the chair and leans against the EPIC sensors the changes in electric potential will normally send both the
1818
SENSOR TECHNOLOGY
Figure 4 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit HP filter corner frequency is 50mHz LP filter in demo box has corner frequency of 30Hz
Figure 6 ECG signals measured from a subject wearing a wool-mix sweater over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 8-25Hz The heart rate can be easily extracted
Figure 5 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit Software filters limit the bandwidth to 8-25Hz
Figure 7 ECG signals measured from a subject wearing a polyester fleece over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 16-40Hz The heart rate can be easily extracted
CABLE SHIELDINGCareful shielding is necessary to reduce unwanted noise artifacts Grounding the shielding of the sensor cable via the connection between the outer casing of the sensor plugs and the metal surround of the socket on the control electronics is recommended
CONCLUSIONEPIC sensors can be used to measure ECG signals without physical skin contact While
sensors can be embedded in a chair or seat the techniques are equally applicable to sensors mounted on a mattress in clothing or in other situations There are many variables that will affect signal quality from the strength of cardiac signal generated by the individual being measured to clothing to the surrounding environment but the designs given here are a starting point in establishing an optimum system for a particular application infin
Find us at Booth 37310World Maker Faire New York
Figure 4 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit HP filter corner frequency is 50mHz LP filter in demo box has corner frequency of 30Hz
Figure 6 ECG signals measured from a subject wearing a wool-mix sweater over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 8-25Hz The heart rate can be easily extracted
Figure 5 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit Software filters limit the bandwidth to 8-25Hz
Figure 7 ECG signals measured from a subject wearing a polyester fleece over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 16-40Hz The heart rate can be easily extracted
CABLE SHIELDINGCareful shielding is necessary to reduce unwanted noise artifacts Grounding the shielding of the sensor cable via the connection between the outer casing of the sensor plugs and the metal surround of the socket on the control electronics is recommended
CONCLUSIONEPIC sensors can be used to measure ECG signals without physical skin contact While
sensors can be embedded in a chair or seat the techniques are equally applicable to sensors mounted on a mattress in clothing or in other situations There are many variables that will affect signal quality from the strength of cardiac signal generated by the individual being measured to clothing to the surrounding environment but the designs given here are a starting point in establishing an optimum system for a particular application infin
Find us at Booth 37310World Maker Faire New York
20
SENSOR TECHNOLOGY
SmallerThan a
Grain Sand
of
Analysts project that by
2020 there will be over
50 billion connected
devices in the now-nascent
Internet of Things (IoT) However
the technology that will enable the
IoT of the future may look a little
different than todayrsquosmdashin fact
you may not be able to see it at all
Many new mobile devices require
motion sensors in order to monitor
analyze and deliver real-time data
and analysis to improve the way
consumers interact with everyday
technology While traditional
sensor platforms require multichip
modules or stacked die within a
device mCube a new MEMS sensor
company is driving the emergence
of Sensor 30 which will lead the
development of the smallest
sensors to datemdashsmaller than a
grain of sand By EEWeb Contributing Writers
mCubersquos Sensors Enable IoMTInterview with Ben Lee President and CEO of mCube
INDUSTRY INTERVIEW
21
SmallerThan a
Grain Sand
of
Analysts project that by
2020 there will be over
50 billion connected
devices in the now-nascent
Internet of Things (IoT) However
the technology that will enable the
IoT of the future may look a little
different than todayrsquosmdashin fact
you may not be able to see it at all
Many new mobile devices require
motion sensors in order to monitor
analyze and deliver real-time data
and analysis to improve the way
consumers interact with everyday
technology While traditional
sensor platforms require multichip
modules or stacked die within a
device mCube a new MEMS sensor
company is driving the emergence
of Sensor 30 which will lead the
development of the smallest
sensors to datemdashsmaller than a
grain of sand By EEWeb Contributing Writers
mCubersquos Sensors Enable IoMTInterview with Ben Lee President and CEO of mCube
22
SENSOR TECHNOLOGY
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
INDUSTRY INTERVIEW
23
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
24
SENSOR TECHNOLOGY
Since sensors are so small and affordable donrsquot be surprised to find unique applications in the future Lee speculates that ldquofarmers might have sensor tags to monitor livestock for abnormal activity patterns of grazing potential illness and herd behaviorrdquo Commercial trucking might involve motion sensors connected to video cameras in rear-view mirrors to better assess the cause of an accident and driving conditions For shipping Lee describes ldquomotion sensors embedded directly onto packages to record jarring motions or accidents in order to determine when and how contents were damagedrdquo
As of 2014 mCubersquos complete intertial sensor portfolio contains an accelerometer magnetometer and its proprietary iGyrotrade gyroscope offering nine degrees of freedom (9DoF) Through reductions in cost power consumption and size mCubersquos sensor offerings make it possible to place them onto nearly any object or devicemdashin some cases without packaging ldquoWe aspire to put one or more MEMS motion sensors on anything that movesrdquo remarks Lee And with the IoMT taking shape and consumer expectations for connected moving devices becoming more concrete developers of new applications will turn to solutions like mCube to deliver truly cutting-edge connected devices
ldquoAt mCube we aspire to put one or more MEMS motion sensors on
anything that movesrdquo
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 15
Complete Inertial Motion Sensor Portfolio
Solutions for up to 9DoF (Degrees of Freedom)
Accelerometer
Magnetometer
iGyroTM
3DoF 3DoF
9DoF
2x2mm
3x3mm 3DoF 6DoF
14x14mm
3x3mm
3x3mm
2626
SENSOR TECHNOLOGY
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
27
TECH REPORT
27
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
2828
SENSOR TECHNOLOGY
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
29
TECH REPORT
29
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
3030
SENSOR TECHNOLOGY
to enable the kind of constant and complex data accumulation that the Biostamp promises
In the interim MC10 is partnering up with other medical and pharmaceutical companies to develop integrated sensor and monitoring products The company plans to become a certified medical-ready partner for companies who donrsquot have access to this unique and proprietary technology Even the US Army has begun working with MC10 on military-grade sensors that will add further safety features for troops in the field This funding from NIH grants Department of Defense grants as well as foundation grants will help the company get one step closer to realization of devices so flexible that users might forget theyrsquore wearing them
ldquoThe company has been bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devicesrdquo
Join the
DESIGNERS OF THINGS conference in San Francisco on
September 23 and 24
Dedicated to the explosive and exciting potential of Wearable
Tech 3D Printing and the Internet of Things the conference
provides the growing design and development community
around these technologies a meeting place to discuss and
showcase the newest products
Click here for more info
httpwwwdesignersofthingscomsanfranciscoscheduler
speakersheth-nirav-rav33310
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Sierra CircuitsA Complete PCB Resource
PLUS The Ground rdquo Myth in PrintedCircuits
ldquo
PCB Resin Reactor+
Ken BahlCEO of Sierra Circuits
Let There Be
How Cree reinvented the light bulb
LIGHT
David ElienVP of Marketing amp Business
Development Cree Inc
New LED Filament Tower
Cutting Edge Flatscreen Technologies
+
+
M o v i n g T o w a r d s
a Clean Energy
FUTUREmdash Hugo van Nispen COO of DNV KEMA
MCU Wars 32-bit MCU Comparison
Cutting Edge
SPICEModeling
Freescale and TI Embedded
Modules
ARMCortex
Programming
From Concept to
Reality Wolfgang Heinz-Fischer
Head of Marketing amp PR TQ-Group
Low-Power Design Techniques
TQ-Grouprsquos Comprehensive Design Process
+
+
PowerDeveloper
Octobe r 20 13
Designing forDurability
View more EEWeb magazinesmdash Click Here
7
TECH REPORT
7
As the quality of output from transducers declines to meet application demands system
requirements such as measurement range accuracy speed and power consumption continue to increase squeezing the performance of sensor signal conditioning (SSC) circuits from both ends and making the task of designing them exponentially more difficult
integrity level (ASIL) for automotive applications These requirements include detection and notification of faults due to open or short circuits out-of-range parameters aging sensors and excessive temperature Additionally the SSC must be able to monitor these faults while tolerant of shorts to ground or supply voltage supply overvoltage conditions or reverse battery connections
ldquoOne of the key features of next-generation SSCs
is flexibilityrdquoldquoA highly efficient and powerful
reduced-instruction-set computer coordinates numerous control and
computational tasksrdquo
NEXT GENERATION TO THE RESCUE
In the same way increasing demands have spurred a new class of sensors Zentrum Mikroelektronik (ZMDI) is developing and introducing the next generation of SSC products and technologies to the sensor marketplace This article describes some of the most important and beneficial new features of these new SSCs
FLEXIBILITY IS A BEAUTIFUL THING
One of the key features of next-generation SSCs is flexibility The types and combinations of physical quantities measured for products are growing rapidly and new SSCs must facilitate fast development of complex sensor modules with low component counts and a user interface that is easy to learn and use This requires a signal interface that is configurable for a wide range of signals and correction algorithms that are much more complex than second or third order polynomial curve fitting offered by previous generations of SSCs For example a single application might require the conditioning of two temperature inputs one being a diode and the other a thermocouple and two resistive pressure bridges with widely varying output levels each of which require linearization and calibration
Flexibility is not limited only to signal types and ranges however Another dimension of configurability is required for the sequence of signal processing tasks Typically some signals must be acquired at a much higher rate than others and the
quantization and correction algorithms must be reconfigured quickly from one measurement to another in a programmable fashion In addition to this sometimes it is necessary to perform math operations between signals like subtracting two pressure inputs to generate a differential pressure output The SSC must generate a user-programmable sequence that samples the inputs in a defined order and rate correct each signal according to a user-defined calibration algorithm and combine the conditioned outputs into an orderly stream of data
Finally flexibility must include the number and type of output signals and protocols Reliability safety weight and noise constraints are also driving the creation of innovative new output protocols like single-edge nibble transmission (SENT) for the automotive industry Next-generation SSCs must support new interfaces like SENT along with the traditional analog one-wire and serial interfaces such as I2Ctrade and SPI In fact the SENT interface is output only and requires an auxiliary interface like I2C to configure and calibrate the SSC
Another important feature for next-generation SSCs is the ability to perform self-testing and diagnostics to meet critical safety standards like the automotive safety
I2Ctrade is a trademark of NXP
88
SENSOR TECHNOLOGY
PUTTING IT ALL TOGETHER
Figure 1 shows the block diagram of a next-generation SSC In this particular case the SSC supports two temperature inputsmdashone resistive one diodemdashand two resistive bridge inputs The conditioning signal chain includes sensor check and common mode (SCCM) adjustment multiplexing (MUX) programmable gain (PGA) from 1 to 200 VV and an analog to digital converter (ADC) with adjustable sample rate and resolution from 12 to 18 bits
The SSC in figure 1 looks similar to other SSCs that are presently available but most of its potential and flexibility lies in the calibration microcontroller (CMC) A highly efficient and powerful reduced instruction set computer (RISC) coordinates the numerous control and computational tasks necessary to provide the tremendous amount of flexibility required for next-generation SSCs The controller also combines the multiple output data packets into a structured stream in a wide variety of formats that can be either analog or digital
The cycle of tasks performed by the RISC engine consists of three main types measurement tasks conditioning tasks and output tasks Measurement tasks include operations that select the MUX input and signal polarities the gain and offset of the signal path the speed and resolution of the quantizer and auxiliary tasks such as auto-zeroing gain stages The output values of all the main measurement tasks are stored in registers for processing by the conditioning tasks These tasks range from simple operations like shifting and synchronization to basic math functions such as add subtract multiply and divide to complex functions such as logarithms polynomial evaluation spline curve fitting and digital filtering Output tasks include synchronization of data streams formatting packetizing encoding error detection and safety features like redundancy or inversion
The SSC shown in figure 1 provides for up to 20 measurement tasks and 62 conditioning tasks enabling thousands
of different combinations of signal processing sequences for each of the four inputs The number of output tasks varies greatly depending on the type of output but for a complex protocol like SENT the number can be in the dozens
MAKING IT EASY
However it is also vitally important that the flexibility power and complexity of next-generation SSCs do not require a commensurate level of time and resources for system designers implementing them The example shown in figure 1 is a member of a product family that is preconfigured by the manufacturer for a specific application using firmware All of the measurement conditioning and output tasks are programmed so that the designer need only focus on determining gain resolution and calibration coefficients for the correction algorithm all of which are facilitated by software that is easy to use and
Figure 1 An example block diagram of a next-generation SSC from ZMDI
ldquoOne thing that should not be flexible in next-generation
SSCs is the user interfacerdquo
consistent across the product line Special use cases can be implemented easily in firmware by the manufacturer should the need arise but the standard factory configuration will cover the majority of designs Additional family members of the product line are optimized for different numbers and types of inputs and outputs and also preconfigured for the intended application use
Finally one thing that should not be flexible in next-generation SSCs is the user interface including the physical dimensions pin or pad locations and software user interface The product family exemplified in figure 1 has a standardized footprint pinout and software user interface to minimize the costs time and resources associated with board layout calibration and climbing the learning curve
9
TECH REPORT
9
PUTTING IT ALL TOGETHER
Figure 1 shows the block diagram of a next-generation SSC In this particular case the SSC supports two temperature inputsmdashone resistive one diodemdashand two resistive bridge inputs The conditioning signal chain includes sensor check and common mode (SCCM) adjustment multiplexing (MUX) programmable gain (PGA) from 1 to 200 VV and an analog to digital converter (ADC) with adjustable sample rate and resolution from 12 to 18 bits
The SSC in figure 1 looks similar to other SSCs that are presently available but most of its potential and flexibility lies in the calibration microcontroller (CMC) A highly efficient and powerful reduced instruction set computer (RISC) coordinates the numerous control and computational tasks necessary to provide the tremendous amount of flexibility required for next-generation SSCs The controller also combines the multiple output data packets into a structured stream in a wide variety of formats that can be either analog or digital
The cycle of tasks performed by the RISC engine consists of three main types measurement tasks conditioning tasks and output tasks Measurement tasks include operations that select the MUX input and signal polarities the gain and offset of the signal path the speed and resolution of the quantizer and auxiliary tasks such as auto-zeroing gain stages The output values of all the main measurement tasks are stored in registers for processing by the conditioning tasks These tasks range from simple operations like shifting and synchronization to basic math functions such as add subtract multiply and divide to complex functions such as logarithms polynomial evaluation spline curve fitting and digital filtering Output tasks include synchronization of data streams formatting packetizing encoding error detection and safety features like redundancy or inversion
The SSC shown in figure 1 provides for up to 20 measurement tasks and 62 conditioning tasks enabling thousands
of different combinations of signal processing sequences for each of the four inputs The number of output tasks varies greatly depending on the type of output but for a complex protocol like SENT the number can be in the dozens
MAKING IT EASY
However it is also vitally important that the flexibility power and complexity of next-generation SSCs do not require a commensurate level of time and resources for system designers implementing them The example shown in figure 1 is a member of a product family that is preconfigured by the manufacturer for a specific application using firmware All of the measurement conditioning and output tasks are programmed so that the designer need only focus on determining gain resolution and calibration coefficients for the correction algorithm all of which are facilitated by software that is easy to use and
Figure 1 An example block diagram of a next-generation SSC from ZMDI
ldquoOne thing that should not be flexible in next-generation
SSCs is the user interfacerdquo
consistent across the product line Special use cases can be implemented easily in firmware by the manufacturer should the need arise but the standard factory configuration will cover the majority of designs Additional family members of the product line are optimized for different numbers and types of inputs and outputs and also preconfigured for the intended application use
Finally one thing that should not be flexible in next-generation SSCs is the user interface including the physical dimensions pin or pad locations and software user interface The product family exemplified in figure 1 has a standardized footprint pinout and software user interface to minimize the costs time and resources associated with board layout calibration and climbing the learning curve
1212
SENSOR TECHNOLOGY
The human heartbeat is arguably the single most important (ldquolife-and-deathrdquo) diagnostic indicator Thus electrocardiograms (ECGs) are one of the most significant diagnostic methods in that
they monitor heart function ECGs are not only used in a clinical setting but are increasingly seen in personal health devices Traditionally ECG measurement conductive electrodes have been applied which are directly attached to the skin With the help of contact gel (wet or solid) to ensure that there is good electrical contact between the skin and the sensor direct resistive contact is made with the patient However conventional electrodes possess various disadvantages which are not conducive for long-term use in non-clinical settings In addition to being potentially messy metal allergies can cause skin irritations and as a single-use item they are quite expensive
Non-contact ECG measurementusing EPIC Sensors
Measuring electrocardiogram (ECG) signals without skin contact is now possible using novel Electric Potential Integrated Circuit (EPIC) sensors
By Alan Lowne CEO of Saelig Co Inc
13
TECH REPORT
13
The human heartbeat is arguably the single most important (ldquolife-and-deathrdquo) diagnostic indicator Thus electrocardiograms (ECGs) are one of the most significant diagnostic methods in that
they monitor heart function ECGs are not only used in a clinical setting but are increasingly seen in personal health devices Traditionally ECG measurement conductive electrodes have been applied which are directly attached to the skin With the help of contact gel (wet or solid) to ensure that there is good electrical contact between the skin and the sensor direct resistive contact is made with the patient However conventional electrodes possess various disadvantages which are not conducive for long-term use in non-clinical settings In addition to being potentially messy metal allergies can cause skin irritations and as a single-use item they are quite expensive
Non-contact ECG measurementusing EPIC Sensors
Measuring electrocardiogram (ECG) signals without skin contact is now possible using novel Electric Potential Integrated Circuit (EPIC) sensors
By Alan Lowne CEO of Saelig Co Inc
1414
SENSOR TECHNOLOGY
Non-contact measurement of electrophysiological signals is of great interest in healthcare settings with the potential of reducing disposable costs speeding up or simplifying measurement techniques Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact Monitoring vehicle drivers for health and alertness by detecting heart rate and respiration or determining car occupancy to adjust the ride handling and air bag deployment with the varying size and location of occupants is a vast potential market
Capacitive (insulated) electrodes can register ECG signals without conductive contact to the bodyndasheven through clothesndashand represent
an attractive alternative for a wide range of new applications EPIC (Electric Potential Integrated Circuit) is a completely new sensor technology resulting from research at the University of Sussex (UK) Novel ultra high impedance EPIC sensors measure electric field changes without requiring physical or resistive contact This award winning patent-protected sensor can rapidly measure electric potential sources such as electrophysiological signals or even spatial electric fields It therefore has the ability to measure ECGs without direct skin contact By adjusting the DSP and amplification circuitry the sensors can be tuned for detection at a distance as required for differing automotive applications EPIC sensor electrodes can be easily and discretely incorporated inside car seat backs to acquire the necessary biometric data
Signals measured on the human body always include a large amount of noise the major component of this being 50 or 60 Hz power line noise capacitively-coupled to the body from the surrounding electricity supply Measurements such as ECG depend on being able to extract the small electrophysiological signals from the much larger noise signals EPIC sensors can be used in ldquocontact moderdquo for ECG measurement where the subject touches both the capacitive electrode surface and some metal at the system ground directly with the skin This ground reference allows filtering and differential amplification of signals from two sensors to be effective in removing the mains frequency noise leaving a high quality ECG signal In non-contact ECG measurement there is ndash by definition - no skin contact and thus no direct connection can be made between the subjectrsquos body and the system ground Some other method of reducing the power line noise is therefore required to
EPIC Sensors incontact with clothing
Conductive fabric in contactwith clothing eg on chair seat
Output
EPICdemo box
Figure 1 Basic configuration for non-contact ECG measurement including capacitively-oocupied DR circuit
OP-AMP
+5V
-5V
Vout
Rf (27KΩ)
Ra(11KΩ)
Rb(11KΩ)
Rp (15MΩ) To conductive fabric on chair thus capacitively coupled to body
Inputs from outputs of demo box
A
BC
(1nF)
Figure 2 DPL circuit Voltage gain is set by Rf Rp limits current fed back to the body (see text)Operational amplifier output Vout = - (VA + VB) Rf 11K
enable the ECG signal to be extracted reliably and accurately One such method utilizes an approach very similar to the ldquoDriven Right Legrdquo (DRL) system that is used for the same purpose in conventional ECG measurement techniques In conventional ECG the DRL signal is coupled directly to the patientrsquos skin The DRL signal reduces power line noise on the sensor signals by feeding back an inverted average of the signals from two sensors on to the patientrsquos body In non-contact ECG the generated DRL signal can be capacitively-coupled to the body through clothing via a piece of conductive material placed ndash for instance ndash on the seat or back of a chair Capacitive coupling of DRL signals is described by Lim et al1 and Lee et al2
SYSTEM DESIGNAn ECG system can therefore be built into a chair a mattress or clothing for instance The DRL circuit improves the sensor signalnoise ratio enormously In the example in Figure 1 EPIC sensors are mounted on a chair back such that the electrodes touch the clothing on the subjectrsquos back when resting normally against the back of the chair The generated DRL signal is connected to a piece of conductive material
placed either on the seat of the chair or at the bottom of the chair back contacting the subjectrsquos clothing in the normal sitting position Copper-coated nylon fabric is one possible material suitable for the DRL coupling material but other conductive materials may be equally successful A thin non- conductive material such as a cotton fabric may be used to cover both the sensors and the DRL coupling fabric if required for instance when building the sensors into a seat Consideration must be given as to how material will reduce the coupling capacitance between the sensor and the subject or add additional noise to the signals through static charging effectsFigure 2 shows the design of the DRL circuit It is a standard summing amplifier generating an amplified and inverted signal that is the average of the individual signals A and B
The optimum value for Rf will be dependent on the type of sensors being used as well as the clothing being worn by the subject being measured It should be set to achieve maximum noise reduction while ensuring circuit stability A value of 27kohms is suggested as a suitable starting point for EPIC sensors
15
TECH REPORT
15
Non-contact measurement of electrophysiological signals is of great interest in healthcare settings with the potential of reducing disposable costs speeding up or simplifying measurement techniques Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact Monitoring vehicle drivers for health and alertness by detecting heart rate and respiration or determining car occupancy to adjust the ride handling and air bag deployment with the varying size and location of occupants is a vast potential market
Capacitive (insulated) electrodes can register ECG signals without conductive contact to the bodyndasheven through clothesndashand represent
an attractive alternative for a wide range of new applications EPIC (Electric Potential Integrated Circuit) is a completely new sensor technology resulting from research at the University of Sussex (UK) Novel ultra high impedance EPIC sensors measure electric field changes without requiring physical or resistive contact This award winning patent-protected sensor can rapidly measure electric potential sources such as electrophysiological signals or even spatial electric fields It therefore has the ability to measure ECGs without direct skin contact By adjusting the DSP and amplification circuitry the sensors can be tuned for detection at a distance as required for differing automotive applications EPIC sensor electrodes can be easily and discretely incorporated inside car seat backs to acquire the necessary biometric data
Signals measured on the human body always include a large amount of noise the major component of this being 50 or 60 Hz power line noise capacitively-coupled to the body from the surrounding electricity supply Measurements such as ECG depend on being able to extract the small electrophysiological signals from the much larger noise signals EPIC sensors can be used in ldquocontact moderdquo for ECG measurement where the subject touches both the capacitive electrode surface and some metal at the system ground directly with the skin This ground reference allows filtering and differential amplification of signals from two sensors to be effective in removing the mains frequency noise leaving a high quality ECG signal In non-contact ECG measurement there is ndash by definition - no skin contact and thus no direct connection can be made between the subjectrsquos body and the system ground Some other method of reducing the power line noise is therefore required to
EPIC Sensors incontact with clothing
Conductive fabric in contactwith clothing eg on chair seat
Output
EPICdemo box
Figure 1 Basic configuration for non-contact ECG measurement including capacitively-oocupied DR circuit
OP-AMP
+5V
-5V
Vout
Rf (27KΩ)
Ra(11KΩ)
Rb(11KΩ)
Rp (15MΩ) To conductive fabric on chair thus capacitively coupled to body
Inputs from outputs of demo box
A
BC
(1nF)
Figure 2 DPL circuit Voltage gain is set by Rf Rp limits current fed back to the body (see text)Operational amplifier output Vout = - (VA + VB) Rf 11K
enable the ECG signal to be extracted reliably and accurately One such method utilizes an approach very similar to the ldquoDriven Right Legrdquo (DRL) system that is used for the same purpose in conventional ECG measurement techniques In conventional ECG the DRL signal is coupled directly to the patientrsquos skin The DRL signal reduces power line noise on the sensor signals by feeding back an inverted average of the signals from two sensors on to the patientrsquos body In non-contact ECG the generated DRL signal can be capacitively-coupled to the body through clothing via a piece of conductive material placed ndash for instance ndash on the seat or back of a chair Capacitive coupling of DRL signals is described by Lim et al1 and Lee et al2
SYSTEM DESIGNAn ECG system can therefore be built into a chair a mattress or clothing for instance The DRL circuit improves the sensor signalnoise ratio enormously In the example in Figure 1 EPIC sensors are mounted on a chair back such that the electrodes touch the clothing on the subjectrsquos back when resting normally against the back of the chair The generated DRL signal is connected to a piece of conductive material
placed either on the seat of the chair or at the bottom of the chair back contacting the subjectrsquos clothing in the normal sitting position Copper-coated nylon fabric is one possible material suitable for the DRL coupling material but other conductive materials may be equally successful A thin non- conductive material such as a cotton fabric may be used to cover both the sensors and the DRL coupling fabric if required for instance when building the sensors into a seat Consideration must be given as to how material will reduce the coupling capacitance between the sensor and the subject or add additional noise to the signals through static charging effectsFigure 2 shows the design of the DRL circuit It is a standard summing amplifier generating an amplified and inverted signal that is the average of the individual signals A and B
The optimum value for Rf will be dependent on the type of sensors being used as well as the clothing being worn by the subject being measured It should be set to achieve maximum noise reduction while ensuring circuit stability A value of 27kohms is suggested as a suitable starting point for EPIC sensors
1616
SENSOR TECHNOLOGY
Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact
7660SwitchedCapacitorVoltage
Converter
1
2
3
4
8
7
6
5
OP-AMP
Rb(11K)
Ra(11K)
Rf (27KΩ)
Rp (15MΩ)DRLOutput
1nFVout
6Vbatterypack4xAA
+6V
-6V10microF
10microF
A
B
Figure 3 DRL circuit including battery power supply and voltage converter to provide -6v rail Inputs A and B are buffered outputs from the sensors and may be taken from the A and B outputs of the EPIC demo box Ground should be connected to the sensor 0V the shielding of the BNC A and B outputs on the demo box being a suitable connection point See figure 2 and the text for further comments on the DRL design
sensors and the DRL circuit into saturation Because the system contains some large impedances and hence has some very long RC time constants settling times of tens of seconds can be needed before a clean ECG signal is seen During this period the signal can either appear very noisy or be virtually flat depending on whether one or both sensors or the DRL circuit are ldquorailingrdquo The subject should sit still during this time and wait for the circuit to settle since continually adjusting position will only make matters worse Settling times can sometimes be reduced by turning off the power to the demo box for a few seconds
CLOTHINGGood results can be obtained with one or two layers of cotton material between the sensors and the skin Other materials including a wool-mix sweater and a polyester fleece in addition
to two layers of cotton material have been successful Examples are shown in Figures 6 and 7 If the key greatest interest is in the ldquoR-Rrdquo interval adjusting filter settings to reduce or re-center the signal bandwidth can give improved signal quality
STATICBecause there is no direct physical contact between the subject and any grounding point there is no path for any static build up to be discharged Under most circumstances static build-up does not present a problem butdepending on factors including clothing footwear flooring humidity levels in the air and so forth static build up can sometimes prevent the cardiac signal from being seen clearly Product design must take into account a discharge to the system ground to remove the static charge
Rp the protection resistor is included to limit the current that can be fed back to the human body This resistor is essential in ensuring that the subjectrsquos wellbeing is not endangered and must not be omitted
IMPLEMENTATIONThe demonstration of non-contact ECG is best performed using an EPIC demonstration kit Plessey part no PS25003 which includes the necessary drive circuitry and switchable 50Hz and 60Hz notch filters The inputs to the DRL circuit can be taken from the BNC outputs ldquoA amp Brdquo on the front of the demo box The DRL circuit will require its own bipolar power supply plusmn5V or plusmn6V is suggested A circuit design including a battery power supply is shown in Figure 3
Plesseyrsquos compact sensors (PS2520x) and disc sensors (PS25101) provide equally good results although for demonstration purposes disc sensors are simplest to fix to a chair to make contact with the occupantrsquos back Compact sensors are recommended when designing a custom-built system
EPIC sensors which are designed for contact electrophysiology sensing give excellent results in most cases Initial trials suggest that custom modifications to the sensor design (eg lower gain and higher input impedance) can offer increased sensitivity and the ability to detect weaker ECG signalsThe shape of the measured ECG trace ndash in terms of relative magnitudes of the P Q R S and T waves ndash will depend on the positioning of the sensors behind the subjectrsquos back If the desire is only to measure the ldquoR-Rrdquo interval to determine heart rate then the positioning of the sensors is not critical Placing one sensor either side of the spine separated by 6rdquo -10rdquo (15-25 cm) at approximately the same height as the heart is recommended as a starting point For applications where signals from other parts of the cardiac cycle are required the user should refer to texts on bio-electronic signals for guidance on sensor position
SETTLING TIMEWhen a subject first sits in the chair and leans against the EPIC sensors the changes in electric potential will normally send both the
17
TECH REPORT
17
Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact
7660SwitchedCapacitorVoltage
Converter
1
2
3
4
8
7
6
5
OP-AMP
Rb(11K)
Ra(11K)
Rf (27KΩ)
Rp (15MΩ)DRLOutput
1nFVout
6Vbatterypack4xAA
+6V
-6V10microF
10microF
A
B
Figure 3 DRL circuit including battery power supply and voltage converter to provide -6v rail Inputs A and B are buffered outputs from the sensors and may be taken from the A and B outputs of the EPIC demo box Ground should be connected to the sensor 0V the shielding of the BNC A and B outputs on the demo box being a suitable connection point See figure 2 and the text for further comments on the DRL design
sensors and the DRL circuit into saturation Because the system contains some large impedances and hence has some very long RC time constants settling times of tens of seconds can be needed before a clean ECG signal is seen During this period the signal can either appear very noisy or be virtually flat depending on whether one or both sensors or the DRL circuit are ldquorailingrdquo The subject should sit still during this time and wait for the circuit to settle since continually adjusting position will only make matters worse Settling times can sometimes be reduced by turning off the power to the demo box for a few seconds
CLOTHINGGood results can be obtained with one or two layers of cotton material between the sensors and the skin Other materials including a wool-mix sweater and a polyester fleece in addition
to two layers of cotton material have been successful Examples are shown in Figures 6 and 7 If the key greatest interest is in the ldquoR-Rrdquo interval adjusting filter settings to reduce or re-center the signal bandwidth can give improved signal quality
STATICBecause there is no direct physical contact between the subject and any grounding point there is no path for any static build up to be discharged Under most circumstances static build-up does not present a problem butdepending on factors including clothing footwear flooring humidity levels in the air and so forth static build up can sometimes prevent the cardiac signal from being seen clearly Product design must take into account a discharge to the system ground to remove the static charge
Rp the protection resistor is included to limit the current that can be fed back to the human body This resistor is essential in ensuring that the subjectrsquos wellbeing is not endangered and must not be omitted
IMPLEMENTATIONThe demonstration of non-contact ECG is best performed using an EPIC demonstration kit Plessey part no PS25003 which includes the necessary drive circuitry and switchable 50Hz and 60Hz notch filters The inputs to the DRL circuit can be taken from the BNC outputs ldquoA amp Brdquo on the front of the demo box The DRL circuit will require its own bipolar power supply plusmn5V or plusmn6V is suggested A circuit design including a battery power supply is shown in Figure 3
Plesseyrsquos compact sensors (PS2520x) and disc sensors (PS25101) provide equally good results although for demonstration purposes disc sensors are simplest to fix to a chair to make contact with the occupantrsquos back Compact sensors are recommended when designing a custom-built system
EPIC sensors which are designed for contact electrophysiology sensing give excellent results in most cases Initial trials suggest that custom modifications to the sensor design (eg lower gain and higher input impedance) can offer increased sensitivity and the ability to detect weaker ECG signalsThe shape of the measured ECG trace ndash in terms of relative magnitudes of the P Q R S and T waves ndash will depend on the positioning of the sensors behind the subjectrsquos back If the desire is only to measure the ldquoR-Rrdquo interval to determine heart rate then the positioning of the sensors is not critical Placing one sensor either side of the spine separated by 6rdquo -10rdquo (15-25 cm) at approximately the same height as the heart is recommended as a starting point For applications where signals from other parts of the cardiac cycle are required the user should refer to texts on bio-electronic signals for guidance on sensor position
SETTLING TIMEWhen a subject first sits in the chair and leans against the EPIC sensors the changes in electric potential will normally send both the
1818
SENSOR TECHNOLOGY
Figure 4 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit HP filter corner frequency is 50mHz LP filter in demo box has corner frequency of 30Hz
Figure 6 ECG signals measured from a subject wearing a wool-mix sweater over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 8-25Hz The heart rate can be easily extracted
Figure 5 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit Software filters limit the bandwidth to 8-25Hz
Figure 7 ECG signals measured from a subject wearing a polyester fleece over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 16-40Hz The heart rate can be easily extracted
CABLE SHIELDINGCareful shielding is necessary to reduce unwanted noise artifacts Grounding the shielding of the sensor cable via the connection between the outer casing of the sensor plugs and the metal surround of the socket on the control electronics is recommended
CONCLUSIONEPIC sensors can be used to measure ECG signals without physical skin contact While
sensors can be embedded in a chair or seat the techniques are equally applicable to sensors mounted on a mattress in clothing or in other situations There are many variables that will affect signal quality from the strength of cardiac signal generated by the individual being measured to clothing to the surrounding environment but the designs given here are a starting point in establishing an optimum system for a particular application infin
Find us at Booth 37310World Maker Faire New York
Figure 4 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit HP filter corner frequency is 50mHz LP filter in demo box has corner frequency of 30Hz
Figure 6 ECG signals measured from a subject wearing a wool-mix sweater over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 8-25Hz The heart rate can be easily extracted
Figure 5 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit Software filters limit the bandwidth to 8-25Hz
Figure 7 ECG signals measured from a subject wearing a polyester fleece over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 16-40Hz The heart rate can be easily extracted
CABLE SHIELDINGCareful shielding is necessary to reduce unwanted noise artifacts Grounding the shielding of the sensor cable via the connection between the outer casing of the sensor plugs and the metal surround of the socket on the control electronics is recommended
CONCLUSIONEPIC sensors can be used to measure ECG signals without physical skin contact While
sensors can be embedded in a chair or seat the techniques are equally applicable to sensors mounted on a mattress in clothing or in other situations There are many variables that will affect signal quality from the strength of cardiac signal generated by the individual being measured to clothing to the surrounding environment but the designs given here are a starting point in establishing an optimum system for a particular application infin
Find us at Booth 37310World Maker Faire New York
20
SENSOR TECHNOLOGY
SmallerThan a
Grain Sand
of
Analysts project that by
2020 there will be over
50 billion connected
devices in the now-nascent
Internet of Things (IoT) However
the technology that will enable the
IoT of the future may look a little
different than todayrsquosmdashin fact
you may not be able to see it at all
Many new mobile devices require
motion sensors in order to monitor
analyze and deliver real-time data
and analysis to improve the way
consumers interact with everyday
technology While traditional
sensor platforms require multichip
modules or stacked die within a
device mCube a new MEMS sensor
company is driving the emergence
of Sensor 30 which will lead the
development of the smallest
sensors to datemdashsmaller than a
grain of sand By EEWeb Contributing Writers
mCubersquos Sensors Enable IoMTInterview with Ben Lee President and CEO of mCube
INDUSTRY INTERVIEW
21
SmallerThan a
Grain Sand
of
Analysts project that by
2020 there will be over
50 billion connected
devices in the now-nascent
Internet of Things (IoT) However
the technology that will enable the
IoT of the future may look a little
different than todayrsquosmdashin fact
you may not be able to see it at all
Many new mobile devices require
motion sensors in order to monitor
analyze and deliver real-time data
and analysis to improve the way
consumers interact with everyday
technology While traditional
sensor platforms require multichip
modules or stacked die within a
device mCube a new MEMS sensor
company is driving the emergence
of Sensor 30 which will lead the
development of the smallest
sensors to datemdashsmaller than a
grain of sand By EEWeb Contributing Writers
mCubersquos Sensors Enable IoMTInterview with Ben Lee President and CEO of mCube
22
SENSOR TECHNOLOGY
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
INDUSTRY INTERVIEW
23
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
24
SENSOR TECHNOLOGY
Since sensors are so small and affordable donrsquot be surprised to find unique applications in the future Lee speculates that ldquofarmers might have sensor tags to monitor livestock for abnormal activity patterns of grazing potential illness and herd behaviorrdquo Commercial trucking might involve motion sensors connected to video cameras in rear-view mirrors to better assess the cause of an accident and driving conditions For shipping Lee describes ldquomotion sensors embedded directly onto packages to record jarring motions or accidents in order to determine when and how contents were damagedrdquo
As of 2014 mCubersquos complete intertial sensor portfolio contains an accelerometer magnetometer and its proprietary iGyrotrade gyroscope offering nine degrees of freedom (9DoF) Through reductions in cost power consumption and size mCubersquos sensor offerings make it possible to place them onto nearly any object or devicemdashin some cases without packaging ldquoWe aspire to put one or more MEMS motion sensors on anything that movesrdquo remarks Lee And with the IoMT taking shape and consumer expectations for connected moving devices becoming more concrete developers of new applications will turn to solutions like mCube to deliver truly cutting-edge connected devices
ldquoAt mCube we aspire to put one or more MEMS motion sensors on
anything that movesrdquo
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 15
Complete Inertial Motion Sensor Portfolio
Solutions for up to 9DoF (Degrees of Freedom)
Accelerometer
Magnetometer
iGyroTM
3DoF 3DoF
9DoF
2x2mm
3x3mm 3DoF 6DoF
14x14mm
3x3mm
3x3mm
2626
SENSOR TECHNOLOGY
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
27
TECH REPORT
27
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
2828
SENSOR TECHNOLOGY
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
29
TECH REPORT
29
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
3030
SENSOR TECHNOLOGY
to enable the kind of constant and complex data accumulation that the Biostamp promises
In the interim MC10 is partnering up with other medical and pharmaceutical companies to develop integrated sensor and monitoring products The company plans to become a certified medical-ready partner for companies who donrsquot have access to this unique and proprietary technology Even the US Army has begun working with MC10 on military-grade sensors that will add further safety features for troops in the field This funding from NIH grants Department of Defense grants as well as foundation grants will help the company get one step closer to realization of devices so flexible that users might forget theyrsquore wearing them
ldquoThe company has been bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devicesrdquo
Join the
DESIGNERS OF THINGS conference in San Francisco on
September 23 and 24
Dedicated to the explosive and exciting potential of Wearable
Tech 3D Printing and the Internet of Things the conference
provides the growing design and development community
around these technologies a meeting place to discuss and
showcase the newest products
Click here for more info
httpwwwdesignersofthingscomsanfranciscoscheduler
speakersheth-nirav-rav33310
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Sierra CircuitsA Complete PCB Resource
PLUS The Ground rdquo Myth in PrintedCircuits
ldquo
PCB Resin Reactor+
Ken BahlCEO of Sierra Circuits
Let There Be
How Cree reinvented the light bulb
LIGHT
David ElienVP of Marketing amp Business
Development Cree Inc
New LED Filament Tower
Cutting Edge Flatscreen Technologies
+
+
M o v i n g T o w a r d s
a Clean Energy
FUTUREmdash Hugo van Nispen COO of DNV KEMA
MCU Wars 32-bit MCU Comparison
Cutting Edge
SPICEModeling
Freescale and TI Embedded
Modules
ARMCortex
Programming
From Concept to
Reality Wolfgang Heinz-Fischer
Head of Marketing amp PR TQ-Group
Low-Power Design Techniques
TQ-Grouprsquos Comprehensive Design Process
+
+
PowerDeveloper
Octobe r 20 13
Designing forDurability
View more EEWeb magazinesmdash Click Here
88
SENSOR TECHNOLOGY
PUTTING IT ALL TOGETHER
Figure 1 shows the block diagram of a next-generation SSC In this particular case the SSC supports two temperature inputsmdashone resistive one diodemdashand two resistive bridge inputs The conditioning signal chain includes sensor check and common mode (SCCM) adjustment multiplexing (MUX) programmable gain (PGA) from 1 to 200 VV and an analog to digital converter (ADC) with adjustable sample rate and resolution from 12 to 18 bits
The SSC in figure 1 looks similar to other SSCs that are presently available but most of its potential and flexibility lies in the calibration microcontroller (CMC) A highly efficient and powerful reduced instruction set computer (RISC) coordinates the numerous control and computational tasks necessary to provide the tremendous amount of flexibility required for next-generation SSCs The controller also combines the multiple output data packets into a structured stream in a wide variety of formats that can be either analog or digital
The cycle of tasks performed by the RISC engine consists of three main types measurement tasks conditioning tasks and output tasks Measurement tasks include operations that select the MUX input and signal polarities the gain and offset of the signal path the speed and resolution of the quantizer and auxiliary tasks such as auto-zeroing gain stages The output values of all the main measurement tasks are stored in registers for processing by the conditioning tasks These tasks range from simple operations like shifting and synchronization to basic math functions such as add subtract multiply and divide to complex functions such as logarithms polynomial evaluation spline curve fitting and digital filtering Output tasks include synchronization of data streams formatting packetizing encoding error detection and safety features like redundancy or inversion
The SSC shown in figure 1 provides for up to 20 measurement tasks and 62 conditioning tasks enabling thousands
of different combinations of signal processing sequences for each of the four inputs The number of output tasks varies greatly depending on the type of output but for a complex protocol like SENT the number can be in the dozens
MAKING IT EASY
However it is also vitally important that the flexibility power and complexity of next-generation SSCs do not require a commensurate level of time and resources for system designers implementing them The example shown in figure 1 is a member of a product family that is preconfigured by the manufacturer for a specific application using firmware All of the measurement conditioning and output tasks are programmed so that the designer need only focus on determining gain resolution and calibration coefficients for the correction algorithm all of which are facilitated by software that is easy to use and
Figure 1 An example block diagram of a next-generation SSC from ZMDI
ldquoOne thing that should not be flexible in next-generation
SSCs is the user interfacerdquo
consistent across the product line Special use cases can be implemented easily in firmware by the manufacturer should the need arise but the standard factory configuration will cover the majority of designs Additional family members of the product line are optimized for different numbers and types of inputs and outputs and also preconfigured for the intended application use
Finally one thing that should not be flexible in next-generation SSCs is the user interface including the physical dimensions pin or pad locations and software user interface The product family exemplified in figure 1 has a standardized footprint pinout and software user interface to minimize the costs time and resources associated with board layout calibration and climbing the learning curve
9
TECH REPORT
9
PUTTING IT ALL TOGETHER
Figure 1 shows the block diagram of a next-generation SSC In this particular case the SSC supports two temperature inputsmdashone resistive one diodemdashand two resistive bridge inputs The conditioning signal chain includes sensor check and common mode (SCCM) adjustment multiplexing (MUX) programmable gain (PGA) from 1 to 200 VV and an analog to digital converter (ADC) with adjustable sample rate and resolution from 12 to 18 bits
The SSC in figure 1 looks similar to other SSCs that are presently available but most of its potential and flexibility lies in the calibration microcontroller (CMC) A highly efficient and powerful reduced instruction set computer (RISC) coordinates the numerous control and computational tasks necessary to provide the tremendous amount of flexibility required for next-generation SSCs The controller also combines the multiple output data packets into a structured stream in a wide variety of formats that can be either analog or digital
The cycle of tasks performed by the RISC engine consists of three main types measurement tasks conditioning tasks and output tasks Measurement tasks include operations that select the MUX input and signal polarities the gain and offset of the signal path the speed and resolution of the quantizer and auxiliary tasks such as auto-zeroing gain stages The output values of all the main measurement tasks are stored in registers for processing by the conditioning tasks These tasks range from simple operations like shifting and synchronization to basic math functions such as add subtract multiply and divide to complex functions such as logarithms polynomial evaluation spline curve fitting and digital filtering Output tasks include synchronization of data streams formatting packetizing encoding error detection and safety features like redundancy or inversion
The SSC shown in figure 1 provides for up to 20 measurement tasks and 62 conditioning tasks enabling thousands
of different combinations of signal processing sequences for each of the four inputs The number of output tasks varies greatly depending on the type of output but for a complex protocol like SENT the number can be in the dozens
MAKING IT EASY
However it is also vitally important that the flexibility power and complexity of next-generation SSCs do not require a commensurate level of time and resources for system designers implementing them The example shown in figure 1 is a member of a product family that is preconfigured by the manufacturer for a specific application using firmware All of the measurement conditioning and output tasks are programmed so that the designer need only focus on determining gain resolution and calibration coefficients for the correction algorithm all of which are facilitated by software that is easy to use and
Figure 1 An example block diagram of a next-generation SSC from ZMDI
ldquoOne thing that should not be flexible in next-generation
SSCs is the user interfacerdquo
consistent across the product line Special use cases can be implemented easily in firmware by the manufacturer should the need arise but the standard factory configuration will cover the majority of designs Additional family members of the product line are optimized for different numbers and types of inputs and outputs and also preconfigured for the intended application use
Finally one thing that should not be flexible in next-generation SSCs is the user interface including the physical dimensions pin or pad locations and software user interface The product family exemplified in figure 1 has a standardized footprint pinout and software user interface to minimize the costs time and resources associated with board layout calibration and climbing the learning curve
1212
SENSOR TECHNOLOGY
The human heartbeat is arguably the single most important (ldquolife-and-deathrdquo) diagnostic indicator Thus electrocardiograms (ECGs) are one of the most significant diagnostic methods in that
they monitor heart function ECGs are not only used in a clinical setting but are increasingly seen in personal health devices Traditionally ECG measurement conductive electrodes have been applied which are directly attached to the skin With the help of contact gel (wet or solid) to ensure that there is good electrical contact between the skin and the sensor direct resistive contact is made with the patient However conventional electrodes possess various disadvantages which are not conducive for long-term use in non-clinical settings In addition to being potentially messy metal allergies can cause skin irritations and as a single-use item they are quite expensive
Non-contact ECG measurementusing EPIC Sensors
Measuring electrocardiogram (ECG) signals without skin contact is now possible using novel Electric Potential Integrated Circuit (EPIC) sensors
By Alan Lowne CEO of Saelig Co Inc
13
TECH REPORT
13
The human heartbeat is arguably the single most important (ldquolife-and-deathrdquo) diagnostic indicator Thus electrocardiograms (ECGs) are one of the most significant diagnostic methods in that
they monitor heart function ECGs are not only used in a clinical setting but are increasingly seen in personal health devices Traditionally ECG measurement conductive electrodes have been applied which are directly attached to the skin With the help of contact gel (wet or solid) to ensure that there is good electrical contact between the skin and the sensor direct resistive contact is made with the patient However conventional electrodes possess various disadvantages which are not conducive for long-term use in non-clinical settings In addition to being potentially messy metal allergies can cause skin irritations and as a single-use item they are quite expensive
Non-contact ECG measurementusing EPIC Sensors
Measuring electrocardiogram (ECG) signals without skin contact is now possible using novel Electric Potential Integrated Circuit (EPIC) sensors
By Alan Lowne CEO of Saelig Co Inc
1414
SENSOR TECHNOLOGY
Non-contact measurement of electrophysiological signals is of great interest in healthcare settings with the potential of reducing disposable costs speeding up or simplifying measurement techniques Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact Monitoring vehicle drivers for health and alertness by detecting heart rate and respiration or determining car occupancy to adjust the ride handling and air bag deployment with the varying size and location of occupants is a vast potential market
Capacitive (insulated) electrodes can register ECG signals without conductive contact to the bodyndasheven through clothesndashand represent
an attractive alternative for a wide range of new applications EPIC (Electric Potential Integrated Circuit) is a completely new sensor technology resulting from research at the University of Sussex (UK) Novel ultra high impedance EPIC sensors measure electric field changes without requiring physical or resistive contact This award winning patent-protected sensor can rapidly measure electric potential sources such as electrophysiological signals or even spatial electric fields It therefore has the ability to measure ECGs without direct skin contact By adjusting the DSP and amplification circuitry the sensors can be tuned for detection at a distance as required for differing automotive applications EPIC sensor electrodes can be easily and discretely incorporated inside car seat backs to acquire the necessary biometric data
Signals measured on the human body always include a large amount of noise the major component of this being 50 or 60 Hz power line noise capacitively-coupled to the body from the surrounding electricity supply Measurements such as ECG depend on being able to extract the small electrophysiological signals from the much larger noise signals EPIC sensors can be used in ldquocontact moderdquo for ECG measurement where the subject touches both the capacitive electrode surface and some metal at the system ground directly with the skin This ground reference allows filtering and differential amplification of signals from two sensors to be effective in removing the mains frequency noise leaving a high quality ECG signal In non-contact ECG measurement there is ndash by definition - no skin contact and thus no direct connection can be made between the subjectrsquos body and the system ground Some other method of reducing the power line noise is therefore required to
EPIC Sensors incontact with clothing
Conductive fabric in contactwith clothing eg on chair seat
Output
EPICdemo box
Figure 1 Basic configuration for non-contact ECG measurement including capacitively-oocupied DR circuit
OP-AMP
+5V
-5V
Vout
Rf (27KΩ)
Ra(11KΩ)
Rb(11KΩ)
Rp (15MΩ) To conductive fabric on chair thus capacitively coupled to body
Inputs from outputs of demo box
A
BC
(1nF)
Figure 2 DPL circuit Voltage gain is set by Rf Rp limits current fed back to the body (see text)Operational amplifier output Vout = - (VA + VB) Rf 11K
enable the ECG signal to be extracted reliably and accurately One such method utilizes an approach very similar to the ldquoDriven Right Legrdquo (DRL) system that is used for the same purpose in conventional ECG measurement techniques In conventional ECG the DRL signal is coupled directly to the patientrsquos skin The DRL signal reduces power line noise on the sensor signals by feeding back an inverted average of the signals from two sensors on to the patientrsquos body In non-contact ECG the generated DRL signal can be capacitively-coupled to the body through clothing via a piece of conductive material placed ndash for instance ndash on the seat or back of a chair Capacitive coupling of DRL signals is described by Lim et al1 and Lee et al2
SYSTEM DESIGNAn ECG system can therefore be built into a chair a mattress or clothing for instance The DRL circuit improves the sensor signalnoise ratio enormously In the example in Figure 1 EPIC sensors are mounted on a chair back such that the electrodes touch the clothing on the subjectrsquos back when resting normally against the back of the chair The generated DRL signal is connected to a piece of conductive material
placed either on the seat of the chair or at the bottom of the chair back contacting the subjectrsquos clothing in the normal sitting position Copper-coated nylon fabric is one possible material suitable for the DRL coupling material but other conductive materials may be equally successful A thin non- conductive material such as a cotton fabric may be used to cover both the sensors and the DRL coupling fabric if required for instance when building the sensors into a seat Consideration must be given as to how material will reduce the coupling capacitance between the sensor and the subject or add additional noise to the signals through static charging effectsFigure 2 shows the design of the DRL circuit It is a standard summing amplifier generating an amplified and inverted signal that is the average of the individual signals A and B
The optimum value for Rf will be dependent on the type of sensors being used as well as the clothing being worn by the subject being measured It should be set to achieve maximum noise reduction while ensuring circuit stability A value of 27kohms is suggested as a suitable starting point for EPIC sensors
15
TECH REPORT
15
Non-contact measurement of electrophysiological signals is of great interest in healthcare settings with the potential of reducing disposable costs speeding up or simplifying measurement techniques Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact Monitoring vehicle drivers for health and alertness by detecting heart rate and respiration or determining car occupancy to adjust the ride handling and air bag deployment with the varying size and location of occupants is a vast potential market
Capacitive (insulated) electrodes can register ECG signals without conductive contact to the bodyndasheven through clothesndashand represent
an attractive alternative for a wide range of new applications EPIC (Electric Potential Integrated Circuit) is a completely new sensor technology resulting from research at the University of Sussex (UK) Novel ultra high impedance EPIC sensors measure electric field changes without requiring physical or resistive contact This award winning patent-protected sensor can rapidly measure electric potential sources such as electrophysiological signals or even spatial electric fields It therefore has the ability to measure ECGs without direct skin contact By adjusting the DSP and amplification circuitry the sensors can be tuned for detection at a distance as required for differing automotive applications EPIC sensor electrodes can be easily and discretely incorporated inside car seat backs to acquire the necessary biometric data
Signals measured on the human body always include a large amount of noise the major component of this being 50 or 60 Hz power line noise capacitively-coupled to the body from the surrounding electricity supply Measurements such as ECG depend on being able to extract the small electrophysiological signals from the much larger noise signals EPIC sensors can be used in ldquocontact moderdquo for ECG measurement where the subject touches both the capacitive electrode surface and some metal at the system ground directly with the skin This ground reference allows filtering and differential amplification of signals from two sensors to be effective in removing the mains frequency noise leaving a high quality ECG signal In non-contact ECG measurement there is ndash by definition - no skin contact and thus no direct connection can be made between the subjectrsquos body and the system ground Some other method of reducing the power line noise is therefore required to
EPIC Sensors incontact with clothing
Conductive fabric in contactwith clothing eg on chair seat
Output
EPICdemo box
Figure 1 Basic configuration for non-contact ECG measurement including capacitively-oocupied DR circuit
OP-AMP
+5V
-5V
Vout
Rf (27KΩ)
Ra(11KΩ)
Rb(11KΩ)
Rp (15MΩ) To conductive fabric on chair thus capacitively coupled to body
Inputs from outputs of demo box
A
BC
(1nF)
Figure 2 DPL circuit Voltage gain is set by Rf Rp limits current fed back to the body (see text)Operational amplifier output Vout = - (VA + VB) Rf 11K
enable the ECG signal to be extracted reliably and accurately One such method utilizes an approach very similar to the ldquoDriven Right Legrdquo (DRL) system that is used for the same purpose in conventional ECG measurement techniques In conventional ECG the DRL signal is coupled directly to the patientrsquos skin The DRL signal reduces power line noise on the sensor signals by feeding back an inverted average of the signals from two sensors on to the patientrsquos body In non-contact ECG the generated DRL signal can be capacitively-coupled to the body through clothing via a piece of conductive material placed ndash for instance ndash on the seat or back of a chair Capacitive coupling of DRL signals is described by Lim et al1 and Lee et al2
SYSTEM DESIGNAn ECG system can therefore be built into a chair a mattress or clothing for instance The DRL circuit improves the sensor signalnoise ratio enormously In the example in Figure 1 EPIC sensors are mounted on a chair back such that the electrodes touch the clothing on the subjectrsquos back when resting normally against the back of the chair The generated DRL signal is connected to a piece of conductive material
placed either on the seat of the chair or at the bottom of the chair back contacting the subjectrsquos clothing in the normal sitting position Copper-coated nylon fabric is one possible material suitable for the DRL coupling material but other conductive materials may be equally successful A thin non- conductive material such as a cotton fabric may be used to cover both the sensors and the DRL coupling fabric if required for instance when building the sensors into a seat Consideration must be given as to how material will reduce the coupling capacitance between the sensor and the subject or add additional noise to the signals through static charging effectsFigure 2 shows the design of the DRL circuit It is a standard summing amplifier generating an amplified and inverted signal that is the average of the individual signals A and B
The optimum value for Rf will be dependent on the type of sensors being used as well as the clothing being worn by the subject being measured It should be set to achieve maximum noise reduction while ensuring circuit stability A value of 27kohms is suggested as a suitable starting point for EPIC sensors
1616
SENSOR TECHNOLOGY
Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact
7660SwitchedCapacitorVoltage
Converter
1
2
3
4
8
7
6
5
OP-AMP
Rb(11K)
Ra(11K)
Rf (27KΩ)
Rp (15MΩ)DRLOutput
1nFVout
6Vbatterypack4xAA
+6V
-6V10microF
10microF
A
B
Figure 3 DRL circuit including battery power supply and voltage converter to provide -6v rail Inputs A and B are buffered outputs from the sensors and may be taken from the A and B outputs of the EPIC demo box Ground should be connected to the sensor 0V the shielding of the BNC A and B outputs on the demo box being a suitable connection point See figure 2 and the text for further comments on the DRL design
sensors and the DRL circuit into saturation Because the system contains some large impedances and hence has some very long RC time constants settling times of tens of seconds can be needed before a clean ECG signal is seen During this period the signal can either appear very noisy or be virtually flat depending on whether one or both sensors or the DRL circuit are ldquorailingrdquo The subject should sit still during this time and wait for the circuit to settle since continually adjusting position will only make matters worse Settling times can sometimes be reduced by turning off the power to the demo box for a few seconds
CLOTHINGGood results can be obtained with one or two layers of cotton material between the sensors and the skin Other materials including a wool-mix sweater and a polyester fleece in addition
to two layers of cotton material have been successful Examples are shown in Figures 6 and 7 If the key greatest interest is in the ldquoR-Rrdquo interval adjusting filter settings to reduce or re-center the signal bandwidth can give improved signal quality
STATICBecause there is no direct physical contact between the subject and any grounding point there is no path for any static build up to be discharged Under most circumstances static build-up does not present a problem butdepending on factors including clothing footwear flooring humidity levels in the air and so forth static build up can sometimes prevent the cardiac signal from being seen clearly Product design must take into account a discharge to the system ground to remove the static charge
Rp the protection resistor is included to limit the current that can be fed back to the human body This resistor is essential in ensuring that the subjectrsquos wellbeing is not endangered and must not be omitted
IMPLEMENTATIONThe demonstration of non-contact ECG is best performed using an EPIC demonstration kit Plessey part no PS25003 which includes the necessary drive circuitry and switchable 50Hz and 60Hz notch filters The inputs to the DRL circuit can be taken from the BNC outputs ldquoA amp Brdquo on the front of the demo box The DRL circuit will require its own bipolar power supply plusmn5V or plusmn6V is suggested A circuit design including a battery power supply is shown in Figure 3
Plesseyrsquos compact sensors (PS2520x) and disc sensors (PS25101) provide equally good results although for demonstration purposes disc sensors are simplest to fix to a chair to make contact with the occupantrsquos back Compact sensors are recommended when designing a custom-built system
EPIC sensors which are designed for contact electrophysiology sensing give excellent results in most cases Initial trials suggest that custom modifications to the sensor design (eg lower gain and higher input impedance) can offer increased sensitivity and the ability to detect weaker ECG signalsThe shape of the measured ECG trace ndash in terms of relative magnitudes of the P Q R S and T waves ndash will depend on the positioning of the sensors behind the subjectrsquos back If the desire is only to measure the ldquoR-Rrdquo interval to determine heart rate then the positioning of the sensors is not critical Placing one sensor either side of the spine separated by 6rdquo -10rdquo (15-25 cm) at approximately the same height as the heart is recommended as a starting point For applications where signals from other parts of the cardiac cycle are required the user should refer to texts on bio-electronic signals for guidance on sensor position
SETTLING TIMEWhen a subject first sits in the chair and leans against the EPIC sensors the changes in electric potential will normally send both the
17
TECH REPORT
17
Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact
7660SwitchedCapacitorVoltage
Converter
1
2
3
4
8
7
6
5
OP-AMP
Rb(11K)
Ra(11K)
Rf (27KΩ)
Rp (15MΩ)DRLOutput
1nFVout
6Vbatterypack4xAA
+6V
-6V10microF
10microF
A
B
Figure 3 DRL circuit including battery power supply and voltage converter to provide -6v rail Inputs A and B are buffered outputs from the sensors and may be taken from the A and B outputs of the EPIC demo box Ground should be connected to the sensor 0V the shielding of the BNC A and B outputs on the demo box being a suitable connection point See figure 2 and the text for further comments on the DRL design
sensors and the DRL circuit into saturation Because the system contains some large impedances and hence has some very long RC time constants settling times of tens of seconds can be needed before a clean ECG signal is seen During this period the signal can either appear very noisy or be virtually flat depending on whether one or both sensors or the DRL circuit are ldquorailingrdquo The subject should sit still during this time and wait for the circuit to settle since continually adjusting position will only make matters worse Settling times can sometimes be reduced by turning off the power to the demo box for a few seconds
CLOTHINGGood results can be obtained with one or two layers of cotton material between the sensors and the skin Other materials including a wool-mix sweater and a polyester fleece in addition
to two layers of cotton material have been successful Examples are shown in Figures 6 and 7 If the key greatest interest is in the ldquoR-Rrdquo interval adjusting filter settings to reduce or re-center the signal bandwidth can give improved signal quality
STATICBecause there is no direct physical contact between the subject and any grounding point there is no path for any static build up to be discharged Under most circumstances static build-up does not present a problem butdepending on factors including clothing footwear flooring humidity levels in the air and so forth static build up can sometimes prevent the cardiac signal from being seen clearly Product design must take into account a discharge to the system ground to remove the static charge
Rp the protection resistor is included to limit the current that can be fed back to the human body This resistor is essential in ensuring that the subjectrsquos wellbeing is not endangered and must not be omitted
IMPLEMENTATIONThe demonstration of non-contact ECG is best performed using an EPIC demonstration kit Plessey part no PS25003 which includes the necessary drive circuitry and switchable 50Hz and 60Hz notch filters The inputs to the DRL circuit can be taken from the BNC outputs ldquoA amp Brdquo on the front of the demo box The DRL circuit will require its own bipolar power supply plusmn5V or plusmn6V is suggested A circuit design including a battery power supply is shown in Figure 3
Plesseyrsquos compact sensors (PS2520x) and disc sensors (PS25101) provide equally good results although for demonstration purposes disc sensors are simplest to fix to a chair to make contact with the occupantrsquos back Compact sensors are recommended when designing a custom-built system
EPIC sensors which are designed for contact electrophysiology sensing give excellent results in most cases Initial trials suggest that custom modifications to the sensor design (eg lower gain and higher input impedance) can offer increased sensitivity and the ability to detect weaker ECG signalsThe shape of the measured ECG trace ndash in terms of relative magnitudes of the P Q R S and T waves ndash will depend on the positioning of the sensors behind the subjectrsquos back If the desire is only to measure the ldquoR-Rrdquo interval to determine heart rate then the positioning of the sensors is not critical Placing one sensor either side of the spine separated by 6rdquo -10rdquo (15-25 cm) at approximately the same height as the heart is recommended as a starting point For applications where signals from other parts of the cardiac cycle are required the user should refer to texts on bio-electronic signals for guidance on sensor position
SETTLING TIMEWhen a subject first sits in the chair and leans against the EPIC sensors the changes in electric potential will normally send both the
1818
SENSOR TECHNOLOGY
Figure 4 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit HP filter corner frequency is 50mHz LP filter in demo box has corner frequency of 30Hz
Figure 6 ECG signals measured from a subject wearing a wool-mix sweater over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 8-25Hz The heart rate can be easily extracted
Figure 5 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit Software filters limit the bandwidth to 8-25Hz
Figure 7 ECG signals measured from a subject wearing a polyester fleece over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 16-40Hz The heart rate can be easily extracted
CABLE SHIELDINGCareful shielding is necessary to reduce unwanted noise artifacts Grounding the shielding of the sensor cable via the connection between the outer casing of the sensor plugs and the metal surround of the socket on the control electronics is recommended
CONCLUSIONEPIC sensors can be used to measure ECG signals without physical skin contact While
sensors can be embedded in a chair or seat the techniques are equally applicable to sensors mounted on a mattress in clothing or in other situations There are many variables that will affect signal quality from the strength of cardiac signal generated by the individual being measured to clothing to the surrounding environment but the designs given here are a starting point in establishing an optimum system for a particular application infin
Find us at Booth 37310World Maker Faire New York
Figure 4 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit HP filter corner frequency is 50mHz LP filter in demo box has corner frequency of 30Hz
Figure 6 ECG signals measured from a subject wearing a wool-mix sweater over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 8-25Hz The heart rate can be easily extracted
Figure 5 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit Software filters limit the bandwidth to 8-25Hz
Figure 7 ECG signals measured from a subject wearing a polyester fleece over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 16-40Hz The heart rate can be easily extracted
CABLE SHIELDINGCareful shielding is necessary to reduce unwanted noise artifacts Grounding the shielding of the sensor cable via the connection between the outer casing of the sensor plugs and the metal surround of the socket on the control electronics is recommended
CONCLUSIONEPIC sensors can be used to measure ECG signals without physical skin contact While
sensors can be embedded in a chair or seat the techniques are equally applicable to sensors mounted on a mattress in clothing or in other situations There are many variables that will affect signal quality from the strength of cardiac signal generated by the individual being measured to clothing to the surrounding environment but the designs given here are a starting point in establishing an optimum system for a particular application infin
Find us at Booth 37310World Maker Faire New York
20
SENSOR TECHNOLOGY
SmallerThan a
Grain Sand
of
Analysts project that by
2020 there will be over
50 billion connected
devices in the now-nascent
Internet of Things (IoT) However
the technology that will enable the
IoT of the future may look a little
different than todayrsquosmdashin fact
you may not be able to see it at all
Many new mobile devices require
motion sensors in order to monitor
analyze and deliver real-time data
and analysis to improve the way
consumers interact with everyday
technology While traditional
sensor platforms require multichip
modules or stacked die within a
device mCube a new MEMS sensor
company is driving the emergence
of Sensor 30 which will lead the
development of the smallest
sensors to datemdashsmaller than a
grain of sand By EEWeb Contributing Writers
mCubersquos Sensors Enable IoMTInterview with Ben Lee President and CEO of mCube
INDUSTRY INTERVIEW
21
SmallerThan a
Grain Sand
of
Analysts project that by
2020 there will be over
50 billion connected
devices in the now-nascent
Internet of Things (IoT) However
the technology that will enable the
IoT of the future may look a little
different than todayrsquosmdashin fact
you may not be able to see it at all
Many new mobile devices require
motion sensors in order to monitor
analyze and deliver real-time data
and analysis to improve the way
consumers interact with everyday
technology While traditional
sensor platforms require multichip
modules or stacked die within a
device mCube a new MEMS sensor
company is driving the emergence
of Sensor 30 which will lead the
development of the smallest
sensors to datemdashsmaller than a
grain of sand By EEWeb Contributing Writers
mCubersquos Sensors Enable IoMTInterview with Ben Lee President and CEO of mCube
22
SENSOR TECHNOLOGY
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
INDUSTRY INTERVIEW
23
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
24
SENSOR TECHNOLOGY
Since sensors are so small and affordable donrsquot be surprised to find unique applications in the future Lee speculates that ldquofarmers might have sensor tags to monitor livestock for abnormal activity patterns of grazing potential illness and herd behaviorrdquo Commercial trucking might involve motion sensors connected to video cameras in rear-view mirrors to better assess the cause of an accident and driving conditions For shipping Lee describes ldquomotion sensors embedded directly onto packages to record jarring motions or accidents in order to determine when and how contents were damagedrdquo
As of 2014 mCubersquos complete intertial sensor portfolio contains an accelerometer magnetometer and its proprietary iGyrotrade gyroscope offering nine degrees of freedom (9DoF) Through reductions in cost power consumption and size mCubersquos sensor offerings make it possible to place them onto nearly any object or devicemdashin some cases without packaging ldquoWe aspire to put one or more MEMS motion sensors on anything that movesrdquo remarks Lee And with the IoMT taking shape and consumer expectations for connected moving devices becoming more concrete developers of new applications will turn to solutions like mCube to deliver truly cutting-edge connected devices
ldquoAt mCube we aspire to put one or more MEMS motion sensors on
anything that movesrdquo
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 15
Complete Inertial Motion Sensor Portfolio
Solutions for up to 9DoF (Degrees of Freedom)
Accelerometer
Magnetometer
iGyroTM
3DoF 3DoF
9DoF
2x2mm
3x3mm 3DoF 6DoF
14x14mm
3x3mm
3x3mm
2626
SENSOR TECHNOLOGY
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
27
TECH REPORT
27
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
2828
SENSOR TECHNOLOGY
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
29
TECH REPORT
29
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
3030
SENSOR TECHNOLOGY
to enable the kind of constant and complex data accumulation that the Biostamp promises
In the interim MC10 is partnering up with other medical and pharmaceutical companies to develop integrated sensor and monitoring products The company plans to become a certified medical-ready partner for companies who donrsquot have access to this unique and proprietary technology Even the US Army has begun working with MC10 on military-grade sensors that will add further safety features for troops in the field This funding from NIH grants Department of Defense grants as well as foundation grants will help the company get one step closer to realization of devices so flexible that users might forget theyrsquore wearing them
ldquoThe company has been bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devicesrdquo
Join the
DESIGNERS OF THINGS conference in San Francisco on
September 23 and 24
Dedicated to the explosive and exciting potential of Wearable
Tech 3D Printing and the Internet of Things the conference
provides the growing design and development community
around these technologies a meeting place to discuss and
showcase the newest products
Click here for more info
httpwwwdesignersofthingscomsanfranciscoscheduler
speakersheth-nirav-rav33310
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Sierra CircuitsA Complete PCB Resource
PLUS The Ground rdquo Myth in PrintedCircuits
ldquo
PCB Resin Reactor+
Ken BahlCEO of Sierra Circuits
Let There Be
How Cree reinvented the light bulb
LIGHT
David ElienVP of Marketing amp Business
Development Cree Inc
New LED Filament Tower
Cutting Edge Flatscreen Technologies
+
+
M o v i n g T o w a r d s
a Clean Energy
FUTUREmdash Hugo van Nispen COO of DNV KEMA
MCU Wars 32-bit MCU Comparison
Cutting Edge
SPICEModeling
Freescale and TI Embedded
Modules
ARMCortex
Programming
From Concept to
Reality Wolfgang Heinz-Fischer
Head of Marketing amp PR TQ-Group
Low-Power Design Techniques
TQ-Grouprsquos Comprehensive Design Process
+
+
PowerDeveloper
Octobe r 20 13
Designing forDurability
View more EEWeb magazinesmdash Click Here
9
TECH REPORT
9
PUTTING IT ALL TOGETHER
Figure 1 shows the block diagram of a next-generation SSC In this particular case the SSC supports two temperature inputsmdashone resistive one diodemdashand two resistive bridge inputs The conditioning signal chain includes sensor check and common mode (SCCM) adjustment multiplexing (MUX) programmable gain (PGA) from 1 to 200 VV and an analog to digital converter (ADC) with adjustable sample rate and resolution from 12 to 18 bits
The SSC in figure 1 looks similar to other SSCs that are presently available but most of its potential and flexibility lies in the calibration microcontroller (CMC) A highly efficient and powerful reduced instruction set computer (RISC) coordinates the numerous control and computational tasks necessary to provide the tremendous amount of flexibility required for next-generation SSCs The controller also combines the multiple output data packets into a structured stream in a wide variety of formats that can be either analog or digital
The cycle of tasks performed by the RISC engine consists of three main types measurement tasks conditioning tasks and output tasks Measurement tasks include operations that select the MUX input and signal polarities the gain and offset of the signal path the speed and resolution of the quantizer and auxiliary tasks such as auto-zeroing gain stages The output values of all the main measurement tasks are stored in registers for processing by the conditioning tasks These tasks range from simple operations like shifting and synchronization to basic math functions such as add subtract multiply and divide to complex functions such as logarithms polynomial evaluation spline curve fitting and digital filtering Output tasks include synchronization of data streams formatting packetizing encoding error detection and safety features like redundancy or inversion
The SSC shown in figure 1 provides for up to 20 measurement tasks and 62 conditioning tasks enabling thousands
of different combinations of signal processing sequences for each of the four inputs The number of output tasks varies greatly depending on the type of output but for a complex protocol like SENT the number can be in the dozens
MAKING IT EASY
However it is also vitally important that the flexibility power and complexity of next-generation SSCs do not require a commensurate level of time and resources for system designers implementing them The example shown in figure 1 is a member of a product family that is preconfigured by the manufacturer for a specific application using firmware All of the measurement conditioning and output tasks are programmed so that the designer need only focus on determining gain resolution and calibration coefficients for the correction algorithm all of which are facilitated by software that is easy to use and
Figure 1 An example block diagram of a next-generation SSC from ZMDI
ldquoOne thing that should not be flexible in next-generation
SSCs is the user interfacerdquo
consistent across the product line Special use cases can be implemented easily in firmware by the manufacturer should the need arise but the standard factory configuration will cover the majority of designs Additional family members of the product line are optimized for different numbers and types of inputs and outputs and also preconfigured for the intended application use
Finally one thing that should not be flexible in next-generation SSCs is the user interface including the physical dimensions pin or pad locations and software user interface The product family exemplified in figure 1 has a standardized footprint pinout and software user interface to minimize the costs time and resources associated with board layout calibration and climbing the learning curve
1212
SENSOR TECHNOLOGY
The human heartbeat is arguably the single most important (ldquolife-and-deathrdquo) diagnostic indicator Thus electrocardiograms (ECGs) are one of the most significant diagnostic methods in that
they monitor heart function ECGs are not only used in a clinical setting but are increasingly seen in personal health devices Traditionally ECG measurement conductive electrodes have been applied which are directly attached to the skin With the help of contact gel (wet or solid) to ensure that there is good electrical contact between the skin and the sensor direct resistive contact is made with the patient However conventional electrodes possess various disadvantages which are not conducive for long-term use in non-clinical settings In addition to being potentially messy metal allergies can cause skin irritations and as a single-use item they are quite expensive
Non-contact ECG measurementusing EPIC Sensors
Measuring electrocardiogram (ECG) signals without skin contact is now possible using novel Electric Potential Integrated Circuit (EPIC) sensors
By Alan Lowne CEO of Saelig Co Inc
13
TECH REPORT
13
The human heartbeat is arguably the single most important (ldquolife-and-deathrdquo) diagnostic indicator Thus electrocardiograms (ECGs) are one of the most significant diagnostic methods in that
they monitor heart function ECGs are not only used in a clinical setting but are increasingly seen in personal health devices Traditionally ECG measurement conductive electrodes have been applied which are directly attached to the skin With the help of contact gel (wet or solid) to ensure that there is good electrical contact between the skin and the sensor direct resistive contact is made with the patient However conventional electrodes possess various disadvantages which are not conducive for long-term use in non-clinical settings In addition to being potentially messy metal allergies can cause skin irritations and as a single-use item they are quite expensive
Non-contact ECG measurementusing EPIC Sensors
Measuring electrocardiogram (ECG) signals without skin contact is now possible using novel Electric Potential Integrated Circuit (EPIC) sensors
By Alan Lowne CEO of Saelig Co Inc
1414
SENSOR TECHNOLOGY
Non-contact measurement of electrophysiological signals is of great interest in healthcare settings with the potential of reducing disposable costs speeding up or simplifying measurement techniques Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact Monitoring vehicle drivers for health and alertness by detecting heart rate and respiration or determining car occupancy to adjust the ride handling and air bag deployment with the varying size and location of occupants is a vast potential market
Capacitive (insulated) electrodes can register ECG signals without conductive contact to the bodyndasheven through clothesndashand represent
an attractive alternative for a wide range of new applications EPIC (Electric Potential Integrated Circuit) is a completely new sensor technology resulting from research at the University of Sussex (UK) Novel ultra high impedance EPIC sensors measure electric field changes without requiring physical or resistive contact This award winning patent-protected sensor can rapidly measure electric potential sources such as electrophysiological signals or even spatial electric fields It therefore has the ability to measure ECGs without direct skin contact By adjusting the DSP and amplification circuitry the sensors can be tuned for detection at a distance as required for differing automotive applications EPIC sensor electrodes can be easily and discretely incorporated inside car seat backs to acquire the necessary biometric data
Signals measured on the human body always include a large amount of noise the major component of this being 50 or 60 Hz power line noise capacitively-coupled to the body from the surrounding electricity supply Measurements such as ECG depend on being able to extract the small electrophysiological signals from the much larger noise signals EPIC sensors can be used in ldquocontact moderdquo for ECG measurement where the subject touches both the capacitive electrode surface and some metal at the system ground directly with the skin This ground reference allows filtering and differential amplification of signals from two sensors to be effective in removing the mains frequency noise leaving a high quality ECG signal In non-contact ECG measurement there is ndash by definition - no skin contact and thus no direct connection can be made between the subjectrsquos body and the system ground Some other method of reducing the power line noise is therefore required to
EPIC Sensors incontact with clothing
Conductive fabric in contactwith clothing eg on chair seat
Output
EPICdemo box
Figure 1 Basic configuration for non-contact ECG measurement including capacitively-oocupied DR circuit
OP-AMP
+5V
-5V
Vout
Rf (27KΩ)
Ra(11KΩ)
Rb(11KΩ)
Rp (15MΩ) To conductive fabric on chair thus capacitively coupled to body
Inputs from outputs of demo box
A
BC
(1nF)
Figure 2 DPL circuit Voltage gain is set by Rf Rp limits current fed back to the body (see text)Operational amplifier output Vout = - (VA + VB) Rf 11K
enable the ECG signal to be extracted reliably and accurately One such method utilizes an approach very similar to the ldquoDriven Right Legrdquo (DRL) system that is used for the same purpose in conventional ECG measurement techniques In conventional ECG the DRL signal is coupled directly to the patientrsquos skin The DRL signal reduces power line noise on the sensor signals by feeding back an inverted average of the signals from two sensors on to the patientrsquos body In non-contact ECG the generated DRL signal can be capacitively-coupled to the body through clothing via a piece of conductive material placed ndash for instance ndash on the seat or back of a chair Capacitive coupling of DRL signals is described by Lim et al1 and Lee et al2
SYSTEM DESIGNAn ECG system can therefore be built into a chair a mattress or clothing for instance The DRL circuit improves the sensor signalnoise ratio enormously In the example in Figure 1 EPIC sensors are mounted on a chair back such that the electrodes touch the clothing on the subjectrsquos back when resting normally against the back of the chair The generated DRL signal is connected to a piece of conductive material
placed either on the seat of the chair or at the bottom of the chair back contacting the subjectrsquos clothing in the normal sitting position Copper-coated nylon fabric is one possible material suitable for the DRL coupling material but other conductive materials may be equally successful A thin non- conductive material such as a cotton fabric may be used to cover both the sensors and the DRL coupling fabric if required for instance when building the sensors into a seat Consideration must be given as to how material will reduce the coupling capacitance between the sensor and the subject or add additional noise to the signals through static charging effectsFigure 2 shows the design of the DRL circuit It is a standard summing amplifier generating an amplified and inverted signal that is the average of the individual signals A and B
The optimum value for Rf will be dependent on the type of sensors being used as well as the clothing being worn by the subject being measured It should be set to achieve maximum noise reduction while ensuring circuit stability A value of 27kohms is suggested as a suitable starting point for EPIC sensors
15
TECH REPORT
15
Non-contact measurement of electrophysiological signals is of great interest in healthcare settings with the potential of reducing disposable costs speeding up or simplifying measurement techniques Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact Monitoring vehicle drivers for health and alertness by detecting heart rate and respiration or determining car occupancy to adjust the ride handling and air bag deployment with the varying size and location of occupants is a vast potential market
Capacitive (insulated) electrodes can register ECG signals without conductive contact to the bodyndasheven through clothesndashand represent
an attractive alternative for a wide range of new applications EPIC (Electric Potential Integrated Circuit) is a completely new sensor technology resulting from research at the University of Sussex (UK) Novel ultra high impedance EPIC sensors measure electric field changes without requiring physical or resistive contact This award winning patent-protected sensor can rapidly measure electric potential sources such as electrophysiological signals or even spatial electric fields It therefore has the ability to measure ECGs without direct skin contact By adjusting the DSP and amplification circuitry the sensors can be tuned for detection at a distance as required for differing automotive applications EPIC sensor electrodes can be easily and discretely incorporated inside car seat backs to acquire the necessary biometric data
Signals measured on the human body always include a large amount of noise the major component of this being 50 or 60 Hz power line noise capacitively-coupled to the body from the surrounding electricity supply Measurements such as ECG depend on being able to extract the small electrophysiological signals from the much larger noise signals EPIC sensors can be used in ldquocontact moderdquo for ECG measurement where the subject touches both the capacitive electrode surface and some metal at the system ground directly with the skin This ground reference allows filtering and differential amplification of signals from two sensors to be effective in removing the mains frequency noise leaving a high quality ECG signal In non-contact ECG measurement there is ndash by definition - no skin contact and thus no direct connection can be made between the subjectrsquos body and the system ground Some other method of reducing the power line noise is therefore required to
EPIC Sensors incontact with clothing
Conductive fabric in contactwith clothing eg on chair seat
Output
EPICdemo box
Figure 1 Basic configuration for non-contact ECG measurement including capacitively-oocupied DR circuit
OP-AMP
+5V
-5V
Vout
Rf (27KΩ)
Ra(11KΩ)
Rb(11KΩ)
Rp (15MΩ) To conductive fabric on chair thus capacitively coupled to body
Inputs from outputs of demo box
A
BC
(1nF)
Figure 2 DPL circuit Voltage gain is set by Rf Rp limits current fed back to the body (see text)Operational amplifier output Vout = - (VA + VB) Rf 11K
enable the ECG signal to be extracted reliably and accurately One such method utilizes an approach very similar to the ldquoDriven Right Legrdquo (DRL) system that is used for the same purpose in conventional ECG measurement techniques In conventional ECG the DRL signal is coupled directly to the patientrsquos skin The DRL signal reduces power line noise on the sensor signals by feeding back an inverted average of the signals from two sensors on to the patientrsquos body In non-contact ECG the generated DRL signal can be capacitively-coupled to the body through clothing via a piece of conductive material placed ndash for instance ndash on the seat or back of a chair Capacitive coupling of DRL signals is described by Lim et al1 and Lee et al2
SYSTEM DESIGNAn ECG system can therefore be built into a chair a mattress or clothing for instance The DRL circuit improves the sensor signalnoise ratio enormously In the example in Figure 1 EPIC sensors are mounted on a chair back such that the electrodes touch the clothing on the subjectrsquos back when resting normally against the back of the chair The generated DRL signal is connected to a piece of conductive material
placed either on the seat of the chair or at the bottom of the chair back contacting the subjectrsquos clothing in the normal sitting position Copper-coated nylon fabric is one possible material suitable for the DRL coupling material but other conductive materials may be equally successful A thin non- conductive material such as a cotton fabric may be used to cover both the sensors and the DRL coupling fabric if required for instance when building the sensors into a seat Consideration must be given as to how material will reduce the coupling capacitance between the sensor and the subject or add additional noise to the signals through static charging effectsFigure 2 shows the design of the DRL circuit It is a standard summing amplifier generating an amplified and inverted signal that is the average of the individual signals A and B
The optimum value for Rf will be dependent on the type of sensors being used as well as the clothing being worn by the subject being measured It should be set to achieve maximum noise reduction while ensuring circuit stability A value of 27kohms is suggested as a suitable starting point for EPIC sensors
1616
SENSOR TECHNOLOGY
Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact
7660SwitchedCapacitorVoltage
Converter
1
2
3
4
8
7
6
5
OP-AMP
Rb(11K)
Ra(11K)
Rf (27KΩ)
Rp (15MΩ)DRLOutput
1nFVout
6Vbatterypack4xAA
+6V
-6V10microF
10microF
A
B
Figure 3 DRL circuit including battery power supply and voltage converter to provide -6v rail Inputs A and B are buffered outputs from the sensors and may be taken from the A and B outputs of the EPIC demo box Ground should be connected to the sensor 0V the shielding of the BNC A and B outputs on the demo box being a suitable connection point See figure 2 and the text for further comments on the DRL design
sensors and the DRL circuit into saturation Because the system contains some large impedances and hence has some very long RC time constants settling times of tens of seconds can be needed before a clean ECG signal is seen During this period the signal can either appear very noisy or be virtually flat depending on whether one or both sensors or the DRL circuit are ldquorailingrdquo The subject should sit still during this time and wait for the circuit to settle since continually adjusting position will only make matters worse Settling times can sometimes be reduced by turning off the power to the demo box for a few seconds
CLOTHINGGood results can be obtained with one or two layers of cotton material between the sensors and the skin Other materials including a wool-mix sweater and a polyester fleece in addition
to two layers of cotton material have been successful Examples are shown in Figures 6 and 7 If the key greatest interest is in the ldquoR-Rrdquo interval adjusting filter settings to reduce or re-center the signal bandwidth can give improved signal quality
STATICBecause there is no direct physical contact between the subject and any grounding point there is no path for any static build up to be discharged Under most circumstances static build-up does not present a problem butdepending on factors including clothing footwear flooring humidity levels in the air and so forth static build up can sometimes prevent the cardiac signal from being seen clearly Product design must take into account a discharge to the system ground to remove the static charge
Rp the protection resistor is included to limit the current that can be fed back to the human body This resistor is essential in ensuring that the subjectrsquos wellbeing is not endangered and must not be omitted
IMPLEMENTATIONThe demonstration of non-contact ECG is best performed using an EPIC demonstration kit Plessey part no PS25003 which includes the necessary drive circuitry and switchable 50Hz and 60Hz notch filters The inputs to the DRL circuit can be taken from the BNC outputs ldquoA amp Brdquo on the front of the demo box The DRL circuit will require its own bipolar power supply plusmn5V or plusmn6V is suggested A circuit design including a battery power supply is shown in Figure 3
Plesseyrsquos compact sensors (PS2520x) and disc sensors (PS25101) provide equally good results although for demonstration purposes disc sensors are simplest to fix to a chair to make contact with the occupantrsquos back Compact sensors are recommended when designing a custom-built system
EPIC sensors which are designed for contact electrophysiology sensing give excellent results in most cases Initial trials suggest that custom modifications to the sensor design (eg lower gain and higher input impedance) can offer increased sensitivity and the ability to detect weaker ECG signalsThe shape of the measured ECG trace ndash in terms of relative magnitudes of the P Q R S and T waves ndash will depend on the positioning of the sensors behind the subjectrsquos back If the desire is only to measure the ldquoR-Rrdquo interval to determine heart rate then the positioning of the sensors is not critical Placing one sensor either side of the spine separated by 6rdquo -10rdquo (15-25 cm) at approximately the same height as the heart is recommended as a starting point For applications where signals from other parts of the cardiac cycle are required the user should refer to texts on bio-electronic signals for guidance on sensor position
SETTLING TIMEWhen a subject first sits in the chair and leans against the EPIC sensors the changes in electric potential will normally send both the
17
TECH REPORT
17
Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact
7660SwitchedCapacitorVoltage
Converter
1
2
3
4
8
7
6
5
OP-AMP
Rb(11K)
Ra(11K)
Rf (27KΩ)
Rp (15MΩ)DRLOutput
1nFVout
6Vbatterypack4xAA
+6V
-6V10microF
10microF
A
B
Figure 3 DRL circuit including battery power supply and voltage converter to provide -6v rail Inputs A and B are buffered outputs from the sensors and may be taken from the A and B outputs of the EPIC demo box Ground should be connected to the sensor 0V the shielding of the BNC A and B outputs on the demo box being a suitable connection point See figure 2 and the text for further comments on the DRL design
sensors and the DRL circuit into saturation Because the system contains some large impedances and hence has some very long RC time constants settling times of tens of seconds can be needed before a clean ECG signal is seen During this period the signal can either appear very noisy or be virtually flat depending on whether one or both sensors or the DRL circuit are ldquorailingrdquo The subject should sit still during this time and wait for the circuit to settle since continually adjusting position will only make matters worse Settling times can sometimes be reduced by turning off the power to the demo box for a few seconds
CLOTHINGGood results can be obtained with one or two layers of cotton material between the sensors and the skin Other materials including a wool-mix sweater and a polyester fleece in addition
to two layers of cotton material have been successful Examples are shown in Figures 6 and 7 If the key greatest interest is in the ldquoR-Rrdquo interval adjusting filter settings to reduce or re-center the signal bandwidth can give improved signal quality
STATICBecause there is no direct physical contact between the subject and any grounding point there is no path for any static build up to be discharged Under most circumstances static build-up does not present a problem butdepending on factors including clothing footwear flooring humidity levels in the air and so forth static build up can sometimes prevent the cardiac signal from being seen clearly Product design must take into account a discharge to the system ground to remove the static charge
Rp the protection resistor is included to limit the current that can be fed back to the human body This resistor is essential in ensuring that the subjectrsquos wellbeing is not endangered and must not be omitted
IMPLEMENTATIONThe demonstration of non-contact ECG is best performed using an EPIC demonstration kit Plessey part no PS25003 which includes the necessary drive circuitry and switchable 50Hz and 60Hz notch filters The inputs to the DRL circuit can be taken from the BNC outputs ldquoA amp Brdquo on the front of the demo box The DRL circuit will require its own bipolar power supply plusmn5V or plusmn6V is suggested A circuit design including a battery power supply is shown in Figure 3
Plesseyrsquos compact sensors (PS2520x) and disc sensors (PS25101) provide equally good results although for demonstration purposes disc sensors are simplest to fix to a chair to make contact with the occupantrsquos back Compact sensors are recommended when designing a custom-built system
EPIC sensors which are designed for contact electrophysiology sensing give excellent results in most cases Initial trials suggest that custom modifications to the sensor design (eg lower gain and higher input impedance) can offer increased sensitivity and the ability to detect weaker ECG signalsThe shape of the measured ECG trace ndash in terms of relative magnitudes of the P Q R S and T waves ndash will depend on the positioning of the sensors behind the subjectrsquos back If the desire is only to measure the ldquoR-Rrdquo interval to determine heart rate then the positioning of the sensors is not critical Placing one sensor either side of the spine separated by 6rdquo -10rdquo (15-25 cm) at approximately the same height as the heart is recommended as a starting point For applications where signals from other parts of the cardiac cycle are required the user should refer to texts on bio-electronic signals for guidance on sensor position
SETTLING TIMEWhen a subject first sits in the chair and leans against the EPIC sensors the changes in electric potential will normally send both the
1818
SENSOR TECHNOLOGY
Figure 4 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit HP filter corner frequency is 50mHz LP filter in demo box has corner frequency of 30Hz
Figure 6 ECG signals measured from a subject wearing a wool-mix sweater over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 8-25Hz The heart rate can be easily extracted
Figure 5 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit Software filters limit the bandwidth to 8-25Hz
Figure 7 ECG signals measured from a subject wearing a polyester fleece over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 16-40Hz The heart rate can be easily extracted
CABLE SHIELDINGCareful shielding is necessary to reduce unwanted noise artifacts Grounding the shielding of the sensor cable via the connection between the outer casing of the sensor plugs and the metal surround of the socket on the control electronics is recommended
CONCLUSIONEPIC sensors can be used to measure ECG signals without physical skin contact While
sensors can be embedded in a chair or seat the techniques are equally applicable to sensors mounted on a mattress in clothing or in other situations There are many variables that will affect signal quality from the strength of cardiac signal generated by the individual being measured to clothing to the surrounding environment but the designs given here are a starting point in establishing an optimum system for a particular application infin
Find us at Booth 37310World Maker Faire New York
Figure 4 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit HP filter corner frequency is 50mHz LP filter in demo box has corner frequency of 30Hz
Figure 6 ECG signals measured from a subject wearing a wool-mix sweater over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 8-25Hz The heart rate can be easily extracted
Figure 5 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit Software filters limit the bandwidth to 8-25Hz
Figure 7 ECG signals measured from a subject wearing a polyester fleece over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 16-40Hz The heart rate can be easily extracted
CABLE SHIELDINGCareful shielding is necessary to reduce unwanted noise artifacts Grounding the shielding of the sensor cable via the connection between the outer casing of the sensor plugs and the metal surround of the socket on the control electronics is recommended
CONCLUSIONEPIC sensors can be used to measure ECG signals without physical skin contact While
sensors can be embedded in a chair or seat the techniques are equally applicable to sensors mounted on a mattress in clothing or in other situations There are many variables that will affect signal quality from the strength of cardiac signal generated by the individual being measured to clothing to the surrounding environment but the designs given here are a starting point in establishing an optimum system for a particular application infin
Find us at Booth 37310World Maker Faire New York
20
SENSOR TECHNOLOGY
SmallerThan a
Grain Sand
of
Analysts project that by
2020 there will be over
50 billion connected
devices in the now-nascent
Internet of Things (IoT) However
the technology that will enable the
IoT of the future may look a little
different than todayrsquosmdashin fact
you may not be able to see it at all
Many new mobile devices require
motion sensors in order to monitor
analyze and deliver real-time data
and analysis to improve the way
consumers interact with everyday
technology While traditional
sensor platforms require multichip
modules or stacked die within a
device mCube a new MEMS sensor
company is driving the emergence
of Sensor 30 which will lead the
development of the smallest
sensors to datemdashsmaller than a
grain of sand By EEWeb Contributing Writers
mCubersquos Sensors Enable IoMTInterview with Ben Lee President and CEO of mCube
INDUSTRY INTERVIEW
21
SmallerThan a
Grain Sand
of
Analysts project that by
2020 there will be over
50 billion connected
devices in the now-nascent
Internet of Things (IoT) However
the technology that will enable the
IoT of the future may look a little
different than todayrsquosmdashin fact
you may not be able to see it at all
Many new mobile devices require
motion sensors in order to monitor
analyze and deliver real-time data
and analysis to improve the way
consumers interact with everyday
technology While traditional
sensor platforms require multichip
modules or stacked die within a
device mCube a new MEMS sensor
company is driving the emergence
of Sensor 30 which will lead the
development of the smallest
sensors to datemdashsmaller than a
grain of sand By EEWeb Contributing Writers
mCubersquos Sensors Enable IoMTInterview with Ben Lee President and CEO of mCube
22
SENSOR TECHNOLOGY
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
INDUSTRY INTERVIEW
23
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
24
SENSOR TECHNOLOGY
Since sensors are so small and affordable donrsquot be surprised to find unique applications in the future Lee speculates that ldquofarmers might have sensor tags to monitor livestock for abnormal activity patterns of grazing potential illness and herd behaviorrdquo Commercial trucking might involve motion sensors connected to video cameras in rear-view mirrors to better assess the cause of an accident and driving conditions For shipping Lee describes ldquomotion sensors embedded directly onto packages to record jarring motions or accidents in order to determine when and how contents were damagedrdquo
As of 2014 mCubersquos complete intertial sensor portfolio contains an accelerometer magnetometer and its proprietary iGyrotrade gyroscope offering nine degrees of freedom (9DoF) Through reductions in cost power consumption and size mCubersquos sensor offerings make it possible to place them onto nearly any object or devicemdashin some cases without packaging ldquoWe aspire to put one or more MEMS motion sensors on anything that movesrdquo remarks Lee And with the IoMT taking shape and consumer expectations for connected moving devices becoming more concrete developers of new applications will turn to solutions like mCube to deliver truly cutting-edge connected devices
ldquoAt mCube we aspire to put one or more MEMS motion sensors on
anything that movesrdquo
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 15
Complete Inertial Motion Sensor Portfolio
Solutions for up to 9DoF (Degrees of Freedom)
Accelerometer
Magnetometer
iGyroTM
3DoF 3DoF
9DoF
2x2mm
3x3mm 3DoF 6DoF
14x14mm
3x3mm
3x3mm
2626
SENSOR TECHNOLOGY
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
27
TECH REPORT
27
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
2828
SENSOR TECHNOLOGY
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
29
TECH REPORT
29
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
3030
SENSOR TECHNOLOGY
to enable the kind of constant and complex data accumulation that the Biostamp promises
In the interim MC10 is partnering up with other medical and pharmaceutical companies to develop integrated sensor and monitoring products The company plans to become a certified medical-ready partner for companies who donrsquot have access to this unique and proprietary technology Even the US Army has begun working with MC10 on military-grade sensors that will add further safety features for troops in the field This funding from NIH grants Department of Defense grants as well as foundation grants will help the company get one step closer to realization of devices so flexible that users might forget theyrsquore wearing them
ldquoThe company has been bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devicesrdquo
Join the
DESIGNERS OF THINGS conference in San Francisco on
September 23 and 24
Dedicated to the explosive and exciting potential of Wearable
Tech 3D Printing and the Internet of Things the conference
provides the growing design and development community
around these technologies a meeting place to discuss and
showcase the newest products
Click here for more info
httpwwwdesignersofthingscomsanfranciscoscheduler
speakersheth-nirav-rav33310
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Sierra CircuitsA Complete PCB Resource
PLUS The Ground rdquo Myth in PrintedCircuits
ldquo
PCB Resin Reactor+
Ken BahlCEO of Sierra Circuits
Let There Be
How Cree reinvented the light bulb
LIGHT
David ElienVP of Marketing amp Business
Development Cree Inc
New LED Filament Tower
Cutting Edge Flatscreen Technologies
+
+
M o v i n g T o w a r d s
a Clean Energy
FUTUREmdash Hugo van Nispen COO of DNV KEMA
MCU Wars 32-bit MCU Comparison
Cutting Edge
SPICEModeling
Freescale and TI Embedded
Modules
ARMCortex
Programming
From Concept to
Reality Wolfgang Heinz-Fischer
Head of Marketing amp PR TQ-Group
Low-Power Design Techniques
TQ-Grouprsquos Comprehensive Design Process
+
+
PowerDeveloper
Octobe r 20 13
Designing forDurability
View more EEWeb magazinesmdash Click Here
1212
SENSOR TECHNOLOGY
The human heartbeat is arguably the single most important (ldquolife-and-deathrdquo) diagnostic indicator Thus electrocardiograms (ECGs) are one of the most significant diagnostic methods in that
they monitor heart function ECGs are not only used in a clinical setting but are increasingly seen in personal health devices Traditionally ECG measurement conductive electrodes have been applied which are directly attached to the skin With the help of contact gel (wet or solid) to ensure that there is good electrical contact between the skin and the sensor direct resistive contact is made with the patient However conventional electrodes possess various disadvantages which are not conducive for long-term use in non-clinical settings In addition to being potentially messy metal allergies can cause skin irritations and as a single-use item they are quite expensive
Non-contact ECG measurementusing EPIC Sensors
Measuring electrocardiogram (ECG) signals without skin contact is now possible using novel Electric Potential Integrated Circuit (EPIC) sensors
By Alan Lowne CEO of Saelig Co Inc
13
TECH REPORT
13
The human heartbeat is arguably the single most important (ldquolife-and-deathrdquo) diagnostic indicator Thus electrocardiograms (ECGs) are one of the most significant diagnostic methods in that
they monitor heart function ECGs are not only used in a clinical setting but are increasingly seen in personal health devices Traditionally ECG measurement conductive electrodes have been applied which are directly attached to the skin With the help of contact gel (wet or solid) to ensure that there is good electrical contact between the skin and the sensor direct resistive contact is made with the patient However conventional electrodes possess various disadvantages which are not conducive for long-term use in non-clinical settings In addition to being potentially messy metal allergies can cause skin irritations and as a single-use item they are quite expensive
Non-contact ECG measurementusing EPIC Sensors
Measuring electrocardiogram (ECG) signals without skin contact is now possible using novel Electric Potential Integrated Circuit (EPIC) sensors
By Alan Lowne CEO of Saelig Co Inc
1414
SENSOR TECHNOLOGY
Non-contact measurement of electrophysiological signals is of great interest in healthcare settings with the potential of reducing disposable costs speeding up or simplifying measurement techniques Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact Monitoring vehicle drivers for health and alertness by detecting heart rate and respiration or determining car occupancy to adjust the ride handling and air bag deployment with the varying size and location of occupants is a vast potential market
Capacitive (insulated) electrodes can register ECG signals without conductive contact to the bodyndasheven through clothesndashand represent
an attractive alternative for a wide range of new applications EPIC (Electric Potential Integrated Circuit) is a completely new sensor technology resulting from research at the University of Sussex (UK) Novel ultra high impedance EPIC sensors measure electric field changes without requiring physical or resistive contact This award winning patent-protected sensor can rapidly measure electric potential sources such as electrophysiological signals or even spatial electric fields It therefore has the ability to measure ECGs without direct skin contact By adjusting the DSP and amplification circuitry the sensors can be tuned for detection at a distance as required for differing automotive applications EPIC sensor electrodes can be easily and discretely incorporated inside car seat backs to acquire the necessary biometric data
Signals measured on the human body always include a large amount of noise the major component of this being 50 or 60 Hz power line noise capacitively-coupled to the body from the surrounding electricity supply Measurements such as ECG depend on being able to extract the small electrophysiological signals from the much larger noise signals EPIC sensors can be used in ldquocontact moderdquo for ECG measurement where the subject touches both the capacitive electrode surface and some metal at the system ground directly with the skin This ground reference allows filtering and differential amplification of signals from two sensors to be effective in removing the mains frequency noise leaving a high quality ECG signal In non-contact ECG measurement there is ndash by definition - no skin contact and thus no direct connection can be made between the subjectrsquos body and the system ground Some other method of reducing the power line noise is therefore required to
EPIC Sensors incontact with clothing
Conductive fabric in contactwith clothing eg on chair seat
Output
EPICdemo box
Figure 1 Basic configuration for non-contact ECG measurement including capacitively-oocupied DR circuit
OP-AMP
+5V
-5V
Vout
Rf (27KΩ)
Ra(11KΩ)
Rb(11KΩ)
Rp (15MΩ) To conductive fabric on chair thus capacitively coupled to body
Inputs from outputs of demo box
A
BC
(1nF)
Figure 2 DPL circuit Voltage gain is set by Rf Rp limits current fed back to the body (see text)Operational amplifier output Vout = - (VA + VB) Rf 11K
enable the ECG signal to be extracted reliably and accurately One such method utilizes an approach very similar to the ldquoDriven Right Legrdquo (DRL) system that is used for the same purpose in conventional ECG measurement techniques In conventional ECG the DRL signal is coupled directly to the patientrsquos skin The DRL signal reduces power line noise on the sensor signals by feeding back an inverted average of the signals from two sensors on to the patientrsquos body In non-contact ECG the generated DRL signal can be capacitively-coupled to the body through clothing via a piece of conductive material placed ndash for instance ndash on the seat or back of a chair Capacitive coupling of DRL signals is described by Lim et al1 and Lee et al2
SYSTEM DESIGNAn ECG system can therefore be built into a chair a mattress or clothing for instance The DRL circuit improves the sensor signalnoise ratio enormously In the example in Figure 1 EPIC sensors are mounted on a chair back such that the electrodes touch the clothing on the subjectrsquos back when resting normally against the back of the chair The generated DRL signal is connected to a piece of conductive material
placed either on the seat of the chair or at the bottom of the chair back contacting the subjectrsquos clothing in the normal sitting position Copper-coated nylon fabric is one possible material suitable for the DRL coupling material but other conductive materials may be equally successful A thin non- conductive material such as a cotton fabric may be used to cover both the sensors and the DRL coupling fabric if required for instance when building the sensors into a seat Consideration must be given as to how material will reduce the coupling capacitance between the sensor and the subject or add additional noise to the signals through static charging effectsFigure 2 shows the design of the DRL circuit It is a standard summing amplifier generating an amplified and inverted signal that is the average of the individual signals A and B
The optimum value for Rf will be dependent on the type of sensors being used as well as the clothing being worn by the subject being measured It should be set to achieve maximum noise reduction while ensuring circuit stability A value of 27kohms is suggested as a suitable starting point for EPIC sensors
15
TECH REPORT
15
Non-contact measurement of electrophysiological signals is of great interest in healthcare settings with the potential of reducing disposable costs speeding up or simplifying measurement techniques Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact Monitoring vehicle drivers for health and alertness by detecting heart rate and respiration or determining car occupancy to adjust the ride handling and air bag deployment with the varying size and location of occupants is a vast potential market
Capacitive (insulated) electrodes can register ECG signals without conductive contact to the bodyndasheven through clothesndashand represent
an attractive alternative for a wide range of new applications EPIC (Electric Potential Integrated Circuit) is a completely new sensor technology resulting from research at the University of Sussex (UK) Novel ultra high impedance EPIC sensors measure electric field changes without requiring physical or resistive contact This award winning patent-protected sensor can rapidly measure electric potential sources such as electrophysiological signals or even spatial electric fields It therefore has the ability to measure ECGs without direct skin contact By adjusting the DSP and amplification circuitry the sensors can be tuned for detection at a distance as required for differing automotive applications EPIC sensor electrodes can be easily and discretely incorporated inside car seat backs to acquire the necessary biometric data
Signals measured on the human body always include a large amount of noise the major component of this being 50 or 60 Hz power line noise capacitively-coupled to the body from the surrounding electricity supply Measurements such as ECG depend on being able to extract the small electrophysiological signals from the much larger noise signals EPIC sensors can be used in ldquocontact moderdquo for ECG measurement where the subject touches both the capacitive electrode surface and some metal at the system ground directly with the skin This ground reference allows filtering and differential amplification of signals from two sensors to be effective in removing the mains frequency noise leaving a high quality ECG signal In non-contact ECG measurement there is ndash by definition - no skin contact and thus no direct connection can be made between the subjectrsquos body and the system ground Some other method of reducing the power line noise is therefore required to
EPIC Sensors incontact with clothing
Conductive fabric in contactwith clothing eg on chair seat
Output
EPICdemo box
Figure 1 Basic configuration for non-contact ECG measurement including capacitively-oocupied DR circuit
OP-AMP
+5V
-5V
Vout
Rf (27KΩ)
Ra(11KΩ)
Rb(11KΩ)
Rp (15MΩ) To conductive fabric on chair thus capacitively coupled to body
Inputs from outputs of demo box
A
BC
(1nF)
Figure 2 DPL circuit Voltage gain is set by Rf Rp limits current fed back to the body (see text)Operational amplifier output Vout = - (VA + VB) Rf 11K
enable the ECG signal to be extracted reliably and accurately One such method utilizes an approach very similar to the ldquoDriven Right Legrdquo (DRL) system that is used for the same purpose in conventional ECG measurement techniques In conventional ECG the DRL signal is coupled directly to the patientrsquos skin The DRL signal reduces power line noise on the sensor signals by feeding back an inverted average of the signals from two sensors on to the patientrsquos body In non-contact ECG the generated DRL signal can be capacitively-coupled to the body through clothing via a piece of conductive material placed ndash for instance ndash on the seat or back of a chair Capacitive coupling of DRL signals is described by Lim et al1 and Lee et al2
SYSTEM DESIGNAn ECG system can therefore be built into a chair a mattress or clothing for instance The DRL circuit improves the sensor signalnoise ratio enormously In the example in Figure 1 EPIC sensors are mounted on a chair back such that the electrodes touch the clothing on the subjectrsquos back when resting normally against the back of the chair The generated DRL signal is connected to a piece of conductive material
placed either on the seat of the chair or at the bottom of the chair back contacting the subjectrsquos clothing in the normal sitting position Copper-coated nylon fabric is one possible material suitable for the DRL coupling material but other conductive materials may be equally successful A thin non- conductive material such as a cotton fabric may be used to cover both the sensors and the DRL coupling fabric if required for instance when building the sensors into a seat Consideration must be given as to how material will reduce the coupling capacitance between the sensor and the subject or add additional noise to the signals through static charging effectsFigure 2 shows the design of the DRL circuit It is a standard summing amplifier generating an amplified and inverted signal that is the average of the individual signals A and B
The optimum value for Rf will be dependent on the type of sensors being used as well as the clothing being worn by the subject being measured It should be set to achieve maximum noise reduction while ensuring circuit stability A value of 27kohms is suggested as a suitable starting point for EPIC sensors
1616
SENSOR TECHNOLOGY
Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact
7660SwitchedCapacitorVoltage
Converter
1
2
3
4
8
7
6
5
OP-AMP
Rb(11K)
Ra(11K)
Rf (27KΩ)
Rp (15MΩ)DRLOutput
1nFVout
6Vbatterypack4xAA
+6V
-6V10microF
10microF
A
B
Figure 3 DRL circuit including battery power supply and voltage converter to provide -6v rail Inputs A and B are buffered outputs from the sensors and may be taken from the A and B outputs of the EPIC demo box Ground should be connected to the sensor 0V the shielding of the BNC A and B outputs on the demo box being a suitable connection point See figure 2 and the text for further comments on the DRL design
sensors and the DRL circuit into saturation Because the system contains some large impedances and hence has some very long RC time constants settling times of tens of seconds can be needed before a clean ECG signal is seen During this period the signal can either appear very noisy or be virtually flat depending on whether one or both sensors or the DRL circuit are ldquorailingrdquo The subject should sit still during this time and wait for the circuit to settle since continually adjusting position will only make matters worse Settling times can sometimes be reduced by turning off the power to the demo box for a few seconds
CLOTHINGGood results can be obtained with one or two layers of cotton material between the sensors and the skin Other materials including a wool-mix sweater and a polyester fleece in addition
to two layers of cotton material have been successful Examples are shown in Figures 6 and 7 If the key greatest interest is in the ldquoR-Rrdquo interval adjusting filter settings to reduce or re-center the signal bandwidth can give improved signal quality
STATICBecause there is no direct physical contact between the subject and any grounding point there is no path for any static build up to be discharged Under most circumstances static build-up does not present a problem butdepending on factors including clothing footwear flooring humidity levels in the air and so forth static build up can sometimes prevent the cardiac signal from being seen clearly Product design must take into account a discharge to the system ground to remove the static charge
Rp the protection resistor is included to limit the current that can be fed back to the human body This resistor is essential in ensuring that the subjectrsquos wellbeing is not endangered and must not be omitted
IMPLEMENTATIONThe demonstration of non-contact ECG is best performed using an EPIC demonstration kit Plessey part no PS25003 which includes the necessary drive circuitry and switchable 50Hz and 60Hz notch filters The inputs to the DRL circuit can be taken from the BNC outputs ldquoA amp Brdquo on the front of the demo box The DRL circuit will require its own bipolar power supply plusmn5V or plusmn6V is suggested A circuit design including a battery power supply is shown in Figure 3
Plesseyrsquos compact sensors (PS2520x) and disc sensors (PS25101) provide equally good results although for demonstration purposes disc sensors are simplest to fix to a chair to make contact with the occupantrsquos back Compact sensors are recommended when designing a custom-built system
EPIC sensors which are designed for contact electrophysiology sensing give excellent results in most cases Initial trials suggest that custom modifications to the sensor design (eg lower gain and higher input impedance) can offer increased sensitivity and the ability to detect weaker ECG signalsThe shape of the measured ECG trace ndash in terms of relative magnitudes of the P Q R S and T waves ndash will depend on the positioning of the sensors behind the subjectrsquos back If the desire is only to measure the ldquoR-Rrdquo interval to determine heart rate then the positioning of the sensors is not critical Placing one sensor either side of the spine separated by 6rdquo -10rdquo (15-25 cm) at approximately the same height as the heart is recommended as a starting point For applications where signals from other parts of the cardiac cycle are required the user should refer to texts on bio-electronic signals for guidance on sensor position
SETTLING TIMEWhen a subject first sits in the chair and leans against the EPIC sensors the changes in electric potential will normally send both the
17
TECH REPORT
17
Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact
7660SwitchedCapacitorVoltage
Converter
1
2
3
4
8
7
6
5
OP-AMP
Rb(11K)
Ra(11K)
Rf (27KΩ)
Rp (15MΩ)DRLOutput
1nFVout
6Vbatterypack4xAA
+6V
-6V10microF
10microF
A
B
Figure 3 DRL circuit including battery power supply and voltage converter to provide -6v rail Inputs A and B are buffered outputs from the sensors and may be taken from the A and B outputs of the EPIC demo box Ground should be connected to the sensor 0V the shielding of the BNC A and B outputs on the demo box being a suitable connection point See figure 2 and the text for further comments on the DRL design
sensors and the DRL circuit into saturation Because the system contains some large impedances and hence has some very long RC time constants settling times of tens of seconds can be needed before a clean ECG signal is seen During this period the signal can either appear very noisy or be virtually flat depending on whether one or both sensors or the DRL circuit are ldquorailingrdquo The subject should sit still during this time and wait for the circuit to settle since continually adjusting position will only make matters worse Settling times can sometimes be reduced by turning off the power to the demo box for a few seconds
CLOTHINGGood results can be obtained with one or two layers of cotton material between the sensors and the skin Other materials including a wool-mix sweater and a polyester fleece in addition
to two layers of cotton material have been successful Examples are shown in Figures 6 and 7 If the key greatest interest is in the ldquoR-Rrdquo interval adjusting filter settings to reduce or re-center the signal bandwidth can give improved signal quality
STATICBecause there is no direct physical contact between the subject and any grounding point there is no path for any static build up to be discharged Under most circumstances static build-up does not present a problem butdepending on factors including clothing footwear flooring humidity levels in the air and so forth static build up can sometimes prevent the cardiac signal from being seen clearly Product design must take into account a discharge to the system ground to remove the static charge
Rp the protection resistor is included to limit the current that can be fed back to the human body This resistor is essential in ensuring that the subjectrsquos wellbeing is not endangered and must not be omitted
IMPLEMENTATIONThe demonstration of non-contact ECG is best performed using an EPIC demonstration kit Plessey part no PS25003 which includes the necessary drive circuitry and switchable 50Hz and 60Hz notch filters The inputs to the DRL circuit can be taken from the BNC outputs ldquoA amp Brdquo on the front of the demo box The DRL circuit will require its own bipolar power supply plusmn5V or plusmn6V is suggested A circuit design including a battery power supply is shown in Figure 3
Plesseyrsquos compact sensors (PS2520x) and disc sensors (PS25101) provide equally good results although for demonstration purposes disc sensors are simplest to fix to a chair to make contact with the occupantrsquos back Compact sensors are recommended when designing a custom-built system
EPIC sensors which are designed for contact electrophysiology sensing give excellent results in most cases Initial trials suggest that custom modifications to the sensor design (eg lower gain and higher input impedance) can offer increased sensitivity and the ability to detect weaker ECG signalsThe shape of the measured ECG trace ndash in terms of relative magnitudes of the P Q R S and T waves ndash will depend on the positioning of the sensors behind the subjectrsquos back If the desire is only to measure the ldquoR-Rrdquo interval to determine heart rate then the positioning of the sensors is not critical Placing one sensor either side of the spine separated by 6rdquo -10rdquo (15-25 cm) at approximately the same height as the heart is recommended as a starting point For applications where signals from other parts of the cardiac cycle are required the user should refer to texts on bio-electronic signals for guidance on sensor position
SETTLING TIMEWhen a subject first sits in the chair and leans against the EPIC sensors the changes in electric potential will normally send both the
1818
SENSOR TECHNOLOGY
Figure 4 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit HP filter corner frequency is 50mHz LP filter in demo box has corner frequency of 30Hz
Figure 6 ECG signals measured from a subject wearing a wool-mix sweater over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 8-25Hz The heart rate can be easily extracted
Figure 5 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit Software filters limit the bandwidth to 8-25Hz
Figure 7 ECG signals measured from a subject wearing a polyester fleece over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 16-40Hz The heart rate can be easily extracted
CABLE SHIELDINGCareful shielding is necessary to reduce unwanted noise artifacts Grounding the shielding of the sensor cable via the connection between the outer casing of the sensor plugs and the metal surround of the socket on the control electronics is recommended
CONCLUSIONEPIC sensors can be used to measure ECG signals without physical skin contact While
sensors can be embedded in a chair or seat the techniques are equally applicable to sensors mounted on a mattress in clothing or in other situations There are many variables that will affect signal quality from the strength of cardiac signal generated by the individual being measured to clothing to the surrounding environment but the designs given here are a starting point in establishing an optimum system for a particular application infin
Find us at Booth 37310World Maker Faire New York
Figure 4 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit HP filter corner frequency is 50mHz LP filter in demo box has corner frequency of 30Hz
Figure 6 ECG signals measured from a subject wearing a wool-mix sweater over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 8-25Hz The heart rate can be easily extracted
Figure 5 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit Software filters limit the bandwidth to 8-25Hz
Figure 7 ECG signals measured from a subject wearing a polyester fleece over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 16-40Hz The heart rate can be easily extracted
CABLE SHIELDINGCareful shielding is necessary to reduce unwanted noise artifacts Grounding the shielding of the sensor cable via the connection between the outer casing of the sensor plugs and the metal surround of the socket on the control electronics is recommended
CONCLUSIONEPIC sensors can be used to measure ECG signals without physical skin contact While
sensors can be embedded in a chair or seat the techniques are equally applicable to sensors mounted on a mattress in clothing or in other situations There are many variables that will affect signal quality from the strength of cardiac signal generated by the individual being measured to clothing to the surrounding environment but the designs given here are a starting point in establishing an optimum system for a particular application infin
Find us at Booth 37310World Maker Faire New York
20
SENSOR TECHNOLOGY
SmallerThan a
Grain Sand
of
Analysts project that by
2020 there will be over
50 billion connected
devices in the now-nascent
Internet of Things (IoT) However
the technology that will enable the
IoT of the future may look a little
different than todayrsquosmdashin fact
you may not be able to see it at all
Many new mobile devices require
motion sensors in order to monitor
analyze and deliver real-time data
and analysis to improve the way
consumers interact with everyday
technology While traditional
sensor platforms require multichip
modules or stacked die within a
device mCube a new MEMS sensor
company is driving the emergence
of Sensor 30 which will lead the
development of the smallest
sensors to datemdashsmaller than a
grain of sand By EEWeb Contributing Writers
mCubersquos Sensors Enable IoMTInterview with Ben Lee President and CEO of mCube
INDUSTRY INTERVIEW
21
SmallerThan a
Grain Sand
of
Analysts project that by
2020 there will be over
50 billion connected
devices in the now-nascent
Internet of Things (IoT) However
the technology that will enable the
IoT of the future may look a little
different than todayrsquosmdashin fact
you may not be able to see it at all
Many new mobile devices require
motion sensors in order to monitor
analyze and deliver real-time data
and analysis to improve the way
consumers interact with everyday
technology While traditional
sensor platforms require multichip
modules or stacked die within a
device mCube a new MEMS sensor
company is driving the emergence
of Sensor 30 which will lead the
development of the smallest
sensors to datemdashsmaller than a
grain of sand By EEWeb Contributing Writers
mCubersquos Sensors Enable IoMTInterview with Ben Lee President and CEO of mCube
22
SENSOR TECHNOLOGY
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
INDUSTRY INTERVIEW
23
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
24
SENSOR TECHNOLOGY
Since sensors are so small and affordable donrsquot be surprised to find unique applications in the future Lee speculates that ldquofarmers might have sensor tags to monitor livestock for abnormal activity patterns of grazing potential illness and herd behaviorrdquo Commercial trucking might involve motion sensors connected to video cameras in rear-view mirrors to better assess the cause of an accident and driving conditions For shipping Lee describes ldquomotion sensors embedded directly onto packages to record jarring motions or accidents in order to determine when and how contents were damagedrdquo
As of 2014 mCubersquos complete intertial sensor portfolio contains an accelerometer magnetometer and its proprietary iGyrotrade gyroscope offering nine degrees of freedom (9DoF) Through reductions in cost power consumption and size mCubersquos sensor offerings make it possible to place them onto nearly any object or devicemdashin some cases without packaging ldquoWe aspire to put one or more MEMS motion sensors on anything that movesrdquo remarks Lee And with the IoMT taking shape and consumer expectations for connected moving devices becoming more concrete developers of new applications will turn to solutions like mCube to deliver truly cutting-edge connected devices
ldquoAt mCube we aspire to put one or more MEMS motion sensors on
anything that movesrdquo
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 15
Complete Inertial Motion Sensor Portfolio
Solutions for up to 9DoF (Degrees of Freedom)
Accelerometer
Magnetometer
iGyroTM
3DoF 3DoF
9DoF
2x2mm
3x3mm 3DoF 6DoF
14x14mm
3x3mm
3x3mm
2626
SENSOR TECHNOLOGY
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
27
TECH REPORT
27
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
2828
SENSOR TECHNOLOGY
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
29
TECH REPORT
29
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
3030
SENSOR TECHNOLOGY
to enable the kind of constant and complex data accumulation that the Biostamp promises
In the interim MC10 is partnering up with other medical and pharmaceutical companies to develop integrated sensor and monitoring products The company plans to become a certified medical-ready partner for companies who donrsquot have access to this unique and proprietary technology Even the US Army has begun working with MC10 on military-grade sensors that will add further safety features for troops in the field This funding from NIH grants Department of Defense grants as well as foundation grants will help the company get one step closer to realization of devices so flexible that users might forget theyrsquore wearing them
ldquoThe company has been bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devicesrdquo
Join the
DESIGNERS OF THINGS conference in San Francisco on
September 23 and 24
Dedicated to the explosive and exciting potential of Wearable
Tech 3D Printing and the Internet of Things the conference
provides the growing design and development community
around these technologies a meeting place to discuss and
showcase the newest products
Click here for more info
httpwwwdesignersofthingscomsanfranciscoscheduler
speakersheth-nirav-rav33310
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Sierra CircuitsA Complete PCB Resource
PLUS The Ground rdquo Myth in PrintedCircuits
ldquo
PCB Resin Reactor+
Ken BahlCEO of Sierra Circuits
Let There Be
How Cree reinvented the light bulb
LIGHT
David ElienVP of Marketing amp Business
Development Cree Inc
New LED Filament Tower
Cutting Edge Flatscreen Technologies
+
+
M o v i n g T o w a r d s
a Clean Energy
FUTUREmdash Hugo van Nispen COO of DNV KEMA
MCU Wars 32-bit MCU Comparison
Cutting Edge
SPICEModeling
Freescale and TI Embedded
Modules
ARMCortex
Programming
From Concept to
Reality Wolfgang Heinz-Fischer
Head of Marketing amp PR TQ-Group
Low-Power Design Techniques
TQ-Grouprsquos Comprehensive Design Process
+
+
PowerDeveloper
Octobe r 20 13
Designing forDurability
View more EEWeb magazinesmdash Click Here
13
TECH REPORT
13
The human heartbeat is arguably the single most important (ldquolife-and-deathrdquo) diagnostic indicator Thus electrocardiograms (ECGs) are one of the most significant diagnostic methods in that
they monitor heart function ECGs are not only used in a clinical setting but are increasingly seen in personal health devices Traditionally ECG measurement conductive electrodes have been applied which are directly attached to the skin With the help of contact gel (wet or solid) to ensure that there is good electrical contact between the skin and the sensor direct resistive contact is made with the patient However conventional electrodes possess various disadvantages which are not conducive for long-term use in non-clinical settings In addition to being potentially messy metal allergies can cause skin irritations and as a single-use item they are quite expensive
Non-contact ECG measurementusing EPIC Sensors
Measuring electrocardiogram (ECG) signals without skin contact is now possible using novel Electric Potential Integrated Circuit (EPIC) sensors
By Alan Lowne CEO of Saelig Co Inc
1414
SENSOR TECHNOLOGY
Non-contact measurement of electrophysiological signals is of great interest in healthcare settings with the potential of reducing disposable costs speeding up or simplifying measurement techniques Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact Monitoring vehicle drivers for health and alertness by detecting heart rate and respiration or determining car occupancy to adjust the ride handling and air bag deployment with the varying size and location of occupants is a vast potential market
Capacitive (insulated) electrodes can register ECG signals without conductive contact to the bodyndasheven through clothesndashand represent
an attractive alternative for a wide range of new applications EPIC (Electric Potential Integrated Circuit) is a completely new sensor technology resulting from research at the University of Sussex (UK) Novel ultra high impedance EPIC sensors measure electric field changes without requiring physical or resistive contact This award winning patent-protected sensor can rapidly measure electric potential sources such as electrophysiological signals or even spatial electric fields It therefore has the ability to measure ECGs without direct skin contact By adjusting the DSP and amplification circuitry the sensors can be tuned for detection at a distance as required for differing automotive applications EPIC sensor electrodes can be easily and discretely incorporated inside car seat backs to acquire the necessary biometric data
Signals measured on the human body always include a large amount of noise the major component of this being 50 or 60 Hz power line noise capacitively-coupled to the body from the surrounding electricity supply Measurements such as ECG depend on being able to extract the small electrophysiological signals from the much larger noise signals EPIC sensors can be used in ldquocontact moderdquo for ECG measurement where the subject touches both the capacitive electrode surface and some metal at the system ground directly with the skin This ground reference allows filtering and differential amplification of signals from two sensors to be effective in removing the mains frequency noise leaving a high quality ECG signal In non-contact ECG measurement there is ndash by definition - no skin contact and thus no direct connection can be made between the subjectrsquos body and the system ground Some other method of reducing the power line noise is therefore required to
EPIC Sensors incontact with clothing
Conductive fabric in contactwith clothing eg on chair seat
Output
EPICdemo box
Figure 1 Basic configuration for non-contact ECG measurement including capacitively-oocupied DR circuit
OP-AMP
+5V
-5V
Vout
Rf (27KΩ)
Ra(11KΩ)
Rb(11KΩ)
Rp (15MΩ) To conductive fabric on chair thus capacitively coupled to body
Inputs from outputs of demo box
A
BC
(1nF)
Figure 2 DPL circuit Voltage gain is set by Rf Rp limits current fed back to the body (see text)Operational amplifier output Vout = - (VA + VB) Rf 11K
enable the ECG signal to be extracted reliably and accurately One such method utilizes an approach very similar to the ldquoDriven Right Legrdquo (DRL) system that is used for the same purpose in conventional ECG measurement techniques In conventional ECG the DRL signal is coupled directly to the patientrsquos skin The DRL signal reduces power line noise on the sensor signals by feeding back an inverted average of the signals from two sensors on to the patientrsquos body In non-contact ECG the generated DRL signal can be capacitively-coupled to the body through clothing via a piece of conductive material placed ndash for instance ndash on the seat or back of a chair Capacitive coupling of DRL signals is described by Lim et al1 and Lee et al2
SYSTEM DESIGNAn ECG system can therefore be built into a chair a mattress or clothing for instance The DRL circuit improves the sensor signalnoise ratio enormously In the example in Figure 1 EPIC sensors are mounted on a chair back such that the electrodes touch the clothing on the subjectrsquos back when resting normally against the back of the chair The generated DRL signal is connected to a piece of conductive material
placed either on the seat of the chair or at the bottom of the chair back contacting the subjectrsquos clothing in the normal sitting position Copper-coated nylon fabric is one possible material suitable for the DRL coupling material but other conductive materials may be equally successful A thin non- conductive material such as a cotton fabric may be used to cover both the sensors and the DRL coupling fabric if required for instance when building the sensors into a seat Consideration must be given as to how material will reduce the coupling capacitance between the sensor and the subject or add additional noise to the signals through static charging effectsFigure 2 shows the design of the DRL circuit It is a standard summing amplifier generating an amplified and inverted signal that is the average of the individual signals A and B
The optimum value for Rf will be dependent on the type of sensors being used as well as the clothing being worn by the subject being measured It should be set to achieve maximum noise reduction while ensuring circuit stability A value of 27kohms is suggested as a suitable starting point for EPIC sensors
15
TECH REPORT
15
Non-contact measurement of electrophysiological signals is of great interest in healthcare settings with the potential of reducing disposable costs speeding up or simplifying measurement techniques Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact Monitoring vehicle drivers for health and alertness by detecting heart rate and respiration or determining car occupancy to adjust the ride handling and air bag deployment with the varying size and location of occupants is a vast potential market
Capacitive (insulated) electrodes can register ECG signals without conductive contact to the bodyndasheven through clothesndashand represent
an attractive alternative for a wide range of new applications EPIC (Electric Potential Integrated Circuit) is a completely new sensor technology resulting from research at the University of Sussex (UK) Novel ultra high impedance EPIC sensors measure electric field changes without requiring physical or resistive contact This award winning patent-protected sensor can rapidly measure electric potential sources such as electrophysiological signals or even spatial electric fields It therefore has the ability to measure ECGs without direct skin contact By adjusting the DSP and amplification circuitry the sensors can be tuned for detection at a distance as required for differing automotive applications EPIC sensor electrodes can be easily and discretely incorporated inside car seat backs to acquire the necessary biometric data
Signals measured on the human body always include a large amount of noise the major component of this being 50 or 60 Hz power line noise capacitively-coupled to the body from the surrounding electricity supply Measurements such as ECG depend on being able to extract the small electrophysiological signals from the much larger noise signals EPIC sensors can be used in ldquocontact moderdquo for ECG measurement where the subject touches both the capacitive electrode surface and some metal at the system ground directly with the skin This ground reference allows filtering and differential amplification of signals from two sensors to be effective in removing the mains frequency noise leaving a high quality ECG signal In non-contact ECG measurement there is ndash by definition - no skin contact and thus no direct connection can be made between the subjectrsquos body and the system ground Some other method of reducing the power line noise is therefore required to
EPIC Sensors incontact with clothing
Conductive fabric in contactwith clothing eg on chair seat
Output
EPICdemo box
Figure 1 Basic configuration for non-contact ECG measurement including capacitively-oocupied DR circuit
OP-AMP
+5V
-5V
Vout
Rf (27KΩ)
Ra(11KΩ)
Rb(11KΩ)
Rp (15MΩ) To conductive fabric on chair thus capacitively coupled to body
Inputs from outputs of demo box
A
BC
(1nF)
Figure 2 DPL circuit Voltage gain is set by Rf Rp limits current fed back to the body (see text)Operational amplifier output Vout = - (VA + VB) Rf 11K
enable the ECG signal to be extracted reliably and accurately One such method utilizes an approach very similar to the ldquoDriven Right Legrdquo (DRL) system that is used for the same purpose in conventional ECG measurement techniques In conventional ECG the DRL signal is coupled directly to the patientrsquos skin The DRL signal reduces power line noise on the sensor signals by feeding back an inverted average of the signals from two sensors on to the patientrsquos body In non-contact ECG the generated DRL signal can be capacitively-coupled to the body through clothing via a piece of conductive material placed ndash for instance ndash on the seat or back of a chair Capacitive coupling of DRL signals is described by Lim et al1 and Lee et al2
SYSTEM DESIGNAn ECG system can therefore be built into a chair a mattress or clothing for instance The DRL circuit improves the sensor signalnoise ratio enormously In the example in Figure 1 EPIC sensors are mounted on a chair back such that the electrodes touch the clothing on the subjectrsquos back when resting normally against the back of the chair The generated DRL signal is connected to a piece of conductive material
placed either on the seat of the chair or at the bottom of the chair back contacting the subjectrsquos clothing in the normal sitting position Copper-coated nylon fabric is one possible material suitable for the DRL coupling material but other conductive materials may be equally successful A thin non- conductive material such as a cotton fabric may be used to cover both the sensors and the DRL coupling fabric if required for instance when building the sensors into a seat Consideration must be given as to how material will reduce the coupling capacitance between the sensor and the subject or add additional noise to the signals through static charging effectsFigure 2 shows the design of the DRL circuit It is a standard summing amplifier generating an amplified and inverted signal that is the average of the individual signals A and B
The optimum value for Rf will be dependent on the type of sensors being used as well as the clothing being worn by the subject being measured It should be set to achieve maximum noise reduction while ensuring circuit stability A value of 27kohms is suggested as a suitable starting point for EPIC sensors
1616
SENSOR TECHNOLOGY
Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact
7660SwitchedCapacitorVoltage
Converter
1
2
3
4
8
7
6
5
OP-AMP
Rb(11K)
Ra(11K)
Rf (27KΩ)
Rp (15MΩ)DRLOutput
1nFVout
6Vbatterypack4xAA
+6V
-6V10microF
10microF
A
B
Figure 3 DRL circuit including battery power supply and voltage converter to provide -6v rail Inputs A and B are buffered outputs from the sensors and may be taken from the A and B outputs of the EPIC demo box Ground should be connected to the sensor 0V the shielding of the BNC A and B outputs on the demo box being a suitable connection point See figure 2 and the text for further comments on the DRL design
sensors and the DRL circuit into saturation Because the system contains some large impedances and hence has some very long RC time constants settling times of tens of seconds can be needed before a clean ECG signal is seen During this period the signal can either appear very noisy or be virtually flat depending on whether one or both sensors or the DRL circuit are ldquorailingrdquo The subject should sit still during this time and wait for the circuit to settle since continually adjusting position will only make matters worse Settling times can sometimes be reduced by turning off the power to the demo box for a few seconds
CLOTHINGGood results can be obtained with one or two layers of cotton material between the sensors and the skin Other materials including a wool-mix sweater and a polyester fleece in addition
to two layers of cotton material have been successful Examples are shown in Figures 6 and 7 If the key greatest interest is in the ldquoR-Rrdquo interval adjusting filter settings to reduce or re-center the signal bandwidth can give improved signal quality
STATICBecause there is no direct physical contact between the subject and any grounding point there is no path for any static build up to be discharged Under most circumstances static build-up does not present a problem butdepending on factors including clothing footwear flooring humidity levels in the air and so forth static build up can sometimes prevent the cardiac signal from being seen clearly Product design must take into account a discharge to the system ground to remove the static charge
Rp the protection resistor is included to limit the current that can be fed back to the human body This resistor is essential in ensuring that the subjectrsquos wellbeing is not endangered and must not be omitted
IMPLEMENTATIONThe demonstration of non-contact ECG is best performed using an EPIC demonstration kit Plessey part no PS25003 which includes the necessary drive circuitry and switchable 50Hz and 60Hz notch filters The inputs to the DRL circuit can be taken from the BNC outputs ldquoA amp Brdquo on the front of the demo box The DRL circuit will require its own bipolar power supply plusmn5V or plusmn6V is suggested A circuit design including a battery power supply is shown in Figure 3
Plesseyrsquos compact sensors (PS2520x) and disc sensors (PS25101) provide equally good results although for demonstration purposes disc sensors are simplest to fix to a chair to make contact with the occupantrsquos back Compact sensors are recommended when designing a custom-built system
EPIC sensors which are designed for contact electrophysiology sensing give excellent results in most cases Initial trials suggest that custom modifications to the sensor design (eg lower gain and higher input impedance) can offer increased sensitivity and the ability to detect weaker ECG signalsThe shape of the measured ECG trace ndash in terms of relative magnitudes of the P Q R S and T waves ndash will depend on the positioning of the sensors behind the subjectrsquos back If the desire is only to measure the ldquoR-Rrdquo interval to determine heart rate then the positioning of the sensors is not critical Placing one sensor either side of the spine separated by 6rdquo -10rdquo (15-25 cm) at approximately the same height as the heart is recommended as a starting point For applications where signals from other parts of the cardiac cycle are required the user should refer to texts on bio-electronic signals for guidance on sensor position
SETTLING TIMEWhen a subject first sits in the chair and leans against the EPIC sensors the changes in electric potential will normally send both the
17
TECH REPORT
17
Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact
7660SwitchedCapacitorVoltage
Converter
1
2
3
4
8
7
6
5
OP-AMP
Rb(11K)
Ra(11K)
Rf (27KΩ)
Rp (15MΩ)DRLOutput
1nFVout
6Vbatterypack4xAA
+6V
-6V10microF
10microF
A
B
Figure 3 DRL circuit including battery power supply and voltage converter to provide -6v rail Inputs A and B are buffered outputs from the sensors and may be taken from the A and B outputs of the EPIC demo box Ground should be connected to the sensor 0V the shielding of the BNC A and B outputs on the demo box being a suitable connection point See figure 2 and the text for further comments on the DRL design
sensors and the DRL circuit into saturation Because the system contains some large impedances and hence has some very long RC time constants settling times of tens of seconds can be needed before a clean ECG signal is seen During this period the signal can either appear very noisy or be virtually flat depending on whether one or both sensors or the DRL circuit are ldquorailingrdquo The subject should sit still during this time and wait for the circuit to settle since continually adjusting position will only make matters worse Settling times can sometimes be reduced by turning off the power to the demo box for a few seconds
CLOTHINGGood results can be obtained with one or two layers of cotton material between the sensors and the skin Other materials including a wool-mix sweater and a polyester fleece in addition
to two layers of cotton material have been successful Examples are shown in Figures 6 and 7 If the key greatest interest is in the ldquoR-Rrdquo interval adjusting filter settings to reduce or re-center the signal bandwidth can give improved signal quality
STATICBecause there is no direct physical contact between the subject and any grounding point there is no path for any static build up to be discharged Under most circumstances static build-up does not present a problem butdepending on factors including clothing footwear flooring humidity levels in the air and so forth static build up can sometimes prevent the cardiac signal from being seen clearly Product design must take into account a discharge to the system ground to remove the static charge
Rp the protection resistor is included to limit the current that can be fed back to the human body This resistor is essential in ensuring that the subjectrsquos wellbeing is not endangered and must not be omitted
IMPLEMENTATIONThe demonstration of non-contact ECG is best performed using an EPIC demonstration kit Plessey part no PS25003 which includes the necessary drive circuitry and switchable 50Hz and 60Hz notch filters The inputs to the DRL circuit can be taken from the BNC outputs ldquoA amp Brdquo on the front of the demo box The DRL circuit will require its own bipolar power supply plusmn5V or plusmn6V is suggested A circuit design including a battery power supply is shown in Figure 3
Plesseyrsquos compact sensors (PS2520x) and disc sensors (PS25101) provide equally good results although for demonstration purposes disc sensors are simplest to fix to a chair to make contact with the occupantrsquos back Compact sensors are recommended when designing a custom-built system
EPIC sensors which are designed for contact electrophysiology sensing give excellent results in most cases Initial trials suggest that custom modifications to the sensor design (eg lower gain and higher input impedance) can offer increased sensitivity and the ability to detect weaker ECG signalsThe shape of the measured ECG trace ndash in terms of relative magnitudes of the P Q R S and T waves ndash will depend on the positioning of the sensors behind the subjectrsquos back If the desire is only to measure the ldquoR-Rrdquo interval to determine heart rate then the positioning of the sensors is not critical Placing one sensor either side of the spine separated by 6rdquo -10rdquo (15-25 cm) at approximately the same height as the heart is recommended as a starting point For applications where signals from other parts of the cardiac cycle are required the user should refer to texts on bio-electronic signals for guidance on sensor position
SETTLING TIMEWhen a subject first sits in the chair and leans against the EPIC sensors the changes in electric potential will normally send both the
1818
SENSOR TECHNOLOGY
Figure 4 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit HP filter corner frequency is 50mHz LP filter in demo box has corner frequency of 30Hz
Figure 6 ECG signals measured from a subject wearing a wool-mix sweater over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 8-25Hz The heart rate can be easily extracted
Figure 5 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit Software filters limit the bandwidth to 8-25Hz
Figure 7 ECG signals measured from a subject wearing a polyester fleece over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 16-40Hz The heart rate can be easily extracted
CABLE SHIELDINGCareful shielding is necessary to reduce unwanted noise artifacts Grounding the shielding of the sensor cable via the connection between the outer casing of the sensor plugs and the metal surround of the socket on the control electronics is recommended
CONCLUSIONEPIC sensors can be used to measure ECG signals without physical skin contact While
sensors can be embedded in a chair or seat the techniques are equally applicable to sensors mounted on a mattress in clothing or in other situations There are many variables that will affect signal quality from the strength of cardiac signal generated by the individual being measured to clothing to the surrounding environment but the designs given here are a starting point in establishing an optimum system for a particular application infin
Find us at Booth 37310World Maker Faire New York
Figure 4 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit HP filter corner frequency is 50mHz LP filter in demo box has corner frequency of 30Hz
Figure 6 ECG signals measured from a subject wearing a wool-mix sweater over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 8-25Hz The heart rate can be easily extracted
Figure 5 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit Software filters limit the bandwidth to 8-25Hz
Figure 7 ECG signals measured from a subject wearing a polyester fleece over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 16-40Hz The heart rate can be easily extracted
CABLE SHIELDINGCareful shielding is necessary to reduce unwanted noise artifacts Grounding the shielding of the sensor cable via the connection between the outer casing of the sensor plugs and the metal surround of the socket on the control electronics is recommended
CONCLUSIONEPIC sensors can be used to measure ECG signals without physical skin contact While
sensors can be embedded in a chair or seat the techniques are equally applicable to sensors mounted on a mattress in clothing or in other situations There are many variables that will affect signal quality from the strength of cardiac signal generated by the individual being measured to clothing to the surrounding environment but the designs given here are a starting point in establishing an optimum system for a particular application infin
Find us at Booth 37310World Maker Faire New York
20
SENSOR TECHNOLOGY
SmallerThan a
Grain Sand
of
Analysts project that by
2020 there will be over
50 billion connected
devices in the now-nascent
Internet of Things (IoT) However
the technology that will enable the
IoT of the future may look a little
different than todayrsquosmdashin fact
you may not be able to see it at all
Many new mobile devices require
motion sensors in order to monitor
analyze and deliver real-time data
and analysis to improve the way
consumers interact with everyday
technology While traditional
sensor platforms require multichip
modules or stacked die within a
device mCube a new MEMS sensor
company is driving the emergence
of Sensor 30 which will lead the
development of the smallest
sensors to datemdashsmaller than a
grain of sand By EEWeb Contributing Writers
mCubersquos Sensors Enable IoMTInterview with Ben Lee President and CEO of mCube
INDUSTRY INTERVIEW
21
SmallerThan a
Grain Sand
of
Analysts project that by
2020 there will be over
50 billion connected
devices in the now-nascent
Internet of Things (IoT) However
the technology that will enable the
IoT of the future may look a little
different than todayrsquosmdashin fact
you may not be able to see it at all
Many new mobile devices require
motion sensors in order to monitor
analyze and deliver real-time data
and analysis to improve the way
consumers interact with everyday
technology While traditional
sensor platforms require multichip
modules or stacked die within a
device mCube a new MEMS sensor
company is driving the emergence
of Sensor 30 which will lead the
development of the smallest
sensors to datemdashsmaller than a
grain of sand By EEWeb Contributing Writers
mCubersquos Sensors Enable IoMTInterview with Ben Lee President and CEO of mCube
22
SENSOR TECHNOLOGY
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
INDUSTRY INTERVIEW
23
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
24
SENSOR TECHNOLOGY
Since sensors are so small and affordable donrsquot be surprised to find unique applications in the future Lee speculates that ldquofarmers might have sensor tags to monitor livestock for abnormal activity patterns of grazing potential illness and herd behaviorrdquo Commercial trucking might involve motion sensors connected to video cameras in rear-view mirrors to better assess the cause of an accident and driving conditions For shipping Lee describes ldquomotion sensors embedded directly onto packages to record jarring motions or accidents in order to determine when and how contents were damagedrdquo
As of 2014 mCubersquos complete intertial sensor portfolio contains an accelerometer magnetometer and its proprietary iGyrotrade gyroscope offering nine degrees of freedom (9DoF) Through reductions in cost power consumption and size mCubersquos sensor offerings make it possible to place them onto nearly any object or devicemdashin some cases without packaging ldquoWe aspire to put one or more MEMS motion sensors on anything that movesrdquo remarks Lee And with the IoMT taking shape and consumer expectations for connected moving devices becoming more concrete developers of new applications will turn to solutions like mCube to deliver truly cutting-edge connected devices
ldquoAt mCube we aspire to put one or more MEMS motion sensors on
anything that movesrdquo
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 15
Complete Inertial Motion Sensor Portfolio
Solutions for up to 9DoF (Degrees of Freedom)
Accelerometer
Magnetometer
iGyroTM
3DoF 3DoF
9DoF
2x2mm
3x3mm 3DoF 6DoF
14x14mm
3x3mm
3x3mm
2626
SENSOR TECHNOLOGY
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
27
TECH REPORT
27
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
2828
SENSOR TECHNOLOGY
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
29
TECH REPORT
29
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
3030
SENSOR TECHNOLOGY
to enable the kind of constant and complex data accumulation that the Biostamp promises
In the interim MC10 is partnering up with other medical and pharmaceutical companies to develop integrated sensor and monitoring products The company plans to become a certified medical-ready partner for companies who donrsquot have access to this unique and proprietary technology Even the US Army has begun working with MC10 on military-grade sensors that will add further safety features for troops in the field This funding from NIH grants Department of Defense grants as well as foundation grants will help the company get one step closer to realization of devices so flexible that users might forget theyrsquore wearing them
ldquoThe company has been bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devicesrdquo
Join the
DESIGNERS OF THINGS conference in San Francisco on
September 23 and 24
Dedicated to the explosive and exciting potential of Wearable
Tech 3D Printing and the Internet of Things the conference
provides the growing design and development community
around these technologies a meeting place to discuss and
showcase the newest products
Click here for more info
httpwwwdesignersofthingscomsanfranciscoscheduler
speakersheth-nirav-rav33310
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Sierra CircuitsA Complete PCB Resource
PLUS The Ground rdquo Myth in PrintedCircuits
ldquo
PCB Resin Reactor+
Ken BahlCEO of Sierra Circuits
Let There Be
How Cree reinvented the light bulb
LIGHT
David ElienVP of Marketing amp Business
Development Cree Inc
New LED Filament Tower
Cutting Edge Flatscreen Technologies
+
+
M o v i n g T o w a r d s
a Clean Energy
FUTUREmdash Hugo van Nispen COO of DNV KEMA
MCU Wars 32-bit MCU Comparison
Cutting Edge
SPICEModeling
Freescale and TI Embedded
Modules
ARMCortex
Programming
From Concept to
Reality Wolfgang Heinz-Fischer
Head of Marketing amp PR TQ-Group
Low-Power Design Techniques
TQ-Grouprsquos Comprehensive Design Process
+
+
PowerDeveloper
Octobe r 20 13
Designing forDurability
View more EEWeb magazinesmdash Click Here
1414
SENSOR TECHNOLOGY
Non-contact measurement of electrophysiological signals is of great interest in healthcare settings with the potential of reducing disposable costs speeding up or simplifying measurement techniques Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact Monitoring vehicle drivers for health and alertness by detecting heart rate and respiration or determining car occupancy to adjust the ride handling and air bag deployment with the varying size and location of occupants is a vast potential market
Capacitive (insulated) electrodes can register ECG signals without conductive contact to the bodyndasheven through clothesndashand represent
an attractive alternative for a wide range of new applications EPIC (Electric Potential Integrated Circuit) is a completely new sensor technology resulting from research at the University of Sussex (UK) Novel ultra high impedance EPIC sensors measure electric field changes without requiring physical or resistive contact This award winning patent-protected sensor can rapidly measure electric potential sources such as electrophysiological signals or even spatial electric fields It therefore has the ability to measure ECGs without direct skin contact By adjusting the DSP and amplification circuitry the sensors can be tuned for detection at a distance as required for differing automotive applications EPIC sensor electrodes can be easily and discretely incorporated inside car seat backs to acquire the necessary biometric data
Signals measured on the human body always include a large amount of noise the major component of this being 50 or 60 Hz power line noise capacitively-coupled to the body from the surrounding electricity supply Measurements such as ECG depend on being able to extract the small electrophysiological signals from the much larger noise signals EPIC sensors can be used in ldquocontact moderdquo for ECG measurement where the subject touches both the capacitive electrode surface and some metal at the system ground directly with the skin This ground reference allows filtering and differential amplification of signals from two sensors to be effective in removing the mains frequency noise leaving a high quality ECG signal In non-contact ECG measurement there is ndash by definition - no skin contact and thus no direct connection can be made between the subjectrsquos body and the system ground Some other method of reducing the power line noise is therefore required to
EPIC Sensors incontact with clothing
Conductive fabric in contactwith clothing eg on chair seat
Output
EPICdemo box
Figure 1 Basic configuration for non-contact ECG measurement including capacitively-oocupied DR circuit
OP-AMP
+5V
-5V
Vout
Rf (27KΩ)
Ra(11KΩ)
Rb(11KΩ)
Rp (15MΩ) To conductive fabric on chair thus capacitively coupled to body
Inputs from outputs of demo box
A
BC
(1nF)
Figure 2 DPL circuit Voltage gain is set by Rf Rp limits current fed back to the body (see text)Operational amplifier output Vout = - (VA + VB) Rf 11K
enable the ECG signal to be extracted reliably and accurately One such method utilizes an approach very similar to the ldquoDriven Right Legrdquo (DRL) system that is used for the same purpose in conventional ECG measurement techniques In conventional ECG the DRL signal is coupled directly to the patientrsquos skin The DRL signal reduces power line noise on the sensor signals by feeding back an inverted average of the signals from two sensors on to the patientrsquos body In non-contact ECG the generated DRL signal can be capacitively-coupled to the body through clothing via a piece of conductive material placed ndash for instance ndash on the seat or back of a chair Capacitive coupling of DRL signals is described by Lim et al1 and Lee et al2
SYSTEM DESIGNAn ECG system can therefore be built into a chair a mattress or clothing for instance The DRL circuit improves the sensor signalnoise ratio enormously In the example in Figure 1 EPIC sensors are mounted on a chair back such that the electrodes touch the clothing on the subjectrsquos back when resting normally against the back of the chair The generated DRL signal is connected to a piece of conductive material
placed either on the seat of the chair or at the bottom of the chair back contacting the subjectrsquos clothing in the normal sitting position Copper-coated nylon fabric is one possible material suitable for the DRL coupling material but other conductive materials may be equally successful A thin non- conductive material such as a cotton fabric may be used to cover both the sensors and the DRL coupling fabric if required for instance when building the sensors into a seat Consideration must be given as to how material will reduce the coupling capacitance between the sensor and the subject or add additional noise to the signals through static charging effectsFigure 2 shows the design of the DRL circuit It is a standard summing amplifier generating an amplified and inverted signal that is the average of the individual signals A and B
The optimum value for Rf will be dependent on the type of sensors being used as well as the clothing being worn by the subject being measured It should be set to achieve maximum noise reduction while ensuring circuit stability A value of 27kohms is suggested as a suitable starting point for EPIC sensors
15
TECH REPORT
15
Non-contact measurement of electrophysiological signals is of great interest in healthcare settings with the potential of reducing disposable costs speeding up or simplifying measurement techniques Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact Monitoring vehicle drivers for health and alertness by detecting heart rate and respiration or determining car occupancy to adjust the ride handling and air bag deployment with the varying size and location of occupants is a vast potential market
Capacitive (insulated) electrodes can register ECG signals without conductive contact to the bodyndasheven through clothesndashand represent
an attractive alternative for a wide range of new applications EPIC (Electric Potential Integrated Circuit) is a completely new sensor technology resulting from research at the University of Sussex (UK) Novel ultra high impedance EPIC sensors measure electric field changes without requiring physical or resistive contact This award winning patent-protected sensor can rapidly measure electric potential sources such as electrophysiological signals or even spatial electric fields It therefore has the ability to measure ECGs without direct skin contact By adjusting the DSP and amplification circuitry the sensors can be tuned for detection at a distance as required for differing automotive applications EPIC sensor electrodes can be easily and discretely incorporated inside car seat backs to acquire the necessary biometric data
Signals measured on the human body always include a large amount of noise the major component of this being 50 or 60 Hz power line noise capacitively-coupled to the body from the surrounding electricity supply Measurements such as ECG depend on being able to extract the small electrophysiological signals from the much larger noise signals EPIC sensors can be used in ldquocontact moderdquo for ECG measurement where the subject touches both the capacitive electrode surface and some metal at the system ground directly with the skin This ground reference allows filtering and differential amplification of signals from two sensors to be effective in removing the mains frequency noise leaving a high quality ECG signal In non-contact ECG measurement there is ndash by definition - no skin contact and thus no direct connection can be made between the subjectrsquos body and the system ground Some other method of reducing the power line noise is therefore required to
EPIC Sensors incontact with clothing
Conductive fabric in contactwith clothing eg on chair seat
Output
EPICdemo box
Figure 1 Basic configuration for non-contact ECG measurement including capacitively-oocupied DR circuit
OP-AMP
+5V
-5V
Vout
Rf (27KΩ)
Ra(11KΩ)
Rb(11KΩ)
Rp (15MΩ) To conductive fabric on chair thus capacitively coupled to body
Inputs from outputs of demo box
A
BC
(1nF)
Figure 2 DPL circuit Voltage gain is set by Rf Rp limits current fed back to the body (see text)Operational amplifier output Vout = - (VA + VB) Rf 11K
enable the ECG signal to be extracted reliably and accurately One such method utilizes an approach very similar to the ldquoDriven Right Legrdquo (DRL) system that is used for the same purpose in conventional ECG measurement techniques In conventional ECG the DRL signal is coupled directly to the patientrsquos skin The DRL signal reduces power line noise on the sensor signals by feeding back an inverted average of the signals from two sensors on to the patientrsquos body In non-contact ECG the generated DRL signal can be capacitively-coupled to the body through clothing via a piece of conductive material placed ndash for instance ndash on the seat or back of a chair Capacitive coupling of DRL signals is described by Lim et al1 and Lee et al2
SYSTEM DESIGNAn ECG system can therefore be built into a chair a mattress or clothing for instance The DRL circuit improves the sensor signalnoise ratio enormously In the example in Figure 1 EPIC sensors are mounted on a chair back such that the electrodes touch the clothing on the subjectrsquos back when resting normally against the back of the chair The generated DRL signal is connected to a piece of conductive material
placed either on the seat of the chair or at the bottom of the chair back contacting the subjectrsquos clothing in the normal sitting position Copper-coated nylon fabric is one possible material suitable for the DRL coupling material but other conductive materials may be equally successful A thin non- conductive material such as a cotton fabric may be used to cover both the sensors and the DRL coupling fabric if required for instance when building the sensors into a seat Consideration must be given as to how material will reduce the coupling capacitance between the sensor and the subject or add additional noise to the signals through static charging effectsFigure 2 shows the design of the DRL circuit It is a standard summing amplifier generating an amplified and inverted signal that is the average of the individual signals A and B
The optimum value for Rf will be dependent on the type of sensors being used as well as the clothing being worn by the subject being measured It should be set to achieve maximum noise reduction while ensuring circuit stability A value of 27kohms is suggested as a suitable starting point for EPIC sensors
1616
SENSOR TECHNOLOGY
Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact
7660SwitchedCapacitorVoltage
Converter
1
2
3
4
8
7
6
5
OP-AMP
Rb(11K)
Ra(11K)
Rf (27KΩ)
Rp (15MΩ)DRLOutput
1nFVout
6Vbatterypack4xAA
+6V
-6V10microF
10microF
A
B
Figure 3 DRL circuit including battery power supply and voltage converter to provide -6v rail Inputs A and B are buffered outputs from the sensors and may be taken from the A and B outputs of the EPIC demo box Ground should be connected to the sensor 0V the shielding of the BNC A and B outputs on the demo box being a suitable connection point See figure 2 and the text for further comments on the DRL design
sensors and the DRL circuit into saturation Because the system contains some large impedances and hence has some very long RC time constants settling times of tens of seconds can be needed before a clean ECG signal is seen During this period the signal can either appear very noisy or be virtually flat depending on whether one or both sensors or the DRL circuit are ldquorailingrdquo The subject should sit still during this time and wait for the circuit to settle since continually adjusting position will only make matters worse Settling times can sometimes be reduced by turning off the power to the demo box for a few seconds
CLOTHINGGood results can be obtained with one or two layers of cotton material between the sensors and the skin Other materials including a wool-mix sweater and a polyester fleece in addition
to two layers of cotton material have been successful Examples are shown in Figures 6 and 7 If the key greatest interest is in the ldquoR-Rrdquo interval adjusting filter settings to reduce or re-center the signal bandwidth can give improved signal quality
STATICBecause there is no direct physical contact between the subject and any grounding point there is no path for any static build up to be discharged Under most circumstances static build-up does not present a problem butdepending on factors including clothing footwear flooring humidity levels in the air and so forth static build up can sometimes prevent the cardiac signal from being seen clearly Product design must take into account a discharge to the system ground to remove the static charge
Rp the protection resistor is included to limit the current that can be fed back to the human body This resistor is essential in ensuring that the subjectrsquos wellbeing is not endangered and must not be omitted
IMPLEMENTATIONThe demonstration of non-contact ECG is best performed using an EPIC demonstration kit Plessey part no PS25003 which includes the necessary drive circuitry and switchable 50Hz and 60Hz notch filters The inputs to the DRL circuit can be taken from the BNC outputs ldquoA amp Brdquo on the front of the demo box The DRL circuit will require its own bipolar power supply plusmn5V or plusmn6V is suggested A circuit design including a battery power supply is shown in Figure 3
Plesseyrsquos compact sensors (PS2520x) and disc sensors (PS25101) provide equally good results although for demonstration purposes disc sensors are simplest to fix to a chair to make contact with the occupantrsquos back Compact sensors are recommended when designing a custom-built system
EPIC sensors which are designed for contact electrophysiology sensing give excellent results in most cases Initial trials suggest that custom modifications to the sensor design (eg lower gain and higher input impedance) can offer increased sensitivity and the ability to detect weaker ECG signalsThe shape of the measured ECG trace ndash in terms of relative magnitudes of the P Q R S and T waves ndash will depend on the positioning of the sensors behind the subjectrsquos back If the desire is only to measure the ldquoR-Rrdquo interval to determine heart rate then the positioning of the sensors is not critical Placing one sensor either side of the spine separated by 6rdquo -10rdquo (15-25 cm) at approximately the same height as the heart is recommended as a starting point For applications where signals from other parts of the cardiac cycle are required the user should refer to texts on bio-electronic signals for guidance on sensor position
SETTLING TIMEWhen a subject first sits in the chair and leans against the EPIC sensors the changes in electric potential will normally send both the
17
TECH REPORT
17
Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact
7660SwitchedCapacitorVoltage
Converter
1
2
3
4
8
7
6
5
OP-AMP
Rb(11K)
Ra(11K)
Rf (27KΩ)
Rp (15MΩ)DRLOutput
1nFVout
6Vbatterypack4xAA
+6V
-6V10microF
10microF
A
B
Figure 3 DRL circuit including battery power supply and voltage converter to provide -6v rail Inputs A and B are buffered outputs from the sensors and may be taken from the A and B outputs of the EPIC demo box Ground should be connected to the sensor 0V the shielding of the BNC A and B outputs on the demo box being a suitable connection point See figure 2 and the text for further comments on the DRL design
sensors and the DRL circuit into saturation Because the system contains some large impedances and hence has some very long RC time constants settling times of tens of seconds can be needed before a clean ECG signal is seen During this period the signal can either appear very noisy or be virtually flat depending on whether one or both sensors or the DRL circuit are ldquorailingrdquo The subject should sit still during this time and wait for the circuit to settle since continually adjusting position will only make matters worse Settling times can sometimes be reduced by turning off the power to the demo box for a few seconds
CLOTHINGGood results can be obtained with one or two layers of cotton material between the sensors and the skin Other materials including a wool-mix sweater and a polyester fleece in addition
to two layers of cotton material have been successful Examples are shown in Figures 6 and 7 If the key greatest interest is in the ldquoR-Rrdquo interval adjusting filter settings to reduce or re-center the signal bandwidth can give improved signal quality
STATICBecause there is no direct physical contact between the subject and any grounding point there is no path for any static build up to be discharged Under most circumstances static build-up does not present a problem butdepending on factors including clothing footwear flooring humidity levels in the air and so forth static build up can sometimes prevent the cardiac signal from being seen clearly Product design must take into account a discharge to the system ground to remove the static charge
Rp the protection resistor is included to limit the current that can be fed back to the human body This resistor is essential in ensuring that the subjectrsquos wellbeing is not endangered and must not be omitted
IMPLEMENTATIONThe demonstration of non-contact ECG is best performed using an EPIC demonstration kit Plessey part no PS25003 which includes the necessary drive circuitry and switchable 50Hz and 60Hz notch filters The inputs to the DRL circuit can be taken from the BNC outputs ldquoA amp Brdquo on the front of the demo box The DRL circuit will require its own bipolar power supply plusmn5V or plusmn6V is suggested A circuit design including a battery power supply is shown in Figure 3
Plesseyrsquos compact sensors (PS2520x) and disc sensors (PS25101) provide equally good results although for demonstration purposes disc sensors are simplest to fix to a chair to make contact with the occupantrsquos back Compact sensors are recommended when designing a custom-built system
EPIC sensors which are designed for contact electrophysiology sensing give excellent results in most cases Initial trials suggest that custom modifications to the sensor design (eg lower gain and higher input impedance) can offer increased sensitivity and the ability to detect weaker ECG signalsThe shape of the measured ECG trace ndash in terms of relative magnitudes of the P Q R S and T waves ndash will depend on the positioning of the sensors behind the subjectrsquos back If the desire is only to measure the ldquoR-Rrdquo interval to determine heart rate then the positioning of the sensors is not critical Placing one sensor either side of the spine separated by 6rdquo -10rdquo (15-25 cm) at approximately the same height as the heart is recommended as a starting point For applications where signals from other parts of the cardiac cycle are required the user should refer to texts on bio-electronic signals for guidance on sensor position
SETTLING TIMEWhen a subject first sits in the chair and leans against the EPIC sensors the changes in electric potential will normally send both the
1818
SENSOR TECHNOLOGY
Figure 4 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit HP filter corner frequency is 50mHz LP filter in demo box has corner frequency of 30Hz
Figure 6 ECG signals measured from a subject wearing a wool-mix sweater over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 8-25Hz The heart rate can be easily extracted
Figure 5 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit Software filters limit the bandwidth to 8-25Hz
Figure 7 ECG signals measured from a subject wearing a polyester fleece over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 16-40Hz The heart rate can be easily extracted
CABLE SHIELDINGCareful shielding is necessary to reduce unwanted noise artifacts Grounding the shielding of the sensor cable via the connection between the outer casing of the sensor plugs and the metal surround of the socket on the control electronics is recommended
CONCLUSIONEPIC sensors can be used to measure ECG signals without physical skin contact While
sensors can be embedded in a chair or seat the techniques are equally applicable to sensors mounted on a mattress in clothing or in other situations There are many variables that will affect signal quality from the strength of cardiac signal generated by the individual being measured to clothing to the surrounding environment but the designs given here are a starting point in establishing an optimum system for a particular application infin
Find us at Booth 37310World Maker Faire New York
Figure 4 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit HP filter corner frequency is 50mHz LP filter in demo box has corner frequency of 30Hz
Figure 6 ECG signals measured from a subject wearing a wool-mix sweater over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 8-25Hz The heart rate can be easily extracted
Figure 5 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit Software filters limit the bandwidth to 8-25Hz
Figure 7 ECG signals measured from a subject wearing a polyester fleece over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 16-40Hz The heart rate can be easily extracted
CABLE SHIELDINGCareful shielding is necessary to reduce unwanted noise artifacts Grounding the shielding of the sensor cable via the connection between the outer casing of the sensor plugs and the metal surround of the socket on the control electronics is recommended
CONCLUSIONEPIC sensors can be used to measure ECG signals without physical skin contact While
sensors can be embedded in a chair or seat the techniques are equally applicable to sensors mounted on a mattress in clothing or in other situations There are many variables that will affect signal quality from the strength of cardiac signal generated by the individual being measured to clothing to the surrounding environment but the designs given here are a starting point in establishing an optimum system for a particular application infin
Find us at Booth 37310World Maker Faire New York
20
SENSOR TECHNOLOGY
SmallerThan a
Grain Sand
of
Analysts project that by
2020 there will be over
50 billion connected
devices in the now-nascent
Internet of Things (IoT) However
the technology that will enable the
IoT of the future may look a little
different than todayrsquosmdashin fact
you may not be able to see it at all
Many new mobile devices require
motion sensors in order to monitor
analyze and deliver real-time data
and analysis to improve the way
consumers interact with everyday
technology While traditional
sensor platforms require multichip
modules or stacked die within a
device mCube a new MEMS sensor
company is driving the emergence
of Sensor 30 which will lead the
development of the smallest
sensors to datemdashsmaller than a
grain of sand By EEWeb Contributing Writers
mCubersquos Sensors Enable IoMTInterview with Ben Lee President and CEO of mCube
INDUSTRY INTERVIEW
21
SmallerThan a
Grain Sand
of
Analysts project that by
2020 there will be over
50 billion connected
devices in the now-nascent
Internet of Things (IoT) However
the technology that will enable the
IoT of the future may look a little
different than todayrsquosmdashin fact
you may not be able to see it at all
Many new mobile devices require
motion sensors in order to monitor
analyze and deliver real-time data
and analysis to improve the way
consumers interact with everyday
technology While traditional
sensor platforms require multichip
modules or stacked die within a
device mCube a new MEMS sensor
company is driving the emergence
of Sensor 30 which will lead the
development of the smallest
sensors to datemdashsmaller than a
grain of sand By EEWeb Contributing Writers
mCubersquos Sensors Enable IoMTInterview with Ben Lee President and CEO of mCube
22
SENSOR TECHNOLOGY
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
INDUSTRY INTERVIEW
23
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
24
SENSOR TECHNOLOGY
Since sensors are so small and affordable donrsquot be surprised to find unique applications in the future Lee speculates that ldquofarmers might have sensor tags to monitor livestock for abnormal activity patterns of grazing potential illness and herd behaviorrdquo Commercial trucking might involve motion sensors connected to video cameras in rear-view mirrors to better assess the cause of an accident and driving conditions For shipping Lee describes ldquomotion sensors embedded directly onto packages to record jarring motions or accidents in order to determine when and how contents were damagedrdquo
As of 2014 mCubersquos complete intertial sensor portfolio contains an accelerometer magnetometer and its proprietary iGyrotrade gyroscope offering nine degrees of freedom (9DoF) Through reductions in cost power consumption and size mCubersquos sensor offerings make it possible to place them onto nearly any object or devicemdashin some cases without packaging ldquoWe aspire to put one or more MEMS motion sensors on anything that movesrdquo remarks Lee And with the IoMT taking shape and consumer expectations for connected moving devices becoming more concrete developers of new applications will turn to solutions like mCube to deliver truly cutting-edge connected devices
ldquoAt mCube we aspire to put one or more MEMS motion sensors on
anything that movesrdquo
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 15
Complete Inertial Motion Sensor Portfolio
Solutions for up to 9DoF (Degrees of Freedom)
Accelerometer
Magnetometer
iGyroTM
3DoF 3DoF
9DoF
2x2mm
3x3mm 3DoF 6DoF
14x14mm
3x3mm
3x3mm
2626
SENSOR TECHNOLOGY
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
27
TECH REPORT
27
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
2828
SENSOR TECHNOLOGY
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
29
TECH REPORT
29
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
3030
SENSOR TECHNOLOGY
to enable the kind of constant and complex data accumulation that the Biostamp promises
In the interim MC10 is partnering up with other medical and pharmaceutical companies to develop integrated sensor and monitoring products The company plans to become a certified medical-ready partner for companies who donrsquot have access to this unique and proprietary technology Even the US Army has begun working with MC10 on military-grade sensors that will add further safety features for troops in the field This funding from NIH grants Department of Defense grants as well as foundation grants will help the company get one step closer to realization of devices so flexible that users might forget theyrsquore wearing them
ldquoThe company has been bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devicesrdquo
Join the
DESIGNERS OF THINGS conference in San Francisco on
September 23 and 24
Dedicated to the explosive and exciting potential of Wearable
Tech 3D Printing and the Internet of Things the conference
provides the growing design and development community
around these technologies a meeting place to discuss and
showcase the newest products
Click here for more info
httpwwwdesignersofthingscomsanfranciscoscheduler
speakersheth-nirav-rav33310
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Sierra CircuitsA Complete PCB Resource
PLUS The Ground rdquo Myth in PrintedCircuits
ldquo
PCB Resin Reactor+
Ken BahlCEO of Sierra Circuits
Let There Be
How Cree reinvented the light bulb
LIGHT
David ElienVP of Marketing amp Business
Development Cree Inc
New LED Filament Tower
Cutting Edge Flatscreen Technologies
+
+
M o v i n g T o w a r d s
a Clean Energy
FUTUREmdash Hugo van Nispen COO of DNV KEMA
MCU Wars 32-bit MCU Comparison
Cutting Edge
SPICEModeling
Freescale and TI Embedded
Modules
ARMCortex
Programming
From Concept to
Reality Wolfgang Heinz-Fischer
Head of Marketing amp PR TQ-Group
Low-Power Design Techniques
TQ-Grouprsquos Comprehensive Design Process
+
+
PowerDeveloper
Octobe r 20 13
Designing forDurability
View more EEWeb magazinesmdash Click Here
15
TECH REPORT
15
Non-contact measurement of electrophysiological signals is of great interest in healthcare settings with the potential of reducing disposable costs speeding up or simplifying measurement techniques Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact Monitoring vehicle drivers for health and alertness by detecting heart rate and respiration or determining car occupancy to adjust the ride handling and air bag deployment with the varying size and location of occupants is a vast potential market
Capacitive (insulated) electrodes can register ECG signals without conductive contact to the bodyndasheven through clothesndashand represent
an attractive alternative for a wide range of new applications EPIC (Electric Potential Integrated Circuit) is a completely new sensor technology resulting from research at the University of Sussex (UK) Novel ultra high impedance EPIC sensors measure electric field changes without requiring physical or resistive contact This award winning patent-protected sensor can rapidly measure electric potential sources such as electrophysiological signals or even spatial electric fields It therefore has the ability to measure ECGs without direct skin contact By adjusting the DSP and amplification circuitry the sensors can be tuned for detection at a distance as required for differing automotive applications EPIC sensor electrodes can be easily and discretely incorporated inside car seat backs to acquire the necessary biometric data
Signals measured on the human body always include a large amount of noise the major component of this being 50 or 60 Hz power line noise capacitively-coupled to the body from the surrounding electricity supply Measurements such as ECG depend on being able to extract the small electrophysiological signals from the much larger noise signals EPIC sensors can be used in ldquocontact moderdquo for ECG measurement where the subject touches both the capacitive electrode surface and some metal at the system ground directly with the skin This ground reference allows filtering and differential amplification of signals from two sensors to be effective in removing the mains frequency noise leaving a high quality ECG signal In non-contact ECG measurement there is ndash by definition - no skin contact and thus no direct connection can be made between the subjectrsquos body and the system ground Some other method of reducing the power line noise is therefore required to
EPIC Sensors incontact with clothing
Conductive fabric in contactwith clothing eg on chair seat
Output
EPICdemo box
Figure 1 Basic configuration for non-contact ECG measurement including capacitively-oocupied DR circuit
OP-AMP
+5V
-5V
Vout
Rf (27KΩ)
Ra(11KΩ)
Rb(11KΩ)
Rp (15MΩ) To conductive fabric on chair thus capacitively coupled to body
Inputs from outputs of demo box
A
BC
(1nF)
Figure 2 DPL circuit Voltage gain is set by Rf Rp limits current fed back to the body (see text)Operational amplifier output Vout = - (VA + VB) Rf 11K
enable the ECG signal to be extracted reliably and accurately One such method utilizes an approach very similar to the ldquoDriven Right Legrdquo (DRL) system that is used for the same purpose in conventional ECG measurement techniques In conventional ECG the DRL signal is coupled directly to the patientrsquos skin The DRL signal reduces power line noise on the sensor signals by feeding back an inverted average of the signals from two sensors on to the patientrsquos body In non-contact ECG the generated DRL signal can be capacitively-coupled to the body through clothing via a piece of conductive material placed ndash for instance ndash on the seat or back of a chair Capacitive coupling of DRL signals is described by Lim et al1 and Lee et al2
SYSTEM DESIGNAn ECG system can therefore be built into a chair a mattress or clothing for instance The DRL circuit improves the sensor signalnoise ratio enormously In the example in Figure 1 EPIC sensors are mounted on a chair back such that the electrodes touch the clothing on the subjectrsquos back when resting normally against the back of the chair The generated DRL signal is connected to a piece of conductive material
placed either on the seat of the chair or at the bottom of the chair back contacting the subjectrsquos clothing in the normal sitting position Copper-coated nylon fabric is one possible material suitable for the DRL coupling material but other conductive materials may be equally successful A thin non- conductive material such as a cotton fabric may be used to cover both the sensors and the DRL coupling fabric if required for instance when building the sensors into a seat Consideration must be given as to how material will reduce the coupling capacitance between the sensor and the subject or add additional noise to the signals through static charging effectsFigure 2 shows the design of the DRL circuit It is a standard summing amplifier generating an amplified and inverted signal that is the average of the individual signals A and B
The optimum value for Rf will be dependent on the type of sensors being used as well as the clothing being worn by the subject being measured It should be set to achieve maximum noise reduction while ensuring circuit stability A value of 27kohms is suggested as a suitable starting point for EPIC sensors
1616
SENSOR TECHNOLOGY
Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact
7660SwitchedCapacitorVoltage
Converter
1
2
3
4
8
7
6
5
OP-AMP
Rb(11K)
Ra(11K)
Rf (27KΩ)
Rp (15MΩ)DRLOutput
1nFVout
6Vbatterypack4xAA
+6V
-6V10microF
10microF
A
B
Figure 3 DRL circuit including battery power supply and voltage converter to provide -6v rail Inputs A and B are buffered outputs from the sensors and may be taken from the A and B outputs of the EPIC demo box Ground should be connected to the sensor 0V the shielding of the BNC A and B outputs on the demo box being a suitable connection point See figure 2 and the text for further comments on the DRL design
sensors and the DRL circuit into saturation Because the system contains some large impedances and hence has some very long RC time constants settling times of tens of seconds can be needed before a clean ECG signal is seen During this period the signal can either appear very noisy or be virtually flat depending on whether one or both sensors or the DRL circuit are ldquorailingrdquo The subject should sit still during this time and wait for the circuit to settle since continually adjusting position will only make matters worse Settling times can sometimes be reduced by turning off the power to the demo box for a few seconds
CLOTHINGGood results can be obtained with one or two layers of cotton material between the sensors and the skin Other materials including a wool-mix sweater and a polyester fleece in addition
to two layers of cotton material have been successful Examples are shown in Figures 6 and 7 If the key greatest interest is in the ldquoR-Rrdquo interval adjusting filter settings to reduce or re-center the signal bandwidth can give improved signal quality
STATICBecause there is no direct physical contact between the subject and any grounding point there is no path for any static build up to be discharged Under most circumstances static build-up does not present a problem butdepending on factors including clothing footwear flooring humidity levels in the air and so forth static build up can sometimes prevent the cardiac signal from being seen clearly Product design must take into account a discharge to the system ground to remove the static charge
Rp the protection resistor is included to limit the current that can be fed back to the human body This resistor is essential in ensuring that the subjectrsquos wellbeing is not endangered and must not be omitted
IMPLEMENTATIONThe demonstration of non-contact ECG is best performed using an EPIC demonstration kit Plessey part no PS25003 which includes the necessary drive circuitry and switchable 50Hz and 60Hz notch filters The inputs to the DRL circuit can be taken from the BNC outputs ldquoA amp Brdquo on the front of the demo box The DRL circuit will require its own bipolar power supply plusmn5V or plusmn6V is suggested A circuit design including a battery power supply is shown in Figure 3
Plesseyrsquos compact sensors (PS2520x) and disc sensors (PS25101) provide equally good results although for demonstration purposes disc sensors are simplest to fix to a chair to make contact with the occupantrsquos back Compact sensors are recommended when designing a custom-built system
EPIC sensors which are designed for contact electrophysiology sensing give excellent results in most cases Initial trials suggest that custom modifications to the sensor design (eg lower gain and higher input impedance) can offer increased sensitivity and the ability to detect weaker ECG signalsThe shape of the measured ECG trace ndash in terms of relative magnitudes of the P Q R S and T waves ndash will depend on the positioning of the sensors behind the subjectrsquos back If the desire is only to measure the ldquoR-Rrdquo interval to determine heart rate then the positioning of the sensors is not critical Placing one sensor either side of the spine separated by 6rdquo -10rdquo (15-25 cm) at approximately the same height as the heart is recommended as a starting point For applications where signals from other parts of the cardiac cycle are required the user should refer to texts on bio-electronic signals for guidance on sensor position
SETTLING TIMEWhen a subject first sits in the chair and leans against the EPIC sensors the changes in electric potential will normally send both the
17
TECH REPORT
17
Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact
7660SwitchedCapacitorVoltage
Converter
1
2
3
4
8
7
6
5
OP-AMP
Rb(11K)
Ra(11K)
Rf (27KΩ)
Rp (15MΩ)DRLOutput
1nFVout
6Vbatterypack4xAA
+6V
-6V10microF
10microF
A
B
Figure 3 DRL circuit including battery power supply and voltage converter to provide -6v rail Inputs A and B are buffered outputs from the sensors and may be taken from the A and B outputs of the EPIC demo box Ground should be connected to the sensor 0V the shielding of the BNC A and B outputs on the demo box being a suitable connection point See figure 2 and the text for further comments on the DRL design
sensors and the DRL circuit into saturation Because the system contains some large impedances and hence has some very long RC time constants settling times of tens of seconds can be needed before a clean ECG signal is seen During this period the signal can either appear very noisy or be virtually flat depending on whether one or both sensors or the DRL circuit are ldquorailingrdquo The subject should sit still during this time and wait for the circuit to settle since continually adjusting position will only make matters worse Settling times can sometimes be reduced by turning off the power to the demo box for a few seconds
CLOTHINGGood results can be obtained with one or two layers of cotton material between the sensors and the skin Other materials including a wool-mix sweater and a polyester fleece in addition
to two layers of cotton material have been successful Examples are shown in Figures 6 and 7 If the key greatest interest is in the ldquoR-Rrdquo interval adjusting filter settings to reduce or re-center the signal bandwidth can give improved signal quality
STATICBecause there is no direct physical contact between the subject and any grounding point there is no path for any static build up to be discharged Under most circumstances static build-up does not present a problem butdepending on factors including clothing footwear flooring humidity levels in the air and so forth static build up can sometimes prevent the cardiac signal from being seen clearly Product design must take into account a discharge to the system ground to remove the static charge
Rp the protection resistor is included to limit the current that can be fed back to the human body This resistor is essential in ensuring that the subjectrsquos wellbeing is not endangered and must not be omitted
IMPLEMENTATIONThe demonstration of non-contact ECG is best performed using an EPIC demonstration kit Plessey part no PS25003 which includes the necessary drive circuitry and switchable 50Hz and 60Hz notch filters The inputs to the DRL circuit can be taken from the BNC outputs ldquoA amp Brdquo on the front of the demo box The DRL circuit will require its own bipolar power supply plusmn5V or plusmn6V is suggested A circuit design including a battery power supply is shown in Figure 3
Plesseyrsquos compact sensors (PS2520x) and disc sensors (PS25101) provide equally good results although for demonstration purposes disc sensors are simplest to fix to a chair to make contact with the occupantrsquos back Compact sensors are recommended when designing a custom-built system
EPIC sensors which are designed for contact electrophysiology sensing give excellent results in most cases Initial trials suggest that custom modifications to the sensor design (eg lower gain and higher input impedance) can offer increased sensitivity and the ability to detect weaker ECG signalsThe shape of the measured ECG trace ndash in terms of relative magnitudes of the P Q R S and T waves ndash will depend on the positioning of the sensors behind the subjectrsquos back If the desire is only to measure the ldquoR-Rrdquo interval to determine heart rate then the positioning of the sensors is not critical Placing one sensor either side of the spine separated by 6rdquo -10rdquo (15-25 cm) at approximately the same height as the heart is recommended as a starting point For applications where signals from other parts of the cardiac cycle are required the user should refer to texts on bio-electronic signals for guidance on sensor position
SETTLING TIMEWhen a subject first sits in the chair and leans against the EPIC sensors the changes in electric potential will normally send both the
1818
SENSOR TECHNOLOGY
Figure 4 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit HP filter corner frequency is 50mHz LP filter in demo box has corner frequency of 30Hz
Figure 6 ECG signals measured from a subject wearing a wool-mix sweater over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 8-25Hz The heart rate can be easily extracted
Figure 5 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit Software filters limit the bandwidth to 8-25Hz
Figure 7 ECG signals measured from a subject wearing a polyester fleece over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 16-40Hz The heart rate can be easily extracted
CABLE SHIELDINGCareful shielding is necessary to reduce unwanted noise artifacts Grounding the shielding of the sensor cable via the connection between the outer casing of the sensor plugs and the metal surround of the socket on the control electronics is recommended
CONCLUSIONEPIC sensors can be used to measure ECG signals without physical skin contact While
sensors can be embedded in a chair or seat the techniques are equally applicable to sensors mounted on a mattress in clothing or in other situations There are many variables that will affect signal quality from the strength of cardiac signal generated by the individual being measured to clothing to the surrounding environment but the designs given here are a starting point in establishing an optimum system for a particular application infin
Find us at Booth 37310World Maker Faire New York
Figure 4 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit HP filter corner frequency is 50mHz LP filter in demo box has corner frequency of 30Hz
Figure 6 ECG signals measured from a subject wearing a wool-mix sweater over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 8-25Hz The heart rate can be easily extracted
Figure 5 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit Software filters limit the bandwidth to 8-25Hz
Figure 7 ECG signals measured from a subject wearing a polyester fleece over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 16-40Hz The heart rate can be easily extracted
CABLE SHIELDINGCareful shielding is necessary to reduce unwanted noise artifacts Grounding the shielding of the sensor cable via the connection between the outer casing of the sensor plugs and the metal surround of the socket on the control electronics is recommended
CONCLUSIONEPIC sensors can be used to measure ECG signals without physical skin contact While
sensors can be embedded in a chair or seat the techniques are equally applicable to sensors mounted on a mattress in clothing or in other situations There are many variables that will affect signal quality from the strength of cardiac signal generated by the individual being measured to clothing to the surrounding environment but the designs given here are a starting point in establishing an optimum system for a particular application infin
Find us at Booth 37310World Maker Faire New York
20
SENSOR TECHNOLOGY
SmallerThan a
Grain Sand
of
Analysts project that by
2020 there will be over
50 billion connected
devices in the now-nascent
Internet of Things (IoT) However
the technology that will enable the
IoT of the future may look a little
different than todayrsquosmdashin fact
you may not be able to see it at all
Many new mobile devices require
motion sensors in order to monitor
analyze and deliver real-time data
and analysis to improve the way
consumers interact with everyday
technology While traditional
sensor platforms require multichip
modules or stacked die within a
device mCube a new MEMS sensor
company is driving the emergence
of Sensor 30 which will lead the
development of the smallest
sensors to datemdashsmaller than a
grain of sand By EEWeb Contributing Writers
mCubersquos Sensors Enable IoMTInterview with Ben Lee President and CEO of mCube
INDUSTRY INTERVIEW
21
SmallerThan a
Grain Sand
of
Analysts project that by
2020 there will be over
50 billion connected
devices in the now-nascent
Internet of Things (IoT) However
the technology that will enable the
IoT of the future may look a little
different than todayrsquosmdashin fact
you may not be able to see it at all
Many new mobile devices require
motion sensors in order to monitor
analyze and deliver real-time data
and analysis to improve the way
consumers interact with everyday
technology While traditional
sensor platforms require multichip
modules or stacked die within a
device mCube a new MEMS sensor
company is driving the emergence
of Sensor 30 which will lead the
development of the smallest
sensors to datemdashsmaller than a
grain of sand By EEWeb Contributing Writers
mCubersquos Sensors Enable IoMTInterview with Ben Lee President and CEO of mCube
22
SENSOR TECHNOLOGY
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
INDUSTRY INTERVIEW
23
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
24
SENSOR TECHNOLOGY
Since sensors are so small and affordable donrsquot be surprised to find unique applications in the future Lee speculates that ldquofarmers might have sensor tags to monitor livestock for abnormal activity patterns of grazing potential illness and herd behaviorrdquo Commercial trucking might involve motion sensors connected to video cameras in rear-view mirrors to better assess the cause of an accident and driving conditions For shipping Lee describes ldquomotion sensors embedded directly onto packages to record jarring motions or accidents in order to determine when and how contents were damagedrdquo
As of 2014 mCubersquos complete intertial sensor portfolio contains an accelerometer magnetometer and its proprietary iGyrotrade gyroscope offering nine degrees of freedom (9DoF) Through reductions in cost power consumption and size mCubersquos sensor offerings make it possible to place them onto nearly any object or devicemdashin some cases without packaging ldquoWe aspire to put one or more MEMS motion sensors on anything that movesrdquo remarks Lee And with the IoMT taking shape and consumer expectations for connected moving devices becoming more concrete developers of new applications will turn to solutions like mCube to deliver truly cutting-edge connected devices
ldquoAt mCube we aspire to put one or more MEMS motion sensors on
anything that movesrdquo
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 15
Complete Inertial Motion Sensor Portfolio
Solutions for up to 9DoF (Degrees of Freedom)
Accelerometer
Magnetometer
iGyroTM
3DoF 3DoF
9DoF
2x2mm
3x3mm 3DoF 6DoF
14x14mm
3x3mm
3x3mm
2626
SENSOR TECHNOLOGY
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
27
TECH REPORT
27
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
2828
SENSOR TECHNOLOGY
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
29
TECH REPORT
29
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
3030
SENSOR TECHNOLOGY
to enable the kind of constant and complex data accumulation that the Biostamp promises
In the interim MC10 is partnering up with other medical and pharmaceutical companies to develop integrated sensor and monitoring products The company plans to become a certified medical-ready partner for companies who donrsquot have access to this unique and proprietary technology Even the US Army has begun working with MC10 on military-grade sensors that will add further safety features for troops in the field This funding from NIH grants Department of Defense grants as well as foundation grants will help the company get one step closer to realization of devices so flexible that users might forget theyrsquore wearing them
ldquoThe company has been bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devicesrdquo
Join the
DESIGNERS OF THINGS conference in San Francisco on
September 23 and 24
Dedicated to the explosive and exciting potential of Wearable
Tech 3D Printing and the Internet of Things the conference
provides the growing design and development community
around these technologies a meeting place to discuss and
showcase the newest products
Click here for more info
httpwwwdesignersofthingscomsanfranciscoscheduler
speakersheth-nirav-rav33310
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Sierra CircuitsA Complete PCB Resource
PLUS The Ground rdquo Myth in PrintedCircuits
ldquo
PCB Resin Reactor+
Ken BahlCEO of Sierra Circuits
Let There Be
How Cree reinvented the light bulb
LIGHT
David ElienVP of Marketing amp Business
Development Cree Inc
New LED Filament Tower
Cutting Edge Flatscreen Technologies
+
+
M o v i n g T o w a r d s
a Clean Energy
FUTUREmdash Hugo van Nispen COO of DNV KEMA
MCU Wars 32-bit MCU Comparison
Cutting Edge
SPICEModeling
Freescale and TI Embedded
Modules
ARMCortex
Programming
From Concept to
Reality Wolfgang Heinz-Fischer
Head of Marketing amp PR TQ-Group
Low-Power Design Techniques
TQ-Grouprsquos Comprehensive Design Process
+
+
PowerDeveloper
Octobe r 20 13
Designing forDurability
View more EEWeb magazinesmdash Click Here
1616
SENSOR TECHNOLOGY
Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact
7660SwitchedCapacitorVoltage
Converter
1
2
3
4
8
7
6
5
OP-AMP
Rb(11K)
Ra(11K)
Rf (27KΩ)
Rp (15MΩ)DRLOutput
1nFVout
6Vbatterypack4xAA
+6V
-6V10microF
10microF
A
B
Figure 3 DRL circuit including battery power supply and voltage converter to provide -6v rail Inputs A and B are buffered outputs from the sensors and may be taken from the A and B outputs of the EPIC demo box Ground should be connected to the sensor 0V the shielding of the BNC A and B outputs on the demo box being a suitable connection point See figure 2 and the text for further comments on the DRL design
sensors and the DRL circuit into saturation Because the system contains some large impedances and hence has some very long RC time constants settling times of tens of seconds can be needed before a clean ECG signal is seen During this period the signal can either appear very noisy or be virtually flat depending on whether one or both sensors or the DRL circuit are ldquorailingrdquo The subject should sit still during this time and wait for the circuit to settle since continually adjusting position will only make matters worse Settling times can sometimes be reduced by turning off the power to the demo box for a few seconds
CLOTHINGGood results can be obtained with one or two layers of cotton material between the sensors and the skin Other materials including a wool-mix sweater and a polyester fleece in addition
to two layers of cotton material have been successful Examples are shown in Figures 6 and 7 If the key greatest interest is in the ldquoR-Rrdquo interval adjusting filter settings to reduce or re-center the signal bandwidth can give improved signal quality
STATICBecause there is no direct physical contact between the subject and any grounding point there is no path for any static build up to be discharged Under most circumstances static build-up does not present a problem butdepending on factors including clothing footwear flooring humidity levels in the air and so forth static build up can sometimes prevent the cardiac signal from being seen clearly Product design must take into account a discharge to the system ground to remove the static charge
Rp the protection resistor is included to limit the current that can be fed back to the human body This resistor is essential in ensuring that the subjectrsquos wellbeing is not endangered and must not be omitted
IMPLEMENTATIONThe demonstration of non-contact ECG is best performed using an EPIC demonstration kit Plessey part no PS25003 which includes the necessary drive circuitry and switchable 50Hz and 60Hz notch filters The inputs to the DRL circuit can be taken from the BNC outputs ldquoA amp Brdquo on the front of the demo box The DRL circuit will require its own bipolar power supply plusmn5V or plusmn6V is suggested A circuit design including a battery power supply is shown in Figure 3
Plesseyrsquos compact sensors (PS2520x) and disc sensors (PS25101) provide equally good results although for demonstration purposes disc sensors are simplest to fix to a chair to make contact with the occupantrsquos back Compact sensors are recommended when designing a custom-built system
EPIC sensors which are designed for contact electrophysiology sensing give excellent results in most cases Initial trials suggest that custom modifications to the sensor design (eg lower gain and higher input impedance) can offer increased sensitivity and the ability to detect weaker ECG signalsThe shape of the measured ECG trace ndash in terms of relative magnitudes of the P Q R S and T waves ndash will depend on the positioning of the sensors behind the subjectrsquos back If the desire is only to measure the ldquoR-Rrdquo interval to determine heart rate then the positioning of the sensors is not critical Placing one sensor either side of the spine separated by 6rdquo -10rdquo (15-25 cm) at approximately the same height as the heart is recommended as a starting point For applications where signals from other parts of the cardiac cycle are required the user should refer to texts on bio-electronic signals for guidance on sensor position
SETTLING TIMEWhen a subject first sits in the chair and leans against the EPIC sensors the changes in electric potential will normally send both the
17
TECH REPORT
17
Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact
7660SwitchedCapacitorVoltage
Converter
1
2
3
4
8
7
6
5
OP-AMP
Rb(11K)
Ra(11K)
Rf (27KΩ)
Rp (15MΩ)DRLOutput
1nFVout
6Vbatterypack4xAA
+6V
-6V10microF
10microF
A
B
Figure 3 DRL circuit including battery power supply and voltage converter to provide -6v rail Inputs A and B are buffered outputs from the sensors and may be taken from the A and B outputs of the EPIC demo box Ground should be connected to the sensor 0V the shielding of the BNC A and B outputs on the demo box being a suitable connection point See figure 2 and the text for further comments on the DRL design
sensors and the DRL circuit into saturation Because the system contains some large impedances and hence has some very long RC time constants settling times of tens of seconds can be needed before a clean ECG signal is seen During this period the signal can either appear very noisy or be virtually flat depending on whether one or both sensors or the DRL circuit are ldquorailingrdquo The subject should sit still during this time and wait for the circuit to settle since continually adjusting position will only make matters worse Settling times can sometimes be reduced by turning off the power to the demo box for a few seconds
CLOTHINGGood results can be obtained with one or two layers of cotton material between the sensors and the skin Other materials including a wool-mix sweater and a polyester fleece in addition
to two layers of cotton material have been successful Examples are shown in Figures 6 and 7 If the key greatest interest is in the ldquoR-Rrdquo interval adjusting filter settings to reduce or re-center the signal bandwidth can give improved signal quality
STATICBecause there is no direct physical contact between the subject and any grounding point there is no path for any static build up to be discharged Under most circumstances static build-up does not present a problem butdepending on factors including clothing footwear flooring humidity levels in the air and so forth static build up can sometimes prevent the cardiac signal from being seen clearly Product design must take into account a discharge to the system ground to remove the static charge
Rp the protection resistor is included to limit the current that can be fed back to the human body This resistor is essential in ensuring that the subjectrsquos wellbeing is not endangered and must not be omitted
IMPLEMENTATIONThe demonstration of non-contact ECG is best performed using an EPIC demonstration kit Plessey part no PS25003 which includes the necessary drive circuitry and switchable 50Hz and 60Hz notch filters The inputs to the DRL circuit can be taken from the BNC outputs ldquoA amp Brdquo on the front of the demo box The DRL circuit will require its own bipolar power supply plusmn5V or plusmn6V is suggested A circuit design including a battery power supply is shown in Figure 3
Plesseyrsquos compact sensors (PS2520x) and disc sensors (PS25101) provide equally good results although for demonstration purposes disc sensors are simplest to fix to a chair to make contact with the occupantrsquos back Compact sensors are recommended when designing a custom-built system
EPIC sensors which are designed for contact electrophysiology sensing give excellent results in most cases Initial trials suggest that custom modifications to the sensor design (eg lower gain and higher input impedance) can offer increased sensitivity and the ability to detect weaker ECG signalsThe shape of the measured ECG trace ndash in terms of relative magnitudes of the P Q R S and T waves ndash will depend on the positioning of the sensors behind the subjectrsquos back If the desire is only to measure the ldquoR-Rrdquo interval to determine heart rate then the positioning of the sensors is not critical Placing one sensor either side of the spine separated by 6rdquo -10rdquo (15-25 cm) at approximately the same height as the heart is recommended as a starting point For applications where signals from other parts of the cardiac cycle are required the user should refer to texts on bio-electronic signals for guidance on sensor position
SETTLING TIMEWhen a subject first sits in the chair and leans against the EPIC sensors the changes in electric potential will normally send both the
1818
SENSOR TECHNOLOGY
Figure 4 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit HP filter corner frequency is 50mHz LP filter in demo box has corner frequency of 30Hz
Figure 6 ECG signals measured from a subject wearing a wool-mix sweater over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 8-25Hz The heart rate can be easily extracted
Figure 5 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit Software filters limit the bandwidth to 8-25Hz
Figure 7 ECG signals measured from a subject wearing a polyester fleece over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 16-40Hz The heart rate can be easily extracted
CABLE SHIELDINGCareful shielding is necessary to reduce unwanted noise artifacts Grounding the shielding of the sensor cable via the connection between the outer casing of the sensor plugs and the metal surround of the socket on the control electronics is recommended
CONCLUSIONEPIC sensors can be used to measure ECG signals without physical skin contact While
sensors can be embedded in a chair or seat the techniques are equally applicable to sensors mounted on a mattress in clothing or in other situations There are many variables that will affect signal quality from the strength of cardiac signal generated by the individual being measured to clothing to the surrounding environment but the designs given here are a starting point in establishing an optimum system for a particular application infin
Find us at Booth 37310World Maker Faire New York
Figure 4 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit HP filter corner frequency is 50mHz LP filter in demo box has corner frequency of 30Hz
Figure 6 ECG signals measured from a subject wearing a wool-mix sweater over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 8-25Hz The heart rate can be easily extracted
Figure 5 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit Software filters limit the bandwidth to 8-25Hz
Figure 7 ECG signals measured from a subject wearing a polyester fleece over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 16-40Hz The heart rate can be easily extracted
CABLE SHIELDINGCareful shielding is necessary to reduce unwanted noise artifacts Grounding the shielding of the sensor cable via the connection between the outer casing of the sensor plugs and the metal surround of the socket on the control electronics is recommended
CONCLUSIONEPIC sensors can be used to measure ECG signals without physical skin contact While
sensors can be embedded in a chair or seat the techniques are equally applicable to sensors mounted on a mattress in clothing or in other situations There are many variables that will affect signal quality from the strength of cardiac signal generated by the individual being measured to clothing to the surrounding environment but the designs given here are a starting point in establishing an optimum system for a particular application infin
Find us at Booth 37310World Maker Faire New York
20
SENSOR TECHNOLOGY
SmallerThan a
Grain Sand
of
Analysts project that by
2020 there will be over
50 billion connected
devices in the now-nascent
Internet of Things (IoT) However
the technology that will enable the
IoT of the future may look a little
different than todayrsquosmdashin fact
you may not be able to see it at all
Many new mobile devices require
motion sensors in order to monitor
analyze and deliver real-time data
and analysis to improve the way
consumers interact with everyday
technology While traditional
sensor platforms require multichip
modules or stacked die within a
device mCube a new MEMS sensor
company is driving the emergence
of Sensor 30 which will lead the
development of the smallest
sensors to datemdashsmaller than a
grain of sand By EEWeb Contributing Writers
mCubersquos Sensors Enable IoMTInterview with Ben Lee President and CEO of mCube
INDUSTRY INTERVIEW
21
SmallerThan a
Grain Sand
of
Analysts project that by
2020 there will be over
50 billion connected
devices in the now-nascent
Internet of Things (IoT) However
the technology that will enable the
IoT of the future may look a little
different than todayrsquosmdashin fact
you may not be able to see it at all
Many new mobile devices require
motion sensors in order to monitor
analyze and deliver real-time data
and analysis to improve the way
consumers interact with everyday
technology While traditional
sensor platforms require multichip
modules or stacked die within a
device mCube a new MEMS sensor
company is driving the emergence
of Sensor 30 which will lead the
development of the smallest
sensors to datemdashsmaller than a
grain of sand By EEWeb Contributing Writers
mCubersquos Sensors Enable IoMTInterview with Ben Lee President and CEO of mCube
22
SENSOR TECHNOLOGY
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
INDUSTRY INTERVIEW
23
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
24
SENSOR TECHNOLOGY
Since sensors are so small and affordable donrsquot be surprised to find unique applications in the future Lee speculates that ldquofarmers might have sensor tags to monitor livestock for abnormal activity patterns of grazing potential illness and herd behaviorrdquo Commercial trucking might involve motion sensors connected to video cameras in rear-view mirrors to better assess the cause of an accident and driving conditions For shipping Lee describes ldquomotion sensors embedded directly onto packages to record jarring motions or accidents in order to determine when and how contents were damagedrdquo
As of 2014 mCubersquos complete intertial sensor portfolio contains an accelerometer magnetometer and its proprietary iGyrotrade gyroscope offering nine degrees of freedom (9DoF) Through reductions in cost power consumption and size mCubersquos sensor offerings make it possible to place them onto nearly any object or devicemdashin some cases without packaging ldquoWe aspire to put one or more MEMS motion sensors on anything that movesrdquo remarks Lee And with the IoMT taking shape and consumer expectations for connected moving devices becoming more concrete developers of new applications will turn to solutions like mCube to deliver truly cutting-edge connected devices
ldquoAt mCube we aspire to put one or more MEMS motion sensors on
anything that movesrdquo
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 15
Complete Inertial Motion Sensor Portfolio
Solutions for up to 9DoF (Degrees of Freedom)
Accelerometer
Magnetometer
iGyroTM
3DoF 3DoF
9DoF
2x2mm
3x3mm 3DoF 6DoF
14x14mm
3x3mm
3x3mm
2626
SENSOR TECHNOLOGY
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
27
TECH REPORT
27
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
2828
SENSOR TECHNOLOGY
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
29
TECH REPORT
29
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
3030
SENSOR TECHNOLOGY
to enable the kind of constant and complex data accumulation that the Biostamp promises
In the interim MC10 is partnering up with other medical and pharmaceutical companies to develop integrated sensor and monitoring products The company plans to become a certified medical-ready partner for companies who donrsquot have access to this unique and proprietary technology Even the US Army has begun working with MC10 on military-grade sensors that will add further safety features for troops in the field This funding from NIH grants Department of Defense grants as well as foundation grants will help the company get one step closer to realization of devices so flexible that users might forget theyrsquore wearing them
ldquoThe company has been bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devicesrdquo
Join the
DESIGNERS OF THINGS conference in San Francisco on
September 23 and 24
Dedicated to the explosive and exciting potential of Wearable
Tech 3D Printing and the Internet of Things the conference
provides the growing design and development community
around these technologies a meeting place to discuss and
showcase the newest products
Click here for more info
httpwwwdesignersofthingscomsanfranciscoscheduler
speakersheth-nirav-rav33310
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Sierra CircuitsA Complete PCB Resource
PLUS The Ground rdquo Myth in PrintedCircuits
ldquo
PCB Resin Reactor+
Ken BahlCEO of Sierra Circuits
Let There Be
How Cree reinvented the light bulb
LIGHT
David ElienVP of Marketing amp Business
Development Cree Inc
New LED Filament Tower
Cutting Edge Flatscreen Technologies
+
+
M o v i n g T o w a r d s
a Clean Energy
FUTUREmdash Hugo van Nispen COO of DNV KEMA
MCU Wars 32-bit MCU Comparison
Cutting Edge
SPICEModeling
Freescale and TI Embedded
Modules
ARMCortex
Programming
From Concept to
Reality Wolfgang Heinz-Fischer
Head of Marketing amp PR TQ-Group
Low-Power Design Techniques
TQ-Grouprsquos Comprehensive Design Process
+
+
PowerDeveloper
Octobe r 20 13
Designing forDurability
View more EEWeb magazinesmdash Click Here
17
TECH REPORT
17
Monitoring long-term medical conditions within the home or observing pilots drivers soldiers and others in safety critical situations is now possible without needing skin contact
7660SwitchedCapacitorVoltage
Converter
1
2
3
4
8
7
6
5
OP-AMP
Rb(11K)
Ra(11K)
Rf (27KΩ)
Rp (15MΩ)DRLOutput
1nFVout
6Vbatterypack4xAA
+6V
-6V10microF
10microF
A
B
Figure 3 DRL circuit including battery power supply and voltage converter to provide -6v rail Inputs A and B are buffered outputs from the sensors and may be taken from the A and B outputs of the EPIC demo box Ground should be connected to the sensor 0V the shielding of the BNC A and B outputs on the demo box being a suitable connection point See figure 2 and the text for further comments on the DRL design
sensors and the DRL circuit into saturation Because the system contains some large impedances and hence has some very long RC time constants settling times of tens of seconds can be needed before a clean ECG signal is seen During this period the signal can either appear very noisy or be virtually flat depending on whether one or both sensors or the DRL circuit are ldquorailingrdquo The subject should sit still during this time and wait for the circuit to settle since continually adjusting position will only make matters worse Settling times can sometimes be reduced by turning off the power to the demo box for a few seconds
CLOTHINGGood results can be obtained with one or two layers of cotton material between the sensors and the skin Other materials including a wool-mix sweater and a polyester fleece in addition
to two layers of cotton material have been successful Examples are shown in Figures 6 and 7 If the key greatest interest is in the ldquoR-Rrdquo interval adjusting filter settings to reduce or re-center the signal bandwidth can give improved signal quality
STATICBecause there is no direct physical contact between the subject and any grounding point there is no path for any static build up to be discharged Under most circumstances static build-up does not present a problem butdepending on factors including clothing footwear flooring humidity levels in the air and so forth static build up can sometimes prevent the cardiac signal from being seen clearly Product design must take into account a discharge to the system ground to remove the static charge
Rp the protection resistor is included to limit the current that can be fed back to the human body This resistor is essential in ensuring that the subjectrsquos wellbeing is not endangered and must not be omitted
IMPLEMENTATIONThe demonstration of non-contact ECG is best performed using an EPIC demonstration kit Plessey part no PS25003 which includes the necessary drive circuitry and switchable 50Hz and 60Hz notch filters The inputs to the DRL circuit can be taken from the BNC outputs ldquoA amp Brdquo on the front of the demo box The DRL circuit will require its own bipolar power supply plusmn5V or plusmn6V is suggested A circuit design including a battery power supply is shown in Figure 3
Plesseyrsquos compact sensors (PS2520x) and disc sensors (PS25101) provide equally good results although for demonstration purposes disc sensors are simplest to fix to a chair to make contact with the occupantrsquos back Compact sensors are recommended when designing a custom-built system
EPIC sensors which are designed for contact electrophysiology sensing give excellent results in most cases Initial trials suggest that custom modifications to the sensor design (eg lower gain and higher input impedance) can offer increased sensitivity and the ability to detect weaker ECG signalsThe shape of the measured ECG trace ndash in terms of relative magnitudes of the P Q R S and T waves ndash will depend on the positioning of the sensors behind the subjectrsquos back If the desire is only to measure the ldquoR-Rrdquo interval to determine heart rate then the positioning of the sensors is not critical Placing one sensor either side of the spine separated by 6rdquo -10rdquo (15-25 cm) at approximately the same height as the heart is recommended as a starting point For applications where signals from other parts of the cardiac cycle are required the user should refer to texts on bio-electronic signals for guidance on sensor position
SETTLING TIMEWhen a subject first sits in the chair and leans against the EPIC sensors the changes in electric potential will normally send both the
1818
SENSOR TECHNOLOGY
Figure 4 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit HP filter corner frequency is 50mHz LP filter in demo box has corner frequency of 30Hz
Figure 6 ECG signals measured from a subject wearing a wool-mix sweater over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 8-25Hz The heart rate can be easily extracted
Figure 5 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit Software filters limit the bandwidth to 8-25Hz
Figure 7 ECG signals measured from a subject wearing a polyester fleece over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 16-40Hz The heart rate can be easily extracted
CABLE SHIELDINGCareful shielding is necessary to reduce unwanted noise artifacts Grounding the shielding of the sensor cable via the connection between the outer casing of the sensor plugs and the metal surround of the socket on the control electronics is recommended
CONCLUSIONEPIC sensors can be used to measure ECG signals without physical skin contact While
sensors can be embedded in a chair or seat the techniques are equally applicable to sensors mounted on a mattress in clothing or in other situations There are many variables that will affect signal quality from the strength of cardiac signal generated by the individual being measured to clothing to the surrounding environment but the designs given here are a starting point in establishing an optimum system for a particular application infin
Find us at Booth 37310World Maker Faire New York
Figure 4 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit HP filter corner frequency is 50mHz LP filter in demo box has corner frequency of 30Hz
Figure 6 ECG signals measured from a subject wearing a wool-mix sweater over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 8-25Hz The heart rate can be easily extracted
Figure 5 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit Software filters limit the bandwidth to 8-25Hz
Figure 7 ECG signals measured from a subject wearing a polyester fleece over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 16-40Hz The heart rate can be easily extracted
CABLE SHIELDINGCareful shielding is necessary to reduce unwanted noise artifacts Grounding the shielding of the sensor cable via the connection between the outer casing of the sensor plugs and the metal surround of the socket on the control electronics is recommended
CONCLUSIONEPIC sensors can be used to measure ECG signals without physical skin contact While
sensors can be embedded in a chair or seat the techniques are equally applicable to sensors mounted on a mattress in clothing or in other situations There are many variables that will affect signal quality from the strength of cardiac signal generated by the individual being measured to clothing to the surrounding environment but the designs given here are a starting point in establishing an optimum system for a particular application infin
Find us at Booth 37310World Maker Faire New York
20
SENSOR TECHNOLOGY
SmallerThan a
Grain Sand
of
Analysts project that by
2020 there will be over
50 billion connected
devices in the now-nascent
Internet of Things (IoT) However
the technology that will enable the
IoT of the future may look a little
different than todayrsquosmdashin fact
you may not be able to see it at all
Many new mobile devices require
motion sensors in order to monitor
analyze and deliver real-time data
and analysis to improve the way
consumers interact with everyday
technology While traditional
sensor platforms require multichip
modules or stacked die within a
device mCube a new MEMS sensor
company is driving the emergence
of Sensor 30 which will lead the
development of the smallest
sensors to datemdashsmaller than a
grain of sand By EEWeb Contributing Writers
mCubersquos Sensors Enable IoMTInterview with Ben Lee President and CEO of mCube
INDUSTRY INTERVIEW
21
SmallerThan a
Grain Sand
of
Analysts project that by
2020 there will be over
50 billion connected
devices in the now-nascent
Internet of Things (IoT) However
the technology that will enable the
IoT of the future may look a little
different than todayrsquosmdashin fact
you may not be able to see it at all
Many new mobile devices require
motion sensors in order to monitor
analyze and deliver real-time data
and analysis to improve the way
consumers interact with everyday
technology While traditional
sensor platforms require multichip
modules or stacked die within a
device mCube a new MEMS sensor
company is driving the emergence
of Sensor 30 which will lead the
development of the smallest
sensors to datemdashsmaller than a
grain of sand By EEWeb Contributing Writers
mCubersquos Sensors Enable IoMTInterview with Ben Lee President and CEO of mCube
22
SENSOR TECHNOLOGY
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
INDUSTRY INTERVIEW
23
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
24
SENSOR TECHNOLOGY
Since sensors are so small and affordable donrsquot be surprised to find unique applications in the future Lee speculates that ldquofarmers might have sensor tags to monitor livestock for abnormal activity patterns of grazing potential illness and herd behaviorrdquo Commercial trucking might involve motion sensors connected to video cameras in rear-view mirrors to better assess the cause of an accident and driving conditions For shipping Lee describes ldquomotion sensors embedded directly onto packages to record jarring motions or accidents in order to determine when and how contents were damagedrdquo
As of 2014 mCubersquos complete intertial sensor portfolio contains an accelerometer magnetometer and its proprietary iGyrotrade gyroscope offering nine degrees of freedom (9DoF) Through reductions in cost power consumption and size mCubersquos sensor offerings make it possible to place them onto nearly any object or devicemdashin some cases without packaging ldquoWe aspire to put one or more MEMS motion sensors on anything that movesrdquo remarks Lee And with the IoMT taking shape and consumer expectations for connected moving devices becoming more concrete developers of new applications will turn to solutions like mCube to deliver truly cutting-edge connected devices
ldquoAt mCube we aspire to put one or more MEMS motion sensors on
anything that movesrdquo
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 15
Complete Inertial Motion Sensor Portfolio
Solutions for up to 9DoF (Degrees of Freedom)
Accelerometer
Magnetometer
iGyroTM
3DoF 3DoF
9DoF
2x2mm
3x3mm 3DoF 6DoF
14x14mm
3x3mm
3x3mm
2626
SENSOR TECHNOLOGY
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
27
TECH REPORT
27
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
2828
SENSOR TECHNOLOGY
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
29
TECH REPORT
29
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
3030
SENSOR TECHNOLOGY
to enable the kind of constant and complex data accumulation that the Biostamp promises
In the interim MC10 is partnering up with other medical and pharmaceutical companies to develop integrated sensor and monitoring products The company plans to become a certified medical-ready partner for companies who donrsquot have access to this unique and proprietary technology Even the US Army has begun working with MC10 on military-grade sensors that will add further safety features for troops in the field This funding from NIH grants Department of Defense grants as well as foundation grants will help the company get one step closer to realization of devices so flexible that users might forget theyrsquore wearing them
ldquoThe company has been bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devicesrdquo
Join the
DESIGNERS OF THINGS conference in San Francisco on
September 23 and 24
Dedicated to the explosive and exciting potential of Wearable
Tech 3D Printing and the Internet of Things the conference
provides the growing design and development community
around these technologies a meeting place to discuss and
showcase the newest products
Click here for more info
httpwwwdesignersofthingscomsanfranciscoscheduler
speakersheth-nirav-rav33310
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Sierra CircuitsA Complete PCB Resource
PLUS The Ground rdquo Myth in PrintedCircuits
ldquo
PCB Resin Reactor+
Ken BahlCEO of Sierra Circuits
Let There Be
How Cree reinvented the light bulb
LIGHT
David ElienVP of Marketing amp Business
Development Cree Inc
New LED Filament Tower
Cutting Edge Flatscreen Technologies
+
+
M o v i n g T o w a r d s
a Clean Energy
FUTUREmdash Hugo van Nispen COO of DNV KEMA
MCU Wars 32-bit MCU Comparison
Cutting Edge
SPICEModeling
Freescale and TI Embedded
Modules
ARMCortex
Programming
From Concept to
Reality Wolfgang Heinz-Fischer
Head of Marketing amp PR TQ-Group
Low-Power Design Techniques
TQ-Grouprsquos Comprehensive Design Process
+
+
PowerDeveloper
Octobe r 20 13
Designing forDurability
View more EEWeb magazinesmdash Click Here
1818
SENSOR TECHNOLOGY
Figure 4 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit HP filter corner frequency is 50mHz LP filter in demo box has corner frequency of 30Hz
Figure 6 ECG signals measured from a subject wearing a wool-mix sweater over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 8-25Hz The heart rate can be easily extracted
Figure 5 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit Software filters limit the bandwidth to 8-25Hz
Figure 7 ECG signals measured from a subject wearing a polyester fleece over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 16-40Hz The heart rate can be easily extracted
CABLE SHIELDINGCareful shielding is necessary to reduce unwanted noise artifacts Grounding the shielding of the sensor cable via the connection between the outer casing of the sensor plugs and the metal surround of the socket on the control electronics is recommended
CONCLUSIONEPIC sensors can be used to measure ECG signals without physical skin contact While
sensors can be embedded in a chair or seat the techniques are equally applicable to sensors mounted on a mattress in clothing or in other situations There are many variables that will affect signal quality from the strength of cardiac signal generated by the individual being measured to clothing to the surrounding environment but the designs given here are a starting point in establishing an optimum system for a particular application infin
Find us at Booth 37310World Maker Faire New York
Figure 4 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit HP filter corner frequency is 50mHz LP filter in demo box has corner frequency of 30Hz
Figure 6 ECG signals measured from a subject wearing a wool-mix sweater over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 8-25Hz The heart rate can be easily extracted
Figure 5 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit Software filters limit the bandwidth to 8-25Hz
Figure 7 ECG signals measured from a subject wearing a polyester fleece over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 16-40Hz The heart rate can be easily extracted
CABLE SHIELDINGCareful shielding is necessary to reduce unwanted noise artifacts Grounding the shielding of the sensor cable via the connection between the outer casing of the sensor plugs and the metal surround of the socket on the control electronics is recommended
CONCLUSIONEPIC sensors can be used to measure ECG signals without physical skin contact While
sensors can be embedded in a chair or seat the techniques are equally applicable to sensors mounted on a mattress in clothing or in other situations There are many variables that will affect signal quality from the strength of cardiac signal generated by the individual being measured to clothing to the surrounding environment but the designs given here are a starting point in establishing an optimum system for a particular application infin
Find us at Booth 37310World Maker Faire New York
20
SENSOR TECHNOLOGY
SmallerThan a
Grain Sand
of
Analysts project that by
2020 there will be over
50 billion connected
devices in the now-nascent
Internet of Things (IoT) However
the technology that will enable the
IoT of the future may look a little
different than todayrsquosmdashin fact
you may not be able to see it at all
Many new mobile devices require
motion sensors in order to monitor
analyze and deliver real-time data
and analysis to improve the way
consumers interact with everyday
technology While traditional
sensor platforms require multichip
modules or stacked die within a
device mCube a new MEMS sensor
company is driving the emergence
of Sensor 30 which will lead the
development of the smallest
sensors to datemdashsmaller than a
grain of sand By EEWeb Contributing Writers
mCubersquos Sensors Enable IoMTInterview with Ben Lee President and CEO of mCube
INDUSTRY INTERVIEW
21
SmallerThan a
Grain Sand
of
Analysts project that by
2020 there will be over
50 billion connected
devices in the now-nascent
Internet of Things (IoT) However
the technology that will enable the
IoT of the future may look a little
different than todayrsquosmdashin fact
you may not be able to see it at all
Many new mobile devices require
motion sensors in order to monitor
analyze and deliver real-time data
and analysis to improve the way
consumers interact with everyday
technology While traditional
sensor platforms require multichip
modules or stacked die within a
device mCube a new MEMS sensor
company is driving the emergence
of Sensor 30 which will lead the
development of the smallest
sensors to datemdashsmaller than a
grain of sand By EEWeb Contributing Writers
mCubersquos Sensors Enable IoMTInterview with Ben Lee President and CEO of mCube
22
SENSOR TECHNOLOGY
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
INDUSTRY INTERVIEW
23
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
24
SENSOR TECHNOLOGY
Since sensors are so small and affordable donrsquot be surprised to find unique applications in the future Lee speculates that ldquofarmers might have sensor tags to monitor livestock for abnormal activity patterns of grazing potential illness and herd behaviorrdquo Commercial trucking might involve motion sensors connected to video cameras in rear-view mirrors to better assess the cause of an accident and driving conditions For shipping Lee describes ldquomotion sensors embedded directly onto packages to record jarring motions or accidents in order to determine when and how contents were damagedrdquo
As of 2014 mCubersquos complete intertial sensor portfolio contains an accelerometer magnetometer and its proprietary iGyrotrade gyroscope offering nine degrees of freedom (9DoF) Through reductions in cost power consumption and size mCubersquos sensor offerings make it possible to place them onto nearly any object or devicemdashin some cases without packaging ldquoWe aspire to put one or more MEMS motion sensors on anything that movesrdquo remarks Lee And with the IoMT taking shape and consumer expectations for connected moving devices becoming more concrete developers of new applications will turn to solutions like mCube to deliver truly cutting-edge connected devices
ldquoAt mCube we aspire to put one or more MEMS motion sensors on
anything that movesrdquo
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 15
Complete Inertial Motion Sensor Portfolio
Solutions for up to 9DoF (Degrees of Freedom)
Accelerometer
Magnetometer
iGyroTM
3DoF 3DoF
9DoF
2x2mm
3x3mm 3DoF 6DoF
14x14mm
3x3mm
3x3mm
2626
SENSOR TECHNOLOGY
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
27
TECH REPORT
27
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
2828
SENSOR TECHNOLOGY
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
29
TECH REPORT
29
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
3030
SENSOR TECHNOLOGY
to enable the kind of constant and complex data accumulation that the Biostamp promises
In the interim MC10 is partnering up with other medical and pharmaceutical companies to develop integrated sensor and monitoring products The company plans to become a certified medical-ready partner for companies who donrsquot have access to this unique and proprietary technology Even the US Army has begun working with MC10 on military-grade sensors that will add further safety features for troops in the field This funding from NIH grants Department of Defense grants as well as foundation grants will help the company get one step closer to realization of devices so flexible that users might forget theyrsquore wearing them
ldquoThe company has been bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devicesrdquo
Join the
DESIGNERS OF THINGS conference in San Francisco on
September 23 and 24
Dedicated to the explosive and exciting potential of Wearable
Tech 3D Printing and the Internet of Things the conference
provides the growing design and development community
around these technologies a meeting place to discuss and
showcase the newest products
Click here for more info
httpwwwdesignersofthingscomsanfranciscoscheduler
speakersheth-nirav-rav33310
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Sierra CircuitsA Complete PCB Resource
PLUS The Ground rdquo Myth in PrintedCircuits
ldquo
PCB Resin Reactor+
Ken BahlCEO of Sierra Circuits
Let There Be
How Cree reinvented the light bulb
LIGHT
David ElienVP of Marketing amp Business
Development Cree Inc
New LED Filament Tower
Cutting Edge Flatscreen Technologies
+
+
M o v i n g T o w a r d s
a Clean Energy
FUTUREmdash Hugo van Nispen COO of DNV KEMA
MCU Wars 32-bit MCU Comparison
Cutting Edge
SPICEModeling
Freescale and TI Embedded
Modules
ARMCortex
Programming
From Concept to
Reality Wolfgang Heinz-Fischer
Head of Marketing amp PR TQ-Group
Low-Power Design Techniques
TQ-Grouprsquos Comprehensive Design Process
+
+
PowerDeveloper
Octobe r 20 13
Designing forDurability
View more EEWeb magazinesmdash Click Here
Figure 4 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit HP filter corner frequency is 50mHz LP filter in demo box has corner frequency of 30Hz
Figure 6 ECG signals measured from a subject wearing a wool-mix sweater over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 8-25Hz The heart rate can be easily extracted
Figure 5 Non-contact ECG signals measured through a single layer of cotton clothing with a capacitively coupled DRL circuit Software filters limit the bandwidth to 8-25Hz
Figure 7 ECG signals measured from a subject wearing a polyester fleece over a cotton shirt Sensors attached to the chair-back were covered with an additional layer of cotton material Filter settings limit the bandwidth to 16-40Hz The heart rate can be easily extracted
CABLE SHIELDINGCareful shielding is necessary to reduce unwanted noise artifacts Grounding the shielding of the sensor cable via the connection between the outer casing of the sensor plugs and the metal surround of the socket on the control electronics is recommended
CONCLUSIONEPIC sensors can be used to measure ECG signals without physical skin contact While
sensors can be embedded in a chair or seat the techniques are equally applicable to sensors mounted on a mattress in clothing or in other situations There are many variables that will affect signal quality from the strength of cardiac signal generated by the individual being measured to clothing to the surrounding environment but the designs given here are a starting point in establishing an optimum system for a particular application infin
Find us at Booth 37310World Maker Faire New York
20
SENSOR TECHNOLOGY
SmallerThan a
Grain Sand
of
Analysts project that by
2020 there will be over
50 billion connected
devices in the now-nascent
Internet of Things (IoT) However
the technology that will enable the
IoT of the future may look a little
different than todayrsquosmdashin fact
you may not be able to see it at all
Many new mobile devices require
motion sensors in order to monitor
analyze and deliver real-time data
and analysis to improve the way
consumers interact with everyday
technology While traditional
sensor platforms require multichip
modules or stacked die within a
device mCube a new MEMS sensor
company is driving the emergence
of Sensor 30 which will lead the
development of the smallest
sensors to datemdashsmaller than a
grain of sand By EEWeb Contributing Writers
mCubersquos Sensors Enable IoMTInterview with Ben Lee President and CEO of mCube
INDUSTRY INTERVIEW
21
SmallerThan a
Grain Sand
of
Analysts project that by
2020 there will be over
50 billion connected
devices in the now-nascent
Internet of Things (IoT) However
the technology that will enable the
IoT of the future may look a little
different than todayrsquosmdashin fact
you may not be able to see it at all
Many new mobile devices require
motion sensors in order to monitor
analyze and deliver real-time data
and analysis to improve the way
consumers interact with everyday
technology While traditional
sensor platforms require multichip
modules or stacked die within a
device mCube a new MEMS sensor
company is driving the emergence
of Sensor 30 which will lead the
development of the smallest
sensors to datemdashsmaller than a
grain of sand By EEWeb Contributing Writers
mCubersquos Sensors Enable IoMTInterview with Ben Lee President and CEO of mCube
22
SENSOR TECHNOLOGY
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
INDUSTRY INTERVIEW
23
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
24
SENSOR TECHNOLOGY
Since sensors are so small and affordable donrsquot be surprised to find unique applications in the future Lee speculates that ldquofarmers might have sensor tags to monitor livestock for abnormal activity patterns of grazing potential illness and herd behaviorrdquo Commercial trucking might involve motion sensors connected to video cameras in rear-view mirrors to better assess the cause of an accident and driving conditions For shipping Lee describes ldquomotion sensors embedded directly onto packages to record jarring motions or accidents in order to determine when and how contents were damagedrdquo
As of 2014 mCubersquos complete intertial sensor portfolio contains an accelerometer magnetometer and its proprietary iGyrotrade gyroscope offering nine degrees of freedom (9DoF) Through reductions in cost power consumption and size mCubersquos sensor offerings make it possible to place them onto nearly any object or devicemdashin some cases without packaging ldquoWe aspire to put one or more MEMS motion sensors on anything that movesrdquo remarks Lee And with the IoMT taking shape and consumer expectations for connected moving devices becoming more concrete developers of new applications will turn to solutions like mCube to deliver truly cutting-edge connected devices
ldquoAt mCube we aspire to put one or more MEMS motion sensors on
anything that movesrdquo
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 15
Complete Inertial Motion Sensor Portfolio
Solutions for up to 9DoF (Degrees of Freedom)
Accelerometer
Magnetometer
iGyroTM
3DoF 3DoF
9DoF
2x2mm
3x3mm 3DoF 6DoF
14x14mm
3x3mm
3x3mm
2626
SENSOR TECHNOLOGY
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
27
TECH REPORT
27
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
2828
SENSOR TECHNOLOGY
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
29
TECH REPORT
29
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
3030
SENSOR TECHNOLOGY
to enable the kind of constant and complex data accumulation that the Biostamp promises
In the interim MC10 is partnering up with other medical and pharmaceutical companies to develop integrated sensor and monitoring products The company plans to become a certified medical-ready partner for companies who donrsquot have access to this unique and proprietary technology Even the US Army has begun working with MC10 on military-grade sensors that will add further safety features for troops in the field This funding from NIH grants Department of Defense grants as well as foundation grants will help the company get one step closer to realization of devices so flexible that users might forget theyrsquore wearing them
ldquoThe company has been bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devicesrdquo
Join the
DESIGNERS OF THINGS conference in San Francisco on
September 23 and 24
Dedicated to the explosive and exciting potential of Wearable
Tech 3D Printing and the Internet of Things the conference
provides the growing design and development community
around these technologies a meeting place to discuss and
showcase the newest products
Click here for more info
httpwwwdesignersofthingscomsanfranciscoscheduler
speakersheth-nirav-rav33310
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Sierra CircuitsA Complete PCB Resource
PLUS The Ground rdquo Myth in PrintedCircuits
ldquo
PCB Resin Reactor+
Ken BahlCEO of Sierra Circuits
Let There Be
How Cree reinvented the light bulb
LIGHT
David ElienVP of Marketing amp Business
Development Cree Inc
New LED Filament Tower
Cutting Edge Flatscreen Technologies
+
+
M o v i n g T o w a r d s
a Clean Energy
FUTUREmdash Hugo van Nispen COO of DNV KEMA
MCU Wars 32-bit MCU Comparison
Cutting Edge
SPICEModeling
Freescale and TI Embedded
Modules
ARMCortex
Programming
From Concept to
Reality Wolfgang Heinz-Fischer
Head of Marketing amp PR TQ-Group
Low-Power Design Techniques
TQ-Grouprsquos Comprehensive Design Process
+
+
PowerDeveloper
Octobe r 20 13
Designing forDurability
View more EEWeb magazinesmdash Click Here
20
SENSOR TECHNOLOGY
SmallerThan a
Grain Sand
of
Analysts project that by
2020 there will be over
50 billion connected
devices in the now-nascent
Internet of Things (IoT) However
the technology that will enable the
IoT of the future may look a little
different than todayrsquosmdashin fact
you may not be able to see it at all
Many new mobile devices require
motion sensors in order to monitor
analyze and deliver real-time data
and analysis to improve the way
consumers interact with everyday
technology While traditional
sensor platforms require multichip
modules or stacked die within a
device mCube a new MEMS sensor
company is driving the emergence
of Sensor 30 which will lead the
development of the smallest
sensors to datemdashsmaller than a
grain of sand By EEWeb Contributing Writers
mCubersquos Sensors Enable IoMTInterview with Ben Lee President and CEO of mCube
INDUSTRY INTERVIEW
21
SmallerThan a
Grain Sand
of
Analysts project that by
2020 there will be over
50 billion connected
devices in the now-nascent
Internet of Things (IoT) However
the technology that will enable the
IoT of the future may look a little
different than todayrsquosmdashin fact
you may not be able to see it at all
Many new mobile devices require
motion sensors in order to monitor
analyze and deliver real-time data
and analysis to improve the way
consumers interact with everyday
technology While traditional
sensor platforms require multichip
modules or stacked die within a
device mCube a new MEMS sensor
company is driving the emergence
of Sensor 30 which will lead the
development of the smallest
sensors to datemdashsmaller than a
grain of sand By EEWeb Contributing Writers
mCubersquos Sensors Enable IoMTInterview with Ben Lee President and CEO of mCube
22
SENSOR TECHNOLOGY
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
INDUSTRY INTERVIEW
23
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
24
SENSOR TECHNOLOGY
Since sensors are so small and affordable donrsquot be surprised to find unique applications in the future Lee speculates that ldquofarmers might have sensor tags to monitor livestock for abnormal activity patterns of grazing potential illness and herd behaviorrdquo Commercial trucking might involve motion sensors connected to video cameras in rear-view mirrors to better assess the cause of an accident and driving conditions For shipping Lee describes ldquomotion sensors embedded directly onto packages to record jarring motions or accidents in order to determine when and how contents were damagedrdquo
As of 2014 mCubersquos complete intertial sensor portfolio contains an accelerometer magnetometer and its proprietary iGyrotrade gyroscope offering nine degrees of freedom (9DoF) Through reductions in cost power consumption and size mCubersquos sensor offerings make it possible to place them onto nearly any object or devicemdashin some cases without packaging ldquoWe aspire to put one or more MEMS motion sensors on anything that movesrdquo remarks Lee And with the IoMT taking shape and consumer expectations for connected moving devices becoming more concrete developers of new applications will turn to solutions like mCube to deliver truly cutting-edge connected devices
ldquoAt mCube we aspire to put one or more MEMS motion sensors on
anything that movesrdquo
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 15
Complete Inertial Motion Sensor Portfolio
Solutions for up to 9DoF (Degrees of Freedom)
Accelerometer
Magnetometer
iGyroTM
3DoF 3DoF
9DoF
2x2mm
3x3mm 3DoF 6DoF
14x14mm
3x3mm
3x3mm
2626
SENSOR TECHNOLOGY
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
27
TECH REPORT
27
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
2828
SENSOR TECHNOLOGY
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
29
TECH REPORT
29
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
3030
SENSOR TECHNOLOGY
to enable the kind of constant and complex data accumulation that the Biostamp promises
In the interim MC10 is partnering up with other medical and pharmaceutical companies to develop integrated sensor and monitoring products The company plans to become a certified medical-ready partner for companies who donrsquot have access to this unique and proprietary technology Even the US Army has begun working with MC10 on military-grade sensors that will add further safety features for troops in the field This funding from NIH grants Department of Defense grants as well as foundation grants will help the company get one step closer to realization of devices so flexible that users might forget theyrsquore wearing them
ldquoThe company has been bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devicesrdquo
Join the
DESIGNERS OF THINGS conference in San Francisco on
September 23 and 24
Dedicated to the explosive and exciting potential of Wearable
Tech 3D Printing and the Internet of Things the conference
provides the growing design and development community
around these technologies a meeting place to discuss and
showcase the newest products
Click here for more info
httpwwwdesignersofthingscomsanfranciscoscheduler
speakersheth-nirav-rav33310
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Sierra CircuitsA Complete PCB Resource
PLUS The Ground rdquo Myth in PrintedCircuits
ldquo
PCB Resin Reactor+
Ken BahlCEO of Sierra Circuits
Let There Be
How Cree reinvented the light bulb
LIGHT
David ElienVP of Marketing amp Business
Development Cree Inc
New LED Filament Tower
Cutting Edge Flatscreen Technologies
+
+
M o v i n g T o w a r d s
a Clean Energy
FUTUREmdash Hugo van Nispen COO of DNV KEMA
MCU Wars 32-bit MCU Comparison
Cutting Edge
SPICEModeling
Freescale and TI Embedded
Modules
ARMCortex
Programming
From Concept to
Reality Wolfgang Heinz-Fischer
Head of Marketing amp PR TQ-Group
Low-Power Design Techniques
TQ-Grouprsquos Comprehensive Design Process
+
+
PowerDeveloper
Octobe r 20 13
Designing forDurability
View more EEWeb magazinesmdash Click Here
INDUSTRY INTERVIEW
21
SmallerThan a
Grain Sand
of
Analysts project that by
2020 there will be over
50 billion connected
devices in the now-nascent
Internet of Things (IoT) However
the technology that will enable the
IoT of the future may look a little
different than todayrsquosmdashin fact
you may not be able to see it at all
Many new mobile devices require
motion sensors in order to monitor
analyze and deliver real-time data
and analysis to improve the way
consumers interact with everyday
technology While traditional
sensor platforms require multichip
modules or stacked die within a
device mCube a new MEMS sensor
company is driving the emergence
of Sensor 30 which will lead the
development of the smallest
sensors to datemdashsmaller than a
grain of sand By EEWeb Contributing Writers
mCubersquos Sensors Enable IoMTInterview with Ben Lee President and CEO of mCube
22
SENSOR TECHNOLOGY
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
INDUSTRY INTERVIEW
23
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
24
SENSOR TECHNOLOGY
Since sensors are so small and affordable donrsquot be surprised to find unique applications in the future Lee speculates that ldquofarmers might have sensor tags to monitor livestock for abnormal activity patterns of grazing potential illness and herd behaviorrdquo Commercial trucking might involve motion sensors connected to video cameras in rear-view mirrors to better assess the cause of an accident and driving conditions For shipping Lee describes ldquomotion sensors embedded directly onto packages to record jarring motions or accidents in order to determine when and how contents were damagedrdquo
As of 2014 mCubersquos complete intertial sensor portfolio contains an accelerometer magnetometer and its proprietary iGyrotrade gyroscope offering nine degrees of freedom (9DoF) Through reductions in cost power consumption and size mCubersquos sensor offerings make it possible to place them onto nearly any object or devicemdashin some cases without packaging ldquoWe aspire to put one or more MEMS motion sensors on anything that movesrdquo remarks Lee And with the IoMT taking shape and consumer expectations for connected moving devices becoming more concrete developers of new applications will turn to solutions like mCube to deliver truly cutting-edge connected devices
ldquoAt mCube we aspire to put one or more MEMS motion sensors on
anything that movesrdquo
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 15
Complete Inertial Motion Sensor Portfolio
Solutions for up to 9DoF (Degrees of Freedom)
Accelerometer
Magnetometer
iGyroTM
3DoF 3DoF
9DoF
2x2mm
3x3mm 3DoF 6DoF
14x14mm
3x3mm
3x3mm
2626
SENSOR TECHNOLOGY
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
27
TECH REPORT
27
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
2828
SENSOR TECHNOLOGY
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
29
TECH REPORT
29
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
3030
SENSOR TECHNOLOGY
to enable the kind of constant and complex data accumulation that the Biostamp promises
In the interim MC10 is partnering up with other medical and pharmaceutical companies to develop integrated sensor and monitoring products The company plans to become a certified medical-ready partner for companies who donrsquot have access to this unique and proprietary technology Even the US Army has begun working with MC10 on military-grade sensors that will add further safety features for troops in the field This funding from NIH grants Department of Defense grants as well as foundation grants will help the company get one step closer to realization of devices so flexible that users might forget theyrsquore wearing them
ldquoThe company has been bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devicesrdquo
Join the
DESIGNERS OF THINGS conference in San Francisco on
September 23 and 24
Dedicated to the explosive and exciting potential of Wearable
Tech 3D Printing and the Internet of Things the conference
provides the growing design and development community
around these technologies a meeting place to discuss and
showcase the newest products
Click here for more info
httpwwwdesignersofthingscomsanfranciscoscheduler
speakersheth-nirav-rav33310
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Sierra CircuitsA Complete PCB Resource
PLUS The Ground rdquo Myth in PrintedCircuits
ldquo
PCB Resin Reactor+
Ken BahlCEO of Sierra Circuits
Let There Be
How Cree reinvented the light bulb
LIGHT
David ElienVP of Marketing amp Business
Development Cree Inc
New LED Filament Tower
Cutting Edge Flatscreen Technologies
+
+
M o v i n g T o w a r d s
a Clean Energy
FUTUREmdash Hugo van Nispen COO of DNV KEMA
MCU Wars 32-bit MCU Comparison
Cutting Edge
SPICEModeling
Freescale and TI Embedded
Modules
ARMCortex
Programming
From Concept to
Reality Wolfgang Heinz-Fischer
Head of Marketing amp PR TQ-Group
Low-Power Design Techniques
TQ-Grouprsquos Comprehensive Design Process
+
+
PowerDeveloper
Octobe r 20 13
Designing forDurability
View more EEWeb magazinesmdash Click Here
22
SENSOR TECHNOLOGY
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
INDUSTRY INTERVIEW
23
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
24
SENSOR TECHNOLOGY
Since sensors are so small and affordable donrsquot be surprised to find unique applications in the future Lee speculates that ldquofarmers might have sensor tags to monitor livestock for abnormal activity patterns of grazing potential illness and herd behaviorrdquo Commercial trucking might involve motion sensors connected to video cameras in rear-view mirrors to better assess the cause of an accident and driving conditions For shipping Lee describes ldquomotion sensors embedded directly onto packages to record jarring motions or accidents in order to determine when and how contents were damagedrdquo
As of 2014 mCubersquos complete intertial sensor portfolio contains an accelerometer magnetometer and its proprietary iGyrotrade gyroscope offering nine degrees of freedom (9DoF) Through reductions in cost power consumption and size mCubersquos sensor offerings make it possible to place them onto nearly any object or devicemdashin some cases without packaging ldquoWe aspire to put one or more MEMS motion sensors on anything that movesrdquo remarks Lee And with the IoMT taking shape and consumer expectations for connected moving devices becoming more concrete developers of new applications will turn to solutions like mCube to deliver truly cutting-edge connected devices
ldquoAt mCube we aspire to put one or more MEMS motion sensors on
anything that movesrdquo
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 15
Complete Inertial Motion Sensor Portfolio
Solutions for up to 9DoF (Degrees of Freedom)
Accelerometer
Magnetometer
iGyroTM
3DoF 3DoF
9DoF
2x2mm
3x3mm 3DoF 6DoF
14x14mm
3x3mm
3x3mm
2626
SENSOR TECHNOLOGY
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
27
TECH REPORT
27
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
2828
SENSOR TECHNOLOGY
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
29
TECH REPORT
29
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
3030
SENSOR TECHNOLOGY
to enable the kind of constant and complex data accumulation that the Biostamp promises
In the interim MC10 is partnering up with other medical and pharmaceutical companies to develop integrated sensor and monitoring products The company plans to become a certified medical-ready partner for companies who donrsquot have access to this unique and proprietary technology Even the US Army has begun working with MC10 on military-grade sensors that will add further safety features for troops in the field This funding from NIH grants Department of Defense grants as well as foundation grants will help the company get one step closer to realization of devices so flexible that users might forget theyrsquore wearing them
ldquoThe company has been bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devicesrdquo
Join the
DESIGNERS OF THINGS conference in San Francisco on
September 23 and 24
Dedicated to the explosive and exciting potential of Wearable
Tech 3D Printing and the Internet of Things the conference
provides the growing design and development community
around these technologies a meeting place to discuss and
showcase the newest products
Click here for more info
httpwwwdesignersofthingscomsanfranciscoscheduler
speakersheth-nirav-rav33310
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Sierra CircuitsA Complete PCB Resource
PLUS The Ground rdquo Myth in PrintedCircuits
ldquo
PCB Resin Reactor+
Ken BahlCEO of Sierra Circuits
Let There Be
How Cree reinvented the light bulb
LIGHT
David ElienVP of Marketing amp Business
Development Cree Inc
New LED Filament Tower
Cutting Edge Flatscreen Technologies
+
+
M o v i n g T o w a r d s
a Clean Energy
FUTUREmdash Hugo van Nispen COO of DNV KEMA
MCU Wars 32-bit MCU Comparison
Cutting Edge
SPICEModeling
Freescale and TI Embedded
Modules
ARMCortex
Programming
From Concept to
Reality Wolfgang Heinz-Fischer
Head of Marketing amp PR TQ-Group
Low-Power Design Techniques
TQ-Grouprsquos Comprehensive Design Process
+
+
PowerDeveloper
Octobe r 20 13
Designing forDurability
View more EEWeb magazinesmdash Click Here
INDUSTRY INTERVIEW
23
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 11
mCube Technology Leapfrogs Existing Players
Cos
t S
ize
Pow
er
Performance Function Integration
Hybrid MCM
Stacked Chip
3D Single-chip
MEMS
IC
ldquoMotion sensors are key components in consumer devicesrdquo says Ben Lee president and CEO of mCube The need for smaller more powerful sensors has emerged from the rise in mobile applications such as gaming devices tablets sports equipment and wearable technology This wave of new applications is a part of the Internet of Moving Things (IoMT) which depends on high-functioning sensors like accelerometers gyroscopes and magnetometers to deliver dynamic performance specs for these moving devices mCube has developed microelectromechanical system (MEMS) sensors with significant size reductions that allow for simplified integration and implementation in new IoMT applications
To achieve MEMS integration with electronics mCube developed a monolithic single-chip structural design that is integrated with an application-specific integrated circuit (ASIC) ldquomCube is the first companyrdquo tells Lee ldquoto successfully bring to market an integrated MEMS+ASIC in high volume productionrdquo Whereas traditional MEMS devices occupied a larger area with lower yields mCubersquos MEMS is fabricated directly on top of the complementary metal-oxide semiconductor allowing for unparalleled integration and performance This is achieved by bonding a single crystal silicon wafer to the surface of a CMOS plate A cap is then bonded over the MEMS structures at the wafer level and is protected in a hermetic environment
With this unique process mCube is able to overcome traditional drawbacks of integrating MEMS due to the fact that it is entirely monolithic meaning the alignment tolerance between MEMS and CMOS in mCubersquos accelerometer is 01 μm as opposed to traditional distances of 3 to 5 μm As consumer needs are driving rapid size reductions in the IoMT market mCube positions itself ahead of the curve by enabling integrated powerful and seemingly invisible sensor technology
Just how small is mCubersquos solution Maximum size reduction is achieved by ohmically connecting the MEMS to the underlying CMOS through 3 μm vias mCubersquos integrated device has four times fewer the number of connected bonds which ends up significantly reducing the surface area needed for implementation and ultimately the cost
ldquomCube has developed MEMS sensors with significant size reductions that allow for simplified integration in new
IoMT applicationsrdquo
The mCube monolithic single-chip platform shown above in a schematic cross-section integrates MEMS with CMOS more efficiently than in any other commercial MeMS product
24
SENSOR TECHNOLOGY
Since sensors are so small and affordable donrsquot be surprised to find unique applications in the future Lee speculates that ldquofarmers might have sensor tags to monitor livestock for abnormal activity patterns of grazing potential illness and herd behaviorrdquo Commercial trucking might involve motion sensors connected to video cameras in rear-view mirrors to better assess the cause of an accident and driving conditions For shipping Lee describes ldquomotion sensors embedded directly onto packages to record jarring motions or accidents in order to determine when and how contents were damagedrdquo
As of 2014 mCubersquos complete intertial sensor portfolio contains an accelerometer magnetometer and its proprietary iGyrotrade gyroscope offering nine degrees of freedom (9DoF) Through reductions in cost power consumption and size mCubersquos sensor offerings make it possible to place them onto nearly any object or devicemdashin some cases without packaging ldquoWe aspire to put one or more MEMS motion sensors on anything that movesrdquo remarks Lee And with the IoMT taking shape and consumer expectations for connected moving devices becoming more concrete developers of new applications will turn to solutions like mCube to deliver truly cutting-edge connected devices
ldquoAt mCube we aspire to put one or more MEMS motion sensors on
anything that movesrdquo
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 15
Complete Inertial Motion Sensor Portfolio
Solutions for up to 9DoF (Degrees of Freedom)
Accelerometer
Magnetometer
iGyroTM
3DoF 3DoF
9DoF
2x2mm
3x3mm 3DoF 6DoF
14x14mm
3x3mm
3x3mm
2626
SENSOR TECHNOLOGY
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
27
TECH REPORT
27
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
2828
SENSOR TECHNOLOGY
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
29
TECH REPORT
29
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
3030
SENSOR TECHNOLOGY
to enable the kind of constant and complex data accumulation that the Biostamp promises
In the interim MC10 is partnering up with other medical and pharmaceutical companies to develop integrated sensor and monitoring products The company plans to become a certified medical-ready partner for companies who donrsquot have access to this unique and proprietary technology Even the US Army has begun working with MC10 on military-grade sensors that will add further safety features for troops in the field This funding from NIH grants Department of Defense grants as well as foundation grants will help the company get one step closer to realization of devices so flexible that users might forget theyrsquore wearing them
ldquoThe company has been bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devicesrdquo
Join the
DESIGNERS OF THINGS conference in San Francisco on
September 23 and 24
Dedicated to the explosive and exciting potential of Wearable
Tech 3D Printing and the Internet of Things the conference
provides the growing design and development community
around these technologies a meeting place to discuss and
showcase the newest products
Click here for more info
httpwwwdesignersofthingscomsanfranciscoscheduler
speakersheth-nirav-rav33310
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Sierra CircuitsA Complete PCB Resource
PLUS The Ground rdquo Myth in PrintedCircuits
ldquo
PCB Resin Reactor+
Ken BahlCEO of Sierra Circuits
Let There Be
How Cree reinvented the light bulb
LIGHT
David ElienVP of Marketing amp Business
Development Cree Inc
New LED Filament Tower
Cutting Edge Flatscreen Technologies
+
+
M o v i n g T o w a r d s
a Clean Energy
FUTUREmdash Hugo van Nispen COO of DNV KEMA
MCU Wars 32-bit MCU Comparison
Cutting Edge
SPICEModeling
Freescale and TI Embedded
Modules
ARMCortex
Programming
From Concept to
Reality Wolfgang Heinz-Fischer
Head of Marketing amp PR TQ-Group
Low-Power Design Techniques
TQ-Grouprsquos Comprehensive Design Process
+
+
PowerDeveloper
Octobe r 20 13
Designing forDurability
View more EEWeb magazinesmdash Click Here
24
SENSOR TECHNOLOGY
Since sensors are so small and affordable donrsquot be surprised to find unique applications in the future Lee speculates that ldquofarmers might have sensor tags to monitor livestock for abnormal activity patterns of grazing potential illness and herd behaviorrdquo Commercial trucking might involve motion sensors connected to video cameras in rear-view mirrors to better assess the cause of an accident and driving conditions For shipping Lee describes ldquomotion sensors embedded directly onto packages to record jarring motions or accidents in order to determine when and how contents were damagedrdquo
As of 2014 mCubersquos complete intertial sensor portfolio contains an accelerometer magnetometer and its proprietary iGyrotrade gyroscope offering nine degrees of freedom (9DoF) Through reductions in cost power consumption and size mCubersquos sensor offerings make it possible to place them onto nearly any object or devicemdashin some cases without packaging ldquoWe aspire to put one or more MEMS motion sensors on anything that movesrdquo remarks Lee And with the IoMT taking shape and consumer expectations for connected moving devices becoming more concrete developers of new applications will turn to solutions like mCube to deliver truly cutting-edge connected devices
ldquoAt mCube we aspire to put one or more MEMS motion sensors on
anything that movesrdquo
Proprietary and Confidential copy 2014 mCube Inc All rights reserved 15
Complete Inertial Motion Sensor Portfolio
Solutions for up to 9DoF (Degrees of Freedom)
Accelerometer
Magnetometer
iGyroTM
3DoF 3DoF
9DoF
2x2mm
3x3mm 3DoF 6DoF
14x14mm
3x3mm
3x3mm
2626
SENSOR TECHNOLOGY
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
27
TECH REPORT
27
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
2828
SENSOR TECHNOLOGY
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
29
TECH REPORT
29
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
3030
SENSOR TECHNOLOGY
to enable the kind of constant and complex data accumulation that the Biostamp promises
In the interim MC10 is partnering up with other medical and pharmaceutical companies to develop integrated sensor and monitoring products The company plans to become a certified medical-ready partner for companies who donrsquot have access to this unique and proprietary technology Even the US Army has begun working with MC10 on military-grade sensors that will add further safety features for troops in the field This funding from NIH grants Department of Defense grants as well as foundation grants will help the company get one step closer to realization of devices so flexible that users might forget theyrsquore wearing them
ldquoThe company has been bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devicesrdquo
Join the
DESIGNERS OF THINGS conference in San Francisco on
September 23 and 24
Dedicated to the explosive and exciting potential of Wearable
Tech 3D Printing and the Internet of Things the conference
provides the growing design and development community
around these technologies a meeting place to discuss and
showcase the newest products
Click here for more info
httpwwwdesignersofthingscomsanfranciscoscheduler
speakersheth-nirav-rav33310
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Sierra CircuitsA Complete PCB Resource
PLUS The Ground rdquo Myth in PrintedCircuits
ldquo
PCB Resin Reactor+
Ken BahlCEO of Sierra Circuits
Let There Be
How Cree reinvented the light bulb
LIGHT
David ElienVP of Marketing amp Business
Development Cree Inc
New LED Filament Tower
Cutting Edge Flatscreen Technologies
+
+
M o v i n g T o w a r d s
a Clean Energy
FUTUREmdash Hugo van Nispen COO of DNV KEMA
MCU Wars 32-bit MCU Comparison
Cutting Edge
SPICEModeling
Freescale and TI Embedded
Modules
ARMCortex
Programming
From Concept to
Reality Wolfgang Heinz-Fischer
Head of Marketing amp PR TQ-Group
Low-Power Design Techniques
TQ-Grouprsquos Comprehensive Design Process
+
+
PowerDeveloper
Octobe r 20 13
Designing forDurability
View more EEWeb magazinesmdash Click Here
2626
SENSOR TECHNOLOGY
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
27
TECH REPORT
27
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
2828
SENSOR TECHNOLOGY
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
29
TECH REPORT
29
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
3030
SENSOR TECHNOLOGY
to enable the kind of constant and complex data accumulation that the Biostamp promises
In the interim MC10 is partnering up with other medical and pharmaceutical companies to develop integrated sensor and monitoring products The company plans to become a certified medical-ready partner for companies who donrsquot have access to this unique and proprietary technology Even the US Army has begun working with MC10 on military-grade sensors that will add further safety features for troops in the field This funding from NIH grants Department of Defense grants as well as foundation grants will help the company get one step closer to realization of devices so flexible that users might forget theyrsquore wearing them
ldquoThe company has been bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devicesrdquo
Join the
DESIGNERS OF THINGS conference in San Francisco on
September 23 and 24
Dedicated to the explosive and exciting potential of Wearable
Tech 3D Printing and the Internet of Things the conference
provides the growing design and development community
around these technologies a meeting place to discuss and
showcase the newest products
Click here for more info
httpwwwdesignersofthingscomsanfranciscoscheduler
speakersheth-nirav-rav33310
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Sierra CircuitsA Complete PCB Resource
PLUS The Ground rdquo Myth in PrintedCircuits
ldquo
PCB Resin Reactor+
Ken BahlCEO of Sierra Circuits
Let There Be
How Cree reinvented the light bulb
LIGHT
David ElienVP of Marketing amp Business
Development Cree Inc
New LED Filament Tower
Cutting Edge Flatscreen Technologies
+
+
M o v i n g T o w a r d s
a Clean Energy
FUTUREmdash Hugo van Nispen COO of DNV KEMA
MCU Wars 32-bit MCU Comparison
Cutting Edge
SPICEModeling
Freescale and TI Embedded
Modules
ARMCortex
Programming
From Concept to
Reality Wolfgang Heinz-Fischer
Head of Marketing amp PR TQ-Group
Low-Power Design Techniques
TQ-Grouprsquos Comprehensive Design Process
+
+
PowerDeveloper
Octobe r 20 13
Designing forDurability
View more EEWeb magazinesmdash Click Here
27
TECH REPORT
27
SKINTIGHT
Flexible Sensors Collect Vitals
By Alex Maddalena Contributing Writer
Electronics are becoming increasingly omnipresent in our
everyday lives Industry trends of reduced device sizes
seamless integration in our environments and wireless
connectivity are changing the way consumers interact with
technology One of the upsides of ubiquitous technology is
the collection of data that was previously inaccessible An
example of this is wearable health monitorsmdashbracelets and
bands that collect vital health statistics to inform users of
trends in their everyday activity which could ultimately lead
to healthier lifestyle and activity choices However one of the
biggest burdens of these health monitors is their form factormdash
rigid electronics are not the most natural option for wearing
during physical activities
Technology
2828
SENSOR TECHNOLOGY
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
29
TECH REPORT
29
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
3030
SENSOR TECHNOLOGY
to enable the kind of constant and complex data accumulation that the Biostamp promises
In the interim MC10 is partnering up with other medical and pharmaceutical companies to develop integrated sensor and monitoring products The company plans to become a certified medical-ready partner for companies who donrsquot have access to this unique and proprietary technology Even the US Army has begun working with MC10 on military-grade sensors that will add further safety features for troops in the field This funding from NIH grants Department of Defense grants as well as foundation grants will help the company get one step closer to realization of devices so flexible that users might forget theyrsquore wearing them
ldquoThe company has been bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devicesrdquo
Join the
DESIGNERS OF THINGS conference in San Francisco on
September 23 and 24
Dedicated to the explosive and exciting potential of Wearable
Tech 3D Printing and the Internet of Things the conference
provides the growing design and development community
around these technologies a meeting place to discuss and
showcase the newest products
Click here for more info
httpwwwdesignersofthingscomsanfranciscoscheduler
speakersheth-nirav-rav33310
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Sierra CircuitsA Complete PCB Resource
PLUS The Ground rdquo Myth in PrintedCircuits
ldquo
PCB Resin Reactor+
Ken BahlCEO of Sierra Circuits
Let There Be
How Cree reinvented the light bulb
LIGHT
David ElienVP of Marketing amp Business
Development Cree Inc
New LED Filament Tower
Cutting Edge Flatscreen Technologies
+
+
M o v i n g T o w a r d s
a Clean Energy
FUTUREmdash Hugo van Nispen COO of DNV KEMA
MCU Wars 32-bit MCU Comparison
Cutting Edge
SPICEModeling
Freescale and TI Embedded
Modules
ARMCortex
Programming
From Concept to
Reality Wolfgang Heinz-Fischer
Head of Marketing amp PR TQ-Group
Low-Power Design Techniques
TQ-Grouprsquos Comprehensive Design Process
+
+
PowerDeveloper
Octobe r 20 13
Designing forDurability
View more EEWeb magazinesmdash Click Here
2828
SENSOR TECHNOLOGY
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
29
TECH REPORT
29
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
3030
SENSOR TECHNOLOGY
to enable the kind of constant and complex data accumulation that the Biostamp promises
In the interim MC10 is partnering up with other medical and pharmaceutical companies to develop integrated sensor and monitoring products The company plans to become a certified medical-ready partner for companies who donrsquot have access to this unique and proprietary technology Even the US Army has begun working with MC10 on military-grade sensors that will add further safety features for troops in the field This funding from NIH grants Department of Defense grants as well as foundation grants will help the company get one step closer to realization of devices so flexible that users might forget theyrsquore wearing them
ldquoThe company has been bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devicesrdquo
Join the
DESIGNERS OF THINGS conference in San Francisco on
September 23 and 24
Dedicated to the explosive and exciting potential of Wearable
Tech 3D Printing and the Internet of Things the conference
provides the growing design and development community
around these technologies a meeting place to discuss and
showcase the newest products
Click here for more info
httpwwwdesignersofthingscomsanfranciscoscheduler
speakersheth-nirav-rav33310
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Sierra CircuitsA Complete PCB Resource
PLUS The Ground rdquo Myth in PrintedCircuits
ldquo
PCB Resin Reactor+
Ken BahlCEO of Sierra Circuits
Let There Be
How Cree reinvented the light bulb
LIGHT
David ElienVP of Marketing amp Business
Development Cree Inc
New LED Filament Tower
Cutting Edge Flatscreen Technologies
+
+
M o v i n g T o w a r d s
a Clean Energy
FUTUREmdash Hugo van Nispen COO of DNV KEMA
MCU Wars 32-bit MCU Comparison
Cutting Edge
SPICEModeling
Freescale and TI Embedded
Modules
ARMCortex
Programming
From Concept to
Reality Wolfgang Heinz-Fischer
Head of Marketing amp PR TQ-Group
Low-Power Design Techniques
TQ-Grouprsquos Comprehensive Design Process
+
+
PowerDeveloper
Octobe r 20 13
Designing forDurability
View more EEWeb magazinesmdash Click Here
29
TECH REPORT
29
As a result MC10 a flexible device developer based in Cambridge Massachusettes is developing a
new kind of wearable device with UCB a patient-centric biopharmaceutical leader that will redefine ldquoformrdquo in ldquoform factorrdquo The Biostamptrade a prototype from MC10 is a flexible sensor that effortlessly adheres to the body and is able to bend stretch and flex along with the user The device is as unobtrusive as a Band-Aid that can link to any bluetooth-enabled mobile device to deliver real-time data on the bodyrsquos vital statisticsmdasheverything from hydration levels and heart rate to UV exposure and body temperature The Biostamp will enable users to receive real-time data about their health
MC10 was founded by Professor John Rogers back in 2008 after years of seminal research on flexible technology at Bell Laboratories and UIUC (University of Illinois UrbanandashChampaign) The goal of the research was to develop ways of implementing electronics everywhere imaginable by breaking down the devicersquos form factors Rogers and his colleagues eventually developed a way to form silicon on incredibly thin elastomers while still maintaining its properties MC10 is the culmination of this extensive
and groundbreaking research and is the exclusive licensee of the patent portfolio that Professor Rogers built up over the years of research
The innovations in materials science revolved around the deconstruction of the base material silicon Rogersrsquo team was first able to dramatically reduce the thickness profile of the silicon down to a nano scale The second innovation was the development of discrete chiplets of silicon which could then be distributed onto arrays comprised of nanomaterials In the case of the Biostamp the array is then embedded onto flexible rubber band-like material that still maintains the silicon semiconductor characteristics allowing for unprecedented uses adhering to the human body and this allows continuous monitoring
ldquoProfessor Rogers is very passionate about the idea of being able to change peoplersquos lives through electronicsrdquo said head of market development Nirav Sheth offering a summary of the companyrsquos mission statement ldquoAt MC10 we are all about dissolving boundaries between humans and electronicsrdquo The Biostamprsquos functionality reflects the central tenets of the company by
ldquoThe Biostamp device is as unobtrusive as a Band-Aid and can link to any mobile device to deliver real-time
data on the bodyrsquos vital statisticsrdquo
ldquoWe never looked at MC10 as a purely consumer
technology companyrdquo Sheth claimed ldquoIt is also a medical
health companyrdquo
collecting data that will ultimately help users make important decisions about aspects of their health In fact the device is undergoing crucial patient testing to determine the efficacy of the data it yields and whether it can provide concrete claims on the health of the user ldquoWe never looked at MC10 as a purely consumer technology companyrdquo Sheth claimed ldquoIt is also a medical health companyrdquo
Considering themselves a medical health company poses a unique challenge to the MC10 team because the market for ubiquitous technology like the Biostamp does not fully exist yet However this does not deter MC10 from continuing development of the device on all frontsmdashfrom material sciences research to software and hardware development In fact the company has been building its team by bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devices in the back end ldquoThe software aspects may be in the long term the most differentiating aspects of the technologyrdquo Sheth stated explaining the companyrsquos software-related investment Conversely the hardware had to be at a certain advanced level
3030
SENSOR TECHNOLOGY
to enable the kind of constant and complex data accumulation that the Biostamp promises
In the interim MC10 is partnering up with other medical and pharmaceutical companies to develop integrated sensor and monitoring products The company plans to become a certified medical-ready partner for companies who donrsquot have access to this unique and proprietary technology Even the US Army has begun working with MC10 on military-grade sensors that will add further safety features for troops in the field This funding from NIH grants Department of Defense grants as well as foundation grants will help the company get one step closer to realization of devices so flexible that users might forget theyrsquore wearing them
ldquoThe company has been bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devicesrdquo
Join the
DESIGNERS OF THINGS conference in San Francisco on
September 23 and 24
Dedicated to the explosive and exciting potential of Wearable
Tech 3D Printing and the Internet of Things the conference
provides the growing design and development community
around these technologies a meeting place to discuss and
showcase the newest products
Click here for more info
httpwwwdesignersofthingscomsanfranciscoscheduler
speakersheth-nirav-rav33310
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Sierra CircuitsA Complete PCB Resource
PLUS The Ground rdquo Myth in PrintedCircuits
ldquo
PCB Resin Reactor+
Ken BahlCEO of Sierra Circuits
Let There Be
How Cree reinvented the light bulb
LIGHT
David ElienVP of Marketing amp Business
Development Cree Inc
New LED Filament Tower
Cutting Edge Flatscreen Technologies
+
+
M o v i n g T o w a r d s
a Clean Energy
FUTUREmdash Hugo van Nispen COO of DNV KEMA
MCU Wars 32-bit MCU Comparison
Cutting Edge
SPICEModeling
Freescale and TI Embedded
Modules
ARMCortex
Programming
From Concept to
Reality Wolfgang Heinz-Fischer
Head of Marketing amp PR TQ-Group
Low-Power Design Techniques
TQ-Grouprsquos Comprehensive Design Process
+
+
PowerDeveloper
Octobe r 20 13
Designing forDurability
View more EEWeb magazinesmdash Click Here
3030
SENSOR TECHNOLOGY
to enable the kind of constant and complex data accumulation that the Biostamp promises
In the interim MC10 is partnering up with other medical and pharmaceutical companies to develop integrated sensor and monitoring products The company plans to become a certified medical-ready partner for companies who donrsquot have access to this unique and proprietary technology Even the US Army has begun working with MC10 on military-grade sensors that will add further safety features for troops in the field This funding from NIH grants Department of Defense grants as well as foundation grants will help the company get one step closer to realization of devices so flexible that users might forget theyrsquore wearing them
ldquoThe company has been bringing on board app developers with cloud computing and algorithm development expertise to help support MC10rsquos devicesrdquo
Join the
DESIGNERS OF THINGS conference in San Francisco on
September 23 and 24
Dedicated to the explosive and exciting potential of Wearable
Tech 3D Printing and the Internet of Things the conference
provides the growing design and development community
around these technologies a meeting place to discuss and
showcase the newest products
Click here for more info
httpwwwdesignersofthingscomsanfranciscoscheduler
speakersheth-nirav-rav33310
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
Sierra CircuitsA Complete PCB Resource
PLUS The Ground rdquo Myth in PrintedCircuits
ldquo
PCB Resin Reactor+
Ken BahlCEO of Sierra Circuits
Let There Be
How Cree reinvented the light bulb
LIGHT
David ElienVP of Marketing amp Business
Development Cree Inc
New LED Filament Tower
Cutting Edge Flatscreen Technologies
+
+
M o v i n g T o w a r d s
a Clean Energy
FUTUREmdash Hugo van Nispen COO of DNV KEMA
MCU Wars 32-bit MCU Comparison
Cutting Edge
SPICEModeling
Freescale and TI Embedded
Modules
ARMCortex
Programming
From Concept to
Reality Wolfgang Heinz-Fischer
Head of Marketing amp PR TQ-Group
Low-Power Design Techniques
TQ-Grouprsquos Comprehensive Design Process
+
+
PowerDeveloper
Octobe r 20 13
Designing forDurability
View more EEWeb magazinesmdash Click Here
Your Circuit Starts HereSign up to design share and collaborate
on your next projectmdashbig or small
Click Here to Sign Up
eewebcomregister
Join Today
READY TO LAUNCH
For the launch of the Tiva C Series Connected LaunchPad TI has partnered with Exosite mentioned briefly above to provide easy access to the LaunchPad from the Internet The LaunchPad takes about 10 minutes to set up and you can immediately interact with it across the Internet and do things like turn an LED on and off remotely from the website and see the reported temperature as well It can also display approximate geographic location based on the assigned IP address and display a map of all other connected LaunchPad owners if they are active and plugged-in to Exosite ldquoIn addition it supports a basic game by enabling someone to interface to the Connected LaunchPad through a serial port from a terminal while someone else is playing with them through their browser It is basically showing how you can interact remotely with this product and a user even if you are across the globerdquo Folkens explained
START DEVELOPING
The Tiva C Series Connected LaunchPad is shipping now and the price is right at $1999 USD it is less than half the price of other Ethernet-ready kits The LaunchPad comes complete with quick start and user guides and ample online support to ensure developers of all backgrounds are well equipped to begin creating cloud-based applications ldquoWe have assembled an online support team to monitor the Engineering-to-Engineering (or E2E) Communityrdquo Folkens said ldquoAlong with this you also got a free Code Composer Studio Integrated Development Environment which allows developers to use the full capability We also support other tool chains like Keil IAR and Mentor Embedded
Affordable versatile and easy to use the Tiva Series Connected LaunchPad is well suited for a broad audience and promises to facilitate the expansion of ingenious IoT applications in the cloud As Folkens concluded ldquoThe target audiences actually are the hobbyists students and professional engineers A better way of looking at it is that we are targeting people with innovative ideas and trying to help them get those ideas launched into the cloudrdquo
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Development Cree Inc
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Cutting Edge
SPICEModeling
Freescale and TI Embedded
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Programming
From Concept to
Reality Wolfgang Heinz-Fischer
Head of Marketing amp PR TQ-Group
Low-Power Design Techniques
TQ-Grouprsquos Comprehensive Design Process
+
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PowerDeveloper
Octobe r 20 13
Designing forDurability
View more EEWeb magazinesmdash Click Here
Sierra CircuitsA Complete PCB Resource
PLUS The Ground rdquo Myth in PrintedCircuits
ldquo
PCB Resin Reactor+
Ken BahlCEO of Sierra Circuits
Let There Be
How Cree reinvented the light bulb
LIGHT
David ElienVP of Marketing amp Business
Development Cree Inc
New LED Filament Tower
Cutting Edge Flatscreen Technologies
+
+
M o v i n g T o w a r d s
a Clean Energy
FUTUREmdash Hugo van Nispen COO of DNV KEMA
MCU Wars 32-bit MCU Comparison
Cutting Edge
SPICEModeling
Freescale and TI Embedded
Modules
ARMCortex
Programming
From Concept to
Reality Wolfgang Heinz-Fischer
Head of Marketing amp PR TQ-Group
Low-Power Design Techniques
TQ-Grouprsquos Comprehensive Design Process
+
+
PowerDeveloper
Octobe r 20 13
Designing forDurability
View more EEWeb magazinesmdash Click Here