JP2013053935A - Automatic analyzer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an automatic analyzer including a dispensation mechanism capable of suppressing reduction of dispensation accuracy due to a temperature change caused by nozzle inside cleaning operation without being influenced by arrangement of a passage of a syringe part in dispensation of a sample or a reagent and having highly accurate dispensation accuracy.SOLUTION: The automatic analyzer has dispensation means including a dispensation nozzle for dispensing a predetermined amount of measurement liquid, a negative pressure generation source for absorbing/discharging the measurement liquid into/from the dispensation nozzle, a dispensation passage for connecting the negative pressure generation source to the dispensation nozzle, and a transmission liquid supply mechanism for supplying a liquid serving as pressure transmission medium into the dispensation passage. The automatic analyzer further includes a bypass passage for supplying the liquid to the way of the dispensation passage as rinse water and isothermal control means for controlling temperature so that the temperature of rinse water supplied to the way of the dispensation passage becomes equal to the fluid temperature of the dispensation nozzle.

Description

  The present invention relates to an automatic analyzer for performing qualitative / quantitative analysis of biological samples such as blood and urine, and more particularly to an automatic analyzer having a dispensing mechanism for dispensing a predetermined amount of a sample, a reagent or the like. .

  In general, automatic analyzers perform qualitative and quantitative analysis of sample components such as blood or urine, and in order to ensure analysis accuracy, the mixing ratio of sample and reagent dispensing amounts is important. In addition, the accuracy of the dispensing amount of the reagent is required.

  In a conventional automatic analyzer, the dispensing mechanism is composed of a pipe filled with ion exchange water using a movable plunger driven by a syringe tube and a pressure transmission medium inside, and a dispensing nozzle. Dosing amount is controlled. Every time the sample to be dispensed changes, the inside and outside of the dispensing probe is washed to suppress the influence of the carry over on the analysis results. A method using is generally used.

  In order to ensure the accuracy of the dispensed volume, it is required that the volume change during the dispensing operation of the ion exchange water, which is the pressure transmission medium, is extremely small relative to the dispensed volume, and the generation of bubbles due to pressure fluctuations is suppressed. For this purpose, deaerated water is used.

  In addition, there is a concern that the dispensing accuracy may be affected by the temperature change in the pipe. In the invention described in Patent Document 1, although it is a method using gas as a pressure transmission medium, it is equipped with a temperature sensor and is detected by the temperature sensor. It is stated that the dispensing volume is fair based on the value.

Japanese National Patent Publication No. 11-509623

  In recent years, emphasis has been placed on reducing the amount of reaction solution per analysis item for the purpose of dealing with trace samples such as children, reducing the burden on patients, reducing the amount of waste from environmental considerations, and reducing reagent costs. / Because it is necessary to ensure the ratio of reagents, the amount of dispensing in specimens is being reduced.

  Moreover, the volume change of the system water, which is the pressure transmission medium of the dispensing pipe, is caused by the variation in the internal temperature of each part including the syringe, the fluid temperature starting from the supply temperature of the system water, and the ambient temperature. Caused by piping temperature difference. Therefore, the volume change in the piping changes with the amount of movement of the system water in the piping during the dispensing operation. With regard to the amount of movement of system water during the dispensing operation, the cleaning operation is more than tens of times the amount of specimen aspiration and discharge, and the volume changes depending on whether or not washing is included during the dispensing operation. The amount varies greatly.

  In addition, the volume change with and without the cleaning operation is constant when the cleaning time is considered to be constant regardless of the dispensing volume. It grows with the development.

  Actually, the cleaning range of the probe contamination range is difficult to reduce by volume ratio considering that the amount of dust is sucked and discharged with respect to the actual dispensing amount. The effect of accuracy is a problem associated with the small amount of dispensed water.

  In addition, there is a means to control the temperature in the entire flow path in order to suppress the volume change of the system water in the flow path, but there are many thermal fluctuation factors in the automatic analyzer, and it is difficult to control the entire flow path. . It is also effective to shorten the length of the affected pipe by making the syringe mechanism and the nozzle drive mechanism as close as possible.

  However, since the syringe mechanism needs to visually check the replacement maintenance and operation state of the drive seal portion, the arrangement of the syringe mechanism is limited to a place with good accessibility on the device, and the nozzle drive mechanism is also limited by other device layouts. If this is included, there are many cases where it is difficult to realize an arrangement configuration in which the two mechanisms are close to each other. In addition, when temperature control of the entire system is considered, the syringe mechanism itself has a drive unit, so there is also a potential to affect heat.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an automatic analyzer provided with a dispensing means that copes with the above-described problems and suppresses a drop in dispensing accuracy due to a temperature change.

  The present invention communicates a dispensing nozzle for dispensing a predetermined amount of a measuring liquid, a negative pressure generating source for causing the dispensing nozzle to suck and discharge the measuring liquid, and a negative pressure generating source and the dispensing nozzle. In an automatic analyzer having a dispensing means having a dispensing channel and a transmission liquid supply mechanism for supplying a liquid as a pressure transmission medium in the dispensing channel, the liquid is washed in the middle of the dispensing channel. A bypass channel supplied as water and an isothermal control means for controlling the temperature of the wash water supplied in the middle of the dispensing channel to be equal to the fluid temperature of the dispensing nozzle are provided.

The present invention also provides a dispensing nozzle for dispensing a predetermined amount of the measuring liquid, a negative pressure generating source for causing the dispensing nozzle to suck and discharge the measuring liquid, the negative pressure generating source, A dispensing flow path that communicates with the dispensing nozzle, a transmission liquid supply mechanism that supplies liquid as a pressure transmission medium in the dispensing flow path,
In an automatic analyzer having a dispensing means comprising a bypass channel for supplying cleaning water in the middle of a dispensing channel, a cleaning water supply mechanism for supplying cleaning water, and a middle of the dispensing channel. And isothermal control means for controlling the temperature of the washing water to be equal to the fluid temperature of the dispensing nozzle.

  According to the present invention, in dispensing a sample or a reagent, a high-precision dispensing that suppresses a drop in dispensing accuracy due to a temperature change caused by a nozzle internal cleaning operation without being affected by the arrangement of the flow path of the syringe unit. It is possible to provide an automatic analyzer equipped with a dispensing mechanism having a dispensing accuracy.

  Hereinafter, the present invention will be described with reference to the drawings.

  First, the embodiment shown in FIG. 1 will be described. Dispensing means of the automatic analyzer according to the present embodiment includes a syringe 1 (negative pressure generation source), a pipe 3 for dispensing (dispensing flow path), and a water supply tank 9 (transfer liquid) containing a liquid of a pressure transmission medium. Supply mechanism), pump 8 (sends the liquid of the pressure transmission medium), dispensing nozzle 2 for dispensing the sample in the sample container 10, three-way joint 4 (communication portion), bypass pipe 12 (bypass channel), bypass Solenoid valve 5 for use (supply valve for bypass), solenoid valve 7 for syringe (supply valve for syringe), temperature control unit 6 (isothermal control means), plunger drive mechanism 11, plunger 13, and water supply tank 9 A main supply pipe 20 (main supply flow path) connecting the suction side of the pump 8 and a syringe supply pipe 21 (syringe supply flow path) connecting one of the discharge side of the pump 8 and the electromagnetic valve 7 are provided. The bypass pipe 12 is connected to the other side of the discharge side of the pump 8.

The transmission liquid supply mechanism includes the water supply tank 9, the pump 8, the main supply pipe 20, the syringe supply pipe 21, and the electromagnetic valve 7. The discharge side of the pump 8 is divided into two hands. The flow path is divided into a transmission liquid supply flow path connected to the syringe supply pipe 21 and a wash water supply flow path connected to the bypass pipe 12. As the liquid in the water supply tank 9, the liquid supplied from the transmission liquid supply channel to the pipe 3 for dispensing (dispensing channel) is used as the transmission liquid, and the liquid supplied from the bypass pipe 12 to the dispensing nozzle 2 is washed. Use water.

  The pressure transmission medium in the dispensing operation from the syringe 1 is replenished as ion exchange water from the water supply tank 9 via the pump 8, and the flow path is blocked by the electromagnetic valve 7. Since the water supply tank 9 is replenished with water via a customer-side water supply facility, the temperature may differ from the device environment depending on the environment, which is one of the causes of volume change during dispensing. Further, the ion exchange water is also supplied from the pump 8 to the bypass pipe 12 between the syringe 1 and the dispensing nozzle 2. In this configuration, ion-exchanged water is used as the liquid / washing water for the pressure transmission medium. Further, replenishment of the bypass pipe 12 and blockage of the flow path are controlled by the electromagnetic valve 5.

  The procedure for dispensing a specimen based on this configuration is shown below.

  If air bubbles stay during the dispensing operation, it becomes a damper and may affect the dispensing accuracy. Therefore, as an initial operation, the solenoid valve 7 and the solenoid valve 5 are opened in the drive state of the pump 8, and the entire area in the flow path is opened. The air bubbles are discharged and filled with ion exchange water as a pressure transmission medium.

  The sample dispensing operation includes the plunger 13 including a ball screw and a pulse motor in a state where the dispensing nozzle 2 is immersed in the sample container 10 with the solenoid valve 7 and the solenoid valve 5 closed. The plunger is driven downward by the plunger drive mechanism 11, and the amount of suction is controlled by controlling the amount of lowering. Before performing the sample aspirating operation, it is desirable to aspirate the air layer between the system water (ion exchange water of the pressure transmission medium) in the pipe (dispensing flow path) and the sample in order to prevent mixing.

  In addition, in order to prevent the specimen from thinning, the specimen is generally aspirated together with a dummy specimen in addition to the actual dispensing specimen. After the sample is aspirated, the dispensing nozzle 2 is raised and moved, and lowered into the reaction container. Then, the plunger drive mechanism 11 is controlled, and the plunger 13 is moved up by the amount corresponding to the target dispensing amount, thereby supplying the system water. The specimen is ejected through.

  In addition, internal cleaning of the nozzle after the discharge operation is not indispensable for multiple measurements within the same sample, but when the sample is switched, there is a concern that the analysis result may be affected by the carry-over, so that the inside of the nozzle Cleaning is required. When the cleaning operation is not included, the movement amount of the system water in the pipe 3 depends on the suction amount / pipe diameter, but is about several CMs, and the risk of undergoing a temperature change is low.

  However, when the cleaning water amount necessary for carrying over prevention is passed, the movement amount of the system water in the pipe 3 is more than tens of times the movement amount (several CM), and the cleaning liquid is temporarily passed through the syringe. It is difficult to prevent the influence when the arrangement distance restriction and the temperature control of the temperature inside the apparatus are taken into consideration. Further, the pipe length that is affected by temperature during the cleaning operation is also from the solenoid valve 7 to the dispensing nozzle 2.

  Therefore, in the embodiment of the present invention, the bypass channel 12 is connected (communication) in the middle of the pipe 3 for dispensing (dispensing channel), and the washing water is supplied as close as possible to the dispensing nozzle 2. . The bypass channel 12 was connected to the pipe 3 for dispensing (dispensing channel) via the solenoid valve 5 and the nipple 4. Since the nipple 4 is as close as possible to the dispensing nozzle 2, the temperature influence range is narrowed from the electromagnetic valve 5 to the dispensing nozzle 2. Since only the electromagnetic valve 5 and the nipple 4 are configured, the flow path for supplying the cleaning water can be configured to be short. Compared with the conventional cleaning water supply flow path comprising the water supply tank 9, the syringe 1, and the pipe 3 for dispensing, the influence of the temperature change can be minimized.

  In addition, in order to prevent a volume change accompanying the inflow of the washing water, the temperature of the system water (washing water) flowing into the electromagnetic valve 5 is also the same as the temperature of the dispensing flow path from the electromagnetic valve 5 to the dispensing nozzle 2. Therefore, the fluid temperature is controlled isothermally by the temperature control unit 6 (isothermal control means) before flowing into the electromagnetic valve 5. Temperature control measures the temperature in the vicinity of the dispensing nozzle as a reference, and there is also a means realized by PID control of a heater or refrigerator (heating or cooling means), but a heat exchange part is provided in the vicinity of the dispensing nozzle It may be a configuration. In this case, it is necessary to control the temperature of a region that exceeds the amount of water consumed for the cleaning operation.

  Further, the isothermal control means is a dispensing nozzle so that the amount of water supplied per time in the washing operation using the washing water can be stored in a temperature difference that does not affect the dispensing accuracy of the measurement liquid. Temperature control is performed in one cycle time of dispensing operation including cleaning, sample aspiration, and discharge. The dispensing nozzle can be quickly cleaned for each dispensing of different specimens.

  The temperature effect of the washing water and the isothermal control will be further described.

  The main factor that affects the temperature of the wash water is the volume change of the water due to the temperature difference between the pipe (dispensing flow path) and the water in the pipe. (This is the sum of the entire flow path of the local volume change ΔV based on the temperature difference between the piping after the cleaning operation and the piping water temperature.) Ideally, the temperature of the piping is constant and the temperature of the inflowing cleaning solution is the same. If it does, the phenomenon will not occur.

  However, it is difficult to control the entire piping path to the same temperature because the distance between the syringe section and the dispensing nozzle requires a dispositional distance and is affected by surrounding units. For this reason, if it is a bypass flow path, it can be connected to the vicinity of the dispensing nozzle, and the flow path that is the main cause of temperature influence (from the bypass solenoid valve to the dispensing nozzle) can also be limited. The influence of temperature can be reduced by allowing the cleaning liquid to flow into the ambient temperature of the limited flow path region under isothermal control.

  Another embodiment shown in FIG. 2 will be described. This embodiment is characterized in that the cleaning water supply mechanism is provided separately from the transmission liquid supply mechanism. A liquid feed pump 14 that is different from the pump 17 that supplies the ion exchange water in the water supply tank 9 to the syringe 1 is provided. The washing water in the washing water supply tank 15 is supplied to the bypass channel 12 by the liquid feed pump 14. The cleaning water supply mechanism for supplying cleaning water includes a water supply tank 15 for cleaning water and a pump 14 for supplying cleaning water. Other configurations are the same as those of the embodiment shown in FIG.

  In the embodiment shown in FIG. 1 described above, ion exchange water is used for both the pressure transmission medium from the syringe and the washing water. In contrast, in this embodiment, a dedicated cleaning liquid 15 is used as the cleaning liquid 15. The use of physiological saline as a cleaning solution is considered appropriate when considering the effect of cleaning between samples and suppressing the influence on analysis. Moreover, the physiological saline improves the washing efficiency compared to the ion exchange water.

  In this structure, it is necessary to have the liquid feed pump 14 for washing water independently. The method for controlling the temperature of the pipe is the same as that of the first embodiment shown in FIG. 1, and the isothermal control from the solenoid valve 5 to the dispensing nozzle 2 and the temperature of the washing water flowing into the solenoid valve 5 are controlled to be equalized with the flow path. There is a need to.

  Usually, the dispensing nozzle is provided in the dispensing drive mechanism. By disposing the communicating part that connects the bypass flow path to the pipe for dispensing (dispensing flow path) in the non-movable part of the dispensing drive mechanism, the temperature effect of the washing water is suppressed without hindering the dispensing operation. Can do.

  The dispensing nozzle generally has a configuration of a circular pipe, but may have any shape because it is for the purpose of sucking and discharging a sample (specimen). Moreover, in order to improve heat insulation, the structure which coat | covered the metal with the material with high heat insulation, such as a double pipe or resin, may be sufficient. The dispensing nozzle may have a liquid level detection function.

  The negative pressure generation source for performing the suction / discharge operation of the sample through the dispensing nozzle includes a drive mechanism that performs movable control of pushing and pulling the plunger connected to the syringe tube with a seal structure, and a diaphragm structure. It may be a micro pump that drives the pump with a motor, a piezoelectric element, or the like.

  In addition, the pressure transmission medium for performing the suction and discharge is not suitable for gas because incompressibility is required when a small amount of sample is dispensed. Therefore, water is generally used as the pressure transmission medium, and it is appropriate to use deaerated water in order to prevent foaming effects. However, any medium having incompressibility may be used. Absent. The piping is generally a resin tube or a metallic pipe, but it is desirable to have a structure that takes heat insulation into consideration.

  The pressure transmission medium connected to the negative pressure generation source and the cleaning liquid connected to the bypass channel may be the same solution. When the same solution is used, the liquid supply mechanism may have the same structure.

  The supply valve (solenoid valve) in the bypass piping that supplies the cleaning liquid is either a system that connects a T-shaped nipple that bypasses the two-way valve or a three-way valve (a valve that combines the solenoid valve and the nipple). A control method may be used.

  The method of isothermally controlling the temperature between the cleaning liquid supply valve and the dispensing nozzle is controlled by placing it in a separate temperature control system from the flow path before the cleaning liquid supply valve to the tip of the nozzle in the range affected by the cleaning operation. Or a method in which only the influence of the internal heat source is suppressed by a fan or the like so that the region at the nozzle tip from the cleaning liquid supply valve becomes room temperature, and only the inflow temperature of the cleaning liquid is thermally controlled.

It is a figure which shows the schematic structure of the dispensing mechanism with which the Example of this invention is mounted in an automatic analyzer. FIG. 10 is a diagram illustrating a schematic configuration of a dispensing mechanism mounted on an automatic analyzer, according to another embodiment of the present invention.

DESCRIPTION OF SYMBOLS 1 ... Syringe 2 ... Dispensing nozzle 3 ... Piping 4 ... 3-way joint 5 ... Solenoid valve 6 ... Temperature control unit 7 ... Solenoid valve 8 ... Pump 9 ... Water supply tank 10 ... Sample container 11 ... Plunger drive mechanism 12 ... Bypass piping 13 ... plunger 14 ... pump 2
15 ... Water supply tank for washing water (saline)
20 ... Main supply pipe 21 ... Syringe supply pipe

Claims (6)

A dispensing nozzle for dispensing a predetermined amount of the measuring liquid;
A negative pressure generating source for causing the dispensing nozzle to suck and discharge the measurement liquid;
A dispensing flow path communicating the negative pressure generating source and the dispensing nozzle;
A transmission liquid supply mechanism for supplying a liquid as a pressure transmission medium into the dispensing flow path;
In an automatic analyzer having a dispensing means comprising
A bypass flow path for supplying the liquid as wash water in the middle of the dispensing flow path;
An automatic analyzer comprising an isothermal control means for controlling the temperature of the wash water supplied in the middle of the dispensing flow path to be equal to the fluid temperature of the dispensing nozzle. The automatic analyzer according to claim 1, wherein
An automatic analyzer characterized in that a communication portion for communicating the bypass channel with the dispensing channel is provided in the vicinity of the dispensing nozzle. The automatic analyzer according to claim 1, wherein
The isothermal control means cleans the dispensing nozzle so that the amount of water supplied at a time in the washing operation using the washing water can be stored in a temperature difference that does not affect the dispensing accuracy of the measurement liquid. An automatic analyzer characterized in that the temperature is controlled in one cycle time of a dispensing operation including aspiration and discharge of a specimen. The automatic analyzer according to claim 1, wherein
2. The automatic analyzer according to claim 1, wherein the isothermal control means includes heating and cooling means provided in the bypass flow path. A dispensing nozzle for dispensing a predetermined amount of the measuring liquid;
A negative pressure generating source for causing the dispensing nozzle to suck and discharge the measurement liquid;
A dispensing flow path communicating the negative pressure generating source and the dispensing nozzle;
A transmission liquid supply mechanism for supplying a liquid as a pressure transmission medium into the dispensing flow path;
In an automatic analyzer having a dispensing means comprising
A bypass flow path for supplying cleaning water in the middle of the dispensing flow path;
A cleaning water supply mechanism for supplying the cleaning water;
An automatic analyzer comprising an isothermal control means for controlling the temperature of the wash water supplied in the middle of the dispensing flow path to be equal to the fluid temperature of the dispensing nozzle. The automatic analyzer according to claim 1 or 5,
A nozzle drive mechanism for turning the dispensing nozzle up and down;
An automatic analyzer characterized in that a nozzle drive mechanism is provided in a place where the dispensing channel and the bypass channel communicate with each other.

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