Automatic analysis device and sample dispensing method

Abstract

According to the present invention, accurate and stable dispensing can be achieved regardless of the amount of a sample contained in a sample container during a stage of feeding into an automatic analysis device. This automatic analysis device is provided with: a liquid level detection device (13) that detects the liquid level of a specimen contained in a specimen container (11a); a dispensing device (21) for dispensing a sample by means of a dispensing probe (42); a liquid level detection unit (50) that outputs a liquid level detection signal indicating that the dispensing probe comes into contact with a specimen contained in the specimen container, on the basis of a change in capacitance between the dispensing probe and the specimen contained in the specimen container; and a dispensing control unit (44) that controls the operation of the dispensing device, and the liquid level detection unit includes a liquid level detection circuit in which the output voltage changes in accordance with the capacitance between the dispensing probe and a sample housed in the sample container. A liquid level detection signal for stopping the dropping of the dispensing probe is generated by comparing the output voltage of the liquid level detection circuit with a threshold value, and the threshold value is set at least on the basis of the liquid level of the specimen detected by the liquid level detection device.

Description

Technical Field

[0001] The present invention relates to an automatic analyzer and a liquid dispensing method, and in particular to an automatic analyzer and a liquid dispensing method which are accompanied by processing of multiple items and multiple dispensing. Background Art

[0002] Conventionally, there are known automatic analyzers for samples such as blood and body fluids that add reagents to the blood or body fluids and optically detect the reaction between the reagents and the sample. Such automatic analyzers are provided with a liquid level detection mechanism for detecting the liquid level in order to accurately perform the sample or reagent dispensing process. Prior art literature Patent Literature

[0003] Patent Document 1: Japanese Patent Application Publication No. 2012-37236 Summary of the invention Technical problem to be solved by the invention

[0004] Patent Document 1 discloses that a threshold voltage for detecting a liquid level is corrected based on the liquid level height in the liquid level detection mechanism. However, the calibration method disclosed in this disclosure assumes that the sample container is filled to the maximum height.

[0005] However, in reality, the specimen is often fed into the device before the specimen container reaches its maximum capacity. Therefore, if the threshold voltage is calculated based on the premise that the specimen is contained to the maximum height of the specimen container, it will inevitably deviate from the optimal threshold.

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an automatic analysis device and a dispensing method capable of more accurately dispensing a sample or a reagent. Technical means for solving technical problems

[0007] As one embodiment of the present invention, an automatic analyzer includes: a liquid level detection device that detects the liquid level of a specimen contained in a specimen container; a dispensing device that dispenses the specimen contained in the specimen container through a dispensing probe; a liquid level detection unit that outputs a liquid level detection signal indicating that the dispensing probe has contacted the specimen based on a change in electrostatic capacitance between the dispensing probe and the specimen contained in the specimen container; and a dispensing control unit that controls the operation of the dispensing device, the dispensing control unit lowers the dispensing probe toward the specimen container in the dispensing device, receives a liquid level detection signal from the liquid level detection unit, and stops the dispensing probe from descending, the liquid level detection unit having a liquid level detection circuit whose output voltage changes according to the electrostatic capacitance between the dispensing probe and the specimen contained in the specimen container, and generates a liquid level detection signal by comparing the output voltage of the liquid level detection circuit with a threshold value, and the dispensing control unit sets the threshold value based on at least the liquid level of the specimen contained in the specimen container detected by the liquid level detection device. Effects of the Invention

[0008] Regardless of the amount of the sample contained in the sample container at the stage of feeding into the automatic analyzer, accurate and stable dispensing can be achieved. Other problems and new features will become clear from the description and drawings of this specification. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a schematic diagram showing the structure of an automatic analysis device. Figure 2A This is a diagram showing the main parts of the sample dispensing device. Figure 2B It is a diagram showing a configuration example of a liquid level detection circuit. Figure 3 This is a diagram showing the temporal change in the output voltage of the signal amplifier when the dispensing probe is lowered and raised. Figure 4 It is a diagram showing the main parts of the reagent dispensing device. Figure 5 This is a flowchart showing the processing procedure of the sample aliquoting process. Figure 6 This is an example of the structure of a threshold setting table. Figure 7 This is an example of the structure of a threshold setting table. Figure 8 This is a flowchart showing the processing procedure (modification example) of the sample aliquoting process. DETAILED DESCRIPTION

[0010] Hereinafter, referring to the accompanying drawings, an automatic analyzer having a dispensing device for dispensing blood, urine, or other specimens or reagents is used as an example to illustrate an embodiment. In addition, the present invention is not limited to this embodiment. In addition, in the description of the accompanying drawings, the same reference numerals are marked on the same parts.

[0011] Figure 1 : is a schematic diagram showing the structure of the automatic analyzer of this embodiment. The automatic analyzer includes: a sample transfer mechanism 1 for sending a sample to be analyzed into the device; a measurement mechanism 2 for dispensing the sample and the reagent into a cuvette 24a respectively and optically measuring the reaction occurring in the cuvette 24a after the dispensing; and a control mechanism 3 for controlling the entire automatic analyzer and analyzing the measurement results of the measurement mechanism 2. Through the cooperation of these mechanisms, biochemical analysis of multiple samples can be automatically performed.

[0012] First, the specimen transfer mechanism 1 will be described. Liquid specimens such as blood and urine are contained in specimen containers 11a, and a plurality of specimen containers 11a are placed on a specimen rack 11 and transported into the device. The specimen rack 11 is transported by the specimen transfer mechanism 1 in the direction of the arrow in the figure and sequentially transferred to the measuring mechanism 2. The specimen transfer mechanism 1 includes a specimen information reading device 12 that reads information from an information storage medium attached to the specimen container 11a. As the information storage medium, for example, a barcode or an RFID tag can be used. The specimen information reading device 12 reads information such as specimen information and the type of the specimen container 11a from the information storage medium and outputs the information to the control unit 31. In addition, the specimen transfer mechanism 1 also includes a liquid level detection device 13 that detects the liquid level of the specimen contained in the specimen container 11a. The liquid level detection device 13 detects the liquid level of the specimen contained in the specimen container 11a and outputs the information to the control unit 31. The liquid level detection device 13 detects the liquid level of the sample contained in the sample container 11a by emitting infrared light or visible light to the transferred sample container 11a and detecting the change of the reflected light or the change of the refractive index of the light transmitted through the sample. The method of detecting the liquid level is not limited to the above, and the liquid level of the sample contained in the sample container 11a may be acquired from the captured image of the sample container 11a by photographing the sample container 11a. In this case, the type of the sample container 11a may be determined from the image information of the sample container 11a.

[0013] Next, the measurement mechanism 2 is described. The measurement mechanism 2 includes, as main components, a sample dispensing device 21, a reaction table 24, a reagent reservoir 27, a reagent dispensing device 23, a stirring unit 25, a photometry unit 26, and a cleaning unit 22.

[0014] The specimen dispensing device 21 dispenses the specimen in the specimen container 11a into the cuvette 24a arranged on the reaction table 24. The reaction table 24 is driven by a driving mechanism (not shown) under the control of the control unit 31, and can rotate about a vertical line passing through the center of the reaction table 24 as a rotation axis, and move the cuvette 24a to a specified position to perform specimen or reagent dispensing, stirring, photometry, etc.

[0015] The reagent storehouse 27 stores a plurality of reagent containers 27a for accommodating the reagents dispensed into the cuvette 24a. The reagent containers 27a can be freely loaded and unloaded in the reagent storehouse 27. The reagent storehouse 27 is driven by a driving mechanism (not shown) under the control of the control unit 31, and can be rotated clockwise or counterclockwise with the plumb line passing through the center of the reagent storehouse 27 as the rotation axis to transfer the desired reagent container 27a to the reagent suction position of the reagent dispensing device 23. A lid (not shown) that can be opened and closed freely is provided above the reagent storehouse 27. In addition, the reagent storehouse 27 has a cold-keeping function. When the reagent storehouse 27 stores the reagent container 27a inside and the lid is closed, the reagent contained in the reagent container 27a is cooled to suppress the evaporation or denaturation of the reagent.

[0016] An information storage medium recording reagent information related to the reagent contained in the reagent container 27a is attached to the side of the reagent container 27a. For example, the information storage medium stores reagent information such as the analysis item using the reagent, the name of the reagent, batch information, and reagent container information. As the information storage medium, for example, a bar code or an RFID tag can be used. A reagent information reading device 28 for reading the information storage medium attached to the reagent container 27a is provided in the reagent warehouse 27. The reagent information reading device 28 reads the reagent information and the type of the reagent container 27a for containing the reagent from the information storage medium, and outputs it to the control unit 31. The reagent information reading device 28 outputs the information of the information storage medium read by the reagent information reading device 28 to the control unit 31 corresponding to the position of the reagent container 27a attached with the information storage medium in the reagent warehouse 27.

[0017] The stirring unit 25 stirs the sample and reagent dispensed into the cuvette 24a to promote the reaction. The photometric unit 26 irradiates the cuvette 24a with analytical light from a light source, splits the light transmitted or scattered from the liquid in the cuvette 24a, and measures the intensity of each wavelength of light with a light receiving element, thereby measuring the absorbance of the reaction solution of the sample and reagent as the analysis object at a wavelength unique to the reaction solution.

[0018] The cleaning unit 22 sucks and discharges the mixed liquid in the cuvette 24a after the measurement by the photometer 26 through the cleaning nozzle, and cleans the cuvette 24a after the analysis process by injecting and sucking a cleaning liquid such as detergent or cleaning water.

[0019] Next, the control mechanism 3 will be described. The control mechanism 3 includes a control unit 31, an input unit 32, an analysis unit 33, and an output unit 34. The control mechanism 3 is constituted by an information processing device such as a PC (personal computer).

[0020] The control unit 31 controls the entire automatic analyzer. The input unit 32 has input devices such as a keyboard and a mouse, and obtains various information required for sample analysis and instruction information for analysis actions from the outside. The user can input sample information, reagent information, container information, probe type, etc. from the input unit 32. The analysis unit 33 performs component analysis of the sample based on the absorbance measured by the photometric unit 26. The output unit 34 has output devices such as a display, a printer, and a speaker, and outputs various information including the analysis results of the sample. In addition, the output unit 34 can also output various information to an external device via a communication network not shown in the figure.

[0021] In the automatic analyzer constructed as above, for the plurality of cuvettes 24a arranged on the reaction table 24, after the sample dispensing device 21 dispenses the sample in the sample container 11a, and the reagent dispensing device 23 dispenses the reagent in the reagent container 27a, the photometric unit 26 measures the spectral intensity of the mixed solution after the sample and the reagent react, and the analysis unit 33 analyzes the measurement results, thereby automatically performing component analysis of the sample, etc. The cleaning unit 22 cleans the cuvette 24a after the measurement so that it can be reused, and a series of analysis operations are continuously repeated.

[0022] like Figure 2A As shown, the sample dispensing device 21 includes a dispensing probe 42 made of a conductive metal material, and the dispensing probe 42 is supported by an arm 41a, and the arm 41a is supported by a support 41b. The probe driving unit 43 raises and lowers the support 41b in the vertical direction, and at the same time rotates the arm 41a about a vertical line L passing through a joint between the arm 41a and the support 41b as a central axis, thereby inserting the dispensing probe 42 into the sample container 11a containing the sample.

[0023] The operation of the sample dispensing device 21 is controlled by the dispensing control unit 44. The operation of the dispensing device can be roughly divided into the driving of the probe, the suction and discharge of the sample and other liquids, Figure 2A The components related to the driving of the probe are extracted and shown. The dispensing control unit 44 is composed of a control substrate or a microcomputer having a CPU, RAM and ROM, and includes a control unit 45, a threshold setting unit 46, and a storage unit 47. The liquid level detection unit 50 is a circuit board that outputs a liquid level detection signal when the tip of the dispensing probe 42 contacts the specimen in the specimen container 11a.

[0024] The operation of the specimen dispensing device 21 when dispensing the specimen in the specimen container 11a will be described. The control unit 45 of the dispensing control unit 44 rotates the arm 41a by controlling the probe driving unit 43, thereby positioning the dispensing probe 42 on the specimen container 11a. Subsequently, the control unit 45 controls the probe driving unit 43 to lower the support column 41b, thereby lowering the dispensing probe 42 toward the specimen container 11a. When the tip of the dispensing probe 42 is inserted into the specimen in the specimen container 11a, the liquid level detection unit 50 outputs a liquid level detection signal to the control unit 45. After receiving the liquid level detection signal, the control unit 45 stops the descent of the dispensing probe 42 and transfers to the suction operation of the specimen.

[0025] With Figure 2B , an example of the circuit configuration of the liquid level detection circuit of the liquid level detection unit 50 will be described. The voltage detection unit 51 of the liquid level detection unit 50 includes a power supply V, a capacitor Cs connected in parallel with the power supply V, and a capacitance component C formed between the dispensing probe 42 and the sample stage 49. The capacitance component C is the combined capacitance of the electrostatic capacitance C1 between the dispensing probe 42 and the specimen, the electrostatic capacitance C2 between the specimen and the sample stage 49, and the electrostatic capacitance C3 between the dispensing probe 42 and the sample stage 49. The electrostatic capacitances C1 and C3 change as the dispensing probe 42 moves up and down, and the electrostatic capacitance C1 becomes 0 when the dispensing probe 42 contacts the specimen. The change in this capacitance component C can be detected as the voltage of the capacitor Cs. Therefore, the signal amplifier 52 amplifies and outputs the voltage between the electrodes of the capacitor Cs, compares it with the threshold value for determining the liquid level detection stored in the storage unit 54 in the comparison unit 53, and after binarizing the comparison result of the comparison unit 53 by the A / D converter 55, outputs it as a liquid level detection signal.

[0026] Figure 3 It schematically shows Figure 2A The relationship between the time when the dispensing probe 42 of the specimen dispensing device 21 in Figure 3 descends and rises after contacting the specimen and the output voltage from the signal amplifier 52. As Figure 3 shown, as the dispensing probe 42 descends and approaches the specimen contained in the specimen container 11a, the voltage output from the signal amplifier 52 increases. After the dispensing probe 42 contacts the liquid level and starts to rise, as it moves away from the liquid level, the voltage output from the signal amplifier 52 decreases again. Thus, since the output voltage of the signal amplifier 52 increases monotonically before the dispensing probe 42 contacts the liquid level, it can be determined that the dispensing probe 42 has contacted the liquid level when the output voltage of the signal amplifier 52 exceeds a specified threshold value.

[0027] However, the waveform of the output voltage of the signal amplifier 52 varies depending on the type of the specimen container 11a containing the specimen, the shape of the specimen container 11a, and the specimen in the specimen container 11a. In particular, it varies greatly depending on the amount of the specimen. Figure 3The waveforms 61 and 62 shown in FIG. 1 are examples of the same sample contained in the same container. The waveform 61 is a signal waveform when the sample amount is large, and the waveform 62 is a signal waveform when the sample amount is small. Therefore, in this embodiment, the threshold setting unit 46 of the dispensing control unit 44 sets a threshold for determining liquid level detection each time the sample dispensing device 21 performs dispensing, and the comparison unit 53 of the liquid level detection unit 50 determines the liquid level detection based on the threshold.

[0028] Figure 4 FIG. 2 shows an example of the structure of the reagent dispensing device 23. Figure 2A The sample dispensing device 21 shown in the figure is similarly constructed, so repeated description is omitted. In the case of the reagent dispensing device 23, the signal waveform of the output voltage of the signal amplifier 82 changes according to the amount of reagent contained in the reagent container 27a. Therefore, in this embodiment, the threshold setting unit 76 of the dispensing control unit 74 sets a threshold value for determining liquid level detection each time the reagent dispensing device 23 performs dispensing, and the comparison unit 83 of the liquid level detection unit 80 determines the liquid level detection based on the threshold value.

[0029] Next, the sample dispensing process performed by the sample dispensing device 21 will be described. Figure 5 To show Figure 2A Flow chart of the processing steps of the sample dispensing process of the sample dispensing device 21 shown in FIG. The sample information reading device 12 reads the sample information and the container information from the information storage medium attached to the sample container 11a containing the sample to be dispensed, and the liquid level detection device 13 reads the liquid level of the sample. In addition, the reading of the container information can also be performed in the liquid level detection device 13. These information are transmitted to the dispensing control unit 44 of the sample dispensing device 21 via the control unit 31 of the control mechanism 3 (S01). What is shown here is an example of automatically reading these information by the automatic analyzer, and the user can also input these information from the input unit 32 of the control mechanism 3. Subsequently, the threshold setting unit 46 of the dispensing control unit 44 sets the threshold for liquid level judgment based on the information read in step S01 and the threshold setting table stored in the storage unit 47. The set threshold is stored in the storage unit 54 of the liquid level detection unit 50 (S02).

[0030] Figure 6 An example of the structure of the threshold setting table is shown in FIG. Figure 6 In the example of , the threshold value can be set according to the combination of factors that affect the threshold value for liquid level determination. Here, as factors, the sample type 91, the container shape 92, the liquid level 93, and the probe type 94 can be listed, and the threshold value 95 is determined by these combinations. In step S02, according to the information read in step S01, the corresponding record in the threshold setting table is selected and the threshold value is set.

[0031] The specimen type 91 roughly divides the specimen into, for example, plasma, whole blood, and urine. The container shape 92 can be divided based on the characteristics that particularly affect the signal waveform of the output voltage of the signal amplifier 82. For example, it can also be divided according to the height of the container. An example of dividing the liquid level 93 into several ranges is shown. The amount of specimen calculated based on the container shape and the liquid level rather than only the liquid level can also correspond to the threshold. Since the exposure degree of the metal part of the dispensing probe as the electrode of the electrostatic capacitance component C and the diameter of the dispensing probe will affect the signal waveform of the output voltage of the signal amplifier 82, the probe type 94 is distinguished. In addition to the liquid level or the amount of the specimen, the threshold is set according to the specimen type, container shape, and probe type, so that a higher accuracy threshold setting can be achieved. In addition, it is not necessary to set the threshold based on all these factors, and the threshold can also be set by further considering other factors. In addition, an example of setting the threshold using a table is shown here, and the threshold can also be set by a calculation formula with these factors as variables.

[0032] Next, the control unit 45 of the dispensing control unit 44 controls the probe driving unit 43 to lower the dispensing probe 42 into the specimen container 11a (S03). During the descent of the dispensing probe 42, the comparison unit 53 of the liquid level detection unit 50 compares the output voltage of the signal amplifier 52 with the threshold value set in the storage unit 54 (S04). When the output voltage is less than the threshold value (S05: No), the dispensing probe 42 continues to descend and the liquid level determination is continued (S03 to S05). On the other hand, when the output voltage is above the threshold value, the A / D converter 55 outputs a digital liquid level detection signal to the dispensing control unit 44 (S06). The control unit 45 of the dispensing control unit 44 receives the liquid level detection signal and controls the probe driving unit 43 to stop the descent of the dispensing probe 42 (S07).

[0033] Here, the liquid level detection based on electrostatic capacitance may cause erroneous detection due to static electricity or bubbles from the outside mixing into the sample. Therefore, it is desirable to add step S08 to verify whether the actual drop amount is appropriate based on the liquid level information.

[0034] The control unit 45 of the dispensing control unit 44 estimates the required descent amount of the dispensing probe 42 (hereinafter referred to as the necessary descent amount) based on the liquid level information obtained in step S01. In addition, the control unit 45 calculates the actual descent amount of the dispensing probe 42 from the start of the descent of the dispensing probe 42 in step S03 to the stop of the descent of the dispensing probe 42 in step S07 (hereinafter referred to as the actual descent amount). For example, the actual descent distance of the dispensing probe 42 can be calculated based on the number of pulses of the pulse motor provided to the probe driving unit 43. The actual descent amount of the dispensing probe 42 is stored in the storage unit 47.

[0035] The control unit 45 of the dispensing control unit 44 compares the necessary descent amount estimated based on the liquid level information with the actual descent amount, and if they are the same or the error is within the allowable range, it is determined that the liquid level is properly detected. On the other hand, when the error exceeds the allowable range, for example, the process returns to step S03 and executes the descent of the dispensing probe again.

[0036] Thereafter, the control unit 45 executes a dispensing operation of sucking the specimen from the specimen container 11 a and discharging the specimen into the cuvette 24 a ( S09 ), and washes the dispensing probe 42 in a washing tank (not shown) ( S10 ).

[0037] After that, the control unit 31 of the control mechanism 3 confirms whether there are multiple items of measurement for the specimen (S11). In the case of multiple items of measurement (S11: Yes), the threshold setting unit 46 calculates the amount of specimen in the specimen container 11a based on the amount of specimen before dispensing and the dispensing amount, and resets the threshold (S12). In addition, in the case of a liquid level error detection based on the drop amount (S08), the necessary drop amount is updated based on the liquid level height information acquired in step S01 or the actual drop amount and the dispensing amount stored in the storage unit 47. Then, the dispensing process is started again. In the case of no multiple items of measurement (S11: No), the dispensing process of the specimen is terminated.

[0038] Figure 5 The sample dispensing process of the sample dispensing device 21 is described as an example, but the reagent dispensing process of the reagent dispensing device 23 is also the same. The description of the repeated content is omitted, and only the differences are described. In step S01, the information required for setting the threshold is calculated from the reagent information read by the reagent information reading device 28 or input by the user and registered in the device. The threshold setting for the liquid level detection of the reagent can also be performed based on the threshold setting table stored in the storage unit 77 of the dispensing control unit 74.

[0039] Figure 7 , an example of the configuration of the threshold setting table for the reagent dispensing device 23 is shown. The threshold setting table for the reagent dispensing device 23 is the same as the threshold setting table for the specimen dispensing device 21. However, in general, when the shape of the container is determined based on the reagent, the container shape information may not be required. The information required for the threshold setting includes the reagent amount 103, but the reagent amount is obtained from the control unit 31 of the control mechanism 3 in step S01. The control unit 31 stores the reagent dispensing amount after the reagent container 27a is stored in the reagent storage 27 and starts to be used. Using this information, the amount of reagent stored in the reagent container 27a or the liquid level of the reagent can be calculated.

[0040] In this embodiment, a liquid level detection device 13 is provided, and a threshold value for liquid level determination is set based on the liquid level height read from the sample container 11a fed into the device, thereby improving the accuracy of liquid level detection of the sample. In particular, when the amount of sample contained in the sample container 11a is small, if the threshold value is set based on the premise that the maximum amount of sample contained in the sample container 11a is contained, liquid level detection errors are likely to occur. In addition, in the case of multiple dispensing or multiple items of inspection, the threshold value after the second time is calculated based on the liquid amount obtained using the initial liquid level detection result, so that the threshold value after the second time can also be set with high accuracy.

[0041] Figure 8 A flowchart showing a modified example of the sample dispensing process in the sample dispensing device 21 is shown. Figure 5 The difference of the flowchart shown in FIG. 1 is that after the specimen suction operation is performed, it is determined whether the specimen has been successfully sucked based on the output voltage of the signal amplifier 52. Figure 5 The explanation will focus on the differences in the flowcharts.

[0042] When the estimated descent amount is equal to the actual descent amount (S08: Yes), the specimen dispensing device 21 starts the dispensing action and first performs the suction action (S21). During the suction action of the dispensing probe 42, the comparison unit 53 of the liquid level detection unit 50 compares the output voltage of the signal amplifier 52 with the threshold value set in the storage unit 54 (S22). When the output voltage is above the threshold value, the specimen dispensing device 21 continues to receive the liquid level detection signal and continues the dispensing action (S09). The insertion amount of the front end of the dispensing probe 42 is set so that the front end still contacts the liquid surface when the specimen is sucked to prevent air from mixing. Therefore, during the suction action, the output voltage of the signal amplifier 52 is above the threshold value, which indicates that the specimen is being sucked normally.

[0043] In this case, for example, when bubbles formed on the surface of the specimen are mistakenly detected as the liquid surface and the suction operation is started, for example, during the suction operation, the tip of the dispensing probe 42 is away from the liquid surface. At this time, the output voltage of the signal amplifier 52 is less than the threshold value (S23: No), indicating that the suction operation is not performed normally. Therefore, when it is determined that the specimen cannot be normally aspirated in the first dispensing operation from the specimen container 11a (S24: Yes), the process returns to step S03 and the lowering operation of the dispensing probe 42 toward the specimen container 11a is restarted. For example, when the cause of the aspiration operation is bubbles on the surface of the specimen, there is a high possibility that the aspiration can be performed correctly in the second aspiration operation. On the other hand, when it is determined again in step S23 that the specimen cannot be normally aspirated (S24: No), there is a high possibility that the threshold value used for liquid level detection is inappropriate. Therefore, the specimen holder 11 holding the specimen container 11a is returned to the specimen transfer mechanism 1, and the liquid level height of the specimen is read again by the liquid level height detection device 13 (S01), and the threshold value is reset (S02). At this time, reading of information by the specimen information reading device 12 can be omitted.

[0045] Figure 8 The flowchart of FIG. 2 shows the sample dispensing process, but the same process can also be applied to the reagent dispensing process performed by the reagent dispensing device 23.

[0046] In addition, the present invention is not limited to the above-mentioned embodiments, but also includes various modified examples. For example, the above-mentioned embodiments are detailed descriptions for the purpose of facilitating the understanding of the present invention, and are not limited to all structures described. In addition, a part of the structure of a certain embodiment may be replaced with the structure of other embodiments, and the structure of other embodiments may be added to the structure of a certain embodiment. In addition, other structures may be added, deleted, or replaced with a part of the structure of each embodiment. Description of symbols 1: Sample transfer mechanism, 2: Measuring mechanism, 3: Control mechanism, 11: Sample holder, 11a: Sample container, 12: Sample information reading device, 13: Liquid level detection device, 21: Sample dispensing device, 22: Cleaning unit, 23: Reagent dispensing device, 24: Reaction table, 24a: Cuvette, 25: Stirring unit, 26: Photometric unit, 27: Reagent storage, 27a: Reagent container, 28: Reagent information reading device, 31: Control unit, 32: Input unit, 33: Analysis unit, 34: Output unit, 41a, 71a: Arm, 41b, 71b: Support, 42 , 72: dispensing probe, 43, 73: probe driving unit, 44, 74: dispensing control unit, 45, 75: control unit, 46, 76: threshold setting unit, 47, 77: storage unit, 49: sample stage, 50, 80: liquid level detection unit, 51, 81: voltage detection unit, 52, 82: signal amplifier, 53, 83: comparison unit, 54, 84: storage unit, 55, 85: A / D converter, 61, 62: waveform, 91: specimen type, 92, 102: container shape, 93: liquid level height, 94, 104: probe type, 95, 105: threshold value.

Claims

1. An automatic analysis device, It is characterized in that include: a liquid level detection device for detecting the liquid level of the specimen contained in the specimen container; a dispensing device for dispensing a specimen contained in the specimen container by means of a dispensing probe; a liquid level detection unit that outputs a liquid level detection signal indicating that the dispensing probe has contacted the specimen based on a change in electrostatic capacitance between the dispensing probe and the specimen contained in the specimen container; as well as A dispensing control unit, which controls the operation of the dispensing device, The dispensing control unit causes the dispensing probe to descend toward the specimen container in the dispensing device, receives the liquid level detection signal from the liquid level detection unit, and stops the dispensing probe from descending. The liquid level detection unit includes a liquid level detection circuit, the output voltage of which changes according to the electrostatic capacitance between the dispensing probe and the specimen contained in the specimen container, and the liquid level detection unit generates the liquid level detection signal by comparing the output voltage of the liquid level detection circuit with a threshold value. The dispensing control unit sets the threshold value based on at least the liquid level of the specimen contained in the specimen container detected by the liquid level detection device.

2. The automatic analysis device according to claim 1, It is characterized in that A sample information reading device is included, which reads information about the sample container and / or the sample contained in the sample container from an information recording medium attached to the sample container, The dispensing control unit sets the threshold value based on a combination of a liquid level of the specimen contained in the specimen container and information on the specimen container and / or the specimen contained in the specimen container read by the specimen information reading device.

3. The automatic analysis device according to claim 2, It is characterized in that The dispensing control unit sets the threshold value based on a combination of the shape of the specimen container, the type of the specimen contained in the specimen container, the liquid level of the specimen contained in the specimen container, and the type of the dispensing probe.

4. The automatic analysis device according to claim 1, It is characterized in that The dispensing control unit compares the necessary descent amount of the dispensing probe estimated based on the liquid level of the specimen contained in the specimen container detected by the liquid level detection device with the actual descent amount of the dispensing probe that stops upon receiving the liquid level detection signal. When the error between the necessary descent amount and the actual descent amount exceeds an allowable range, the dispensing device causes the dispensing probe to be lowered again toward the specimen container.

5. The automatic analysis device according to claim 1, It is characterized in that When the specimen is dispensed from the specimen container multiple times, the dispensing control unit resets the threshold value based on the liquid level of the specimen contained in the specimen container calculated based on the liquid level of the specimen contained in the specimen container detected by the liquid level detection device and the amount of specimen dispensed.

6. The automatic analysis device according to claim 5, It is characterized in that The dispensing control unit compares the necessary descent amount of the dispensing probe estimated based on the liquid level of the specimen contained in the specimen container with the actual descent amount of the dispensing probe stopped upon receiving the liquid level detection signal, and in the case where the error between the necessary descent amount and the actual descent amount exceeds an allowable range, the dispensing device causes the dispensing probe to be lowered again toward the specimen container. In the case where the specimen is dispensed from the specimen container multiple times, the dispensing control unit updates the necessary descent amount based on the liquid level of the specimen contained in the specimen container detected by the liquid level detection device, or the liquid level of the specimen contained in the specimen container calculated based on the actual descent amount and the dispensed specimen amount.

7. The automatic analysis device according to claim 1, It is characterized in that When the dispensing device sucks the specimen contained in the specimen container, The liquid level detection unit generates the liquid level detection signal by comparing the output voltage of the liquid level detection circuit with the threshold value. The dispensing control unit, when not receiving the liquid surface detection signal and when suction from the specimen container is the first time, causes the dispensing probe to be lowered again toward the specimen container in the dispensing device.

8. The automatic analysis device according to claim 7, It is characterized in that When the liquid level detection unit does not generate the liquid level detection signal and the aspiration from the specimen container is the second or later time, the liquid level detection device detects the liquid level of the specimen contained in the specimen container again.

9. A method for dispensing a sample, which is a method for dispensing a sample by an automatic analysis device. The automatic analysis device include: A liquid level detection device for detecting the liquid level of a specimen contained in a specimen container; a dispensing device for dispensing the specimen contained in the specimen container through a dispensing probe; a liquid level detection unit for outputting a liquid level detection signal indicating that the dispensing probe has contacted the specimen based on a change in electrostatic capacitance between the dispensing probe and the specimen contained in the specimen container; and a dispensing control unit for controlling the operation of the dispensing device. The sample dispensing method is characterized in that: The liquid level detection unit includes a liquid level detection circuit whose output voltage changes according to the electrostatic capacitance between the dispensing probe and the specimen contained in the specimen container. The dispensing control unit causes the dispensing probe to descend toward the sample container in the dispensing device. The liquid level detection unit generates the liquid level detection signal by comparing the output voltage of the liquid level detection circuit with a threshold value. The dispensing control unit receives the liquid level detection signal from the liquid level detection unit and stops the dispensing probe from descending. The dispensing control unit sets the threshold value based on at least the liquid level of the specimen contained in the specimen container detected by the liquid level detection device.

10. The sample dispensing method according to claim 9, It is characterized in that When the specimen is dispensed from the specimen container multiple times, the dispensing control unit resets the threshold value based on the liquid level of the specimen contained in the specimen container calculated based on the liquid level of the specimen contained in the specimen container detected by the liquid level detection device and the amount of specimen dispensed.

11. The sample dispensing method according to claim 10, It is characterized in that The dispensing control unit compares the necessary descent amount of the dispensing probe estimated based on the liquid level of the specimen contained in the specimen container with the actual descent amount of the dispensing probe stopped upon receiving the liquid level detection signal, and in the case where the error between the necessary descent amount and the actual descent amount exceeds an allowable range, the dispensing device causes the dispensing probe to be lowered again toward the specimen container. When the specimen is dispensed from the specimen container multiple times, the dispensing control unit updates the necessary descent amount based on the liquid level of the specimen contained in the specimen container detected by the liquid level detection device, or the liquid level of the specimen contained in the specimen container calculated based on the actual descent amount and the dispensed specimen amount.

12. The sample dispensing method according to claim 9, It is characterized in that When the dispensing device sucks the specimen contained in the specimen container, The liquid level detection unit generates the liquid level detection signal by comparing the output voltage of the liquid level detection circuit with the threshold value. The dispensing control unit, when not receiving the liquid surface detection signal and when suction from the specimen container is the first time, causes the dispensing probe to be lowered again toward the specimen container in the dispensing device.

13. The sample dispensing method according to claim 12, It is characterized in that When the liquid level detection unit does not generate the liquid level detection signal and the aspiration from the specimen container is the second or later time, the liquid level detection device detects the liquid level of the specimen contained in the specimen container again.

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