Optimum Design and Test of a Novel Bionic Electronic Stethoscope based on the Cruciform Microcantilever with Leaf Microelectromechanical Systems Structure

Abstract

This paper proposes a heart sound sensing structure and system by combining the traditional auscultation structure and human‐like ear eardrum gas–solid coupling sound conduction process. This system is based on the lever pickup mechanism of eardrum vibration and the traditional stethoscope pickup amplification, microelectromechanical system (MEMS) technology, and the detection principle of piezoresistive and Wheatstone bridge. The optimal size and process parameters of the biomimetic sensor structure are given through theoretical calculation and numerical simulation on Comsol and SRIM. Computer numerical control, 3D printing, MEMS technology, and 3D heterogeneous integration technology are used to complete the precise processing and encapsulation of the proposed structure. After the performance tests, results show that the optimal structure can collect directional signals, with a bandwidth from 10 Hz to 1 kHz, which can effectively cover the range of the heart frequency. The signal‐to‐noise ratio is improved by 2.3 dB compared with the 3M stethoscope. An electrocardiogram and phonocardiogram synchronization detection system is developed with this structure. The structure and system can be effectively applied to the high‐quality collection and intelligent recognition of heart sound data sets. The recognition accuracy can reach 98.5%. It is highly effective for early screening and intelligent diagnosis of cardiovascular diseases.

3D‐Printed Bionic Ear for Sound Identification and Localization Based on In Situ Polling of PVDF‐TrFE Film

“…Zhang et al designed a heart sound sensor based on the traditional auscultation structure and human-like ear eardrum. [23] Zhou et al proposed a new bionic acoustic sensor according to the fish ear structure. [24] They started to combined the acoustic and bionic.…”

Acoustically Enhanced Triboelectric Stethoscope for Ultrasensitive Cardiac Sounds Sensing and Disease Diagnosis

“…Low-intensity and low-frequency (20-600 Hz) cardiac sounds provide essential clinical information for the identification and diagnosis of various heart diseases. [1][2][3][4][5] Currently, electronic stethoscope, a noninvasive instrument of diagnosing cardiac disorders by acquiring the acoustic signal during heart contraction, new mechanism that is piezoelectric-superior for perceiving both low-intensity and low-frequency heart acoustic signal is highly desired.…”

“…Low‐intensity and low‐frequency (20–600 Hz) cardiac sounds provide essential clinical information for the identification and diagnosis of various heart diseases. [ 1–5 ] Currently, electronic stethoscope, a noninvasive instrument of diagnosing cardiac disorders by acquiring the acoustic signal during heart contraction, plays an irreplaceable role for the initial assessment in medical field and personal health management. [ 5–8 ] The sensitivity and signal perceptual fidelity of the stethoscope are determined by the rational acoustic and electronic design, their economic costs and popularity.…”

“…Among numerous sensing mechanisms, [ 9–15 ] piezoelectric sensors have been widely employed owing to its simple structure, high consistency, and self‐powered features. [ 2,16–19 ] However, without the assistance of complex filtering and amplification circuits, conventional piezoelectric stethoscope fails to realize the high sensitivity on detecting the heart acoustic signal for the following aspects. On one hand, piezoelectric unit holds the linear electromechanical constitutive relation, [ 20–23 ] in this case, tiny deformation induced by low‐intensity acoustic stimuli leads to a small output magnitude especially in the pressure range for medical purpose.…”