Automatic analyzer and control method thereof

Abstract

The purpose of the present invention is to provide an automatic analysis device that uses a capacitive-type liquid surface sensing function and is capable of determining horizontal position shift of a probe. To realize the foregoing, this automatic analysis device includes a dispensing mechanism, a capacitance measurement unit, and a control unit, wherein the control unit includes: a liquid surface sensing unit that senses the liquid surface of a liquid on the basis of the capacitance measured by the capacitance measurement unit; a peak value calculation unit that, when the dispensing mechanism is driven in the horizontal direction, calculates a peak value of the capacitance caused by each of a first member and a second member installed separated by a predetermined interval in a movement direction, on one side and another side sandwiching the movement trajectory of the probe; and a position determination unit that compares a first peak value caused by the first member and a second peak value caused by the second member to determine the horizontal position of the probe.

Description

[Technical Field]

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

[0002] Automated analyzers used in clinical testing are equipped with probes for dispensing reagents and samples. To improve the dispensing accuracy and cleaning efficiency of the probe, it is necessary to adjust the probe so that it stops at the center of the dispensing position or the cleaning position. For example, Patent Document 1 discloses a technology that uses a capacitance detection mechanism used in the liquid level detection function of an automated analyzer to detect deviations in the lowered position of the probe. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-033551 Summary of the Invention [Problem to be solved by the invention]

[0004] The technique described in Patent Document 1 can detect positional deviation of the probe in the height direction, but has difficulty in detecting positional deviation of the probe in the horizontal direction. An object of the present invention is to provide an automatic analyzer that can determine horizontal positional deviation of a probe by utilizing a capacitance-type liquid level detection function in the automatic analyzer, and a control method thereof. [Means for solving the problem]

[0005] In order to solve the above problems, the automatic analyzer of the present invention is an automatic analyzer comprising a dispensing mechanism capable of driving a probe that aspirates or dispenses liquid in horizontal and vertical directions, a capacitance measuring unit provided on the probe that measures the capacitance between it and its surroundings, and a control unit that controls the dispensing mechanism and the capacitance measuring unit, wherein the control unit comprises: a liquid level detection unit that detects the liquid level based on the capacitance measured by the capacitance measuring unit; a peak value calculation unit that calculates peak values ​​of capacitance caused by a first member and a second member installed on one side and the other side of the movement trajectory of the probe, separated by a predetermined distance in the movement direction, when the dispensing mechanism is driven horizontally; and a position determination unit that compares the first peak value caused by the first member and the second peak value caused by the second member to determine the horizontal position of the probe.

[0006] In addition, the control method for an automatic analyzer according to the present invention includes the steps of: a control unit detecting the liquid level based on the capacitance measured by the capacitance measuring unit; a step of the control unit calculating, when the dispensing mechanism is driven horizontally, peak values ​​of capacitance caused by a first member and a second member installed on one side and the other side of the movement trajectory of the probe, at a predetermined distance in the movement direction; and a step of the control unit comparing the first peak value caused by the first member with the second peak value caused by the second member to determine the horizontal position of the probe. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide an automatic analyzer capable of determining horizontal positional deviation of a probe and a control method thereof. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing the overall configuration of an automatic analyzer. [Figure 2] FIG. 2 is a schematic diagram showing a dispensing mechanism and a determination jig. [Figure 3] FIG. [Figure 4] FIG. 10 is a top view showing the rotation trajectory of the probe and the determination jig. [Figure 5] 10 is a graph showing the capacitance measured for each distance traveled by the probe. [Figure 6] FIG. 2 is a functional block diagram of an automatic analyzer. [Figure 7] 10 is a flowchart for determining and correcting the probe position. DETAILED DESCRIPTION OF THE INVENTION

[0009] FIG. 1 is a perspective view showing the overall configuration of an automatic analyzer. The automatic analyzer dispenses a sample (specimen) and a reagent into a plurality of reaction vessels 2, respectively, to cause a reaction, and measures the reacted liquid. The automatic analyzer includes a reaction disk (incubator) 1, a reagent disk 9, a specimen transport mechanism 17, reagent dispensing mechanisms 7 and 8, specimen dispensing mechanisms 11 and 12, a cleaning mechanism 3, a spectrophotometer 4, stirring mechanisms 5 and 6, cleaning pumps (not shown), cleaning tanks 13, 14, 22, 23, 56, and 57, and a control unit 21. Although not shown in FIG. 1, the automatic analyzer further includes a display unit 51 and an input unit 52.

[0010] Reaction vessels 2 are arranged circumferentially on the reaction disk 1. A sample transport mechanism 17 is installed near the reaction disk 1 to move sample racks 16 carrying sample vessels 15 (test tubes). The sample vessels 15 contain test specimens such as blood, and are placed on the sample racks 16 and transported by the sample transport mechanism 17. Sample dispensing mechanisms 11 and 12, which can rotate and move up and down, are installed between the reaction disk 1 and the sample transport mechanism 17. The sample dispensing mechanisms 11 and 12 are equipped with sample probes 11a and 12a, which move in an arc around the rotation axis of the sample dispensing mechanisms 11 and 12 to dispense samples from the sample vessels 15 to the reaction vessels 2.

[0011] A plurality of reagent bottles 10 can be placed on the circumference of the reagent disk 9. The reagent disk 9 is kept refrigerated. Reagent dispensing mechanisms 7 and 8 that can rotate and move up and down are installed between the reaction disk 1 and the reagent disk 9. The reagent dispensing mechanisms 7 and 8 are each equipped with a reagent probe 7a and 8a, which moves in an arc around the rotation axis to access the reagent disk 9 and dispense reagent from the reagent bottle 10 into the reaction vessel 2.

[0012] Around the reaction disk 1, there are arranged a washing mechanism 3 that washes reaction vessels 2 that have been measured, stirring mechanisms 5 and 6 that stir the mixture (reaction solution) of reagent and specimen in the reaction vessel 2, a light source (not shown) that irradiates the mixture (reaction solution) in the reaction vessel 2 with light and measures its absorbance, for example, and a spectrophotometer 4. Washing tanks 13, 14, 57, 56, 23, and 22 are respectively installed within the movement ranges of the specimen dispensing mechanisms 11 and 12, the reagent dispensing mechanisms 7 and 8, and the stirring mechanisms 5 and 6. Each mechanism of the automated analyzer is connected to and controlled by a control unit 21 via an interface 50 (not shown in FIG. 1).

[0013] The analysis process of test samples by an automated analyzer is generally carried out in the following order: First, the sample probe 11a of the sample dispensing mechanism 11 aspirates the sample from the sample container 15 placed on the sample rack 16 transported near the reaction disk 1 by the sample transport mechanism 17, and dispenses it into the reaction container 2 on the reaction disk 1. Next, the reagent probe 7a of the reagent dispensing mechanism 7 or the reagent probe 8a of the reagent dispensing mechanism 8 aspirates the reagent to be used for the analysis from the reagent bottle 10 on the reagent disk 9, and dispenses it into the reaction container 2 into which the sample was previously dispensed. Next, the mixing mechanism 5 mixes the mixture of the sample and reagent in the reaction container 2.

[0014] Thereafter, light generated from a light source is transmitted through a reaction vessel 2 containing the mixed solution, and the luminosity of the transmitted light is measured by a spectrophotometer 4. The luminosity measured by the spectrophotometer 4 is sent to the control unit 21 via an A / D converter and an interface 50. The control unit 21 performs calculations to calculate, for example, the concentration of a predetermined component of an analysis item corresponding to a reagent from the absorbance of the mixed solution (reaction solution). The obtained measurement results are displayed on a display unit 51 (omitted from FIG. 1 ). Note that, although an automatic analyzer that determines the concentration of a predetermined component using a spectrophotometer 4 will be described as an example, the technology disclosed in the embodiments described below may also be used in an automatic immunoanalyzer or an automatic coagulation analyzer that measures samples using other photometers.

[0015] Here, the automated analyzer has a liquid level detection function that detects whether the probe has contacted the liquid level based on a change in the capacitance of the probe tip. In this embodiment, the capacitance measurement unit provided in the probe for this liquid level detection is repurposed to determine whether the probe has shifted horizontally. Below, we will explain in detail a method for determining the deviation of the probe's movement trajectory based on the capacitance measured between the probe and a determination jig that is fixed or detachably provided on the automated analyzer, and correcting the probe position as necessary.

[0016] 2 is a schematic diagram showing a single-axis dispensing mechanism with a rotation radius R and a determination jig placed in an automatic analyzer. The following description will be given using the above-mentioned reagent dispensing mechanism 7 as an example, but the present invention can also be applied to other dispensing mechanisms, such as the above-mentioned specimen dispensing mechanisms 11 and 12 and reagent dispensing mechanism 8.

[0017] As shown in FIG. 2 , the reagent dispensing mechanism 7 includes a reagent probe 7a that aspirates or dispenses liquid, an arm 7b that supports the reagent probe 7a, and a rotating shaft 7c that can rotate horizontally and move vertically. The reagent probe 7a can rotate within a horizontal plane and move up and down in the vertical direction in response to the operation of the rotating shaft 7c by the control unit 21. The reagent probe 7a can also aspirate and dispense liquid in response to the operation of a syringe (not shown) by the control unit 21. For example, the reagent probe 7a of the reagent dispensing mechanism 7 rotates and moves above the vertical projection of the reagent bottle 10, then descends to immerse itself in the reagent in the reagent bottle 10 and aspirate the reagent. Next, the reagent probe 7a of the reagent dispensing mechanism 7 rises, rotates, and moves above the vertical projection of the reaction vessel 2, then descends to dispense the reagent into the reaction vessel 2.

[0018] Furthermore, the reagent probe 7a is provided with a capacitance measuring unit 70 that measures the capacitance between the reagent probe 7a and its surroundings. The capacitance measuring unit 70 transmits the measured capacitance to the control unit 21 via the interface 50 (see FIG. 6).

[0019] Furthermore, a determination jig 100 for determining positional deviation of the reagent probe 7a is placed in a location corresponding to the horizontal movement trajectory of the reagent probe 7a, for example, in the washing tank 57 for washing the reagent probe 7a. The determination jig 100 has a first member 101 and a second member 102 located on one side and the other side of the movement trajectory of the reagent probe 7a. The first member 101 and the second member 102 are made of a conductive material and are connected to a GND potential.

[0020] The location of the determination jig 100 is not limited to the washing tank, as long as it is within the movement range of the probe and is a structure that does not rotate. For example, in the case of the sample probes 11a and 12a, the determination jig 100 can also be placed in a thermostatic bath that maintains the temperature of the reaction vessel 2, or in the disposal hole of the reaction vessel 2. Furthermore, the determination jig 100 may be pre-fixed to a structure on the automatic analyzer, or may be detachable. If the determination jig 100 is detachable, it is attached, for example, before determining the positional deviation of the reagent probe 7a and detached after determining the positional deviation of the reagent probe 7a.

[0021] FIG. 3 is a perspective view showing the structure of the judging jig 100. As shown in FIG. 3, the judging jig 100 of this embodiment is composed of a base 103 on the bottom surface and two members, a first member 101 and a second member 102, protruding upward from the base 103. As described above, the judging jig 100 is preferably made of a conductive material, but may be made of other materials as long as the capacitance changes depending on the presence or absence of the first member 101 and the second member 102. The base 103, the first member 101, and the second member 102 may integrally constitute the judging jig 100, or the judging jig 100 may be constituted by assembling separate members.

[0022] Next, how the movement trajectory and capacitance of the reagent probe 7a change when the position is normal and when it is misaligned will be described with reference to Figs. 4 and 5. Fig. 4 is a top view showing the rotation trajectory of the probe and the determination jig, and Fig. 5 is a graph showing the capacitance measured for each movement distance of the probe. Note that circumferential positions a to d in Fig. 4 correspond to movement distances A to D in Fig. 5.

[0023] As shown in FIG. 4, the first member 101 and the second member 102 are disposed at a predetermined distance in the direction of movement of the reagent probe 7a. Therefore, as shown in FIG. 5, the capacitance measured by the capacitance measuring unit 70 exhibits two peaks as the reagent probe 7a moves. Specifically, when the reagent probe 7a starts to rotate from circumferential position a, the capacitance gradually increases. When the reagent probe 7a reaches circumferential position b, which is the closest point to the first member 101, the capacitance reaches a first peak value (P1). As the reagent probe 7a continues to rotate, the capacitance gradually decreases, and then begins to increase again at the midpoint between circumferential positions b and c. When the reagent probe 7a continues to rotate and reaches circumferential position c, which is the closest point to the second member 102, the capacitance reaches a second peak value (P2), and then gradually decreases. In addition, if the distance between the first member 101 and the second member 102 is too close in the moving direction of the reagent probe 7a, the two peaks will overlap and become difficult to distinguish, so it is desirable to set the distance between the center positions of each member to, for example, 10 mm or more.

[0024] The first member 101 is placed on the inner diameter side of the circular movement trajectory of the reagent probe 7a, and the second member 102 is placed on the outer diameter side of the circular movement trajectory of the reagent probe 7a. When the position of the reagent probe 7a is normal, the reagent probe 7a is preset to pass through the radial midpoint between the outer diameter end of the first member 101 and the inner diameter end of the second member 102. Therefore, when the reagent probe 7a is in the normal position and its movement trajectory is trajectory T0 in Fig. 4, the capacitance measured by the capacitance measuring unit 70 will have a waveform as shown by the solid line in Fig. 5. That is, the first peak value (P1) caused by the first member 101 and the second peak value (P2) caused by the second member 102 are substantially the same.

[0025] However, when the reagent probe 7a is displaced toward the inner diameter side and the movement trajectory is as shown in T1 in FIG. 4, the first peak value (P1) becomes larger than the second peak value (P2), as indicated by the dotted line in FIG. 5. On the other hand, when the reagent probe 7a is displaced toward the outer diameter side and the movement trajectory is as shown in T2 in FIG. 4, the second peak value (P2) becomes larger than the first peak value (P1), as indicated by the dashed line in FIG. 5. Therefore, the radial positional deviation of the reagent probe 7a can be determined by calculating the first peak value (P1) and the second peak value (P2) and comparing which value is larger. In this way, since the determination is made by relative comparison of multiple peak values, the determination accuracy is higher than that when a determination is made by comparing any one peak value (absolute value) with a reference value.

[0026] Furthermore, it is also possible to determine the circumferential positional deviation of the reagent probe 7a based on whether the amount of movement (rotation angle D1) or the movement time from the rotation start position (circumferential position a in FIG. 4) to the position corresponding to the first peak value (P1) (circumferential position b in FIG. 4) is within a predetermined range. Note that the amount of movement (rotation angle D2) or the movement time from the rotation start position (circumferential position a in FIG. 4) to the position corresponding to the second peak value (P2) (circumferential position c in FIG. 4) may also be used to determine the circumferential positional deviation of the reagent probe 7a. Furthermore, the reference circumferential position is not limited to the rotation start position, and may be another position (for example, circumferential position d in FIG. 4).

[0027] In this embodiment, the first member 101 and the second member 102 have a shape that is convex toward the movement trajectory of the reagent probe 7a, so that the capacitance increases sharply when the tip of the convex portion and the reagent probe 7a are at the shortest distance, and then decreases sharply when the reagent probe 7a passes the shortest distance. As a result, the peak of the capacitance measured by the capacitance measuring unit 70 becomes more pronounced, improving the accuracy of determining misalignment.

[0028] Fig. 6 is a functional block diagram of the automatic analyzer, in which functions other than those for capacitance calculation are omitted.

[0029] The control unit 21 is a computer equipped with a processor and a memory, and includes a liquid level detection unit 21a, a peak value calculation unit 21b, a position determination unit 21c, and a position correction unit 21d, as shown in Fig. 6. The liquid level detection unit 21a, the peak value calculation unit 21b, the position determination unit 21c, and the position correction unit 21d are functions realized by the processor executing a program stored in the memory.

[0030] The liquid level detection unit 21a detects whether the probe has reached the liquid level from a change in capacitance measured by the capacitance measurement unit 70 when the dispensing mechanism is lowered. The peak value calculation unit 21b calculates the peak values ​​of the capacitance caused by the first member 101 and the second member 102. The position determination unit 21c compares the first peak value (P1) and the second peak value (P2) to determine the radial position of the probe. The position determination unit 21c can also determine the circumferential position of the probe based on whether the movement amount or movement time from the reference position of the probe to the position corresponding to the first peak value (P1) or the second peak value (P2) is within a predetermined range.

[0031] In addition to the dispensing mechanism (reagent dispensing mechanism 7 as an example here) and capacitance measuring unit 70, control unit 21 is also connected to display unit 51 and input unit 52 via interface 50. Display unit 51 is, for example, a display, and displays a warning or the like when the result of position determination is abnormal. Input unit 52 is, for example, a keyboard, and is used when the user inputs operation information or the like.

[0032] Next, the process flow for determining deviation in the probe movement trajectory and correcting the probe position will be described with reference to FIG. 7. FIG. 7 is a flowchart related to determining and correcting the probe position. Below, an automatic adjustment function that also corrects the probe position when it is determined that there is a position deviation will be described. However, the automatic analyzer may determine the probe position deviation and output a warning, and the probe position correction may be performed by a maintenance person. The automatic adjustment function may be executed when replacing the probe or thermostatic chamber, or when initializing or maintaining the automatic analyzer.

[0033] First, the automatic adjustment function starts when a maintenance person operates the execution button for the automatic adjustment function using the input unit 52. Then, the control unit 21 outputs a message to the display unit 51 prompting the user to attach the determination jig 100 to a predetermined location of the automatic analyzer (step S1). Note that if the determination jig 100 is previously fixed to the cleaning tank 57 or the like of the automatic analyzer, step S1 is not necessary.

[0034] When the maintenance person installs the evaluation jig 100 and operates the confirmation button, the control unit 21 drives the reagent dispensing mechanism 7 in the vertical direction, and the reagent probe 7a moves to a predetermined height for position evaluation (step S2). Furthermore, the control unit 21 drives the reagent dispensing mechanism 7 in the horizontal direction, and the reagent probe 7a moves to the evaluation start point (step S3).

[0035] Next, the reagent probe 7a starts to rotate from the determination start point, first passes near the first member 101, then passes near the second member 102, and reaches the determination end point (step S4). At this time, the peak value calculation unit 21b of the control unit 21 calculates the first peak value (P1) and the second peak value (P2), and also calculates the movement amount or movement time from the determination start point to the position corresponding to the first peak value (P1) (step S5).

[0036] If the peak value, the movement amount, or the movement time cannot be calculated in step S5, a warning or the like urging the user to confirm whether the evaluation jig 100 is correctly installed is output via the display unit 51 (step S6). On the other hand, if the peak value or the like can be calculated in step S5, the position determination unit 21c determines whether the first peak value (P1) and the second peak value (P2) are substantially the same (step S7).

[0037] If it is determined in step S7 that the values ​​are not the same, the reagent probe 7a is misaligned in the radial direction. That is, if P1 is greater than P2, the position determination unit 21c determines that the reagent probe 7a is misaligned in the inner diameter direction, and if P2 is greater than P1, the position determination unit 21c determines that the reagent probe 7a is misaligned in the outer diameter direction. The position correction unit 21d corrects the radial position of the reagent probe 7a according to the determination result by the position determination unit 21c (step S8). If the reagent dispensing mechanism 7 does not have an actuator that can move the reagent probe 7a in the radial direction, a message urging the maintenance person to correct the position may be output via the display unit 51. Once the position correction is complete, the process returns to step S4. On the other hand, if it is determined in step S7 that the values ​​are the same, the radial position of the reagent probe 7a is normal, so the circumferential position of the reagent probe 7a is determined. Therefore, the position determination unit 21c determines whether the movement amount or movement time calculated in step S6 is within a predetermined range (step S9).

[0038] If it is determined in step S9 that the value is outside the predetermined range, the reagent probe 7a is misaligned in the circumferential direction, and the position corrector 21d calculates the difference from the design value as the circumferential adjustment value (step S10). Next, the position corrector 21d determines whether the adjustment value is within a specified range (step S11).

[0039] If it is determined in step S11 that the adjustment value is outside the specified range, a warning is output via the display unit 51 (step S12). On the other hand, if it is determined in step S11 that the adjustment value is within the specified range, the adjustment value is reflected in the automatic analyzer (step S13), and the automatic adjustment function ends.

[0040] As described above, in this embodiment, the radial and circumferential positional deviation of the probe is determined and the position is corrected as necessary, thereby ensuring that liquid is aspirated and discharged at the appropriate probe position, thereby improving the reliability of the automatic analyzer.

[0041] Furthermore, the present invention is not limited to the above-described embodiment, and various modifications are possible. For example, in the above-described embodiment, the dispensing mechanism rotates on one axis, causing the probe to trace a circular trajectory, but as long as the dispensing mechanism can be driven horizontally, it may rotate on multiple axes or move linearly.

[0042] In particular, the following modifications of the judging jig 100 are possible.

[0043] For example, the horizontal cross-sectional shape of the first member 101 and the second member 102 is not limited to that shown in Fig. 4, and the horizontal cross-section may be circular or polygonal. Furthermore, the height-direction contour (slope) of the portions of the first member 101 and the second member 102 that face the movement trajectory may be made to follow the height-direction contour (slope) of the capacitance measuring unit 70 at the tip of the probe, thereby increasing the extent of the increase in capacitance when each member and the probe approach each other, and improving the S / N ratio.

[0044] 3, the first member 101 and the second member 102 may be concave relative to the base 103. In this case, the capacitance decreases when the first member and the second member are approached, and the position of the probe is determined by calculating the minimum value of the capacitance caused by each member.

[0045] Furthermore, the number of members provided on the evaluation jig 100 is not limited to two, the first member and the second member, but may be three or more. Furthermore, when determining only the circumferential positional deviation of the probe and not the radial positional deviation of the probe, the evaluation jig 100 does not need to have multiple convex or concave members, but only needs to have a single member that is convex or concave along the movement trajectory of the probe. [Explanation of symbols]

[0046] 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, 22, 23, 56, 57...washing tank, 15...sample container, 16...sample rack, 17...sample transport mechanism, 21...control unit, 21a...liquid level detection unit, 21b...peak value calculation unit, 21c...position determination unit, 21d...position correction unit, 50...interface, 51...display unit, 52...input unit, 70...capacitance measurement unit, 100...determination jig, 101...first member, 102...second member, 103...base

Claims

1. a dispensing mechanism that can drive a probe that sucks or dispenses a liquid in a horizontal direction and a vertical direction; and a capacitance measuring unit that is provided on the probe and measures the capacitance between the probe and its surroundings; a control unit that controls the dispensing mechanism and the capacitance measuring unit; An automatic analyzer comprising: The control unit a liquid level detection unit that detects the liquid level based on the capacitance measured by the capacitance measurement unit; a peak value calculation unit that calculates peak values ​​of capacitances caused by a first member and a second member that are installed on one side and the other side of a movement trajectory of the probe and spaced a predetermined distance apart in the movement direction when the dispensing mechanism is driven in a horizontal direction; a position determination unit that determines a horizontal position of the probe by comparing a first peak value caused by the first member with a second peak value caused by the second member; An automatic analyzer having:

2. The automatic analyzer according to claim 1, the first member is disposed on an inner diameter side of a circular movement locus of the probe, and the second member is disposed on an outer diameter side of the circular movement locus of the probe, The position determination unit determines that the probe is shifted toward the inner diameter side when the first peak value is greater than the second peak value, and determines that the probe is shifted toward the outer diameter side when the second peak value is greater than the first peak value.

3. The automatic analyzer according to claim 2, The position determination unit determines that the probe is shifted circumferentially if the amount of movement or the time it takes for the probe to move from its reference position to the position corresponding to the first peak value or the second peak value is outside a predetermined range.

4. The automatic analyzer according to claim 3, The control unit The automatic analyzer further comprises a position correction unit that corrects the position of the probe when it is determined that the probe is misaligned.

5. The automatic analyzer according to claim 2, The first member and the second member have a shape that is convex toward the movement trajectory of the probe.

6. The automatic analyzer according to claim 1, The automated analyzer, wherein the first member and the second member are attached before determining the horizontal position of the probe and are removed after determining the horizontal position of the probe.

7. The automatic analyzer according to claim 1, a washing tank for washing the probe; The first member and the second member are fixed to the washing tank.

8. (delete)

9. a dispensing mechanism that can drive a probe that sucks or dispenses a liquid in a horizontal direction and a vertical direction; and a capacitance measuring unit that is provided on the probe and measures the capacitance between the probe and its surroundings; a control unit that controls the dispensing mechanism and the capacitance measuring unit; A method for controlling an automatic analyzer comprising: the control unit detecting the liquid level based on the capacitance measured by the capacitance measurement unit; a step in which the control unit calculates, when the dispensing mechanism is driven in a horizontal direction, peak values ​​of capacitance caused by a first member and a second member that are installed on one side and the other side of a movement trajectory of the probe and that are spaced a predetermined distance apart in the movement direction; the control unit comparing a first peak value caused by the first member with a second peak value caused by the second member to determine a horizontal position of the probe; A method for controlling an automatic analyzer having the above structure.

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