JP2018061675A - Detector and measuring device - Google Patents

Abstract

A detection device capable of improving the utilization efficiency of light emitted to a living body is provided.
A light emitting unit that emits light to a living body, a light receiving unit that receives light from the living body, a reflecting unit that reflects light emitted from the light emitting unit toward the living body, and a light that travels toward the light receiving unit. A detection apparatus comprising: a shielding body 50 integrally formed with a light shielding portion 64 that shields a part of the light.
[Selection] Figure 3

Description

  The present invention relates to a technique for measuring biological information.

  Various measurement techniques for non-invasively measuring biological information such as pulse waves have been proposed. For example, in Patent Document 1, in a pulse wave sensor including a light emitting element that emits light to a living body and a light receiving element that receives light arriving from the living body by light emission of the light emitting element, between the light emitting element and the light receiving element, The structure which installed the light-shielding member is disclosed.

JP 2001-61796 A

  By the way, for example, in order to realize downsizing or portability of a device for measuring biological information, it is important to reduce power consumption. Therefore, it is required to increase the proportion of light that actually passes through the living body and reaches the light receiving element (that is, light use efficiency) out of the light emitted from the light emitting element. In view of the above circumstances, an object of the present invention is to improve the utilization efficiency of light emitted to a living body.

  In order to solve the above problems, a detection device according to a first aspect of the present invention includes a light emitting unit that emits light to a living body, a light receiving unit that receives light from the living body, and light emitted from the light emitting unit. And a shielding body in which a light-shielding portion that shields part of the light traveling toward the light-receiving portion is integrally formed. In the above aspect, since the reflection part that reflects the light emitted from the light emitting part to the living body is installed, it is possible to improve the utilization efficiency of the light emitted to the living body. Further, since the reflecting portion and the light shielding portion are integrally formed, there is an advantage that the configuration of the detection apparatus is simplified as compared with a configuration in which the reflecting portion and the light shielding portion are formed separately.

  In a preferred example of the first aspect, the light shielding portion is a plate-like portion located between the light receiving portion and the living body, and has an opening through which light from the living body toward the light receiving portion passes. In the above aspect, since the light shielding part in which the opening is formed is installed, for example, stray light that travels toward the light receiving part without passing through the living body is blocked by the light shielding part. Therefore, it is possible to detect light from a living body under a high S / N ratio.

  In a preferred example of the first aspect, the light emitting unit includes a first light emitting element and a second light emitting element that emit light having different wavelengths, and the light receiving unit is emitted from the living body by light emission of the first light emitting element. A first light receiving element that receives incoming light; and a second light receiving element that receives light arriving from the living body by light emission of the second light emitting element, wherein the shield includes the first light receiving element and the first light receiving element. The partition part located between 2 light receiving elements is included, and the said reflection part, the said light-shielding part, and the said partition part are integrally formed. In the above aspect, since the partition part between the first light receiving element and the second light receiving element is formed integrally with the reflection part and the light shielding part, the partition part separate from the reflection part and the light shielding part is installed. There is an advantage that the configuration of the detection apparatus is simplified as compared with the above.

  In a preferred example of the first aspect, the reflecting portion includes a first side wall portion positioned on the light receiving portion side as viewed from the light emitting portion, and a second side wall portion positioned on the side opposite to the light receiving portion as viewed from the light emitting portion. The angle of the first side wall part with respect to a reference direction perpendicular to the substrate on which the light emitting part is mounted is greater than the angle of the second side wall part with respect to the reference direction. In the above aspect, since the angle of the first side wall portion with respect to the reference direction exceeds the angle of the second side wall portion, it is possible to improve the utilization efficiency of the light emitted to the living body.

  The detection device according to the second aspect of the present invention includes a light emitting unit that emits light to a living body, a light receiving unit that receives light from the living body, and a reflecting unit that reflects light emitted from the light emitting unit to the living body side. And the reflection part includes a first side wall part located on the light receiving part side as seen from the light emitting part and a second side wall part located on the opposite side to the light receiving part as seen from the light emitting part. The angle of the first side wall with respect to a reference direction perpendicular to the substrate on which the light emitting unit is mounted is greater than the angle of the second side wall with respect to the reference direction. In the above aspect, since the reflection part that reflects the light emitted from the light emitting part to the living body is installed, it is possible to improve the utilization efficiency of the light emitted to the living body. And since the angle of the 1st side wall part with respect to a reference direction exceeds the angle of the 2nd side wall part, compared with the composition where the angle of the 1st side wall part is less than the angle of the 2nd side wall part, the light which the light-emitting part emitted The above-mentioned effect of improving the utilization efficiency is particularly remarkable.

  In a preferred example of the second aspect, the angle of the first side wall portion with respect to the reference direction is 15 ° or more and 45 ° or less (more preferably 25 ° or more and 35 ° or less). The angle of the second side wall portion with respect to the reference direction is not less than 0 ° and not more than 15 ° (more preferably 0 °). According to the above aspect, the above-mentioned effect that the utilization efficiency of the light emitted from the light emitting unit is improved is particularly remarkable.

  In a preferred example of the second aspect, the light emitting unit includes a plurality of light emitting elements arranged in a first direction, and the reflecting unit is viewed from the light emitting element of the plurality of light emitting elements in the first direction. A third side wall located on the center line side of the shield along a second direction perpendicular to the first side, and a fourth side wall located on the side opposite to the third side wall as viewed from the one light emitting element. In addition, an angle of the third sidewall portion with respect to the reference direction is greater than an angle of the fourth sidewall portion with respect to the reference direction. For example, the angle of the third side wall portion with respect to the reference direction is 20 ° or more and 40 ° or less, and the angle of the fourth side wall portion with respect to the reference direction is 0 ° or more and 20 ° or less. According to the above aspect, the above-mentioned effect that the utilization efficiency of the light emitted from the light emitting unit is improved is particularly remarkable.

  A measurement apparatus according to a preferred aspect of the present invention includes the detection apparatus according to any one of the above-described aspects, and an information analysis unit that specifies biological information from a detection signal indicating a detection result by the detection apparatus.

It is a side view of the measuring device concerning a 1st embodiment of the present invention. It is a block diagram of a measuring device. It is a top view of a detection apparatus. It is sectional drawing of a detection apparatus. It is sectional drawing of a shield. It is a simulation result of the relationship between the angle of a side wall part and received light intensity. It is a top view of the detecting device in a 2nd embodiment. It is sectional drawing of the detection apparatus in 2nd Embodiment. It is a simulation result of the relationship between the angle of the side wall part and light reception intensity in 2nd Embodiment. It is a top view of the detecting device in a 3rd embodiment. It is sectional drawing of the detection apparatus in 3rd Embodiment. It is a simulation result of the relationship between the angle of the side wall part and light reception intensity in 3rd Embodiment. It is sectional drawing of the detection apparatus in a modification.

<First Embodiment>
FIG. 1 is a side view of a measuring apparatus 100 according to the first embodiment of the present invention. The measurement apparatus 100 according to the first embodiment is a biological measurement device that non-invasively measures biological information of a subject, which is an example of a living body, and a part to be measured in the body of the subject (hereinafter referred to as “measurement part”). Attach to M. The measuring apparatus 100 according to the first embodiment is a wristwatch-type portable device including a casing 12 and a belt 14, and a belt-like belt 14 that is an example of the measurement site M is wound around the wrist to wrap the subject. Can be worn on the wrist. In 1st Embodiment, a test subject's pulse wave (for example, pulse rate) and oxygen saturation (SpO2) are illustrated as biometric information. The pulse wave means a time change of the volume in the blood vessel linked to the heartbeat. The oxygen saturation means a ratio (%) of hemoglobin combined with oxygen in hemoglobin in the blood of the subject, and is an index for evaluating the respiratory function of the subject.

  FIG. 2 is a configuration diagram focusing on the function of the measuring apparatus 100. As illustrated in FIG. 2, the measurement apparatus 100 according to the first embodiment includes a control device 20, a storage device 22, a display device 24, and a detection device 30. The control device 20 and the storage device 22 are installed inside the housing unit 12. As illustrated in FIG. 1, the display device 24 (for example, a liquid crystal display panel) is installed on the surface of the housing 12 opposite to the measurement site M, and various images including measurement results are displayed by the control device 20. Display under control.

  The detection device 30 in FIG. 2 is an optical sensor module that generates a detection signal D according to the state of the measurement site M. For example, the surface of the housing 12 facing the measurement site M (hereinafter referred to as “detection surface”). 16 is installed. The detection surface 16 is a surface that contacts the measurement site M. As illustrated in FIG. 2, the detection device 30 of the first embodiment includes a light emitting unit 32, a light receiving unit 34, a drive circuit 36, and an output circuit 38. One or both of the drive circuit 36 and the output circuit 38 can be installed as an external circuit of the detection device 30. That is, the drive circuit 36 and the output circuit 38 can be omitted from the detection device 30.

  The light emitting unit 32 is a light source that emits light to the measurement site M. The light emitting section 32 of the first embodiment includes a plurality of light emitting elements E (E1, E2, E3) that emit light of different wavelengths. Specifically, the light emitting element E1 emits green light (wavelength: 520 nm to 550 nm) to the measurement site M. The light emitting element E2 emits red light (wavelength: 600 nm to 800 nm) to the measurement site M, and the light emitting element E3 emits near infrared light (wavelength: 800 nm to 1300 nm) to the measurement site M. For example, a bare chip type LED (Light Emitting Diode) is suitably employed as the light emitting element E, but a bullet type LED may be used as the light emitting element E. The light emitting element E1 is an example of a first light emitting element, and the light emitting element E2 and the light emitting element E3 are examples of a second light emitting element. In addition, the wavelength of the light which each light emitting element E radiate | emits is not limited to the above illustration.

  The drive circuit 36 causes each of the plurality of light emitting elements E to emit light by supplying a drive current. The drive circuit 36 of the first embodiment causes each of the plurality of light emitting elements E to emit light periodically in a time division manner. The light emitted from each light emitting element E enters the measurement site M and is repeatedly reflected and scattered inside the measurement site M, then exits to the housing unit 12 side and reaches the light receiving unit 34. That is, the detection device 30 of the first embodiment is a reflective optical sensor in which the light emitting unit 32 and the light receiving unit 34 are located on one side with respect to the measurement site M.

  The light receiving unit 34 receives light coming from the measurement site M by the light emission of the light emitting unit 32. The light receiving unit 34 of the first embodiment includes a plurality of light receiving elements R (R1, R2). Each light receiving element R generates a detection signal corresponding to the intensity of light incident on the light receiving surface. For example, a photodiode (PD: Photo Diode) is preferably used as the light receiving element R. The light receiving element R1 (illustrated as the first light receiving element) receives the green light emitted from the light emitting element E1 and passed through the measurement site M, and generates a detection signal corresponding to the received light intensity. The light receiving element R2 (an example of the second light receiving element) is red light that has exited from the light emitting element E2 and passed through the measurement site M, or near red that has exited from the light emitting element E3 and passed through the inside of the measurement site M. External light is received and a detection signal corresponding to the received light intensity is generated.

  The output circuit 38 includes, for example, an A / D converter that converts the detection signal generated by each light receiving element R from analog to digital, and an amplification circuit that amplifies the converted detection signal (both not shown). ), A plurality of detection signals D (D1, D2, D3) corresponding to different wavelengths are generated. The detection signal D1 is a signal representing the light reception intensity of the light receiving element R1 when the light emitting element E1 emits green light. The detection signal D2 is a signal representing the light reception intensity of the light receiving element R2 when the light emitting element E2 emits red light, and the detection signal D3 is the signal of the light receiving element R2 when the light emitting element E3 emits near infrared light. It is a signal representing the received light intensity. Since the amount of light absorbed by blood differs between when the blood vessel is dilated and when it is contracted, each detection signal D includes a pulse that includes a periodic fluctuation component corresponding to the pulsation component (volume pulse wave) of the artery inside the measurement site M. It is a wave signal.

  The control device 20 of FIG. 2 is an arithmetic processing device such as a CPU (Central Processing Unit) or an FPGA (Field-Programmable Gate Array), and controls the entire measuring device 100. The storage device 22 is configured by, for example, a nonvolatile semiconductor memory, and stores a program executed by the control device 20 and various data used by the control device 20. A configuration in which the functions of the control device 20 are distributed over a plurality of integrated circuits, or a configuration in which some or all of the functions of the control device 20 are realized with dedicated electronic circuits may be employed. In FIG. 2, the control device 20 and the storage device 22 are illustrated as separate elements. However, the control device 20 including the storage device 22 can be realized by, for example, an ASIC (Application Specific Integrated Circuit) or the like. .

  The control device 20 of the first embodiment specifies the biological information of the subject from the plurality of detection signals D (D1, D2, D3) generated by the detection device 30 by executing the program stored in the storage device 22. . Specifically, the control device 20 specifies the pulse wave of the subject from the detection signal D1 indicating the received light intensity of green light by the light receiving element R1. For example, the pulse rate of the subject is specified from the detection signal D1. Further, the control device 20 analyzes the detection signal D2 indicating the received light intensity of the infrared light by the light receiving element R2 and the detection signal D3 indicating the received light intensity of the near infrared light by the light receiving element R2, thereby detecting the oxygen of the subject. Specify saturation. As understood from the above description, the control device 20 of the first embodiment functions as an information analysis unit that specifies biological information from the detection signal D indicating the detection result by the detection device 30. The control device 20 causes the display device 24 to display the biological information specified from the detection signal D. It is also possible to notify the user of the measurement result by voice output. A configuration in which a warning (possibility of physical function failure) is notified to the user when the pulse rate or oxygen saturation changes to a value outside the predetermined range is also suitable.

  3 is a plan view of the detection device 30, and FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. As illustrated in FIGS. 3 and 4, an X direction, a Y direction, and a Z direction that are orthogonal to each other are assumed. The XY plane is a plane parallel to the detection surface 16, and the Z direction (example of the reference direction) is a direction perpendicular to the XY plane. The direction of the normal line on the surface of the measurement site M that contacts the detection surface 16 can also be expressed as the Z direction. As illustrated in FIG. 3 and FIG. 4, the detection device 30 of the first embodiment includes a light receiving unit 32 and a light receiving unit 34 illustrated in FIG. 2, a container 40, a mounting substrate 46, a shield 50, and a protective plate. 60.

  The container 40 is a structure that houses each element (the light emitting unit 32, the light receiving unit 34, the mounting substrate 46, and the shield 50) of the detection device 30. Specifically, the container 40 is a box-shaped member including a rectangular flat plate-shaped bottom surface portion 42 and a rectangular frame-shaped side surface portion 44 protruding from the periphery of the bottom surface portion 42 to the positive side in the Z direction. The inner peripheral surface of the side surface portion 44 has a light shielding property. For example, the inner peripheral surface of the side surface 44 is colored black by anodizing the container 40 made of aluminum. That is, reflection on the inner peripheral surface of the side surface portion 44 is suppressed. In addition, the material and manufacturing method of the container 40 are arbitrary. For example, the container 40 can be formed by injection molding of a resin material. A configuration in which the container 40 is formed integrally with the housing 12 is also suitable.

  The mounting board 46 is a wiring board on which a plurality of wirings are formed. As illustrated in FIG. 4, the light emitting unit 32 (light emitting element E) and the light receiving unit 34 (light receiving element R) are mounted on the surface of the mounting substrate 46. The mounting substrate 46 is installed inside the housing 40 in a state where the surface on which the light emitting unit 32 and the light receiving unit 34 are mounted is parallel to the XY plane. As understood from the above description, the direction perpendicular to the mounting substrate 46 (the direction of the normal to the mounting surface) can be grasped as the Z direction.

  Specifically, each light emitting element E (E1, E2, E3) of the light emitting unit 32 is mounted on the surface of the mounting substrate 46 in a state where the irradiation surface (for example, the surface of the bare chip) is parallel to the XY plane. . As understood from the above description, the direction perpendicular to the irradiation surface of the light emitting element E can be grasped as the Z direction (example of the reference direction). Further, in the configuration in which the LED is used as the light emitting element E, for example, the direction in which the p-type semiconductor layer and the n-type semiconductor layer are stacked can be grasped as the Z direction.

  As illustrated in FIG. 3, in the first embodiment, a plurality of light emitting elements E (E 1, E 2, E 3) are arranged in the X direction (illustrated in the first direction) at intervals. Specifically, a light emitting element E2 that emits red light is installed on the negative side in the X direction when viewed from the light emitting element E1 that emits green light. The light emitting element E3 that emits near-infrared light is disposed on the opposite side of the light emitting element E2 with the light emitting element E1 interposed therebetween. That is, the light emitting element E1 is located between the light emitting element E2 and the light emitting element E3.

  Each light receiving element R (R1, R2) of the light receiving unit 34 is mounted on the surface of the mounting substrate 46 in a state where the light receiving surface is parallel to the XY plane. As understood from the above description, the direction perpendicular to the light receiving surface of the light receiving element R can be grasped as the Z direction (example of the reference direction). The plurality of light receiving elements R of the first embodiment are arranged in the Y direction (exemplification of the second direction) at intervals. Specifically, the light receiving element R1 is positioned on the positive side in the Y direction when viewed from the plurality of light emitting elements E, and the light receiving element R2 is positioned on the opposite side of the plurality of light emitting elements E across the light receiving element R1. The drive circuit 36 and the output circuit 38 can be mounted on the mounting board 46 in the form of an IC chip. However, as described above, the drive circuit 36 and the output circuit 38 can be installed outside the detection device 30.

  The shield 50 is a structure including the reflection part 52, the light shielding part 54, and the partition part 56, and overlaps the mounting substrate 46 (or the bottom part 42 of the container 40) when viewed from the Z direction. The reflection part 52, the light-shielding part 54, and the partition part 56 are integrally formed. For example, a light-reflective shielding body 50 in which the reflecting portion 52, the light shielding portion 54, and the partition wall portion 56 are integrally formed by pressing a flat plate material made of stainless steel and having a thickness of about 0.1 mm. Is formed. In addition, the material and manufacturing method of the shield 50 are arbitrary. For example, a thin film made of a reflective material such as aluminum is formed on a part of the structure (reflecting portion 52) or the entire surface formed by injection molding of a resin material by a film forming technique such as vapor deposition or plating. It is also possible to form the body 50. As illustrated in FIG. 3 and FIG. 4, the reflection part 52 is located on the negative side in the Y direction when viewed from the light shielding part 54, and the partition wall part 56 is located on the opposite side of the reflection part 52 across the light shielding part 54.

  The reflecting part 52 is a part that reflects the light emitted from the light emitting part 32 (the plurality of light emitting elements E) toward the measurement site M, and as illustrated in FIGS. 3 and 4, the bottom part 72, the side wall part 74 </ b> A, And a side wall portion 74B. The bottom surface portion 72 is a flat plate-like portion that is long in the X direction. Since the surface on the negative side in the Z direction of the bottom surface portion 72 is in contact with the surface of the mounting substrate 46, the bottom surface portion 72 is maintained in a state parallel to the XY plane. As illustrated in FIGS. 3 and 4, a plurality of (three) openings 76 corresponding to different light emitting elements E are formed in the bottom surface portion 72. Each light emitting element E mounted on the mounting substrate 46 is positioned inside the opening 76 corresponding to the light emitting element E in the bottom surface portion 72. Therefore, the irradiation surface of each light emitting element E is exposed inside the opening 76.

  The side wall portion 74A (illustrated as the first side wall portion) continues to the peripheral edge on the positive side in the Y direction in the bottom surface portion 72, and the side wall portion 74B (illustrated as the second side wall portion) extends in the Y direction among the bottom surface portion 72. Continuing on the negative edge. That is, the side wall portion 74A is located on the light receiving portion 34 side (the positive side in the Y direction) when viewed from the light emitting portion 32, and the side wall portion 74B is the opposite side from the light receiving portion 34 as viewed from the light emitting portion 32 (the negative side in the Y direction). ). As illustrated in FIG. 4, the side wall portion 74A is a portion whose surface makes an angle θA (0 ° ≦ θA <90 °) with respect to the Z direction, and the side wall portion 74B has a surface having an angle with respect to the Z direction. This is a portion that forms θB (0 ° ≦ θB <90 °). As understood from the above description, the side wall portion 74A and the side wall portion 74B are installed so as to sandwich the light emitting portion 32. That is, the light emitting unit 32 (the plurality of light emitting elements E) is disposed on the bottom surface of the space surrounded by the side wall portions 74A and 74B of the shield 50 and the side surface portion 44 of the container 40. Each light emitting element E can be sealed (molded) by filling a light transmissive resin material between the side wall 74A and the side wall 74B.

  FIG. 5 is an explanatory diagram illustrating the relationship between the shield 50 and the light path. As illustrated in FIG. 5, the light emitted from the irradiation surface of each light emitting element E travels in the Z direction as illustrated by the arrow a0, and other than the Z direction as illustrated by the arrows a1 and a2. It also proceeds in the direction (direction inclined with respect to the Z direction). The light traveling from the light emitting element E in the direction of the arrow a1 is reflected to the measurement site M side on the surface of the side wall 74A. Similarly, light traveling from the light emitting element E in the direction of the arrow a2 is reflected to the measurement site M side on the surface of the side wall 74B. Therefore, according to the first embodiment, the proportion of light incident on the measurement site M (that is, light utilization efficiency) out of the light emitted from the light emitting unit 32 is improved as compared with the configuration in which the reflecting unit 52 is not installed. It is possible to make it.

  As illustrated in FIG. 3 and FIG. 4, the light shielding portion 54 of the shield 50 is a flat plate portion located between the light receiving element R 1 and the measurement site M and parallel to the XY plane. A rectangular opening 58 is formed in the light shielding portion 54 of the first embodiment. The opening 58 is a through hole formed in a region overlapping the light receiving element R1 when viewed from the Z direction. That is, the light receiving surface of the light receiving element R 1 is exposed inside the opening 58. In other words, the light-shielding portion 54 can be said to be a rectangular frame-shaped portion along the periphery of the light-receiving surface of the light-receiving element R1. As illustrated by the arrow b0 in FIG. 5, part of the light traveling toward the light receiving element R1 passes through the opening 58 and enters the light receiving surface of the light receiving element R1, but as indicated by the arrow b1, travels toward the light receiving element R1. The other part of the light is blocked by the light blocking portion 54. For example, stray light (for example, external light such as sunlight or illumination light) traveling toward the light receiving element R1 without passing through the measurement site M is blocked by the light shielding unit 54 and does not reach the light receiving element R1. The green light emitted from the light emitting element E1 passes through the inside of the measurement site M, passes through the opening 58 of the light shielding part 54, and enters the light receiving surface of the light receiving element R1.

  The partition wall 56 of the shield 50 is a flat plate portion located between the light receiving element R1 and the light receiving element R2. The partition wall portion 56 of the first embodiment is a portion of the light shielding portion 54 that protrudes from the peripheral edge on the positive side in the Y direction to the negative side in the Z direction, and the peripheral edge on the opposite side to the light shielding portion 54 is the surface of the mounting substrate 46. To touch. Accordingly, the partition wall 56 intersects the surface of the mounting substrate 46 perpendicularly. As understood from the above description, the partition wall 56 functions as a partition that partitions the space above the mounting substrate 46 into a space in which the light receiving element R1 is installed and a space in which the light receiving element R2 is installed.

  The protection plate 60 is a flat plate material that covers and protects the elements (the light emitting unit 32, the light receiving unit 34, the mounting substrate 46, and the shielding body 50) accommodated in the housing body 40, and against the light shielding unit 54 of the shielding body 50. Installed at intervals. That is, the light emitting unit 32, the light receiving unit 34, the mounting substrate 46, and the shield 50 are located between the protective plate 60 and the bottom surface 42 of the container 40. The distance between the protective plate 60 and the bottom surface portion 42 is, for example, about 1 mm. The surface on the positive side in the Z direction of the protection plate 60 is the detection surface 16 of FIG.

  As illustrated in FIGS. 3 and 4, the protection plate 60 of the first embodiment includes a light transmitting part 62 and a light shielding part 64. The light transmitting part 62 is a light transmitting part, and the light shielding part 64 is a light shielding part. For example, the protection plate 60 of the first embodiment can be formed by two-color molding using a light-transmitting resin material that becomes the light-transmitting portion 62 and a light-blocking resin material that becomes the light-blocking portion 64. As illustrated in FIG. 3, the light shielding portion 64 is formed between the reflecting portion 52 of the shield 50 and the opening 58 of the light shielding portion 54 in a plan view (that is, viewed from the positive side in the Z direction). It is a part that extends. The light transmitting part 62 is a part other than the light shielding part 64 in the protective plate 60.

  A buffer body 68 is installed between the protection plate 60 and the shield body 50 (the light shielding portion 54). The buffer body 68 is a member formed of a porous material such as a sponge, for example. The distance between the protective plate 60 and the shield 50 (that is, the height of the buffer body 68) is, for example, about 0.25 mm. When pressed by contact of the measurement site M with the detection surface 16, the protective plate 60 can be deformed. The buffer body 68 is a member for suppressing the protection plate 60 deformed by the contact of the measurement site M from colliding with the shield body 50. The buffer body 68 of the first embodiment is made of a light shielding material and extends in the X direction so as to overlap the light shielding portion 64 of the protection plate 60 when viewed from the Z direction. As understood from the above description, the light shielding part 64 and the buffer body 68 form a light shielding wall that is long in the X direction. As illustrated by an arrow c in FIG. 5, the light traveling directly from the light emitting unit 32 (that is, without entering the measurement site M) toward the light receiving unit 34 is blocked by the light shielding unit 64 and the buffer 68. . Therefore, it is possible to reduce the possibility that stray light that is emitted from the light emitting element E and does not enter the measurement site M reaches the light receiving unit 34.

  In the above configuration, the green light emitted from the light emitting element E1 proceeds to the measurement site M side directly or indirectly by reflection at the reflecting portion 52, and passes through the light transmitting portion 62 of the protective plate 60. Incident on the measurement site M. The green light emitted from the measurement site M to the negative side in the Z direction passes through the light transmitting portion 62 of the protection plate 60, passes through the opening 58 of the light shielding portion 54, and enters the light receiving element R1. On the other hand, the red light emitted from the light-emitting element E2 or the near-infrared light emitted from the light-emitting element E3 travels directly or indirectly to the measurement site M, and passes through the light transmitting portion 62 of the protective plate 60 for measurement. It enters the part M. Infrared light or near infrared light emitted from the measurement site M to the negative side in the Z direction passes through the light transmitting portion 62 of the protective plate 60 and enters the light receiving element R2.

  Next, from the viewpoint of improving the utilization efficiency of the light emitted from the light emitting element E, the angle θA of the side wall portion 74A and the angle θB of the side wall portion 74B with respect to the Z direction are examined. FIG. 6 is a chart showing the result of calculating the intensity of light reaching the light receiving element R2 from the light emitting element E2 by simulation for a plurality of cases in which each of the angle θA and the angle θB is changed. In FIG. 6, the light receiving intensity of the light receiving element R2 when the intensity of light emitted from the light emitting element E2 is 1 (W) is shown.

  As understood from FIG. 6, the side wall portion 74A located on the light receiving portion 34 side when viewed from the light emitting portion 32 has the light receiving element R2 when the angle θA is set to a value within the range of 15 ° to 40 °. There is a tendency that the received light intensity by becomes high. Considering the above tendency, the angle θA of the side wall portion 74A is set to 15 ° to 40 ° (15 ° ≦ θA ≦ 40 °), and more preferably set to 25 ° to 35 °. (25 ° ≦ θA ≦ 35 °).

  On the other hand, with respect to the side wall portion 74B located on the side opposite to the light receiving portion 34 when viewed from the light emitting portion 32, the light receiving intensity by the light receiving element R2 when the angle θB is set to a value within the range of 0 ° to 15 °. Tend to be higher. Considering the above tendency, the angle θB of the side wall 74B is set to 0 ° or more and 15 ° or less (0 ° ≦ θB ≦ 15 °). More preferably, the angle θB is set to 0 °. That is, a configuration in which the side wall portion 74B intersects the bottom surface portion 72 perpendicularly (projects from the bottom surface portion 72 to the negative side in the Z direction) is preferable.

  As understood from the above examples, a configuration in which the angle θA of the side wall portion 74A exceeds the angle θB of the side wall portion 74B is preferable. Specifically, the side wall portion 74A is inclined with respect to the Z direction by an angle θA within a range of 15 ° or more and 40 ° or less (more preferably 25 ° or more and 35 ° or less). A configuration parallel to the direction (θB = 0 °) is preferable. That is, in the first embodiment, the angle θA of the side wall portion 74A is different from the angle θB of the side wall portion 74B.

  As described above, in the first embodiment, since the reflecting portion 52 and the light shielding portion 54 are integrally formed, the detection device 30 is compared with a configuration in which the reflecting portion 52 and the light shielding portion 54 are formed separately. The configuration is simplified. Specifically, it is possible to reduce the number of parts of the detection device 30 and reduce the manufacturing cost of the detection device 30. In the first embodiment, in particular, the partition wall portion 56 positioned between the light receiving element R1 and the light receiving element R2 is also formed integrally with the reflecting portion 52 and the light shielding portion 54. Therefore, the reflecting portion 52 and the light shielding portion 54 are separated from each other. There is an advantage that the configuration of the detection device 30 is simplified compared to the configuration in which the partition wall portion 56 is installed.

  Further, in the first embodiment, since the light shielding portion 54 in which the opening 58 is formed is installed between the light receiving element R1 and the measurement site M, stray light (that travels toward the light receiving element R1 without passing through the measurement site M). For example, external light such as sunlight or illumination light) is blocked by the light shielding unit 54. Therefore, it is possible to generate the detection signal D having a high SN ratio.

  In the first embodiment, the angle θA of the side wall 74A with respect to the Z direction (reference direction) exceeds the angle θB of the side wall 74B. Therefore, as described with reference to FIG. 6, it is possible to improve the utilization efficiency of the light emitted from the light emitting unit 32. Particularly in the first embodiment, the angle θA of the side wall 74A is 15 ° to 40 ° (more preferably 25 ° to 35 °), and the angle θB of the side wall 74B is 0 ° to 15 °. The following (more preferably 0 °). Therefore, the above-described effect of improving the utilization efficiency of the light emitted from the light emitting unit 32 is particularly remarkable.

Second Embodiment
A second embodiment of the present invention will be described. In addition, about the element which an effect | action or function is similar to 1st Embodiment in each structure illustrated below, the code | symbol used by description of 1st Embodiment is diverted, and each detailed description is abbreviate | omitted suitably.

  FIG. 7 is a plan view of the detection device 30 in the second embodiment, and FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. As illustrated in FIGS. 7 and 8, the reflecting portion 52 of the shield 50 in the detection device 30 of the second embodiment includes a side wall portion 741a in addition to the side wall portion 74A and the side wall portion 74B similar to those of the first embodiment. And side wall part 741b, side wall part 742C and side wall part 742D, and side wall part 743C and side wall part 743D. The side wall portion 741a and the side wall portion 741b are inclined surfaces extending between the side wall portion 74A and the side wall portion 74B, and are located on both sides of the light emitting element E1 in the X direction. That is, the light emitting element E1 is positioned on the bottom surface of the space surrounded by the side wall portion 74A, the side wall portion 74B, the side wall portion 741a, and the side wall portion 741b. Similarly, the side wall part 742C and the side wall part 742D are formed at positions sandwiching the light emitting element E2 in the X direction, and surround the light emitting element E2 together with the side wall part 74A and the side wall part 74B. The side wall part 743C and the side wall part 743D are formed at positions sandwiching the light emitting element E3 in the X direction, and surround the light emitting element E3 together with the side wall part 74A and the side wall part 74B.

  From the viewpoint of improving the utilization efficiency of the light emitted from the light emitting element E2, the angle θC of the side wall portion 742C and the angle θD of the side wall portion 742D with respect to the Z direction (example of the reference direction) are examined. As illustrated in FIG. 7, a center line L of the shield 50 along the Y direction is assumed. The side wall portion 742C is a portion located on the center line L side as viewed from the light emitting element E2 (illustrative example of the third side wall portion), and the side wall portion 742D is a portion located on the side opposite to the center line L as viewed from the light emitting element E2. (Exemplary fourth side wall portion). FIG. 9 is a chart showing the result of calculating the intensity of light reaching the light receiving element R2 from the light emitting element E2 by simulation for a plurality of cases where the angle θC and the angle θD are changed. In FIG. 9, similarly to FIG. 6, the light receiving intensity of the light receiving element R2 when the intensity of light emitted from the light emitting element E2 is 1 (W) is shown.

  As can be understood from FIG. 9, with respect to the side wall portion 742C located on the center line L side as viewed from the light emitting element E2, when the angle θC is set to a value within the range of 20 ° to 40 °, the light receiving element R2 There is a tendency that the received light intensity by becomes high. Considering the above tendency, the angle θC of the side wall portion 742C is set to 20 ° or more and 40 ° or less (20 ° ≦ θC ≦ 40 °). More preferably, the angle θC is set to 40 °.

  On the other hand, with respect to the side wall portion 742D located on the side opposite to the center line L when viewed from the light emitting element E2, the intensity of light received by the light receiving element R2 when the angle θD is set to a value within the range of 0 ° to 20 °. Tend to be higher. Considering the above tendency, the angle θD of the side wall portion 742D is set to 0 ° or more and 20 ° or less (0 ° ≦ θD ≦ 20 °). More preferably, the angle θD is set to 0 °. That is, a configuration in which the side wall portion 742D intersects perpendicularly with respect to the bottom surface portion 72 (projects from the bottom surface portion 72 to the negative side in the Z direction) is preferable. As understood from the above examples, a configuration in which the angle θC of the side wall part 742C (example of the third side wall part) exceeds the angle θD of the side wall part 742D (example of the fourth side wall part) is suitable.

  A similar configuration is adopted for the light emitting element E3 that is symmetrical to the light emitting element E2 with the center line L in between. The side wall portion 743C corresponding to the light emitting element E3 is a portion (example of the third side wall portion) located on the center line L side as viewed from the light emitting element E3, and the side wall portion 743D is the center line L as viewed from the light emitting element E3. It is the part (example of the 4th side wall part) located in the other side. Similar to the relationship between the side wall portion 742C and the side wall portion 742D, the angle θC of the side wall portion 743C with respect to the Z direction (example of the reference direction) exceeds the angle θD of the side wall portion 743D (θC> θD). Specifically, the angle θC of the side wall portion 743C is set to 20 ° to 40 ° (more preferably 40 °), and the angle θD of the side wall portion 743D is set to 0 ° to 20 ° (more preferably). 0 °). In addition, the angle with respect to the Z direction is arbitrary for each of the side wall 741a and the side wall 741b corresponding to the light emitting element E1.

  The configuration in which the reflection portion 52, the light shielding portion 54, and the partition portion 56 are integrally formed, and the configuration in which the angle θA of the side wall portion 74A exceeds the angle θB of the side wall portion 74B are the same as in the first embodiment. Therefore, the same effects as those of the first embodiment are realized in the second embodiment. In the second embodiment, the angle θC of the side wall part 742C or the side wall part 743C exceeds the angle θD of the side wall part 742D or the side wall part 743D. Therefore, as described with reference to FIG. 9, it is possible to increase the utilization efficiency of the light emitted from the light emitting element E2 or the light emitting element E3. In the second embodiment, in particular, the angle θC of the side wall 742C or the side wall 743C is 20 ° or more and 40 ° or less, and the angle θD of the side wall 742D or the side wall 743D is 0 ° or more and 20 ° or less. Therefore, the above-described effect of improving the utilization efficiency of the light emitted from the light emitting element E2 or the light emitting element E3 is particularly remarkable.

<Third Embodiment>
FIG. 10 is a plan view of the detection device 30 according to the third embodiment, and FIG. 11 is a cross-sectional view taken along the line XI-XI in FIG. As illustrated in FIG. 10, the light emitting unit 32 of the detection device 30 in the third embodiment includes one light emitting element E that emits green light. The light receiving unit 34 includes one light receiving element R that receives green light coming from the measurement site M when the light emitting element E emits light. That is, the detection device 30 of the third embodiment has a configuration in which the light emitting element E2, the light emitting element E3, and the light receiving element R2 are omitted from the first embodiment. In addition, the wavelength of the light which the light emitting element E radiate | emits is not limited to the above illustration (green light).

  As in the first embodiment, the shielding body 50 is a structure in which the reflection portion 52, the light shielding portion 54, and the partition wall portion 56 are integrally formed. The reflection portion 52 includes the bottom surface portion 72, the side wall portion 74A, and the side wall. Part 74B. The angle θA of the side wall portion 74A and the angle θB of the side wall portion 74B with respect to the Z direction (example of the reference direction) will be examined below. FIG. 12 is a chart showing the result of calculating the intensity of light reaching the light receiving element R from the light emitting element E by simulation for a plurality of cases in which each of the angle θA and the angle θB is changed.

  As understood from FIG. 6, the side wall portion 74A located on the light receiving portion 34 side when viewed from the light emitting portion 32 has an angle θA with respect to the Z direction in the range of 15 ° or more and 40 ° or less, as in the first embodiment. A configuration set to a numerical value (more preferably in the range of 25 ° or more and 35 ° or less) is preferable. Similarly to the first embodiment, the angle θB of the side wall portion 74B located on the side opposite to the light receiving portion 34 when viewed from the light emitting portion 32 is within the range of 0 ° or more and 15 ° or less with respect to the angle θB with respect to the Z direction. A configuration set to a numerical value (more preferably 0 °) is preferable. As understood from the above illustration, also in the third embodiment, the angle θA of the side wall portion 74A exceeds the angle θB of the side wall portion 74B. In the third embodiment, the same effect as in the first embodiment is realized.

<Modification>
Each form illustrated above can be variously modified. Specific modifications are exemplified below. Two or more modes arbitrarily selected from the following examples can be appropriately combined.

(1) In each of the above-described embodiments, the configuration in which the reflection portion 52, the light shielding portion 54, and the partition wall portion 56 of the shielding body 50 are integrally formed is illustrated. However, the reflection portion 52 is formed separately from the light shielding portion 54. The structure which formed the partition part 56 separately from the light-shielding part 54 may be employ | adopted. The partition wall 56 can be omitted. Further, in each of the above-described embodiments, the entire shield 50 need not have light reflectivity. For example, a configuration in which only the surface on the measurement site M side of the reflecting portion 52 has light reflectivity may be employed. Further, instead of the partition wall portion 56 exemplified in each of the above-described embodiments (or together with the partition wall portion 56 exemplified in each of the above-described embodiments), the partition wall portion is formed on the reflection portion 52 side (for example, directly below the light shielding portion 64) as viewed from the opening 58. 56 can also be formed. In the above configuration, the part of the shielding body 50 exemplified in the above-described embodiments on the side opposite to the reflection part 52 when viewed from the opening 58 can be omitted.

(2) In each of the above-described embodiments, the measurement device 100 equipped with the detection device 30 is exemplified. However, as a device separate from the element (information analysis unit realized by the control device 20) that generates the biological information of the subject. It is also possible to configure the detection device 30. For example, the detection signal D (D1, D2, D3) generated by the detection device 30 is transmitted to an information device (for example, a mobile phone or a smartphone) by wire or wireless, and information is obtained by analyzing the detection signal D received from the detection device 30. The device generates biological information about the subject. That is, an information analysis unit that generates biological information from the detection signal D is realized by an information device (for example, a cooperation between an arithmetic processing unit such as a CPU and software such as application software). As understood from the above description, the detection device 30 is realized as a single device that generates the detection signal D, and is not an essential requirement until the generation of biological information. For example, the detection device 30 can be mounted on a back cover that can be attached to and detached from the casing 12 of the measurement device 100.

  In each of the above embodiments, the measurement apparatus 100 including the display device 24 is illustrated. However, the display device 24 may be separated from the measurement apparatus 100. For example, an information device display capable of wired or wireless communication with the measurement device 100 is used as the display device 24, and the biological information calculated by the control device 20 (information analysis unit) of the measurement device 100 is transmitted to the information device. It is also possible to display on the display device 24 of the information device.

(3) In each of the above-described embodiments, the detection surface 16 of the protection plate 60 is a flat surface. However, the detection surface 16 may be a curved surface. For example, as illustrated in FIG. 13, a configuration in which the detection surface 16 includes an arcuate projection (convex portion) with which the measurement site M contacts is also assumed. According to the configuration of FIG. 13, the surface of the measurement site M is sufficiently in close contact with the detection surface 16 (the gap between the measurement site M and the detection surface 16 is reduced). There is an advantage that the possibility of light scattering due to the gap between the surface 16 can be prevented. The protective plate 60 illustrated in FIG. 13 can be similarly applied to the second embodiment and the third embodiment.

(4) In each of the above-described embodiments, the measurement device 100 that can be mounted on the wrist of the subject has been exemplified. However, the specific configuration (mounting position) of the measurement device 100 is arbitrary. For example, a patch type that can be affixed to the subject's body, an earring type that can be attached to the subject's auricle, a finger-mounted type that can be attached to the subject's fingertips (for example, a fingernail type), and a head mount that can be attached to the subject's head Any type of measuring apparatus 100 such as a mold may be employed.

(5) In the above-described embodiments, the pulse wave (for example, pulse rate) and oxygen saturation of the subject are exemplified as the biological information, but the type of the biological information is not limited to the above examples. For example, a configuration that measures blood flow rate and blood pressure as biological information and a configuration that measures various blood component concentrations such as blood glucose concentration, hemoglobin concentration, blood oxygen concentration, and neutral fat concentration as biological information are also adopted. Can be done. In the configuration in which the blood flow velocity is measured as biological information, a laser irradiator that emits a narrow-band coherent laser beam emitted through resonance by the resonator is preferably used as the light emitting unit 32.

DESCRIPTION OF SYMBOLS 100 ... Measuring apparatus, 12 ... Housing | casing part, 14 ... Belt, 16 ... Detection surface, 20 ... Control apparatus, 22 ... Memory | storage device, 24 ... Display apparatus, 30 ... Detection apparatus, 32 ... Light-emitting part, 34 ... Light-receiving part, 36 ... Drive circuit, 38 ... Output circuit, 40 ... Container, 42 ... Bottom part, 44 ... Side part, 50 ... Shielding body, 52 ... Reflecting part, 54 ... Light shielding part, 56 ... Partition wall part, 58 ... Opening part, 60 ... protective plate, 62 ... translucent part, 64 ... light shielding part, 68 ... buffer, 72 ... bottom face part, 74A, 74B, 741a, 741b, 742C, 742D, 743C, 743D ... side wall part.

Claims (12)

A light emitting unit for emitting light to a living body;
A light receiving unit for receiving light from the living body;
A detection apparatus comprising: a reflection unit configured to reflect light emitted from the light emitting unit toward the living body; and a shielding body integrally formed with a light shielding unit configured to block a part of the light traveling toward the light receiving unit. The detection device according to claim 1, wherein the light shielding unit is a plate-like portion positioned between the light receiving unit and the living body, and has an opening through which light traveling from the living body toward the light receiving unit passes. The light emitting unit includes a first light emitting element and a second light emitting element that emit light having different wavelengths,
The light receiving unit includes a first light receiving element that receives light coming from the living body by light emission of the first light emitting element, and a second light receiving element that receives light coming from the living body by light emission of the second light emitting element. Including
The shield includes a partition wall portion located between the first light receiving element and the second light receiving element,
The detection device according to claim 1, wherein the reflection portion, the light shielding portion, and the partition wall portion are integrally formed. The reflective portion is
A first side wall portion located on the light receiving portion side when viewed from the light emitting portion;
A second side wall portion located on the opposite side of the light receiving portion as seen from the light emitting portion,
The detection device according to any one of claims 1 to 3, wherein an angle of the first side wall portion with respect to a reference direction perpendicular to a substrate on which the light emitting unit is mounted is greater than an angle of the second side wall portion with respect to the reference direction. A light emitting unit for emitting light to a living body;
A light receiving unit for receiving light from the living body;
A reflection part that reflects the light emitted from the light emitting part to the living body side;
The reflective portion is
A first side wall portion located on the light receiving portion side when viewed from the light emitting portion;
A second side wall portion located on the opposite side of the light receiving portion as seen from the light emitting portion,
An angle of the first side wall portion with respect to a reference direction perpendicular to the substrate on which the light emitting unit is mounted exceeds an angle of the second side wall portion with respect to the reference direction. The detection device according to claim 4 or 5, wherein an angle of the first side wall portion with respect to the reference direction is not less than 15 ° and not more than 45 °. The detection device according to claim 6, wherein an angle of the first side wall portion with respect to the reference direction is not less than 25 ° and not more than 35 °. The detection device according to any one of claims 4 to 7, wherein an angle of the second side wall portion with respect to the reference direction is not less than 0 ° and not more than 15 °. The detection device according to claim 8, wherein an angle of the second side wall portion with respect to the reference direction is 0 °. The light emitting unit includes a plurality of light emitting elements arranged in a first direction,
The reflecting portion is a third side wall portion located on the center line side of the shield along a second direction perpendicular to the first direction when viewed from one light emitting element of the plurality of light emitting elements; A fourth side wall located on the opposite side of the third side wall as viewed from one light emitting element,
The detection device according to claim 4, wherein an angle of the third side wall portion with respect to the reference direction is greater than an angle of the fourth side wall portion with respect to the reference direction. The angle of the third side wall portion with respect to the reference direction is 20 ° or more and 40 ° or less,
The detection device according to claim 10, wherein an angle of the fourth side wall portion with respect to the reference direction is not less than 0 ° and not more than 20 °. The detection device according to any one of claims 1 to 11,
A measurement apparatus comprising: an information analysis unit that identifies biological information from a detection signal indicating a detection result by the detection apparatus.

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