Shunt sound measurement device and shunt sound measurement method

Abstract

The present invention outputs an index that has a high correlation with FV from biological sound data that includes shunt sound at a low computational load. A shunt sound measurement device (1) comprises an acquisition unit (10) that acquires biological sound data that includes shunt sound, a bandpass filter (21) that extracts a specific frequency component from the biological sound data, an amplitude detection unit (22) that detects an amplitude value for the extracted specific frequency component, an averaging unit (23) that calculates an average value that averages the detected amplitude value over time, a calculation unit (24) that multiplies the calculated average value by a prescribed value to calculate an index value, and an output unit (25) that outputs the calculated index value.

Description

Shunt sound measuring device and shunt sound measuring method

[0001] The present invention relates to a technique for measuring shunt sounds.

[0002] When a dialysis patient's shunt narrows, they undergo shunt repair surgery. Furthermore, if the shunt narrowing worsens, shunt reconstruction surgery becomes necessary. Shunt reconstruction surgery places a significant burden on the patient, increases pain, and increases the risk of surgical infection. Therefore, early detection of shunt narrowing through vascular access (VA) monitoring can help reduce the patient's physical and mental pain.

[0003] In clinical practice, FV (Flow Volume, brachial artery blood flow), which is blood flow measured using an ultrasound imaging diagnostic device (echo diagnostic device), has been established as an index for evaluating shunt function. The Japanese Society for Dialysis Therapy guidelines indicate that a decrease in FV may indicate the occurrence of shunt stenosis.

[0004] However, measurement using an ultrasound imaging diagnostic device requires skill, and not all dialysis staff can perform it. In addition, the cost of installing an ultrasound imaging diagnostic device is high.

[0005] Therefore, the applicant has focused on auscultation, which is simple and can be performed frequently, and has developed a detection device that detects blood flow using shunt sounds (Patent Document 1).

[0006] Japanese Patent Application Publication No. 2022-91851

[0007] The inventors are further advancing research and development on the device described in Patent Document 1, aiming to realize a technology that can output an index that is highly correlated with FV with a small computational load.

[0008] An object of one aspect of the present invention is to realize a technology for outputting an index highly correlated with FV from biological sound data including shunt sounds with a small computational load.

[0009] In order to solve the above problems, a shunt sound measuring device according to one embodiment of the present invention comprises an acquisition means for acquiring biological sound data including shunt sounds, a band-pass filter for extracting specific frequency components from the biological sound data acquired by the acquisition means, an amplitude detection means for detecting the amplitude value of the specific frequency component extracted by the band-pass filter, an averaging means for calculating an average value obtained by averaging the amplitude values ​​detected by the amplitude detection means over time, a calculation means for calculating an index value by multiplying a specified value by the average value calculated by the averaging means, and an output means for outputting the index value calculated by the calculation means.

[0010] Furthermore, a shunt sound measurement method according to one aspect of the present invention includes an acquisition step of acquiring biological sound data including shunt sounds, an extraction step of extracting specific frequency components from the biological sound data acquired in the acquisition step using a band-pass filter, an amplitude detection step of detecting amplitude values ​​of the specific frequency components extracted in the extraction step, an averaging step of calculating an average value obtained by averaging the amplitude values ​​detected in the amplitude detection step over time, a calculation step of calculating an index value by multiplying a specified value by the average value calculated in the averaging step, and an output step of outputting the index value calculated in the calculation step.

[0011] Furthermore, the shunt sound measuring device according to each aspect of the present invention may be realized by a computer. In this case, the control program for the shunt sound measuring device, which causes the computer to operate as each part (software element) of the shunt sound measuring device, thereby realizing the shunt sound measuring device on a computer, and the computer-readable recording medium on which the control program is recorded, also fall within the scope of the present invention.

[0012] According to one aspect of the present invention, an index highly correlated with FV can be output from body sound data including shunt sounds with a small computational load.

[0013] 1 is a block diagram showing an example of the configuration of a shunt sound measuring device according to embodiment 1. FIG. 2 is a diagram showing an example of the appearance of the shunt sound measuring device according to embodiment 1. FIG. 3 is a flow diagram showing an example of the flow of a shunt sound measuring method according to embodiment 1. FIG. 4 is a diagram showing an example of biological sound data acquired in the shunt sound measuring method according to embodiment 1. FIG. 5 is a diagram showing an example of specific frequency components extracted in the shunt sound measuring method according to embodiment 1. FIG. 6 is a diagram showing an example of amplitude values ​​detected in the shunt sound measuring method according to embodiment 1. FIG. 7 is a diagram showing an example of amplitude values ​​averaged in the shunt sound measuring method according to embodiment 1. FIG. 8 is a diagram showing an example of a typical shunt sound waveform of a patient with a good shunt condition. FIG. 9 is a diagram showing an example of a typical shunt sound waveform of a patient with a poor shunt condition. FIG. 10 is a graph showing the results of optimization of the frequency band of a specific frequency component in the shunt sound measuring method according to embodiment 1. FIG. 11 is a graph showing the results of optimization of the frequency band of a specific frequency component in the shunt sound measuring method according to embodiment 1. FIG. 12 is a table showing differences in correlation coefficients depending on the frequency band of a specific frequency component in the shunt sound measuring method according to embodiment 1.

[0014] [Embodiment 1] An embodiment of the present invention will be described in detail below. Fig. 1 is a block diagram showing an example of the configuration of a shunt sound measuring device 1. The shunt sound measuring device 1 is a device that acquires biological sound data including shunt sounds and outputs an index value that has a high correlation with FV.

[0015] In the following, a configuration in which the shunt sound measuring device 1 is an electronic stethoscope will be described, but the shunt sound measuring device 1 is not limited to an electronic stethoscope and may be, for example, a general-purpose computer such as a personal computer, or a dedicated machine such as a dialysis console. Examples of personal computers include laptop computers, tablet terminals, and smartphones.

[0016] In this specification, the term "shunt sound" refers to the sound generated by blood flow at the shunt formation site (the anastomosis site, or the blood vessels near the shunt). The term "shunt" includes both autologous intravascular shunts (AVF, Arteriovenous Fistula) and artificial intravascular shunts (AVG, Arteriovenous Graft).

[0017] The shunt sound measuring device 1 includes an acquisition unit (acquisition means) 10, an audio output processing unit 16, an operation unit 17, a display unit 18, a D / A conversion unit 19, and an analysis processing unit 20. The acquisition unit 10 includes a sensor 11 and an A / D conversion unit 12. The analysis processing unit 20 includes a band-pass filter 21, an amplitude detection unit (amplitude detection means) 22, an averaging unit (averaging means) 23, a calculation unit (calculation means) 24, and an output unit (output means) 25. An external audio output device 6 is also connected to the shunt sound measuring device 1. The audio output device 6 may be included in the shunt sound measuring device 1.

[0018] Fig. 2 is a diagram showing an example of the appearance of the shunt sound measurement device 1. As shown in Fig. 2, in one example, the shunt sound measurement device 1 is an electronic stethoscope, and the audio output device 6 is an earphone. An operation unit 17 and a display unit 18 are provided on the front side of the shunt sound measurement device 1. A sensor 11 is provided on the back side of the shunt sound measurement device 1. The sensor 11 is placed against the skin near the shunt formation site and collects biological sounds including shunt sounds. The user can start measurement and check the output indicators using the operation unit 17 and display unit 18 provided on the surface opposite the sensor 11.

[0019] The sensor 11 outputs an analog signal representing the body sound of the measurement target. The sensor 11 is, for example, a microphone that collects the body sound, or an acoustic sensor such as an acceleration sensor or a pressure sensor, but is not limited to these.

[0020] The A / D converter 12 samples the analog signal output by the sensor 11 and converts it into digital data. This allows the acquisition unit 10 to acquire body sound data including shunt sounds. Note that the acquisition unit 10 may be configured to acquire body sound data from an external sensor without including the sensor 11. The acquisition unit 10 may further include a processing unit that processes the body sound data, such as a noise removal processing unit or a downsampling processing unit.

[0021] The operation unit 17 accepts operations such as starting measurement from the user. In the example shown in FIG. 2 , the operation unit 17 is a physical button, but is not limited to this and may be a touch panel or other input interface. In one aspect, the acquisition unit 10 starts acquiring sound data including the shunt sound in response to the operation unit 17 accepting an operation to start measurement from the user. In another aspect, the acquisition unit 10 may start acquiring sound data including the shunt sound in response to a contact detection device (not shown) detecting that the sensor 11 is in appropriate contact with the measurement target. An example of a contact detection device is a pressure sensor, but is not limited to this.

[0022] The display unit 18 is a display that displays the indicators output by the output unit 25, and may be, for example, a segment LED, a liquid crystal display, etc. In one aspect, in addition to or instead of the display unit 18, a speaker or the like that outputs the indicators output by the output unit 25 as audio may be provided.

[0023] The audio output processing unit 16 processes the body sound data and outputs the processed body sound data as audio. For example, the audio output processing unit 16 processes the body sound data by filtering the body sound data. More specifically, for example, the audio output processing unit 16 processes the body sound data by applying a hearing correction filter to the body sound data. Examples of hearing correction filters include a BEL filter and a DIA filter. The BEL filter is a filter for reproducing sounds heard when using the bell surface of a stethoscope, and cuts out high-frequency components to make low-pitched sounds easier to hear. The DIA filter is a filter for reproducing sounds heard when using the diaphragm surface of a stethoscope, and makes high-pitched sounds easier to hear. For example, the operation unit 17 may have a switch for switching between bell mode and diaphragm mode, and the hearing correction filter may be switched based on the switching of this switch.

[0024] The D / A conversion unit 19 converts the body sound data output by the audio output processing unit 16 into an analog signal and outputs the converted signal to the audio output device 6. The audio output device 6 is, for example, an earphone or a speaker. The D / A conversion unit 19 may include an analog filter (not shown) that suppresses high frequencies after D / A conversion.

[0025] The analysis processing unit 20 analyzes the body sound data and outputs the analysis results. In this embodiment, the analysis processing unit 20 analyzes the body sound data including the shunt sound and outputs an index that has a high correlation with FV.

[0026] The band-pass filter 21 extracts a specific frequency component from the body sound data acquired by the acquisition unit 10. The frequency band of the specific frequency component can be set to a frequency band including the main component of the shunt sound, and in one embodiment, is 40 Hz or more and 170 Hz or less.

[0027] The amplitude detection unit 22 detects the amplitude value of the specific frequency component extracted by the band-pass filter 21. The amplitude detection unit 22 may detect the amplitude value by, for example, converting the specific frequency component into an absolute value, or may detect the amplitude value using other methods such as envelope detection, peak detection, square-law detection, Hilbert transform, etc.

[0028] The averaging unit 23 calculates an average value by averaging the amplitude values ​​detected by the amplitude detection unit 22 over time. The temporal averaging may be, for example, a moving average calculated using an FIR filter, or a recursive average calculated using an IIR filter. The averaging unit 23 may include, for example, a low-pass filter, and may average the amplitude values ​​over time using the low-pass filter. The type of low-pass filter is not particularly limited, and may be an FIR filter or an IIR filter. In one embodiment, "averaging" may be "smoothing." That is, the averaging unit 23 may calculate the amplitude value by smoothing the amplitude values ​​detected by the amplitude detection unit 22 over time as the above-mentioned average value.

[0029] The calculation unit 24 calculates an index value by multiplying the average value calculated by the averaging unit 23 by a specified value. In one aspect, the calculation unit 24 calculates the index value by multiplying the average value by a specified value (gain) so that the index value indicates a value in the range of 0 to 999, similar to FV.

[0030] The specified value may be adjusted before product shipment using a device that applies a quantitative signal or vibration to the stethoscope to correct for variations in sensitivity of the sensor 11, etc., and written as the specified value in a non-volatile memory (not shown) (of the CPU) of the shunt sound measuring device 1 or an external storage device (not shown), and read when the power is turned on. The specified value may also be configured to be changeable from a dialysis console, a personal computer, etc.

[0031] The output unit 25 outputs the index value calculated by the calculation unit 24 to the display unit 18. This allows the display unit 18 to display the index value. In one aspect, the output unit 25 may output the index value so that the index value is displayed on the display unit 18 a specified time after the start of measurement. In this case, the index value may be displayed only once a specified time after the start of measurement, or the displayed index value may be updated at specific time intervals. The specified time and the specific time interval are not particularly limited, but may be, for example, 5 seconds.

[0032] 3 is a flow chart showing an example of the flow of the shunt sound measurement method according to this embodiment. In one aspect, the shunt sound measurement method is started in response to the operation unit 17 receiving an operation to start measurement from the user.

[0033] In step S11 (acquisition step), the acquisition unit 10 acquires body sound data including shunt sounds. Specifically, the sensor 11 is placed against the shunt formation site and collects body sounds for a predetermined time, thereby acquiring the body sound data including the shunt sound. The sound collection time is not particularly limited and can be various, for example, about 10 seconds. An example of the body sound data acquired at this time is shown in FIG. 4. In FIGS. 4 to 7, the horizontal axis represents time (seconds) and the vertical axis represents normalized amplitude.

[0034] In step S12 (extraction step), the analysis processing unit 20 extracts specific frequency components from the body sound data acquired in step S11 using the band-pass filter 21. As described above, the frequency band of the specific frequency components can be set to a frequency band including the shunt sound, and in one embodiment, is 40 Hz to 170 Hz. An example of the specific frequency components extracted at this time is shown in FIG. 5.

[0035] In step S13 (amplitude detection step), the analysis processing unit 20 detects the amplitude value of the specific frequency component extracted in step S12 using the amplitude detection unit 22. An example of the detected amplitude value is shown in FIG.

[0036] In step S14 (averaging step), the analysis processing unit 20 calculates an average value by averaging the amplitude values ​​detected in step S13 over time using the averaging unit 23 (e.g., a low-pass filter). An example of the average value calculated at this time is shown in FIG.

[0037] In step S15 (calculation step), the analysis processing unit 20 calculates an index value by multiplying the average value calculated in step S14 by a specified value using the calculation unit 24. At this time, the calculation unit 24 may calculate the index value using a specified value that is set so that the index value is a numerical value within a predetermined numerical range (e.g., 0 to 999). As described above, the specified value may be set in advance inside the shunt sound measuring device 1, or may be set externally.

[0038] In step S16 (output step), the analysis processing unit 20 outputs the index value calculated in step S15 to the display unit 18 via the output unit 25. In one aspect, the analysis processing unit 20 may output the index value so that the index value is displayed on the display unit 18 a specified time after the start of measurement. In this case, the index value may be displayed only once a specified time after the start of measurement, or the displayed index value may be updated at specific time intervals. The specified time and the specific time interval are not particularly limited, but may be, for example, 5 seconds.

[0039] As described above, the analysis processing unit 20 can calculate the index value without performing complex processing such as a Fourier transform. The calculated index value has a high correlation with FV, as will be described later. Therefore, according to this embodiment, an index value having a high correlation with FV can be output from body sound data including shunt sounds with a small calculation load.

[0040] As described above, in one aspect, the band-pass filter 21 extracts specific frequency components in a frequency band of 40 Hz to 170 Hz from the biological sound data acquired by the acquisition unit 10. This is because extracting specific frequency components containing the main component of the shunt sound can remove noise unrelated to the shunt sound. For example, high-frequency noise includes noise caused by holding a stethoscope. Low-frequency noise includes noise caused by the amplifier and body movement.

[0041] It is known that the fundamental frequency of shunt sound is 100 Hz to 150 Hz. It is also known that the frequency spectrum of 400 Hz or higher increases as the narrowing of the shunt progresses. In addition, in Patent Document 1, the frequency band of 100 Hz to 300 Hz is extracted to determine the intensity of the shunt sound.

[0042] In response to this, the inventors, through their own investigations, have unexpectedly found that when specific frequency components in a frequency band of 40 Hz to 170 Hz are extracted, the amplitude values ​​of the extracted specific frequency components are detected, the detected amplitude values ​​are averaged over time to calculate an average value, and the calculated average value is multiplied by a specified value to calculate an index value, an index having a higher correlation with FV is obtained than when specific frequency components in other frequency bands are extracted.The reason why a higher correlation with FV is obtained when the high frequency range is more restricted than in Patent Document 1 is thought to be related to muscle sounds caused by the measurer holding the electronic stethoscope, rather than the subject.

[0043] Fig. 8 shows an example of a typical shunt sound waveform in a patient with a good shunt condition. Fig. 9 and Fig. 10 show examples of a typical shunt sound waveform in a patient with a bad shunt condition. In Fig. 8 to Fig. 10, the horizontal axis represents time and the vertical axis represents amplitude.

[0044] The period indicated by "S" in the figure is called the systole, which is the period from when the heart starts to contract until it finishes contracting, during which blood is forcefully pushed out and a strong blood flow occurs. Patent Document 1 discloses a configuration in which data corresponding to this systole is extracted to determine the intensity of the shunt sound. However, in this embodiment, based on the inventors' unique findings, an index highly correlated with FV is calculated from data not limited to the systole.

[0045] This is based on the following reason. That is, typical shunt sound waveforms from a patient with a poor shunt condition include a case where the overall volume is low, as in the example shown in Figure 9, a case where the sound is interrupted, as in the example shown in Figure 10, and a case where the sound is interrupted and low in volume, which is a combination of these (not shown). According to Patent Document 1, by focusing on the systolic period and extracting features, it is possible to obtain an index that distinguishes between these cases. On the other hand, by focusing on the average amplitude, as in this embodiment, it is believed that sufficient accuracy can be obtained in all cases without limiting the period to the systolic period.

[0046] [Example] The frequency band of the specific frequency component in the shunt sound measurement method described in embodiment 1 was optimized. That is, while changing the frequency band of the specific frequency component to be extracted, the correlation coefficient between the index calculated by the shunt sound measurement method described in embodiment 1 and FV was calculated, and the upper and lower frequency limits at which the correlation coefficient was maximized were verified. Note that, since AVF accounts for a larger proportion than AVG in vascular access in Japan, verification was performed on AVF.

[0047] The target patients were maintenance dialysis patients (AVF), and verification was performed on 536 cases. Specifically, during ultrasound echocardiography of the target patients, sounds were collected for 10 seconds at the shunt formation site (shunt anastomosis site) using an electronic stethoscope according to the shunt sound measurement method described in embodiment 1, and then FV (brachial artery blood flow) was measured using an ultrasound imaging diagnostic device. Then, an index was calculated based on the collected biological sound data.

[0048] First, the upper frequency limit was fixed at 300 Hz, and the lower frequency limit was changed in 5 Hz increments to verify the frequency at which the correlation coefficient between the calculated index and FV was maximized. The results are shown in Figure 11. In Figure 11, the vertical axis represents the correlation coefficient, and the horizontal axis represents the lower frequency limit.

[0049] In addition, the lower limit frequency was fixed at 5 Hz, and the upper limit frequency was changed in 5 Hz increments to verify the frequency at which the correlation coefficient between the calculated index and FV was maximized. The results are shown in Figure 12. In Figure 12, the vertical axis represents the correlation coefficient, and the horizontal axis represents the upper limit frequency.

[0050] As shown in Fig. 11, the correlation coefficient was highest when the lower limit frequency was set to 40 Hz. Also, as shown in Fig. 12, the correlation coefficient was highest when the upper limit frequency was set to 170 Hz. From the above, it was determined that the optimal range of the frequency band of the specific frequency component in the shunt noise measurement method described in embodiment 1 is 40 Hz or more and 170 Hz or less.

[0051] Furthermore, the correlation coefficients between the calculated index and FV were compared between the case where the specific frequency component of 100 Hz to 300 Hz, which is the frequency band used in Patent Document 1, was used and the case where the specific frequency component of 40 Hz to 170 Hz was used. The target patients were maintenance dialysis patients (AVF), and verification was performed on 536 cases. The results are shown in Figure 13.

[0052] As shown in Figure 13, it was shown that the correlation coefficient between the calculated index and FV was higher when specific frequency components of 40 Hz or more and 170 Hz or less were used than when specific frequency components of 100 Hz or more and 300 Hz or less were used.

[0053] Statistical analysis was performed using EZR (registered trademark). EZR is statistical software that extends the functions of R and R Commander. Spearman's Rank Correlation Coefficient was used for statistical analysis to examine the relationship between the calculated index and FV.

[0054] [Additional Notes] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

[0055] [Summary] The shunt sound measuring device according to the first aspect of the present invention is configured to include an acquisition means for acquiring biological sound data including shunt sound, a band-pass filter for extracting specific frequency components from the biological sound data acquired by the acquisition means, an amplitude detection means for detecting the amplitude value of the specific frequency component extracted by the band-pass filter, an averaging means for calculating an average value obtained by averaging the amplitude values ​​detected by the amplitude detection means over time, a calculation means for calculating an index value by multiplying a specified value by the average value calculated by the averaging means, and an output means for outputting the index value calculated by the calculation means for each unit time.

[0056] According to the above configuration, an index value highly correlated with FV can be output from biological sound data including shunt sounds with a small computational load. The small computational load allows for miniaturization of the hardware required for calculations, lower costs, and lower power consumption. Furthermore, the low power consumption allows for battery operation, reducing the volume of the power supply unit and enabling the miniaturization of the device. In addition, since shunt sounds are acquired, which are relatively easy to measure, the time required for measurement can be shortened.

[0057] Furthermore, in the shunt sound measuring device according to the second aspect of the present invention, in addition to the configuration of the shunt sound measuring device according to the first aspect described above, a configuration is adopted in which the frequency band of the specific frequency component is 40 Hz or more and 170 Hz or less.

[0058] According to the above configuration, it is possible to output an index value that has a higher correlation with FV.

[0059] Furthermore, in the shunt sound measuring device according to the third aspect of the present invention, in addition to the configuration of the shunt sound measuring device according to the first or second aspect described above, the averaging means is configured to average the amplitude values ​​by a low-pass filter.

[0060] According to the above configuration, the index value can be output with a small calculation load.

[0061] Furthermore, in the shunt sound measuring device according to the third aspect of the present invention, in addition to the configuration of the shunt sound measuring devices according to the first to third aspects described above, a configuration that is an electronic stethoscope is adopted.

[0062] According to the above configuration, a compact configuration is possible, and index values ​​highly correlated with FV can be output through a short measurement using auscultation, which is relatively easy to measure. In particular, because the computational load is small, an inexpensive CPU can be built into the electronic stethoscope to realize an analysis processing unit. Furthermore, because the computational load is small, the CPU clock frequency can be lowered, enabling low power consumption. Low power consumption enables longer battery life when battery-powered. Longer battery life further reduces the need for battery replacement and charging. Furthermore, lowering the CPU clock frequency makes it easier to take measures against unwanted radiation, enabling lower costs and smaller size.

[0063] Furthermore, a shunt sound measurement method according to a fourth aspect of the present invention includes an acquisition step of acquiring biological sound data including shunt sounds, an extraction step of extracting specific frequency components from the biological sound data acquired in the acquisition step using a band-pass filter, an amplitude detection step of detecting amplitude values ​​of the specific frequency components extracted in the extraction step, an averaging step of calculating an average value obtained by averaging the amplitude values ​​detected in the amplitude detection step over time, a calculation step of calculating an index value by multiplying a specified value by the average value calculated in the averaging step, and an output step of outputting the index value calculated in the calculation step for each unit time.

[0064] According to the above configuration, an index value highly correlated with FV can be output from biological sound data including shunt sounds with a small computational load. The small computational load allows for miniaturization of the hardware required for calculations, lower costs, and lower power consumption. Furthermore, the low power consumption allows for battery operation, reducing the volume of the power supply unit and enabling the miniaturization of the device. In addition, since shunt sounds are acquired, which are relatively easy to measure, the time required for measurement can be shortened.

[0065] [Example of implementation by software] The functions of the shunt sound measuring device 1 (hereinafter referred to as the "device") can be realized by a program that causes a computer to function as the device, and a program that causes a computer to function as each control block of the device.

[0066] In this case, the device includes a computer having at least one control device (e.g., a processor) and at least one storage device (e.g., a memory) as hardware for executing the program. The functions described in each of the above embodiments are realized by executing the program using the control device and storage device.

[0067] The program may be non-transitory and may be recorded on one or more computer-readable recording media. The recording media may or may not be included in the device. In the latter case, the program may be supplied to the device via any wired or wireless transmission medium.

[0068] Furthermore, some or all of the functions of the control blocks can be realized by logic circuits. For example, an integrated circuit in which a logic circuit that functions as each of the control blocks is formed is also included in the scope of the present invention. In addition, the functions of the control blocks can also be realized by, for example, a quantum computer.

[0069] Furthermore, each process described in each of the above embodiments may be executed by AI (Artificial Intelligence). In this case, the AI ​​may run on the control device or on another device (for example, an edge computer or a cloud server).

[0070] Furthermore, the above configuration can improve the convenience of devices (diagnostic support for medical professionals) in remote consultations using electronic stethoscopes, etc. Such effects also contribute to the achievement of Goal 3 of the Sustainable Development Goals (SDGs) advocated by the United Nations, "Ensure healthy lives and promote well-being for all at all ages."

[0071] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

[0072] REFERENCE SIGNS LIST 1 shunt sound measuring device 10 acquisition unit 11 sensor 12 A / D conversion unit 16 audio output processing unit 17 operation unit 18 display unit 19 D / A conversion unit 20 analysis processing unit 21 band-pass filter 22 amplitude detection unit 23 averaging unit 24 calculation unit 25 output unit

Claims

1. A shunt sound measuring device comprising: an acquisition means for acquiring biological sound data including a shunt sound; a bandpass filter for extracting a specific frequency component from the biological sound data acquired by the acquisition means; an amplitude detection means for detecting an amplitude value of the specific frequency component extracted by the bandpass filter; an averaging means for calculating an average value by averaging over time the amplitude values ​​detected by the amplitude detection means; a calculation means for multiplying a specified value by the average value calculated by the averaging means to calculate an index value; and an output means for outputting the index value calculated by the calculation means.

2. The shunt sound measuring device according to claim 1, wherein the frequency band of the specific frequency component is 40 Hz or more and 170 Hz or less.

3. The shunt sound measuring device according to claim 1, wherein the averaging means averages the amplitude values ​​using a low-pass filter.

4. A shunt sound measuring device according to any one of claims 1 to 3, which is an electronic stethoscope.

5. A shunt sound measuring method comprising: an acquisition step of acquiring biological sound data including a shunt sound; an extraction step of extracting a specific frequency component from the biological sound data acquired in the acquisition step using a bandpass filter; an amplitude detection step of detecting an amplitude value of the specific frequency component extracted in the extraction step; an averaging step of calculating an average value by averaging over time the amplitude values ​​detected in the amplitude detection step; a calculation step of multiplying a specified value by the average value calculated in the averaging step to calculate an index value; and an output step of outputting the index value calculated in the calculation step.

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