project overview overview | relevance | design goals | signal acquisition | signal processing |...
TRANSCRIPT
Project Overview
Overview | Relevance | Design Goals | Signal Acquisition | Signal Processing | Future Work
Our product: • Rehabilitation device Recumbent stationary bicycle• Electromyography of quadriceps muscles Feedback• User-friendly interface Autonomous recovery
Our customers: • Post-ACL repair patients
Phase II and III of rehabilitation Assist in at-home exercises
1) EMG signals differ between patellofemoral pain syndrome patients and control
Cowan SM, et al. Arch Phys Med Rehabil. (2001) 82:183-189.
2) Literature on EMG acquisition on bicycles Garrett WE, Kirkendall DT. Exercise and Sport Science. Lippincott Williams & Wilkins.
(2000)
3) Quadricep EMG signals differ between ACL patients and control when cycling
Hunt MA, et al. Clinical Biomechanics. (2003) 18: 393-400.
Clinical Relevance
Overview | Relevance | Design Goals | Signal Acquisition | Signal Processing | Future Work
1) EMG signals differ between patellofemoral pain syndrome patients and control
Cowan SM, et al. Arch Phys Med Rehabil. (2001) 82:183-189.
2) Literature on EMG acquisition on bicycles Garrett WE, Kirkendall DT. Exercise and Sport Science. Lippincott Williams & Wilkins.
(2000)
3) Quadricep EMG signals differ between ACL patients and control when cycling
Hunt MA, et al. Clinical Biomechanics. (2003) 18: 393-400.
Clinical Relevance
Overview | Relevance | Design Goals | Signal Acquisition | Signal Processing | Future Work
1) EMG signals differ between patellofemoral pain syndrome patients and control
Cowan SM, et al. Arch Phys Med Rehabil. (2001) 82:183-189.
2) Literature on EMG acquisition on bicycles Garrett WE, Kirkendall DT. Exercise and Sport Science. Lippincott Williams & Wilkins.
(2000)
3) Quadricep EMG signals differ between ACL patients and control when cycling
Hunt MA, et al. Clinical Biomechanics. (2003) 18: 393-400.
Clinical Relevance
Overview | Relevance | Design Goals | Signal Acquisition | Signal Processing | Future Work
I. Signal Acquisition
A. Collect EMG data while cyclingB. Correlate crank angle with EMG signal
II. Signal Processing
A. Filtering noise B. Algorithms to analyze signalC. Developing user-friendly interface
III. Testing
A. Protocol optimizationB. Proof of concept
Design Goals
Overview | Relevance | Design Goals | Signal Acquisition | Signal Processing | Future Work
Components and Setup
Overview | Relevance | Design Goals | Signal Acquisition | Signal Processing | Future Work
EMG Electrode Placement
Overview | Relevance | Design Goals | Signal Acquisition | Signal Processing | Future Work
Cowan SM, et al. Arch Phys Med Rehabil. (2001) 82:183-189.
Electrode placement on the quadriceps
muscles
Hall Effect Sensor
Overview | Relevance | Design Goals | Signal Acquisition | Signal Processing | Future Work
Difference in timing between up and down stroke
400
425
450
475
500
1
Tim
e (
ms)
Downstroke time (180 degrees)Updstroke time (180 degrees)
90o
180o
270o
0o
Magnets
Volt
age (
volt
s)EMG Acquisition
Overview | Relevance | Design Goals | Signal Acquisition | Signal Processing | Future Work
Time (ms)
VMO, ~50 rpm, Hall effect sensor at 180o
Volt
age (
volt
s)EMG Acquisition
Overview | Relevance | Design Goals | Signal Acquisition | Signal Processing | Future Work
Time (ms)
VMO, ~40 rpm, Hall effect sensor at 0o and 180o
The Butterworth Filter
Overview | Relevance | Design Goals | Signal Acquisition | Signal Processing | Future Work
Unfiltered Data
Overview | Relevance | Design Goals | Signal Acquisition | Signal Processing | Future Work
Filtered Data
Overview | Relevance | Design Goals | Signal Acquisition | Signal Processing | Future Work
Cowan SM, et al. Arch Phys Med Rehabil. (2001) 82:183-189.
Magnitude of VMO Muscle Activation (7 cycles)
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
0 90 180 270 360
Crank Angle (degrees)
EM
G (
norm
alize
d)
Integrated Data
Overview | Relevance | Design Goals | Signal Acquisition | Signal Processing | Future Work
Garrett WE, Kirkendall DT. Exercise and Sport Science. Lippincott Williams & Wilkins. (2000)
Experiments
Overview | Relevance | Design Goals | Signal Acquisition | Signal Processing | Future Work
Experiment TestMinimum muscle warm-up time for repeatable EMG signals
With warm-up prescribed from Cowan SM, et al. (2001) vs. no warmup
Effect of changing electrode position on EMG signal
Change electrode placement at set distances
Effect of individual differences on EMG signals for non-injured volunteers
Measure EMG signals amongst several people
Minimum resistance/speed for even pedaling AND VMO/VL stimulation
Increase the resistance (e.g. low, medium, high settings)
1. Develop a user-friendly GUI
2. Correlate position with crank angle more precisely
3. More signal processing for de-noising
4. Process the signal and plot as a function of crank angle or time
5. Proof of concept studies with current recovering ACL patients
Future Work
Overview | Relevance | Design Goals | Signal Acquisition | Signal Processing | Future Work
Bloopers
Overview | Relevance | Design Goals | Signal Acquisition | Signal Processing | Future Work
Acknowledgements
Overview | Relevance | Design Goals | Signal Acquisition | Signal Processing | Future Work
Dr. William MacaulayOrthopedic Surgeon, Columbia University Medical CenterDirector of Center for Hip and Knee Replacement
Dr. Ranjan GuptaDepartment Chair of Orthopaedic Surgery, UC Irvine Professor of Orthopaedics, Anatomy & Neurobiology, and BME
James GossettAssociate Athletic Director, Columbia University
Dr. Evan JohnsonDirector of Physical Therapy at the Spine CenterAdministrative Director of the Spine Center
Julianne CostaOccupational Therapist RegisteredPhysical Therapist
Dr. Tim WrightOrthopaedic Biomechanics and Biomaterials Hospital of Special Surgery
Dr. Clark HungAssociate Professor of Biomedical Engineering
Dr. Gordana Vunjak-NovakovicProfessor of Biomedical Engineering
Dr. Paul SajdaAssociate Professor of Biomedical Engineering
Dr. Elizabeth HillmanAssistant Professor of Biomedical Engineering
Keith YeagerSenior Staff Associate, Laboratory Manager
Sean BurgessTeaching Assistant
Robert MaidhofTeaching Assistant
Viktor GamarnikBME Senior, SMArtView