1. An Assortment of Electrical and Computer Engineering Topics in Biomedical Engineering Edward (Ted) A. Clancy Department of Electrical and Computer Engineering Department of Biomedical Engineering Worcester Polytechnic Institute, USA EAC12–100c Copyright Edward A. Clancy, 2011. Some rights reserved. Content in this presentation is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 License. This license is more fully described at: http://creativecommons.org/licenses/by-nc-sa/3.0/.http://creativecommons.org/licenses/by-nc-sa/3.0/ Many of the videos shown during this presentation are posted at: http://ece.wpi.edu/~ted/teach.htmhttp://ece.wpi.edu/~ted/teach.htm

2. Electrical Activity in the Human Body BiosignalElectrical activity of the … Example Uses Electrocardiogram (ECG or EKG) … heart (www.aic.cuhk.edu.hk) - Patient monitoring - Diagnose “heart attack,” arrhythmia Electroencephalogram (EEG) … brain (www.cogneuro.ox.ac.uk) - Anesthesia monitoring - Seizure analysis Electromyogram (EMG) … muscles (people.uleth.ca ) - Prosthesis control - Motion control, ergonomics studies -Clinical EMG exam -Clinical gait analysis - Sports, exercise Electrophysiologic Monitoring EAC08–201

3. Simple ECG Lead System From: nurseCE.com EAC08–202 Electrophysiologic Monitoring

4. ECG—Electrocardiogram Electrical activity of the heart EAC08–203 Electrophysiologic Monitoring

5. ECG Arrhythmias notAbnormal rates (fast, slow, varied, not varied!) Abnormal shapes EAC08–204 www.physionet.org Electrophysiologic Monitoring

6. Measuring Respiration from ECG Respiration modulates the ECG! Many more direct measures –Chest band, capnograph (for CO 2 ), chest impedance EAC08–205a Moody et al., Computers in Cardiology 12:113–116, 1985. Electrophysiologic Monitoring

7. “Alternation is Everything” Alternans –Every other beat alternation in shape –Associated with sudden cardiac death EAC08–206 Healthy Alternans Clancy M.S., 1987. Electrophysiologic Monitoring

8. Ambulatory Monitors www.nihonkohden.com EAC08–207 Monitor abnormal rates, shapes, etc. ECG, Blood pressure, SaO 2, respiration, … Electrophysiologic Monitoring

9. EEG—Electroencephalogram Electrical activity of the brain EAC08–208 www.abc.net.au Electrophysiologic Monitoring

10. Some Characteristic EEG EAC08–209 medical-dictionary.thefreedictionary.com Electrophysiologic Monitoring

11. Epilepsy Abnormal brain discharges –Altered consciousness, abnormal movement/ sensation, changed behavior –Seizures EEG: Spike discharges EAC08–210 epilepsygroup.com Electrophysiologic Monitoring

12. Motor Unit Decomposition EAC08–211 Sweep speed = 10 ms/div; Sensitivity = 1.0mV/div Motor unit potential with reinnervation Decomposition Shows: Firing times, firing shapes Scientific, physiologic, clinical information (http://www.neuro.wustl.edu/neuromuscular/pathol/diagrams/linkedpot.htm) Partial Denervation: EMG High amplitude, long duration, polyphasic, late potentials Electrophysiologic Monitoring

13. Neuro-Prostheses “Emerging” field; Sub-set of neural engineering Any prosthesis related to nerves, e.g. –Brain –Sensory nerves –Motor nerves Early successes: –Cochlear implants –Deep brain stimulation EAC09–002 Neuro-Prostheses

14. Cochlear Implants EAC09–003 www.hearingloss-wa.org www.childrensspecialists.com Restore Hearing Neuro-Prostheses

15. Deep Brain Stimulation Reduce tremor in Parkinson’s Suppress depression ‒ experimental EAC09–004 www.henryfordhealth.org Neuro-Prostheses

16. Other Neuroprosthesis Research Artificial vision –Retinal and cortical prostheses Cortical and deep brain implants Motor neuroprostheses Functional electrical stimulation Artificial sensation –Motor position, velocity, force; temperature EAC09–005 Neuro-Prostheses

17. Goal: 1970’s “Six Million Dollar Man” EAC09–006 See file: “sixmilliondollarman.flv” Limb Prostheses Video available on YouTube.com

18. Body-Powered Upper Limbs Basic concepts date to civil War medicine EAC09–007 See file: “Prosthetic Arm Tip #2: Tying a Shoe.flv” Limb Prostheses Video available on YouTube.com

19. EMGamp: Myoelectric Control of Prosthesis EAC09–008 Use remnant muscle EMG to command electric hand, wrist, elbow –Some lower limb prosthetics research Boston Elbow — Liberating Technologies, Holliston, MA Limb Prostheses

20. EMG Amplitude (EMGamp) Estimation EAC09–009 EMGamp EMG amplitude 0–10 mV (~1.5 mV rms) Surface EMG frequency bandlimited at 2000 Hz EMG Amplitude (EMGamp): “Intensity” of recorded EMG –“Time-varying standard deviation of EMG signal” Original estimator: Inman et al. [1956] –Analog full-wave rectify and RC low pass filter Electrode-Amplifier (From Liberating Technologies) – Varies with force Limb Prostheses

21. Nerve Re-Innervation for Myocontrol RIC Arm; www.popsci.com Kuiken nerve re- innervation surgery Nerves from severed limb re-connected to pectoralis muscle regions Several myocontrol sites created Substantial improvement EAC09–010 Limb Prostheses

22. Myoelectric Control Example (Movie) EAC09–011 Jesse Sullivan video (Available on YouTube.com) Limb Prostheses (Click on black edge): “bionic_arm_BB.wmv”

23. Recent Limb Prosthetics Efforts Major current effort by U.S. military to improve prosthetic limbs –Improved myoelectric controls –Embedded neural-/myo-sensors for control/sensation –Directly connect limb to bone EAC09–012 Limb Prostheses 1) See file: “CNN Tech 08-05-16 Hand To Amputees.flv” 2) See file: “DARPA's Bionic Arm.flv” Both videos from YouTube.com

24. EMG Testing Simulator 2010 WPI senior project (Jung, Meklenburg, Patrick) Emulates EMG signal. Used as testing input to new prosthesis, prosthesis under repair. EAC10–012a Limb Prostheses (Click on photo)

25. Some Lower-Limb Prosthesis Research Hugh Herr, MIT Variable damper knee prosthesis –See file “knee.ram” EAC09–013

26. Rehab: Herr Ankle-Foot Orthosis Compliant ankle: See file: “AAFO.ram” EAC09–015

27. Rehab: MIT-MANUS CompliantCompliant wrist, elbow rehab robot EAC10–016a See file: “CNN 14 May 2006.mpg” Developing ankle robot Sroke/TBI Rehabilitation From MIT Newman Lab (Click just below in white)

28. Steve Bitar Heartbeat Monitor Lab Phototransistor monitors finger pulse pressure (photoplethysmogram—PPG) Simple lab used in WPI ECE, etc. See: http://ece.wpi.edu/~sjbitar/Project_Pulse_Kit/ http://ece.wpi.edu/~sjbitar/Project_Pulse_Kit/ EAC10–100

29. Bitar Heartbeat Monitor Lab (2) If oscilloscope is used, only require: –R1, R2, LED1, Q1, 9 V battery EAC10–101

30. Bitar Heartbeat Monitor Lab (3) Hold finger over LED, monitor collector of Q1 EAC10–102 DC coupled, low gain AC coupled, high gain

31. Active Research in Limb Prostheses Walter Reed Hospital, Military Amputee Research Program (MARP) [http://www.tatrc.org/prosthetics] [http://www.tatrc.org/portfolios.html#advanced_prosthetics] “Advanced Prosthetics and Human Performance” Portfolio; Telemedicine and Advanced Technology Research Center (TATRC), U.S. Army Medical Research and Materiel Commandhttp://www.tatrc.org/prostheticshttp://www.tatrc.org/portfolios.html#advanced_prosthetics [http://www.ninds.nih.gov/research/npp/resources/] National Institutes of Health (NIH), National Institute of Neurological Disorders and Stroke (NINDS), “Neural Interfaces Resources & Contracts” web pagehttp://www.ninds.nih.gov/research/npp/resources/ [http://www.darpa.mil/dso/thrusts/bio/restbio_tech/revprost/index.htm] “Revolutionizing Prosthetics” Program, Defense Advanced Research Projects Agency (DARPA)http://www.darpa.mil/dso/thrusts/bio/restbio_tech/revprost/index.htm [http://www.jhuapl.edu/newscenter/pressreleases/2007/070426.asp] April 2007 update on the work of John’s Hopkins researchers on the DARPA “Revolutionizing Prosthetics” projecthttp://www.jhuapl.edu/newscenter/pressreleases/2007/070426.asp EAC09–017