AUTOMATIC ANALYSIS DEVICE CONTROL METHOD, AND AUTOMATIC ANALYSIS DEVICE

In an automatic analyzer, detection sensitivity in flow rate measurement in a cleaning system having a low pressure and a low flow rate is improved. The present disclosure proposes a control method for an automatic analyzer including a liquid feed pump that feeds, through a flow path, a cleaning liquid to a cleaning mechanism of a dispensing nozzle, and a control unit that controls an operation of the liquid feed pump. The control method includes: operating, by the control unit, the liquid feed pump to feed the cleaning liquid to a low-pressure flow path having a low pressure and a low flow rate, the low-pressure flow path constituting at least a part of the flow path; and operating, by the control unit, a flow rate estimation mechanism provided in the low-pressure flow path to obtain a flow rate estimation value in the low-pressure flow path.

TECHNICAL FIELD

The present disclosure relates to a control method for an automatic analyzer, and an automatic analyzer.

BACKGROUND ART

An automatic analyzer, for example, a biochemical automatic analyzer, analyzes components of a biological sample (hereinafter referred to as a “sample”) such as serum or urine. In such a biochemical automatic analyzer, generally, a sample and a reagent are dispensed into a reaction container using a dispensing nozzle and reacted with each other, and a change in color tone or turbidity generated in a reaction solution is optically measured by a photometry unit such as a spectrophotometer. Therefore, contamination or the like of the nozzle affects dispensing accuracy, and as a result, also affects reliability of the automatic analyzer. Therefore, after dispensing a sample or the like, the sample or the like adhering to an outer wall or an inner side of the nozzle is cleaned using a cleaning liquid.

For example, PTL 1 discloses that “The cleaning liquid circulates around the outside of the probe through the cleaning cell to clean the outside of the probe more thoroughly. Similarly, it is known to cause the cleaning liquid to flow through the probe. The cleaning liquid is preferably divided by a plurality of continuous bubbles, and the bubbles are likely to rub against an inner surface of the probe when the bubbles pass through the probe, and further promote removal of a carried substance”.

CITATION LIST

Patent Literature

SUMMARY OF INVENTION

Technical Problem

In an automatic analyzer, when performance of a pump that supplies a cleaning liquid for cleaning a nozzle deteriorates due to aging or a flow path from the pump to a discharge port of the cleaning liquid is clogged, a flow rate of the cleaning liquid changes. When a cleaning liquid amount s small, for example, the nozzle cannot be sufficiently cleaned and a carryover or the like may occur. In order to cope with such a change in the cleaning liquid amount, generally, a pressure of the flow path is mainly measured to detect an abnormality.

Such an abnormality detection technique based on pressure measurement is applied to a flow path having a relative high pressure and a high flow rate, and cannot be applied to a flow path having a low pressure and a low flow rate. In recent years, attempts are made to introduce a cleaning system having a low pressure and a low flow rate, but in the related art as in PTL 1, no study is made on detection sensitivity in a cleaning system having a low pressure and a low flow rate.

In view of such a situation, the present disclosure proposes a technique for improving detection sensitivity in flow rate measurement in a cleaning system having a low pressure and a low flow rate in an automatic analyzer.

Solution to Problem

In order to solve the above problems, for example, a configuration described in the claims is adopted.

The present disclosure includes a plurality of methods for solving the above problems, and for example, the present disclosure proposes a control method for an automatic analyzer including a liquid feed pump that feeds, through a flow path, a cleaning liquid to a cleaning mechanism of a dispensing nozzle, and a control unit that controls an operation of the liquid feed pump, in which the control method includes operating, by the control unit, the liquid feed pump to feed the cleaning liquid to a low-pressure flow path having a low pressure and a low flow rate, the low-pressure flow path constituting at least a part of the flow path, and operating, by the control unit, a flow rate estimation mechanism provided in the low-pressure flow path to obtain a flow rate estimation value in the low-pressure flow path.

Additional features related to the present disclosure will be clarified based on the description of the present description and the accompanying drawings. Aspects of the present disclosure may be achieved and implemented using elements, combinations of various elements, the following detailed description, and accompanying claims.

It is necessary to understand that description of the present description is merely a typical example, and is not intended to limit the scope of the claims or application examples of the present disclosure in any way.

Advantageous Effects of Invention

According to the present disclosure, detection sensitivity in flow rate measurement in a cleaning system having a low pressure and a low flow rate can be improved in an automatic analyzer.

DESCRIPTION OF EMBODIMENTS

The present embodiment discloses a technique of estimating a flow rate in a cleaning system having a low pressure and a low flow rate (for example, an outer cleaning flow path) in an automatic analyzer, detecting a cleaning abnormality based on the estimated flow rate, and adjusting a flow rate of a liquid feed pump. In the present embodiment, a low pressure can be defined as, for example, 10 kPa or less, and a low flow rate can be defined as a flow rate due to liquid feeding at a low pressure (10 kPa). A high pressure can be defined as 100 kPa or more.

Hereinafter, an embodiment of the present disclosure will be described with reference to the accompanying drawings. In the accompanying drawings, functionally the same elements may be denoted by the same reference numerals. The accompanying drawings show specific embodiments and implementation examples according to the principle of the disclosure, but the embodiments and the implementation examples are provided for understanding the present disclosure and are not by no means to be used to limit the present disclosure.

<Configuration Example of Automatic Analyzer>

FIG.1is a diagram showing an overall schematic configuration example of an automatic analyzer100according to the present embodiment. The automatic analyzer100includes a reagent disk102on which a plurality of reagent containers101are mounted, a reaction disk103that mixes a reagent with a sample to measure a reaction, a reagent dispensing mechanism104that aspirates and discharges a reagent, a sample dispensing mechanism105that aspirates and discharges a sample, and a control unit (a processor)214that controls opening and closing of a liquid feed pump202and valves (seeFIG.2). The automatic analyzer100may include other components.

The reagent dispensing mechanism104includes a reagent nozzle (not shown) for dispensing a reagent. The sample dispensing mechanism105includes a sample dispensing nozzle110for dispensing a sample.

A sample loaded into the automatic analyzer is loaded into a sample container (a test tube)108and is transported by being mounted on a rack106. A plurality of sample containers108are mounted on the rack106. The sample is urine or a sample derived from blood such as serum or whole blood.

The sample dispensing mechanism105moves, by a rotation operation, the sample dispensing nozzle110to an aspiration position at which a sample is aspirated from the sample container108, a discharge position at which the sample is discharged to a cell109, and a cleaning position at which a tip end of the sample dispensing nozzle110is cleaned in a cleaning tank107.

Further, the sample dispensing mechanism105lowers the sample dispensing nozzle110according to heights of the sample container108, the cell109, and the cleaning tank107at the aspiration position, the discharge position, and the cleaning position. The sample dispensing nozzle110and the reagent nozzle are provided with a liquid contact detection sensor for detecting a liquid surface, and contacting with a target liquid (a sample or a reagent) can be confirmed based on a sensor signal.

The automatic analyzer100measures a mixed liquid of a sample and a reagent contained in the cell109to analyze a concentration of a predetermined component in the sample. A general configuration of the automatic analyzer100is described above.

<Configuration Example of Cleaning System Flow Path>

Although a cleaning system flow path of the sample dispensing nozzle110is described as an example in the present embodiment, the technique according to the present embodiment can also be applied to a case of a reagent nozzle in which the same nozzle is cleaned and repeatedly used. The present embodiment is also applicable to an apparatus for dispensing a sample and a reagent using the same nozzle.

FIG.2is a diagram showing a schematic configuration example of a cleaning flow path of a dispensing mechanism (the sample dispensing mechanism105) in the automatic analyzer100according to the present embodiment.

A cleaning system flow path of the automatic analyzer100includes, for example, an inner cleaning flow path206and an outer cleaning flow path207, and is implemented by a cleaning liquid storage container201, the liquid feed pump202that feeds a cleaning liquid, the cleaning tank107for cleaning an outer wall of a nozzle, a sample syringe203for aspirating and discharging a sample, the sample dispensing nozzle (hereinafter, simply referred to as a dispensing nozzle)110, a three-way electromagnetic valve204provided downstream of the liquid feed pump202, and a three-way electromagnetic valve208provided upstream of the dispensing nozzle110.

The three-way electromagnetic valve204selectively connects the inner cleaning flow path206for supplying a cleaning liquid into the dispensing nozzle110and the outer cleaning flow path207for supplying the cleaning liquid to the cleaning tank107for cleaning an outer wall of the dispensing nozzle110to a cleaning liquid supply flow path205for feeding the cleaning liquid by the liquid feed pump202.

The three-way electromagnetic valve208switches a connection source of the dispensing nozzle110. When the dispensing nozzle110is connected to the inner cleaning flow path206, the cleaning liquid can be supplied to the dispensing nozzle110to clean the inside of the dispensing nozzle110. When the dispensing nozzle110is connected to a dispensing flow path209, a sample can be aspirated or discharged using the sample syringe203. The sample syringe203and the dispensing flow path209are filled with degassed water supplied through a two-way electromagnetic valve210.

A bubble generation unit implemented by a three-way electromagnetic valve211is provided at a predetermined position (upstream) of the outer cleaning flow path207, and a bubble sensor212and a bubble sensor213are disposed at a constant interval downstream of the three-way electromagnetic valve211. Bubbles (air) can be introduced into the outer cleaning flow path207through the three-way electromagnetic valve211(by opening an atmospheric relief valve NC), and the bubbles (a boundary surface between the cleaning liquid and air) are detected by the bubble sensors. Since the outer cleaning flow path207is a flow path that operates at a low pressure (for example, 10 kPa or less as described above) and a low flow rate, bubbles are less likely to collapse when the bubbles (air) are introduced into the outer cleaning flow path207, and detection becomes easy. It is possible to avoid a risk of deteriorating dispensing accuracy due to bubbles mixing into the sample syringe203.

FIG.3is a flowchart showing dispensing operation control processing according to the present embodiment. The dispensing operation includes an inner cleaning operation, an outer cleaning operation, and a sample dispensing operation, and in the present embodiment, a flow rate of the liquid feed pump202is estimated during the outer cleaning operation.

First, the control unit214operates the liquid feed pump202to supply the cleaning liquid from the cleaning liquid storage container201to the inner cleaning flow path206through the cleaning liquid supply flow path205, and performs inner cleaning for the dispensing nozzle110.

The control unit214switches the three-way electromagnetic valve204to connect the cleaning liquid supply flow path205to the outer cleaning flow path207. When the outer cleaning flow path207is not filled with the cleaning liquid, the control unit214operates the liquid feed pump202to fill the outer cleaning flow path207(for example, a flow path up to the cleaning tank107) with the cleaning liquid.

The control unit214switches three-way electromagnetic valve211that is a bubble generation unit to an atmospheric relief side for a certain time. During this time, the cleaning liquid inside the outer cleaning flow path207is discharged from the cleaning tank107due to falling under own weight of the cleaning liquid.

Thereafter, the control unit214returns the three-way electromagnetic valve211to a closed state and causes the liquid feed pump202to feed the cleaning liquid. Then, a boundary surface between the cleaning liquid and air (may be a boundary surface between the cleaning liquid and air in a bubble) moves in the outer cleaning flow path. The control unit214obtains a time difference between a time at which the boundary surface between the cleaning liquid and air passes through the bubble sensor212and a time at which the boundary surface between the cleaning liquid and air passes through the bubble sensor213, and calculates a bubble moving speed V (the number of bubble sensors may be one).

After the bubble moving speed V is calculated, the control unit214obtains an estimated flow rate Q based on a cross-sectional area S of the outer cleaning flow path207according to a flow rate estimation formula Q=V·S.

The control unit214compares the estimated flow rate Q with a preset target flow rate Q0to determine whether the estimated flow rate Q is within a normal range. Specifically, it is determined whether |Q−Q0| is less than a flow rate error allowable range ΔQ. When |Q−Q0|<ΔQ (YES in step305: the flow rate is within the normal range), the processing proceeds to step306. On the other hand, when |Q−Q0|≥ΔQ (NO in step305: the flow rate is out of the normal range), the processing proceeds to step309.

The control unit214operates the liquid feed pump202to supply the cleaning liquid to the outer cleaning flow path207, and performs outer cleaning for the dispensing nozzle110. The outer cleaning can be performed by spraying the cleaning liquid to a tip end of the dispensing nozzle110in the cleaning tank107.

The control unit214controls the three-way electromagnetic valve208to close a cleaning liquid supply side and open a sample liquid supply side, thereby switching to a dispensing flow path.

The control unit214moves the dispensing nozzle110to the sample container108and performs a dispensing operation. When the dispensing operation is completed, the processing is ended.

The control unit214notifies of a cleaning abnormality (for example, notification by voice or notification by displaying a warning message on a display screen), and ends the processing without performing the dispensing operation.

For example, when it is determined in the processing shown inFIG.3that a flow rate determination result is out of the normal range (NO in step305), the flow rate may be adjusted to be within the normal range (flow rate adjustment processing). Even in a case where the processing shown inFIG.3is not executed, when an operator (a user) wants to adjust the flow rate, the flow rate adjustment processing may be executed by inputting an instruction to execute the flow rate adjustment processing.FIG.4is a flowchart showing the flow rate adjustment processing according to the present embodiment.

The control unit214performs the same operations as those in steps303and304, measures a moving speed V of bubbles (a boundary surface between the cleaning liquid and air), and calculates the estimated flow rate Q. When the flow rate adjustment processing is executed after cleaning abnormality notification processing (step309inFIG.3), step401may not be executed. In this case, a value of the estimated flow rate Q calculated in step304can be used.

The control unit214obtains an adjusted pump drive voltage E′ based on a ratio between the estimated flow rate Q and the target flow rate Q0and a pre-adjustment pump drive voltage E according to a formula E′=E*(Q0/Q), and sets the adjusted pump drive voltage as a drive voltage (a pump drive voltage) of the liquid feed pump202.

Again, the control unit214performs the same operations as those in steps303and304, measures a moving speed V of bubbles (a boundary surface between the cleaning liquid and air), and calculates the estimated flow rate Q.

The control unit214compares the estimated flow rate Q with the preset target flow rate Q0to determine whether the estimated flow rate Q is within a normal range. Specifically, it is determined whether |Q−Q0| is less than the flow rate error allowable range ΔQ. When |Q−Q0|<ΔQ (YES in step404: the flow rate is within the normal range), the flow rate adjustment processing is ended. On the other hand, when |Q−Q0|≥ΔQ (NO in step404: the flow rate is out of the normal range), the processing proceeds to step405.

The control unit214notifies of a cleaning abnormality (for example, notification by voice or notification by displaying a warning message on a display screen), and ends the processing without performing the dispensing operation. Although the cleaning abnormality is notified when a difference between the estimated flow rate Q and the target flow rate Q0is equal to or larger than the flow rate error allowable range ΔQ in the present embodiment, the processing may proceed to step402without notifying the cleaning abnormality, and a pump drive voltage adjustment may be performed until the difference between the estimated flow rate Q and the target flow rate Q0is less than the flow rate error allowable range ΔQ (loop processing from step402to step404).

Modification

The technique according to the present disclosure is not limited to the above-described embodiment, and includes various modifications. For example, the above-described embodiment has been described in detail to facilitate understanding of the technique according to the present disclosure, and is not necessarily limited to those including all the configurations described above. A part of a configuration according to one embodiment can be replaced with a configuration according to another embodiment, and other components can be added to components according to the present embodiment. In addition, another configuration can be added to, deleted from, or replaced with a part of configurations according to one embodiment. Hereinafter, modifications will be exemplified.

In the above-described embodiment, the flow rate abnormality determination processing and the flow rate adjustment processing based on a flow rate (an inner cleaning flow rate) of the outer cleaning flow path207are described. However, depending on conditions (for example, when a flow rate of the inner cleaning flow path206(an inner cleaning flow rate) is more important than the outer cleaning flow rate or when it is desired to control the inner cleaning flow rate), it may be necessary to determine a flow rate abnormality or adjust a flow rate based on the inner cleaning flow rate.

In such a case, even when drive voltages of the liquid feed pump202are the same, pressure losses are different depending on a difference in diameters of pipes or lengths of pipes constituting flow paths, and thus an inner cleaning flow path flow rate QAand an outer cleaning flow path flow rate QBare different. On the other hand, what is affected by changes over time is mainly an inner element of the liquid feed pump202such as a motor rotation speed, and a diameter and a length of a pipe of an outer flow path do not change. Therefore, it is expected that a correlation between the inner cleaning flow path flow rate QAand the outer cleaning flow path flow rate QBdoes not greatly change over time.

Therefore, before the automatic analyzer100is shipped as a product, a correlation coefficient k=QA/QBbetween the inner cleaning flow path flow rate QAand the outer cleaning flow path flow rate QBis obtained using a flowmeter or the like, and is stored in an internal memory (not shown) of the control unit214. In this manner, the inner cleaning flow rate can be estimated based on an estimated value of the outer cleaning flow rate according to an inner cleaning flow rate estimation formula QA=kQB. By using the estimated inner cleaning flow rate QA, it is possible to execute the flow rate abnormality determination processing and the flow rate adjustment processing based on the inner cleaning flow rate in the same procedure as in the above-described embodiment.

When there are a plurality of dispensing mechanisms and liquid feed pumps, a configuration can be adopted in which flow rate estimation mechanisms are collectively disposed at one place of the cleaning liquid supply flow path205most upstream of a cleaning flow path, and the above-described flow rate estimation processing can be applied to such a configuration. The dispensing mechanisms and cleaning mechanisms can be reduced in size by the plurality of flow rate estimation mechanisms at one place.

When there are a plurality of dispensing mechanisms and liquid feed pumps, a configuration can be adopted in which flow rate estimation mechanisms are collectively disposed at one place of a waste liquid tank (not shown) connected to the cleaning tank107most downstream of a cleaning flow path, and the above-described flow rate estimation processing can be applied to such a configuration. The dispensing mechanisms and cleaning mechanisms can be reduced in size by collecting the plurality of flow rate estimation mechanisms at one place.

Although various kinds of processing are executed by one control unit214in the above-described embodiment, the processing may be divided and executed by a plurality of control units. The plurality of control units may be incorporated in the automatic analyzer100or may be provided outside of the automatic analyzer100.

In addition to a mode in which bubbles are generated and a flow rate is estimated based on a moving speed of the bubbles, a flow rate in the outer cleaning flow path207may be estimated by a thermal flowmeter including a heater and a temperature sensor or a Coriolis flowmeter using a Coriolis force.

SUMMARY

(i) An automatic analyzer according to the present embodiment performs an operation of operating a liquid feed pump to feed a cleaning liquid to a low-pressure flow path having a low pressure and a low flow rate (for example, a flow path for feeding the cleaning liquid at 10 kPa) constituting at least a part of a flow path, operating a flow rate estimation mechanism (for example, a mechanism that introduces air (bubbles) and estimates a flow rate based on a moving speed of the air, a mechanism that estimates a flow rate using a thermal flowmeter, a mechanism that estimates a flow rate using a Coriolis flowmeter, and the like) installed in the low-pressure flow path to obtain a flow rate estimation value in the low-pressure flow path. Accordingly, detection sensitivity in flow rate measurement in a cleaning system having a low pressure and a low flow rate can be improved in an automatic analyzer including a dispensing mechanism.

(ii) When the mechanism that estimates the flow rate based on the moving speed of the boundary surface between the air (bubbles) and the cleaning liquid is used, an air introduction mechanism is controlled to introduce air into the low-pressure flow path, a movement of the boundary surface between the air and the cleaning liquid is detected by a sensor, and the flow rate estimation value in the low-pressure flow path is obtained based on a volume of the low-pressure flow path and the moving speed of the boundary surface in the low-pressure flow path calculated based on a detection signal from the sensor. Since a three-way electromagnetic valve can be used as the air introduction mechanism, the flow rate estimation mechanism can be implemented at low cost, and the automatic analyzer can be reduced in size. Here, the boundary surface between the air and the cleaning liquid is generated by introducing the air into an outer cleaning flow path corresponding to the low-pressure flow path.

(iii) As for the flow rate estimation value, a determination may be made to determine whether the flow rate estimation value is within a preset normal flow rate range, and a determination result may be output, or flow rate adjustment processing for adjusting a flow rate of the liquid feed pump may be executed.

(iv) Functions of the embodiment of the present disclosure can also be implemented by software program codes. In this case, a storage medium that records the program code is provided in a system or a device, and a computer (or CPU or MPU) of the system or the device reads the program code stored in the storage medium. In this case, the program code read from the storage medium implements the functions of the above-described embodiment, and the program code and the storage medium that stores the program code constitute the present disclosure. Examples of the storage medium for supplying such a program code include a flexible disk, a CD-ROM, a DVD-ROM, a hard disk, an optical disk, a magneto-optical disk, a CD-R, a magnetic tape, a nonvolatile memory card, and a ROM.

An operating system (OS) or the like operating on a computer may perform a part or all of actual processing based on an instruction of the program code, and the functions of the above-described embodiment may be implemented by the processing. Further, after the program code read from the storage medium is written in a memory on the computer, a CPU or the like of the computer may perform a part or all of actual processing based on an instruction of the program code, and the functions of the above-described embodiment may be implemented by the processing.

Further, the software program code for implementing the functions of the embodiment may be stored, by distributing via a network, in a storage unit such as a hard disk or a memory of the system or the device or a storage medium such as a CD-RW or a CD-R, and the computer (or CPU or MPU) of the system or the device may read and execute the program code stored in the storage unit or the storage medium at the time of use.

Finally, it is necessary to understand that processes and techniques described here are not essentially related to any specific device, and can be implemented by any appropriate combination of components. Further, various types of devices for general purposes can be used in accordance with teachings described here. It may be advantageous to configure a dedicated device to execute steps of the method described here. Various inventions can be formed by appropriately combining a plurality of components disclosed in the embodiment. For example, several components may be deleted from all components disclosed in the embodiment. Further, components belonging to different embodiments may be appropriately combined. Although the present disclosure has been described in relation to specific examples, the specific examples are used for description only, and are not intended to limit the present disclosure in all viewpoints. It is understood that there are many combinations of hardware, software, and firmware suitable for implementing the present disclosure for those skilled in the present field. For example, the above-described software can be implemented in a wide range of programs or script languages such as assembler, C/C++, perl, Shell, PHP, and Java (registered trademark).

Further, control lines and information lines considered to be necessary for description are shown in the above-described embodiment, and not all control lines and information lines in a product are necessarily shown. All configurations may be connected to one another.

REFERENCE SIGNS LIST