Automated analyzer

Abstract

The purpose of the present invention is to provide an automatic analysis device capable of detecting abnormalities at the time of aspiration with high accuracy even when the amount of a reagent used for analysis is small. This automatic analysis device is provided with: a dispensing mechanism that dispenses a reagent from a reagent container to a reaction container; a control unit that controls the dispensing mechanism so as to discharge the reagent in a second predetermined amount into the reagent container after suctioning the reagent in an amount including at least the second predetermined amount in addition to a first predetermined amount used for analysis, and then discharge the reagent in the first predetermined amount into the reaction container; and a pressure sensor that measures the pressure in the dispensing mechanism, the control unit determines whether or not the reagent is normally sucked on the basis of the value measured by the pressure sensor when the dispensing mechanism sucks the reagent, and if the first predetermined amount is equal to or greater than a predetermined first predetermined amount threshold value, the control unit determines whether or not the reagent is normally sucked on the basis of the value measured by the pressure sensor, and if the first predetermined amount is equal to or greater than the predetermined first predetermined amount threshold value, the control unit controls the dispensing mechanism to dispense the reagent. The second predetermined amount is a constant value independent of the first predetermined amount, and when the first predetermined amount is less than the first predetermined amount threshold, the second predetermined amount is greater than the constant value.

Description

Technical Field

[0001] The present invention relates to an automatic analyzing device. Background Art

[0002] Automatic analyzers that analyze biological samples such as blood and urine have a dispensing mechanism for dispensing reagents and samples into reaction vessels. The dispensing mechanism activates a syringe connected to a nozzle via a flow path, thereby aspirating or ejecting reagents, etc., and a pressure sensor is provided in the flow path. Regarding this dispensing mechanism, Patent Document 1 discloses a technique that compares the difference between the pressure sensor output before the start of the aspiration operation and the pressure sensor output during the aspiration operation with a threshold (pressure threshold) to detect a dispensing anomaly.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2007-315984 Summary of the Invention

[0006] Problems to be solved by the invention

[0007] However, when the suction volume is small, the difference between the pressure sensor output before suction and the pressure sensor output during suction becomes smaller, so the pressure threshold needs to be reduced. As a result, it is difficult to distinguish between normal and normal times, which can easily lead to false detection.

[0008] The present invention has been made in view of such a problem, and an object of the present invention is to provide an automatic analyzer capable of detecting an abnormality during aspiration with high accuracy even when the amount of reagent used in the analysis is small.

[0009] Means for solving problems

[0010] In order to solve the above-mentioned problem, the automatic analysis device of the present invention comprises: a dispensing mechanism that dispenses reagent from a reagent container into a reaction container; a control unit that controls the dispensing mechanism so that after sucking out the reagent containing at least a second specified amount in addition to the first specified amount used in the analysis, the second specified amount of the reagent is ejected into the reagent container, and then the first specified amount of the reagent is ejected into the reaction container; and a pressure sensor that measures the pressure in the dispensing mechanism, and the control unit determines whether the reagent is sucked out normally based on the measured value of the pressure sensor when the dispensing mechanism sucks out the reagent, wherein, when the first specified amount is above a predetermined first specified amount threshold, the second specified amount is independent of the first specified amount and is a constant value, and when the first specified amount is less than the first specified amount threshold, the second specified amount is more than the constant value.

[0011] Effects of the Invention

[0012] According to the present invention, it is possible to provide an automatic analyzer capable of detecting an abnormality during aspiration with high accuracy even when the amount of reagent used in the analysis is small. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 This is a diagram schematically showing the overall configuration of an automatic analyzer.

[0014] Figure 2 This is a diagram schematically showing the flow path structure of the reagent dispensing mechanism and the reagent bottles.

[0015] Figure 3 This is a diagram showing an example of the operation sequence for reagent dispensing.

[0016] Figure 4 This is a flowchart showing a method for determining dry suction.

[0017] Figure 5 This is a flowchart showing a method for adjusting the amount of reagent aspiration.

[0018] Figure 6A This is a diagram showing an example (comparative example) in which the amount of reagent suction was not adjusted.

[0019] Figure 6B It is a diagram showing an example (embodiment) in which the amount of reagent suction is adjusted.

[0020] Figure 7 This is a diagram showing an example of a method for setting a pressure threshold value for determining empty suction. DETAILED DESCRIPTION

[0021] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

[0022] (Overall Structure of Automatic Analyzer)

[0023] The automatic analyzer is a device that dispenses a sample such as blood or urine and a reagent into a reaction container 2, causes them to react, and measures the liquid after the reaction. Figure 1 This is a diagram schematically showing the overall structure of the automatic analyzer. Figure 1 As shown, the automatic analyzer is composed of a sample transport mechanism 8, a reagent disk 3, a reaction disk 1, a sample dispensing mechanism 9, reagent dispensing mechanisms 11, 13, stirring mechanisms 17, 18, a cleaning mechanism 15, a control unit 24, and the like.

[0024] Reaction containers 2 are arranged in a circular pattern on a reaction disk 1. Reaction containers 2 are containers for storing a mixed solution of a sample and a reagent, and multiple reaction containers are arranged on the reaction disk 1. A sample transport mechanism 8 is located near the reaction disk 1. This transport mechanism transports a sample rack 7 carrying multiple sample containers 6 containing samples to be analyzed. The reaction containers 2 are immersed in a reaction tank filled with a thermally conductive medium (e.g., constant-temperature water) whose temperature is controlled at, for example, 37°C. The constant-temperature water circulates within the reaction tank, thereby maintaining the temperature of the reaction containers 2 at a constant level of 37°C.

[0025] The reagent disk 3 can place a plurality of reagent bottles 4 (reagent containers) containing reagents used for analysis on its circumference, and also functions as a cooling storage for keeping the reagent bottles 4 cool.

[0026] A sample dispensing mechanism 9 for dispensing samples from the sample container 6 to the reaction container 2 is arranged between the reaction disk 1 and the sample transport mechanism 8. The sample dispensing mechanism 9 has a sample nozzle 10 that can rotate in the horizontal direction and move in the vertical direction, with its front end facing downward. A cleaning tank 19 for cleaning the sample nozzle 10 with cleaning water is arranged in the operating range of the sample dispensing mechanism 9. In addition, reagent dispensing mechanisms 11 and 13 for dispensing reagents from the reagent bottle 4 to the reaction container 2 are provided between the reaction disk 1 and the reagent disk 3. The reagent dispensing mechanisms 11 and 13 respectively have reagent nozzles 12 and 14 that can rotate in the horizontal direction and move in the vertical direction, with their front ends facing downward. Cleaning tanks 20 and 21 for cleaning the reagent nozzles 12 and 14 with cleaning water are arranged in the operating range of the reagent dispensing mechanisms 11 and 13.

[0027] Arranged around the reaction disk 1 are stirring mechanisms 17 and 18 , a spectrophotometer (not shown) for measuring the absorbance of the reaction solution by measuring light transmitted from a light source (not shown) through the reaction solution in the reaction container 2 , and a cleaning mechanism 15 for cleaning the used reaction container 2 .

[0028] The stirring mechanisms 17 and 18 can rotate horizontally and move vertically, and stir the mixture of the sample and reagent (reaction solution) by being inserted into the reaction container 2. Within the operating range of the stirring mechanisms 17 and 18, cleaning tanks 22 and 23 for cleaning the stirring mechanisms 17 and 18 with cleaning water are arranged.

[0029] The control unit 24 is composed of a computer, etc., and controls the operation of each mechanism constituting the automatic analyzer and performs calculation processing to obtain the concentration of a predetermined component in the sample. Figure 1 In order to simplify the diagram, the connection relationship between each mechanism constituting the automatic analyzer and the control unit 24 is omitted.

[0030] In the automatic analyzer constructed as described above, analysis and processing are performed roughly according to the following process. First, the control unit 24 dispenses the sample in the sample container 6 on the sample rack 7 transported by the sample transport mechanism 8 to the vicinity of the reaction disk 1 into the reaction container 2 on the reaction disk 1 through the sample nozzle 10 of the sample dispensing mechanism 9. Thereafter, the control unit 24 cleans the sample nozzle 10 in the cleaning tank 19. Next, the control unit 24 dispenses the reagent in the reagent bottle 4 on the reagent disk 3 into the reaction container 2 into which the sample was previously dispensed through the reagent nozzles 12 and 14 of the reagent dispensing mechanisms 11 and 13. Thereafter, the control unit 24 cleans the reagent nozzles 12 and 14 in the cleaning tanks 20 and 21.

[0031] Next, the control unit 24 stirs the sample and reagent mixture in the reaction vessel 2 using the stirring mechanisms 17 and 18. The control unit 24 then transmits light generated by the light source through the reaction vessel 2 containing the mixture and measures the intensity of the transmitted light using a spectrophotometer. The photometric information measured by the spectrophotometer is transmitted to the control unit 24 via an A / D converter and an interface. The control unit 24 then calculates the concentration of the specified component of the analysis item based on the received photometric information and displays the calculated result on a display unit (not shown) or other device, or stores it in a storage unit (not shown).

[0032] (Structure of the reagent dispensing mechanism)

[0033] Then, according to Figure 2 The structures of the reagent dispensing mechanisms 11 and 13 will be described in detail.

[0034] Figure 2This diagram schematically illustrates the flow path structure and reagent bottles of the reagent dispensing mechanism. The reagent dispensing mechanisms 11 and 13 primarily comprise reagent nozzles 12 and 14 and a syringe 25. By operating the syringe 25, which is connected to the reagent nozzles 12 and 14, the reagent in the reagent bottle 4 is dispensed into the reaction vessel. The syringe 25 is provided with a plunger 30, which is connected to a motor 31. The motor 31 then drives the plunger 30, thereby aspirating or ejecting the reagent to be dispensed from the reagent nozzles 12 and 14.

[0035] Furthermore, a flow path from the reagent nozzles 12 and 14 via the syringe 25, solenoid valve 27, and liquid feed pump 28 to the water supply pump 29 is formed by a tube 26, and the flow path is filled with system water. System water refers to water used for pressure transmission, etc., and is typically purified water such as ion-exchanged water. When cleaning the inside of the reagent nozzles 12 and 14, the solenoid valve 27 is opened, and the system water (cleaning water) supplied by the water supply pump 29 is ejected from the front end of the reagent nozzles 12 and 14. Furthermore, a pressure sensor 32 is connected to a branch midway along the flow path from the reagent nozzles 12 and 14 to the syringe 25, enabling measurement of the pressure within the flow path.

[0036] When the reagent dispensing mechanisms 11 and 13 dispense the reagent, they first move the reagent nozzles 12 and 14 to a position (reagent suction position) for drawing the reagent from the reagent bottle 4 while maintaining the solenoid valve 27 closed. Next, when the tips of the reagent nozzles 12 and 14 reach the reagent liquid level, the plungers 40 are driven in the suction direction, thereby drawing the reagent into the reagent nozzles 12 and 14. Thereafter, the reagent nozzles 12 and 14 move to a position (reagent discharge position) for dispensing the reagent into the reaction vessel 2. In this state, the plungers 40 are driven in the discharge direction, thereby dispensing the reagent into the reaction vessel 2. Furthermore, after the reagent dispensing mechanisms 11 and 13 have dispensed the reagent, the reagent nozzles 12 and 14 move to the cleaning tanks 20 and 21 to perform cleaning on the inside and outside of the reagent nozzles 12 and 14.

[0037] (Reagent dispensing action)

[0038] Next, use Figure 3 The details of the reagent dispensing operation will be described. Figure 3 : is a diagram showing an example of the sequence of reagent dispensing operations. Figure 3 In, with Figure 2 Different from the above, the structure of the reagent dispensing mechanism is simplified.

[0039] First, in the (1) pre-dispensing step, the control unit 24 moves the reagent nozzles 12 and 14 that have been cleaned inside and outside toward the reagent aspiration position above the reagent bottle 4. At this time, the reagent nozzles 12 and 14 are filled with the system water used for cleaning inside.

[0040] Next, in the (2) segmented air aspiration process, the control unit 24 moves the syringe 25 in the aspiration direction to aspirate segmented air. The segmented air is the air that separates the system water from the reagent, and serves to prevent the reagent from contacting the system water during aspiration, thereby diluting the reagent.

[0041] Next, in the (3) reagent aspiration step, the control unit 24 lowers the reagent nozzles 12 and 14 to the reagent aspiration position, and while the reagent nozzles 12 and 14 are immersed in the liquid level in the reagent bottle 4, the syringe 25 moves in the aspiration direction to aspirate the reagent. At this time, the amount of the aspirated reagent includes, in addition to the amount (i.e., the amount used for analysis) ejected into the reaction vessel 2 in the (5) second ejection step described later, the first predetermined amount, and also includes, in addition to the second predetermined amount, the amount of the reagent returned to the reagent bottle 4 in the (4) first ejection step described later. Furthermore, in the (3) reagent aspiration step, in addition to the first predetermined amount and the second predetermined amount, the amount of the reagent aspirated also includes, in addition to the first predetermined amount and the second predetermined amount, a third predetermined amount, a virtual amount that is aspirated extraneously to prevent dilution of the reagent by the system water remaining in the reagent nozzles 12 and 14. Furthermore, the third predetermined amount varies depending on the total of the first predetermined amount and the second predetermined amount, and the greater the total, the greater the third predetermined amount. Furthermore, in the (3) reagent aspirating step, the pressure sensor 32 measures the pressure in the flow path within a predetermined time range during the aspirating operation of the syringe 25 and stores the pressure in a storage unit (not shown).

[0042] Next, in the (4) first ejection step, the control unit 24 moves the syringe 25 in the ejection direction while the reagent nozzles 12 and 14 are immersed in the liquid level in the reagent bottle 4, thereby ejecting a portion of the reagent in the reagent nozzles 12 and 14. The ejection amount of the reagent in the (4) first ejection step, i.e., the second predetermined amount, includes the syringe operation amount (gap ejection amount) required to eliminate the backlash generated during the transition from the (3) reagent aspiration step to the (4) first ejection step. Here, backlash refers to a slight idle motion generated when the direction of the syringe 25 is reversed due to the gap between the various mechanisms constituting the syringe 25.

[0043] Next, the control unit 24 causes the reagent nozzles 12 and 14 to rise, move horizontally above the reaction container 2, which is the reagent ejection position, and then lower it again. Thereafter, in the second ejection step (5), the control unit 24 causes the syringe 25 to move in the ejection direction to eject a portion of the reagent remaining in the reagent nozzles 12 and 14 into the reaction container 2. The ejection amount of the reagent in the second ejection step (5), i.e., the first predetermined amount, corresponds to the amount of reagent required for the actual analysis. In addition, in the second ejection step (5), the syringe 25 moves in the same direction as the previous ejection action. Therefore, there is no need to consider the tooth gap, and the required amount of reagent can be ejected with high precision.

[0044] At the end of the second ejection step (5), a third predetermined amount of reagent, which is a virtual amount, remains in the reagent nozzles 12 and 14. However, when the reagent nozzles 12 and 14 are subsequently moved to the cleaning tanks 20 and 21 to clean the insides of the reagent nozzles 12 and 14, the third predetermined amount of reagent is discharged into the cleaning tanks 20 and 21 together with the cleaning water supplied from the liquid delivery pump 28.

[0045] (Abnormal judgment during suction)

[0046] Next, according to Figure 4 The method for determining abnormalities during suction is described in detail. Here, insufficient suction of the reagent by the dispensing mechanism, i.e., empty suction, is cited as an example of a determination target for abnormal suction. However, other determination targets may also include a situation where the dispensing mechanism is clogged with reagent or where air bubbles have entered the dispensing mechanism.

[0047] Figure 4 This is a flowchart showing a method for determining dry suction. Figure 4 The steps shown are assumed to be executed by the control unit 24 , but may be executed by an abnormality determination control unit that is different from the control unit 24 .

[0048] First, the control unit 24 reads out data of measurement values ​​of the pressure sensor 32 stored in a storage unit (not shown) (step S401 ).

[0049] Next, the control unit 24 calculates a predetermined index using the measurement value of the pressure sensor 32 (step S402). Here, the index in this embodiment is calculated based on the value obtained by integrating the measurement value of the pressure sensor 32, but an index calculated by other methods may also be used.

[0050] The control unit 24 then determines whether the indicator satisfies a predetermined determination condition (step S403). In this embodiment, the following description uses an example of whether the indicator is greater than a constant k as the determination condition, but other determination conditions may also be used. If the indicator does not satisfy the determination condition, that is, if the indicator ≤ k, the control unit 24 determines that the condition is normal (step S404).

[0051] On the other hand, if the indicator satisfies the determination condition in step S403, that is, if the indicator > k, the control unit 24 determines that a purge abnormality has occurred (step S405). In this case, the control unit 24 suspends the dispensing of the reagent from the reagent bottle 4 (step S406). Furthermore, the control unit 24 causes a display unit (not shown) to display an alarm indicating that a purge abnormality has occurred and that the dispensing of the reagent has been suspended (step S407).

[0052] also, Figure 4The abnormality determination process shown is as long as Figure 3 After the reagent suction process (3) in the above, it can be performed at any time. However, it is preferred that Figure 3 In (5), abnormality determination is performed before the second ejection step to prevent the reagent from being ejected into the reaction container 2 during an abnormality.

[0053] (Adjustment of reagent aspiration volume)

[0054] Here, the inventors' research results show that if the amount of reagent sucked in the (3) reagent suction process is small, the difference between the index calculated during normal suction and the index calculated during empty suction is small, making it difficult to determine whether empty suction has occurred, and prone to misjudgment. Therefore, in this embodiment, when the amount of reagent used in the analysis is less than a predetermined threshold value (first predetermined amount threshold value), the reagent suction amount is adjusted (increased) so as to be an amount that can ensure the accuracy of the judgment. That is, in the (3) reagent suction process, the reagent is excessively sucked from the reagent bottle 4, and the excessively sucked reagent is returned to the reagent bottle 4 in the (4) first ejection process. Thus, the consumption of the reagent can be suppressed, and the abnormality of empty suction can be detected with high precision.

[0055] according to Figure 5 A specific method for adjusting the reagent aspiration amount will be described. Figure 5 This is a flowchart showing a method for adjusting the amount of reagent aspiration.

[0056] First, the control unit 24 obtains the usage amount of the reagent corresponding to the analysis request item as the first predetermined amount (step S501 ).

[0057] Then, the control unit 24 determines whether the first predetermined amount is greater than or equal to the first predetermined amount threshold (step S502). If the first predetermined amount is greater than or equal to the first predetermined amount threshold, the control unit 24 sets the second predetermined amount as the backlash discharge amount (constant value) (step S503).

[0058] On the other hand, when the first predetermined amount is smaller than the first predetermined amount threshold, the control unit 24 makes the second predetermined amount larger than the backlash discharge amount (step S504 ).

[0059] Next, use Figure 6A as well as Figure 6B The effect of adjusting the amount of reagent suction is explained. Figure 6A as well as Figure 6B In FIG, the vertical axis is set to the output value of the pressure sensor 32, but it is not limited to the measured value of the pressure, and can also be the current value detected by the pressure sensor 32. Figure 6A and Figure 6B The inter-tooth gap ejection volume of the syringe 25 used to obtain the pressure waveform shown was set to 2 μL.

[0060] <Comparative Example>

[0061] First, according to Figure 6A An example (comparative example) in which the amount of reagent suction was not adjusted will be described.

[0062] Figure 6A As a comparative example, the diagram shows an example of the pressure waveform during normal suction and the pressure waveform during dry suction when the first predetermined amount is 10 μL and the second predetermined amount is only the gap ejection amount. Figure 6A In the case of the third predetermined amount being 5 μL, in the comparative example, in the (3) reagent aspiration step, only 10+2+5=17 μL of reagent is aspirated. Figure 6A The difference in pressure waveforms between normal suction and empty suction is small, so the differences in various indicators also become small. Therefore, it is difficult to set the judgment conditions that clearly identify empty suction and difficult to judge empty suction with high accuracy.

[0063] <Example>

[0064] Then, according to Figure 6B An example (Example) in which the amount of reagent suction is adjusted will be described. Figure 6B As an example, the diagram shows an example of the pressure waveform during normal suction and the pressure waveform during dry suction when the first predetermined amount is 10 μL and the second predetermined amount is the gap discharge amount + adjustment amount 40 μL. Figure 6B In the case of the third predetermined amount is set to 7 μL, then in the embodiment, in the (3) reagent suction step, 10+2+40+7=59 μL of reagent is sucked. Figure 6B The difference in pressure waveforms between normal suction and empty suction is large, so the differences in various indicators also become large. Therefore, it is easy to set the judgment conditions that clearly identify empty suction, and empty suction can be judged with high accuracy.

[0065] And, according to Figure 6B It can be seen that if the first predetermined amount is 50 μL or more, even when the second predetermined amount is only the gap ejection amount, the aspirated amount of the reagent in the (3) reagent aspiration step is 59 μL or more, and it is possible to accurately determine the empty aspiration. Therefore, if a value of 50 μL or more is set as the first predetermined amount threshold, when the first predetermined amount is greater than the first predetermined amount threshold, the second predetermined amount can be set to the gap ejection amount (2 μL) without relying on the first predetermined amount.

[0066] On the other hand, when the first prescribed amount is less than the first prescribed amount threshold, the second prescribed amount is made greater than the inter-gap ejection amount (2 μL). Specifically, the sum of the first prescribed amount and the second prescribed amount becomes the sum of the first prescribed amount threshold and the inter-gap ejection amount. For example, when the first prescribed amount is 20 μL, the second prescribed amount is set to the inter-gap ejection amount (2 μL) + 30 μL, and the sum of the first prescribed amount and the second prescribed amount is the same as the sum of the first prescribed amount threshold (for example, 50 μL) and the inter-gap ejection amount (2 μL). Thus, even if the amount of reagent used in the analysis is small, the accuracy of the determination of the empty suction can be well maintained. In addition, in the first ejection process (4), the reagent diluted in the reagent nozzles 12 and 14 is returned to the reagent bottle 4, but even if the second prescribed amount increases, the number of times of return does not increase, so the dilution of the reagent in the reagent bottle 4 is suppressed to the same degree.

[0067] Furthermore, when the first predetermined amount is less than the first predetermined amount threshold, the sum of the first predetermined amount and the second predetermined amount may be greater than the sum of the first predetermined amount threshold and the backlash discharge amount. For example, when the first predetermined amount is 20 μL, the second predetermined amount may be set to the backlash discharge amount (2 μL) + 50 μL, such that the sum of the first predetermined amount and the second predetermined amount is greater than the sum of the first predetermined amount threshold (e.g., 50 μL) and the backlash discharge amount (2 μL).

[0068] Furthermore, the first predetermined amount threshold is not limited to 50 μL, and a different value may be used depending on the type of reagent, the inner diameter of the reagent nozzles 12 and 14, the sensitivity of the pressure sensor 32, etc. For example, when the reagent contains an organic solvent (e.g., acetonitrile), the pressure difference between normal aspiration and empty aspiration tends to be smaller than when the reagent does not contain an organic solvent. Therefore, the first predetermined amount threshold may be set to a larger value.

[0069] (How to set the pressure threshold)

[0070] Below, use Figure 7 An example of a method for setting a threshold value (pressure threshold value) for determining a dispensing abnormality will be described. Figure 7 This is a diagram showing an example of a method for setting a pressure threshold value for determining empty suction.

[0071] exist Figure 7 Figure 2 shows an example where the sum of the first and second predetermined quantities among multiple indicators calculated using multiple past pressure waveform data is the sum of a hypothetical value and a constant value (backlash discharge amount). The distribution A of the indicator during dry suction falls within a range defined by a predetermined standard deviation relative to the average value a of the multiple indicators, while the distribution B of the indicator during normal suction falls within a range defined by a predetermined standard deviation relative to the average value b of the multiple indicators.

[0072] Here, if distribution A and distribution B do not overlap, the condition containing only distribution A (in Figure 7 In the example, the indicator (>k) is set as the criterion for determining whether air suction is considered empty, so a hypothetical value is suitable for the pressure threshold. However, when distributions A and B are similar, only low-precision conditions can be set as the criterion, and the hypothetical value in this case is not sufficient as the pressure threshold. Therefore, it is preferable to set a hypothetical value as the pressure threshold, which is the difference between distributions A and B, equal to or greater than a constant value.

[0073] Description of Reference Numerals

[0074] 1...Reaction disk, 2...Reaction container, 3...Reagent disk, 4...Reagent bottle, 6...Sample container, 7...Sample rack, 8...Sample transport mechanism, 9...Sample dispensing mechanism, 10...Sample nozzle, 11, 13...Reagent dispensing mechanism, 12, 14...Reagent nozzle, 15...Cleaning mechanism, 17, 18...Stirring mechanism, 19...Cleaning tank, 20, 21...Cleaning tank, 22, 23...Cleaning tank, 24...Controller, 25...Syringe, 26...Tube, 27...Solenoid valve, 28...Liquid delivery pump, 29...Water supply pump, 30...Plunger, 31...Motor, 32...Pressure sensor

Claims

1. An automatic analysis device comprising: a dispensing mechanism for dispensing reagents from the reagent container into the reaction container; a control unit that controls the dispensing mechanism so that, after sucking the reagent including at least a second predetermined amount in addition to the first predetermined amount used for analysis, the second predetermined amount of reagent is ejected into the reagent container, and thereafter the first predetermined amount of reagent is ejected into the reaction container; and a pressure sensor that measures the pressure in the dispensing mechanism, The control unit determines whether the reagent is normally aspirated based on the measurement value of the pressure sensor when the dispensing mechanism aspirates the reagent. It is characterized in that When the first predetermined amount is equal to or greater than a predetermined first predetermined amount threshold, the second predetermined amount is a constant value independent of the first predetermined amount. When the first predetermined amount is smaller than the first predetermined amount threshold, the second predetermined amount is larger than the constant value.

2. The automatic analysis device according to claim 1, characterized in that The constant value is a gap discharge amount required to eliminate gaps generated when the movement direction of the syringe constituting the dispensing mechanism is reversed.

3. The automatic analysis device according to claim 1, characterized in that When the first predetermined amount is smaller than the first predetermined amount threshold, the total of the first predetermined amount and the second predetermined amount is equal to or greater than the total of the first predetermined amount threshold and the constant value.

4. The automatic analysis device according to claim 1, characterized in that When the first predetermined amount is smaller than the first predetermined amount threshold, the sum of the first predetermined amount and the second predetermined amount is the sum of the first predetermined amount threshold and the constant value.

5. The automatic analysis device according to claim 1, characterized in that When the reagent contains an organic solvent, the first predetermined amount threshold is larger than when the reagent does not contain the organic solvent.

6. The automatic analysis device according to claim 1, characterized in that The first predetermined amount threshold is a value of 50 μL or more.

7. The automatic analysis device according to claim 1, characterized in that The control unit calculates an index using the measured value, and determines whether the suction is normal or abnormal based on the index. When the sum of the first prescribed amount and the second prescribed amount is the sum of the first prescribed amount threshold and the constant value, the distribution during normal attraction and the distribution during abnormal attraction in the indicator calculated based on the measured value do not overlap with each other, and the difference between the distributions is greater than the constant amount.

8. The automatic analysis device according to claim 7, characterized in that The distribution is a range defined by a predetermined standard deviation relative to an average value of the plurality of indicators.

9. The automatic analysis device according to claim 7, characterized in that The index is calculated based on a value obtained by integrating the measured value.

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