Fig. 1. The concept and system overview of non-contact continuous nocturnal blood pressure (BP) monitor.

a A typical use scenario of our system, where the fiber optic sensing mat is placed beneath the user’s pillow. b The system prototype deployed in the real world. c Block diagrams of the system. The data preparation stage preprocesses ballistocardiogram signals for posture recognition and fiducial point delineation. The feature extraction stage extracts meaningful features for training a base model. The base model will be directly deployed in the edge device, while a Random Forest model is trained as the personalized regressor to infer the BP in the edge. The customized user interface enables WiFi connectivity for live vital sign monitoring. d System’s circuit and block diagram. The fiber optic sensing capability primarily builds upon a laser emitter, a section of multimode fiber, and a photodiode receiver. e Sample waveforms from time-synchronized electrocardiogram (ECG), ballistocardiogram (BCG), and finger cuff-based pulse sensors. BPF is a bandpass filter, Vref is reference voltage, VBUS is USB power voltage, and a.u. is arbitrary units.