JP7507653B2 - Electronic stethoscope - Google Patents

Description

The present invention relates to an electronic stethoscope.

An electronic stethoscope converts biological sounds into biological sound signals using sensor elements such as a microphone placed inside the sound collection unit, and outputs the signals to earphones or the like after signal processing such as amplification and filtering is performed by a signal processing circuit. The power source that drives the sensor elements and signal processing circuit is supplied from a built-in battery (Patent Document 1).

Japanese Patent Publication No. 61-11099

However, if an electronic stethoscope is equipped with a highly sensitive sensor element to detect small sounds and vibrations generated within the body, it will also detect noise from the surrounding environment. For example, noise emitted from commercial power wiring in a room is received by the electrically floating subject or stethoscope, and is detected by the sensor element via the subject or stethoscope. The present invention aims to provide an electronic stethoscope that can reduce the influence of noise from the surrounding environment that is detected by the sensor element via the subject, etc.

In order to achieve the above-mentioned object, the invention of claim 1 of the present application is an electronic stethoscope that is powered by an internal battery, converts biological sounds collected by a sound collection unit into biological sound signals by a sensor element, and processes the biological sound signals by a signal processing circuit, characterized in that a first electrode is placed on the surface of the sound collection unit that comes into contact with the subject , and the high power supply potential or low power supply potential set in the signal processing circuit is varied in synchronization with the change in potential detected by the first electrode, thereby reducing noise superimposed on the biological sound signal via the subject .

The invention of claim 2 of the present application is characterized in that, in the electronic stethoscope described in claim 1, the sound collection unit is equipped with a gripping portion, a second electrode is placed on the surface of the gripping portion held by the stethoscope, and the high power supply potential or low power supply potential set in the signal processing circuit is changed in synchronization with the change in potential detected by the first electrode and the second electrode, thereby reducing noise superimposed on the biological sound signal via both the stethoscope and the subject .

The invention according to claim 3 of the present application is characterized in that in the electronic stethoscope according to claim 1 or 2, the first electrode is made of conductive gel.

The electronic stethoscope of the present invention is configured so that the first electrode can come into contact with the subject's body surface during auscultation, and the signal detected by the first electrode is superimposed on a signal wiring that is at a predetermined constant potential of the signal processing circuit, thereby making the potential of the subject the same as the constant potential of the signal processing circuit. As a result, even if noise via the subject is superimposed on the biological sound signal obtained from the subject, the predetermined constant potential of the signal processing circuit also fluctuates along with the noise, reducing the effect of the noise and making it possible to detect small biological sounds.

Furthermore, by configuring the stethoscope to be able to come into contact with the second electrode during auscultation and superimposing the signal detected by the second electrode on a signal wiring that is at a predetermined constant potential of the signal processing circuit, the potential of the stethoscope and the constant potential of the signal processing circuit can be made the same potential. As a result, even if noise via the stethoscope is superimposed on the biological sound signal obtained from the stethoscope, the predetermined constant potential of the signal processing circuit also fluctuates along with the noise, reducing the effect of the noise and making it possible to detect even quieter biological sounds.

It is preferable to form the first electrode that comes into contact with the subject from a conductive gel, as this allows for seamless contact with the subject's body surface and reduces the effects of noise transmitted through the air.

1 is an explanatory diagram of an electronic stethoscope according to a first embodiment of the present invention; 1 is a partial cross-sectional view of an electronic stethoscope according to a first embodiment of the present invention. FIG. 4 is an explanatory diagram of an electronic stethoscope according to a second embodiment of the present invention. FIG. 4 is a partial cross-sectional view of an electronic stethoscope according to a second embodiment of the present invention.

The electronic stethoscope of the present invention is an electronic stethoscope that is powered by a built-in battery, converts biological sounds into biological sound signals using a sensor element such as a microphone arranged in the sound collection section, and further performs signal processing such as amplification and filtering on this biological sound signal in a signal processing circuit, and outputs it to an ear tip or the like. In particular, the electronic stethoscope of the present invention is configured to include a first electrode in the sound collection section, or further includes a second electrode in the gripping section of the sound collection section, thereby reducing the influence of noise in signal processing of biological sound signals on which noise via the subject or the stethoscope is superimposed. Below, an embodiment of the present invention will be described in detail.

Figure 1 is an explanatory diagram of the electronic stethoscope of the first embodiment, and is a block diagram of the main components. The electronic stethoscope of this embodiment, like a general electronic stethoscope, is equipped with a sound collection unit 1 that contacts the body surface of the person to be stethographed to collect biological sounds, a sensor element 2 such as a microphone inside the sound collection unit 1 that converts biological sounds into biological sound signals, a signal processing circuit 3 that receives the biological sound signals output from the sensor element 2 and performs signal processing such as amplification and filtering, and a battery 4 that supplies power to the signal processing circuit 3 and the sensor element 2. In particular, the electronic stethoscope of this embodiment has a first electrode 5 disposed on the surface part of the sound collection unit 1 that contacts the person to be stethographed. 6 is an output terminal for the signal-processed biological sound signal output from the signal processing circuit 3, and like a general electronic stethoscope, it is connected to an earphone, speaker, ear tip, etc. (not shown) so that the stethoscope can hear the biological sound signal.

The power supply potential supplied from the battery 4 is applied to the signal processing circuit 3 and is supplied either directly or boosted to the desired circuit elements that make up the signal processing circuit 3. In an electronic stethoscope that incorporates the battery 4, a constant potential such as a low power supply potential or a high power supply potential is set in the signal processing circuit 3.

In the example shown in FIG. 1, the negative pole of the battery 4 is connected to one terminal of the signal processing circuit 3, and the positive pole is connected to the other terminal of the signal processing circuit 3. Within the signal processing circuit 3, the signal wiring connected to the negative pole of the battery 4 is at a low power supply potential, and the signal wiring connected to the positive pole of the battery 4 is at a high power supply potential. Since the first electrode 5 is connected to the negative pole of the battery 4, the first electrode 5 is configured to be connected to the signal wiring at the low power supply potential.

When a stethoscope is operated by a stethoscope performer, power is supplied from the battery 4 to the signal processing circuit 3 and other components. In this state, when the sound collector 1 is brought into contact with the body surface of the person being stethoscope, the sensor element 2 converts the body sound into a body sound signal and outputs it to the signal processing circuit 3. During auscultation, the first electrode 5 is also in contact with the body surface of the person being stethoscope.

If there is an environmental noise source consisting of an unnecessary fluctuating electric field around the subject, the subject will receive the noise radiated from that noise source. For example, if there is a commercial power line, the subject will receive the noise radiated from the commercial power line. As a result, the sensor element 2 detects the subject's biological sounds superimposed with noise transmitted through the subject, and converts them into a biological sound signal superimposed with noise. This biological sound signal is input to the signal processing circuit 3 for signal processing.

Meanwhile, the first electrode 5, made of a conductive material, detects the fluctuation in the potential of the subject's body surface caused by noise received by the subject. As shown in FIG. 1, this first electrode 5 is connected to the negative pole of the battery 4 and to a signal wiring that is at the low power supply potential of the signal processing circuit 3 that is connected to this negative pole. In an electronic stethoscope that has a built-in battery 4, a predetermined constant potential is set by the potential supplied from the battery 4, so when the first electrode 5 is connected to the signal wiring that is at the low power supply potential, the low power supply potential of the signal processing circuit 3 fluctuates in synchronization with the change in potential detected by the first electrode 5.

By varying the low power supply potential in this way, it is possible to perform the desired signal processing while reducing the effects of noise caused by the subject.

The biological sound signal that has undergone a predetermined signal processing in the signal processing circuit 3 is output to the output terminal 6. The auscultator can listen to the biological sound signal from an earphone or the like connected to the output terminal 6.

Figure 2 is an explanatory diagram of an electronic stethoscope in which the first electrode 5 is made of conductive gel, showing a cross-sectional view of the sound collection unit 1. The electronic stethoscope shown in Figure 2 is equipped with a bell-shaped sound collection unit 1, and a first electrode 5 made of conductive gel is formed around the entire periphery of the opening of this sound collection unit 1. This first electrode 5 is connected to the signal processing circuit 3 via the inside of the sound collection unit 1.

By forming the first electrode 5 from a conductive gel in this way, the sound collection unit 1 can be brought into contact with the subject's body surface without any gaps, and in addition to reducing noise transmitted through the subject by the first electrode 5, it is also possible to reduce the effects of noise that enters the sound collection unit 1 through the air from around the subject.

Next, the second embodiment will be described. In the first embodiment described above, an electronic stethoscope capable of reducing the influence of noise through the stethoscope has been described, but noise radiated from the surrounding environment is received not only by the stethoscope but also by the stethoscope. The electronic stethoscope of this embodiment is an electronic stethoscope that can reduce the influence of noise through the stethoscope. FIG. 3 is an explanatory diagram of the electronic stethoscope of the second embodiment, and is a block diagram of the main components. As in the first embodiment described above, it is equipped with a sound collection unit 1 that contacts the body surface of the stethoscope to collect biological sounds, a sensor element 2 such as a microphone that converts biological sounds into biological sound signals inside the sound collection unit 1, a signal processing circuit 3 that inputs the biological sound signal output from the sensor element 2 and performs signal processing such as amplification and filtering, and a battery 4 that supplies power to the signal processing circuit 3 and the sensor element 2. In addition, the electronic stethoscope of this embodiment has a first electrode 5 arranged on the surface part of the sound collection unit 1 that contacts the stethoscope, and a second electrode 7 arranged on the surface part that contacts the stethoscope holding the sound collection unit 1. 6 is an output terminal for the signal-processed biological sound signal output from the signal processing circuit 3, and is connected to an earphone, speaker, ear tip, etc. (not shown) so that the auscultator can hear the biological sound signal.

The power supply potential supplied from the battery 4 is applied to the signal processing circuit 3 and is supplied either directly or boosted to the desired circuit elements that make up the signal processing circuit 3. In an electronic stethoscope that incorporates the battery 4, a constant potential such as a low power supply potential or a high power supply potential is set in the signal processing circuit 3.

In the example shown in FIG. 3, the negative pole of the battery 4 is connected to one terminal of the signal processing circuit 3, and the positive pole is connected to the other terminal of the signal processing circuit 3. Within the signal processing circuit 3, the signal wiring connected to the negative pole of the battery 4 is at a low power supply potential, and the signal wiring connected to the positive pole of the battery 4 is at a high power supply potential. Since the first electrode 5 and the second electrode 7 are both connected to the negative pole of the battery 4, the first electrode 5 and the second electrode 7 are connected to the signal wiring at the low power supply potential.

When a stethoscope is operated by a stethoscope performer, power is supplied from the battery 4 to the signal processing circuit 3 etc. When the stethoscope is held by the stethoscope performer in this state (corresponding to the gripping part) and the sound collecting part 1 is brought into contact with the body surface of the person being stethoscope, the sensor element 2 converts the body sound into a body sound signal and outputs it to the signal processing circuit 3. During auscultation, the first electrode 5 is in contact with the body surface of the person being stethoscope and the second electrode 7 is in contact with the stethoscope.

If there is an environmental noise source consisting of an unnecessary fluctuating electric field around the person being stethoscope and the stethoscope, the person being stethoscope and the stethoscope will receive the noise radiated from the noise source. For example, if there is a commercial power supply line, the person being stethoscope and the stethoscope will receive the noise radiated from the commercial power supply line. As a result, the sensor element 2 detects the body sounds of the person being stethoscope that are superimposed with noise via the person being stethoscope. Furthermore, the sensor element 2 detects the noise received by the stethoscope through the sound collection unit 1. In this way, the sensor element 2 detects the body sounds superimposed with noise via the person being stethoscope and the stethoscope, and converts them into a body sound signal superimposed with noise. This body sound signal is input to the signal processing circuit 3, where it is processed.

On the other hand, the first electrode 5 made of a conductive material detects the fluctuation of the potential of the subject's body surface caused by the noise received by the subject. The second electrode 7 detects the fluctuation of the potential of the subject caused by the noise received by the subject. As shown in FIG. 3, the first electrode 5 and the second electrode 7 are connected to the negative pole of the battery 4 and to a signal wiring that is the low power supply potential of the signal processing circuit 3 connected to the negative pole. In an electronic stethoscope with a structure that incorporates the battery 4, a predetermined constant potential is set by the potential supplied from the battery 4, so when the first electrode 5 and the second electrode 7 are connected to the signal wiring that is the low power supply potential, the low power supply potential of the signal processing circuit 3 fluctuates in synchronization with the change in potential detected by the first electrode 5 and the second electrode 7.

By varying the low power supply potential in this way, it is possible to perform the desired signal processing while reducing the effects of noise caused by the subject and the auscultator.

The body sound signal that has undergone a predetermined signal processing in the signal processing circuit 3 is output to the output terminal 6. The auscultator can listen to the body sound from an earphone or the like connected to the output terminal 6.

Figure 4 is an explanatory diagram of an electronic stethoscope in which the first electrode 5 is formed from a conductive gel and the second electrode 7 is formed from a metal plate, showing a cross-sectional view of the sound collection unit 1. The electronic stethoscope shown in Figure 4 is equipped with a bell-shaped sound collection unit 1, and a first electrode 5 made of conductive gel is formed around the entire circumference of the opening of the sound collection unit 1. This first electrode 5 is connected to the signal processing circuit 3 via the inside of the sound collection unit 1. In addition, a second electrode 7 made of a metal plate is formed on the surface of the sound collection unit 1 that is held by the stethoscope ...

By forming the first electrode 5 from a conductive gel in this way, the sound collection unit 1 can be brought into contact with the subject's body surface without any gaps, and the first electrode 5 can reduce noise transmitted through the subject, as well as the effects of noise that enters the sound collection unit 1 from the air around the subject.

Although the embodiments of the present invention have been described above, it goes without saying that the present invention is not limited to the above embodiments. For example, the sound collection unit 1 may be a membrane type that is limited to a bell shape. In this case, the first electrode 5 may be placed on the membrane to an extent that does not affect the detection of biological sounds, and may be variously modified to a planar, mesh, stripe, etc. shape. The second electrode 7 formed on the membrane can also function as an electric field shield.

The constant potential of the signal processing circuit connected to the first electrode 5 and the second electrode 7 is not limited to the low power supply potential, but can be changed to a high power supply potential or a reference potential set within the signal processing circuit.

The first electrode 5 and the second electrode 7 can be made of any desired material, and the method of connecting the first electrode 5 and the second electrode 7 to the constant potential of the signal processing circuit 3 can also be changed as appropriate. This connection is not limited to a wired connection, and wireless transmission is also possible.

1: Sound collection unit, 2: Sensor element, 3: Signal processing circuit, 4: Battery, 5: First electrode, 6: Output terminal, 7: Second electrode

Claims (3)

In an electronic stethoscope, power is supplied from a built-in battery, a body sound collected by a sound collecting section is converted into a body sound signal by a sensor element, and the body sound signal is processed by a signal processing circuit,
A first electrode is disposed on a surface of the sound collecting unit that contacts the subject,
An electronic stethoscope characterized by reducing noise superimposed on the biological sound signal via the subject by varying the high power supply potential or low power supply potential set in the signal processing circuit in synchronization with changes in the potential detected by the first electrode . 2. The electronic stethoscope of claim 1,
The sound collection unit includes a grip portion,
A second electrode is placed on a surface of the grip part that is gripped by a stethoscope;
An electronic stethoscope characterized by reducing noise superimposed on the biological sound signal via the subject and the stethoscope by varying the high power supply potential or low power supply potential set in the signal processing circuit in synchronization with changes in the potential detected at the first electrode and the second electrode . 3. The electronic stethoscope according to claim 1,
11. An electronic stethoscope, wherein the first electrode is made of a conductive gel.

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