Author(s)

L. Mesin

Abstract

Surface electromyogram (EMG) is a bio-electrical signal detected non-invasively (over the skin) and reflecting features of the bio-electrical sources associated to muscle contraction. Surface EMG signal modelling has important applications in the interpretation of experimental EMG data, for a deeper understanding of the physiological mechanisms of muscle contraction. This study addresses the issue of introducing a general analytical method to study multi layer volume conductors (i.e., to solve a Poisson problem on domains constituted by multiple layered sub-domains, with different electrical conductivities). The method provides the solution to a multi plane layer problem, once the solutions of the homogeneous Dirichlet and Neumann problems in a one layer volume conductor are available. The same method can be applied to cylindrical layer volume conductors (some indications are given). It is applied to add a fat layer over a bipinnate muscle layer (i.e., a muscle which has two groups of fibres with two orientations) which was analytically studied in the literature (considering only the muscle layer). The study provides an implementation of the results in a complete surface EMG generation model (including finite length fibres), and shows representative results of the application of the model proposed. Poisson equation models different physical and biological situations. Thus, the method introduced can find applications in other fields of interest for the applied sciences. Keywords: Poisson equation, multi layer volume conductor, Fourier transform, surface electromyogram.

Keywords

Poisson equation, multi layer volume conductor, Fourier transform, surface electromyogram.