Automatic analysis device

Abstract

The present invention provides an automatic analysis device, which can detect abnormalities in a flow path including failures of an electromagnetic valve and a pressure change unit by using an existing sensor for measuring the amount of liquid in a container. The automatic analysis device operates a syringe (103), a first electromagnetic valve (104) and a second electromagnetic valve (105), performs prescribed suction, ejection and discharge operations in a container (101), a liquid discharge unit (108) and a flow path system (113, 114), and determines whether the flow path system has abnormalities based on the amount of liquid measured by a sensor (102).

Description

Technical Field

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

[0002] In the field of automatic analysis devices for qualitative / quantitative analysis of biological samples such as blood and urine, in clinical examinations for analyzing components contained in biological samples such as blood and urine of patients, qualitative / quantitative analysis of target components in the sample is performed by reacting the sample with the reagent. In this case, in order to provide a specified amount of sample and reagent to a reaction container for reacting the sample and the reagent, a liquid supply mechanism called a dispensing mechanism is used. In order to provide the liquid, the pressure in the nozzle for sucking the liquid is set to negative pressure by using a syringe, and after the sucked liquid is sucked into the nozzle, the pressure in the nozzle is set to positive pressure by using a syringe, and a specified amount of liquid is ejected into the reaction container.

[0003] In Patent Document 1, a pressure sensor is provided in the piping connecting the dispensing nozzle and the dispensing syringe, and the output in the piping is measured by the pressure sensor, and an abnormality of any one of the solenoid valve, the gear pump and the water supply tank is detected based on the output. In addition, Patent Document 2 discloses that a fault of the solenoid valve is detected by including an action sensor in the solenoid valve.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2014-25812

[0007] Patent Document 2: Japanese Patent Application Publication No. 2015-14990 Summary of the invention

[0008] Technical problem to be solved by the invention

[0009] Adding a pressure sensor to a device or installing a sensor on a solenoid valve as in these prior arts increases the device cost. Furthermore, adding a sensor to a flow path or a solenoid valve changes the control circuit and flow path relative to the existing device structure, thereby limiting applicable products and the scope of application.

[0010] Therefore, the present invention provides an automatic analyzer capable of detecting abnormalities related to a flow path system by using sensors that detect the liquid amounts of reagents, washing reagents, measurement objects, etc., which are originally provided in the automatic analyzer.

[0011] Technical solutions adopted to solve technical problems

[0012] An automatic analyzing device as one embodiment of the present invention comprises: a sensor for measuring the amount of liquid in a container for storing liquid; a flow path system; a discharge portion for discharging liquid from the flow path system; a syringe connected to a branching portion of the flow path system and causing a pressure change in the flow path; and a control portion, wherein the flow path system comprises a first flow path from a nozzle for sucking or ejecting liquid from the container to the branching portion, and a second flow path from the branching portion to the discharge portion, wherein the first flow path comprises a first electromagnetic valve for opening and closing the first flow path, and the second flow path comprises a second electromagnetic valve for opening and closing the second flow path, wherein the control portion operates the syringe, the first electromagnetic valve, and the second electromagnetic valve to perform prescribed sucking, ejecting, and discharging actions in the container, the discharge portion, and the flow path system, and determines whether the flow path system has an abnormality based on the amount of liquid measured by the sensor.

[0013] Effects of the Invention

[0014] According to the present invention, without installing an operation sensor of the electromagnetic valve or a pressure sensor of the flow path system, an abnormality of the flow path including a failure of the electromagnetic valve or the pressure changing unit can be detected by using an existing sensor for measuring the amount of liquid in the container.

[0015] Other objects and novel features will become apparent from the description of this specification and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is the flow path system of the automatic analyzer involved in Example 1.

[0017] Figure 2 This is a flow chart for detecting abnormalities in a flow path system.

[0018] Figure 3 This is a flow chart for determining the abnormal location of the flow system.

[0019] Figure 4 This is the flow path system of the immune automatic analyzer involved in Example 2.

[0020] Figure 5 This is a flow chart for detecting abnormalities in a flow path system.

[0021] Figure 6 This is a flow chart for determining the abnormal location of the flow system.

[0022] Figure 7 This is the flow path system of the flow-type electrolyte concentration measuring device involved in Example 3.

[0023] Figure 8 This is a flow chart for detecting abnormalities in a flow path system. DETAILED DESCRIPTION

[0024] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0025] Example 1

[0026] Embodiment 1 is an automatic analyzer 100 that detects abnormalities occurring in a flow path system using a sensor that measures the amount of liquid.

[0027] Figure 1 1 is a diagram schematically showing a flow path system for delivering various liquids in the automatic analyzer 100. The flow path system of the automatic analyzer 100 includes: a container 101 for storing liquid; a liquid volume sensor 102 for measuring the liquid volume in the container 101; a syringe 103 for sucking or ejecting liquid by changing the pressure in the flow path; a first electromagnetic valve 104 and a second electromagnetic valve 105 that are always open (normally open: the flow path is closed when power is supplied); a nozzle 112 for sucking or ejecting liquid from the container 101; and a flow path 106 that connects the nozzle 112 to the nozzle 112. Nozzle 112 and the first solenoid valve 104; a bifurcation 107; a flow path 120, which connects the bifurcation 107 and the first solenoid valve 104; a flow path 109, which connects the second solenoid valve 105 and the bifurcation 107; a flow path 110, which connects the bifurcation 107 and the syringe 103; and a flow path 111, which connects the second solenoid valve 105 and the discharge part 108. The flow path system of the automatic analysis device 100 can deliver the liquid in the container 101 to the discharge part 108.

[0028] In addition, here, the container 101 and the discharge part 108 are set to have almost the same height, so that the pressure at the front end of the nozzle 112 and the pressure at the front end of the flow path 111 connected to the discharge part 108 become equal, and even if the electromagnetic valves 104 and 105 are opened, the liquid will not flow in the flow path system unless the syringe 103 acts. Therefore, in this example, electromagnetic valves that are always open are used as the first electromagnetic valve 104 and the second electromagnetic valve 105. However, the role of the electromagnetic valve is to be able to control whether the flow of the flow path is stopped or flows. Depending on the structure of the flow path, the electromagnetic valve can also be always closed (normally closed: the flow path is opened when power is turned on), and it is irrelevant to the structure of the valve. A pinch valve, a diaphragm valve, a non-diaphragm valve, etc. can also be used.

[0029] The first flow path 113 is a flow path from the container 101 to the branching portion 107, which is composed of the nozzle 112, the flow path 106, the first electromagnetic valve 104, and the flow path 120. In addition, the second flow path 114 is a flow path from the discharge portion 108 to the branching portion 107, which is composed of the flow path 109, the second electromagnetic valve 105, and the flow path 111.

[0030] The control unit 115 controls the first solenoid valve 104, the second solenoid valve 105 and the syringe 103. In addition, it also includes an output unit 117 and an input unit 118 that constitute an interface with the user. For example, the input unit 118 includes a keyboard or a mouse, and the output unit 117 includes a display or a printer. The control unit 115 further includes a storage unit 116, for example, to store the output result of the liquid volume sensor 102.

[0031] The liquid amount sensor 102 can measure the amount of liquid in the container 101, and the measuring method can be any electrostatic capacitance type, electrode type, optical type, ultrasonic type, float type, etc., and can also be a weight sensor. The liquid amount sensor 102 is originally provided so that the liquid stored in the container 101 does not become insufficient and the suction amount does not become insufficient. When the liquid amount sensor 102 detects that the amount of liquid in the container 101 becomes less than a predetermined amount, the control part 115 ends the analysis operation and provides an alarm to the output part 117 to notify the user to replenish the liquid or replace the container 101, thereby prompting the user to replenish the liquid.

[0032] In addition, the discharge portion 108 may be in the form of a container, and the liquid amount sensor 102 may be included in the discharge portion 108 instead of being included in the container 101 .

[0033] In addition, the action of sending the liquid in the container to the flow path is called suction, the action of removing unnecessary liquid in the flow path (sending it to the discharge part 108) is called discharge, and the action of sending the liquid in the flow path to the container is called ejection.

[0034] Figure 2 This is an example of a flowchart for detecting abnormality in the flow path system in the automatic analyzer 100 .

[0035] First, the control unit 115 measures the liquid volume A0 of the container 101 through the liquid volume sensor 102 (step S200). Here, the information obtained by the liquid volume sensor 102 is different depending on the type of sensor included in the container 101. For example, when the sensor is a liquid level detection sensor, it is the height of the liquid level, and when the sensor is a weight sensor, it is the weight of the liquid. The control unit 115 converts the output information of the liquid volume sensor 102 into the liquid volume of the container 101 and stores it in the storage unit 116. In addition, if the liquid volume of the container 101 is determined in advance, step S200 can be omitted. In this case, the control unit 115 can substitute an initial value corresponding to the liquid volume of the container 101 as the liquid volume A0.

[0036] Next, the control unit 115 opens the first solenoid valve 104, closes the second solenoid valve 105, and generates a negative pressure in the flow path through the syringe 103, thereby sucking the liquid in the container 101 from the nozzle 112 and filling the liquid into the first flow path 113 (step S201).

[0037] Next, a negative pressure is further generated in the flow path through the syringe 103 to send the liquid into the flow path 110. In addition, a positive pressure is generated in the flow path through the syringe 103 in a state where the second solenoid valve 105 is open and the first solenoid valve 104 is closed. As a result, the liquid in the flow path 110 is discharged to the liquid discharge unit 108 via the second flow path 114 (step S202).

[0038] Next, the control unit 115 determines whether the operations in steps S201 and S202 have been performed a specified number of times (step S203). If it is less than the specified number of times, the control unit 115 repeats the operations in steps S201 and S202. By performing the operations in steps S201 and S202 a specified number of times, the target value of the assumed suction amount of the liquid from the container 101 is set to B1.

[0039] Next, the control unit 115 measures the liquid volume A1 of the container 101 through the liquid volume sensor 102 (step S204). The liquid volume A1 is stored in the storage unit 116. The control unit 115 calculates the liquid volume A3 obtained by subtracting the liquid volume A1 from the liquid volume A0 (step S205). This is the actual liquid volume sucked from the container 101 in step S201. Subtract the target liquid volume B1 from the actually sucked liquid volume A3, and compare it with the threshold value C1 determined in consideration of the deviation of the device, the measurement deviation of the liquid volume sensor 102, etc. (step S206). When |A3 - B1| < C1, the control unit 115 determines that the suction amount is normal and the flow path system is normal (step S207). On the other hand, when |A3 - B1| ≥ C1, that is, when the actually sucked liquid volume A3 deviates from the target value B1, the control unit 115 determines that an abnormality has occurred in the flow path system (step S208), displays an alarm on the output unit 117 (step S209), and ends the abnormality detection of the flow path system.

[0040] In addition, it is not limited to the method for determining the abnormality of the flow path system in step S206. For example, the pre-determined threshold values C2 and C3 can also be used. If C2 < A1 < C3, it is determined to be normal. In this case, when A1 ≤ C2 or C3 ≤ A1, it is determined to be abnormal.

[0041] Here, the thresholds C1, C2, and C3 used by the control unit 115 to judge the abnormality of the flow path system in step S206 may be, for example, predetermined fixed values ​​or statistical quantities. For example, when the liquid volume sensor 102 is a liquid level sensor and the liquid level height is used as the liquid volume, four times the labeled deviation calculated based on the measured value of the liquid level height so far may be determined. In addition, in the judgment of abnormality, it is not limited to the discrimination method based on the threshold value, and statistical processing based on the MT (Mahalanobis Taguchi) method, the linear discrimination method, etc. may also be used.

[0042] As the cause of abnormality in the flow path system of the automatic analyzer 100, there are possible reasons for opening and closing failure of the first electromagnetic valve 104 or the second electromagnetic valve 105, failure of the syringe 103, clogging of the nozzle 112 or the liquid discharge section 108, liquid leakage of the first flow path 113 or the second flow path 114, etc. Since even if any of the failures occurs, it becomes impossible to send a normal amount of liquid from the container 101 to the liquid discharge section 108, and thus it becomes impossible to ensure the basic function of the automatic analyzer. The influence of each of the above-mentioned failures will be described.

[0043] First, the failure of the first electromagnetic valve 104 means that the closing action cannot be performed. Therefore, in step S202, when the first electromagnetic valve 104 remains in the open state, the liquid flows back to the container 101. Since the failure of the second electromagnetic valve 105 also cannot perform the closing action, in step S201, when the second electromagnetic valve 105 is in the open state, the liquid is sucked from the second flow path 114, and the specified amount of liquid cannot be sucked from the container 101.

[0044] Furthermore, if the syringe 103 fails, a predetermined amount of liquid cannot be sucked in step S201. In step S202, the blockage of the discharge portion 108 generates excessive pressure in the second flow path 114, and when the first electromagnetic valve 104 is opened again in step S201, the liquid flows back to the container 101. In this way, the abnormality of the flow path system is reflected in the amount of liquid finally sucked from the container 101. Therefore, the abnormality of the flow path system can be determined regardless of the cause of the abnormality.

[0045] In addition, in the case where the solenoid valve is always closed (normally closed), when a fault occurs in the opposite way to the solenoid valve that is always open, the flow path cannot be opened. Therefore, due to the fault of the first solenoid valve 104, insufficient suction occurs when sucking from the container 101. Similarly, due to the fault of the second solenoid valve 105, liquid cannot be discharged, so a pressure higher than the normal pressure is applied to the second flow path 114, and similar to the case where the discharge portion 108 is blocked as described above, when the first solenoid valve 104 is opened again, the liquid flows back to the container 101. In this way, even in the case where the solenoid valve is always closed, it is possible to utilize Figure 2 A flowchart is used to determine abnormalities in the flow path system.

[0046] Figure 3 An example of a flowchart for determining the abnormal part of the flow path system is shown. In Figure 2 When it is determined that there is an abnormality in the flow path system in the flowchart or when the user confirms the operation of the unit related to the flow path system, it is implemented.

[0047] First, as a preparatory operation, the control unit 115 executes Figure 2 Steps S201 and S202 of the flowchart and fills the first flow path 113 and the second flow path 114 with liquid (step S300).

[0048] Then, in the same manner as in step S200, the liquid volume A30 of the container 101 is measured, and the output information of the liquid volume sensor 102 is stored in the storage unit 116 (step S301).

[0049] Next, with the first solenoid valve 104 and the second solenoid valve 105 open, the control unit 115 applies a positive pressure through the syringe 103 to cause the liquid to flow back into the container 101 and be discharged to the drainage unit 108 (step S302). As described above, since the drainage unit 108 and the suction nozzle 112 are set to have the same height, there will be no liquid flow caused by the pressure difference of the atmospheric pressure.

[0050] Then, in the same manner as in step S200, the control unit 115 measures the liquid volume A31 of the container 101 after spraying, subtracts the liquid volume A30 before the backflow, and thus obtains the backflow liquid volume (spray volume) A32, which is stored in the storage unit 116 (step S303).

[0051] Next, the control unit 115 calculates the difference between the actual backflow liquid volume A32 and the target liquid volume B31 when backflow occurs in the normal state, and compares it with the threshold C31 determined in consideration of the deviation of the device, the measurement deviation of the liquid volume sensor 102, etc. (step S304). When |A32 - B31| ≥ C31 is satisfied (when there is a deviation between the target value and the measured value), it is determined whether the insufficient spray volume is caused by a pressure shortage due to a failure other than the solenoid valve, that is, a failure of the syringe 103, or a blockage or liquid leakage in the first flow path 113 or the second flow path 114 (step S312), and an alarm is displayed on the output unit 117 and the measurement is ended (step S315). In addition, when |A32 - B31| < C31, the control unit 115 determines that the spray is normal, and then proceeds to the determination of the abnormality of the solenoid valve.

[0052] With Figure 2is the same as step S201 of the flowchart. The control unit 115 closes the second electromagnetic valve 105 and aspirates the liquid from the container 101 through the syringe 103 (step S305). Then, in the same manner as step S200, the control unit 115 measures the liquid volume A33 of the container 101 after aspiration, subtracts the liquid volume A33 from the liquid volume A31 before aspiration to obtain the aspirated liquid volume A34, and stores it in the storage unit 116 (step S306).

[0053] Next, the same as Figure 2 step S206 of the flowchart, the control unit 115 calculates the difference between the target liquid volume B32 when aspirated under normal conditions and the actually aspirated liquid volume A34, and compares it with the threshold value C32 (step S307). When |A34 - B32| ≥ C32 (when there is a deviation between the target value and the measured value), the control unit 115 determines that the second electromagnetic valve 105 has failed (step S313), and displays an alarm on the output unit 117 and ends the measurement (step S315). This is because when the normally open second electromagnetic valve 105 fails, it is always in the open state, and the liquid in the second flow path 114 is also inadvertently aspirated by the syringe 103. On the other hand, when |A34 - B32| < C32, the control unit 115 determines that the second electromagnetic valve 105 is normal, and then proceeds to the abnormality determination of the first electromagnetic valve 104.

[0054] The same as Figure 2 step S202 of the flowchart, the control unit 115 closes the first electromagnetic valve 104 and discharges the liquid to the liquid discharge unit 108 through the syringe 103 (step S308). Then, in the same manner as step S200, the control unit 115 measures the liquid volume A35 of the container 101 after liquid discharge, subtracts the liquid volume A33 before liquid discharge to obtain the changed liquid volume A36, and stores it in the storage unit 116 (step S309). If the first electromagnetic valve 104 is normally closed, the liquid volume of the container 101 remains unchanged before and after liquid discharge, so the changed liquid volume A36 becomes approximately zero.

[0055] Therefore, the control unit 115 compares the threshold value C33 determined considering various deviations with the changed liquid volume A36 (step S310). When |A36| ≥ C33, since it is considered to be inadvertently discharged into the container 101, the control unit 115 determines that the first electromagnetic valve 104 has failed (step S314), displays an alarm on the output unit 117, and ends the measurement (step S315). In addition, when |A36| < C33, the control unit 115 determines that the flow path system is normal and ends the operation (step S311).

[0056] In addition, the control unit 115 may count the number of operations i of steps S300 to S311 and repeat the operation until the number of operations n specified in advance is reached. By repeating the inspection, the detection accuracy of the electromagnetic valve failure can be improved.

[0057] In addition, in each abnormality judgment, the threshold value can be further classified, and a process can be added to judge that a small change is a liquid leakage, and a relatively large change is a solenoid valve failure. In addition, a step of judging liquid leakage by measuring the change in the liquid amount of the container 101 with the first solenoid valve 104 and the second solenoid valve 105 open and the syringe 103 stationary can be added.

[0058] In this way, by identifying the cause of the abnormality including the failure of the electromagnetic valve, a quick repair can be performed, the period during which the device is not used at the customer's site can be shortened, and the impact of the failure on clinical examination work can be minimized.

[0059] Example 2

[0060] Embodiment 2 is an automatic analyzer 200 using immunoassay to detect abnormalities occurring in a flow path system using a sensor for measuring liquid volume. In the figure, components identical to those described in Embodiment 1 are denoted by the same reference numerals, and description thereof is omitted.

[0061] exist Figure 4 1 and 2 , a detection unit and a configuration related thereto that perform immunoassay in the immune automatic analyzer 200 are extracted and shown. The immune automatic analyzer 200 measures a biological sample (hereinafter referred to as a specimen) such as blood or urine from a patient.

[0062] The flow cell detection unit 201 includes: a flow path 202 through which the reaction liquid sucked by the nozzle 112, the luminescence auxiliary reagent or the washing reagent for auxiliary detection flows; and a detector 213, which is used to detect the luminescence of the measurement object. In the reaction container 203, the measurement object forms a complex modified by magnetic particles and luminescent substances by the reaction between the antigen and the antibody. The detector 213 is provided with a magnetic particle holding unit not shown, and the magnetic particle holding unit holds / adsorbs the complex reaching the detector 213 to the flow cell detection unit 201. Then, the reaction liquid as a solvent for the complex is removed, and the luminescent substance bound to the complex is induced by the luminescence auxiliary reagent, and the luminescence amount is detected by the detector 213. The control unit 115 calculates the concentration of the measurement object based on the result detected by the detector 213. The calculated concentration of the measurement object is output from the output unit 117. This series of processes performed by the flow cell detection unit 201 is called immunoassay.

[0063] The automatic analyzer 200 includes a container replacement mechanism 206, which can move the reaction container 203, the luminescence auxiliary reagent container 204, and the cleaning reagent container 205 in the up-down direction or left-right direction by a pulse motor. Since the rotation amount of the pulse motor is determined by the number of pulses instructed, and the rotation amount of the motor is proportional to the moving distance of the container, accurate positioning can be performed. The nozzle 112 can suck the liquid in the configured container through the container replacement mechanism 206 without moving.

[0064] The first flow path 113 is a flow path from the container 205 to the branching portion 107, which is composed of the nozzle 112, the flow path 130 connecting the nozzle 112 and the flow path 202, the flow path 202, the flow path 106 connecting the flow path 202 and the first electromagnetic valve 104, the first electromagnetic valve 104, and the flow path 120. In addition, the second flow path 114 is a flow path from the discharge portion 108 to the branching portion 107, which is composed of the flow path 109, the second electromagnetic valve 105, the atmospheric pressure opening portion 217, and the flow path 111. The second flow path 114 is provided with the atmospheric pressure opening portion 217, and by making the static pressure acting on the nozzle 112 and the atmospheric pressure opening portion 217 constant, the fluid can be maintained in the flow path even when the first electromagnetic valve 104 and the second electromagnetic valve 105 are opened.

[0065] In addition, in the cleaning reagent container 205, the cleaning reagent is appropriately supplied from the reagent supply bottle 211 to the cleaning reagent container 205 through the dispensing machine 210 including the flow path 212, the electromagnetic valve 207, the syringe 208 and the electromagnetic valve 209. Although not shown in the figure, the reagent is also supplied to the luminescence auxiliary reagent container 204 through the same structure. In Embodiment 2, the first electromagnetic valve 104 and the second electromagnetic valve 105 are pinch valves that are always open (normally open: the flow path is closed when power is turned on), and the electromagnetic valves 207 and 209 are electromagnetically operated valves that are always closed.

[0066] Figure 5 This is an example of a flowchart for detecting abnormality in the flow path system in the automatic analyzer 200 .

[0067] As a preparatory operation before starting measurement, the control unit 115 dispenses the luminescence assisting reagent into the luminescence assisting reagent container 204 via the dispenser 210 and dispenses a liquid amount required for the next measurement into the cleaning reagent container 205 (step S500 ).

[0068] First, the container replacement mechanism 206 rotates and moves the reaction container 203 up and down, thereby inserting the nozzle 112 into the reaction container 203. Next, the first electromagnetic valve 104 is opened, the second electromagnetic valve 105 is closed, and the syringe 103 generates negative pressure in the first flow path 113, thereby sucking the reaction liquid of the reaction container 203 from the nozzle 112 (step S501). The magnetic particles of the complex are attracted and held by the magnetic particle holding unit (not shown), so that the measurement object is held in the flow path 202 of the detection unit 201.

[0069] Then, the container replacement mechanism 206 installs the luminescence assisting agent container 204 at a position where the nozzle 112 can suck, and the luminescence assisting agent in the luminescence assisting agent container 204 is sucked (step S502 ). Thus, the luminescence assisting agent is sucked into the flow channel 202 .

[0070] Next, in the detection unit 201, the unreacted components of the reaction solution are removed and replaced with a luminescence auxiliary reagent to induce a luminescence reaction of the luminescent marker in the complex of the object to be measured, and the object to be measured is detected by detecting its luminescence for qualitative / quantitative analysis (step S503). In the flow cell detection unit 201, the complex after adsorbing / holding the magnetic particles is dispersed in the luminescence auxiliary reagent by opening the magnetic particle holding unit. Close the first solenoid valve 104, open the second solenoid valve 105, and cause the syringe 103 to eject. This is to return the piston of the syringe to its original position so that the suction action can be performed again. Along with this, a portion of the reaction solution and the luminescence auxiliary reagent used for measurement is discharged to the discharge unit 108 (step S504).

[0071] Next, the container exchange mechanism 206 causes the cleaning reagent container 205 to rise toward the nozzle 112 after moving to the bottom of the nozzle 112. If the liquid level detection sensor 102b, whose front end is set at the same height as the nozzle 112 in parallel, detects the liquid level of the cleaning reagent container 205, the rise stops. The control unit 115 calculates the liquid volume of the container 205 based on the remaining number of pulses (hereinafter referred to as remaining pulses) until the position of the upper limit of the movement of the pulse motor that detects the liquid level, and stores it in the storage unit 116. The stored physical quantity can be either the remaining pulse or the moving pulse, as long as it is a value that can grasp the liquid volume (step S505).

[0072] The control unit 115 determines the state of the flow system based on the amount of liquid in the cleaning reagent container 205 (step S506), and if it is outside the range of a threshold value determined in consideration of device deviation or measurement deviation, determines that a failure has occurred in the flow system (step S514), displays an alarm on the output unit 117, and ends the measurement (step S515). Details of the method for determining a failure in the flow system will be described later.

[0073] Next, the control unit 115 causes the syringe 103 to perform a suction action (step S507) while the first electromagnetic valve 104 is open and the second electromagnetic valve 105 is closed. At this time, the cleaning reagent container 205 is raised by the container exchange mechanism 206, so as to maintain the front end of the nozzle 112 always immersed in the liquid surface to prevent the suction of bubbles. Next, the first electromagnetic valve 104 is closed, the second electromagnetic valve 105 is opened, and the syringe 103 is caused to perform a spraying action (so that positive pressure is generated in the flow path). Thus, the reaction solution, luminescence auxiliary reagent, and cleaning reagent used for the measurement are discharged to the liquid discharge unit 108 (step S508).

[0074] Next, similar to step S505, the liquid level detection sensor 102b measures the liquid level of the luminescence auxiliary reagent container 204, and stores the result in the storage unit 116. The control unit 115 determines the state of the flow system based on the liquid amount of the luminescence auxiliary reagent container 204 (step S510), and if it is outside the range of the threshold value determined in consideration of the device deviation or the measurement deviation, it is determined that a failure has occurred in the flow system (step S514), and an alarm is displayed on the output unit 117, and the measurement is terminated (step S515). The details of the method for determining the failure of the flow system will be described later.

[0075] Next, similar to step S502, the luminescence assisting reagent is sucked to fill the flow path 202 of the detection unit 201 with the luminescence assisting reagent (step S511). This is to fill the flow path 202 of the detection unit 201 with the luminescence assisting reagent in advance in preparation for the next measurement so as to stabilize the electrochemical conditions of the flow path 202 of the detection unit 201.

[0076] Next, the control unit 115 dispenses the luminescence assisting reagent or the cleaning reagent into each container up to the target value using the dispensing machine 210 based on the liquid amounts of the luminescence assisting reagent container 204 and the cleaning reagent container 205 stored in the storage unit 116 (step S512 ).

[0077] Then, steps S501 to S512 are repeated until a predetermined number of analyses are completed (step S513).

[0078] In this flowchart, liquid level detection is performed for the liquid suction action in step S507 and step S511, and the liquid level detection is used to detect the liquid volume in the container (steps S505 and S509). For this purpose, in one measurement cycle (steps S501 to S512), the liquid volume is measured once for each of the cleaning reagent and the luminescence auxiliary reagent, and then compared with the measurement result in the previous measurement cycle to determine the failure of the flow system. No new steps are added only for detecting the liquid volume in the container, thereby eliminating the need to redefine the sequence of the automatic analyzer and preventing the time required for one cycle from being extended. On the other hand, since the failure of the flow system can be detected in the next measurement cycle in which the failure of the flow system occurs, the control unit 115 provides an alarm by tracing back to the measurement result of the previous cycle. In addition, it is recommended that the user perform maintenance actions for determining the fault location described later ( Figure 6 In addition, it can be set to automatically execute after the alarm is output. Figure 6 The system structure of the maintenance actions.

[0079] The abnormality determination method of the flow path system in step S506 and step S510 is described. If the flow path system fails, the liquid amount of the container changes as follows. In the case where the first electromagnetic valve 104 fails and is always in the open state, the liquid flows back to the first flow path 113 during the action of the syringe 103 to discharge the liquid to the discharge portion 108 (steps S504, S508). As a result, the liquid amount of the luminescence auxiliary reagent container 204 and the cleaning reagent container 205 increases compared to the normal state. In addition, when the second electromagnetic valve 105 fails, the liquid contained in the second flow path 114 is unintentionally sucked in the action of sucking the luminescence auxiliary reagent or the cleaning reagent (steps S505, S509). As a result, since the specified amount of liquid cannot be sucked from the first flow path 113, the liquid amount of the luminescence auxiliary reagent container 204 and the cleaning reagent container 205 is insufficiently sucked compared to the normal state. Furthermore, when the pressure in the flow path drops due to a fault such as liquid leakage from the syringe 103, or when a blockage or leakage occurs in the flow path 113, the nozzle 112 is insufficiently sucked, and thus the amount of liquid in the luminescence auxiliary reagent container 204 and the cleaning reagent container 205 is insufficiently sucked compared to a normal state. Therefore, a fault in the flow path system can be determined by detecting such insufficient suction.

[0080] The statistic used to judge the abnormality of the flow path system may be a value related to the liquid volume, or may be a residual pulse or a liquid volume calculated based on the residual pulse, or may be the height of the liquid surface or the weight of the liquid depending on the type of sensor. In addition, as a method for judging the abnormality of the flow path system, not only a judgment method using a predetermined fixed range (threshold value) can be adopted, but also a method of judging by using the difference between the last measured value or the difference between the target value and the measured value as a threshold value, a method of comparing with past values ​​stored in the storage unit and performing statistical processing, etc. For example, the threshold value may be set to a variable threshold value obtained by adding 4 times the standard deviation to the average value calculated based on the measured values ​​of the liquid level height so far.

[0081] In addition, in this flow chart, the abnormality of the flow system is detected by both the cleaning reagent and the luminescence auxiliary reagent. This is because the detection accuracy can be improved by increasing the number of detections. It is also possible to perform only one of them.

[0082] Figure 6 An example of a flowchart for determining an abnormal location in a flow path system is shown in FIG. Figure 5 This is performed when it is determined in the flowchart that there is an abnormality in the flow system, or before or after the start of the analysis operation.

[0083] First, the control unit 115 dispenses a predetermined amount of cleaning reagent into the empty cleaning reagent container 205 through the dispensing machine 210 (step S600). In addition, although the cleaning reagent container 205 is used as an example here, it can also be a luminescence auxiliary reagent container 204 or a container capable of holding other liquids. Figure 6 In the example, these containers are marked as "container*". Next, the liquid level detection sensor 102b measures the liquid level of the cleaning reagent container 205. The control unit 115 determines whether the liquid level of the cleaning reagent container 205, i.e., the dispensing amount, is normal (step S601). When the dispensing amount is below the threshold, the failure of the dispensing machine 210, the damage of the cleaning reagent container 205, or the abnormality of the liquid level detection sensor 102b is determined (step S609), and an alarm is displayed on the output unit 117 and the measurement is terminated (step S613). Since the solenoid valves 207 and 209 of the dispensing machine 210 are electromagnetically operated valves that are always closed, they will not open when they fail. Therefore, when the solenoid valves 207 and 209 fail, the normal amount cannot be sucked from the reagent supply bottle 211, resulting in insufficient liquid in the cleaning reagent container 205. In addition, the liquid amount may be insufficient due to a rupture of the cleaning reagent container 205 , a blockage or liquid leakage of the flow path 212 of the dispensing machine 210 , or a failure of the syringe 208 .

[0084] The change in the amount of liquid that the liquid level detection sensor 102b can detect depends on the time resolution of the liquid level detection. In order to detect minute changes in the amount of liquid, such as liquid leakage, it is necessary to improve the time resolution of the liquid level detection. Usually, the sampling interval of the liquid level detection sensor is about 3 milliseconds, and in order to narrow the sampling interval, the control substrate of the sensor needs to be changed. However, even if the sampling interval of the liquid level detection sensor is not changed, the time resolution of the liquid level detection can be improved. That is, the following situation can be used: according to the sampling period of the liquid level detection sensor 102b and the speed of the liquid surface entering the container, the resolution of the change in the amount of liquid in the container detected by the liquid level detection sensor, that is, the amount of liquid that can be determined. Specifically, if during the normal analysis operation ( Figure 5 Flow chart) makes the suction nozzle move at a speed of about 180mm / sec. During maintenance ( Figure 6 ), the moving speed of the suction nozzle is slowed down to about 18 mm / sec. Thus, the liquid volume detection resolution based on the liquid level detection sensor 102b is increased by 10 times, and a liquid volume change of 10 μl can be determined, and even a trace amount of liquid leakage can be detected.

[0085] because Figure 6 The processing after step S602 in Figure 3 The processing after step S302 of the flowchart in is the same, so the detailed description is omitted.

[0086] Example 3

[0087] Example 3 is an automatic analyzer 300 (1000) for measuring electrolyte concentration, which detects abnormalities occurring in a flow path system by using a sensor for measuring liquid volume. Figure 7 ). In the figure, the same reference numerals are given to the same components as those described in Example 1 or Example 2, and the description thereof is omitted.

[0088] In the flow-type electrolyte concentration measuring device 300, 15 μl of the sample in the test tube (not shown) is graded and discharged into the dilution tank 313 through the dispensing nozzle 303 of the dispensing unit 301. The dispensing unit 301 has a driving mechanism 302, a nozzle 303, and a liquid level detection sensor 102b. The liquid level detection sensor 102b is an electrostatic capacitance type sensor that utilizes the change in electrostatic capacitance when the dispensing nozzle 303 is charged and the nozzle 303 adheres to the liquid surface. In the blood used for the measurement of the automatic analyzer, the supernatant layer of the sample called serum is attracted to the dispensing nozzle 303, so an electrostatic capacitance type sensor for detecting the liquid level is required in the dispensing nozzle 303.

[0089] The automatic analyzer 300 includes a first detector 304 and a second detector 305. The first detector 304 is an ion selective electrode part that constitutes three electrodes, namely, a chloride ion electrode, a potassium ion electrode, and a sodium ion electrode, and includes a flow path 306 inside. The second detector 305 is a comparison electrode and includes a flow path 307 inside. By appropriately operating the syringe 103 and the second electromagnetic valve 308, the third electromagnetic valve 309, and the fourth electromagnetic valve 310 that are always closed, the comparison electrode liquid in the comparison electrode liquid bottle 311 is introduced into the flow path 307 of the second detector 305. The dispensing machine 210 replenishes the internal standard solution and the diluent from the reagent supply bottle 211 to the dilution tank 313. Since the potential difference (electromotive force) between each ion selective electrode of the first detector 304 and the comparison electrode of the second detector 305 changes with the concentration of the ion to be analyzed in the liquid introduced into each flow path, the electromotive force is measured by the potential measuring part 314, and the ion concentration is calculated by the control part 115 and output to the output part 117.

[0090] The first solenoid valve 104 is a normally open pinch valve, and the second solenoid valve 308, the third solenoid valve 309, and the fourth solenoid valve 310 are normally closed solenoid valves. All the solenoid valves can switch or open and close the flow path, and operate appropriately according to the direction or timing of the introduced liquid.

[0091] In the present embodiment, the liquid level detection sensor 102b for measuring the liquid level of the specimen of the dispensing nozzle 303 is used to measure the liquid level of the dilution tank 313, thereby detecting faults related to the flow path system. Therefore, the function for detecting abnormalities in the flow path system can be installed without the need for additional devices. If the liquid level of the dilution tank 313 can be measured, the liquid level detection sensor of the dispensing nozzle 303 can also be an electrode type sensor, regardless of the type of sensor. In addition, an optical type, ultrasonic type, or float type liquid volume sensor for measuring the liquid volume of the dilution tank 313 can be provided in the dilution tank 313, instead of using the liquid level detection sensor 102b of the dispensing nozzle 303. In addition, in order to measure the liquid volume of the dilution tank 313, a weight sensor can also be installed in the dilution tank.

[0092] Figure 8 An example of a flowchart for detecting abnormality in a flow path system is shown. This is different from the electrolyte concentration measurement operation usually performed by the flow-type electrolyte concentration measurement device 300.

[0093] First, as a preliminary preparation operation, the dispensing machine 210 dispenses a predetermined amount of the specimen and the diluent into the dilution tank 313 (step S800). Then, the liquid level detection sensor 102b of the dispensing nozzle 303 measures the liquid level in the dilution tank 313 (step S801). The control unit 115 determines whether the liquid level in the dilution tank 313, i.e., the dispensing amount, is normal (step S801). The method for determining whether it is normal is the same as that of Figure 6The step S601 in the flowchart of is the same. When the amount of liquid in the dilution tank 313 is small, it is considered that the dilution tank 313 is damaged, the syringe 208 of the dispensing machine 210, the electromagnetic valve 207, the electromagnetic valve 209 is faulty, or the liquid level detection sensor 102b is faulty (step S811). In the case of a fault, an alarm is output and the measurement is terminated (step S815).

[0094] Next, the first electromagnetic valve 104 and the third electromagnetic valve 309 are opened, and the second electromagnetic valve 308 and the fourth electromagnetic valve 310 are closed. Next, the syringe 103 applies negative pressure to the flow path to attract the diluted sample from the dilution tank 313 to the flow path 306 of the first detector 304. After that, the third electromagnetic valve 309 is closed, and the fourth electromagnetic valve 310 is opened to make the syringe 103 perform a discharge action. This is to return the piston of the syringe to its original position so that the suction action can be performed again. (Step S803).

[0095] Here, the control unit 115 measures the amount of liquid after suction by the liquid level detection sensor 102b of the dispensing nozzle 303. The method for determining the amount of suction in step S804 is the same as that in step S806. Figure 3 Here, when the amount of liquid sucked is small, it is judged that there is a failure of the syringe 103 or a failure of the third solenoid valve 309 or the fourth solenoid valve 310, or a liquid leakage or blockage in the flow path 113 (step S812). In the case of a failure, an alarm is output and the measurement is terminated (step S815).

[0096] Next, the second solenoid valve 308 and the third solenoid valve 309 are opened, and the first solenoid valve 104 and the fourth solenoid valve 310 are closed. Next, negative pressure is applied to the flow path by the syringe 103 to introduce the comparison electrode solution from the comparison electrode solution bottle 311 into the flow path 307 of the second detector 305 (step S805).

[0097] Here, the control unit 115 measures the change amount of the diluent by the liquid level detection sensor 102b of the dispensing nozzle 303 (step S806). The determination method of the change amount in step S807 uses the same Figure 3 Here, when the amount of liquid changes, it is considered that the first electromagnetic valve 104 has a fault (step S813).

[0098] Next, the first electromagnetic valve 104, the second electromagnetic valve 308 and the third electromagnetic valve 309 are opened, the fourth electromagnetic valve 310 is closed, and the syringe 103 applies positive pressure to the flow path, thereby generating a backflow in the comparison electrode solution bottle 311 and the dilution tank 313 (step S808).

[0099] Next, the amount of liquid after discharge is measured by the liquid level detection sensor 102b of the dispensing nozzle 303. The method for determining discharge in step S809 uses the same Figure 3 The same method as step S304 of the flowchart of FIG. 8 is used (step S809). Here, if the amount of liquid increases, it is considered that there is a failure in the second electromagnetic valve 308. If the above steps are completed normally, it is determined that the flow path system is normal and the measurement is completed (step S810).

[0100] In addition, in this embodiment, as in Example 1, Figure 2 As in the flowchart of , an action for determining a fault may be added to the flowchart during the analysis process.

[0101] In addition, the present invention is not limited to the above-mentioned embodiments, but also includes various modified examples. For example, the above-mentioned embodiments are detailed descriptions for the purpose of facilitating the understanding of the present invention, and are not limited to all structures described. In addition, a part of the structure of a certain embodiment can be replaced with the structure of other embodiments, and the structure of other embodiments can also be added to the structure of a certain embodiment. In addition, with respect to a part of the structure of each embodiment, other structures can also be added, deleted, or replaced.

[0102] Description of symbols

[0103] 100, 200…automatic analyzer; 101…container; 102…liquid volume sensor; 102b…liquid level detection sensor; 103, 208…syringe; 104, 105, 207, 209, 308, 309, 310…solenoid valve; 106, 109, 110, 111, 120, 202, 212, 306, 307…flow path; 107…branching portion; 108…liquid discharge portion; 112…nozzle; 113…first flow path; 114…second flow path; 115…control unit; 116…storage unit; 117…output unit; 118…input unit; 201…flow cell detection unit; 203…reaction container; 204…luminescence auxiliary reagent container; 205…cleaning reagent container; 206…container exchange mechanism; 210…dispensing machine; 211…reagent supply bottle; 213…detector; 217…atmospheric pressure opening unit; 300…flow-type electrolyte concentration measuring device; 301…dispensing unit; 302…driving mechanism; 303…dispensing nozzle; 304…first detector; 305…second detector; 311…comparison electrode solution bottle; 313…dilution tank; 314…potential measuring unit.

Claims

1. An automatic analysis device, characterized in that: have: A sensor for measuring a liquid level in a container containing a liquid; Flow system; a liquid discharge portion that discharges liquid from the flow path system; a syringe connected to the branching portion of the flow path system and causing the pressure in the flow path to change; and Control Department, The flow path system comprises: a first flow path extending from a nozzle for sucking or ejecting liquid from the container to the branching portion; and a second flow path extending from the branching portion to the liquid discharge portion, wherein the first flow path includes a first solenoid valve for opening and closing the first flow path, and the second flow path includes a second solenoid valve for opening and closing the second flow path, The control unit operates the syringe, the first electromagnetic valve, and the second electromagnetic valve to perform predetermined suction, ejection, and discharge operations in the container, the discharge unit, and the flow path system, and determines whether the flow path system has an abnormality based on the amount of liquid measured by the sensor. The control unit opens the first solenoid valve and the second solenoid valve when the first flow path and the second flow path are filled with liquid from the container to enable the syringe to perform a spraying action, and determines whether the flow path included in the flow path system is blocked or whether there is any abnormality in the syringe based on the liquid amount measured by the sensor.

2. The automatic analysis device according to claim 1, characterized in that Having an output portion, The control unit outputs an alarm to the output unit when determining that an abnormality exists in the flow path system.

3. The automatic analysis device according to claim 1, characterized in that When the control unit determines that the flow path included in the flow path system and the syringe are normal, the control unit closes the second solenoid valve and causes the syringe to perform a suction operation to suck the liquid contained in the container, and determines whether there is any abnormality in the second solenoid valve based on the liquid amount measured by the sensor.

4. The automatic analysis device according to claim 3, characterized in that When the control unit determines that the second electromagnetic valve is normal, the control unit closes the first electromagnetic valve and performs a discharge operation of discharging liquid into the liquid discharge unit through the syringe, and determines whether the first electromagnetic valve has an abnormality based on the liquid amount measured by the sensor.

5. An automatic analysis device, characterized in that: have: a sensor that measures the amount of liquid in any of a reaction container storing a reaction solution, a cleaning reagent container storing a cleaning reagent, and a luminescence auxiliary reagent container storing a luminescence auxiliary reagent; Flow system; a liquid discharge portion that discharges liquid from the flow path system; a syringe connected to the branching portion of the flow path system and causing the pressure in the flow path to change; and Control Department, The flow path system comprises: a first flow path extending from a nozzle for sucking or ejecting liquid from the arbitrary container to the branching portion; and a second flow path, the second flow path extending from the branching portion to the liquid discharge portion, including a first solenoid valve for opening and closing the first flow path on the first flow path and a flow cell detection portion between the nozzle and the first solenoid valve, and including a second solenoid valve for opening and closing the second flow path on the second flow path, The control unit operates the syringe, the first solenoid valve, and the second solenoid valve, and sequentially repeats a measurement operation based on the flow cell detection unit, a suction operation of sucking the cleaning reagent from the cleaning reagent container, a discharge operation of discharging the liquid used for the measurement operation remaining in the flow path system to the liquid discharge unit, and a suction operation of sucking the luminescence auxiliary reagent from the luminescence auxiliary reagent container, The control unit performs at least one of a first measurement of the liquid volume of the cleaning reagent container based on the sensor before the suction action of the cleaning reagent after the i-th measurement action, and a second measurement of the liquid volume of the luminescence auxiliary reagent container based on the sensor before the suction action of the luminescence auxiliary reagent after the i-th measurement action, and at least one of a third measurement of the liquid volume of the cleaning reagent container based on the sensor before the suction action of the cleaning reagent after the (i+1)-th measurement action, and a fourth measurement of the liquid volume of the luminescence auxiliary reagent container based on the sensor before the suction action of the luminescence auxiliary reagent after the (i+1)-th measurement action, The control unit determines whether there is an abnormality in the flow system based on the amount of the washing reagent calculated based on the first measurement result and the third measurement result or the amount of the luminescence assisting reagent calculated based on the second measurement result and the fourth measurement result.

6. The automatic analysis device according to claim 5, characterized in that The control unit compares the amount of the washing reagent calculated based on the first measurement result and the third measurement result or the amount of the luminescence assisting reagent calculated based on the second measurement result and the fourth measurement result with a predetermined threshold value, thereby determining whether the flow system has an abnormality.

7. The automatic analysis device according to claim 5, characterized in that Having an output portion, The control unit outputs an alarm to the output unit regarding the i-th measurement result of the flow cell detection unit when it is determined that an abnormality exists in the flow channel system.

8. The automatic analysis device according to claim 5, characterized in that The control unit opens the first solenoid valve and the second solenoid valve when the first flow path and the second flow path are filled with liquid from the arbitrary container to enable the syringe to perform a spraying action, and determines whether the flow path included in the flow path system is blocked or whether there is any abnormality with the syringe based on the spraying amount toward the arbitrary container calculated according to the difference in liquid volume before and after the spraying action measured by the sensor.

9. The automatic analysis device according to claim 8, characterized in that When the control unit determines that the discharge volume is normal, the control unit closes the second solenoid valve and causes the syringe to perform a suction operation to suck the liquid contained in the arbitrary container, and determines whether the second solenoid valve has any abnormality based on the suction volume of the liquid from the arbitrary container calculated based on the difference in liquid volume before and after the suction operation measured by the sensor.

10. The automatic analysis device according to claim 9, characterized in that When the control unit determines that the second solenoid valve is normal, the control unit closes the first solenoid valve and causes the syringe to perform a spray action, thereby performing a discharge action to discharge the liquid into the discharge unit, and determines whether there is any abnormality in the first solenoid valve based on the change in the liquid volume of the arbitrary container calculated based on the difference in the liquid volume before and after the discharge action measured by the sensor.

11. The automatic analysis device according to any one of claims 8 to 10, characterized in that: The sensor is a liquid level detection sensor, The speed at which the suction nozzle for detecting the liquid level of the arbitrary container protrudes into the liquid level is set to be slower than that during the analysis operation.

12. An automatic analysis device, characterized in that: have: Dilution tank; a dispensing unit including a liquid level detection sensor for detecting a liquid level of the dilution tank and dispensing a specimen into the dilution tank; Flow system; a liquid discharge portion that discharges liquid from the flow path system; a syringe connected to the branching portion of the flow path system and causing the pressure in the flow path to change; and Control Department, The flow path system includes: a first flow path extending from a nozzle that sucks or ejects liquid from the dilution tank to the branching portion; and a second flow path, the second flow path extending from the bifurcation to the comparison electrode solution bottle, including a first solenoid valve for opening and closing the first flow path and a first detector between the nozzle and the first solenoid valve on the first flow path, and including a second solenoid valve for opening and closing the second flow path and a second detector between the bifurcation and the second solenoid valve on the second flow path, In the flow path from the branching portion to the liquid discharge portion of the flow path system, a third electromagnetic valve is included between the branching portion and the syringe, and a fourth electromagnetic valve is included between the syringe and the liquid discharge portion. The control unit opens the first solenoid valve and the third solenoid valve, closes the second solenoid valve and the fourth solenoid valve, and causes the syringe to perform a suction action, thereby performing a first suction action of the diluted specimen stored in the dilution tank. Thereafter, the control unit closes the third solenoid valve and opens the fourth solenoid valve to cause the syringe to perform a first ejection action, and determines whether the flow path is blocked, the syringe is abnormal, or whether there is an abnormality in the third solenoid valve or the fourth solenoid valve based on the amount of the diluted specimen sucked calculated by detecting the liquid level of the liquid stored in the dilution tank before and after the first suction action and the first ejection action using the liquid level detection sensor of the dispensing unit.

13. The automatic analysis device according to claim 12, characterized in that: When the aspiration amount of the diluted specimen is normal, the control unit opens the second solenoid valve and the third solenoid valve, closes the first solenoid valve and the fourth solenoid valve, and causes the syringe to perform aspiration, thereby performing a second aspiration action of the comparison electrode liquid contained in the comparison electrode liquid bottle, and uses the liquid level detection sensor of the dispensing unit to detect the liquid level of the liquid contained in the dilution tank before and after the second aspiration action, and judges whether there is any abnormality in the first solenoid valve based on the change in the liquid level before and after the second aspiration action.

14. The automatic analysis device according to claim 13, characterized in that: When the control unit determines that the first solenoid valve is normal, the control unit opens the first solenoid valve, the second solenoid valve and the third solenoid valve to make the syringe perform a second ejection action, uses the liquid level detection sensor of the dispensing unit to detect the liquid level of the liquid contained in the dilution tank before and after the second ejection action, and determines whether the second solenoid valve has any abnormality based on the change in the liquid level before and after the second ejection action.

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