CN1942754A - Optical element and optical measurement device using the same - Google Patents

Abstract

It is possible to form a groove to be in contact with a sample without subjecting an optical element material to machining or etching and provide an optical element not lowering the optical measurement accuracy by light scattering by the groove. The optical element is formed by a light irradiation prism having a light emission surface from which light is emitted to irradiate the sample, a light reception prism having a light reception surface for receiving light fed back from the sample, and a light reduction unit arranged between the light irradiation prism and the light reception prism. By combination of the light irradiation prism and the light reception prism, a concave portion with which the sample is brought into contact is formed and the light emitted from the light emission surface is introduced to the light reception surface by direct proceeding through the sample in contact with the concave portion.

Description

Optical element and optical measurement device using the same

technical field

The present invention relates to an optical element for optically measuring a sample such as biological tissue or solution to measure the concentration of glucose, cholesterol, urea, triglyceride, etc. in the sample, and an optical measurement device using the optical element.

Background technique

Various optical elements and optical measurement devices have been proposed to measure specific components in biological tissues or solutions. For example, International Publication No. 01/58355A1 proposes a method of contacting living tissue with an optical element having a groove, and obtaining information inside a living body using a difference in refractive index between the groove and the living tissue.

Here, FIG. 8 is a structural view of a conventional optical element having a groove proposed in International Publication No. 01/58355A1. Arrows in FIG. 8 indicate paths of light emitted from the light source 44 . The light (arrow X in FIG. 8 ) incident on the side surface 42 a of the groove 42 of the optical element 41 passes through the living tissue 48 and is emitted from the side surface 42 b. By detecting the emitted light with a detector or the like, information on living tissue can be obtained.

Contents of the invention

The problem that the present invention tries to solve

The groove portion 42 of the above-mentioned existing optical element is mainly directly formed on the plane of the material used for the optical element by mechanical processing such as plane grinding or ultrasonic processing, or etching, etc. Damage occurs on the formed groove portion 42, making it difficult to obtain a smooth processed surface and to process it into a predetermined shape.

For example, the groove portion 42 shown in FIG. 8 is formed into a V shape by rotating a grindstone having a V-shaped processing surface and pressing it against the flat surface of the material used for the optical element. This method will cause the processing accuracy and surface roughness to be directly affected by the precision of the shape of the grindstone. With the wear of the grindstone, the depth and shape of the groove portion 42 will change, and the surface roughness will increase, making it difficult to accurately align the groove. The portion 42 is processed into a predetermined shape. In addition, when the depth and shape of the groove portion 32 change, and the processed surface roughness increases, the actual optical path will deviate from the designed path, and light will be scattered on the surface of the groove portion 42, resulting in a decrease in measurement accuracy.

Further, the light irradiated from the light source 44 is generally parallel light, but not completely parallel light. Therefore, the light reflected by the bottom surface 42c of the groove portion 42 (arrow Y in FIG. 8 ), the light reflected by the surface other than the groove portion 42 (arrow Z in FIG. 8 ), and the light not incident on the living tissue 48 are passed through. Unnecessary light such as light (not shown) emitted after internal reflection on the incident surface 42 a and the optical element 42 is also detected simultaneously with the above-mentioned light X, resulting in a decrease in measurement accuracy.

Therefore, the present invention draws on the above-mentioned conventional problems, and aims to provide an optical element that can be formed simply and has excellent measurement accuracy and a highly reliable optical element using the optical element by an easy and simple method. Optical measuring device.

Problem solution

The optical element of the present invention has:

a light-irradiating prism having a light-exit surface from which light impinging on the sample emerges;

A light-receiving prism having a light-receiving surface by which light returned from the sample is received;

a light intensity reducing unit provided between the light irradiation prism and the light receiving prism,

The light-irradiating prism is combined with the light-receiving prism to form a concave portion in contact with the sample,

The light emitted from the light emitting surface travels straight through the sample in contact with the concave portion, and enters the light receiving surface.

Here, the "light intensity reducing part" in the present invention refers to a member or part having a function of reducing the light quantity of passing light. In addition, the "light reduction" in the present invention means that when the light moves between two or more media, the light quantity of the outgoing light is reduced relative to the light quantity of the incident light, that is, the transmitted light quantity is reduced. This includes, for example, (i) reducing the amount of light transmitted by changing the refractive index (reflectivity) between media; and (ii) reducing the amount of light transmitted by intercepting light (such as reflection or absorption, etc.) .

In addition, the optical measurement device of the present invention includes:

The above-mentioned optical element of the present invention;

A light source that emits light toward the light irradiation prism in order to irradiate light from the light irradiation prism to the sample;

A photodetector for detecting light returning from the sample to the light receiving prism.

The effect of the invention

According to the present invention, it is possible to easily form an optical element having a concave portion, and to obtain an optical element that suppresses a decrease in measurement accuracy due to unnecessary light such as reflected light inside the optical element.

In addition, with the optical element of the present invention, a highly reliable optical measurement device can be realized easily and simply.

Description of drawings

FIG. 1 is a diagram showing the configuration of an optical measurement device according to a first embodiment of the present invention.

FIG. 2 is a characteristic diagram showing wavelength characteristics of a transmitted detection light quantity when the transmitted detection light quantity of a finger is measured using the optical measurement device of FIG. 1 .

3 is a diagram showing a modified configuration of the optical measurement device according to the first embodiment of the present invention.

Fig. 4 is a diagram showing the configuration of an optical measurement device according to a second embodiment of the present invention.

Fig. 5 is a diagram showing the configuration of an optical measurement device according to a third embodiment of the present invention.

Fig. 6 is a diagram showing the configuration of an optical measurement device according to a fourth embodiment of the present invention.

Fig. 7 is a diagram showing the configuration of an optical measurement device according to a fifth embodiment of the present invention.

Fig. 8 is a structural diagram of a conventional optical element having a groove portion in contact with a sample.

Detailed ways

The optical element of the present invention is provided with: a light irradiation prism having a light exit surface from which light irradiated on a sample is emitted; a light receiving prism having a light receiving surface from which light returned from the above sample passes. Receiving: The light intensity reducing part is provided between the above-mentioned light-irradiating prism and the above-mentioned light-receiving prism, characterized in that,

The light-irradiating prism and the light-receiving prism are combined to form a recess in contact with the sample, and the light emitted from the light-emitting surface travels straight through the sample in contact with the recess and enters the light-receiving surface. .

With this structure, it is possible to reduce the amount of light that enters the light receiving prism among the light that has passed through the light irradiation prism but has not passed through the sample. That is, it is possible to reduce the amount of light entering the light-receiving prism without passing through the sample among the light passing through the light-irradiating prism. In addition, it is possible to suppress unnecessary light from reaching a photodetector described later, and it is possible to reliably suppress a decrease in measurement accuracy.

In addition, after each surface of the light emitting prism and light receiving prism constituting the recess is processed, the recess is formed by combining the light emitting element and the light receiving prism, so after forming the recess, it is not necessary to smooth the surface of the recess. Therefore, it is possible to easily form a concave portion with a smooth surface, and it is possible to obtain an optical element that does not degrade optical measurement accuracy due to light scattering in the concave portion.

The above-mentioned concave portion can be easily constituted by, for example, combining planar processed surfaces. In addition, the above-mentioned concave portion may be formed using a composite plane composed of a plurality of planes such as a stepped shape by using the disclosed technology. In addition, the above-mentioned concave portion may be formed by combining curved surfaces.

In addition, since the above-mentioned concave portion is formed by combining the light-irradiating prism and the light-receiving prism after processing them into predetermined shapes, it is particularly easy to process the bottom of the concave portion with high precision.

The light intensity reducing portion may be a gap portion provided between the light irradiation prism and the light receiving prism.

With this structure, since the refractive index of the light-irradiating prism and the light-receiving prism are different from the refractive index of the gap portion, reflected light is generated at each interface, and therefore, it is possible to reduce the amount of light passing through the light-irradiating prism that does not pass through the sample. And the amount of light incident on the light-receiving prism. In addition, it is possible to suppress unnecessary light from reaching a photodetector described later, and it is possible to reliably suppress a decrease in measurement accuracy.

In addition, the light intensity reducing unit may be a light shielding unit provided between the light irradiation prism and the light receiving prism.

With this structure, with the light shielding portion provided between the light-irradiating prism and the light-receiving prism, it is possible to intercept light that enters the light-receiving prism without passing through the sample, out of the light passing through the light-irradiating prism. In addition, it is possible to suppress unnecessary light from reaching a photodetector described later, and it is possible to reliably suppress a decrease in measurement accuracy.

Furthermore, the optical element of the present invention preferably includes a spacer provided between the light emitting prism and the light receiving prism.

With this structure, by changing the thickness of the spacer to change the distance between the light-irradiating prism and the light-receiving prism, it is possible to easily adjust the measurement position in the depth direction in the sample. If the distance between the light-irradiating element and the light-receiving element is increased, the concave portion in contact with the sample becomes deeper, and as a result, the deep position of the sample can be measured. Conversely, if the distance between the light emitting element and the light receiving element is reduced, it becomes difficult for the sample to penetrate into the concave portion, and as a result, the surface layer portion of the sample can be measured.

In addition, the spacer can be formed using the same material as that of the above-mentioned light intensity reducing portion. For example, if the spacer is formed of a material having a lower refractive index than the light-irradiating prism and the light-receiving prism, the spacer can have the same function as the above-mentioned light intensity reducing portion.

Preferably, the light emitting surface of the light irradiation prism is a planar first inclined portion in contact with the sample, and the light receiving surface of the light receiving prism is a planar second inclined portion in contact with the sample, The first inclined portion and the second inclined portion face each other to form the recessed portion, and a cross section of the recessed portion in a direction perpendicular to the first inclined portion and the second inclined portion is substantially V-shaped.

With this structure, after the first inclined portion and the second inclined portion are optically polished, the first inclined portion and the second inclined portion are placed in opposing positions to form a V-shaped recess that contacts the sample. A concave portion with a smooth surface and high optical precision is easily obtained. In addition, when the shape of the concave portion is V-shaped, the sample is easily fixed and the optical path length can be stabilized.

Furthermore, it is preferable that the optical element of the present invention includes a cover that covers a part of the concave portion and forms a sample storage unit in combination with the light emitting prism and the light receiving prism. Such a cover may include, for example, a first cover and a second cover arranged to cover the side surfaces of the light irradiation prism and the light output prism and open the upper surface of the concave portion.

With this structure, since the sides of the concave portion are surrounded by the light irradiation prism, the light receiving prism, and the cover, even if the sample is in a liquid state, the sample can be stored in the concave portion functioning as a sample storage unit so that it does not spill out.

Furthermore, it is preferable that the optical element of the present invention includes adjustment means for adjusting the distance between the light emitting prism and the light receiving prism.

With this structure, the distance between the light irradiation prism and the light receiving prism can be changed easily and simply, and the measurement position in the depth direction of the sample can be adjusted more easily and simply. If the distance between the light-irradiating prism and the light-receiving prism is increased, the concave portion in contact with the sample becomes deeper, and as a result, the deep position of the sample can be measured. Conversely, if the distance between the light emitting element and the light receiving element is reduced, it becomes difficult for the sample to penetrate into the concave portion, and as a result, the surface layer portion of the sample can be measured.

The optical measurement device of the present invention is characterized in that it includes: the above-mentioned optical element of the present invention; a light source that emits light toward the light-irradiating prism in order to irradiate light from the light-irradiating prism to the sample; The above-mentioned light-receiving prism detects the light with a photodetector.

With this structure, by using the above-mentioned optical element of the present invention, it is possible to provide a highly reliable optical measurement device in an easy and simple manner.

The optical measurement device of the present invention preferably includes a spectroscopic element disposed between the light receiving prism and the photodetector.

With this configuration, only the light required for measurement can be sent to the photodetector more reliably, and measurement accuracy can be improved.

Hereinafter, representative embodiments of the present invention will be described in detail with reference to the drawings. However, in the following description, the same reference numerals are given to the same or corresponding parts, and repeated description thereof may be omitted.

In addition, the embodiment described below shows an example of this invention, and does not limit this invention.

[the first embodiment]

1 is a diagram showing the configuration of an optical measurement device (component concentration measurement device) using an optical element (measurement element) in a first embodiment of the present invention, and arrows in the diagram indicate optical paths. First, the optical elements will be described below.

As shown in Figure 1, the optical element 12 is formed by combining a light-irradiating prism 13 for irradiating light to the sample and a light-receiving prism 14 for receiving light returned from the sample. A recess 15 for contacting the sample is formed therebetween. In addition, in the present embodiment, a light-shielding portion for intercepting light between the light-irradiating prism 13 and the light-receiving prism 14 is formed as the light-intensity reducing portion 19 .

The concave portion 15 is formed by polishing the first inclined portion 13a contacting the sample in the light irradiation prism 13 and the second inclined portion 14a contacting the sample in the light receiving element 14 respectively to become smooth surfaces, and then irradiating the light to the prism 13 and the light receiving element. 14 are connected so that the first inclined portion 13a and the second inclined portion 14a face each other to form a V shape.

Before the light-irradiating prism 13 and the light-receiving prism 14 are connected together, the first inclined portion 13a and the second inclined portion 14a of the planar shape are respectively optically polished, so the first inclined portion 13a and the second inclined portion 13a can be easily Portion 14a becomes smooth. Therefore, the concave portion 15 having a high optical precision surface can be easily obtained.

In addition, since the optical element 12 of this embodiment can be disassembled into the light emitting prism 13 and the light receiving prism 14, it is easier to clean the concave portion than the conventional non-decomposable optical element (see FIG. 8 ).

The constituent materials of the light emitting prism 13 and the light receiving prism 14 can use well-known materials in this field.

When measuring a substance whose absorption peak is in the mid-infrared region, silicon, germanium, SiC, diamond, ZnSe, ZnS, KrS, or the like can be used.

Like glucose whose absorption peaks are at wavenumbers 1033 cm ¹ and 1080 cm ¹ , in the case of measuring a substance whose absorption peak is in the mid-infrared region, it is considered that its infrared wavelength is about 9 to 10 microns, its transmittance is high, and its processability is good. , High mechanical strength, so silicon or germanium is preferably used.

In addition, when measuring a substance whose absorption peak is in the near-infrared region, fused silica, single crystal silicon, optical glass, transparent resin, or the like can be used.

The light intensity reducing part 19 in this embodiment is, for example, a film-shaped, sheet-shaped, plate-shaped or rod-shaped light-shielding part, and its function is to prevent the light that does not reach the concave part of the light passing through the light irradiation prism—that is, the light that does not reach the concave portion. Light passing through the sample enters a light-receiving prism.

Metal reflective films such as Al, Cu, or Ag, absorbing films such as Cr or black ink, or dielectric multilayer films are preferably used for the light-shielding portion. A multilayer film formed of a metal layer and a dielectric layer may also be used. The film-forming method of the light-shielding part in this case may use well-known methods, such as a vacuum evaporation method, a sputtering method, or a CVD method. In addition, the film may be formed directly on the surface of the light-irradiating prism 13 or the light-receiving prism 14, or may be formed on the two prisms separately and then connected.

In addition, the light-shielding part may use, for example, an aluminum foil, a Cu metal sheet, or the like other than a sheet made of the material of the above-mentioned film. Either the metal sheet can be pasted directly on the light-irradiating prism 13 or the light-receiving prism 14, or the two prisms can be bonded together after the metal sheets are respectively pasted on the two prisms.

Furthermore, the said light-shielding part may use the plate which consists of the said film or the material of the said plate piece.

The optical measurement device of this embodiment can be produced by using the optical element 12 of this embodiment having the above-mentioned structure. The optical measurement device of this embodiment includes: an optical element 12, a light source 11 that emits light, a spectroscopic element 16 that splits light returned from a sample via a light receiving prism 14, and a light beam that detects light passing through the spectroscopic element 16. detector 17. By using the optical element 12 with high optical precision, the measurement accuracy can be improved and high reliability can be obtained.

In addition, the light intensity reducing part 19 prevents the above-mentioned light that does not pass through the sample from entering the light receiving prism, so that the light that does not pass through the sample, the light reflected from the surface forming the concave portion, and the excess light from the light source will not reach the photodetector. 17. Therefore, the S/N ratio of the optical measurement device is improved.

Here, the selectable range of the light source 11 is not particularly limited as long as it is light including the absorption wavelength of the measurement component to be measured.

For example, for light in the mid-infrared region, a Globar light source in which SiC is sintered into rods, a _CO2 laser, a tungsten lamp, an infrared pulse light source, or a QCL light source can be used.

When measuring a substance having a strong absorption peak in the mid-infrared region, such as glucose, it is preferable to use, for example, a Globar light source, an infrared pulse light source, or a QCL light source.

In addition, when measuring a substance whose absorption peak is in the near-infrared region, for example, a halogen light source, a semiconductor laser, or an LED can be used. It is well known that glucose has an absorption peak not only in the mid-infrared region but also in the near-infrared region, and it is preferable to use, for example, a DFB laser or a DBR laser used in LED optical communications.

For the spectroscopic element 16, for example, a grating element, an optical filter element, or the like can be used. Alternatively, FT-IR, laser spectroscopy, or the like may be used. In addition, the position of the spectroscopic element is not particularly limited.

In addition, materials well known in the art can be used for the photodetector 17 . For example, pyroelectric sensors or thermopiles, thermistors, and MCT detectors (a type of quantum type detector—HgCdTe detector) are used in the mid-infrared region. In the near-infrared region, for example, InGaAs detectors, photodiodes, PbS detectors, InSb detectors, InAs detectors, or sensor arrays of these detectors are used.

Next, a method for measuring the concentration of a component using the optical measuring device of the present invention will be described. Here, the case of measuring the biological tissue of the finger will be described.

First, the finger 18 is pressed against the recess 15 of the optical element 12 . At this time, as shown in FIG. 1 , the finger 18 can be inserted into the concave portion 15 by lightly pressing. Then, after light is irradiated to the recessed portion of the finger 18, the light emitted from the light source 11 reaches the light irradiation prism 13 of the optical element 12, and the light that reaches the light irradiation prism 13 reaches the concave portion 15 or the light shielding portion provided on the optical element 12. 19.

Then, the light reaching the light intensity reducing portion 19 is absorbed or reflected so as not to enter the light receiving prism 14 . The light reaching the concave portion 15 is refracted due to the difference in refractive index between the light irradiation prism 13 and the finger 18 when exiting the concave portion 15 , and passes through the finger 18 .

On the other hand, the light passing through the finger 18 enters the light receiving prism 14 . Since the light travels along the above-mentioned path, the light-receiving prism 14 can easily receive most of the light that goes straight in the finger 18 , and the light passing through the light-receiving prism 14 reaches the photodetector 17 through the light-splitting element 16 . Based on the light detected by the photodetector 17, parameters of living tissue such as glucose concentration can be calculated.

The transmission distance of light through the finger 18 is not particularly limited, and can be set, for example, to about 1 to 2 mm. In addition, the angle formed by the first inclined portion and the second inclined portion in the concave portion 15 is not particularly limited, and may be set to, for example, 90 degrees.

Here, the incident angle of light with respect to the finger 18 as a sample is determined by the shape of the concave portion 15 , the refractive index of the light irradiation prism 13 and the light receiving prism 14 , and the like. The refractive index of the light irradiation prism 13 and the light receiving prism 14 is preferably larger than that of the sample. When performing the measurement, it is desirable to allow the light passing through the sample to reach the photodetector 17 as much as possible. Therefore, it is preferable to set the concave portion 15 in consideration of not only the refractive index of the optical element 12 but also the refractive index of the sample. The shape of and the angle of incidence of the light relative to the finger 18 .

In addition, the spectroscopic element 16 can transmit only light necessary for component concentration detection, for example. The component concentration is calculated from the light detected by the photodetector 17 . That is, different components will absorb and reduce light of a specific wavelength, and the amount of light reduction depends on the concentration of the component, so the concentration of the component can be calculated based on the amount of light reduction.

Next, an example of the result of measuring the biological tissue of the finger 18 using the above-mentioned optical measuring device of the present invention is shown in FIG. 2 . The horizontal axis represents the wavelength, and the vertical axis represents an arbitrary value of the amount of detected light. In addition, A shows the measurement result before the finger 18 is pressed against the concave portion, and B shows the measurement result when the finger 18 is pressed against the concave portion.

From these results, it can be seen that the frequency spectrum when the finger 18 is pressed is greatly changed from the frequency spectrum before the finger 18 is pressed. This is because most of the light emitted by the light source 11 is absorbed by blood components such as water, glucose, neutral fat, and cholesterol in the finger 18 and various components constituting the finger 18, and the amount of light decreases. For example, light at 1.4 microns is greatly reduced, which is comparable to the absorption spectrum of water, indicating the presence of water in living organisms.

In addition, FIG. 3 is a diagram showing a modified configuration of the optical measurement device according to the present embodiment. This deformation is used to measure the concentration of components in sample liquids such as solutions or liquids. In addition to the detector 17, the optical element 12 further has a first measurement cover 20a and a second measurement cover 20b.

The first measurement cover 20a and the second measurement cover 20b cover the light emitting prism 13 and the light receiving prism 14 while opening the upper part of the recess 15 .

That is, the recess 15 is surrounded by the first slope 13a, the second slope 14a, the first measurement cover 20a, and the second measurement cover 20b, and functions as a sample storage unit for storing the sample solution 21. Therefore, the sample liquid 21 can be stored in the concave portion 15 without being spilled.

With this structure, in this modification, it is only necessary to add the measurement cover to the structure of FIG. 1 in this way, and the components of the sample liquid can be easily measured.

[the second embodiment]

4 is a diagram showing the configuration of an optical measurement device (component concentration measurement device) in a second embodiment of the present invention using the optical element (measurement element) of the present invention, and arrows in the figure indicate optical paths. First, the optical elements will be described below.

As shown in FIG. 4 , the optical element 12 is formed by combining a light-irradiating prism 13 for radiating light to the sample and a light-receiving prism 14 for receiving light returned from the sample. The light-irradiating prism 13 and the light-receiving prism 14 A substantially V-shaped recess 15 for contacting the sample is formed therebetween. In addition, in this embodiment, a light intensity reducing portion 19 is provided between the light irradiation prism 13 and the light receiving prism 14, which regulates the distance between the light irradiation prism 13 and the light receiving prism 14, and reduces the amount of light passing through the light irradiation prism. 13 but not passing through the sample, the amount of light entering the light-receiving prism 14.

The light intensity reducing portion 19 is made of a material (such as glass or plastic) whose refractive index is lower than that of the light-irradiating prism 13 and the light-receiving prism 14, and its function is to reduce The amount of light entering the light-receiving prism 14 among the light passing through the light-irradiating prism 13 but not passing through the sample.

The thickness (width) of the light intensity reducing part 19, that is, the distance between the light irradiation prism 13 and the light receiving prism 14 is not particularly limited, but in the case of measuring, for example, living tissue, if the optical path is too long, the absorption of water will be too large. , so it is preferably less than or equal to 3mm.

In this embodiment, the light intensity reducing portion 19 has a rectangular parallelepiped shape, and the concave portion 15 is formed in a substantially V-shape by combining the light emitting prism 13 , the light receiving prism 14 , and the light intensity reducing portion 19 . In addition, the planar first inclined portion 13a contacting the sample in the light-irradiating prism 13 and the planar second inclined portion 14a contacting the sample in the light-receiving prism 14 are arranged to face each other, constituting the side surfaces of the concave portion 15, and the light intensity reducing portion 19. The upper surface of the concave portion 15 is located between the lower end of the first inclined portion 13a and the lower end of the second inclined portion 14a, and constitutes the bottom portion of the concave portion 15.

Therefore, changing the thickness (width) of the light intensity reducing portion 19 can easily change the optical path of the light passing through the concave portion 15 . That is, if the thickness of the light intensity reducing portion 19 is increased, the distance between the light irradiation prism 13 and the light receiving prism 14 increases, the living tissue penetrates into the concave portion 15, and the deep living tissue can be measured. In addition, if the thickness of the light intensity reducing part 19 is reduced, the distance between the light irradiation prism 13 and the light receiving prism 14 is reduced, and it is possible to measure the living tissue at the outer surface. In this way, the light intensity reducing portion 19 functions as a spacer, and by appropriately setting the thickness of the light intensity reducing portion 19 , it is possible to measure a living tissue at a desired measurement depth.

Here, the tissues of the finger 18 include the outermost epidermis 18a, the lower part of the dermis 18b, and the subcutaneous fat 18c. For example, when measuring the glucose concentration, it is preferable to measure the dermis 18b between the epidermis 18a and the subcutaneous fat 18c, and it is preferable to pass more light through this part.

If, for example, the absorption wavelength of glucose with a wavelength of 1600 nm is used, the distance that the light passes through the finger 18 may be set to about 1 to 2 mm. If it exceeds 3mm, the water absorption will increase. In addition, the substantially V-shaped angle formed by the concave portion 15 (the angle formed by the first inclined portion and the second inclined portion) may be set to 90° to 120°.

According to the optical measuring device of this embodiment, while obtaining the same effects as those of the above-mentioned first embodiment, most of the light passing through the skin 18 b of the finger 18 can be detected by the photodetector 17 . In addition, in the optical element 12, the light intensity reducing part 19 capable of functioning as a spacer between the light irradiation prism 13 and the light receiving prism 14 is arranged, and the distance between the light irradiation prism 13 and the light receiving prism 14 is changed so that the measured depth is relative to An individual optimization can increase the amount of light passing through a particular part of the finger 18, increasing the signal strength in the photodetector 17 based on that light. Therefore, with the optical measurement device of the present embodiment, the S/N ratio of detected light can be increased, and high-precision component concentration measurement can be realized.

[the third embodiment]

5 is a diagram showing the configuration of an optical measurement device (component concentration measurement device) in a third embodiment of the present invention using the optical element (measurement element) of the present invention, and arrows in the figure indicate optical paths. First, the optical elements will be described below. In addition, description of the same parts as those of the second embodiment in the optical measurement device of the third embodiment will be omitted.

The light intensity reducing portion 29 of the present embodiment also functions as a spacer. The portion opposite to the later-described light intensity reducing portion 29 located below the concave portion 25 in the light emitting prism 23 and the light receiving prism 24 is a plane in which the distance between the light emitting prism 23 and the light receiving prism 24 becomes larger as it gets closer to the bottom. Shaped inclined portion 23b and 24b constitute. The light intensity reducing portion 29 having a trapezoidal cross section in the direction perpendicular to the inclined portions 23b and 24b is disposed between the light emitting prism 23 and the light receiving prism 24 in contact with the inclined portions 23b and 24b.

Adjusting units for adjusting the distance between the light-irradiating prism 23 and the light-receiving prism 24 are provided on the side and bottom surfaces of the light-irradiating prism 23 and the light-receiving prism 24 .

The adjusting unit is composed of moving elements—screw 21, which is used to move the light intensity reducing portion 29 in the up and down direction, a holding portion 26 for holding the screw 21, and the holding portion 26, the light irradiation prism 23, the holding portion 26 and the light receiving unit. Deformable deformation elements 27 and 28 are formed in the gaps of the prism 24 .

The screw 21 is disposed below the light intensity reducing portion 29 , and the light intensity reducing portion 29 is pressed down by the screw 21 to push the light intensity reducing portion 29 upward. At this time, if the shift amount is small, the distance between the light irradiation prism 23 and the light receiving prism 24 can be set shorter; if the shift amount is large, the distance between the light irradiation prism 23 and the light receiving prism 24 can be set shorter long. The deformation elements 27 and 28 elastically absorb displacement amounts accompanying the movement of the light irradiation prism 23 and the light receiving prism 24 .

Although not shown in the figure, it is preferable to tighten the light emitting prism 23 and the light receiving prism 24 with screws so that the light emitting prism 23 and the light receiving prism 24 do not move after moving. Alternatively, an adhesive may be used for fixing.

In addition, in the present embodiment, the screw 21 is used as the moving element, but the moving element is not limited thereto.

The deformation elements 27 and 28 can use, for example, elastic materials or elastic materials. The elastic material is not particularly limited, and for example, acrylic rubber, polyurethane rubber, silicone rubber, fluororubber, styrene-butadiene rubber, butadiene rubber, isoprene rubber, nitrile rubber, neoprene rubber or butadiene rubber can be used. base rubber etc.

The material constituting the holding portion 26 is not particularly limited, but plastic, metal, or the like is preferably used. The metal is preferably, for example, aluminum or stainless steel.

[the fourth embodiment]

6 is a diagram showing the configuration of an optical measurement device (component concentration measurement device) in a fourth embodiment of the present invention using the optical element (measurement element) of the present invention, and arrows in the figure indicate optical paths. First, the optical elements will be described below. In addition, description of the same parts as those of the first embodiment in the optical measurement device of the fourth embodiment will be omitted.

The optical measuring device of the present embodiment is composed of a light irradiation prism 13 and a light receiving prism 14 via a spacer 39, except that the light intensity reducing part 19 formed by the gap between the light irradiation prism 13 and the light receiving prism 14 is provided. Other parts are the same as those of the first embodiment.

In this embodiment, since the refractive index of the gap is smaller than that of the light-irradiating prism 13 and the light-receiving prism 14, it is possible to reduce the amount of light that passes through the light-irradiating prism 13 and enters the light-receiving prism without passing through the sample. The amount of light from the prism 14. In addition, it is possible to suppress the arrival of unnecessary light that does not require detection, and it is possible to reliably suppress a decrease in measurement accuracy.

[fifth embodiment]

7 is a diagram showing the configuration of an optical measurement device (component concentration measurement device) in a fifth embodiment of the present invention using the optical element (measurement element) of the present invention, and arrows in the figure indicate optical paths. First, the optical elements will be described below. In addition, the description of the same parts as those of the second embodiment in the optical measurement device of the fifth embodiment will be omitted.

The optical measurement device of the present embodiment is composed of the light irradiation prism 13 and the light receiving prism 14 through the spacer 39, and between the spacer 39 and the light irradiation prism 13 and between the spacer 39 and the light receiving prism 14, a film-shaped light-shielding device is arranged. The light intensity reducing part 19 constituted by the part.

The spacer 39 has a rectangular parallelepiped shape, and the concave portion 15 is formed into a substantially V-shape by a combination of the light irradiation prism 13 , the light receiving prism 14 , the spacer 39 , and the light intensity reducing portion 19 . In addition, the planar first inclined portion 13a contacting the sample in the light irradiation prism 13 and the planar second inclined portion 14a contacting the sample in the light receiving prism 14 are arranged to face each other, constituting the side surface of the concave portion 15 and the upper surface of the spacer 19, respectively. The surface is located between the lower end of the first inclined portion 13a and the lower end of the second inclined portion 14a, and constitutes the bottom surface of the concave portion 15 .

Therefore, changing the thickness (width) of the spacer 39 can easily change the optical path of the light passing through the concave portion 15 . That is, if the thickness of the spacer 39 is increased, the distance between the light irradiation prism 13 and the light receiving prism 14 increases, the living tissue penetrates into the recess 15, and the living tissue at a deeper site can be measured. In addition, if the thickness of the spacer 19 is reduced, the distance between the light irradiation prism 13 and the light receiving prism 14 will be reduced, and the living tissue of a relatively superficial layer can be measured. In this manner, by appropriately setting the thickness of the spacer 39 , it is possible to measure a living tissue at a desired measurement depth.

After the first inclined portion 13a and the second inclined portion 14a are respectively optically polished to become a smooth surface, the light irradiation prism 13 and the light receiving prism 14 are connected through the spacer 39, so that the first inclined portion 13a and the second inclined portion 14a is opposed, thereby easily forming the side portion of the recessed portion 15 through which light passes. In addition, before the light irradiation prism 13 and the light receiving prism 14 are connected together, the first inclined portion 13a and the second inclined portion 14a of the planar shape are respectively optically polished, so the first inclined portion 13a and the second inclined portion 14a can be easily formed. 2. The inclined portion 14a becomes smooth. Therefore, the concave portion 15 having a high optical precision surface can be easily obtained.

The material of the spacer 39 is not particularly limited, but it is preferably a material that has high mechanical strength, easily absorbs and transmits light used for measurement, and hardly reflects light. For example, glass or plastic is preferable, and if a material having a lower refractive index than the light-irradiating prism 13 and the light-receiving prism 14 is used, the spacer 39 can be provided with the function of the above-mentioned light intensity reducing portion.

The thickness (width) of the spacer 39, that is, the distance between the light-irradiating prism 13 and the light-receiving prism 14, is not particularly limited, but in the case of measuring, for example, living tissue, if the optical path is too long, the absorption of water is too large, so Preferably it is less than or equal to 3mm.

In addition, the materials in the above-described embodiments may be employed as the light intensity reducing portion 19 .

The best embodiments of the present invention have been described above, but the present invention is not limited to these embodiments, and design changes can be made through combinations of various structural elements within the scope described in the claims.

For example, in the above-mentioned embodiment, the recesses 15, 25 are approximately V-shaped, but it is also possible to make the first inclined portion and the second inclined portion into a curved surface to form an approximately U-shaped recess, or to combine the first inclined portion and the second inclined portion. The second inclined portion is made into a stepped shape to form a stepped concave portion.

In the above-mentioned embodiment, the case where a finger is used as a sample has been described, but the sample is not limited thereto. In addition to fingers, biological tissues such as lips, forearms and ears can also be measured.

In addition, in the modification of the first embodiment, the sample liquid in a static state has been described, but the present invention is not limited thereto, and fluids may also be measured. For example, the flow channel through which the sample liquid flows is connected to the side surface corresponding to the concave portion 15 of the first measurement cover 20a, the flow channel through which the sample liquid flows out is connected to the side surface corresponding to the concave portion 15 of the second measurement cover 20b, and the concave portion 15 is used as a flow channel for the sample liquid, whereby components in the fluid can also be easily measured.

Industrial applicability

The optical element and optical measuring device of the present invention are suitably applied to devices for measuring component concentrations of, for example, liquids, solutions, fluids, and living tissues.

claims

(Amended in accordance with Article 19 of the Treaty)

1. (Modified) An optical element, which has:

a light-irradiating prism having a light-exit surface from which light impinging on the sample emerges;

A light-receiving prism having a light-receiving surface by which light returned from the sample is received;

a light intensity reducing unit provided between the light irradiation prism and the light receiving prism,

The light intensity reducing part is a light shielding part provided between the light irradiation prism and the light receiving prism,

The light-irradiating prism and the light-receiving prism are combined to form a recess in contact with the sample, and the light emitted from the light-emitting surface travels straight through the sample in contact with the recess and enters the light-receiving surface. .

2. (After modification) The optical element according to claim 1, further comprising a gap portion provided between the light emitting prism and the light receiving prism.

3. (deleted)

4. The optical element according to claim 1, further comprising a spacer provided between the light emitting prism and the light receiving prism.

5. The optical element of claim 1,

The above-mentioned light exit surface of the above-mentioned light irradiation prism is a planar first inclined portion in contact with the above-mentioned sample,

The above-mentioned light-receiving surface of the above-mentioned light-receiving prism is a planar second inclined portion contacting the above-mentioned sample,

The first inclined portion and the second inclined portion face each other to form the recessed portion, and a cross section of the recessed portion in a direction perpendicular to the first inclined portion and the second inclined portion is substantially V-shaped.

6. The optical element according to claim 1, comprising a cover that covers a part of the concave portion and forms a sample storage unit in combination with the light emitting prism and the light receiving prism.

7. The optical element according to claim 1, further comprising an adjusting unit for adjusting the distance between the light emitting prism and the light receiving prism.

8. An optical measurement device comprising:

The optical element of claim 1;

A light source that emits light toward the light irradiation prism in order to irradiate light from the light irradiation prism to the sample;

A photodetector for detecting light returning from the sample to the light receiving prism.

9. The optical measuring device according to claim 8, comprising a spectroscopic element disposed between the light receiving prism and the photodetector.

Claims (9)

1. optical element, it possesses:

Light irradiation prism, it has light-emitting face, and the light that shines on the sample penetrates from this exit facet;

The light-receiving prism, it has light receiving surface, and the light that returns from above-mentioned sample is received by this light receiving surface;

Light intensity reduction portion is arranged between above-mentioned light irradiation prism and the above-mentioned light-receiving prism,

Above-mentioned light irradiation prism and above-mentioned light-receiving prism are combined, formed and the contacted recess of above-mentioned sample,

The light that penetrates from above-mentioned light-emitting face is injected above-mentioned light receiving surface advancing with the contacted above-mentioned sample cathetus of above-mentioned recess.

2. optical element as claimed in claim 1, above-mentioned light intensity reduction portion is arranged on the clearance portion between above-mentioned light irradiation prism and the above-mentioned light-receiving prism.

3. optical element as claimed in claim 1, above-mentioned light intensity reduction portion is arranged on the light shielding part between above-mentioned light irradiation prism and the above-mentioned light-receiving prism.

4. optical element as claimed in claim 1, it further possesses the spacer that is arranged between above-mentioned light irradiation prism and the above-mentioned light-receiving prism.

5. optical element as claimed in claim 1,

The above-mentioned light-emitting face of above-mentioned light irradiation prism is the 1st plane rake that contacts with above-mentioned sample,

The above-mentioned light receiving surface of above-mentioned light-receiving prism is the 2nd plane rake that contacts with above-mentioned sample,

Above-mentioned the 1st rake and above-mentioned the 2nd rake be mutually in the face of forming above-mentioned recess, and above-mentioned recess with above-mentioned the 1st rake direction vertical with above-mentioned the 2nd rake on the section shape that roughly is in the shape of the letter V.

6. optical element as claimed in claim 1, it possesses covering, and this covering is covered with the part of above-mentioned recess and combines with above-mentioned light irradiation prism and above-mentioned light-receiving prism and forms sample preservation portion.

7. optical element as claimed in claim 1, it further possesses adjustment unit, is used for adjusting the distance between above-mentioned light irradiation prism and the above-mentioned light-receiving prism.

8. optical detecting device, it possesses:

Optical element as claimed in claim 1;

In order to make light shine above-mentioned sample and to the irradiant light source of above-mentioned light irradiation prism from above-mentioned light irradiation prism;

The photodetector that the light that turns back to above-mentioned light-receiving prism from above-mentioned sample is detected.

9. optical detecting device as claimed in claim 8, it possesses the beam splitter that is configured between above-mentioned light-receiving prism and the above-mentioned photodetector.

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