Download - High-Intensity Focused Ultrasound Therapy Array May1005 Alex Apel Stephen Rashid Justin Robinson
High-Intensity Focused Ultrasound Therapy Array
May1005
Alex ApelStephen RashidJustin Robinson
Need and Problem StatementNeed
A research tool to provide data on phase error correction in high-intensity ultrasound arrays
ProblemTo provide a PC based interface for a user to
control the phase and duration of a four channel array of ultrasound transducers
Existing solutions
System Architecture
PCSoftware
Microcontroller Circuit
Serial
Control Logic
Analog Hardware
Control Logic
Analog Hardware
Control Logic
Analog Hardware
Control Logic
Analog Hardware
Users and Operating EnvironmentResearchers
Advancement of ultrasound therapy technology
To be used in a laboratory with a controlled environment
User InterfaceInputs
Phase control per channelPulse lengthStart and Stop
Available OutputRelative phase from feedback loop
RequirementsPhase Control
Set phase of each channel360º of control
Duty Cycle Control20 ms cycle timeVariable between 0.01% and 1%
ScalabilityPotential to expand system
DeliverablesComputer Software
A CD installer. Needs Microsoft .NET Framework (Win2000 SP4 or newer).
Application provides UI with Microcontroller BoardDriver Board
Driver board controls multiple transducer control circuits.Driver board is manipulated via a RS232 connection to the user
PC.Transducer Card
(4x) Controls the Analog Power Circuits. Allows for concurrent processes.
Analog Power Circuits (4x) Amplify the waveform and provide power to Transducer.
End User GuideReference on how each element of the system works. Guide to
using the software.
Work BreakdownDesign and Documentation Process
Group influence and final decision makingDiversity of knowledge allows for specialties in decision
makingComputer Software
Primary focus area of Justin RobinsonDigital Circuit and Microcontroller Software
Primary focus of Alex ApelAnalog Power Circuits
Primary Focus of Stephan RashidEnd User Guide
Sum of group knowledge of the device and its functionalityGroup Contribution
Task Hours Cost
Problem Definition 84 $1680
Technology/Implementation Considerations/Selection 79 $1580
System Design 77 $1540
System Implementation 104 $2080
System Tesing 82 $1640
System Documentation 55 $1100
System Demonstration 12 $240
Project Reporting 185 $3700
Totals 678 $13,560
Item Cost
Microcontroller Dev Board $159
H Bridge Amplifier $100 - $660
Supporting Discrete Parts $100
Total $359 - $919
RisksLoss of Team Member
Reduce knowledge baseLose time commitmentMitigated by effective communication and system scope
scalabilityLoss of Transducer
Needed to display resultsIrreplaceable, costEmulation circuit for testing
Lack of Expertise Risk posed by time restrictionsMay lead to poor decision makingEffective use of external resources and knowledge bases
System RequirementsPower
500W per Channel0.01% to 0.1%, Max 1% Duty Cycle20 ms Cycle Period
ScalabilityFuture system may control 500 elements
Operating FrequencyMaximum amplitude at 1.1 MHz Wish of 3.3 MHz
Phase Control360º of phase correction 8 bit resolution = 1.4º Allows for a 1.2 nm3 focal point
Functional DecompositionInput
Relative Phase ControlSignal PeriodSignal Duty Cycle
GenerationPower: 500WFeedback Generation
ProcessingFrequency 1.1 – 3.3
MHzAdjustable Duty Cycle20 ms Cycle PeriodPhase CorrectionWaveform Generation
PCSoftware
Microcontroller Circuit
Serial
Control Logic
Analog Hardware
Control Logic
Analog Hardware
Control Logic
Analog Hardware
Control Logic
Analog Hardware
GUI
Input•Relative Transducer Phase•Transducer Amplitude•Signal Period•Signal Duty Cycle•Start/Stop GenerationOutput•Phase
Micro
Transducer
Output•Mechanical Wave
RS-232
Transducer
Output•Mechanical Wave
TransducerControl Logic
TransducerAnalog Hardware
Phas
e Co
rrec
tion
User PC SoftwareGUI
Transducer Input [1..n]•ID•Relative Phase•Amplitude
Global Input•Signal Period•Signal Duty Cycle•Start/Stop Generation
Misc.•Save Input Data•Load Input Data
Transducer•ID : int•Relative Phase : int•Amplitude : int
•AdjPhase() : int•AdjAmplitude() : int
File Storage
Comm.Out
InSerial
Lab PC
Microcontroller CircuitSerial Interface to PCMicrocontrollerStorage and Correction
of Waveforms
System of addressing multiple transducers
Assertion and Control of global time frame
Transducer Control CircuitFeedback Collection Waveform AssertionConcurrent Access
Analog Hardware Design
H Bridge Controller
H Bridg
e
Power Supply
Transducer
Hi/Lo
On/Off
To Digital Phase Correction
Test PlanUnit Tests
Comm. Test
Integration Tests
Comm. Test
System TestComm. Test
PC PCRS-232
PC MicroRS-232
PC MicroRS-232 Hydro
phone
Transducer
Simulation & ModelingIdentifying Needs of Generated Waveform
Transducers Operate at Odd HarmonicsFourier Analysis of Proposed Waveforms
P-Spice Modeling of CircuitryH-Bridge Amplifier BehaviorFrequency Characteristics
AcknowledgmentsDr. Timothy Bigelow
Dr. Randy Geiger
Texas Instruments