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IE 552 Mechanics of Musculoskeletal System Dr. Andris Freivalds Class #30. Ch. 7 – Instrumentation. Need instrumentation or data collection Must meet certain criteria: Validity – measurement matches function Reliability – accurate and repeatable Distinguish between normal/abnormal
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IE 552 Mechanics of Musculoskeletal System Dr. Andris Freivalds Class #30 IE 552
Ch. 7 – Instrumentation • Need instrumentation or data collection • Must meet certain criteria: • Validity – measurement matches function • Reliability – accurate and repeatable • Distinguish between normal/abnormal • Not alter function measured (Hawthorne) • Safe to use • Simple, portable, cheap IE 552
Flexible Goniometers IE 552
Static Calibration IE 552
Dynamic Calibration IE 552
Pressure & Force Distribution • Inked paper • Thermal paper • Hydraulic sensors • Optical systems • Flexible capacitors • Force sensing resistors • 2 layers conductive film • Spacer is compressed IE 552
Force Sensing Resistors • Force sensing problems → dome cap • Force vs. pressure measurement • Flexibility and bending → errors • Sensor decay, log transformation IE 552
Pressure Measurement IE 552
FSR Applications: • Seat pan pressure • Hand tool grip IE 552
Integrated Touch Glove IE 552
Touch Glove Applications Hand Tool Grip Windshield Handling IE 552
Finger Joint Angles As Function of Grip Dia. IE 552
Nerve Conduction Measurement IE 552
Electrode Placement (Median Nerve) Sensory (antidromic) Motor (orthodromic) IE 552
Nerve Conduction Waveform IE 552
Changes Over Time Onset Latency Nerve Conduction Velocity IE 552
Limitations of Nerve Conduction • Individual variations • Temperature –NCV ↓ as Temp↓ • Age effect – NCV ↓ as age ↓ • BMI (gender) effect IE 552