Novel force myography sensor to measure muscle contractions for controlling hand prostheses

Abstract

This paper presents a dual-channel, noninvasive force myography (FMG) sensor to extract muscle contraction information for controlling hand prostheses. The sensor was prepared using a pair of force-sensitive resistors (FSRs) mounted inside a rigid base for sensing the force exerted by contracting muscles through polydimethylsiloxane (PDMS) couplers. The device employs a dedicated signal conditioning circuitry for producing an output voltage proportional to the muscular contractile force. The static and dynamic characteristics of the sensor (i.e., sensitivity, drift, precision, hysteresis, and frequency response) were determined and analyzed using the recorded measurements to demonstrate its effectiveness. The frequency response of the designed sensor was sufficiently large to detect the rapidly varying FMG signals. The output assessment for the simultaneous acquisition of electromyography (EMG) and FMG from flexor muscles of subjects was performed using a two-tailed paired t-test, which showed a high correlation coefficient (r > 0.87) with a p-value less than 0.0001. Furthermore, a successful trial of the FMG sensor was made on five subjects to control a prosthetic hand in real-time, employing the proportional strategy. These experiments revealed that the designed sensor may provide an alternative to the EMG device. © 2019, © 2019 Taylor & Francis Group, LLC.