A novel approach for non-invasive, simultaneous, and realtime monitoring of BCG, BPW, and heart sounds with flexible and bio-compatible piezoelectric AlN sensor

Monitoring physiological cardiovascular parameters such as heart rate, heart rate variability (HRV), heart sounds, blood pressure wave (BPW), pulse wave velocity (PWV), and cardio-ankle vascular index (CAVI) is crucial for the early diagnosis of cardiovascular diseases. While hospital monitoring devices are consistently reliable, they are often expensive, bulky, and require well-trained personnel. Low-cost, highly accessible, and easy-to-use devices that continuously monitor these parameters are extremely important as they can address these issues, helping individuals to stay informed about their health status. Here is reported a new method for simultaneously measuring cardiovascular bio-indicators by analyzing Ballistocardiogram (BCG), BPW, and heart sound traces, achieved by a single acquisition, exploiting a thin, flexible, bio-compatible, and non-invasive piezoelectric sensor based on a 1 μm thick aluminum nitride film and a flexible 25 μm thick Kapton substrate. A CAVI = 6.8 ± 0.3, and the other 26 parameters are measured from four arterial pulse sites – carotid, brachial, radial, and posterior tibial arteries – providing a comprehensive subject's health profile. The proposed approach offers a non-invasive method for continuous health monitoring, exploiting a bio-compatible, low-cost, and low-power technology that can also be a powerful tool for disease prevention, facilitating personalized medical diagnosis and therapies simultaneously.