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Published on: August 2, 2016
Implantable biaxial piezoresistive accelerometer for sensorimotor control
Qiang Zou1, Wei Tan, Eun Sok Kim
1Department of EE-Electrophysics, University of Southern California, Los Angeles, CA 90089, USA.
Summary
This study presents a novel biaxial piezoresistive accelerometer for neuromuscular stimulators. This device accurately measures acceleration, enabling precise orientation tracking of human body segments without integrating velocity signals.
Area of Science:
- Biomedical Engineering
- Sensor Technology
- Biomechanics
Background:
- Miniature accelerometers are crucial for wearable devices and biomechanical analysis.
- Existing accelerometers face challenges with cross-axis sensitivity and integration drift for orientation tracking.
Purpose of the Study:
- To design, fabricate, and test a novel biaxial piezoresistive accelerometer.
- To integrate this accelerometer into a miniature neuromuscular stimulator (BION).
- To develop an orientation tracking method for human segments using the accelerometer.
Main Methods:
- Design of a biaxial piezoresistive accelerometer with a symmetric twin mass structure.
- Fabrication and testing of the accelerometer, including sensitivity and cross-axis analysis.
- Development of an orientation tracking algorithm using joint angle measurements from biaxial accelerometers.
Main Results:
- The biaxial accelerometer achieved X and Z axis sensitivities of 0.10 mV/g/V and 1.40 mV/g/V, respectively.
- Sensitivities increased to 0.65 mV/g/V and 2.40 mV/g/V with added silicon mass.
- Cross-axis sensitivity was minimized to less than 3.3% across all axes.
- A method for orientation tracking was demonstrated, avoiding integration errors.
Conclusions:
- The novel biaxial piezoresistive accelerometer offers accurate acceleration measurement with low cross-axis sensitivity.
- The accelerometer is suitable for integration into miniature neuromuscular stimulators.
- The developed orientation tracking method provides a drift-free solution for human segment movement analysis.
