Biological information measuring device and biological information measuring system

Abstract

To solve the problem with a light transmission material which reflects a laser beam on a surface and a reverse face that there is a case where interference light is generated by surface reflection light reflected on the surface and reverse face reflection light reflected on the reverse face, and the interference light deteriorates biological information measurement accuracy.SOLUTION: A biological information measuring device includes a light emission part for emitting a laser beam to a living body, a light transmission member for reflecting a part of the laser beam and dividing it into a first light flux and a second light flux, a first light reception part for detecting the first light flux, and a second light reception part for detecting scattering light. The light transmission member includes a first surface on which the laser beam is made incident and a second surface on which the laser beam made incident on the first surface is made incident. When a parallel axis parallel to an intersection of an incidence plane in which the light emission part and the first light reception part are arranged, and the first surface is represented as a first axis, and an orthogonal axis orthogonal to the first axis on the first surface is represented as a second axis, a first diameter D1 along the first axis of the laser beam and a second diameter D2 along the second axis of the laser beam have relationships of D1<D2.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present disclosure relates to a biological information measuring device and a biological information measuring system. [Background technology]

[0002] There is known a bioinformation measuring device that emits laser light to a living body. Patent Document 1 describes a bioinformation acquiring device that is an example of a bioinformation measuring device. The bioinformation acquiring device described in Patent Document 1 includes a light branching element, a first light receiving element, a second light receiving element, and a differential circuit. The light branching element is made of a light-transmitting material that branches the laser light. The first light receiving element receives a first light beam branched by the light branching element. The second light receiving element receives scattered light scattered by the living body. The differential circuit is connected to the first light receiving element and the second light receiving element. The differential circuit outputs a light detection signal. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-144578 A Summary of the Invention [Problem to be solved by the invention]

[0004] The light-transmitting material reflects the laser light on its front and back surfaces. The front-side reflected light reflected on the front surface and the back-side reflected light reflected on the back surface may generate interference light. The interference light reduces the measurement accuracy of biological information. [Means for solving the problem]

[0005] The biological information measurement device of the present disclosure includes a light emitting unit that emits laser light onto a living body, a light transmission member that reflects a part of the laser light and separates it into a first light beam and a second light beam, a first light receiving unit that detects the first light beam, and a second light receiving unit that detects scattered light generated when the second light beam is incident on the living body. The light transmission member has a first surface on which the laser light is incident and a second surface on which the laser light incident on the first surface is incident. When a parallel axis parallel to the intersection line between the incident surface where the light emitting unit and the first light receiving unit are arranged and the first surface is defined as the first axis, and an orthogonal axis orthogonal to the first axis on the first surface is defined as the second axis, a first diameter D1 of the laser light along the first axis and a second diameter D2 of the laser light along the second axis have a relationship of D1 < D2.

[0006] The biological information measurement system of the present disclosure includes a biological information measurement device having a light emitting unit that emits laser light onto a living body, a light transmission member that reflects a part of the laser light and separates it into a first light beam and a second light beam, a first light receiving unit that detects the first light beam and generates a first detection signal, a second light receiving unit that detects scattered light generated when the second light beam is incident on the living body and generates a second detection signal, a differential circuit that inputs the first detection signal and the second detection signal and generates an output signal, and a communication unit that transmits the output signal, and a control device having a terminal communication unit that receives the output signal and an analysis unit that analyzes the biological information of the living body using the output signal. The light transmission member has a first surface on which the laser light is incident and a second surface on which the laser light incident on the first surface is incident. When a parallel axis parallel to the intersection line between the incident surface where the light emitting unit and the first light receiving unit are arranged and the first surface is defined as the first axis, and an orthogonal axis orthogonal to the first axis on the first surface is defined as the second axis, a first diameter D1 of the laser light along the first axis and a second diameter D2 of the laser light along the second axis have a relationship of D1 < D2.

Brief Description of the Drawings

[0007] [Figure 1] A diagram showing a schematic configuration of the measurement device. [Diagram 2] A diagram showing a schematic configuration of the measurement surface of the measurement device. [Diagram 3] FIG. 2 is a block diagram showing the configuration of a measurement device. [Figure 4] FIG. 2 is a diagram showing a schematic configuration of a laser beam emitted from a light-emitting element unit. [Diagram 5] FIG. 2 is a diagram showing an outline of optical measurement by a detection unit. [Figure 6] FIG. 4 is an enlarged view showing a configuration of reflected light in the vicinity of a light branching element. [Figure 7] FIG. 2 is a diagram showing a schematic configuration of a spot on the surface of a light branching element. [Figure 8] FIG. 4 is an enlarged view showing a configuration of reflected light in the vicinity of a light branching element. [Figure 9] FIG. 2 is a diagram showing an outline of optical measurement by a detection unit. [Figure 10] FIG. 4 is a diagram showing an enlarged configuration of reflected light in the vicinity of the cover glass. [Figure 11] FIG. 1 shows a schematic configuration of spots on the surface of a cover glass. [Figure 12] FIG. 4 is a diagram showing an enlarged configuration of reflected light in the vicinity of the cover glass. [Figure 13] FIG. 1 is a diagram showing a schematic configuration of a measurement system. [Figure 14] FIG. 1 is a block diagram showing the configuration of a measurement system. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] FIG. 1 shows a schematic configuration of a measuring device 100. The measuring device 100 measures biological information such as blood flow rate, blood volume, blood flow velocity, pulse rate, or various data related to biological information. A user M corresponds to an example of a living body. The measuring device 100 shown in FIG. 1 is a wristwatch-type portable device that is worn on a measurement site of the user M. The measuring device 100 is worn on the wrist of the user M. The measuring device 100 is not limited to a wristwatch type. The measuring device 100 is not limited in form as long as it is configured to be worn by the user M. The measuring device 100 measures blood flow rate, blood volume, blood flow velocity, pulse rate, etc. over time. The measuring device 100 may measure biological information other than blood flow rate, etc. The measuring device 100 measures, for example, blood oxygen saturation, skin perfusion pressure, etc. The measuring device 100 includes a housing 1 and a belt 2. The housing 1 houses a detection unit 3 and a display unit 4. The measuring device 100 corresponds to an example of a biological information measuring device.

[0009] The housing 1 is an exterior that houses units and the like provided in the measuring device 100. The housing 1 has a measurement surface 1a and a display surface 1b. The measurement surface 1a is a surface that faces the measurement site of the user M. At least a portion of the measurement surface 1a contacts the measurement site of the user M. The display surface 1b is a surface that is visible to the user M. In addition to the detection unit 3 and the display unit 4, the housing 1 houses a control unit 30, a memory 40, and the like, which will be described later. The housing 1 corresponds to an example of a case.

[0010] The belt 2 is a member used when attaching the housing 1 to the measurement site of the user M. The belt 2 is attached to the side of the housing 1, etc. The belt 2 is wrapped around the measurement site to attach the housing 1 to the measurement site of the user M. The measuring device 100 shown in FIG. 1 includes the belt 2, but is not limited to this. The measuring device 100 does not have to include the belt 2. The measuring device 100 may be attached to the chest, arm, etc. of the user M by tape or the like. It is preferable that the measuring device 100 is wrapped around the measurement site of the user M using the belt 2. The measuring device 100 is attached to the measurement site of the user M using the belt 2, and thereby the arrangement of the light emitting element unit 10 and the light receiving element unit 20, which will be described later, with respect to the user M is determined. The belt 2 corresponds to an example of a band.

[0011] The detection unit 3 is disposed on the measurement surface 1a of the housing 1. The detection unit 3 is disposed at a position facing the measurement site of the user M. The detection unit 3 acquires various data used when measuring biological information.

[0012] The display unit 4 is disposed on the display surface 1b of the housing 1. The display unit 4 is configured to be visible to the user M. The display unit 4 displays various types of measured biometric information. The display unit 4 may display information other than the biometric information, such as a reliability index of the biometric information, time, etc. The display unit 4 does not necessarily have to be provided.

[0013] FIG. 2 shows a schematic configuration of the measurement surface 1a of the measurement device 100. FIG. 2 shows a schematic configuration of the measurement surface 1a of the measurement device 100 when viewed from the measurement site side of the user M. The measurement surface 1a shown in FIG. 2 is configured in a circular shape, but is not limited to this. The measurement surface 1a may be configured in various shapes such as a rectangular shape or an elliptical shape. A detection unit 3 is disposed on the measurement surface 1a. The detection unit 3 has a light-emitting element unit 10 and a light-receiving element unit 20. The detection unit 3 may have a temperature detection sensor, a power supply terminal, etc., which are not shown.

[0014] Several figures including FIG. 2 show an XYZ coordinate system. The X-axis is an axis parallel to the direction in which the light-emitting element unit 10 and the light-receiving element unit 20 are arranged. The +X direction is a direction from the light-emitting element unit 10 toward the light-receiving element unit 20. The -X direction is a direction from the light-receiving element unit 20 toward the light-emitting element unit 10. The Y-axis is an axis perpendicular to the X-axis within the measurement surface 1a. The +Y direction is a direction from the bottom to the top of FIG. 2. The -Y direction is a direction from the top to the bottom of FIG. 2. The Z-axis is an axis perpendicular to the measurement surface 1a. The +Z direction is a direction from the measurement surface 1a toward the display surface 1b. The -Z direction is a direction from the display surface 1b toward the measurement surface 1a.

[0015] The belt 2 is attached to the housing 1 of the measuring device 100. The belt 2 is attached to the housing 1 parallel or approximately parallel to the X-axis. By attaching the belt 2 to the housing 1 parallel or approximately parallel to the X-axis, the light emitting element unit 10 and the light receiving element unit 20 are arranged in the circumferential direction of the wrist of the user M. It is preferable that the belt 2 is attached parallel or approximately parallel to the arrangement direction in which the light emitting element unit 10 including the laser light emitting element 11 and the light receiving element unit 20 including the light receiving element 21 are arranged. Approximately parallel indicates that the intersection angle between the X-axis and the arrangement direction is within 5°. A decrease in measurement accuracy due to the body movement of the user M is suppressed.

[0016] The light-emitting element unit 10 emits light toward the measurement site of the user M. The light-emitting element unit 10 has a laser light-emitting element 11. The light-emitting element unit 10 may have a light-emitting element other than the laser light-emitting element 11. The light-emitting element other than the laser light-emitting element 11 is, for example, configured with a bare chip type or a bullet type LED (Light Emitting Diode). The light-emitting element unit 10 may have a plurality of laser light-emitting elements 11. The number of laser light-emitting elements 11 is set appropriately.

[0017] The laser light emitting element 11 emits laser light toward the living body. The laser light emitting element 11 is composed of a semiconductor laser. As an example, the laser light emitting element 11 is composed of a vertical cavity surface emitting laser. The configuration of the laser light emitting element 11 is appropriately set according to the wavelength range of the emitted laser light. The laser light emitting element 11 emits laser light of a predetermined wavelength in the near infrared region. As an example, the wavelength of the emitted laser light is in the range of 800 nm to 1300 nm. The frequency of the emitted laser light is in the range of 75 THz to 400 THz. The laser light emitting element 11 corresponds to an example of a light emitting unit.

[0018] The light receiving element unit 20 receives the reflected light RL and the scattered light SL. The reflected light RL is light reflected by the cover glass 5 or the light branching element 27 described later. The reflected light RL corresponds to an example of a first light beam. The scattered light SL is light scattered by a living body. The light receiving element unit 20 receives the scattered light SL generated when the light emitting element unit 10 emits laser light to the living body. The light receiving element unit 20 has a light receiving element 21 that receives the reflected light RL and the scattered light SL. The light receiving element 21 is composed of one or more photodiodes. The photodiode is an element whose photoelectric conversion layer is composed of indium gallium arsenide (InGaAs), gallium arsenide (GaAs), silicon, or the like. The photodiode used in the light receiving element 21 is appropriately selected depending on the wavelength of the light to be received, etc. The light receiving element 21 corresponds to an example of a light receiving section.

[0019] FIG. 3 shows a block configuration of the measuring device 100. FIG. 3 shows the measuring device 100 excluding the belt 2. The measuring device 100 accommodates various units and the like in a housing 1. The measuring device 100 includes a detection unit 3, a control unit 30, a memory 40, a display unit 4, and a communication interface 50. The housing 1 is provided with a housing opening 1c at a position facing the user M. The housing opening 1c passes the laser light emitted from the laser light emitting element 11. A cover glass 5 may be attached to the housing opening 1c. When the cover glass 5 is not provided, the housing opening 1c passes the transmitted light TL that has passed through the light branching element 27. The housing opening 1c corresponds to an example of a passage opening. The measuring device 100 shown in FIG. 3 has a cover glass 5 provided in the housing opening 1c.

[0020] The cover glass 5 is a protective member that prevents foreign matter such as dust from entering the housing 1. The cover glass 5 is attached to the housing 1. The cover glass 5 may or may not be attached to the housing 1. The cover glass 5 is provided at a position facing the measurement site of the user M. The cover glass 5 transmits the laser light emitted from the laser light emitting element 11. The cover glass 5 transmits the scattered light SL generated at the measurement site of the user M. The scattered light SL that transmits through the cover glass 5 is received by the light receiving element 21. The cover glass 5 is made of a light transmitting material such as glass. At least a part of the cover glass 5 may be in contact with the user M. The cover glass 5 functions as the light branching element 27 when the light emitting element unit 10 does not have the light branching element 27. When the cover glass 5 functions as the light branching element 27, the cover glass 5 corresponds to an example of a light transmitting member. When the light emitting element unit 10 has the light branching element 27, the cover glass 5 functions as a protective member.

[0021] The detection unit 3 is an optical sensor module that detects data related to biological information measured using laser light as a light detection signal. The detection unit 3 includes a light-emitting element unit 10, a drive circuit 13, a light-receiving element unit 20, and a signal conversion unit 23.

[0022] The light-emitting element unit 10 emits laser light toward the user M. The light-emitting element unit 10 has a laser light-emitting element 11. The light-emitting element unit 10 may have a light branching element 27. The light-emitting element unit 10 may have a shaping optical system (not shown). The shaping optical system shapes the shape of the laser light spot LS. The laser light-emitting element 11 emits laser light as emitted light OL to the user M. The emitted light OL passes through the housing opening 1c or a cover glass 5 attached to the housing opening 1c and is irradiated to the user M.

[0023] The drive circuit 13 drives the laser light emitting element 11. The drive circuit 13 causes the laser light emitting element 11 to emit light under the control of the control unit 30. The drive circuit 13 controls the light emission timing, light emission time, emitted light amount, etc. of the laser light emitting element 11. The drive circuit 13 may also control the wavelength of the laser light emitted by the laser light emitting element 11, the size of the laser light spot LS, etc.

[0024] The light receiving element unit 20 receives reflected light RL and scattered light SL. The scattered light SL is generated when the light emitting element unit 10 irradiates laser light toward the user M. The scattered light SL is generated when transmitted light TL that has passed through at least one of the cover glass 5 and the light branching element 27 is incident on a measurement site of the user M. The light receiving element unit 20 has a first light receiving element 21a, a second light receiving element 21b, and a condenser lens 25 described later. The light receiving element unit 20 may have a beam splitter, a prism, etc.

[0025] The first light receiving element 21a receives the reflected light RL. The reflected light frequency fr, which is the frequency of the reflected light RL, is the same as the emitted light frequency f0, which is the frequency of the emitted light OL. The first light receiving element 21a receives light having a frequency f0. The first light receiving element 21a receives the reflected light RL and converts it into a first electrical signal. The first light receiving element 21a transmits the first electrical signal to the signal conversion unit 23. The first light receiving element 21a corresponds to an example of a first light receiving section. The first electrical signal corresponds to an example of a first detection signal.

[0026] The second light receiving element 21b receives the scattered light SL. The scattered light SL includes a first component light that is a diffuse reflection of the transmitted light TL by stationary tissue, and a second component light that is a diffuse reflection of the transmitted light TL by red blood cells moving in the capillaries. The first frequency f1, which is the frequency of the first component light, is the same as the emitted light frequency f0 of the emitted light OL emitted by the laser light emitting element 11. The second frequency f2, which is the frequency of the second component light, varies with respect to the emitted light frequency f0 due to the Doppler effect according to the moving speed of the red blood cells. The second frequency f2 varies with respect to the emitted light frequency f0 by a frequency shift amount proportional to the moving speed of the red blood cells. The second light receiving element 21b detects an optical beat signal reflecting the frequency shift amount. The second light receiving element 21b receives the scattered light SL that includes the optical beat signal, and converts it into a second electrical signal. The second light receiving element 21b transmits the second electrical signal to the signal conversion unit 23. The second light receiving element 21b corresponds to an example of a second light receiving section. The second electrical signal corresponds to an example of a second detection signal.

[0027] The first light receiving element 21a and the second light receiving element 21b may be composed of different photodiodes, or may be composed of one photodiode. The photodiode is divided into a plurality of light receiving regions, and each of the plurality of light receiving regions functions as the first light receiving element 21a and the second light receiving element 21b. The light receiving element unit 20 may have an element that receives light other than laser light.

[0028] The signal conversion unit 23 receives the first electrical signal and the second electrical signal transmitted from the light receiving element unit 20. The signal conversion unit 23 generates an optical detection signal using the first electrical signal and the second electrical signal and transmits it to the control unit 30. The optical detection signal includes an optical beat signal. The signal conversion unit 23 includes a differential amplifier 24. The signal conversion unit 23 may include an extraction circuit, an analog-digital conversion circuit, etc. The extraction circuit extracts an AC component from the electrical signal. The analog-digital conversion circuit converts the analog signal into a digital signal. The optical detection signal corresponds to an example of an output signal.

[0029] The differential amplifier 24 receives the first electrical signal and the second electrical signal. The differential amplifier 24 amplifies the difference voltage between the first electrical signal and the second electrical signal by a constant coefficient. The differential amplifier 24 outputs the amplified difference voltage. By outputting the difference voltage, the differential amplifier 24 extracts a signal corresponding to the second component light fluctuated by the Doppler effect. The differential amplifier 24 generates a light detection signal using the first electrical signal and the second electrical signal. The differential amplifier 24 corresponds to an example of a differential circuit.

[0030] The control unit 30 is a control controller that controls the operation of various units. As an example, the control unit 30 is a processor having a CPU (Central Processing Unit). The control unit 30 is composed of one or more processors. The control unit 30 may be composed of an FPGA (Field-Programmable Gate Array) or an ASIC (Application Specific Integrated Circuit). The control unit 30 may have a semiconductor memory such as a RAM (Random Access Memory) or a ROM (Read Only Memory). The semiconductor memory functions as a work area of ​​the control unit 30. The control unit 30 functions as a detection control unit 31, a data processing unit 33, and a display control unit 35 by executing a control program stored in the memory 40. The detection control unit 31, the data processing unit 33, and the display control unit 35 are functional units. The control unit 30 controls the light-emitting element unit 10 and the light-receiving element unit 20 by each functional unit.

[0031] The detection control unit 31 controls the light-emitting element unit 10 and the light-receiving element unit 20. The detection control unit 31 controls the driving of the laser light-emitting element 11 via the drive circuit 13. The detection control unit 31 adjusts the light emission timing, light emission intensity, light emission pattern, etc. of the laser light-emitting element 11. The detection control unit 31 controls the light-receiving element 21. The detection control unit 31 adjusts the light-receiving timing of the light-receiving element 21, the output timing of the first electrical signal and the second electrical signal, etc.

[0032] The data processing unit 33 calculates the biological information using the light detection signal. The data processing unit 33 performs frequency analysis such as fast Fourier transform on the light detection signal. The data processing unit 33 calculates an intensity spectrum from the light detection signal by performing frequency analysis. The data processing unit 33 calculates the blood volume, blood flow rate, etc. from the intensity spectrum. The blood volume is an index related to the number of red blood cells in a unit volume. The blood volume is an index related to the blood volume of the user M. The blood flow rate is the volume of blood moving in an artery per unit time. The blood flow rate is an index related to the blood flow rate of the user M. The data processing unit 33 may calculate the blood pressure, etc. using the blood flow rate. The data processing unit 33 may calculate the pulse rate, etc. using the light detection signal. The data processing unit 33 outputs the biological information such as the blood volume, blood flow rate, etc. to the display control unit 35. The data processing unit 33 may transmit the biological information such as the blood volume, blood flow rate, etc. to the memory 40, the communication interface 50, etc. The data processing unit 33 corresponds to an example of a calculation unit.

[0033] The display control unit 35 controls the display of the display unit 4. The display control unit 35 causes the display unit 4 to display various images by transmitting display data to the display unit 4. The display control unit 35 acquires bioinformation from the data processing unit 33 at a predetermined timing. The display control unit 35 generates display data including blood volume and the like. The display control unit 35 may also generate display data including blood pressure and the like. The display control unit 35 outputs the display data to the display unit 4. The display control unit 35 causes the display unit 4 to display the bioinformation based on the display data.

[0034] The memory 40 stores various data. The memory 40 stores control data for operating various units, various data measured by the control unit 30, etc. The memory 40 stores various calculation data used by the data processing unit 33. The memory 40 may also store biological information measured by the data processing unit 33. The memory 40 stores a control program operated by the control unit 30. The memory 40 is composed of a ROM, a RAM, etc.

[0035] The communication interface 50 is an interface circuit that is communicatively connected to the tablet terminal 200. The communication interface 50 is connected to the tablet terminal 200 by wire or wirelessly in accordance with a predetermined protocol. The communication interface 50 includes, for example, a connection port for wired communication and an antenna for wireless communication. The communication interface 50 receives control data, information related to the user M, and the like from the tablet terminal 200. The communication interface 50 transmits various types of biological information to the tablet terminal 200. The communication interface 50 may transmit measurement data such as a light detection signal. The communication interface 50 may be communicatively connected to an external device other than the tablet terminal 200. The communication interface 50 corresponds to an example of a communication unit.

[0036] FIG. 4 shows a schematic configuration of the laser light emitted from the light-emitting element unit 10. FIG. 4 shows a perspective view of the laser light-emitting element 11, the light-receiving element 21, and the glass member 60. The glass member 60 represents the cover glass 5 or the light branching element 27. FIG. 4 shows the incident surface IS. The incident surface IS is an imaginary surface on which the laser light-emitting element 11 and the first light-receiving element 21a are disposed. User M is omitted in FIG. 4. The measurement site of user M is located below the glass member 60. The glass member 60 represents a light-transmitting member.

[0037] The emitted light OL is a laser light emitted from the laser light emitting element 11. The emitted light OL is emitted toward the user M. The emitted light OL enters the inside of the glass member 60 from a surface S1 of the glass member 60. The surface S1 is the surface on which the emitted light OL enters. The surface S1 is the surface facing the laser light emitting element 11. The surface S1 is the surface on which the laser light of the cover glass 5 or the light branching element 27 enters. The surface S1 corresponds to an example of a first surface.

[0038] The transmitted light TL that enters the interior of the glass member 60 passes through the interior of the glass member 60. The transmitted light TL that reaches the rear surface S2 of the glass member 60 passes through the rear surface S2 and irradiates the measurement site of the user M. The rear surface S2 is the surface onto which the transmitted light TL that is incident on the front surface S1 is incident. The rear surface S2 is the surface onto which the laser light that is incident on the cover glass 5 or the front surface S1 of the light branching element 27 is incident. The rear surface S2 corresponds to an example of the second surface.

[0039] A portion of the output light OL is reflected by the surface S1 of the glass member 60. The surface reflected light RL1 reflected by the surface S1 travels toward the first light receiving element 21a. The surface reflected light RL1 is an example of reflected light RL. The surface reflected light RL1 is received by the first light receiving element 21a.

[0040] The emitted light OL and the surface reflected light RL1 pass through the incident surface IS. The incident surface IS intersects with the surface S1. The incident surface IS and the surface S1 intersect at the intersection line IL. Here, a parallel axis parallel to the intersection line IL is represented as the first optical axis A1. An orthogonal axis on the surface S1 that is perpendicular to the intersection line IL is represented as the second optical axis A2. A vertical axis that is perpendicular to the surface S1 is represented as the third optical axis A3. The first optical axis A1 corresponds to an example of the first axis. The second optical axis A2 corresponds to an example of the second axis.

[0041] First embodiment The first embodiment shows an optical configuration in which a detection unit 3 having a light branching element 27 detects a light detection signal. In the first embodiment, the first light receiving element 21a receives reflected light RL reflected by the light branching element 27. In the first embodiment, a cover glass 5 may or may not be provided. The first light receiving element 21a does not receive cover glass reflected light reflected by the cover glass 5.

[0042] FIG. 5 shows an outline of optical measurement by the detection unit 3. FIG. 5 shows the cover glass 5, the laser light emitting element 11, the first light receiving element 21a, the second light receiving element 21b, the condenser lens 25, and the light branching element 27. FIG. 5 shows the reflected light RL, the transmitted light TL, and the scattered light SL when the laser light emitting element 11 emits the emitted light OL toward the user M. FIG. 5 shows the emitted light OL, the reflected light RL, the transmitted light TL, and the scattered light SL on the incident surface IS. The laser light emitting element 11, the first light receiving element 21a, and the second light receiving element 21b are arranged along the X-axis. The arrangement direction of the laser light emitting element 11, the first light receiving element 21a, and the second light receiving element 21b is parallel to the X-axis.

[0043] The outgoing light OL is emitted by the laser light emitting element 11 toward the measurement site of the user M. The outgoing light OL is incident on the light branching element 27. The outgoing light OL is split into reflected light RL and transmitted light TL by the light branching element 27. The outgoing light OL is reflected by the front surface S1 and the back surface S2 of the light branching element 27.

[0044] The reflected light RL is light that is the output light OL reflected by the optical branching element 27. The reflected light RL includes a front surface reflected light RL1 and a rear surface reflected light RL2. The reflected light RL is reflected in the +Z direction. The reflected light RL is reflected toward the first light receiving element 21a. The reflected light RL is received by the first light receiving element 21a.

[0045] The surface reflected light RL1 is light that is generated when the output light OL is reflected by the surface S1 of the optical branching element 27. The surface reflected light RL1 is generated when a portion of the output light OL is reflected by the surface S1. The surface reflected light RL1 is reflected toward the first light receiving element 21a. The surface reflected light RL1 is received by the first light receiving element 21a.

[0046] The back surface reflected light RL2 is light that is generated when the outgoing light OL that entered the front surface S1 is reflected by the back surface S2 of the optical branching element 27. The back surface reflected light RL2 is generated when a portion of the transmitted light TL that entered the front surface S1 is reflected by the back surface S2. The back surface reflected light RL2 is reflected toward the first light receiving element 21a. The back surface reflected light RL2 passes through the inside of the optical branching element 27. The back surface reflected light RL2 is emitted to the outside from the front surface S1. The back surface reflected light RL2 is received by the first light receiving element 21a.

[0047] The transmitted light TL is light transmitted from the light branching element 27. The transmitted light TL is irradiated towards the measurement site of the user M. The transmitted light TL shown in FIG. 5 passes through the cover glass 5 and irradiates the measurement site of the user M. If the cover glass 5 is not provided, the transmitted light TL passes through the housing opening 1c and irradiates the measurement site of the user M. The transmitted light TL corresponds to an example of the second light flux.

[0048] When the transmitted light TL is incident on the cover glass 5, cover glass reflected light is generated. The cover glass reflected light is light reflected by the surface of the cover glass 5. It is preferable that the cover glass reflected light is not received by the first light receiving element 21a. The first light receiving element 21a and the light branching element 27 are provided at a position where the first light receiving element 21a does not receive the cover glass reflected light.

[0049] The scattered light SL is generated by irradiating the measurement site of the user M with the transmitted light TL. The scattered light SL is light reflected by the biological tissue or red blood cells of the user M. The scattered light SL passes through the cover glass 5 or the housing opening 1c. The scattered light SL is collected by the collecting lens 25. The collected scattered light SL is received by the second light receiving element 21b.

[0050] The collecting lens 25 collects the scattered light SL. The collecting lens 25 collects the scattered light SL, thereby increasing the light intensity of the scattered light SL. Fig. 5 shows one collecting lens 25, but is not limited to this. A plurality of collecting lenses 25 may be provided on the optical path of the scattered light SL.

[0051] The second light receiving element 21b receives the scattered light SL. The second light receiving element 21b receives the scattered light SL collected by the collecting lens 25. The second light receiving element 21b receives the scattered light SL and generates a second electrical signal.

[0052] When the cover glass 5 is attached to the housing opening 1c, it is preferable that the second light receiving element 21b does not receive the light reflected by the cover glass. A light blocking member that prevents the second light receiving element 21b from receiving the light reflected by the cover glass may be provided between the cover glass 5 and the second light receiving element 21b.

[0053] Fig. 6 shows an enlarged configuration of reflected light RL near the light branching element 27. Fig. 6 omits the laser light emitting element 11, the cover glass 5, the light receiving element 21, the condenser lens 25, the transmitted light TL, and the scattered light SL. Fig. 6 shows a schematic configuration of the front surface reflected light RL1 and the back surface reflected light RL2 near the light branching element 27. Fig. 6 shows the first incident angle θ1 of the emitted light OL, the first glass thickness t1 of the light branching element 27, the first spot diameter SD1, and the overlapping area DA.

[0054] The first incidence angle θ1 of the output light OL is the angle at which the output light OL is incident on the surface S1 of the light branching element 27. The first incidence angle θ1 is the angle between the output light OL incident on the light branching element 27 and an axis parallel to the third optical axis A3. The third optical axis A3 is an axis perpendicular to the first optical axis A1 and the second optical axis A2. The output light OL is incident on the surface S1 of the light branching element 27 at the first incidence angle θ1.

[0055] The first glass thickness t1 of the light branching element 27 is a thickness along the third optical axis A3 of the light branching element 27. The first glass thickness t1 is set in advance. The light branching element 27 is made of a light-transmitting material with the first glass thickness t1 and a first glass refractive index n1. The first glass thickness t1 corresponds to an example of the thickness t of the light-transmitting member. The first glass refractive index n1 corresponds to an example of the refractive index n of the light-transmitting member.

[0056] The first spot diameter SD1 is the diameter along the first optical axis A1 of the output light OL. The first spot diameter SD1 is the diameter along the first optical axis A1 of the spot LS on the surface S1 of the light branching element 27. The first spot diameter SD1 corresponds to an example of the first diameter D1 along the first axis.

[0057] The overlapping area DA is an area where the front surface reflected light RL1 and the back surface reflected light RL2 overlap. In the overlapping area DA, interference light between the front surface reflected light RL1 and the back surface reflected light RL2 occurs. The front surface reflected light RL1 and the back surface reflected light RL2 have different phases. The front surface reflected light RL1 and the back surface reflected light RL2 overlap, generating interference light with a different frequency from the output light OL. When the interference light is received by the first light receiving element 21a, the detection accuracy of the light detection signal decreases. It is preferable that the overlapping area DA is set narrow.

[0058] Fig. 7 shows a schematic configuration of the spot LS on the surface S1 of the light branching element 27. Fig. 7 shows the shape of the spot LS of the laser light on the surface S1. Fig. 7 shows a first spot diameter SD1 along the first optical axis A1 of the spot LS and a second spot diameter SD2 along the second optical axis A2.

[0059] The second spot diameter SD2 is a diameter along the second optical axis A2 of the output light OL. The second spot diameter SD2 is a diameter along the second optical axis A2 of the spot LS on the surface S1 of the light branching element 27. The second spot diameter SD2 corresponds to an example of a second diameter D2 along the second axis.

[0060] When the first spot diameter SD1 becomes smaller, the overlapping area DA decreases. When the overlapping area DA decreases, the interference light between the surface reflected light RL1 and the back surface reflected light RL2 decreases. A decrease in the detection accuracy of the optical detection signal due to the interference light can be suppressed. On the other hand, when the first spot diameter SD1 becomes smaller, the light amounts of the reflected light RL and the scattered light SL decrease. When the light amounts of the reflected light RL and the scattered light SL decrease, the detection accuracy of the optical detection signal decreases due to the decrease in the light amount. The second spot diameter SD2 does not affect the overlapping area DA. Even if the second spot diameter SD2 increases, it is difficult for the measurement accuracy of the optical detection signal due to the interference light to decrease. Therefore, the first spot diameter SD1 and the second spot diameter SD2 are in the relationship of SD1 < SD2. Since the shape of the spot LS is not circular and the first spot diameter SD1 is smaller than the second spot diameter SD2, a decrease in the detection accuracy of the optical detection signal due to the interference light can be suppressed. Since the shape of the spot LS is such that the second spot diameter SD2 is larger than the first spot diameter SD1, a decrease in the light amounts of the scattered light SL and the reflected light RL can be suppressed.

[0061] The measuring device 100 includes a laser light emitting element 11 that emits laser light to the user M, an optical branching element 27 that reflects a part of the laser light and separates it into a reflected light RL and a transmitted light TL, a first light receiving element 21a that detects the reflected light RL, and a second light receiving element 21b that detects the scattered light SL generated when the transmitted light TL is incident on the user M. The optical branching element 27 has a front surface S1 on which the laser light is incident and a back surface S2 on which the laser light incident on the front surface S1 is incident. When the first optical axis A1 is a parallel axis parallel to the intersection line IL between the incident surface IS where the laser light emitting element 11 and the first light receiving element 21a are arranged and the front surface S1, and the second optical axis A2 is an orthogonal axis orthogonal to the first optical axis A1 on the front surface S1, the first spot diameter SD1 along the first optical axis A1 of the laser light and the second spot diameter SD2 along the second optical axis A2 of the laser light have a relationship of SD1 < SD2. The shape of the laser light spot LS is not circular, and the first spot diameter SD1 is smaller than the second spot diameter SD2, thereby suppressing a decrease in the detection accuracy of the light detection signal due to interference light. The shape of the spot LS is such that the second spot diameter SD2 is larger than the first spot diameter SD1, thereby suppressing a decrease in the light intensity of the scattered light SL and the reflected light RL.

[0062] The measuring device 100 includes a differential amplifier 24 that inputs a first electrical signal obtained by receiving reflected light RL with the first light receiving element 21a and a second electrical signal obtained by receiving scattered light SL with the second light receiving element 21b, and a data processing unit 33 that calculates bioinformation using the light detection signal output from the differential amplifier 24. The measuring device 100 can obtain biological information such as blood volume using the light detection signal.

[0063] The measuring device 100 is attached to a housing 1, and includes a belt 2 that is wrapped around a user M. The belt 2 is preferably attached parallel or approximately parallel to the arrangement direction of the laser light emitting elements 11 and the second light receiving elements 21b. By arranging the laser light emitting element 11 and the second light receiving element 21b along the circumferential direction of the wrist of the user M, a decrease in measurement accuracy due to the body movement of the user M is suppressed.

[0064] Fig. 8 shows an enlarged configuration of reflected light RL near the light branching element 27. Fig. 8 omits the laser light emitting element 11, the light receiving element 21, the condenser lens 25, the transmitted light TL, and the scattered light SL. Fig. 8 shows a schematic configuration of the front surface reflected light RL1 and the back surface reflected light RL2 near the light branching element 27. Fig. 8 shows the first incident angle θ1 of the emitted light OL, the first glass thickness t1 of the light branching element 27, and the first spot diameter SD1.

[0065] FIG. 8 shows a state in which the first spot diameter SD1 satisfies the relationship of the following formula (1). SD1<(t1×sinθ1) / n1 (1) When the first spot diameter SD1 is a diameter having the relationship of formula (1), the front surface reflected light RL1 and the back surface reflected light RL2 do not overlap as shown in Fig. 8. An overlapping area DA where the front surface reflected light RL1 and the back surface reflected light RL2 overlap is not formed. The occurrence of interference light between the front surface reflected light RL1 and the back surface reflected light RL2 is suppressed. The decrease in detection accuracy of the light detection signal due to interference light between the front surface reflected light RL1 and the back surface reflected light RL2 is further suppressed.

[0066] The first spot diameter SD1, the incident angle θ1 of the laser light to the surface S1, the first glass thickness t1 of the light branching element 27, and the refractive index n1 of the light branching element 27 are expressed as follows: SD1<(t1×sinθ1) / n1 It is preferable that the relationship be: This further suppresses the deterioration of the detection accuracy of the light detection signal caused by the interference light between the front-surface reflected light RL1 and the rear-surface reflected light RL2.

[0067] Second embodiment The second embodiment shows a configuration using a detection unit 3 that detects reflected light RL reflected by a cover glass 5. In the second embodiment, a first light receiving element 21a receives reflected light RL reflected by the cover glass 5. The second embodiment does not include a light branching element 27. The cover glass 5 functions as the light branching element 27 in the first embodiment.

[0068] FIG. 9 shows an outline of optical measurement by the detection unit 3. FIG. 9 shows the cover glass 5, the laser light emitting element 11, the first light receiving element 21a, the second light receiving element 21b, the condenser lens 25, and the reflecting mirror 29. FIG. 9 shows the reflected light RL and the scattered light SL when the laser light emitting element 11 emits the emitted light OL toward the user M. FIG. 9 shows the emitted light OL, the reflected light RL, and the scattered light SL on the incident surface IS. The laser light emitting element 11, the first light receiving element 21a, and the second light receiving element 21b are arranged along the X-axis. The arrangement direction of the laser light emitting element 11, the first light receiving element 21a, and the second light receiving element 21b is parallel or approximately parallel to the X-axis.

[0069] The outgoing light OL is emitted by the laser light emitting element 11 toward the measurement site of the user M. The outgoing light OL is incident on the cover glass 5. The outgoing light OL is separated into reflected light RL and transmitted light TL by the cover glass 5. The outgoing light OL is reflected by the front surface S1 and the back surface S2 of the cover glass 5.

[0070] The reflected light RL is light that is the emitted light OL reflected by the cover glass 5. The reflected light RL includes front-surface reflected light RL1 and back-surface reflected light RL2. The reflected light RL is reflected in the +Z direction. The reflected light RL is reflected toward the reflecting mirror 29. The reflected light RL is reflected by the reflecting mirror 29 toward the first light receiving element 21a. The reflected light RL is received by the first light receiving element 21a.

[0071] The surface reflected light RL1 is light that is the emitted light OL reflected by the surface S1 of the cover glass 5. The surface reflected light RL1 is generated when a portion of the emitted light OL is reflected by the surface S1. The surface reflected light RL1 is reflected toward the reflecting mirror 29. The surface reflected light RL1 is reflected by the reflecting mirror 29 toward the first light receiving element 21a. The surface reflected light RL1 is received by the first light receiving element 21a.

[0072] The back surface reflected light RL2 is light that is produced when the outgoing light OL that entered the front surface S1 is reflected by the back surface S2 of the cover glass 5. The back surface reflected light RL2 is generated when a portion of the transmitted light TL that entered the front surface S1 is reflected by the back surface S2. The back surface reflected light RL2 is reflected toward the reflecting mirror 29. The back surface reflected light RL2 passes through the inside of the cover glass 5. The back surface reflected light RL2 is emitted to the outside from the front surface S1. The back surface reflected light RL2 is reflected by the reflecting mirror 29 toward the first light receiving element 21a. The back surface reflected light RL2 is received by the first light receiving element 21a.

[0073] The reflecting mirror 29 reflects the reflected light RL toward the first light receiving element 21a. The reflecting mirror 29 reflects the front surface reflected light RL1 and the back surface reflected light RL2 toward the first light receiving element 21a. The reflecting mirror 29 is provided at a position where the front surface reflected light RL1 and the back surface reflected light RL2 pass through. Providing the reflecting mirror 29 increases the degree of freedom in the arrangement position of the first light receiving element 21a.

[0074] The transmitted light TL is light that has passed through the cover glass 5. The transmitted light TL is irradiated toward the measurement site of the user M. The transmitted light TL passes through the cover glass 5 and irradiates the measurement site of the user M.

[0075] The scattered light SL is generated by irradiating the measurement site of the user M with the transmitted light TL. The scattered light SL is light reflected by the biological tissue and red blood cells of the user M. The scattered light SL passes through the cover glass 5. The scattered light SL is collected by the collecting lens 25. The collected scattered light SL is received by the second light receiving element 21b.

[0076] The collecting lens 25 collects the scattered light SL. The collecting lens 25 collects the scattered light SL to increase the light intensity of the scattered light SL. Fig. 9 shows one collecting lens 25, but is not limited to this. A plurality of collecting lenses 25 may be provided on the optical path of the scattered light SL.

[0077] The second light receiving element 21b receives the scattered light SL. The second light receiving element 21b receives the scattered light SL collected by the collecting lens 25. The second light receiving element 21b receives the scattered light SL and generates a second electrical signal.

[0078] Fig. 10 shows an enlarged configuration of the reflected light RL in the vicinity of the cover glass 5. Fig. 10 omits the laser light emitting element 11, the cover glass 5, the first light receiving element 21a, the second light receiving element 21b, the condenser lens 25, the reflecting mirror 29, the transmitted light TL, and the scattered light SL. Fig. 10 shows a schematic configuration of the front surface reflected light RL1 and the back surface reflected light RL2 in the vicinity of the cover glass 5. Fig. 10 shows the second incident angle θ2 of the emitted light OL, the second glass thickness t2 of the cover glass 5, the third spot diameter SD3, and the overlapping area DA.

[0079] The second incidence angle θ2 of the output light OL is the angle at which the output light OL is incident on the surface S1 of the cover glass 5. The second incidence angle θ2 is the angle between the output light OL incident on the cover glass 5 and an axis parallel to the third optical axis A3. The output light OL is incident on the surface S1 of the cover glass 5 at the second incidence angle θ2.

[0080] The second glass thickness t2 of the cover glass 5 is a thickness along the third optical axis A3 of the cover glass 5. The second glass thickness t2 is set in advance. The cover glass 5 is made of a light-transmitting material with the second glass thickness t2 and the second glass refractive index n2. The second glass thickness t2 corresponds to an example of the thickness t of the light-transmitting member. The second glass refractive index n2 corresponds to an example of the refractive index n of the light-transmitting member.

[0081] The third spot diameter SD3 is a diameter along the first optical axis A1 of the output light OL. The third spot diameter SD3 is a diameter along the first optical axis A1 of the spot LS on the surface S1 of the cover glass 5. The third spot diameter SD3 corresponds to an example of the first diameter D1 along the first axis.

[0082] The overlapping area DA is an area where the front surface reflected light RL1 and the back surface reflected light RL2 overlap. In the overlapping area DA, interference light between the front surface reflected light RL1 and the back surface reflected light RL2 occurs. The front surface reflected light RL1 and the back surface reflected light RL2 have different phases. The front surface reflected light RL1 and the back surface reflected light RL2 overlap, generating interference light with a different frequency from the output light OL. When the interference light is received by the first light receiving element 21a, the detection accuracy of the light detection signal decreases. It is preferable that the overlapping area DA is set narrow.

[0083] FIG. 11 shows a schematic configuration of the spot LS on the surface S1 of the cover glass 5. FIG. 11 shows the shape of the laser light spot LS on the surface S1. FIG. 11 shows a third spot diameter SD3 along the first optical axis A1 of the spot LS and a fourth spot diameter SD4 along the second optical axis A2.

[0084] The fourth spot diameter SD4 is the diameter along the second optical axis A2 of the emitted light OL. The fourth spot diameter SD4 is the diameter along the second optical axis A2 of the spot LS on the surface S1 of the cover glass 5. The fourth spot diameter SD4 corresponds to an example of a second diameter D2 along the second axis.

[0085] When the third spot diameter SD3 becomes smaller, the overlapping region DA decreases. When the overlapping region DA decreases, the interference light between the surface reflected light RL1 and the back surface reflected light RL2 decreases. A decrease in the detection accuracy of the optical detection signal due to the interference light can be suppressed. On the other hand, when the third spot diameter SD3 becomes smaller, the light amounts of the reflected light RL and the scattered light SL decrease. When the light amounts of the reflected light RL and the scattered light SL decrease, the detection accuracy of the optical detection signal decreases due to the decrease in the light amount. The fourth spot diameter SD4 does not affect the overlapping region DA. Even if the fourth spot diameter SD4 becomes larger, it is difficult for the measurement accuracy of the optical detection signal due to the interference light to decrease. Therefore, the third spot diameter SD3 and the fourth spot diameter SD4 are in the relationship of SD3 < SD4. Since the shape of the spot LS is not circular and the third spot diameter SD3 is smaller than the fourth spot diameter SD4, a decrease in the detection accuracy of the optical detection signal due to the interference light can be suppressed. Since the shape of the spot LS is such that the fourth spot diameter SD4 is larger than the third spot diameter SD3, a decrease in the light amounts of the scattered light SL and the reflected light RL can be suppressed.

[0086] The measuring device 100 includes a laser emitting element 11 that emits laser light to the user M, a cover glass 5 that reflects a part of the laser light and separates it into a reflected light RL and a transmitted light TL, a first light receiving element 21a that detects the reflected light RL, and a second light receiving element 21b that detects scattered light SL generated when the transmitted light TL enters the user M. The cover glass 5 has a front surface S1 on which the laser light is incident and a back surface S2 on which the laser light incident on the front surface S1 is incident. When a parallel axis parallel to the intersection line IL between the incident surface IS where the laser emitting element 11 and the first light receiving element 21a are arranged and the front surface S1 is defined as the first optical axis A1, and an orthogonal axis orthogonal to the first optical axis A1 on the front surface S1 is defined as the second optical axis A2, the third spot diameter SD3 along the first optical axis A1 of the laser light and the fourth spot diameter SD4 along the second optical axis A2 of the laser light have a relationship of SD3 < SD4. Since the shape of the spot LS of the laser light is not circular and the third spot diameter SD3 is smaller than the fourth spot diameter SD4, a decrease in the detection accuracy of the light detection signal due to interference light can be suppressed. Since the shape of the spot LS is such that the fourth spot diameter SD4 is larger than the third spot diameter SD3, a decrease in the light amounts of the scattered light SL and the reflected light RL can be suppressed.

[0087] The measuring device 100 has a housing 1 that houses the laser emitting element 11, the first light receiving element 21a, and the second light receiving element 21b. The housing 1 has a housing opening 1c at a position facing the user M, and the cover glass 5 is attached to the housing opening 1c. Since the cover glass 5 has a function of separating the reflected light RL and the transmitted light TL, the optical branching element 27 can be omitted.

[0088] Fig. 12 shows an enlarged configuration of reflected light RL in the vicinity of the cover glass 5. Fig. 12 omits the laser light emitting element 11, the first light receiving element 21a, the second light receiving element 21b, the condenser lens 25, the reflecting mirror 29, the transmitted light TL, and the scattered light SL. Fig. 12 shows a schematic configuration of the front surface reflected light RL1 and the back surface reflected light RL2 in the vicinity of the cover glass 5. Fig. 12 shows the second incident angle θ2 of the emitted light OL, the second glass thickness t2 of the cover glass 5, and the third spot diameter SD3.

[0089] FIG. 12 shows a state in which the third spot diameter SD3 satisfies the relationship of the following formula (2). SD3<(t2×sinθ2) / n2 (2) When the third spot diameter SD3 is a diameter having the relationship of formula (2), the front surface reflected light RL1 and the back surface reflected light RL2 do not overlap as shown in Fig. 12. An overlapping area DA where the front surface reflected light RL1 and the back surface reflected light RL2 overlap is not formed. The occurrence of interference light between the front surface reflected light RL1 and the back surface reflected light RL2 is suppressed. The decrease in detection accuracy of the light detection signal due to interference light between the front surface reflected light RL1 and the back surface reflected light RL2 is further suppressed.

[0090] Third embodiment The third embodiment illustrates a system for analyzing biological information using a measurement system 1000. The measurement device 100 transmits a light detection signal to a tablet terminal 200. The measurement device 100 may transmit a first electrical signal and a second electrical signal to the tablet terminal 200. The tablet terminal 200 calculates the biological information using the light detection signal. Alternatively, the tablet terminal 200 calculates the biological information using the first electrical signal and the second electrical signal. The tablet terminal 200 analyzes the biological information and displays the analysis result on a display 210.

[0091] 13 shows a schematic configuration of a measurement system 1000. The measurement system 1000 measures blood flow, blood volume, blood flow velocity, pulse rate, etc. The measurement system 1000 evaluates heart rate, blood pressure, etc. using the measurement results. As an example, the measurement system 1000 evaluates blood pressure, etc. using blood flow as an index. The measurement system 1000 corresponds to an example of a biological information measurement system.

[0092] The measurement system 1000 includes a measurement device 100 and a tablet terminal 200. The measurement device 100 and the tablet terminal 200 are communicatively connected. The measurement system 1000 shown in FIG. 13 communicatively connects the measurement device 100 and the tablet terminal 200 wirelessly. The connection between the measurement device 100 and the tablet terminal 200 is not limited to wireless. The measurement device 100 and the tablet terminal 200 may be communicatively connected by wire. The tablet terminal 200 corresponds to an example of a control device.

[0093] FIG. 14 shows a block configuration of a measurement system 1000. The measurement system 1000 includes a measurement device 100 and a tablet terminal 200. The configuration of the measurement device 100 shown in FIG. 14 is the same as that of the measurement device 100 shown in FIG. 3, except for the function of the data processing unit 33. The detection unit 3 of the measurement device 100 has a light branching element 27. The optical configuration of the measurement device 100 is the same as that shown in FIG. 5. The laser light emitting element 11 emits laser light having a relationship of first spot diameter SD1<second spot diameter SD2 toward the user M. The laser light emitting element 11 may emit laser light having the relationship of the above formula (1) toward the user M.

[0094] The data processing unit 33 receives the light detection signal transmitted from the signal converting unit 23. The data processing unit 33 causes the light detection signal to be transmitted to the tablet terminal 200 via the communication interface 50. The data processing unit 33 causes the light detection signal to be transmitted to the tablet terminal 200 at a predetermined timing. The data processing unit 33 may transmit a plurality of light detection signals to the tablet terminal 200 as a light detection signal group. The data processing unit 33 may receive an electrical signal from the signal converting unit 23 and transmit it to the tablet terminal 200.

[0095] The tablet terminal 200 can calculate biological information such as blood volume. The tablet terminal 200 analyzes the biological information. The tablet terminal 200 analyzes the health condition of the user M based on the biological information. The tablet terminal 200 includes a display 210, a terminal control unit 220, a terminal memory 230, and a terminal communication interface 240.

[0096] The terminal control unit 220 is a terminal control controller that controls the operation of various units in the tablet terminal 200. The terminal control unit 220 analyzes the biometric information of the user M. As an example, the terminal control unit 220 is a terminal processor having a CPU. The terminal control unit 220 is composed of one or more processors. The terminal control unit 220 may have a semiconductor memory such as a RAM or a ROM. The semiconductor memory functions as a work area for the terminal control unit 220. The terminal control unit 220 functions as a data generation unit 221, an analysis unit 223, and a communication control unit 225 by executing an analysis application AP stored in the terminal memory 230. The terminal control unit 220 corresponds to an example of an analysis unit.

[0097] The data generating unit 221 is a functional unit that operates in the terminal control unit 220. The data generating unit 221 calculates biological information such as blood volume. When the data generating unit 221 acquires a light detection signal from the measurement device 100, the data generating unit 221 calculates the biological information using the light detection signal. The data generating unit 221 has the same function as the data processing unit 33 in the first embodiment, and calculates the biological information. The data generating unit 221 outputs the biological information to the analysis unit 223.

[0098] The analysis unit 223 is a functional unit that operates in the terminal control unit 220. The analysis unit 223 acquires the biometric information output from the data generation unit 221. The analysis unit 223 analyzes the health condition of the user M by analyzing the biometric information. The analysis unit 223 outputs the analysis result of the biometric information to the display 210. The analysis unit 223 may store the analysis result in the terminal memory 230. The analysis unit 223 may generate chart data using the biometric information. The analysis unit 223 outputs the generated chart data to the display 210. The display 210 displays various charts based on the chart data.

[0099] The communication control unit 225 is a functional unit that operates in the terminal control unit 220. The communication control unit 225 controls communication with the measurement device 100. The communication control unit 225 establishes a communication connection with the measurement device 100. The communication control unit 225 causes the measurement device 100 to transmit a light detection signal or a group of light detection signals at a predetermined timing. The communication control unit 225 may cause the measurement device 100 to transmit an electrical signal at a predetermined timing.

[0100] The terminal memory 230 stores various types of data. The terminal memory 230 stores control data for operating various units in the tablet terminal 200. The terminal memory 230 may store various analysis data analyzed by the terminal control unit 220. The terminal memory 230 stores an analysis application AP that runs on the terminal control unit 220.

[0101] The analysis application AP is executed by the terminal control unit 220 to operate various functional units. The analysis application AP causes the terminal control unit 220 to operate as a data generation unit 221, an analysis unit 223, and a communication control unit 225. The analysis application AP may cause the terminal control unit 220 to operate as a functional unit other than the data generation unit 221, the analysis unit 223, and the communication control unit 225.

[0102] The terminal communication interface 240 is a terminal interface circuit that communicates with the measuring device 100. The terminal communication interface 240 is connected to the measuring device 100 by wire or wirelessly according to a predetermined protocol. The terminal communication interface 240 includes, for example, a connection port for wired communication, an antenna for wireless communication, etc. The terminal communication interface 240 receives a light detection signal or a group of light detection signals. The terminal communication interface 240 transmits various control data for controlling the operation of the measuring device 100, information related to the user M, etc. to the measuring device 100. The terminal communication interface 240 may communicate with an external device other than the measuring device 100. The terminal communication interface 240 corresponds to an example of a terminal communication unit.

[0103] The measurement system 1000 includes a measuring device 100 and a tablet terminal 200. The measuring device 100 includes a laser emitting element 11 that emits laser light to the user M, an optical branching element 27 that reflects a part of the laser light and separates it into a reflected light RL and a transmitted light TL, a first light receiving element 21a that detects the reflected light RL and generates a first electrical signal, a second light receiving element 21b that detects scattered light SL generated when the transmitted light TL enters the user M and generates a second electrical signal, a differential amplifier 24 that inputs the first electrical signal and the second electrical signal and generates a light detection signal, and a communication interface 50 that transmits the light detection signal. The tablet terminal 200 includes a terminal communication interface 240 that receives the light detection signal, and a terminal control unit 220 that analyzes the biological information of the user M using the light detection signal. The optical branching element 27 has a surface S1 on which the laser light is incident and a back surface S2 on which the laser light incident on the surface S1 is incident. When a parallel axis parallel to the intersection line IL between the incident surface IS where the laser emitting element 11 and the first light receiving element 21a are arranged and the surface S1 is defined as the first optical axis A1, and an orthogonal axis orthogonal to the first optical axis A1 on the surface S1 is defined as the second optical axis A2, the first spot diameter SD1 along the first optical axis A1 of the laser light and the second spot diameter SD2 along the second optical axis A2 of the laser light have a relationship of SD1 < SD2. The shape of the laser light spot LS is not circular, and the first spot diameter SD1 is smaller than the second spot diameter SD2, thereby suppressing a decrease in the detection accuracy of the light detection signal due to interference light. The shape of the spot LS is such that the second spot diameter SD2 is larger than the first spot diameter SD1, thereby suppressing a decrease in the light intensity of the scattered light SL and the reflected light RL. [Explanation of symbols]

[0104] 1...housing, 1a...measurement surface, 1b...display surface, 1c...housing opening, 2...belt, 3...detection unit, 4...display unit, 5...cover glass, 10...light-emitting element unit, 11...laser light-emitting element, 13...drive circuit, 20...light-receiving element unit, 21...light-receiving element, 21a...first light-receiving element, 21b...second light-receiving element, 23...signal conversion unit, 24...differential amplifier, 25...condensing lens, 27...light branching element, 29...reflection mirror, 30...control unit, 31...detection control unit, 33...data processing unit, 35...display control unit, 40...memory, 50...communication interface, 60...glass member, 100...measuring device, 200...tablet terminal, 210...display, 220...terminal control unit unit, 221...data generation unit, 223...analysis unit, 225...communication control unit, 230...terminal memory, 240...terminal communication interface, 1000...measurement system, A1...first optical axis, A2...second optical axis, A3...third optical axis, AP...analysis application, DA...overlapping area, IL...intersection line, IS...incident surface, LS...spot, M...user, OL...outgoing light, RL...reflected light, RL1...front surface reflected light, RL2...rear surface reflected light, S1...front surface, S2...rear surface, SD1...first spot diameter, SD2...second spot diameter, SD3...third spot diameter, SD4...fourth spot diameter, SL...scattered light, t1...first glass thickness, t2...second glass thickness, TL...transmitted light, θ1...first incident angle, θ2...second incident angle.

Claims

1. a light emitting unit that emits laser light onto a living body; a light transmitting member that reflects a part of the laser light and separates it into a first light beam and a second light beam; a first light receiving unit that detects the first light beam; a second light receiving unit that detects scattered light generated when the second light beam is incident on the living body; Preparation, the light transmitting member has a first surface onto which the laser light is incident and a second surface onto which the laser light incident on the first surface is incident, When a parallel axis parallel to an intersection line between an incident surface on which the light emitting unit and the first light receiving unit are arranged and the first surface is defined as a first axis, and an orthogonal axis orthogonal to the first axis on the first surface is defined as a second axis, a first diameter D1 of the laser light along the first axis and a second diameter D2 of the laser light along the second axis are defined as follows: D1 < D2 and The first diameter D1, the incident angle θ of the laser light to the first surface, the thickness t of the light transmitting member, and the refractive index n of the light transmitting member are expressed as follows: D1<(t×sinθ) / n have a relationship of Biometric information measuring device.

2. a differential circuit that receives a first detection signal obtained by receiving the first light beam at the first light receiving unit and a second detection signal obtained by receiving the scattered light at the second light receiving unit; a calculation unit that calculates biological information using an output signal output from the differential circuit; Equipped with The biological information measuring device according to claim 1 .

3. a case that houses the light emitting unit, the first light receiving unit, and the second light receiving unit; the case has a passage opening at a position facing the living body, The light transmitting member is attached to the passage opening. The biological information measuring device according to claim 1 .

4. a band attached to the case and wrapped around the living body; the band is attached parallel or approximately parallel to the arrangement direction of the light-emitting unit and the second light-receiving unit; The biological information measuring device according to claim 3 .

5. a light-emitting unit that emits laser light to a living body; a light-transmitting member that reflects a portion of the laser light and separates it into a first light beam and a second light beam; a first light-receiving unit that detects the first light beam and generates a first detection signal; a second light-receiving unit that detects scattered light generated when the second light beam is incident on the living body and generates a second detection signal; a differential circuit that receives as input the first detection signal and the second detection signal and generates an output signal; and a communication unit that transmits the output signal; a control device including a terminal communication unit that receives the output signal and an analysis unit that analyzes biometric information of the living body using the output signal; the light transmitting member has a first surface onto which the laser light is incident and a second surface onto which the laser light incident on the first surface is incident, When a parallel axis parallel to an intersection line between an incident surface on which the light emitting unit and the first light receiving unit are arranged and the first surface is defined as a first axis, and an orthogonal axis orthogonal to the first axis on the first surface is defined as a second axis, a first diameter D1 of the laser light along the first axis and a second diameter D2 of the laser light along the second axis are defined as follows: D1 < D2 and The first diameter D1, the incident angle θ of the laser light to the first surface, the thickness t of the light transmitting member, and the refractive index n of the light transmitting member are expressed as follows: D1<(t×sinθ) / n have a relationship of Biometric information measurement system.

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