JP2012176225A - Biological information detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To significantly reduce restrictions in positioning a living body part on a measurement position, to reduce operational burdens on a user, to enable a simple and compact circuit configuration, and to reduce power consumption.SOLUTION: A light detection unit 100 is configured such that sensor light 4 of a light emitting element 1 is made incident on a prism 2 made of a rectangular body plate from its incidence plane 2a, and the sensor light 4 repeats total reflection in the prism 2 and is emitted from an emission plane 2c and received by a light receiving element 3. When a living body part is brought into contact with the sensor surface of the prism 2, the living body part is irradiated with the sensor light from the prism 2 by the change of a refractive index on the contact surface to generate scattered light, a light component of the scattered light made incident again in the prism 2 is received by the light receiving element 3, and the light receiving signal is input to a signal processing unit 200 to detect the waveform of the volume pulse waves of the living body part.

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 (Settop Box), the user attribute is determined from the volume pulse wave of the user, and based on the determination result. Thus, a system for selecting and distributing contents 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).
In addition, as a technique that takes into account the operational burden on the user when measuring the volume pulse wave, a technique has been proposed in which a large number of light receiving elements are arranged at positions where the living body part of the user may touch (for example, (See Patent Document 2).

JP 2007-259912 A JP 2009-039568 A

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, which hinders the user's original behavior. As a result, the usability in operation is lowered, which is not preferable.
On the other hand, according to the method described in Patent Document 2, since the restriction of the alignment of the living body part to the measurement position where the light receiving element is installed is reduced, the burden on the user's operation is reduced. However, since the number of parts of the device and the number of circuit channels increase, the complexity and size of the device configuration and the increase in power consumption are inevitable.

  The present invention has been made paying attention to the above circumstances, and the object of the present invention is to greatly reduce the restriction on the alignment of the living body part to the measurement position, thereby reducing the operational burden on the user, and the circuit configuration. It is an object of the present invention to provide a biological information detection device that is easy to downsize and reduce power consumption.

  To achieve the above object, according to a first aspect of the present invention, there is provided an apparatus for detecting information relating to volume pulse waves from a living body part. The device has a plate shape or a columnar shape and receives light incident from the first side surface. A prism that guides to the second side surface while totally reflecting between the upper surface and the lower surface, which are contact surfaces of the part, and emits the light emitted from the second side surface of the prism to the outside. A light receiving element that receives light and outputs a light reception signal corresponding to the amount of light received, and a signal processing unit are provided. The signal processing unit detects a change in the amount of received light that occurs when a living body part contacts the upper surface of the prism based on the light reception signal output from the light receiving element. Information representing a change in quantity is configured to be output as information representing the volume pulse wave of the living body part.

That is, when a living body part comes into contact with the upper surface of the prism, scattered light irradiated and scattered on the living body part is received by a light receiving element installed on the side surface of the prism, and the change in the amount of received light is a volume pulse wave of the living body part. It is detected as information representing.
Therefore, no matter what position on the upper surface of the prism the living body part contacts, information representing the volume pulse wave of the living body part can be detected based on the change in the amount of received light due to this contact. For this reason, the restriction | limiting of the alignment of the biological body part to a measurement position can be reduced significantly, and the burden on a user's operation can be reduced. In addition, it is not necessary to arrange a large number of sensors in order to reduce the burden on the user's operation, thereby preventing an increase in the number of parts of the device and the number of channels of the circuit, thereby simplifying the circuit configuration and reducing the power consumption. Can be reduced. Furthermore, the shape and size of the prism can be arbitrarily designed as long as the incident light is within the range of total reflection within the prism. In other words, if the device is installed in a place where a living body part such as a finger of a user touches frequently, the volume pulse wave can be detected only by the user living in the same manner as usual, and as a result, various uses Is available.

The first aspect of the present invention is also characterized by comprising the following various aspects.
In the first aspect, the prism is further provided with a light emitting element that allows light to enter from the first side surface. 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.

  In the second aspect, a condensing optical system is disposed between the second side surface of the prism and the light receiving element, and the light emitted from the second side surface is condensed by the condensing optical system and received by the light receiving element. It is what I did. If it does in this way, the light radiate | emitted from a prism can be received efficiently, and it will become possible to improve a measurement precision by this.

  In the third aspect, a reflection optical system is arranged at a position in contact with or opposite to the lower surface of the prism, and light leaked from the lower surface of the prism is reflected by the reflection optical system and re-entered into the prism from the lower surface. It is a thing. If it does in this way, the light which leaks from the lower surface of a prism can be reduced as a result, the received light quantity of a light receiving element can be raised, and it becomes possible to raise a measurement precision by this.

  According to a second aspect of the present invention, there is provided an apparatus for detecting information relating to a volume pulse wave from a living body part, and a surface emitting source that emits surface light, and light that is surface-emitted from the surface emitting source having a plate shape or a column shape. After being introduced from the lower surface, a prism that guides to the side surface while totally reflecting between the upper surface and the lower surface, which are contact surfaces of the living body part, and emits light from the side surface of the prism is received. A light receiving element that outputs a light reception signal corresponding to the amount of light received, and a signal processing unit. The signal processing unit detects a change in the amount of received light that occurs when a living body part comes into contact with the upper surface of the prism based on the light reception signal output from the light receiving element. The information representing the change in quantity is configured to be output as information representing the volume pulse wave of the living body part.

  Therefore, the same effect can be obtained in the second aspect as in the first aspect. Further, according to the second aspect, since the light emitted from the surface light source is incident on the prism, the amount of light can be made uniform at any position on the upper surface of the prism. For this reason, it is possible to detect a uniform change in the amount of received light regardless of the position on the prism upper surface, thereby reducing variations in detection results of volume pulse waves due to the contact position.

The following various aspects are also conceivable in the second aspect of the present invention.
A 1st aspect comprises the said surface emitting source by a single or several light emitting element. In this way, light emitted from a single or a plurality of light emitting elements can be directly incident on the prism.
In the second aspect, the surface light source is configured by a light guide member that has a plate shape and emits light incident from the side surface thereof from the upper surface. In this way, surface light emission can be realized using a small number of light emitting elements.
A 3rd aspect is further provided with the light emitting element which injects light into the side surface of the said light guide member. In this way, as described in the first aspect, it is possible to always perform highly accurate and stable measurement even when a sufficient amount of received light cannot be obtained with natural light or room light.

  In the fourth aspect, a condensing optical system is disposed between the side surface of the prism and the light receiving element, and the light emitted from the side surface of the prism is condensed by the condensing optical system and received by the light receiving element. Is. If it does in this way, the light radiate | emitted from a prism can be received efficiently, and it will become possible to improve a measurement precision by this.

  According to a third aspect of the present invention, in an apparatus for detecting information on volumetric pulse waves from a living body part, the light incident from the side surface is totally reflected between the upper surface and the lower surface when the living body part is not in contact with the living body part. In a state in which the part is in contact with the upper surface, an elastic transparent member that emits scattered light from the living body part of the incident light from the lower surface, and scattered light emitted from the lower surface of the elastic transparent member is introduced from the upper surface, and the upper surface and the lower surface. A prism that is guided to the side surface while being totally reflected between the light source and the outside, and a light receiving element that receives the light emitted from the side surface of the prism and outputs a light reception signal corresponding to the amount of light received; A signal processing unit is provided. Then, the signal processing unit detects a change in the amount of received light that occurs when the living body part comes into contact with the upper surface of the elastic transparent member based on the light reception signal output from the light receiving element, and the detected amount of received light The information representing the change in the frequency is output as information representing the volume pulse wave of the living body part.

  Therefore, as described in the first and second aspects, the same effect can be obtained in the third aspect. Further, according to the third aspect, since the contact surface of the living body part is made of an elastic transparent member, it is possible to generate more light scattering due to the contact of the living body part, thereby improving the detection accuracy of the volume pulse wave. It becomes possible to raise more.

Also in this third aspect, the following modes can be considered.
In the first aspect, the elastic transparent member is further provided with a light emitting element that allows light to enter from the side surface. In this way, as described in the first and second aspects, even when a sufficient amount of received light cannot be obtained with natural light or room light, it is possible to always perform highly accurate and stable measurement.

  In the second aspect, a condensing optical system is disposed between the side surface of the prism and the light receiving element so that light emitted from the side surface of the prism is condensed and received by the light receiving element. If comprised in this way, the light radiate | emitted from a prism can be received efficiently, and it becomes possible to improve a measurement precision by this.

  In the third aspect, a reflective optical system is disposed at a position in contact with or opposite to the lower surface of the prism so that scattered light leaked from the lower surface of the prism is reflected and re-entered into the prism from the lower surface. . If it does in this way, the light which leaks from the lower surface of a prism can be reduced as a result, the received light quantity of a light receiving element can be raised, and it becomes possible to raise a measurement precision by this.

  According to a fourth aspect of the present invention, the main component of the incident light is formed in a plate shape or a columnar shape, and the light incident from the first side surface is totally reflected between the upper surface and the lower surface serving as a contact surface of the living body part. In a biological information detecting apparatus, comprising: a prism that guides light to the second side surface and emits the light from the second side surface to the outside; and a light emitting element that enters light from the first side surface into the prism. The light receiving element is disposed opposite to the surface excluding the second side surface, and when the living body part comes into contact with the upper surface of the prism, the light is scattered by the living body part and leaks from the surface excluding the second side surface of the prism. Is received by the light receiving element. Then, 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 comes into contact with the upper surface of the prism is detected, and information indicating the detected change in the amount of received light Is output as information representing the volume pulse wave of the living body part.

  With this configuration, even when the amount of sensor light incident on the prism from the light emitting element is set to be large in order to increase detection sensitivity, the light receiving element is scattered by the living body part and leaks from the side surface of the prism as described above. Only the light component and the small sensor light that naturally leaks from the side and top and bottom surfaces of the prism are received, and the main sensor light with the large light quantity is not received. For this reason, it is possible to prevent saturation of the light receiving element and to detect a change in the light component scattered in the living body part with high sensitivity, thereby improving the accuracy of obtaining biological information.

  Furthermore, the following aspects are also conceivable in the first to fourth aspects. That is, it further includes an ambient light receiving unit having at least an ambient light receiving element having the same or similar light receiving characteristics as the light receiving element, and receives the ambient light leaking from the prism by the ambient light receiving unit and receives the received light signal. Is output. The signal processing unit further includes an ambient light component removing unit, and is included in the received light signal from the received light signal output from the light receiving element based on the received ambient light signal output from the ambient light receiving unit. The ambient light signal component is removed, and the received light signal from which the ambient light signal component is removed is subjected to processing for detecting the change in the amount of received light.

  With this configuration, when the information representing the volume pulse wave of the living body part is to be obtained, the ambient light detection unit receives and detects the ambient light that is the same as or similar to the ambient light included in the light received by the light receiving element. Is done. An environment included in the light reception signal output from the light receiving element based on a signal representing the environment light received and detected by the environment light detection unit by the environment light component removal unit newly provided in the signal processing unit Noise components derived from light are removed. For this reason, it becomes possible to detect the waveform of the volume pulse wave based on the received light signal from which the noise component derived from the ambient light has been removed, and it becomes possible to further improve the detection accuracy of the volume pulse waveform.

  In other words, according to the present invention, it is possible to greatly reduce the restriction on the alignment of the living body part to the measurement position, thereby reducing the burden on the user's operation, and to simplify the circuit configuration and reduce the power consumption. A living body information detection apparatus can be provided.

The figure which shows the structure of Example 1 of the biometric information detection apparatus concerning 1st Embodiment of this invention. The figure which shows the structure of Example 2 and Example 3 of the photon detection unit used with the biological information detection apparatus shown in FIG. The figure for using it for operation | movement description of the photon detection unit used with the biological information detection apparatus shown in FIG. The figure which shows the structure of Example 4 of the photon detection unit used with the biological information detection apparatus shown in FIG. The figure which shows the structure of Example 5 of the photon detection unit used with the biological information detection apparatus shown in FIG. The figure which shows the structure of Example 6 of the photon detection unit used with the biological information detection apparatus shown in FIG. The figure which shows the structure of Example 1 of the photon detection unit used with the biometric information detection apparatus concerning 2nd Embodiment of this invention. The figure for using it for operation | movement description of the photon detection unit shown in FIG. The figure which shows the structure of Example 2 of the photon detection unit shown in FIG. The figure which shows the structure of Example 3 of the photon detection unit shown in FIG. The figure which shows the structure of Example 1 of the photon detection unit used with the biological information detection apparatus concerning the 3rd Embodiment of this invention. The figure for using for operation | movement description of the photon detection unit shown in FIG. The figure which shows the structure of Example 2, 3 and 4 of the photon detection unit shown in FIG. The figure which shows the structure of Example 5 of the photon detection unit shown in FIG. The figure which shows the structure of Example 8 of the photon detection unit in the biological information detection apparatus which concerns on 1st Embodiment of this invention. The figure which shows the 1st structure of Example 9 of the biometric information detection apparatus concerning 1st Embodiment of this invention. The figure which shows the 2nd structure of Example 9 of the biometric information detection apparatus concerning 1st Embodiment of this invention. The figure which shows the 3rd structure of Example 9 of the biometric information detection apparatus concerning 1st Embodiment of this invention. The figure which shows the 1st structure of Example 5 of the biometric information detection apparatus concerning 2nd Embodiment of this invention. The figure which shows the 2nd structure of Example 5 of the biometric information detection apparatus concerning 2nd Embodiment of this invention. The figure which shows the 3rd structure of Example 5 of the biometric information detection apparatus concerning 2nd Embodiment of this invention. The figure which shows the 1st structure of Example 6 of the biometric information detection apparatus concerning 1st Embodiment of this invention. The figure which shows the 2nd structure of Example 6 of the biometric information detection apparatus concerning 1st Embodiment of this invention. The figure which shows the 3rd structure of Example 6 of the biometric information detection apparatus concerning 1st Embodiment of this invention. The figure which shows the structure of Example 1 of the photon detection unit used with the biometric information detection apparatus concerning 4th Embodiment of this invention. The figure which shows the 1st structure of Example 2 of the biometric information detection apparatus concerning 4th Embodiment of this invention. The figure which shows the 2nd structure of Example 2 of the biometric information detection apparatus concerning 4th Embodiment of this invention.

Hereinafter, various embodiments according to the present invention will be described with reference to the drawings.
[First Embodiment]
Example 1
FIG. 1 is a diagram showing a configuration of Example 1 of the biological information detecting 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 prism 2 formed in a rectangular plate having a strip shape, and the light emitting element 1 is disposed opposite to a first end surface (first side surface) 2 a that functions as an incident surface of the prism 2. The light receiving element 3 is disposed opposite to a second end surface (second side surface) 2c that functions as an emission surface.

  The light emitting element 1 is composed of, for example, an LED (Light Emitting Diode), and the sensor light 4 is incident on the prism 2 from the incident surface 2a. As the sensor light 4, for example, near infrared light having a wavelength of 0.7 to 2.5 μm is used. This is because hemoglobin in blood has a characteristic of absorbing near infrared light having this wavelength. However, it is not necessarily limited to this wavelength.

  The prism 2 is preferably transparent to the sensor light 4 irradiated by the light emitting element 1 and has a higher refractive index than air. For example, the prism 2 is made of acrylic resin (refractive index 1.49). Used. However, it is not necessarily limited to this material and this refractive index. The upper surface of the prism 2 functions as a sensor surface 2b that contacts a living body part that is a measurement object.

  The light receiving element 3 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 receives the sensor light 4 emitted from the emission surface 2c of the prism 2. 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.

Next, operation | movement of the photon detection unit 100 is demonstrated among the biological information detection apparatuses comprised as mentioned above.
The sensor light 4 of the light-emitting element 1 incident on the prism 2 from the incident surface 2a of the prism 2 is totally reflected between the sensor surface 2b and the lower surface in the prism 2, for example, as shown in FIG. , The light reaches the emission surface 2c, is emitted from the emission surface 2c, and is received by the light receiving element 3.

At this time, the conditions for totally reflecting the sensor light 4 are defined as follows. That is, the critical angle θ when the sensor light 4 is emitted from the sensor surface 2b or the lower surface of the prism 2 to the external air layer is expressed by the reflection law when the refractive index of the prism 2 is n1 and the refractive index of air is n2. And 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 prism 2, the refractive index n2 of air is 1, so that θ = 42.155 ° is calculated from the above (1). The That is, if the sensor light 4 is incident on the inside of the prism 2 so that the sensor light 4 is incident on the sensor surface 2b and the lower surface of the prism 2 at an angle smaller than θ = 42.155 °, the incident sensor light is incident. 4 is transmitted to the exit surface 2c by repeating total reflection without leaking from the sensor surface 2b or the lower surface of the prism 2 to the outside.

Now, in this state, for example, as shown in FIG. 3B, it is assumed that the person to be inspected touches his / her fingertip as the living body part 7 to an arbitrary position P on the sensor surface 2 b of the prism 2. At this time, the critical angle θ ′ when the sensor light 4 is emitted from the sensor surface 2b of the prism 2 to the living body part 7 is set such 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. It should be noted that the refractive index of the skin of the living body part is 1.35, for example, described in detail in Toyoda Ueda, “Study on skin permeability using transdermal device”, 2007, Meisei University research report meeting. Has been.

  Therefore, when the living body part 7 is brought into contact with the position P on the upper surface (sensor surface) 2b of the prism 2, the sensor light 4 in the prism 2 enters the position P at an incident angle of 64.964 ° to 90 °. The light component 4pb is totally reflected as in (a) before contact, but the light component 4pa incident on the contact position P at an angle of 42.155 ° to 64.964 ° in the prism 2 is Without being totally reflected, it leaks to the outside from the sensor surface 2 b of the prism 2 and is irradiated onto the living body part 7 to become scattered light 5.

  The amount of the scattered light 5 varies according to the amount of hemoglobin in the blood. This is because hemoglobin in blood has the property of absorbing infrared light, so that the amount of light scattered outside the living body part 7 is absorbed in accordance with the volume change of peripheral blood vessels existing inside the living body part 7. This is because the ratio of the amount of light changes. The light component 6 that is a part of the scattered light 5 enters the prism 2 again from the sensor surface 2b, and then is totally reflected inside the prism 2 to become a part of the sensor light 4, and is emitted from the emission surface 2c. The light receiving element 3 receives the light. The light component 6 that becomes a part of the sensor light 4 after re-entering the prism 2 is a component whose incident angle with respect to the upper surface and the lower surface inside the prism 2 is larger than 42.155 ° described above.

  As described above, the light amount of the light component 6 included in a part of the sensor light 4 changes according to the blood volume in the living body part 7. For this reason, the signal level of the light reception signal output from the light receiving element 3 is also a value reflecting the change in the blood volume in the living body part 7. Here, the blood volume in the living body part 7 changes with time according to the pulsation of the heart. For this reason, the temporal change in the signal level of the light receiving signal represents the waveform of the volume pulse wave, and it is possible to determine the degree of hardening of the blood vessel in the living body, the pulse interval, its periodicity, etc. It becomes possible to recognize the user from the characteristics of the waveform data of the pulse wave.

(Examples 2 and 3)
As the shape of the prism 2, in addition to the rectangular plate having the strip shape shown in FIG. 1 as Example 1, for example, the sensor surface 2b is formed in a curved surface as shown in Example 2 of FIG. Alternatively, as shown in Example 3 in FIG. 2B, a cylindrical shape may be used as the sensor surface 2b. In short, the sensor light 4 is totally reflected inside the prism 2, and at the position where the living body part is in contact, a part of it leaks to the outside of the prism 2, and the scattered light scattered on the living body part reenters the inside, The shape of the prism 2 may be any shape as long as it retains the characteristic of total internal reflection again.

Example 4
Furthermore, the incident angle of the sensor light 4 on the prism 2 is desirably set so that the sensor light 4 incident on the prism 2 is totally reflected in the widest possible region of the sensor surface 2b. For this reason, what is shown in Example 4 of FIG. 4 (a)-(d) can be considered as arrangement | positioning and a structure of the light emitting element 1, for example.

First, what is shown in FIG. 4A is one in which the incident angle is set large with respect to the sensor surface 2 b of the prism 2 by using a light emitting element 1 having a relatively wide directivity angle. Next, what is shown in FIG. 4B is an arrangement in which the light emitting element 1 is arranged at an angle with respect to the sensor surface 2b of the prism 2, and what is shown in FIG. Is set to an angle that is not perpendicular to the sensor surface 2b. 4 (d) is provided with a filter 1a having a function of diffusing light between the light emitting element 1 and the incident surface 2a of the prism 2. In FIG. In short, the arrangement and configuration of the light emitting elements 1 may be determined so that the sensor light 4 incident on the prism 2 is totally reflected on the sensor surface 2b regardless of the position.
Further, the light emitting diode (LED) used as the light emitting element 1 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.

(Example 5)
FIG. 5 shows a configuration of Example 5 of the light detection unit 100 in the biological information detection apparatus according to the first embodiment. In the fifth embodiment, a condensing lens 8 is disposed between the emission surface 2 c of the prism 2 and the light receiving element 3. With this configuration, the light receiving accuracy of the light receiving element 3 can be increased.

(Example 6)
FIG. 6 shows a configuration of Example 6 of the light detection unit 100 in the biological information detection apparatus according to the first embodiment. In the sixth embodiment, the reflecting mirror 9 is arranged on the lower surface of the prism 2 through a slight air layer.
With this configuration, of the scattered light re-entered into the prism from the sensor surface 2b of the prism 2 after being scattered at the living body part 7, it is emitted from the lower surface of the prism 2 to the outside without being totally reflected inside the prism 2. The light 4x is reflected by the reflecting mirror 9 and can be irradiated to the living body part 7 again. As a result, it is possible to increase the irradiation light quantity for the living body part 7 and improve the acquisition accuracy of the biological information.

(Example 7)
In order to increase the contact area of the living body part 7 with the sensor surface 2b of the prism 2, the sensor surface 2b of the prism 2 may be coated with silicon or the like. If it does in this way, it will become possible to increase the light quantity leaked from the sensor surface 2b of the prism 2, and to acquire biological information more accurately. However, the processing in that case is not limited to this example.
Further, a polarizing plate for blocking ambient light may be provided on the sensor surface 2b of the prism 2. In this way, disturbance light can be prevented from entering the prism 2 and biological information can be acquired with higher accuracy.

(Example 8)
FIG. 15 shows the configuration of Example 8 of the light detection unit 100 in the biological information detection apparatus according to the first embodiment. In the first embodiment, the light emitting element 1 and the light receiving element 3 are opposed to each other, but in the eighth embodiment, the light receiving element 3 is placed at a position where the sensor light 4 incident on the prism 2 from the light emitting element 1 is not directly received. It is arranged.

  That is, in the configuration of FIG. 15, the light receiving element 3 is disposed so as to face the side surface of the prism 2. As the arrangement position, in the configuration of FIG. 15, one light receiving element 3 is arranged on the side surface in the vicinity of the contact position of the living body part 7, but the light receiving element 3 is arranged to cover the entire side surface of the prism 2. A plurality may be arranged. The positional relationship between the light emitting element 1 and the light receiving element 3 may be an orthogonal relationship, but is not limited to this, and the light receiving element out of the sensor light 4 incident on the prism 2 from the light emitting element 1. 3 may be in a positional relationship in which the amount of light directly incident on 3 is small.

  As an example, a surface selected from the other side surfaces, the upper surface, and the lower surface of the prism 2 except for the side surface 2c of the prism 2 from which the main light component of the sensor light 4 incident on the prism 2 from the light emitting element 1 is emitted. The light receiving element 3 is disposed to face the other. As a specific method for determining the positional relationship, for example, a position where the amount of light incident on the light receiving element 3 by the sensor light 4 does not exceed the upper limit (dynamic range) of the amount of light that can be detected by the light receiving element 3 is selected. A method can be considered.

  With this configuration, the light component 6 that has been scattered in the living body part 7 and then reentered into the prism 2 and totally reflected from the inside of the prism 2 and leaked from the side surface of the prism 2, and the amount of light leaked from the side surface of the prism 2. The small sensor light 4 is received by the light receiving element 3. For this reason, the main sensor light 4 having a large amount of light emitted from the emission surface 2 c is not received by the light receiving element 3.

  Incidentally, in the configuration illustrated in the first embodiment (FIG. 1), the amount of the sensor light 4 incident on the prism 2 from the light emitting element 1 is large, and as a result, the main sensor light 4 emitted from the exit surface 2c of the prism 2 is obtained. May exceed the upper limit (dynamic range) of the amount of light that can be detected by the light receiving element 3. In this case, the light receiving element 3 is saturated, and it becomes difficult to detect the light amount change of the light component 6.

  On the other hand, with the configuration of the eighth embodiment, even when the light amount of the sensor light 4 incident from the light emitting element 1 into the prism 2 is set to be large in order to increase the detection sensitivity, the light receiving element 3 has a living body as described above. Only the light component 6 scattered by the portion 7 and leaking from the side surface of the prism and the sensor light 4 having a small light amount that naturally leaks from the side surface other than the side surface 2c of the prism 2 are received, and the main sensor light 4 having a large light amount is received. Not. For this reason, it is possible to prevent the light receiving element 3 from being saturated and to detect a change in the light component 6 scattered in the living body part 7 with high sensitivity, thereby improving the accuracy of obtaining biological information.

Example 9
FIG. 16 shows a configuration of Example 9 of the biological information detecting apparatus according to the first embodiment. In FIG. 16, the same parts as those in FIG.
In the ninth embodiment, in addition to the light detection unit 100 described in the first embodiment, an ambient light detection unit 300 for outputting an ambient light signal corresponding to a change in ambient light is newly provided. The signal processing unit 210 is newly provided with an ambient light noise removing unit 24.

  The ambient light detection unit 300 is for detecting ambient light that represents a change in the amount of light in the usage environment of the light detection unit 100, and includes an ambient light receiving element 302. The ambient light receiving element 302 is disposed such that the light receiving surface thereof faces the same surface as the light receiving surface of the prism 2 of the light detection unit 100, generates an ambient light signal corresponding to the ambient light, and generates the ambient light signal. Is output to the ambient light noise removing unit 24 of the signal processing unit 210. Based on the ambient light signal output from the ambient light detection unit 300, the ambient light noise removal unit 24 subtracts the ambient light-derived noise component from the light reception signal transmitted by the light receiving element 3 of the light detection unit 100. To remove.

  The ambient light receiving element 302 uses the same light receiving element as the light receiving element 3 of the light detection unit 100, or has the same or similar light receiving characteristics as the light receiving element 3, so that the light receiving element 3 receives light. It is possible to accurately generate a noise component derived from ambient light included in the received light signal.

  With such a configuration, the ambient light detection unit 300 generates an ambient light signal corresponding to the same ambient light as the ambient light generated in the usage environment of the light detection unit 100 while the light detection unit 100 is in use. And input to the ambient light noise removing unit 24 of the signal processing unit 210. Then, the ambient light noise removing unit 24 removes noise components derived from ambient light from the light reception signal output from the light receiving element 3 of the light detection unit 100 based on the ambient light signal output from the ambient light detection unit 300. The received light signal from which the noise component derived from the ambient light has been removed is input to the waveform processing / output unit 23 via the amplification unit 21 and the A / D conversion unit 22. Therefore, the waveform processing / output unit 23 can detect the waveform of the volume pulse wave based on the received light signal from which the noise component derived from the environmental light is removed.

  The ambient light detection unit 300 may be modified as follows. That is, FIG. 16 illustrates the case where only the ambient light receiving element 302 is provided, but the ambient light detecting unit 310 may be configured by the ambient light receiving element 302 and the ambient light prism 303 as shown in FIG. The ambient light prism 303 is made of the same material as the prism 2 of the light detection unit 100 and has the same shape and size, and is arranged close to and parallel to the prism 2. The ambient light receiving element 302 is disposed opposite to the light emitting end of the ambient light prism 303, and receives ambient light emitted after entering the ambient light prism 303.

  There is a possibility that the ambient light has a characteristic change such that the gain of the ambient light itself decreases in the process from entering the prism 2 and traveling through the prism 2 until it is emitted. However, with this configuration, it is possible to reproduce the environmental light characteristic change that occurs in the prism 2 in the environmental light prism 303, and thus, excellent light reception in which noise components derived from environmental light are more accurately removed. It becomes possible to detect the signal.

Further, as shown in FIG. 18, the ambient light detection unit 320 may include an ambient light receiving element 302, an ambient light prism 303, and an ambient light emitting element 304. The ambient light emitting element 304 is disposed so as to face the surface of the ambient light prism 303 that serves as the light incident end. As the ambient light emitting element 304, it is desirable to use an element having the same type or the same or similar characteristics as the light emitting element 1 of the light detection unit 100.
With this configuration, the ambient light receiving element 302 can detect a signal similar to the ambient light component included in the received light signal detected by the light receiving element 3 of the light detection unit 100 as the ambient light signal. Become.

  Further, as a means for the removal process in the ambient light noise removing unit 24, filtering is performed in addition to subtracting the ambient light signal output from the ambient light detection unit 300, 310, or 320 from the received light signal output from the light detection unit 100. Processing may be used to remove wavelength components peculiar to the ambient light signal.

  In addition, the installation number of the ambient light detection units 300, 310, or 320 is not particularly limited, and may be a single installation or a plurality of installations. When a plurality of environmental light signals are installed, for example, it is conceivable that the environmental light signals are generated by averaging the environmental light signals detected by the plurality of environmental light detection units.

  The installation position of the ambient light detection unit 300, 310, or 320 is a position where a signal close to ambient light-derived noise included in the light reception signal detected by the light receiving element 3 of the light detection unit 100 can be detected as the ambient light signal. Desirably, as an example, it may be installed at a position adjacent to the light detection unit 100, but is not limited thereto.

  As described above in detail, according to the ninth embodiment, for example, the biological information acquisition apparatus is used in an environment where the ambient light fluctuates due to a change in the image of a television receiver or the like. Even in such a situation, it is possible to remove the noise component and generate a good light reception signal.

  As described above in detail, in the first embodiment, the light detection unit 100 causes the sensor light 4 of the light-emitting element 1 to enter the prism 2 made of a rectangular plate having a strip shape from the incident surface 2a. Is configured to repeat total reflection in the prism 2 and to be emitted from the emission surface 2 c and received by the light receiving element 3. When the biological part 7 comes into contact with the sensor surface 2b of the prism 2, a part of the sensor light 4 is irradiated from the prism 2 to the biological part 7 due to a change in the refractive index on the contact surface to generate scattered light 5. The scattered light 5 re-enters the prism 2 to generate a light component 6 that is totally reflected inside the prism 2, and the sensor light 4 including the light component 6 is received by the light receiving element 3. By inputting the received light signal to the signal processing unit 200, the volume pulse wave waveform of the living body part 7 is detected.

  Therefore, regardless of the position on the sensor surface 2b of the prism 2, the living body part 7 can detect the waveform of the volume pulse wave of the living body part 7 based on the change in the amount of light received by the contact. For this reason, the restriction | limiting of the alignment of the biological body part 7 can be reduced significantly, and the burden on a user's operation can be reduced. In addition, it is not necessary to arrange a large number of sensors in order to reduce the burden on the user's operation, thereby preventing an increase in the number of parts of the device and the number of channels of the circuit, thereby simplifying the circuit configuration and reducing the power consumption. Can be reduced.

[Second Embodiment]
Example 1
In the second embodiment of the present invention, a light guide plate is disposed on a surface opposite to the sensor surface of the prism with an air layer therebetween, and sensor light surface-emitted from the upper surface of the light guide plate is applied to the prism. Incident from the bottom. In this state, when the living body part comes into contact with the sensor surface of the prism, the light emitted from the end of the prism is received by the light receiving element, and the received light signal is processed by the signal processing unit. The feature of the waveform of the volume pulse wave of the living body part is detected.

  FIG. 7 shows the configuration of Example 1 of the light detection unit used in the biological information detecting apparatus according to the second embodiment of the present invention. Since the signal processing unit 200 is the same as that of the first embodiment, the illustration thereof is omitted. Also, for the light detection unit 110, the same parts as those in FIG.

  On the lower surface side of the prism 2, a light guide plate 10 is disposed so as to face a slight air layer. The light guide plate 10 has a plane dimension set to the same size as the prism 2, and converts the sensor light 4 emitted from the light emitting element 1 into a surface emitting sensor light 4a that is incident from the end face and emits surface light. Light 4 a is emitted from the upper surface and is incident on the lower surface of the prism 2. That is, the light guide plate 10 is realized by employing a known technique used in a backlight of a liquid crystal display.

  The incident angle of the surface emitting sensor light 4a surface-emitted from the light guide plate 10 to the prism 2 is incident on the prism 2 without being totally reflected when entering the prism 2, passes through the prism 2, and the sensor. The angle is set such that the light can be emitted upward from the surface 2b. As an example of the incident angle, 0 ° is optimal, but other angles, for example, a slightly angled angle of about 1 ° to 10 ° may be used.

Because of such a configuration, when the fingertip that is the living body part 7 is brought into contact with the sensor surface 2b of the prism 2, the surface-emitting sensor light 4a is scattered on the living body part 7 as shown in FIG. 5 occurs. A part of the scattered light 5 enters the prism 2 from the sensor surface 2 b of the prism 2 to become a light component 6 that totally reflects inside the prism 2, and the light component 6 is reflected at the end of the prism 2 while totally reflecting inside the prism 2. And is received by the light receiving element 3.
Therefore, also in the second embodiment, the signal characteristic of the volume pulse wave of the living body part 7 can be detected by processing the light reception signal from the light receiving element 3 by the signal processing unit 200.

(Example 2)
FIG. 9 shows a configuration of Example 2 of the biological information detecting apparatus according to the second embodiment. In the second embodiment, the light emitting elements 1 and 1 are disposed on the opposite end faces of the light guide plate 10 so that light is incident on the light guide plate 10, and the light receiving elements 3 and 3 are provided on both end faces of the prism 2, respectively. It is arranged so as to receive the light emitted from the prism 2. The light reception signals output from the light receiving elements 3 and 3 are combined in the signal processing unit 200.

  If comprised in this way, the dispersion | variation by the incident position of the surface emission with respect to the prism 2 can be reduced, and the total value of the light reception amount of the scattered light by the biological body part 7 can be increased. For this reason, the signal level of the received light signal obtained from the light receiving element 3 can be increased no matter where the living body part 7 is brought into contact with the sensor surface 2b of the prism 2, thereby further increasing the detection accuracy of the volume pulse wave. It becomes possible.

(Example 3)
FIG. 10 shows a configuration of Example 3 of the light detection unit 110 according to the second embodiment. In the third embodiment, a condenser lens 8 is disposed between the emission surface of the prism 2 and the light receiving element 3, and the light component 6 emitted from the emission surface of the prism 2 is collected by the condenser lens 8 and received. The element 3 is configured to receive light.
Since it is such a structure, it becomes possible to increase the received light quantity of the light component 6 in the light receiving element 3, and it becomes possible to further improve the detection accuracy of the volume pulse wave in the signal processing unit 200 by this.

Example 4
Further, by processing the sensor surface 2b of the prism 2, the contact area when the sensor 2b of the prism 2 and the living body part 7 come into contact with each other may be increased. If it does in this way, it will become possible to increase the light quantity of the scattered light 5, and to improve the detection accuracy of biological information.
As an example, it is conceivable to coat the sensor surface 2b of the prism 2 with silicon. Furthermore, a polarizing plate that blocks disturbance light at a specific angle may be attached to the sensor surface 2 b of the prism 2. For example, it is conceivable to attach a polarizing plate having a property of blocking disturbance light incident perpendicularly to the sensor surface 2b of the prism 2. As a result, it is possible to suppress the influence of disturbance light without blocking the scattered light 5 from entering the inside of the prism 2 and improve the detection accuracy of biological information.

(Example 5)
FIG. 19 shows a configuration of Example 5 of the biological information detecting apparatus according to the second embodiment. In FIG. 19, the same parts as those in FIG.
In the fifth embodiment, in addition to the light detection unit 110 described in the first embodiment, an ambient light detection unit 300 for outputting an ambient light signal corresponding to a change in ambient light is newly provided. The signal processing unit 210 is newly provided with an ambient light noise removing unit 24.

  The ambient light detection unit 300 is for detecting ambient light that represents a change in the amount of light in the usage environment of the light detection unit 110, and includes an ambient light receiving element 302. The ambient light receiving element 302 is disposed such that the light receiving surface thereof corresponds to the same surface as the light receiving surface of the prism 2 of the light detection unit 110, generates an ambient light signal corresponding to the ambient light, and generates the ambient light signal. Is output to the ambient light noise removing unit 24 of the signal processing unit 210. Based on the ambient light signal output from the ambient light detection unit 300, the ambient light noise removal unit 24 subtracts a noise component derived from ambient light from the light reception signal transmitted by the light receiving element 3 of the light detection unit 110. To remove.

  Note that the ambient light receiving element 302 uses the same light receiving element as the light receiving element 3 of the light detection unit 110 or has the same or similar light receiving characteristics as the light receiving element 3 so that the light receiving element 3 receives light. It is possible to accurately generate a noise component derived from ambient light included in the received light signal.

  With such a configuration, the ambient light detection unit 300 generates an ambient light signal corresponding to the same ambient light as that generated in the usage environment of the light detection unit 110 during use of the light detection unit 110. And input to the ambient light noise removing unit 24 of the signal processing unit 210. Then, in the ambient light noise removing unit 24, based on the ambient light signal output from the ambient light detection unit 300, a noise component derived from ambient light is removed from the received light signal output from the light receiving element 3 of the light detection unit 110. The received light signal from which the noise component derived from the ambient light has been removed is input to the waveform processing / output unit 23 via the amplification unit 21 and the A / D conversion unit 22. Therefore, the waveform processing / output unit 23 can detect the waveform of the volume pulse wave based on the received light signal from which the noise component derived from the environmental light is removed.

  The ambient light detection unit 300 may be modified as follows. That is, FIG. 19 illustrates the case where only the ambient light receiving element 302 is provided. However, as shown in FIG. 20, the ambient light detecting unit 330 includes the ambient light receiving element 302, the ambient light prism 303, and the ambient light guide plate 305. You may comprise. The ambient light guide plate 305 is made of the same material as the light guide plate 10 of the light detection unit 110 and has the same shape and size, and is arranged close to and parallel to the light guide plate 10. The ambient light prism 303 is made of the same material as the prism 2 of the light detection unit 110 and has the same shape and size, and is arranged close to and parallel to the prism 2. The ambient light receiving element 302 is disposed opposite to the light emitting end of the ambient light prism 303 and receives ambient light emitted after entering the ambient light prism 303 from the ambient light guide plate 305.

  Ambient light itself may change its characteristics such that the gain of the ambient light itself decreases after it passes through the light guide plate 10 and then enters the prism 2, travels through the prism 2 and is emitted. There is sex. However, with this configuration, it is possible to reproduce the environmental light characteristic change that occurs while passing through the light guide plate 10 and the prism 2 in the environmental light guide plate 305 and the environmental light prism 303, and thereby the environmental light source. It is possible to detect a good light reception signal from which the noise component is removed with higher accuracy.

Further, as shown in FIG. 21, the ambient light detection unit 340 may include an ambient light receiving element 302, an ambient light prism 303, an ambient light light emitting element 304, and an ambient light light guide plate 305. The ambient light emitting element 304 is disposed to face the surface of the ambient light guide plate 305 that serves as a light incident end. As the ambient light emitting element 304, it is desirable to use an element having the same type or the same or similar characteristics as the light emitting element 1 of the light detection unit 110.
With this configuration, the ambient light receiving element 302 can detect a signal similar to the ambient light component included in the received light signal detected by the light receiving element 3 of the light detection unit 110 as the ambient light signal. Become.

  Further, as a means for the removal processing in the ambient light noise removing unit 24, in addition to subtracting the ambient light signal output from the ambient light detection unit 300, 330 or 340 from the light reception signal output from the light detection unit 110, filtering is performed. Processing may be used to remove wavelength components peculiar to the ambient light signal.

  In addition, the installation number of the ambient light detection units 300, 330, or 340 is not particularly limited, and may be single or plural. When a plurality of environmental light signals are installed, for example, it is conceivable that the environmental light signals are generated by averaging the environmental light signals detected by the plurality of environmental light detection units.

  The installation position of the ambient light detection unit 300, 330, or 340 is a position where a signal close to noise derived from ambient light included in the light reception signal detected by the light receiving element 3 of the light detection unit 110 can be detected as the ambient light signal. Desirably, as an example, it may be installed at a position adjacent to the light detection unit 110, but is not limited thereto.

  As described above in detail, according to the fifth embodiment, for example, the biological information acquisition apparatus is used in an environment where the ambient light fluctuates due to a change in the image of a television receiver or the like. Even in such a situation, it is possible to remove the noise component and generate a good light reception signal.

  As described above in detail, in the light detection unit 110 according to the second embodiment, the light guide plate 10 is arranged on the surface opposite to the sensor surface 2b of the prism 2 with a slight air layer therebetween, and this light guide plate. Sensor light surface-emitted from 10 is incident on the prism 2 from its lower surface. In this state, when the living body part 7 comes into contact with the sensor surface 2 b of the prism 2, the light component 6 emitted from the end of the prism 2 in the sensor light is received by the light receiving element 3.

  Therefore, since the same effect as that of the first embodiment described above can be obtained, the light emitted from the light guide member 11 is incident on the prism 2. The light quantity can be made uniform at any position. For this reason, even if the living body part 7 is brought into contact with any position on the sensor surface of the prism 2, it is possible to detect a uniform change in the amount of received light, thereby reducing variations in the detection result of the volume pulse wave due to the contact position. be able to.

[Third Embodiment]
Example 1
In the third embodiment of the present invention, a transparent elastic member is arranged with a slight air layer being separated from the sensor surface of the prism, and light of the light emitting element is incident on the elastic member from its end surface. When the living body part comes into contact with the elastic member in this state, the incident light is irradiated to the living body part due to elastic deformation of the elastic member, and a part of the scattered light generated thereby is incident on the prism through the elastic member. Then, the light emitted from the prism end portion of the incident light is received by the light receiving element, and the received light signal is processed by the signal processing unit to detect the characteristic of the volume pulse wave waveform of the living body part. Is.

  FIG. 11 shows the configuration of Example 1 of the light detection unit used in the biological information detecting apparatus according to the third embodiment of the present invention. Since the signal processing unit 200 is the same as that of the first embodiment, the illustration thereof is omitted. Also, with respect to the light detection unit 120, the same parts as those in FIG.

  A transparent elastic member 11 is disposed on the upper surface of the prism 2 with a slight air layer therebetween. The light emitting element 1 is disposed on one end face of the elastic member 11, and the light receiving element 3 is disposed on one end face of the prism 2. The sensor light 4 emitted from the light emitting element 1 travels straight in the elastic member 11 as shown in FIG. 12A or is totally reflected in the elastic member 11. For this reason, the sensor light 4 does not leak to the prism 2.

On the other hand, when the fingertip which is the living body part 7 is pressed against the surface of the elastic member 11, the living body part 7 sinks into the elastic member 11 as shown in FIG. Irradiated and scattered light 5 is generated. A part of the scattered light 5 passes through the elastic member 11 and enters the inside of the prism 2, and further, the light component 6 that is a part of the scattered light 5 repeats total reflection inside the prism 2 from the end face of the prism 2. The light is emitted and received by the light receiving element 3.
Therefore, also in the third embodiment, the signal characteristics of the volume pulse wave of the living body part 7 can be detected by processing the light reception signal from the light receiving element 3 by the signal processing unit 200.

(Example 2)
FIG. 13A shows the configuration of Example 2 of the light detection unit 120 according to the third embodiment. In the second embodiment, the light emitting elements 1 and 1 are disposed on the opposite end surfaces of the elastic member 11 so that light is incident on the elastic member 11, and the light receiving elements 3 and 3 are respectively provided on both end surfaces of the prism 2. It is arranged so as to receive the light emitted from the prism 2. The light reception signals output from the light receiving elements 3 and 3 are combined in the signal processing unit 200.

  If comprised in this way, the dispersion | variation in the light quantity by the position inside the elastic member 11 can be reduced, and the total value of the light reception amount of the scattered light by the biological body part 7 can be increased. For this reason, the signal level of the light reception signal obtained from the light receiving element 3 can be maintained high regardless of where the living body part 7 is brought into contact with the elastic member 11, thereby further improving the detection accuracy of the volume pulse wave. It becomes.

(Example 3)
FIG. 13B shows a configuration of Example 3 of the light detection unit 120 according to the third embodiment. In the third embodiment, the reflecting mirror 12 is disposed on the other end surface different from the end surface on which the light emitting element 1 of the elastic member 11 is disposed, and the light emitted from the end surface other than the light incident end of the elastic member 11 is reflected on the reflecting mirror. 12 is configured to be reflected by 12 and re-entered into the elastic member 11.
With such a configuration, it is possible to reduce the variation in the amount of light depending on the position inside the elastic member 11 without increasing a new light emitting element, and to increase the amount of light received by the light component 6 in the light receiving element 3. The detection accuracy of the volume pulse wave in the signal processing unit 200 can be further increased.

Example 4
FIG. 13C shows the configuration of Example 4 of the light detection unit 120 according to the third embodiment. In the fourth embodiment, a condenser lens 8 is disposed between the exit surface of the prism 2 and the light receiving element 3, and the light component 6 emitted from the exit surface of the prism 2 is collected by the condenser lens 8 to receive light. The element 3 is configured to receive light.
Since it is such a structure, it becomes possible to increase the light reception amount of the emitted light in the light receiving element 3, and it becomes possible to further improve the detection accuracy of the volume pulse wave in the signal processing unit 200 by this.

(Example 5)
FIG. 14 shows a configuration of Example 5 of the light detection unit 120 according to the third embodiment. In the fifth embodiment, the reflecting mirror 9 is disposed opposite to the lower surface of the prism 2 with a slight air layer therebetween.
If comprised in this way, among the scattered light 5 which generate | occur | produced by the biological body part 7, the light which passed through the prism 2 and leaked from the lower surface will be reflected by the said reflecting mirror 9, and will re-enter into the prism 2. FIG. A part of the re-incident light is received by the light receiving element 3 emitted from the end face of the prism 2. At the same time, another part of the re-incident light is re-irradiated to the living body part 7 through the elastic member 11. For this reason, it is possible to increase the amount of received light component 6 in the light receiving element 3, thereby further increasing the volumetric pulse wave detection accuracy in the signal processing unit 200.

(Example 6)
FIG. 22 shows a configuration of Example 6 of the biological information detecting apparatus according to the third embodiment. In FIG. 22, the same parts as those in FIG.
In the sixth embodiment, in addition to the light detection unit 120 described in the first embodiment, an ambient light detection unit 300 for outputting an ambient light signal corresponding to a change in ambient light is newly provided. The signal processing unit 210 is newly provided with an ambient light noise removing unit 24.

  The ambient light detection unit 300 is for detecting ambient light that represents a change in the amount of light in the usage environment of the light detection unit 100, and includes an ambient light receiving element 302. The ambient light receiving element 302 is disposed such that the light receiving surface thereof faces the same surface as the light receiving surface of the prism 2 of the light detection unit 120, generates an ambient light signal corresponding to the ambient light, and generates the ambient light signal. Is output to the ambient light noise removing unit 24 of the signal processing unit 210. Based on the ambient light signal output from the ambient light detection unit 300, the ambient light noise removing unit 24 subtracts the ambient light-derived noise component from the received light signal transmitted by the light receiving element 3 of the light detection unit 120. To remove.

  The ambient light receiving element 302 uses the same light receiving element as the light receiving element 3 of the light detection unit 120, or has the same or similar light receiving characteristics as the light receiving element 3, so that the light receiving element 3 receives light. It is possible to accurately generate a noise component derived from ambient light included in the received light signal.

  With such a configuration, the ambient light detection unit 300 generates an ambient light signal corresponding to the same ambient light as the ambient light generated in the usage environment of the light detection unit 120 while the light detection unit 120 is in use. And input to the ambient light noise removing unit 24 of the signal processing unit 210. Then, in the ambient light noise removing unit 24, based on the ambient light signal output from the ambient light detection unit 300, a noise component derived from ambient light is removed from the received light signal output from the light receiving element 3 of the light detection unit 120. The received light signal from which the noise component derived from the ambient light has been removed is input to the waveform processing / output unit 23 via the amplification unit 21 and the A / D conversion unit 22. Therefore, the waveform processing / output unit 23 can detect the waveform of the volume pulse wave based on the received light signal from which the noise component derived from the environmental light is removed.

  The ambient light detection unit 300 may be modified as follows. That is, FIG. 22 illustrates the case where only the ambient light receiving element 302 is provided. However, as shown in FIG. 23, the ambient light detecting unit 350 includes the ambient light receiving element 302, the ambient light prism 303, and the ambient light elastic member 306. You may comprise. The ambient light elastic member 306 is made of the same material as the elastic member 11 of the light detection unit 110 and has the same shape and size, and is disposed close to and parallel to the elastic member 11. The ambient light prism 303 is made of the same material as the prism 2 of the light detection unit 120 and has the same shape and size, and is arranged close to and parallel to the prism 2. The ambient light receiving element 302 is disposed opposite to the light emitting end of the ambient light prism 303 and receives ambient light emitted after entering the ambient light prism 303 through the ambient light elastic member 306.

  Ambient light enters the prism 2 through the elastic member 11, and further changes in the characteristics of the ambient light itself, such as a decrease in gain of the ambient light itself, in the process from traveling through the prism 2 to exiting. There is sex. However, with this configuration, it is possible to reproduce changes in the characteristics of the ambient light generated in the elastic member 11 and the prism 2 in the ambient light elastic member 306 and the ambient light prism 303, thereby causing noise derived from the ambient light. It is possible to detect a good light reception signal from which components have been removed with higher accuracy.

Further, as shown in FIG. 24, the ambient light detection unit 360 may include an ambient light receiving element 302, an ambient light prism 303, an ambient light emitting element 304, and an ambient light elastic member 306. The ambient light emitting element 304 is disposed so as to face the surface that becomes the light incident end of the ambient light elastic member 306. As the ambient light emitting element 304, it is desirable to use an element having the same type or the same or similar characteristics as the light emitting element 1 of the light detection unit 100.
With this configuration, the ambient light receiving element 302 can detect a signal similar to the ambient light component included in the received light signal detected by the light receiving element 3 of the light detection unit 120 as the ambient light signal. Become.

  Further, as a means for the removal process in the ambient light noise removing unit 24, filtering is performed in addition to subtracting the ambient light signal output from the ambient light detection unit 300, 350, or 360 from the received light signal output from the light detection unit 100. Processing may be used to remove wavelength components peculiar to the ambient light signal.

  In addition, the installation number of the ambient light detection units 300, 350, or 360 is not particularly limited, and may be single or plural. When a plurality of environmental light signals are installed, for example, it is conceivable that the environmental light signals are generated by averaging the environmental light signals detected by the plurality of environmental light detection units.

  The installation position of the ambient light detection unit 300, 350, or 360 is a position where a signal close to ambient light-derived noise included in the light reception signal detected by the light receiving element 3 of the light detection unit 120 can be detected as the ambient light signal. Desirably, as an example, it may be installed at a position adjacent to the light detection unit 120, but is not limited thereto.

  As described above in detail, according to the sixth embodiment, for example, the biological information acquisition apparatus is used in an environment where the ambient light fluctuates due to a change in the image of a television receiver or the like. Even in such a situation, it is possible to remove the noise component and generate a good light reception signal.

  As described above in detail, in the third embodiment, the transparent elastic member 11 is disposed with a slight air layer on the upper surface of the prism 2, and the light of the light emitting element 1 is incident on the elastic member 11 from its end face. . When the living body part 7 comes into contact with the elastic member 11 in this state, the incident light is irradiated to the living body part 7 due to elastic deformation of the elastic member 11, and a part of the scattered light generated thereby is passed through the elastic member 11. The light is incident on the prism 2. In the incident light, the light receiving element 3 receives the light component 6 emitted from the end of the prism 2.

  Therefore, not only the same effect as the first embodiment described above can be obtained, but also the contact surface of the living body part 7 is made of the transparent elastic member 11, so that the light by contact with the living body part 7 can be obtained. More scattering can be generated, which makes it possible to further increase the detection accuracy of the volume pulse wave.

[Fourth Embodiment]
Example 1
The fourth embodiment of the present invention is a further improvement of the second embodiment, in which a single or a plurality of light emitting elements that constitute a surface emitting source facing the surface opposite to the sensor surface of the prism. An element is disposed, and sensor light emitted from the single or plural light emitting elements is incident on the prism from its lower surface. In this state, when the living body part comes into contact with the sensor surface of the prism, the light emitted from the end of the prism is received by the light receiving element, and the received light signal is processed by the signal processing unit. The feature of the waveform of the volume pulse wave of the living body part is detected.

  FIG. 25 shows the configuration of Example 1 of the photodetecting unit used in the biological information detecting apparatus according to the fourth embodiment of the present invention. Since the signal processing unit 200 is the same as that of the first embodiment, the illustration thereof is omitted. Also, with respect to the light detection unit 130, the same parts as those in FIG.

  On the lower surface side of the prism 2, a plurality of light emitting elements 1 </ b> A arranged at equal intervals are opposed to each other. These light emitting elements 1A are for direct incidence of the sensor light 4a from the lower surface of the prism 2, and the incident angle is incident on the prism 2 without being totally reflected when entering the prism 2, and passes through the prism 2. Thus, the angle is set such that the light can be emitted upward from the sensor surface 2b. As an example of the incident angle, 0 ° is optimal, but other angles, for example, a slightly angled angle of about 1 ° to 10 ° may be used.

  Because of such a configuration, when the fingertip that is the living body part 7 is brought into contact with the sensor surface 2b of the prism 2, the sensor light 4a is irradiated to the living body part 7 and scattered as shown in FIG. Occurs. A part of the scattered light 5 enters the prism 2 from the sensor surface 2 b of the prism 2 to become a light component 6 that totally reflects inside the prism 2, and the light component 6 is reflected at the end of the prism 2 while totally reflecting inside the prism 2. And is received by the light receiving element 3.

  Therefore, also in the fourth embodiment, the signal characteristic of the volume pulse wave of the living body part 7 can be detected by processing the light reception signal from the light receiving element 3 by the signal processing unit 200. Further, by using a plurality of light emitting elements 1A arranged at equal intervals as a surface light source, compared to the case where the light emitting element 1 and the light guide plate 10 are used as a surface light source as described in the second embodiment. Thus, it becomes possible to efficiently make the sensor light with higher illuminance incident on the prism 2.

(Example 2)
FIG. 26 shows a configuration of Example 2 of the biological information detecting apparatus according to the fourth embodiment. In FIG. 26, the same parts as those in FIG.
In the second embodiment, in addition to the light detection unit 130 described in the first embodiment, an ambient light detection unit 300 for outputting an ambient light signal corresponding to a change in ambient light is newly provided. The signal processing unit 210 is newly provided with an ambient light noise removing unit 24.

  The ambient light detection unit 300 is for detecting ambient light that represents a change in the amount of light in the usage environment of the light detection unit 110, and includes an ambient light receiving element 302. The ambient light receiving element 302 has a light receiving surface disposed at a position corresponding to the same light receiving surface as the prism 2 of the light detection unit 110, generates an ambient light signal corresponding to the ambient light, and generates the ambient light signal. Is output to the ambient light noise removing unit 24 of the signal processing unit 210. Based on the ambient light signal output from the ambient light detection unit 300, the ambient light noise removal unit 24 subtracts a noise component derived from ambient light from the light reception signal transmitted by the light receiving element 3 of the light detection unit 110. To remove.

  The ambient light receiving element 302 uses the same light receiving element as the light receiving element 3 of the light detection unit 130, or has the same or similar light receiving characteristics as the light receiving element 3, so that the light receiving element 3 receives light. It is possible to accurately generate a noise component derived from ambient light included in the received light signal.

  With this configuration, the ambient light detection unit 300 generates an ambient light signal corresponding to the same ambient light as that generated in the usage environment of the light detection unit 130 while the light detection unit 130 is in use. And input to the ambient light noise removing unit 24 of the signal processing unit 210. Then, in the ambient light noise removing unit 24, based on the ambient light signal output from the ambient light detection unit 300, noise components derived from ambient light are removed from the light reception signal output by the light receiving element 3 of the light detection unit 130. The received light signal from which the noise component derived from the ambient light has been removed is input to the waveform processing / output unit 23 via the amplification unit 21 and the A / D conversion unit 22. Therefore, the waveform processing / output unit 23 can detect the waveform of the volume pulse wave based on the received light signal from which the noise component derived from the environmental light is removed.

The ambient light detection unit 300 may be modified as follows. That is, FIG. 26 illustrates the case where only the ambient light receiving element 302 is provided, but as shown in FIG. 27, the ambient light detecting units 370 are arranged at equal intervals with the ambient light receiving element 302 and the ambient light prism 303. A plurality of ambient light emitting elements 304A constituting a surface light source may be used. Each ambient light emitting element 304A is disposed to face the surface of the ambient light prism 303 that serves as a light incident end. For each ambient light emitting element 304A, it is desirable to use an element having the same type or the same or similar characteristics as each light emitting element 1A of the light detection unit 130.
With this configuration, the ambient light receiving element 302 can detect a signal similar to the ambient light component included in the received light signal detected by the light receiving element 3 of the light detection unit 130 as the ambient light signal. Become.

  Further, as a means for the removal process in the ambient light noise removing unit 24, a filtering process is used in addition to subtracting the ambient light signal output from the ambient light detection unit 300 or 370 from the received light signal output from the light detection unit 130. A wavelength component peculiar to the environmental light signal may be removed.

  In addition, the installation number of the ambient light detection units 300 or 370 is not particularly limited, and may be single or plural. When a plurality of environmental light signals are installed, for example, it is conceivable that the environmental light signals are generated by averaging the environmental light signals detected by the plurality of environmental light detection units.

  Further, the installation position of the ambient light detection unit 300 or 370 is preferably a position where a signal close to noise derived from ambient light included in the light reception signal detected by the light receiving element 3 of the light detection unit 130 can be detected as the ambient light signal. For example, it may be installed at a position adjacent to the light detection unit 130, but is not limited thereto.

  As described above in detail, according to the second embodiment, for example, the biological information acquisition apparatus is used in an environment where the ambient light fluctuates due to a change in the image of a television receiver or the like. Even in such a situation, it is possible to remove the noise component and generate a good light reception signal.

  As described above in detail, in the light detection unit 130 according to the fourth embodiment, a single or a plurality of light emitting elements that are arranged at equal intervals on the surface of the prism 2 opposite to the sensor surface 2b and constitute a surface light source. The element 1A is arranged, and sensor light emitted from the light emitting element 1A is directly incident on the prism 2 from its lower surface. In this state, when the living body part 7 comes into contact with the sensor surface 2 b of the prism 2, the light component 6 emitted from the end of the prism 2 in the sensor light is received by the light receiving element 3.

  Therefore, not only can the same effect as the first embodiment described above be obtained, but also the sensor light emitted from the light emitting element 1A is directly incident on the prism 2, so that the sensor surface of the prism 2 The light quantity can be made uniform at a sufficient level at any position. For this reason, even if the living body part 7 is brought into contact with any position on the sensor surface of the prism 2, it is possible to detect a uniform change in the amount of received light, thereby reducing variations in the detection result of the volume pulse wave due to the contact position. be able to.

[Other Embodiments]
In each of the first to third embodiments, the light emitting element 1 is provided, and the sensor light 4 generated by the light emitting element 1 is incident on the prism 2 or the like. 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 4. In this way, the light emitting element 1 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 embodiments described above, the case where the prism 2 made of a rectangular plate is used as an example, but a prism made of a square, rectangular, circular, elliptical or polygonal plate may be used. Good. In order to realize this, a plurality of light emitting elements 1 and 1 are dispersedly arranged on the side surface of the prism 2 or the elastic member 11 and sensor light is incident on the prism 2 from multiple directions, whereby the prism 2 or the elastic member 11 What is necessary is just to comprise so that sensor light may be irradiated with respect to the biological body part 7 even if the biological body part 7 is made to contact any position of the upper surface.

In addition, the shape of the prism, the type of the light receiving element, the configuration of the signal processing unit and its processing contents, the use of the volume pulse wave, and the like can be variously modified without departing from the scope of the present invention.
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.

  DESCRIPTION OF SYMBOLS 1,1A ... Light emitting element, 2 ... Prism, 2a ... Incident surface, 2b ... Sensor surface, 2c ... Outgoing surface, 3 ... Light receiving element, 4 ... Sensor light, 4a ... Surface reflection sensor light, 5 ... Scattered light, 6 ... Light component, 7 ... living body part, 8 ... condensing lens, 9, 12 ... reflecting mirror, 10 ... light guide plate, 11 ... transparent elastic member, 21 ... amplification part, 22 ... A / D conversion part, 23 ... waveform processing Output unit, 24 ... Ambient light noise removal unit, 100, 110, 120, 130 ... Light detection unit, 200,210 ... Signal processing unit, 300,310,320,330,340,350,360,370 ... Ambient light Detection unit 302... Ambient light receiving element 303... Ambient light prism 304, 304 A ... Ambient light emitting element 305... Ambient light guide plate 306.

Claims (17)

In a biological information detection apparatus for detecting information related to volume pulse waves from a biological part,
The plate-like or columnar light that is incident from the first side surface is guided to the second side surface while being totally reflected between the upper surface and the lower surface serving as the contact surface of the living body part, and the second side surface to the outside. An outgoing prism;
A light receiving element that receives light emitted from the second side surface of the prism 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 surface of the prism is detected, and information indicating the change in the amount of received light detected is A biological information detection apparatus comprising: a signal processing unit that outputs information representing a volume pulse wave of a biological part.   The living body information detecting apparatus according to claim 1, further comprising a light emitting element that makes light incident from the first side surface into the prism.   And a condensing optical system that is disposed between the second side surface of the prism and the light receiving element and condenses the light emitted from the second side surface and causes the light receiving element to receive the light. The biological information detection device according to claim 1 or 2.   2. The reflection optical system according to claim 1, further comprising: a reflection optical system that is disposed at a position in contact with or opposite to the lower surface of the prism, and reflects light leaked from the lower surface of the prism and re-enters the prism from the lower surface. The biological information detection apparatus according to any one of 1 to 3. In a biological information detection apparatus for detecting information related to volume pulse waves from a biological part,
The main component of the incident light is guided to the second side surface while totally reflecting between the upper surface and the lower surface, which are the contact surfaces of the living body site, with the light incident from the first side surface having a plate shape or a column shape. A prism that exits from the second side surface;
A light emitting element for entering light from the first side surface into the prism;
When a living body part comes into contact with the upper surface of the prism, light that is scattered by the living body part and leaks from a surface other than the second side surface of the prism is received, and a light reception signal corresponding to the received light amount is output. A light receiving element;
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 surface of the prism is detected, and information indicating the change in the amount of received light detected is A biological information detection apparatus comprising: a signal processing unit that outputs information representing a volume pulse wave of a biological part. An ambient light receiving element having at least an ambient light receiving element having the same or similar light receiving characteristics as the light receiving element, further receiving an ambient light leaking from the prism and outputting the received light signal;
And the said signal processing part removes the signal component of the environmental light contained in the said light reception signal from the light reception signal output from the said light receiving element based on the environment light light reception signal output from the said environment light light reception part, 6. The ambient light component removing unit that provides the received light signal from which the ambient light signal component has been removed to a process for detecting a change in the amount of received light. Biological information detection device. In a biological information detection apparatus for detecting information related to volume pulse waves from a biological part,
A surface emitting source that emits surface light;
A plate-like or columnar shape is introduced, and the light emitted from the surface emitting source is introduced from the lower surface thereof, and then guided to the side surface while totally reflecting between the upper surface and the lower surface serving as the contact surface of the living body part. A prism emitting to the outside;
A light receiving element that receives light emitted from the side surface of the prism 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 surface of the prism is detected, and information indicating the change in the amount of received light detected is A biological information detection apparatus comprising: a signal processing unit that outputs information representing a volume pulse wave of a biological part.   The living body information detecting apparatus according to claim 7, wherein the surface emitting source is configured by a single or a plurality of light emitting elements.   8. The living body information detecting apparatus according to claim 7, wherein the surface light source is formed of a light guide member that has a plate shape and emits light incident from the side surface thereof from the upper surface.   The living body information detecting apparatus according to claim 9, further comprising a light emitting element that makes light incident on the light guide member from a side surface thereof.   8. A condensing optical system that is disposed between a side surface of the prism and the light receiving element, further collects light emitted from the side surface and causes the light receiving element to receive the light. The biological information detection apparatus according to any one of 10. An ambient light receiving unit having at least an ambient light receiving element having the same or similar light receiving characteristics as the light receiving element, receiving ambient light leaking from the prism through the light guide member, and outputting the received light signal; In addition,
And the said signal processing part removes the signal component of the environmental light contained in the said light reception signal from the light reception signal output from the said light receiving element based on the environment light light reception signal output from the said environment light light reception part, The ambient light component removing unit that provides the received light signal from which the ambient light signal component has been removed to a process for detecting a change in the amount of received light is further provided. Biological information detection device. In a biological information detection apparatus for detecting information related to volume pulse waves from a biological part,
In a state where the living body part is not in contact with the plate, light incident from the side surface is linearly or totally reflected between the upper surface and the lower surface, and when the living body part is in contact with the upper surface, the incident light depends on the living body part. An elastic transparent member that emits scattered light from the lower surface;
Introducing scattered light emitted from the lower surface of the elastic transparent member from the upper surface and guiding it to the side surface while totally reflecting between the upper surface and the lower surface, a prism that emits from the side surface to the outside,
A light receiving element that receives light emitted from the side surface of the prism 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, the change in the amount of received light that occurs when a living body part contacts the upper surface of the elastic transparent member is detected, and the information representing the detected change in the amount of received light And a signal processing unit for outputting the information as information representing the volume pulse wave of the living body part.   The biological information detecting apparatus according to claim 13, further comprising a light emitting element that allows light to enter the elastic transparent member from a side surface thereof.   14. A condensing optical system that is disposed between a side surface of the prism and the light receiving element, and that condenses light emitted from the side surface and causes the light receiving element to receive the light. 14. The biological information detecting device according to 14.   And a reflection optical system that is disposed at a position that is in contact with or faces the lower surface of the prism, and that reflects scattered light leaking from the lower surface of the prism and re-enters the prism from the lower surface. Item 16. The biological information detection device according to any one of Items 13 to 15. An ambient light receiving unit having at least an ambient light receiving element having the same or similar light receiving characteristics as the light receiving element, receiving ambient light leaking from the prism through the elastic transparent member, and outputting the received light signal; In addition,
And the said signal processing part removes the signal component of the environmental light contained in the said light reception signal from the light reception signal output from the said light receiving element based on the environment light light reception signal output from the said environment light light reception part, The ambient light component removing unit that provides the received light signal from which the ambient light signal component has been removed to the process for detecting the change in the amount of received light is further provided. Biological information detection device.

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