JP2014113349A - Biological sound collection apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a biological sound collection apparatus capable of clearly listening biological sound without changing the direction of a contact surface part.SOLUTION: A plurality of sound collection parts are housed in a contact surface part coming in contact with a biological body, and collect sound transferred from the contact surface part. A direction detecting part detects the direction of a head of a user. A signal processing part generates acoustic signals corresponding to respective right and left directions of the head on the basis of the arrangement of the plurality of sound collection parts and the direction detected by the direction detecting part, from the acoustic signals collected by each of the plurality of sound collection parts.

Description

  The present invention relates to a biological sound collection device.

2. Description of the Related Art Conventionally, auscultation for listening to sound emitted by a living body has been performed as a means for detecting the activity state of the living body. When performing auscultation, a stethoscope that collects body sounds such as heart sounds, breathing sounds, blood flow sounds, and the like generated along with the activity of the body and amplifies the collected body sounds may be used. Stethoscopes include stereo stethoscopes that can listen to heart sounds and the like in stereo.
For example, Patent Document 1 discloses first and second detectors that detect heart sounds and the like, first and second amplifiers that amplify signals of the first and second detectors, and the first and second detectors. A stethoscope is described which comprises a hearing instrument that converts the output of two amplifiers into sound.

JP 58-109037 A

  However, the conventional biological sound collection device only amplifies the biological sound that has arrived at the first and second detectors. Therefore, the listener may not be able to determine from which direction the biological sound has come. In order to determine the direction of arrival of the body sound coming from different directions, the listener changes the arrangement direction of the first and second detectors on the contact surface portion that houses the sound collection unit that detects the body sound. Unless it is rotated around an axis perpendicular to the contact surface and reapplied to the living body, the direction of arrival of a specific biological sound cannot be determined and it cannot be heard clearly.

  The present invention has been made in view of the above points, and provides a biological sound collection apparatus that can clearly hear a biological sound without changing the direction of the contact surface portion.

  The present invention has been made to solve the above-described problems, and one aspect of the present invention is a sound collection unit housed in a contact surface portion that comes into contact with a living body, and a sound transmitted from the contact surface portion. A plurality of sound collecting units for collecting sound, a direction detecting unit for detecting the direction of the user's head, and an acoustic signal collected by each of the plurality of sound collecting units, the arrangement of the plurality of sound collecting units and And a signal processing unit that generates acoustic signals corresponding to the left and right directions of the head based on the direction detected by the direction detection unit.

  According to the present invention, a body sound can be clearly heard without changing the direction of the contact surface portion.

It is the schematic which shows the external appearance structure of the biological sound collection device which concerns on the 1st Embodiment of this invention. It is a schematic block diagram which shows the internal structure of the biological sound collection device which concerns on this embodiment. It is the schematic which shows the external appearance structure of the biological sound collection device which concerns on the 2nd Embodiment of this invention. It is a schematic block diagram which shows the internal structure of the biological sound collection device which concerns on this embodiment. It is the schematic which shows the external appearance structure of the biological sound collection device which concerns on the 3rd Embodiment of this invention. It is a schematic block diagram which shows the internal structure of the biological sound collection device which concerns on this embodiment. It is a schematic block diagram which shows the internal structure of the biological sound collection device which concerns on 4th Embodiment of this invention.

(First embodiment)
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic diagram illustrating an external configuration of a biological sound collection apparatus 1 according to the present embodiment.
FIG. 1A shows the whole body sound collection device 1. The biological sound collection device 1 includes a chest piece 11, a cable 12, two ear pieces 13-1, 13-2, and a direction detection unit 14. The biological sound collection device 1 is, for example, a stethoscope.

The chest piece (contact surface portion) 11 collects sounds coming from the inside of the living body (for example, lungs, heart) when contacting a part (for example, chest) of the surface of the living body (for example, human body). It is a face part.
The cable 12 transmits a signal from the chest piece 11 to each of the ear pieces 13-1 and 13-2 and a signal from the direction detection unit 14 to the chest piece 11. The chest piece 11 is fixed to one end of the cable 12, and the ear pieces 13-1 and 13-2 are fixed to the other end of the cable 12, respectively.
The earpieces 13-1 and 13-2 are acoustic reproduction units that reproduce sound based on the acoustic signal transmitted from the chestpiece 11. The earpieces 13-1 and 13-2 are covered with an elastic body so as to be fixed when inserted into the left ear external auditory canal on the left side of the user's head and the right ear external auditory canal on the right side. The sound reproduced from the tip is radiated.
The direction detection unit 14 detects a direction in which the head is facing as a part of the user's body. In the present embodiment, for example, the inclination of the median plane with respect to the direction of gravity is detected as the direction in which the head is facing. The direction detection unit 14 is fixed to a position adjacent to one of the two ear pieces, for example, the ear piece 13-1. The direction detection unit 14 outputs a direction signal indicating the detected direction to the chest piece 11 via the cable 12.

  FIG. 1B shows an example of the surface of the chest piece 11. A knob portion 115 is disposed at the center of the surface. The surface of the knob portion 115 is raised more than its surroundings. The shape of the surface of the knob portion 115 is substantially rectangular, and the length in the vertical direction is longer than the width in the horizontal direction with respect to the paper surface. With this shape, the user is urged to pinch the left and right side surfaces of the knob part 115 with his / her fingers and arrange the chestpiece 11 with the longitudinal direction of the knob part 115 in the direction of the user's midline.

  An LED (Light Emitting Diode) group (direction display unit) 114 is formed on the outer periphery of the surface of the chest piece 11. The LED group 114 has N (N is an integer greater than or equal to the number of microphones described later, 24 in the example shown in FIG. 1B), and the LEDs 114-1 to 114-N are arranged on the outer periphery. It is arranged at equal intervals along. The AA ′ line is a line indicating the direction of the user's head detected by the direction detection unit 14. The first characters L and R of the two arrows facing away from the AA ′ line indicate the left side region (left side region) and the right side region (right side region) from the median plane of the user, respectively. The BB ′ line indicates a line connecting the left and right ears of the user. The direction of the BB ′ line is a direction perpendicular to the AA ′ line. The small square filled with the BB 'line indicates two LEDs that emit light. These two LEDs face each other across the center of the surface of the chest piece 11 and are arranged in a direction that most closely approximates the direction of the line segment that connects the user's left and right ears. The user can determine the direction perpendicular to the direction detected by the direction detection unit 14 as the direction of his / her left and right ears by visually recognizing the two LEDs that emit light. Thereby, the user can also recognize the direction of the user's own head indicated by the two LEDs. Therefore, the user can determine to which direction the sound direction perceived by tilting the head is to be changed, using the two LEDs that emit light as a clue. Further, each LED is arranged on the outer periphery of the surface of the chest piece 11 so that even if the user holds the chest piece 11 with a finger or the like, the entire LED is not covered with the finger or the like. The total extension of the area becomes longer. Since the resolution of the displayed angle is reduced by densely arranging the LEDs in this area, the LED that emits light is changed by a slight change in the direction of the head, and the user can easily identify the change in direction. Can do. In addition, illustration of the cable 12 is abbreviate | omitted in FIG.1 (b).

  Here, the colors of light emitted by the two LEDs may be the same or different from each other. For example, the left LED may emit blue light and the right LED emit red light with the user's head as a reference. Therefore, a wavelength selection / addition / adjustment type LED light source that includes LED elements that emit light of a plurality of colors is used as each LED. The LED light source of the wavelength selection / addition / adjustment method can change the color of light emitted as the LED light source by changing the ratio of power applied to each LED element constituting the LED light source.

  FIG. 1C shows the back surface of the chest piece 11. The back surface of the chest piece 11 is a surface that is in contact with the surface of the living body, and the shape thereof is substantially circular. The chest piece 11 includes M microphones (sound collecting units) 111-1 to 111 -M. M may be 3 or an integer larger than 3, but in the following description, a case where M is 4 is taken as an example. Each of the microphones 111-1 to 111-4 is an electroacoustic transducer that converts an incoming sound into an electric signal to generate an analog acoustic signal. The surfaces of the microphones 111-1 to 111-4 are each covered with a diaphragm (not shown). The outer periphery of the diaphragm is fixed to the housing of the chest piece 11. The surface of each diaphragm is brought into contact with the surface of the living body and transmits the vibration that has reached the surface of the living body to the microphones 111-1 to 111-4.

The centers o _{1 to} o ₄ of the microphones 111-1 to 111-4 are equidistant from the center o of the back surface of the chest piece 11 and are arranged at equal intervals in different directions. The s ₁ o line, s ₂ o line, s ₃ o line, and s ₄ o line indicated by broken lines are o ₄ and o ₁ , o ₁ and o ₂ , o ₂ and o ₃ , and o ₃ and o, respectively. _{4 is} a line that passes through an intermediate point ₄ and divides an area (microphone corresponding area) corresponding to each of the microphones 111-1 to 111-4. The size of the microphone corresponding area is indicated by angles θ _{1 to} θ ₄ formed by two broken lines sandwiching the corresponding microphones. In the example illustrated in FIG. 1C, θ _{1 to} θ ₄ are all 90 °. In FIG. 1C, the direction indicated by the line AA ′ is horizontally reversed from the direction shown in FIG. The left side area and the right side area indicated by the letters L and R at the tip of the arrows that are opposite to each other across the line AA ′ are also shown on the right side and the left side, respectively. θ is an angle formed between the s ₂ o line and the AA ′ line, and corresponds to an inclination angle θ described later.

  FIG. 1 (d) shows another example of the surface of the chest piece 11. Similarly to the chest piece 11 shown in FIG. 1B, the chest piece 11 shown in FIG. 1D has a knob portion 115, and the LED group 114 is formed on the surface of the knob portion 115. The LED group 114 has N elongated LEDs 114-1 to 114-N each having one end facing the center of the LED group 114 and the other end arranged at equal intervals. Filled elongated areas on the BB 'line indicate two LEDs that are emitting light. The two LEDs indicate that the direction connecting the other ends is the direction that most closely approximates the direction of the line connecting the left and right ears of the detected user.

  In the present embodiment, an image display unit (not shown) may be provided as a direction display unit that displays the direction of the user's head. The image display unit is, for example, an LCD (Liquid Crystal Display, liquid crystal display). The image display unit displays an image in a mode corresponding to the detected direction of the user's head. The image of the aspect corresponding to the direction of the head is, for example, an image of the back of the head of a person such as a doctor inclined in that direction, characters indicating the direction (L: Left (left), R: Right (right), etc.) ).

Next, the internal configuration of the biological sound collection device 1 will be described.
FIG. 2 is a schematic block diagram showing the internal configuration of the biological sound collection apparatus 1 according to the present embodiment.
The chest piece 11 includes four microphones 111-1 to 111-4 and N LEDs 114-1 to 114 -N, and four more analog-to-digital (A / D) converters 112-1. To 112-4 and a data processing unit (signal processing unit) 113. The A / D converters 112-1 to 112-4 and the data processing unit 113 are accommodated in the housing of the chest piece 11.
The microphones 111-1 to 111-4 output the generated acoustic signals to the A / D converters 112-1 to 112-4, respectively.
The A / D converters 112-1 to 112-4 respectively convert the analog acoustic signals input from the microphones 111-1 to 111-4 (sampling frequency is, for example, 2.4 kHz, quantization accuracy is , For example, 16 bits) to generate a digital acoustic signal. The A / D converters 112-1 to 112-4 output the generated acoustic signals to the data processing unit 113, respectively.

The data processing unit 113 applies the acoustic signals s _{1 to} s ₄ input from the A / D converters 112-1 to 112-4 based on the inclination angle θ indicated by the direction signal input from the direction detection unit 14. multiplying the acoustic signal corresponding to the left and right ears (left audio signal _{s l,} right audio signal _{s r)} to calculate the weight coefficient _{w l1 ~w l4, w r1 ~w} r4 for calculating. This weighting coefficient indicates the contribution of each input acoustic signal to each of the left acoustic signal s ₁ and the right acoustic signal s _r . The data processing unit 113, for example, equation (1), among the weighting coefficient _w l1 as shown in _{(2) ~w l4, w r1} ~w r4 to correspond to each microphone regions (FIG. 1 (c)) The ratio of the part belonging to each of the left region and the right region is determined.
[W _l ] = (θ / 90, 1, (90−θ) / 90, 0) (0 ° ≦ θ <90 °),
(0, (90 + θ) / 90, 1, −θ / 90) (−90 ° ≦ θ <0 °) (1)
[W _r ] = ((90−θ) / 90, 0, θ / 90, 1) (0 ≦ θ <90 °),
(1, −θ / 90, 0, (90 + θ) / 90) (−90 ° ≦ θ <0 °) (2)
In the formula (1), _{[w l]} is a weight vector comprising weighting factors _w l1 _{to w l4} as respective elements _{(w l1, w l2, w} l3, w l4). In the formula (2), _{[w r]} is a weight vector comprising weighting factors _w r1 _{to w r4} as respective elements _{(w r1, w r2, w} r3, w r4).

The data processing unit 113 extracts band components of a predetermined frequency band (for example, 20 Hz-1 kHz) for each of the acoustic signals s _{1 to} s ₄ input from the A / D converters 112-1 to 112-4, respectively. Process (band pass process). As a result, aliasing distortion due to aliasing, DC component, low frequency noise, and the like are removed. Note that the frequency band in the band-pass process may be variable according to an operation input, for example. Thereby, an appropriate frequency band can be selected according to the sound to be listened to (auscultated) (lung, heart, etc.). For example, the frequency band for heart sounds is 20-200 Hz, and the frequency band for breath sounds is 100-600 Hz.
The data processing unit 113, the weighting factor to the acoustic signal _s 1 ~s ₄ obtained by extracting the band component _{w l1 ~w l4, w r1 ~w} r4 to adding a value obtained by multiplying each (weighted addition) to the left audio signal _{s l} The right acoustic signal s _r is calculated. For example, the data processing unit 113 calculates the left acoustic signal s ₁ and the right acoustic signal s _r using Equations (3) and (4), respectively.
s ₁ = 1/2 [w ₁ ] [s] ^T (3)
s _r = 1/2 [ _wr ] [s] ^T (4)
In equations (3) and (4), [s] is a vector (s ₁ , s ₂ , s ₃ , s ₄ ) including acoustic signals s _{1 to} s ₄ as elements, and T is a transposition of the vector.

For example, when the tilt angle θ is 0 ° (upright), the left acoustic signal s ₁ and the right acoustic signal s _r are calculated as shown in Expression (5).
s ₁ = (s ₂ + s ₃ ) / 2, s _r = (s ₁ + s ₄ ) / 2 (5)
When the inclination angle θ is 45 ° (right oblique direction), the left acoustic signal s ₁ and the right acoustic signal s _r are calculated as shown in Expression (6).
s ₁ = (s ₁ + 2s ₂ + s ₃ ) / 4, s _r = (s ₁ + s ₃ + 2s ₄ ) / 4 (6)
When the inclination angle θ is −45 ° (left oblique direction), the left acoustic signal s ₁ and the right acoustic signal s _r are calculated as shown in Expression (7).
s ₁ = (s ₂ + 2s ₃ + s ₄ ) / 4, s _r = (2s ₁ + s ₂ + s ₄ ) / 4 (7)
In this way, the level difference between the left acoustic signal s ₁ and the right acoustic signal s _r is virtually arranged on the left side and the right side of the direction (tilt angle θ) detected by the direction detection unit 14. The level difference between the acoustic signals collected by the (virtual microphone) can be made equal. In the present embodiment, level differences between acoustic signals collected by microphones virtually arranged on the left and right sides in the directions detected as the left acoustic signal s ₁ and the right acoustic signal s _r are made equal. If possible, the data processing unit 113 may use another calculation formula without using the formulas (1) to (4).

The data processing unit 113 outputs the calculated left acoustic signal s ₁ and right acoustic signal s _r to the earpieces 13-1 and 13-2 via the cable 12, respectively.
The data processing unit 113 supplies power to two of the LEDs 114-1 to 114 -N corresponding to the calculated inclination angle θ (for example, the direction of the line AA ′ in FIG. 1B). As a result, the two LEDs supplied with power emit light (for example, FIG. 1B).

The earpiece 13-1 includes a D / A (Digital to Analog, digital analog) converter 131-1 and an earphone 132-1.
The D / A converter 131-1 D / A converts the digital left acoustic signal input from the data processing unit 113 to generate an analog left acoustic signal. The sampling frequency and the quantization accuracy are the same between the D / A converter 131-1 and the A / D converters 112-1 to 112-4.
The D / A converter 131-1 outputs the generated left acoustic signal to the earphone 132-1.
Earphone 132-1 reproduces the sound presented to the left ear based on the analog left acoustic signal input from D / A converter 131-1.
The earpiece 13-2 has the same configuration as the earpiece 13-1, but reproduces the sound presented to the right ear based on the digital right sound signal input from the data processing unit 113.

As described above, the direction detection unit 14 is fixed at a position adjacent to the earpiece 13-1, and includes the acceleration sensor 141 and the inclination estimation unit 142.
The acceleration sensor (acceleration detector) 141 detects the gravitational acceleration of the earth when the user wearing the earpiece 13-1 is stationary. The acceleration sensor 141 is, for example, a triaxial acceleration sensor. The acceleration sensor 141 outputs an acceleration signal indicating the detected acceleration to the chest piece 11.

  Two of the sensitivity axes of the acceleration sensor 141 (x-axis and y-axis) are set in predetermined directions, for example, directions of line segments connecting the left and right ears of the user with the earpiece 13-1 attached ( x direction) and the user's front-rear direction (y direction). At this time, with the user standing upright, the gravitational acceleration is detected on the remaining sensitivity axes (z-axis), and the gravitational acceleration is not detected on the sensitivity axes (x-axis and y-axis) whose directions are aligned. On the other hand, when the user tilts his / her head to the left or right, a change in acceleration on the remaining sensitivity axis (z axis) is detected. When the tilt angle θ is increased from 0 ° to 90 ° with reference to the tilt angle θ (0 °) in a state where the head is upright, the gravitational acceleration on the remaining sensitivity axis (z axis) is from 0G to 1G. Increase to. Further, it is possible to detect whether the user has tilted his / her head to the left or right based on the polarity of gravity acceleration detected on one sensitivity axis (x-axis). For example, when the head is tilted to the left, the value of gravitational acceleration detected on one sensitivity axis (x-axis) is a negative value, and when the head is tilted to the right, 1 The value of the gravitational acceleration detected on the two sensitivity axes (x-axis) becomes a positive value.

  The tilt estimation unit (direction estimation unit) 142 detects the direction of the user's head as the tilt angle θ based on the acceleration signal input from the acceleration sensor 141. For example, the inclination estimation unit 142 may determine the inclination angle θ of the user's head based on the acceleration on one sensitivity axis (x axis) and the acceleration on the remaining sensitivity axis (z axis) indicated by the input acceleration signal. (FIG. 1C) is calculated. Here, the inclination estimation unit 142 determines that the inclination angle θ increases from 0 ° to 90 ° as the value of the gravitational acceleration on the remaining sensitivity axis (z axis) increases, and the sensitivity axis (x axis). The relationship between the polarity of the gravitational acceleration detected in step) and the tilt angle is used. The inclination estimation unit 142 outputs a direction signal indicating the inclination angle θ to the data processing unit 113 via the cable 12.

  As described above, in the present embodiment, the M sound collecting units are sound collecting units accommodated in the contact surface portion that comes into contact with the living body, and collect sound transmitted from the contact surface portion. In this embodiment, the direction of the user's head is detected, and the arrangement of the M sound collecting units and the direction detected by the direction detecting unit are detected from the acoustic signals collected by each of the M sound collecting units. Based on this, acoustic signals corresponding to the left and right directions of the head are generated. Thereby, the sound based on the acoustic signal corresponding to the left and right directions of the detected head is reproduced. Therefore, the user can change the direction of his / her head by changing the direction of his / her head without changing the direction in which the contact surface portion containing the M sound collecting portions is brought into contact with the living body. Can be heard clearly.

(Second Embodiment)
The second embodiment of the present invention will be described below with reference to the drawings. In the embodiments described below, the same reference numerals are given to the same configurations as those in the first embodiment, and the description is used.
FIG. 3 is a schematic diagram showing an external configuration of the biological sound collection device 2 according to the present embodiment.
FIG. 3A shows the whole body sound collection device 2. The biological sound collection device 2 includes a chest piece 21, a cable 12, two ear pieces 13-1, 13-2, and a direction detection unit 24. The direction detection unit 24 includes an imaging unit 241.
The imaging unit 241 includes an imaging device (for example, a charge coupled device (CCD)) and captures a surrounding image at a wide angle (for example, a viewing angle of 60 ° to 120 °). The direction of the optical axis of the imaging unit 241 is, for example, obliquely below the front of the user in a state where the earpiece 13-1 is attached to one ear of the user. Thereby, the imaging unit 241 captures an image of a visual field extending from the front to the lower side of the user.

  FIG. 3B shows an example of the surface of the chest piece 21. The chest piece 21 has the same configuration as the chest piece 11 (FIG. 1). However, in the chest piece 21, the LED group 114 (FIGS. 1B and 1D) is omitted, and the two markers 215-1 and 215-2 are provided on the plane portion of the surface of the chest piece 21 and the knob portion 115. It is arranged at a symmetrical position with respect to. In FIG. 3B, the shapes of the markers 215-1 and 215-2 are a star shape and a cross shape, respectively. However, in the present embodiment, the shape is not limited to this. Also good. The markers 215-1 and 215-2 may be configured to include light emitters such as LEDs. The number of markers 215-1 and the like is not limited to two, and may be one or more than two, for example, three.

Next, the internal configuration of the biological sound collection device 2 will be described.
FIG. 4 is a schematic block diagram showing the internal configuration of the biological sound collection device 2 according to this embodiment.
The chest piece 21 includes a data processing unit 213 instead of the data processing unit 113 in the chest piece 11 of FIG. 2, and the LEDs 114-1 to 114-N are omitted. In the data processing unit 213, processing for supplying power to the LEDs 114-1 to 114-N in the data processing unit 113 (FIG. 2) is omitted.

  The direction detection unit 24 includes an inclination estimation unit 242 in addition to the imaging unit 241. In the inclination estimation unit 242, image signals indicating the images of the markers 215-1 and 215-2 are stored in advance. The inclination estimation unit 242 collates while changing the position (coordinates) of the image signal input from the imaging unit 241 and the object signal indicating the image of the object stored in advance, and each object is represented. Detect position. Here, for example, markers 215-1 and 215-2 are used as subjects. In collation with the subject signal, the inclination estimation unit 242 calculates, for example, an index value (for example, SAD (Sum of Absolute Differences)) indicating similarity with the input image signal. The inclination estimation unit 242 determines a position indicating that the index values are most similar (for example, SAD is minimum) as the position (coordinates) of the subject.

The inclination estimation unit 242 determines the direction of a line segment connecting the subjects whose positions are detected, and determines an angle formed between the determined direction and a predetermined direction as an inclination angle θ. Here, the predetermined direction may be a horizontal direction in the image coordinate system of the imaging unit 241, or an inclination determined based on an image captured by the imaging unit 241 when the chestpiece 21 comes into contact with the living body. The angle θ may be used. This is because the user holds the knob part 115 with one hand and places the chest piece 21 on the surface of the living body, and at the beginning of use, the longitudinal direction of the knob part 115 and the direction of the median surface of the user may be shifted. . By setting the predetermined direction as a direction at the beginning of use, an error in a newly determined direction can be corrected when the deviation that occurs at the beginning of use is corrected.
In addition, the inclination estimation part 242 is a subject to detect the position, in addition to the markers 215-1 and 215-2, a part of the user's body, for example, a pattern attached to the eyes, ears, indoor wall surface, etc. A known subject as a position target can be used.

The data processing unit 213 includes, for example, one or both of the following configurations (1) and (2), detects that the chest piece 21 is placed on the surface of the living body, and has started use May be determined. (1) It is determined whether or not the signal values of the acoustic signals s _{1 to} s ₄ respectively input from the A / D converters 112-1 to 112-4 exceed a predetermined signal level threshold, and the threshold Is determined to have exceeded (2) It is determined whether or not the pressure detected by the pressure sensor provided on the back surface of the chest piece 21 in contact with the surface of the living body exceeds a predetermined pressure threshold, and it is determined that the threshold has been exceeded. The data processing unit 213 generates a use start signal indicating that use has started, and outputs the generated use start signal to the tilt estimation unit 242 to request a direction signal indicating the tilt angle θ.

The data processing unit 213 uses the inclination angle θ input from the inclination estimation unit 242, and similarly receives the sound input from the A / D converters 112-1 to 112-4 as in the data processing unit 113 (FIG. 2). Based on the signals s _{1 to} s ₄ , the left acoustic signal s ₁ and the right acoustic signal s _r are calculated. The data processing unit 213 outputs the calculated left acoustic signal s ₁ and right acoustic signal s _r to the earpieces 13-1 and 13-2, respectively.

  As described above, according to the present embodiment, the direction of the head relative to the contact surface portion is detected regardless of the direction of gravity in order to detect the head direction based on the contact surface portion based on the captured image. Based on this, acoustic signals corresponding to the left and right sides of the direction can be generated more accurately.

(Third embodiment)
The third embodiment of the present invention will be described below with reference to the drawings. In the embodiments described below, the same reference numerals are given to the same configurations as those in the first and second embodiments, and the description is incorporated.
FIG. 5 is a schematic diagram showing an external configuration of the biological sound collection device 3 according to the present embodiment.
FIG. 5A shows the whole body sound collection device 3. The biological sound collection device 3 includes a chest piece 31, a cable 12, and two ear pieces 13-1 and 13-2.
The biological sound collection device 3 according to the present embodiment includes an imaging unit 241 provided on the surface of the chest piece 31, in which the biological sound collection device 2 (FIG. 3A) is provided adjacent to the earpiece 13-1. It is.

  FIG. 5B shows an example of the surface of the chest piece 31. The chest piece 31 has the same configuration as the chest piece 21 (FIG. 3B). However, in the chest piece 31, the two markers 215-1 and 215-2 are omitted, and the imaging unit 241 is disposed on the surface of the knob unit 115. The direction of the optical axis of the imaging unit 241 is a direction perpendicular to the surface of the chest piece 31. Thereby, when the user is using the chestpiece 31, images of the user's head and earpieces 13-1 and 13-2 worn by the user are taken.

Next, the internal configuration of the biological sound collection device 3 will be described.
FIG. 6 is a schematic block diagram showing the internal configuration of the biological sound collection device 3 according to this embodiment.
In the biological sound collection device 3, the direction detection unit 24 (FIG. 4) is omitted. The chest piece 31 includes a data processing unit 313 instead of the data processing unit 213 in the chest piece 21 of FIG. 4, and further includes an imaging unit 241 and an inclination estimation unit 342.

The tilt estimation unit 342 also stores in advance image signals indicating images of known subjects such as markers and parts of the user's body, for example, eyes. Similar to the tilt estimation unit 242, the tilt estimation unit 342 collates the image signal input from the imaging unit 241 with a subject signal indicating a pre-stored subject image while changing the position of each subject. Detect the represented position. The inclination estimation unit 342 is arranged in the horizontal direction with respect to each other such as the positions of the left and right eyes of the user and the positions of markers (not shown) mounted on the front surfaces of the earpieces 13-1 and 13-2. The positions of a plurality of subjects assumed to have been detected are detected.
The inclination estimation unit 342 determines the direction of the line segment connecting the positions of the plurality of subjects, and determines the inclination angle θ based on the direction determined in the same manner as the inclination estimation unit 242. Similar to the tilt estimation unit 242, the tilt estimation unit 342 determines that the use has started, and sets the tilt angle at the time when it is determined that the use has been started as a predetermined direction to the newly determined tilt angle θ. The angle formed may be defined as the inclination angle θ.

The data processing unit 313 uses the inclination angle θ input from the inclination estimation unit 342, and the sound input from each of the A / D converters 112-1 to 112-4 similarly to the data processing unit 213 (FIG. 2). Based on the signals s _{1 to} s ₄ , the left acoustic signal s ₁ and the right acoustic signal s _r are calculated. The data processing unit 213 outputs the calculated left acoustic signal s ₁ and right acoustic signal s _r to the earpieces 13-1 and 13-2 via the cable 12.
The data processing unit 313 uses the inclination angle θ input from the inclination estimation unit 242, and the sound input from each of the A / D converters 112-1 to 112-4 similarly to the data processing unit 113 (FIG. 2). Based on the signals s _{1 to} s ₄ , the left acoustic signal s ₁ and the right acoustic signal s _r are calculated.

  Thus, according to this embodiment, the direction of the head with reference to the contact surface portion can be detected based on the image captured by the imaging unit integrated with the contact surface portion. It is possible to more stably generate acoustic signals corresponding to the left and right sides of the direction detected with reference to the contact surface portion whose direction changes more slowly than the head.

(Fourth embodiment)
The fourth embodiment of the present invention will be described below with reference to the drawings. In the embodiments described below, the same reference numerals are assigned to the same configurations as those in the first to third embodiments, and the description is incorporated.
The external configuration of the biological sound collection device 4 according to the present embodiment includes a chest piece 41 instead of the chest piece 11 of the biological sound collection device 1 (FIG. 1A). The shape of the chest piece 41 may be the same as the shape of the chest piece 11 (FIG. 1A).

Next, the internal configuration of the biological sound collection device 4 will be described.
FIG. 7 is a schematic block diagram showing the internal configuration of the biological sound collection device 4 according to this embodiment.
The chest piece 11 includes four microphones 111-1 to 111-4, a data processing unit 413, two A / D converters 112-1 and 112-2, and a band processing unit 416. The A / D converters 112-1 and 112-2 and the band processing unit 416 are accommodated in the housing of the chest piece 11.

The data processing unit 413 calculates the tilt angle θ of the user's head based on the acceleration signal input from the acceleration sensor 141 as in the data processing unit 113 (FIG. 1). The data processing unit 413 has a microphone corresponding area in which the calculated inclination angle θ belongs to the direction θ _l perpendicular to the left side and the direction θ _r perpendicular to the right side with respect to the front direction of the median plane of the user's head (see FIG. 1 (c)). As a result, the acoustic signals collected by the microphones arranged in the directions closest to the left ear direction θ _l and the right ear direction θ _r corresponding to the tilt angle θ are respectively the left acoustic signal s _l and the right acoustic signal. The signal s _r is selected.
However, when the direction θ _l and the direction θ _r indicate the direction of the boundary of the microphone corresponding area, the data processing unit 413 may determine one of the microphone corresponding areas inside the boundary. The data processing unit 413 selects the acoustic signals collected by the microphones related to the determined microphone corresponding areas as the left acoustic signal s ₁ and the right acoustic signal s _r .

The data processing unit 413, for example, when the inclination angle θ is 0 ° (upright) _selects a _{s l = s 1, s r} = s 2.
For example, the data processing unit 413 selects s _l = s ₂ and s _r = s ₄ when the inclination angle θ is 45 ° (right oblique direction).
The data processing unit 413, for example, when the inclination angle θ is -45 ° (left oblique direction) _selects a _{s l = s 3, s r} = s 1.
The data processing unit 413 outputs the selected left acoustic signal s ₁ and right acoustic signal s _r to the A / D converters 112-1 and 112-2, respectively.

The band processing unit 416 performs the above-described bandpass processing on the digital left acoustic signal s ₁ and right acoustic signal s _r input from the A / D converters 112-1 and 112-2, respectively, and sets a predetermined frequency. Extract the band component of the band. The band processing unit 416 outputs the left acoustic signal s ₁ and the right acoustic signal s _r extracted from the band components to the earpieces 13-1 and 13-2 via the cable 12, respectively.
In the above description, the band processing unit 416 is configured separately from the data processing unit 413 in order to include the two A / D converters 112-1 and 112-2 and perform band-pass processing digitally. However, the present embodiment is not limited to this. The band processing unit 416 may be integrated with the data processing unit 413 as a configuration for performing analog processing as long as the band processing unit 416 is configured by an analog filter that performs band pass processing in an analog manner. Further, as long as digital acoustic signals are obtained from the respective microphones, the band processing unit 416 and the data processing unit 413 may be integrated as a configuration for performing digital processing.

  As described above, in the present embodiment, the left and right directions of the head corresponding to the direction detected by the direction detection unit are arranged in the most approximate direction from the direction in which each of the M sound collection units is arranged. The sound signals collected by the sound collecting units are selected. Thereby, in this embodiment, it is possible to realize a biological sound collecting apparatus that can listen to a biological sound clearly with a simple configuration without changing the direction of the contact surface portion.

In the above-described embodiment, the data processing units 113, 213, and 313 and the band processing unit 416 may perform analog processing to generate the left acoustic signal s ₁ and the right acoustic signal s _r . In that case, the A / D converters 112-1 to 112-M and the D / A converters 131-1 and 131-2 may be omitted.
In the embodiment described above, the inclination angle θ estimated by the inclination estimation units 142, 242, 342, and 142 is processed by the data processing units 113, 213, 313, and 413 with respect to the acoustic signal such as calculation of a weighting coefficient and selection of the acoustic signal. The case where it is used as it is is described as an example. This embodiment is not limited to this. In the present embodiment, the angle ψ adjusted as a function that increases monotonously with respect to the increase in the tilt angle θ may be used for processing the acoustic signal in the data processing units 113, 213, 313, and 413 instead of the tilt angle θ. Good. For example, by adjusting the angle ψ = α · θ (α is a real number greater than 1, for example, 2), the left sound obtained when the direction changes more than the inclination of the user's head A signal s _l and a right acoustic signal s _r are generated. Further, by setting α to a real number larger than 0 and smaller than ₁ , the left acoustic signal s _l and the right acoustic signal s _r obtained when the direction changes less than the inclination of the user's head are generated. The

In the above-described embodiment, the sound based on the left acoustic signal s ₁ and the right acoustic signal s _r generated by the data processing units 113, 213, and 313 or the band processing unit 416 is reproduced by the chest pieces 11, 21, 31, and 41. May be. In this case, the cable 12 is configured to include a tube material made of two elastic bodies (for example, vinyl chloride, neoprene rubber, etc.), and the left acoustic signal _sl , A sound based on the acoustic signal s _r is transmitted. The other ends of the respective pipe members are connected to the ear pieces 13-1 and 13-2 so as to radiate sound transmitted from the openings of the ear pieces 13-1 and 13-2.

In the embodiment described above, the direction detection units 14 and 24 may be integrated with one of the ear pieces 13-1 and 13-2, for example, disposed inside the ear piece 13-1.
In the embodiment described above, the chest pieces 11, 21, and 41 may include the inclination estimation units 142, 242, and 142, respectively. In that case, the direction detection units 14 and 24 may omit the inclination estimation units 142 and 242, respectively.
The biological sound collection devices 1 and 4 according to the above-described embodiments may include a direction detection unit 24 instead of the direction detection unit 14.

Note that some of the biological sound collection devices 1, 2, 3, 4 in the above-described embodiment, for example, the data processing units 113, 213, 313, 413, the inclination estimation units 242, 342, and the band processing unit 416 are configured by a computer. It may be realized. In that case, the program for realizing the control function may be recorded on a computer-readable recording medium, and the program recorded on the recording medium may be read by a computer system and executed. Here, the “computer system” is a computer system built in the biological sound collection device 1, 2, 3 or 4, and includes an OS and hardware such as peripheral devices. The “computer-readable recording medium” refers to a storage device such as a flexible medium, a magneto-optical disk, a portable medium such as a ROM and a CD-ROM, and a hard disk incorporated in a computer system. Furthermore, the “computer-readable recording medium” is a medium that dynamically holds a program for a short time, such as a communication line when transmitting a program via a network such as the Internet or a communication line such as a telephone line, In such a case, a volatile memory inside a computer system serving as a server or a client may be included and a program that holds a program for a certain period of time. The program may be a program for realizing a part of the functions described above, and may be a program capable of realizing the functions described above in combination with a program already recorded in a computer system.
Moreover, you may implement | achieve part or all of the biological sound collection apparatuses 1, 2, 3, 4 in embodiment mentioned above as integrated circuits, such as LSI (Large Scale Integration). Each functional block of the biological sound collection device 1, 2, 3, 4 may be individually made into a processor, or a part or all of them may be integrated into a processor. Further, the method of circuit integration is not limited to LSI, and may be realized by a dedicated circuit or a general-purpose processor. Further, in the case where an integrated circuit technology that replaces LSI appears due to progress in semiconductor technology, an integrated circuit based on the technology may be used.

In addition, this invention can be implemented also with the following aspects.
(1) A sound collecting unit housed in a contact surface part that comes into contact with a living body, a plurality of sound collecting parts collecting sound transmitted from the contact surface part, and a direction for detecting the direction of the user's head Corresponding to the left and right directions of the head based on the arrangement of the sound collectors and the direction detected by the direction detector from the sound signals collected by the detector and each of the sound collectors A biological sound collection device comprising: a signal processing unit that generates acoustic signals to be transmitted.

(2) The signal processing unit is a weight based on the left and right directions of the head corresponding to the direction in which each of the plurality of sound collecting units is arranged and the direction of the head detected by the direction detection unit, The biological sound collecting apparatus according to (1), wherein the acoustic signals collected by each of the plurality of sound collecting units are weighted and added to generate acoustic signals corresponding to left and right directions of the head, respectively.

(3) The signal processing unit is arranged in a direction in which the left and right directions of the head corresponding to the direction detected by the direction detection unit from the direction in which each of the plurality of sound collection units is arranged are closest to each other. The biological sound collection device according to (1), wherein each of the acoustic signals collected by the collected sound collection unit is selected.

(4) An acoustic reproduction unit that reproduces sound based on the acoustic signal generated by the signal processing unit, wherein the acoustic reproduction unit is mounted in each of the left and right directions of the head, and at least one of the acoustic reproduction unit And an acceleration detection unit that detects gravitational acceleration, and the direction detection unit determines the direction of the head based on the direction of gravity acceleration detected by the acceleration detection unit. The biological sound collecting device according to any one of (1) to (3), wherein the biological sound collecting device is determined.

(5) The direction detection unit includes: an imaging unit that captures an image of the head; and a direction estimation unit that estimates a direction of the head based on an image captured by the imaging unit. The biological sound collection device according to any one of (1) to (3).

(6) The biological sound collection device according to any one of (1) to (5), further including a direction display unit that displays left and right directions of the head detected by the direction detection unit.

(7) A sound collecting unit housed in a contact surface part that comes into contact with a living body, and detects a plurality of sound collecting parts that collect sound transmitted from the contact surface part and a direction of the user's head. In the biological sound collection method in the biological sound collection device including a direction detection unit, the biological sound collection device includes an arrangement of the plurality of sound collection units from an acoustic signal collected by each of the plurality of sound collection units. And a body sound collection method including a signal processing step of generating acoustic signals corresponding to the directions of the left and right ears of the head based on the direction detected by the direction detection unit.

  According to (1) and (7) described above, the sound based on the acoustic signals corresponding to the left and right directions of the detected head is reproduced. Therefore, the user listens to the sound according to the changed direction by changing the direction of his / her head without changing the direction in which the contact surface portion accommodating the sound collection unit is brought into contact with the living body. be able to. Thereby, a body sound can be heard clearly, without changing the direction of a contact surface part.

According to (2) described above, in order to generate acoustic signals corresponding to the left and right directions by weighting corresponding to the left and right directions of the head detected for the acoustic signals collected by the plurality of sound collecting units, The direction of sound perceived by the user can be controlled smoothly.
According to the above (3), since the acoustic signals corresponding to the left and right directions of the head detected from the acoustic signals respectively collected by the plurality of sound collecting units are selected, the contact surface portion can be configured with a simple configuration. A body sound can be heard clearly without changing the direction.

According to (4) described above, since the direction of the user's head is detected based on the direction of gravity, there is no need to provide a direction reference. Therefore, processing according to the direction of the user's head can be realized with a simple configuration.
According to (5) described above, since the direction of the user's head can be detected based on the captured image, the direction relative to the imaging unit can be detected regardless of the direction of gravity. Therefore, the process according to the direction of the user's head can be realized more accurately.
According to (6) described above, since the user can visually recognize the left and right directions of the detected head, the user can change the direction of sound perceived by tilting the head.

  As described above, the embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to the above, and various design changes and the like can be made without departing from the scope of the present invention. It is possible to

1, 2, 3, 4 ... biological sound collection device, 11, 21, 31 ... chestpiece,
111 (111-1 to 111-M): microphone,
112 (112-1 to 112-M) ... A / D converter,
113, 213, 313, 413 ... data processing unit,
114 ... LED group, 114-1 to 114-N ... LED, 115 ... knob part,
12 ... Cable,
13 (13-1, 13-2) ... earpiece,
131 (131-1, 131-2) ... D / A converter,
132 (132-1, 132-2) ... earphones,
14, 24 ... direction detection unit, 141 ... acceleration sensor,
215 (215-1, 215-2) ... marker,
241 ... Imaging unit, 142, 242, 342 ... Inclination estimation unit,
416: Band processing unit

Claims (5)

A sound collecting unit housed in a contact surface part that comes into contact with a living body, and a plurality of sound collecting parts that collect sound transmitted from the contact surface part;
A direction detection unit for detecting the direction of the user's head;
Based on the acoustic signals collected by each of the plurality of sound collection units, the acoustic signals corresponding to the left and right directions of the head are determined based on the arrangement of the plurality of sound collection units and the direction detected by the direction detection unit. A signal processor to generate each;
A biological sound collecting apparatus comprising:   The signal processing unit is weighted based on the left and right directions of the head corresponding to the direction in which each of the plurality of sound collecting units is disposed and the direction of the head detected by the direction detection unit. 2. The biological sound collection apparatus according to claim 1, wherein the sound signals collected by each of the sound collection units are weighted and added to generate sound signals corresponding to the left and right directions of the head, respectively.   The signal processing unit is a collecting unit in which left and right directions of the head corresponding to a direction detected by the direction detecting unit from a direction in which each of the plurality of sound collecting units is arranged are arranged in a direction that is most approximated. The biological sound collecting apparatus according to claim 1, wherein each of the acoustic signals collected by the sound unit is selected. An acoustic reproduction unit that reproduces sound based on an acoustic signal generated by the signal processing unit, the acoustic reproduction unit being mounted in each of the left and right directions of the head; and
An acceleration detection unit that is disposed at a position within a predetermined range from at least one of the sound reproduction units, and detects a gravitational acceleration;
The biological sound collection device according to claim 1, wherein the direction detection unit determines a direction of the head based on a direction of gravitational acceleration detected by the acceleration detection unit. The biological sound collection device according to claim 1, further comprising a direction display unit that displays left and right directions of the head detected by the direction detection unit.

Images