Subcutaneous and Continuous Blood Pressure Monitoring by PMUTs in an Ambulatory Sheep

This paper reports a subcutaneous blood pressure (BP) monitoring system with AlN-based, piezoelectric micromachined ultrasonic transducers (PMUTs) on an ambulatory sheep. Compared to the state-of-art, three distinctive achievements have been demonstrated: (1) precision and continuous measurements of the blood pressure from the diameter changes of blood vessels as small as 2.3 μm by means of ultrasonic detections; (2) experimental validations in both in vitro artery models and an acute animal study; and (3) the first continuous and silent blood pressure monitoring system without a cuff toward a fully implantable system based on MEMS technologies.