Non-invasive carotid artery monitoring by using aluminum nitride pmut close-packed arrays

In this work, we present a prototype for the first time of using miniaturized aluminum nitride (AlN) micro-machined piezoelectric ultrasonic transducer (PMUT) arrays for non-invasive carotid artery monitoring. The designed hexagonal close-packed PMUT arrays device is in size of 3x3mm(2), which contains four independent arrays. And any two of arrays can be used to accomplish pulseecho method on skin tissue above carotid artery. The artery pulsation is successfully acquired with high signal-to-noise ratio and transformed to depth positioning image along time domain. Besides heart rate, the largest relative displacement of carotid artery wall to neck skin is also estimated via long time recording.