Design and Optimization of Flexible and Stretchable Ultrasonic Transducer Array for Arterial Blood Pressure Monitoring

As one of the important vital signs, blood pressure is an indicator of cardiovascular risk assessment. Central arterial pressure has a strong pathophysiological relationship with target organ damage and cardiovascular disease. Arterial blood pressure (ABP) monitoring has high predictive value for cardiovascular and cerebrovascular events. In this work, the ultrasonic piezoelectric transducer array we designed and optimized differs from conventional rigid ultrasound probes. The transducer array is compact in size ( $39\times 37\times0.71$ mm), stretchable, and flexible, which can attach seamlessly to human skin. ABP monitoring based on the flexible ultrasonic transducer array has advantages over existing techniques, such as being insensitive to motion and allowing continuous blood pressure detection without any injury or vascular occlusion. The flexible transducer array has been used to achieve continuous blood pressure detection of the human carotid artery in specific excitation and phased array-focused emission mode. Compared with the medical central arterial pressure detector, the correctness of the flexible array for measuring blood pressure was verified. In addition to systolic and diastolic blood pressure values, the blood pressure waveform is abundant in physical information about arterial elasticity and heart function, and it has great potential for application in hospital and home environments.