Noninvasive measurement of temperature for simulated tissue based on piezoelectric micromachined ultrasonic transducers

This paper reports a noninvasive measurement of temperature for simulated tissue based on an AlN piezoelectric micromachined ultrasonic transducer array. Polydimethylsiloxane and a built-in heating plate are used to simulate the thermal therapy of human tissue. Based on time-of-flight (ToF) from the simulated tissue surface to the heating plate surface and corresponding temperature data, the piecewise linear fitting method is used to fit the ToF-temperature curve, and its sensitivity is 41.5 ns degrees C-1 (below 50 degrees C) and 30.5 ns degrees C-1 (from 50 degrees C to 65 degrees C). The average error of real-time temperature measurements is 0.58 degrees C for temperatures below 65 degrees C. The proposed method can provide a good solution for temperature detection during thermal therapy.