Detection system parameters' effects on amplitude and spectral features of SFAP generated from a cylindrical multilayer volume conductor

Abstract

The electromyographic (EMG) signal represents the electrical variations of muscles activities. It can be detected on the skin surface above the aimed muscle. The assessment of the effects of anatomical, physiological and detection system parameters on the shape of the detected surface EMG signal is more evident by using the signal generated by a single fibre action potential (SFAP). Amplitude and spectral characteristics of the detected signal are good estimators of the effects of the anatomical, physiological and detection system parameters on the shape of generated signal. In this work, we interpret the effects of the detection system parameters (the fibres inclination angle and the inter-electrode distance) on the average rectified value (ARV) and on the median frequency (MDF) of the surface SFAP signal generated in a multilayer cylindrical volume conductor contains the limb muscle. The potential is detected on the skin surface with a detection system which is constituted by eight 1D and 2D spatial filters and a grid of nine point electrodes. We show that the increase of the fibres inclination angle decreases the ARV and the MDF of the simulated signal and that the increase of the inter-electrode distance increases them.