JPH0577765U - Sampling device for automatic chemical analyzer - Google Patents

Abstract

(57) [Abstract] [Purpose] To prevent the formation of a liquid bridge between the sampling nozzle and the liquid level sensor electrode, and to prevent the distance from changing. A liquid level sensor electrode 18 is provided around a side portion of the sampling nozzle 2 via an insulating member 16, and the tip of the liquid level sensor electrode 18 is set at a position slightly retracted from the tip of the sampling nozzle 2. It is set. The insulating member 16 exists up to the tip of the sampling nozzle 2,
The tip of the sampling nozzle 2 has a tip end surface which is tapered and covers the tip of the electrode 18. A conducting circuit 8 for liquid level detection is connected between the sampling nozzle 2 and the electrode 18.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to an automatic chemical analyzer for performing biochemical tests and other chemical analyzes of samples such as blood and urine, and to a sampling device for dispensing samples and reagents into a reaction container.

[0002]

[Prior Art]

 In an automatic chemical analyzer, a sample such as blood is dispensed into a reaction container, and a reagent is added to the sample for each measurement item to detect the reaction between the sample and the reagent. In a sample dispensing mechanism for dispensing a sample into a reaction container and a reagent dispensing mechanism for dispensing a reagent, a sampling device equipped with a sampling nozzle for sucking a sample or a reagent and discharging it into a reaction container is used. The sampling device is provided with a sampling nozzle and a liquid level sensor for detecting the liquid level of a sample or a reagent.

An example of a conventional sampling device is that shown in FIG. 1 or 2. In FIG. 1, the sampling nozzle 2 and the electrode 4 of the liquid level sensor are integrally formed in a state of being insulated by an insulating member 6. The tip of the sampling nozzle 2 and the tip of the electrode 4 both project from the insulating member 6. A conduction circuit 8 is provided between the sampling nozzle 2 and the electrode 4 in order to detect the liquid level by detecting the conduction between the sampling nozzle 2 and the electrode 4. Taking the case of sampling the sample as an example, the sampling nozzle 2 and the electrode 4 of the liquid level sensor are immersed in the sample 12 contained in the sample container 10 to suck the sample. When the sampling nozzle 2 and the electrode 4 come into contact with the liquid surface of the sample 12, the sampling nozzle 2 and the electrode 4 are electrically connected, and the liquid level is detected by the conduction circuit 4.

In the sampling device of FIG. 2, a part (for example, the bottom surface) 14 of the sample container 10a is composed of a conductive member, and liquid level detection is performed between the sampling nozzle 2 and the conductive member 14 of the sample container. The conduction circuit 8 for use is connected. In the case of FIG. 2, one sampling nozzle is used, and the liquid level is detected from the difference in dielectric capacitance between when the tip of the sampling nozzle 2 is in the air and when it is in the sample 12.

[0005]

[Problems to be solved by the device]

 When dispensing a sample that is a sampling device and then another sample, or when dispensing a reagent and then another reagent, the tip of the sampling nozzle is washed with washing water. In the sampling device shown in FIG. 1, the cleaning liquid adheres to the sampling nozzle 2 and the electrode 4 (hereinafter referred to as a bridge) due to the contamination of the sampling nozzle 2 and the increase / decrease in the amount of cleaning water. The conduction circuit 8 may detect conduction when the surface is not touched, or the electrode 4 may collide with the reaction container and the distance between the sampling nozzle 2 and the tip of the electrode 4 may change to detect the liquid level. There is a drawback that the electrical conductivity at that time changes. In addition, the sampling device in Fig. 2 has low sensitivity for detecting the liquid level, and the distance from when the sampling nozzle 2 reaches the liquid level until it stops is not constant, and is effective even near the bottom of the sample container or reagent bottle. It has the drawback that it cannot be sucked. Further, in the case of FIG. 2, there is also a problem that the conductivity and the dielectric constant of the material of the sample container, the cup holder holding the sample container, or the reagent bottle are restricted. The present invention has a highly sensitive liquid level sensor that prevents liquid bridges between the sampling nozzle and the liquid level sensor electrode from changing and the gap between them, and prevents malfunctions when detecting the liquid level. It is intended to provide a sampling device.

[0006]

[Means for Solving the Problems]

 In the present invention, the electrode of the liquid level sensor is integrally provided to the sampling nozzle via an insulating member, the tip of the liquid level sensor electrode is positioned at a position retracted from the tip of the sampling nozzle, and the electrode of the liquid level sensor electrode is positioned. The tip surface is covered with the insulating member.

[0007]

[Action]

 Since the tip surface of the liquid level sensor electrode is covered with the insulating member, even if the cleaning water is attached to the tip portion of the sampling nozzle, a short circuit between the sampling nozzle and the electrode is unlikely to occur due to the attached liquid. Further, since the tip of the liquid level sensor electrode does not project and is covered with an insulating member, the distance between the tip of the sampling nozzle and the tip of the electrode may change even if the tip of the sampling device collides with a reaction container or the like. There is no.

[0008]

【Example】

 FIG. 3 shows an embodiment. The same parts as those in FIG. 1 are designated by the same reference numerals. In FIG. 3, a liquid level sensor electrode 18 is provided around the side of the sampling nozzle 2 via an insulating member 16 and concentrically with the sampling nozzle 2. The tip of the liquid level sensor electrode 18 is set to a position slightly retracted from the tip of the sampling nozzle 2. When the distance D between the tip of the electrode 18 and the tip of the sampling nozzle 2 is too large, the amount of the sample or reagent that cannot be inhaled and remains will increase and waste will increase. The insulating member 16 exists up to the tip of the sampling nozzle 2, and the tip portion of the sampling nozzle 2 has a tip surface that is tapered and covers the tip of the electrode 18. A conducting circuit 8 for liquid level detection is connected between the sampling nozzle 2 and the electrode 18. This sampling device is attached to, for example, the tip of an arm so that it can be moved between the sample container (or reagent container) and the reaction container and washing pot.

The operation of the embodiment shown in FIG. 3 will be described. When inhaling the sample, the sampling device descends toward the sample, the sampling nozzle 2 first contacts the liquid surface of the sample, and then the electrode 18 contacts the liquid surface. When the tip of the electrode 18 touches the liquid surface, the potential of the conducting circuit 8 changes and the liquid surface is detected. Therefore, the descending of this sampling device is stopped, and information on the suction amount is sent from, for example, a computer so that the liquid does not run out and it is stopped at the shortest distance. Next, the sample is sucked, the sampling device moves to the reaction container, and the sucked sample is discharged. Then, after moving to the washing pot and washing the sampling nozzle, the same operation is repeated. The same operation is performed when the reagent is used for dispensing.

FIG. 4 shows another embodiment. In FIG. 3, the electrode 18 of the liquid level sensor is configured to surround the side of the sampling nozzle 2, whereas in the embodiment of FIG. 4, the electrode 20 is placed on the insulating member 16 surrounding the side of the sampling nozzle 2. It is formed in a band shape along the axial direction.

FIG. 5 shows an example of a biochemical automatic analyzer to which the present invention is applied. A sample such as blood is put in a sample container, and a sample rack 22 in which a plurality of sample containers are arranged is moved along a belt conveyor type transport path 24. The transport path 24 is composed of an outward path 24a for transferring the sample rack 22 from left to right in the figure and a reverse path 24b for transferring the sample rack from right to left. In the figure, a sample rack supply section 26 for sending the sample rack 22 to the outward path 24a is provided at the left end portion of the outward path 24a, and a storage section 28 for accommodating the sample rack 22 after the measurement is provided at the left end portion of the return path 24b. Is provided. In the figure, at the right end portion of the transport path 24, there is provided a rack standby section 30 for primarily storing the sample rack 22 sent through the outward path 24a and sending it out to the return path 24b. The sample rack 22 is stopped at the sample dispensing positions of the analysis units 46a and 46b during transfer on the outward path 24a and dispensed to the reaction tubes of the analysis units 46a and 46b. In the return path 24b, the sample that needs retesting is re-dispensed according to the measurement result of the sample dispensed and measured in the outward path 24a.

Two analysis units 32 a and 32 b are arranged along the transport path 24. Both have the same structure. In each analysis unit, a reaction disk 34 in which a reaction container 35 also serving as a cuvette is arranged is arranged near the transport path 24, and in the transport paths 24a and 24b, a sample is dispensed at a sample dispensing position near the reaction disk 34. A stop device (not shown) for stopping the rack 22 is provided. A pipettor 36 having a nozzle is arranged to dispense a sample into the reaction container 35 from the sample rack 22 stopped on the transport path 24a or 24b. Each of the analysis units 32a and 32b is provided with two turntable type reagent storages 38a and 38b for dispensing a reagent into the reaction container 35, and each of the reagent storages 38a and 38b is provided with a reagent. Dispensers 40a and 40b for dispensing are provided. A cleaning mechanism 42 is provided for cleaning the reaction container after completion of the analysis with the reaction disk 34. The reaction disk 34 is provided with an optical analysis unit for measuring the reaction of the reaction container 35 containing the sample and the reagent, but it is not shown.

The sample rack supply unit 26 and the storage unit 28 are provided with an interface and a CPU 44, each analysis unit 32a and 32b is also provided with an interface and CPUs 46a and 46b, and the standby unit 30 is also provided with an interface. And CPU 48 are provided. The CPUs 44, 46a, 46b and 48 are connected to the main CPU 50. A CRT 52, a keyboard 54 and a printer 56 are further connected to the main CPU 50.

The sampling device of the present invention is not limited to the automatic biochemical analysis device shown in FIG. 5, but can be applied to other various types of automatic chemical analysis devices. The electrodes of the liquid level sensor may be formed not only by a thick plate-shaped member as shown in the embodiment, but also by forming a thin film on the surface of the insulating member 16 by vapor deposition or plating. In that case, the outer shape of the probe portion of the sampling device can be reduced.

[0015]

[Effect of the device]

 In the present invention, since the tip surface of the electrode of the liquid level sensor is covered with the insulating member, the malfunction due to the formation of the liquid bridge and the change in conductivity does not occur. Since the electrode of the liquid level sensor is provided near the sampling nozzle, there is no problem of insufficient sensitivity compared to the one with only the nozzle as shown in Fig. 2, and the processing speed is reduced or the processing speed is increased. The cost increase can be suppressed.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of a probe portion of a conventional sampling device.

FIG. 2 is a cross-sectional view showing another example of the probe portion of the conventional sampling device.

FIG. 3 is a diagram showing a probe portion of one embodiment,
(A) is a vertical sectional view, (B) is a bottom view, and (C) is (A).
3 is a cross-sectional view taken along line XX ′ in FIG.

FIG. 4 is a view showing a probe portion of another embodiment,
(A) is a vertical sectional view, (B) is a bottom view, and (C) is (A).
3 is a cross-sectional view taken along line YY ′ of FIG.

FIG. 5 is a schematic perspective view showing an example of a biochemical automatic analyzer to which the present invention is applied.

[Explanation of symbols]

 2 Sampling nozzle 8 Conducting circuit 10 Sample container 12 Sample 16 Insulating member 18, 20 Electrode of liquid level sensor

Claims (1)

[Scope of utility model registration request] 1. An electrode of a liquid level sensor is integrally provided on a sampling nozzle movably supported between a sample container or a reagent container and a reaction container via an insulating member,
A sampling device in which the tip of the electrode is positioned at a position retracted from the tip of the sampling nozzle, and the tip surface of the electrode is covered with the insulating member.