Microphone circuit used for electronic stethoscope

Abstract

The invention provides a microphone circuit used for an electronic stethoscope. The microphone circuit comprises a power supply module; a pick-up module used for acquiring sound signals; an amplification and low-pass filtering module, which is used for amplifying the sound signals in an adjustable manner, and is used to inhibit the high frequency noises; an AC amplitude limiting module, which is used to prevent the excessive high AC voltage output by the microphone circuit; and a microphone earphone joint J1. The power supply module is connected with the pick-up module. One end of the amplification and low-pass filtering module is connected with the pick-up module by a peripheral circuit 1, and the other end is connected with the AC amplitude limiting module by a peripheral circuit 2, and the noises of the friction caused by the moving of the stethoscope can be inhibited. The amplification and low-pass filtering module is provided with an adjustable resistor P1, and the amplification factor of the sound signal can be adjusted by changing the resistance value of the adjustable resistor P1. The microphone circuit used for the electronic stethoscope is advantageous in that the physiological sound signal can be amplified effectively, and at the same time, the stability of the frequency characteristics can be guaranteed; and the noises of the friction caused by the moving of the stethoscope can be inhibited.

Description

technical field [0001] The invention relates to the field of medical equipment, more specifically, to a microphone circuit of an electronic stethoscope. Background technique [0002] Stethoscope is a commonly used diagnostic tool for doctors. The traditional acoustic stethoscope has simple structure, poor anti-interference ability, and inaccurate diagnosis. With the advancement of electronic technology, electronic stethoscopes are gradually being widely used because of their accurate diagnosis and strong ability to resist noise interference. [0003] In the circuit of the existing electronic stethoscope, the microphone amplifier circuit and the filter circuit are the key components of the electronic stethoscope, which largely determines the sound quality of the electronic stethoscope. Although there are many microphone amplifier circuits, most of them are designed for applications such as telephones, toys, television sets or computers. Compared with the above-mentioned app...

AI Technical Summary

Problems solved by technology

[0004] In the process of using the electronic stethoscope, sometimes due to the weak audio signal, the signal sampling will be inaccurate, and sometimes there will be intermittent phenomena

Because the magnification of the existing electronic stethoscope cannot be adjusted, or the amplified signal makes the frequency characteristic unstable and the signal is distorted, which brings troubles to the diagnosis of the disease and brings a very serious safety hazard to the personal safety of the patient.

[0005] In addition, when the electronic stethoscope moves, it is easy to produce harsh friction sound due to friction with skin and clothes, and it is also easy to produce whistling sound when the sound loop forms positive feedback

The friction sound generated by the movement of the stethoscope can also cause interference, which greatly affects the diagnosis of the disease.

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