Speed Settling of AC-Coupled Amplifier for Active Contactless ECG Electrode

Contactless electrodes have the ability of long- term wearable physiological recording to meet the massive data requirements in digital health. Active electrodes have been used to avoid noise induced by the high-impedance contactless electrodes for better data quality. However, the settling time of the active contactless electrodes is relatively long (e.g., several seconds), restricting the use of contactless electrodes in frequent power on-off operations to save power which is usually supplied by a battery. We develop a low-power active contactless electrode circuit based on the AC-coupled amplifier with a speed-up settling property. Simulation results demonstrated that the ECG baseline drifted during the settling period after power on was eliminated. The proposed electrode is suitable for power-saving operations in long-term wearable ECG applications.