A 46 μW motion artifact reduction bio-signal sensor with ICA based adaptive DC level control for sleep monitoring system

A motion artifact reduction multi-channel bio-signal sensor is proposed for sleep monitoring system with the help of independent component analysis (ICA). To prevent signal saturation due to large motion artifacts, adaptive DC level control (ADLC) is adopted to adjust the DC level of the signal. The current-controlled level shifter (CCLS) is used in ADLC for the shifting voltage step as small as 3mV with low power consumption. The shifted voltages and the motion artifacts are recovered by the ICA. The ICA also detects only the channels suffered from motion artifact and enables ADLC circuit of those selected channels to reduce standby power dissipation. The proposed 4-channel sleep monitoring sensor is implemented in a 0.13μm CMOS process, and consumes only 46μW. With the proposed ADLC, 17.7 times larger motion artifact cannot saturate signal.