JPH06148207A - Sample dispensing system of automatic chemical analyzer - Google Patents

Abstract

PURPOSE:To provide a system which can conduct sample dispensation without misrecognizing bubbles as a liquid surface even when they develop in a liquid surface of a reagent liquid or the like dispensed into reaction tubes. CONSTITUTION:A mask circuit 11 is provided which can on-off control the action of a liquid surface detection circuit 4 which outputs judgment signals recognizing whether a liquid surface under detection and a pipette probe 2 make liquid surface contacts and stopping descents of the probe 2, and the mask circuit 11 is turned on during sample discharge to stop the liquid surface detection circuit 4, so that stopping descent of the probe 2 is controlled not by signals from a liquid surface sensor and the like, but by a predetermined calculated value and the like from a computer 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic chemical analyzer for continuously performing biochemical analysis by discharging a sample or the like sucked by a pipette probe onto a liquid surface of a reagent or the like already dispensed in a reaction tube. Regarding sample dispensing system.

[0002]

2. Description of the Related Art Conventional automatic chemical analyzers dispense samples using a single pipette probe equipped with a liquid level sensor in order to reduce contamination and improve dispensing accuracy. ing. Here, the liquid level sensor detects the liquid level of the sample or reagent liquid dispensed into the reaction tube, minimizes the contact between the sample liquid and the pipette probe, and attaches more samples than necessary to the pipette probe. It is devised not to do it. Also, when the amount of sample discharged and mixed into the reaction tube at the time of sample dispensing is as small as 2 μl, sample dispensing cannot be performed accurately. Therefore, the reagent solution with a large dispensing amount is dispensed first and the reagent is detected by the liquid level sensor. It employs a method that detects the surface of the liquid and discharges a small amount of sample from the pipette probe.

[0003]

However, the above-mentioned method for dispensing a small amount of sample causes a problem in the case of a reagent solution or the like in which the components easily foam. That is, bubbles are generated when the reagent is dispensed into the reaction tube first, and at the time of sample dispensing, the liquid level sensor installed in the pipette probe detects the bubble of the reagent as the liquid level and the sample is removed from the pipette probe. May be discharged.

Dispensing a small amount of sample in bubbles such as a reagent solution as described above worsens the liquid discharge of the solution discharged from the tip of the pipette probe, and a fixed amount of sample from the pipette probe to the reagent or the like. It cannot be discharged into the solution, resulting in poor sample dispensing accuracy or measurement error.
Inevitably re-examination is required.

The present invention has been made to solve the above problems, and provides a sample dispensing system of an automatic chemical analyzer capable of accurately dispensing a sample even when a reagent or the like is bubbled in a reaction tube. The purpose is to do.

[0006]

A sample dispensing system for an automatic chemical analyzer according to the present invention operates a sampling pump to suck a fixed amount of a solution of a sample or a reagent into a pipette probe, and at the same time, to put these solutions into a reaction tube. In a sample dispensing system that dispenses inside, a liquid level sensor that outputs an information signal of the contact between the pipette probe and the liquid surface to be detected, and a liquid level contact between the liquid surface to be detected and the pipette probe based on this information signal Liquid level detection circuit that outputs a judgment signal that can recognize presence / absence, mask circuit that controls ON / OFF of the circuit operation of the liquid level detection circuit, and pulse motor drive that moves the sampling pump or pipette probe up and down based on the input signal Based on the operation signal generating means for outputting these operation signals to the circuit and the program stored in the memory means, etc. Based on the control processing signal for performing the liquid level detection circuit and the determination signal output from the liquid level detection circuit, when the liquid level contact is recognized, the stop processing signal that stops the descending of the pipette probe and the mask circuit stops the liquid level detection circuit. hand,
When ejecting a sample sucked by a pipette probe into the reaction tube, the contact between the reagent in the reaction tube and the pipette probe that dispenses the sample should be minimized based on the numerical value of the liquid amount of the reagent etc. ejected into the reaction tube first. A pipette probe lowering position required to suppress the pipette probe to a limit, and a stop processing signal for stopping the pipette probe lowering based on the calculated value; To do.

Further, in this sample dispensing system, when the liquid level detecting circuit is stopped by the mask circuit to dispense the sample, the liquid level detecting circuit is activated after the pipette probe is lowered to a proper position in the reaction tube. Then, based on the determination signal output from the liquid level detection circuit, the arithmetic processing means is provided with a processing function of detecting the presence or absence of discharge abnormality of the reagent or the like previously dispensed in the reaction tube and outputting an abnormality detection signal. good.

[0008]

According to the sample dispensing system of the automatic chemical analyzer of the above means, when the sample or the like is sucked by the pipette probe, the liquid level detection circuit is activated to cause the nozzle of the pipette probe on the liquid level in the container. A small amount of sample liquid can be aspirated by slightly contacting the sample liquid, and when the sample liquid is discharged to the reagent dispensed into the reaction tube, even if bubbles are formed on the liquid surface of the reagent,
The sample liquid or the like can be accurately discharged onto the liquid surface of the reagent or the like without stopping the liquid level detection circuit by the mask circuit and detecting the bubbles as the liquid surface. In addition, in order to dispense the sample,
If the liquid level detection circuit is activated after stopping the pipette probe from descending, the presence or absence of liquid level contact can be determined, so the presence or absence of abnormal discharge of reagents etc. in the previously dispensed reaction tube can also be detected. be able to.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a sample dispensing system of an automatic chemical analyzer according to the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the outline of a sample dispensing apparatus of an automatic chemical analyzer.

The automatic chemical analyzer operates the sampling pump 1 to take in the sample amount required for the inspection of a plurality of items into one pipette probe 2 in advance for each item, and dispenses it into the reaction tube 3 first. This device is capable of continuously measuring the reaction by dispensing on the liquid surface of the reagent solution S. As the reaction tube 3 for mixing the reagent solution S and the sample solution, although illustration is omitted, a plurality of reaction tubes having the same shape are provided, and the shape has an inner diameter of 5 mm × 6 mm and a length of 40 mm. There is.

As the pipette probe 2, one equipped with a liquid level sensor for outputting a contact information signal, which fluctuates when the tip of the nozzle comes into contact with the liquid level, to the liquid level detection circuit 4, is used. It is integrated with the probe 2.

The upper part of the pipette probe 2 is supported by the tip of the sampling arm 5 so as to form a right angle. When the sampling arm 5 is moved up and down, the pulse motor drive circuit 7 is operated based on an operation signal output from the computer 6 described later, and the drive mechanism unit 8 is operated based on the output signal from the pulse motor drive circuit 7. It is performed by driving.

Inside the sampling arm 5, a conduit 9 having one end connected to the tip of the pipette probe 2 is guided, and the other end of the conduit 9 is connected to the sampling pump 1 and the sampling pump 1 and the pipette probe. Two
And are connected by a conduit 9. Here, the sampling pump 1 operates to quantitatively suck a solution of a sample or a reagent and a gas into the pipette probe 2, and to discharge the sucked sample liquid or the like. Furthermore, a wire 10 having one end connected to the output terminal of the liquid level sensor of the pipette probe 2 is guided to the sampling arm 5 and connected to the input terminal of the liquid level detection circuit 4.

The liquid level detection circuit 4 outputs to the computer 6 a judgment signal capable of recognizing whether or not the liquid level to be detected is in contact with the pipette probe 2 based on the information signal output from the liquid level sensor. The liquid level detection circuit 4 includes a mask circuit 1
1 is connected, and the operation of the liquid level detection circuit 4 can be controlled to be turned on / off by the mask circuit 11.

FIG. 2 is a block diagram showing the functions of the main parts of the basic configuration of this embodiment.

The computer 6 includes various test items required for chemical analysis, measurement parameters such as a sample dispensing amount and a reagent dispensing amount which are minimum required for measuring those items, and the reaction tube 3 used. External input means 61 for inputting a shape and the like, memory means 62 for storing input information, arithmetic processing means 63 for performing arithmetic processing based on an input signal and stored information, and a program, and this arithmetic processing A discharge abnormality of a reagent liquid or the like is detected by an operation signal generation means 64 for outputting a signal for operating the pulse motor drive circuit 7 or the sampling pump 1 based on the processing signal of the means 63, and a discharge abnormality detection process performed by the arithmetic processing means 63. In this case, the display signal generating means 65 for outputting a signal for displaying the ejection abnormality on the display means 12 such as a display is provided.

Further, in the arithmetic processing means 63, the mask circuit 1
When the liquid level detection circuit 4 is stopped by 1 and the sample sucked by the pipette probe 2 is discharged to the reaction tube 3,
Based on the numerical value of the liquid amount of the reagent or the like previously discharged to the reaction tube 3, the pipette probe descending position required to minimize the contact between the reagent liquid or the like in the reaction tube 3 and the pipette probe 2 for sample dispensing is determined. A descending position calculation process for calculating is performed. Then, a stop processing signal for stopping the pipette probe 2 from descending to a proper position in the reaction tube based on the calculated value of the descending position calculation processing is output to the operation signal generating means.

When the mask circuit 11 is turned off and the liquid level detection circuit 4 is operated to suck the sample into the pipette probe 2, when the tip of the pipette probe 2 comes into contact with the liquid level of the sample or the like, the liquid level is detected. A signal indicating that the liquid surface is in contact is input from the circuit 4 to the computer 6, and the arithmetic processing means 6 of the computer 6 is input.
At 3, the pipette probe lowering stop process is performed. Then, this stop processing signal is input to the operation signal generating means 64, the operation signal is output from the operation signal generating means 64 to the pulse motor drive circuit 7, and the lowering of the pipette probe 2 is stopped.

In the discharge abnormality detection processing in the arithmetic processing means 63, when the mask circuit 11 is operated by the program and the liquid level detection circuit 4 is stopped to perform sample dispensing, the pipette probe 2 is placed at an appropriate position inside the reaction tube 3. After the descent control is performed, the liquid level detection circuit 4 is actuated, and based on the determination signal output from the liquid level detection circuit 4, the reaction tube 2 previously dispensed
It is for determining whether or not there is any abnormal discharge of the reagent or the like.
When the ejection abnormality is detected in this way, the processing signal is inputted from the arithmetic processing means 63 to the display signal generating means 65, and the abnormality detecting signal can be outputted from the display signal generating means 65 to the display means 12 such as a display. .

Although not shown in this embodiment, the operation of the sample pump 1 may be stopped and controlled so that the sample dispensing is prohibited as a process when the discharge abnormality is detected. Next, the operation of the sample dispensing apparatus having the above-mentioned configuration when the mask circuit 11 is specifically used will be described.

First, a reagent dispensed amount 2 which is a measurement parameter
00 μl and a sample dispensed amount of 4 μl are stored in the memory means 62 via the external input means 61 of the computer 6.

First, 200 μl of the reagent S was dispensed into the reaction tube 3, and the reagent S was located at a position h ₂ 6.6 mm from the bottom P of the reaction tube 3.
It is assumed that bubbles are formed on this liquid surface.

Since the total displacement amount H of the pipette probe is stored in the memory means 62 of the computer 6, the probe descending amount h ₁ is calculated by the descending position calculating processing function of the arithmetic processing means 63 as h ₁ = H− The calculated value of h ₂ is calculated. Then, the mask circuit 11 is operated based on the program of the computer 6 to stop the liquid level detection circuit 4, and the pulse motor drive circuit 7 is operated via the operation signal generating means 64 to pipette above the reaction tube 3. The probe 2 is moved, and the pipette probe 2 is lowered by the required lowering amount h ₁ and stopped. When the liquid level detection circuit 4 is operated and it is detected that there is no abnormal discharge of the reagent or the like, an operation signal is input to the sample pump 1 via the operation signal generation means 64 and a liquid volume of 4 μl is output from the nozzle of the pipette probe 2. The sample is discharged and the sample is dispensed.

When the liquid level detection circuit 4 is actuated and an abnormal discharge of a reagent or the like is detected, a processing signal is output from the arithmetic processing means 63 to the display signal generating means 65, and the display signal generating means 65 displays. A display signal is output to the display means 12 and the discharge abnormality is displayed on the display means 12. This allows the operator to know the discharge abnormality and check the reaction tube in which the discharge abnormality has occurred.

[0026]

According to the sample dispensing system of the automatic chemical analyzer of the present invention, even when the sample is dispensed to the reagent that easily foams, if the mask circuit is turned on, the liquid level detection circuit is stopped and the reaction is already performed. The tip of the pipette probe can be brought into contact with the liquid surface on an appropriate liquid surface by calculating the probe descending position from the amount of the reagent discharged into the tube. Therefore, the malfunction of misidentifying the bubbles as the liquid surface and discharging the sample is eliminated. or,
Since the sample is not ejected into the bubbles, the liquid running out of the sample is improved, the dispensing accuracy of the sample is improved, and the reliability of the device is also improved. Further, since the rate of re-inspection is reduced, the inspection time can be shortened as a result, and the operator's burden can be reduced.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an outline of a sample dispensing apparatus used in an embodiment of the present invention.

FIG. 2 is a block diagram showing a function of a main part of a basic configuration of the embodiment.

[Explanation of symbols]

 1 Sampling pump 2 Pipette probe 3 Reaction tube 4 Liquid level detection circuit 5 Sampling arm 6 Computer 7 Pulse motor drive circuit 11 Mask circuit

Claims (2)

[Claims] 1. A sample dispensing system for an automatic chemical analysis device, which operates a sampling pump to suck a solution of a sample or a reagent into a pipette probe in a fixed amount and dispenses the solution into a reaction tube. And a liquid level sensor that outputs an information signal of the contact between the liquid level and the liquid level to be detected, and a liquid level detection circuit that outputs a determination signal that can recognize the presence or absence of the liquid level contact between the liquid level to be detected and the pipette probe based on this information signal. And a mask circuit for controlling the circuit operation of the liquid level detection circuit on and off, and an operation signal generation means for outputting these operation signals to a pulse motor drive circuit for vertically moving a sampling pump or a pipette probe based on an input signal. And a control processing signal for performing sample dispensing based on the program stored in the memory means, and a judgment output from the liquid level detection circuit. Based on the signal, when the liquid level contact is recognized, the stop processing signal that stops the descending of the pipette probe and when the liquid level detection circuit is stopped by the mask circuit and the sample sucked by the pipette probe is discharged into the reaction tube , Calculate the pipette probe descending position required to minimize the contact between the reagent in the reaction tube and the pipette probe that dispenses the sample, from the numerical value of the liquid volume of the reagent previously discharged into the reaction tube. A sample dispensing system for an automatic chemical analyzer, comprising: a stop processing signal for stopping the descending of the pipette probe based on a calculated value; and an arithmetic processing means for outputting the operation signal generating means. 2. When the liquid level detection circuit is stopped by the mask circuit and a sample is dispensed, the pipette probe is controlled to descend to a proper position in the reaction tube, and then the liquid level detection circuit is operated to output from the liquid level detection circuit. 2. The automatic chemical analyzer according to claim 1, wherein the arithmetic processing means is provided with a processing function of detecting whether or not there is a discharge abnormality of the reagent previously dispensed in the reaction tube based on the determined signal, and outputting the abnormality detection signal. Sample dispensing system.