Near-infrared blood glucose detection device

Abstract

The invention belongs to the field of blood glucose detection, and discloses a near-infrared blood glucose detection device, which comprises a light emitting assembly, a light receiving assembly, a first light receiving assembly and a second light receiving assembly, the first shading element surrounds the light source and the outer side of the first optical element, and the light source is used for emitting near-infrared light to the first optical element; the first optical element is used for collimating the received near-infrared light and then emitting the near-infrared light to the surface of an object to be detected; the light receiving assembly comprises a photosensitive element, a second optical element and a second shading element, the second shading element is arranged on the outer side of the photosensitive element and the outer side of the second optical element in a surrounding mode, and the second optical element is used for receiving emergent light of the surface of the to-be-detected object and emitting the emergent light into the photosensitive element after collimating the emergent light. The first optical element is arranged to collimate the light emitted by the light source, so that the light can be emitted into the surface of the to-be-detected object in the same direction, the walking path of the light in the skin is clearer, the loss of the light can be reduced, and the signal-to-noise ratio of the detection device is improved.

Description

Technical Field

[0001] This invention relates to the field of blood glucose detection technology, and more particularly to a near-infrared blood glucose detection device. Background Technology

[0002] Near-infrared spectroscopy refers to electromagnetic waves with wavelengths between the visible and mid-infrared regions, ranging from 0.7 to 2.5 μm. Near-infrared spectroscopy technology involves illuminating experimental samples with a near-infrared light source and then analyzing the effective information carried by the substance based on the transmitted or reflected light, enabling accurate and rapid detection of the content of one or more components in the analyte.

[0003] Near-infrared spectroscopy can be applied to various biological samples, such as biological specimens and tissues. Near-infrared light is emitted onto biological samples, and the absorption, scattering, and reflection characteristics of near-infrared light within the tissues are used to study the sample composition and the content of specific substances. Near-infrared light is primarily absorbed by the overtones and combination frequencies of vibrations of hydrogen-containing groups. The absorption of specific near-infrared light contains information about the composition and molecular structure of organic compounds. Therefore, near-infrared absorption spectroscopy can serve as an effective carrier for obtaining information about substances. Furthermore, according to the Lambert-Beer law, the intensity of absorption of a substance at a specific wavelength is related to the concentration of the absorbing substance; therefore, the concentration of a substance can be obtained by measuring the intensity of its absorption at a specific wavelength.

[0004] Currently, near-infrared spectroscopy is used for non-invasive human detection, such as detecting glucose levels in human blood. Normal human blood glucose concentration varies very little within the range of 4.4–10.0 mmol / L; however, the effective signal from these changes is extremely weak when using near-infrared spectroscopy for non-invasive detection. Therefore, a high signal-to-noise ratio (SNR) is required for the entire detection system to detect the blood glucose signal; and the higher the SNR, the more accurate the detected blood glucose concentration. Thus, effectively improving the SNR of near-infrared spectroscopy blood glucose detection devices is a problem that needs to be solved. Summary of the Invention

[0005] The purpose of this application is to provide a near-infrared blood glucose detection device to improve the signal-to-noise ratio of near-infrared spectral blood glucose detection.

[0006] The technical solution provided in this application is as follows:

[0007] A near-infrared blood glucose detection device, comprising:

[0008] Optical transmitting component and optical receiving component;

[0009] The light emitting assembly includes a light source, a first optical element, and a first light-shielding element; the first light-shielding element is disposed outside the light source and the first optical element, and the light source is used to emit near-infrared light toward the first optical element; the first optical element is used to collimate the received near-infrared light and emit it toward the surface of the object to be tested;

[0010] The light receiving component includes a photosensitive element, a second optical element, and a second light-shielding element. The second light-shielding element is disposed outside both the photosensitive element and the second optical element. The second optical element is used to receive the emitted light from the surface of the object under test and collimate the emitted light before shining it into the photosensitive element.

[0011] In some embodiments, the end of the second optical element away from the photosensitive element is a light-receiving surface, which is an outwardly convex arc surface that extends beyond the second light-shielding element.

[0012] In some embodiments, a circuit board is also included, on which both the light source and the photosensitive element are disposed. One end of the first light-shielding element and the second light-shielding element are fixedly connected to the circuit board. The first optical element is disposed on the side of the light source away from the circuit board, and the second optical element is disposed on the side of the photosensitive element away from the circuit board.

[0013] In some embodiments, the radius of curvature of the arc surface is R1;

[0014] in,

[0015] d1 is the length of the photosensitive area of ​​the photosensitive element; ds is the outer diameter of the second optical element; h is the distance from the end of the second light-shielding element away from the circuit board to the end of the second optical element close to the photosensitive element.

[0016] In some embodiments, when there is only one light source, the outer diameter of the end of the first optical element closest to the light source is equal to the outer diameter of the end of the first optical element furthest from the light source.

[0017] In some embodiments, when there are multiple light sources, the longitudinal section of the first optical element is trapezoidal, and the outer diameter of the end of the first optical element closer to the light source is greater than the outer diameter of the end of the first optical element farther from the light source.

[0018] In some embodiments, the first light-shielding element has a first mounting hole and a second mounting hole that are connected to each other. The diameter of the first mounting hole is smaller than the diameter of the second mounting hole. A first step is formed at the connection between the first mounting hole and the second mounting hole. The light source is located in the first mounting hole. The first optical element is located in the second mounting hole and its end near the light source abuts against the first step. The outer sidewall of the first optical element is in contact with the inner sidewall of the first light-shielding element.

[0019] In some embodiments, the second light-shielding element has a third mounting hole and a fourth mounting hole that are connected to each other. The diameter of the third mounting hole is smaller than that of the fourth mounting hole. The connection between the third mounting hole and the fourth mounting hole forms a second step. The photosensitive element is located in the third mounting hole. The second optical element is located in the fourth mounting hole, and one end of the second optical element near the photosensitive element abuts against the second step. The outer sidewall of the second optical element is in contact with the inner sidewall of the second light-shielding element.

[0020] In some embodiments, the first optical element is composed of multiple optical fibers, or the first optical element is a collimating lens.

[0021] In some embodiments, the second optical element consists of multiple optical fibers, or the second optical element is a collimating lens.

[0022] The technical advantage of this application is that by setting the first optical element to collimate the near-infrared light emitted by the light source, the near-infrared light can enter the surface of the object to be tested in the same direction, the path of the near-infrared light in the skin is clearer, the loss of light can be reduced, thereby improving the signal-to-noise ratio of the near-infrared blood glucose detection device, and thus making the detected blood glucose concentration more accurate. Attached Figure Description

[0023] The present application will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0024] Figure 1 This is a schematic diagram of the structure of a near-infrared blood glucose detection device provided in a specific embodiment of this application;

[0025] Figure 2 This is a top view of a near-infrared blood glucose detection device provided in a specific embodiment of this application;

[0026] Figure 3 This is a schematic diagram illustrating the principle of light coupling between the first and second optical elements provided in a specific embodiment of this application;

[0027] Figure 4 This is a schematic diagram illustrating the detection process of a near-infrared blood glucose detection device according to a specific embodiment of this application;

[0028] Figure 5 This is a schematic diagram of a near-infrared blood glucose detection device provided in a specific embodiment of this application.

[0029] Explanation of icon numbers:

[0030] 100, Light emitting component; 110, Light source; 120, First optical element; 121, Incident surface; 122, Exit surface; 130, First light-shielding element; 131, First step portion;

[0031] 200, light receiving component; 210, photosensitive element; 220, second optical element; 221, arc surface; 230, second light-shielding element; 231, second step portion;

[0032] 300. Fiber optic cable;

[0033] 400. Circuit board. Detailed Implementation

[0034] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application can also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0035] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the specific implementation methods of this application will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without creative effort.

[0036] To keep the drawings concise, each drawing only schematically shows the parts relevant to this application, and they do not represent the actual structure of the product. Furthermore, for ease of understanding, in some drawings, only one of the components with the same structure or function is schematically shown, or only one is labeled. In this document, "one" not only means "only one," but can also mean "more than one."

[0037] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0038] In this document, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linkage" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; or they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0039] In the embodiments shown in the accompanying drawings, the directional indications (such as up, down, left, right, front, and back) are relative rather than absolute when describing the structure and movement of the various components, and are not intended to limit the direction of the product during actual use.

[0040] Furthermore, in the description of this application, ordinal numbers, such as "first" and "second," are used only to distinguish related objects and should not be construed as indicating or implying the relative importance or order between related objects.

[0041] Example 1

[0042] like Figure 1 and Figure 2 As shown, a near-infrared blood glucose detection device includes a light emitting component 100 and a light receiving component 200. The light emitting component 100 includes a light source 110, a first optical element 120, and a first light-shielding element 130. The first light-shielding element 130 surrounds the light source 110 and the first optical element 120. The light source 110 is used to emit near-infrared light to the first optical element 120. The light source 110 can be a near-infrared LED, a near-infrared LD, a near-infrared VCSEL, etc. In this embodiment, the number of light sources 110 can be one or more. The first optical element 120 is used to collimate the received near-infrared light and emit it onto the surface of the object to be tested. The function of the first optical element 120 is to reduce the emission angle of the light source 110 and collimate the near-infrared light emitted by the light source 110 so that the near-infrared light is emitted parallel to the surface of the object to be tested (i.e., the skin surface). The first light-shielding element 130 is an opaque barrier, primarily serving a light-shielding function. The material of the first light-shielding element 130 can be plastic or synthetic fiber (PLC), etc. The surface of the first light-shielding element 130 is coated with a black light-shielding material and given a matte finish to prevent near-infrared light emitted by the light source 110 from passing through the first light-shielding element 130. The first light-shielding element 130 has a closed annular structure, and its cross-section can be rectangular to achieve light shading from all sides.

[0043] The light receiving assembly 200 includes a photosensitive element 210, a second optical element 220, and a second light-shielding element 230. The second light-shielding element 230 is disposed outside both the photosensitive element 210 and the second optical element 220. The second optical element 220 receives the emitted light from the surface of the object under test and collimates the emitted light before directing it into the photosensitive element 210. The second light-shielding element 230 is an opaque barrier, primarily serving a light-shielding function. The material of the second light-shielding element 230 can be plastic or synthetic fiber (PLC), etc. The surface of the second light-shielding element 230 is coated with a black light-shielding material and has a matte finish to prevent near-infrared light from passing through. The second light-shielding element 230 has a closed annular structure to achieve circumferential light shading. The second optical element 220 receives the emitted light from the surface of the object to be tested. The near-infrared light emitted from the surface of the object is uncollimated, containing light rays from various directions. These emitted rays are collimated by the second optical element 220 and then enter the photosensitive element 210. The second optical element 220 can collect more effective light information, and collimation allows more effective light to enter the photosensitive element 210, thereby improving the signal-to-noise ratio. The photosensitive element 210 can be a photodiode (PD), with a photosensitive wavelength range of 900–1700 nm. The photosensitive element 210 can calculate the blood glucose level of the object to be tested based on the received near-infrared light.

[0044] like Figure 3 As shown, the working process of the near-infrared blood glucose detection device in this embodiment is as follows: Near-infrared light emitted by the light source 110 is collimated by the first optical element 120 and emitted parallel to the surface of the object to be tested (i.e., the skin surface). After absorption and scattering by various substances in the skin, the light emitted from the skin is emitted. The light emitted from the skin is non-collimated light, containing light from various directions. This light is collimated by the second optical element 220 and radiates to the photosensitive part of the photosensitive element 210 for analysis to calculate the blood glucose value.

[0045] In this embodiment, by setting the first optical element 120 to collimate the near-infrared light emitted by the light source 110, the near-infrared light can enter the surface of the object to be tested in the same direction. The path of the near-infrared light in the skin is clearer, which can reduce light loss and improve the signal-to-noise ratio of the near-infrared blood glucose detection device, thereby making the detected blood glucose concentration more accurate.

[0046] In this embodiment, when there is only one light source 110, the outer diameter of the end of the first optical element 120 near the light source 110 can be equal to the outer diameter of the end of the first optical element 120 away from the light source 110, that is, the outer diameter of the incident surface 121 of the first optical element 120 is equal to the outer diameter of the exit surface 122.

[0047] Furthermore, the first optical element 120 and the second optical element 220 can each be a collimating lens. Preferably, as shown below... Figure 4As shown, the first optical element 120 and the second optical element 220 are each composed of multiple optical fibers 300. The core diameter of the optical fiber 300 is 1–200 μm, and the numerical aperture of the optical fiber is NA, which ranges from 0.2 to 1.5, where NA = n*sinθ. max Where n is the refractive index of the fiber core, θ max The maximum incident angle is θ. The maximum angle of the emitted light from light source 110 is θ. When θ < θ max When, θ max The light ray 101 inside the fiber is coupled into the fiber 300, undergoes total internal reflection within the fiber 300, propagates along the fiber 300, and finally exits at a small angle; greater than θ. max The light ray 102 cannot couple into the optical fiber 300 and is ultimately absorbed by the light-blocking wall. Therefore, θ max The larger the better, that is, the larger the optical fiber numerical aperture NA, the better, so that more light emitted by the light source 110 is coupled into the optical fiber 300 of the first optical element 120, and at the same time, more light scattered by the skin is coupled into the optical fiber 300 of the second optical element 220.

[0048] Furthermore, such as Figure 1 As shown, the near-infrared blood glucose detection device also includes a circuit board 400, a light source 110 and a photosensitive element 210, both of which are disposed on the circuit board 400. One end of the first light-shielding element 130 and the second light-shielding element 230 is fixedly connected to the circuit board 400. The first optical element 120 is disposed on the side of the light source 110 away from the circuit board 400, and the second optical element 220 is disposed on the side of the photosensitive element 210 away from the circuit board 400.

[0049] For example, the circuit board 400 is provided with a first fixing hole and a second fixing hole. One end of the first light-shielding element 130 extends into the first fixing hole and is fixedly connected to the circuit board 400 with glue; one end of the second light-shielding element 230 extends into the second fixing hole and is fixedly connected to the circuit board 400 with glue. The light source 110 and the first optical element 120 are disposed in the first light-shielding element 130 and are arranged sequentially along the direction perpendicular to the circuit board 400. The end of the first optical element 120 away from the light source 110 is flush with the end of the first light-shielding element 130 away from the circuit board 400.

[0050] The photosensitive element 210 and the second optical element 220 are disposed within the second light-shielding element 230 and arranged sequentially along the direction perpendicular to the circuit board 400. The outer wall of the first light-shielding element 130 and the outer wall of the second light-shielding element 230 can contact each other, or there can be a gap between the first light-shielding element 130 and the second light-shielding element 230, such that the horizontal distance d between the center position of the light source 110 and the center position of the photosensitive element 210 ranges from 2 to 10 mm. The end of the first light-shielding element 130 away from the circuit board 400 can be flush with the end of the second light-shielding element 230 away from the circuit board 400.

[0051] Preferred, such as Figure 1 As shown, the end of the second optical element 220 furthest from the photosensitive element 210 is a light-receiving surface, which is an outwardly convex arc surface 221. The arc surface 221 extends beyond the end of the second light-shielding element 230 furthest from the circuit board 400. Near-infrared light, after being absorbed and scattered by various substances in the skin, exits the skin as non-collimated light, containing light from various directions. This light enters the second optical element 220, and the side of the second optical element 220 that receives the light is the arc surface 221. The arc surface 221 allows more light from various directions emitted from the skin to be coupled into the second optical element 220, further reducing the loss of useful light and thus further improving the signal-to-noise ratio of the infrared blood glucose detection device.

[0052] like Figure 3 As shown, the radius of curvature of the arc surface 221 of the second optical element 220 is R1;

[0053] in,

[0054] d1 is the length of the photosensitive area of ​​the photosensitive element 210; ds is the outer diameter of the second optical element 220. When the outer wall of the second optical element 220 is attached to the inner wall of the second light-shielding element 230, the outer diameter of the second optical element 220 is equal to the inner diameter of the second light-shielding element 230; h is the distance from the end of the second light-shielding element 230 away from the circuit board 400 to the end of the second optical element 120 near the photosensitive element 210. The two endpoints of the arc surface 221 are flush with the ends of the second light-shielding element 230 away from the circuit board 400, and the height of the first optical element 120 is also h. When the radius of curvature R of the arc surface 221 is within the above range, the arc surface 221 can receive more near-infrared light scattered by the skin, thereby improving the signal-to-noise ratio of the near-infrared blood glucose detection device.

[0055] Furthermore, such as Figure 1 and Figure 2As shown, the shape of the first light-shielding element 130 is adapted to the shape of the first optical element 120, and the structure of the second light-shielding element 230 is adapted to the shape of the second optical element 220. For example, when the first optical element 120 and the second optical element 220 are rectangular, the cross-sections of the first light-shielding element 130 and the second light-shielding element 230 are also rectangular.

[0056] Specifically, such as Figure 1 As shown, the first light-shielding element 130 has a first mounting hole and a second mounting hole that are connected. The diameter of the first mounting hole is smaller than that of the second mounting hole. The connection between the first mounting hole and the second mounting hole forms a first step portion 131. The light source 110 is located in the first mounting hole. The maximum outer diameter of the light source 110 can be smaller than the inner diameter of the first mounting hole. The first optical element 120 is located in the second mounting hole and its end near the light source 110 abuts against the first step portion 131. There is a distance h1 between the first optical element 120 and the light source 110. The distance h1 is reasonably set so that the near-infrared light emitted by the light source 110 can be coupled into the first optical element 120 as much as possible. The outer sidewall of the first optical element 120 is in contact with the inner sidewall of the first light-shielding element 130. The first step portion 131 can limit the first optical element 120. The first optical element 120 and the first light-shielding element 130 can be fixedly connected together by glue or the like.

[0057] like Figure 1 As shown, the second light-shielding element 230 has a third mounting hole and a fourth mounting hole that are connected to each other. The diameter of the third mounting hole is smaller than that of the fourth mounting hole. The connection between the third and fourth mounting holes forms a second step portion 231. The photosensitive element 210 is located in the third mounting hole, and the maximum outer diameter of the photosensitive element 210 is smaller than the inner diameter of the third mounting hole. The second optical element 220 is located in the fourth mounting hole, and the end of the second optical element 220 closest to the photosensitive element 210 abuts against the second step portion 231. The outer sidewall of the second optical element 220 is in contact with the inner sidewall of the second light-shielding element 230. The second step portion 231 can limit the position of the second optical element 220. The second optical element 220 and the second light-shielding element 230 can be fixedly connected together by adhesive or the like.

[0058] Example 2

[0059] A near-infrared blood glucose detection device also includes a light emitting component 100 and a light receiving component 200. The difference between this embodiment and the first embodiment above is that the number of light sources 110 is different and the structure of the first optical element 120 is different. The structures of other components in this embodiment are the same as those in the first embodiment above, and will not be described again here.

[0060] When the number of light sources 110 is greater than one, due to the physical size of the light sources 110, there is a distance between the centers of two light sources 110. At this time, the light spot area of ​​the emitted light from multiple light sources 110 increases, which leads to a decrease in the final signal-to-noise ratio. In this embodiment, by changing the overall shape of the first optical element 120, the light emitted from the two light sources 110 is made to overlap as much as possible, thereby reducing the light spot area of ​​the light sources 110 and improving the signal-to-noise ratio.

[0061] Specifically, in this embodiment, as Figure 5 As shown, the longitudinal section of the first optical element 120 is trapezoidal, and the outer diameter of the end of the first optical element 120 closer to the light source 110 is larger than the outer diameter of the end of the first optical element 120 farther from the light source 110. The overall shape of the first optical element 120 is trapezoidal. The opening at the incident surface 121 of the first optical element 120 is large, and the opening at the exit surface 122 is small. The size of the incident surface 121 is determined by the overall size of the light source 110, ensuring that the incident surface 121 can cover all the light sources 110. The light emitted by the light source 110 is coupled into the first optical element 120 from the incident surface 121 and converges towards the center, making the light spot on the final exit surface 122 relatively small. Generally, the area of ​​the light spot emitted from the first optical element 120 is equal to the area of ​​the exit surface 122 of the first optical element 120. The reduction of the light spot area emitted from the first optical element 120 improves the signal-to-noise ratio of the near-infrared blood glucose detection device.

[0062] In this embodiment, when the first optical element 120 is composed of multiple optical fibers 300, each optical fiber 300 has a structure that is thicker at the top and thinner at the bottom, so as to ensure that the light coupled into the incident surface 121 converges in the middle, thereby reducing the light spot area of ​​the exit surface 122.

[0063] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0064] It should be noted that the above embodiments can be freely combined as needed. The above description is only a preferred embodiment of this application. It should be pointed out that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the protection scope of this application.

Claims

1. A near-infrared blood glucose detection device, characterized in that, include: Optical transmitting component and optical receiving component; The light emitting component includes a light source, a first optical element, and a first light-shielding element; The first light-shielding element is disposed outside the light source and the first optical element. The light source is used to emit near-infrared light to the first optical element. The first optical element is used to collimate the received near-infrared light and emit it onto the surface of the object to be tested. The light receiving component includes a photosensitive element, a second optical element, and a second light-shielding element. The second light-shielding element is disposed outside both the photosensitive element and the second optical element. The second optical element is used to receive the emitted light from the surface of the object under test and collimate the emitted light before shining it into the photosensitive element.

2. The near-infrared blood glucose detection device according to claim 1, characterized in that, The end of the second optical element away from the photosensitive element is a light-receiving surface, which is an outwardly convex arc surface that extends beyond the second light-shielding element.

3. The near-infrared blood glucose detection device according to claim 2, characterized in that, It also includes a circuit board, on which the light source and the photosensitive element are both disposed. One end of the first light-shielding element and the second light-shielding element are fixedly connected to the circuit board. The first optical element is disposed on the side of the light source away from the circuit board, and the second optical element is disposed on the side of the photosensitive element away from the circuit board.

4. The near-infrared blood glucose detection device according to claim 3, characterized in that, The radius of curvature of the arc surface is R1; in, d1 is the length of the photosensitive area of ​​the photosensitive element; ds is the outer diameter of the second optical element; h is the distance from the end of the second light-shielding element away from the circuit board to the end of the second optical element close to the photosensitive element.

5. A near-infrared blood glucose detection device according to any one of claims 1 to 4, characterized in that, When there is one light source, the outer diameter of the end of the first optical element closer to the light source is equal to the outer diameter of the end of the first optical element farther from the light source.

6. A near-infrared blood glucose detection device according to any one of claims 1 to 4, characterized in that, When there are multiple light sources, the longitudinal section of the first optical element is trapezoidal, and the outer diameter of the end of the first optical element closer to the light source is greater than the outer diameter of the end of the first optical element farther from the light source.

7. The near-infrared blood glucose detection device according to claim 3, characterized in that, The first light-shielding element has a first mounting hole and a second mounting hole that are connected. The diameter of the first mounting hole is smaller than the diameter of the second mounting hole. A first step is formed at the connection between the first mounting hole and the second mounting hole. The light source is located in the first mounting hole. The first optical element is located in the second mounting hole and its end near the light source abuts against the first step. The outer sidewall of the first optical element is in contact with the inner sidewall of the first light-shielding element.

8. A near-infrared blood glucose detection device according to claim 3, characterized in that, The second light-shielding element has a third mounting hole and a fourth mounting hole that are connected to each other. The diameter of the third mounting hole is smaller than that of the fourth mounting hole. The connection between the third mounting hole and the fourth mounting hole forms a second step. The photosensitive element is located in the third mounting hole. The second optical element is located in the fourth mounting hole, and the end of the second optical element closer to the photosensitive element abuts against the second step. The outer sidewall of the second optical element is in contact with the inner sidewall of the second light-shielding element.

9. A near-infrared blood glucose detection device according to claim 1, characterized in that, The first optical element is composed of multiple optical fibers, or the first optical element is a collimating lens.

10. A near-infrared blood glucose detection device according to claim 1, characterized in that, The second optical element is composed of multiple optical fibers, or the second optical element is a collimating lens.

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