JP3492870B2 - Automatic analyzer - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an automatic analyzer, and more particularly to an automatic analyzer suitable for quantitatively or qualitatively analyzing components in a sample such as blood or urine.

[0002]

2. Description of the Related Art Automatic analyzers are widely used from small devices to large devices. In recent years, along with the increase in the number of specimens (the number of samples to be inspected), it is desired to realize a device with high processing capacity, and a parallel system is adopted in which a plurality of small devices are arranged to form a large device. However, the parallel method inevitably doubles the number of parts, and is not a good idea in terms of cost and reliability.

Efforts have been made to reduce the analysis cycle time in order to increase the throughput of automatic analyzers. The first factor that determines the analysis cycle time is the sample dispensing cycle time. Usually, in an automatic analyzer, it is necessary to dispense a fixed amount of sample corresponding to the analysis item. For example, if n items are to be analyzed, it is necessary to dispense the sample approximately n times with respect to the same sample (in some cases, two items may be analyzed in one reaction container, and therefore, they may not exactly match). By shortening the cycle time of this sample dispensing, the analysis cycle time is shortened, and thus the throughput of the analyzer is enhanced.

When performing sample dispensing a plurality of times with respect to the same sample as in the case of analyzing a plurality of items, the sample dispensing cycle time of each time is generally the same. in this case,
In order to increase the sample throughput, efforts are usually made to keep the sample dispensing cycle time the same each time, while shortening the cycle time.

[0005]

When it is necessary to perform multiple sample dispensings for the same sample, the first sample dispensing usually takes longer than the subsequent sample dispensings. . That is, in the first dispense cycle,
Cleaning of the inner and outer walls of the sample dispensing probe is necessary to prevent the cariover from another sample dispensed in the previous dispensing cycle, and the cleaning of the sample in the sample dispensing probe It is necessary to aspirate extra sample to prevent the effect of sample dilution effect due to diffusion into water (dummy sample aspiration), and the sample dispensing probe descends to bring it into contact with the sample liquid surface. If there is a limit, there is a limit to increase the descending speed.

The descending speed of the sample dispensing probe in the first sample dispensing cannot be increased so much that the descending of the sample dispensing probe is stopped at the moment when its tip comes into contact with the sample liquid surface. This is necessary, but if the descending speed of the sample dispensing probe is too fast, a shock will occur when the sample dispensing probe is stopped, causing a problem that washing water jumps out into the sample from its tip. On the other hand, in the second and subsequent dispensings, the sample liquid level is known by the first liquid level detection, so the tip of the sample dispensing probe descends near the sample liquid level. Until the contact with the liquid surface, and then slowly descending until it comes into contact with the liquid surface, thereby increasing the average descending speed of the sample dispensing probe.

As described above, when the same sample is dispensed a plurality of times, the sample dispensing time is shorter in the subsequent sample dispensing than in the first sample dispensing, Generally, each sample dispensing cycle time is the same, so the sample dispensing cycle time is
Needs to be decided based on long sample dispensing time,
This is a cause of shortening the analysis cycle time and thus hindering the improvement of the sample throughput.

Japanese Patent Publication No. 6-40100 proposes a sample dispensing method for an automatic analyzer. This refers to a slow dispense over two cycles when the sample dispense volume is low. However, no special consideration has been given to shortening the sample dispensing cycle time.

An object of the present invention is to provide an automatic analyzer capable of enhancing the sample dispensing efficiency and improving the sample processing ability.

[0010]

The present invention relates to an automatic analyzer for performing a plurality of sample dispensing on the same sample and performing an analysis on each of the dispensed samples.
It is characterized in that the time required for subsequent sample dispensing is set shorter than the time required for the first sample dispensing of the plurality of sample dispenses.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION FIG. 4 shows an example of an automatic analyzer for carrying out the present invention. Sample 2 in sample container 1 (see Figure 1)
Inside the reaction container 4 on the reaction disk 16 via the sample dispensing probe 10 (see FIG. 1) of the sampling mechanism 3 using the sample syringe mechanism 20 (see also FIG. 1) including the sample syringe 11 and the plunger 12. Dispense into. To the reaction container, the reagent 6 corresponding to the analysis item is added via the reagent probe of the reagent sampling mechanism 5 using the reagent syringe mechanism 17, and the sample and the reagent dispensed using the stirring mechanism 7. Homogenize the mixing of. The change in absorbance of the reaction solution in which the reaction has started is measured with a photometer 8, and A / D conversion and data processing are performed to print the analysis result. After completion of the analysis, the reaction container is washed with the washing water from the washing pump 18 in the washing tank 15 through the washing mechanism 9 and reused for a new analysis. The reagent 19 is used when necessary.

The sample dispensing operation according to the present invention will be described with reference to FIG. FIG. 1A shows a sample dispensing operation for the first analysis item after the sample switching. First, the solenoid valves 3 and 14 are opened in the cleaning tank 15 to clean the inner and outer walls of the sample dispensing probe 10. Next, the sample dispensing probe is moved and lowered into and inserted into the sample container 1, and the sample dispensing probe is in contact with the sample liquid surface. The descent of the probe is stopped, and the height of the liquid surface is stored in the memory device of the microcomputer.

Then, the plunger 12 of the sample syringe 11 is moved down to suck the sample into the sample dispensing probe. The sample suction amount at this time is a dummy amount (20 μl)
+ Volume used for reaction (5 μl) = 25 μl. After that, the sample dispensing probe moves up to move into the reaction container 4, and the plunger in the sample syringe is moved up to discharge the sample in an amount of 5 μl used for the reaction.

After that, the sample dispensing probe moves upward, and continuously shifts to the sample dispensing operation for the same sample for the analysis of the second analysis item shown in FIG. 1 (b). That is, since the sample is the same as that shown in FIG. 1 (a), the inner and outer walls of the sample dispensing probe are not washed, and the sample is again put in the same sample container (with 20 μl of dummy left in the sample dispensing probe). Descend to. This descent can be done much faster than in Figure 1 (about 5 times). Because the height of the liquid level is stored in advance (even if the sample is sucked in the previous cycle and the liquid level drops, the current liquid level can be predicted from the suction amount and the cross-sectional area of the sample container). The sample dispensing probe descends at a high speed to near the liquid surface, deceleration is controlled near the liquid surface (about 5 mm before), and when plunging into the liquid surface, the speed is almost the same as at the time of the first sample dispensing. Slow down.

In FIG. 1, assuming that the first sample dispensing cycle time is T1 and the second and subsequent sample dispensing cycle times are T2, T3, ... Tn, T1 =
The relationship of mT2 = mT3 ... = mTn is satisfied. m is an integer other than 1. Specifically, in the example of FIG. 1, T1 = 4 seconds, T2 = T3 ... Tn = 2 seconds, m
This is an example in which = 2 is set.

FIG. 2 shows a descending velocity diagram of the sample dispensing probe. FIG. 2 (a) shows the speed at the time of the first analysis item dispensing lowering, and FIG. 2 (b) shows the speed at the second analysis item dispensing lowering. Since the descending drive of the sample dispensing probe is performed by the stepping motor, the descending speed can be controlled by controlling the pulse rate applied to the motor. After detecting the liquid level, a certain pulse is applied to the motor and then the pulse is stopped to stop the motor. The area of the shaded area corresponds to the amount of the sample dispensing probe thrust into the liquid surface. 2A and 2B, the shaded areas can have the same area (quantity). Also, the speed at which the sample dispensing probe stops can be the same.

Next, the plunger of the sample syringe is lowered to aspirate 6 μl of the amount used for the reaction for the second analysis item. The sample dispensing probe moves up and moves into the reaction vessel, and the amount used for the reaction for the second analysis item is 6μ.
l is discharged. After the discharge is completed, the sample dispensing probe moves up and the sample dispensing for the third analysis item is started.

The second sample after the third sample dispensing (see FIG. 2)
(B)) Similarly, the inner and outer walls of the sample dispensing probe are not washed and no dummy suction is performed. The sample dispensing probe lowers in the sample container by controlling the shortest time, the cycle time can be shortened. is there.

FIG. 3 shows the time sequence of the operation of FIG. 3A shows a sample dispensing cycle for the first analysis item, and FIG. 3B shows a sample dispensing cycle for the second and subsequent analysis items. As described with reference to FIG. 1, T1 = mT2 = mT3 ...
(M is an integer except 1) is satisfied. In particular,
T1 = 4 seconds, T2 = T3 ... = Tn = 2 seconds, m = 2
An example of is shown. The cycle time of the reaction disk 16 is the same as 2 seconds of T2 each time. Even if T1 is lengthened by sample dispensing, the cycle of the reaction disk 16 is not affected, and this is operated in a 2-second cycle. That is, when the cycle becomes long at T1, analysis can be performed without disturbing the cycle of the reaction disk by passing the empty reaction container.

When m = 3 and T1 is set to 6 seconds, therefore, the amount of dummy is further increased in the case of a sample such as urine which is close to water-soluble and the sample is strongly thinned due to diffusion into washing water. Therefore, prevention of thinning of the sample becomes more effective.

The cleaning time of the inner and outer walls of the sample dispensing probe is determined by the degree of the cariober, and the degree of the cariober depends on the type of sample. Therefore, it is desirable that the value of m can be changed according to the type of sample.

Table 1 shows that (1) a completely random access method with a cycle of 2 seconds (difficult to realize at this time), (2) T1 = 4 seconds, T2 = T3 ... = Tn = 2 seconds in which the present invention is implemented. A comparison of sample (specimen) throughputs in the near complete random access system and (3) 4 second cycle complete random access system is shown.

[0023]

[Table 1]

Table 1 shows the number of requested items per sample in the vertical direction and shows the sample processing speed (sample / hour) at that time. The 2-second cycle complete random access method (1) is a method that is difficult to realize at present. This (2)
Compared with the above, the major result is that the sample processing capacity is outstanding only when requesting one item. However, the outstanding sample processing capacity of 1800 samples / hour does not make much sense. Only one inspection center has a demand for very limited applications, and most facilities have 90
There is a demand for a method in which 0 sample / hour is sufficient, and the sample processing speed is difficult to decrease even if the number of requested items is large. (1) and (2) show that almost the same sample processing speed can be obtained when the number of requested items per sample is large.

In the examples, the cleaning timing of the inner and outer walls of the sample dispensing probe showed the first example of sample dispensing. However, depending on the interpretation, it may be interpreted that the sample is washed in the last cycle of the sample. it can. However, the technical scope of the present invention should not be influenced by the difference in where the starting point on such a time chart is taken.

[0026]

According to the present invention, there is provided an automatic analyzer capable of improving the sample dispensing efficiency and the sample processing capacity.

[Brief description of drawings]

FIG. 1 is a diagram for explaining an example of a sample dispensing operation in an automatic analyzer according to the present invention.

FIG. 2 is a descending velocity diagram as an example of a sample dispensing probe in an automatic analyzer according to the present invention.

FIG. 3 is a diagram showing a time sequence as an example of a sample dispensing operation in the automatic analyzer according to the present invention.

FIG. 4 is a conceptual diagram of an automatic analyzer as an example for carrying out the present invention.

[Explanation of symbols]

1: sample container, 2: sample, 4: reaction container, 10: sample dispensing probe, 13, 14: solenoid valve, 15: washing tank, 1
6: Reaction disk, 17: Reagent syringe mechanism, 18: Washing pump, 20: Sample syringe mechanism.

Continuation of front page (56) Reference JP-A-7-63772 (JP, A) JP-A-3-54474 (JP, A) JP-A-4-290941 (JP, A) JP-A-3-24461 (JP , A) JP 7-198725 (JP, A) JP 2-77652 (JP, A) JP 6-40100 (JP, B2) JP 61-29670 (JP, B2) JP 3-45340 (JP, B2) JP 5-11846 (JP, B2) JP 6-25771 (JP, B2) JP 3-46786 (JP, B2) Patent 2515938 (JP, B2) European patent Published application 741297 (EP, A 1) (58) Fields investigated (Int.Cl. ⁷ , DB name) G01N 35/00-35/10 G01N 1/00-1/44 JISST file (JOIS)

Claims (2)

(57) [Claims] 1. A sample container for accommodating a sample, a sample dispensing probe for dispensing a sample from the sample container, and a reaction container for mixing a sample and a reagent, and performing a plurality of sample dispensing for the same sample. In the automatic analyzer that executes the analysis on each of the dispensed samples, a process including washing of the sample dispensing probe, suction of the sample from the sample container, and discharge of the sample to the reaction container is performed. One sample dispensing cycle, and the cycle time of the sample dispensing cycle for the first sample dispensing of the plurality of sample dispensings is m times the cycle time of the subsequent sample dispensing cycle (m is 1 An automatic analyzer characterized by being set to a time of (excluding integer). 2. The automatic analyzer according to claim 1, wherein the m-fold value can be changed according to the type of the sample.