Electrode contact noise in surface biopotential measurements

1 October 1992

conference paper
Published by Institute of Electrical and Electronics Engineers (IEEE)

Vol. 1, 123-124
https://doi.org/10.1109/iembs.1992.5760887

Abstract

Skin-Electrode interlace noise is important in high resolution surface biopotential recordings. In order to determine its contribution, we have carried out several measurements. First, we measured the noise power spectrum density of several pairs of Ag/AgCl electrodes placed face to face and then placed on the body surface (leg and arm). We simultaneously measured the impedance of these pairs of electrodes and calculated the thermal noise associated to their real part. We found that noise at low frequencies is larger than noise at high frequencies, the power spectrum density increasing as 1/f. We have also found that calculated thermal noise is lower than measured electrode noise. Next, we measured noise and impedance for different electrode areas. For electrodes placed face to face we found that noise and resistance increase when electrode area decreases. For electrodes placed on the body surface, "noise" power spectrum density (probably EMG) increases when electrode area increases. We also calculated the Probability Density Function (PDF) of electrode noise. We found that it looks gaussian for electrodes placed face to face, but not for electrodes placed on the body surface.

Keywords

This publication has 2 references indexed in Scilit:

Differential mode interferences in biopotential amplifiers
Published by Institute of Electrical and Electronics Engineers (IEEE) ,2003
The origin and characterization of the primary signal, noise, and interference sources in the high frequency electrocardiogram
Proceedings of the IEEE, 1977