A Wireless 8-Channel ECG Biopotential Acquisition System for Dry Electrodes

A wireless 8-channel biopotential acquisition system for capturing electrocardiogram (ECG) using dry electrodes is presented. The ECG system consists of copper electrodes, a micropowered 8-channel custom ASIC, and an off-the-shelf microprocessor and bluetooth radio. Each analog channel of the custom ECG front-end is composed of a chopper-modulated instrumentation amplifier (CMIA) with chopping spike filter (CSF), a programmable gain amplifier (PGA), and a output buffer. Implemented in standard a 0.35 gm CMOS technology, the ECG front-end consumes 101 mu A from a 2.7 V supply, occupying 5 mm(2) of chip area. Measurement results show an input impedance of 1 G Omega, an input-referred noise of 0.97 mu Vrms (0.5 similar to 100 Hz), and a CM of 114 dB. Finally, a complete wireless 8-channel ECG monitoring system incorporating this analog front-end is demonstrated, showing successful recordings of a capture ECG waveform using a smart phone.