JPH0229989B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dispensing device for an automatic analyzer.

For example, in an automatic analyzer that quantitatively analyzes a predetermined component in a sample liquid such as blood or urine, there is a sample dispensing device that dispenses the sample liquid into a reaction tube, and a reagent that dispenses reagents according to the analysis item. Various dispensing devices such as dispensing devices are used. In such automatic analyzers, in order to increase analytical throughput, the reaction tubes are intermittently or continuously transferred along a predetermined path at a relatively high speed, and the various dispensing devices adjust the dispensing volume according to this transfer cycle. The period is also determined. The various types of conventional dispensing devices described above are designed to ensure that the flow rates are equal in the process of aspirating the sample liquid or reagent and the process of discharging the aspirated sample liquid or reagent during the dispensing cycle. In other words, when a syringe pump is used, the piston is always reciprocated at a constant speed. Therefore, when dispensing a highly viscous sample liquid or reagent, the mechanical suction process of the dispensing device ends before the prescribed amount of the sample liquid or reagent to be dispensed has been aspirated. Therefore, it had the disadvantage of poor dispensing accuracy.

An object of the present invention is to eliminate the above-mentioned drawbacks and to provide an automatic analyzer that is appropriately configured so that a desired amount can always be accurately dispensed even if the sample liquid or reagent to be dispensed has high viscosity. It provides equipment.

The dispensing device for an automatic analyzer of the present invention is a dispensing device for an automatic analyzer that dilutes a sample liquid or reagent in a container with a diluent contained in a diluent container and dispenses the diluted sample into a reaction tube. A means for aspirating and discharging a highly viscous sample liquid or reagent, a means for driving the suction/discharge means, and a drive speed of the driving means so as to aspirate and discharge the sample liquid or reagent at different flow rates. The invention is characterized by comprising means for controlling.

The present invention will be described in detail below with reference to the drawings.

FIG. 1 shows the configuration of an embodiment of a dispensing device of an automatic analyzer of the present invention, in which a sample liquid 2 in a sample container 1 is transferred to a diluent 4 contained in a diluent container 3.
The solution is diluted at a predetermined ratio and dispensed into the reaction tube 5. An opening/closing valve 7, a syringe pump 8, and a probe 6, which can be raised and lowered at a sample liquid 2 suction position, and which can be moved to a position where a predetermined amount of the sample liquid 2 aspirated is discharged into the reaction tube 5 together with a predetermined amount of diluent 4. It communicates with the diluent container 4 via an on-off valve 9. The piston 10 of the syringe pump 8 is attached to an arm 1 on a guide plate 11 that is movably provided on a fixed member (not shown).
2 is provided and connected to this arm 12 via a set screw 13. Further, the guide plate 11 is provided with a rack 14 extending in the lifting direction. In this example, the guide plate 11 is raised and lowered by the pulse motor 15 to cause the piston 10 to reciprocate, and the driving frequency of the pulse motor 15 is controlled so that the suction process of the sample liquid 2 is slower than the discharge process. The drive speed of the piston 10 is slowed down during the suction process. For this purpose, the pulse motor 15 is attached to a fixed member (not shown), and a pinion 16 is fixed to the output end of the pulse motor 15.
is engaged with a rack 14 provided on the guide plate 11. Further, the drive circuit 17 of the pulse motor 15 includes two oscillators 18A and 18B with different oscillation frequencies.
are connected via a switching circuit 19, and this switching circuit 19 is controlled by a control circuit 20 to select one of the oscillators 18A and 18B. In this example, the oscillation frequency of oscillator 18A is 640pps, and the oscillation frequency of oscillator 18B is 640pps.
160 pps, and the pulse motor 15 is driven by selecting the oscillator 18B during the suction process of the common sample liquid 2 and the oscillator 18A during the discharging process.

An example of the operation of the dispensing device of the automatic analyzer of this embodiment will be described below with reference to the time chart shown in FIG. In this embodiment, the dispensing period is 6 seconds, and the flow path from the diluent container 3 to the tip of the probe 6 is filled with the diluent 4. First, close the on-off valve 7, open the on-off valve 9, and turn on the oscillator 1.
8A is selected, the pulse motor 15 is driven for one second, the pinion 16 is rotated to the left, the piston 10 is lowered via the guide plate 11, and a predetermined amount of the diluent 4 is sucked into the syringe pump 8. Next, with the tip of the probe 6 positioned in the air, the on-off valve 7 is opened, the on-off valve 9 is closed, and the oscillator 18
B is selected and the pulse motor 15 is slightly driven so that the pinion 16 rotates in the same direction as described above to suck air from the probe 6 and form an air layer at its tip. Then, with the tip of the probe 6 immersed in the sample liquid 2 in the sample container 1, the oscillator 18B is selected again and the pulse motor 15 is driven for 1 second to rotate the pinion 16 in the same direction as above. and aspirate a predetermined amount of sample liquid 2. Next, probe 6
After the tip of the tube faces the opening of the reaction tube 5, the oscillator 18A is selected, the pulse motor 15 is driven, the pinion 16 is rotated to the right, the piston 10 is raised, and a predetermined amount of the diluted liquid 4 is aspirated. Then, the sample liquid 2 is discharged into the reaction tube 5. Thereafter, by repeating the above-described sequential operations, successive sample solutions are diluted and dispensed into successive reaction tubes.

According to the above example, sample liquid 2 in an amount of 1/4 of diluent 4 is aspirated at 1/4 of the flow rate, so even if sample liquid 2 is highly viscous, the predetermined amount can be drawn with sufficient accuracy. It can be aspirated and therefore has good dispensing accuracy. In addition, aspirating the diluted liquid 4 and aspirating the diluted liquid 4 and sample liquid 2, which have no significant effect on dispensing accuracy,
Since the flow rate of each discharge can be increased, the dispensing cycle can also be shortened.

Note that the present invention is not limited to the above-mentioned example, and can be modified or changed in many ways. For example, in the above example, two oscillators 18A and 18B with different oscillation frequencies were selectively used to drive the pulse motor 15, but by connecting a frequency divider to one oscillator, The pulse motor 15 can be configured to be driven by selectively utilizing the frequency, or can be configured to be driven by selectively switching its resistance value or capacitance using one CR oscillator. . Furthermore, instead of switching the drive frequency of the pulse motor 15, a speed change mechanism having a plurality of gears is interposed between the pinion 16 and the rack 14, and the gear ratio is selectively changed to control the suction and discharge flow speeds. It can also be configured to do so. Therefore, in this case, various motors other than the pulse motor can be used. Further, an AC motor may be used instead of the pulse motor 15 to change its polarity and driving frequency, or a DC motor may be used to change its driving voltage to control the flow rate of suction and discharge of the sample liquid or reagent. You can also do that. Furthermore, the discharge flow rate can be controlled to be slower than the suction flow rate so that air bubbles are not mixed into the dispensed liquid discharged into the reaction tube 5. Furthermore, in addition to the syringe pump 8, various suction/discharge means can also be used. Furthermore, the present invention is applicable not only to a sample dispensing device but also to a dispensing device for highly concentrated (generally highly viscous) reagents that require dilution.

As explained in detail above, the present invention is configured so that the suction flow rate and discharge flow rate of the sample liquid or reagent can be controlled, so even if the sample liquid or reagent has high viscosity, it can be dispensed with high precision. The purpose of the invention can be effectively achieved.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the configuration of an embodiment of the dispensing device of the automatic analyzer of the present invention, and FIG. 2 is a time chart for explaining an embodiment of the operation of the dispensing device shown in FIG. 1. FIG. 1... Sample container, 2... Sample liquid, 3... Diluent container, 4... Diluent, 5... Reaction tube, 6... Probe, 7, 9... Open/close valve, 8... Syringe pump, 10... Piston, 11... Guide plate, 12
... Arm, 13 ... Set screw, 14 ... Rack, 15 ... Pulse motor, 16 ... Pinion,
17...drive circuit, 18A, 18B...oscillator,
19... Switching circuit, 20... Control circuit.

Claims (1)

[Claims] 1 The sample liquid or reagent in the container is diluted with the diluent contained in the diluent container and dispensed into the reaction tube. It is characterized by comprising a means for discharging, a means for driving the suction/discharge means, and a means for controlling the driving speed of the drive means so that the sample liquid or reagent is aspirated and discharged at different flow rates. Dispensing device for automatic analyzer.