An Investigation of Acoustic Chamber Design for Recording AMG Signal

Abstract

We are exploring a new method of detecting the mechanical changes that occur when muscles contract: the Acoustomyography (AM G). This method of acquiring the sounds emitted by the muscles during a muscular contraction is a non-invasive technique based on the use of an acoustic sensor formed by a resonance chamber and a microphone. We will show in this study the effect of the geometry and dimensions of the resonance chamber where the microphone will be housed on the AMG signal collected. To show the robustness of the acquisition system developed, we will compare the results obtained at the output of the acoustic sensor with those obtained at the output of a muscle force sensor (dynamometer). By varying the amplitude of the force developed from 10 to 100% MVC, we noticed that the amplitude of the AMG signal is clearly correlated with the measured developed muscle force. During this study, a six-channel wearable armband was also developed to secure the acoustic sensors to the skin.