JP3964291B2 - Analytical instrument - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a small analytical instrument that can perform fecal occult blood analysis and the like.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, large analyzers that automatically perform fecal occult blood analysis from samples collected by mass screening or the like are known (see, for example, Patent Document 1).
[0003]
In this large analyzer, a large amount of cuvettes (mixing containers) that are disposable or washed and reused are set, and while the cuvette is linearly transferred, the sample liquid from the sample collection container and the liquid from the reagent bottle are transferred to an empty cuvette. Each reagent is dispensed, and photometric measurement of the degree of coloration is performed.
[0004]
The photometric unit is composed of a light source, a filter, and an optical fiber, and the optical path is formed so that the measurement light from the light source is wavelength-converted by the filter and irradiated to the cuvette by the optical fiber.
[0005]
[Patent Document 1]
JP-A-8-35969 [0006]
[Problems to be solved by the invention]
The conventional automatic analyzers as described above are large and suitable for analyzing a large amount of specimens, and the photometry unit also requires a light source, a filter, an optical fiber, etc. It has become an obstacle when doing.
[0007]
On the other hand, as a light source having a specific wavelength necessary for sample analysis, it is conceivable to use a light emitting element by an LED (light emitting diode). However, the emission spectrum of this LED changes due to self-heating at the time of lighting or environmental temperature. The amount of light changes. Therefore, the light-emitting element using the above-mentioned LED is used as a light source for an analytical instrument that requires high accuracy, such as analyzing the sample component through transmission photometry of the color change caused by mixing the reagent and the sample as described above. It is difficult to do.
[0008]
In other words, LEDs have the characteristic that the center wavelength of the emission spectrum fluctuates under the influence of temperature, and is affected by changes in the environmental temperature, and the temperature also changes due to self-heating as a result of lighting, affecting photometric analysis. give. Further, the LED basically has a characteristic that the light emission intensity (light quantity) changes according to the magnitude of the applied current, and this light quantity change also has a problem of affecting photometric analysis.
[0009]
By the way, in the case of analyzing the sample component based on the color mixing degree of the reagent and the sample mixed in the cuvette as described above, the coloration degree is also affected by the temperature. The cuvette is heated and held at a predetermined temperature and installed so as to obtain a color change corresponding to the amount of the sample component with high accuracy.
[0010]
Accordingly, in view of the above points, the present invention reduces the size of the apparatus by configuring the colorimetric reaction between the reagent and the sample in the cuvette to be transmitted and measured using a light emitting element of the LED, and changes the temperature of the LED. It is another object of the present invention to provide a small analytical instrument which can stabilize light emission spectrum and light emission intensity due to current change and perform accurate photometry.
[0011]
[Means for Solving the Problems]
The analytical instrument of the present invention is an analytical instrument that analyzes a sample component by mixing a reagent and a sample liquid in a cuvette, photometrically measuring the color change thereof, and a temperature control block for controlling the temperature of the cuvette; and a photometry unit consisting of a light emitting element and a light receiving element by the LED for transmitting metering the color change of the reagent and the specimen solution in the cuvette, the light emitting element of the photometric unit, temperature is inserted into the temperature control block It is characterized by being adjusted and driven by a constant current.
[0013]
【The invention's effect】
According to the present invention as described above, a light-emitting element using an LED is used as a light source of a photometry unit that performs transmission photometry, and the apparatus is made compact, and the light-emitting element is fixed to a member having a large heat capacity, and preheating temperature control is performed. In order to stabilize the emission spectrum and emission intensity by maintaining a constant temperature without being affected by the outside temperature and self-heating, and further stabilizing the emission spectrum and emission intensity by driving at a constant current, High-precision photometric analysis can be performed.
[0014]
Using a temperature control block on the sample tray that controls the temperature of the cuvette mixed with the reagent and the sample liquid, the LED temperature is controlled at the same time. This temperature control block has a large heat capacity, is less susceptible to self-heating, changes in outside air temperature, and temperature control, and has stable characteristics.
[0015]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 is a perspective view showing a schematic mechanism of an example of an automatic analyzer, FIG. 2 is a perspective view of a sample tray, FIG. 3 is a schematic sectional view of a sample tray in an analysis state, and FIG. 4 is a perspective view of a cuvette, a specimen container, and a nozzle tip. FIG. 5 and FIG. 5 are cross-sectional views showing a cuvette opening state by the opening mechanism.
[0016]
This automatic analyzer 1 includes a disposable cuvette 11 as a mixing container in which a dry reagent R is enclosed as shown in FIG. 4A, a sample container 12 containing a sample liquid as shown in FIG. A disposable nozzle tip 13 attached to the tip of a later-described suction nozzle 41 for sucking and discharging the liquid as shown in (c) is used as a consumable item.
[0017]
The cuvette 11 is formed into a substantially rectangular tube shape with a translucent resin, and is configured as a measurement unit 11a that has a particularly transparent lower wall surface and allows measurement light to pass therethrough. In the case of fecal occult blood analysis, a lyophilized reagent R made of a colloidal gold reagent is accommodated, and a seal 11c made of metal foil is welded to the upper end opening to enclose the reagent R therein. The reagent R is dissolved by injecting a lysis solution at the time of analysis. Further, the sample container 12 includes a collar portion 12a that protrudes outward on the outer periphery of the upper portion and engages with the mounting hole, into which a sample solution in which a fecal sample collected from a sample collection container (not shown) is dissolved and stored is injected. The In addition, the nozzle tip 13 is formed in a pipette shape, and the tip of the suction nozzle 41 is fitted to the upper end opening, and a liquid is sucked and accommodated by introducing suction pressure, and discharged to the cuvette 11 by introducing discharge pressure. To do.
[0018]
The automatic analyzer 1 includes a circular sample tray 3 that can mount a plurality (for example, 10 sets) of the cuvette 11, the sample container 12, and the nozzle chip 13 on the front flat portion of the apparatus main body 2, and the vertical movement and swivel movement. A dispenser 4 having an aspirating nozzle 41, a photometric unit 5 (see FIG. 3) by an LED which is installed inside the sample tray 3 and transmits and measures the color change of the reagent R and the sample liquid in the cuvette 11; A light shielding cover 6 that covers the sample tray 3 above the photometric unit 5, an unsealing mechanism 7 (see FIG. 5) that is installed in the light shielding cover 6 and that opens and seals the seal 11 c of the cuvette 11, and in the vicinity of the sample tray 3 The chip discarding unit 8 is disposed, and a bottle mounting unit 9 on which a solution bottle 14 containing a solution of the reagent R is mounted.
[0019]
The apparatus main body 2 includes an operation unit 21 installed at the upper part, a front cover 22 that covers the analysis mechanism such as the sample tray 3 and the dispenser 4, and a chip disposal box 23 installed at the lower part so as to be able to be pulled out. .
[0020]
The basic operation of fecal occult blood analysis is as follows. First, the seal 11c of the cuvette 11 is opened, and then the solution is dispensed from the solution bottle 14 by the dispenser 4 to dissolve the reagent R, and then the sample container A predetermined amount of sample liquid is dispensed from 12 to the cuvette 11 and stirred. Next, every time the measurement position is passed, the change in color is measured by the photometry unit 5, and fecal occult blood is obtained from the initial value and the degree of coloration after a predetermined time.
[0021]
Next, the structure of each part will be specifically described. First, as shown in FIGS. 2 and 3, the sample tray 3 includes a disk-shaped rotary table 31 that is rotationally driven in the forward direction and the reverse direction, a temperature control block 32 that does not rotate below, and a heat shield cover. 33.
[0022]
The rotary table 31 has a plurality of circular mounting holes 34 concentrically holding the sample container 12 on the outer peripheral side, a plurality of rectangular mounting holes 35 concentrically holding the cuvette 11 on the inner peripheral side, and a circular mounting hole 34. Ten cylindrical mounting portions 36 that are adjacent to each other and hold the nozzle tip 13 on the outer peripheral side are equally divided into the circumference. A support shaft 37 is provided at the center of the lower surface of the rotary table 31 and is pivotably supported through the central portion of the temperature control block 32. A gear 38 is fixed to the lower end portion of the support shaft 37, and a timing belt (not shown) is hung and is rotated by a drive motor.
[0023]
The temperature control block 32 is made of a metal such as aluminum and has a large and large heat capacity. A heater 39 is installed at the bottom to adjust the heating to a predetermined temperature, and the lower part of the cuvette 11 mounted on the rotary table 31 moves on the upper surface. An annular recess 32a is provided, and the cuvette 11 is heated to a predetermined temperature by heating the air in the recess 32a. The bottom surface and the outer periphery of the temperature control block 32 are covered with a heat insulating cover 33 made of resin to obtain the heat retaining effect of the temperature control block 32, and the sample container 12 and the nozzle chip 13 are placed in the annular space 33a formed in the outer periphery. The lower part passes along with the rotation of the rotary table 31.
[0024]
Further, the photometric unit 5 is installed inside the temperature control block 32. The photometric unit 5 includes a light emitting element 51 of an LED installed on one side and an opposite side opposite to the measuring unit 11a of the cuvette 11 moving in the concave portion 32a between the inner and outer circumferences of the concave portion 32a. The light receiving element 52 is provided. The light emitting element 51 (LED) is attached to the temperature control block 32 by the mounting member 51a, and the light receiving element 52 (photo sensor) is also attached to the temperature control block 32 by the mounting member 52a. Each of them is heated by the temperature control block 32 to the temperature control temperature and stably maintained at a constant temperature. The temperature control temperature of the temperature control block 32 is higher than the temperature due to self-heating when the light emitting element 51 is turned on, and since the heat capacity is large, the temperature change is small and it is stably maintained at a constant temperature during photometry.
[0025]
The light emitting element 51 (LED) is connected to a constant current drive circuit 55, and is lit by applying a constant drive current to a specified current value. The constant current drive and the temperature control stabilize the emission spectrum and emission intensity of the light emitting element 51 in a constant state, and ensure the accuracy of photometric analysis.
[0026]
The light receiving element 52 generates a signal (voltage) having a magnitude corresponding to the amount of light received from the light emitting element 51 through which the photometry of a predetermined wavelength (color) is transmitted through the cuvette 11 and sends it to the control unit. The control unit calculates the analysis result of the specimen component (hemoglobin) from the color change according to the signal.
[0027]
In the fecal occult blood analysis, two wavelengths of the main wavelength and the sub wavelength are measured, and two sets of the light emitting element 51 and the light receiving element 52 are provided. The LEDs of the two sets of light emitting elements 51 have different emission wavelengths, and are installed in accordance with the pitch of the mounting interval of the cuvettes 11 of the rotary table 31 (the opening interval of the rectangular mounting holes 35). It is located between the light-emitting element 51 and the light-receiving element 52 and can perform photometry, and the coloration degree is sequentially measured each time.
[0028]
The light-shielding cover 6 that covers the light metering unit 5 and blocks the influence of external light is installed on the upper portion of the sample tray 3 in a range where the light metering unit 5 is installed so as to be undulated. The outer peripheral side portion is rotatably supported by a horizontal shaft, and a portion covering the center portion of the sample tray 3 is lifted.
[0029]
The unsealing mechanism 7 installed in the light shielding cover 6 includes an unsealing pin 71 that is arranged so as to be movable up and down at the intersection of the rotational movement locus of the cuvette 11 and the turning locus of the suction nozzle 41. Is installed in a pin installation portion 61 arranged in a protruding manner on the light shielding cover 6 as shown in FIG. The opening pin 71 has a round bar shape in the shaft portion, but the tip end portion 71a is formed in a multi-sided taper shape, for example, a four-sided pyramid shape, and is opened by opening a hole in the seal 11c of the cuvette 11. The unsealing pin 71 is biased upward by a spring 72, and the unsealing operation is performed by depressing the suction nozzle 41 of the dispenser 4.
[0030]
Furthermore, the lower surface of the light shielding cover 6 is provided with a cuvette presser 62 at the time of opening for preventing the unsealed opening pin 71 from engaging with the opening hole of the seal 11 c and lifting the cuvette 11. A cuvette presser 63 (see FIG. 2) at the time of stirring is provided on the side portion. The cuvette presser 62 at the time of opening is constituted by a tip of a cylindrical portion through which the unsealing pin 71 is inserted at the lower portion of the pin installation portion 61, and a lower end portion thereof can be brought into contact with an upper surface edge portion of the cuvette 11. Also serves as a guide for the opening pin 71. The cuvette presser 63 at the time of stirring is for preventing the tip of the nozzle tip 13 from being inserted deeply into the cuvette 11 from the opening hole and engaging the opening hole of the seal 11c to lift the cuvette 11, and the light shielding cover 6 is formed so as to protrude in the shape of a plate above the edge of the lower cuvette 11 on the side portion.
[0031]
The dispenser 4 (FIG. 1) is provided with a rod-like suction nozzle 41 extending downward at the lower end of the swivel arm 42, and dispenses the sample liquid and the dissolved liquid and stirs and mixes both liquids. The swivel arm 42 is supported so as to be vertically movable along a guide rod (not shown), and a rotary plate holding the guide rod is rotationally driven by a timing belt hung from a drive motor. As a result, the turning arm 42 is driven to turn, and a feed screw (not shown) installed at the turning center is screwed to the turning arm 42, and the turning arm 42 is moved up and down by the rotational drive of the feed screw. Yes.
[0032]
The tip of the suction nozzle 41 is mounted with the pipette-shaped nozzle tip 13 as described above by the downward movement of the swivel arm 42, and the sample liquid and the lysate are sucked into the nozzle tip 13 and discharged. After use, the swivel arm 42 is moved upward with the upper end of the nozzle tip 13 engaged with the engaging groove of the tip discarding portion 8 to be disengaged and dropped into the lower disposal box 23 To dispose of it. The tip discarding unit 8 is disposed on the turning locus of the suction nozzle 41.
[0033]
The suction nozzle 41 has an air passage (not shown) that opens at the tip, and an air pipe from a syringe pump (not shown) installed in the apparatus main body 2 is connected to the air passage. The syringe pump is an air pump having a syringe-like piston, and a negative pressure or a positive pressure (suction / discharge pressure) generated by driving the syringe is introduced into the suction nozzle 41.
[0034]
In addition, the automatic analyzer 1 includes a control unit (not shown) linked to the operation unit 21 in the apparatus main body 2. This control unit controls the operation of the sample tray 3, the dispenser 4 and the photometry unit 5, and calculates the analysis result based on the photometry of the photometry unit 5.
[0035]
Next, the operation of this embodiment will be described. First, before the analysis, the sample container 12 containing each sample solution is mounted on the sample tray 3, and the cuvette 11 and the nozzle chip 13 are mounted at the set position, and the solution bottle 14 is further attached. Set and prepare for measurement.
[0036]
Thereafter, the start button of the operation unit 21 is operated to start the analysis process. At the initial time, the rotary table 31 of the sample tray 3 is rotated once, the cuvette 11 is detected by the photometric unit 5, and the sample analysis of the mounted positions is started in order.
[0037]
Next, the cuvette 11 corresponding to the sample container 12 to be analyzed is rotated by rotating the rotary table 31 and the opening pin 71 is pushed down by the suction nozzle 41 to open the seal 11c. Next, the rotary table 31 is rotated to move the nozzle tip 13 below the swiveling position of the suction nozzle 41 and is attached to the suction nozzle 41. Subsequently, the cuvette 11 is positioned below the swiveling position of the suction nozzle 41 and the suction nozzle 41 is swung to the position of the dissolving liquid bottle 14 to suck a predetermined amount of the dissolving liquid into the nozzle tip 13. It moves up and inject | pours a solution into cuvette 11 from an opening hole, and reagent R is dissolved.
[0038]
Next, the rotary table 31 is rotated to move the sample container 12 below the swiveling position of the suction nozzle 41 to suck a predetermined amount of sample liquid into the nozzle tip 13 and then move onto the cuvette 11 to move into the cuvette 11. The sample liquid is dispensed, and the nozzle tip 13 is further inserted into the cuvette 11, and the liquid in the cuvette 11 is repeatedly aspirated and discharged into the nozzle tip 13 to stir and mix the reagent liquid and the sample liquid. . The used nozzle tip 13 is removed from the suction nozzle 41 by the tip discarding unit 8 and dropped and discarded downward.
[0039]
Then, the cuvette 11 in which the reagent solution and the sample solution are mixed is adjusted to a predetermined temperature by the temperature adjustment block 32, and is sequentially moved to the photometry unit 5 by the rotation of the rotary table 31, and the light emitting element 51, the light receiving element 52, and the like. Thus, photometry of the transmission optical density is performed each time. While continuing the above measurement, a series of analysis operations following the opening of the next cuvette 11 are performed simultaneously. The analysis result based on the photometry is output, and the process is terminated.
[0040]
In the embodiment as described above, the photometric unit 5 is configured compactly by the light emitting element 51 and the light receiving element 52 by LEDs, and further installed in the temperature control block 32 to be heated and held, and by the constant current drive circuit 55. By driving at a constant current, the emission spectrum and emission intensity were stabilized, and photometric analysis with high accuracy could be performed even if an LED was used, and the apparatus could be downsized.
[0041]
The reagent to be enclosed in the cuvette 11 is preferably a freeze-dried, powdered, granular, or tablet-dried reagent, but a liquid reagent can also be enclosed. In addition, the reagent is enclosed in the cuvette in advance and made disposable. However, an empty disposable or washed cuvette may be mounted, and the reagent may be dispensed into the cuvette instead of the solution. In addition to fecal occult blood analysis, the design can be changed to analyze urine components (for example, urine protein).
[Brief description of the drawings]
1 is a perspective view showing a schematic configuration of an automatic analyzer according to an embodiment of the present invention. FIG. 2 is a perspective view of a sample tray in FIG. 1. FIG. 3 is a schematic sectional view of a sample tray in an analysis state. 4] Perspective view of cuvette, specimen container and nozzle tip [FIG. 5] Cross-sectional view showing the cuvette opening state by the opening mechanism [Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Automatic analyzer 2 Apparatus main body 3 Sample tray 4 Dispenser 5 Photometry part 6 Shading cover 7 Unsealing mechanism 8 Chip discard part 9 Bottle mounting part
11 Cuvette R Reagent
12 Sample container
13 Nozzle tip
21 Operation unit
31 Rotating table
32 Temperature control block
41 Suction nozzle
42 Swivel arm
51 Light Emitting Element (LED)
52 Photo detector
55 Constant current drive circuit

Claims (1)

An analytical instrument that analyzes a sample component by mixing a reagent and a sample solution in a cuvette and measuring the color change thereof,
Comprising a temperature control block for temperature control of the cuvette, and a photometry unit consisting of LED and by the light emitting element and a light receiving element for transmitting metering the color change of the reagent and the specimen solution in said cuvette,
The light-emitting element of the photometry unit is inserted into the temperature control block to be temperature-controlled, and is driven with a constant current.

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