Textile-based ECG acquisition system with capacitively coupled electrodes

In most traditional electrocardiogram (ECG) detection procedures, wet electrodes must be glued to the skin during the procedure and may cause problems such as inconvenience and skin irritation. Furthermore, the quality of the acquired signals decreases because the glue dehydrates over time. In this study, a non-contact ECG acquisition system based on capacitive coupling textile electrodes with low-power consumption and high input impedance is presented. We designed electrodes that have a composite and textile structure. A kind of conductive textile with stainless steel wire creates these electrodes. We wove the conductive textile that has good electrical conductivity with a surface resistivity of 1.25 Ω/sq. Both circuit models of the skin–electrode interface and amplifier for the capacitively coupled textile electrode were established, and the output signal-to-noise ratio (SNR) of the front-end circuit was proposed. The integrated system combines amplification, filter circuit and analogue-to-digital converter. The final measurement shows that the ECG signals acquired by our system are adequate for heartbeat detection and applicable to clinical practice.