Photometric and analytical devices

Abstract

[Problem] To provide a photometry device that can measure accurate scattered light intensity in a short time. [Solution] This photometry device 5 comprises: a light source 51 that radiates light onto an irradiation area of a cuvette 2 disposed in a photometric position P; a base member 52 opposite the light source 51; and a plurality of first light-receiving elements 53 that are disposed, on the base member 52, within a planar region demarcated by a first radiation direction and a second radiation direction centering around the optical axis of transmitted light output from the cuvette 2 in the photometric position P, and respectively receive scattered light scattered by the cuvette 2 in the photometric position P.

Description

Technical Field

[0001] The present invention mainly relates to an analyzer for analyzing a reaction solution of a sample and a reagent.

Background Art

[0002] Conventionally, an analyzer that analyzes the components of a sample by reacting the sample and a reagent is known. In this type of analyzer, a plurality of cuvettes containing the sample and the reagent are arranged annularly on a cuvette table and the cuvette table is rotated, and the cuvette is passed through a photometric position between a light source and a spectroscopic detector arranged sandwiching the cuvette. At this time, the components of the sample are analyzed by measuring the absorbance from the amount of light transmitted through the cuvette.

[0003] Depending on the reagent used in the analyzer, there are items that cannot be measured with high sensitivity only by absorbance. Therefore, there is a technique that utilizes the property that light scatters when light is applied to the reagent (for example, Patent Document 1). Patent Document 1 discloses a reaction disk (cuvette table) that holds reaction vessels (cuvettes) on a circumference and repeats rotation and stop, a light source that is arranged at a photometric position and irradiates light to a reaction vessel that contains a mixed solution of a sample and a reagent, and a detector (light receiving element) that detects scattered light or transmitted light from the mixed solution. The detector is arranged symmetrically at equal angles or at equal intervals around the optical axis of the irradiation light from the light source in a plane perpendicular to the moving direction of the reaction vessel due to the rotation of the reaction disk, and a value obtained by averaging and / or a sum of the light amount data from each detector is used to calculate the concentration of the measurement target substance in the mixed solution. That is, in Patent Document 1, scattered light is received by light receiving elements linearly arranged in the vertical direction.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

[0005] The intensity of scattered light from particles is much lower than that of transmitted light. Furthermore, particles undergo fluctuations due to the thermal motion of water molecules (Brownian motion), and these fluctuations cause significant variation in the distribution of scattered light depending on the direction of radiation. In Patent Document 1, the photodetectors that receive the scattered light are arranged linearly, which presents a problem in that accurate measurement of the intensity of scattered light is not possible with short-duration photometry (e.g., 100us).

[0006] The present invention has been made to solve the above problems, and aims to provide a photometric device that can accurately measure the intensity of scattered light in a short amount of time. [Means for solving the problem]

[0007] The photometric apparatus according to the present invention is characterized by comprising: a light source that irradiates light onto the irradiated area of ​​a cuvette placed at a photometric position; a base member facing the light source; and a plurality of first photodetectors arranged on the base member in a planar region demarcated by a first radiation direction and a second radiation direction centered on the optical axis of the transmitted light emitted from the cuvette at the photometric position, each receiving scattered light scattered from the cuvette. [Effects of the Invention]

[0008] According to the present invention, a photometric device capable of accurately measuring the intensity of scattered light in a short time can be provided. [Brief explanation of the drawing]

[0009] [Figure 1] This is a plan view showing the configuration of an analytical device relating to one embodiment of the present invention. [Figure 2] This is a side view showing the configuration of the optical sensor. [Figure 3] This is a perspective view showing the detailed configuration of the photometric device. [Figure 4]This is a schematic diagram showing the positional relationship between the cuvette and the base member. [Figure 5] This graph shows the relationship between scattered light intensity (amount of scattered light) and particle size. [Figure 6] (A) is a perspective view of the filter section in the first embodiment, and (B) is a perspective view of the filter section in the second embodiment. [Modes for carrying out the invention]

[0010] Embodiments of the present invention will be described below with reference to the accompanying drawings. However, the present invention is not limited to the embodiments described below.

[0011] (Overall configuration of the analytical instrument) Figure 1 is a plan view showing the schematic configuration of an analytical device 1 according to one embodiment of the present invention. The analytical device 1 is a device for analyzing a reaction solution of a sample (e.g., blood, urine, etc.) and a reagent, and mainly comprises a cuvette table 3 in which rows of cuvettes 2 are arranged in a ring, a drive unit 4, a photometric device 5, a light sensor 6, and an analysis unit 7.

[0012] The cuvette table 3 is formed in an annular shape in plan view, and multiple cuvettes 2 are arranged along the annular direction (the arc-shaped arrow line in Figure 1). The cuvettes 2 are containers for holding samples and reagents, and have the shape of a cube or rectangular prism with an open top. Inside or around the cuvette table 3, there are sample compartments (not shown) for holding sample containers and reagent compartments (not shown) for holding reagent containers. After the cuvettes 2 are placed on the cuvette table 3, samples and reagents are supplied to the cuvettes 2 from the sample containers and reagent containers using a pipette (not shown).

[0013] The drive unit 4 is a member that rotates the rows of cuvettes 2 in the circumferential direction. In the present embodiment, the drive unit 4 includes a drive gear 41 and a driven gear 42 connected to the cuvette table 3. The drive gear 41 is attached to a stepping motor (not shown), and by driving the stepping motor to rotate the drive gear 41, the cuvette table 3 can be rotated via the driven gear 42. Note that the mechanism for rotating the cuvette table 3 is not limited to this. For example, a pulley may be attached to the central axis of the cuvette table 3 and the pulley may be driven by a timing belt.

[0014] The photometric device 5 is a member that irradiates each cuvette 2 passing through the photometric position P during the rotation of the rows of cuvettes 2 with light and measures the emitted light from the irradiated area of the cuvette 2 at the photometric position P. In FIG. 1, as members constituting the photometric device 5, a light source 51, a base member 52, and a first light receiving element 53 are shown. A more detailed configuration of the photometric device 5 will be described later.

[0015] The cuvette table 3 is provided with slits 31 arranged corresponding to each cuvette 2. The number of slits 31 is the same as the number of cuvettes 2, and each slit 31 is arranged in the circumferential direction at the outer peripheral edge of the cuvette table 3.

[0016] The optical sensor 6 is a member that detects the slit 31. As shown in FIG. 2, the optical sensor 6 has a U-shape and includes a light source 61 and a light receiving element 62 that face each other with the outer peripheral edge of the cuvette table 3 interposed therebetween. Only while the slit 31 passes between the light source 61 and the light receiving element 62, the emitted light from the light source 61 reaches the light receiving element 62, and the voltage signal photoelectrically converted by the light receiving element 62 is output to the analysis unit 7.

[0017] Which cuvette 2 corresponds to which slit 31 can be grasped by a known method. In this embodiment, in the initialization operation, origin detection is performed by detecting, with an origin sensor (not shown) installed on the fixed side, a dog for origin detection (not shown) that rotates together with the cuvette table 3. After that, when the cuvette table 3 is rotated again, by counting the slits 31 passing through the optical sensor 6, it is possible to monitor which cuvette 2 is passing near the photometric position P or near the photometric device 5.

[0018] (Configuration of photometric device) FIG. 3 is a perspective view showing a detailed configuration of the photometric device 5. The photometric device 5 mainly includes a light source 51, a base member 52, a plurality of first light receiving elements 53, a mirror 54, a spectroscopic mirror 55, a plurality of second light receiving elements 56, and a filter unit 57.

[0019] The light source 51 irradiates light onto the irradiated region of each cuvette 2 disposed at the photometric position P. The light incident on the irradiated region of the cuvette 2 passes through the inside of the cuvette 2 and exits from the irradiated region (accurately, the back surface of the irradiated region) of the cuvette 2. As the light source 51, for example, a halogen lamp that irradiates light of multiple wavelengths (e.g., 380 nm to 800 nm) in a predetermined wavelength band can be used.

[0020] The base member 52 is an annular flat plate facing the light source 51. The base member 52 has a circular opening 52a at the center, and the transmitted light emitted from the cuvette 2 passes through the opening 52a.

[0021] As shown in Figure 4, the first photodetector 53 is positioned on the side of the base member 52 facing the photometric position P. Specifically, the first photodetector 53 is positioned on the base member 52 in a planar region demarcated by a first radiation direction D1 and a second radiation direction D2 centered on the optical axis La of the transmitted light emitted from the cuvette 2 at the photometric position P, and receives scattered light scattered from the cuvette 2 at the photometric position P. The planar region in which the first photodetector 53 is positioned is an annular region on the base member 52 surrounding the optical axis La, and is a region based on the scattering range due to fluctuations of particles in the reaction solution of the cuvette 2. In this embodiment, the first photodetector 53 is positioned planarly in the annular region.

[0022] The first radiation direction D1 is the direction from the photometric position P toward the inner edge of the base member 52 (the edge of the opening 52a), and the second radiation direction D2 is the direction from the photometric position P toward the outer edge of the base member 52. In Figure 4, the photometric position P is shown as a point, but it is not particularly limited as long as it is a portion of the reaction liquid within the cuvette 2 along the optical axis La. Furthermore, the first radiation direction D1 may be the direction toward the outer edge of the base member 52 toward the photometric position P, and the second radiation direction D2 may be the direction toward the inner edge of the base member 52 toward the outer edge of the base member 52.

[0023] Some of the light passing through the inside of cuvette 2 is scattered by the particles in the reaction solution and exits cuvette 2 as scattered light. This scattering is called Rayleigh scattering, and the intensity of the scattered light can be calculated using the following formula. I(θ)=(I0π 4 d 6 / 8R 2 λ 4 )*(m 2 -1 / m 2 +1)*(1+cos 2 θ) I(θ): Scattered light intensity θ: scattering angle I0: Incident light intensity d: particle size R: Distance from the scattering particle m: refractive index of the solvent λ: Wavelength θ: Scattering angle relative to incident light

[0024] Thus, the scattered light intensity I(θ) is inversely proportional to the scattering angle θ. The scattering angle θ is the angle between the direction of emission of the scattered light and the optical axis La.

[0025] Figure 5 is a graph showing the relationship between scattered light intensity (amount of scattered light) and particle size. It can be seen that the scattered light intensity is mainly large when the scattering angle is 20° to 30°. Therefore, in this embodiment, as shown in Figure 4, the angle θ1 between the first radiation direction D1 and the optical axis La is set to 20°, and the angle θ2 between the second radiation direction D2 and the optical axis La is set to 30°. That is, the angle between the line connecting the first photodetector 53 and the photometric position P and the optical axis La is 20° to 30°, and most of the scattered light emitted from the cuvette 2 is incident on the first photodetector 53. Each first photodetector 53 converts the scattered light into photoelectricity and outputs a voltage signal of strength corresponding to the amount of light to the analysis unit 7. The analysis unit 7 calculates the total value of the voltage signals from each first photodetector 53 as the scattered light intensity.

[0026] As described in [Problems to be Solved by the Invention], the distribution of scattered light varies greatly depending on the direction of radiation due to the Brownian motion of particles. In other words, scattered light is not emitted uniformly in a radial direction. In contrast, in this embodiment, since a plurality of first photodetectors 53 are arranged in a planar manner, even if there is local variation in the amount of scattered light, the amount of scattered light in the entire region where the first photodetectors 53 are arranged remains almost constant. Therefore, it is possible to correct for variations in the amount of scattered light and accurately measure the intensity of scattered light in a short time.

[0027] Note that the values ​​of angles θ1 and θ2 are not limited to those shown above and can be changed as appropriate depending on the particle size. In this embodiment, the base member 52 is movable along the optical axis La by a drive mechanism (not shown), and angles θ1 and θ2 can be adjusted by moving the base member 52.

[0028] The transmitted light that passes through the aperture 52a is incident on the spectral mirror 55 via the mirror 54, and the spectral mirror 55 spectrally separates the incident light into wavelength bands and reflects them to the second photodetector 56. Each second photodetector 56 converts transmitted light of different wavelength bands into photoelectric signals and outputs a voltage signal of an intensity corresponding to the amount of light to the analysis unit 7.

[0029] Alternatively, the base member 52 may not have an opening 52a, and the second light-receiving element 56 may be placed near the center of the base member 52. However, as in this embodiment, arranging the second light-receiving element 56 on the opposite side of the base member 52 from the photometric position P makes it easier to install the optical system for spectrally separating the transmitted light.

[0030] As shown in Figure 3, the filter section 57 is connected to a rotating shaft 58a that is rotated by a motor 58. As shown in Figures 6(A) and (B), the filter section 57 comprises a cylindrical section 573 and single-wavelength filters 574 provided inside both ends of the cylindrical section 573. Two circular through holes 57a are formed on opposing sides of the middle section of the cylindrical section 573 in the longitudinal direction. The central axis of the cylindrical section 573, the line connecting the centers of the two through holes 57a, and the longitudinal direction of the rotating shaft 58a are perpendicular to each other.

[0031] In the first embodiment, as shown in Figure 6(A), the filter section 57 is oriented so that the central axis of the cylindrical section 573 coincides with the direction of emission of light L1 from the light source 51. At this time, multi-wavelength light L1 passes through the single-wavelength filter 574, and the single-wavelength filter 574 allows single-wavelength (for example, 700 nm) light L2 to pass through. The light L2 is scattered at the photometric position P and emitted from each cuvette 2, and is received by the first photodetector 53.

[0032] In the second embodiment, as shown in Figure 6(B), the filter section 57 is oriented such that the line connecting the centers of the two through holes 57a coincides with the direction of emission of light L1. At this time, multi-wavelength light L1 in a predetermined wavelength band passes directly through the through holes 57a. The light L1 is transmitted through the photometric position P and emitted from each cuvette 2, and is received by the second photodetector 56.

[0033] In this way, by switching between the first and second embodiments, both transmitted and scattered light of the reaction solution can be measured.

[0034] (Additional notes) The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Forms obtained by appropriately combining the technical means disclosed in the embodiments are also included in the technical scope of the present invention.

[0035] For example, in the above embodiment, the first light-receiving element 53 was arranged planarly in an annular region on the base member 52, but the arrangement is not limited to an annular shape as long as it is planar. For example, the first light-receiving element 53 can also be arranged in the shape of a rectangular frame or an arc. Furthermore, the planar region on which the first light-receiving element 53 is arranged may be a discontinuous surface.

[0036] Furthermore, although the photometric device 5 according to the above embodiment was capable of measuring both transmitted and scattered light of the reaction solution, it may also be capable of measuring only scattered light. In this case, a light source that emits single-wavelength light, such as a semiconductor laser, can be used as the light source 51, and it is not necessary to provide the filter section 57.

[0037] Furthermore, in the photometric device 5 according to the above embodiment, as shown in Figure 3, the base member 52 is positioned on the opposite side of the photometric position P from the light source 51 (i.e., positioned between the photometric position P and the mirror 54), and the plurality of first light-receiving elements 53 are positioned on the side of the base member 52 facing the photometric position P, but the device is not limited to this. The base member 52 may be positioned between the photometric position P and the light source 51 (or filter section 57), and the plurality of first light-receiving elements 53 may be positioned on the side of the base member 52 facing the photometric position P. [Explanation of Symbols]

[0038] 1 Analyzer 2 cuvettes 3. Cuvette Table 31 slits 4. Drive Unit 41 Drive gear 42 Driven gear 5 Photometering device 51 Light source 52 Base member 52a opening 53 First photodetector 54 Miller 55 Spectroscopic Mirror 56. Second photodetector 57 Filter section 573 Cylindrical section 574 Single-Wavelength Filter 57a Passing hole 58 Motor 58a Rotation axis 6. Light sensor 61 Light source 62 Photodetector 7 Analysis Department D1 First radial direction D2 2nd radial direction La optical axis P photometry position

Claims

1. A light source that illuminates the area to be illuminated by the cuvette positioned at the photometric location, A base member facing the aforementioned light source, On the base member, a plurality of first photodetectors are arranged in a planar region demarcated by a first radiation direction and a second radiation direction centered on the optical axis of the transmitted light emitted from the cuvette at the photometric position, and each receives scattered light scattered from the cuvette. A drive mechanism for moving the base member along the optical axis, A photometric device equipped with a photometer.

2. The photometric apparatus according to claim 1, wherein the planar region is an annular region on the base member surrounding the optical axis.

3. The measuring device according to claim 1 or claim 2, wherein the planar region is a region based on the scattering range due to fluctuations of particles in the reaction solution of the cuvette.

4. The photometric apparatus according to any one of claims 1 to 3, further comprising a second light-receiving element for receiving the transmitted light.

5. The base member has an opening through which the transmitted light passes, The photometric device according to claim 4, wherein the second light-receiving element is arranged on the opposite side of the base member from the photometric position.

6. The angle between the first radiation direction and the optical axis is smaller than the angle between the second radiation direction and the optical axis. The angle between the first radiation direction and the optical axis is 20° or more. The photometric apparatus according to any one of claims 1 to 5, wherein the angle between the second radiation direction and the optical axis is 30° or less.

7. The aforementioned light source emits light of a single wavelength, The photometric apparatus according to any one of claims 1 to 6, wherein the plurality of first light-receiving elements receive the single-wavelength light scattered at the photometric position and emitted from the cuvette.

8. The aforementioned light source emits multi-wavelength light, The photometric apparatus according to claim 5, wherein the second light-receiving element receives the multi-wavelength light emitted from the cuvette after passing through the photometric position.

9. The aforementioned light source emits multi-wavelength light, A photometric apparatus according to any one of claims 1 to 8, wherein a filter section having a first mode for passing the multi-wavelength light through a single-wavelength filter and a second mode for passing the multi-wavelength light as is is disposed between the light source and the photometric position.

10. A photometric apparatus according to any one of claims 1 to 9, A cuvette table in which the rows of the aforementioned cuvettes are arranged in a ring, A drive unit that rotates the row of cuvettes in an annular direction to pass each cuvette through the photometric position, An analytical apparatus comprising: an analytical unit that analyzes the contents of the cuvette based on photometric data from the photometric device;

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