Wearable sensors and feedback system to improve breathing technique
UNIVERSITY COLLEGE DUBLIN � DUBLIN CITY UNIVERSITY � TYNDALL NATIONAL INSTITUTE
Shirley Coyle 1, Edmond Mitchell 2, Noel O’Connor 2, TomásWard3 and Dermot Diamond 2
1 CLARITY Centre for Sensor Web Technologies, NCSR, D ublin City University, Dublin 9
2 CLARITY Centre for Sensor Web Technologies, CDVP, D ublin City University, Dublin 9
3Biomedical Engineering Group, Dept. of Electronic E ngineering, National University of Ireland Maynooth
Overview
• Introduction
• Sensors
• Data acquisition and processing
UNIVERSITY COLLEGE DUBLIN � DUBLIN CITY UNIVERSITY � TYNDALL NATIONAL INSTITUTE
• Data acquisition and processing
• User feedback
• Conclusions
Importance of Breathing
Breathing – naturally occuring
Unique system– both voluntary and involuntaryWe can influence the involuntary autonomic nervous system using our
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nervous system using our voluntary breath
By breathing in a slow, deep and regular manner, the heartbeat become smooth and regular, blood pressure normalizes, stress hormones drop, and muscles relax.
Importance of breathing technique
Sports performance
• Use of full lung capacity to maximise oxygen delivery to muscles
• Use of breathing techniques to calm and focus, e.g before kicking a penalty in soccer or a serve in tennis
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Clinical applications
• Chronic Obstructive Pulmonary Disease (COPD)
• Anxiety treatment
• Cystic fibrosis
• Respiratory rehabilitation
Breathing exercises for patients
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Kigin C., Breathing Exercises for the Medical Patien t: The Art and the Science, Physical Therapy/Volume 70, Number 11, November 1990
Aim – to develop a feedback system for patients to improve their breathing technique, by monitoring thoracic and abd ominal movements. Give feedback to the user graphically
Sensor must beComfortableRobustStraightforward to use
Wearable sensor/”Smart garment”
Breathing monitoring system –system requirements
UNIVERSITY COLLEGE DUBLIN � DUBLIN CITY UNIVERSITY � TYNDALL NATIONAL INSTITUTE
Wearable sensor/”Smart garment”
Feedback/Application must: Grab users attentionHave a simple interfaceFocus user for the full duration of the programEncourage user to correct their breathing rate
and low cost, easy to install on computer systems
Breathing monitoring system
Wearable Sensor Microcontroller
and
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Wearable Sensor - detect body
movement due to breathing
andWireless connection
Data processing and
User feedback
Fabric stretch sensors to measure body movements
Carbon black
++Elastomer
Cure Piezo-resistive sensor
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Wacker ELASTOSIL® LR 3163 A/BLiquid Silicone Rubbers (LSR)
Screen printed onto fabric
Carbon elastomer stretch sensors
300
350
400
4502mm
4mm
7mm
11mm
Stretch sensor - Carbon loaded rubber screen printed onto lycra fabric. Elongation causes increase in resistan ce
2
47
11
10
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0
50
100
150
200
250
0 1 2 3 4 5 6 7
Elongation (cm)
kOhm Sensor widths
2mm, 4mm, 7mm, 11mm, (length 10cm)
Average Gauge factor l(R-Ro)/(R(l-lo) = 1.6
Carbon elastomer stretch sensors
Sensor lengths 20cm, 14cm, 10cm 300
400
500
600
700
kOhm
20cm
14cm
10cm
20
14
10
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20cm, 14cm, 10cm (width 5mm)
0
100
200
0 2 4 6 8 10
Elongation (cm)GF
20cm 2.17049414cm 1.00624610cm 0.486631
Sensors – “Smart shirt”Fabric stretch sensors monitor the expansion and contraction of the ribcage and abdomen during breathing.
4 Carbon-Elastomer(CE) sensors (piezo -resistive) are screen -printed Micro-
CE Sensor
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(piezo -resistive) are screen -printed onto the front of the t-shirt
Sensors connected using conductive stainless steel thread.
Resistor leads are embroidered
Sew-in micro-controller Conductive thread
Micro-controller
Breathing monitoring t-shirt
Sensor 1
Sensor 2
Investigation of thoraco-abdominal movement using CE sensors
UNIVERSITY COLLEGE DUBLIN � DUBLIN CITY UNIVERSITY � TYNDALL NATIONAL INSTITUTE
-3
-2.5
-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
0 5 10 15 20 25 30 35 40
Time(s)
Chest
Abdomen
Breathing signal (Normalised data )
Abdominal breathingThoracic breathing
Breathing monitoring system
SensorArduino
microcontroller User feedback
Arduino- open-source electronics prototyping platform
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- open-source electronics prototyping platform
Arduino Pro MiniSize: 1.7cm x 3.4cmAnalog Input Pins : 6Digital I/O Pins :14 Microcontroller: ATmega168 or ATmega328
Arduino LilypadSewable microcontroller
Bluetooth connectionBluesmiRFWireless serial cable replacementTransmits any serial stream from 9600 to 115200bps
Breathing monitoring system
SensorArduino microcontroller
FlashApplication
The name Physput is derived from Phys iological input
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Allows a user to emulate standard computer input using non-standard input.
Primarily designed to facilitate the design of alternative input devices.
Reads data from the serial port and maps this data to standard input e.g. mouse movements and key presses.
Version 1 written by Edmond Mitchell
PhysputWritten by Edmond Mitchell
Breathing monitoring system
SensorArduino microcontroller
FlashApplication
Most popular method for adding animation and interactivity to Web Pages.
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Pages.
Can create rich Internet applications
Available free for web browsers such as a Internet Explorer and MozillaFirefox
99.3% 1 of all Internet desktop users have the Flash Player installed
User feedback interface
Start of breathing exercise
02468
101214161820
0 50 100 150 200 250 300 350Bre
athi
ng R
ate
(bre
aths
/min
)
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0 50 100 150 200 250 300 350Bre
athi
ng R
ate
(bre
aths
/min
)
Time(s)
Sensormedics Vmax
Breathing patterns measured using the textile sensor and gold standard Sensormedics Vmax
Feedback application encourages constant breathing rate in syncronisation with the avatar
Deep breathing exercise
115 120 125 130 135 140 145 150 155 160-2.5
-2
-1.5
-1
-0.5
0
0.5
1
1.5
2
2.5T
hora
co-a
bdom
inal
mov
emen
t
abdomenchest
Before
breathing
exercise
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115 120 125 130 135 140 145 150 155 160
Time(s)
265 270 275 280 285 290 295 300 305 310-1
-0.5
0
0.5
1
1.5
2
Time(s)
Tho
raco
-abd
omin
al m
ovem
ent
chestabdomen
During
breathing
exercise
User feedback
0 5 10 15 20 25 30 35 40 45 50-3
-2
-1
0
1
2
3
Time(s)
Tho
raci
c m
ovem
ent
Measured
Reference
Grade A
R~90%
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After performing the exercise the user is presented with a breathing efficiency grade.
The grade is calculated by cross correlating the users breathing pattern with a reference breathing pattern embedded in the program
0 10 20 30 40 50-3
-2
-1
0
1
2
Time(s)
Tho
raci
c m
ovem
ent
Measured
Reference
Grade F
R~90%
R~40%
User feedback – multiple sensor input
UNIVERSITY COLLEGE DUBLIN � DUBLIN CITY UNIVERSITY � TYNDALL NATIONAL INSTITUTE
Real-time sensor signal versus computer generated accurate signal
The avatar encourages the user to perform diaphragmatic breathing.
The user aims to synchronise their breathing signal with the avatar
Real time feedback is given
Score given at the end of the exercise
Two sensors - placed at chest and abdomen
Breathing trainer
UNIVERSITY COLLEGE DUBLIN � DUBLIN CITY UNIVERSITY � TYNDALL NATIONAL INSTITUTE
Conclusions/future directions
•Developed wearable wireless system to measure breat hing patterns, using textile sensors
•Developed user-friendly interface to help users imp rove their breathing
•Low cost, accessible system
UNIVERSITY COLLEGE DUBLIN � DUBLIN CITY UNIVERSITY � TYNDALL NATIONAL INSTITUTE
•Low cost, accessible system
•Next stage to consult the target user groups for fe edback –Physiotherapists and Occupational therapists
•Clinical trials
Thanks to…- Edmond Mitchell , Centre for Digital Video Processing, CLARITY Centre for sensor Web Technologies, DCU
- Dr. Tomás Ward , Biomedical Engineering Group, National University of Ireland, Maynooth
- Stroke Rehab Unit, Adelaide and Meath Hospital, Tallaght
UNIVERSITY COLLEGE DUBLIN � DUBLIN CITY UNIVERSITY � TYNDALL NATIONAL INSTITUTE
- Gregory May, Dept. of Human Health and Performance, DCU
- Prof. Noel O’Connor, Prof Niall Moyna, Prof. Dermot Diamond , CLARITY Centre for sensor Web Technologies, DCU
- This work is supported by Science Foundation Ireland under grant 07/CE/I1147