Electronic auscultation device

Abstract

To appropriately control the level of the output sound of an electronic auscultation device.SOLUTION: Determining a motion state of the electronic auscultation device as one of a first state, a second state in which stability of the motion is higher than stability of the motion in the first state, and a third state in which stability of the motion is higher than stability of the motion in the second state, based on a detection value of the detection unit; And adjusting means for adjusting a level of the biological sound signal with a gain determined based on the determined motion state of the electronic stethoscope apparatus, wherein the adjusting means changes the gain toward a first gain when the motion state of the electronic stethoscope apparatus is determined to be a first state, changes the gain toward a second gain when the motion state of the electronic stethoscope apparatus is determined to be a second state, and changes the gain toward a third gain when the motion state of the electronic stethoscope apparatus is determined to be a third state, and the second gain is larger than the first gain and the third gain.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to an electronic auscultation device. [Background technology]

[0002] Electronic auscultation devices for acquiring body sounds based on vibrations on the body surface are becoming popular. Electronic auscultation devices have a vibration detection unit that detects vibrations on the body surface and generates a body sound signal that indicates the detection result. Electronic auscultation devices are configured so that the level of the body sound signal can be adjusted using an amplifier or the like to make it easier for the auscultator to hear the body sounds.

[0003] The vibration detection unit of the electronic auscultation device can also detect vibrations unrelated to vibrations on the body surface. For example, when the vibration detection unit comes into contact with the subject, it can detect vibrations unrelated to vibrations on the body surface. Furthermore, the vibration detection unit can detect airborne vibrations caused by conversation between the auscultator and the subject or environmental sounds. In such cases, the body sound signal output from the vibration detection unit is a signal indicating noise unrelated to body sounds. Generally, the vibrations detected by the vibration detection unit when the vibration detection unit is brought into contact with the subject are larger than the vibrations caused by vibrations on the body surface. Therefore, the sound output from the electronic auscultation device when the vibration detection unit is brought into contact with the subject (hereinafter referred to as output sound) can be at a level that is uncomfortable for the auscultator. Furthermore, although the vibrations detected by the vibration detection unit due to conversation or environmental sounds are relatively small, if the gain of the amplifier of the electronic auscultation device is high, the output sound can be at a level that is uncomfortable for the auscultator.

[0004] For this reason, Patent Document 1 discloses a configuration in which the output sound level is reduced for a certain period of time after the electronic auscultation device is brought into contact with the subject. Patent Document 2 also discloses a configuration in which the output of the electronic auscultation device is muted until the electronic auscultation device is brought into contact with the subject, the muting is released a predetermined period of time after the electronic auscultation device is brought into contact with the subject, and the output of the electronic auscultation device is muted again after a certain period of time has passed since the muting was released. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2020-78642 [Patent Document 2] Japanese Patent Application Publication No. 10-24033 Summary of the Invention [Problem to be solved by the invention]

[0006] In the configuration of Patent Document 1, output sounds based on conversation sounds and environmental sounds before the electronic auscultation device is brought into contact with the subject are output from the electronic auscultation device, which can be unpleasant for the auscultator. In the configuration of Patent Document 2, the output of the electronic auscultation device is muted after a given time has elapsed since muting was released, which can lead to the mute state being entered during auscultation depending on the given time setting. Furthermore, depending on the given time setting, the unmuted state may remain even after auscultation has ended, resulting in the output sounds based on conversation sounds and environmental sounds being output from the electronic auscultation device, which can be unpleasant for the auscultator.

[0007] The present invention provides a technique for appropriately controlling the output sound level of an electronic auscultation device. [Means for solving the problem]

[0008] According to one aspect of the present invention, an electronic auscultation device comprises an output means for outputting a biological sound signal indicating biological sounds based on vibrations of the surface of a living body; a detection means for detecting the movement of the electronic auscultation device; and an adjustment means for determining the movement state of the electronic auscultation device as one of a first state, a second state having a movement stability higher than that of the first state, or a third state having a movement stability higher than that of the second state based on the detection value of the detection means, and adjusting the level of the biological sound signal with a gain determined based on the determined movement state of the electronic auscultation device, wherein the adjustment means changes the gain toward a first gain when the movement state of the electronic auscultation device is determined to be the first state, changes the gain toward a second gain when the movement state of the electronic auscultation device is determined to be the second state, and changes the gain toward a third gain when the movement state of the electronic auscultation device is determined to be the third state, the second gain being greater than the first gain and the third gain. [Effects of the Invention]

[0009] According to the present invention, the output sound level of an electronic auscultation device can be appropriately controlled. [Brief explanation of the drawings]

[0010] [Figure 1] 1A and 1B illustrate example exterior views of an electronic auscultation device, according to some embodiments. [Figure 2] 1A-1C illustrate example chestpiece configurations, according to some embodiments. [Figure 3] FIG. 1 is a block diagram illustrating an example configuration of an electronic auscultation device according to one embodiment. [Figure 4] 10 is a flowchart of a gain determination process according to one embodiment. [Figure 5] 10A and 10B are diagrams showing examples of time variations of evaluation values ​​and gains according to one embodiment. [Figure 6] 1A-1C illustrate example chestpiece configurations, according to some embodiments. [Figure 7] FIG. 1 illustrates an example configuration of an electronic auscultation device according to one embodiment. [Figure 8] 10 is a flowchart of a gain determination process according to one embodiment. [Figure 9] 10A and 10B are diagrams showing examples of time variations of evaluation values ​​and gains according to one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. Note that the following embodiments do not limit the scope of the invention claimed. Although multiple features are described in the embodiments, not all of these multiple features are necessarily essential to the invention, and multiple features may be combined arbitrarily. Furthermore, in the accompanying drawings, the same reference numerals are used to designate the same or similar components, and redundant explanations will be omitted.

[0012] In addition, in the following drawings, a coordinate system CS, which is a three-dimensional Cartesian coordinate system having an x-axis, a y-axis, and a z-axis, is shown as necessary.

[0013] First Embodiment 1(A) and 1(B) show the general appearance of an electronic auscultation device 100. The electronic auscultation device 100 includes a chestpiece 110 and a grip portion 120. The chestpiece 110 is the part that comes into contact with a living body during diagnosis using the electronic auscultation device 100. The chestpiece 110 is also called a displacement detection device or a diaphragm displacement detection device because it detects displacement of the living body surface via a diaphragm. The chestpiece 110 can also be called a living body vibration detection device because it detects vibrations on the living body surface.

[0014] The chestpiece 110 is attached to one end of the grip 120 (negative side of the x-axis in FIG. 1). The grip 120 is the part that is gripped when a user of the electronic auscultation device 100 (e.g., a doctor, nurse, or public health nurse) presses the diaphragm of the chestpiece 110 against the surface of a living body. Hereinafter, the "user of the electronic auscultation device 100" will be simply referred to as the "user." The grip 120 may also be called a handle, a grip, a handle, or the like.

[0015] The grip part 120 has a battery and a circuit board inside a housing 121. The battery stores operating power for the electronic auscultation device 100. The circuit board has circuit elements for controlling the operation of the electronic auscultation device 100. The grip part 120 has a display unit 122, an operation unit 123, a power switch 124, and a connector 125 on the outer surface of the housing 121.

[0016] The display unit 122 displays the status of the electronic auscultation device 100. For example, the display unit 122 may include multiple indicators (four indicators in the example of FIG. 1(A)). Each indicator may be configured with a light-emitting diode (LED). The multiple indicators may include an indicator indicating whether the power of the electronic auscultation device 100 is on or off. The multiple indicators may include an indicator indicating the current operating mode of the electronic auscultation device 100. The multiple indicators may include an indicator indicating whether the electronic auscultation device 100 is wirelessly connected to an external device. The multiple indicators may include an indicator indicating whether the chestpiece 110 is pressed against a living body surface. Instead of or in addition to the multiple indicators, the display unit 122 may display the status of the electronic auscultation device 100 using a liquid crystal panel or an electrostatic panel.

[0017] The operation unit 123 accepts operations from the user. The operation unit 123 may include, for example, multiple physical buttons. In the example of FIG. 1, the operation unit 123 has adjustment buttons (up button 123a and down button 123b) for adjusting the level of the output sound, and a mode switching button 123c for switching the operation mode of the electronic auscultation device 100. The operation unit 123 may include a touch panel instead of multiple physical buttons. Furthermore, the display unit 122 and the operation unit 123 may be integrated as a touch screen.

[0018] The power switch 124 is a switch that switches the power of the electronic auscultation device 100 on and off. The connector 125 is a connector for receiving a cable or a connector of an external device. Power is supplied from the external device to the battery of the grip portion 120 through the connector 125. The power switch 124 may be provided on the chestpiece 110 instead of the grip portion 120. The connector 125 may be provided on the chestpiece 110 instead of the grip portion 120. Furthermore, the electronic auscultation device 100 may not include the connector 125. In this case, the electronic auscultation device 100 may have a wireless charging function or may be configured to have a replaceable battery.

[0019] Fig. 2 shows the configuration of chestpiece 110. The upper side of Fig. 2 is a cross-sectional view of chestpiece 110, and the lower side of Fig. 2 is a plan view of chestpiece 110. Note that in the plan view of Fig. 2, only light-emitting circuit board 203, light-receiving circuit board 205, diaphragm 206, and reflecting member 207 are shown in order to clarify the positional relationship of the components.

[0020] The light-emitting element 202 is a light source that emits light. In this embodiment, the light-emitting element 202 is a light-emitting diode (LED), but other light-emitting elements such as a laser diode (LD) can also be used as the light-emitting element 202. The light-emitting element 202 is mounted on a light-emitting circuit board 203. For example, a peripheral circuit for controlling the light emission of the light-emitting element 202 is mounted on the light-emitting circuit board 203. The light-emitting circuit board 203 including the light-emitting element 202 functions as a light-emitting unit.

[0021] The light receiving element 204 receives light and generates an electrical signal based on the amount of received light. The light receiving element 204 may be, for example, a phototransistor or a complementary metal-oxide semiconductor (CMOS) sensor. In this embodiment, the number of light receiving elements 204 is one, but a configuration using multiple light receiving elements 204 is also possible. The light receiving element 204 is mounted on a light receiving circuit board 205. Peripheral circuits and the like are mounted on the light receiving circuit board 205 for reading out signals from the light receiving element 204 and outputting electrical signals. The light receiving circuit board 205 including the light receiving element 204 functions as a light receiving unit.

[0022] The holding member 201 holds the light-emitting circuit board 203 and the light-receiving circuit board 205. The light-emitting circuit board 203 and the light-receiving circuit board 205 are fixed to the holding member 201. The holding member 201 also holds a diaphragm 206. The diaphragm 206 extends along the xy plane of the coordinate system CS. The diaphragm 206 is a membrane having a circular outer edge in a plan view. The diaphragm 206 is arranged to contact a biological surface. The diaphragm 206 forms part of the outer surface of the chestpiece 110. The diaphragm 206 has an outer surface 206a that is arranged to contact a biological surface when the electronic auscultation device 100 is in use, and an inner surface 206b that is opposite the outer surface 206a.

[0023] Diaphragm 206 has fixed portion 206c fixed to holding member 201. Fixed portion 206c is located on the outer periphery of diaphragm 206. The inner periphery of diaphragm 206 (i.e., the portion inside fixed portion 206c) is not fixed to holding member 201. Therefore, diaphragm 206 can vibrate in the z-axis direction with fixed portion 206c as a node. Specifically, when chestpiece 110 is in use, diaphragm 206 vibrates with fixed portion 206c as a node in response to vibrations on the surface of the living body. In this vibration, center 206e of diaphragm 206 becomes an antinode. Diaphragm 206 functions as a vibrating unit.

[0024] The reflecting member 207 is a reflecting portion that reflects light emitted from the light-emitting element 202. The reflecting member 207 is adhered to the inner surface 206b of the diaphragm 206, and therefore vibrates in the z-axis direction in conjunction with the vibration of the diaphragm 206, which is in close contact with the surface of a living body. The reflecting member 207 has a circular outer edge in a plan view. The outer edge of the reflecting member 207 may have other shapes. The reflecting member 207 is positioned to cover a region 206d including the center 206e of the diaphragm 206. Since the displacement of the diaphragm 206 changes most significantly at the center 206e, the vibration of the diaphragm 206 can be detected with high sensitivity by reflecting light from the light-emitting element 202 in the region including the center 206e. Note that, although the reflecting member 207 is positioned to cover the center 206e in this embodiment, the reflecting member 207 may also be positioned to cover a region of the diaphragm 206 that does not include the center 206e. The reflecting member 207 is formed, for example, of an aluminum-deposited film.

[0025] The light emitting element 202 emits light toward the reflecting member 207, and the upper surface of the reflecting member 207 reflects the light emitted by the light emitting element 202. That is, the upper surface of the reflecting member 207 functions as a light reflecting surface. In the following description, the reflection of light on the upper surface of the reflecting member 207 (i.e., the light reflecting surface) will be simply referred to as light being reflected by the reflecting member 207. The reflecting member 207 specularly reflects (in other words, specularly reflects) the light emitted by the light emitting element 202. In the following description, as shown in FIG. 2(B), the light traveling from the light emitting element 202 toward the reflecting member 207 will be referred to as incident light 211, and the light after the incident light 211 is reflected will be referred to as reflected light 212.

[0026] In this embodiment, the reflecting member 207 is a separate member from the diaphragm 206. However, the reflecting member 207 may be a coating layer applied to the diaphragm 206. The reflecting member 207 may also be a sticker or the like attached to the diaphragm 206. The reflecting member 207 may be formed as the same member as the diaphragm 206, and at least a part of the inner surface 206b of the diaphragm 206 may also serve as a reflecting portion. For example, the entire inner surface 206b of the diaphragm 206 may have a high reflectivity that can reflect light to an extent that can be detected by the light receiving element 204. Alternatively, only a region of the inner surface 206b of the diaphragm 206 that is reached by light irradiated by the light emitting element 202 may have such a high reflectivity.

[0027] When diaphragm 206 is not in contact with the surface of the living body, light emitting element 202 can be arranged to irradiate region 207a of reflecting member 207 that includes a portion covering center 206e of diaphragm 206. When diaphragm 206 is not in contact with the surface of the living body, diaphragm 206 is flat.

[0028] In this embodiment, as described above, an LED that emits diffused light is used as the light-emitting element 202. Therefore, the chestpiece 110 has an aperture 209 that limits the range of light emitted from the light-emitting element 202. The aperture 209 allows only a portion of the light emitted by the light-emitting element 202 to be irradiated onto the reflecting member 207. In the example of FIG. 2, an opening formed in the holding member 201 corresponds to the aperture 209. Note that, in this embodiment, a component that emits diffused light has been described as an example of the light-emitting element 202, but instead, a component that emits linear light may be used as the light-emitting element 202, and the linear light may be irradiated toward the region 207a. Note that the aperture 209 may also be used when the light-emitting element 202 is a component that emits linear light.

[0029] The light receiving element 204 is disposed so as to receive the reflected light 212. Specifically, the light receiving element 204 is disposed at a position where the amount of received reflected light 212 changes due to vibration of the diaphragm 206 in the z-axis direction. The light receiving element 204 is disposed so as to receive more light of the reflected light 212 when the diaphragm 206 is not in contact with the surface of the living body (i.e., when the diaphragm 206 is flat) than when the diaphragm 206 is vibrating. Therefore, the light receiving element 204 outputs an electrical signal corresponding to the vibration of the diaphragm 206. The electrical signal output by the light receiving element 204 is output via a peripheral circuit mounted on the light receiving circuit board 205.

[0030] The chestpiece 110 has an aperture 210 that limits the range of light that enters the light receiving element 204. The aperture 210 prevents diffusely reflected light from entering the light receiving element 204, and allows only at least a portion of the light from the reflecting member 207 (i.e., the primarily reflected light) to reach the light receiving element 204. In the example of FIG. 2, an opening formed in the holding member 201 functions as the aperture 210. Alternatively, the aperture 210 may be formed in a different manner.

[0031] A housing 208 is attached to the outer circumferential upper surface of the holding member 201. The housing 208 covers the light-emitting circuit board 203 and the light-receiving circuit board 205 and prevents ambient sound from entering the housing 208. The outer edges of the diaphragm 206, the holding member 201, and the housing 208 may coincide with one another in a plan view with respect to the outer surface 206a of the diaphragm 206. In this embodiment, the housing 208 is made of stainless steel.

[0032] By fixing the diaphragm 206 to the holding member 201, an internal space surrounded by the diaphragm 206 and the holding member 201 is formed. The internal space is sealed in order to prevent light different from the light reflected by the light emitting element 202 from entering the light receiving element 204. Furthermore, the diaphragm 206 has a light-blocking property in order to prevent light different from the light reflected by the light emitting element 202 from entering the light receiving element 204. Alternatively or in addition to this, the diaphragm 206 may be covered with a light-blocking film. Similarly, the holding member 201 may have a light-blocking property or may be covered with a light-blocking film.

[0033] In this embodiment, a status detection sensor 300 is attached to the holding member 201. The status detection sensor 300 may be attached to the inner surface of the housing 208 instead of the holding member 201. The status detection sensor 300 is a sensor that detects the movement of the chestpiece 110. Note that if the grip portion 120 moves integrally with the chestpiece 110, the status detection sensor 300 may be provided on the grip portion 120. In other words, if the overall movement of the electronic auscultation device 100 is similar to the movement of the chestpiece 110, the status detection sensor 300 only needs to detect the movement of the electronic auscultation device 100. The status detection sensor 300 may have, as a detection element, an acceleration sensor that detects acceleration as a detected value of the movement of the chestpiece 110. Alternatively, the status detection sensor 300 may have, as a detection element, an angular velocity sensor (gyro sensor) that detects angular velocity as a detected value of the movement of the chestpiece 110. The status detection sensor 300 outputs a detection value at each sampling period.

[0034] In the following description, it is assumed that the status detection sensor 300 has a triaxial acceleration sensor as a detection element. Furthermore, it is assumed that the axial directions of the triaxial acceleration sensor coincide with the x-, y-, and z-axis directions of the coordinate system CS shown in the figure. Therefore, the detected values ​​output by the status detection sensor 300 at each sampling period are accelerations in the x-, y-, and z-axis directions. However, as will be clear from the following description, the axial directions of the acceleration sensor do not have to coincide with the x-, y-, and z-axis directions.

[0035] In the following description, the components of the chestpiece 110 for outputting an electrical signal corresponding to the vibration of the diaphragm 206, i.e., the light-emitting element 202, the light-emitting circuit board 203, the light-receiving element 204, the light-receiving circuit board 205, and the reflecting member 207, are referred to as the vibration detection unit 200 (see FIG. 3). Furthermore, the electrical signal corresponding to the vibration of the diaphragm 206 output by the vibration detection unit 200 is referred to as a body sound signal. The vibration detection unit 200 may also be referred to as a body sound signal output unit that outputs a body sound signal.

[0036] 3 is a block diagram of the electronic auscultation device 100 according to this embodiment. The biological sound signal output by the vibration detection unit 200 is input to the adjustment unit 402 of the grip unit 120. The detection value (detection result) detected by the condition detection sensor 300 is input to the gain setting unit 403 of the grip unit 120. In this embodiment, the detection value output by the condition detection sensor 300 is the acceleration in each of the x-axis, y-axis, and z-axis directions. The storage unit 404 of the grip unit 120 stores two thresholds in advance: a first threshold and a second threshold smaller than the first threshold.

[0037] The gain setting unit 403 determines a gain based on the detection value from the state detection sensor 300 and the first and second thresholds stored in the storage unit 404, and notifies the adjustment unit 402 of the determined gain by a gain setting signal. Details of the gain determination method will be described later. The gain setting unit 403 may be configured as hardware using an application specific integrated circuit (ASIC) or the like. Alternatively, the gain setting unit 403 may be realized as software by causing one or more processors to execute an appropriate program. Alternatively, the gain setting unit 403 may be realized as a combination of hardware and software.

[0038] The level setting unit 401 notifies the adjustment unit 402 of the reference level set by the user by operating the adjustment buttons (up button 123a and down button 123b) of the operation unit 123 by using a level setting signal. The adjustment unit 402 has, for example, an amplifier. The adjustment unit 402 determines the adjusted level of the body sound signal based on the reference level indicated by the level setting signal and the gain indicated by the gain setting signal, and outputs the level-adjusted body sound signal as an output signal. In this embodiment, the level of the output signal (the level of the adjusted body sound signal) is R×g, where R is the reference level indicated by the level setting signal and g is the gain indicated by the gain setting signal. In this embodiment, the gain g is a value between 0 and 1.

[0039] The output unit 405 outputs an output signal to the outside. For example, the output unit 405 is a jack for connecting earphones or headphones. The output unit 405 outputs the output signal to the earphones or headphones via the jack. The earphones or headphones output sound corresponding to the output signal. For example, the output unit 405 is a wireless transmitter that wirelessly transmits data for reproducing the sound indicated by the output signal. For example, the output unit 405 generates data from the output signal and outputs the generated data to wireless earphones or wireless headphones. The wireless earphones or wireless headphones output sound corresponding to the output signal based on the data. For example, the output unit 405 generates data from the output signal and transmits the generated data to a personal computer or a portable information processing device such as a smartphone or tablet. The personal computer or portable information processing device outputs sound corresponding to the output signal based on the data, or stores the data in a memory device for later playback.

[0040] A method for determining the gain in the gain setting unit 403 will be described below. The gain setting unit 403 calculates an evaluation value for evaluating the state of movement of the electronic auscultation device 100, more specifically, the chestpiece 110 (hereinafter referred to as the movement state), based on the detection values ​​from the vibration detection unit 200 over a predetermined past period. The evaluation value may be a value corresponding to the instability (or stability) of the movement of the chestpiece 110. The evaluation value may also be a value corresponding to the instability (or stability) of the posture of the chestpiece 110. As an example, the evaluation value may be a value that increases as the movement or posture of the chestpiece 110 becomes more unstable.

[0041] In this embodiment, the evaluation value is the variance of multiple detection values ​​over a predetermined period of time. The variance is an example of a value that indicates the variation in the multiple detection values. Note that other values ​​that indicate the variation in the multiple detection values ​​or values ​​based on the variance can also be used as the evaluation value. A large variation in the multiple detection values, for example, a large variance, indicates that the chestpiece 110 is moving unstably (has an unstable posture). On the other hand, a small variation in the multiple detection values, for example, a small variance, indicates that the chestpiece 110 is moving steadily (has a stable posture). For example, if the chestpiece 110 is left stationary on a desk, the evaluation value will be approximately 0.

[0042] In this way, in the following explanation, the evaluation value is assumed to be higher as the movement of the chestpiece 110 becomes unstable, but the evaluation value may also be lower as the movement of the chestpiece 110 becomes unstable. The predetermined past period used to calculate the evaluation value and the sampling period of the state detection sensor 300 are determined so as to obtain the evaluation value necessary to classify the movement state of the electronic auscultation device 100. As an example, the sampling period is set to 10 ms, and the evaluation value can be calculated based on 50 detection values ​​over the past 500 ms.

[0043] In this embodiment, the detected values ​​indicate the accelerations in the x-axis, y-axis, and z-axis directions, and therefore the variances used as the evaluation values ​​are also calculated for each of the x-axis, y-axis, and z-axis directions. In other words, in this embodiment, the evaluation value is a collective term for the variances of the accelerations in the x-axis, y-axis, and z-axis directions.

[0044] Gain setting unit 403 compares the evaluation value with a first threshold and a second threshold stored in storage unit 404, and classifies the movement state of chestpiece 110 into three states: a first state, a second state, and a third state. Specifically, if the evaluation value is greater than the first threshold, gain setting unit 403 determines the movement state of chestpiece 110 to be the first state. If the evaluation value is equal to or less than the first threshold and greater than the second threshold, gain setting unit 403 determines the movement state of chestpiece 110 to be the second state. If the evaluation value is equal to or less than the second threshold, gain setting unit 403 determines the movement state of chestpiece 110 to be the third state.

[0045] Alternatively, the gain setting unit 402 may be configured to determine the first state when the evaluation value is equal to or greater than the first threshold, the second state when the evaluation value is less than the first threshold and equal to or greater than the second threshold, and the third state when the evaluation value is less than the second threshold. In other words, when the evaluation value is equal to a threshold, it is optional whether to determine the state as greater than the threshold or as less than the threshold. Therefore, more generally, the gain setting unit 402 determines the first state when the evaluation value is within the first range, the second state when the evaluation value is within the second range, and the third state when the evaluation value is within the third range. Here, values ​​within the first range are greater than values ​​within the second range, and values ​​within the second range are greater than values ​​within the third range. Values ​​included in all ranges from the first range to the third range encompass the ranges that the evaluation value can take.

[0046] In this embodiment, the evaluation value includes variance values ​​in the x-axis, y-axis, and z-axis directions, and "an evaluation value greater than the threshold" means that at least one of the three variance values ​​is greater than the threshold. Conversely, "an evaluation value smaller than the threshold" means that all three variance values ​​are smaller than the threshold. Furthermore, "an evaluation value equal to or greater than the threshold" means that at least one of the three variance values ​​is equal to or greater than the threshold, and "an evaluation value equal to or less than the threshold" means that all three variance values ​​are equal to or less than the threshold.

[0047] The first state is a state in which the electronic auscultation device 100 is moving unstably, for example, corresponding to a state in which the user is manually moving the electronic auscultation device 100 toward the subject for auscultation. In the following description, the first state is also referred to as the "unstable non-auscultation state." The third state is a state in which the electronic auscultation device 100 is moving stably (including a stationary state), for example, corresponding to a state in which the electronic auscultation device 100 is left on a desk. In the following description, the third state is also referred to as the "stable non-auscultation state." Furthermore, in the following description, the unstable non-auscultation state and the stable non-auscultation state are collectively referred to as the "non-auscultation state." The second state is a state in which the movement of the electronic auscultation device 100 is moderately unstable, corresponding to a state in which the user is performing auscultation using the electronic auscultation device 100. In the following description, the second state is also referred to as the "auscultation state."

[0048] The first threshold and the second threshold are determined, for example, experimentally, so as to be able to accurately determine whether or not auscultation is being performed with the electronic auscultation device 100, that is, whether or not the device is in an auscultating state.

[0049] When the gain setting unit 403 determines that the movement state of the electronic auscultation device 100 is an unstable non-auscultation state, it sets the target gain to G1. When the gain setting unit 403 determines that the movement state of the electronic auscultation device 100 is an auscultation state, it sets the target gain to G2. When the gain setting unit 403 determines that the movement state of the electronic auscultation device 100 is a stable non-auscultation state, it sets the target gain to G3. Here, the target gains G1 and G3 are smaller than the target gain G2. The target gains G1 and G3 may be the same value or different values. Hereinafter, for simplicity of explanation, unless it is clearly stated that the target gains G1 and G3 are different values, the target gains G1 and G3 will be considered to be the same value. Furthermore, the target gain in the third state will be referred to as target gain G1 rather than target gain G3.

[0050] The target gain G2 is set to 1 or a value close to 1 so as to minimize the difference between the output signal level and the reference level. On the other hand, the target gains G1 and G3 can be set to 0 or a value close to 0, such as 0.1, so as not to cause discomfort to the user due to the output signal. In this embodiment, the target gains G1 and G3 have the same value. However, if the target gains G1 and G3 are different, the target gain G3 can be set to a value smaller than the target gain G1. As an example, the target gain G3 can be set to 0 and the target gain G3 can be set to 0.1. This is because the third state mainly corresponds to a state in which the electronic auscultation device 100 is left unattended, and therefore a very low output sound level is not a problem. On the other hand, in the first state, the user may be holding the electronic auscultation device 100 and listening to the output sound, so it may be preferable for the user to hear environmental sounds at a level that does not cause discomfort.

[0051] The gain setting unit 403 may be configured to gradually increase (change) the gain toward the target gain G2, rather than immediately changing the gain to the target gain G2, even when it determines that the non-auscultation state has transitioned to the auscultation state. The rate of increase (rate of change) of the gain does not need to be constant. Alternatively, the gain setting unit 403 may be configured to immediately change the gain to the target gain G1, when it determines that the auscultation state has transitioned to the non-auscultation state. The gain setting unit 403 may also be configured to gradually decrease the gain toward the target gain G1, rather than immediately changing the gain to the target gain G1, when it determines that the auscultation state has transitioned to the non-auscultation state. However, the absolute value of the rate of decrease (rate of change) of the gain due to the transition to the non-auscultation state is set to be greater than the absolute value of the rate of increase of the gain due to the transition to the auscultation state.

[0052] By configuring the gain setting unit 403 in this manner, the level of the output signal of the electronic auscultation device 100 gradually increases when transitioning from the non-auscultation state to the auscultation state. This prevents the level of the sound based on the output signal from momentarily increasing, which would cause discomfort to the user. On the other hand, when transitioning from the auscultation state to the non-auscultation state, the level of the sound based on the output signal quickly decreases, which prevents the output of a sound that would cause discomfort to the user, even if the vibration detection unit 200 detects vibrations other than those of a living body.

[0053] 4 is a flowchart of the gain determination process by the gain setting unit 403. In S10, the gain setting unit 403 obtains an evaluation value. In S11, the gain setting unit 403 compares the evaluation value with a first threshold value to determine whether the electronic auscultation device 100 is in an unstable non-auscultation state (first state). If the evaluation value is greater than the first threshold value, that is, if the electronic auscultation device 100 is determined to be in an unstable non-auscultation state, the gain setting unit 403 sets the target gain to G1 in S15.

[0054] If it is determined that the electronic auscultation device 100 is not in an unstable non-auscultation state (first state), the gain setting unit 403 compares the evaluation value with a second threshold value in S12 to determine whether the electronic auscultation device 100 is in a stable non-auscultation state (third state). If the evaluation value is equal to or less than the second threshold value, that is, if it is determined to be in a stable non-auscultation state, the gain setting unit 403 sets the target gain to G1 in S15. If it is determined that the electronic auscultation device 100 is not in a stable non-auscultation state (third state), the gain setting unit 403 determines that the electronic auscultation device 100 is in an auscultation state and sets the target gain to G2 in S13. In S14, the gain setting unit 403 notifies the adjustment unit 402 of the gain determined based on the target gain. As described above, if the target gain is G2, the gain setting unit 403 gradually increases the gain to be notified to the adjustment unit 402 from the current gain toward gain G2. After the gain reaches gain G2, the gain is kept constant at gain G2. When the target gain is G1, gain setting unit 403 immediately sets the gain to be notified to adjustment unit 402 to gain G1. Even when the target gain is G1, the gain to be notified to adjustment unit 402 can be configured to gradually decrease from the current gain toward gain G1.

[0055] FIG. 5 shows an example of the change over time in the evaluation value and gain. Note that the evaluation value actually includes three values ​​for each of the three directions, but in FIG. 5, it is represented as one value for simplicity. From time t0 to time t1, the electronic auscultation device 100 is placed on a desk, and the evaluation value is equal to or less than the second threshold. Therefore, the gain setting unit 403 notifies the adjustment unit 402 of the gain G1. When the user lifts the electronic auscultation device 100 from the desk, the evaluation value exceeds the second threshold at time t1, and further exceeds the first threshold at time t2. Because the evaluation value is within the range between the second threshold and the first threshold from time t1 to time t2, the gain setting unit 403 gradually increases the gain notified to the adjustment unit 402 toward the gain G2. However, because the evaluation value exceeds the first threshold at time t2, the gain setting unit 403 changes the gain notified to the adjustment unit 402 to the gain G1 at time t2. Since the period from time t1 to time t2 is short, the gain is relatively small when time t2 is reached.

[0056] During the period from time t2 to time t3, the user is moving the electronic auscultation device 100 toward the subject, and the evaluation value is greater than the first threshold, so the gain setting unit 403 notifies the adjustment unit 402 of gain G1. For example, the user brings the chestpiece 110 into contact with the subject and begins auscultation, so that from time t3 onward, the evaluation value falls within the range between the second threshold and the first threshold. Therefore, from time t3 onward, the gain setting unit 403 gradually increases the gain notified to the adjustment unit 402 toward gain G2. As shown in FIG. 5, at time t4, the gain notified to the adjustment unit 402 becomes gain G2, and thereafter, the gain setting unit 403 keeps the gain notified to the adjustment unit 402 constant at G2.

[0057] As described above, the movement of the electronic auscultation device 100 is detected, and based on the detection results, it is determined whether the electronic auscultation device 100 is in an auscultation state (state 2) where auscultation is being performed, or in a non-auscultation state (states 1 and 3) where auscultation is not being performed. If the electronic auscultation device is in an auscultation state, the gain, which is a parameter for adjusting the level of the output signal, is increased toward gain G2. On the other hand, if the electronic auscultation device is not in an auscultation state, the gain is decreased toward gain G1 or gain G3. This configuration makes it possible to prevent the user from feeling uncomfortable due to noise output when not auscultating. In other words, the level of the output signal (output sound) of the electronic auscultation device can be appropriately controlled.

[0058] Although the chestpiece 110 in FIG. 2 detects vibration of the diaphragm 206 based on the amount of received reflected light and outputs a biological sound signal, the configuration of the chestpiece 110 is not limited to that shown in FIG. 2. FIG. 6 shows another configuration example of the chestpiece 110. As shown in FIG. 6, the chestpiece 110 has a microphone 220 held by a holding member 201. The microphone 220 detects sound generated by vibration of the diaphragm 206 accompanying vibration of the biological surface and outputs a biological sound signal. The chestpiece 110 may further include a piezoelectric element that detects pressure due to vibration of the biological surface. The piezoelectric element detects pressure due to vibration of the biological surface directly or via the diaphragm 206 and outputs a biological sound signal indicating changes in pressure over time. The chestpiece 110 may further include an acceleration sensor that detects the acceleration of vibration of the biological surface. The acceleration sensor detects the acceleration of the vibrations on the body surface directly or via the diaphragm 206, and outputs a body sound signal indicating the change in acceleration over time. Furthermore, the chestpiece 110 may include a gyro sensor that detects the angular velocity of the vibrations on the body surface. The gyro sensor detects the angular velocity of the vibrations on the body surface directly or via the diaphragm 206, and outputs a body sound signal indicating the change in angular velocity over time.

[0059] Second Embodiment Next, the second embodiment will be described, focusing on the differences from the first embodiment. Figure 7 is a block diagram of the electronic auscultation device 100 according to this embodiment. One of the differences from the configuration shown in Figure 3 is that a first threshold, a second threshold, and a third threshold are stored in the storage unit 404. The first threshold is greater than the third threshold, and the third threshold is greater than the second threshold.

[0060] The evaluation value in the first embodiment was the variance of acceleration in each of the x-axis, y-axis, and z-axis directions. In this embodiment, the variance of acceleration in the z-axis direction is used as the first evaluation value, and the variance of acceleration in each of the x-axis and y-axis directions is used as the second evaluation value. In addition, in the first embodiment, a single first threshold value was used to determine whether or not there is an unstable non-auscultation state (first state). In this embodiment, two threshold values, a first threshold value and a third threshold value, are used to determine whether or not there is an unstable non-auscultation state (first state).

[0061] In this embodiment, too, the three axial directions of the acceleration sensor included in the status detection sensor 300 are assumed to coincide with the x-, y-, and z-axis directions of the coordinate system CS. Therefore, the detected values ​​output by the status detection sensor 300 at each sampling period are accelerations in the x-, y-, and z-axis directions. If the relative angles between the three axial directions of the acceleration sensor and the three axial directions of the coordinate system CS are known, the accelerations in the x-, y-, and z-axis directions can be calculated based on the accelerations in the three axial directions output by the acceleration sensor. Therefore, the three axial directions of the acceleration sensor do not have to coincide with the x-, y-, and z-axis directions of the coordinate system CS.

[0062] The gain setting unit 403 of this embodiment determines the movement state of the electronic auscultation device 100 to be an unstable non-auscultation state (first state) when the first evaluation value is greater than the first threshold or when the second evaluation value is greater than the third threshold. The gain setting unit 403 determines the movement state of the electronic auscultation device 100 to be a stable non-auscultation state (third state) when both the first evaluation value and the second evaluation value are equal to or less than the second threshold. The gain setting unit 403 determines the movement state of the electronic auscultation device 100 to be an auscultation state (second state) when the first evaluation value is equal to or less than the first threshold, the second evaluation value is equal to or less than the third threshold, and both the first evaluation value and the second evaluation value are greater than the second threshold.

[0063] As in the first embodiment, the second evaluation value being greater than the threshold value means that at least one of the x-axis variance value and the y-axis variance value is greater than the threshold value, the second evaluation value being equal to or greater than the threshold value means that at least one of the x-axis variance value and the y-axis variance value is equal to or greater than the threshold value, the second evaluation value being smaller than the threshold value means that both the x-axis variance value and the y-axis variance value are smaller than the threshold value, and the second evaluation value being equal to or less than the threshold value means that both the x-axis variance value and the y-axis variance value are equal to or less than the threshold value.

[0064] Furthermore, as described in the first embodiment, when the evaluation value is equal to the threshold value, it is arbitrary whether to determine that the evaluation value is greater than the threshold value or less than the threshold value.

[0065] In summary, in this embodiment, the criteria for determining a stable non-auscultation state (third state) are the same as in the first embodiment. On the other hand, in this embodiment, the criteria for determining an unstable non-auscultation state (first state) are different from those in the first embodiment. Specifically, the first evaluation value evaluates the instability of movement in the z direction, and the second evaluation value evaluates the instability of movement in a direction intersecting the z direction, more specifically, in a direction perpendicular to the z direction. In this embodiment, the third threshold value compared with the second evaluation value to determine whether or not the state is unstable non-auscultation is smaller than the first threshold value compared with the first evaluation value.

[0066] For example, after picking up the electronic auscultation device 100 from a desk, the user may hold the electronic auscultation device 100 in their hand for a while without moving it significantly, rather than immediately bringing the electronic auscultation device 100 into contact with the subject and starting auscultation. Furthermore, when auscultating multiple locations, the user may hold the electronic auscultation device 100 in their hand between auscultations without moving it significantly. Hereinafter, the state in which the user holds the electronic auscultation device 100 in their hand without moving it significantly will be referred to as the "user-held state." The user-held state is a non-auscultatory state, but the stability of the movement of the electronic auscultation device 100 is higher than when the electronic auscultation device 100 is picked up from a desk, for example.

[0067] To classify the user's holding state as a non-auscultation state, the first threshold value in the first embodiment may be set to a relatively small value. However, during auscultation, the state detection sensor 300 detects acceleration in the z-axis direction in response to vibrations on the surface of the living body. If the evaluation value in the z-axis direction exceeds the first threshold value due to this acceleration in the z-axis direction, the gain is changed to G2 even during auscultation, and the level of the living body sound becomes lower.

[0068] For this reason, in this embodiment, the evaluation value in the first embodiment is separated into a first evaluation value in the z direction and second evaluation values ​​in the x and y directions. The z direction is the direction in which the angle with the vibration direction of the biological surface is smaller than the x and y directions when detecting vibrations on the biological surface. The third threshold value, which is compared with the second evaluation value to determine whether the state is an unstable non-auscultation state (first state), is set smaller than the first threshold value, which is compared with the first evaluation value. This configuration accurately determines whether the user's holding state is included in the unstable non-auscultation state, and suppresses the output of sounds that may be unpleasant to the user in the non-auscultation state.

[0069] 8 is a flowchart of the gain determination process in this embodiment. In S20, the gain setting unit 403 calculates a first evaluation value and a second evaluation value. In S21, the gain setting unit 403 compares the first evaluation value with a first threshold value to determine whether the electronic auscultation device 100 is in an unstable non-auscultation state (first state). If the first evaluation value is greater than the first threshold value, that is, if the electronic auscultation device 100 is determined to be in an unstable non-auscultation state, the gain setting unit 403 sets the target gain to G1 in S26.

[0070] If the first evaluation value is equal to or less than the first threshold, the gain setting unit 403 compares the second evaluation value with a third threshold to determine whether the electronic auscultation device 100 is in an unstable non-auscultation state (first state) in S22. If the second evaluation value is greater than the third threshold, that is, if it is determined to be in an unstable non-auscultation state, the gain setting unit 403 sets the target gain to G1 in S26.

[0071] If it is determined that the electronic auscultation device 100 is not in the unstable non-auscultation state (first state), the gain setting unit 403 compares the first evaluation value and the second evaluation value with a second threshold value in S23 to determine whether the electronic auscultation device 100 is in the stable non-auscultation state (third state). If both the first evaluation value and the second evaluation value are equal to or less than the second threshold value, that is, if it is determined that the electronic auscultation device 100 is in the stable non-auscultation state, the gain setting unit 403 sets the target gain to G1 in S26. If it is determined that the electronic auscultation device 100 is not in the stable non-auscultation state (third state), the gain setting unit 403 determines that the electronic auscultation device 100 is in the auscultation state (second state), and sets the target gain to G2 in S24. The gain setting unit 403 notifies the adjustment unit 402 of the gain in S25. The gain changing method is the same as in the first embodiment.

[0072] FIG. 9 shows an example of the change over time of the evaluation value and gain. Note that the second evaluation value actually includes two values ​​for each of the two directions, but in FIG. 9 it is shown as one value for simplicity. During the period from time t10 to time t11, the user picks up the electronic auscultation device 100 from the desk, and both the first evaluation value and the second evaluation value exceed the first threshold. Therefore, the gain setting unit 403 notifies the adjustment unit 402 of the gain G1.

[0073] The period from time t11 to time t17 corresponds to the user-held state. From time t11 to time t17, both the first evaluation value and the second evaluation value are below the first threshold, but are lower than the third threshold only sporadically. Therefore, from time t11 to time t17, except for the period when the second evaluation value is lower than the third threshold, the gain setting unit 403 notifies the adjustment unit 402 of the gain G1. Furthermore, during the period when the second evaluation value is lower than the third threshold, the gain setting unit 403 increases the gain notified to the adjustment unit 402 toward G2. However, because the period when the second evaluation value is lower than the third threshold is short, the gain notified to the adjustment unit 402 does not increase very much. For example, in the first embodiment, the gain notified to the adjustment unit 402 is increased toward G2 during the period from time t11 to time t17.

[0074] The period from time t17 to time t18 corresponds to a state in which the user is moving the chestpiece 110 to bring it into contact with the non-measured person. As the user brings the chestpiece 110 into contact with the non-measured person and begins auscultation, from time t18 onwards, the first evaluation value falls within the range between the second threshold and the first threshold, and the second evaluation value falls within the range between the second threshold and the third threshold. Therefore, from time t18 onwards, the gain setting unit 403 gradually increases the gain notified to the adjustment unit 402 towards gain G2. As shown in FIG. 9, at time t19, the gain notified to the adjustment unit 402 becomes G2, and thereafter, the gain setting unit 403 keeps the gain notified to the adjustment unit 402 constant at G2.

[0075] Note that after time t18, the first evaluation value increases sporadically. This is because the state detection sensor 300 detects acceleration in the z-axis direction due to vibrations on the surface of the living body. For example, if the first threshold in the first embodiment is set to the same value as the third threshold in this embodiment in order to classify the user's holding state as a non-auscultation state, the configuration of the first embodiment would change the gain to gain G2 each time the first evaluation value increases sporadically after time t18. On the other hand, in this embodiment, the first threshold applied to the first evaluation value and the third threshold applied to the second evaluation value are different, so the auscultation state can be accurately detected and the gain can be prevented from decreasing during auscultation.

[0076] As described above, according to this embodiment, it is possible to accurately determine whether or not the electronic auscultation device is in a non-auscultation state, and therefore it is possible to appropriately control the level of the output sound of the electronic auscultation device based on the determined state.

[0077] [Other embodiments] The present invention can also be realized by supplying a program that realizes one or more functions of the above-described embodiments to a system or device via a network or a storage medium, and having one or more processors in the computer of the system or device read and execute the program.The present invention can also be realized by a circuit (e.g., ASIC) that realizes one or more functions.

[0078] The disclosure of this embodiment includes the following configuration. (Configuration 1) An electronic stethoscope device, comprising: an output means for outputting a body sound signal indicating a body sound based on vibration of the body surface; a detection means for detecting movement of the electronic auscultation device; an adjusting means for determining the movement state of the electronic auscultation device based on the detection value of the detecting means as one of a first state, a second state having a movement stability higher than that of the first state, and a third state having a movement stability higher than that of the second state, and adjusting the level of the biological sound signal with a gain determined based on the determined movement state of the electronic auscultation device; Equipped with The adjusting means is When the movement state of the electronic auscultation device is determined to be the first state, the gain is changed toward a first gain; When the movement state of the electronic auscultation device is determined to be the second state, the gain is changed toward a second gain; When the movement state of the electronic auscultation device is determined to be the third state, the gain is changed toward a third gain; The electronic auscultation device, wherein the second gain is greater than the first gain and the third gain. (Configuration 2) 2. The electronic auscultation device according to claim 1, wherein the adjustment means calculates an evaluation value indicating the variation of a plurality of detection values ​​of the detection means over a predetermined period in the past, and determines the operating state of the electronic auscultation device based on the evaluation value. (Configuration 3) 3. The electronic auscultation device according to claim 2, wherein the evaluation value is a value based on a variance of the plurality of detection values ​​of the detection means over the past predetermined period. (Configuration 4) The adjusting means is If the evaluation value is greater than a first threshold, the movement state of the electronic auscultation device is determined to be the first state; If the evaluation value is smaller than the second threshold, the movement state of the electronic auscultation device is determined to be the third state; If the evaluation value is smaller than the first threshold and larger than the second threshold, the movement state of the electronic auscultation device is determined to be the second state; 4. The electronic auscultation device of claim 2 or 3, wherein the first threshold is greater than the second threshold. (Configuration 5) the evaluation values ​​include a first evaluation value in a first direction and a second evaluation value in a second direction different from the first direction; the first direction is a direction that forms a smaller angle with the vibration direction of the biological surface than the second direction when the output means detects the vibration of the biological surface; The adjusting means is If the first evaluation value is greater than a first threshold value or the second evaluation value is greater than a third threshold value, the movement state of the electronic auscultation device is determined to be the first state; If both the first evaluation value and the second evaluation value are smaller than a second threshold, the movement state of the electronic auscultation device is determined to be the third state; If the first evaluation value is smaller than the first threshold, the second evaluation value is smaller than the third threshold, and both the first evaluation value and the second evaluation value are larger than the second threshold, the movement state of the electronic auscultation device is determined to be the second state; 4. The electronic auscultation device of configuration 2 or 3, wherein the first threshold is greater than the third threshold, and the third threshold is greater than the second threshold. (Configuration 6) 6. The electronic auscultation device according to any one of configurations 1 to 5, wherein the adjustment means adjusts the absolute value of the rate of increase when increasing the gain to be smaller than the absolute value of the rate of decrease when decreasing the gain. (Configuration 7) The adjusting means is When the movement state of the electronic auscultation device is determined to be the first state, the gain is set to the first gain; When the movement state of the electronic auscultation device is determined to be the third state, the gain is set to the third gain; 7. An electronic auscultation device according to any one of configurations 1 to 6, wherein when the movement state of the electronic auscultation device is determined to be the second state, the gain is increased toward the second gain, and when the gain reaches the second gain, the gain is made constant at the second gain. (Configuration 8) 8. The electronic auscultation device of any one of configurations 1 to 7, wherein the first gain is equal to the third gain. (Configuration 9) 9. The electronic auscultation device according to any one of configurations 1 to 8, wherein the detection means includes an acceleration sensor, and the detected value is acceleration. (Configuration 10) 9. The electronic auscultation device according to any one of configurations 1 to 8, wherein the detection means includes a gyro sensor, and the detected value is an angular velocity. (Configuration 11) 11. The electronic auscultation device according to any one of configurations 1 to 10, wherein the output means includes a membrane that is brought into contact with the surface of the living body, and a microphone that detects sound generated by vibration of the membrane and outputs the living body sound signal. (Configuration 12) 11. The electronic auscultation device according to any one of configurations 1 to 10, wherein the output means includes a membrane to be brought into contact with the surface of the living body, a light source that irradiates light onto the membrane, and a light-receiving element that receives the light irradiated onto the membrane by the light source and reflected from the membrane, and outputs a signal corresponding to the amount of the reflected light received as the living body sound signal. (Configuration 13) 11. The electronic auscultation device according to any one of configurations 1 to 10, wherein the output means includes a piezoelectric element that detects pressure due to vibrations on the surface of the living body and outputs the living body sound signal. (Configuration 14) 11. The electronic auscultation device according to any one of configurations 1 to 10, wherein the output means includes an acceleration sensor that detects acceleration of vibrations on the surface of the living body and outputs the living body sound signal. (Configuration 15) 11. The electronic auscultation device according to any one of configurations 1 to 10, wherein the output means includes a gyro sensor that detects the angular velocity of vibration of the surface of the living body and outputs the living body sound signal.

[0079] The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Accordingly, the following claims are appended to apprise the public of the scope of the invention. [Explanation of symbols]

[0080] 200: vibration detection unit, 300: state detection sensor, 402: adjustment unit

Claims

1. An electronic stethoscope device, comprising: an output means for outputting a body sound signal indicating a body sound based on vibration of the body surface; a detection means for detecting movement of the electronic auscultation device; an adjusting means for determining the movement state of the electronic auscultation device based on the detection value of the detecting means as one of a first state, a second state having a movement stability higher than that of the first state, and a third state having a movement stability higher than that of the second state, and adjusting the level of the biological sound signal with a gain determined based on the determined movement state of the electronic auscultation device; Equipped with The adjusting means is When the movement state of the electronic auscultation device is determined to be the first state, the gain is changed toward a first gain; When the movement state of the electronic auscultation device is determined to be the second state, the gain is changed toward a second gain; When the movement state of the electronic auscultation device is determined to be the third state, the gain is changed toward a third gain; The electronic auscultation device, wherein the second gain is greater than the first gain and the third gain.

2. 2. The electronic auscultation device according to claim 1, wherein the adjustment means calculates an evaluation value indicating the variation of a plurality of detection values ​​of the detection means over a predetermined past period, and determines the operating state of the electronic auscultation device based on the evaluation value.

3. 3. The electronic auscultation device according to claim 2, wherein the evaluation value is a value based on a variance of the plurality of detection values ​​of the detection means over the predetermined past period.

4. The adjusting means is If the evaluation value is greater than a first threshold, the movement state of the electronic auscultation device is determined to be the first state; If the evaluation value is smaller than a second threshold, the movement state of the electronic auscultation device is determined to be the third state; If the evaluation value is smaller than the first threshold and larger than the second threshold, the movement state of the electronic auscultation device is determined to be the second state; The electronic auscultation device of claim 2 , wherein the first threshold is greater than the second threshold.

5. the evaluation values ​​include a first evaluation value in a first direction and a second evaluation value in a second direction different from the first direction; the first direction is a direction that forms a smaller angle with the vibration direction of the biological surface than the second direction when the output means detects the vibration of the biological surface; The adjusting means is If the first evaluation value is greater than a first threshold value or the second evaluation value is greater than a third threshold value, the movement state of the electronic auscultation device is determined to be the first state; If both the first evaluation value and the second evaluation value are smaller than a second threshold, the movement state of the electronic auscultation device is determined to be the third state; If the first evaluation value is smaller than the first threshold, the second evaluation value is smaller than the third threshold, and both the first evaluation value and the second evaluation value are larger than the second threshold, the movement state of the electronic auscultation device is determined to be the second state; The electronic auscultation device of claim 2 , wherein the first threshold is greater than the third threshold, and the third threshold is greater than the second threshold.

6. 6. The electronic auscultation device according to claim 1, wherein the adjusting means adjusts the absolute value of the rate of increase of the gain when increasing the gain to be smaller than the absolute value of the rate of decrease of the gain when decreasing the gain.

7. The adjusting means is When the movement state of the electronic auscultation device is determined to be the first state, the gain is set to the first gain; When the movement state of the electronic auscultation device is determined to be the third state, the gain is set to the third gain; 6. The electronic auscultation device according to claim 1, wherein when the movement state of the electronic auscultation device is determined to be the second state, the gain is increased toward the second gain, and when the gain reaches the second gain, the gain is made constant at the second gain.

8. The electronic auscultation device of claim 1 , wherein the first gain is equal to the third gain.

9. 6. The electronic auscultation device according to claim 1, wherein the detecting means includes an acceleration sensor, and the detected value is acceleration.

10. 6. The electronic auscultation device according to claim 1, wherein the detection means includes a gyro sensor, and the detected value is an angular velocity.

11. 6. The electronic auscultation device according to claim 1, wherein the output means includes a membrane that is brought into contact with the surface of the living body, and a microphone that detects sound generated by vibration of the membrane and outputs the living body sound signal.

12. 6. The electronic auscultation device according to claim 1, wherein the output means includes a membrane to be brought into contact with the surface of the living body, a light source that irradiates the membrane with light, and a light-receiving element that receives the light irradiated onto the membrane by the light source and reflected from the membrane, and outputs a signal corresponding to the amount of the reflected light received as the living body sound signal.

13. 6. The electronic auscultation device according to claim 1, wherein the output means includes a piezoelectric element that detects pressure due to vibrations on the surface of the living body and outputs the living body sound signal.

14. 6. The electronic auscultation device according to claim 1, wherein the output means includes an acceleration sensor that detects acceleration of vibrations on the surface of the living body and outputs the living body sound signal.

15. 6. The electronic auscultation device according to claim 1, wherein the output means includes a gyro sensor that detects the angular velocity of vibration of the surface of the living body and outputs the living body sound signal.

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