JP2013118904A - Pulse wave sensor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pulse wave sensor for highly accurately measuring pulse waves without restricting the behavior of a subject.SOLUTION: The pulse wave sensor 1 includes: a casing 10 to be attached to an external ear E; and an optical sensor section 11 which is provided in the casing 10, and acquires pulse wave data by irradiating the external ear E with light emitted from a light-emitting section 11A and detecting by a light-receiving section 11B the strength of the light returning after passing through the living body.

Description

  The present invention relates to a pulse wave sensor.

  A conventional pulse wave sensor is configured to measure a pulse wave using a light emitting unit that irradiates light on a fingertip of a subject and a light receiving unit that detects the intensity of light transmitted through the living body.

  In addition, Patent Document 1 and Patent Document 2 can be cited as examples of related art related to the above.

Japanese Patent Application Laid-Open No. 5-212016 International Publication No. 2002/066222 Pamphlet

  However, in the conventional structure in which the pulse wave is measured with the fingertip of the subject, it is necessary to restrict the behavior of the subject so that the pulse wave sensor does not drop from the fingertip during the measurement of the pulse wave. In addition, the pulse wave measurement at the fingertip has a problem that it is easily affected by noise caused by the movement of the subject.

  In view of the above-described problems found by the inventors of the present application, an object of the present invention is to provide a pulse wave sensor capable of performing pulse wave measurement with high accuracy without restricting the behavior of a subject. .

  In order to achieve the above object, a pulse wave sensor according to the present invention includes a housing that is attached to the outer ear, and is provided in the housing to irradiate light from the light emitting unit to the outer ear and transmit through the living body to return. The optical sensor unit acquires the pulse wave data by detecting the intensity of the incoming light by the light receiving unit (first configuration).

  In the pulse wave sensor having the first configuration, the casing may be configured to have a speaker (second configuration).

  The pulse wave sensor having the second configuration may be configured to have a control unit (third configuration) that controls the output operation of the speaker in accordance with the pulse wave data.

  The pulse wave sensor having any one of the first to third configurations may have a configuration (fourth configuration) including a communication unit that transmits the pulse wave data to the information terminal.

  Further, in the pulse wave sensor having any one of the first to fourth configurations, the housing has a shape that fits a hollow portion surrounded by the tragus and the antitragus (fifth configuration). It is good to.

  In the pulse wave sensor having the fifth configuration, the light receiving unit may be configured to be disposed closer to the ear canal than the light emitting unit (sixth configuration).

  In the pulse wave sensor having any one of the first to fourth configurations, the housing may have a configuration (seventh configuration) having a shape covering the auricle.

  In the pulse wave sensor having the seventh configuration, the housing may have a configuration (eighth configuration) having a protruding member that supports the optical sensor unit on a surface facing the auricle.

  In the pulse wave sensor having any one of the first to fourth configurations, the casing may have a configuration (9th configuration) having a clip member suspended from the auricle.

  Moreover, the pulse wave sensor which consists of the said 9th structure WHEREIN: The said clip member is good to make it the structure (10th structure) which carry | supports the said optical sensor part in the location contact | abutted with the said pinna.

  In the pulse wave sensor having the first configuration, the housing may have a configuration (eleventh configuration) having an earplug structure for measuring a pulse wave inside the ear canal.

  In the pulse wave sensor having any one of the first to eleventh configurations, the optical sensor unit includes a bowl-shaped case, a first region on which the light emitting unit is placed, and the light receiving unit. A configuration (a twelfth configuration) having a light shielding wall that is divided into the second region to be placed is preferable.

  In the pulse wave sensor having the twelfth configuration, a relationship of H1> H2> H3 is established between the height H1 of the light shielding wall, the height H2 of the light emitting portion, and the height H3 of the light receiving portion. (13th configuration) is preferable.

  In the pulse wave sensor having the thirteenth configuration, the case may be configured to be embedded in a shape protruding from the housing (fourteenth configuration).

  In the pulse wave sensor having any one of the first to fourteenth configurations, the optical sensor unit may be configured to have a buffer member (fifteenth configuration) between the housing and the casing.

  In the pulse wave sensor having any one of the first to fifteenth configurations, the output wavelength of the light emitting unit may be configured to belong to the visible light region of about 600 nm or less (sixteenth configuration).

  According to the present invention, it is possible to provide a pulse wave sensor capable of performing pulse wave measurement with high accuracy without restricting the behavior of the subject, and therefore, the use scene of the pulse wave sensor can be expanded.

Schematic diagram for explaining the principle of pulse wave measurement Waveform diagram showing how the attenuation (absorbance) of light in a living body changes over time External view showing one configuration example of pulse wave sensor Block diagram showing a configuration example of a pulse wave sensor Front view schematically showing an example of mounting the earphone 1X on the first form and the outer ear E Front view schematically showing a second form of the earphone 1X and an example of attachment to the outer ear E Front view schematically showing a third embodiment of the earphone 1X and an example of attachment to the outer ear E Front view schematically showing a fourth embodiment of the earphone 1X and an example of attachment to the outer ear E System diagram showing a variation of the pulse wave sensor (earplug structure) Sectional drawing which shows the 1st structural example of the optical sensor part 11 typically Sectional drawing which shows the 2nd structural example of the optical sensor part 11 typically Waveform diagram showing correlation between offset distance ΔH and signal intensity Waveform diagram showing correlation between inter-element distance W1 and signal intensity Sectional drawing which shows the 3rd structural example of the optical sensor part 11 typically Sectional drawing which shows the 4th structural example of the optical sensor part 11 typically Sectional drawing which shows the 5th structural example of the optical sensor part 11 typically Sectional drawing which shows the 6th structural example of the optical sensor part 11 typically Sectional drawing which shows the 7th structural example of the optical sensor part 11 typically Circuit diagram showing a first configuration example of the filter unit 27 Circuit diagram showing a second configuration example of the filter unit 27 Output waveform diagram of filter unit 27 System diagram showing an application example to a hearing aid

<Principle of pulse wave measurement>
FIG. 1 is a schematic diagram for explaining the principle of pulse wave measurement, and FIG. 2 is a waveform diagram showing how the attenuation (absorbance) of light in a living body changes with time.

In the pulse wave measurement by the volume pulse wave method, for example, as shown in FIG. 1, a part of a living body pressed against a measurement window (in FIG. 1, the outer ear E (the ear pinna (ear shell) of the ear structure and the ear canal) The light intensity emitted from the light emitting part (LED [Light Emitting Diode], etc.) toward the combined part)) is transmitted through the body and comes out of the body by the light receiving part (photodiode, phototransistor, etc.) Detected. Here, as shown in FIG. 2, the attenuation (absorbance) of light due to living tissue and venous blood (deoxygenated hemoglobin Hb) is constant, but the attenuation of light due to arterial blood (oxygenated hemoglobin HbO ₂ ) ( Absorbance) varies with time due to pulsation. Therefore, the volume pulse wave is measured by measuring the change in the absorbance of the peripheral artery using the “biological window” (wavelength range in which light is easily transmitted through the living body) from the visible region to the near infrared region. Can do.

  The pulse wave sensor (light emitting part and light receiving part) is attached to any part of the outer ear E (boat-like fossa E1, earring E2, earring E3, antitragus E4, ear canal E5, upper earring leg E6, triangular). It may be a fovea E7, a lower leg ring E8, a concha E9, a tragus E10, an intercuspid notch E11, and an earlobe E12), or other than the outer ear E (fingertip, third joint of the finger, forehead) , Between the eyebrows, the tip of the nose, the cheeks, below the eyes, and the temples).

<What you can understand from the pulse wave>
Note that the pulse wave under the control of the heart and the independent nerve does not always exhibit a constant behavior, but causes various changes (fluctuations) depending on the condition of the subject. Accordingly, various body information of the subject can be obtained by analyzing the change (fluctuation) of the pulse wave. For example, from the heart rate, it is possible to know the exercise ability, the degree of tension, and the like of the subject, and from the heart rate variability, it is possible to know the fatigue level, the degree of sleep, the magnitude of stress, and the like. Further, from the acceleration pulse wave obtained by differentiating the pulse wave twice with respect to the time axis, the blood vessel age, arteriosclerosis degree, etc. of the subject can be known.

<Pulse wave sensor>
3 and 4 are an external view and a block diagram showing a configuration example of the pulse wave sensor, respectively. The pulse wave sensor 1 of this configuration example includes an earphone (headphone) 1X and a main unit 1Y, and is provided as a portable audio player having a pulse wave measurement function. Note that the concept of an audio player includes not only a dedicated audio playback device but also a mobile phone terminal, a smartphone, a mobile game terminal, and the like having an audio playback function.

  The earphone 1X is an inner ear type that is used by being attached to the user's external ear E (particularly the auricle (ear shell)), and includes a housing 10, an optical sensor unit 11, a speaker 12, a driver 13, and a cord 14 And the connector 15.

  The housing 10 is a member on which the optical sensor unit 11, the speaker 12, and the driver 13 are mounted. The housing | casing 10 has a shape which fits the hollow part (boat part of the conch E9) enclosed by the tragus E10 and the antitragus E4. The housing 10 may be an open type or a sealed type.

  The optical sensor unit 11 is provided on the side surface of the housing 10 and irradiates a predetermined portion of the outer ear E from the light emitting unit 11A, and the light receiving unit 11B detects the intensity of light transmitted through the living body and returning. By doing so, pulse wave data is acquired. FIG. 3 shows a configuration in which one optical sensor unit 11 is mounted on one of the right ear housing and the left ear housing 10. However, the present invention is not limited to this, and a plurality of optical sensor units 11 may be mounted on one casing 10, or one or a plurality of optical sensor sections 11 may be mounted on both casings. Good. A configuration in which only one optical sensor unit 11 is mounted can give priority to reduction of power consumption, cost reduction, and the like as compared to a configuration in which a plurality of optical sensor units 11 are mounted. On the other hand, in the case of a configuration in which a plurality of optical sensor units 11 are mounted, pulse wave detection can be performed by adding each sensor output to increase S / N or selecting and using the sensor output having the highest S / N. The accuracy can be improved. In the case where a plurality of optical sensor units 11 are selectively used, waste of electric power can be prevented by cutting off the power supply to the optical sensor units 11 that are not used.

  In the pulse wave sensor 1 of this configuration example, the optical sensor unit 11 has a configuration in which a light emitting unit 11A and a light receiving unit 11B are provided on opposite sides of a living body (so-called transmission type, see broken line arrow in FIG. ), The light emitting unit 11A and the light receiving unit 11B are both provided on the same side with respect to the living body (so-called reflection type, see solid line arrow in FIG. 1). In addition, the inventors of the present application have actually confirmed through experiments that pulse waves can be sufficiently measured in the external ear E. The specific structure of the optical sensor unit 11 will be described in detail later.

  The speaker 12 converts an audio signal (electric signal) transmitted from the main unit 1Y via the driver 13 into a sound wave and outputs the sound wave. As a driving method of the speaker 12, a dynamic type is generally used, but other driving methods (magnetic type, balanced armature type, piezoelectric type, crystal type, electrostatic type, etc.) may be adopted.

  The driver 13 generates a driving signal for the speaker 12 based on the audio signal (electric signal) transmitted from the main unit 1Y.

  The cord 14 is a member for electrically connecting the housing 10 of the earphone 1X and the main unit 1Y. The code 14 includes a signal transmission line and a power supply line.

  The connector 15 is attached to one end of the cord 14 and is a member for attaching and detaching the earphone 1X and the main unit 1Y.

  In place of the cord 14 and the connector 15, by providing a wireless communication module in both the housing 10 of the earphone 1X and the main unit 1Y, it is possible to connect the two wirelessly. In particular, when the main unit 1Y has a waterproof structure, it is desirable to wirelessly connect the two from the viewpoint of completely eliminating the external terminals of the main unit 1Y. In that case, since it becomes impossible to supply electric power from the main unit 1Y to the housing 10 side of the earphone 1X, it is necessary to separately prepare a power supply unit on the housing 10 side of the earphone 1X.

  The main unit 1Y includes a housing 20, a control unit 21, an operation unit 22, a display unit 23, a storage unit 24, a communication unit 25, a power supply unit 26, and a filter unit 27. When the main unit 1Y is a mobile phone terminal having an audio playback function, a microphone, a speaker, a telephone line connection unit, and the like are further added in addition to the above components.

  The housing 20 is a member that houses the control unit 21, the operation unit 22, the display unit 23, the storage unit 24, the communication unit 25, the power supply unit 26, and the filter unit 27. Note that the housing 20 is desirably waterproofed to prevent failure due to submersion or the like.

  The control unit 21 not only individually realizes both the audio playback function and the pulse wave measurement function, but also combines the two functions to produce a new added value. Overall control of the overall operation. As the control unit 21, a CPU [Central Processing Unit] or the like can be preferably used. The specific operation of the control unit 21 will be described in detail later.

  The operation unit 22 is a human interface that receives an input operation (power on / off, volume adjustment, music selection, etc.) of a user (subject). As the operation unit 22, in addition to various keys and buttons, a touch panel or the like can be suitably used.

  The display unit 23 is provided on the surface of the main unit 1Y, and outputs display information (including information related to audio reproduction, including pulse wave measurement results). As the display unit 23, a liquid crystal display panel or the like can be suitably used.

  The storage unit 24 includes a ROM [read only memory] that stores various programs read and executed by the control unit 21 in a nonvolatile manner, and a volatile RAM [random access memory] used as a program execution area of the control unit 21. And a built-in (or detachable) flash memory for allowing a user (subject) to store arbitrary music data in a nonvolatile manner.

  Further, the storage unit 24 is a RAM or EEPROM [Electrically Erasable Programmable] that stores pulse wave data (raw data or processed data subjected to various processes) obtained by the control unit 21 in a volatile or non-volatile manner. ROM]. In this way, with the configuration having the pulse wave data storage means, for example, the accumulated data in the storage unit 24 can be collectively transmitted externally at predetermined intervals, so that the communication unit 25 is intermittently transmitted. It becomes possible to make it a stand-by state, and it becomes possible to extend the battery drive time of the pulse wave sensor 1 by extension.

  The communication unit 25 transmits the measurement data (raw data, processed data subjected to various processes, or stored data in the storage unit 24) of the pulse wave sensor 1 to the external information terminal 2 (data server, personal computer, or the like). Send to or wirelessly. In particular, if the measurement data of the pulse wave sensor 1 is wirelessly transmitted to the information terminal 2, it is not necessary to connect the pulse wave sensor 1 and the information terminal 2 by wire. Measurement data can be transmitted in real time without restricting the above. In particular, when the main unit 1Y has a waterproof structure, it is desirable to adopt a wireless transmission method as an external transmission method of measurement data from the viewpoint of completely eliminating the external terminals of the main unit 1Y. When wirelessly transmitting measurement data to the information terminal 2 at a short distance (several meters to several tens of meters), a Bluetooth (registered trademark) wireless communication module or the like can be suitably used as the communication unit 25. Further, when measuring data is transmitted to the remote information terminal 2 via the Internet or the like, a wireless LAN [local area network] module or the like can be suitably used as the communication unit 25.

  The power supply unit 26 includes a battery and a DC / DC converter, converts an input voltage from the battery into a desired output voltage, and supplies the output voltage to each unit of the pulse wave sensor 1. Thus, with the battery-driven pulse wave sensor 1, it is not necessary to connect an external power supply cable when measuring the pulse wave. Therefore, the pulse wave measurement can be performed without restricting the action of the user (subject). Can be done. In addition, as said battery, it is desirable to use the secondary battery (A lithium ion secondary battery, an electric double layer capacitor, etc.) which can be charged repeatedly. Thus, if it is the structure using a secondary battery as a battery, since the troublesome battery replacement | work operation | work will become unnecessary, the convenience of the pulse wave sensor 1 can be improved. Further, as a power supply method from the outside during battery charging, a contact power supply method using a USB [Universal Serial Bus] cable or the like may be used, or an electromagnetic induction method, an electric field coupling method, and a magnetic field resonance method. For example, a non-contact power feeding method may be used. However, when the pulse wave sensor 1 has a waterproof structure, it is desirable to adopt a non-contact power feeding method as an external power supply method from the viewpoint of completely eliminating the external terminal of the main unit 1Y.

  The filter unit 27 performs filter processing, amplification processing, and analog / digital conversion processing on the output signal (detection signal of the light receiving unit) of the optical sensor unit 11 and transmits the result to the control unit 21. Although a filter unit may be provided on the housing 10 side of the earphone 1X, it is considered that noise is likely to be superimposed during signal transmission from the housing 10 of the earphone 1X to the main unit 1Y via the cord 14. The filter unit 27 is preferably provided on the main unit 1Y side. A specific circuit configuration of the filter unit 27 will be described later in detail.

  As described above, the pulse wave sensor 1 of the present configuration example includes the housing 10 attached to the outer ear E and the light emitted from the light emitting unit 11A to the outer ear E by being emitted from the light emitting unit 11A and transmitted through the living body. The optical sensor unit 11 acquires pulse wave data by detecting the intensity of the returning light with the light receiving unit 11B.

  By adopting such a configuration, unless the user (subject) intentionally removes the pulse wave sensor 1 from the outer ear E, there is little possibility that the pulse wave sensor 1 will drop out of the outer ear E during measurement of the pulse wave. Therefore, it is possible to measure the pulse wave without restricting the behavior of the user (subject).

  In particular, since the outer ear E is a part with less body movement compared to fingers and arms, the output signal of the optical sensor unit 11 is not easily affected by body movement noise, and it is possible to measure pulse waves with high accuracy. It becomes.

  In addition, if the pulse wave sensor 1 has the optical sensor unit 11 mounted on the earphone 1X attached to the outer ear E for the purpose of listening to sound, the user (subject) has the pulse wave sensor 1 with a pulse wave measurement function. Since it can be worn on a daily basis as a portable audio player, it becomes possible to eliminate the sense of resistance to wearing the pulse wave sensor 1, and thus contribute to the expansion of usage scenes and the development of new user groups. Is possible.

  In addition, the control unit 21 that comprehensively controls the operation of the entire pulse wave sensor 1 not only individually realizes both the audio playback function and the pulse wave measurement function, but also newly combines both functions in combination. In order to produce added value, a function of controlling the output operation of the speaker 12 according to the pulse wave data is provided.

  More specifically, the control unit 21 performs various types of signal processing on the output signal of the filter unit 27, thereby various information regarding the pulse wave (pulse wave fluctuation, heart rate, heart rate fluctuation, and acceleration pulse). Wave) and the analysis result is fed back to the audio playback operation.

  For example, the control unit 21 determines the physical condition, mental state, or sleep state of the user (subject) based on the analysis result of the pulse wave data, and adjusts the volume, selects a song, or turns on the power based on the determination result. Automatically turn off / off. With such a configuration, it is possible to realize an audio playback operation that cannot be realized with a portable audio player alone.

  In FIG. 4, the configuration in which the earphone 1 </ b> X and the main unit 1 </ b> Y are separated is described as an example, but the configuration of the present invention is not limited to this, and the configuration in which the earphone 1 </ b> X and the main unit 1 </ b> Y are integrated. It doesn't matter. In that case, the cord 14 and the plug 15 are unnecessary.

  In addition, various variations of the form of the earphone 1 </ b> X and the example of mounting to the outer ear E are conceivable as shown in FIGS. 5A to 5D. FIGS. 5A to 5D are front views schematically showing first to fourth forms of the earphone 1 </ b> X and examples of attaching the earphone 1 </ b> E to the external ear E in each form.

  For example, the earphone 1X of the first form (FIG. 5A) is an inner ear type that is used by being attached to the outer ear E, as in FIG. 3, and the housing 10 is connected to the tragus E10 and the antitragus E4. It has a shape (for example, a spherical shape or a cylindrical shape) that fits into the enclosed hollow portion (the boat part of the concha E9). In the earphone 1 </ b> X of the first form, the optical sensor unit 11 is brought into contact with the hollow portion.

  The earphone 1X of the second form (FIG. 5B) is an earplug type (canal type) that is used by deeply pushing an earpiece made of silicon, foamed urethane, or the like into the ear canal E5. Similarly to the first form (FIG. 5A), it has a shape that fits into a hollow part (boat part of the concha E9) surrounded by the tragus E10 and the antitragus E4. In the earphone 1 </ b> X of the second form, the optical sensor unit 11 is brought into contact with the hollow part as in the first form.

  Earphone 1 </ b> X of the third form (FIG. 5C) is a headphone type provided with a housing 10 shaped to cover the entire auricle E. The left and right (for right ear / left ear) housing 10 has a shape in which the head is sandwiched between a headband over the head or a neckband (both not shown) over the back of the neck. In the earphone 1 </ b> X of the third form, the housing 10 has a protruding member 10 x that supports the optical sensor unit 11 on the surface (inner side surface) facing the auricle E. The protruding member 10x protrudes toward the auricle E, and, for example, the optical sensor unit 11 is mounted on the tip thereof. Therefore, in the earphone 1X of the third form, the optical sensor unit 11 is brought into contact with a portion (for example, the earlobe E12) facing the tip of the protruding member 10x. In the earphone 1X of the third form, the housing 10 that covers the entire auricle E also functions as a light shielding member that covers the optical sensor unit 11. With such a configuration, it is possible to stably measure pulse waves without being affected by external light.

  The earphone 1X of the fourth form (FIG. 5D) is an ear hook type having a clip member 10y suspended from the pinna E. The clip member 10y carries the optical sensor unit 11 at a location where it abuts on the auricle E. Therefore, in the earphone 1X of the fourth embodiment, the optical sensor unit 11 is brought into contact with the upper side of the upper ear ring leg E6, the triangular fossa E7, the lower side ear ring leg E8, or the back side of the concha E9.

  In the above description, the configuration in which the optical sensor unit 11 is provided in the earphone or the headphone has been described as an example. However, the configuration of the present invention is not limited to this, and for example, a modification of FIG. As described above, a configuration in which the optical sensor unit 11 is mounted on the housing 10 having the earplug structure and the pulse wave is measured inside the ear canal E5 is also conceivable. In this case, the housing 10 is inserted deeply by closing the ear canal E5, and the optical sensor unit 11 is in contact with the inner wall surface of the ear canal E5. With the pulse wave sensor 1 having such an earplug structure, the subject can be relaxed using the original function of the earplug, so that it is not necessary to apply excessive stress to the subject during the pulse wave measurement. From such a feature, the pulse wave sensor 1 having an earplug structure can be suitably used as a pleasant sleep sensor (a sensor that obtains knowledge about a sleep state of a subject from pulse wave information).

<Optical sensor part (structure)>
FIG. 7 is a cross-sectional view schematically illustrating a first configuration example of the optical sensor unit 11. The optical sensor unit 11 of the first configuration example includes a case 11a, a light shielding wall 11b, a translucent plate 11z, a light emitting unit x, and a light receiving unit y.

  The case 11a is a bowl-shaped member that houses the light emitting part x and the light receiving part y. The case 11a is embedded in the housing 10 so that the transparent plate 11z that closes the opening surface thereof is flush with the surface of the housing 10 (the surface facing the outer ear E).

  The light shielding wall 11b is a member that divides the case 11a into a first area where the light emitting part x is placed and a second area where the light receiving part y is placed. By providing the light shielding wall 11b, it is possible to block light that is directly incident on the light receiving part y from the light emitting part x, so that it is possible to improve the detection accuracy of the pulse wave data. The case 11a and the light shielding wall 11b are preferably formed integrally.

  The translucent plate 11z is a translucent member that closes the opening surface of the case 11a. By providing the translucent plate 11z, the light emitting part x and the light receiving part y can be prevented from being contaminated (attachment of dust or the like). Therefore, the light emitting part x and the light receiving part y are not sealed with a resin or the like. (Light emitting chip and light receiving chip) can be used.

  In the case of the optical sensor unit 11 of the first configuration example, after the light emitting unit x irradiates the outer ear E with light, the light receiving unit y detects the intensity of light transmitted through the outer ear E and returned to the user ( It is possible to obtain pulse wave data of the subject.

  However, in the optical sensor unit 11 of the first configuration example, since the translucent plate 11z exists between the outer ear E, the light emitting unit x, and the light receiving unit y, light is emitted through the translucent plate 11z without passing through the outer ear E. There is a possibility that light may be directly incident from the part x to the light receiving part y. Further, in the optical sensor unit 11 of the first configuration example, external light may leak into the light receiving unit y when the adhesion between the optical sensor unit 11 and the outer ear E is impaired. When light that does not pass through the outer ear E is incident on the light receiving unit y, the pulse wave data detection accuracy (S / N) is lowered. Therefore, in order to improve the pulse wave data detection accuracy, the above problem It is important to eliminate the problem.

  FIG. 8 is a cross-sectional view schematically showing a second configuration example of the optical sensor unit 11. The optical sensor unit 11 of the second configuration example includes a case 11a, a light shielding wall 11b, a light emitting unit X, and a light receiving unit Y. That is, in the optical sensor unit 11 of the second configuration example, the above-described translucent plate 11z is excluded.

  The case 11a is a bowl-shaped member that houses the light emitting unit X and the light receiving unit Y. The outer dimensions (height H0, width W0, depth D0) of the case 11a are designed to be, for example, H0 = 1.5 mm, W0 = 4.5 mm, and D0 = 3.0 mm. The case 11a is embedded in the casing 10 so as to protrude from the surface of the casing 10 by a predetermined dimension H4 (for example, H4 = 0.3 mm). With such a configuration, it is possible to block outside light leaking into the light receiving unit Y by the protruding portion of the case 11a, so that it is possible to improve the detection accuracy of the pulse wave data.

  The light shielding wall 11b is a member that divides the case 11a into a first area where the light emitting part X is placed and a second area where the light receiving part Y is placed. Similar to the first embodiment described above, by providing the light blocking wall 11b, it is possible to block the light that is directly incident on the light receiving unit Y from the light emitting unit X, so that it is possible to improve the detection accuracy of the pulse wave data. It becomes. The case 11a and the light shielding wall 11b are preferably formed integrally.

  The light emitting unit X includes a substrate X1, a light emitting chip X2, a sealing body X3, a wire X4, and a conductor X5. The substrate X1 is a member on which the light emitting chip X2 is placed. The light emitting chip X2 is a light emitting element (for example, a green LED bare chip) that outputs light of a predetermined wavelength. The sealing body X3 is a translucent member that seals the light emitting chip X2. The wire X4 is a member that electrically connects the light emitting chip X2 and the conductor X5. The conductor X5 is a conductive member formed from the upper surface to the lower surface of the substrate X1, and is soldered to the wiring pattern formed on the bottom surface of the case 11a.

  The light receiving unit Y includes a substrate Y1, a light receiving chip Y2, a sealing body Y3, a wire Y4, and a conductor Y5. The substrate Y1 is a member on which the light receiving chip Y2 is placed. The light receiving chip Y2 is a photoelectric conversion element (for example, a bare chip of a phototransistor having photosensitivity in the near infrared region to the visible region) that converts light belonging to a predetermined wavelength region into an electric signal. The sealing body Y3 is a translucent member that seals the light receiving chip Y2. The wire Y4 is a member that electrically connects the light receiving chip Y2 and the conductor Y5. The conductor Y5 is a conductive member formed from the upper surface to the lower surface of the substrate Y1, and is soldered to the wiring pattern formed on the bottom surface of the case 11a.

  As described above, in the optical sensor unit 11 of the second configuration example, a package type semiconductor device is used as the light emitting unit X and the light receiving unit Y instead of a bare chip. Therefore, since it is not necessary to cover the opening surface of the case 11a with a translucent plate, it is possible to eliminate the concern that light is directly incident on the light receiving unit Y from the light emitting unit X through the translucent plate. As a result, the detection accuracy of pulse wave data can be increased.

  Further, in the optical sensor unit 11 of the second configuration example, a relationship of H1> H2 is established between the height H1 of the light shielding wall 11b and the height H2 of the light emitting unit X. The height H1 of the light shielding wall 11b indicates the distance (for example, H1 = 1.4 mm) from the bottom surface of the case 11a to the upper end of the light shielding wall 11b. Further, the height H2 of the light emitting portion X indicates the distance (for example, H2 = 0.5 mm) from the bottom surface of the case 11a to the light emitting surface of the light emitting chip X2. However, considering that the light emitting chip X2 is very thin compared to the substrate X1, the thickness of the substrate X1 can be handled as the height H2 of the light emitting portion X.

  If the dimensional design satisfying the above relational expression is performed, the light directly incident on the light receiving part Y from the light emitting part X can be effectively blocked by the light shielding wall 11b, so that the detection accuracy of the pulse wave data is improved. It becomes possible.

  However, if the height H2 of the light emitting portion X is designed to be too small compared to the height H1 of the light shielding wall 11b, the light emitted from the light emitting portion X is scattered or attenuated before reaching the living body 2, The intensity of the light detected by the light receiving unit Y decreases, and the detection accuracy of the pulse wave data decreases. Therefore, an optimum design range exists for the offset distance ΔH (= H1−H2) obtained by subtracting the height H2 of the light emitting portion X from the height H1 of the light shielding wall 11b.

  FIG. 9 is a waveform diagram showing the correlation between the offset distance ΔH and the signal intensity (peak-to-peak value of the received light signal). In order from the top, ΔH = 0.6 mm, 0.7 mm, 0.9 mm, 1. The received light waveforms when 1 mm and 2.1 mm are depicted. It can be seen from FIG. 8 that the signal intensity becomes maximum when the offset distance ΔH is 0.9 mm. In view of this experimental result, it can be said that the offset distance ΔH is desirably within the design range of 0 mm <ΔH <2 mm (more preferably, 0.6 mm ≦ ΔH ≦ 1.4 mm).

  For example, when the light emitting part X including the sealing body X3 having a thickness of 0.6 mm is used and the offset distance ΔH is designed to be 0.9 mm, the upper surface of the sealing body X3 is 0 from the upper end of the light shielding wall 11b. The thickness of the substrate X1 may be designed so that the height position is recessed by 3 mm.

  Further, in the optical sensor unit 11 of the second configuration example, a relationship of H2> H3 is established between the height H2 of the light emitting unit X and the height H3 of the light receiving unit Y. The height H3 of the light receiving unit Y indicates the distance (for example, H3 = 0.3 mm) from the bottom surface of the case 11a to the light receiving surface of the light receiving chip Y2. However, in view of the fact that the light receiving chip Y2 is very thin compared to the substrate Y1, the thickness of the substrate Y1 can be handled as the height H3 of the light receiving portion Y.

  If the dimensional design satisfying the above relational expression is performed, it becomes difficult for external light to reach the light receiving unit Y, so that the detection accuracy of the pulse wave data can be improved.

  Next, how the signal intensity changes according to the inter-element distance W1 between the light emitting part X and the light receiving part Y will be considered with reference to FIG. FIG. 10 is a waveform diagram showing the correlation between the inter-element distance W1 and the signal intensity. From the top, W1 = 0.1 mm, 0.5 mm, 1.0 mm, 3.0 mm, and 5.0 mm. The received light waveform at a certain time is depicted. FIG. 9 shows that the signal intensity is maximized when the inter-element distance W1 is 0.5 mm. In view of this experimental result, it can be said that the inter-element distance W1 is preferably within the design range of 0.1 mm ≦ W1 ≦ 3.0 mm (more preferably 0.2 mm ≦ W2 ≦ 0.8 mm).

  Next, a modified example of the optical sensor unit 11 will be described with reference to FIGS. 11A to 11D. 11A to 11D are cross-sectional views schematically showing third to sixth configuration examples of the optical sensor unit 11, respectively. The third configuration example to the sixth configuration example are substantially the same as the above-described second configuration example, and various components are added in order to further improve the detection accuracy of the pulse wave data.

  For example, the optical sensor unit 11 of the third configuration example (FIG. 11A) has a condenser lens 11 c on the light emitting unit X. By providing the condensing lens 11c, the light emitted from the light emitting unit X can be collected and applied to the outer ear E, so that the intensity of the light detected by the light receiving unit Y is increased and the detection accuracy of the pulse wave data is increased. It becomes possible to improve.

  In the optical sensor unit 11 of the fourth configuration example (FIG. 11B), the first region where the light emitting unit X is placed is covered with a lid member 11d having an opening d1 smaller than the light emitting region of the light emitting unit X. Has been. For example, when the light emitting area of the light emitting part X is a 0.7 mm square rectangular area, the opening d1 may be formed in a circular shape with a diameter of 0.5 mm or a rectangular shape with a 0.5 mm square. By providing the lid member 11d, it is possible to prevent the light emitted from the light emitting part X from diffusing and to block the light directly incident on the light receiving part Y from the light emitting part X. The accuracy can be increased.

  Further, in the optical sensor unit 11 of the fifth configuration example (FIG. 11C), the second region where the light receiving unit Y is placed is covered with a lid member 11e having an opening d2 larger than the light receiving region of the light receiving unit Y. Has been. For example, when the light receiving area of the light receiving portion Y is a rectangular area of 0.7 mm square, the opening d2 may be formed in a circular shape having a diameter of 1.0 mm or a rectangular shape having a 1.0 mm square. By providing the lid member 11e, it is possible to block external light that leaks into the light receiving unit Y, and thus it is possible to improve the detection accuracy of pulse wave data.

  In the optical sensor unit 11 of the sixth configuration example (FIG. 11D), at least one of the light emitting unit X and the light receiving unit Y selectively allows only a predetermined wavelength component (near the output peak wavelength of the light emitting unit X) to pass therethrough. Color filters X6 and Y6 are included. By providing the color filters X6 and Y6, unnecessary wavelength components can be removed, so that the detection accuracy of pulse wave data can be increased.

  Next, a further modification of the optical sensor unit 11 will be described with reference to FIG. FIG. 12 is a cross-sectional view schematically illustrating a seventh configuration example of the optical sensor unit 11. The seventh configuration example is substantially the same configuration as the second configuration example described above, and is devised to further improve the detection accuracy of the pulse wave data.

  The optical sensor unit 11 of the seventh configuration example includes a buffer member 11f between the housing 10 and the case 11a. As the buffer member 11f, rubber, synthetic sponge, or the like can be suitably used. By setting it as such a structure, since the adhesiveness of the optical sensor part 11 and the outer ear E can be improved, it becomes possible to measure a pulse wave stably.

  Note that the components added in the third configuration example (FIG. 11A) to the sixth configuration example (FIG. 11D) and the seventh configuration example (FIG. 12) may be applied independently. It may be applied in any combination.

  In addition, in any case of adopting any of the above-described configurations, the light receiving unit Y may be disposed on the side closer to the ear canal E5 than the light emitting unit X (or the back side of the ear canal E5). By adopting such a configuration, it becomes difficult for outside light to leak into the light receiving unit Y, so that the detection accuracy of pulse wave data can be increased.

<Filter section>
FIG. 13 is a circuit diagram illustrating a first configuration example of the filter unit 27. The filter unit 27 of the first configuration example includes a current / voltage conversion circuit 100, a first-order CR high-pass filter circuit 110 (hereinafter referred to as an HPF [high pass filter] circuit 110), an amplifier circuit 120, and a first-order CR low-pass. A filter circuit 130 (hereinafter referred to as an LPF [low pass filter] circuit 130) and an amplifier circuit 140 are included.

  The current / voltage conversion circuit 100 is a circuit that converts a current signal output from the optical sensor unit 11 into a voltage signal, and includes a resistor R1 (for example, 200 kΩ). The anode of the light emitting diode that forms the optical sensor unit 11 is connected to the application terminal of the power supply voltage VDD. The cathode of the light emitting diode is connected to the ground terminal. The collector of the phototransistor forming the optical sensor unit 11 is connected to the application terminal of the power supply voltage VDD via the resistor R1. The emitter of the phototransistor is connected to the ground terminal.

  The HPF circuit 110 is a circuit that removes a low-frequency component superimposed on the output signal of the current / voltage conversion circuit 100, and includes a capacitor C1 (for example, 0.1 μF) and a resistor R2 (for example, 4.7 MΩ). The first end of the capacitor C1 is connected to the collector of the phototransistor that forms the optical sensor unit 11. The second terminal of the capacitor C1 is connected to the ground terminal via the resistor R2. Note that the cut-off frequency of the HPF circuit 110 configured as described above is designed to be 0.34 Hz.

  The amplifier circuit 120 is a circuit that amplifies the output signal of the HPF circuit 110, and includes an operational amplifier OP1, a resistor R3 (for example, 100 kΩ), a resistor R4 (for example, 10 kΩ), a capacitor C2 (for example, 0.01 μF), and a capacitor C3. (For example, 0.1 μF). The non-inverting input terminal (+) of the operational amplifier OP1 is connected to the second terminal of the capacitor C1. The inverting input terminal (−) of the operational amplifier OP1 is connected to the output terminal of the operational amplifier OP1 through the resistor R3, and is also connected to the ground terminal through the resistor R4. The first power supply terminal of the operational amplifier OP1 is connected to the application terminal of the power supply voltage VDD. The second power supply terminal of the operational amplifier OP1 is connected to the ground terminal. The capacitor C2 is connected in parallel with the resistor R3. The capacitor C3 is connected between the first power supply terminal of the operational amplifier OP1 and the ground terminal.

  The LPF circuit 130 is a circuit that removes a high-frequency component superimposed on the output signal of the amplifier circuit 120, and includes a resistor R5 (for example, 100 kΩ) and a capacitor C4 (for example, 1.0 μF). The first end of the resistor R5 is connected to the output end of the operational amplifier OP1. A second terminal of the resistor R5 is connected to the ground terminal via the capacitor C4. Note that the cut-off frequency of the LPF circuit 130 configured as described above is set to 1.6 Hz.

  The amplifier circuit 140 is a circuit that amplifies the output signal of the LPF circuit 130, and includes an operational amplifier OP2, a variable resistor R6 (for example, 500 kΩ), a resistor R7 (for example, 10 kΩ), a capacitor C5 (for example, 0.01 μF), and a capacitor. C6 (for example, 0.1 μF). The non-inverting input terminal (+) of the operational amplifier OP2 is connected to the second terminal of the resistor R5. The inverting input terminal (−) of the operational amplifier OP2 is connected to the output terminal of the operational amplifier OP2 through the variable resistor R6, and is also connected to the ground terminal through the resistor R7. The first power supply terminal of the operational amplifier OP2 is connected to the application terminal of the power supply voltage VDD. The second power supply terminal of the operational amplifier OP2 is connected to the ground terminal. The capacitor C5 is connected in parallel with the variable resistor R6. The capacitor C6 is connected between the first power supply terminal and the ground terminal of the operational amplifier OP2.

  With the filter unit 27 of the first configuration example, the noise component superimposed on the output signal of the optical sensor unit 11 can be removed with a simple circuit configuration, and the detection accuracy of the pulse wave data can be increased.

  However, in the filter unit 27 of the first configuration example, the body motion noise (noise component of about 6.0 Hz generated by exercise such as walking) may not be sufficiently removed in some cases, and the user (subject) In order to detect the pulse wave at the time of exercise with high accuracy, there was room for further improvement (see the lower part of FIG. 15).

  FIG. 14 is a circuit diagram illustrating a second configuration example of the filter unit 27. The filter unit 27 of the second configuration example includes a current / voltage conversion circuit 200, a primary CR high-pass filter circuit 210 (hereinafter referred to as an HPF circuit 210), a voltage follower circuit 220, and a secondary CR low-pass filter circuit 230 ( (Hereinafter referred to as LPF circuit 230), amplifier circuit 240, sixth-order band pass filter circuit 250 (hereinafter referred to as BPF [band pass filter] circuit 250), amplifier circuit 260, intermediate voltage generation circuit 270, Have

  The current / voltage conversion circuit 200 is a circuit that converts a current signal output from the optical sensor unit 11 into a voltage signal, and includes a resistor R8 (for example, 200 kΩ) and a resistor R9 (for example, 430Ω). The anode of the light emitting diode that forms the optical sensor unit 11 is connected to the application terminal of the power supply voltage VDD. The cathode of the light emitting diode is connected to the ground terminal via a resistor R9. The collector of the phototransistor forming the photosensor unit 11 is connected to the application terminal of the power supply voltage VDD via the resistor R8. The emitter of the phototransistor is connected to the ground terminal.

  The HPF circuit 210 is a circuit that removes a low-frequency component superimposed on the output signal of the current / voltage conversion circuit 200, and includes a capacitor C7 (for example, 1.0 μF) and a resistor R10 (for example, 240 kΩ). The first end of the capacitor C7 is connected to the collector of the phototransistor that forms the optical sensor unit 11. The second end of the capacitor C7 is connected to the application end of the intermediate voltage VM via the resistor R10. The cutoff frequency of the HPF circuit 210 having the above configuration is designed to be 0.66 Hz.

  The voltage follower circuit 220 is a circuit that transmits the output signal of the HPF circuit 110 to the subsequent stage, and includes an operational amplifier OP3 and a capacitor C8 (for example, 0.1 μF). The non-inverting input terminal (+) of the operational amplifier OP3 is connected to the second terminal of the capacitor C7. The inverting input terminal (−) of the operational amplifier OP3 is connected to the output terminal of the operational amplifier OP3. The first power supply terminal of the operational amplifier OP3 is connected to the application terminal of the power supply voltage VDD. The second power supply terminal of the operational amplifier OP3 is connected to the ground terminal. The capacitor C8 is connected between the first power supply terminal and the ground terminal of the operational amplifier OP3.

  The LPF circuit 230 is a circuit that removes a high frequency component superimposed on the output signal of the voltage follower circuit 220, and includes a resistor R11 (eg, 620 kΩ), a resistor R12 (eg, 620 kΩ), a capacitor C9 (eg, 1.0 μF), Capacitor C10 (for example, 1.0 μF). The first end of the resistor R11 is connected to the output end of the operational amplifier OP3. The second end of the resistor R11 is connected to the first end of the resistor R12, and is connected to the application end of the intermediate voltage VM via the capacitor C9. The second end of the resistor R12 is connected to the application end of the intermediate voltage VM via the capacitor C10. Note that the cut-off frequency of the LPF circuit 230 configured as described above is set to 0.26 Hz.

  The amplifier circuit 240 is a circuit that amplifies the output signal of the LPF circuit 230, and includes an operational amplifier OP4, a resistor R13 (for example, 10 kΩ), a resistor R14 (for example, 1 kΩ), and a capacitor C11 (for example, 0.1 μF). . The non-inverting input terminal (+) of the operational amplifier OP4 is connected to the second terminal of the resistor R12. The inverting input terminal (−) of the operational amplifier OP4 is connected to the output terminal of the operational amplifier OP4 through the resistor R13, and is also connected to the application terminal of the intermediate voltage VM through the resistor R14. The first power supply terminal of the operational amplifier OP4 is connected to the application terminal of the power supply voltage VDD. The second power supply terminal of the operational amplifier OP4 is connected to the ground terminal. The capacitor C11 is connected between the first power supply terminal of the operational amplifier OP4 and the ground terminal.

  The BPF circuit 250 is a circuit that removes low-frequency components and high-frequency components superimposed on the output signal of the amplifier circuit 240, and includes operational amplifiers OP5 to OP7, a resistor R15 (for example, 75 kΩ), a resistor R16 (for example, 2 MΩ), and a resistor. R17 (for example, 150 kΩ), resistor R18 (for example, 130 kΩ), resistor R19 (for example, 91 kΩ), resistor R20 (for example, 620 kΩ), resistor R21 (for example, 43 kΩ), resistor R22 (for example, 30 kΩ), and resistor R23 (for example) For example, 200 kΩ), capacitor C12 (for example, 1 μF), capacitor C13 (for example, 1 μF), capacitor C14 (for example, 0.1 μF), capacitor C15 (for example, 1 μF), capacitor C16 (for example, 1 μF), and capacitor C17 (for example) For example, 0.1 μF) and capacitor C18 (for example, 1 μF) Includes a capacitor C19 (e.g. 1 .mu.F), capacitor C20 (e.g. 0.1ĩF), the.

  The first end of the resistor R15 is connected to the output end of the operational amplifier OP4. The 2nd end of resistance R15 is connected to the application end of intermediate voltage VM via resistance R16. The non-inverting input terminal (+) of the operational amplifier OP5 is connected to the application terminal for the intermediate voltage VM. The inverting input terminal (−) of the operational amplifier OP5 is connected to the second terminal of the resistor R15 through the capacitor C12, and is also connected to the output terminal of the operational amplifier OP5 through the resistor R17. The first power supply terminal of the operational amplifier OP5 is connected to the application terminal of the power supply voltage VDD. The second power supply terminal of the operational amplifier OP5 is connected to the ground terminal. The capacitor C13 is connected between the second end of the resistor R15 and the output end of the operational amplifier OP5. The capacitor C14 is connected between the first power supply terminal and the ground terminal of the operational amplifier OP5.

  The first end of the resistor R18 is connected to the output end of the operational amplifier OP5. The 2nd end of resistance R18 is connected to the application end of intermediate voltage VM via resistance R19. The non-inverting input terminal (+) of the operational amplifier OP6 is connected to the application terminal for the intermediate voltage VM. The inverting input terminal (−) of the operational amplifier OP6 is connected to the second terminal of the resistor R18 via the capacitor C15, and is also connected to the output terminal of the operational amplifier OP6 via the resistor R20. The first power supply terminal of the operational amplifier OP6 is connected to the application terminal of the power supply voltage VDD. The second power supply terminal of the operational amplifier OP6 is connected to the ground terminal. The capacitor C16 is connected between the second end of the resistor R18 and the output end of the operational amplifier OP6. The capacitor C17 is connected between the first power supply terminal of the operational amplifier OP6 and the ground terminal.

  The first end of the resistor R21 is connected to the output end of the operational amplifier OP6. The 2nd end of resistance R21 is connected to the application end of intermediate voltage VM via resistance R22. The non-inverting input terminal (+) of the operational amplifier OP7 is connected to the application terminal for the intermediate voltage VM. The inverting input terminal (−) of the operational amplifier OP7 is connected to the second terminal of the resistor R21 via the capacitor C18, and is also connected to the output terminal of the operational amplifier OP7 via the resistor R23. The first power supply terminal of the operational amplifier OP7 is connected to the application terminal of the power supply voltage VDD. The second power supply terminal of the operational amplifier OP7 is connected to the ground terminal. The capacitor C19 is connected between the second end of the resistor R21 and the output end of the operational amplifier OP7. The capacitor C20 is connected between the first power supply terminal and the ground terminal of the operational amplifier OP7.

  The BPF circuit 250 having the above configuration has a pass frequency band of 0.80 to 2.95 Hz.

  The amplifier circuit 260 is a circuit that amplifies the output signal of the BPF circuit 250, and includes an operational amplifier OP8, a variable resistor R24 (for example, 1 MΩ), a resistor R25 (for example, 1 kΩ), and a capacitor C21 (for example, 0.1 μF). Including. The non-inverting input terminal (+) of the operational amplifier OP8 is connected to the output terminal of the operational amplifier OP7. The inverting input terminal (−) of the operational amplifier OP8 is connected to the output terminal of the operational amplifier OP8 through the variable resistor R24, and is also connected to the application terminal of the intermediate voltage VM through the resistor R25. The first power supply terminal of the operational amplifier OP8 is connected to the application terminal of the power supply voltage VDD. The second power supply terminal of the operational amplifier OP8 is connected to the ground terminal. The capacitor C21 is connected between the first power supply terminal and the ground terminal of the operational amplifier OP8.

  The intermediate voltage generation circuit 260 is a circuit that divides the power supply voltage VDD by half to generate an intermediate voltage VM (= VDD / 2), and includes a resistor R26 (for example, 1 kΩ), a resistor R27 (for example, 1 kΩ), Capacitor C22 (0.1 μF). A first end of the resistor R26 is connected to an application end of the power supply voltage VDD. The second end of the resistor R26 and the first end of the resistor R27 are both connected to the application end of the intermediate voltage VM. A second end of the resistor R27 is connected to the ground end. The capacitor C22 is connected in parallel with the resistor R27.

  Since the body movement noise of the user (subject) can be appropriately removed with the filter unit 27 of the second configuration example, not only the pulse wave when the user (subject) is at rest, but also when the user (subject) is exercising. It is also possible to detect a pulse wave during walking (for example, during walking) with high accuracy (see the upper part of FIG. 15).

  In the filter unit 27 of the second configuration example, the HPF circuit 210, the LPF filter circuit 230, the amplifier circuit 240, the BPF circuit 250, and the amplifier circuit 260 all use the intermediate voltage VM (= VDD / 2) as the reference voltage. Therefore, the output signal of the filter unit 27 has a waveform whose amplitude fluctuates up and down with respect to the intermediate voltage VM. Therefore, with the filter unit 27 of the second configuration example, saturation of the output signal (sticking to the power supply voltage VDD or the ground voltage) can be prevented and pulse wave data can be detected correctly.

<Application to hearing aids>
FIG. 16 is a system diagram showing an application example to a hearing aid. The pulse wave sensor 1 of FIG. 16 is provided as a hearing aid having a pulse wave measurement function. The specific configuration of the pulse wave sensor 1 is basically the same as that of FIG. 4 described above, but the components (such as a sound collection microphone) for functioning as a hearing aid instead of a portable audio player are appropriately used. Must be included.

  In addition, it is assumed that the information terminal 2 that is the transmission destination of the pulse wave data and the analysis result (safety information, etc.) is installed in a remote place. Therefore, when this configuration is adopted, the pulse wave sensor 1 is connected to the information terminal 2 (such as a data server of a medical institution or a personal computer owned by a remote family) via the network 3. It is desirable to provide a communication unit (such as a wireless LAN module).

  Among users (subjects) who need hearing aids, there are many elderly people who need health management and safety confirmation from a remote location. However, it is not always easy for elderly people to install or maintain a plurality of electronic devices (here, hearing aids and pulse wave sensors) individually and appropriately.

  On the other hand, the pulse wave sensor 1 provided as a hearing aid having a pulse wave measurement function is a hearing aid itself for the user (subject) and does not make the user aware of the measurement of the pulse wave. It becomes possible to reduce the burden. In addition, by monitoring the pulse wave data transmitted from the pulse wave sensor 1 and the analysis result thereof at the remote information terminal 2, even if a user (subject) 's health condition is abnormal, it can be quickly performed. It becomes possible to cope.

  Of course, it is also possible to implement the configuration of the present invention (configuration for measuring pulse waves with the outer ear E) as a single pulse wave sensor that does not have additional functions such as an audio playback function and a hearing aid function. .

<Consideration on output wavelength>
In the experiment, in the so-called reflection type pulse wave sensor 1, the output wavelength of the light emitting part is set to λ1 (infrared: 940 nm), λ2 (green: 630 nm), and λ3 (blue: 468 nm), and the output intensity of the light emitting part ( The behavior when the drive current value was changed to 1 mA, 5 mA, and 10 mA was investigated. As a result, in the visible light region having a wavelength of about 600 nm or less, the absorption coefficient of oxygenated hemoglobin HbO ₂ is increased, and the peak intensity of the measured pulse wave is increased. Therefore, it is relatively easy to acquire the waveform of the pulse wave. I understood.

In the pulse oximeter for detecting the oxygen saturation of arterial blood, the difference between the absorption coefficient (solid line) of oxygenated hemoglobin HbO ₂ and the absorption coefficient (broken line) of deoxygenated hemoglobin Hb is maximized. Although the wavelength (around 700 nm) is widely used as the output wavelength of the light emitting unit, the above experimental results are obtained when considering use as a pulse wave sensor (particularly a so-called reflection type pulse wave sensor). It can be said that it is desirable to use a visible light region having a wavelength of 600 nm or less as the output wavelength of the light emitting unit as shown in FIG.

<Other variations>
The configuration of the present invention can be variously modified in addition to the above-described embodiment without departing from the gist of the invention. That is, the above-described embodiment is an example in all respects and should not be considered as limiting, and the technical scope of the present invention is not the description of the above-described embodiment, but the claims. It should be understood that all modifications that come within the meaning and range of equivalents of the claims are included.

  The present invention can be used as a technology for enhancing the convenience of a pulse wave sensor, and includes various devices such as healthcare support devices, game devices, music devices, pet communication tools, and driver's sleep control devices. It can be applied to various fields.

E outer ear E1 scaphoid E2 ear ring E3 anti-oval ring E4 anti tragus E5 outer ear canal E6 upper anti ear ring leg E7 triangular fossa E8 lower anti ear ring leg E9 concha E10 Audio player, hearing aid)
1X Earphone (Headphone)
1Y Main unit 2 Information terminal (data server, personal computer, etc.)
3 Network 10 Housing 10x Projection member 10y Clip member 11 Optical sensor unit 11A Light emitting unit 11B Light receiving unit 11a Case 11b Light blocking wall 11c Condensing lens 11d, 11e Lid member 11f Buffer member (rubber, synthetic sponge, etc.)
11z Translucent plate 12 Speaker 13 Driver 14 Code 15 Connector 20 Case 21 Control unit 22 Operation unit 23 Display unit 24 Storage unit 25 Communication unit 26 Power supply unit 27 Filter unit x Light emitting unit (light emitting chip)
y Light receiving part (light receiving chip)
X light emitting part X1 substrate X2 light emitting chip X3 sealing body X4 wire X5 conductor X6 color filter Y light receiving part Y1 substrate Y2 light receiving chip Y3 sealing body Y4 wire Y5 conductor Y6 color filter 100 current / voltage conversion circuit 110 primary CR High-pass filter circuit 120 Amplifier circuit 130 Primary CR low-pass filter circuit 140 Amplifier circuit 200 Current / voltage conversion circuit 210 Primary CR high-pass filter circuit 220 Voltage follower circuit 230 Secondary CR low-pass filter circuit 240 Amplifier circuit 250 Sixth-order band-pass filter circuit 260 Amplifier circuit 270 Intermediate voltage generation circuit R1-R27 Resistor C1-C22 Capacitor OP1-OP8 Operational amplifier

Claims (16)

A housing attached to the outer ear;
An optical sensor unit that obtains pulse wave data by irradiating the outer ear with light from the light emitting unit and detecting the intensity of the light transmitted through the living body and returning by the light receiving unit;
A pulse wave sensor comprising:   The pulse wave sensor according to claim 1, wherein the casing includes a speaker.   The pulse wave sensor according to claim 2, further comprising a control unit that controls an output operation of the speaker in accordance with the pulse wave data.   The pulse wave sensor according to any one of claims 1 to 3, further comprising a communication unit that transmits the pulse wave data to an information terminal.   The pulse wave sensor according to any one of claims 1 to 4, wherein the case has a shape that fits into a hollow portion surrounded by the tragus and the antitragus.   The pulse wave sensor according to claim 5, wherein the light receiving unit is disposed closer to the ear canal than the light emitting unit.   The pulse wave sensor according to any one of claims 1 to 4, wherein the casing has a shape covering the auricle.   The pulse wave sensor according to claim 7, wherein the casing has a protruding member that supports the optical sensor unit on a surface facing the auricle.   The pulse wave sensor according to any one of claims 1 to 4, wherein the casing includes a clip member suspended from the auricle.   The pulse wave sensor according to claim 9, wherein the clip member carries the optical sensor unit at a location where the clip member abuts on the auricle.   The pulse wave sensor according to claim 1, wherein the casing has an earplug structure for measuring a pulse wave inside the external auditory canal.   The optical sensor unit includes a bowl-shaped case, and a light shielding wall that divides the case into a first region on which the light emitting unit is placed and a second region on which the light receiving unit is placed. The pulse wave sensor according to any one of claims 1 to 11.   The relationship of H1> H2> H3 is established among the height H1 of the light shielding wall, the height H2 of the light emitting unit, and the height H3 of the light receiving unit. Pulse wave sensor.   The pulse wave sensor according to claim 13, wherein the case is embedded so as to protrude from the housing.   The pulse wave sensor according to claim 1, wherein the optical sensor unit includes a buffer member between the optical sensor unit and the housing.   The pulse wave sensor according to any one of claims 1 to 15, wherein an output wavelength of the light emitting unit belongs to a visible light region of approximately 600 nm or less.