Dispensing device and automatic analyzer

Abstract

Provided is a dispensing device which prevents the occurrence of dispensing abnormality. This dispensing device comprises: a dispensing mechanism 101 which is provided with a probe 101p for dispensing liquid; a detection unit 102 which is provided with a liquid level sensor for measuring capacitance between a distal end of the probe and a reference electric potential surface, thereby outputting a capacitance signal; and a signal processing unit 103 which determines the state of the probe on the basis of a change in a temporal waveform of the capacitance signal.

Description

[Technical Field]

[0001] The present invention relates to a dispensing device and an automatic analyzer equipped with the dispensing device. [Background technology]

[0002] In automated analyzers, such as biochemical automated analyzers, the test sample reacts with a reagent to analyze the components of biological samples, and the resulting changes in color and turbidity are optically measured using a photometric unit such as a spectrophotometer. The most commonly used method for detecting the liquid level of the test sample is the capacitance change method, which detects the change in capacitance when a probe touches the liquid level. However, when using such a liquid level sensor, the liquid level may not be accurately detected if the tip of the probe is dirty or if the probe is damaged. This can lead to inaccurate sampling, resulting in dispensing errors such as sample return or empty suction.

[0003] Patent Document 1 discloses the formation of a fluorine-containing diamond carbon layer on the probe surface to suppress carryover. If the probe's surface treatment layer is cracked or damaged due to some kind of impact or contact, the metal nozzle comes into direct contact with air, causing a significant change in capacitance, making it possible to detect a probe abnormality. Since a probe with a cracked or damaged surface treatment layer is at risk of causing carryover, the system stores the sample analyzed when an abnormality is detected, making it possible to reacquire the analysis data after replacing the probe. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-44623 Summary of the Invention [Problem to be solved by the invention]

[0005] The probe abnormality detected in Patent Document 1 is an abnormality in the surface treatment layer of the probe. However, dispensing abnormalities can also be caused by the adhesion of dirt, finer scratches, or deterioration. Furthermore, while Patent Document 1 detects abnormalities in the probe that have occurred, it is desirable to detect deterioration or abnormalities in the probe at an early stage so that maintenance can be performed and data abnormalities that require retesting can be prevented before they occur.

[0006] An object of the present invention is to provide a dispensing device that can detect changes in a probe, such as deterioration, before an abnormality occurs in the probe, and an automatic analyzer using the same. [Means for solving the problem]

[0007] A dispensing device that is one embodiment of the present invention has a dispensing mechanism equipped with a probe that dispenses liquid, a detection unit equipped with a liquid level sensor that measures the capacitance between the tip of the probe and a reference potential surface and outputs a capacitance signal, and a signal processing unit that determines the state of the probe based on changes in the time waveform of the capacitance signal. [Effects of the Invention]

[0008] A dispensing device or automatic analyzer that prevents the occurrence of dispensing abnormalities is provided. [Brief explanation of the drawings]

[0009] [Figure 1A] FIG. 2 is a block diagram showing a schematic configuration of the dispensing device. [Figure 1B] 5A and 5B are diagrams for explaining a capacitance signal detected by a liquid level sensor. [Figure 2A] 10 shows the time waveforms of the capacitance signal Cs and the probe operation determination signal S. [Figure 2B] 10 shows the time waveforms of the capacitance signal Cs and the probe operation determination signal S. [Figure 2C] 10 shows the time waveforms of the capacitance signal Cs and the probe operation determination signal S. [Figure 2D] 10 shows the time waveforms of the capacitance signal Cs and the probe operation determination signal S. [Figure 3] 10 is a flowchart for acquiring a reference capacitance signal SCs. [Figure 4] 10 is an example of an alarm display setting screen. [Figure 5] 10 is a flowchart for determining the state of a probe in use. [Figure 6] 10 is a flowchart for determining the state of a probe in use. [Figure 7] 10 is an example of a display screen of an intraday time series control chart. [Figure 8] 10 is an example of a display screen of an inter-day time series control chart. [Figure 9] 10 is an example of a probe state evaluation screen. [Figure 10] FIG. 1 is a schematic diagram illustrating the configuration of an automatic analyzer. DETAILED DESCRIPTION OF THE INVENTION

[0010] FIG. 10 is a schematic diagram of an automated analyzer 100 that performs biochemical analysis. A biological sample to be analyzed, such as blood or urine (hereinafter simply referred to as a sample), is contained in a sample container 15. One or more sample containers 15 are mounted on a sample rack 16 and transported by a sample transport mechanism 17. Reagents used in sample analysis are contained in reagent bottles 10, and multiple reagent bottles 10 are arranged circumferentially on a reagent disk 9. The sample and reagent are mixed and reacted in a reaction container 2. Multiple reaction containers 2 are arranged circumferentially on a reaction disk 1. The sample is dispensed from a sample container 15 transported to a sample dispensing position by the sample transport mechanism 17 into a reaction container 2 by a first or second sample dispensing mechanism 11, 12. Meanwhile, reagents are dispensed from reagent bottles 10 into reaction containers 2 by reagent dispensing mechanisms 7, 8. The mixture (reaction liquid) of the sample and reagent dispensed into the reaction vessel 2 is stirred by stirring mechanisms 5 and 6, and the absorbance of the reaction liquid is measured by the spectrophotometer 4 by measuring transmitted light obtained from a light source (not shown) through the reaction liquid in the reaction vessel 2. As part of the analysis process in the automatic analyzer 100, the concentration of a predetermined component of an analysis item corresponding to the reagent, etc. is calculated from the absorbance of the mixture (reaction liquid) measured by the spectrophotometer 4. The reaction vessel 2 after measurement is washed by the washing mechanism 3.

[0011] The first (second) sample dispensing mechanism 11 (12) has a sample probe 11a (12a) arranged with its tip facing downward, and a sample pump 19 is connected to the sample probe 11a (12a). The first (second) sample dispensing mechanism 11 (12) is configured to be able to rotate horizontally and move up and down, and dispenses the sample from the sample container 15 to the reaction container 2 by inserting the sample probe 11a (12a) into the sample container 15 to aspirate the sample, and inserting the sample probe 11a (12a) into the reaction container 2 to discharge the sample. An ultrasonic cleaner 23 (24) is arranged within the operating range of the first (second) sample dispensing mechanism 11 (12) to clean the sample probe 11a (12a) with a cleaning solution. When a cleaning liquid other than water is used, a cleaning tank 13 (14) for cleaning the sample probe 11a (12a) is provided to remove the cleaning liquid with water.

[0012] The reagent dispensing mechanisms 7, 8 have reagent probes 7a, 8a arranged with their tips facing downward, and a reagent pump 18 is connected to the reagent probes 7a, 8a. The reagent dispensing mechanisms 7, 8 are configured to be able to rotate horizontally and move up and down, and dispense the reagent from the reagent bottle 10 to the reaction vessel 2 by inserting the reagent probes 7a, 8a into the reagent bottle 10 to suck in the reagent, and by inserting the reagent probes 7a, 8a into the reaction vessel 2 to discharge the reagent. Washing tanks 32, 33 for washing the reagent probes 7a, 8a with a washing solution are arranged within the operating range of the reagent dispensing mechanisms 7, 8.

[0013] The stirring mechanisms 5 and 6 are configured to be capable of horizontal rotation and vertical movement, and stir the mixture of sample and reagent (reaction liquid) by being inserted into the reaction vessel 2. Washing tanks 30 and 31 for washing the stirring mechanisms 5 and 6 with a washing liquid are disposed within the operating range of the stirring mechanisms 5 and 6. A washing pump 20 is also connected to the washing mechanism 3.

[0014] The overall operation of the automatic analyzer 100 is controlled by a control device 21. An input / output device 22 is also connected to the control device 21. The input / output device 22 includes an input unit such as a keyboard or buttons for inputting instructions from the user, and a display unit for displaying a GUI for the user to input instructions and the operating status of the automatic analyzer. Note that, for simplicity of illustration, in FIG. 1, the connections between the control device 21 and each mechanism constituting the automatic analyzer 100 are partially omitted.

[0015] FIG. 1A is a block diagram showing the schematic configuration of the dispensing device of this embodiment. The dispensing mechanism 101 corresponds to the sample dispensing mechanisms 11 and 12 and the reagent dispensing mechanisms 7 and 8 shown in FIG. 8. The dispensing device includes the dispensing mechanism 101, a detection unit 102, and a signal processing unit 103. The detection unit 102 includes sensors for monitoring the state of the probe 101p, such as a liquid level sensor that detects the liquid level of the liquid 101s contained in the container 101v and a pressure sensor that detects the pressure inside the probe 101p. Here, the liquid level sensor performs capacitive liquid level detection. In this case, as shown in FIG. 1B, the liquid level sensor measures the capacitance Cs between the tip of the probe 101p and ground (reference potential surface). The capacitance Cs is the combined capacitance of the capacitance C1 between the tip of the probe 101p and the liquid 101s and the capacitance C2 between the liquid 101s and ground. After the tip of the probe 101p comes into contact with the liquid 101s, the capacitance Cs becomes equal to C2, and this change can be used to detect contact between the probe 101p and the surface of the liquid 101s. The pressure sensor detects the pressure P inside the probe 101p. The pressure inside the probe changes depending on the suction or discharge operation performed by the probe 101p. Therefore, based on the sensing information from the detection unit 102, information can be obtained as to whether the probe operation is being performed normally.

[0016] The signal processing unit 103 is implemented as a signal processing module equipped with, for example, a microprocessor and a memory. A control unit 104 of the signal processing unit 103 controls the probe operation based on the capacitance signal Cs, which is the output of the liquid level sensor from the detection unit 102, and the pressure signal P, which is the output of the pressure sensor, and also monitors the probe operation, and outputs a probe operation determination signal S, which indicates the probe operation status, to the control device 21 of the device.

[0017] In this embodiment, the detection method will be described in detail later, but the state of the probe is detected in signal processing unit 103 based on the detection signal Cs from the liquid level sensor. To this end, signal processing unit 103 is equipped with a calculation unit 105, a storage unit 106, and a determination unit 107. The calculation unit 105 calculates a waveform change index based on, for example, the area of ​​the capacitance signal Cs, the storage unit 106 stores the area of ​​the capacitance signal Cs and the calculation results of the calculation unit 105, and the determination unit 107 determines the state of the probe based on the waveform change index. Details will be described later.

[0018] The upper part of FIG. 2A shows the time waveform of the capacitance signal Cs, which is the output of the liquid level sensor, and the lower part shows the time waveform of the probe operation determination signal S output by the control unit 104 of the signal processing unit 103. The probe in FIG. 2A is a signal waveform obtained when a normal probe immediately after replacement is operated. The probe operation determination signal S is essentially binarized, with a high-level signal output during the suction section 201 where the probe performs the suction operation and the discharge section 202 where the probe performs the discharge operation, and a low-level signal output during other sections. Thus, while the probe operation determination signal S input from the signal processing unit 103 to the device control unit 21 is essentially binarized, it can be seen that the capacitance signal Cs contains more information than the capacitance signal Cs. For example, in the movement section 203 where the probe is being moved by the dispensing mechanism and the cleaning section 204 where the probe is being cleaned, the probe operation determination signal S remains low-level and unchanged, while different values ​​are output for the capacitance signal Cs. Furthermore, the values ​​of the probe operation determination signal S are the same (high level) in the suction section 201 and the discharge section 202, but the capacitance signal Cs in the suction section 201 and the capacitance signal Cs in the discharge section 202 output different values.

[0019] The inventors discovered that the state of the probe can be determined using information from this capacitance signal Cs, which is discarded during the generation process of the probe operation determination signal S. For example, the capacitance signal Cs, which indicates the capacitance between the probe and ground, changes in signal waveform after continued use compared to immediately after probe replacement due to dirt, scratches, aging, etc. As shown in Figure 2A, the capacitance signal Cs continuously detects small voltage changes, making it possible to grasp the state of the probe during actual operation in real time.

[0020] 2B shows the time waveform of the capacitance signal Cs (top row) and the time waveform of the probe operation determination signal S (bottom row) when dirt adheres to the probe midway. In the suction section 211, the suction operation is performed when the probe is free of dirt, and in the suction section 212, the suction operation is performed when the probe is dirty. In this case, it can be seen that while the probe operation determination signal S does not change due to the adhesion of dirt, the amplitude of the capacitance signal Cs in the suction section 212 is lower than the amplitude of the capacitance signal Cs in the suction section 211.

[0021] FIG. 2C shows the time waveform of the capacitance signal Cs (top) and the time waveform of the probe operation determination signal S (bottom) when the probe is damaged. In this case, it can be seen that the capacitance signal Cs repeatedly exhibits a triangular noise waveform 233 due to the scratch. The influence of such a noise waveform does not necessarily appear in the probe operation determination signal S. For example, noise waveform 234 is superimposed on the waveform of the capacitance signal Cs, which originally indicates the probe's dispensing operation, and therefore the high-level signal indicating the dispensing interval 232 is not output in the probe operation determination signal S. The timing at which the dispensing mechanism performs the dispensing operation is determined by the operation sequence of the automated analyzer. Therefore, the control device 21 of the automated analyzer determines from the probe operation determination signal S that the dispensing operation was not performed properly and issues a dispensing error warning. However, in the other intervals in FIG. 2C, the probe operation determination signal S outputs high-level signals indicating the aspiration interval 231 and the dispensing interval 232, so the control device 21 does not issue a dispensing error warning.

[0022] In this way, the time waveform of the capacitance signal Cs may enable early detection of a probe abnormality or a sign of such an abnormality that does not necessarily appear in the probe operation determination signal S. Not only is there the presence of a noise waveform, but a comparison with the time waveform of the capacitance signal Cs in Fig. 2A also reveals that the amplitude of the capacitance signal Cs in the suction section 231 is reduced.

[0023] FIG. 2D also shows an example of the time waveform of the capacitance signal Cs (top) and the time waveform of the probe operation determination signal S (bottom) when the probe is damaged. In this example, it can be seen that a spike 241 appears in the time waveform of the capacitance signal Cs. The timing of the occurrence of the spike 241 occurs when the probe is being moved by the dispensing mechanism, and therefore it is thought that environmental factors such as static electricity are affecting the damaged surface. Although the spike 241 does not appear in the probe operation determination signal S, it is an indicator that the probe is damaged.

[0024] In this way, the time waveform of the capacitance signal Cs fluctuates depending on the state of the probe, and by capturing this fluctuation, it is possible to capture the state of the probe during actual operation in real time.

[0025] 3 is a flowchart for acquiring the reference capacitance signal SCs. The reference capacitance signal SCs is the capacitance signal Cs immediately after the probe is replaced. After the probe is replaced (S01), the automatic analyzer starts a dispensing operation, and the control unit 104 of the signal processing unit 103 starts recording the capacitance signal Cs output from the liquid level sensor of the detection unit 102.

[0026] The control unit 104 of the signal processing unit 103 records the time waveform of the capacitance signal Cs for a certain period from when the probe suctions the liquid (S03) to when the probe is cleaned after discharging the liquid (S04), and the calculation unit 105 calculates the area of ​​the time waveform of the capacitance signal Cs (S05). The control unit 104 stores the recorded time waveform and area of ​​the capacitance signal Cs in the memory unit 106 as the time waveform and area (reference area) of the reference capacitance signal SCs (S06). The time waveform and reference area of ​​the reference capacitance signal SCs are updated using the same procedure the next time the probe is replaced.

[0027] In this embodiment, the state of the probe is determined based on changes in the waveform of the capacitance signal Cs (reference capacitance signal SCs) immediately after probe replacement and the capacitance signal Cs of the probe in use during a certain period from liquid dispensing to cleaning.

[0028] As shown in Figure 2A, the fixed interval (a≦t≦b, t: time) is defined as a: the time when liquid suction begins, and b: the time when probe cleaning ends. In this case, if the magnitude of the capacitance signal Cs is f(t) (f(t)≧0, a≦t≦b), the waveform area WA of the capacitance signal Cs can be calculated using Equation 1.

[0029]

number

[0030] Here, the area ratio AR (%) of the waveform area WA2 of the capacitance signal Cs of the probe in use to the waveform area WA1 (reference area) of the reference capacitance signal SCs, as shown in (Equation 2), can be used as an index of the change in the waveform. The area ratio AR (%) is calculated by the calculation unit 105 of the signal processing unit 103.

[0031]

number

[0032] The determination unit 107 of the signal processing unit 103 determines the state of the probe based on the area ratio AR (%).

[0033] An example of determining the state of a probe using the above-described indicator of waveform change will be described below, but the method of calculating the indicator of the waveform change of the capacitance signal Cs is not limited to the above. For example, the range of the fixed interval in which the waveform of the capacitance signal Cs is stored is not limited to the above example. The capacitance signal Cs is continuously input to the signal processing unit 103 in real time. Therefore, any interval other than the above-described fixed interval may be set to determine the state. Furthermore, the indicator of waveform change is not limited to the area ratio. For example, it can be the difference between the waveform area WA2 and the waveform area WA1 (reference area). Furthermore, instead of the area, the waveform change may be determined using the peak of the waveform from when the probe aspirates and discharges the liquid, or the average value of the waveform over a fixed interval. Instead of using a single indicator, a combination of multiple indicators may be used.

[0034] By performing appropriate maintenance according to the condition of the probe, the inspection efficiency can be improved. Therefore, the probe condition determination criteria based on the index of waveform change are set in advance in the determination unit 107. Fig. 4 shows an alarm display setting screen 401 for displaying an alarm on the display unit of the automatic analyzer according to the condition of the probe. The probe selection unit 402 can set the condition determination criteria for each probe. In the probe condition setting unit 403, the probe condition is set step by step based on the deviation from the normal probe area ratio AR (%) = 100. For example, values are set for available for use (±A%) 404, cleaning recommended (±B%) 405, use with caution (±C%) 406, replacement recommended (±D%) 407, warning (±E%) 408, respectively. For example, values are set such that A < B < C < D < E, and maintenance corresponding to the degree of deviation from the normal value is recommended to the user. In addition, the above settings can be cancelled by the cancel button 409 or the set value can be updated by the update button 410.

[0035] The signal processing unit 103 outputs the determination result to the control device 21 of the automatic analyzer, and can display available for use, cleaning recommended, use with caution, replacement recommended, warning, or display an alarm in the case of use with caution, replacement recommended, warning. Alternatively, an LED lamp can be attached to the probe head cover of the dispensing mechanism 101, and the signal processing unit 103 can notify the user of the probe condition by lighting or flashing the LED lamp according to the probe condition determination.

[0036] In this embodiment, the waveform of the capacitance signal Cs of the probe in use and the waveform area WA of the capacitance signal Cs, which are acquired by the determination unit 107 each time the probe status is determined, are temporarily stored in the memory unit 106. Furthermore, if the determination unit 107 determines that the deviation of the index is greater than or equal to the caution level (±C%), the control unit 21 determines that an abnormality has occurred in the probe, displays an alarm, and automatically performs a retest, starting a new measurement from the start of the liquid dispensing operation. Abnormal values ​​in the capacitance signal Cs can be caused not only by a probe abnormality but also by unexpected causes such as static electricity or air bubbles. In such cases, remeasurement often results in a normal dispensing operation the second time. An example of this is the phenomenon known as probe carry-back. This phenomenon occurs when liquid flows around the outside of the probe during liquid dispensing, preventing it from being deposited in the container and resulting in the liquid being carried back with the outside of the probe. In this case, an abnormality occurs in the waveform of the capacitance signal Cs, but normal dispensing operation usually returns to normal upon remeasurement.

[0037] FIG. 5 shows a flowchart for determining the status of a probe in use. When measurement begins (S11), the control unit 104 of the signal processing unit 103 begins recording the capacitance signal Cs output from the liquid level sensor of the detection unit 102 (S12). The period during which the capacitance signal Cs of the probe in use is recorded is the same period during which the reference capacitance signal SCs was acquired. The control unit 104 records the time waveform of the capacitance signal Cs for a certain period from when the probe suctions the liquid (S13) to when the probe is washed after discharging the liquid (S14). The calculation unit 105 calculates the area of ​​the time waveform of the capacitance signal Cs (S15). The control unit 104 temporarily stores the recorded time waveform and area of ​​the capacitance signal Cs in the memory unit 106 as the time waveform and area of ​​the capacitance signal Cs of the probe in use (S16).

[0038] The calculation unit 105 calculates a waveform change index, here an area ratio AR (%), using the waveform area WA1 of the reference capacitance signal SCs and the waveform area WA2 of the capacitance signal Cs of the probe in use, both of which are stored in the storage unit 106. The determination unit 107 determines whether the area ratio AR (%) exceeds a threshold value (S17). The threshold value may be, for example, a setting value for recommended cleaning (±B%, see FIG. 4). If the waveform change index does not exceed the threshold value (NO in S17), the control unit 104 temporarily stores the acquired value of the waveform change index of the probe in use in the storage unit 106 (S21).

[0039] On the other hand, if the waveform change index exceeds the threshold value (YES in S17), the control device 21 of the automatic analyzer determines whether to perform remeasurement (S18). For example, the control device 21 determines to perform remeasurement if the waveform change index exceeds the set value for caution in use (±C%, see FIG. 4). If remeasurement is not to be performed, the control unit 104 temporarily stores the acquired value of the waveform change index of the probe in use in the memory unit 106 (S21).

[0040] If the waveform change index exceeds the remeasurement threshold (YES in S18), the control device 21 remeasures the liquid using the probe in use. Remeasurement is determined based on whether the remeasurement threshold is exceeded for the first time or for two consecutive times. The first remeasurement (YES in S19) begins with recording the capacitance signal Cs. If the remeasurement threshold is exceeded for two consecutive times (NO in S19), the control device 21 does not perform remeasurement, but instead displays a warning alarm on the display of the device and adds a comment to the test item sampled by the probe in use saying "Measurement not performed due to probe abnormality" (S20). The user can check the status of the probe in use on the display of the automated analyzer (S23).

[0041] The calculation unit 105 creates intra-day and inter-day time series management tables for the probes in use from the values ​​of the waveform change indexes of the probes in use that are temporarily stored in the memory unit 106 (S22). The time series management tables will be described later. The time series management tables can also be displayed on the display unit of the automated analyzer, allowing the user to check the status of the probes in use (S23). Note that the creation of the time series management tables in steps S22 and S23 may be performed by the control device 21, with the values ​​of the waveform change indexes being transferred from the signal processing unit 103 to the control device 21. Since the creation of time series management tables requires low real-time performance, this reduces the processing load on the signal processing unit 103.

[0042] Figure 6 shows a flowchart for determining the state of a probe in use from waveform abnormalities such as the spikes shown in Figure 2D. Steps that perform the same processing as in the flowchart of Figure 5 are given the same reference numerals and redundant explanations will be omitted.

[0043] If the waveform change index exceeds the threshold value (YES in S17), the control device 21 of the automated analyzer determines whether to perform remeasurement (S18). For example, the control device 21 determines to perform remeasurement if the waveform change index exceeds the set value for caution in use (±C%, see FIG. 4). If remeasurement is not to be performed, the control unit 104 temporarily stores the acquired value of the waveform change index of the probe in use in the memory unit 106 (S21).

[0044] If the waveform change index exceeds the remeasurement threshold (YES in S18), the judgment unit 107 determines whether an abnormal waveform, such as a spike, is detected in the waveform of the capacitance signal Cs (S31). If an abnormal waveform is detected (YES in S31), the control unit 21 remeasures the liquid using the probe in use. As with the flowchart in Figure 5, remeasurement is performed once, and if an abnormal waveform is detected twice in a row (NO in S19), the control unit 21 does not perform remeasurement and instead displays a warning alarm on the display unit of the device along with a comment such as "Spike occurred in XX probe" (S32). The user checks the status of the probe in use on the display unit of the automated analyzer (S23) and performs maintenance or replacement of the probe.

[0045] An example of the display screen of an intra-day time series control chart displayed on the display unit of an automated analyzer is shown in Figure 7. The intra-day time series control chart is created using the waveform change index of the probe in use stored in memory unit 106 in step S21 of the flowchart in Figure 5 or Figure 6. The intra-day time series control chart should be updated each time step S21 is executed.

[0046] The display screen 701 includes a probe selection section 702, a previous replacement date display section 703, and an intra-day time series control chart display section 704. The previous replacement date and the intra-day time series control chart for the probe selected in the probe selection section 702 are displayed in the display sections 703 and 704, respectively.

[0047] The intra-day time series control chart has the operating time of the dispensing device from power-on to power-off on the horizontal axis and the waveform change index (here, area ratio AR (%)) on the vertical axis, and the value of the waveform change index for the corresponding operating time on the day is plotted each time step S21 is executed. Note that in the case of an automatic analyzer that operates 24 hours a day, it is recommended that a new intra-day time series control be created when 24 hours have passed.

[0048] The intraday time series control chart also displays the numerical value (%) set on the alarm display setting screen 401. The probe time series control (intraday) displays the alarm setting 705 set on the alarm display setting screen 401 (see FIG. 4). Generally, when a probe in use deteriorates, the amplitude of the waveform of the capacitance signal Cs decreases compared to a new probe, and the area ratio AR (%) decreases. On the other hand, when an abnormality such as dirt or scratches occurs, the area ratio AR (%) may increase due to a noise waveform in the capacitance signal Cs, as shown in FIG. 2C. Therefore, an abnormality in the probe in use causes the area ratio AR (%) to deviate from the ideal value of 100%.

[0049] In this way, the intra-day time series control chart plots the number of dispensed items for a selected probe for one day, allowing for status management of probes in use. If multiple plots on the intra-day time series control chart are irregular at the end of testing, this suggests that some kind of abnormality has occurred in the probe in use. When a marker plotted on the intra-day time series control chart is selected, it is recommended that the time waveform and area of ​​the capacitance signal Cs stored in the memory unit 106 of the signal processing unit 103 be displayed. From this information, the user can estimate and predict abnormalities such as liquid carryover, empty suction, and spikes.

[0050] An example of the display screen of an interday time series control chart displayed on the display unit of an automatic analyzer is shown in Figure 8. The interday time series control chart is created using the waveform change indices of the probe in use stored in the memory unit 106 in step S21 of the flowchart in Figure 5 or Figure 6. The interday time series control chart plots the average values ​​of the waveform change indices for one day.

[0051] The display screen 801 includes a probe selection section 802, a previous replacement date display section 803, and an interday time series control chart display section 804. The previous replacement date and interday time series control chart for the probe selected in the probe selection section 802 are displayed in the display sections 803 and 804, respectively. Furthermore, the number of days since replacement 806 and the number of days since last cleaning 807 for the selected probe are displayed as information.

[0052] In the intra-day time series control chart shown in Figure 8, the horizontal axis shows the number of days since probe replacement, the vertical axis shows the waveform change index (here, area ratio AR (%)), and the average value of the waveform change index for one day is plotted. Also, the value 805 set as the cleaning recommendation on the alarm display setting screen 401 is displayed. From this information, the user can detect dirt, scratches, deterioration over time, etc. on the probe while in use, and can consider the timing of maintenance.

[0053] Here, an example has been shown in which the waveform change index is graphed and displayed on the screen, but a model may also be created using the value of the waveform change index as an explanatory variable to predict the recommended replacement time for a probe in use.

[0054] Furthermore, the user can objectively evaluate the probe condition after maintenance using the waveform change index. An example of a probe condition evaluation screen 901 is shown in FIG.

[0055] When the probe that has undergone maintenance is selected in the probe selection unit 902 and the test execution button 904 is pressed, the automatic analyzer tests the dispensing mechanism 101 using a dummy sample or system water, and the waveform change index (here, area ratio AR (%)) calculated by the signal processing unit 103 and the judgment result are displayed in the evaluation value display unit 903 and judgment display unit 905, respectively. Here, an example is shown in which a result of 90% or more is judged as passing. At this time, when the result confirmation button 906 is pressed, the time waveform and area of ​​the capacitance signal Cs stored in the memory unit 106 of the signal processing unit 103 can be displayed. [Explanation of symbols]

[0056] 1: reaction disk, 2: reaction vessel, 3: cleaning mechanism, 4: spectrophotometer, 5, 6: stirring mechanism, 7, 8: reagent dispensing mechanism, 7a, 8a: reagent probe, 9: reagent disk, 10: reagent bottle, 11, 12: sample dispensing mechanism, 11a, 12a: sample probe, 13, 14, 30, 31, 32, 33: cleaning tank, 15: sample vessel, 16: sample rack, 17: sample transport mechanism, 18: reagent pump, 19: sample pump , 20: cleaning pump, 21: control device, 22: input / output device, 23, 24: ultrasonic cleaner, 100: automatic analyzer, 101: dispensing mechanism, 101p: probe, 101v: container, 101s: liquid, 102: detection unit, 103: signal processing unit, 104: control unit, 105: calculation unit, 106: memory unit, 107: determination unit, 201, 211, 231: suction section, 202, 232: discharge section, 203: movement section, 20 4: Cleaning section, 233, 234: Noise waveform, 241: Spike, 401: Alarm display setting screen, 402: Probe selection section, 403: Probe status setting section, 404: Usable, 405: Cleaning recommended, 406: Usage caution, 407: Replacement recommended, 408: Warning, 409: Cancel button, 410: Update button, 701: Display screen, 702: Probe selection section, 703: Last replacement date display section, 704: Daily time series management Diagram display section, 705: alarm setting, 801: display screen, 802: probe selection section, 803: last replacement date display section, 804: daily time series control chart display section, 805: recommended cleaning setting value, 806: number of days since replacement, 807: number of days since last cleaning, 901: probe condition evaluation screen, 902: probe selection section, 903: evaluation value display section, 904: test execution button, 905: judgment display section, 906: result confirmation button.

Claims

1. a dispensing mechanism including a probe for dispensing a liquid; a detection unit including a liquid level sensor that measures the capacitance between the tip of the probe and a reference potential surface and outputs a capacitance signal; a signal processing unit that determines a state of the probe based on a change in the time waveform of the capacitance signal; the signal processing unit stores a time waveform of the capacitance signal during a dispensing operation of the dispensing mechanism immediately after replacing the probe as a reference capacitance signal waveform; The signal processing unit determines the state of the probe based on a waveform change index that indicates a change in the time waveform of the capacitance signal from the reference capacitance signal waveform during a dispensing operation of the dispensing mechanism.

2. (delete)

3. In claim 1, the signal processing unit stores, as a reference area, an area of ​​the reference capacitance signal waveform in a predetermined section during the dispensing operation of the dispensing mechanism immediately after the replacement of the probe; A dispensing device in which the waveform change index is the area ratio of the area in the specified section of the time waveform of the capacitance signal during the dispensing operation of the dispensing mechanism to the reference area.

4. In claim 3, The predetermined section is a section from when the probe starts suctioning the liquid to when the probe finishes washing.

5. In claim 1, The signal processing unit detects spikes included in the time waveform of the capacitance signal during a dispensing operation of the dispensing mechanism.

6. In claim 1, the dispensing mechanism includes an LED lamp; The signal processing unit causes the LED lamp to emit light in accordance with the determined state of the probe.

7. An automatic analyzer using the dispensing device according to claim 1 for dispensing a sample or a reagent, An automatic analyzer that recommends to a user maintenance measures according to the value of the waveform change index.

8. In claim 7, a display device; The automatic analyzer displays on the display device a setting screen for setting a range of values ​​of the waveform change index for which the maintenance action is recommended to the user.

9. In claim 7, If the value of the waveform change index exceeds a predetermined threshold, the automatic analyzer performs a remeasurement of the measurement in which the liquid was dispensed by the dispensing operation.

10. In claim 9, If the value of the waveform change index due to the dispensing operation of the dispensing mechanism in the remeasurement exceeds the predetermined threshold, the automatic analyzer outputs an alarm to the user without performing another remeasurement.

11. In claim 7, An automatic analyzer that remeasures the measurement in which the liquid was dispensed by the dispensing operation when the value of the waveform change index exceeds a predetermined threshold and the time waveform of the capacitance signal during the dispensing operation of the dispensing mechanism contains a spike.

12. In claim 11, If the value of the waveform change index due to the dispensing operation of the dispensing mechanism in the re-measurement exceeds the predetermined threshold value and the time waveform of the capacitance signal during the dispensing operation of the dispensing mechanism in the re-measurement contains a spike, the automatic analyzer outputs an alarm to the user without performing another re-measurement.

13. In claim 7, a display device; Displaying an intraday time series control chart on the display device, The intra-day time series control chart of an automatic analyzer has the horizontal axis representing the operating time of the dispensing device on that day and the vertical axis representing the value of the waveform change index, and the value of the waveform change index during the operating time of the dispensing device is plotted.

14. In claim 7, a display device; Displaying an inter-day time series control chart on the display device, The daily time series control chart of the automatic analyzer has the number of days elapsed since the probe of the dispensing device replaced on the horizontal axis and the value of the waveform change index on the vertical axis, and the average value of the waveform change index per day over the number of days elapsed for the dispensing device is plotted.

15. In claim 7, a display device; the signal processing unit determines a state of the probe based on the waveform change index due to a dispensing operation of the dispensing mechanism after maintenance of the probe; The display device is an automatic analyzer that displays the determination result by the signal processing unit.

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