JP3212130B2 - Liquid dispensing method and liquid dispensing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid dispensing method and a liquid dispensing apparatus, and more particularly, to dispensing a sample or a reagent into a reaction vessel by an immunological analyzer using an antigen-antibody reaction. The present invention relates to a dispensing method and an apparatus suitably used for the dispensing.

2. Description of the Related Art Immunological analysis using an antigen-antibody reaction is widely performed for examining viruses, hormones and the like present in a specimen. Depending on the test solution such as a serum test solution or a plasma test solution, the antigen or antibody may have a considerably high concentration. For this reason, in an automatic analyzer that performs an immunological analysis, it is important to prevent carry-over between samples in order to enhance the reliability of the analysis result. To prevent carryover, it is effective to dispense a specimen using a disposable type dispensing tip. In addition, in order to improve the reliability of the analysis result, it is indispensable to prevent carryover and to surely dispense the test solution. To do this, check that there is a sufficient amount of test solution in the test solution container, accurately measure the height of the test solution in the test solution container, and check the tip of the dispensing tip. It is necessary to dive a certain amount in the solution and to confirm that a predetermined amount of the test solution has been dispensed from the test solution container into the reaction container.

For this reason, for example, Japanese Patent Application Laid-Open No. Sho 62-24726
No. 1 discloses a method of measuring the height of a test solution surface in a test solution container and controlling the descending amount of a dispensing tip at a suction position based on the measurement result.

[0002]

However, in the method disclosed in Japanese Patent Application Laid-Open No. 62-247261, the height of the test solution is measured by placing a measuring device before the suction position of the test solution. Therefore, the difference between the stop position, which is different for each container generated when the test solution container moves from the position before the suction position to the suction position, and the change in the test solution mode such as the generation or disappearance of bubbles, the measurement value and the The actual height of the test solution may be different. In this way, when the actual test solution height and the measured value are different, if the actual height is lower than the measured value,
If the dispensing tip is short of the test solution and the dispensing volume is insufficient, or if the actual height is higher than the measured value, the dispensing tip dives too much and the test solution container When the tip of the dispensing tip comes into contact with the bottom or clot of the blood, poor dispensing may occur. The present invention pays attention to such a problem, and accurately detects the height of the test solution twice before and after suction of the test solution, and detects the height of the test solution in the test solution container before suction. Whether the amount of the test solution is sufficient and whether or not the amount of the test solution sucked from the test solution container is a predetermined amount, and these amounts deviate from the predetermined values. In this case, it is an object of the present invention to provide a liquid dispensing method and a liquid dispensing apparatus which recognizes this and reflects it on the test result.

[0003]

In order to solve the above-mentioned problems, a liquid dispensing method according to the present invention uses a disposable type dispensing tip to remove a liquid from a first container containing a test liquid. And dispensing the liquid by discharging the sucked liquid into the second container. In the dispensing method, before and after suction of the liquid by the dispensing tip, the height of the liquid surface is increased twice. Measuring the liquid before suctioning the liquid, and determining whether there is a dispensing abnormality from the difference between the measured value after the liquid suction and the measured value before the liquid suction, and the height of the liquid surface. The measurement is performed by moving a liquid level measuring mechanism of a non-contact type with the liquid level to a position above the liquid surface to be measured.

Further, the liquid dispensing apparatus of the present invention uses a disposable type dispensing tip to aspirate a liquid from a first container containing a test liquid, and transfers the sucked liquid to a second container. In a liquid dispensing apparatus configured to dispense liquid by discharging to a dispensing tip transfer means for moving the dispensing tip from a liquid suction position to a discharge position, and moving to the liquid suction position; A non-contact type liquid level measuring unit installed so as to be able to withdraw from the suction position, a liquid suction and discharge operation by the dispensing tip, an operation of the dispensing tip transfer unit, and an operation of the liquid level measuring unit are controlled. And a control processing means for processing the output of the liquid level measurement means, and an output means for outputting a determination result of the presence / absence of dispensing abnormality, wherein the liquid level measurement means sucks the liquid from the first container. Front and suction The height of the liquid level is measured at the same time, the control processing means determines whether or not there is a dispensing abnormality based on the output of the liquid level measuring means, and outputs the determination result by the output means. It is characterized by the following.

As described above, in the liquid dispensing method and apparatus of the present invention, the height of the liquid surface to be dispensed is measured at the liquid suction position, so that the liquid height can be accurately measured. It is possible to measure the height of the liquid before and after dispensing the liquid, and to determine the sufficient amount in the first container (test solution container) from the value measured before dispensing. It is determined whether or not there is a test solution, and the difference between the measured value before dispensing and the measured value after dispensing is compared with a predetermined value.
It is determined whether or not the amount of the test solution dispensed at the predetermined time is a predetermined value. In addition, a certain amount of dipping into the liquid at the tip of the dispensing tip can be secured from the first measurement result, and the shortage of the dispensing amount or the improper dispensing is accurately detected, and such an abnormality occurs. At times, this fact is output to improve the reliability of the inspection result.

[0006]

FIG. 1 is a diagram showing the overall configuration of a liquid dispensing apparatus according to the present invention. The test solution container 2 containing the test solution 1 is transferred to the suction position by the test solution container transfer means 4 based on a command from the test solution container transfer control means 3. Based on a command from the liquid level measuring device movement control means 5, the liquid level measuring device 6 is moved to a position above the liquid container 2 at the suction position, and the height of the liquid sample 1 stored in the liquid container 2 is adjusted. Measure (first measurement). After the measurement, the test solution level measuring device 6 is retracted from the test solution surface. The first measurement result is sent to the central processing unit 7, where it is compared with a predetermined value. If the first measurement value is smaller than the predetermined value, the test solution in the container 2 is insufficient. Therefore, it is determined that a sufficient amount of the test solution cannot be sucked.

Next, the dispensing tip transfer means 9 is driven based on a command from the dispensing tip transfer control means 8 to transfer the dispensing tip 10 onto the test solution container 2 and lower the dispensing tip 10 for inspection. Aspirate the liquid. At this time, the central processing unit 7 calculates a descending pulse of the dispensing tip 10 based on the above-mentioned first measurement value, and drives the dispensing tip transfer means 9 via the dispensing tip transfer control means 8. The dispensing tip transfer means 9 lowers the dispensing tip 10 according to this command. This descending pulse is calculated to a value such that the tip of the dispensing tip 10 dives into the test solution 1 by a fixed amount and stops.

Next, the dispenser 12 is driven in response to a command from the dispenser control unit 11 to cause the dispensing tip 10 to suck a predetermined amount of the test solution, After the dispensing tip transfer means 9 is raised, the dispensing tip is transferred to the discharge position. As will be described later, the dispensing tip 10 is further transferred to the discarding position after discharging the test solution and discarded here. Then, a new dispensing tip is mounted at the dispensing tip mounting position and transferred to the suction position. Is done.

While the dispensing tip 10 is moving between the discharging position, the discarding position, and the mounting position in this manner, the test solution level measuring device 6 is moved onto the test solution 2 again, and the test solution after the suction is completed. The height of the surface is measured (second measurement). In the central processing unit 7,
A change in the height of the test solution surface is calculated in advance from the inner diameter of the test solution container 2 and the suction amount sucked by the dispensing tip 10,
By comparing the calculated value with the difference in the height of the test solution before and after dispensing, the difference is equal to or more than a certain amount (for example, 0.5 mm or more).
If so, it is determined that a dispensing abnormality has occurred. This may be due to poor sealing of the dispensing tip 10 or the dispenser 1
2 and the operation of the liquid level measuring device 6 may be considered.

When the shortage of the test solution and the dispensing abnormality occur, the buzzer or the CRT
The operator is notified of the dispensing abnormality by displaying it on the screen or the like. The central processing unit 7 is connected to an output device 14 such as a printer for outputting a test result. When outputting the test result, an abnormal mark is added to a column of a corresponding sample so that an operator can output the test result. Be able to confirm that dispensing has occurred.

After the second measurement of the test liquid level is completed, the test liquid level measuring device 6 is retracted from the test liquid container 2 and the next test liquid container is transferred to the suction position. To be repeated.

[0012]

FIG. 2 is a view showing a moving path between a dispensing tip 10 and a test solution level measuring device 6 in a dispensing apparatus according to the present invention. The test solution containers 2 are accommodated in a row in the rack 2a, and are transferred to the test solution suction position A by the test solution transfer device 4 such as a belt conveyor. The test surface level measuring means 6
A liquid level sensor 6a and a liquid level signal processing unit 6b are provided. The liquid level sensor 6a is controlled by the liquid level measuring device transfer control means 5.
Is moved to above the test solution container 2 located at the test solution suction position A, and the first measurement of the height of the test solution surface is performed. After the completion of the first measurement, the liquid level sensor 6a is retracted from the suction position A. The first liquid level signal measured by the liquid level sensor 6a is sent to the liquid level signal processing unit 6b via the cable 6c, and is finally processed by the central processing unit 7.

On the other hand, the dispensing tip transfer means 9 mounts the disposable type dispensing tip 10 at the dispensing tip mounting position B to which the disposable type dispensing tip 10 is sequentially sent, and performs the above-described first dispensing. After the end of the measurement,
This is transferred to the liquid suction position A. In accordance with the descending pulse based on the calculation performed in the central processing unit 7, the dispensing tip 1
Dispense tip 10 until the tip of 0 goes down a certain amount from the test solution surface
Is lowered, and the dispenser 12 is driven to aspirate a predetermined amount of the test solution. After the suction, the dispensing tip 10 is raised and moved to the test solution discharge position C, and the sucked test solution is discharged into the reaction container 21. After the discharge, the dispensing tip 10 is transferred to the dispensing tip discarding position D, and the used dispensing tip 10 is discarded.

At the timing when the dispensing tip 10 is transferred to the discharge position C and the disposal position D by the dispensing tip transfer means 9 as described above, the test surface sensor 61 is again moved to the test container 2.
To the top of the sample, the height of the test solution surface after the suction of the test solution is measured (second measurement), and then retracted.

The above operations are repeated for each sample to dispense a large number of samples. Since the measurement of the sample surface is completed in about one second including the movement operation of the sample surface sensor, a large number of samples can be processed at high speed.

FIGS. 3 (a), 3 (b) and 3 (c) are views showing the first and second measurement steps of the test liquid surface and the test liquid suction step. As shown in FIG. 3A, the first measurement of the height of the test solution is performed by the test surface sensor 6a before the suction of the test solution. The measurement may be performed using ultrasonic waves,
The measurement may be performed using an optical distance measurement method. Next, as shown in FIG. 3B, the test solution level sensor 6 a is retracted, and the dispensing tip 10 is moved onto the test solution container 2. The dispensing tip 10 is lowered so that the tip of the dispensing tip 10 dives below the test solution by a predetermined amount x, and the dispenser 12 is operated to suck a predetermined amount of the test solution. After the end of the suction, the dispensing tip 10 is raised and moved to the discharge position, and
And the chip 10 is discarded at the disposal position. In the meantime, as shown in FIG. 3 (c), the test liquid level sensor 6a is moved over the test liquid container 2 again, and the second measurement of the test liquid level is performed. The central processing unit 7 compares the first measurement result with a predetermined value to determine whether the amount of the test solution in the test solution container before the suction is sufficient, and activates the dispenser 12. The change amount v of the liquid surface is calculated from the suction amount of the test solution sucked and sucked and the inner diameter z of the test solution container 2. The difference y from the height is detected, and the difference y is compared with the calculated change amount v of the liquid surface. If the comparison result is a predetermined value or more, it is determined that the dispensing is abnormal. Thus, an alarm is issued by the alarm generating unit 13 and the output device 14 outputs the effect.
In determining the dispensing abnormality, it is necessary to consider an amount corresponding to the measurement resolution as an error.

FIG. 4 is a diagram showing an example of an output format indicating the inspection result. As the output device 14, a printer, a CRT screen, or the like is used. If a dispensing error occurs, a mark indicating the dispensing error is attached to the column of the corresponding sample and output. In the format 30 shown in FIG. 4, an abnormal mark output area 31, a sample number area 32, a sample ID number area 33, and a test result area 34 are provided. An abnormal mark represented by # "is attached. The operator can determine at a glance that a dispensing abnormality has occurred, and improve the reliability of the inspection.

Further, when a dispensing abnormality occurs,
The alarm generation unit 13 may sound a buzzer or display on the CRT screen 14 that a dispensing abnormality has occurred, thereby notifying the operator of the occurrence of the dispensing abnormality at an early stage. With such a configuration, the retest can be performed at an early stage.

As described above, in the liquid dispensing method and dispensing apparatus of the present invention, the height of the test liquid surface is measured at the position where the test liquid is suctioned, so that the height of the test liquid surface is accurately measured. The sample surface can be measured twice before and after suctioning the test solution, and a sufficient amount can be stored in the test solution container 2 based on the measurement result before the first suction. Accurate detection of dispensing abnormalities because it detects whether or not there is any test solution, and the fact that the suction volume is insufficient is detected based on the difference between the first measurement result and the second measurement result. Thus, the reliability of the inspection result can be improved. In addition, since the measurement of the sample surface is performed using a non-contact measurement method, carry-over between samples can be prevented. In addition, by notifying the operator of a dispensing error with a buzzer, etc., it is possible to carry out an early re-inspection. Properties can be further enhanced.

[Brief description of the drawings]

FIG. 1 is a diagram showing an entire configuration of a liquid dispensing apparatus of the present invention.

FIG. 2 is a view for explaining a movement path between a liquid level sensor and a dispensing tip in the liquid dispensing apparatus of the present invention.

FIG. 3 is a diagram for explaining a first and second liquid surface measurement steps and a test liquid suction step;

FIG. 4 is a diagram showing an example of an output format of the liquid dispensing apparatus of the present invention.

[Explanation of symbols]

 1 Test solution 2 Test solution container 3 Test solution container transfer control means 4 Test solution container transfer means 5 Test solution level measurement device control means 6 Test solution level measurement device 7 Central processing unit 8 Dispensing tip transfer control means 9 Dispensing tip transfer Means 10 Dispensing tip 11 Dispenser control means 12 Dispenser 13 Alarm generating unit 14 Output device 21 Reaction vessel 22 Dispensing tip disposing unit 6a Liquid level sensor

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G01N 35/00-35/10 G01N 1/00-1/44 G01F 23/00 G01F 23/14-23 / 28

Claims (2)

(57) [Claims] 1. A dispenser for dispensing a liquid by using a disposable type dispensing tip to suck a liquid from a first container storing a test liquid and discharging the sucked liquid into a second container. In the injection method, the height of the liquid surface is measured twice before and after suction of the liquid by the dispensing tip, and the measured value before the liquid suction and the measured value after the liquid suction and the liquid suction are measured. While judging the presence or absence of the dispensing abnormality from the difference from the previous measurement value, the height of the liquid level is measured by moving the liquid level and the non-contact type liquid level measurement mechanism to above the test liquid level. A liquid dispensing method, characterized in that the liquid dispensing is performed. 2. A method for dispensing a liquid by sucking a liquid from a first container containing a test liquid using a disposable type dispensing tip, and discharging the sucked liquid into a second container. In the liquid dispensing apparatus configured as described above, dispensing tip transfer means for moving the dispensing tip from the liquid suction position to the discharge position, and moved to the liquid suction position,
A non-contact type liquid level measuring unit installed so as to be able to withdraw from the suction position, a liquid suction and discharge operation by the dispensing tip, an operation of the dispensing tip transfer unit, and an operation of the liquid level measuring unit are controlled. And a control processing means for processing the output of the liquid level measurement means, and an output means for outputting a determination result of the presence / absence of dispensing abnormality, wherein the liquid level measurement means sucks the liquid from the first container. The height of the liquid surface is measured before and after suction, and the control processing means determines whether there is a dispensing abnormality based on the output of the liquid level measurement means, and outputs the determination result by the output means. A liquid dispensing apparatus characterized in that: