JPS6118981B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a biochemical analysis method, and particularly to an analysis method that performs multi-item analysis.

Generally, biochemical analysis methods employed in hospitals and the like are carried out by placing a certain amount of serum in a reaction container, adding reagents to cause a chemical reaction, and measuring the amount of light absorbed.

Biochemical analysis based on absorbance can be further divided into two types. One is the End Point method, in which measurement is performed at the point when a steady state has been reached after the reaction has completed for more than 10 minutes. The other one is enzymes in serum (e.g.
GOT, GPT) and reagents are mixed to observe the rate of change in the amount of ultraviolet light absorbed as the reaction progresses.
It is called the assay method. When measuring multiple items at the same time, both of these measurement methods are often used together.
In other words, the optimal system is achieved by using different measurement methods depending on the measurement item.

In either method, a mixed liquid is introduced into a container called a flow cell that has an optical device of a certain length, and the amount of light absorbed is measured.

On the other hand, since the Rate Assay method measures the rate of change, long-term drift in the absolute value level is allowed to some extent, whereas the End method measures the absolute value, so drifts in the light source and photodetector are fatal. It is. Therefore, it is necessary to perform drift correction at any time. For example, there is a method in which light of the same wavelength is passed through two optical paths and alternately enters the detector. However, in the case of a multi-item measuring device, securing two optical paths for each item is often accompanied by difficulties such as an increase in the size of the device and an increase in cost.

This invention was made in view of the above circumstances, and its purpose is to have a simple configuration,
An object of the present invention is to provide an automatic analysis method capable of performing measurements by a late method and an end method in parallel without reducing processing speed, and performing drift correction for each measurement by the end method.

FIG. 2 is a block diagram showing the overall configuration of an embodiment of the present invention. In the figure, reference numeral 1 denotes a reaction tube containing a sample, which is intermittently moved in the direction of arrow A by a belt 2 and a drive unit 3 at a constant speed.
Reference numeral 4 denotes a sample dispensing device, which injects a desired amount of a collected sample, such as serum, into the reaction tube 1. While the reaction tube 1 is being moved at a constant speed in the direction of the arrow A while being kept at a constant temperature by the constant temperature bath 5, a reagent is injected from the reagent injection device 6 or 7. When the reaction tube 1 reaches position B, the sample in the reaction tube 1 is sucked into the flow cell in the detection device 8. The absorbance of the sample is determined by the detection device 8. This is outputted by the output device 9.

After further discarding the remaining sample, the reaction tube 1 is circulated through a washing section 10 and a drying section 11, and is used again. Although it is not clear from Fig. 2, a plurality of reaction tubes 1 corresponding to the test items are indicated by arrow A.
are arranged in parallel in the vertical direction, and at position B, using a plurality of detection devices 8 provided corresponding to each of these reaction tubes 1, some are analyzed by the late method and the rest by the end method. The structure is as follows. In the case of the late method, the reaction change with the reagent injected by the reagent injector 7 near position B is measured over a predetermined period of time. On the other hand, in the case of the end method, the reagent injection device 6 far from position B
The reagent is injected into the reaction tube and guided to the flow cell within a few minutes.

FIG. 3 is a configuration diagram of the detection device 8. 12 is a sample suction tube, 13 is a flow cell, 14 is a zipper,
15 is a light source, 16 is a photodetector, 17 is an A/D converter, and 18 is a suction tube position control circuit.

When the reaction tube 1 reaches position B, the suction pump 14 is driven by a control mechanism (not shown), and the sample in the reaction tube 1 is guided to the flow cell 13 via the suction tube 12. At this time, the output light from the light source 15 is transferred to the flow cell 1.
3 and the flow cell 1 is detected by the photodetector 16.
The amount of light transmitted through 3 is converted into an electrical signal. This electrical signal is converted into absorbance via a logarithmic converter (not shown), and if necessary, the absorbance is further converted into concentration or units, and then output as digital data from the output device 9 via the A/D converter 17. .

The detection device 8 having such a configuration can be used for measurements using either the late method or the end method. The difference is that in the late method, the sample is kept in the flow cell for a long time.
3, and detects the absorbance multiple times at appropriate sampling times, whereas the endo method detects the absorbance multiple times at appropriate sampling times.
The point is that the absorbance is detected only once. Therefore, when measurements by the late method and measurements by the end method are performed in parallel, the sample measured by the end method does not need to remain in the flow cell for a long time.

Therefore, as shown in Fig. 4, the detection device 8 divides the period during which the sample is sucked into the flow cell into two minutes using the late method and performs the measurement using the end method.
The first half is used for measurement, and the second half is used as a calibration cycle for correcting dirt on the flow cell 13 and drift of the photodetector 16. That is, in the first half of the measurement cycle, the sample is sucked into the flow cell and the absorbance is measured as described above, as in the case of the late method, and then in the calibration cycle, the position control circuit 18 is driven by a control circuit (not shown). . The position control circuit 18 takes out the suction tube 12 from the reaction tube 1 and transfers it to the distilled water supply section 19. At the same time, the suction pump 14 is driven, and the suction pump 14
3, the sample for which the measurement has been completed is discarded from point C, and distilled water is introduced into the flow cell 13.

In this state, the light source 15 irradiates the flow cell 13 with output light as in the first half of the measurement cycle,
The amount of light transmitted through the flow cell 13 is detected by a photodetector 16. The output of the photodetector 16 at this time is used as a reference signal since the flow cell 13 does not contain any sample. By correcting this reference signal, highly accurate measurements can be performed.

That is, as shown in FIG. 5, in the measurement using the end method, since the region where the reaction between the sample and the reagent is saturated is measured, the measurement varies as shown by the broken line due to the flow cell dirt and the drift of the photodetector. Therefore, the absorbance of distilled water (assumed to be 0% Ab) is determined and drift correction is performed.

When the measurement cycle (and calibration cycle) is thus completed, a cycle for cleaning the flow cell 13 is performed. This washing cycle can be performed in exactly the same way with both the late method and end method detection devices.

In FIG. 4, a indicates a measurement cycle using the late method, b indicates a measurement cycle using the late method, and c indicates when the position control circuit 18 controls either the reaction tube 1 or the distilled water supply section 19. d indicates the suction/exhaust operation of the zipper 14;
e indicates the output signal of the photodetector 16.

As described above in detail, according to the present invention, it is possible to perform drift correction in measurements using the end method without any reduction in processing speed.
In the above embodiment, the calibration cycle was performed after the measurement cycle using the end method, but it goes without saying that the order may be reversed.

[Brief explanation of the drawing]

Fig. 1 is a diagram for explaining a measurement cycle and a washing cycle in an automatic analyzer, Fig. 2 is a diagram showing an embodiment of the present invention, and Fig. 3 is a diagram showing a part of an embodiment of the invention. One configuration diagram, FIGS. 4a to 4e are timing charts of an embodiment of the present invention, and FIG. 5 is a diagram showing drift in measurement by the end method. 1... Reaction tube, 8... Detection device, 13... Flow cell.

Claims (1)

[Scope of Claims] 1. While transporting a large number of reaction tubes each containing a sample to be analyzed, the samples in the plurality of reaction tubes are introduced into the respective flow cells for a predetermined time required for measurement by the late method. In an automatic analysis method that alternately performs a measurement cycle in which the optical properties of each sample are measured by the late method and a washing cycle in which each flow cell is washed, a part of the flow cell is measured by the end method. In addition, for a flow cell that performs measurement by the end method, the measurement cycle is divided into an end method measurement cycle and a calibration cycle. In this calibration cycle, a reference solution is introduced into the flow cell and its optical characteristics are measured to obtain a reference signal, and the measurement results obtained by the end method obtained in the end method measurement cycle are used in the calibration cycle. An automatic analysis method characterized by correction using a reference signal obtained by.