SleepABP: Noninvasive Ambulatory Blood Pressure Monitoring Based on Ballistocardiogram in Sleep State

Blood pressure (BP) is one of the vital signssignals used to evaluate the health status of the human body, a. And continuous ambulatory blood pressure (ABP) monitoring can accurately and comprehensively reflect the physiological status of the cardiovascular system. ABP is mainly measured using ambulatory sphygmomanometer, by regularly collecting the pressure changes in blood vessels. However, this method is usually intrusive, inconvenient, and expensive. In this paper, we develop SleepABP, a novel natural, continuous and accurate ABP monitoring system for daily sleep scenarios. SleepABP is based on the Ballistocardiogram (BCG) signal, which relies on measuring the tiny fluctuations (impulses) in the body caused by the continuous beating of the heart. Specifically, the proposed BCG sensing system monitors the pulses from the user's head applying the piezoelectric ceramic sensor. The BCG signals are recorded simultaneously, and the BCG cycle restoration algorithm is used to extract the continuous and complete BCG cycles for constructing the multi-dimensional features of the blood pressure prediction. SleepABP was evaluated on 16 participants under various sleeping conditions, positions, and personal internal factors. The RMSE results of diastolic blood pressure 3.22 mmHg and systolic blood pressure 3.5 mmHg demonstrates the system's effectiveness and feasibility in a daily sleeping environment.