A 2.4µA continuous-time electrode-skin impedance measurement circuit for motion artifact monitoring in ECG acquisition systems

A continuous time electrode skin impedance monitoring system is implemented in parallel with ECG monitoring. To avoid degradation of the ECG signal quality, chopper stabilized AC current sources are adopted. Measured impedance signal is used as a reference signal input for a post processing adaptive filter removing motion artifacts in the ECG signal. The impedance measurement core is implemented in 0.5μm CMOS process and dissipates 2.4μA from a 2V.