High-Sensitivity Electric Potential Sensors for Non-Contact Monitoring of Physiological Signals

The paper describes highly-sensitive passive electric potential sensors (EPS) for non-contact detection of multiple biophysical signals, including electrocardiogram (ECG), respiration cycle (RC), and electroencephalogram (EEG). proposed EPS uses an optimized transimpedance amplifier (TIA), a single guarded sensing electrode, adaptive cancellation loop (ACL) to maximize sensitivity (DC $= 150\,\,\text{G}\Omega $ ) in the presence power line interference (PLI) motion artifacts. Tests were performed on healthy adult volunteers noisy unshielded indoor environments. Useful ranges ECG, RC, EEG measurements, as validated against reference contact sensors, observed be approximately 50 cm, 100 5 respectively. ECG RC signals also successfully measured through wooden tables subjects sleep-like postures. integrated with wireless microcontroller realize sensor nodes capable streaming acquired data remote base station real-time.