A Bionic MEMS Electronic Stethoscope With Double-Sided Diaphragm Packaging

Sicun Duan,Guojun Zhang,Weidong Wang,Sai Zhang,Xi Yang,Yu Zhang

doi:10.1109/access.2021.3058148

Sicun Duan, Guojun Zhang + Show 4 more

Open Access

https://doi.org/10.1109/access.2021.3058148

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Abstract

In this paper, an electronic stethoscope is designed based on a bionic Micro-Electro-Mechanical System (MEMS) sound-sensitive sensor. Inspired by the strong sound reflection effect of the water-air interface, a double-sided diaphragm MEMS electronic stethoscope (DMES) encapsulated by a novel double-sided diaphragm packaging is proposed. The double-sided diaphragm packaging’s superiority is verified by comparing a single diaphragm MEMS electronic stethoscope (SMES) with DMES. The frequency of the clinical heart sound signal is mostly in the range of 20–600 Hz. Finite simulation results show that for the same incident sound source, the sound pressure level inside double-sided diaphragm packaging is 4dB higher than that of single diaphragm packaging in this frequency band. Furthermore, the actual auscultation test results show that the signal-to-noise ratio (SNR) of DMES reaches 41.3dB, which is 2.2dB higher than SMES. Besides, comparing the heart sound signals collected by DMES and a commercial electronic stethoscope (Model 3200, 3M Littmann, USA), the high consistency of the two signals’ characteristic parameters in the time domain and frequency domain proves the feasibility of DMES. Finally, DMES has the advantages of low cost, and its SNR is 10.2db higher than that of the 3M electronic stethoscope. All these show that DMES has a broad prospect in the popularization of basic medical treatment.

Highlights

The number of deaths caused by Cardiovascular diseases (CVDS) is expected to rise with an increase in the average age of the world’s population [1]
diaphragm MEMS electronic stethoscope (DMES) has the advantages of low cost, and its signal-to-noise ratio (SNR) is 10.2db higher than that of the 3M electronic stethoscope
Xue et al [13] proposed a bionic Micro-Electro-Mechanical System (MEMS) sound-sensitive sensor that simulates the working principle of fish’s neuromast organ to detect underwater acoustic fields. Because this sensor is very sensitive in the low-frequency band, and the frequency of clinical heart sound signals is mainly concentrated in the low-frequency range of 20-600Hz, an improved version of the sensor, shaped like a lollipop, is adopted to design the electronic stethoscope in this research [14]

Summary

INTRODUCTION

The number of deaths caused by Cardiovascular diseases (CVDS) is expected to rise with an increase in the average age of the world’s population [1]. Xue et al [13] proposed a bionic MEMS sound-sensitive sensor that simulates the working principle of fish’s neuromast organ to detect underwater acoustic fields Because this sensor is very sensitive in the low-frequency band, and the frequency of clinical heart sound signals is mainly concentrated in the low-frequency range of 20-600Hz, an improved version of the sensor, shaped like a lollipop, is adopted to design the electronic stethoscope in this research [14]. The symmetrical beams corresponding to these pizoresistors are placed in the same direction as the sound source, parallel to the bottom diaphragm In this way, the acoustic sensor performs the maximum acoustoelectric conversion and achieves auscultation application. As the depth of the packaging shell of DMES is 2cm, which is very shallow, the return time t is far less than 0.05ms, which means that in the frequency range of 20-600Hz, the original sound pressure level inside the shell will be amplified, with a maximum increase of 6dB

FINITE SIMULATION

CONCLUSION

DISCUSSION