Auscultation collecting head with adjustable resonant frequency

Abstract

The invention provides an auscultation collecting head with the adjustable resonant frequency, and aims at solving the problems of non-ideal sound pickup effect, low signal-to-noise ratio and high distortion degree of the existing auscultation head. The inner cavity area and volume of a resonant cavity are designed to reach the optimal matching with a microphone, i.e., the frequency of the resonant cavity is automatically changed by changing the volume and the shape of the resonant cavity in a pressing mode, so that the sound pickup effect of the microphone is the best. The auscultation collecting head consists of a resonant cavity case, a built-in probe (an electret capacitance microphone), a pre-amplification circuit, a signal filter circuit and an A / D conversion circuit. According to the frequency characteristics and the sensitivity of the electret capacitance microphone, the relevant parameters of the resonant cavity case are designed again by using the relationship of the resonant cavity and the resonant frequency, so that the human body sound signal picked by the resonant cavity can be magnified to the sensitivity range of the microphone, and the frequency of the human sound signal is modulated to the frequency range corresponding to a relatively flat section of the microphone frequency response curve.

Description

technical field [0001] The invention relates to the technical field of medical equipment, in particular to a stethoscope head of an electronic stethoscope. Background technique [0002] Since the stethoscope has been used clinically, it has played a very important role when doctors see patients. The doctor can hear the patient's heart sounds, breath sounds, lung sounds and other murmurs with the help of the stethoscope, that is, the patient's condition can be diagnosed through the stethoscope. In recent years, in order to meet the needs of reality, stethoscopes have been continuously optimized, and now there are mainly stethoscopes with traditional structures and electronic stethoscopes. Both traditional stethoscopes and electronic stethoscopes have a bell-shaped or membrane-shaped auscultation head, and the effect of picking up sound is not obvious enough. In order to amplify the physiological sound, someone proposed to put the microphone directly on the chest to collect,...

AI Technical Summary

Problems solved by technology

Both traditional stethoscopes and electronic stethoscopes use bell-shaped or membrane-shaped auscultation heads, and the effect of picking up sound is not obvious enough.

In order to amplify the physiological sound, someone proposed to put the microphone directly on the chest to collect, and then amplify the physiological sound signal through the amplification circuit, but this will cause the environmental noise signal to be picked up and amplified at the same time. If it does not fall within the sensitive area of ​​the microphone, the sound pickup effect of the microphone is not ideal, for example, the signal-to-noise ratio is low and part of the physiological sound signal is missed

Also someone has proposed the method that microphone is directly connected on the traditional stethoscope, but the stethoscope structure that this method makes is complicated, is unfavorable for popularizing and applying

In order to amplify the human body sound signal, a stethoscope head designed with a resonant cavity is used to pick up the sound. However, the resonant cavity of the traditional stethoscope is designed to meet the sensitivity of the human cochlea, not the sensitivity of the microphone.

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