JP2011232205A - Light analyzer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light analyzer capable of accurate measurement with a high precision with respect to analysis of a specimen in a measurement cell.SOLUTION: The light analyzer comprises: a centrifuge rotor which has a chip holding part holding a microchip provided with a measurement cell housing the specimen; a rotational driving mechanism which rotationally drives the centrifuge rotor; a measurement chamber in which the centrifuge rotor is housed; a light source which irradiates the measurement cell of the microchip; and a light receiving part which receives light transmitted through the measurement cell. In the light analyzer, light from the light source is made incident on the measurement cell through openings for light introduction formed in the measurement chamber and the centrifuge rotor respectively, and respective absorbed amounts of measurement light and reference light different by wavelength, out of light transmitted through the measurement cell, are measured to analyze the specimen in the measurement cell. Between the light source and the opening for light introduction of the measurement chamber, an illuminance uniformizing means which uniformizes light illuminance of the measurement light and the reference light in a light incident surface to the measurement cell is disposed.

Description

  The present invention relates to an optical analyzer (biochemical analyzer) for measuring the concentration of a detection target component contained in a specimen for biochemical analysis, for example, by absorptiometry.

In recent years, it has been called “μ-TAS (μ-Total Analysis System)” or “Lab on a chip”, which can be applied with micromachine technology to make chemical analysis finer than conventional devices. An analysis method using a microchip is attracting attention.
An analysis system using such a microchip (hereinafter referred to as a “microchip analysis system”) is a method of mixing, reacting, separating, and mixing reagents in a micro-channel formed on a small substrate by micromachine fabrication technology. It aims to perform all the steps of analysis including extraction and detection, and is used, for example, for analysis of blood in the medical field, analysis of biomolecules such as ultra-trace amounts of proteins and nucleic acids, and the like.
In particular, when analyzing human blood using a microchip analysis system, for example, (1) the amount of blood (specimen) required for the analysis test may be small, reducing the burden on the patient. (2) Since the amount of reagent used by mixing with blood can be reduced, the analysis cost can be reduced, and (3) the device itself can be configured as a small one. Development is being promoted because of the advantages of being able to perform analysis easily.

  In general, in such a microchip analysis system, for example, an absorptiometric analysis method is used as a method for measuring the concentration of a detection target component in a sample. For example, Patent Document 1 describes an optical analysis device for analyzing and testing a sample for biochemical analysis such as blood (serum or plasma may be used) using a microchip having a plurality of measurement cells. In this optical analyzer, as shown in FIG. 14, the centrifugal rotor 25 disposed coaxially with the measurement chamber 21 in the measurement chamber 21 is rotationally driven and held by the chip holder 26 in the centrifugal rotor 25. When a centrifugal force is applied to the microchip 60 thus prepared, for example, a test solution is prepared by mixing with a reagent and a reaction process, and a prepared test solution is sent to each measurement cell. In the state where the centrifugal rotor 25 is stopped, the light from the light source lamp 41 irradiated through the lens 42 and the optical filter 43 is reflected by the reflection mirror 45. The light is introduced into one measurement cell 63 through the light introduction opening 22A in the outer casing 22 constituting the measurement chamber 21, the light introduction opening 25A in the centrifugal rotor 25, and the light introduction opening 27A in the chip holding part 26. Then, the amount of light having a specific wavelength (measurement light) set according to the test solution that has passed through the test solution in the measurement cell 63 and light having a wavelength different from the wavelength of the measurement light (reference light) ) Is simultaneously detected by a light receiver (not shown). Reference numeral 52 in FIG. 14 denotes an optical fiber that guides light that has passed through the measurement cell 63 of the microchip 60 to a light receiver.

When the photometric process for one measurement cell is completed, the centrifugal rotor 25 is driven to rotate, and the amount of movement thereof is controlled based on the signal from the encoder, so that the light from the light source lamp 41 is applied to the adjacent measurement cell. The position is controlled so as to be introduced, and the rotation of the centrifugal rotor 25 is stopped. In this state, the photometric process is performed. Then, after such a photometric process is sequentially performed for all the measurement cells, the second photometric process is performed again in order from the measurement cell 63 for which the photometric process was first performed, for example. By repeating such a process a predetermined number of times, a plurality of pieces of data (the amount of light for measurement and the amount of light for reference) for each photometric process are acquired.
Then, the light amount fluctuation of the measurement light obtained for each measurement cell at each time of the photometric processing is compensated based on the light quantity fluctuation of the reference light, and the absorbance is calculated. The concentration of the detected component to be detected is calculated.

A specific description will be given of a method for calculating the absorbance of the measurement light. For example, disturbance of the light amount emitted from the light source lamp 41 such as superimposition of the power source frequency, minute flicker due to arc fluctuation, long-period fluctuation, etc. As shown in FIG. 15, the fluctuations due to the same tendencies are similar to each other with almost the same fluctuation width over almost the entire wavelength range (in FIG. 15, for convenience, the amounts of light of two different wavelength lights over time The amount of disturbance due to the light source lamp 41 is reduced by subtracting the amount of reference light having a wavelength that is not absorbed by the test solution from the amount of measurement light having a wavelength that is absorbed by the test solution. The effect can be compensated.
For example, FIG. 16 shows the change over time in the amount of light for each of the wavelength that is absorbed by the test solution (measurement light λ1) and the wavelength that is not absorbed by the test solution (reference light λ2). By subtracting the light amount of the reference light from the light amount of the reference light, the disturbance due to the light source lamp 41 as described above can be compensated, and the measurement light is absorbed by the test solution as shown in FIG. The degree (change in light quantity with time) can be captured.

JP 2007-322208 A

However, it has been found that even if the light amount fluctuation of the measurement light is compensated (two-wavelength correction) based on the light quantity fluctuation of the reference light, the measurement cannot be performed with high accuracy. That is, the light emitted from the light source lamp 41 travels in a manner that light on the short wavelength side is condensed and light on the long wavelength side is diffused due to chromatic aberration caused by the bulb and the lens 42 constituting the light source lamp 41. . For this reason, as shown in FIG. 18, the illuminance peak position for the measurement light and the illuminance peak position for the reference light are different from each other in the opening surface of the light introduction opening 22A of the measurement chamber 21. Therefore, the measurement light and the reference light cannot be incident on the measurement cell 63 with uniform illuminance, and the measurement cannot be performed with sufficiently high accuracy.
In particular, when the photometric operation is performed in a state where the centrifugal rotor 25 is stopped, the stop position of the centrifugal rotor 25 is, for example, on the order of several tens of μm (light introduction opening of the measurement chamber 21) every time the photometric process is performed. There may be variations in which the opening diameter of 22A is 3 mm, for example, and the inner diameter of the measurement cell 63 is 1 mm, for example. As described above, the photometry process is repeatedly performed a predetermined number of times for one measurement cell 63. As shown in FIG. 18, the measurement cell for the light introduction opening 22A of the measurement chamber 21 in the previous photometry process is performed. If there is a variation in the stop position (broken line) of 63 and the stop position (solid line) of the measurement cell 63 with respect to the light introduction opening 22A of the measurement chamber 21 during the next photometric processing, Since the illuminance peak positions of the measurement light and the reference light from the light source lamp 41 are different from each other, for example, at the stop position (measurement position) in the previous photometric process, the light incident surface with respect to the measurement cell 63 , The illuminance of the measurement light λ1 at the short wavelength side is larger than the illuminance of the reference light λ2 at the long wavelength side, and the stop position ( In the measurement position), in the light incident surface with respect to the measurement cell 63, a phenomenon occurs such that the illuminance of the reference light λ2 having the longer wavelength is greater than the illuminance of the measurement light λ1 having the shorter wavelength. Accordingly, the measurement light λ1 and the reference light λ2 cannot be incident on the measurement cell 63 with uniform illuminance, and measurement cannot be performed with sufficiently high accuracy. Note that regions L1 and L2 indicated by the alternate long and short dash line in FIG. 18 are an effective irradiation region of the measurement light λ1 and an effective irradiation region of the reference light λ2 each having an illuminance of a certain level or more.

  When the light source is constituted by an LED light source, for example, a plurality of red light emitting LED chips, blue light emitting LED chips, and green light emitting LED chips are arranged on a substrate and packaged. However, even when such an LED light source is used, the wavelength within the opening surface of the light introduction opening 22A of the measurement chamber 21 is caused by chromatic aberration caused by the condenser lens and the arrangement state of the LED chips. The illuminance peak position exists at a different position every time, and the above problem occurs.

  The present invention has been made based on the above circumstances, and an object thereof is to provide an optical analyzer capable of accurately measuring with high accuracy the analysis of the specimen in the measurement cell. is there.

An optical analyzer according to the present invention includes a centrifugal rotor having a chip holding portion for holding a microchip having a measurement cell for containing a sample, a rotation drive mechanism for rotating the centrifugal rotor, and the centrifugal rotor accommodated therein. A measurement chamber, a light source that irradiates light to the measurement cell in the microchip, and a light receiving unit that receives the light transmitted through the measurement cell, and the light from the light source is formed in the measurement chamber. Of the light that has entered the measurement cell through the light introduction opening and the light introduction opening formed in the centrifugal rotor and transmitted through the measurement cell, the measurement light having a different wavelength and the reference light In the optical analyzer that analyzes the specimen in the measurement cell by measuring the amount of each light absorption,
Between the light source and the light introduction opening of the measurement chamber, an illuminance equalizing means for equalizing the illuminance of the measurement light and the reference light in the light incident surface with respect to the measurement cell is disposed. It is characterized by being.

  In the optical analyzer of the present invention, the illuminance equalizing means includes a light guide in which a plurality of optical fibers are irregularly bundled, and the light guide has one end surface facing the light source and the other end surface. May be arranged to face the light introduction opening of the measurement chamber.

  Further, in the optical analyzer of the present invention, the illuminance equalizing means can be constituted by an integrator lens or a diffusing plate.

  According to the optical analyzer of the present invention, the measurement light and the reference light emitted from the light source are incident on the measurement cell at a uniform illuminance. The influence of the chromatic aberration of the optical system for allowing light to enter the cell can be suppressed, and desired measurement (analysis) can be performed with high accuracy and high reliability.

It is a perspective view which shows the external appearance of the structure in an example of the optical analyzer of this invention. It is a top view which shows roughly the internal structure of the optical analyzer shown in FIG. It is sectional drawing which shows the outline of a structure of the measurement part in the optical analyzer shown in FIG. It is an expanded sectional view which shows roughly the principal part structure of a measurement part. It is (A) top view and (B) sectional drawing which show the outline of a structure in an example of the microchip used in the optical analyzer of this invention. It is an idea figure for demonstrating the effect | action of a random fiber. It is an expanded sectional view which shows roughly the principal part structure of the measurement part in the other example of the optical analyzer of this invention. It is an ideal view for demonstrating the effect | action of an integrator lens. It is an expanded sectional view which shows roughly the principal part structure of the measurement part in the further another example of the optical analyzer of this invention. 5 is a graph showing temporal changes in the amount of measurement light and the amount of reference light in Experimental Example 1. 14 is a graph showing a change with time of the light amount of the measurement light, in which the light amount variation of the measurement light in Example 1 was compensated by the light amount variation of the reference light. 6 is a graph showing temporal changes in the light amount of measurement light and the light amount of reference light in Comparative Experimental Example 1. 6 is a graph showing a change over time in the amount of light for measurement, in which a variation in the amount of light for measurement is compensated by a variation in the amount of light for reference light in Comparative Experimental Example 1. It is sectional drawing for description which shows roughly the principal part structure in an example of the conventional optical analyzer. It is a graph which shows the time-dependent change of the light quantity of the light from a light source lamp. It is a graph which shows the time-dependent change of the light quantity of the light for measurement acquired in an actual optical analyzer, and the light quantity of the reference light. It is a graph which shows the time-dependent change of the light quantity of the measurement light in which the light quantity fluctuation of the measurement light was compensated by the light quantity fluctuation of the reference light. FIG. 6 is an explanatory diagram showing a relationship between a measurement cell stop position (measurement position), an illuminance peak position of measurement light, and an illuminance peak position of reference light when the photometric operation is performed with the centrifugal rotor stopped. is there.

<First Embodiment>
FIG. 1 is a perspective view showing the appearance of the configuration of an example of the optical analyzer of the present invention, FIG. 2 is a plan view schematically showing the internal structure of the optical analyzer shown in FIG. 1, and FIG. Sectional drawing which shows the outline of a structure of the measurement part in the optical analyzer to show, FIG. 4 is an expanded sectional view which shows schematically the principal part structure of a measurement part.
The optical analysis device 10 is for analyzing and testing a sample for biochemical analysis such as blood (serum or plasma may be used), for example, using a microchip 60, and the whole is, for example, a box-shaped casing. 11, the measurement unit 20 disposed at the center position inside the casing 11, the light source unit 40 disposed at the right rear side of the measurement unit 20, and the left side of the measurement unit 20 A control unit 15 including a light receiving unit 50 disposed at a position of the CPU, a CPU board 15A mounted with a functional element such as a signal processing circuit disposed at a position on the rear side of the measurement unit 20, and a measurement unit 20. The power supply unit 14 is disposed at a position on the lower front side, and the output unit 16 includes a printer 16A disposed at a position aligned with the power supply unit 14 in the width direction.
The casing 11 includes a lid 11A that is made up of an upper wall portion facing the measurement unit 20 and a front wall portion continuous with the measurement unit 20 and is rotated about an axis extending along the width direction to open the chip insertion unit 12. The operation panel 13 provided with the panel-like display part 13A is provided at a position on the upper surface of the casing 11 aligned with the lid 11A in the width direction.
In FIGS. 1 and 2, 17 is a power input terminal, 18 is a power switch, and 19 is a data output terminal.

As shown in FIG. 3, the measuring unit 20 includes, for example, a hollow cylindrical centrifuge rotor 25 having a tip holding portion 26 for holding a microchip 60 in a hollow cylindrical outer casing 22 on the same axis. The measurement chamber 21 is disposed, and the drive motor 24 is disposed in such a manner that the drive shaft 24A extends in the vertical direction (vertical direction) through the center of the lower surface of the centrifugal rotor 25, and the drive motor The centrifugal rotor 25 is rotationally driven by driving 24. In FIG. 2, reference numeral 23 denotes a motor driver.
A direction switching gear 27 whose outer diameter is smaller than the radius of the centrifugal rotor 25 is rotatably supported on the bottom wall of the centrifugal rotor 25 so as to be rotatable about an axis parallel to the rotational axis C of the centrifugal rotor 25. An appropriate holder member (not shown) is provided on the upper surface of the direction switching gear 27, whereby the chip holding portion 26 is configured. The tip holding unit 26 is positioned on the outer peripheral edge side of the centrifugal rotor 25.
In addition, the measuring unit 20 may have a plurality of chip holding units 26. In this embodiment, the rotation axis center C is sandwiched in order to maintain the rotation balance of the centrifugal rotor 25 in an appropriate state. At the opposite position (a point-symmetrical position with respect to the rotational axis center C), a tip holding portion 26 composed of the direction switching gear 27 having the same configuration is formed.

Each of the lower wall of the outer casing 22, the centrifugal rotor 25, and the direction switching gear 27 constituting the chip holding unit 26, the measurement cell 63 of the microchip 60 in a state where the microchip 60 is held by the chip holding unit 26. Are formed in the radial direction position where the light from the light source section 40 is introduced into the measurement cell 63 of the microchip 60, and the upper wall of the outer casing 22 is formed. Is formed with an opening 22B in which, for example, an optical fiber 52 for guiding the light passing through the measurement cell 63 of the microchip 60 to the light receiving unit 50 is mounted.
In addition, a planar heater 35 for maintaining the temperature in the measurement chamber 21 at a constant temperature, for example, 37 ° C. during the photometric process is provided in a part of the upper and lower surfaces of the outer casing 22. The output is controlled based on the temperature detected by the thermistor 36.
Further, on the upper wall of the outer casing 22, information unique to the microchip 60 displayed by, for example, a bar code provided in the chip insertion opening 28 and the microchip 60 is provided above the measurement chamber 21. A barcode reading window 29 for reading by the barcode reader 37 is formed.

  The measurement unit 20 includes a chip direction switching mechanism 30 that constitutes a rotational drive mechanism that is independent of the drive mechanism that rotationally drives the centrifugal rotor 25 for adjusting the attitude of the microchip 60 held by the chip holding unit 26. The tip direction switching mechanism 30 meshes with a direction switching gear 27 that constitutes a tip holding portion 26 that is rotatably provided with respect to the drive shaft 24A of the drive motor 24 via a ball bearing 32, for example. And a tip direction switching motor 31 which is a driving source for driving the driving gear 33 to rotate. An encoder 38 is connected to the drive motor 24 for rotating the centrifugal rotor 25, and the stop position of the centrifugal rotor 25 is controlled based on a signal from the encoder 38.

The light source unit 40 includes, for example, a light source lamp 41 that emits light in a wavelength region ranging from an ultraviolet region to an infrared region, a lens 42 that irradiates the light emitted from the light source lamp 41 in parallel light, and an optical filter 43. It is comprised by. Reference numeral 44 denotes an air cooling fan for cooling the light source lamp 41 when the lamp is turned on.
As the light source, for example, an LED light source that emits white light may be used.

  The light receiving unit 50 includes a light receiver 51 that can simultaneously measure a plurality of wavelengths, for example, a concave diffraction grating multiwavelength photometer, and one end of light transmitted through the measurement cell 63 is placed on the upper wall of the outer casing 22. The light is guided to the light receiver 51 by, for example, an optical fiber 52 attached to the formed opening 22B.

For example, as shown in FIG. 5, the microchip 60 used in the optical analyzer 10 has a flat shape as a whole. For example, the measurement chip 63, a separation cell (not shown), a mixing cell (not shown), Transparent substrates 62 </ b> A and 62 </ b> B are provided on both surfaces of the chip body 61 in which a flow path including weighing means (not shown) is formed.
In the microchip 60, a plurality of, for example, seven measurement cells 63 are spaced apart at positions on the same circumference as the rotational axis center C of the centrifugal rotor 25 in a state where the measurement cells 63 are held by the chip holder 26 of the centrifugal rotor 25. In order to ensure a sufficiently large transmission optical path length necessary for absorbance measurement, each has an elongated form in which the dimension (length) in the thickness direction is extremely large compared to the cross-sectional diameter (inner diameter). Have.
As a specific configuration example of the measurement cell 63, for example, the inner diameter is 1 mm, the length is 10 mm, and the volume (the amount of the inspection liquid to be inspected) is about 10 μl (microliter).
In FIG. 5, reference numeral 65 denotes, for example, a bar code attached to the upper surface of the microchip 60, and displays information unique to the microchip 60 such as measurement items and measurement methods by itself.

Thus, in the optical analyzer 10, the light for the measurement light and the reference light in the light incident surface with respect to the measurement cell 63 is disposed between the light source 40 and the light introduction opening 22 </ b> A of the measurement chamber 21. Illuminance equalizing means for equalizing the illuminance is provided.
The illuminance uniforming means in this example includes, for example, a light guide (hereinafter, referred to as “random fiber”) 70 in which a plurality of optical fibers are irregularly bundled, and is configured by one end face of each optical fiber. The arrangement state of the optical fibers on the other end surface (light emitting portion) 70B constituted by the one end surface (light incident portion) 70A and the other end surface of each optical fiber is random.
The random fiber 70 is disposed such that one end surface thereof faces the light emitting portion of the light source unit 40 and the other end surface thereof faces the light introducing opening 22 </ b> A in the measurement chamber 21.

The number of optical fibers constituting the random fiber 70 is preferably 100 or more, for example.
Moreover, it is preferable that the strand diameter of each optical fiber is in the range of 0.05 to 0.5 mm, for example, and even if they have strand diameters of the same size, They may have different wire diameters.
The bundle diameter of the random fiber 70 is, for example, 1.0 to 5.0 mm, and the total length is, for example, 100 mm or more.

Hereinafter, the operation of the optical analyzer will be described.
First, when the optical analysis device 10 is operated in a state where the microchip 60 into which a sample such as blood collected from a subject and a reagent are injected is mounted on the chip holding unit 26, the barcode of the microchip 60 is displayed. Information unique to the microchip 60 such as the measurement conditions displayed by the 65 itself is read by the barcode reader 37, and the operating conditions of the optical analyzer 10 are set based on this information, and the centrifugal rotor 25 is driven to rotate. By doing so, the centrifugal force acting on the microchip 60 is used to separate the measurement target liquid from the specimen, the distribution process for distributing the measurement target liquid to each measurement cell 63, and a certain amount of the measurement target liquid. Weighing process for separating the sample, mixing and reacting the liquid to be measured and the reagent, reacting to prepare the test liquid, and each measurement of the prepared test liquid Liquid feeding Le 63, the process of filling, the chip direction switching operation of adjusting the direction (position) of the microchip 60 are sequentially performed while performed between each treatment. In the above, as a reagent, what is used in the conventional optical analyzer can be used, and it selects according to the target test | inspection item (detection target component).

  After the series of pre-processing operations as described above are performed, the photometric operation is performed for each measurement cell 63 filled with the adjusted test solution. That is, for example, the lens 42 and the optical filter 43 are placed in a state in which the light from the light source unit 40 is aligned with one measurement cell 63 in the microchip 60 and rotation of the centrifugal rotor 25 is stopped. The light from the light source lamp 41 irradiated via the light is introduced into the measurement cell 63 in the vertical direction from the lower side of the measurement chamber 21 via the random fiber 70. And among the light that has passed through the test solution in the measurement cell 63, the light amount of the measurement light having a specific wavelength that is absorbed by the test solution set according to the test solution and the measurement light that is not absorbed by the test solution The amount of reference light having a wavelength different from that of light is simultaneously detected by a light receiver 51 connected via an optical fiber 52.

  The photometric operation is performed, for example, by repeatedly performing a photometric process for all the measurement cells a plurality of times, with a photometric process for a predetermined time for one measurement cell as one processing unit. That is, when the measurement of the absorbance of one measurement cell is completed, the centrifugal rotor 25 is driven to rotate, and the amount of movement thereof is controlled based on the signal from the encoder 38, so that the adjacent measurement cell where the photometric operation is to be performed. In contrast, the position of the light source 40 is controlled so that light from the light source 40 is introduced, and the rotation of the centrifugal rotor 25 is stopped. In this state, the photometric process is performed. Then, after such photometric processing is sequentially performed on all the measurement cells, the second photometric processing is performed again in order from, for example, the measurement cell on which the first photometric processing has been performed. By repeating such a process a predetermined number of times, a plurality of data (the amount of light for measurement and the amount of light for reference) for each photometric process are acquired for one measurement cell.

  Then, for each measurement cell 63, the light amount of the reference light is subtracted from the light amount of the measurement light every time the photometric process is performed, and the variation in the light amount of the measurement light is compensated by the light amount variation of the reference light. Processing for calculating the amount of light is performed, and the absorbance is calculated based on the change over time in the amount of light for measurement, and the concentration of the detection target component contained in the test solution in the measurement cell 63 is calculated based on the result. The Such data processing is performed on the test solution in all the measurement cells 63, and the result is displayed on the panel-like display unit 13A and output by the printer 16A.

  As the measurement light used in the photometric operation, for example, any one of 12 wavelengths of 340, 405, 450, 480, 505, 546, 570, 600, 660, 700, 750, and 800 nm (± 10 nm) is used. Is selected according to the detection target component, and the reference light is selected from light having a wavelength other than the wavelength selected as the measurement light.

  Thus, according to the optical analyzer 10 described above, by providing the illuminance uniformizing means comprising the random fiber 70, as shown in FIG. 6, the light emitted from the light source lamp 41 (wavelength light λA, The wavelength light λB) is incident on one end face (light incident portion) 70A of the random fiber 70 through the lens 42 and the optical filter 43, passes through the random fiber 70, and is emitted from the other end face (light emitting portion) 70B. In any wavelength light λA and λB, the light irradiation surface has a uniform illuminance distribution, and the measurement light and the reference light to be detected by the light receiver 51 are measured cells 63 in the microchip 60. Since the light is incident at a uniform illuminance, the light quantity fluctuation caused by the chromatic aberration of the optical system such as the bulb and the lens 42 constituting the light source lamp 41, and photometry When the operation is performed in a state where the centrifugal rotor 25 is stopped, it is possible to suppress fluctuations in the amount of light caused by variations in the stop position of the measurement cell 63 with respect to the light introduction opening 22A of the measurement chamber 21 with high accuracy. The desired analysis can be performed with high reliability.

  Although one embodiment of the present invention has been described above, the present invention is not limited to the above embodiment.

Second Embodiment
FIG. 7 is an explanatory cross-sectional view schematically showing a main configuration of a measurement unit in another example of the optical analyzer of the present invention.
This optical analyzer is the integrator according to the first embodiment, in which the illuminance equalizing means for equalizing the illuminance of the measurement light and the reference light in the light incident surface with respect to the measurement cell is not a random fiber but an integrator. Except for being constituted by the lens 71, it has the same configuration as the optical analyzer according to the first embodiment. In FIG. 7, reference numeral 46 denotes a condensing lens, and 45 reflects light emitted from the integrator lens 71 so as to pass through the measurement cell 63 of the microchip 60 in the vertical direction from the lower side of the measurement chamber 21. For the sake of convenience, the same reference numerals are given to the reflection mirrors to be introduced and the same constituent members as those of the optical analyzer according to the first embodiment.

For example, the integrator lens 71 has a configuration in which a plurality of rod lenses 71A each having a convex surface on both sides are bundled, and light incident from one end surface 711 of the integrator lens 71 is transmitted through each rod lens 71A. Then, the light is emitted from the other end surface 712.
In the configuration example of the integrator lens 71, the outer diameter is 3 to 10 mm, the length is 10 to 50 mm, the outer diameter of each rod lens 71A is 1 to 5 mm, and the number of rod lenses 71A is one or more.
Further, the integrator lens 71 may be constituted by, for example, a rod-shaped integrator made of a cylindrical rod lens made of quartz glass or a hollow cylindrical rod lens having an inner surface as a mirror surface.

  Also in the optical analyzer having such a configuration, the same effect as that according to the first embodiment, that is, the illuminance uniformizing means including the integrator lens 71 is provided. Light (wavelength light λA, wavelength light λB) emitted from the lamp 41 is incident on one end surface (light incident portion) 711 of the integrator lens 71 through the lens 42 and the optical filter 43, passes through the integrator lens 71, and others. The light emitted from the end face (light emitting part) 712 has a uniform illuminance distribution on the light irradiation surface for any wavelength light (λA, λB), and the measurement to be detected by the light receiver 51. Since the working light and the reference light are incident on the measurement cell 63 in the microchip 60 with uniform illuminance, the light constituting the light source lamp 41 And the stop position of the measurement cell 63 with respect to the light introduction opening 22A of the measurement chamber 21 when the photometric operation is performed with the centrifugal rotor stopped. Therefore, it is possible to suppress fluctuations in the amount of light caused by the variation in the above, and to perform a desired analysis with high accuracy and high reliability.

<Third Embodiment>
FIG. 9 is an explanatory cross-sectional view schematically showing a main configuration of a measurement unit in still another example of the optical analyzer of the present invention.
This optical analyzer is the optical analyzer according to the first embodiment, wherein the illuminance equalizing means for equalizing the illuminance of the measurement light and the reference light in the light incident surface with respect to the measurement cell is not a random fiber. Except for being constituted by the diffusion plate 72, it has the same configuration as the optical analyzer according to the first embodiment. In FIG. 9, reference numeral 45 denotes a reflection mirror that reflects light from the light source lamp 41 and introduces it from the lower side of the measurement chamber 21 so as to pass through the measurement cell 63 of the microchip 60 in the vertical direction. Constituent members that are the same as those of the optical analyzer according to the embodiment are denoted by the same reference numerals for convenience.

The diffusing plate 72 is constituted by, for example, a disc-shaped holographic diffusing plate that shapes light from the light source lamp 41 incident through the lens 42 and the optical filter 43 into a circular shape or an elliptic shape and emits the light with a constant output. Has been.
The diffusion angle of the diffusion plate 72 is preferably about 0.5 to 20 °, for example, when the diffusion type is circular.
The outer diameter of the diffusion plate 72 is, for example, 1 to 10 mm, and the thickness is, for example, 1 mm.

  The optical analyzer having such a configuration also has the same effect as that of the first embodiment, that is, the light emitted from the light source lamp 41 by including the illuminance uniformizing means including the diffusion plate 72. Is incident on the lower end surface (light incident surface) of the diffusing plate 72 through the lens 42 and the optical filter 43, passes through the diffusing plate 72, and is emitted from the upper end surface (light emitting surface) at any wavelength. The light also has a uniform illuminance distribution on the light irradiation surface, and the measurement light and the reference light to be detected by the light receiver 51 enter the measurement cell 63 in the microchip 60 with a uniform illuminance. Therefore, the light quantity fluctuation caused by the chromatic aberration of the optical system such as the bulb and the lens 42 constituting the light source lamp 41 and the photometric operation are performed with the centrifugal rotor 25 stopped. In this case, fluctuations in the amount of light caused by variations in the stop position of the measurement cell 63 with respect to the light introduction opening 22A of the measurement chamber 21 can be suppressed, and the intended analysis can be performed with high accuracy and high reliability. .

Hereinafter, experimental examples performed for confirming the effects of the present invention will be described.
<Experimental example 1>
An optical analyzer (10) according to the present invention was produced according to the configuration shown in FIGS.
The opening diameter of the light introducing opening (22A) in the measurement chamber is 3 mm, the opening diameter of the light introducing opening (25A) in the centrifugal rotor (25) is 3 mm, and the light introducing opening in the direction switching gear (27). The aperture diameter of (27A) is φ3 mm, and the light source lamp (41) is a xenon lamp with an output power of 50 W.
The random fiber (70) as the illuminance uniforming means has a bundle diameter of 3 mm and a total length of 200 mm, the number of optical fibers constituting the random fiber (70) is about 200, and the strand diameter of each optical fiber is The diameter is 0.2 mm, and the separation distance between the other end face (light emitting face) of the random fiber (70) and the lower end face of the microchip is about 7 mm.
The microchip (60) has seven measurement cells (63), each measurement cell (63) has an inner diameter of φ1 mm, a length of 10 mm, and a capacity of about 10 μl.

Using a control serum (Strol) as a sample and a uric acid kit “N-assay UA-L Nittobo” (Nitto-Bo Medical Co., Ltd.) as a reagent, these are injected into a microchip (60) in a predetermined amount, and an optical analyzer. The centrifugal rotor (25) is rotationally driven while adjusting the direction of the microchip (60), and the above separation process, distribution process, weighing process, mixing reaction process, and liquid feeding of the prepared test liquid are performed. After sequentially performing the filling process, the above-described photometric operation was performed for each measurement cell filled with the test solution, and the light amount of the measurement light and the light amount of the reference light were measured for one measurement cell (63). . The results are shown in FIG.
The processing conditions of the photometric operation are, for example, that the time required for one processing unit for one measuring cell is 1 sec, the number of times of the photometric processing for one measuring cell is 15, and the measuring light is light having a wavelength of 600 nm, for reference The light was set at a wavelength of 800 nm.
The measurement principle is as follows. That is, uric acid in a specimen is decomposed into allantoin, carbon dioxide, and hydrogen peroxide by an enzyme reaction as shown in the following reaction formula 1, and the hydrogen peroxide produced thereby is present in the presence of peroxidase (POD). Then, TOOS [N-ethyl-N- (2-hydroxy-3-sulfopropyl) -m-toluidine sodium] and 4-aminoantipyrine are subjected to oxidative condensation, and a reddish purple quinone dye which is a condensate formed thereby [ By measuring the component to be detected] spectroscopically, the concentration of UA (uric acid, test item) in the sample can be calculated.

As shown in FIG. 10, with respect to the measurement light, as the reaction between the specimen and the reagent proceeds, the amount of light tends to increase substantially linearly over time (simple increase to the right), that is, Shows the change in the amount of light over time due to the absorption of the measurement light by the test solution. From this result, the variation in the stop position of the measurement cell at the time of the photometric process and the chromatic aberration due to the bulbs constituting the light source lamp, etc. It was confirmed that they were not affected by or suppressed. In addition, since the reference light is not absorbed by the specimen even when the reaction between the specimen and the reagent proceeds, no change in the quantity of light is observed over time, and the detected quantity of light is substantially It was confirmed that it was constant.
The reason for this is considered to be that the illuminance of the measurement light (wavelength 600 nm) and the illuminance of the reference light (wavelength 800 nm) and the illuminance of the reference light (wavelength 800 nm) are made uniform by the action of the random fiber. It is done.
Therefore, in this experimental example (specimen, reagent), by subtracting the light amount of the reference light from the light amount of the measurement light every time the photometric process is performed, the light amount fluctuation of the measurement light is caused by the light amount fluctuation of the reference light. The compensated light quantity of the measurement light is calculated (FIG. 11). The difference between the light quantity of the measurement light in the first light measurement process and the light quantity of the measurement light in the fifteenth light measurement process (the light quantity over time). It is assumed that the concentration of UA (uric acid) in the sample can be accurately obtained with high accuracy based on the absorbance obtained thereby.

<Comparative Experimental Example 1>
According to the configuration shown in FIG. 14, there is no illuminance equalizing means, and the light irradiated from the light source lamp (41) through the lens (42) and the optical filter (43) is reflected by the reflection mirror (45) to make micro- A comparative optical analyzer having the same configuration as that manufactured in Experimental Example 1 was prepared except that it was configured to enter the measurement cell (63) in the chip (60), and the same as in Experimental Example 1 above. The light measurement operation was performed, and the light quantity of the measurement light and the light quantity of the reference light were measured for one measurement cell. The results are shown in FIG.

  As shown in FIG. 12, with respect to the measurement light, as the reaction between the specimen and the reagent proceeds, the amount of light at the 15th photometric process is larger than the amount of light at the first photometric process, Although the amount of light showed a tendency to increase with time, it was confirmed that the variation in measured values was large. In addition, regarding the reference light, even when the reaction between the sample and the reagent proceeds, the light amount may vary every time the photometric process is performed even though the sample light is not absorbed by the sample. confirmed. From this result, it can be considered that the measurement cell is greatly influenced by variations in the stop position of the measurement cell at the time of photometric processing and chromatic aberration caused by a bulb constituting the light source lamp. FIG. 13 plots the value obtained by subtracting the light amount of the reference light from the light amount of the measurement light (the light amount of the measurement light after two-wavelength correction) every time the photometric process is performed. And the twelfth metering process, and the light amount tends to decrease (for example, lower right, reverse) at the fourteenth metering process and the fifteenth metering process. It is assumed that the concentration of UA (uric acid, test item) in the sample cannot be obtained accurately with high accuracy.

DESCRIPTION OF SYMBOLS 10 Optical analyzer 11 Casing 11A Cover body 12 Chip insertion part 13 Operation panel 13A Panel-shaped display part 14 Power supply part 15 Control part 15A CPU board 16 Output part 16A Printer 17 Power input terminal 18 Power switch 19 Data output terminal 20 Measurement part 21 Measuring chamber 22 Outer casing 22A Light introduction opening 22B Opening 23 Motor driver 24 Drive motor 24A Drive motor drive shaft 25 Centrifugal rotor 25A Light introduction opening 26 Chip holder 27 Direction switching gear 27A Light introduction gear Opening portion 28 Chip insertion opening portion 29 Bar code reading window 30 Tip direction switching mechanism 31 Tip direction switching motor 32 Ball bearing 33 Driving gear 35 Heater 36 Thermistor 37 Bar code reader 38 Encoder 40 Light source portion 41 Light source lamp 42 Lens 43 Optical Filter 44 Air Cooling Fan 45 Reflecting Mirror 46 Condensing Lens 50 Light Receiving Part 51 Light Receiver 52 Optical Fiber 60 Microchip 61 Chip Body 62A, 62B Transparent Substrate 63 Measurement Cell 65 Barcode 70 Random Fiber 70A One End Surface (Light Incident Part)
70B The other end surface (light emitting part)
71 integrator lens 71A rod lens 711 one end surface (light incident part)
712 Other end surface (light emitting part)
72 Diffusion plate C Center of rotation axis of centrifugal rotor

Claims (4)

A centrifugal rotor having a chip holding unit for holding a microchip having a measurement cell for containing a sample, a rotation driving mechanism for rotationally driving the centrifugal rotor, a measurement chamber in which the centrifugal rotor is housed, and the micro A light source for irradiating light to the measurement cell in the chip, and a light receiving unit for receiving the light transmitted through the measurement cell, and the light from the light source is formed in the light introduction opening formed in the measurement chamber; Of the light that is incident on the measurement cell and transmitted through the measurement cell through the light introduction opening formed in the centrifugal rotor, the amount of light absorption of each of the measurement light and the reference light having different wavelengths is obtained. In the optical analyzer that measures and analyzes the sample in the measurement cell,
Between the light source and the light introduction opening of the measurement chamber, an illuminance equalizing means for equalizing the illuminance of the measurement light and the reference light in the light incident surface with respect to the measurement cell is disposed. A characteristic optical analyzer.   The illuminance equalizing means comprises a light guide in which a plurality of optical fibers are irregularly bundled, and the light guide has one end surface facing the light source and the other end surface being a light introduction opening of the measurement chamber. The optical analyzer according to claim 1, wherein the optical analyzer is opposed to the unit.   The optical analysis apparatus according to claim 1, wherein the illuminance uniformizing unit includes an integrator lens.   The optical analyzer according to claim 1, wherein the illuminance uniformizing unit is formed of a diffusion plate.

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