Time and frequency dependence of disposable ECG electrode-skin impedance.
The magnitude and phase of disposable electrode-skin impedance were studied as functions of time, 0-48 hours, and frequency, 1 Hz-1 kHz. For both unabraded and mildly abraded skin, the impedance decreased as a function of time steadily or exponentially with time constants of several hours. Impedance decreased as a function of frequency by factors of 2 to 20 with greatest change at low frequencies. For heavily abraded skin, the impedance decreased slightly and then increased as a function of time especially at low frequencies. Impedance imbalance between pairs of identical electrodes applied in a like manner to the forearm were often greater than k omega, nearly equal to individual electrode-skin impedances, and decreased with time. Electrode impedance imbalance is particularly important because it affects noise levels in ECG recordings.
D002712:Chlorides; D004209:Disposable Equipment; D004553:Electric Conductivity; D004562:Electrocardiography / Q000295:instrumentation*; D004566:Electrodes; D004582:Electronics, Medical / Q000295:instrumentation; D005782:Gels; D006801:Humans; D012834:Silver; D012867:Skin / Q000033:anatomy & histology; D012879:Skin Physiological Phenomena; D013997:Time Factors
D002712:Chlorides; D005782:Gels; D012834:Silver