MEASURING DEVICE FOR BIOLOGICAL COMPONENTS

Abstract

Measuring device (1c, 1d) for biological components for measuring a component using heat generation of a biological sample (5) that absorbs excitation light (17), wherein the measuring device (1c, 1d) for biological components has the following: an optical medium (10) which has a sample support surface (12) on which the biological sample (5) is arranged, wherein the optical medium (10) is transparent to the excitation light (17) and is made of chalcogenide glass which has a lower thermal conductivity than zinc sulfide, and a refractive index of the optical medium (10) is changed by the heat generation of the biological sample (5) which absorbs the excitation light (17); an excitation light source (16) for emitting the excitation light (17), which moves through the optical medium (10) in the direction of the sample support surface (12); a scanning light source (20) for emitting scanning light (21) which moves through the optical medium (10), a light position detector (25) for detecting the position of the scanning light (21) emerging from the optical medium (10), and a temperature sensor (35) for measuring the temperature of the optical medium (10), wherein the optical medium (10) is also transparent to the scanning light (21), wherein the light position detector (25) detects a first position (22a) of the scanning light (21) exiting the optical medium (10) when the excitation light source (16) does not emit excitation light (17), and a second position (22b) of the scanning light (21) exiting the optical medium (10) in which a refractive index gradient region (18) is generated by the heat generation caused by the excitation light (17) when the excitation light source (16) emits the excitation light (17), where the component is measured based on the first position (22a) and the second position (22b), and wherein the temperature sensor (35) is attached to an area of ​​the sample support surface (12), wherein the area is away from the biological sample (5), the excitation light (17) and the scanning light (21).

Description

TECHNICAL FIELD

[0001] The present invention relates to a measuring device for biological components. STATE OF THE ART

[0002] National Patent Application JP 2017-519214 A (PTL 1) discloses a non-invasive analysis system comprising an optical medium, an infrared light source, a scanning light source, and a photodiode. Specifically, a biological sample is placed on a surface of the optical medium. The infrared light source emits infrared light. The infrared light travels through the optical medium to illuminate the biological sample. The infrared light is absorbed by the biological sample, causing the biological sample to generate heat. The amount of absorption heat of the biological sample varies depending on the amount or concentration of a biological component present in the sample or on the surface of the sample.

[0003] The scanning light source emits visible light toward the optical medium. The scanning light is completely internally reflected at an interface between the optical medium and the biological sample and exits the optical medium. The absorption heat of the biological sample is transferred to the optical medium to change the refractive index of the optical medium. The change in the refractive index of the optical medium affects the total internal reflection of the scanning light at the interface between the optical medium and the biological sample, changing the direction of travel of the scanning light exiting the optical medium. The photodiode detects a change in the direction of travel of the scanning light. The amount or concentration of a biological component is measured based on the change in the direction of travel of the scanning light detected by the photodiode.For example, if the sample is a patient's skin, the patient's blood sugar level is measured as a biological component.

[0004] PTL 2 discloses a biological substance measuring device comprising: an infrared light source unit for emitting infrared light having wavelengths covering all or part of the absorption wavelength range of a biological substance; a prism for transmitting the infrared light emitted from the infrared light source unit while contacting the surface of the organism and emitting the infrared light toward the surface of the organism; a light source for radiating light of a wavelength in the visible light or near infrared light range toward the prism; and a light position detector for detecting the path of the light from the light source by detecting the light from the light source emitted by the prism.

[0005] PTL 3 relates to a device for analyzing a material, comprising an excitation emission device for generating at least one electromagnetic excitation beam, in particular an excitation light beam, having at least one excitation wavelength, and a detection device for detecting a reaction signal, and a device for analyzing the material on the basis of the detected reaction signal (SR). LITERATURE LISTPATENTLITERATURE PTL 1: National Patent Application Publication JP 2017- 519 214 A PTL 2: WO 2019 / 150 543 A1 PTL 3: US 2018 / 0 328 835 A1 SUMMARY OF THE INVENTION TECHNICAL PROBLEM

[0006] However, in the non-invasive analysis system disclosed in PTL 1, the optical medium is formed of zinc sulfide (ZnS). Zinc sulfide (ZnS) has a high thermal conductivity of 27.2 W / (m·K). The absorption heat of the biological sample is transferred to the optical medium and quickly diffuses into the optical medium. As a result, the change in the refractive index of a part of the optical medium located on the optical path of the scanning light becomes smaller. This prevents the biological component from being measured with high accuracy. The present invention was made in view of the problems described above, and therefore, an object of the present invention is to provide a biological component measuring device capable of measuring a biological component with improved accuracy. SOLUTION TO THE PROBLEM

[0007] A biological component measuring device according to a first aspect of the present invention comprises an optical medium, an excitation light source, a scanning light source, and a light position detector. The optical medium has a sample support surface. The excitation light source emits excitation light toward the sample placed on the sample support surface, which light travels through the optical medium. The scanning light source emits scanning light that travels through the optical medium. The light position detector detects a position of the scanning light emerging from the optical medium. In the plan view of the sample support surface, an optical path of the scanning light in the optical medium overlaps a part of the sample support surface irradiated with the excitation light. The optical medium is formed of chalcogenide glass.

[0008] A biological component measuring device according to a second aspect of the present invention comprises an optical medium, an excitation light source, a scanning light source, and a light position detector. The optical medium has a sample support surface. The excitation light source emits excitation light toward the sample placed on the sample support surface, which light travels through the optical medium. The scanning light source emits scanning light that travels through the optical medium. The light position detector detects a position of the scanning light emerging from the optical medium. In the plan view of the sample support surface, an optical path of the scanning light in the optical medium overlaps a part of the sample support surface irradiated with the excitation light. The optical medium is made of a material with a thermal conductivity of less than or equal to 15.0 W / (m·K). ADVANTAGEOUS EFFECTS OF THE INVENTION

[0009] In the biological component measuring device according to the first aspect of the present invention, the optical medium is formed of chalcogenide glass. In the biological component measuring device according to the second aspect of the present invention, the optical medium is formed of a material having a thermal conductivity of less than or equal to 15.0 W / (m·K). In the biological component measuring devices according to the first and second aspects of the present invention, the thermal conductivity of the optical medium material is lower than the thermal conductivity (27.2 W / (m·K)) of zinc sulfide (ZnS). Therefore, transfer of the absorption heat of the sample results in a larger change in the refractive index in a refractive index gradient region formed in the optical medium.This enables the biological component measuring devices according to the first and second aspects of the present invention to measure a biological component with improved accuracy. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a diagram schematically showing a biological component measuring apparatus according to a first embodiment. Fig. 2 is a flowchart of a method for measuring biological components according to the first embodiment. Fig. 3 is a diagram schematically illustrating a biological component measuring apparatus according to a modification of the first embodiment. Fig. 4 is a diagram schematically illustrating a biological component measuring apparatus according to a second embodiment. Fig. 5 is a diagram schematically showing a biological component measuring apparatus according to a third embodiment. Fig. 6 is a diagram schematically showing a biological component measuring apparatus according to a fourth embodiment. Fig. 7 is a diagram schematically showing a biological component measuring apparatus according to a fifth embodiment. Fig. 8 is a control block diagram of a pressing unit of the biological component measuring apparatus according to the fifth embodiment. Fig. 9 is a diagram schematically showing a biological component measuring apparatus according to a sixth embodiment. DESCRIPTION OF EMBODIMENTS

[0010] Embodiments are described below. Note that the same components are designated by the same reference numerals to avoid redundant descriptions. First embodiment

[0011] With reference to Fig. 1, a biological component measuring device 1 according to a first embodiment is described. The biological component measuring device 1 mainly comprises an optical medium 10, an excitation light source 16, a scanning light source 20, a light position detector 25, and a biological component detection unit 27.

[0012] The optical medium 10 has a first surface 11, a second surface 12 located on the side of the optical medium 10 opposite the first surface 11, a third surface 13 connecting the first surface 11 and the second surface 12, and a fourth surface 14 connecting the first surface 11 and the second surface 12 and located on the side of the optical medium 10 opposite the third surface 13. The first surface 11 of the optical medium 10 is a surface onto which the excitation light 17 emitted by the excitation light source 16 impinges. The second surface 12 is a sample support surface. A sample 5 is arranged on the second surface 12 and is in contact with the second surface 12. The sample 5 is, for example, the skin or a body fluid of a patient.If a liquid is to be measured, the sample 5 is a liquid contained in a transparent sample container. The third surface 13 is a surface onto which the scanning light 21 emitted by the light source 20 impinges. A direction perpendicular to the third surface 13 is inclined relative to the incident direction of the scanning light 21. The fourth surface 14 is a surface from which the scanning light 21 emerges. The fourth surface 14 is inclined relative to the exit direction of the scanning light 21. The optical medium 10 can be, for example, a total internal reflection prism (TIR prism).

[0013] The optical medium 10 is transparent to the excitation light 17. The fact that the optical medium 10 is transparent to the excitation light 17 means that the light transmittance of the optical medium 10 with respect to the excitation light 17 is greater than or equal to 25%. The light transmittance of the optical medium 10 with respect to the excitation light 17 can be greater than or equal to 50%, greater than or equal to 75%, or greater than or equal to 90%. The optical medium 10 is transparent to the scanning light 21. The fact that the optical medium 10 is transparent to the scanning light 21 means that the light transmittance of the optical medium 10 with respect to the scanning light 21 is greater than or equal to 25%. The light transmittance of the optical medium 10 with respect to the scanning light 21 can be greater than or equal to 50%, greater than or equal to 75%, or greater than or equal to 90%.

[0014] The optical medium 10 is made of a material with a thermal conductivity of less than or equal to 15.0 W / (m·K). The thermal conductivity of the material of the optical medium 10 can be less than or equal to 10.0 W / (m·K), less than or equal to 5.0 W / (m·K), less than or equal to 3.0 W / (m·K), less than or equal to 2.0 W / (m·K), or less than or equal to 1.0 W / (m·K). The thermal conductivity of the material of the optical medium 10 is greater than or equal to 0.5 times the thermal conductivity of the sample 5. The thermal conductivity of the material of the optical medium 10 may be greater than or equal to 0.75 times the thermal conductivity of the sample 5, may be greater than or equal to the thermal conductivity of the sample 5, may be greater than or equal to 1.5 times the thermal conductivity of the sample 5, or may be greater than or equal to 2.0 times the thermal conductivity of the sample 5.

[0015] The optical medium 10 is formed of chalcogenide glass. For example, the chalcogenide glass contains 2 mol% to 22 mol%, inclusive, of germanium (Ge), 6 mol% to 34 mol%, inclusive, of at least one element selected from the group consisting of antimony (Sb) and bismuth (Bi), 1 mol% to 20 mol%, inclusive, of tin (Sn), and 58 mol% to 70 mol%, inclusive, of at least one element selected from the group consisting of sulfur (S), selenium (Se), and tellurium (Te). The chalcogenide glass has a thermal conductivity of 0.36 W / (m·K).

[0016] The excitation light source 16 emits excitation light 17 toward the sample 5 located on the sample support surface (second surface 12). The excitation light 17 is emitted by the excitation light source 16 and impinges on the optical medium 10 through the first surface 11. The excitation light 17 travels through the optical medium 10. The excitation light 17 impinges on the sample 5 through the second surface 12. The excitation light 17 is absorbed by a biological component present in the sample 5 or on a surface 6 of the sample 5. For example, when a patient's blood sugar level is measured with the biological component measuring device 1, the biological component is glucose present in the interstitial fluid in the epidermis. The excitation light 17 is absorbed by the biological component and generates absorption heat in the sample 5.The absorption heat of the sample 5 is transferred to the optical medium 10. A temperature gradient region is created in the optical medium 10, and correspondingly, a refractive index gradient region 18 is created in the optical medium 10.

[0017] A wavelength of the excitation light 17 is determined in accordance with the absorption wavelength of the biological component present in the sample 5 or on the surface 6 of the sample 5. The wavelength of the excitation light 17 may be longer than the wavelength of the scanning light 21. The wavelength of the excitation light 17 is, for example, greater than or equal to 6.0 µm. The wavelength of the excitation light 17 may be greater than or equal to 8.0 µm. The wavelength of the excitation light 17 is, for example, less than or equal to 13.0 µm. The wavelength of the excitation light 17 may be less than or equal to 11.0 µm. The excitation light 17 may be light with a variety of wavelengths. For example, when the patient's blood sugar level is measured with the biological component measuring device 1, the wavelength of the excitation light 17 falls within a wavelength range that includes the wavelength of a fingerprint spectrum of glucose (e.g.a wavelength range from greater than or equal to 8.5 µm to less than or equal to 10 µm). The excitation light source 16 is, for example, a quantum cascade laser capable of emitting broadband infrared light. The sample 5 can be irradiated with reference light that is not absorbed by the biological component present in the sample 5 or on the surface 6 of the sample 5, together with the excitation light 17.

[0018] The scanning light source 20 emits scanning light 21. The scanning light 21 impinges on the optical medium 10 through the third surface 13. The scanning light 21 is deflected by the third surface 13 and travels through the optical medium 10 toward the interface between the optical medium 10 (second surface 12) and the sample 5. In the plan view of the sample support surface (second surface 12), an optical path of the scanning light 21 in the optical medium 10 overlaps with a part of the sample support surface (second surface 12) that is irradiated with excitation light 17. The scanning light 21 is completely reflected internally at the interface between the optical medium 10 (second surface 12) and the sample 5. As the scanning light 21 moves through the optical medium 10, the scanning light 21 passes through the refractive index gradient region 18, which is generated in the optical medium 10 by the absorption heat of the sample 5.The scanning light 21 is refracted by the refractive index gradient region 18, and the direction of movement of the scanning light 21 changes accordingly. The scanning light 21 (first outgoing scanning light 21a and second outgoing scanning light 21b) exits the fourth surface 14 of the optical medium 10.

[0019] The wavelength of the scanning light 21 is, for example, greater than or equal to 1100 nm. The wavelength of the scanning light 21 may be greater than or equal to 1300 nm. The wavelength of the scanning light 21 is, for example, less than or equal to 1700 nm. Therefore, an inexpensive semiconductor laser for optical communication, such as an InGaAsP-based semiconductor laser or an InGaNAs-based semiconductor laser, can be used as the light source for the scanning light 21. In addition, the scanning light 21 is not visible light, so the risk of damage to the human eye caused by the scanning light 21 can be reduced. The power of the scanning light 21 is, for example, less than or equal to 5 mW. This can reduce the risk of damage to the human eye caused by the scanning light 21.

[0020] The light position detector 25 detects a position of the scanning light 21 (first outgoing scanning light 21a and second outgoing scanning light 21b) emitted from the optical medium 10. The light position detector 25 detects a first position 22a of the scanning light 21 (first outgoing scanning light 21a) when the sample 5 is not irradiated with excitation light 17. The first position 22a of the scanning light 21 (first outgoing scanning light 21a) is a position of the scanning light 21 (first outgoing scanning light 21a) detected by the light position detector 25 when the sample 5 is not irradiated with excitation light 17. The light position detector 25 detects a second position 22b of the scanning light 21 (second outgoing scanning light 21b) when the sample 5 is irradiated with excitation light 17.The second position 22b of the scanning light 21 (second outgoing scanning light 21b) is a position of the scanning light 21 (second outgoing scanning light 21b) detected by the light position detector 25 when the sample 5 is irradiated with excitation light 17. Irradiating the sample 5 with excitation light 17 causes the position of the scanning light 21 detected by the light position detector 25 to shift from the first position 22a to the second position 22b.

[0021] The light position detector 25 outputs the first position 22a of the scanning light 21 (first outgoing scanning light 21a) and the second position 22b of the scanning light 21 (second outgoing scanning light 21b) to the biological component detection unit 27. The light position detector 25 is, for example, a photodiode or a semiconductor position detection element.

[0022] The biological component detection unit 27 is connected to the light position detector 25. The biological component detection unit 27 calculates a displacement amount δ of the scanning light 21, which is a distance between the first position 22a and the second position 22b, to obtain the amount or concentration of the biological component present in the sample 5 or on the surface 6 of the sample 5 based on the displacement amount δ of the scanning light 21. The biological component detection unit 27 is, for example, one of the functions implemented by a processing unit.

[0023] With reference to Fig. 2, a method for measuring biological components according to the present embodiment using the biological component measuring device 1 will be described.

[0024] The method for measuring biological components according to the present embodiment includes detecting the first position 22a of the scanning light 21 (first outgoing scanning light 21a) using the light position detector 25 without irradiating the sample 5 with excitation light 17 (S1). Since the sample 5 is not irradiated with excitation light 17, no absorption heat is generated in the sample 5. No temperature gradient region is generated in the optical medium 10, and accordingly, no refractive index gradient region 18 is generated in the optical medium 10. When the sample 5 is not irradiated with excitation light 17, the scanning light 21 (first outgoing scanning light 21a) exits the optical medium 10. The first position 22a of the scanning light 21 (first outgoing scanning light 21a) is a position of the scanning light 21 (first outgoing scanning light 21a) detected by the light position detector 25.

[0025] The method for measuring biological components according to the present embodiment includes detecting the second position 22b of the scanning light 21 (second outgoing scanning light 21b) using the light position detector 25 while irradiating the sample 5 with excitation light 17 (S2). Since the sample 5 is irradiated with excitation light 17, the excitation light 17 is absorbed by the biological component present in the sample 5 or on the surface 6 of the sample 5. The excitation light 17 is absorbed by the biological component and generates absorption heat in the sample 5. The absorption heat of the sample 5 is transferred to the optical medium 10. The temperature gradient region is generated in the optical medium 10, and the refractive index gradient region 18 is correspondingly generated in the optical medium 10.The scanning light 21 is refracted by the refractive index gradient region 18, and the movement direction of the scanning light 21 changes accordingly. When the sample 5 is irradiated with the excitation light 17, the scanning light 21 (second outgoing scanning light 21b) exits the optical medium 10. The second position 22b of the scanning light 21 (second outgoing scanning light 21b) is a position of the scanning light 21 (second outgoing scanning light 21b) detected by the light position detector 25. Irradiation of the sample 5 with the excitation light 17 causes the position of the scanning light 21 detected by the light position detector 25 to shift from the first position 22a to the second position 22b.

[0026] The biological component measurement method according to the present embodiment includes calculating the displacement amount δ of the scanning light 21 (S3). Specifically, the biological component detection unit 27 calculates the distance between the first position 22a and the second position 22b to obtain the displacement amount δ of the scanning light 21.

[0027] The biological component measurement method according to the present embodiment includes obtaining the amount or concentration of the biological component present in the sample 5 or on the surface 6 of the sample 5 based on the shift amount δ of the scanning light 21 (S4). For example, the biological component detection unit 27 is connected to a memory (not shown). The memory stores a data table in which the type of biological component, the shift amount δ of the scanning light 21, and the amount or concentration of the biological component are associated with each other. The biological component detection unit 27 consults the data table to obtain the amount or concentration of the biological component associated with the type of biological component and the shift amount δ of the scanning light 21.

[0028] With reference to Fig. 3, a biological component measuring apparatus 1a according to a first modification of the present embodiment will be described. According to the first modification of the present embodiment, the direction perpendicular to the third surface 13 of the optical medium 10 is parallel to the incident direction of the scanning light 21. The fourth surface 14 is parallel to the third surface 13. The scanning light 21 travels along the sample support surface (second surface 12) without being completely reflected inside the sample support surface (second surface 12). A method of measuring biological components using the biological component measuring apparatus 1a is the same as the method of measuring biological components using the biological component measuring apparatus 1.According to a second modification of the present embodiment, the scanning light 21 may be fully reflected inside the interface between the sample support surface (second surface 12) and the sample 5 several times.

[0029] The effects of the biological component measuring device 1, 1a according to the present embodiment will be described.

[0030] The biological component measuring device 1, 1a according to the present embodiment includes an optical medium 10, an excitation light source 16, a scanning light source 20, and a light position detector 25. The optical medium 10 includes the sample support surface (second surface 12). The excitation light source 16 emits excitation light 17 toward the sample 5 placed on the sample support surface (second surface 12), which travels through the optical medium 10. The scanning light source 20 emits scanning light 21, which travels through the optical medium 10. The light position detector 25 detects the position of the scanning light 21 emerging from the optical medium 10. In the plan view of the sample support surface (second surface 12), the optical path of the scanning light 21 in the optical medium 10 intersects with a part of the sample support surface (second surface 12) that is irradiated with excitation light 17.The optical medium 10 is made of chalcogenide glass.

[0031] The chalcogenide glass has a lower thermal conductivity than the thermal conductivity (27.2 W / (m K)) of zinc sulfide (ZnS). Therefore, the transfer of absorption heat from sample 5 results in a larger change in the refractive index of the refractive index gradient region 18 formed in the optical medium 10. This enables the biological component measuring device 1, 1a according to the present embodiment to measure the biological component with improved accuracy.

[0032] In the biological component measuring device 1, 1a according to the present embodiment, the wavelength of the scanning light 21 is greater than or equal to 1300 nm and less than or equal to 1700 nm. This makes it possible to reduce the risk of damage to human eyes caused by the scanning light 21. Furthermore, an inexpensive semiconductor laser for use in optical communications can be used as the scanning light source 20, making it possible to reduce the cost of the biological component measuring device 1, 1a.

[0033] In the biological component measuring device 1 according to the present embodiment, the scanning light 21 is completely internally reflected at the sample support surface (second surface 12). This allows the distance by which the scanning light 21 travels through the refractive index gradient region 18 to be increased. This enables the biological component measuring device 1 according to the present embodiment to measure the biological component with improved accuracy.

[0034] In the biological component measuring device 1a according to the present embodiment, the scanning light 21 travels along the sample support surface (second surface 12) without being completely reflected inside the sample support surface (second surface 12). This enables the biological component measuring device 1a according to the present embodiment to measure the biological component with improved accuracy.

[0035] The biological component measuring device 1, 1a according to the present embodiment further includes a biological component detection unit 27 connected to the light position detector 25. The light position detector 25 outputs to the biological component detection unit 27 the first position 22a of the scanning light 21 (first outgoing scanning light 21a) when the sample 5 is not irradiated with the excitation light 17, and the second position 22b of the scanning light 21 (second outgoing scanning light 21b) when the sample 5 is irradiated with the excitation light 17. The biological component detection unit 27 calculates the shift amount δ of the scanning light 21, which is a distance between the first position 22a and the second position 22b, to obtain the amount or concentration of the biological component present in the sample 5 or on the surface 6 of the sample 5 based on the shift amount δ of the scanning light 21.This enables the biological component measuring device 1, 1a according to the present embodiment to measure the biological component with improved accuracy.

[0036] The biological component measuring device 1, 1a according to the present embodiment includes an optical medium 10, an excitation light source 16, a scanning light source 20, and a light position detector 25. The optical medium 10 includes the sample support surface (second surface 12). The excitation light source 16 emits excitation light 17 toward the sample 5 placed on the sample support surface (second surface 12), which travels through the optical medium 10. The scanning light source 20 emits scanning light 21, which travels through the optical medium 10. The light position detector 25 detects the position of the scanning light 21 emerging from the optical medium 10. In the plan view of the sample support surface (second surface 12), the optical path of the scanning light 21 in the optical medium 10 intersects with a part of the sample support surface (second surface 12) that is irradiated with excitation light 17.The optical medium 10 is formed of a material having a thermal conductivity of less than or equal to 15.0 W / (m·K).

[0037] Therefore, the thermal conductivity of the material of the optical medium 10 is lower than the thermal conductivity (27.2 W / (m K)) of zinc sulfide (ZnS). The transfer of absorption heat from the sample 5 results in a larger change in the refractive index of the refractive index gradient region 18 formed in the optical medium 10. This enables the biological component measuring device 1, 1a according to the present embodiment to measure the biological component with improved accuracy.

[0038] In the biological component measuring device 1, 1a according to the present embodiment, the thermal conductivity of the material of the optical medium 10 is less than or equal to 1.0 W / (m·K). Therefore, the thermal conductivity of the material of the optical medium 10 is lower than the thermal conductivity (27.2 W / (m·K)) of zinc sulfide (ZnS). The transfer of the absorption heat of the sample 5 results in a larger change in the refractive index of the refractive index gradient region 18 formed in the optical medium 10. This enables the biological component measuring device 1, 1a according to the present embodiment to measure the biological component with improved accuracy.

[0039] In the biological component measuring device 1, 1a according to the present embodiment, the thermal conductivity of the material of the optical medium 10 is greater than or equal to 0.5 times the thermal conductivity of the sample 5. This prevents most of the absorption heat generated in the sample 5 from dissipating in the sample 5 and causes this absorption heat to be transferred to the optical medium 10. This enables the biological component measuring device 1, 1a according to the present embodiment to measure the biological component with improved accuracy. Second embodiment

[0040] With reference to Fig. 4, a biological component measuring device 1b according to a second embodiment is described. The biological component measuring device 1b according to the present embodiment is similar in structure to the biological component measuring device 1 according to the first embodiment, but differs mainly in the following points.

[0041] The biological component measuring device 1b further includes an optical chopper 30 and a lock-in amplifier 31. The optical chopper 30 is arranged in the optical path of the excitation light 17. The optical chopper 30 interrupts the excitation light 17 at a desired frequency. The lock-in amplifier 31 is connected to the optical chopper 30 and the light position detector 25. The lock-in amplifier 31 selectively amplifies a signal synchronized with the chopping frequency of the optical chopper 30 from among the signals related to the position of the scanning light 21 output from the light position detector 25. This makes it possible to remove noise contained in the signal related to the position of the scanning light 21 output from the light position detector 25. This enables the biological component measuring device 1b to measure the biological component with improved accuracy. Third embodiment

[0042] With reference to Fig. 5, a biological component measuring device 1c according to a third embodiment is described. The biological component measuring device 1c according to the present embodiment is similar in structure to the biological component measuring device 1 according to the first embodiment, but differs mainly in the following points.

[0043] The biological component measuring device 1c further includes a temperature sensor 35. The biological component measuring device 1c may also include a display 36. The temperature sensor 35 is, for example, attached to a region of the optical medium 10 that is remote from the sample 5, the excitation light 17, and the scanning light 21. In particular, the temperature sensor 35 is attached to a region of the sample support surface (second surface 12) of the optical medium 10 that is remote from the sample 5, the excitation light 17, and the scanning light 21. The temperature sensor 35 measures the temperature of the optical medium 10. The temperature sensor 35 outputs a first signal related to the temperature of the optical medium 10 to the display 36. The temperature sensor 35 is, for example, a thermistor. The display 36 displays the temperature of the optical medium 10 or a fluctuation range of the temperature of the optical medium 10 per unit time.The display 36 is, for example, a liquid crystal display device or the like. When there is a difference between a first temperature of the optical medium 10 and a second temperature of the sample 5, heat is transferred between the optical medium 10 and the sample 5. This heat transfer affects the refractive index gradient region 18 created in the optical medium 10, making accurate measurement of the biological component difficult. Since the optical medium 10 is made of a material with low thermal conductivity, such as chalcogenide glass, it takes longer to transition from a state (thermal non-equilibrium state) in which the fluctuation range of the first temperature of the optical medium 10 per unit time is greater than an allowable temperature fluctuation range (e.g., 0.1°C / min) to a state (thermal non-equilibrium state) in which the fluctuation range of the first temperature of the optical medium 10 per unit time is less than or equal to the allowable temperature fluctuation range (e.g., 0.1°C / min).

[0044] The biological component measuring device 1c can obtain the fluctuation range of the first temperature of the optical medium 10 per unit time, that is, the degree of heat transfer between the optical medium 10 and the sample 5, using the temperature sensor 35. If the fluctuation range of the first temperature of the optical medium 10 per unit time measured by the temperature sensor 35 is greater than the allowable temperature fluctuation range (e.g., 0.1 °C / min) (thermal non-equilibrium state) after the sample 5 is placed on the sample support surface (second surface 12) of the optical medium 10, the measurement of the biological component using the biological component measuring device 1c is not performed. If the fluctuation range of the first temperature of the optical medium 10 per unit time is less than or equal to the allowable temperature fluctuation range (e.g.,0.1 °C / min) (thermal non-equilibrium state) after the sample 5 is placed on the sample support surface (second surface 12) of the optical medium 10, the measurement of the biological component is started using the biological component measuring device 1c.

[0045] The biological component measuring apparatus 1c according to the present embodiment also produces the following effects in addition to the effects produced by the biological component measuring apparatus 1 according to the first embodiment. The biological component measuring device 1c according to the present embodiment further includes a temperature sensor 35 that measures the temperature of the optical medium 10. This enables the temperature sensor 35 to measure temperature fluctuations of the optical medium 10 caused by heat transfer between the optical medium 10 and the sample 5. Even if the optical medium 10 is formed of a material with low thermal conductivity, such as chalcogenide glass, it is possible to accurately determine the timing at which the biological component measurement can be performed without being affected by heat transfer between the optical medium 10 and the sample 5. This enables the biological component measuring device 1c according to the present embodiment to measure the biological component with improved accuracy. Fourth embodiment

[0046] With reference to Fig. 6, a biological component measuring device 1d according to a fourth embodiment is described. The biological component measuring device 1d according to the present embodiment is similar in structure to the biological component measuring device 1c according to the third embodiment, but differs mainly in the following points.

[0047] The biological component measuring device 1d further includes a temperature controller 37 and a temperature controller 38. The temperature controller 37 is mounted, for example, on a portion of the optical medium 10 that is remote from the sample 5, the excitation light 17, and the scanning light 21. Specifically, the temperature controller 37 is mounted on a portion of the sample support surface (second surface 12) of the optical medium 10 that is remote from the sample 5, the excitation light 17, and the scanning light 21. The temperature controller 37 controls the temperature of the optical medium 10. The temperature controller 37 is, for example, a Peltier unit or an electric heating wire. The temperature sensor 35 also outputs the first signal related to the temperature of the optical medium 10 to the temperature controller 38.

[0048] The temperature controller 38 is connected to the temperature sensor 35 and the temperature controller 37. The temperature controller 38 controls the temperature controller 37 based on the first signal output from the temperature sensor 35, which signal relates to the temperature of the optical medium 10. Specifically, the temperature controller 37 is controlled so that the fluctuation range of the first temperature of the optical medium 10 per unit time, measured by the temperature sensor 35, is less than or equal to the allowable temperature fluctuation range (e.g., 0.1°C / min). For example, when the first temperature of the optical medium 10 is lower than the second temperature of the sample 5 and the fluctuation range of the first temperature of the optical medium 10 per unit time is greater than the allowable temperature fluctuation range, the temperature controller 38 controls the temperature controller 37 so that the temperature controller 37 heats the optical medium 10.When the first temperature of the optical medium 10 is higher than the second temperature of the sample 5 and the fluctuation range of the first temperature of the optical medium 10 per unit time is larger than the allowable temperature fluctuation range, the temperature controller 38 controls the temperature controller 37 to cause the temperature controller 37 to cool the optical medium 10.

[0049] The biological component measuring device 1d according to the present embodiment also produces the following effects in addition to the effects produced by the biological component measuring device 1c according to the third embodiment.

[0050] The biological component measuring device 1d according to the present embodiment further includes a temperature controller 37 that controls the temperature of the optical medium 10, and a temperature controller 38. The temperature controller 38 controls the temperature controller 37 based on the first signal related to the temperature of the optical medium 10 output from the temperature sensor 35. This makes it possible, even when the optical medium 10 is made of a material with low thermal conductivity, such as chalcogenide glass, to shorten the time required from placing the sample 5 on the sample support surface (second surface 12) of the optical medium 10 to substantially eliminating heat transfer between the optical medium 10 and the sample 5 to perform the biological component measurement.This enables the biological component measuring device 1d to measure the biological component with improved accuracy and in a shorter time. Fifth embodiment

[0051] With reference to the Fig. 7 and Fig. 8, a biological component measuring device 1e according to a fifth embodiment is described. The biological component measuring device 1e according to the present embodiment is similar in structure to the biological component measuring device 1 according to the first embodiment, but differs mainly in the following points.

[0052] The biological component measuring device 1e further comprises a positioning element 40 which determines the position of the sample 5 in the moving direction (left-right direction of Fig. 7) of the scanning light 21. The positioning member 40 includes a pair of clamping members 41 and a connecting member 42 that connects the pair of clamping members 41. Each of the two clamping members 41 includes a bottom plate 41a and a wall 41b extending from the bottom plate 41a in the direction perpendicular to the sample support surface (second surface 12). The bottom plate 41a is in surface contact with the sample support surface (second surface 12). The wall 41b is in contact with a side surface of the sample 5. The pair of walls 41b of the pair of clamping members 41 clamp the sample 5 in the moving direction of the scanning light 21.

[0053] The biological component measuring device 1e further includes a pressing unit 44, a pressure sensor 48, and a pressure controller 49. The pressing unit 44 presses the sample 5 against the sample support surface (second surface 12). The pressing unit 44 includes, for example, a pressing plate 45, a ball screw 46 that moves the pressing plate 45 in the direction perpendicular to the sample support surface (second surface 12), and a motor 47 that rotates the ball screw 46. According to a modification of the present embodiment, the pressing plate 45 may be pressed toward the sample 5 by an elastic member such as a spring.

[0054] The pressure sensor 48 is attached to the pressure unit 44. In particular, the pressure sensor 48 is attached to the pressure plate 45. The pressure sensor 48 measures the pressure with which the pressure unit 44 presses the sample 5. The pressure sensor 48 outputs a second signal to the pressure controller 49, which signal relates to the pressure with which the pressure unit 44 presses the sample 5. The pressure sensor 48 is, for example, an overpressure sensor or a capacitive pressure sensor.

[0055] As in Fig. As shown in Figure 8, the pressure controller 49 is connected to the pressing unit 44 (e.g., the motor 47) and the pressure sensor 48. The pressure controller 49 controls the pressing unit 44 based on the second signal related to the pressure output from the pressure sensor 48. Specifically, the pressing unit 44 (motor 47) is controlled so that the pressure exerted on the sample 5 and measured by the pressure sensor 48 corresponds to the reference pressure. Specifically, when the pressure exerted on the sample 5 is lower than the reference pressure, the pressure controller 49 moves the pressing plate 45 toward the sample support surface (second surface 12) to equalize the pressure exerted on the sample 5 to the reference pressure. When the pressure applied to the sample 5 is higher than the reference pressure, the pressure controller 49 moves the pressure plate 45 away from the sample support surface (second surface 12) to equalize the pressure applied to the sample 5 to the reference pressure.

[0056] The biological component measuring device 1e according to the present embodiment also produces the following effects in addition to the effects produced by the biological component measuring device 1 according to the first embodiment.

[0057] The biological component measuring device 1e according to the present embodiment further includes a pressing unit 44, a pressure sensor 48, and a pressure controller 49. The pressing unit 44 presses the sample 5 against the sample support surface (second surface 12). The pressure sensor 48 measures the pressure with which the pressing unit 44 presses the sample 5. The pressure controller 49 controls the pressing unit 44 based on the second signal related to the pressure output from the pressure sensor 48. Therefore, the contact pressure between the sample 5 and the optical medium 10 can be kept constant. The transfer of the absorption heat of the sample 5 to the optical medium 10 becomes stable. This enables the biological component measuring device 1e to measure the biological component with improved accuracy.

[0058] The biological component measuring device 1e according to the present embodiment further includes a positioning element 40 that defines the position of the sample 5 in the moving direction of the scanning light 21. Therefore, even if the sample 5 is a movable sample such as a patient's finger, it is possible to position the sample 5 relative to the excitation light 17 and the scanning light 21 in the moving direction of the scanning light 21. This enables the biological component measuring device 1e to measure the biological component with improved accuracy. Sixth embodiment

[0059] With reference to Fig.9, a biological component measuring device 1f according to a sixth embodiment is described. The biological component measuring device 1f according to the present embodiment is similar in structure to the biological component measuring device 1 according to the first embodiment, but differs mainly in the following points. The biological component measuring device 1f further includes a light intensity detector 51 and a light source controller 52. The biological component measuring device 1f may further include a light beam splitter 50.

[0060] The light intensity detector 51 detects the intensity of the excitation light 17 emitted by the excitation light source 16. The light intensity detector 51 is, for example, a photodiode. In particular, the light beam splitter 50 is arranged in the optical path of the excitation light 17. The light beam splitter 50 is, for example, a plate light beam splitter, a prism light beam splitter, or an optical fiber light beam splitter. The light beam splitter 50 causes a portion of the excitation light 17 to reach the light intensity detector 51. In particular, the light beam splitter 50 reflects the portion of the excitation light 17 to the light intensity detector 51. The light intensity detector 51 detects the light intensity of the portion of the excitation light 17. The light intensity detector 51 outputs a signal related to the intensity of the excitation light 17.

[0061] The light source controller 52 is connected to the excitation light source 16. The light source controller 52 controls the excitation light source 16. Specifically, the light source controller 52 controls a current supplied to the excitation light source 16 to control the intensity of the excitation light 17 emitted by the excitation light source 16. The light source controller 52 is connected to the light intensity detector 51. The light source controller 52 receives the signal related to the intensity of the excitation light 17 from the light intensity detector 51. The light source controller 52 controls the excitation light source 16 based on the signal related to the intensity of the excitation light 17 detected by the light intensity detector 51 to keep the intensity of the excitation light 17 emitted by the excitation light source 16 constant.

[0062] The biological component measuring device 1f according to the present embodiment also produces the following effects in addition to the effects produced by the biological component measuring device 1 according to the first embodiment.

[0063] The biological component measuring device 1f according to the present embodiment further includes a light intensity detector 51 that detects the light intensity of the excitation light 17, and a light source controller 52 that controls the excitation light source 16 based on the signal related to the intensity of the excitation light 17 output from the light intensity detector 51.

[0064] When the excitation light source 16 is operated for a long period of time, the light intensity of the excitation light 17 emitted by the excitation light source 16 may decrease. A decrease in the light intensity of the excitation light 17 results in lower accuracy in the measurement of the biological component. According to the present embodiment, the light source controller 52 controls the excitation light source 16 based on the signal related to the intensity of the excitation light 17 output from the light intensity detector 51. As a result, the light intensity of the excitation light 17 emitted by the excitation light source 16 can be maintained for a long period of time. This enables the biological component measuring device 1f to measure the biological component with improved accuracy over a long period of time.

[0065] It should be understood that the first to sixth embodiments disclosed herein are illustrative and not restrictive in all respects. At least two of the first to sixth embodiments disclosed herein may be combined as long as there is no inconsistency. For example, the second to fifth embodiments may be combined with the modification of the first embodiment. The sixth embodiment may be combined with any of the second to fifth embodiments. The scope of the present invention is defined by the claims rather than the above description and is intended to include the claims, equivalents of the claims, and all modifications within the scope. LIST OF REFERENCE SYMBOLS 1, 1a, 1b, 1c, 1d, 1e, 1f Measuring device for biological components, 5 sample, 6 Surface, 10 optical medium, 11 first surface, 12 second surface, 13 third surface, 14 fourth surface, 16 Excitation light source, 17 Excitation light, 18 Refractive index gradient range, 20 scanning light source, 21 scanning light, 21a first outgoing scanning light, 21b second outgoing scanning light, 22a first position, 22b second position, 25 light position detector, 27 Recording unit for biological components, 30 optical chopper, 31 lock-in amplifiers, 35 temperature sensor, 36 displays, 37 temperature controllers, 38 temperature control, 40 positioning element, 41 clamping element, 41a base plate, 41b Wall, 42 connecting element, 44 pressure unit, 45 pressure plate, 46 ball screw, 47 engine, 48 pressure sensor, 49 pressure control, 50 light beam splitters, 51 light intensity detector, 52 Light source control

Claims

[1] A biological component measuring device (1c, 1d) for measuring a component using heat generation of a biological sample (5) which absorbs excitation light (17), the biological component measuring device (1c, 1d) comprising: an optical medium (10) having a sample support surface (12) on which the biological sample (5) is arranged, wherein the optical medium (10) is transparent to the excitation light (17) and is formed from chalcogenide glass which has a lower thermal conductivity than zinc sulfide, and a refractive index of the optical medium (10) is changed by the heat generation of the biological sample (5) which absorbs the excitation light (17); an excitation light source (16) for emitting the excitation light (17), which moves through the optical medium (10) in the direction of the sample support surface (12); a scanning light source (20) for emitting scanning light (21) moving through the optical medium (10), a light position detector (25) for detecting a position of the scanning light (21) emerging from the optical medium (10), and a temperature sensor (35) for measuring a temperature of the optical medium (10), wherein the optical medium (10) is also permeable to the scanning light (21), wherein the light position detector (25) detects a first position (22a) of the scanning light (21) emerging from the optical medium (10) when the excitation light source (16) does not emit excitation light (17), and a second position (22b) of the scanning light (21) emerging from the optical medium (10) in which a refractive index gradient region (18) is generated by the heat generation caused by the excitation light (17) when the excitation light source (16) emits the excitation light (17), wherein the component is measured based on the first position (22a) and the second position (22b), and wherein the temperature sensor (35) is attached to a region of the sample support surface (12), the region being remote from the biological sample (5), the excitation light (17) and the scanning light (21). [2] The biological component measuring device (1c, 1d) according to claim 1, wherein the scanning light (21) has a wavelength of greater than or equal to 1300 nm and less than or equal to 1700 nm. [3] A biological component measuring device (1b) according to claim 1 or 2, further comprising: an optical chopper (30) arranged in an optical path of the excitation light (17); and a lock-in amplifier (31) connected to the optical chopper (30) and the light position detector (25). [4] A biological component measuring device (1d) according to any one of claims 1 to 3, further comprising: a temperature controller (37) for controlling the temperature of the optical medium (10); and a temperature controller (38) for controlling the temperature controller (37) based on a first signal relating to the temperature of the optical medium (10) output by the temperature sensor (35). [5] A biological component measuring device (1e) according to any one of claims 1 to 4, further comprising: a pressing unit (44) for pressing the biological sample (5) onto the sample support surface (12); a pressure sensor (48) for measuring the pressure with which the pressing unit (44) presses the biological sample (5); and a pressure controller (49) for controlling the pressing unit (44) based on a second signal related to the pressure output by the pressure sensor (48). [6] A biological component measuring device (1e) according to any one of claims 1 to 5, further comprising a positioning element (40) for defining a position of the biological sample (5) in a moving direction of the scanning light (21). [7] A measuring device (1c, 1d) for biological components according to any one of claims 1 to 6, wherein the scanning light (21) is completely reflected at the sample support surface (12) inside. [8] A biological component measuring device (1a) according to any one of claims 1 to 6, wherein the scanning light (21) moves along the sample support surface (12) without being completely reflected at the sample support surface (12) inside. [9] A biological component measuring device (1c, 1d) according to any one of claims 1 to 8, further comprising a biological component detecting unit (27) connected to the light position detector (25), wherein the light position detector (25) outputs the first position (22a) and the second position (22b) to the biological component detection unit (27), and the biological component detection unit (27) calculates a shift amount of the scanning light (21), which is a distance between the first position (22a) and the second position (22b), and obtains an amount or concentration of the component present in the biological sample (5) or on a surface of the biological sample (5) based on the shift amount.

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