Multimodal Analog Front-end for Wearable Biosensors

Wearable sensors afford convenience in daily health monitoring, though many challenges in the development of such systems need to be overcome. Here, we present a low power, multimodal analog front-end (AFE) for wearable health monitoring sensors. The AFE integrated circuit was designed and fabricated with standard 65 nm CMOS technology. Three sensor AFEs, bio-potential, photoplethysmography (PPG) and bioelectrical impedance analysis (BIA), were integrated on the same die with an area of 2.5x2.5 mm(2). The power consumption is within 380 mu W for single AFE operation modes and 1.92 mW for concurrent operation modes with a 1.2V power supply. Results from each individual AFE showed high-quality, motion-robust signals (Electrocardiogram, PPG and BIA) that correlated with those obtained from clinical grade gold-standard devices for similar applications. Such multi-functional, non-intrusive systems permit users to effortlessly self-monitor multiple physiological parameters.