Measurement of the conductive fabric contact impedance for bioelectrical signal acquisition purposes

Abstract

Information about the physiological state of the human organism can be obtained by detecting bioelectrical signals. The detection electrodes are a critical point in the measurement chain. The use of textile electrodes is advantageous due to comfort and less stressful measurement of bioelectrical signals for the patient. A unique automatized measurement system was proposed to measure contact impedance magnitude and phase. This research investigated several conductive textile materials in terms of impedance at the artificial electrode–skin interface to select the most appropriate material for ECG signal acquisition. The most suitable samples for further investigation appeared to be polyamide fibre covered with pure silver, without/with antioxidant treatment. These materials were further compared to conventional Ag/AgCl electrodes while measuring ECG on living subjects. Signal quality metrics show a high level of similarity between the ECG signals measured by textile electrodes and conventional Ag/AgCl electrodes.