Temporomandibular Joint Disorder (TMJD) Diagnostics System University of Connecticut Biomedical Engineering Senior Design Spring 2011 Michael Jorgensen Mariana Hu Kerry Semle
Overview Introduction Client background Purpose of design project General Overview of EMG
Project overview Neuroband Data Acquisition Unit Circuit design LabVIEW program
Budget Conclusion Acknowledgements References and Further Reading Questions and comments
Client Background Dr. Mark Litt, Ph.D. Clinical Psychologist at the University of Connecticut Health Center Expert in Temporomandibular Joint Disorder and chronic orofacial pain treatment methods Research interests include: Influence of Cognitions and Affects on Pain and Illness Psychoneuroimmunology
Purpose of Design Project Electromyography (EMG) Detect bruxism (teeth clenching / grinding) events
Reduce dependency on sleep lab diagnosis Allow patients to be screened comfortably in their own home Obtain data consistent with natural sleeping patterns
Maintain accuracy and efficacy of sleep labs
User-friendly Patient Clinician
Improve screening and diagnosis of TMJD
General Overview of EMG Electromyography (EMG) Record electrical activity produced by skeletal muscles
Facial muscles involved in TMJD Left and Right Temporalis Left and Right Masseter
Project Overview
Neuroband Data Acquisition Unit Uses Dr. Diane’s Neuroband EEG headband Ports for electrode snap leads located within chin strap and headband Features 9 electrode leads: Two disposable electrodes per muscle One reference electrode located on the patient’s forehead
Circuit Design Circuit requirements Amplify EMG signals High input impedance High CMRR Patient protection circuitry Size consideration Budget
Circuit Flowchart
Schematic (one circuit)
Printed Circuit Board ExpressPCB Software Four Layer PCB
Circuit Enclosure
Circuit Enclosure (cont.)
LabVIEW Program Flowcharts EMG
View EMG = TRUE
Select muscle
Selec file
Read from file
Rectify EMG
Rms EMG
Display
LabVIEW Program Flowcharts
Start DAQ = TRUE
Data Acquisition
Data > Threshold?
Split signal
Yes
Extract Portion of Signal
Write to file
No
LabVIEW Program (cont.) Clinician’s Front Panel for viewing EMG: Select muscle using tabs Select file to view Adjust speed
LabVIEW Program (cont.) Clinician’s Front Panel for setting threshold for EMG data storage
LabVIEW Program (cont.) Patient’s Front Panel to begin and stop data acquisition LED Indicates signal acquisition started
Budget and Total Cost Device Cost (each): Component
Cost
Circuit
$117.51
PCB
$40.73
Electrodes
$36.33
Leads
$192.45
Neuroband Components
$80.00
DAQ
$169.00
Laptop
$1,200.00
TOTAL
$1,836.02
Total allotment: $6,000 Prototyping cost: $2,451.07 Remaining allocation: $3,548.93
Conclusion The product works!
Portable User friendly Data acquisition unit acquires signals Circuitry filters data LabVIEW program analyzes, stores, and displays data LabVIEW program will work on any Microsoft Windows computer
We were significantly under budget
Acknowledgments Dr. Mark Litt, Ph.D. Dr. John Enderle, Ph.D. Emily Jacobs Marek Wartenberg Dave Kaputa Sonia Helena Contreras Ortiz Antonio Costa Penny Dobbins
References and Further Reading Cram, Jeffrey. Introduction to Surface Electromyography. 1st. Jones & Bartlett Publishers, 1998. Print. Crider, Andrew, Alan G. Glaros, and Richard N. Gevirtz. "Efficacy of Biofeedback-Based Treatments for Temporomandibular Disorders." Applied Psychophysiology and Biofeedback 30.4 (2005): 33345. Print. Doering, S., J. A. Boeckmann, S. Hugger, and P. Young. "Ambulatory Polysymnography for the Assessment of Sleep Bruxism." Journal of Oral Rehabilitation 35 (2008): 572-76. Print. Galaros, A. G., Z. Owais, and L. Lausten. "Reduction in Parafunctional Activity: a Potential Mechanism for the Effectiveness of Splint Therapy." Journal of Oral Rehabilitation 34 (2007): 97104. Print. Galaros, Alan G., Karen Williams, and Leonard Lausten. "Diurinal Variation in Pain Reports in Temporomandibular Disorder Patients and Control Subjects." Journal of Orofacial Pain 22.2 (2008): 115-21. Print. Gallo, Luigi M., Gilles Lavigne, Pierre Rompre, and Sandro Palla. "Reliability of Scoring EMG Orofacial Events: Polysymnography Compared with Ambulatory Recordings." European Sleep Research Society 6 (1997): 259-63. Print. Kato, Takafumi, Norman M. Thie, Jacques Y. Montplaisir, and Gilles J. Lavigne. "Bruxism and Orofacial Movements During Sleep." Dental Clinics of North America 45.4 (2001): 657-84. Print. Philips Semiconductor, "UART to Bluetooth Interfacing." NXP Semiconductors. Philips 43 Kraus, Steven. Temporomandibular Disorders. 2nd ed. New York, NY: Churchill Livingstone Inc., 1994. Print. Robertson, Gordon. “Electromyography: Processing.” University of Ottawa, 05, 11 2007. Web. Apr 2011. www.health.uottawa.ca/biomech/courses/apa4311/emg-p2.pps. Webster, John. Medical Instrumentation Application and Design. 2nd ed. Boston, MA: Houghton Mifflin Company, 1992. Print.
Questions and Comments