JP5111328B2 - Automatic analyzer - Google Patents

Description

  The present invention relates to an automatic analyzer that performs qualitative / quantitative analysis on specimens such as blood and urine, and more particularly to an automatic analyzer that includes a dispensing mechanism that transfers a predetermined amount of a liquid such as a sample or a reagent.

  In general, an automatic analyzer is accompanied by an operation (hereinafter referred to as “dispensing”) in which a predetermined amount of a sample from a sample container and a reagent from a reagent container are aspirated and discharged to a reaction container. An automatic analyzer is required to obtain an accurate and reproducible analysis result above all. To that end, it is important to perform the above-described dispensing operation accurately and with good reproducibility.

  On the other hand, in recent years, from the viewpoint of reducing running costs, it is also required to reduce the amount of reaction solution, that is, to reduce the amount of dispensing. In general, the amount of variation relative to the amount of dispensing is relative to the amount of dispensing. However, it is disadvantageous from the viewpoint of improving dispensing accuracy.

  In view of the above, development of a microdispensing technique that has little effect on dispensing accuracy is required.

  In automatic analyzers that perform continuous analysis, the dispensing nozzle draws the sample from the sample container, moves it to the reaction container, discharges the sample to the reaction container, moves to the washing position, and rinses with washing water After that, the sample is moved again to the sample container and dispensed for the next item measurement. Although the above description is related to sample dispensing, since the same applies to reagent dispensing, only sample dispensing will be described below.

  In the above operation, when the dispensing nozzle aspirates the sample and then pulls it up from the sample container, if a part of the sample adheres or remains on the tip of the nozzle, it is brought into the reaction container (see FIG. 2A). ). The same applies when the specimen is discharged from the reaction container and then pulled out from the reaction container. In this case, a part of the specimen is taken out (see FIG. 2B). The former is called sample bring-in and the latter is called sample take-out, and these amounts affect the dispersion of the dispensed amount.

  Further, after washing the dispensing nozzle, the washing water adhering to or remaining at the tip of the nozzle is brought into the specimen container (see FIG. 2C, hereinafter referred to as washing water carry-in), and the specimen is thinned. There is also a problem of errors between items.

  The effect of each liquid adhering to the tip of the dispensing nozzle, especially the effect on analysis accuracy, increases as the dispensed amount becomes smaller, so a problem that must be solved in order to reduce the amount of the reaction solution one of.

  As an approach to the above problem, it is possible to either prevent adhesion or remove after adhesion.

  As a method for preventing the liquid from adhering, surface treatment such as electrolytic polishing and water repellent coating may be applied to the tip of the dispensing nozzle. However, the current situation is that the effect is not maintained due to dirt, peeling of the water repellent coating, and the like.

  Moreover, as a method of removing after adhering, Patent Document 1 describes a method of applying a blow air current to the tip of a dispensing nozzle.

  Patent Documents 2 and 3 describe examples in which a pump or a solenoid valve is used as a method for applying a blown airflow.

JP-A-57-127853 JP 2004-101480 A JP 2000-74929 A

  Although it is desirable to improve the dispensing accuracy by removing the liquid adhering to the tip of the dispensing nozzle, the dispensing sequence increases. However, it is not desirable to extend the dispensing cycle time and sacrifice the dispensing throughput. Therefore, it is desirable that the dispensing nozzle tip attached liquid removing function can be added without changing the conventional dispensing cycle time. That is, it is desirable that gas can be ejected while the dispensing nozzle is moving without stopping the operation of the dispensing nozzle at the stage where the dispensing nozzle is separated from the liquid surface and the gas should be ejected.

  In the above-mentioned patent document, although the examination around that has not been made, as a first conceivable method, a method of controlling gas ejection in a sequence, that is, a state in which the dispensing nozzle starts to rise from a state in which it has entered the liquid and is constant A method of ejecting gas after time can be considered. However, if the timing is too late, the dispensing nozzle rises while the liquid is attached to the tip, and the attached liquid is scattered from a high position. If droplets are mixed with another specimen, there is a risk of erroneous measurement. If the droplets adhere to the apparatus, there is a risk of not only contamination of the apparatus but also infection during cleaning. On the other hand, if the timing is too early, the tip of the dispensing nozzle may not be separated from the liquid level, or it may be ineffective due to splashing when the liquid level passes.

  An object of the present invention is to provide an automatic analyzer that includes a dispensing mechanism that includes a mechanism that removes liquid adhering to the tip of a dispensing nozzle and is less likely to affect other components during removal.

  As means for solving the above problems, the following configuration is adopted.

  That is, a dispensing nozzle for dispensing a specimen or a reagent, a sensor for monitoring the state of the dispensing nozzle, and the dispensing nozzle are engaged, and gas can be ejected to the tip of the dispensing nozzle. In a dispensing device provided with a gas ejection nozzle and a gas supply device that supplies gas ejected from the gas ejection nozzle, the gas supply device is controlled according to the state of the dispensing nozzle. The state of the dispensing nozzle is a liquid level sensor that detects whether the liquid level of the liquid to be dispensed is in contact with the tip of the dispensing nozzle (detects whether the dispensing nozzle is in contact with other objects) It can be detected using a contact sensor, a pressure sensor (which detects the pressure in the dispensing nozzle), or the like.

  The present invention has the following effects.

  That is, the original purpose of minimizing sample / reagent carry-in / take-out and thereby minimizing the variation in the dispensed amount can be realized without inconveniences such as a reduction in processing capacity and sample scattering.

  In addition, the purpose of minimizing the amount of washing water brought in and minimizing errors caused by thinning can be realized without inconveniences such as a reduction in processing capacity and scattering of specimens.

  Furthermore, after removing the liquid adhering to the tip of the dispensing nozzle, there is no fear that the specimen will be scattered even if the dispensing nozzle is moved at high speed. Therefore, the processing capability of the system can be increased by actively moving at high speed.

  Further, by combining the present invention with the liquid level detection function, reliable liquid level detection is possible, so that the reliability of dispensing can be improved.

  FIG. 1 shows a dispensing apparatus of the present invention.

  Dispensing nozzle 1 composed of a hollow tube is connected to syringe 4 via pipe 3, and further, water supply pump 6 and water supply tank 7 are connected via electromagnetic valve 5, and the inside of the flow path is water (system water) 8. be satisfied. The main dispensing operation for specimens and reagents is performed with the above-described configuration. That is, the specimen and reagent are dispensed by the reciprocating motion of the plunger 9 in the syringe, and the inside of the dispensing nozzle is cleaned by the system water supplied by the water supply pump, which is switched by the electromagnetic valve.

  On the other hand, the gas ejection nozzle 2 is engaged with the dispensing nozzle, and the opening of the gas ejection nozzle is directed to the tip of the dispensing nozzle. Even if the dispensing nozzle and the gas ejection nozzle have a structure in which two nozzles are arranged in parallel, either the structure in which the dispensing nozzle is arranged in a concentric shape with the inner pipe and the gas ejection nozzle as an outer pipe, either I do not care. There may be a plurality of gas ejection nozzles.

  The gas ejection nozzle is connected to the gas supply device 11 via the pipe 10, and the ejection gas is supplied from here. As the gas supply device, a combination of an air pump and a solenoid valve, or a mechanism like an air cannon can be considered.

  The dispensing nozzle and the gas ejection nozzle engaged with the dispensing nozzle can be moved to predetermined positions such as the inside of the sample container and the reaction container by a driving device (not shown). Driving methods include θ-z driving and xyz driving.

  By the way, the dispensing nozzle is provided with various detection functions in order to monitor its state. This has been introduced in many documents and is actually implemented in many devices.

  For example, Japanese Patent Laid-Open No. 2000-213978 describes an example in which a dispensing nozzle has a liquid level detection function.

  Japanese Patent Application Laid-Open No. 2001-91522 describes an example in which a dispensing nozzle has a contact detection function.

  As an in-pipe pressure detection function of the dispensing nozzle, an example of Japanese Patent Application Laid-Open No. 2004-125780 in which a pressure sensor is incorporated in a dispensing flow path is given.

  The present invention is to control the gas supply device so as to optimize the timing of removing the attached liquid based on the signals of these detection functions.

  Signals obtained from the various detectors 12 are sent to the control unit 13, which controls the gas supply device according to the flow of FIG.

  Hereinafter, it demonstrates according to the flow of actual dispensing. Since the flow of the sample dispensing and the reagent dispensing are almost the same, the sample dispensing will be described here.

  The dispensing nozzle moves onto the specimen container 14 and descends while effecting the liquid level detection. When a liquid level detection signal is received, the dispensing nozzle stops the descent due to the signal interruption. In this state, the sample is aspirated. After the sample is aspirated, the dispensing nozzle starts to rise, and the liquid level is also monitored at this time. The controller continues to rise until a signal for detaching the liquid level is received, and when the signal is received, the control unit issues a command to eject gas to the gas supply device. As a result, the sample adhering or remaining at the tip of the dispensing nozzle is blown back to the sample container, and the sample can be kept to a minimum. Thereafter, the dispensing nozzle may be moved at high speed as necessary. It should be noted that the period from when the signal is received until the gas is ejected may be sandwiched for a predetermined time at the same time.

  After sample aspiration, the dispensing nozzle moves onto the reaction vessel 15 and descends into the reaction vessel. In many cases, the reaction vessel descends while searching the bottom of the reaction vessel using a liquid level sensor or a contact sensor. Here, consider the case of descending while using the contact sensor. When the dispensing nozzle hits the bottom of the reaction vessel, the contact sensor enters and stops descending. In this state, the specimen is discharged. In such a case, in many cases, the tip of the dispensing nozzle is cut obliquely and the device is capable of discharging even if the nozzle tip is in contact with the container bottom. When the specimen discharge is finished, the dispensing nozzle starts to rise, but continues to rise until the contact sensor is turned off, and when it is turned off, the control unit issues a gas ejection command to the gas supply device. As a result, the specimen adhering to the tip of the nozzle is blown down to the reaction container, and the specimen can be taken out to the minimum. It should be noted that a predetermined time may be sandwiched between the time when the contact sensor is turned off and the time when gas is ejected.

  After a series of dispensing operations is completed, the dispensing nozzle moves to the washing tank 16 and is washed. At this time, the liquid level sensor is utilized. In addition to cleaning the inside of the dispensing nozzle with system water, washing is performed by applying washing water from the outside to the outer wall of the dispensing nozzle. The control unit issues a gas ejection command to the gas supply device. Thereby, the adhering water is blown off.

  FIG. 4 shows that when the dispensing nozzle descends for sample aspiration, after the liquid level detection is stopped, the gas is ejected and the presence of the liquid level is checked again to ensure that the dispensing nozzle is reliably under the liquid level. It is a method to be able to note. If the surface of the specimen or reagent is bubbling, the bubbling surface may be erroneously detected as a liquid level and stopped. If such a false detection occurs, a predetermined amount cannot be dispensed, leading to poor measurement results. If the present invention is used, reliable liquid level detection is possible, and thus reliability can be improved.

  As shown in FIG. 4, the dispensing nozzle moves onto the sample container and descends while effecting the liquid level detection. When a liquid level detection signal is input, the lowering of the nozzle is stopped by the signal interruption. After that, gas is blown out and the liquid level is confirmed again. Here, if it is determined that there is a liquid level, the process proceeds to the next operation as it is. If it is determined that there is no liquid level, the process returns to lowering the nozzle again. This loop is repeated until it is determined that there is a liquid level after gas ejection, but an alarm may be issued several times.

  Next, the movement when the in-pipe pressure sensor is used will be described.

  The liquids handled by the dispensing device range from low to high in viscosity and wettability, and the degree of adhesion to the dispensing nozzle and the ease of running out of the liquid during gas ejection vary. From the standpoint of removing only the adhering liquid, it is only necessary to strengthen the gas jet. However, it is desirable to avoid the jetting that is unnecessary in terms of energy because the risk of splashing is increased in a liquid with good drainage. It is desirable to be able to control the liquidity. The goodness of liquid breakage is a complicated mechanism such as the viscosity of the liquid and the wettability of the tube, but it can be roughly estimated by measuring the internal pressure during suction. In-pipe pressure sensors used for clogging detection and abnormal suction detection are used, and the flow rate, flow rate, time, etc. of the gas to be ejected are controlled according to this signal.

  FIG. 1 shows a configuration example of an automatic analyzer according to an embodiment of the present invention. An automatic analyzer generally has a specimen disk 101 for setting a specimen in the apparatus, a specimen dispensing apparatus 102 for dispensing the specimen, a reaction cell 103 as a reaction container, and a reaction disk as a holder thereof. 104, a reagent disk 105 for setting a reagent according to a measurement item, a reagent dispensing mechanism 106 for dispensing the reagent, a stirring mechanism 107 for stirring the sample dispensed into the reaction cell and the reagent, A photometer 108 for colorimetrically analyzing the reaction liquid, a washing mechanism 109 for sucking the reaction liquid after the analysis and washing the reaction cell, and a control section thereof. By incorporating the dispensing device of the present invention into either or both of the sample dispensing device and the reagent dispensing device, an automatic analyzer utilizing the advantages of the present invention can be made.

It is a schematic block diagram of the dispensing apparatus in connection with this invention. It is a figure for demonstrating the subject in dispensing operation | movement. It is a figure which shows the algorithm which controls gas ejection using the dispensing apparatus of this invention. An algorithm for reliably detecting the liquid level by using the dispensing apparatus of the present invention to detect the liquid level of the dispensing nozzle, then ejecting gas to the tip of the dispensing nozzle and monitoring the liquid level again will be shown. It is a schematic block diagram of the automatic analyzer which can apply the dispensing apparatus of this invention.

Explanation of symbols

1 Dispensing nozzle 2 Gas ejection nozzle 3 Piping (for dispensing)
4 Syringe 5 Solenoid valve 6 Water supply pump 7 Water supply tank 8 Water (system water)
9 Plunger 10 Piping (for gas ejection)
DESCRIPTION OF SYMBOLS 11 Gas supply apparatus 12 Detector 13 Control part 101 Sample disk 102 Sample dispensing apparatus 103 Reaction cell 104 Reaction disk 105 Reagent disk 106 Reagent dispensing apparatus 107 Stirring mechanism 108 Photometer 109 Cleaning mechanism

Claims (3)

A dispensing nozzle for dispensing liquid;
A state monitoring sensor for monitoring the state of the dispensing nozzle;
A gas ejection nozzle that is engaged with the dispensing nozzle and ejects gas to the tip of the dispensing nozzle;
A gas supply device for supplying gas ejected from the gas ejection nozzle;
A control mechanism for controlling the gas supply device based on information from the state monitoring sensor,
The state monitoring sensor is a contact sensor that detects whether or not the dispensing nozzle is in contact with the bottom of the reaction container when the dispensing nozzle discharges the liquid into the reaction container.
Controlling gas ejection of the gas supply device based on an off signal of the contact sensor accompanying the rise after the liquid ejection of the dispensing nozzle that has been in contact with the reaction container bottom during the liquid ejection. Automatic analyzer characterized by The automatic analyzer according to claim 1, wherein
Furthermore, the pressure sensor which detects the pressure in the nozzle of a dispensing nozzle is provided, The flow volume of the gas which the said gas supply apparatus ejects, the flow velocity, or the injection time is controlled according to the signal of the said pressure sensor. Automatic analyzer. The automatic analyzer according to claim 1 or 2,
An automatic analyzer comprising a control mechanism for controlling the dispensing nozzle to move at a high speed after gas is ejected from the gas ejection nozzle .

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