Modelling Research on the Mechanism of Non-contact ECG Measurement Based on Capacitive Coupling

摘要

Traditional Ag/AgCl electrodes have following disadvantages, complicated preparation, corrosion harm to skin, and body movement prohibited. Non-contact ECG measurement has attracted much attention because it can overcome the abovementioned shortcomings and realize the long-term monitoring. The ECG signal is extracted through the coupling capacitance between the metal layer of electrodes and skin. However, the mechanism is poorly studied. In this paper, the multi-layer dielectric parallel plate capacitance model is established to verify the basic principle of non-contact ECG measurement and to explore the influence of related factors on the coupling effect. Coupling potential and capacitance will increase with the increase of the ε_r of the clothing and decrease with the increase of the distance between the electrode and skin. Other factors such as the thickness of the clothing and the measuring angle of the electrode are also studied.