Performance of Flexible Non-contact Electrodes in Bioelectrical Signal Measurements

Abstract

Electrocardiography (ECG) and electroencephalograph (EEG) are two physiological signals closely related with human health, and their measurements can help to detect various diseases in the clinic. Long-term physiological signal monitoring is usually needed to catch any possible diseases which may be missed in conventional short-term monitoring. Currently, wet electrodes are widely used in the clinic to obtain physiological signals. However, wet electrodes require adhesives or conductive gels to improve the quality of recorded signals, and may introduce skin irritation. Based on the Capacitive coupling principle, this study proposed a flexible non-contact electrode that can collect physiological electrical signals without direct contacts with the skin. Moreover, it can attach firmly than common conductive electrodes because of its flexibility. The results showed that the proposed non-contact electrode could reliably obtain high quality physiological signals, and the performance could be comparable to the conventional wet electrodes. Alpha waves could be clearly detected when the subjects closed their eyes, with the non-contact electrodes placed over the hair. This study might provide a reliable solution for long-term monitoring of physiological signals for those whose disorders could not be diagnosed over a short period of time.