Non-contact Low Power EEG/ECG Electrode for High Density Wearable Biopotential Sensor Networks

A non-contact capacitive biopotential electrode with a common-mode noise suppression circuit is presented. The sensor network utilizes a single conductive sheet to establish a common body wide reference line, eliminating the need for an explicit signal ground connection. Each electrode senses the local biopotential with a differential gain of 46dB over a 1-100Hz bandwidth. Signals are digitized directly on board with a 16-bit ADC. The coin sized electrode consumes 285uA from a single 3.3V supply, and interfaces with a serial data bus for daisy-chain integration in body area sensor networks.