JP2007240329A - Dispensing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a dispensing device capable of discriminating the suction state of a liquid sample regardless of a dispensation amount, when dispensing the liquid sample. <P>SOLUTION: This dispensing device equipped with a dispensing means for sucking/discharging the liquid sample by a sample probe by connecting a dispensing pump to the sample probe through a pipe, and by allowing the dispensing pump to perform suction/discharge operation, and a pressure detection means for detecting the pressure of the pipe including the sample probe, is provided with a temporary discharge section for discharging quantitatively the liquid sample after suction and before discharge of the liquid sample by the dispensing means, and is equipped with a suction state discrimination means for discriminating the suction state of the liquid sample based on output from the pressure detection means in the temporary discharge section. In the case of empty suction, a negative pressure is generated by suction of air just after discharge resulting from discharge of the air not receiving viscosity of the liquid sample, and a pressure change in the temporary discharge section becomes large compared with normal suction. Namely, empty suction can be discriminated stably and accurately by observing the large pressure change. In addition, since the discharge amount is always constant in the temporary discharge section, the change of the interval or the number of integration sections or the change of a threshold range is not required. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a dispensing device used in an analyzer for analyzing a sample (liquid sample) such as blood or urine.

  In automated analyzers such as biochemistry, a dispensing device having a dispensing pump and a sample probe connected thereto is provided, and the sample probe can be moved to a sample suction position, a sample discharge position, and a probe washing position, and dispensed. By sucking and discharging the pump, a predetermined amount of sample is dispensed from the sample container into the reaction container. In this type of automatic analyzer, serum or plasma is used as a sample, but since solids such as fibrin are present in the sample, the solids are connected to the sample probe and a pipe connected thereto. May clog. When the sample probe is clogged, a predetermined amount of sample cannot be dispensed into the reaction container, which has a serious adverse effect on the analysis result. On the other hand, there is a case in which the sample probe is not immersed in the sample liquid surface when the sample is sucked and the sample is not sucked. When empty aspiration occurs, the sample cannot be dispensed into the reaction container, which has a serious adverse effect on the analysis result.

  In order to deal with such a problem, a conventional dispensing apparatus connects a pressure sensor to a dispensing flow path system including a sample probe and a dispensing syringe, and measures a pressure fluctuation waveform during sample dispensing. The output of the pressure sensor is sent to an integration arithmetic circuit through an amplifier and an A / D converter. In the integration arithmetic circuit, an integration process is executed at a predetermined sampling frequency for each integration section obtained by dividing the sample suction section into a plurality of sections. The output of the integration arithmetic circuit is sent to the determination circuit. The determination circuit stores a threshold range corresponding to each of a plurality of integration calculation results in advance, and compares them to determine whether or not the suction operation has been performed normally (see, for example, Patent Document 1). ).

JP 2002-333449 A

  In a conventional dispensing apparatus, clogging or empty suction is detected during sample suction. However, since the suction time varies depending on the required dispensing volume, it is necessary to change the interval and the number of each integration interval in which the integration is performed according to the dispensing volume. In addition, since the pressure value varies depending on the required dispensing volume, it is necessary to change the threshold range according to the dispensing volume.

  The present invention has been made in view of the above, and an object of the present invention is to provide a dispensing device that can determine the suction state of a liquid sample without depending on the dispensing amount when dispensing the liquid sample. To do.

  In order to solve the above-described problems and achieve the object, a dispensing apparatus according to claim 1 of the present invention connects a dispensing pump and a dispensing nozzle by a pipe line, and operates the dispensing pump to perform a suction / discharge operation. In a dispensing apparatus comprising a dispensing means for sucking and discharging a liquid sample by a dispensing nozzle and a pressure detecting means for detecting the pressure of the pipe line including the dispensing nozzle, after the liquid sample is sucked by the dispensing means A provisional discharge section for quantitatively discharging a liquid sample before discharge is provided, and suction state determination means for determining the suction state of the liquid sample based on the output of the pressure detection means in the temporary discharge section is provided. To do.

  The dispensing apparatus according to a second aspect of the present invention is the dispensing device according to the first aspect, wherein the suction state determination means compares the integrated value of the pressure in the temporary discharge section with a predetermined threshold value in the temporary discharge section. It is characterized by discriminating the suction state of the sample.

  The dispensing apparatus according to the present invention includes a temporary discharge section for quantitatively discharging a liquid sample after the liquid sample is sucked by the dispensing means and before the discharge, and the liquid is based on the output of the pressure detection means in the temporary discharge section. Determine the suction state of the sample. In other words, in the air suction, the air that is not subjected to the viscosity of the liquid sample is discharged, and a negative pressure is generated by the suction of the air immediately after the discharge, and the pressure change in the temporary discharge section is larger than that in the normal suction. As a result, the idle suction can be determined stably and accurately by observing a large pressure change. Furthermore, since the discharge amount is always constant in the temporary discharge section, there is no need to change the interval or number of integration sections or change the threshold range.

  Exemplary embodiments of a dispensing apparatus according to the present invention will be described below in detail with reference to the accompanying drawings. Note that the present invention is not limited to the embodiments.

  FIG. 1 is a schematic view showing an example of a dispensing apparatus according to the present invention. The dispensing device is used in an analyzer that analyzes a sample (liquid sample) such as blood or urine, and dispenses a predetermined amount of sample from the sample container C1 to the reaction container C2. As shown in FIG. 1, in the dispensing apparatus, a sample probe (dispensing nozzle) 1 and a dispensing pump 2 are connected by a conduit 3 as dispensing means.

  The sample probe 1 can be moved horizontally by the probe driving means 1a to a sample suction position where the sample container C1 containing the sample is located, a sample discharge position where the reaction container C2 for reacting the sample is present, a washing position where the washing tank C3 is located, and the like. Furthermore, it is provided to be movable up and down at each position by the probe driving means 1a.

  The dispensing pump 2 is composed of, for example, a syringe, and performs a suction / discharge operation by the dispensing pump driving means 2a.

  The conduit 3 is made of a flexible tube that does not hinder the movement of the sample probe 1. The inside of the pipe line 3 is filled with washing water including the sample probe 1 and the dispensing pump 2. As the washing water, deaerated water from which air has been removed is used. The washing water filled in the pipe line 3 is accommodated in the tank 4. The tank 4 is connected to the dispensing pump 2 by a pipe line 5. The pipe 5 is a tube similar to the pipe 3. The pipe 5 is provided with a pump 6 and an electromagnetic valve 7. That is, the wash water stored in the tank 4 is filled into the dispensing pump 2, the pipe line 3 and the sample probe 1 through the pipe line 5 by opening the electromagnetic valve 7 and driving the pump 6.

  As shown in FIG. 1, the probe driving means 1 a, the dispensing pump driving means 2 a, the pump 6 and the electromagnetic valve 7 described above are controlled by the dispensing control unit 8. That is, the dispensing control unit 8 controls the probe driving means 1a to move the sample probe 1 in the dispensing operation, and further controls the dispensing pump driving means 2a to cause the dispensing pump 2 to perform suction and discharge operations. Thereby, the dispensing apparatus sucks the sample from the sample container C1 with the sample probe 1 and discharges it to the reaction container C2. On the other hand, the dispensing control unit 8 controls the probe driving unit 1a to move the sample probe 1 in the cleaning operation, and further controls the dispensing pump driving unit 2a to cause the dispensing pump 2 to perform an intake / exhaust operation. Thereby, the dispensing apparatus discharges the sample sucked by the sample probe 1 to the cleaning tank C3 and cleans the sample probe 1.

  Further, pressure detection means 9 is provided in the pipe line 5 (or the pipe line 3). The pressure detection means (pressure sensor) 9 cleans the pipelines 3 and 5 including the sample probe 1 and the dispensing pump 2 when the sample probe 1 sucks and discharges the liquid sample by the suction / discharge operation of the dispensing pump 2. It is for detecting and outputting the pressure of water.

  The output of the pressure detection means 9 is supplied to the suction state determination means 10. The suction state determination unit 10 includes an A / D converter 11 that converts an output from the pressure detection unit 9 into a digital signal, an amplification circuit 12, an integration calculation circuit 13, and a determination circuit 14. The A / D converter 11 converts the output of the pressure detection means 9 into a digital signal. The amplifier circuit 12 amplifies the digital signal output from the A / D converter 11. The integration calculation circuit 13 calculates a digital signal into an integral value. The determination circuit 14 stores a predetermined threshold value and the like, compares the integrated value output from the integration calculation circuit 13 with the threshold value, and outputs a determination result of the suction state of the sample probe 1 based on the comparison. The determination result is supplied to the dispensing control unit 8. In accordance with the determination result, the dispensing control unit 8 outputs a signal indicating that the analysis is continued to an analysis control unit (not shown) that controls the analyzer if it is normal suction, and performs abnormal suction (clogging). If it is empty suction, the sample probe 1 is washed, and the same liquid sample is reanalyzed or another liquid sample is analyzed. The A / D converter 11 and the amplifier circuit 12 are provided in reverse, and the digital signal converted by the A / D converter 11 after the output from the pressure detection means 9 is amplified by the amplifier circuit 12 is supplied to the integration arithmetic circuit 13. You may supply.

  By the way, in the present embodiment, the suction state is determined in the temporary discharge section. Temporary discharge is to discharge a predetermined amount of liquid sample at the position of the sample container C1 after sucking the liquid sample by the sample probe 1 and before discharging to the reaction container C2, and quantitatively discharge the liquid sample. Thus, the tip of the liquid sample is aligned at the suction / discharge port of the sample probe 1. In the temporary discharge section, the discharge amount of the liquid sample is always a constant amount.

  Specifically, the case of determining idle suction will be described with reference to the pressure waveform diagram of FIG. In FIG. 2, the horizontal axis indicates time, and the vertical axis indicates voltage based on the output from the pressure detection means 9. Note that the negative pressure detected by the pressure detection means 9 is a positive voltage, and the positive pressure is a negative voltage. The threshold voltage for normal suction, which is a threshold value, is indicated by a solid line, the voltage for idle suction is indicated by a broken line, and the drive signal (BUSY signal) of the dispensing pump drive means 2a for sucking and discharging the dispensing pump 2 is indicated by a one-dot chain line. It shows with. That is, the section that is first driven by the dispensing pump driving means 2a is the suction section that sucks the liquid sample, and the section that is later driven by the dispensing pump driving means 2a is the temporary discharge section (integration section).

  In the temporary discharge section, air discharge is not affected by the viscosity of the liquid sample during empty suction, so suction of air immediately after discharge generates negative pressure (positive voltage) as shown in FIG. The pressure change in the section increases. That is, it is possible to determine the idle suction stably and accurately by observing this pressure change. Furthermore, as described above, since the discharge amount of the liquid sample is always a constant amount in the temporary discharge section, there is no need to change the interval or number of integration sections or change the threshold range.

  Further, in the suction section, at the time of idle suction, the positive pressure (negative voltage) is large and the output voltage is low compared to normal suction that receives the viscosity of the liquid sample. On the other hand, when clogging occurs in the suction section, the negative pressure (positive voltage) is larger and the output voltage is higher than in normal suction. That is, if it is attempted to discriminate both clogging and empty suction in the suction section, a large voltage range change must be observed. Therefore, it is not necessary to see the positive pressure (negative voltage) compared with the normal suction in all the sections by discriminating the idle suction with the negative pressure (positive voltage) in the temporary discharge section. As a result, by determining clogging in the suction section and determining idle suction in the temporary discharge section, it is possible to stably and accurately determine both because there is no significant change in the voltage range. .

It is the schematic which shows an example of the dispensing apparatus which concerns on this invention. It is a figure which shows a pressure waveform.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sample probe 1a Probe drive means 2 Dispensing pump 2a Dispensing pump drive means 3 Pipe line 4 Tank 5 Pipe line 6 Pump 7 Solenoid valve 8 Dispense control part 9 Pressure detection means 10 Suction state discrimination means 11 A / D converter 12 Amplification circuit 13 Integration operation circuit 14 Discrimination circuit C1 Sample container C2 Reaction container C3 Washing tank

Claims (2)

A dispensing pump and a dispensing nozzle are connected by a pipe line, the dispensing pump is sucked and discharged, a liquid sample is sucked and discharged by the dispensing nozzle, and the pressure of the pipe line including the dispensing nozzle is adjusted. In a dispensing apparatus provided with a pressure detecting means for detecting,
Provision of a temporary discharge section for quantitatively discharging the liquid sample after the liquid sample is aspirated by the dispensing means and before the discharge,
A dispensing apparatus comprising: suction state determination means for determining a suction state of a liquid sample based on an output of a pressure detection means in the temporary discharge section.   2. The component according to claim 1, wherein the suction state determination unit determines the suction state of the liquid sample by comparing an integrated value of the pressure in the temporary discharge section with a predetermined threshold value in the temporary discharge section. Note device.

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