Continuous monitoring of electrode-skin impedance mismatch during bioelectric recordings.
In bioelectric recordings, an electrode-skin impedance mismatch leads to a reduced common-mode rejection ratio (CMRR) of the amplifier. For this reason, the impedance of each individual electrode-skin contact is usually measured prior to a recording. The measurement circuit itself degrades the CMRR and is switched off during the bioelectric recording. In this paper, we present a new method that allows to monitor the electrode-skin impedance in a continuous way without reducing the CMRR of the amplifier. The new method is based on an additional common-mode signal that is superimposed on the bioelectric signal.
Degen
Thomas
T
Swiss Federal Institute of Technology, CH-1015 Lausanne, Switzerland.
Jäckel
Heinz
H
D000465:Algorithms; D003198:Computer Simulation; D017076:Computer-Aided Design; D017097:Electric Impedance; D015716:Electrocardiography, Ambulatory / Q000295:instrumentation* / Q000379:methods*; D004566:Electrodes; D006801:Humans; D008954:Models, Biological; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012879:Skin Physiological Phenomena