JP5798977B2 - Biological information detection device - Google Patents

Description

  The present invention relates to a biological information detection apparatus that detects biological information of a user, for example, for diagnosis of a user's health condition and attribute determination of the user.

  Biological information includes a pulse, a pulse wave, a blood flow, a blood pressure, and the like. Among these, a volume pulse wave, which is a waveform indicating a volume change of a peripheral artery, has attracted attention. Since plethysmogram may provide various useful information about human beings, it is not limited to medical diagnostic fields such as arteriosclerosis and detection of mental stress. Application is under consideration.

  For example, when a user operates an operation terminal typified by a television device, a video device, or a remote controller of an STB (Set Top Box), the user attribute is determined from the volume pulse wave of the user, and the determination result is Based on this, a system for selecting and distributing content suitable for the user has been proposed.

As a method for acquiring the volume pulse wave, a light receiving element is arranged in the vicinity of a living body part where a peripheral artery such as a fingertip or an earlobe exists, and among natural light or light emitted to the living body part by a light emitting element, A technique for measuring a volume change in a peripheral artery by measuring a change in the amount of light that is not absorbed by hemoglobin present in the peripheral artery but scattered outside the living body by a light receiving element is common (for example, Patent Document 1). See).
However, in the method described in Patent Document 1, it is necessary to perform explicit alignment such as placing a biological part such as a fingertip consciously at the installation position of the light receiving element. The action will be hindered, and the usability in operation is lowered, which is not preferable.

On the other hand, several methods for alleviating the need for such explicit alignment have been proposed.
For example, one of the methods is to arrange a large number of light receiving elements at positions where the living body part of the user may come into contact (see, for example, Patent Document 2). As another method, a living body part comes into contact by adding two optical members, a light emitting plate and a light receiving plate, to a conventional volume change measuring device in a peripheral artery using a light emitting device and a light receiving device. A method for realizing irradiation of infrared light and reception of scattered light independent of position has also been proposed (see, for example, Non-Patent Document 1).

JP 2007-259912 A JP 2009-039568 A

Chiaki Hiroshi, Maeda Atshiko, Kobayashi Satoshi: “Implementation and Evaluation of Surface Sensing Technology that Can Acquire Pulse Waves”, Information Processing Society of Japan Interaction 2011, 2011/03/03

  Among these, according to the technique described in Patent Document 2, since the restriction on the alignment of the living body part with respect to the detection position where the light receiving element is installed is reduced, the operational burden on the user is reduced. However, since a large number of light receiving elements must be arranged at the detection position, the number of parts of the device and the number of circuit channels increase, and as a result, the device configuration becomes complicated and large, and the power consumption is inevitable.

On the other hand, the method described in Non-Patent Document 1 has three major problems to be solved.
That is, the first problem is saturation of the light receiving element. Since this method has a configuration in which a light emitting plate and a light receiving plate are stacked one above the other, light other than the light emitted from the light emitting plate through the light receiving plate and irradiated on the living body part is received. Direct light that is received by the light receiving element as it is is generated by repeating total internal reflection inside the plate. When the amount of such direct light is large, the light receiving element is saturated.

  The second problem is an increase in thickness by stacking the light emitting plate and the light receiving plate vertically. The thickness of the light emitting plate and the light receiving plate needs to be designed according to the size of the light emitting element and the light receiving element which are generally spread. For example, if the size of the light emitting element and the light receiving element is 1 to 2 mm, the thickness of the light emitting plate and the light receiving plate is designed to be about 2 to 4 mm, which is twice this value. The thickness of the light emitting plate and the light receiving plate causes an increase in the size of the small electronic device when it is intended to be mounted on a small electronic device such as an STB remote controller without greatly changing its configuration.

  The third problem is attenuation that occurs when light emitted from the light emitting plate is transmitted through the light receiving plate. This attenuation is as high as 10% because, for example, acrylic resin has a transmittance of 90%. A sufficient amount of light is required to stably measure the blood flow in the body part. Therefore, in order to compensate for the amount of attenuation, it is necessary to flow a larger current to the light emitting element, resulting in an increase in power consumption.

  The present invention has been made paying attention to the above circumstances, and the object of the present invention is to reduce restrictions on the alignment of the living body part to the detection position, reduce the operational burden on the user, and saturate the light receiving element. It is another object of the present invention to provide a living body information detecting apparatus that is easy to downsize and reduces power consumption.

In order to achieve the above object, according to a first aspect of the present invention, there is provided a biological information detecting apparatus for detecting information related to a volume pulse wave from a biological part, wherein the first and second optical members, a light emitting element, a light receiving element, And a signal processing unit. Each of the first and second optical members has a plate shape or a column shape, and among these, the first optical member completely transmits light incident from the side end surface between the upper surface and the lower surface serving as a contact surface of the living body part. Reflect. The second optical member are arranged to form a top surface and both coplanar for surface emission of the first adjacent side of the optical member and the upper surface of the light-receiving the first optical member. The light emitting element makes light incident on the first optical member so as to cause the total reflection from the side end face thereof. Then, when the living body part comes into contact with the upper surfaces of the first and second optical members, the scattered light component by the living body part of the light of the light emitting element leaked from the contact position of the first optical member is changed to the first part. After being taken into the second optical member from its upper surface, it is guided to the side end face and emitted. The light receiving element receives light emitted from the side end face of the second optical member and outputs a light reception signal corresponding to the amount of light received. The signal processing unit detects a change in the amount of received light that occurs when a living body part contacts the upper surfaces of the first and second optical members based on the light reception signal output from the light receiving element. Information representing the detected change in the amount of received light is output as information representing the volume pulse wave of the living body part. Further, any upper surfaces of the upper Symbol first optical member and the second optical member is made flat, and the light emitting element and the light receiving element of each of the first optical member and the second optical member It is arranged on the side end face on the same side.

Therefore, according to one aspect of the present invention, the following effects can be obtained.
That is, the first and second optical members are arranged side by side in the horizontal direction. For this reason, the light leaked from the upper surface of the first optical member is not directly incident on the second optical member and guided to the light receiving element as in the case where these optical members are arranged one above the other. This can prevent the light receiving element from being saturated. Further, since the first optical member and the second optical member are arranged side by side in the horizontal direction, the thickness of the apparatus can be reduced.

  The living body part directly contacts the upper surface of the first optical member. For this reason, the light leaked from the upper surface of the first optical member is directly applied to the living body part without being attenuated, thereby providing a sufficient amount of light for stably measuring the blood flow with respect to the living body part. Irradiation is possible, and measurement accuracy can be improved.

  Further, in the configuration of the first optical member, in a steady state, when the incident light is totally reflected in the first optical member and the living body part contacts the upper surface of the first optical member, the change of the critical angle at this time Is used to leak light from the upper surface of the first optical member and irradiate the living body part. For this reason, it is not necessary to provide a backlight structure or the like for forcibly emitting light from the upper surface of the first optical member, thereby making the configuration of the first optical member simple and inexpensive. Can do.

The first aspect of the invention is further comprising a light emitting element incident light to cause the total reflection from the side end face on Symbol in the first optical member. In this way, even when natural light or room light cannot provide a sufficient amount of received light, it is possible to always perform highly accurate and stable measurement.

The 1st viewpoint of this invention is equipped with the following structures as the one aspect. That is, in this aspect, a condensing optical system is disposed between the side end face of the second optical member and the light receiving element, and light emitted from the side end face of the second optical member is condensed by the condensing optical system. The light receiving element receives light. If it does in this way, the light radiate | emitted from a 2nd optical member can be received efficiently, and it will become possible to improve a measurement precision by this.

  That is, according to the present invention, the restriction on the alignment of the living body part to the detection position is greatly reduced, the burden on the user is reduced, and the light receiving element is prevented from being saturated. In addition, a biological information detection apparatus that reduces power consumption can be provided.

The figure which shows the structure of the biometric information detection apparatus concerning 1st Embodiment of this invention. The top view of the photon detection unit used with the biological information detection apparatus shown in FIG. It is a figure for using it for description of operation | movement of the 1st optical member of the photon detection unit used with the biological information detection apparatus shown in FIG. 1, (a) is not making a biological body part contact the 1st optical member. The figure which shows a state, (b) is a figure which shows the state which made the biological body part contact the 1st optical member. The figure for using it for operation | movement description of the 2nd optical member of the photon detection unit used with the biological information detection apparatus shown in FIG. The figure which shows the structure of the photon detection unit used with the biometric information detection apparatus concerning 2nd Embodiment of this invention. The figure which shows the structure of the photon detection unit used with the biological information detection apparatus concerning the 3rd Embodiment of this invention. The figure which shows the structure of the photon detection unit used with the biometric information detection apparatus concerning 4th Embodiment of this invention. The figure which shows the structure of the photon detection unit used with the biological information detection apparatus concerning the 5th Embodiment of this invention. The figure which shows the structure of the photon detection unit used with the biometric information detection apparatus concerning 6th Embodiment of this invention. The figure which shows the structure of the photon detection unit used with the biometric information detection apparatus concerning 7th Embodiment of this invention. The figure which shows the principal part structure of the photon detection unit used with the biometric information detection apparatus concerning 8th Embodiment of this invention.

Embodiments according to the present invention will be described below with reference to the drawings.
[First Embodiment]
(Constitution)
FIG. 1 is a diagram showing a configuration of a biological information detection apparatus according to the first embodiment of the present invention. This biological information detection apparatus includes a light detection unit 100 and a signal processing unit 200.

  The light detection unit 100 includes a first optical member 1 formed into a rectangular shape having a strip shape, and a second optical member 2 similarly formed into a rectangular shape having a strip shape. The first and second optical members 1 and 2 are arranged such that one side surfaces thereof are in contact with each other and the upper surfaces 1b and 2b form the same surface. That is, the 1st and 2nd optical members 1 and 2 are arrange | positioned in the state arranged in the horizontal direction, and each upper surface 1b, 2b functions as a sensor surface which contacts the biological body part 7 which is a detection target.

  The first and second optical members 1 and 2 are preferably transparent to sensor light 5 emitted from a light emitting element 3 to be described later, and have a refractive index higher than that of air. A material having a rate of 1.49) is used. Note that the side surfaces of the first and second optical members 1 and 2 are not necessarily in contact with each other, and may be separated at a predetermined interval. Further, the material and the refractive index are not limited to the above materials and values.

  A light emitting element 3 is disposed opposite to a first side end surface (hereinafter referred to as an incident surface) 1 a that functions as an incident surface of the first optical member 1. The light emitting element 3 is made of, for example, an LED (Light Emitting Diode), and the sensor light 5 is incident on the first optical member from the incident surface 1a. At this time, the arrangement conditions such as the arrangement position and the arrangement angle of the light emitting element 3 with respect to the incident surface 1a of the first optical member 1 are at least one of the sensor light 5 incident on the first optical member 1 from the incident surface 1a. The part is set so as to repeat total reflection between the upper surface 1b and the lower surface in the first optical member 1, for example, as shown in FIG.

  As the sensor light 5, for example, near infrared light having a wavelength of 0.7 to 2.5 μm is used. The reason is that hemoglobin in blood has a property of absorbing near infrared light having this wavelength particularly well. However, the sensor light 5 is not necessarily limited to this wavelength, and may be another wavelength.

  On the other hand, a light receiving element 4 is disposed opposite to a first side end surface (hereinafter referred to as an emission surface) 2 a that functions as an emission surface of the second optical member 2. The light receiving element 4 includes a sensor capable of detecting the amount of light, such as a photodiode, a phototransistor, a CCD (Charge Coupled Device), or a CMOS (Complementary MOS), and a living body emitted from the emission surface 2 a of the second optical member 2. The scattered light component 6 a from the part 7 is received and the received light signal is input to the signal processing unit 200.

  The signal processing unit 200 includes an amplification unit 21, an analog / digital conversion unit (A / D conversion unit) 22, and a waveform processing / output unit 23. The amplifying unit 21 amplifies the analog light reception signal input from the light receiving element 3 by a known amplifier circuit using a so-called operational amplifier or the like and outputs the amplified signal. The A / D conversion unit 22 converts the analog light reception signal output from the amplification unit 21 into a digital signal and outputs the digital signal.

  The waveform processing / output unit 23 takes in the digital received light signal output from the A / D converter and performs waveform analysis of the volume pulse wave. The contents of the analysis process include acquiring the time change of the digital light reception signal as time-series data, smoothing the acquired time-series data to remove the noise component, and time-series data from which the noise component has been removed. There are a process for detecting a detailed change in the waveform of the volume pulse wave by second-order differentiation and a process for detecting the feature of the volume pulse wave based on the detected change in the waveform of the volume pulse wave.

  For example, in the medical diagnostic field, the processing for detecting the feature of the volume pulse wave is to detect the degree of hardening of the blood vessel of the living body, or to detect the peak of the time series data and detect the interval between the detected peaks. It is conceivable to detect the pulse interval, to detect the periodicity of the time series data, and to determine whether or not the living body is in a resting state from the detected periodicity. Also, in the technical field of information input using a remote controller such as a television device, a feature vector is extracted from volume pulse wave waveform data, and the extracted feature vector is regarded as following a probability distribution and clustering is performed. Process. A process for recognizing a user based on the result of the clustering process can be considered. In addition, the use of the process which detects the characteristic of a volume pulse wave is not limited only to these, Other uses may be sufficient.

(Operation)
Next, the operation of the biological information detection apparatus configured as described above will be described.
The sensor light 5 of the light emitting element 3 incident on the first optical member 1 from the incident surface 1a is, for example, between the upper surface and the lower surface in the first optical member 1 as shown in FIG. Repeat total reflection.

At this time, the conditions for the sensor light 5 to repeat total reflection between the upper surface 1b and the lower surface in the first optical member 1 are defined as follows. That is, the critical angle θ when the sensor light 5 is emitted from the upper surface 1b to the external air layer is determined using the law of reflection, where n1 is the refractive index of the first optical member 1 and n2 is the refractive index of the air. It is calculated by the following formula.
θ = arcsin (n2 / n1) (1)
If the acrylic resin having the refractive index n1 = 1.49 described above is used as the first optical member 1, since the refractive index n2 of air is 1, θ = 42.155 from the above (1). Calculated as °. That is, the sensor light 5 is incident on the inside of the first optical member 1 so that the sensor light 5 is incident on the upper surface 1b of the first optical member 1 at an angle larger than θ = 42.155 °. For example, the incident sensor light 5 repeats total reflection between the upper surface 1b and the lower surface without leaking to the outside, and is transmitted to, for example, the second side end surface facing the incident surface 1a.

  Note that it is not necessary to set all of the sensor light 5 incident on the first optical member 1 from the light emitting element 3 to have an angle larger than the above θ = 42.155 °, and from the light emitting element 3 to the first optical member. It is only necessary that at least a part of the sensor light 5 incident on the member 1 includes a component having an angle larger than the above θ = 42.155 °.

In this state, for example, as shown in FIG. 3B, the user as the subject to be inspected uses his / her fingertip as the living body part 7 with the upper surface 1b and the second upper surface of the first optical member 1 constituting the sensor surface. It is assumed that the optical member 2 is in contact with the upper surface 2b of the optical member 2 at the same time. At this time, the critical angle θ ′ at the contact position P of the living body part 7 with respect to the upper surface 1b of the first optical member 1 is assumed that the refractive index n3 of the living body part 7 (skin) is 1.35.
θ ′ = arcsin (n3 / n1) (2)
Thus, θ ′ = 64.964 ° is calculated. In addition, the refractive index of the skin of the living body part 7 is 1.35. For example, in Toyohiro Ueda, “Study on skin permeability using transdermal device”, 2007, Meisei University research report meeting It is described in detail.

  Accordingly, when the living body part 7 comes into contact with an arbitrary position P on the upper surface 1b of the first optical member 1, 64.964 ° to 90 ° with respect to the contact position P in the sensor light 5 in the first optical member 1. The light component incident at the incident angle is totally reflected in the first optical member 1 in the same manner as when the living body part 7 is not in contact, but 42.155 ° to 64 in the first optical member 1. The light component incident on the contact position P at an angle of 964 ° leaks outside from the upper surface 1b of the first optical member 1 as shown in 6 of FIG. 7 is irradiated.

  The light quantity of the irradiation light 6 incident on the living body part 7 changes according to the amount of hemoglobin in the blood. This is because hemoglobin in the blood absorbs infrared light, so that the amount of light scattered and absorbed by the outside of the living body part 7 in accordance with the volume change of the peripheral blood vessels existing inside the living body part 7 This is because the ratio of changes.

  A part of the scattered light component 6a generated by the scattering out of the irradiation light 6 incident on the living body part 7 is incident on the second optical member 2 from its upper surface 2b as shown in FIG. Of the scattered light component 6a incident on the second optical member 2, the second optical member 2 is incident on the second optical member 2 at an incident angle larger than the critical angle θ = 42.155 ° previously defined by the equation (1). The incident component is emitted from the emission surface 2 a while repeating total reflection between the upper surface 2 b and the lower surface of the second optical member 2, and is received by the light receiving element 4.

  The scattered light component 6 a received by the light receiving element 4 is amplified to a predetermined signal level by the amplification unit 21, converted into a digital signal by the A / D conversion unit 22, and taken into the waveform processing / output unit 23. . In the waveform processing / output unit 23, first, the time change of the captured digital received light signal is extracted as time series data, and the extracted time series data is smoothed to remove noise components. Next, the time-series data from which the noise component has been removed is subjected to second-order differentiation, and a detailed change in the waveform of the volume pulse wave is detected. Based on the detected change in the waveform of the volume pulse wave, various features of the living body part 7 are extracted in an information processing unit (not shown).

  That is, the signal level of the light reception signal output from the light receiving element 4 is a value reflecting the change in the blood volume of the peripheral blood vessel in the living body part 7. Here, the blood volume of the peripheral blood vessels in the living body part 7 changes with time due to the pulsation of the heart. For this reason, the time change of the signal level of the light receiving signal represents the waveform of the volume pulse wave, and from this waveform, it is possible to determine the degree of hardening of the peripheral blood vessel, the pulse interval, the periodicity, etc. of the living body part 7. In addition, the user can be recognized from the characteristics of the waveform data of the volume pulse wave.

(Function and effect)
As described above in detail, in the first embodiment, the first and second optical members 1 and 2 are arranged in the horizontal direction so that one side surfaces thereof are in contact with each other and the upper surfaces 1b and 2b form the same surface. The light emitting elements 3 are arranged side by side and opposed to the incident surface 1a of the first optical member 1, and the sensor light 5 emitted by the light emitting elements 3 is placed in the first optical member 1 at the incident surface 1a. It is made to enter from. At this time, the arrangement condition of the light emitting element 3 with respect to the incident surface 1a of the first optical member 1 is that at least a part of the sensor light 5 incident from the light emitting element 3 into the first optical member 1 is the first optical member. 1 is set so as to be totally reflected between the upper surface 1a and the lower surface. Then, when the living body part 7 is brought into contact with the upper surfaces 1b and 2b of the first and second optical members 1 and 2 at the same time, the irradiated light leaks from the first optical member 1 and is applied to the living body part 7. 6, the scattered light component 6 a generated in the living body part 7 is taken into the second optical member 2 from the upper surface 2 b, emitted from the emission surface 2 b, and received by the light receiving element 4. Then, the received light signal of the scattered light component 6a received by the light receiving element 4 is input to the signal processing unit 200, and the change in the volume pulse wave waveform of the living body part 7 is detected to extract the characteristics of the living body part 7. I have to.

Therefore, according to the first embodiment, the following effects can be obtained.
(1) Since the first and second optical members 1 and 2 are arranged side by side in the horizontal direction, the upper surface of the first optical member 1 as in the case where these optical members 1 and 2 are arranged one above the other vertically. Irradiation light 6 leaking from 1b does not directly enter the second optical member 2 and is not guided to the light receiving element 4, thereby preventing the light receiving element 4 from being saturated. Further, as described above, the first optical member 1 and the second optical member 2 are arranged side by side in the horizontal direction, so that the thickness of the light detection unit 100 can be reduced. As a result, when the light detection unit 100 is incorporated into a small electronic device such as a remote controller, an increase in the size in the thickness direction can be prevented.

  (2) The living body part 7 is in direct contact with the upper surface 1 b of the first optical member 1. For this reason, the light leaked from the upper surface 1b of the first optical member 1 is directly radiated to the living body part 7 without being attenuated. As a result, the living body part 7 is not increased without increasing the drive current of the light emitting element 3. On the other hand, it is possible to irradiate with a sufficient amount of light for stably measuring the blood flow rate, and to improve the measurement accuracy.

  (3) The configuration of the light detection unit 100 is such that, in a steady state, the sensor light 5 is totally reflected in the first optical member 1 and the living body part 7 is brought into contact with the upper surface 1b of the first optical member 1. By utilizing the change in the critical angle, the irradiation light 6 is leaked from the upper surface 1b of the first optical member 1, and the living body part 7 is irradiated. For this reason, it is not necessary to provide the first optical member 1 with a backlight structure or the like for forcibly emitting the irradiation light 6 from the upper surface 1b, thereby making the configuration of the light detection unit 100 simple and inexpensive. Can be.

[ Reference Example 1 ]
FIG. 5 is a perspective view showing the configuration of the light detection unit of the biological information detection apparatus as Reference Example 1 , in which 110 denotes the light detection unit. In the figure, the same parts as those in FIG.

  The first and second optical members 1 and 2 are arranged in a state of being arranged in a horizontal direction so that one side surfaces thereof are in contact with each other and the upper surfaces 1b and 2b form the same sensor surface. Yes. The light emitting element 3 is disposed opposite to the second side end face 1 a ′ of the first optical member 1, and the light receiving element 4 is disposed opposite to the first side end face 2 a of the second optical member 2. That is, the light-emitting element 3 and the light-receiving element 4 are arranged to face the side end faces 1a ′ and 2a on the opposite sides of the first and second optical members 1 and 2, respectively.

  With this configuration, when the light detection unit 110 is mounted on a small electronic device such as a remote controller, for example, the light emitting element 3 and the light receiving element are disposed on the same side end surfaces 1a and 2a of the first and second optical members 1 and 2. Even when it is not possible to secure a mounting space for arranging the elements 4 side by side, mounting is possible while maintaining the performance of the light detection unit 110.

[Reference Example 2]
FIG. 6 is a perspective view showing the configuration of the light detection unit of the biological information detection apparatus as Reference Example 2 , in which 120 denotes the light detection unit. In the figure, the same parts as those in FIG.

As in the first embodiment, the first and second optical members 1 and 2 are arranged in the horizontal direction so that one side surfaces thereof are in contact with each other and the upper surfaces 1b and 2b are formed on the same plane. Arranged in a row. The first and second side end faces 1a and 1a 'of the first optical member 1 are arranged to face the light emitting elements 31 and 32, respectively, and the first and second side end faces 2a and 2a of the second optical member 2 are arranged. The light receiving elements 41 and 42 are disposed opposite to 2a ′. That is, the light emitting elements 31 and 32 and the light receiving elements 41 and 42 are arranged to face each other on both side end surfaces of the first and second optical members 1 and 2. The received light signals of the light receiving elements 41 and 42 are combined and then input to the signal processing unit 200.

  If comprised in this way, the sensor light 5 and 5 by the light emitting elements 31 and 32 will inject into the 1st optical member 1 from both the side end surfaces 1a and 1a ', and, thereby, the 1st optical member 1 The light amount of the irradiation light 6 leaking from the upper surface 1b of the first optical member 1 can be made almost uniform no matter which position on the upper surface 1b of the living body part 7 is brought into contact with. Also in the second optical member 2, scattered light components 6a and 6a emitted from both side end faces 2a and 2a 'are received by the light receiving elements 41 and 42, respectively. For this reason, regardless of the position on the upper surface 2b of the second optical member 2, the living body part 7 can always input a light reception signal having a high S / N to the signal processing unit 200. It is possible to perform high detection.

[ Reference Example 3 ]
FIG. 7 is a perspective view showing the configuration of the light detection unit of the biological information detection apparatus as Reference Example 3 , in which 130 indicates the light detection unit. In the figure, the same parts as those in FIG.

As described in the third embodiment, the light detection unit 130 according to the fourth embodiment includes the first optical member 1 in which the light emitting elements 31 and 32 are arranged opposite to each other at both side ends, and both side ends. In this configuration, a plurality of second optical members 2 having light receiving elements 41 and 42 arranged opposite to each other are arranged side by side.
With such a configuration, it is possible to form a wide sensor surface while keeping the variation in detection accuracy due to the contact position low.

[ Reference Example 4 ]
FIG. 8 is a perspective view showing the configuration of the light detection unit of the biological information detection apparatus as Reference Example 4 , in which 140 indicates the light detection unit. In the figure, the same parts as those in FIG.

The light detection unit 140 in the reference example 4 includes a first optical member 11 formed in a comb-teeth shape and a second optical member 21 formed in a comb-teeth shape. The optical members 11 and 21 are arranged so that the protruding pieces 111 and 112 and the protruding pieces 211, 212, and 213 are alternately engaged with each other.

In addition, a plurality of light emitting elements (two cases are illustrated in the figure) 3 and 3 are arranged at a predetermined interval on the base end side portion of the first optical member 11. 3, sensor light is incident on the first optical member 11 from the base end side portion and totally reflected in the protruding pieces 111 and 112. Further, a plurality of light receiving elements (three cases are illustrated in the figure) 4, 4,... Are arranged at regular intervals on the base end side portion of the second optical member 21. These light receiving elements 4, 4,... Receive scattered light components emitted from the base end sides of the protruding pieces 211, 212, and 213, respectively, and input them to the signal processing unit 200.
With this configuration, the light detection unit 140 can be assembled easily and with high accuracy, and a more stable sensor surface can be formed structurally.

[ Reference Example 5 ]
FIG. 9 is a perspective view showing the configuration of the light detection unit of the biological information detection apparatus as Reference Example 5 , in which 150 indicates the light detection unit. In the figure, the same parts as those in FIG.

The light detection unit 150 in Reference Example 5 is formed by bending the first optical member 12 and the second optical member 22 in the thickness direction thereof, and the opposite sides of the first and second optical members 12 and 22. The light emitting element 3 and the light receiving element 4 are arranged opposite to each other at the side end face.

  If comprised in this way, the sensor surface of an optimal shape can be formed, for example according to the shape of the biological body part 7, and this increases the contact area of the biological body part 7 with respect to a sensor surface, and improves the detection accuracy of a volume pulse wave. be able to. In addition, even if the device on which the light detection unit 150 is mounted has a curved surface shape, such as a remote controller, a portable terminal, and a car handle, the light detection unit 150 is designed according to the shape of the device. And can be installed.

Second Embodiment
The incident angle of the sensor light 5 on the first optical member 1 is such that the sensor light 5 incident on the first optical member 1 is totally reflected in the widest possible region of the sensor surface 1b in the first optical member 1. It is desirable to set as follows. For this reason, what is shown, for example in FIG. 10 (a)-(d) as arrangement | positioning and a structure of the light emitting element 3 can be considered.

  First, what is shown in FIG. 10A is one in which the incident angle is set large with respect to the sensor surface 1b of the first optical member 1 by using a light emitting element 3 having a relatively wide directivity angle. Next, what is shown in FIG. 10B is an arrangement in which the light emitting element 3 is arranged at an angle with respect to the sensor surface 1b of the first optical member 1, and what is shown in FIG. The incident surface 1a 'of the optical member 1' is set at an angle that is not perpendicular to the sensor surface 1b. Further, in FIG. 10D, a filter 8 having a function of diffusing light is disposed between the light emitting element 3 and the incident surface 1a ″ of the first optical member 1 ″. In short, the arrangement and configuration of the light-emitting elements 3 may be determined so that the sensor light 5 incident on the first optical member 1 ″ is totally reflected on the sensor surface 1b regardless of the position.

  In addition, a light emitting diode (LED) used as the light emitting element 3 may have a directivity angle of about 8 ° to 15 °, but the directivity angle may be narrower or wider than this, It is not limited to the range specified by this numerical value.

[ Third Embodiment]
FIG. 11 shows a main configuration of a light detection unit in a biological information detection apparatus according to the third embodiment of the present invention. The light detection unit according to the eighth embodiment is one in which a condensing lens 9 is disposed between the emission surface 2 a of the second optical member 2 and the light receiving element 4.
With this configuration, the scattered light component 6 a emitted from the emission surface 2 a of the second optical member 2 can be collected by the collective lens 9 and received by the light receiving element 4. Even when the sensitivity is low, highly accurate detection can be performed.

[Other Embodiments]
In each of the embodiments described above, the light emitting element 3 is provided, and the sensor light 5 emitted from the light emitting element 3 is incident on the first optical member 1. However, when used in an environment where a sufficient amount of natural light or room light can be obtained, the natural light or room light may be used as the sensor light 5. In this way, the light emitting element 3 can be dispensed with, and the number of parts can be reduced correspondingly, thereby making it possible to reduce the size and cost of the apparatus and reduce power consumption.

  In each of the above embodiments, the case where the first optical member 1 and the second optical member 2 made of strip-shaped rectangular plates are used has been described as an example. However, a square, a rectangle, a circle, an ellipse, or many You may use the optical member which consists of a square columnar strip or a plate-shaped body. In addition, the shapes and materials of the first and second optical members, the configuration and processing contents of the signal processing unit, the use of detection information of the volume pulse wave, and the like can be variously modified without departing from the gist of the present invention. It can be implemented.

  In short, the present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the components without departing from the scope of the invention in the implementation stage. Moreover, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the above embodiments. For example, some components may be deleted from all the components shown in each embodiment. Furthermore, you may combine suitably the component covering different embodiment.

  1, 1 ', 1 ", 11, 12 ... first optical member, 2, 21, 22 ... second optical member, 1a, 1a', 1a" ... incident surface, 1b, 2b ... sensor surface, 2a ... Emitting surface, 3 ... Light emitting element, 4 ... Light receiving element, 5 ... Sensor light, 6 ... Irradiation light, 6a ... Scattered light component, 7 ... Living body part, 8 ... Filter, 9 ... Condensing lens, 21 ... Amplifying unit, 22 ... A / D conversion unit, 23 ... waveform processing / output unit, 111,112 ... projection piece of first optical member, 211,212,213 ... projection piece of second optical member, 100,110,120,130 , 140, 150 ... light detection unit, 200 ... signal processing unit.

Claims (2)

In a biological information detection apparatus for detecting information related to volume pulse waves from a biological part,
A first optical member that has a plate shape or a column shape, and totally reflects light incident from the side end surface between an upper surface and a lower surface serving as a contact surface of the living body part;
It is plate-shaped or columnar, and is disposed in a state where an upper surface adjacent to a side surface of the first optical member and serving as a contact surface of the living body part forms substantially the same plane as the upper surface of the first optical member, When a living body part comes into contact with the upper surface of the first optical member, the scattered light component by the living body part of the light leaked from the contact position of the first optical member is taken from the upper surface, and guided to the side end face to be emitted. Two optical members;
A light emitting element that makes light incident on the first optical member so as to cause the total reflection from a side end surface thereof;
A light receiving element that receives light emitted from the side end face of the second optical member and outputs a light reception signal corresponding to the amount of light received;
Based on the light reception signal output from the light receiving element, a change in the amount of received light that occurs when a living body part contacts the upper surfaces of the first and second optical members is detected, and the detected amount of received light A signal processing unit that outputs information representing the change in volume as information representing the volume pulse wave of the living body part ,
Each upper surface of the first optical member and the second optical member is a flat surface,
The biological information detection apparatus , wherein the light emitting element and the light receiving element are disposed on the same side end surfaces of the first optical member and the second optical member, respectively . A condensing optical system that is disposed between a side end surface of the second optical member and the light receiving element, collects light emitted from the side end surface of the second optical member, and causes the light receiving element to receive the light. The biological information detecting apparatus according to claim 1 , further comprising:

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