JP2011149831A - Autoanalyzer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain reduction in the carry-over of a reaction vessel and enhancement of the cleaning efficiency of the reaction vessel, by detecting blood corpuscles remaining after the cleaning of the reaction vessel, without altering the existing system. <P>SOLUTION: Distilled water, or the like, is dispensed in the reaction vessel after normal cleaning, and the autohemolyzing action of the residual blood corpuscles due to the difference in the osmotic pressure is utilized, to subject a wavelength having absorption and a separate wavelength which does not have absorption to two-wavelength photometry in a human blood corpuscle hemolyzed solution so as determine the residual amount of the blood corpuscles in the reaction vessel from the absorbance difference. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an automatic analyzer that performs a qualitative / quantitative analysis of a biological sample, and more particularly to a method for determining remaining blood cells in an automatic analyzer that performs hemolysis of blood cell components in a reaction vessel used for photometry.

  In clinical chemistry analysis, most of biochemical components such as inorganic ions, proteins, nitrogen-containing components, carbohydrates, lipids, enzymes, hormones, and drugs in biological samples such as blood and urine are analyzed by automatic analyzers. ing. The reaction vessel used in this automatic analyzer uses a disposable reaction cuvette in some devices, but in most devices, the reaction cuvette after use is washed for reasons such as reducing running costs. It is used repeatedly.

  As a conventional method for washing a reaction cuvette, there are a method of performing automatic washing with distilled water or the like for each analysis, and a method of washing by injecting a detergent into the reaction cuvette. Patent Document 1 describes a method of determining the cause and degree of contamination from the spectrum of a reaction vessel after washing, and determining the type and concentration of detergent used for washing the reaction vessel.

  In addition, as a method for checking the contamination of the reaction vessel after washing, a method of checking absorbance at the time of water blank measurement performed before the next measurement, or after carrying out special washing of the reaction vessel for all reaction vessels, There was a method of checking the absorbance at the time of water blank measurement to be carried out before use in the next measurement.

  On the other hand, the measurement items of the metabolic syndrome (visceral fat syndrome) screening conducted from April 2008 include HbA1c measurement, and it is expected that the number of HbA1c measurement samples will increase in the future. A general-purpose automatic analyzer capable of measuring HbA1c that can be processed easily is desired. However, since HbA1c is a component present in erythrocytes, it is necessary to hemolyze blood cells obtained by centrifuging blood for measurement. However, the blood cell component is a highly viscous liquid (in some cases, a gel-like substance). When blood cells are dispensed into a reaction vessel and hemolyzed, the blood cell component remains in the reaction vessel in a normal reaction vessel cleaning method. Since the blood cells could not be washed out and the blood cells could carry over to the next analysis, the analysis was difficult with the conventional automatic analyzer.

  In order to realize an automatic analyzer that enables HbA1c measurement, (1) a difference in the concentration of components contained in blood cells and plasma (serum), and (2) a colorimetric wavelength where the absorption wavelength of hemoglobin is 400 to 500 nm. It is necessary to consider measurement errors due to overlapping with the reaction, and (3) the possibility that components of blood cells directly affect the reaction.

  The above-described conventional method for washing a reaction vessel of an automatic analyzer mainly assumes samples with relatively low viscosity such as urine, serum, and plasma, and it cannot be said that it can sufficiently cope with highly viscous blood cells. For this reason, there is a concern that blood cell carryover may occur due to poor cleaning of the reaction container, which may lead to misdiagnosis from a measurement result lacking accuracy, and it remains in the reaction container cleaning method and reaction container to avoid blood cell carryover It can be said that a method for detecting blood cells is needed.

JP-A-5-164762

  In the cell contamination check method of the conventional automatic analyzer described above, the reaction cell was checked for contamination only for the two wavelengths used for the next measurement, and therefore a wavelength that absorbs blood cells was selected for the next measurement. However, it was difficult to detect the remaining blood cells in other cases.

  Moreover, in the method described in the cited document 1, in order to detect the presence or absence of dirt from the peak position of the waveform and the shape of the waveform, a photometer for measuring the absorption spectrum on the apparatus is added to the conventional photometer. It is necessary to mount it, which may lead to an increase in the cost of the device.

  An object of the present invention is to determine the presence or absence of blood cells remaining in a reaction vessel without changing an existing system, thereby reducing carryover of blood cell components through the reaction vessel used for the hemolysis treatment, and for hemolysis treatment. The purpose is to improve the efficiency of washing the reaction vessel.

In order to achieve the above-mentioned purpose, distilled water or the like is dispensed into a reaction vessel that has been subjected to normal washing, and the blood cells remaining in the reaction vessel are autolyzed by the difference in osmotic pressure and absorbed into human blood cell hemolyzed blood. The presence or absence of remaining blood cells in the reaction container is determined from the difference between the absorbances of two wavelengths, i.e., one wavelength and another wavelength that does not absorb.

  By determining the presence or absence of blood cells remaining in the reaction container after washing, carryover of blood cells through the reaction container can be reduced, and the efficiency of washing the reaction container can be improved.

It is a block diagram of the automatic analyzer concerning embodiment of this invention. It is an operation | movement flow concerning embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is an operation principle diagram of the automatic analyzer shown in the present embodiment, and the basic operation is shown next. Between the spectrophotometer 10 and the light source 26, the reaction disk 3 that accommodates the measurement object is disposed. On the outer periphery of the reaction disk 3, a large number of reaction containers 4 such as 160 are provided. Further, the entire reaction disk 3 is held at a predetermined temperature by a thermostatic chamber 9.

  A large number of sample containers 25 are arranged in the sample disk mechanism 1. The sample in the sample container 25 is sucked by the sample nozzle 27 of the sample sampling mechanism 2 and injected into the reaction container 4 at a predetermined position.

  The reagent disk mechanism 5 includes a large number of reagent containers 6. The reagent disk mechanism 5 is provided with a reagent pipetting mechanism 7. The reagent is sucked by the reagent nozzle 28 of the reagent pipetting mechanism 7 and injected into the reaction container 4 at a predetermined position. Absorbance is taken in at the timing when the reaction vessel 4 crosses between the spectrophotometer 10 and the light source 26, converted into a concentration value, and then stored in the hard disk 22 or output to the printer 20. It can also be displayed on the CRT 21 as inspection data.

  After completion of the measurement, the measuring mechanism accommodated in the reaction container 4 by the cleaning mechanism 11 is sucked and discharged, and the reaction container 4 is cleaned by cleaning the inside with cleaning water or cleaning liquid. It will be provided for a simple analysis.

  As other automatic analyzers, a microcomputer 19, an interface 23, a Log converter and A / D converter 18, a reagent pipetter 17, a washing water pump 16, a sample pipettor 15, an operation panel 24, and the like are also required. Depending on the provision.

  In the above configuration, the operator inputs analysis request information using the operation panel 24. The analysis request information input by the operator is stored in a memory in the microcomputer 19. The sample to be measured that is placed in the sample container 25 and set at a predetermined position of the sample disk mechanism 1 is in accordance with the analysis request information stored in the memory of the microcomputer 19 and the sample pipettor 15 and the sample nozzle 27 of the sample sampling mechanism 2. To dispense a predetermined amount into the reaction vessel. The sample nozzle 27 after sample dispensing is washed with water before the next sample is sucked to prevent carry-over between samples. A predetermined amount of reagent is dispensed by the reagent nozzle 28 of the reagent pipetting mechanism 7 into the reaction container containing the sample to be measured. After the reagent dispensing, the reagent nozzle 28 is washed with water and then dispenses a reagent for the next sample. The mixed solution of the sample and the reagent is stirred by the stirring rod 29 of the stirring mechanism 8. After stirring, the stirring rod 29 is washed with water, and then the mixed solution in the next reaction vessel is stirred.

  Since the reaction vessel 4 is held at a constant temperature by the thermostat 9, it is used for both reaction and photometry. In the course of the reaction, the absorbance of the mixed solution is measured by the spectrophotometer 10 at regular intervals using the set wavelength. The measured absorbance is taken into the microcomputer 19 via the Log converter and A / D converter 18 and the interface 23.

  Next, the washing process of the reaction vessel 4 in the present invention will be described. After the above-described measurement is completed, the reaction vessel 4 is subjected to normal washing by the washing mechanism 11 and then injected with distilled water or the like. By injecting distilled water, when blood cell components remain in the reaction vessel 4, an autolysis effect due to osmotic pressure occurs, compared with distilled water in the reaction vessel 4 in which no blood cell components remain. A difference appears in the absorption spectrum. In order to detect this difference, the absorbance is measured at the timing of crossing the optical axis of the spectrophotometer 10 with respect to the reaction vessel 4 filled with distilled water.

  In the measurement of absorbance, it is considered to measure the absorbance near 570 nm, which is absorbed in human blood hemolyzed blood in 2-wavelength photometry, and near 700 nm, which is not absorbed in human blood hemolyzed blood, and calculate the difference. It is done. This is because by measuring the absorbance for two wavelengths at the same time, the measurement value fluctuations derived from the light source 26 are offset and stable photometry is possible.

  FIG. 2 is an example of a flowchart for determining remaining blood cells using the measurement values obtained by the above-described method. The measured absorbance is taken into the microcomputer 19 via the Log converter and A / D converter 18 and the interface 23. Then, the microcomputer 19 checks a blank value for confirming the degree of contamination of the reaction container and the remaining degree of blood cells in the reaction container to determine whether the reaction container can be used for measurement.

  In steps 101 to 104 of FIG. 2, when the analysis of the sample is completed, the reaction vessel is washed, and distilled water is injected, in step 105, all reaction vessels into which distilled water has been injected are distilled as blank values. The absorbance of water is measured. Further, for the reaction vessel used for hemolysis in step 102, in step 106, the absorbance is measured for two wavelengths, a wavelength in which the blood cell component is absorbed and a wavelength in which the blood cell component is not absorbed. As the two wavelengths, for example, 570 nm may be adopted as a wavelength in which the blood cell component is absorbed, and 700 nm is adopted as a wavelength in which the blood cell component does not absorb, but a combination of other wavelengths may be used.

  In step 107, the blank value is checked to detect cell contamination (such as adhesion of serum components to the cell wall), and it is determined whether it can be used for the next measurement. If the absorbance of the blank value is equal to or greater than the threshold value measured in advance, it is determined that the cell dirt is not sufficiently removed, and the process returns to step 103 and the cell is washed again. If the blank value is equal to or less than the threshold value measured in advance, it is determined that the cell dirt can be sufficiently removed by cleaning.

  The reaction container used for hemolysis in step 102 and the absorbance of two wavelengths measured in step 106 proceeds to step 108. Other reaction vessels return to step 102 for use in the next analysis. In step 108, the difference in absorbance between the two wavelengths of 570 nm and 700 nm measured in step 106 is checked, and it is determined whether there is no blood cell remaining in the reaction container and it can be used for the next measurement. If the difference in absorbance between the two wavelengths obtained in step 106 is greater than or equal to the threshold value, it is determined that blood cells remain, and the process returns to step 103 and the reaction vessel is washed again.

  In step 108, if the difference in absorbance between the two wavelengths is smaller than the threshold value, it is determined that there is no remaining blood cell, and is used for the measurement in step 102 as a reaction container that can be used for the next measurement. The threshold value in step 108 is considered to be about 0.03 Abs, for example. This threshold is based on an experimental result that there is about 2.3 Abs absorption at a wavelength of 570 nm when the Hb concentration is about 5000 mg / dL, and the value when the Hb concentration allowable in the reaction vessel is about 50 mg / dL. Set.

  In this flowchart, the remaining blood cells are checked for the reaction vessel used for hemolysis during the previous measurement.For example, the device memorizes what measurement was used before it stopped due to an emergency stop due to some trouble. If not, the control may be performed so that the remaining blood cells are checked for all cells.

DESCRIPTION OF SYMBOLS 1 Sample disk 2 Sample sampling mechanism 3 Reaction disk 4 Reaction container 5 Reagent disk 6 Reagent container 7 Reagent pipetting mechanism 8 Stirring mechanism 9 Thermostatic chamber 10 Spectrophotometer 11 Cleaning mechanism 12 Suction nozzle 13 Detergent 14 Detergent injection nozzle 15 For sample Pipetter 16 Washing water pump 17 Reagent pipetter 18 Log converter and A / D converter 19 Microcomputer 20 Printer 21 CRT
22 Hard disk 23 Interface 24 Operation panel 25 Sample container 26 Light source 27 Sample probe 28 Reagent probe 29 Stirring bar 30 Bar code reader for second reagent 31 Bar code reader for first reagent

Claims (5)

A plurality of reaction containers containing biological samples, including blood cell samples obtained by centrifuging blood at least;
Optical property measuring means for analyzing the optical properties of the sample in the reaction vessel;
A cleaning means for cleaning the inside of the reaction vessel after the analysis is completed;
In the control method of the automatic analyzer equipped with
A first step of injecting a determination liquid into the reaction vessel after being cleaned by the cleaning means;
A second step of measuring optical characteristics at two different wavelengths with respect to the determination liquid in the reaction vessel;
And a third step of determining whether or not blood cell components remain in the reaction container from the optical characteristics measured in the second step. In the control method of the automatic analyzer according to claim 1,
A fourth step of washing the reaction vessel determined to have residual blood cell components in the third step, and washing the reaction vessel again by the washing means;
A fifth step of adding a flag by determining that the reaction vessel in which the remaining blood cell component is smaller than a predetermined threshold in the third step is usable for the next analysis;
A method for controlling an automatic analyzer characterized by comprising: In the control method of the automatic analyzer according to claim 1,
In the second step, for the reaction vessel in which the analysis using blood cell components was performed in the analysis completed before the first step,
A first wavelength that is highly absorbed by the blood cell component;
A method for controlling an automatic analyzer, wherein optical characteristics are measured using a second wavelength that is less absorbed by blood cell components than the first wavelength. In the control method of the automatic analyzer according to claim 1,
In the second step, the optical characteristics for detecting the blood cell component are measured for all reaction vessels regardless of the type of analysis completed before the first step. Control method of automatic analyzer. In the control method of the automatic analyzer of Claim 1,
In the second step, the optical characteristic analysis is performed at a timing when the reaction container passes through the measurement position of the optical characteristic measurement unit.

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