Low-Noise Energy Efficient Readout Front-End for Wearable Continuous Blood Pressure Monitoring Systems

Commercially available wearable systems are increasingly helping people to continuously monitor their health status. To enable continuous monitoring for the battery operated lightweight wearable systems, power consumption is the most critical factor. The battery life of such systems has to be decent to make any acceptable product. In these systems, the power consumption is dominated by the transmitter and readout frontend. This paper presents a low-noise, energy efficient readout front-end, which is dedicated to sensing and pre-processing of vital bio-signals, viz., electrocardiogram and photoplethysmograph for continuous blood pressure estimation. The proposed readout front-end obtains a mid-band gain of 45.97 dB, a band of operation from 0.483 Hz to 967.54 Hz and an input referred noise of 0.184 μV rms while consuming 145.9 nW from a 1 V power supply. The post-layout simulations of the proposed design were carried out using standard 65 nm CMOS technology. Robust performance has been noticed across the corners within 4% variation compared to the typical case.