Multimodal sensor to measure the concurrent electrical and mechanical activity of muscles for controlling a hand prosthesis

Abstract

A wearable sensor was fabricated to provide simultaneous electromyography (EMG) and force myography (FMG) information, from the same muscle location for controlling multi-functional hand prosthesis. The typical mechanical arrangement of the sensor constitutes silver electrodes and a force-sensitive resistor embedded inside the sensor chassis for detecting the electrical and mechanical activity of muscles. The sensor incorporates specific conditioning units for producing quantifiable EMG and FMG outputs from electrodes and force-sensitive resistor. The sensor exhibited excellent sensitivity and repeatability characteristics in recording force signals. The dry electrodes used in the sensor showed a comparable electrode-skin impedance with conventional Ag-AgCl electrodes. The EMG signals obtained with the sensor for ten subjects showed a good correlation and similar signal-to-noise ratio to signals with a traditional EMG sensor. Further, the nature of the measured EMG and FMG signals for the subjects by the sensor were analyzed by determining features such as signal stability and response time. The simultaneously recorded EMG-FMG signals from the sensor for different muscular contractions can be fused to generate a more reliable control for dexterous operation of hand prosthesis. © 2020 Taylor & Francis Group, LLC.