Session: 13-04-01: Applications of Micro and Nano Systems in Medicine and Biology

Paper Number: 147022

147022 - Surface Acoustic Wave (Saw) Force Myography Sensor for Muscle Force Output Identification 

Numerous fields such as physical therapy and sports science require an understanding of the biomechanics involved in limb movements and muscle activity to effectively evaluate physical performance and to customize training or interventions. In more specific applications like controlling exoskeletons and prosthetics, the real-time tracking of limb and muscle parameters like strain, force, and torque is increasingly essential. Force Myography (FMG) emerges as a non-invasive method for assessing muscle function by monitoring volumetric changes in the musculotendinous complex (MC) or the resulting radial force distributions. Most studies focusing on FMG often use force-sensing resistor (FSR) sensors, which are cost-effective and flexible but require consistent skin contact and can be prone to errors. As an alternative, resistive strain sensors, also commonly used, measure muscle deformation without needing skin contact, offering design flexibility and reliability. Despite this, they face challenges like non-linear responses and sensitivity to environmental conditions.

Surface Acoustic Wave (SAW) sensors, known for passive, wireless operation, arise as a promising solution, addressing these issues and demonstrates high strain sensitivity. Despite the known advantages for various sensing applications, its use in muscle force monitoring has yet to be studied. This paper reports our study on custom fabricated single crystalline 128° YX-cut LiNbO₃ SAW sensors for FMG. To demonstrate feasibility in this novel approach for detecting muscle contractions, a wired, rigid sensor setup is used for proof of concept. In the experimental approach, the SAW sensor is incorporated into an armband and affixed to the upper arm to capture muscle contractions during a bicep curl. The results successfully demonstrate the sensor’s capability to measure muscle contractions accurately under various loading conditions. The fabricated sensor is then compared to traditional methods like strain gauge based FMG devices and electromyography (EMG) to emphasize and validate its potential as an alternative muscle force measurement tool.

Presenting Author: Michael Kohler New York Institute of Technology

Presenting Author Biography: Michael C. Kohler received his Bachelor’s degree in Biomedical Engineering from the University of Hartford in 2020. In pursuit of further expertise, he obtained a Master’s degree in Bioengineering from the New York Institute of Technology in 2022. As an active member of professional societies, Michael Kohler is affiliated with the BMES (Biomedical Engineering Society), ASME (American Society of Mechanical Engineers), and IEEE (Institute of Electrical and Electronics Engineering. He is currently pursuing his Ph.D. in Bioengineering at NYIT.

Authors:

Michael Kohler New York Institute of Technology
Ioana Voiculescu The City College of New York
Fang Li New York Institute of Technology