WO2010032507A1

WO2010032507A1 - Dispensing device, automatic analyzing device, and dispensing failure confirming method

Info

Publication number: WO2010032507A1
Application number: PCT/JP2009/055462
Authority: WO
Inventors: 仁啓加瀬
Original assignee: オリンパス株式会社
Priority date: 2008-09-17
Filing date: 2009-03-19
Publication date: 2010-03-25
Also published as: JP2010071766A

Abstract

Provided are a dispensing device, an automatic analyzing device and a dispensing failure confirming method, which can confirm a dead suction due to an erroneous detection of a liquid level or a dispensing failure due to probe clogging, thereby to avoid an erroneous analysis. A dispensing device (5) or (7) uses a dispensing probe (50) to suck the sum of a liquid necessary for the analysis and a dummy liquid from a specimen container (22) or a reagent container (42), discharges the dummy liquid under the control of a dispensing control unit (109) from the specimen container (22) or the reagent container (42), detects the electrostatic capacity change between the dispensing probe (50) and an electrode (4a) at the discharge time by a voltage detecting circuit (113), and decides whether or not the dispensing probe (50) has discharged the liquid, on the basis of the electrostatic capacity change, by a liquid discharge deciding unit (106).

Description

Dispensing device, automatic analyzer and dispensing failure confirmation method

The present invention relates to a dispensing apparatus for dispensing a specimen or a reagent, an automatic analyzer equipped with the dispensing apparatus, and a dispensing failure confirmation method.

Conventionally, in an automatic analyzer that analyzes the components of a sample by reacting the sample with a reagent, when dispensing the sample or reagent, the sample is reliably aspirated and the probe is inserted into the sample or the reagent to minimize the distance between the samples. Or, to prevent carryover between reagents, change in capacitance between the probe itself or an electrode provided near the probe and an electrode provided integrally with or near the specimen or reagent container is detected. An electrostatic capacitance type liquid level detection mechanism is employed.

In such a capacitance type liquid level detection mechanism, the liquid level may be erroneously detected by static electricity charged in the liquid container, and in order to prevent this, the liquid level detection is provided with a mechanism for eliminating the charge of the liquid container. A mechanism is known (see, for example, Patent Document 1).

In addition to the liquid level detection mechanism, a pipe pressure measurement mechanism is provided in the pipe to which the dispensing probe is connected, so that the liquid suction state of the sample or reagent is confirmed by pressure, and dispensing abnormalities are detected by pressure changes. A technique is also disclosed (see, for example, Patent Document 2).

Japanese Patent Laid-Open No. 11-271319 JP 2007-285888 A

However, although the liquid level detection mechanism described in Patent Document 1 can eliminate the charge of the specimen or reagent in the container, it is possible to reduce dispensing failures such as empty suction due to erroneous detection of the liquid level. In the case of clogging or the like, defective dispensing occurs, and there is a problem of finding and eliminating dispensing defects due to clogging of the probe.

In addition, although the liquid level detection mechanism described in Patent Document 2 can confirm dispensing failure due to empty suction or probe clogging, it is necessary to mount a pressure detection mechanism, which is problematic in terms of cost and space. there were.

The present invention has been made in view of the above, and a dispensing device, an automatic analyzer, and an automatic analyzer capable of avoiding misanalysis by confirming dispensing failure due to empty suction due to liquid level erroneous detection or probe clogging An object is to provide a method for confirming dispensing failure.

In order to solve the above-described problems and achieve the object, a dispensing device of the present invention includes a dispensing probe that sucks or discharges a liquid that is conductive and stored in a container, and is integrated with the container or the A dispensing device comprising a liquid level detection mechanism that detects a liquid level of the liquid based on a change in capacitance between the dispensing probe and the electrode. A dispensing control means for sucking a total amount of liquid and dummy liquid required for analysis from the container using the dispensing probe and then controlling the dummy liquid to be discharged on the container; Detection means for detecting a change in capacitance between the dispensing probe and the electrode when discharging the dummy liquid by the dispensing control means, and the dispensing based on the change in capacitance detected by the detection means. Whether the probe ejected liquid Determining a liquid discharge judging means, characterized in that it comprises a.

Further, the dispensing device of the present invention is characterized in that, in the above invention, the detection means is the liquid level detection mechanism.

In the dispensing device of the present invention, in the above invention, the capacitance change time between the dispensing probe and the electrode when discharging the dummy liquid is based on the capacitance change detected by the detection means. Measuring means for measuring the liquid discharge, wherein the liquid discharge determination means determines whether the dispensing probe has discharged a predetermined amount of liquid based on the capacitance change time measured by the measurement means. It is characterized by.

Further, the automatic analyzer of the present invention is an automatic analyzer for reacting a specimen and a reagent in a reaction vessel and analyzing the reaction liquid based on the optical characteristics of the reaction liquid, and any one of the above It comprises the dispensing apparatus as described in above.

Further, in the dispensing failure confirmation method of the automatic analyzer of the present invention, the sample and reagent contained in the container are dispensed into the reaction container, and the dispensed sample and reagent are stirred and reacted in the reaction container, A method for confirming dispensing failure of an automatic analyzer that analyzes the reaction liquid based on optical characteristics of the reaction liquid, the liquid level detection step for detecting the liquid level of the liquid in the container based on a change in capacitance A suction step for sucking a total amount of liquid and dummy liquid required for analysis of the liquid in the container using a dispensing probe; and a dummy liquid for discharging the dummy liquid on the container by the dispensing probe. A discharge step; a detection step of detecting a change in capacitance between the dispensing probe and the electrode when discharging the dummy liquid in the dummy liquid discharge step; and a capacitance detected in the detection step Strange The basis, characterized in that it comprises a liquid discharge determining whether the dispensing probe ejected liquid.

Moreover, the dispensing failure confirmation method of the automatic analyzer according to the present invention is the above invention, wherein the dispensing probe and the electrode at the time of discharging the dummy liquid are based on the capacitance change detected in the detection step. Measuring a capacitance change time between, and the liquid discharge determining step is based on the capacitance change time measured in the measurement step, the dispensing probe has discharged a predetermined amount of liquid It is characterized by determining whether or not.

According to the dispensing device, the automatic analyzer, and the dispensing failure confirmation method according to the present invention, the dispensing probe is used to suck the total amount of the liquid and dummy liquid required for analysis from the sample or reagent container, and And detecting a change in capacitance between the dispensing probe and the electrode when discharging the dummy liquid, and determining whether the dispensing probe has discharged the liquid based on the change in capacitance. In addition, it is possible to avoid misanalysis by confirming dispensing failure due to empty suction or probe clogging due to erroneous liquid level detection.

FIG. 1 is a schematic configuration diagram showing an automatic analyzer according to the first embodiment of the present invention. FIG. 2 is a schematic configuration diagram of a sample dispensing apparatus used in the automatic analyzer shown in FIG. FIG. 3 is a schematic configuration diagram of a liquid level detection mechanism used in the sample dispensing apparatus shown in FIG. FIG. 4 is a flowchart of the dispensing failure confirmation method according to the first embodiment of the present invention. FIG. 5 is an operation diagram for confirming dispensing failure according to the first embodiment of the present invention. FIG. 6 is an enlarged view of the dispensing probe when the dummy sample is discharged by the dispensing probe according to the first embodiment of the present invention. FIG. 7 is a diagram showing a change in capacitance when the dummy specimen is discharged according to the first embodiment of the present invention. FIG. 8 is a schematic configuration diagram of a liquid level detection mechanism used in the sample dispensing apparatus according to the second embodiment of the present invention. FIG. 9 is a flowchart of the dispensing failure confirmation method according to the second embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Automatic analyzer 2 Sample table 21, 31, 41 Storage part 22

Sample container

22a,

42a Opening part

23, 43 Reading part 3 Reaction table 32 Reaction container 33 Photometry apparatus 33a Light source 33b Light receiving part 34 Reaction container washing mechanism 35 Stirring part 4 Reagent table 4a Electrode 42 Reagent container 5 Specimen dispensing device 7 Reagent dispensing device 50 Dispensing probe 51 Arm 52 Support shaft 53

Probe transfer section

54a, 54b Tube 55 Syringe 55a Cylinder 55b Plunger 56 Plunger drive 57 Tank 58 Solenoid valve 59

Pump

6, 8 Dispensing probe cleaning device 9 Measurement mechanism 10

Control mechanism

101, 101A Control unit 102 Input unit 103 Analysis unit 104 Storage unit 105

Output unit

106, 106A Liquid discharge determination unit 107 Transmission / reception unit 108 Static Capacitance change time measurement unit 109

Dispensing control unit

11, 11A Liquid level detection mechanism 111 Oscillation circuit 112 Differentiation circuit 113 Voltage detection circuit L1 Pushed liquid O Vertical axis

Hereinafter, the best mode for carrying out the present invention (hereinafter referred to as “embodiment”) will be described with reference to the accompanying drawings. In addition, this invention is not limited by description of this specification.

(Embodiment 1)
FIG. 1 is a schematic configuration diagram showing an automatic analyzer according to the present invention. As shown in FIG. 1, the automatic analyzer 1 controls a measurement mechanism 9 that measures light passing through a reaction product between a specimen and a reagent, and the entire automatic analyzer 1 including the measurement mechanism 9. And a control mechanism 10 for analyzing a measurement result in the measurement mechanism 9. The automatic analyzer 1 automatically performs analysis of a plurality of samples by cooperation of these two mechanisms.

First, the measurement mechanism 9 will be described. The measurement mechanism 9 roughly includes a sample table 2, a reaction table 3, a reagent table 4, a sample dispensing device 5, a reagent dispensing device 7, and dispensing

probe cleaning devices

6 and 8.

The sample table 2 has a disk-like table and includes a plurality of storage units 21 arranged at equal intervals along the circumferential direction of the table. In each storage unit 21, a sample container 22 containing a sample is detachably stored. The sample container 22 has an opening 22a that opens upward. The sample table 2 is rotated in a direction indicated by an arrow in FIG. 1 by a sample table driving unit (not shown) with a vertical line passing through the center of the sample table 2 as a rotation axis. When the sample table 2 rotates, the sample container 22 is transported to the sample aspirating position where the sample is aspirated by the sample dispensing device 5.

It should be noted that an identification label (not shown) having sample information relating to the type of sample contained and analysis items is attached to the sample container 22. On the other hand, the sample table 2 includes a reading unit 23 that reads information on the identification label of the sample container 22.

The reaction table 3 has an annular table and includes a plurality of storage portions 31 arranged at equal intervals along the circumferential direction of the table. In each storage unit 31, a transparent reaction container 32 for storing a sample and a reagent is detachably stored in a form opening upward. The reaction table 3 is rotated in a direction indicated by an arrow in FIG. 1 by a reaction table driving unit (not shown) with a vertical line passing through the center of the reaction table 3 as a rotation axis. When the reaction table 3 rotates, the reaction container 32 is transported to the sample discharge position where the sample is discharged by the sample dispensing apparatus 5 or the reagent discharge position where the reagent is discharged by the reagent dispensing apparatus 7. An openable and closable lid and a thermostat (not shown) are provided above and below the reaction table 3, respectively. The thermostat is heated and adjusted to a temperature that promotes the reaction between the specimen dispensed into the reaction container 32 and the reagent.

The photometric device 33 has a light source 33a and a light receiving unit 33b. The light source 33a emits analysis light having a predetermined wavelength, and the light receiving unit 33b measures a light beam emitted from the light source 33a and transmitted through the reaction solution in which the sample and the reagent contained in the reaction container 32 have reacted. In the photometric device 33, the light source 33 a and the light receiving portion 33 b are arranged at positions where they oppose each other in the radial direction across the storage portion 31 of the reaction table 3. The reaction table 3 discharges the measured reaction solution from the reaction vessel 32, and stirs the reaction vessel washing mechanism 34 for washing the reaction vessel 32 and the sample and reagent dispensed in the reaction vessel 32. And a stirring unit 35 for promoting the reaction.

The reagent table 4 has a disk-shaped table and includes a plurality of storage portions 41 arranged at equal intervals along the circumferential direction of the table. In each storage unit 41, a reagent container 42 storing a reagent is detachably stored. The reagent container 42 has an opening 42a that opens upward. The reagent table 4 is rotated in a direction indicated by an arrow in FIG. 1 by a reagent table driving unit (not shown) with a vertical line passing through the center of the reagent table 4 as a rotation axis. When the reagent table 4 rotates, the reagent container 42 is transported to the reagent suction position where the reagent is sucked by the reagent dispensing device 7. An openable / closable lid (not shown) is provided above the reagent table 4. In addition, a cold storage tank is provided below the reagent table 4. Therefore, when the reagent container 42 is stored in the reagent table 4 and the lid is closed, the reagent stored in the reagent container 42 is kept at a constant temperature by the cold storage tank and stored in the reagent container 42. Evaporation and denaturation of the reagent can be suppressed.

It should be noted that an identification label (not shown) having reagent information relating to the type and amount of reagent contained is affixed to the reagent container 42. On the other hand, the reagent table 4 includes a reading unit 43 that reads information on the identification label of the reagent container 42.

The sample dispensing device 5 has a dispensing probe for aspirating and discharging a sample attached to the distal end, and freely moves up and down in the vertical direction and rotates around a vertical line passing through its proximal end as a central axis. Provide an arm. The sample dispensing device 5 is provided between the sample table 2 and the reaction table 3, sucks the sample in the sample container 22 transported to a predetermined position by the sample table 2 with a dispensing probe, rotates the arm, The sample is dispensed into the reaction container 32 conveyed to a predetermined position by the reaction table 3, and the sample is transferred into the reaction container 32 on the reaction table 3 at a predetermined timing.

The reagent dispensing apparatus 7 has a dispensing probe for aspirating and discharging the reagent attached to the distal end portion, and freely moves up and down in the vertical direction and rotates around the vertical line passing through its base end portion as a central axis. Provide an arm. The reagent dispensing device 7 is provided between the reagent table 4 and the reaction table 3, sucks the reagent in the reagent container 42 transported to a predetermined position by the reagent table 4 with a dispensing probe, rotates the arm, The reagent is dispensed into the reaction container 32 transported to a predetermined position by the reaction table 3, and the reagent is transferred into the reaction container 32 on the reaction table 3 at a predetermined timing.

FIG. 2 shows a schematic configuration diagram of the specimen dispensing device 5 (the same applies to the reagent dispensing device 7). The sample dispensing device 5 has a dispensing probe 50 as shown in FIG. The dispensing probe 50 is formed in a rod-like shape from stainless steel or the like, and the tip side is tapered. The dispensing probe 50 is attached to the distal end of the arm 51 with the upper proximal end facing downward. The arm 51 is horizontally arranged, and its base end is fixed to the upper end of the support shaft 52. The support shaft 52 is arranged vertically, and is rotated around the vertical axis O by the probe transfer unit 53. When the support shaft 52 rotates, the arm 51 turns in the horizontal direction and moves the dispensing probe 50 in the horizontal direction. Further, the support shaft 52 moves up and down along the vertical axis O by the probe transfer unit 53. When the support shaft 52 moves up and down, the arm 51 moves up and down in the vertical direction, and the dispensing probe 50 moves up and down in the vertical (up and down) direction and in the longitudinal direction of the dispensing probe 50.

One end of a tube 54a is connected to the proximal end of the dispensing probe 50. The other end of the tube 54 a is connected to the syringe 55. The syringe 55 includes a cylindrical cylinder 55a to which the other end of the tube 54a is connected, and a plunger 55b provided so as to be able to advance and retreat in the cylinder 55a while sliding on the inner wall surface of the cylinder 55a. The plunger 55 b is connected to the plunger driving unit 56. The plunger drive unit 56 is configured using, for example, a linear motor, and moves the plunger 55b back and forth with respect to the cylinder 55a. One end of a tube 54b is connected to the cylinder 55a of the syringe 55. The other end of the tube 54b is connected to a tank 57 that contains the extrusion liquid L1. Further, an electromagnetic valve 58 and a pump 59 are connected in the middle of the tube 54b. In addition, as the extrusion liquid L1, an incompressible fluid such as distilled water or degassed water is applied. This extrusion liquid L1 is also applied as cleaning water for cleaning the inside of the dispensing probe 50.

The sample dispensing device 5 drives the pump 59 and opens the electromagnetic valve 58 to fill the extruded liquid L1 accommodated in the tank 57 into the cylinder 55a of the syringe 55 via the tube 54b. The cylinder 55a is filled up to the tip of the dispensing probe 50 through the tube 54a. In such a state that the extrusion liquid L1 is filled up to the tip of the dispensing probe 50, the electromagnetic valve 58 is closed and the pump 59 is stopped. When aspirating the specimen or reagent, the plunger drive unit 56 is driven to move the plunger 55b backward with respect to the cylinder 55a, thereby sucking the tip of the dispensing probe 50 through the extrusion liquid L1. Pressure is applied, and the specimen and reagent are aspirated by this suction pressure. On the other hand, when the specimen or reagent is discharged, the distal end portion of the dispensing probe 50 is driven via the push-out liquid L1 by driving the plunger driving portion 56 and moving the plunger 55b to the cylinder 55a. A discharge pressure is applied to the sample, and the specimen and reagent are discharged by the discharge pressure.

The sample dispensing device 5 (reagent dispensing device 7) includes a liquid level detection mechanism 11 that detects the liquid level of the sample (reagent) dispensed by the dispensing probe. A capacitance type liquid level detection mechanism will be described. FIG. 3 is a schematic configuration diagram of the capacitance type liquid level detection mechanism 11. As shown in FIG. 3, the liquid level detection mechanism 11 includes an oscillation circuit 111, a differentiation circuit 112, and a voltage detection circuit 113.

The oscillation circuit 111 oscillates an AC signal and inputs it to the differentiation circuit 112. As shown in FIG. 3, the differentiating circuit 112 includes

resistors

112a and 112b,

capacitors

112c and 112d, and an operational amplifier 112e, and is adjusted so that input sensitivity is increased depending on the frequency of the AC signal oscillated by the oscillation circuit 111. . The + side input end of the differentiating circuit 112 is connected to the dispensing probe 50 via the lead wire 11a, and an electrostatic capacity is generated between the dispensing probe 50 and the electrode 4a which is the housing ground. The capacitance is generated in parallel with the capacitor 112d. Therefore, the output voltage Vout of the differentiating circuit 112 changes due to the change in capacitance between the dispensing probe 50 and the electrode 4a which is the housing ground. The voltage detection circuit 113 detects the output voltage Vout, and detects whether or not the lower end of the dispensing probe 50 is in contact with the liquid level present in the sample container 22 according to this value. The output voltage signal detected by the voltage detection circuit 113 is output to the control unit 101, and the liquid level of the sample stored in the sample container 22 is detected.

In this case, the differentiation circuit 112 adjusted so that the input sensitivity is increased at the frequency of the oscillation circuit 111 by the capacitance value when the dispensing probe 50 is not in contact with the liquid surface is the capacitance value in the contact state. Then the sensitivity decreases. Therefore, the voltage detection circuit 113 detects the liquid level based on the change in the output voltage Vout.

The liquid level detection mechanism 11 is also used to detect capacitance when determining whether or not the sample can be discharged by the dispensing probe 50 when the sample dummy is discharged from the dispensing probe 50 on the sample container 22. The The dispensing control unit 109 controls the dispensing probe 50 to suck the total amount of the sample and the dummy sample necessary for the analysis from the sample container 22 and then discharge the dummy sample on the sample container 22. The voltage detection circuit 113 detects the output voltage signal from when the dummy sample is discharged from the dispensing probe 50 until it reaches the sample liquid level in the sample container 22 and the discharge of the dummy sample is completed. The output signal detected by the voltage detection circuit 113 is output to the control unit 101, and the liquid discharge determination unit 106 determines whether or not the dummy sample has been discharged based on the output voltage signal. When it is determined that the dummy sample has been discharged, it is determined that the sample sucked together with the dummy sample is sucked by a predetermined amount and discharged, and when it is determined that the dummy sample is not discharged, the sample is sucked together with the dummy sample. It is determined that a predetermined amount of the sample has not been aspirated or discharged, and a warning is given that dispensing is abnormal.

The dispensing probe cleaning device 6 is provided between the sample table 2 and the reaction table 3 and in the middle of the horizontal movement locus of the dispensing probe 50 in the sample dispensing device 5, and dispenses the next sample. In order to perform this, the dispensing probe 50 is washed after the specimen is discharged into the reaction container 32. The dispensing probe cleaning device 8 is provided between the reagent table 4 and the reaction table 3 and in the middle of the horizontal movement trajectory of the dispensing probe 50 in the reagent dispensing device 7, and dispenses the next reagent. In order to perform this, the dispensing probe 50 is washed after the reagent is discharged into the reaction container 32.

Next, the control mechanism 10 will be described. As shown in FIG. 1, the control mechanism 10 includes a control unit 101, an input unit 102, an analysis unit 103, a storage unit 104, an output unit 105, and a transmission / reception unit 107. Each unit included in the control mechanism 10 is electrically connected to the control unit 101. The analysis unit 103 is connected to the photometric device 33 via the control unit 101, analyzes the component concentration of the sample based on the amount of light received by the light receiving unit 33 b, and outputs the analysis result to the control unit 101. The input unit 102 is a part that performs an operation of inputting an inspection item or the like to the control unit 101. For example, a keyboard or a mouse is used. The input unit 102 may be realized by a touch panel.

The storage unit 104 is configured by using a hard disk that magnetically stores information and a memory that loads various programs related to the process from the hard disk and electrically stores them when the automatic analyzer 1 executes the process. Various information including the analysis result of the specimen is stored. The storage unit 104 may include an auxiliary storage device that can read information stored in a storage medium such as a CD-ROM, a DVD-ROM, or a PC card.

The output unit 105 is configured using a printer, a speaker, and the like, and outputs various information related to analysis under the control of the control unit 101. The output unit 105 displays analysis contents, alarms, and the like, and a display panel or the like is used. The transmission / reception unit 107 has a function as an interface for performing transmission / reception of information according to a predetermined format via a communication network (not shown).

The automatic analyzer 1 configured as described above discharges the reagent sucked from the reagent container 42 by the reagent dispensing device 7 to the plurality of reaction containers 32 conveyed along the circumferential direction by the rotating reaction table 3. The reaction container 32 from which the reagent has been discharged is transported along the circumferential direction by the reaction table 3, and the sample is dispensed from the sample container 22 held in the sample table 2 by the sample dispensing device 5, and the photometric device 33. Thus, the light flux that has passed through the reaction solution in which the specimen and the reagent have reacted is measured.

Next, a method for confirming the dispensing failure of the dispensing probe according to the first embodiment will be described with reference to the flowchart shown in FIG. First, the dispensing probe 50 is transported onto the sample container 22 containing the sample to be dispensed by the probe transfer unit 53, and the dispensing probe 50 is lowered into the sample container 22 (step S100). Thereafter, it is determined whether or not the dispensing probe 50 has detected the liquid level (step S101). When the dispensing probe 50 is lowered into the sample container 22, the dispensing probe 50 comes into contact with the sample liquid surface, and the liquid level detection mechanism provided in the dispensing probe 50 causes the liquid level to change due to the change in capacitance caused by the liquid surface contact. Will be detected. Here, when the dispensing probe 50 does not detect the liquid level (No at Step S <b> 101), the process proceeds to Step S <b> 100 and the dispensing probe 50 is further lowered by the probe transfer unit 53. On the other hand, when the dispensing probe 50 detects the liquid level (step S101, Yes), the dispensing probe 50 is lowered by a predetermined amount in order to suck the sample (step S102), and is separated by the negative pressure of the plunger drive unit 56. The specimen is aspirated from the injection probe 50 (step S103). In addition to the amount required for analysis, the amount of sample suction is aspirated by adding a dummy used for sample dummy discharge for checking whether or not the dispensing probe 50 has sucked the sample.

After the sample is aspirated, the dispensing probe 50 is moved up by several millimeters from the sample liquid surface by driving the probe transfer unit 53 (step S104). After rising, under the control of the dispensing control unit 109, the dummy sample is discharged from the dispensing probe 50 (step S105), and the static between the dispensing probe 50 and the electrode 4a which is the housing ground when the dummy sample is discharged is discharged. The liquid level is detected by the liquid level detection mechanism 11, and the liquid discharge determination unit 106 determines whether or not the dummy sample is discharged from the dispensing probe 50 based on the detected capacitance change (step S106). Here, an operation diagram of the dispensing failure confirmation method of the first embodiment shown in FIG. 5, an enlarged view of the dispensing probe at the time of dispensing the dummy sample shown in FIG. 6, and a dummy sample ejection shown in FIG. With reference to the change diagram of the capacitance at the time, the determination method of the dummy specimen discharge by the liquid discharge determination unit 106 will be further described. First, as shown in FIG. 5A, the dispensing probe 50 is lowered into the sample container 22, and the capacitance when the probe tip of the dispensing probe 50 comes into contact with the sample liquid surface is determined as a liquid level detection mechanism. 11 to detect the liquid level based on the change in capacitance. Thereafter, as shown in FIG. 5B, the dispensing probe 50 in the sample container 22 is further lowered by a predetermined amount to suck the sample. After the sample is aspirated, as shown in FIG. 5 (c), the dispensing probe 50 is raised so that it is about several millimeters away from the sample liquid surface in the sample container 22, and a dummy sample is obtained as shown in FIG. 5 (d). Is discharged. The distance between the dispensing probe 50 and the sample liquid surface is set in consideration of the dummy sample discharge amount, the sample viscosity, and the like. When the distance between the dispensing probe 50 and the sample liquid surface is closer, the dummy sample discharge amount can be reduced. However, when the viscosity of the sample is high, a liquid junction state occurs in which the sample and the probe are connected before the dummy sample is discharged. Since there is a risk, the distance shall not cause a liquid junction.

FIG. 6 is an enlarged view when the dispensing probe 50 discharges a dummy sample (FIG. 5D). When the dispensing control unit 109 issues a dummy sample discharge signal to the plunger driving unit 56, FIG. As shown in FIG. 6B, the dummy sample starts to be discharged from the tip of the dispensing probe 50. Thereafter, as shown in FIG. 6C, the dispensing probe 50 and the sample (sample container 22) are discharged from the discharged dummy sample. It becomes a liquid junction state. When the dispensing probe 50 and the sample container 22 are in a liquid junction state with the dummy sample discharged as shown in FIG. 6C, the capacitance between the dispensing probe 50 and the electrode 4a changes greatly. FIG. 7 is a change diagram of the electrostatic capacity when the dummy specimen is discharged. As shown in FIG. 7, when the dummy specimen is ejected, the output voltage decreases with ejection, and the minimum output −ΔV at t1 when the dispensing probe 50 and the specimen container 22 are in a liquid junction state with the ejected dummy specimen. Become. By setting a threshold value in advance for the minimum output value and storing it in the storage unit 104, the liquid discharge determination unit 106 determines whether or not a dummy sample has been discharged by comparing the set threshold value and the minimum output value. The threshold value may be the same as the threshold value when the liquid level detection mechanism 11 detects the liquid level, but may be set to another value.

As a result of the determination by the liquid discharge determination unit 106, when it is determined that a dummy sample has been discharged (Yes in step S106), a predetermined amount of sample necessary for the analysis performed in step S103 is aspirated, and subsequent sample discharge is also performed. It is determined that it is normally performed, and after the dispensing probe 50 is transported to the reaction table 3, the specimen is discharged into the reaction container 32 accommodated in the reaction table 3 (step S107). If it is determined that the dummy sample is not ejected (No in step S106), it is determined that the sample performed in step S103 is not aspirated by a predetermined amount, or ejection is not performed normally, and a dispensing abnormality is not detected. A warning is issued (step S108).

(Embodiment 2)
In the first embodiment, a change in electrostatic capacitance when a dummy sample is discharged is detected on the sample container 22, and when the change is equal to or greater than a threshold, it is determined that the dummy sample has been discharged, and the previous sample suction is normal. In contrast, in the second embodiment, the capacitance change time measurement unit 108 measures the capacitance change time when the dummy sample is discharged, and the dummy sample is detected when the change time is within a predetermined range. It is different in that it is determined that a predetermined amount has been ejected and the sample aspiration is normal. In the first embodiment, even when a predetermined amount of dummy specimen is not ejected and the capacitance change time is short, it is determined that dispensing is normal when a voltage equal to or higher than the threshold is output. In the second embodiment, since it is determined whether or not the dummy sample discharge has been normally performed based on the change time of the capacitance, when the sample suction amount is smaller than the set amount and the dummy sample discharge amount is small, Although sample aspiration is normally performed, it is preferable because it is possible to determine that the dispensing is abnormal even when the dispensing probe 50 is clogged by a foreign substance in the sample and a predetermined amount of dummy sample is not discharged.

FIG. 7 shows a variation diagram of the electrostatic capacity when discharging the dummy specimen, a schematic configuration diagram of the capacitive liquid level detection mechanism 11A shown in FIG. 8, and the dispensing probe shown in FIG. This will be described with reference to a flowchart of a method for confirming dispensing failure. As shown in FIG. 8, the liquid level detection mechanism 11A of the second embodiment includes a capacitance change time measurement unit 108 in the control unit 101A. The capacitance change time measuring unit 108 measures the capacitance change time in the change diagram of the capacitance when discharging the dummy specimen shown in FIG. 7, that is, Δt (t2-t1), and the capacitance change. By setting a predetermined range in advance and storing it in the storage unit 104, the liquid ejection determining unit 106A determines whether a predetermined amount of the dummy sample has been discharged by comparing the set predetermined range with the change time Δt. To do. The predetermined range of the capacitance change time is set according to the discharge amount of the dummy specimen.

As shown in FIG. 9, first, the dispensing probe 50 is transported onto the sample container 22 containing the sample to be dispensed by the probe transfer unit 53, and the dispensing probe 50 is lowered into the sample container 22 (step S200). . Thereafter, it is determined whether or not the dispensing probe 50 has detected the liquid level (step S201). When the dispensing probe 50 descends into the sample container 22, the dispensing probe 50 comes into contact with the sample liquid surface, and the liquid level detection mechanism 11A provided in the dispensing probe 50 causes the liquid to change due to the change in capacitance caused by the liquid surface contact. The surface will be detected. Here, when the dispensing probe 50 does not detect the liquid level (No in step S201), the process proceeds to step S200, and the dispensing probe 50 is lowered by the probe driving means. On the other hand, when the dispensing probe 50 detects the liquid level (step S201, Yes), the dispensing probe 50 is lowered by a predetermined amount in order to suck the sample (step S202), and is separated by the negative pressure of the plunger drive unit 56. The specimen is aspirated from the injection probe 50 (step S203). In addition to the amount required for analysis, the amount of sample aspirated is a sum of the amount of dummy sample used for sample dummy discharge for checking whether or not the dispensing probe 50 has aspirated the sample.

After the sample is aspirated, the dispensing probe 50 is moved up by about several millimeters from the sample liquid surface by driving the probe transfer unit 53 (step S204). After rising, the dummy sample is discharged from the dispensing probe 50 (step S205), the capacitance between the dispensed probe 50 and the electrode 4a after discharge is detected, and the dummy sample is discharged from the dispensing probe 50 by a predetermined amount. It is determined whether or not (step S206). The capacitance change time measurement unit 108 measures the time Δt when the capacitance change ΔV is equal to or greater than the threshold value, and the liquid discharge determination unit 106A determines that the static discharge time Δt is set according to the dummy sample discharge amount. It is determined whether or not the capacitance change time is within a predetermined range. As a result of the determination by the liquid discharge determination unit 106A, when it is determined that a predetermined amount of the dummy sample has been discharged (step S206, Yes), it is determined that the sample performed in step S203 is also aspirated by a predetermined amount and discharge is normally performed. Then, the dispensing probe 50 is transported to the reaction table 3 and the specimen is discharged into the reaction container 32 accommodated in the reaction table 3 (step S207). If it is determined that the predetermined amount of the dummy sample is not ejected (No at Step S206), it is determined that the sample performed at Step S203 is not aspirated by a predetermined amount and the ejection is not normally performed, thereby causing a dispensing error. Is issued (step S208).

In the first and second embodiments, the sample dispensing has been described, but the dispensing failure due to empty aspiration or probe clogging can be confirmed in the same manner for reagent dispensing.

Thus, the present invention can include various embodiments and the like not described herein, and various design changes and the like can be made without departing from the technical idea specified by the claims. It is possible to apply.

As described above, the dispensing device, the automatic analyzer, and the dispensing failure confirmation method of the present invention are effective when it is desired to easily and quickly determine dispensing failures, and particularly for samples that are prone to probe clogging. It is suitable for dispensing.

Claims

A dispensing probe that has conductivity and sucks or discharges the liquid contained in the container; and an electrode that is disposed integrally with or near the container; and the dispensing probe and the electrode A dispensing device comprising a liquid level detection mechanism for detecting the liquid level of the liquid based on a change in capacitance during
Dispensing control means for sucking the total amount of liquid and dummy liquid required for analysis from the container using the dispensing probe and then controlling the dummy liquid to be discharged on the container;
Detecting means for detecting a change in capacitance between the dispensing probe and the electrode when the dummy liquid is discharged by the dispensing control means;
A liquid discharge determining means for determining whether or not the dispensing probe has discharged liquid based on a change in capacitance detected by the detecting means;
A dispensing device comprising:
The dispensing device according to claim 1, wherein the detection means is the liquid level detection mechanism.
Measuring means for measuring a capacitance change time between the dispensing probe and the electrode at the time of discharging the dummy liquid based on the capacitance change detected by the detection means;
The liquid discharge determination means determines whether or not the dispensing probe has discharged a predetermined amount of liquid based on the capacitance change time measured by the measurement means. Or the dispensing apparatus of 2.
An automatic analyzer that reacts a sample and a reagent in a reaction vessel and analyzes the reaction solution based on the optical characteristics of the reaction solution,
An automatic analyzer comprising the dispensing device according to any one of claims 1 to 3.
The sample and reagent contained in the container are dispensed into the reaction container, and the dispensed sample and reagent are stirred and reacted in the reaction container, and the reaction solution is analyzed based on the optical characteristics of the reaction solution. A method for confirming dispensing failure of an automatic analyzer,
A liquid level detection step for detecting the liquid level of the liquid in the container based on a change in capacitance;
A suction step of sucking the total amount of liquid and dummy liquid required for analysis of the liquid in the container using a dispensing probe;
A dummy liquid discharging step of discharging the dummy liquid on the container by the dispensing probe;
In the dummy liquid discharge step, a detection step of detecting a change in capacitance between the dispensing probe and the electrode when discharging the dummy liquid;
A liquid discharge determination step for determining whether or not the dispensing probe has discharged liquid based on the capacitance change detected in the detection step;
A dispensing failure confirmation method for an automatic analyzer characterized by comprising:
Based on the capacitance change detected in the detection step, a measurement step for measuring a capacitance change time between the dispensing probe and the electrode when discharging the dummy liquid;
The liquid discharge determining step includes determining whether or not the dispensing probe has discharged a predetermined amount of liquid based on the capacitance change time measured in the measuring step. The dispensing failure confirmation method of the automatic analyzer described in 1.