JP2000060845A - Biological sound detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a biological sound detector capable of outputting signals not including the signals other than biological sound generated inside the body of a person to be measured. SOLUTION: Since a tightly closed air chamber 66 is provided between a case body 22 and a microphone 40, environmental noise transmitted from the outside of a living body through the air and reaching the case body 22 is reflected or absorbed in the air chamber 66. Also, since the air chamber 66 is tightly closed, the environmental noise does not resonate inside the air chamber 66 either. Thus, the vibration of the diaphragm 50 of the microphone 40 positioned on the inner side of the air chamber 66 inside the case body 22 by the environmental noise is suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention detects a body sound generated in a body and outputs a body sound signal representing the body sound in order to diagnose a disease such as a heart or a respiratory system of the body. The present invention relates to a sound detection device, and particularly to a technique for detecting a body sound in a more suitable state by the body sound detection device.

[0002]

2. Description of the Related Art For example, in order to diagnose a heart disease or a disease such as a respiratory system, a doctor conducts auscultation directly by an auscultation method. However, in the diagnosis by this auscultation method,
Heart sounds, breath sounds, pleural sounds,
Since the volume and tone of body sounds such as arterial sounds and intestinal sounds are different, the objectivity and quantitativeness are poor, and the body sounds cannot be recorded.

Therefore, as an alternative to the auscultatory method or as a means for supplementing the auscultatory method, a body sound detecting device which is mounted on a predetermined portion of the body surface and outputs a body sound signal representing a body sound generated in the living body is used. The diagnosis was made. The body sound signal output from the body sound detecting device has no individual difference depending on the person who measures it and can be obtained as objective information and can be recorded. For example, a heart sound is detected by a microphone mounted on the skin of the chest, a heart sound chart is measured, and a heart disease is diagnosed from the heart sound chart. When a patient has a heart disease, the phonocardiogram obtained by measuring the patient includes a normal heart sound and a murmur generated due to the heart disease. Can be done.

[0004]

However, in addition to the body sound necessary for diagnosis, the signals output from the body sound detecting device include environmental noises generated by persons other than the person to be measured, such as human voice and footsteps. , And door opening / closing sounds are included, and it has been difficult to perform accurate diagnosis. Since part of the environmental noise propagates through the living body tissue of the measurement subject and has a wide frequency band, it is difficult to separate it from the body sound. Therefore, it is quiet for accurate diagnosis. It had to be measured in different places. Further, the above-mentioned conventional body sound detection device is mounted on the body surface of a living body by a double-sided tape or suction, but the condition of the body surface of the person to be measured (for example, the body is thin and the mounting position has large irregularities, skin However, due to the body movement of the person to be measured, the biological sound detection device was displaced, and noise was also generated.

The present invention has been made in view of the above circumstances, and an object of the present invention is to output a signal which does not include a signal other than the body sound generated in the body of the person to be measured. An object is to provide a biological sound detection device that can be used.

[0006]

A first aspect of the present invention for achieving the above object is to provide a housing which is open in one direction and which has a diaphragm and is provided in the housing. It is equipped with a microphone that converts the vibration of the diaphragm into an electric signal, is mounted on the skin of a living body, detects a body sound generated inside the body, and outputs a body sound signal representing the body sound from the microphone. And a sealed air chamber between the housing and the microphone.

[0007]

[Effects of the First Invention] With this configuration, the environmental noise that propagates through the air from outside the body and reaches the housing is reflected or absorbed in the air chamber, and the air chamber is hermetically sealed. Since environmental noise does not resonate in the room, it is possible to prevent the diaphragm of the microphone located inside the air chamber in the housing from vibrating due to the environmental noise.

[0008]

A second aspect of the invention for achieving the above object is to provide a housing having a housing which is open in one direction and a vibrating plate, and which is provided in the housing. It is equipped with a microphone that converts the vibration of the diaphragm into an electric signal, is mounted on the skin of a living body, detects a body sound generated inside the body, and outputs a body sound signal representing the body sound from the microphone. Which includes a vibration absorbing sheet having a through hole smaller than a surface of the microphone on the skin side of the living body, the vibration absorbing sheet being provided in the housing substantially horizontally with respect to an opening surface of the housing. The microphone is fixed to a position on the surface of the vibration absorbing sheet opposite to the skin of the living body, at a position that closes the through hole.

[0009]

[Effects of the Second Invention] In this way, environmental noise is transmitted through the air, or from the air through living tissue,
Even when the noise is transmitted to the housing of the biological sound detecting device, the environmental noise is absorbed by the vibration absorbing sheet, so that vibration of the diaphragm of the microphone due to the environmental noise is suppressed. On the other hand, the body sound passes from the opening of the housing through the through hole of the vibration absorbing sheet positioned substantially horizontally with respect to the opening surface, and vibrates the microphone fixed on the surface of the through hole opposite to the skin of the living body. The plate can be vibrated. Therefore, the environmental noise component included in the body sound signal output from the microphone can be reduced.

[0010]

A third aspect of the present invention for achieving the above object is to provide a housing that is open in one direction and a vibration plate that is provided in the housing to electrically vibrate the diaphragm. A body sound detection device that is equipped with a microphone for converting into a signal, is mounted on the skin of a living body, detects a body sound generated inside the body, and outputs a body sound signal representing the body sound from the microphone. That is, a weight is provided in the housing.

[0011]

[Effect of the third invention] With this configuration, environmental noise is transmitted through the air, or from the air through the living tissue,
Even when the noise is transmitted to the housing of the biological sound detecting device, the environmental noise is shielded by the weight provided in the housing, so that the diaphragm of the microphone is suppressed from being vibrated by the environmental noise. Furthermore, the resonance frequency of the whole body sound detection device can be set to a lower frequency side than the body sound by the weight, and resonance of the body sound in the body sound detection device can be eliminated, so that the body sound is reduced. Since it is possible to detect the body sound signal efficiently and the living body sound detecting device presses the skin of the living body with a suitable constant pressure, it is possible to detect the body sound signal with stable and reproducible.

[0012]

A fourth aspect of the invention for achieving the above object is to provide a microphone having a diaphragm and converting the vibration of the diaphragm into an electric signal. A body sound detection device that is mounted on the skin of a living body, detects a body sound generated inside the body, and outputs a body sound signal representing the body sound from the microphone, which is opened in one direction. A housing for housing the microphone is provided so that a surface of the outer periphery on the opening side is brought into contact with the skin of the living body.

[0013]

[Effect of the fourth invention] According to this structure, when the body sound detecting device is attached to the skin of the living body, the surface of the housing on the opening side which is open in one direction is brought into contact with the skin of the living body. Since the environmental noise propagating through the tissue is blocked by the surface of the housing that contacts the skin, the vibration of the microphone diaphragm is suppressed by the environmental noise.

[0014]

Other Embodiments of the Invention Here, preferably, the biological sound detecting device of the third invention is provided with a vibration absorber between the housing and the weight. With this configuration, displacement of the weight can be suppressed, and the environmental noise propagated to the housing can be absorbed also by the vibration absorber.

Further, preferably, the biological sound detecting device of the fourth invention comprises a soft sheet on a surface of the housing which is brought into contact with the living body. In this way, the environmental noise that has propagated through the living tissue is more preferably blocked at the contact surface of the housing with the skin. Further, there is also an advantage that the mounting position of the biological sound detecting device is preferably prevented from being displaced.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a perspective view showing an external appearance of a heart sound detecting device 10 to which the present invention is applied and which detects a heart sound as a body sound, and FIG. 2 is a cross-sectional view for explaining the structure thereof, which is a chest of a living body. A cross-sectional view of the heart sound detection device 10 mounted on a predetermined heart sound detection site on the central epidermis 11 is shown. 1 and 2, the heart sound detecting device 10 is made of a relatively hard material such as ABS resin, and has a flat cylindrical upper housing 12 that is open in one direction and a relatively hard material. And a flat cylindrical lower housing 14 that is open in both directions, and an annular projection 16 provided on the opening side of the upper housing 12 and a lower housing 14
The annular projection 20 provided on the opening on the side where the bottom portion 18 is not provided is fitted to form a flat cylindrical housing 22 that opens in one direction as a whole.

The bottom portion 18 of the lower housing 14 has a relatively large circular hole 24 in the center, and the surface of the bottom portion 18 located on the side opposite to the side on which the upper housing 12 side is brought into contact with the epidermis 11 of the living body. It becomes the side of.

The upper housing 12 and the lower housing 14
In the inside of the housing 22 formed by, the bottom portion 18 of the lower housing 14 is made of a soft material such as silicon rubber, and the outer diameter is equal to the inner diameter of the housing 22 and the inner diameter is the bottom portion 18. An annular vibration absorber 28, which is slightly smaller than the diameter of the circular hole 24, is fitted to absorb the vibration from the lower housing 14.

Further, the surface of the vibration absorber 28 opposite to the bottom portion 18 is made of a relatively hard resin,
Circular edge 2 whose diameter is slightly shorter than the inner diameter of the housing 22
9 and a convex portion 30 located at the center of the edge portion 29 and having an outer peripheral diameter equal to the inner diameter of the vibration absorber 28, the convex portion 30 forms a hole in the center of the vibration absorber 28. It is fitted so as to penetrate.

On the skin 11 side of the convex portion 30 of the dish-shaped member 32, a tapered sound collecting hole 34 having a smaller diameter toward the bottom side is formed, and a collecting hole which is opened substantially parallel to the opening of the lower housing 14. The opening of the sound hole 34 on the skin 11 side is closed by a relatively hard flexible resin film 36 which has a cap shape and is fitted to the side wall surface of the protrusion 30. The flexible resin film 36 is similar to the flexible resin film provided on the pressing surface of the flat pressing portion of the stethoscope, such as polyvinyl chloride resin having a thickness of about 0.1 mm. An acoustic room is formed inside.

Further, a cylindrical member 38 is provided on the opposite side of the convex portion 30 of the dish-shaped member 32 from the skin 11, thereby forming a housing chamber 42 for housing the microphone 40. On the end surface of the cylindrical member 38 on the sound collecting hole 34 side, a circular vibration absorbing sheet 46 having a through hole 44 having a diameter smaller than the diameter of the microphone 40 in the center is provided on the opening surface of the sound collecting hole 34. In contrast, it is fixed almost horizontally. Further, the accommodation chamber 4 for the vibration absorbing sheet 46
A circular chamber 47, which is thinner than the vibration absorbing sheet 46 in the thickness direction, is formed on the side opposite to 2 in order to enable vibration perpendicular to the surface direction of the vibration absorbing sheet 46.

The vibration absorbing sheet 46 is made of a vibration absorbing material such as butyl rubber.
In the state where the vibration is not propagated to the inside, the thickness in the thickness direction is required so that the vibration absorbing sheet 46 is not bent by the weight of the microphone 40, and therefore the thickness is preferably 1.0 to 2.0 mm. When vibration propagates to the vibration absorbing sheet 46, the vibration absorbing sheet 46 vibrates perpendicularly to the surface direction and absorbs the propagated vibration, and particularly functions as a low-pass filter that preferably eliminates vibration of 50 Hz or less. And
The frequency of the heart sound is 50 Hz or higher (for example, II sound is 100-
Since it is 150 Hz), the heart sound can be detected in a suitable state in which noise on the low frequency side is removed.

The microphone 40 is fixed by an adhesive or the like so as to close the through hole 44 of the vibration absorbing sheet 46 in the accommodating chamber 42, and the microphone case 48 opening to the side of the through hole 44 and the inside of the microphone case 48. A vibration plate 50 that is housed on the side of the through hole 44 so as to be parallel to the vibration absorbing sheet 46 and functions as an electrode,
The fixed electrode 52 facing the diaphragm 50 with a slight gap of about 0.01 to 0.05 mm, and the microphone case 4 thereof.
8 includes a pair of connection terminals 56 connected to the conductor 54 on the side opposite to the through hole 44, and an insulating member 58 that insulates the pair of connection terminals 56 from each other, that is, a condenser microphone. When the diaphragm 50 is vibrated, the heart sound from the skin 11 is detected and a heart sound signal representing the heart sound is output.

The surface of the dish-shaped member 32 on the side opposite to the side in contact with the vibration absorber 28 is in contact with the weight 60. The weight 60 is made of a material having a relatively high specific gravity such as lead, copper, or iron, and preferably has a weight of about 80 to 150 g.
It has a flat cylindrical shape whose diameter is equal to the diameter of the edge portion 29 of the dish-shaped member 32, and is the center of the surface opposite to the side in contact with the dish-shaped member 32, that is, the surface facing the inner flat surface 62 of the upper housing 12. A vibration absorber 64 made of the same material as the vibration absorber 28 is fixedly provided between the portion and a central portion of the inner flat surface 62 of the upper housing.
The weight 60 is sandwiched between the vibration absorber 28 and the vibration absorber 64 in a floating state, and the positional displacement of the weight 60 is suppressed. Since the weight 60 is made of a material having a relatively heavy specific gravity as described above and has the weight described above, noise from the outside of the body is shielded by the weight 60, and the heart sound detecting device 10 has a suitable constant value. Since the living body skin 11 is pressed by the pressing force of
A stable and reproducible heart sound signal can be detected. further,
Since the resonance frequency of the whole heart sound detection device 10 is in a lower frequency range than the frequency of the heart sound, the energy of the heart sound from the inside of the living body is not consumed as the energy for vibrating the body sound detection device 10, and therefore the heart sound is Microphone 4
Efficiently detected at 0.

The diameter of the weight 60 and the diameter of the edge portion 29 of the dish-shaped member 32 are set to be slightly shorter than the inner diameter of the housing 22 as described above, and the weight 60 and the upper housing 1 are further provided.
Since the vibration absorber 64 is fixedly provided between the housing 22 and the weight 22, and the weight 60 and the dish-shaped member 32, a closed air chamber 66 is formed. Environmental noise from outside the living body is reflected at the boundary surface between the closed air chamber 66 and the housing 22 or is absorbed without resonating in the air chamber 66, so that the environmental noise is absorbed inside the air chamber 66. Detection by the provided microphone 40 is suppressed.

Further, the tapered sound collecting hole 34 and the accommodating chamber 42
Is communicated with a tapered sound collecting hole 34 at one end and a communication passage 68 having the other end communicated with the housing chamber 42. Further, the insulating member 58 has an air pressure adjustment penetrating the insulating member 58. Since the hole 70 is provided and the pressures on both sides of the diaphragm 50 are adjusted to be the same, only the fluctuation component (AC component) of the pressure in the tapered sound collecting hole 34 is detected by the microphone 40. .

The conducting wire 54 connected to the connection terminal of the microphone 40 passes through a hole 72 provided in a part of the dish-shaped member 32 and the weight 60, and a through hole 74 provided in the side surface of the housing 22. It is connected to the connection terminal 76 at the tip of the cord 75 inserted into.

A soft sheet 77 is attached to the surface of the flexible resin film 36 which is in contact with the skin 11. The soft sheet 77 constitutes the mounting sheet of this embodiment, has a thickness of, for example, about 0.5 to 2.0 mm, and is 1 ° to about 1 ° with a JIS A type spring hardness tester. It is an elastic body or a gel-like viscous body that has a hardness of about 15 ° and is substantially the same as the skin of a human body, and has the same density as the skin 11. Due to the presence of the soft sheet 77, it is possible to reduce the discomfort when the heart sound detecting device 10 is mounted on the skin 11, and to cover the body hair 78 on the skin 11, that is, the flexible resin film 36 and the skin. Since an air layer is not formed between the heartbeat sound from inside the living body 11 and the heart sound from inside the living body, it is not reflected by the air layer. Further, since the soft sheet 77 has a density substantially similar to that of the skin 11, it can be considered that the specific acoustic resistance R of the soft sheet 77 and the specific acoustic resistance R of the skin 11 are relatively matched. Therefore, there is little reflection at the boundary surface between the skin 11 and the soft sheet 77, and the soft sheet 77 is relatively thin as described above.
Since the absorption of the heart sound in 7 is small, the reduction of the heart sound propagating from the skin 11 into the heart sound detecting device 10 is suppressed.

Further, the bottom portion 18 of the lower housing 14
An annular soft sheet 80 made of the same material as that of the soft sheet 77 and substantially the same as the skin side surface of the bottom portion 18 is attached to the skin 11 side surface. The annular soft sheet 80 reduces a feeling of strangeness when the heart sound detecting device 10 is mounted on the skin 11, and also the lower housing 1
As compared with the case where 8 is directly attached to the skin 11, the environmental noise that propagates through the living tissue and reaches the heart sound detecting device 10 is blocked more preferably. Further, even if there is some unevenness on the skin 11 at the site where the heart sound detecting device 10 is attached, the soft sheet 80 is in close contact with the skin 11, so the heart sound detecting device 10
It is prevented that the mounting position of the is shifted.

FIG. 3 is a diagram for explaining that the heart sounds detected by the heart sound detecting device 82 are reduced by the formation of an air layer in the conventional heart sound detecting device 82 to which the soft sheet 77 is not attached. The state where the heart sound detecting device 82 is attached to a predetermined heart sound detecting portion on the skin 11 of the living body is shown.

In FIG. 3, due to the body hair 78 on the skin 11, the contact surface 84 with the skin of the heart sound detecting device 82 and the skin 11 are detected.
An air layer 86 is formed between and. In this state, when the heart sound wave 88 travels from the skin 11 to the air layer 86 and when it travels from the air layer 86 to the heart sound detecting device 82, a part thereof is reflected as a reflected wave 90, so that the heart sound detecting device 82 detects it. As a result, the number of the sound waves 88 to be generated decreases.

As described above, according to this embodiment, the housing 2
Since the air chamber 66 that is closed is provided between the microphone 2 and the microphone 40, environmental noise that propagates through the air from outside the body and reaches the housing 22 is reflected or absorbed by the air chamber 66, and the air Since the chamber 66 is hermetically closed, environmental noise does not resonate in the air chamber 66. Therefore, the diaphragm 50 of the microphone 40 located inside the air chamber 66 in the housing 22 vibrates due to the environmental noise. It is suppressed to be made.

Further, according to this embodiment, the environmental noise is transmitted through the air, or from the air through the living tissue,
Even when transmitted to the housing 22, the vibration absorbing sheet 4
Since the environmental noise is absorbed by 6, the vibration of the diaphragm 50 of the microphone 40 due to the environmental noise is suppressed. On the other hand, the heart sound passes from the opening of the lower housing 14 through the through hole 44 of the vibration absorbing sheet 46 positioned substantially horizontally with respect to the opening surface, and is fixed to the surface of the through hole 44 opposite to the skin 11 of the living body. The diaphragm 50 of the microphone 40 thus generated can be vibrated. Therefore, the environmental noise component contained in the heart sound signal output from the microphone 40 can be reduced.

Further, according to the present embodiment, the environmental noise is transmitted through the air, or from the air through the living tissue,
Even when the noise is transmitted to the housing 22, the weight 60 provided inside the housing 22 shields the environmental noise.
Vibration of the diaphragm 50 of the microphone 40 due to environmental noise is suppressed. Further, the weight 60 can set the resonance frequency of the entire heart sound detecting device 10 to a lower frequency side than the heart sound, and the heart sound is prevented from resonating in the heart sound detecting device 10, so that the heart sound can be efficiently emitted. Further, since the heart sound detecting device 10 presses the skin 11 with a suitable constant pressure, the heart sound signal can be detected stably and with reproducibility.

Further, according to the present embodiment, the heart sound detecting device 1
When 0 is attached to the skin 11 of the living body, the bottom portion 18 on the opening side of the housing 22 that is open in one direction is brought into contact with the skin 11 of the living body, so that environmental noise propagated in the living tissue is bottom portion 18. Since it is blocked at the contact surface with the skin 11 of
Vibration of the diaphragm 50 of the microphone 40 due to environmental noise is suppressed.

Further, according to this embodiment, since the vibration absorbers 28 and 64 are provided between the housing 22 and the weight 60, the displacement of the weight 60 is suppressed and the vibration absorber 28 is suppressed. , 64 can also absorb the environmental noise propagated to the housing.

Further, according to this embodiment, the lower housing 1
Since the soft sheet 80 is provided on the bottom portion 18 of No. 4, the environmental noise propagating through the living tissue is more preferably blocked at the contact surface of the bottom portion 18 with the skin. In addition, the heart sound detection device 10
There is also an advantage that the mounting position of the is properly prevented.

Although one embodiment of the present invention has been described above with reference to the drawings, the present invention can be applied to other modes.

For example, in the above-described embodiment, the capacitance type microphone is used as the microphone 40, but a piezoelectric type microphone or a moving coil type microphone may be used.

Besides, the present invention can be variously modified without departing from the spirit thereof.

[Brief description of drawings]

FIG. 1 is a perspective view of a heart sound detection device 10 according to an embodiment of the present invention.

FIG. 2 is a sectional view of a heart sound detecting device 10 of the embodiment shown in FIG.

FIG. 3 is a diagram illustrating a state in which a part of the heart sound wave from the inside of the living body is reflected by the air layer.

[Explanation of sign]

10: Heart sound detector 12: Upper housing 14: Lower housing 18: bottom 22: Case 28: Vibration absorber 40: Microphone 44: Through hole 46: Vibration absorbing sheet 50: diaphragm 60: Weight 64: Vibration absorber 66: Air chamber 77, 80: Soft sheet

Claims (6)

[Claims] 1. A housing which is open in one direction,
Provided in the housing with a vibration plate, comprising a microphone for converting the vibration of the vibration plate into an electric signal, mounted on the skin of the living body, to detect the body sound generated inside the living body, A living body sound detecting device for outputting a living body sound signal representing the living body sound from the microphone, characterized in that a sealed air chamber is provided between the housing and the microphone. . 2. A housing which is open in one direction,
Provided in the housing with a vibration plate, comprising a microphone for converting the vibration of the vibration plate into an electric signal, mounted on the skin of the living body, to detect the body sound generated inside the living body, A body sound detecting device for outputting a body sound signal representing the body sound from the microphone, the body sound detecting apparatus having a through hole smaller than a surface of the microphone on the skin side of the body, and being substantially with respect to an opening surface of the housing. A vibration absorbing sheet horizontally provided in the housing is included, and the microphone is fixed to a position on the surface of the vibration absorbing sheet opposite to the skin of the living body to close the through hole. Body sound detection device. 3. A housing opening in one direction,
A microphone that is provided inside the housing and that converts the vibration of the diaphragm into an electric signal; and is attached to the skin of a living body to detect a body sound generated inside the body, and the body sound is output from the microphone. A living body sound detecting device for outputting a living body sound signal representing the living body sound detecting device, characterized in that a weight is provided in the housing. 4. The body sound detecting device according to claim 3, further comprising a vibration absorber between the housing and the weight. 5. A microphone having a diaphragm for converting the vibration of the diaphragm into an electric signal, which is mounted on the skin of a living body to detect a body sound generated inside the living body, and the microphone. A body sound detecting device for outputting a body sound signal representative of the body sound, wherein the microphone is housed so as to be opened in one direction so that a surface of the outer periphery on the opening side is brought into contact with the skin of the body. A living body sound detecting device comprising a housing. 6. The soft sheet is provided on a surface of the housing which is brought into contact with the living body.
Body sound detection device.