METHOD FOR CONTROLLING AUTOMATED ANALYZER AND AUTOMATED ANALYZER

Abstract

In order to improve the detection sensitivity of flow rate measurements in a low-pressure, low flow rate cleaning system of an automatic analysis device, the present disclosure proposes a control method for an automatic analysis device comprising a liquid delivery pump that delivers a cleaning liquid to a cleaning mechanism of a dispensing nozzle through a flow channel, and a control unit that controls operation of the liquid delivery pump. The control method comprises: operating the liquid delivery pump through the control unit to deliver the cleaning liquid to a low-pressure flow channel that constitutes at least a portion of the flow channel and is of a low pressure and a low flow rate; and operating, through the control unit, a flow rate estimating mechanism arranged in the low-pressure flow channel to determine a value of an estimated flow rate in the low-pressure flow channel (see fig. 2).

Description

[Technical Field]

[0001] The present disclosure relates to a control method for an automatic analyzer and an automatic analyzer. [Background technology]

[0002] Automated analyzers, such as biochemical automated analyzers, analyze the components of biological samples (hereinafter referred to as "samples") such as serum and urine. In such automated biochemical analyzers, a dispensing nozzle is generally used to dispense samples and reagents into reaction vessels, respectively, to cause a reaction, and the changes in color and turbidity that occur in the reaction solution are optically measured using a photometric unit such as a spectrophotometer. Therefore, contamination of the nozzle affects the accuracy of dispensing, and as a result, the reliability of the automated analyzer. Therefore, after dispensing the sample, etc., the sample adhering to the outer wall and interior of the nozzle is cleaned with a cleaning solution.

[0003] For example, Patent Document 1 states, "The cleaning fluid passes through the cleaning cell and thus circulates around the exterior of the probe, more thoroughly cleaning the exterior of the probe. Similarly, it is known to pass a cleaning fluid through the probe. Preferably, the cleaning fluid is divided into a plurality of entrained air bubbles, which tend to scrub the interior surface of the probe as they pass, further facilitating the removal of carryover material." [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Publication number 6-43723 Summary of the Invention [Problem to be solved by the invention]

[0005] In automated analyzers, the flow rate of cleaning liquid changes when the performance of the pump that supplies cleaning liquid to clean the nozzles deteriorates over time or when the flow path from the pump to the cleaning liquid outlet becomes clogged. If the amount of cleaning liquid is small, for example, the nozzles may not be cleaned sufficiently, which could result in carryover or other problems. To respond to such changes in the amount of cleaning liquid, abnormalities have generally been detected by measuring the pressure in the flow path.

[0006] This type of abnormality detection technology using pressure measurement is applicable to flow paths with relatively high pressure and high flow rates, but cannot be applied to flow paths with low pressure and low flow rates. In recent years, attempts have been made to introduce low-pressure, low-flow rate cleaning systems, but conventional technologies such as those described in Patent Document 1 have not considered the detection sensitivity in low-pressure, low-flow rate cleaning systems. In view of this situation, the present disclosure proposes a technique for improving the detection sensitivity of flow rate measurements in low-pressure, low-flow rate cleaning systems in automatic analyzers. [Means for solving the problem]

[0007] In order to solve the above problems, for example, the configurations described in the claims are adopted.

[0008] The present disclosure includes multiple means for solving the above-mentioned problems, and as one example, it proposes a control method for an automatic analyzer that includes a liquid delivery pump that delivers cleaning liquid to a cleaning mechanism of a dispensing nozzle via a flow path and a control unit that controls the operation of the liquid delivery pump, the control unit operating the liquid delivery pump to deliver cleaning liquid to a low-pressure flow path that has low pressure and a low flow rate and that constitutes at least a part of the flow path, and the control unit operating a flow rate estimation mechanism installed in the low-pressure flow path to determine an estimated flow rate value in the low-pressure flow path.

[0009] Further features related to the present disclosure will become apparent from the description and accompanying drawings of this specification, and aspects of the present disclosure may be realized and realized by the elements and combinations of various elements and aspects set forth in the following detailed description and the appended claims. It should be understood that the descriptions in this specification are exemplary and illustrative only and are not intended to limit the scope or application of the present disclosure in any way. [Effects of the Invention]

[0010] According to the present disclosure, in an automatic analyzer, it is possible to improve the detection sensitivity of flow rate measurement in a low-pressure, low-flow rate cleaning system. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a diagram showing an example of the overall schematic configuration of an automatic analyzer 100 according to the present embodiment. [Figure 2] FIG. 2 is a diagram showing an example of the schematic configuration of a cleaning flow path of a dispensing mechanism (sample dispensing mechanism 105) in an automatic analyzer 100 according to this embodiment. [Figure 3] 10 is a flowchart illustrating a dispensing operation control process according to the present embodiment. [Figure 4] 6 is a flowchart illustrating a flow rate adjustment process according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] This embodiment discloses a technology for estimating the flow rate in a low-pressure, low-flow rate cleaning system (e.g., an external cleaning flow path) in an automated analyzer, detecting cleaning abnormalities based on the estimated flow rate, and adjusting the flow rate of a liquid delivery pump. In this embodiment, low pressure can be defined as, for example, 10 kPa or less, and low flow rate can be defined as a flow rate resulting from liquid delivery at low pressure (10 kPa). High pressure can be defined as 100 kPa or more.

[0013] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. In the accompanying drawings, functionally identical elements may be designated by the same numerals. Note that the accompanying drawings illustrate specific embodiments and implementation examples according to the principles of the present disclosure, but these are for understanding the present disclosure and are not to be used to interpret the present disclosure in any way as being limiting.

[0014] <Configuration example of an automatic analyzer> 1 is a diagram showing an example of the overall schematic configuration of an automatic analyzer 100 according to this embodiment. The automatic analyzer 100 includes a reagent disk 102 that mounts a plurality of reagent containers 101, a reaction disk 103 that mixes reagents and samples to measure reactions, a reagent dispensing mechanism 104 that aspirates and dispenses reagents, a sample dispensing mechanism 105 that aspirates and dispenses samples, and a control unit (processor) 214 that controls the opening and closing of a liquid delivery pump 202 and various valves (see FIG. 2). The automatic analyzer 100 may include other components.

[0015] The reagent dispensing mechanism 104 includes a reagent nozzle (not shown) for dispensing a reagent, and the sample dispensing mechanism 105 includes a sample dispensing nozzle 110 for dispensing a sample.

[0016] Samples introduced into the automatic analyzer are placed in sample containers (test tubes) 108 and transported on racks 106. A plurality of sample containers 108 are mounted on the racks 106. The samples are blood-derived samples such as serum or whole blood, or urine.

[0017] The sample dispensing mechanism 105 rotates the sample dispensing nozzle 110 to move it to an aspirating position where it aspirates the sample from the sample container 108, an ejecting position where it ejects the sample into the cell 109, and a cleaning position where it cleans the tip of the sample dispensing nozzle 110 in the cleaning tank 107.

[0018] Furthermore, the sample dispensing mechanism 105 lowers the sample dispensing nozzle 110 at the suction position, discharge position, and washing position, according to the heights of the sample container 108, cell 109, and washing tank 107. The sample dispensing nozzle 110 and the reagent nozzle are equipped with liquid contact detection sensors that detect the liquid level, and it is possible to confirm from the sensor signal that they have come into contact with the target liquid (sample or reagent).

[0019] The automatic analyzer 100 analyzes the concentration of a predetermined component in the sample by measuring the photometry of a mixture of the sample and a reagent contained in a cell 109. The general configuration of the automatic analyzer 100 has been described above.

[0020] <Example of cleaning flow path configuration> In this embodiment, the cleaning system flow path of the sample dispensing nozzle 110 will be described as an example, but the technology according to this embodiment can also be applied to a reagent nozzle in which the same nozzle is cleaned and used repeatedly. The technology can also be applied to an apparatus that dispenses both sample and reagent using the same nozzle.

[0021] FIG. 2 is a diagram showing an example of the schematic configuration of a cleaning flow path of a dispensing mechanism (sample dispensing mechanism 105) in the automatic analyzer 100 according to this embodiment. The cleaning system flow path of the automatic analyzer 100 includes, for example, an inner cleaning flow path 206 and an outer cleaning flow path 207, and can be composed of a cleaning liquid storage container 201, a liquid delivery pump 202 that delivers the cleaning liquid, a cleaning tank 107 that cleans the outer wall of the nozzle, a sample syringe 203 that aspirates and ejects the sample, a sample dispensing nozzle (hereinafter abbreviated as dispensing nozzle) 110, a three-way solenoid valve 204 provided downstream of the liquid delivery pump 202, and a three-way solenoid valve 208 provided upstream of the dispensing nozzle 110.

[0022] The three-way solenoid valve 204 selectively connects a cleaning liquid supply flow path 205, which sends the cleaning liquid using the liquid supply pump 202, to an internal washing flow path 206, which supplies the cleaning liquid to the inside of the dispensing nozzle 110, and an external washing flow path 207, which supplies the cleaning liquid to a washing tank 107, which cleans the outer wall of the dispensing nozzle 110.

[0023] In addition, the connection source of the dispensing nozzle 110 can be switched by a three-way electromagnetic valve 208. When connected to the internal washing flow path 206, a washing liquid can be supplied to the dispensing nozzle 110 to wash the inside. When connected to the dispensing flow path 209, a sample can be aspirated or discharged using the sample syringe 203. The inside of the sample syringe 203 and the dispensing flow path 209 are filled with degassed water supplied via a two-way electromagnetic valve 210.

[0024] A bubble generating unit composed of a three-way electromagnetic valve 211 is provided at a predetermined position (upstream side) of the external washing flow path 207, and air bubble sensors 212 and 213 are arranged at a certain distance downstream of the three-way electromagnetic valve 211. Air bubbles (air) can be introduced into the external washing flow path 207 via the three-way electromagnetic valve 211 (by opening the atmospheric release valve NC), and the air bubble sensor detects air bubbles (at the interface between the washing solution and air). Because the external washing flow path 207 operates at low pressure (for example, 10 kPa or less as described above) and low flow rate, introducing air bubbles (air) into the external washing flow path 207 makes the bubbles less likely to collapse and easier to detect. This also avoids the risk of air bubbles getting into the sample syringe 203 and deteriorating dispensing accuracy.

[0025] <Dispensing operation control process> 3 is a flowchart for explaining the dispensing operation control process according to this embodiment. The dispensing operation includes an internal washing operation, an external washing operation, and a sample dispensing operation, and in this embodiment, the flow rate of the liquid feed pump 202 is estimated during the external washing operation.

[0026] (i) Step 301 First, the control unit 214 operates the liquid supply pump 202 to supply the cleaning liquid from the cleaning liquid storage container 201 to the internal cleaning flow path 206 via the cleaning liquid supply flow path 205, thereby cleaning the inside of the dispensing nozzle 110.

[0027] (ii) Step 302 The control unit 214 switches the three-way electromagnetic valve 204 to connect the cleaning liquid supply flow path 205 to the external washing flow path 207. If the external washing flow path 207 is not filled with cleaning liquid, the control unit 214 operates the liquid feed pump 202 to fill the external washing flow path 207 (for example, the flow path to the washing tank 107) with cleaning liquid.

[0028] (iii) Step 303 The control unit 214 switches the three-way electromagnetic valve 211, which is the bubble generating unit, to the atmospheric open side for a certain period of time. During this time, the cleaning liquid inside the external cleaning flow path 207 is discharged from the cleaning tank 107 by gravity.

[0029] (iv) Step 304 Thereafter, the control unit 214 returns the three-way electromagnetic valve 211 to the closed state and sends the cleaning liquid using the liquid sending pump 202. As a result, the interface between the cleaning liquid and air (which may be the interface between the cleaning liquid and air in the bubbles) moves in the external washing flow path. The control unit 214 then determines the time difference between when the interface between the cleaning liquid and air passes the air bubble sensor 212 and the air bubble sensor 213, and calculates the bubble movement speed V (the number of air bubble sensors may be one). After calculating the bubble movement velocity V, the control unit 214 obtains an estimated flow rate Q from the cross-sectional area S of the external washing flow path 207 using a flow rate estimation formula Q=V·S.

[0030] (v) Step 305 The control unit 214 compares the estimated flow rate Q with a preset target flow rate Q0 to determine whether it is within a normal range. Specifically, it determines whether |Q-Q0| is less than the flow rate error allowance ΔQ. If |Q-Q0|<ΔQ (YES in step 305: the flow rate is within the normal range), the process proceeds to step 306. On the other hand, if |Q-Q0|≧ΔQ (NO in step 305: the flow rate is outside the normal range), the process proceeds to step 309.

[0031] (vi) Step 306 The control unit 214 operates the liquid supply pump 202 to supply the cleaning liquid to the external washing flow path 207, thereby performing external washing of the dispensing nozzle 110. Note that the external washing can be performed by spraying the cleaning liquid onto the tip of the dispensing nozzle 110 in the washing tank 107.

[0032] (vii) Step 307 The control unit 214 controls the three-way electromagnetic valve 208 to close the cleaning liquid supply side and open the sample liquid supply side, thereby switching to the dispensing flow path.

[0033] (viii) Step 308 The control unit 214 moves the dispensing nozzle 110 to the sample container 108 and performs the dispensing operation. When the dispensing operation is completed, the process ends.

[0034] (ix) Step 309 The control unit 214 notifies the user of the cleaning abnormality (for example, by giving a voice notification or displaying a warning message on the display screen), and ends the process without performing the dispensing operation.

[0035] <Flow rate adjustment operation> For example, if the flow rate determination result is determined to be outside the normal range in the process of Fig. 3 (NO in step 305), it is possible to adjust the flow rate so that it is within the normal range (flow rate adjustment process). Also, even if the process of Fig. 3 is not being executed, if it is desired to adjust the flow rate, the operator (user) may input an instruction to execute the flow rate adjustment process, thereby executing the flow rate adjustment process. Fig. 4 is a flowchart for explaining the flow rate adjustment process according to this embodiment.

[0036] (i) Step 401 The control unit 214 performs the same operations as in steps 303 and 304, measures the movement speed V of the bubbles (at the interface between the cleaning liquid and the air), and calculates the estimated flow rate Q. Note that, if the flow rate adjustment process is performed immediately after the cleaning abnormality notification process (step 309 in FIG. 3), step 401 does not need to be performed. In this case, the value of the estimated flow rate Q calculated in step 304 can be used.

[0037] (ii) Step 402 The control unit 214 calculates the adjusted pump drive voltage E' using the ratio of the estimated flow rate Q to the target flow rate Q0 and the pre-adjustment pump drive voltage E using the formula E'=E*(Q0 / Q), and sets this as the drive voltage (pump drive voltage) of the liquid delivery pump 202.

[0038] (iii) Step 403 The control unit 214 again executes the same operations as in steps 303 and 304, measures the movement speed V of the bubbles (at the interface between the cleaning liquid and the air), and calculates the estimated flow rate Q.

[0039] (iv) Step 404 The control unit 214 compares the estimated flow rate Q with a preset target flow rate Q0 to determine whether it is within a normal range. Specifically, it determines whether |Q-Q0| is less than the flow rate error tolerance ΔQ. If |Q-Q0|<ΔQ (YES in step 404: the flow rate is within the normal range), the flow rate adjustment process ends. On the other hand, if |Q-Q0|≧ΔQ (NO in step 404: the flow rate is outside the normal range), the process proceeds to step 405.

[0040] (v) Step 405 The control unit 214 issues a warning of a cleaning abnormality (for example, by audio notification or by displaying a warning message on the display screen) and ends the process without performing the dispensing operation. In this embodiment, a cleaning abnormality is issued when the difference between the estimated flow rate Q and the target flow rate Q0 is equal to or greater than the flow rate error tolerance ΔQ, but it is also possible to proceed to step 402 without issuing a warning of a cleaning abnormality and adjust the pump drive voltage until the difference between the estimated flow rate Q and the target flow rate Q0 becomes less than the flow rate error tolerance ΔQ (loop processing from step 402 to step 404).

[0041] <Modification> The technology according to the present disclosure is not limited to the above-described embodiments, but includes various modifications. For example, the above-described embodiments have been described in detail to clearly explain the technology according to the present disclosure, and are not necessarily limited to those including all of the described configurations. Furthermore, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add other components to the components of this embodiment. Furthermore, it is possible to add, delete, or replace other components with part of the configuration of one embodiment. Examples of modifications are given below.

[0042] (i) Variation 1 In the above-described embodiment, the flow rate abnormality determination process and flow rate adjustment process were described based on the flow rate (inner washing flow rate) of the outer washing flow path 207. However, depending on the conditions (for example, when the flow rate (inner washing flow rate) of the inner washing flow path 206 is more important than the outer washing flow rate or when it is desired to control the inner washing flow rate), it may be necessary to determine the flow rate abnormality and adjust the flow rate based on the inner washing flow rate.

[0043] In such a case, even if the drive voltage of the liquid feed pump 202 is the same, the pressure loss varies depending on the diameter and length of the pipes that make up the flow path. A and external washing flow rate Q B On the other hand, the factors that are affected by the change over time are mainly the internal elements of the liquid feed pump 202, such as the motor rotation speed, and the external flow path piping diameter and piping length do not change. For this reason, the internal washing flow path flow rate Q A and external washing flow rate Q B The correlation between is not expected to change significantly over time.

[0044] Therefore, before shipping the automatic analyzer 100, the internal washing flow rate Q A and external washing flow rate Q B The correlation coefficient k=Q A / Q B is calculated and stored in the internal memory (not shown) of the control unit 214. By doing this, the internal washing flow rate estimation formula Q A =kQ B It is possible to estimate the internal washing flow rate from the estimated value of the external washing flow rate. A By using this, it is possible to perform the flow rate abnormality determination process and the flow rate adjustment process based on the internal washing flow rate in the same procedure as in the above-described embodiment.

[0045] (ii) Modification 2 When there are multiple dispensing mechanisms and liquid feed pumps, the flow rate estimation mechanisms can be integrated into one location in the cleaning liquid supply flow path 205, which is the most upstream of the cleaning flow path, and the above-described flow rate estimation process can be applied to such a configuration as well. By integrating multiple flow rate estimation mechanisms into one location, it is possible to reduce the size of the dispensing mechanisms and cleaning mechanisms.

[0046] (iii) Modification 3 When there are multiple dispensing mechanisms and liquid feed pumps, the flow rate estimation mechanisms can be integrated into a single waste liquid tank (not shown) connected to the washing tank 107 at the most downstream of the washing flow path, and the flow rate estimation process described above can be applied to such a configuration as well. By integrating multiple flow rate estimation mechanisms into one location, it becomes possible to reduce the size of the dispensing mechanisms and washing mechanisms.

[0047] (iv) Variation 4 In the above embodiment, various processes are performed by a single control unit 214, but these processes may be divided among multiple control units. Furthermore, these multiple control units may be incorporated into the automatic analyzer 100, or may be provided externally to the automatic analyzer 100.

[0048] (v) Variation 5 In addition to generating bubbles and estimating the flow rate from their movement speed, the flow rate in the external washing flow path 207 may also be estimated using a thermal flow meter equipped with a heater and a temperature sensor or a Coriolis flow meter that uses the Coriolis force.

[0049] <Summary> (i) In the automated analyzer according to this embodiment, a liquid delivery pump is operated to deliver cleaning liquid to a low-pressure, low-flow path (e.g., a path delivering liquid at 10 kPa) that constitutes at least a portion of the path, and a flow rate estimation mechanism (e.g., a mechanism that introduces air (air bubbles) and estimates the flow rate from the speed of their movement, a mechanism that estimates the flow rate using a thermal flow meter, a mechanism that estimates the flow rate using a Coriolis flow meter, etc.) installed in the low-pressure path is operated to perform an operation to determine an estimated flow rate in the low-pressure path. In this way, it is possible to improve the detection sensitivity of flow rate measurements in a low-pressure, low-flow rate cleaning system in an automated analyzer equipped with a dispensing mechanism.

[0050] (ii) When using a mechanism that estimates the flow rate from the movement speed of the interface between air (air bubbles) and the cleaning solution, the estimated flow rate in the low-pressure flow path is determined by controlling the air introduction mechanism to introduce air into the low-pressure flow path, detecting the movement of the interface between the air and the cleaning solution with a sensor, and then calculating the movement speed of the interface in the low-pressure flow path based on the detection signal from the sensor and the volume of the low-pressure flow path. Because a three-way solenoid valve can be used as the air introduction mechanism, the flow rate estimation mechanism can be realized inexpensively and the automated analyzer can be made smaller. Here, the interface between air and the cleaning solution is generated by introducing air into the external cleaning flow path, which corresponds to the low-pressure flow path.

[0051] (iii) The estimated flow rate value may be judged to be within a predetermined normal flow rate range, and the judgment result may be output, or a flow rate adjustment process may be executed to adjust the flow rate of the liquid delivery pump.

[0052] (iv) The functions of the embodiments of the present disclosure can also be realized by software program code. In this case, a storage medium on which the program code is recorded is provided to a system or device, and the computer (or CPU or MPU) of the system or device reads the program code stored on the storage medium. In this case, the program code read from the storage medium itself realizes the functions of the above-mentioned embodiments, and the program code itself and the storage medium on which it is stored constitute the present disclosure. Examples of storage media for providing such program code include flexible disks, CD-ROMs, DVD-ROMs, hard disks, optical disks, magneto-optical disks, CD-Rs, magnetic tapes, non-volatile memory cards, and ROMs.

[0053] In addition, an operating system (OS) running on a computer may perform some or all of the actual processing based on instructions in the program code, and the functions of the above-described embodiments may be realized by this processing. Furthermore, after the program code is read from a storage medium and written to a memory on a computer, a CPU of the computer may perform some or all of the actual processing based on instructions in the program code, and the functions of the above-described embodiments may be realized by this processing.

[0054] Furthermore, the program code of the software that realizes the functions of the embodiments may be distributed via a network and stored in a storage means such as a hard disk or memory of the system or device, or in a storage medium such as a CD-RW or CD-R, so that when in use, the computer (or CPU or MPU) of the system or device reads and executes the program code stored in the storage means or storage medium.

[0055] Finally, it should be understood that the processes and techniques described herein are not inherently related to any particular apparatus, but may be implemented by any suitable combination of components. Furthermore, various types of general-purpose devices can be used in accordance with the teachings described herein. It may prove useful to construct specialized apparatus to perform the method steps described herein. Various inventions can also be formed by suitable combinations of multiple components disclosed in the embodiments. For example, some components may be omitted from all of the components shown in the embodiments. Furthermore, components from different embodiments may be combined as appropriate. While the present disclosure has been described with reference to specific examples, these are intended in all respects to be illustrative and not limiting. Those skilled in the art will recognize that numerous combinations of hardware, software, and firmware are suitable for practicing the present disclosure. For example, the described software can be implemented in a wide variety of programming or scripting languages, including assembler, C / C++, Perl, Shell, PHP, Java, etc.

[0056] Furthermore, in the above-described embodiment, the control lines and information lines are those that are considered necessary for the explanation, and not all control lines and information lines in the product are necessarily shown. All components may be interconnected. [Explanation of symbols]

[0057] 100 automatic analyzer 101 Reagent container 102 Reagent Disk 103 Reaction Disc 104 Reagent dispensing mechanism 105 Sample dispensing mechanism 106 racks 107 Cleaning tank 108 Sample container 109 cells 110 Sample dispensing nozzle (dispensing nozzle) 201 Cleaning solution storage container 202 Liquid transfer pump 203 Sample syringe 204, 208, 211 Three-way solenoid valve 205 Cleaning liquid supply channel 206 Internal wash channel 207 Outside wash channel 209 Dispensing channel 210 Two-way solenoid valve 212,213 Air bubble sensor 214 Control Unit

Claims

1. A control method for an automatic analyzer including a liquid feed pump that feeds a cleaning liquid to a cleaning mechanism of a dispensing nozzle through a flow path, and a control unit that controls the operation of the liquid feed pump, operating the liquid supply pump by the control unit to supply the cleaning liquid to a low-pressure flow path that constitutes at least a part of the flow path and has a low pressure and a low flow rate; operating a flow rate estimation mechanism installed in the low-pressure flow path by the control unit to obtain an estimated flow rate value in the low-pressure flow path; Including, the flow rate estimation mechanism is an air introduction mechanism that supplies air to the low-pressure flow path, Determining the flow rate estimate in the low pressure flow path comprises: controlling the air introducing mechanism by the control unit to introduce air into the low-pressure flow path and generate an interface between the air and the cleaning liquid; activating a sensor by the control unit to detect the boundary surface in the low-pressure flow path; calculating, by the control unit, a moving speed of the boundary surface in the low-pressure flow path based on the detection signal from the sensor; estimating a flow rate of the low-pressure flow path by the liquid feed pump based on a volume of the low-pressure flow path and a moving speed of the boundary surface by the control unit; Including, generating an interface between the air and the cleaning liquid by the control unit by introducing the air into the external washing flow path corresponding to the low-pressure flow path, among the flow paths including an internal washing flow path that supplies cleaning liquid to the inside of the dispensing nozzle and an external washing flow path that supplies cleaning liquid to a washing tank that cleans the outer wall of the dispensing nozzle; moreover, calculating the estimated flow rate value in the external washing flow path of the liquid feed pump by the control unit; The control unit calculates a flow rate estimate value of the inner washing flow path from the flow rate estimate value of the outer washing flow path based on a predetermined correlation equation between the flow rate of the inner washing flow path and the flow rate of the outer washing flow path; When the estimated flow rate value of the interior washing flow path is outside a normal range, the control unit adjusts the flow rate of the liquid feed pump so that the estimated flow rate value of the interior washing flow path matches a given target flow rate; Including, Control method.

2. In claim 1, In the low-pressure flow path, the cleaning liquid is sent at a pressure of 10 kPa or less, The control method further includes determining, by the control unit, whether the flow rate estimated value is within a preset normal flow rate range and outputting a determination result.

3. In claim 1, In the low-pressure flow path, the cleaning liquid is sent at a pressure of 10 kPa or less, The control method further includes executing a flow rate adjustment process by the control unit to adjust the flow rate of the liquid feed pump.

4. In claim 1, the air introduction mechanism includes an atmosphere release solenoid valve, the control unit introduces the air into the low-pressure flow path by opening the atmosphere release electromagnetic valve provided in the low-pressure flow path.

5. In claim 4, Determining the flow rate estimate includes: opening the atmosphere release electromagnetic valve by the control unit to discharge the cleaning liquid filling downstream of the atmosphere release electromagnetic valve; causing the control unit to start liquid feeding by the liquid feed pump and move the boundary surface between the cleaning liquid and the air within the low-pressure flow path; acquiring, by the control unit, information on the movement of the boundary surface detected by the sensor; calculating, by the control unit, a movement speed of the boundary surface based on time information of the movement of the boundary surface; calculating, by the control unit, an estimated flow rate value of the low-pressure flow path by multiplying the moving speed by a cross-sectional area of ​​the low-pressure flow path; A control method comprising:

6. In claim 3, The control unit executes the flow rate adjustment process by adjusting a drive voltage value of the liquid feed pump based on a ratio between the estimated flow rate value and a given target flow rate value.

7. In claim 1, The control unit calculates the estimated flow rate value of the liquid feed pump in a waste liquid flow path or a cleaning liquid supply flow path included in the flow path.

8. A dispensing nozzle; a cleaning solution tank for storing a cleaning solution; a cleaning mechanism for cleaning the dispensing nozzle; a low-pressure flow path that is low-pressure and low-flow rate and that connects the cleaning liquid tank to the cleaning mechanism; a liquid supply pump that supplies a cleaning liquid to the cleaning mechanism through the low-pressure flow path; a control unit that operates the liquid feed pump and a flow rate estimation mechanism installed in the low-pressure flow path to determine an estimated flow rate in the low-pressure flow path; Equipped with the flow rate estimation mechanism is an air introduction mechanism that supplies air to the low-pressure flow path, The control unit a process of controlling the air introduction mechanism to introduce air into the low-pressure flow path and creating an interface between the air and the cleaning liquid; activating a sensor to detect the interface in the low pressure flow path; a process of calculating a moving speed of the boundary surface in the low-pressure flow path based on a detection signal from the sensor; a process of estimating a flow rate of the low-pressure flow path by the liquid feed pump based on a volume of the low-pressure flow path and a moving speed of the boundary surface; Run The control unit a process of introducing the air into the outer washing flow path corresponding to the low-pressure flow path, among flow paths including an inner washing flow path that supplies a washing liquid to the inside of the dispensing nozzle and an outer washing flow path that supplies a washing liquid to a washing tank that cleans the outer wall of the dispensing nozzle, to generate the boundary surface; A process of calculating the estimated flow rate in the external washing flow path of the liquid feed pump; A process of calculating a flow rate estimate value of the inner washing flow path from the flow rate estimate value of the outer washing flow path based on a predetermined correlation equation between the flow rate of the inner washing flow path and the flow rate of the outer washing flow path; If the estimated flow rate value of the interior washing flow path is outside a normal range, a process of adjusting the flow rate of the liquid feed pump so that the estimated flow rate value of the interior washing flow path matches a given target flow rate; To execute Automatic analyzer.

9. In claim 8, In the low-pressure flow path, the cleaning liquid is sent at a pressure of 10 kPa or less, The control unit further executes a process of determining whether the estimated flow rate value is within a preset normal flow rate range and outputting the determination result.

10. In claim 8, In the low-pressure flow path, the cleaning liquid is sent at a pressure of 10 kPa or less, The control unit further executes a flow rate adjustment process to adjust the flow rate of the liquid feed pump.

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