Biological component measuring apparatus

Abstract

The biological composition measuring device (1) includes an optical medium (10), an excitation light source (16), a probe light source (20), and a light position detector (25). The optical medium (10) includes a sample mounting surface (second surface (12)). The excitation light source (16) emits excitation light (17) toward the sample (5) mounted on the sample mounting surface (second surface (12)). The probe light source (20) emits probe light (21) that travels through the optical medium (10). The light position detector (25) detects the position of the probe light (21) emitted from the optical medium (10). The optical medium (10) is formed of chalcogenide glass.

Description

Technical Field

[0001] This disclosure relates to a device for measuring the composition of organisms. Background Technology

[0002] Japanese Patent Publication No. 2017-519214 (Patent Document 1) discloses a noninvasive analysis system comprising an optical medium, an infrared light source, a probe light source, and a photodiode. Specifically, a biological sample is disposed on the surface of the optical medium. The infrared light source emits infrared light. The infrared light passes through the optical medium and irradiates the biological sample. The infrared light is absorbed by the biological sample, causing the sample to heat up. The degree of heat absorption by the biological sample depends on the amount or concentration of biological components in or on the surface of the sample.

[0003] A probe light source emits visible light towards an optical medium. The probe light undergoes total internal reflection at the interface between the optical medium and the biological sample, exiting from the optical medium. The heat absorbed by the biological sample is transferred to the optical medium, causing a change in its refractive index. This change in refractive index affects the total internal reflection of the probe light at the interface, altering the direction of travel of the emitted probe light. A photodiode detects this change in direction. Based on the change in direction detected by the photodiode, the amount or concentration of the biological component is determined. For example, in the case of a patient's skin, the patient's blood glucose level is measured as a biological component.

[0004] Existing technical documents

[0005] Patent Document 1: Japanese Patent Publication No. 2017-519214 Summary of the Invention

[0006] However, in the non-invasive analytical system disclosed in Patent Document 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 heat absorbed by the biological sample is transferred to the optical medium and diffuses rapidly within it. Therefore, the change in refractive index of the portion of the optical medium in the path of the probe light is small. This makes it impossible to determine the biological composition with high precision. This disclosure was made in view of the above-mentioned problems, and its object is to provide a biological composition measuring device capable of measuring biological composition with improved precision.

[0007] The first embodiment of this disclosure provides a biological composition determination device comprising an optical medium, an excitation light source, a detection light source, and a light position detector. The optical medium includes a sample mounting surface. The excitation light source radiates excitation light that propagates through the optical medium towards the sample mounted on the sample mounting surface. The detection light source radiates detection light that propagates through the optical medium. The light position detector detects the position of the detection light emitted from the optical medium. When viewed from above the sample mounting surface, the optical path of the detection light in the optical medium overlaps with the portion of the sample mounting surface illuminated by the excitation light. The optical medium is formed of chalcogenide glass.

[0008] The second embodiment of the present disclosure provides a biological composition measuring device comprising an optical medium, an excitation light source, a detection light source, and a light position detector. The optical medium includes a sample mounting surface. The excitation light source radiates excitation light that propagates through the optical medium toward the sample mounted on the sample mounting surface. The detection light source radiates detection light that propagates through the optical medium. The light position detector detects the position of the detection light emitted from the optical medium. When viewed from above the sample mounting surface, the optical path of the detection light in the optical medium overlaps with the portion of the sample mounting surface illuminated by the excitation light. The optical medium is formed of a material having a thermal conductivity of 15.0 W / (m·K) or less.

[0009] In the biocomposition measuring apparatus of the first embodiment of this disclosure, the optical medium is formed of chalcogenide glass. In the biocomposition measuring apparatus of the second embodiment of this disclosure, the optical medium is formed of a material having a thermal conductivity of 15.0 W / (m·K) or less. In both the first and second embodiments of the biocomposition measuring apparatus of this disclosure, the thermal conductivity of the material forming the optical medium is less than that of zinc sulfide (ZnS) (27.2 W / (m·K)). Therefore, the change in refractive index in the refractive index gradient region formed in the optical medium due to the conduction of the absorbed heat of the sample is greater. The biocomposition measuring apparatuses of the first and second embodiments of this disclosure can measure biocomposition with improved accuracy. Attached Figure Description

[0010] Figure 1 This is a schematic diagram of the biological composition measuring device according to Embodiment 1.

[0011] Figure 2 This is a flowchart illustrating the biological composition determination method of Embodiment 1.

[0012] Figure 3 This is a schematic diagram of a biological composition measuring device according to a variation of Embodiment 1.

[0013] Figure 4 This is a schematic diagram of the biological composition measuring device according to Embodiment 2.

[0014] Figure 5This is a schematic diagram of the biological composition measuring device according to Embodiment 3.

[0015] Figure 6 This is a schematic diagram of the biological composition measuring device according to Embodiment 4.

[0016] Figure 7 This is a schematic diagram of the biological composition measuring device of Embodiment 5.

[0017] Figure 8 This is a control block diagram of the pressing part of the biological composition measuring device in Embodiment 5.

[0018] Figure 9 This is a schematic diagram of the biological composition measuring device according to Embodiment 6.

[0019] (Symbol Explanation)

[0020] 1, 1a, 1b, 1c, 1d, 1e, 1f: Biocomposition Measurement Device; 5: Sample; 6: Surface; 10: Optical Medium; 11: First Surface; 12: Second Surface; 13: Third Surface; 14: Fourth Surface; 16: Excitation Source; 17: Excitation Light; 18: Refractive Index Gradient Region; 20: Probe Source; 21: Probe Light; 21a: First Emitted Probe Light; 21b: Second Emitted Probe Light; 22a: First Position; 22b: Second Position; 25: Light Position Detector; 27: Biocomposition Acquisition Unit; 30: Optical Chopper; 31: Lock-in Amplifier 35: Temperature sensor; 36: Display; 37: Temperature regulator; 38: Temperature controller; 40: Positioning component; 41: Clamping component; 41a: Base plate; 41b: Wall; 42: Connecting component; 44: Pressing part; 45: Pressing plate; 46: Ball screw; 47: Motor; 48: Pressure sensor; 49: Pressure controller; 50: Beam splitter; 51: Light intensity detector; 52: Light source controller. Detailed Implementation

[0021] The following describes the implementation method. Furthermore, the same reference numerals are used for the same structures, and their descriptions are not repeated.

[0022] Implementation method 1.

[0023] Reference Figure 1 The following describes the biological composition measuring device 1 according to Embodiment 1. The biological composition measuring device 1 mainly includes an optical medium 10, an excitation light source 16, a detection light source 20, a light position detector 25, and a biological composition acquisition unit 27.

[0024] The optical medium 10 includes: a first surface 11, a second surface 12 opposite to 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 opposite to the third surface 13. The first surface 11 of the optical medium 10 is the incident surface of excitation light 17 emitted from the excitation light source 16. The second surface 12 is the sample placement surface. The sample 5 is placed on and in contact with the second surface 12. The sample 5 is, for example, a patient's skin or bodily fluid. If the substance being measured is a liquid, the sample 5 is a liquid contained in a transparent sample holder. The third surface 13 is the incident surface of detection light 21 emitted from the detection light source 20. The normal direction of the third surface 13 is inclined relative to the incident direction of the detection light 21. The fourth surface 14 is the emitting surface of the detection light 21. The fourth surface 14 is inclined relative to the emitting direction of the detection light 21. Optical medium 10 may also be, for example, an internal total reflection prism (TIR prism).

[0025] The optical medium 10 is transparent to the excitation light 17. In this specification, the transparency of the optical medium 10 to the excitation light 17 means that the light transmittance of the optical medium 10 to the excitation light 17 is 25% or more. The light transmittance of the optical medium 10 to the excitation light 17 can be 50% or more, 75% or more, or 90% or more. The optical medium 10 is also transparent to the probe light 21. In this specification, the transparency of the optical medium 10 to the probe light 21 means that the light transmittance of the optical medium 10 to the probe light 21 is 25% or more. The light transmittance of the optical medium 10 to the probe light 21 can be 50% or more, 75% or more, or 90% or more.

[0026] The optical medium 10 is formed of a material having a thermal conductivity of 15.0 W / (m·K) or less. The thermal conductivity of the material forming the optical medium 10 can be 10.0 W / (m·K) or less, 5.0 W / (m·K) or less, 3.0 W / (m·K) or less, 2.0 W / (m·K) or less, or 1.0 W / (m·K) or less. The thermal conductivity of the material of the optical medium 10 is at least 0.5 times that of the sample 5. The thermal conductivity of the material of the optical medium 10 can be at least 0.75 times that of the sample 5, greater than or equal to the sample 5, at least 1.5 times that of the sample 5, or at least 2.0 times that of the sample 5.

[0027] The optical medium 10 is formed of chalcogenide glass. The chalcogenide glass contains, for example: 2 mol% to 22 mol% of germanium (Ge); 6 mol% to 34 mol% of at least one element selected from the group consisting of antimony (Sb) and bismuth (Bi); 1 mol% to 20 mol% of tin (Sn); and 58 mol% to 70 mol% of at least one element selected from the group consisting of sulfur (S), selenium (Se), and tellurium (Te). The thermal conductivity of this chalcogenide glass is 0.36 W / (m·K).

[0028] Excitation light source 16 emits excitation light 17 toward sample 5 placed on sample mounting surface (second surface 12). Excitation light 17 is emitted from excitation light source 16 and incident on optical medium 10 from first surface 11. Excitation light 17 travels within optical medium 10. Excitation light 17 is incident on sample 5 from second surface 12. Excitation light 17 is absorbed by biological components in or on surface 6 of sample 5. For example, in the case of obtaining a patient's blood glucose value using biological component measuring device 1, the biological component is sugar present in the interstitial fluid of the epidermis. Absorption of excitation light 17 by biological components causes heat absorption in sample 5. The heat absorption of sample 5 is conducted to optical medium 10. A temperature gradient region is generated inside optical medium 10, and a refractive index gradient region 18 is generated inside optical medium 10.

[0029] The wavelength of the excitation light 17 is determined based on the absorption wavelength of the biological components in or on the surface 6 of sample 5. The wavelength of the excitation light 17 can also be longer than the wavelength of the probe light 21. For example, the wavelength of the excitation light 17 is 6.0 μm or more. The wavelength of the excitation light 17 can also be 8.0 μm or more. The wavelength of the excitation light 17 can be 13.0 μm or less. The wavelength of the excitation light 17 can also be 11.0 μm or less. The excitation light 17 can also be light with multiple wavelengths. For example, when using the biological component measurement device 1 to measure a patient's blood glucose level, the wavelength range of the excitation light 17 is the wavelength range including the fingerprint spectrum of glucose (e.g., a wavelength range of 8.5 μm or more and 10 μm or less). The excitation source 16 is, for example, a quantum cascade laser capable of emitting broadband infrared light. Reference light that is not absorbed by the biological components in or on the surface 6 of sample 5 can also be irradiated onto sample 5 along with the excitation light 17.

[0030] The probe light source 20 emits a probe light 21. The probe light 21 is incident on the optical medium 10 from the third surface 13. The probe light 21 is refracted at the third surface 13 and propagates in the optical medium 10 towards the interface between the optical medium 10 (second surface 12) and the sample 5. When viewed from above the sample mounting surface (second surface 12), the optical path of the probe light 21 in the optical medium 10 overlaps with the portion of the sample mounting surface (second surface 12) illuminated by the excited light 17. The probe light 21 undergoes total internal reflection at the interface between the optical medium 10 (second surface 12) and the sample 5. During its propagation in the optical medium 10, the probe light 21 travels through a refractive index gradient region 18 generated within the optical medium 10 due to the heat absorbed by the sample 5. The probe light 21 is refracted in the refractive index gradient region 18, and its direction of travel changes. The probe light 21 (first emitted probe light 21a, second emitted probe light 21b) is emitted from the fourth surface 14 of the optical medium 10.

[0031] The wavelength of the probe light 21 is, for example, 1100 nm or higher. The wavelength of the probe light 21 can also be 1300 nm or higher. The wavelength of the probe light 21 is, for example, 1700 nm or lower. Therefore, as the light source for the probe light 21, inexpensive semiconductor lasers for optical communication, such as InGaAsP or InGaNAs semiconductor lasers, can be used. Furthermore, since the probe light 21 is not visible light, the risk of damage to the human eye from the probe light 21 can be reduced. The output of the probe light 21 is, for example, 5 mW or less. Therefore, the risk of damage to the human eye from the probe light 21 can be reduced.

[0032] The optical position detector 25 detects the position of the probe light 21 (first emitted probe light 21a, second emitted probe light 21b) emitted from the optical medium 10. The optical position detector 25 detects the first position 22a of the probe light 21 (first emitted probe light 21a) when the sample 5 is not illuminated by the excitation light 17. The first position 22a of the probe light 21 (first emitted probe light 21a) is the position of the probe light 21 (first emitted probe light 21a) detected by the optical position detector 25 when the sample 5 is not illuminated by the excitation light 17. The optical position detector 25 detects the second position 22b of the probe light 21 (second emitted probe light 21b) when the sample 5 is illuminated by the excitation light 17. The second position 22b of the probe light 21 (second emitted probe light 21b) is the position of the probe light 21 (second emitted probe light 21b) detected by the optical position detector 25 when the sample 5 is illuminated by the excitation light 17. When sample 5 is illuminated with excitation light 17, the position of the probe light 21 detected by the light position detector 25 changes from position 1 22a to position 22b.

[0033] The optical position detector 25 outputs the first position 22a of the probe light 21 (first emitted probe light 21a) and the second position 22b of the probe light 21 (second emitted probe light 21b) to the biological component acquisition unit 27. The optical position detector 25 is, for example, a photodiode or a semiconductor position detection element.

[0034] The biological component acquisition unit 27 is connected to the light position detector 25. The biological component acquisition unit 27 calculates the distance between the first position 22a and the second position 22b, i.e., the displacement amount δ of the detection light 21, and obtains the amount or concentration of biological components in the sample 5 or on the surface 6 of the sample 5 based on the displacement amount δ of the detection light 21. The biological component acquisition unit 27 is, for example, one of the functions performed by a computational processing device.

[0035] Reference Figure 2 This describes the biological composition determination method of this embodiment using the biological composition determination device 1.

[0036] The biological composition determination method of this embodiment includes: without irradiating the sample 5 with excitation light 17, using a light position detector 25 to detect the first position 22a of the probe light 21 (first emitted probe light 21a) (S1). Since the sample 5 is not irradiated with excitation light 17, no heat absorption occurs in the sample 5. No temperature gradient region or refractive index gradient region 18 is generated inside the optical medium 10. When the sample 5 is not irradiated with excitation light 17, the probe light 21 (first emitted probe light 21a) is emitted from the optical medium 10. The first position 22a of the probe light 21 (first emitted probe light 21a) is the position of the probe light 21 (first emitted probe light 21a) detected by the light position detector 25.

[0037] The biological component determination method of this embodiment includes: irradiating a sample 5 with excitation light 17 while using a photodetector 25 to detect the second position 22b of the probe light 21 (second emitted probe light 21b) (S2). Since the sample 5 is irradiated with excitation light 17, the excitation light 17 is absorbed by biological components in the sample 5 or on the surface 6 of the sample 5. Absorption of the excitation light 17 by the biological components generates heat of absorption in the sample 5. The heat of absorption of the sample 5 is conducted to the optical medium 10. A temperature gradient region is generated inside the optical medium 10, and a refractive index gradient region 18 is generated inside the optical medium 10. The probe light 21 is refracted in the refractive index gradient region 18, and the direction of travel of the probe light 21 changes. When the sample 5 is irradiated with excitation light 17, the probe light 21 (second emitted probe light 21b) is emitted from the optical medium 10. The second position 22b of the probe light 21 (the second emitted probe light 21b) is the position of the probe light 21 (the second emitted probe light 21b) detected by the light position detector 25. By illuminating the sample 5 with the excitation light 17, the position of the probe light 21 detected by the light position detector 25 changes from the first position 22a to the second position 22b.

[0038] The biological composition determination method of this embodiment includes: calculating the displacement amount δ of the probe light 21 (S3). Specifically, the biological composition acquisition unit 27 calculates the distance between the first position 22a and the second position 22b to obtain the displacement amount δ of the probe light 21.

[0039] The biological component determination method of this embodiment includes: obtaining the amount or concentration of biological components in the sample 5 or on the surface 6 of the sample 5 based on the displacement δ of the probe light 21 (S4). For example, the biological component acquisition unit 27 is connected to a memory (not shown). The memory stores a data table that corresponds to the type of biological component, the displacement δ of the probe light 21, and the amount or concentration of the biological component. The biological component acquisition unit 27 refers to the data table to obtain the amount or concentration of the biological component corresponding to the type of biological component and the displacement δ of the probe light 21.

[0040] Reference Figure 3This embodiment describes the first modification of the biocomposition measuring apparatus 1a. In this first modification, the normal direction of the third surface 13 of the optical medium 10 is parallel to the incident direction of the probe light 21. The fourth surface 14 is parallel to the third surface 13. The probe light 21 does not undergo total internal reflection at the sample mounting surface (second surface 12), but travels along the sample mounting surface (second surface 12). The biocomposition measuring method using the biocomposition measuring apparatus 1a is the same as the biocomposition measuring method using the biocomposition measuring apparatus 1. In the second modification of this embodiment, the probe light 21 may also undergo multiple total internal reflections at the interface between the sample mounting surface (second surface 12) and the sample 5.

[0041] The effects of the biological composition measuring devices 1 and 1a of this embodiment are explained.

[0042] The biological composition measuring apparatus 1, 1a of this embodiment includes an optical medium 10, an excitation light source 16, a detection light source 20, and a light position detector 25. The optical medium 10 includes a sample mounting surface (second surface 12). The excitation light source 16 radiates excitation light 17 that propagates through the optical medium 10 towards the sample 5 mounted on the sample mounting surface (second surface 12). The detection light source 20 radiates detection light 21 that propagates through the optical medium 10. The light position detector 25 detects the position of the detection light 21 emitted from the optical medium 10. When viewed from above the sample mounting surface (second surface 12), the optical path of the detection light 21 in the optical medium 10 overlaps with the portion of the sample mounting surface (second surface 12) illuminated by the excitation light 17. The optical medium 10 is formed of chalcogenide glass.

[0043] The thermal conductivity of chalcogenide glass is lower than that of zinc sulfide (ZnS) (27.2 W / (m·K)). Therefore, the heat absorbed by sample 5 is conducted away, resulting in a larger change in refractive index in the refractive index gradient region 18 formed in the optical medium 10. The biological composition measuring apparatus 1, 1a of this embodiment can measure biological composition with improved accuracy.

[0044] In the biocomposition measuring devices 1 and 1a of this embodiment, the wavelength of the probe light 21 is 1300 nm or more and 1700 nm or less. Therefore, the risk of damage to the human eye caused by the probe light 21 can be reduced. In addition, an inexpensive semiconductor laser for optical communication can be used as the probe light source 20, thus reducing the cost of the biocomposition measuring devices 1 and 1a.

[0045] In the biological composition measuring apparatus 1 of this embodiment, the probe light 21 undergoes total internal reflection at the sample placement surface (second surface 12). Therefore, the distance traveled by the probe light 21 in the refractive index gradient region 18 can be extended. The biological composition measuring apparatus 1 of this embodiment can measure biological composition with improved accuracy.

[0046] In the biological composition measuring apparatus 1a of this embodiment, the probe light 21 does not undergo total internal reflection at the sample placement surface (second surface 12), but instead travels along the sample placement surface (second surface 12). Therefore, the biological composition measuring apparatus 1a of this embodiment can measure biological composition with improved accuracy.

[0047] The biological composition measuring apparatus 1, 1a of this embodiment further includes a biological composition acquisition unit 27 connected to a light position detector 25. The light position detector 25 outputs the first position 22a of the probe light 21 (first emitted probe light 21a) when the sample 5 is not irradiated by the excitation light 17 and the second position 22b of the probe light 21 (second emitted probe light 21b) when the sample 5 is irradiated by the excitation light 17 to the biological composition acquisition unit 27. The biological composition acquisition unit 27 calculates the displacement δ of the probe light 21, i.e., the distance between the first position 22a and the second position 22b, and obtains the amount or concentration of biological components in the sample 5 or on the surface 6 of the sample 5 based on the displacement δ of the probe light 21. Therefore, the biological composition measuring apparatus 1, 1a of this embodiment can measure biological components with improved accuracy.

[0048] The biological composition measuring apparatus 1, 1a of this embodiment includes an optical medium 10, an excitation light source 16, a detection light source 20, and a light position detector 25. The optical medium 10 includes a sample mounting surface (second surface 12). The excitation light source 16 radiates excitation light 17 that propagates through the optical medium 10 towards the sample 5 mounted on the sample mounting surface (second surface 12). The detection light source 20 radiates detection light 21 that propagates through the optical medium 10. The light position detector 25 detects the position of the detection light 21 emitted from the optical medium 10. When viewed from above the sample mounting surface (second surface 12), the optical path of the detection light 21 in the optical medium 10 overlaps with the portion of the sample mounting surface (second surface 12) irradiated by the excitation light 17. The optical medium 10 is formed of a material having a thermal conductivity of 15.0 W / (m·K) or less.

[0049] Therefore, the thermal conductivity of the material of optical medium 10 is less than that of zinc sulfide (ZnS) (27.2 W / (m·K)). The heat absorbed by sample 5 is conducted away, resulting in a larger change in refractive index in the refractive index gradient region 18 formed in optical medium 10. The biological composition measuring apparatus 1, 1a of this embodiment can measure biological composition with improved accuracy.

[0050] In the biological composition measuring apparatus 1 and 1a of this embodiment, the thermal conductivity of the material of the optical medium 10 is 1.0 W / (m·K) or less. Therefore, the thermal conductivity of the material of the optical medium 10 is less than that of zinc sulfide (ZnS) (27.2 W / (m·K)). The heat absorbed by the sample 5 is conducted, resulting in a larger change in refractive index in the refractive index gradient region 18 formed in the optical medium 10. The biological composition measuring apparatus 1 and 1a of this embodiment can measure biological composition with improved accuracy.

[0051] In the biological composition measuring apparatus 1 and 1a of this embodiment, the thermal conductivity of the material of the optical medium 10 is at least 0.5 times that of the sample 5. Therefore, most of the absorbed heat occurring in the sample 5 is prevented from dissipating to the sample 5, and this absorbed heat is conducted to the optical medium 10. The biological composition measuring apparatus 1 and 1a of this embodiment can measure biological composition with improved accuracy.

[0052] Implementation method 2.

[0053] Reference Figure 4 The following describes the biological composition measuring device 1b of Embodiment 2. The biological composition measuring device 1b of this embodiment has the same structure as the biological composition measuring device 1 of Embodiment 1, but differs mainly in the following aspects.

[0054] The biocomposition measuring device 1b also includes an optical chopper 30 and a lock-in amplifier 31. The optical chopper 30 is disposed in the optical path of the excitation light 17. The optical chopper 30 chops the excitation light 17 at an arbitrary frequency. The lock-in amplifier 31 is connected to the optical chopper 30 and the optical position detector 25. The lock-in amplifier 31 selectively amplifies the signal that is synchronized with the chopping frequency of the optical chopper 30 in the signal related to the position of the probe light 21 output from the optical position detector 25. Therefore, noise contained in the signal related to the position of the probe light 21 output from the optical position detector 25 can be removed. The biocomposition measuring device 1b can measure biocomposition with improved accuracy.

[0055] Implementation method 3.

[0056] Reference Figure 5 This describes the biological composition measuring device 1c of Embodiment 3. The biological composition measuring device 1c of this embodiment has the same structure as the biological composition measuring device 1 of Embodiment 1, but differs mainly in the following aspects.

[0057] The biological composition measuring device 1c also includes a temperature sensor 35. The biological composition measuring device 1c may also include a display 36. The temperature sensor 35 is, for example, mounted on a portion of the optical medium 10 that is away from the sample 5, the excitation light 17, and the probe light 21. Specifically, the temperature sensor 35 is mounted on a portion of the sample mounting surface (second surface 12) of the optical medium 10 that is away from the sample 5, the excitation light 17, and the probe 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 the magnitude of temperature change of the optical medium 10 per unit time. The display 36 is, for example, a liquid crystal display device.

[0058] When a temperature difference exists between the first temperature of the optical medium 10 and the second temperature of the sample 5, thermal movement occurs between the optical medium 10 and the sample 5. This thermal movement affects the refractive index gradient region 18 generated within the optical medium 10, making it difficult to accurately determine the biological composition. Since the optical medium 10 is formed of a material with low thermal conductivity, such as chalcogenide glass, it takes a longer time to move from a state where the variation in the first temperature of the optical medium 10 per unit time exceeds the allowable temperature variation range (e.g., 0.1°C / min) (thermal non-equilibrium state) to a state where the variation in the first temperature of the optical medium 10 per unit time is below the allowable temperature variation range (e.g., 0.1°C / min) (thermal non-equilibrium state).

[0059] In the biological composition measuring device 1c, a temperature sensor 35 is used to determine the magnitude of the change in the first temperature of the optical medium 10 per unit time, i.e., the degree of thermal movement between the optical medium 10 and the sample 5. After the sample 5 is placed on the sample mounting surface (second surface 12) of the optical medium 10, during the period when the magnitude of the change in the first temperature of the optical medium 10 per unit time, as measured by the temperature sensor 35, is greater than the allowable temperature change range (e.g., 0.1°C / min) (thermal non-equilibrium state), the biological composition is not measured using the biological composition measuring device 1c. After the sample 5 is placed on the sample mounting surface (second surface 12) of the optical medium 10, when the magnitude of the change in the first temperature of the optical medium 10 per unit time becomes less than or equal to the allowable temperature change range (e.g., 0.1°C / min) (thermal equilibrium state), the biological composition is measured using the biological composition measuring device 1c.

[0060] In addition to the effects of the biological composition measuring device 1 of Embodiment 1, the biological composition measuring device 1c of this embodiment also has the following effects.

[0061] The biological composition measuring apparatus 1c of this embodiment also includes a temperature sensor 35 for measuring the temperature of the optical medium 10. Therefore, the temperature sensor 35 can be used to measure the temperature change of the optical medium 10 caused by thermal movement between the optical medium 10 and the sample 5. Even if the optical medium 10 is made of a material with low thermal conductivity, such as chalcogenide glass, there will be no adverse effects caused by thermal movement between the optical medium 10 and the sample 5, and the timing for accurately measuring biological composition can be determined. The biological composition measuring apparatus 1c of this embodiment can measure biological composition with improved accuracy.

[0062] Implementation method 4.

[0063] Reference Figure 6 This section describes the biological composition measuring device 1d of Embodiment 4. The biological composition measuring device 1d of this embodiment has the same structure as the biological composition measuring device 1c of Embodiment 3, but differs mainly in the following aspects.

[0064] The biological composition measuring device 1d also includes a temperature regulator 37 and a temperature controller 38. The temperature regulator 37 is, for example, mounted on a portion of the optical medium 10 that is away from the sample 5, the excitation light 17, and the probe light 21. Specifically, the temperature regulator 37 is mounted on the sample placement surface (second surface 12) of the optical medium 10 that is away from the sample 5, the excitation light 17, and the probe light 21. The temperature regulator 37 adjusts the temperature of the optical medium 10. The temperature regulator 37 is, for example, a Peltier element or a heating wire. The temperature sensor 35 also outputs a first signal related to the temperature of the optical medium 10 to the temperature controller 38.

[0065] Temperature controller 38 is connected to temperature sensor 35 and temperature regulator 37. Temperature controller 38 controls temperature regulator 37 based on a first signal related to the temperature of optical medium 10 output from temperature sensor 35. Specifically, temperature regulator 37 is controlled such that the variation range of the first temperature of optical medium 10 per unit time measured by temperature sensor 35 is less than or equal to an allowable temperature variation range (e.g., 0.1°C / min). For example, if the first temperature of optical medium 10 is lower than the second temperature of sample 5 and the variation range of the first temperature of optical medium 10 per unit time is greater than the allowable temperature variation range, temperature controller 38 controls temperature regulator 37 to heat optical medium 10. If the first temperature of optical medium 10 is higher than the second temperature of sample 5 and the variation range of the first temperature of optical medium 10 per unit time is greater than the allowable temperature variation range, temperature controller 38 controls temperature regulator 37 to cool optical medium 10.

[0066] In addition to the effects of the biological composition measuring device 1c in Embodiment 3, the biological composition measuring device 1d of this embodiment also has the following effects.

[0067] The biological composition measuring apparatus 1d of this embodiment further includes a temperature regulator 37 and a temperature controller 38 for adjusting the temperature of the optical medium 10. The temperature controller 38 controls the temperature regulator 37 based on a first signal related to the temperature of the optical medium 10 output from the temperature sensor 35. Therefore, even if the optical medium 10 is formed of a material with low thermal conductivity, such as chalcogenide glass, the time from placing the sample 5 on the sample mounting surface (second surface 12) of the optical medium 10 to the point where the heat transfer between the optical medium 10 and the sample 5 substantially disappears, allowing for the measurement of biological composition, can be shortened. The biological composition measuring apparatus 1d can measure biological composition with improved accuracy and in a shorter time.

[0068] Implementation method 5.

[0069] Reference Figure 7 as well as Figure 8 The biological composition measuring device 1e of Embodiment 5 will be described. The biological composition measuring device 1e of this embodiment has the same structure as the biological composition measuring device 1 of Embodiment 1, but differs mainly in the following aspects.

[0070] The biological composition measuring device 1e also has the capability to determine the direction of travel of the probe light 21. Figure 7 A positioning component 40 is used to define the position of sample 5 in the left-right direction. The positioning component 40 includes a pair of clamping components 41 and a connecting component 42 connecting the pair of clamping components 41 to each other. Each pair of clamping components 41 includes a base plate 41a and a wall 41b extending from the base plate 41a along the normal direction of the sample mounting surface (second surface 12). The base plate 41a is in surface contact with the sample mounting surface (second surface 12). The wall 41b is in contact with the side of sample 5. The pair of walls 41b of the pair of clamping components 41 clamp sample 5 in the direction of travel of the probe light 21.

[0071] The biocomposition measuring device 1e also includes a pressing part 44, a pressure sensor 48, and a pressure controller 49. The pressing part 44 presses the sample 5 toward the sample mounting surface (second surface 12). The pressing part 44 includes, for example, a pressing plate 45, a ball screw 46 that moves the pressing plate 45 along the normal direction of the sample mounting surface (second surface 12), and a motor 47 that rotates the ball screw 46. In a variation of this embodiment, an elastic member such as a spring may be used to apply force toward the sample 5 with respect to the pressing plate 45.

[0072] A pressure sensor 48 is disposed on the pressing part 44. Specifically, the pressure sensor 48 is disposed on the pressing plate 45. The pressure sensor 48 measures the pressure of the pressing part 44 pressing the sample 5. The pressure sensor 48 outputs a second signal related to the pressure of the pressing part 44 pressing the sample 5 to the pressure controller 49. The pressure sensor 48 is, for example, an instrument-type pressure sensor or an electrostatic capacitive pressure sensor.

[0073] like Figure 8 As shown, a pressure controller 49 is connected to a pressing unit 44 (e.g., a motor 47) and a pressure sensor 48. The pressure controller 49 controls the pressing unit 44 based on a second pressure-related signal output from the pressure sensor 48. For example, the pressing unit 44 (motor 47) is controlled in such a way that the pressure applied to the sample 5 and measured by the pressure sensor 48 becomes a reference pressure. Specifically, if the pressure applied to the sample 5 is lower than the reference pressure, the pressure controller 49 moves the pressing plate 45 toward the sample mounting surface (second surface 12) in such a way that the pressure applied to the sample 5 equals the reference pressure. If the pressure applied to the sample 5 is higher than the reference pressure, the pressure controller 49 moves the pressing plate 45 away from the sample mounting surface (second surface 12) in such a way that the pressure applied to the sample 5 equals the reference pressure.

[0074] In addition to the effects of the biological composition measuring device 1 of Embodiment 1, the biological composition measuring device 1e of this embodiment also has the following effects.

[0075] The biological composition measuring device 1e of this embodiment further includes a pressing part 44, a pressure sensor 48, and a pressure controller 49. The pressing part 44 presses the sample 5 toward the sample placement surface (second surface 12). The pressure sensor 48 measures the pressure of the pressing part 44 pressing the sample 5. The pressure controller 49 controls the pressing part 44 based on a second pressure-related signal output from the pressure sensor 48. Therefore, the contact pressure of the sample 5 with the optical medium 10 can be kept constant. The conduction of the absorbed heat of the sample 5 to the optical medium 10 becomes stable. The biological composition measuring device 1e can measure biological composition with improved accuracy.

[0076] The biological composition measuring device 1e of this embodiment also includes a positioning member 40 that defines the position of the sample 5 in the direction of travel of the probe light 21. Therefore, even if the sample 5 is a movable sample such as a patient's finger, the sample 5 can be positioned relative to the excitation light 17 and the probe light 21 in the direction of travel of the probe light 21. The biological composition measuring device 1e can measure biological composition with improved accuracy.

[0077] Implementation method 6.

[0078] Reference Figure 9This section describes the biological composition measuring device 1f of Embodiment 6. The biological composition measuring device 1f of this embodiment has the same structure as the biological composition measuring device 1 of Embodiment 1, but differs mainly in the following aspects: The biological composition measuring device 1f also includes a light intensity detector 51 and a light source controller 52. The biological composition measuring device 1f may also include a light beam splitter 50.

[0079] A light intensity detector 51 detects the intensity of the excitation light 17 emitted from the excitation source 16. The light intensity detector 51 is, for example, a photodiode. Specifically, an optical beamsplitter 50 is arranged in the optical path of the excitation light 17. The optical beamsplitter 50 is, for example, a planar optical beamsplitter, a prism optical beamsplitter, or a fiber optic optical beamsplitter. The optical beamsplitter 50 directs a portion of the excitation light 17 toward the light intensity detector 51. For example, the optical beamsplitter 50 reflects a portion of the excitation light 17 toward 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.

[0080] A light source controller 52 is connected to an excitation light source 16. The light source controller 52 controls the excitation light source 16. For example, the light source controller 52 controls the current injected into the excitation light source 16, thereby controlling the intensity of the excitation light 17 emitted from the excitation light source 16. The light source controller 52 is connected to a light intensity detector 51. The light source controller 52 receives a signal related to the intensity of the excitation light 17 from the light intensity detector 51. To maintain a constant intensity of the excitation light 17 emitted from the excitation light source 16, 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.

[0081] In addition to the effects of the biological composition measuring device 1 of Embodiment 1, the biological composition measuring device 1f of this embodiment also has the following effects.

[0082] The biological composition measuring device 1f of this embodiment further includes: a light intensity detector 51 for detecting the light intensity of the excitation light 17; and a light source controller 52 for controlling the excitation light source 16 based on a signal output from the light intensity detector 51 that relates to the intensity of the excitation light 17.

[0083] During the prolonged operation of the excitation light source 16, the intensity of the excitation light 17 emitted from the excitation light source 16 may sometimes decrease. When the intensity of the excitation light 17 decreases, the accuracy of the biological component measurement decreases. However, in this embodiment, the light source controller 52 controls the excitation light source 16 based on a signal related to the intensity of the excitation light 17 output from the light intensity detector 51. Therefore, the intensity of the excitation light 17 emitted from the excitation light source 16 can be maintained for a longer period of time. The biological component measurement apparatus 1f can measure biological components with improved accuracy for an extended period of time.

[0084] It should be understood that embodiments 1-6 disclosed herein are merely illustrative and not restrictive in all respects. At least two of embodiments 1-6 may be combined, provided there is no contradiction. For example, embodiments 2-5 may be combined with variations of embodiment 1. Embodiment 6 may be combined with various embodiments of embodiments 2-5. The scope of this disclosure is not limited to the foregoing description but is set forth in the claims and is intended to include all modifications within the meaning and scope equivalent to the claims.

Claims

1. A biological composition measuring device, which uses the heating effect of a biological sample absorbing excitation light to measure composition, the biological composition measuring device comprising: An optical medium, including a biological sample mounting surface on which the biological sample is placed, the optical medium being transparent to the excitation light and the probe light, being formed of a chalcogenide glass having a lower thermal conductivity than zinc sulfide, and having a change in refractive index due to the heating of the biological sample absorbing the excitation light; An excitation light source is directed toward the surface on which the biological sample is placed, emitting excitation light that travels through the optical medium. A detection light source, emitting detection light that propagates through the optical medium; A light position detector detects the position of the probe light emitted from the optical medium; as well as Temperature sensor, measures the temperature of the optical medium. The optical position detector detects a first position of the probe light emitted from the optical medium, which is transparent to both the excitation light and the probe light, when the excitation source is not emitting the excitation light, and a second position of the probe light emitted from the optical medium, which generates a refractive index gradient region due to the heating caused by the excitation light traveling through the optical medium, which is transparent to both the excitation light and the probe light, when the excitation source is emitting the excitation light. The component is determined based on the first position and the second position. The temperature sensor is mounted on the portion of the biological sample placement surface that is away from the biological sample, the excitation light, and the detection light.

2. The biological composition measuring device according to claim 1, wherein, The wavelength of the probe light is above 1300nm and below 1700nm.

3. The biological composition measuring device according to claim 1, wherein, The biological composition measuring device also includes: An optical chopper is disposed in the optical path of the excitation light; and A lock-in amplifier is connected to the optical chopper and the optical position detector.

4. The biological composition measuring device according to any one of claims 1 to 3, wherein, The biological composition measuring device also includes: A temperature regulator to adjust the temperature of the optical medium; and A temperature controller controls the temperature regulator based on a first signal output from the temperature sensor relating to the temperature of the optical medium.

5. The biological composition measuring device according to any one of claims 1 to 3, wherein, The biological composition measuring device also includes: The pressing part presses the biological sample toward the biological sample placement surface; A pressure sensor measures the pressure applied by the pressing part to the biological sample; and The pressure controller controls the pressing part based on a second signal related to the pressure output from the pressure sensor.

6. The biological composition measuring device according to any one of claims 1 to 3, wherein, The biological composition measuring device also includes a positioning component that defines the position of the biological sample in the direction of travel of the probe light.

7. The biological composition measuring device according to any one of claims 1 to 3, wherein, The probe light undergoes total internal reflection on the surface where the biological sample is placed.

8. The biological composition measuring device according to any one of claims 1 to 3, wherein, The probe light does not undergo total internal reflection on the surface of the biological sample, but instead travels along the surface of the biological sample.

9. The biological composition measuring device according to any one of claims 1 to 3, wherein, The biological composition measuring device also includes a biological composition acquisition unit connected to the optical position detector. The optical position detector outputs the first position and the second position to the biological component acquisition unit. The biological component acquisition unit calculates the distance between the first position and the second position, i.e., the displacement of the probe light, and obtains the amount or concentration of the component in the biological sample or on the surface of the biological sample based on the displacement.

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