Biofeedback System for Improved Athletic Training ECE498 Matt

Biofeedback System for Improved Athletic Training ECE-498 Matt Statton Advisor: Professor Hanson

Introduction Goals of athletic training ◦ Muscle hypertrophy through stimulation Muscle fatigue during a specified repetition range Maximum motor unit recruitment inducing muscle hypertrophy Benefits of effective training ◦ Increased results ◦ Injury prevention Many people do not know how to properly fatigue their muscles ◦ Personal trainers

Biofeedback How it works ◦ Raises awareness of unconscious physiological activities ◦ Control ◦ Adjustment Uses ◦ Anxiety and stress ◦ Hypertension ◦ ADHD

Project Proposal Electrical signals produced by muscles can be used as an indicator of muscle fatigue Giving users the ability to recognize their level of muscle fatigue will lead to improved athletic training ◦ Maximizing muscle fatigue ◦ Decreasing injury

Design Requirements Measure electrical signals from muscles Analyze signal to determine level of muscle fatigue Determine threshold at which muscle fatigue occurs Provide feedback response to user

Design Requirements Measure electrical signals from muscles ◦ Electromyography Intramuscular vs. surface electromyography Cost effectiveness Measurement accuracy

Electromyography Figure 1: Electromyogram from http: //www. dataq. com/images/article_images/emg 1. jpg

Design Requirements Measure electrical signals from muscles ◦ Electromyography Analyze signal to determine level of muscle fatigue ◦ Analog-to-digital conversion ◦ Measure absolute and relative maximum amplitudes of signal Determine threshold at which muscle fatigue occurs Provide feedback response to user

Electromyograph Important components ◦ MAX 666 CPA Voltage Regulator ◦ LT 1494 operational amplifier, A = 1 Provides virtual ground at Vcc/2 ◦ INA 106 differential amplifier, A = 10 Figure 2: Electromyograph circuit based on circuit diagram from http: //instruct 1. cit. cornell. edu/courses/ee 476/Final Projects/s 2005/bsm 24_ajg 47/website/inde x. htm High common-mode rejection ratio

Circuit Creation LPKF Proto. Mat C 20 S Circuit Board Plotter Figure 3: LPKF Circuit Board Plotter from http: //www. lpkf. com/_images/757 -lpkfprotomat-h 100. jpg

Eagle. CAD Figure 4: Eagle. CAD schematic of electromyograph circuit Figure 5: Eagle. CAD board file created from schematic

Circuit. Cam / Board. Master Figure 6: Circuit. Cam circuit board diagram Figure 7: Board. Master circuit board diagram

Printed Circuit Figure 8: Front of printed circuit board Figure 9: Back of printed circuit board

Design Requirements Analyze signal to determine level of muscle fatigue Determine threshold at which muscle fatigue occurs Provide feedback response to user

Electromyograph Signal Analysis Silicon Labs C 8051 F 020 microcontroller ◦ On-board analog-to-digital converter ADC 0 = 12 -bit ADC 1 = 8 -bit ◦ Programmable in C

Electromyograph Signal Analysis Figure 10: Flow chart of electromyograph signal analysis program

Electromyography Figure 11: Contraction and relaxation of muscles of the upper arm from http: //www. zoodu. com/uploads/images/2006 -0810/vlt 9 QAl 2 A 5. jpg

Results Figure 12: Electromyogram of relaxed biceps muscle (Range = 30 m. V) Figure 13: Electromyogram of fully contracted and relaxed biceps muscle (Range = 250 m. V)

Results Figure 14: Electromyogram of slightly contracted and relaxed biceps muscle (Range = 130 m. V) Figure 15: Electromyogram of fully contracted, slightly contracted, and relaxed biceps muscle

Continuing Work Signal processing More sophisticated user interface ◦ ◦ LCD screen Buttons Threshold calibration Low battery indicator Electrode leadwire connectors ◦ FDA regulations

Conclusions The 8051 microcontroller is not yet accurately measuring absolute and relative maximum amplitudes of the signal Electrical signals were successfully measured using surface electromyography Continuing work will be done to successfully analyze the signal and provide users a feedback response based on muscle fatigue

Acknowledgements Professor Hanson Professor Hedrick Ben Bunes

Bibliography Association for Applied Psychophysiology and Biofeedback. 4 June 2008 <http: //www. aapb. org/i 4 a/pages/index. cfm? pageid=1>. Gariety, Arthur and Madoff, Benjamin. ECE 476 Final Project: Wireless Electromyograph. 13 November 2008 <http: //instruct 1. cit. cornell. edu/Courses/ee 476/Final. Projects/s 2005/bsm 24_ajg 47/we bsite/website/index. html>. U. S. National Library of Medicine, National Institutes of Health. Electromyography. 4 June 2008 <http: //www. nlm. nih. gov/medlineplus/ency/article/003929. htm>. http: //www. dataq. com/images/article_images/emg 1. jpg http: //www. lpkf. com/_images/757 -lpkf-protomat-h 100. jpg http: //www. winning. co. za/images/ex. Image 6. jpg http: //www. zoodu. com/uploads/images/2006 -08 -10/vlt 9 QAl 2 A 5. jpg

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