JP2011019799A - Electronic stethoscope - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electronic stethoscope, clearly hearing auscultatory sound of a narrow region and clearly hearing high-frequency sound which has never been heard in the past. <P>SOLUTION: In this electronic stethoscope 1, a chest piece 2 is provided at the end of a bar-like casing. In the chest piece, a value of contact area with the body surface to the volume of a closed space in sampling sound is set larger than 0.1/mm. A microphone constituted by an MEMS (Micro Electro Mechanical Systems) element is provided in the interior of the chest piece. The chest piece is so constructed that a value of contact area with the body surface to the volume of a closed space in sampling sound is set larger than 0.1/mm, whereby the value of contact area with the body surface to the volume of a closed space can be suitably set, so that auscultatory sound of a narrow region can be clearly heard and high-frequency sound which has never heard in the past can be clearly heard. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an electronic stethoscope, and more particularly to a small electronic stethoscope that is small, easy to store, and capable of auscultation in a narrow area.

A stethoscope is widely used as a device for acquiring and diagnosing sounds generated in a living body. In general, a stethoscope is a chestpiece that receives auscultation sounds (ie, body sounds) emitted from the surface of the body, a hollow tube that is connected to it and transmits auscultation sounds as sound waves, and bifurcates for both ears. It is comprised from the eartip attached to the front-end | tip of the hollow tube which was made (for example, refer nonpatent literature 1).
Recently, there is an electronic stethoscope that can convert auscultation sound into an electrical signal, perform signal processing by an electrical circuit, and listen again to the auscultation sound converted into a sound wave (see, for example, Non-Patent Document 2). Furthermore, there are some devices that not only listen to the auscultatory sound with the ear but also analyze the data of the auscultatory sound with a signal processing device.

  Since the conventional general stethoscope listens to the sound wave propagating through the cavity from the chest piece to the ear tip with the ear, the loudness and frequency characteristics of the sound depend on the shape of the chest piece and the volume of the cavity. In particular, since the chestpiece is brought into contact with the skin surface, the volume of the sound to be heard depends on the size of the chestpiece. When auscultating newborns and infants, the auscultation area is small, so it is desirable to use a smaller chestpiece. However, when a small chestpiece is used, the sound to be heard becomes small and difficult to hear.

  By the way, since an electronic stethoscope can perform signal processing with an electric signal, it is possible to amplify the signal and perform auscultation. Many electronic stethoscopes are similar in shape and size to traditional acoustic stethoscopes, and are not suitable for narrow-site auscultation. There is also known an electronic stethoscope in which a general microphone is mounted on a chest piece similar to an acoustic stethoscope (see, for example, Patent Document 1). However, in the electronic stethoscope, the structure of the cavity of the chest piece is the same as a general stethoscope, and there is a large cavity in the microphone mounting portion.

  Here, the acoustic stethoscope has a bell mode that makes low frequency sound easy to hear and a diaphragm mode that makes high frequency sound easier to hear, and these two frequency characteristics are adjusted by the structure of the chest piece. In an electronic stethoscope, a frequency characteristic close to that of an acoustic stethoscope is adjusted by a high-pass filter and a low-pass filter using an electronic circuit.

  In general, a stethoscope listens to sound generated in a living body by bringing a chestpiece into contact with the surface of the living body. The frequency characteristic at this time is determined by the structure of the living body which is an elastic body and the chest piece. A resonance frequency exists due to the mass of the chest piece and the elastic constant of the living body, and the sound that is heard is attenuated as the frequency increases above this resonance frequency. In other words, the sound generated in the living body is vibration generated in the living body. For example, even if the vibration is a constant magnitude (acceleration) with respect to the frequency, the volume of sound heard by the stethoscope depends on the mass if it is below the resonance frequency, and above the resonance frequency. It does not depend on mass but depends on the amplitude of vibration. Since the amplitude of the vibration is inversely proportional to the square of the frequency, even if the vibration generated in the living body has a certain magnitude with respect to the frequency, the vibration is attenuated in inverse proportion to the square of the frequency above the resonance frequency. Furthermore, in an acoustic stethoscope, since a tube exists between the chest piece and the ear tip, a sound having a higher frequency is attenuated. The resonance frequency in a system for auscultating a living body of a general stethoscope is several hundred Hz, and the sensitivity is rapidly attenuated at a frequency higher than this.

  Therefore, for sounds such as heart sounds that are mainly in the band of 300 Hz or less, the sensitivity below the resonance frequency is increased and the auscultation is facilitated by making the stethoscope heavy. In addition, breathing sounds, etc. actually contain high-frequency vibrations, and the sensitivity rapidly decays above the resonance frequency, so when auscultating with the ear, high-frequency sounds are masked by low-frequency sounds and can be heard. Can not.

JP-T 8-506495

3M Littmann CLASSIC II SE STETHOSCOPE, [online], 3M Healthcare Co., Ltd., [searched February 24, 2009], Internet <URL: http://www.mmm.co.jp/hc/littmann/classic2se. html> 3M Littmann ELECTRONICS TETHOSCOPE MODEL4100, [online], 3M Healthcare Co., Ltd. [searched on February 24, 2009], Internet <URL: http://www.mmm.co.jp/hc/littmann/es-4000 .html>

It is possible to perform auscultation similar to that of a conventional acoustic stethoscope with the above-described electronic stethoscope. However, the size of the chestpiece for listening to the sound is the same, and it is difficult to auscultate a narrow part. For this reason, miniaturization and downsizing of the chest piece have been demanded.
Here, if the chestpiece of the electronic stethoscope of Patent Document 1 is reduced in size while maintaining the configuration, sensitivity is lowered and clear auscultation cannot be performed. In particular, since the mass per contact area with the part is small, it is difficult to perform auscultation in the low frequency range.
In addition, since the sensitivity of sound of several hundred Hz or higher becomes lower as the frequency becomes higher, when auscultating with the ear, the high frequency sound is masked by the low frequency sound and is difficult to hear.
The present invention has been made to solve the above-described problems of the prior art, and its purpose is to clearly listen to auscultation sounds in a narrow region and to listen to high-frequency sounds that could not be conventionally auscultated. It is to provide an electronic stethoscope that can.

In order to solve the above-mentioned problem, an electronic stethoscope according to the present invention is an electronic stethoscope provided with a chest piece for collecting sound by contacting the body surface, and the chest piece is used for collecting sound. The value of the contact area with the body surface with respect to the volume of the sealed space is greater than 0.1 / mm. According to this configuration, the value of the contact area with the body surface with respect to the volume of the sealed space can be set appropriately, and the body sound can be acquired satisfactorily.
Moreover, the said electronic stethoscope WHEREIN: The said chest piece may have a microphone in the inside. By adopting the microphone, the value of the contact area with the body surface with respect to the volume of the sealed space can be appropriately set, and the body sound can be acquired satisfactorily.

Further, in the electronic stethoscope, the chest piece may have an opening for forming a sealed space together with a body surface that comes into contact. According to this structure, a biological sound can be acquired favorably by bringing the chest piece into contact with the biological surface.
Moreover, the said electronic stethoscope WHEREIN: The said chest piece may have a diaphragm which contacts a body surface, and may form sealed space with the said diaphragm. According to this structure, a biological sound can be acquired favorably by bringing the chest piece into contact with the biological surface.

In the electronic stethoscope, it is desirable that at least a part of the chest piece that is in contact with the body surface is formed of an elastic material. By adopting an elastic material for the chestpiece, it is possible to improve the adhesion with the body surface and to obtain a good body sound.
Furthermore, the electronic stethoscope may include a convex portion provided at the opening in the sealed space for suppressing a change in the volume of the sealed space when the chestpiece is in contact with the body surface. Good. According to this configuration, when the chest piece is brought into contact with the living body surface, the change in the volume of the sealed space due to the bending of the body surface or the diaphragm is suppressed, and the value of the contact area with the body surface with respect to the volume of the sealed space Can be set appropriately, and the body sound can be acquired satisfactorily.

By the way, it is desirable that the electronic stethoscope has a rod-shaped housing, and the chest piece is provided at an end of the rod-shaped housing. According to this configuration, by bringing the tip of the rod-shaped housing into contact with the surface of the living body, it is possible to obtain a good body sound, and the posture of the auscultating doctor's hand and arm becomes natural, and the hand and arm Less fatigue.
In the electronic stethoscope, the microphone is preferably composed of a MEMS (Micro Electro Mechanical Systems) element. According to this configuration, the value of the contact area with the body surface with respect to the volume of the sealed space when collecting the sound of the chestpiece can be appropriately set, and the body sound can be acquired satisfactorily.

  According to the present invention, in the electronic stethoscope provided with the chestpiece, the value of the contact area with the body surface with respect to the volume of the sealed space when the sound is collected is greater than 0.1 / mm. Accordingly, the value of the contact area with the body surface with respect to the volume of the sealed space can be appropriately set, the auscultation sound of a narrow part can be heard clearly, and the high frequency sound that could not be auscultated conventionally can be heard clearly.

It is a perspective view which shows the external appearance of the electronic stethoscope 1 by embodiment of this invention. It is a figure which shows the structural example of the chest piece of the electronic stethoscope of this invention. The figure (a) is a sectional view and the figure (b) is a view seen from the outside. It is a figure which shows the structural example of the chest piece of the electronic stethoscope of this invention. The figure (a) is a sectional view and the figure (b) is a view seen from the outside. It is a figure which shows the structural example of the chest piece of the electronic stethoscope of this invention. The figure (a) is a sectional view and the figure (b) is a view seen from the outside. It is a functional block diagram which shows an example of an electronic stethoscope. It is a functional block diagram which shows the other example of an electronic stethoscope. It is a figure which shows the relationship of the sound pressure with respect to the height per unit opening area in the case of auscultating a certain desired biological sound. It is a figure which shows the relationship between the sound pressure in a chestpiece, and the value of the opening part area with respect to sealed space volume.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings referred to in the following description, the same parts as those in the other drawings are denoted by the same reference numerals. In the present embodiment, an electronic stethoscope used for auscultation by contacting any skin surface of a human body will be described.
(Overview)
The inventor considered that the relationship S / V between the volume V in the chest piece and the contact area S depends on (influences on) the sound pressure of the electronic stethoscope and the S / V of the S / V considering the noise level of the sound pressure. The lowest standard was found, and the design of a chest piece larger than a predetermined S / V enabled miniaturization.
In the conventional electronic stethoscope, a condenser microphone is used, but in the present invention, a MEMS element, that is, a silicon microphone is used in order to reduce the size of the chestpiece.
By setting the sealed space in the chest piece to a predetermined height, the amplitude of the body sound from the skin surface can be set to a sufficient sound pressure in the audible range.

(Configuration of the device body)
FIG. 1 is a perspective view showing an external appearance of an electronic stethoscope 1 according to an embodiment of the present invention. In the figure, an electronic stethoscope 1 has a cylindrical or cylindrical casing, and a chest piece 2 for collecting sound by contacting a living body skin surface (not shown) at one end thereof. Is provided.
Further, a display / operation unit 3 is provided on the side surface of the housing of the electronic stethoscope 1. The electronic stethoscope 1 is turned on / off, the volume is adjusted, the mode is switched, and the display is performed by the display / operation unit 3.

Furthermore, the other end of the housing of the electronic stethoscope 1 is connected to a wiring 4 for transmitting a biological sound signal to a biological sound reproducing device such as headphones and earphones. Although not shown, a signal processing circuit for processing the auscultatory sound signal, a battery for supplying power to the signal processing circuit, and the like are provided inside the housing of the electronic stethoscope 1.
The frequency characteristic of the body sound acquired from the skin surface by the electronic stethoscope 1 depends on the contact area of the chestpiece 2 with the skin and the mass of the electronic stethoscope 1. As the mass value with respect to the contact area is increased, the resonance frequency is lowered, and the sensitivity of low sounds below the resonance frequency is increased.

(First configuration example of chest piece)
FIG. 2 is a diagram showing a first configuration example of the chest piece 2 provided in the electronic stethoscope 1 of FIG. FIG. 4A is a cross-sectional view of the chest piece, and FIG. 4B is a diagram showing an external configuration when the chest piece is viewed from the direction of arrow Y in FIG.
Referring to FIG. 2, the microphone package 21 is mounted on the printed circuit board 23. A microphone chip 22 which is a MEMS (Micro Electro Mechanical Systems) element is built in the microphone package 21. A sound hole 210 is provided below the microphone package 21, and a sound hole 230 is also provided at the same position on the printed circuit board 23. The printed circuit board 23 is provided inside the outer casing 24 of the chest piece.

  The outer casing 24 is provided with an opening 25. The printed circuit board 23 is provided inside the outer casing 24 so that the positions of the sound holes 230 and 210 are included in the range of the opening 25. A body sound is acquired by the microphone chip 22 through the sound holes 230 and 210 by bringing the portion of the opening 25 of the outer casing 24 into contact with an arbitrary skin surface of the human body.

  Here, referring to FIG. 2B, the chestpiece comes into contact with the skin surface during a living body sound auscultation, and a sealed space 26 is formed by the microphone package 21, the printed board 23, the housing 24 and the skin. The sound pressure in the sealed space 26 is determined by the ratio between the volume of the sealed space and the amplitude of the skin surface of the opening 25. The amplitude of the body sound on the skin surface is about 0.3 μm during breathing in the audible range. In this case, if the height of the sealed space per unit area of the opening 25 is 3 mm, the sound pressure due to the body sound is 10 Pa. The maximum input sound pressure of a general microphone is about 10 to 20 Pa, and by limiting the volume of the sealed space, it is possible to obtain a high sensitivity without distorting the body sound.

In the microphone using the MEMS element, the volume of the microphone package 21 is small. For example, SP0208LE5 manufactured by Knowles has an outer volume of 28.9 mm ³ . For this reason, by using the microphone by the MEMS element, the sound pressure of the sealed space 26 can be sufficiently ensured even if the diameter of the opening of the chest piece is about 3 mm. For this reason, even if the outer diameter of the chestpiece is reduced to an unprecedented size, it can be auscultated well.
In addition, the material of the housing | casing 24 is not specifically limited, Hard resin may be sufficient. Of course, an elastic material such as silicone rubber is desirable for improving the adhesion to the skin.

(Second configuration example of chest piece)
FIG. 3 is a diagram showing a second configuration example of the chest piece provided in the electronic stethoscope 1 of FIG. FIG. 4A is a cross-sectional view of the chest piece, and FIG. 4B is a diagram showing an external configuration when the chest piece is viewed from the direction of arrow Y in FIG.
The basic configuration of the chest piece shown in FIG. 3 is the same as that of FIG. However, the chest piece 2 shown in FIG. 3 is different from the case of FIG. 2 in that a diaphragm (diaphragm) 37 is provided. The outer casing 34 of the chest piece 2 is provided with a recess. A diaphragm 37 is fitted in the recess so as to close the opening 35 of the outer casing 34. The diaphragm 37 contacts the body surface when the electronic stethoscope is used, and transmits the biological sound to the inside of the chest piece 2.

By providing the diaphragm 37, a sealed space 36 is configured. By providing the diaphragm 37, the volume of the sealed space 36 can be limited as compared with the case where the diaphragm 37 is not provided. With such a configuration, the body sound can be acquired with high sensitivity without being distorted.
The material of the diaphragm 37 is not particularly limited. However, when a hard plate such as a glass epoxy plate is used as the vibration plate 37, the peripheral portion 340 of the vibration plate 37 in the chest piece 2 needs to be formed of an elastic material such as silicon rubber. Desirably, the outer casing 34 and the diaphragm 37 are made of integral silicon rubber and can be detached from the casing of the electronic stethoscope.

(Third configuration example of chest piece)
FIG. 4 is a diagram illustrating a third configuration example of the chest piece provided in the electronic stethoscope 1 of FIG. FIG. 4A is a cross-sectional view of the chest piece, and FIG. 4B is a diagram showing an external configuration when the chest piece is viewed from the direction of arrow Y in FIG.
The basic configuration of the chest piece shown in FIG. 4 is the same as that of FIG. However, in the chest piece 2 shown in FIG. 4, a convex portion 38 is provided in the opening 35 in the sealed space 36. In this example, a convex portion 38 is provided at a position where one end is in contact with the printed circuit board 23 and the other end is in contact with the diaphragm 37. In this example, four cylindrical convex portions 38 are provided so as to surround the position of the sound hole 230.

By providing the convex portion 38, when the chest piece 2 is strongly pressed against the body surface, it is possible to prevent the diaphragm 37 from being bent and closing the sound hole 230, thereby reducing the sensitivity.
The convex portion 38 may be formed integrally with the diaphragm 37 or may be formed integrally with the printed board 23. Further, the convex portions 38 are not limited to the case of this example, and the positions and the number of the convex portions 38 are appropriately adjusted so that the change in the volume of the sealed space due to the bending of the body surface or the diaphragm can be suppressed. do it.

(Function configuration example 1)
FIG. 5 is a functional block diagram illustrating an example of an electronic stethoscope. In the figure, an electronic stethoscope 1 includes a microphone package 21, a high-pass filter 11 that cuts a low-frequency component of the output signal of the microphone package 21, and a power amplifier 12 that amplifies the signal after being cut by the high-pass filter 11. And. An earphone 13 is connected to the power amplifier 12.
The cutoff frequency of the high pass filter 11 can be adjusted by the cutoff frequency adjusting unit 14. The power amplifier 12 can adjust the output volume by adjusting the gain by the volume adjustment unit 15.
In such a configuration, the low frequency component of the output signal of the microphone package 21 is cut by the high pass filter 11 and then amplified by the power amplifier 12. The signal amplified by the power amplifier 12 is input to the earphone 13 and output as sound. Therefore, if a doctor or the like wears the earphone 13 in his / her ear, the auscultatory sound can be heard.

(Function configuration example 2)
FIG. 6 is a functional block diagram showing another example of an electronic stethoscope. In the configuration of FIG. 5, the band pass filter 16 is used instead of the high pass filter in the configuration of FIG. 5. The cutoff frequency of the bandpass filter 16 can be adjusted by the cutoff frequency adjusting unit 14.
In such a configuration, a predetermined frequency range of the output signal of the microphone package 21 is input to the power amplifier 12 and amplified by the bandpass filter 16. The signal amplified by the power amplifier 12 is input to the earphone 13 and output as sound. Therefore, if a doctor or the like wears the earphone 13 in his / her ear, the auscultatory sound can be heard.

(Relationship between sound pressure in chestpiece and height per unit opening area)
FIG. 7 is a diagram illustrating a relationship of sound pressure with respect to height per unit opening area when a desired desired body sound is auscultated. In the figure, the horizontal axis represents the height per unit opening area, and the vertical axis represents the sound pressure. If the amplitude of the body sound on the skin surface is constant and the damping effect of air in the sealed space is neglected because the vibration amplitude is small, as shown in the figure, the sound pressure is per unit opening area. Inversely proportional to the height of
Here, when used as a stethoscope, the upper limit of the height per unit opening area is the height at which the sound pressure in the chest piece due to the body sound to be auscultated falls below the background noise level BGN. The upper limit of this height is practically 3 mm.

  Similarly, the lower limit HD of the height per unit opening area is as follows. First, the volume of the sealed space is the sum of the volume of the microphone package and the volume of the chest piece connected thereto. The sound pressure increases as the height of the cavity in the chest piece (that is, the sealed space 26 in FIG. 2A) is lowered. However, if the height is too low, when the stethoscope is applied to the surface of the living body, the skin touches the inner wall of the cavity (upper side, that is, the inner wall on the side far from the skin) in the chestpiece cavity and can be auscultated. Disappear. This is the lower limit HD of the height. It is difficult to specify the lower limit HD of the height by a numerical value. The height is also limited by the maximum input sound pressure of the microphone package used.

Assume that the volume of the enclosed space in the chestpiece is V, the area of the opening of the chestpiece or the area of the diaphragm is S, and the amplitude is d, assuming that the skin surface or the diaphragm is vibrating uniformly. . Then, the volume change due to vibration is S × d.
The volume change rate in the sealed space is (S × d) / V. If the pressure in the space in the steady state is P, the pressure change is P × (S × d) / V, which is the sound. Corresponds to pressure. In order to reduce the size of the chest piece, that is, the contact area S with the skin while maintaining the sound pressure, it is necessary to simultaneously reduce the volume of the sealed space.

  In an acoustic stethoscope, since the volume of the tube is added to the volume in the chest piece, it is difficult to reduce the volume of the sealed space. In addition, when a microphone is attached to a chestpiece in an electronic stethoscope, the volume of the microphone itself is also included in this sealed space. Therefore, it is difficult to reduce the volume of the sealed space using a conventional microphone. By applying the microphone package with the MEMS element to the stethoscope, the occupied volume of the microphone itself can be reduced, and thus the size can be reduced.

(Relationship between the sound pressure in the chest piece and the value of the opening area relative to the volume of the sealed space)
FIG. 8 is a diagram showing the relationship between the sound pressure in the chest piece and the value of the opening area relative to the sealed space volume. In the figure, the horizontal axis represents the value of the opening area with respect to the sealed space volume (/ mm), and the vertical axis represents the sound pressure (dB).
Referring to the figure, when the value of the opening area relative to the sealed space volume is less than 0.1, the sound pressure is less than 60 dB. This sound pressure of 60 dB is a background noise level. Therefore, when the value of the opening area with respect to the sealed space volume is less than 0.1, it is difficult to hear the auscultatory sound. That is, in order to design the chestpiece so that the auscultatory sound can be heard, the value of the opening area relative to the sealed space volume needs to be larger than 0.1.

The inventor measured the sound pressure level by changing the area of the opening and the height of the sealed space. Here, when the volume of the sealed space is Vc and the area of the opening is So, the height of the sealed space per unit area of the opening is Hs = Vc / So.
Example 1
In the configuration of FIG. 2, when the breathing sound in the thorax was auscultated with an electronic stethoscope having an opening area So = 3 mm ² and a height Hs = 3 mm, the breathing sound could be heard. The maximum sound pressure level at this time was about 70 dB.

(Example 2)
In the configuration of FIG. 2, when the breathing sound in the thorax was auscultated with an electronic stethoscope having an opening area So = 7 mm ² and a height Hs = 1.6 mm, the breathing sound could be clearly heard. The maximum sound pressure level at this time was about 76 dB.
(Example 3)
In the configuration of FIG. 2, when an auscultatory breathing sound was auscultated with an electronic stethoscope with an opening area So = 19 mm ² and a height Hs = 0.94 mm, the breathing sound could be heard more clearly. . The maximum sound pressure level at this time was about 80 dB.

(Comparative example)
In the configuration of FIG. 2, when the breathing sound in the thorax was auscultated with an electronic stethoscope having an opening area So = 0.8 mm ² and a height Hs = 10 mm, the breathing sound could not be heard. The sound pressure level of the respiratory sound estimated from the sound pressure level of the respiratory sound of Example 1 and Example 2 was about 60 dB, and the respiratory sound was buried in noise and could not be auscultated.

(Modification)
The case of the electronic stethoscope described above is a columnar or cylindrical shape, but is not limited thereto, and various rod-like cases such as an elliptical column and a rectangular column may be adopted.
In the electronic stethoscope described above, the wiring 4 for transmitting the biological sound signal to the biological sound reproducing device such as headphones and earphones is connected, but the wiring 4 may be detachable. For example, if the jack of the electronic stethoscope 1 and the plug at the end of the wiring 4 are provided, the wiring 4 can be attached and detached.

DESCRIPTION OF SYMBOLS 1 Electronic stethoscope 2 Chest piece 3 Display / operation part 4 Wiring 11 High pass filter 12 Power amplifier 13 Earphone 14 Cutoff frequency adjustment part 15 Volume adjustment part 16 Band pass filter 21 Microphone package 22 Microphone chip 23 Printed circuit boards 24 and 34 Case 25 35 Opening 26, 36 Sealed space 37 Diaphragm 38 Convex 210, 230 Sound hole 340 Peripheral part

Claims (8)

  An electronic stethoscope comprising a chestpiece for contacting a body surface and collecting a sound, wherein the chestpiece has a value of a contact area with the body surface with respect to a volume of a sealed space when the sound is collected An electronic stethoscope characterized by being larger than 0.1 / mm.   2. The electronic stethoscope according to claim 1, wherein the chestpiece has a microphone therein.   3. The electronic stethoscope according to claim 1, wherein the chestpiece has an opening for forming a sealed space together with a contacting body surface.   3. The electronic stethoscope according to claim 1, wherein the chest piece includes a diaphragm that contacts a body surface, and forms a sealed space together with the diaphragm. 4.   5. The electronic auscultation device according to claim 1, wherein at least a part of the chest piece that is in contact with the body surface is formed of an elastic material. vessel.   The electronic stethoscope according to any one of claims 1 to 5, wherein the volume of the sealed space is changed when the chest piece provided at the opening in the sealed space is in contact with the body surface. An electronic stethoscope characterized by having a convex portion for suppressing the above.   The electronic stethoscope according to any one of claims 1 to 6, further comprising: a rod-shaped housing, wherein the chest piece is provided at an end of the rod-shaped housing. Electronic stethoscope.   The electronic stethoscope according to any one of claims 1 to 7, wherein the microphone includes a MEMS element.

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