A comparative study of EMG/sub di/ recording electrodes

Abstract

Electromyographic recording of the diaphragm (EMGdJ have been used to evaluate its finctionalig and its fatigue. This signal is contaminated by the electrical activity of the heart, movement of diaphragm and lung volume change. Conventional recording of EMGdI signal can be achieved in two main ways:(i) insertion of needle electrode in the diaphragm with the risk of lung perjoration, and (ii) using an array of electrodes built in a catheter that can be inserted in the oesophageal conduit and centered in the gastro-oesophageal sphincter. Usually ECG signal overlaps EMGd, signal in a large hand of its spectrum. Several methods were proposed in order to eliminate the ECG signals such as high pass and LMS adaptive filters. In this project we model and simulate the finctionaliq of two gpes of recording electrodes, and to veri& the effect of artefacts on EMGd, signal. The model comists of (ij 30 block filled with air with zero potential at its boundaries, (iij a point source of fuedpotential and variable position, and (iii) an array of electrodes. The potential distribution on the electrodes w a obtained by solving Laplace equation using finite element method. Our simulation results on examined types of electrode geometries showed a reduction of interjerence signals generated by the ECG and other EMG muscles on the EMGdz when ring electrodes were used. More complex geometries are currently under investigation in order to explore the reduction of contamination.