JP6827271B2 - Biological sound acquisition device - Google Patents

Description

The present invention relates to the technical field of a biological sound acquisition device such as an electronic stethoscope.

In this type of device, a technique for reducing noise when acquiring biological sound has been proposed. For example, Patent Document 1 discloses a technique of connecting a sensor support portion and an operation portion via a noise absorbing material in order to reduce noise transmitted from a finger of a doctor or the like.

Japanese Unexamined Patent Publication No. 2012-090909

According to the research by the inventor of the present application, it has been found that most of the environmental sound (ambient noise) is transmitted to the sensor unit via the person to be measured. Therefore, as described in Patent Document 1, it cannot be said that the noise can be sufficiently reduced only by reducing the noise transmitted from the measuring side such as a doctor.

The above-mentioned problems are given as an example of the problems to be solved by the present invention. An object of the present invention is to provide a biological sound acquisition device capable of effectively reducing noise.

In order to solve the above-mentioned problems, the first biological sound acquisition device of the present invention has a main body, an acquisition unit for acquiring biological sound, a front surface in contact with or close to the living body, and the acquisition unit in the main body. A diaphragm having a rear surface for holding is provided, and the main body portion has a connecting portion for communicating the rear surface of the diaphragm with the outside air outside the main body portion.

In order to solve the above-mentioned problems, the second biological sound acquisition device of the present invention has a main body, an acquisition unit for acquiring biological sound, a front surface in contact with or close to the living body, and the acquisition unit in the main body. The main body portion includes a diaphragm having a rear surface for holding, and the main body portion has a transmission portion for transmitting external noise generated outside the main body portion on the rear surface of the diaphragm.

The actions and other gains of the present invention will be apparent from the embodiments described below.

It is a block diagram which shows the structure of the electronic stethoscope which concerns on Example. It is sectional drawing which shows the main part of the chest piece of the electronic stethoscope which concerns on Example. It is a perspective view which shows the structure of the main body part. FIG. 2 is a cross-sectional view taken along the line AA'of FIG. It is a conceptual diagram which shows how the external noise transmitted to the front surface and the rear surface of a diaphragm is canceled out. It is a graph which shows the difference in the intensity of external noise depending on the presence or absence of a communication hole. It is sectional drawing which shows the 1st modification of the main body part. It is sectional drawing which shows the 2nd modification of the main body part.

An embodiment according to the biological sound acquisition device of the present invention will be described.

<1>
In the first biological sound acquisition device according to the present embodiment, in order to solve the above-mentioned problems, the main body, the acquisition unit for acquiring the biological sound, the front surface in contact with or close to the living body, and the acquisition unit are the main body. The main body portion includes a diaphragm having a rear surface to be held inside the portion, and the main body portion has a connecting portion for communicating the rear surface of the diaphragm with the outside air outside the main body portion.

In the first biological sound acquisition device according to the present embodiment, the rear surface of the diaphragm (that is, the surface opposite to the front surface in contact with or close to the living body) and the external air are communicated by the communication portion of the main body portion. There is. As a result, external noise generated outside the main body is transmitted to the rear surface of the diaphragm via the connecting portion.

In addition, external noise generated outside the main body is also transmitted to the front surface of the diaphragm via the living body. Then, external noise is transmitted to the diaphragm from the front surface and the rear surface, respectively. Therefore, the external noise transmitted to the diaphragm is canceled by the noise transmitted to the front surface and the noise transmitted to the rear surface, and is reduced to extremely small noise. Therefore, the external noise acquired by the acquisition unit can be effectively reduced.

On the other hand, the biological sound to be acquired is transmitted from the front surface of the diaphragm via the living body, and is not transmitted from the rear surface. Therefore, the biological sound is not canceled out like the external noise, and is surely acquired by the acquisition unit.

As a result of the above, according to the first biological sound acquisition device according to the present embodiment, it is possible to suitably acquire biological sound while reducing external noise.

<2>
In one aspect of the biological sound acquisition device according to the present embodiment, the main body portion has a hole as the communication portion on the top surface opposite to the bottom surface holding the diaphragm when viewed from the acquisition portion. ing.

According to this aspect, since a hole as a connecting portion is provided on the top surface of the main body portion, external noise can be effectively reduced as described above. Further, the hole provided on the top surface of the main body can also be used as a hole for arranging various wires. Therefore, the structure of the device can be simplified.

<3>
In another aspect of the biological sound acquisition device according to the present embodiment, a grip portion that the user touches is further provided.
The grip portion has a second connecting portion that accommodates the main body portion and connects the external air outside the grip portion with the external air outside the main body portion.

According to this aspect, the external air outside the grip portion and the external air outside the main body portion are communicated with each other by the second connecting portion included in the grip portion. As a result, the external noise generated outside the grip portion is transmitted to the outside air outside the main body portion via the second connecting portion. The external noise transmitted to the external air outside the main body is further transmitted to the rear surface of the diaphragm via the connecting portion.

As a result, external noise is transmitted to each of the front surface and the rear surface of the diaphragm, and it is possible to effectively reduce the noise by canceling each other out.

<4>
In the embodiment further provided with the grip portion described above, the grip portion may have a plurality of holes as the second connecting portion in different directions when viewed from the acquisition portion.

In this case, since the plurality of holes are provided in different directions when viewed from the acquisition portion, external noise generated at a plurality of locations (that is, different directions) can be suitably transmitted to the rear surface of the diaphragm. Further, even if a part of the holes is closed by the user gripping the grip portion, external noise can be suitably transmitted through the other holes. Therefore, it is possible to effectively reduce noise.

<5>
The second biological sound acquisition device according to the present embodiment has a diaphragm having a main body, an acquisition unit for acquiring biological sound, a front surface in contact with or close to the living body, and a rear surface for holding the acquisition unit in the main body. The main body has a transmission portion on the rear surface of the diaphragm for transmitting external noise generated outside the main body.

In the second biological sound acquisition device according to the present embodiment, the external noise generated outside the main body is transmitted to the rear surface of the diaphragm by the transmission unit included in the main body. The transmission portion is composed of, for example, an elastic body filled in a space extending from the outside of the main body to the rear surface of the diaphragm.

In addition, external noise generated outside the main body is also transmitted to the front surface of the diaphragm via the living body. Then, external noise is transmitted to the diaphragm from the front surface and the rear surface. Therefore, the external noise transmitted to the diaphragm is canceled by the noise transmitted to the front surface and the noise transmitted to the rear surface, and is reduced to extremely small noise. Therefore, the external noise acquired by the acquisition unit can be effectively reduced.

On the other hand, the biological sound to be acquired is transmitted from the front surface of the diaphragm via the living body, and is not transmitted from the rear surface. Therefore, the biological sound is not canceled out like noise, and is surely acquired by the acquisition unit.

As a result of the above, according to the second biological sound acquisition device according to the present embodiment, it is possible to suitably acquire biological sound while reducing ambient noise.

An embodiment of the biological sound acquisition device of the present invention will be described with reference to the drawings. In this embodiment, an electronic stethoscope is given as an example of a biological sound acquisition device.

<Configuration of electronic stethoscope>
The configuration of the electronic stethoscope according to the embodiment will be described with reference to FIG. FIG. 1 is a block diagram showing a configuration of an electronic stethoscope according to an embodiment.

In FIG. 1, the electronic stethoscope 100 includes a vibration sensor 11, a bandpass filter 12, a cutoff frequency adjusting unit 13, a power amplifier 14, a volume adjusting unit 15, and an earphone 16.

The vibration sensor 11 is a sensor capable of acquiring a biological sound (for example, a respiratory sound) emitted from a living body. The biological sound signal indicating the biological sound acquired by the vibration sensor is output to the bandpass filter 12. The vibration sensor is a specific example of the “acquisition unit”.

The bandpass filter 12 is a filter that passes only signals in a desired frequency band among the biological sound signals input from the vibration sensor 11. The cutoff frequency cut off by the bandpass filter 12 is adjusted by the cutoff frequency adjusting unit 13. The biological sound signal that has passed through the bandpass filter 12 is output to the power amplifier 14.

The power amplifier 14 changes and outputs the power (intensity) of the biological sound signal according to the set gain. The gain of the power amplifier 14 is adjusted by the volume adjusting unit 15. The biological sound signal that has passed through the power amplifier is output to the earphone 16.

The earphone 16 is configured to be able to output the biological sound indicated by the biological sound signal as a sound.

Next, the configuration of the chest piece (the portion pressed against the living body for auscultation) of the electronic stethoscope 100 will be described with reference to FIGS. 2 to 4. FIG. 2 is a cross-sectional view showing a main part of a chest piece of an electronic stethoscope according to an embodiment, and FIG. 3 is a perspective view showing a configuration of a main body part. Further, FIG. 4 is a cross-sectional view taken along the line AA'of FIG.

In FIG. 2, the vibration sensor 11 is held on the diaphragm 21. The diaphragm 21 is made of silicon rubber, urethane rubber, or the like, and is connected to the main body 22 that houses the vibration sensor 11. The lower surface of the diaphragm 21 in the drawing is a specific example of the “front surface”, and the upper surface is a specific example of the “rear surface”. Further, the lower surface of the main body 22 in the drawing is a specific example of the “bottom surface”, and the upper surface is a specific example of the “top surface”. The vibration sensor 11, the diaphragm 21, and the main body 22 form a vibration detection module.

As shown in FIG. 3, a first connecting hole 22a is formed on the top surface of the main body 22. The first contact hole 22a is a specific example of the "communication section", and connects the rear surface of the diaphragm 21 with the outside air outside the main body section 22. Further, the first connecting hole 22a also has a function of guiding a signal line for transmitting an electric signal (biological sound signal) output from the vibration sensor 11 to the outside of the vibration detection module.

Returning to FIG. 2, the vibration detection module is fixed to the grip portion 24 by the vibration-proof damper 23. Unnecessary vibration (that is, noise) may be generated when the grip portion 24 is touched by, for example, a listener or an auscultated person, but by providing the anti-vibration damper 23, the unnecessary vibration is propagated to the vibration detection module. Can be suppressed.

As shown in FIG. 4, a plurality of second connecting holes 24a are formed in the grip portion 24. The second connecting hole 24a is a specific example of the "second connecting portion", and connects the outside air outside the grip portion 24 with the outside air outside the main body portion 22. The second communication hole 24a is opened in eight directions with the vibration sensor 11 as the center. The second communication hole example is just an example, and may not be in eight directions, and the number may not be eight.

If a plurality of second communication holes 24a are formed, it is possible to communicate with external air in a plurality of directions different from each other when viewed from the vibration sensor 11. Further, even if a part of the second contact hole 24a is blocked by the auscultator gripping the grip portion 24, the contact with the outside air is maintained through the other second contact hole 24a. Can be done.

<Effect of reducing external noise>
Next, the effect of reducing external noise exhibited by the electronic stethoscope 100 according to the present embodiment will be described with reference to FIG. FIG. 5 is a conceptual diagram showing how the external noise transmitted to the front and rear surfaces of the diaphragm is canceled out.

As shown in FIG. 5, external noise (for example, environmental sound) is transmitted from the living body 200 to the front surface of the diaphragm 21 together with the living body sound to be acquired. Therefore, if no measures are taken, a lot of noise will be acquired mixed with the biological sound, and there is a possibility that the diagnosis based on the biological sound cannot be performed accurately.

However, in the present embodiment, as described above, the first communication hole 22a is formed in the main body portion 22, and the second communication hole 24a is formed in the grip portion 24. Therefore, the external noise is also transmitted to the rear surface of the diaphragm 21 through the second connecting hole 24a and the first connecting hole 22a.

Then, the same external noise is transmitted in the same phase to each of the front surface and the rear surface of the diaphragm 21, so that the external noise is canceled out. That is, the vibration caused by the external noise is weakened. Therefore, the external noise acquired by the vibration sensor 11 becomes small.

On the other hand, the biological sound is transmitted only from the front surface of the diaphragm 21. Therefore, the biological sound is acquired by the vibration sensor 11 without being canceled out like the external noise. As a result, in the vibration sensor, external noise is reduced, and it becomes possible to suitably acquire biological sound.

In the following, a specific example of the effect on noise reduction will be described with reference to FIG. FIG. 6 is a graph showing the difference in the intensity of external noise depending on the presence or absence of the connecting hole.

In FIG. 6, the inventor of the present application conducted an experiment in which a vibration detection module was pressed against a living body in a state where white noise was output from an external speaker, and the sound acquired at that time was measured. More specifically, the sound acquired in a state where the first connecting hole 22a is closed with clay (that is, a state simulating a configuration in which the first connecting hole 22a is not formed) and a state where the first connecting hole 22a is not formed is produced. Measured separately.

As a result, it was demonstrated that the acceleration (that is, the intensity of vibration) was clearly smaller in the sound measured in the unclosed state than in the state in which the first connecting hole 22a was closed. That is, it was proved that the noise reduction function according to this embodiment is effective.

<Modification example>
Next, a modification of the vibration detection module will be described with reference to FIGS. 7 and 8. FIG. 7 is a cross-sectional view showing a first modification of the main body. Further, FIG. 8 is a cross-sectional view showing a second modified example of the main body portion.

In the first modification shown in FIG. 7, the moisture permeable waterproof sheet 30 is arranged in the first connecting hole 22a. The moisture-permeable waterproof sheet has the property of allowing air to pass through while being impermeable to water. For this reason,
It is possible to exert a waterproof function while transmitting external noise to the inside of the main body 22. That is, external noise can be canceled out and reduced, and the reliability of the device can be improved.

In the second modification shown in FIG. 8, the elastic body 40 is filled in the entire inside of the main body 22 including the first connecting hole 22a. The elastic body 40 may be made of, for example, silicone or the like. With this configuration, it is possible to more reliably prevent water from entering the main body 22. In addition, external noise is also transmitted to the rear surface of the diaphragm 21 via the elastic body 40. Therefore, it is possible to cancel out the external noise transmitted from each of the front surface and the rear surface of the diaphragm 21 and preferably reduce the external noise.

The present invention is not limited to the above-described embodiment, and can be appropriately modified within the scope of claims and within the scope not contrary to the gist or idea of the invention that can be read from the entire specification, and the acquisition of biological sound accompanied by such modification. The device is also included in the technical scope of the present invention.

11 Vibration sensor 12 Bandpass filter 13 Cutoff frequency adjustment unit 14 Power amplifier 15 Volume adjustment unit 16 Earphone 21 Diaphragm 22 Main body 22a 1st communication hole 23 Anti-vibration damper 24 Grip part 24a 2nd communication hole 30 Moisture permeable waterproof sheet 40 Elastic Body 100 Electronic stethoscope 200 Living body

Claims (3)

With the main body
The acquisition unit that acquires biological sounds,
A diaphragm having a front surface that comes into contact with or close to a living body and a rear surface that holds the acquisition portion inside the main body portion.
Equipped with a grip that the user can touch
The main body portion has a connecting portion that connects the rear surface of the diaphragm and the external air outside the main body portion.
The biological sound acquisition device, characterized in that the grip portion accommodates the main body portion and has a second communication portion for communicating the external air outside the grip portion with the external air outside the main body portion. The living body according to claim 1, wherein the main body portion has a hole as the connecting portion on the top surface opposite to the bottom surface holding the diaphragm when viewed from the acquisition portion. Sound acquisition device. The biological sound acquisition device according to claim 1, wherein the grip portion has a plurality of holes as the second communication portion in different directions when viewed from the acquisition portion.