Comparison Of Differential Surface Emg Circuits And Interelectrode Spacing For Use With Regenerative Peripheral Nerve Interfaces

Abstract

Surface electromyography (sEMG) studies how to detect electrical signals produced by muscles from the surface of the skin [1]. However, the noise and crosstalk from nearby muscles are some of the drawbacks to using a surface EMG system [1]. Single and double differential (SD and DD) surface electrode systems were designed to minimize these drawbacks. Still, sEMG systems have not yet been optimized to detect deep and/or small signals from within the body [1]. This is particularly an issue when considering regenerative peripheral nerve interfaces (RPNIs) for controlling a myoelectric prosthesis because EMG signals from RPNIs are usually too small for surface level detection (approximately 100µV - 2mV) [4]. Since, interelectrode spacing and pick-up volume have a direct relationship [6] these therefore pose an interesting avenue for designing a surface electrode system that can detect EMG signals from RPNIs. Through a model in Maxwell 3D by Ansys, we aim to explore how varying the interelectrode distance from 8mm-40mm can change the spatial pick-up volume of electrodes, and further examine how the SD and DD circuits process the information to determine the best approach for surface detection of an RPNI. In the future, these results will then be validated through human subject testing.