JP5509422B2 - Body sound acquisition terminal, electronic stethoscope and body sound measuring device - Google Patents

Description

  The present invention relates to a biological sound acquisition terminal, an electronic stethoscope, and a biological sound measurement device that can acquire sound data including an ultra-low frequency sound below the audible range, and in particular, ambient noise, voice, sounds transmitted from fingers of doctors, etc. The present invention relates to a technique for removing noise caused by.

  Stethoscopes are widely used in the medical field. In recent years, an electronic auscultation system using a piezoelectric element (see Patent Document 1), which is convenient for leaving the results of auscultation in data, is also known.

As can be understood from the appearance of a membrane-type stethoscope that cuts the low frequency range from the traditional bell-type stethoscope, a high frequency range is important for auscultation of heart sounds. It is recognized that. This has been followed in electronic stethoscopes, and the sound range of approximately 30 Hz or less is usually cut by filtering, and the sound collection structure is not conscious of the low sound range.
This type of electronic auscultation system comprises a stethoscope 91 and a main unit 92 as shown in FIG. The stethoscope 91 includes a case 911, an auscultation surface (film surface) 912, and a PZT 913 (piezoelectric element). A biological sound such as a heart sound from the stethoscope 91 is sent to the main body device 92 via the signal cable 93, and the main body device 92 can analyze the biological sound.

  When the PZT 913 is provided on the auscultation surface 912, sound from the operator's finger or the like is detected as noise. In the membrane-type stethoscope, the membrane 912 serves as a low-frequency cut filter, so that the PZT 913 has a structure for detecting sounds in the audible frequency except for the very low frequency sound through the space S.

JP2009-273817A

However, since the stethoscope 91 used in the auscultation system of FIG. 16 is a membrane type that detects vibrations transmitted through the space S between the PZT 913 and the auscultation surface (membrane surface) 912 as described above, The detection sensitivity of the frequency band has decreased.
Therefore, if it is possible to efficiently detect and analyze a low frequency range of 1 Hz to several tens of Hz, which has not been attracting attention until now, it is highly expected that new progress will be obtained in analysis such as diagnosis of heart disease. The
An object of the present invention is to provide a biological sound acquisition technique that can acquire sound data including ultra-low frequency sound without being affected by ambient noise, voice, and sound transmitted from a finger of a doctor or the like.

(1)
In a biological sound acquisition terminal comprising a sensor support unit for supporting a sound sensor and an operation unit for holding with a finger,
The sound sensor is composed of a piezoelectric element that directly obtains sound from the human body from the skin without going through an air layer,
The biological sound acquisition terminal, wherein the sensor support unit and the operation unit are coupled via a noise absorbing member.

The biological sound acquisition terminal of the present invention acquires sounds generated by a living body such as heart sounds, pulse sounds, and respiratory sounds in a wide frequency range.
The piezoelectric element is a piezoelectric ceramic (piezo element: PZT) or a PZT composite element.
The sensor support part and the operation part can be made of synthetic resin or can be made of metal. In addition, it is necessary to ensure the piezoelectric element side of the sound sensor at atmospheric pressure.
The noise absorbing member absorbs ambient noise, noise transmitted through the voice and the operator's finger, and noise transmitted through the signal cable for connection to the main unit.
As the noise absorbing member, glass wool or an air tube can be used in addition to the synthetic resin foam and gel described below.

(2)
The biological sound acquisition terminal according to (1), wherein the piezoelectric element includes a metal plate having one surface in contact with the skin of a human body and a piezoelectric ceramic formed on the other surface of the metal plate.
A synthetic resin film can be provided on the surface of the metal plate facing the human body. Thereby, the biological sound acquisition terminal does not feel the coldness of the metal plate when touching the human skin, and corrosion of the metal plate is prevented by this synthetic resin film.

(3)
The biological sound acquisition terminal according to (1) or (2), wherein the noise absorbing member is a synthetic resin foam or a gel.

The synthetic resin foam can be open cells or closed cells. In the case of using closed cells, it is preferable to provide means for ensuring that the piezoelectric element side of the sound sensor is at atmospheric pressure.
For example, polyurethane foam can be used as the synthetic resin foam, and the expansion ratio can be determined as appropriate. If the expansion ratio is too high, the noise absorbing effect is reduced. On the other hand, if the expansion ratio is too low, the operability is lowered. For example, the foaming ratio when polyurethane urethane is used for the foam can be appropriately selected from 3 to 10 times.

(4)
The sensor support part and the operation part are both cylindrical,
Inside the operation portion having a large diameter, the sensor support portion having a small diameter is accommodated via the noise absorbing member, or
The biological sound acquisition terminal according to (1), wherein the operation unit having a small diameter is accommodated inside the sensor support unit having a large diameter via the noise absorbing member.

  The sensor support part and the operation part may be long cylinders or flat cylinders.

(5)
The biological sound acquisition terminal according to any one of (1) to (4);
An auscultation circuit for receiving a detection signal from the biological sound acquisition terminal;
In electronic stethoscope with
The auscultation circuit receives a sound signal from the biological sound acquisition terminal, filters the sound signal, and sends the filtered sound signal to a sound output device.

  In the electronic stethoscope of the present invention, the auscultation circuit can be mounted on an amplifier that amplifies the analog sound signal from the sound sensor, an AD converter that converts the analog sound signal into a digital signal, or the main body device.

(6)
The biological sound acquisition terminal according to any one of (1) to (4);
A main unit that receives a detection signal from the biological sound acquisition terminal;
A biological sound measuring device comprising:
The body device is provided with an analysis unit for the received detection signal, a storage unit for the analysis result, and an output unit for the analysis result.

  In the biological sound measuring device of the present invention, an amplifier that amplifies an analog sound signal from a sound sensor and an AD converter that converts an analog signal into a digital signal can be mounted on the biological sound acquisition terminal. A converter can be mounted on the main unit.

  Transmission of the analog signal from the sound sensor to the main body device may be performed by wire or wirelessly. If the analog signal from the sound sensor is transmitted to the main unit and noise is mixed in the analog signal and the detection information deteriorates, the AD converter is not provided in the main unit and the body sound is acquired. It is preferable to provide the terminal. In this case, the driving power of the AD converter may be supplied from the main device when the analog signal is transmitted from the sound sensor to the main device by wire. Further, for example, when an analog signal is transmitted from the sound sensor to the main body device wirelessly, the driving power of the AD converter can be performed by incorporating a battery and a switching regulator in the biological sound acquisition terminal. it can.

In the biological sound acquisition terminal of the present invention, the sensor can be in direct contact with the human body while eliminating ambient noise and voice and noise from the operator's fingers and the like.
Therefore, in the biological sound measuring device of the present invention, the detection frequency is not limited, and vibrations, heart sounds, pulse sounds, and respiratory sounds caused by heartbeats ranging from an extremely low frequency to an audible frequency (1 Hz to several hundreds Hz). Such information can be detected.

FIG. 1 is an explanatory view showing a first embodiment of a biological sound acquisition terminal of the present invention, (A) is an overall explanatory view, and (B) is an enlarged view of an SJ portion of (A). 2A and 2B are explanatory views showing a first design modification example of the first embodiment, in which FIG. 2A shows a case where the noise absorbing member is an air tube, and FIG. 2B shows a case where the noise absorbing member is a gel-containing tube. It is a figure which shows a case. FIG. 3 is an explanatory diagram illustrating a second design modification example of the first embodiment. FIG. 4 is an explanatory view showing a second embodiment of the biological sound acquisition terminal of the present invention. FIG. 5 is an explanatory diagram showing a first design change example of the second embodiment. FIG. 6 is an explanatory diagram illustrating a second design modification example of the second embodiment. FIG. 7 is an explanatory diagram illustrating a third design modification example of the second embodiment. FIG. 8 is an explanatory view showing an embodiment of the electronic stethoscope of the present invention, (A) is a schematic explanatory view, and (B) is a circuit explanatory view. FIG. 9 is an explanatory view showing a first embodiment of the biological sound measuring device of the present invention. FIG. 10 is an explanatory view showing a second embodiment of the biological sound measuring device of the present invention. FIG. 11 is an explanatory view showing a third embodiment of the biological sound measuring device of the present invention. FIG. 12 is an explanatory view showing a fourth embodiment of the biological sound measuring device of the present invention. FIG. 13 shows an example of an output waveform of a biological sound acquisition terminal, a processing waveform by a digital filter, and an output waveform of a display output device in the biological sound measurement device of FIG. FIG. 14A is a diagram showing a body sound acquisition terminal model (experimental device) of the present invention, and FIG. 14B is a diagram showing a conventional body sound acquisition terminal model (experimental device). FIG. 15A shows the response of each PZT sensor when a 50 Hz sine wave (effective value 10 V) is applied to the body sound acquisition terminal model of FIG. 14A and the body sound acquisition terminal model of FIG. FIG. 15B is a waveform diagram when an 8 Hz sine wave (effective value 10 V) is applied to the body sound acquisition terminal model of FIG. 14A and the body sound acquisition terminal model of FIG. It is a wave form diagram which shows the response of each PZT sensor. It is explanatory drawing of a prior art (living sound measuring system).

1 (A) and 1 (B) are explanatory views showing a first embodiment of a biological sound acquisition terminal of the present invention.
1A, the body sound acquisition terminal 1 includes a sensor support unit 111, an operation unit 112, and a noise absorbing member 113.
The sensor support 111 is made of cylindrical polyethylene in this embodiment, and the sound sensor 12 is supported at the lower end. In consideration of the material of the sensor support 111 (for example, by increasing the weight), the noise absorptivity exhibited by the sensor support 111 itself can be increased.

The sound sensor 12 includes a metal plate 122 having one surface (the lower surface in FIG. 1A) facing the human body and a piezoelectric element 121 formed on the other surface of the metal plate 122. Signal lines 1231 and 1232 are drawn from the sound sensor 12 (from both surfaces of the piezoelectric element 121).
The signal lines 1231 and 1232 connected to the sound sensor 12 are connected to the main body device 5 of the biological sound measuring device 50 through the cable port J as the signal cable 31.

The operation unit 112 is a part that a doctor or the like holds with a finger during operation, and is formed of stainless steel in the present embodiment.
The noise absorbing member 113 has a cylindrical shape and is made of closed cell polyurethane foam having a foaming ratio of 5 in FIG. In FIG. 1A, a hole hi is formed in the sensor support 111 and a hole ho is formed in the upper part of the operation unit 112 in order to keep the internal space of the sensor support 111 at atmospheric pressure.

  In this embodiment, the sound sensor 12 is directly brought into contact with human skin, and heart sounds and the like are directly collected. When the sound sensor 12 is not in direct contact with human skin (when there is air between the sensor and human skin), the frequency that can be acquired is greatly limited. In the example of FIG. 1A, sound having a frequency of about 12 Hz to several hundred Hz is collected. In addition, ambient noise, voice, vibration from fingers such as doctors, and vibration transmitted through the signal cable 31 are attenuated or eliminated by the noise absorbing member 113.

  FIG. 1B is an enlarged view of the SJ portion of FIG. As shown in FIG. 1B, the sensor support portion 111 and the operation portion 112 are coupled via a noise absorbing member 113 without being in direct contact. FIG. 1C shows an example in which the sensor support portion 111 and the operation portion 112 are connected by a buffer member 114 such as synthetic rubber.

  In this embodiment, the sound sensor 12 is directly brought into contact with human skin, and heart sounds and the like are directly collected. When the sound sensor 12 is not in direct contact with human skin (when there is air between the sensor and human skin), the frequency that can be acquired is greatly limited. In the example of FIG. 1, as described above, sound having a frequency of about 1 Hz to several hundred Hz is collected. In addition, ambient noise, voice, vibration from fingers such as doctors, and vibration transmitted through the signal cable 31 are attenuated or eliminated by the noise absorbing member 113.

2A and 2B are explanatory views showing a first design change example of the first embodiment.
2A, the body sound acquisition terminal 1 is the same as the body sound acquisition terminal 1 of FIG. 1 except for the configuration of the noise absorbing member 113. In this design change example, the noise absorbing member 113 is composed of three donut-shaped air tubes.
In the design change example of FIG. 2B, the noise absorbing member 113 is formed of a tube in which gel is enclosed.

  Even in these design modification examples, the sound sensor 12 is directly brought into contact with human skin, and heart sounds and the like are directly collected. Even in this design change example, sound having a frequency of about 1 Hz to several hundred Hz is collected, and the noise, voice, vibration from a doctor's finger and vibration transmitted through the signal cable 31 are attenuated or eliminated by the noise absorbing member 113. Is done.

  FIG. 3 is an explanatory diagram showing a second design modification example of the first embodiment. In the biological sound acquisition terminal 1 of FIG. 3, the sensor support unit 111 protrudes in a free state with respect to the operation unit 112. The protrusion of the sensor support 111 is configured to be accommodated in the operation unit 112 when the tip of the support 111 (sound sensor 12) is brought into direct contact with human skin or the like.

In this design change example, the contact pressure of the sound sensor 12 against the human skin or the like can be made constant, so that stable heart sounds and the like can be collected. Even in this design change example, a sound with a frequency of about 12 Hz to several hundreds of Hz is collected, and ambient noise, voice, vibration from a finger of a doctor, and vibration transmitted through the signal cable 31 are attenuated or eliminated by the noise absorbing member 113. Is done.
In the body sound acquisition terminal 1 of FIG. 3, for example, when the state of FIG. 3B is reached, a spring that biases the state of FIG. 3A is interposed between the sensor support unit 111 and the operation unit 112. It can also be provided in

FIG. 4 is an explanatory view showing a second embodiment of the body sound acquisition terminal of the present invention.
In FIG. 4, the biological sound acquisition terminal 2 includes a sensor support unit 211, an operation unit 212, and a noise absorbing member 213.

In the present embodiment, the sensor support portion 211 is made of flat polyethylene, and the sound sensor 22 is supported at the lower end (side in contact with the skin).
The sound sensor 22 includes a metal plate 222 having one surface (the lower surface in FIG. 4) facing the human body, and a piezoelectric element 221 formed on the other surface of the metal plate 222. The signal lines 2231 and 2232 connected to the sound sensor 12 are connected to the main body device 5 of the biological sound measuring device 50 through the cable port J as the signal cable 31.

The operation unit 212 is a part held by a doctor or the like during operation, and is formed of a flat cup-shaped polyethylene in this embodiment. The outer diameter of the operation unit 212 is larger than the outer diameter of the sensor support unit 211, and the operation unit 212 is configured to cover the sensor support unit 211.
In FIG. 4, the noise absorbing member 213 is made of closed-cell polyurethane foam having a foaming ratio of 5. In FIG. 4, in order to maintain the internal space of the sensor support portion 211 at atmospheric pressure, a hole hi is formed in the sensor support portion 211, a hole ho is formed in the operation portion 212, and a hole hm is formed in the noise absorbing member 213.

  In this embodiment, the sound sensor 22 is directly brought into contact with human skin, and heart sounds and the like are directly collected. When the sound sensor 22 is not in direct contact with the human skin (when there is air between the sensor and the human skin), the frequency that can be acquired is greatly limited. In the example of FIG. 4, sound having a frequency of about 12 Hz to several hundred Hz is collected. In addition, ambient noise, voice, vibration from fingers such as doctors, and vibration transmitted through the signal cable 31 are attenuated or eliminated by the noise absorbing member 113.

  FIG. 5 is an explanatory diagram showing a first design modification example of the second embodiment. The body sound acquisition terminal 2 in FIG. 5 is the same as the body sound acquisition terminal 2 in FIG. 4 except for the configuration of the noise absorbing member 213. It is. In this design change example, the noise absorbing member 213 is formed between a part of the upper surface of the sensor support part 211 and a part of the lower surface of the operation part 212.

  Even in this design change example, the sound sensor 22 is directly brought into contact with human skin, and heart sounds and the like are directly collected. Even in this design change example, a sound having a frequency of about 12 Hz to several hundreds of Hz is collected, and ambient noise, voice, vibration from a finger of a doctor, and vibration transmitted through the signal cable 31 are attenuated or eliminated by the noise absorbing member 213. Is done.

FIG. 6 is an explanatory diagram illustrating a second design modification example of the second embodiment. 6, the body sound acquisition terminal 2 includes a sensor support unit 211, an operation unit 212, and a noise absorbing member 213, and generally has the same configuration as the body sound acquisition terminal 2 of FIG.
However, the outer diameter of the sensor support portion 211 is larger than the outer diameter of the operation portion 212, and the sensor support portion 211 is configured to cover the operation portion 212 from below.

  Even in this design change example, the sound sensor 22 is directly brought into contact with human skin, and heart sounds and the like are directly collected. Even in this design change example, a sound having a frequency of about 12 Hz to several hundreds of Hz is collected, and ambient noise, voice, vibration from a finger of a doctor, and vibration transmitted through the signal cable 31 are attenuated or eliminated by the noise absorbing member 213. Is done.

  FIG. 7 is an explanatory diagram illustrating a third design modification example of the second embodiment. The body sound acquisition terminal 2 in FIG. 7 is the same as the body sound acquisition terminal 2 in FIG. 6 except for the configuration of the noise absorbing member 213. It is. In this design change example, the noise absorbing member 213 is formed between a part of the upper surface of the sensor support part 211 and a part of the lower surface of the operation part 212.

  Even in this design change example, the sound sensor 22 is directly brought into contact with human skin, and heart sounds and the like are directly collected. Even in this design change example, a sound having a frequency of about 12 Hz to several hundreds of Hz is collected, and ambient noise, voice, vibration from a finger of a doctor, and vibration transmitted through the signal cable 31 are attenuated or eliminated by the noise absorbing member 213. Is done.

  FIG. 8 is an explanatory view showing an embodiment of the electronic stethoscope of the present invention, (A) is a schematic explanatory view, and (B) is a circuit explanatory view. As shown in FIGS. 8A and 8B, the electronic stethoscope 40 includes a body sound acquisition terminal 2 and an auscultation circuit 4 that receives sound signals from the body sound acquisition terminal 2.

As illustrated in FIG. 8B, the auscultation circuit 4 includes a CPU 41, a storage device 42, a sound output interface 43, a digital filter 44, an AD converter 45, and an amplifier 46.
The analog sound signal from the biological sound acquisition terminal 2 is amplified by the amplifier 46 and converted into a digital signal by the AD converter 45. This digital signal is filtered by the digital filter 44, converted into an audible sound having a desired frequency, and sent to the auscultation unit SS via the sound output interface 43.

  With the electronic stethoscope of the present invention, heart sounds and the like in a frequency band that could not be heard before can be extracted and heard.

FIG. 9 is an explanatory view showing a first embodiment of the biological sound measuring device of the present invention. In FIG. 9, the body sound measurement device 50 includes a body sound acquisition terminal 1 and a main body device 5.
The main device 5 includes a CPU 51, a storage device 52, a display output device (display) 53, a printing device 54, a digital filter 55, an AD converter 56, and an amplifier 57.

  The analog detection signal of the biological sound from the biological sound acquisition terminal 1 is sent to the amplifier 57 via the signal cable 31. This analog detection signal is converted into a digital signal by the AD converter 56. By passing the digital signal through the digital filter 55, a desired signal is extracted.

The storage device 52 stores a detection signal analysis program, and the CPU 51 analyzes the signal by applying this program to the signal that has passed through the digital filter 55. The CPU 51 achieves the function as the detection signal analysis unit in the present invention by executing the detection signal analysis program.
The result of detection signal analysis can be output from the display output device 53 or the printing device 54.

FIG. 10 is an explanatory view showing a second embodiment of the biological sound measuring device of the present invention. In FIG. 10, the body sound measurement device 50 includes a body sound acquisition terminal 1 and a main body device 5.
In the present embodiment, the biological sound acquisition terminal 1 includes a sound sensor 12 and an amplifier 15. Although not shown, power is supplied to the body sound acquisition terminal 1 from the main body device 5 via the signal cable 31 to drive the amplifier 15.
The main device 5 includes a CPU 51, a storage device 52, a display output device (display) 53, a printing device 54, a digital filter 55, and an AD converter 56.

FIG. 11 is an explanatory view showing a third embodiment of the biological sound measuring device of the present invention. In FIG. 11, the body sound measurement device 50 includes a body sound acquisition terminal 1 and a main body device 5.
In the present embodiment, the biological sound acquisition terminal 1 includes a sound sensor 12, an amplifier 15, an AD converter 16, and a USB I / O 17 (USB input / output circuit). Although not shown, power is supplied to the body sound acquisition terminal 1 from the main body device 5 via the signal cable 31 to drive the amplifier 15, the AD converter 16, and the USB I / O 17.
The main device 5 includes a CPU 51, a storage device 52, a display output device (display) 53, a printing device 54, a digital filter 55, and a USB terminal 58.

  FIG. 12 is an explanatory view showing a fourth embodiment of the biological sound measuring device of the present invention. In FIG. 12, the body sound measurement device 50 includes a body sound acquisition terminal 1, an auscultation circuit 4, and a main body device 5.

As shown in FIG. 12, the auscultation circuit 4 includes a CPU 41, a storage device 42, a sound output interface 43, a digital filter 44, an AD converter 45, and an amplifier 46.
The main device 5 includes a CPU 51, a storage device 52, a display output device (display) 53, a printing device 54, a digital filter 55, and a microphone terminal 59. Although not shown, in this embodiment, power is supplied to the auscultation circuit 4 from the main body device 5 via the signal cable 31.

The analog sound signal from the biological sound acquisition terminal 2 is amplified by the amplifier 46 and converted into a digital signal by the AD converter 45. This digital signal is filtered by the digital filter 44, converted into an audible sound having a desired frequency, and sent to the auscultation unit SS via the sound output interface 43.
In the present design change example, the audible sound having the desired frequency is sent to the microphone terminal 59 via the sound output interface 43.

FIG. 13 shows the output waveform of the body sound acquisition terminal 1 (sound sensor 12), the processing waveform by the digital filter 55, and the output waveform of the display output device 53 in the body sound measuring device 50 of FIG.
The output waveform of the sound sensor 12 is a voltage waveform between the terminals, the processing waveform by the digital filter 55 is a waveform obtained by band-pass processing of the 20 to 100 Hz component of the signal from the sound sensor 12, and the output waveform of the display output device 53 Is an electrocardiogram waveform of simultaneous recording.

In each embodiment of the body sound measurement device 50 described above, the body sound measurement device 50 may be activated at the time of auscultation, or the body sound measurement device 50 may be always activated. . In the present embodiment, although not shown, a switch (which may be a touch sensor type switch) for activating the biological sound measurement device 50 may be mounted on the biological sound acquisition terminal 1.
The biological sound measuring apparatus 50 can use a general-purpose computer. In this case, the switch can activate application software (such as an analysis program) on the computer.

Experimental examples are shown below to demonstrate the effects of the present invention.
FIG. 14A is a diagram showing a body sound acquisition terminal model (experimental device) of the present invention. In FIG. 14A, the biological sound acquisition terminal model 6 of the present invention is attached to a plastic plate 61 corresponding to a human body, a sound sensor 62 attached to the upper surface of the plastic plate 61, and a lower surface of the plastic plate 61. And a rubber spacer 64 that supports them. The sound sensor 62 includes a metal substrate 621 having a diameter of 20 mm and a PZT sensor 622. The vibrating body 63 includes a metal substrate 631 having a diameter of 35 mm and a PZT sensor 632.

  On the other hand, FIG. 14B is a diagram showing a body sound acquisition terminal model (experimental device) of the present invention. 14B, the biological sound acquisition terminal model 7 of the present invention is attached to a plastic plate 71 corresponding to a human body and a plastic cylinder 75 having an inner diameter of 14 mm and a height of 13 mm on the upper surface of the plastic plate 71. The sound sensor 72, a vibrating body 73 attached to the lower surface of the plastic plate 71, and a rubber spacer 74 that supports them are configured. The sound sensor 72 has the same structure as the sound sensor 62 of FIG. 14A, and includes a metal substrate 721 having a diameter of 20 mm and a PZT sensor 722. The vibrating body 73 has the same structure as that of the vibrating body 63 in FIG. 14A and includes a metal substrate 731 having a diameter of 35 mm and a PZT sensor 732.

  FIG. 15A shows each PZT when a 50 Hz sine wave (effective value 10 V) is applied to the body sound acquisition terminal model 6 of FIG. 14A and the body sound acquisition terminal model 7 of FIG. It is a wave form diagram which shows the response Vout of a sensor. FIG. 15B shows the results when an 8 Hz sine wave (effective value 10 V) is applied to the body sound acquisition terminal model 6 in FIG. 14A and the body sound acquisition terminal model 7 in FIG. It is a wave form diagram which shows the response Vout of a PZT sensor. In FIGS. 14A and 14B, the pressing pressure P is 43 g.

  In the body sound acquisition terminal model 6 of FIG. 14A, that is, the model of the present invention, the sound sensor 62 is in direct contact with the plastic plate 61, so that a sound (vibration) of 50 Hz can be detected. Of course (see FIG. 15A), 8 Hz sound (vibration) can also be detected well (see FIG. 15B).

On the other hand, in the body sound acquisition terminal model 7 of FIG. 14B, that is, the conventional model, since it is mounted on the plastic plate 71 via the plastic cylinder 75, the sound (vibration) of 50 Hz is detected. Although it is weak, it can be detected, but 8 Hz sound (vibration) cannot be detected at all.
As can be seen from the above experimental example, it is quite difficult to detect a low frequency sound (vibration) including a very low frequency sound with the conventional stethoscope 91 (see FIG. 16) that detects heart sounds and the like via air. However, according to the biological sound acquisition terminals 1 and 2 (see FIGS. 1 to 8) of the present invention in which the sound sensor is in direct contact with the skin, the low frequency sound including the very low frequency sound is used. (Vibration) can be detected well.

  The present invention is not limited to the above embodiment, and various modifications such as downsizing and incorporation into existing devices such as mobile phones and computer mice are possible, and these are excluded from the scope of the present invention. Not what you want.

DESCRIPTION OF SYMBOLS 1, 2 Body sound acquisition terminal 4 Auscultation circuit 5 Main body apparatus 6, 7 Body sound acquisition terminal model 12, 22 Sound sensor 15, 46, 57 Amplifier 16 AD converter 17 USB I / O
31 Signal cable 40 Electronic stethoscope 41, 51 CPU
42, 52 Storage device 43 Sound output interface 44, 55 Digital filter 45, 56 AD converter 50 Body sound measurement device 53 Display output device 54 Printing device 58 USB terminal 59 Microphone terminal 61, 71 Plastic plate 62, 72 Sound sensor 63, 73 Vibrating body 64, 74 Rubber spacer 75 Plastic cylinder 111, 211 Sensor support part 112, 212 Operation part 113, 213 Noise absorbing member 114 Buffer member 121, 221 Piezoelectric element 122, 222 Metal plate 621, 631, 721, 731 Metal substrate 622, 722, 632, 732 PZT sensor 1231, 2231 Signal line J Cable port S Space SS Auscultation part hi, hm, ho hole

Claims (6)

In a biological sound acquisition terminal comprising a sensor support unit for supporting a sound sensor and an operation unit for holding with a finger,
The sound sensor is composed of a piezoelectric element that directly obtains sound from the human body from the skin without going through an air layer,
The biological sound acquisition terminal, wherein the sensor support unit and the operation unit are coupled via a noise absorbing member.   2. The biological sound acquisition terminal according to claim 1, wherein the piezoelectric element includes a metal plate whose one surface is in contact with the skin of a human body and a piezoelectric ceramic formed on the other surface of the metal plate.   The biological sound acquisition terminal according to claim 1, wherein the noise absorbing member is a synthetic resin foam or a gel. The sensor support part and the operation part are both cylindrical,
Inside the operation portion having a large diameter, the sensor support portion having a small diameter is accommodated via the noise absorbing member, or
The biological sound acquisition terminal according to claim 1, wherein the operation unit having a small diameter is accommodated via the noise absorbing member inside the sensor support unit having a large diameter. The biological sound acquisition terminal according to any one of claims 1 to 4,
An auscultation circuit for receiving a detection signal from the biological sound acquisition terminal;
In electronic stethoscope with
The auscultation circuit receives a sound signal from the biological sound acquisition terminal, filters the sound signal, and sends the filtered sound signal to a sound output device. The biological sound acquisition terminal according to any one of claims 1 to 4,
A main unit that receives a detection signal from the biological sound acquisition terminal;
A biological sound measuring device comprising:
The body device is provided with an analysis unit for the received detection signal, a storage unit for the analysis result, and an output unit for the analysis result.