How to Connect Conductive Flexible Textile Tracks to Skin Electrocardiography Electrodes and Protect Them Against Washing

Cardiovascular diseases are the leading cause of lethal issues worldwide. The most effective way to combat these diseases is the real-time monitoring of the electrocardiogram (ECG) that reflects the electrical signals generated by the heart cells. So far, the ECG is recorded by using the cutaneous conventional medical electrodes (Ag/AgCl). These electrodes are not adapted for long-term use as they are not fully integrated into underwear and generally can provoke skin irritation, because of the ionic gel that serves to reduce the impedance of the electrode/ skin interface. The first part of this paper concerns the design and realization by embroidery of three different patterns of conductive tracks that could be adopted as connection lines between an electronic module and ECG electrodes. In order to make these conductive tracks washable, two encapsulation methods have been investigated. The reliability of the developed conductive tracks and encapsulation methods has been analyzed. The second part of this study is focused on the development of washable embroidered ECG bands operating without any ionic gel as alternatives to medical electrodes (Ag/AgCl). The acquisition of ECG signals has been carried out on 3 female and 6 male healthy subjects aged between 25 and 55 years. In the last stage of this paper, we explore the ECG signal in static condition, the spectral power density of the ECG signal, the signal-to-noise ratio (SNR) of ECG electrodes before and after 50 washing cycles.