Design and Implementation of T-type MEMS heart sound sensor

Abstract In view of low sensitivity of traditional stethoscope and valuableness of existing intelligent electronic stethoscope, a T-type MEMS heart sound sensor with high sensitivity, low cost and high SNR is designed, which is combined with MEMS technology, bionic principle, piezoresistive principle and Wheatstone bridge detection principle. Firstly, working principle of T-type MEMS heart sound sensor is introduced; Secondly, theoretical model of T-type sensitive microstructure is established, and its performance is simulated and analyzed by ANSYS finite element simulation software, then the size of T-type sensitive microstructure is determined and T-type MEMS heart sound sensor is made. Finally, T-type MEMS heart sound sensor prototype is tested. The results of tests show that: sensitivity and working frequency band of T-type MEMS heart sound sensor are respectively -183dB@500 Hz and 0–1000 Hz, which have verified correctness and practicability of T-type microstructure. In addition, the acoustic properties of S1 and S2 are analyzed from time domain and frequency domain, which indicates that heart sound signals detected by T-type MEMS heart sound sensor are highly consistent with that of 3200-type electronic stethoscope of 3 M company. Moreover, SNR of T-type MEMS heart sound sensor is 7.9 dB higher than 3200-type electronic stethoscope of 3 M company. The above shows that the T-type MEMS heart sound sensor can provide a powerful basis for early accurate diagnosis of cardiovascular disease and has broad prospects in the field of heart sound detection.