Automatic analysis device and sample-dispensing method

Abstract

The present invention makes it possible to perform dispensing in an accurate and stable manner, regardless of the amount of sample contained in a sample container at a stage of being loaded into an automatic analysis device. This automatic analysis device has: a liquid surface height detection device 13 for detecting the liquid surface height of a sample contained in a sample container 11a; a dispensing device 21 for dispensing the sample by means of a dispensing probe 42; a liquid surface sensing unit 50 that outputs, on the basis of a change in capacitance between the dispensing probe and the sample contained in the sample container, a liquid surface sensing signal indicating that the dispensing probe has come into contact with the sample; and a dispensing control unit 44 for controlling the operation of the dispensing device. The liquid surface sensing unit is provided with a liquid surface sensing circuit that outputs a voltage that changes according to the capacitance between the dispensing probe and the sample contained in the sample container, and performs a comparison between the voltage outputted by the liquid surface sensing circuit and a threshold to generate a liquid surface sensing signal for stopping descent of the dispensing probe, the threshold being set on the basis of at least the liquid surface height of the sample detected by the liquid surface height detection device.

Description

Automated analyzer and sample dispensing method

[0001] The present invention relates to an automatic analyzer and a liquid dispensing method, and more particularly to an automatic analyzer and a liquid dispensing method that involve processing such as dispensing multiple items multiple times.

[0002] Conventionally, automated analyzers for specimens such as blood and body fluids have been known that add a reagent to the blood or body fluid and optically detect the reaction that occurs between the reagent and the specimen. Such automated analyzers are equipped with a liquid level detection mechanism that detects the liquid level in order to accurately dispense the specimen or reagent.

[0003] JP 2012-37236 A

[0004] The liquid level detection mechanism of Patent Document 1 discloses that a threshold voltage for detecting the liquid level is corrected based on the liquid level. However, the disclosed correction method is based on the premise that the sample is contained in the sample container up to its maximum height.

[0005] However, in reality, it is often the case that the sample is loaded into the device when the sample container does not reach its maximum capacity. Therefore, if the threshold voltage is calculated assuming that the sample is contained to the maximum height of the sample container, it is inevitable that the threshold voltage will deviate from the optimum threshold.

[0006] The present invention has been made in view of the above, and has an object to provide an automatic analyzer and a dispensing method that enable more accurate dispensing of a specimen or a reagent.

[0007] An automatic analyzer according to one embodiment of the present invention comprises a liquid level detection device that detects the liquid level of a sample contained in a sample container; a dispensing device that dispenses the sample contained in the sample container using a dispensing probe; a liquid level detection unit that outputs a liquid level detection signal indicating that the dispensing probe has come into contact with the sample based on a change in capacitance between the dispensing probe and the sample contained in the sample container; and a dispensing control unit that controls the operation of the dispensing device. The dispensing control unit causes the dispensing device to lower the dispensing probe toward the sample container and stops the descent of the dispensing probe upon receiving a liquid level detection signal from the liquid level detection unit. The liquid level detection unit is provided with a liquid level detection circuit whose output voltage changes depending on the capacitance between the dispensing probe and the sample contained in the sample container, and generates a 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 sample contained in the sample container detected by the liquid level detection device.

[0008] The present invention provides an automated analyzer that can accurately and stably dispense samples regardless of the amount of sample contained in the sample container when the sample container is delivered to the automated analyzer. Other objects and novel features will become apparent from the description of this specification and the accompanying drawings.

[0009] FIG. 1 is a schematic diagram showing the configuration of an automatic analyzer. FIG. 2 is a diagram showing the main parts of a sample dispensing device. FIG. 3 is a diagram showing an example of the configuration of a liquid level detection circuit. FIG. 4 is a diagram showing the change over time in the output voltage of a signal amplifier when a dispensing probe is lowered and then raised. FIG. 5 is a diagram showing the main parts of a reagent dispensing device. FIG. 6 is a flowchart showing the processing procedure for sample dispensing processing. FIG. 7 is an example of the configuration of a threshold setting table. FIG. 8 is a flowchart showing the processing procedure (variant example) for sample dispensing processing.

[0010] Hereinafter, with reference to the drawings, an embodiment of an automatic analyzer equipped with a dispensing device for dispensing specimens such as blood or urine or reagents will be described. Note that the present invention is not limited to this embodiment. In addition, in the description of the drawings, the same parts are given the same reference numerals.

[0011] 1 is a schematic diagram showing the configuration of an automated analyzer according to this embodiment. The automated analyzer comprises a sample transfer mechanism 1 that transfers samples to be analyzed into the analyzer, a measurement mechanism 2 that dispenses samples and reagents into cuvettes 24a and optically measures reactions that occur in the dispensed cuvettes 24a, and a control mechanism 3 that controls the entire automated analyzer and analyzes the results of measurements made by the measurement mechanism 2. These mechanisms work together to automatically perform biochemical analysis of multiple samples.

[0012] First, the specimen transfer mechanism 1 will be described. Liquid specimens such as blood or urine are contained in specimen containers 11a, and multiple specimen containers 11a are loaded onto a specimen rack 11 and transported into the apparatus. The specimen rack 11 is transported by the specimen transfer mechanism 1 in the direction of the arrow in the figure, and sequentially transported toward the measurement mechanism 2. The specimen transfer mechanism 1 includes a specimen information reader 12 that reads information from an information storage medium attached to the specimen container 11a. Examples of information storage media that can be used include barcodes and RFID tags. The specimen information reader 12 reads information such as specimen information and the type of specimen container 11a from the information storage medium and outputs the information to the control unit 31. The specimen transfer mechanism 1 also includes a liquid level detector 13 that detects the liquid level of the specimen contained in the specimen container 11a. The liquid level detector 13 detects the liquid level of the specimen contained in the specimen container 11a and outputs the detected information to the control unit 31. The liquid level detection device 13 emits infrared light or visible light toward the sample container 11a being transported and detects the liquid level of the sample contained in the sample container 11a by detecting changes in the reflected light or changes in the refractive index of the light passing through the sample. The method of detecting the liquid level is not limited to the above, and the sample container 11a may be imaged and the liquid level of the sample contained in the sample container 11a may be obtained from the image of the sample container 11a. In this case, it is also possible to identify the type of sample container 11a from the image information of the sample container 11a.

[0013] Next, a description will be given of the measurement mechanism 2. The measurement mechanism 2 mainly comprises a sample dispensing device 21, a reaction table 24, a reagent storage 27, a reagent dispensing device 23, a stirring unit 25, a photometry unit 26, and a washing unit 22.

[0014] The specimen dispensing device 21 dispenses specimens from specimen containers 11a into cuvettes 24a arranged on a reaction table 24. Under the control of the control unit 31, the reaction table 24 can be rotated around a vertical line passing through the center of the reaction table 24 as a rotation axis by being driven by a driving mechanism (not shown), and the cuvettes 24a can be transported to a predetermined position for dispensing specimens or reagents, stirring, photometry, etc.

[0015] The reagent storage 27 stores multiple reagent containers 27a that contain reagents to be dispensed into the cuvettes 24a. The reagent containers 27a are detachably stored in the reagent storage 27. Under the control of the control unit 31, the reagent storage 27 can be rotated clockwise or counterclockwise around a vertical line passing through the center of the reagent storage 27 as a rotation axis by a drive mechanism (not shown), thereby transporting the desired reagent container 27a to a reagent aspirating position by the reagent dispensing device 23. A lid (not shown) that can be opened and closed is provided above the reagent storage 27. The reagent storage 27 also has a cooling function, and when the reagent containers 27a are stored inside the reagent storage 27 and the lid is closed, the reagent stored in the reagent containers 27a is cooled, preventing evaporation and denaturation of the reagent.

[0016] An information storage medium on which reagent information regarding the reagent contained in the reagent container 27a is recorded is attached to the side of the reagent container 27a. For example, the information storage medium stores reagent information such as the analysis item for which the reagent is used, the name of the reagent, lot information, and reagent container information. Barcodes and RFID tags, for example, can be used as the information storage medium. The reagent storage 27 is provided with a reagent information reader 28 that reads the information storage medium attached to the reagent container 27a. The reagent information reader 28 reads the reagent information and the type of reagent container 27a containing the reagent from the information storage medium and outputs the information to the control unit 31. The reagent information reader 28 outputs the read information from the information storage medium to the control unit 31, correlating it with the position in the reagent storage 27 of the reagent container 27a to which the information storage medium is attached.

[0017] The agitation unit 25 agitates the specimen and reagent dispensed in the cuvette 24 a to promote the reaction. The photometry unit 26 irradiates the cuvette 24 a with analytical light from a light source, separates the light transmitted through or scattered by the liquid in the cuvette 24 a, and measures the absorbance of the wavelength specific to the reaction liquid between the specimen and reagent to be analyzed by measuring the intensity of each wavelength of light using a light receiving element.

[0018] The cleaning unit 22 uses a cleaning nozzle to suck and discharge the mixed liquid from the cuvette 24a after measurement by the photometry unit 26, and also cleans the cuvette 24a after the analysis process by injecting and sucking in cleaning liquid such as detergent or cleaning water.

[0019] Next, a description will be given of the control mechanism 3. 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 configured 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 includes input devices such as a keyboard and a mouse, and externally acquires various information necessary for sample analysis and instruction information for the analysis operation. A 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 photometry unit 26. The output unit 34 includes output devices such as a display, printer, and speaker, and outputs various information including the sample analysis results. The output unit 34 can also output various information to an external device via a communication network (not shown).

[0021] In the automated analyzer configured as described above, the sample dispensing device 21 dispenses the sample from the sample container 11a into a plurality of cuvettes 24a arranged on the reaction table 24, the reagent dispensing device 23 dispenses the reagent from the reagent container 27a, the photometry unit 26 then performs spectroscopic intensity measurements on the mixture resulting from the reaction between the sample and the reagent, and the analysis unit 33 analyzes the measurement results, thereby automatically analyzing the components of the sample. The washing unit 22 washes the cuvettes 24a after measurement, making them reusable, and the series of analysis operations is continuously repeated.

[0022] 2A, the sample dispensing device 21 includes a dispensing probe 42 made of a conductive metal material, the dispensing probe 42 being supported by an arm 41a, which in turn is supported by a support 41b. A probe driver 43 raises and lowers the support 41b in the vertical direction and rotates the arm 41a about a vertical line L that passes through the joint between the arm 41a and the support 41b, thereby inserting the dispensing probe 42 into a sample container 11a containing a sample.

[0023] The operation of the sample dispensing device 21 is controlled by a dispensing control unit 44. The operation of the dispensing device can be broadly divided into driving the probe and suctioning and dispensing liquid such as a sample, but Fig. 2A shows only the components related to driving the probe. The dispensing control unit 44 is configured by a control board or microcomputer equipped with a CPU, RAM, and ROM, and includes a control unit 45, a threshold setting unit 46, and a memory 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 is in contact with the sample in the sample container 11a.

[0024] The operation of the sample dispensing device 21 when dispensing a sample from a sample container 11a will be described. The control unit 45 of the dispensing control unit 44 controls the probe driving unit 43 to rotate the arm 41a, thereby positioning the dispensing probe 42 above the sample container 11a. The control unit 45 then controls the probe driving unit 43 to lower the support 41b, thereby lowering the dispensing probe 42 toward the sample container 11a. When the tip of the dispensing probe 42 is inserted into the sample in the sample container 11a, the liquid level detection unit 50 outputs a liquid level detection signal to the control unit 45. Upon receiving the liquid level detection signal, the control unit 45 stops the descent of the dispensing probe 42 and proceeds to a sample aspirating operation.

[0025] An example of the liquid level detection circuit configuration in the liquid level detection unit 50 will be described using FIG. 2B . The voltage detection unit 51 of the liquid level detection unit 50 includes a power supply V, a capacitor Cs connected in parallel to 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 a composite capacitance of capacitance C1 between the dispensing probe 42 and the sample, capacitance C2 between the sample and the sample stage 49, and capacitance C3 between the dispensing probe 42 and the sample stage 49. Capacitances C1 and C3 change as the dispensing probe 42 moves up and down, and capacitance C1 becomes zero when the dispensing probe 42 comes into contact with the sample. This change in capacitance component C can be detected as the voltage of capacitor Cs. A signal amplifier 52 amplifies and outputs the voltage between the electrodes of capacitor Cs. The comparison unit 53 compares the voltage with a threshold value stored in memory 54 for determining whether the liquid level is detected. The comparison result by comparison unit 53 is binarized by an A / D converter 55 and output as a liquid level detection signal.

[0026] 3 is a diagram showing the relationship between time and the output voltage from the signal amplifier 52 when the dispensing probe 42 of the sample dispensing device 21 of FIG. 2A is lowered, contacted with the sample, and then raised. As shown in FIG. 3 , the voltage output from the signal amplifier 52 increases as the dispensing probe 42 descends and approaches the sample contained in the sample container 11a. After contacting the liquid surface, the dispensing probe 42 begins to rise, and as it moves away from the liquid surface, the voltage output from the signal amplifier 52 decreases again. In this way, the output voltage of the signal amplifier 52 monotonically increases until the dispensing probe 42 contacts the liquid surface. Therefore, contact with the liquid surface can be determined when the output voltage of the signal amplifier 52 exceeds a predetermined threshold value.

[0027] However, the waveform of the output voltage from the signal amplifier 52 varies depending on the type of 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 significantly depending on the specimen volume. Waveforms 61 and 62 shown in Figure 3 are examples of the same specimen contained in the same container, with waveform 61 being a signal waveform when the specimen volume is large and waveform 62 being a signal waveform when the specimen volume is small. Therefore, in this embodiment, the threshold value setting unit 46 of the dispensing control unit 44 sets a threshold value for determining whether a liquid level has been detected each time the specimen dispensing device 21 performs dispensing, and the comparison unit 53 of the liquid level detection unit 50 determines whether a liquid level has been detected based on that threshold value.

[0028] An example configuration of the reagent dispensing device 23 is shown in Figure 4. The reagent dispensing device 23 is configured in the same manner as the sample dispensing device 21 shown in Figure 2A, so a duplicated description will be omitted. In the case of the reagent dispensing device 23, the signal waveform of the output voltage of the signal amplifier 82 also changes depending on the amount of reagent contained in the reagent container 27a. Therefore, in this embodiment, the threshold value setting unit 76 of the dispensing control unit 74 sets a threshold value for determining whether the liquid level has been detected each time the reagent dispensing device 23 performs dispensing, and the comparison unit 83 of the liquid level detection unit 80 determines whether the liquid level has been detected based on that threshold value.

[0029] Next, the sample dispensing process in the sample dispensing device 21 will be described. FIG. 5 is a flowchart showing the procedure for the sample dispensing process in the sample dispensing device 21 shown in FIG. 2A. The sample information reading device 12 reads sample information and container information from an 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. Note that the container information may be read by the liquid level detection device 13. This information is transferred to the dispensing control unit 44 of the sample dispensing device 21 via the control unit 31 of the control mechanism 3 (S01). Note that while an example has been shown in which this information is automatically read by the automated analyzer, this information may also be input by a user via the input unit 32 of the control mechanism 3. Next, the threshold setting unit 46 of the dispensing control unit 44 sets a threshold value for liquid level determination based on the information read in step S01 and the threshold setting table stored in the memory unit 47. The set threshold value is stored in the memory unit 54 of the liquid level detection unit 50 (S02).

[0030] An example of the configuration of the threshold setting table is shown in Figure 6. In the example of Figure 6, the threshold is configured so that it can be set according to a combination of factors that affect the threshold for liquid level determination. Here, the factors include sample type 91, container shape 92, liquid level height 93, and probe type 94, and a threshold 95 is determined by combining these. In step S02, a corresponding record in the threshold setting table is selected from the information read in step S01, and the threshold is set.

[0031] The sample type 91 broadly classifies samples, such as plasma, whole blood, and urine. The container shape 92 may be classified based on characteristics that particularly affect the signal waveform of the output voltage of the signal amplifier 82. For example, classifications can also be made based on the height of the container. The liquid level 93 is shown as an example of classification into several ranges. Instead of the liquid level, the threshold value may be associated with the sample volume calculated based on the container shape and liquid level. The probe type 94 is classified because the degree of exposure of the metal portion of the dispensing probe, which serves as the electrode for the capacitance component C, and the diameter of the dispensing probe affect the signal waveform of the output voltage of the signal amplifier 82. Setting the threshold value based on the sample type, container shape, and probe type in addition to the liquid level or sample volume enables more accurate threshold setting. Note that it is not necessary to set the threshold value based on all of these factors; other factors may also be taken into consideration. While an example of setting the threshold value using a table is shown here, the threshold value may also be set using a calculation formula that uses these factors as variables.

[0032] Next, the control unit 45 of the dispensing control unit 44 controls the probe driver 43 to lower the dispensing probe 42 into the sample container 11a (S03). While the dispensing probe 42 is lowering, the comparator 53 of the liquid level detection unit 50 compares the output voltage of the signal amplifier 52 with a threshold value set in the memory unit 54 (S04). If the output voltage is less than the threshold value (S05: No), the dispensing probe 42 continues to lower and the liquid level determination continues (S03 to S05). On the other hand, if the output voltage is equal to or greater than the threshold value, the A / D converter 55 outputs a digital liquid level detection signal to the dispensing control unit 44 (S06). Upon receiving the liquid level detection signal, the control unit 45 of the dispensing control unit 44 controls the probe driver 43 to stop the lowering of the dispensing probe 42 (S07).

[0033] Here, since capacitance-based liquid level detection can be erroneous due to external static electricity or bubbles in the sample, it is desirable to add step S08, which verifies whether the actual amount of descent is appropriate based on the liquid level information.

[0034] The control unit 45 of the dispensing control unit 44 estimates the necessary amount of descent of the dispensing probe 42 (hereinafter referred to as the necessary descent amount) from the liquid level height information acquired in step S01. Furthermore, the control unit 45 calculates the actual amount of descent of the dispensing probe 42 (hereinafter referred to as the actual descent amount) from when the descent of the dispensing probe 42 starts in step S03 to when the descent of the dispensing probe 42 stops in step S07. For example, the actual distance descent of the dispensing probe 42 can be calculated from the number of pulses applied to the pulse motor of the probe drive unit 43. This actual descent amount of the dispensing probe 42 is stored in the memory unit 47.

[0035] The control unit 45 of the dispensing control unit 44 compares the required lowering amount estimated from the liquid level information with the actual lowering amount, and if they are the same or the error is within the allowable range, it determines that the liquid level has been detected correctly. On the other hand, if the error exceeds the allowable range, the process returns to, for example, step S03, and the dispensing probe is lowered again.

[0036] Thereafter, the control unit 45 executes dispensing operations such as aspirating the sample from the sample container 11a and dispensing it into the cuvette 24a (S09), and washes the dispensing probe 42 in a washing tank (not shown) (S10).

[0037] The control unit 31 of the control mechanism 3 then checks whether multiple measurements are being performed on the sample (S11). If multiple measurements are being performed (S11: Yes), the threshold setting unit 46 calculates the sample volume in the sample container 11a from the sample volume before dispensing and the dispensed volume, and resets the threshold (S12). Furthermore, if false liquid level detection based on the amount of descent has been performed (S08), the required amount of descent is updated based on the liquid level information acquired in step S01 or the actual amount of descent and the dispensed volume stored in the memory unit 47. Then, the dispensing process is started again. If multiple measurements are not being performed (S11: No), the dispensing process for the sample ends.

[0038] 5 has been described using an example of sample dispensing processing by the sample dispensing device 21, but the same applies to reagent dispensing processing by the reagent dispensing device 23. Explanation of overlapping content will be omitted, and only the differences will be described. In step S01, information required for setting the threshold value is calculated from the reagent information read by the reagent information reading device 28 or entered by the user and registered in the device. The threshold value for detecting the liquid level of the reagent can also be set based on the threshold value setting table stored in the memory unit 77 of the dispensing control unit 74.

[0039] 7 shows an example of the configuration of a threshold setting table for the reagent dispensing device 23. The threshold setting table for the reagent dispensing device 23 is similar to the threshold setting table for the sample dispensing device 21. However, if the container shape is generally determined according to the reagent, container shape information may not be necessary. The information required for threshold setting includes the reagent amount 103, which is obtained from the control unit 31 of the control mechanism 3 in step S01. The control unit 31 stores the amount of reagent dispensed since the reagent container 27a was stored in the reagent storage 27 and began to be used. Using this information, the amount of reagent contained in the reagent container 27a or the liquid level of the reagent can be calculated.

[0040] In this embodiment, the liquid level detection device 13 is provided, and the liquid level determination threshold is set based on the liquid level read from the sample container 11a loaded into the device, thereby improving the accuracy of sample liquid level detection. In particular, when the sample volume contained in the sample container 11a is small, setting the threshold based on the assumption that the sample container 11a contains the maximum volume of sample increases the likelihood of a liquid level detection error. Furthermore, when multiple dispensings or multiple tests are performed, the threshold for the second and subsequent tests can also be set with high accuracy by determining the liquid volume using the result of the initial liquid level detection.

[0041] Figure 8 is a flowchart showing a modified example of the sample dispensing process in the sample dispensing device 21. The difference from the flowchart shown in Figure 5 is that after the sample aspirating operation is performed, it is determined whether the sample has been aspirated based on the output voltage of the signal amplifier 52. The following will mainly explain the differences from the flowchart in Figure 5.

[0042] If the estimated drop amount and the actual drop amount are equal (S08: Yes), the sample dispensing device 21 starts the dispensing operation, first performing the aspirating operation (S21). During the aspirating operation of the dispensing probe 42, the comparator 53 in the liquid level detection unit 50 compares the output voltage of the signal amplifier 52 with a threshold value set in the memory unit 54 (S22). If the output voltage is equal to or greater than the threshold value, the sample dispensing device 21 continues to receive the liquid level detection signal and continues the dispensing operation (S09). To prevent air from entering, the tip of the dispensing probe 42 is set to remain in contact with the liquid surface even when the aspirating operation of the sample is completed. Therefore, during the aspirating operation, the output voltage of the signal amplifier 52 being equal to or greater than the threshold value indicates that the sample is being aspirated normally.

[0043] On the other hand, if a bubble formed on the surface of the specimen is mistakenly detected as the liquid surface and an aspiration operation is initiated, the tip of the dispensing probe 42 may become separated from the liquid surface during the aspiration operation, and in this case the output voltage of the signal amplifier 52 will be less than the threshold value (S23: No), indicating that the aspiration operation was not performed normally.

[0044] Therefore, if it is determined that the sample cannot be aspirated normally during the first dispensing operation from the sample container 11a (S24: Yes), the process returns to step S03 and starts again, starting with lowering the dispensing probe 42 into the sample container 11a. For example, if the cause of the aspirating operation is bubbles on the sample surface, the second aspirating operation is likely to be successful. On the other hand, if it is again determined in step S23 that the sample cannot be aspirated normally (S24: No), the threshold value used for liquid level detection is likely to be inappropriate. Therefore, the sample rack 11 holding the sample container 11a is returned to the sample transfer mechanism 1, the liquid level detector 13 reads the sample liquid level again (S01), and the threshold value is reset (S02). In this case, information reading by the sample information reader 12 can be omitted.

[0045] Although the flowchart in FIG. 8 shows the sample dispensing process, the same process can be applied to the reagent dispensing process by the reagent dispensing device 23.

[0046] The present invention is not limited to the above-described embodiments, but includes various modifications. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and are not necessarily limited to those including all of the described configurations. Furthermore, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, and it is also possible to add the configuration of another embodiment to the configuration of one embodiment. Furthermore, it is possible to add, delete, or replace part of the configuration of each embodiment with other configurations.

[0047] 1: specimen transfer mechanism, 2: measurement mechanism, 3: control mechanism, 11: specimen rack, 11a: specimen container, 12: specimen information reader, 13: liquid level detector, 21: specimen dispenser, 22: cleaning unit, 23: reagent dispenser, 24: reaction table, 24a: cuvette, 25: stirring unit, 26: photometer, 27: reagent storage, 27a: reagent container, 28: reagent information reader, 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 value setting unit, 47, 77: Memory 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: Memory unit, 55, 85: A / D converter, 61, 62: Waveform, 91: Sample type, 92, 102: Container shape, 93: Liquid level height, 94, 104: Probe type, 95, 105: Threshold value.

Claims

1. An automatic analyzer comprising a specimen transfer mechanism into which a specimen container containing a specimen is carried, and a measurement mechanism for measuring the specimen contained in the specimen container transferred from the specimen transfer mechanism, a liquid level height detection device disposed in the specimen transfer mechanism for detecting the liquid level height of the specimen contained in the carried-in specimen container, a dispensing device disposed in the measurement mechanism for dispensing the specimen contained in the specimen container transferred from the specimen transfer mechanism by a dispensing probe, a liquid level detection unit that outputs a liquid level detection signal indicating that the dispensing probe is in contact with the specimen based on a change in 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, wherein the dispensing control unit lowers the dispensing probe toward the specimen container in the dispensing device, and stops the lowering of the dispensing probe upon receiving the liquid level detection signal from the liquid level detection unit, the liquid level detection unit includes a liquid level detection circuit in which an output voltage changes according to the capacitance between the dispensing probe and the specimen contained in the specimen container, and generates the 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 height of the specimen contained in the specimen container detected by the liquid level height detection device when performing the first dispensing from the specimen container.

2. The automatic analyzer according to claim 1, further comprising a specimen information reading device for reading information about the specimen container and / or the specimen contained in the specimen container from an information recording medium attached to the specimen container, wherein the dispensing control unit sets the threshold value based on a combination of the liquid level height of the specimen contained in the specimen container and the information about the specimen container and / or the specimen contained in the specimen container read by the specimen information reading device.

3. The automatic analyzer according to claim 2, wherein 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 height of the specimen contained in the specimen container, and the type of the dispensing probe.

4. The automatic analyzer according to claim 1, The dispensing control unit compares the required descending amount of the dispensing probe estimated based on the liquid level height of the sample contained in the sample container detected by the liquid level height detection device with the actual descending amount of the dispensing probe that has been stopped upon receiving the liquid level detection signal. When the error between the required descending amount and the actual descending amount exceeds the allowable range, the dispensing device is caused to lower the dispensing probe again toward the sample container, in an automatic analyzer.

5. In claim 1, when the sample is dispensed from the sample container a plurality of times, the dispensing control unit re-sets the threshold value based on the liquid level height of the sample contained in the sample container calculated based on the liquid level height of the sample contained in the sample container detected by the liquid level height detection device and the amount of the sample that has already been dispensed, in an automatic analyzer.

6. In claim 5, the dispensing control unit compares the required descending amount of the dispensing probe estimated based on the liquid level height of the sample contained in the sample container with the actual descending amount of the dispensing probe that has been stopped upon receiving the liquid level detection signal. When the error between the required descending amount and the actual descending amount exceeds the allowable range, the dispensing device is caused to lower the dispensing probe again toward the sample container, when the sample is dispensed from the sample container a plurality of times, the dispensing control unit updates the required descending amount based on the liquid level height of the sample contained in the sample container detected by the liquid level height detection device or the liquid level height of the sample contained in the sample container calculated based on the actual descending amount and the amount of the sample that has already been dispensed, in an automatic analyzer.

7. a liquid level height detection device that detects the liquid level height of the sample contained in the sample container; a dispensing device that dispenses the sample contained in the sample container by a dispensing probe; a liquid level detection unit that outputs a liquid level detection signal indicating that the dispensing probe is in contact with the sample based on a change in capacitance between the dispensing probe and the sample contained in the sample container; a dispensing control unit that controls the operation of the dispensing device, and has, the dispensing control unit causes the dispensing device to lower the dispensing probe toward the sample container and stops the lowering of the dispensing probe upon receiving the liquid level detection signal from the liquid level detection unit, the liquid level detection unit includes a liquid level detection circuit in which the output voltage changes due to the capacitance between the dispensing probe and the sample contained in the sample container, and 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 height of the specimen contained in the specimen container detected by the liquid level height detection device. 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. An automatic analyzer in which the dispensing control unit does not receive the liquid level detection signal and, when the suction from the specimen container is the first time, causes the dispensing device to lower the dispensing probe toward the specimen container again.

8. In claim 7, When the liquid level detection unit does not generate the liquid level detection signal and the suction from the specimen container is after the second time, the liquid level height detection device detects again the liquid level height of the specimen contained in the specimen container. An automatic analyzer.

9. A specimen dispensing method in an automatic analyzer including a specimen transfer mechanism into which a specimen container containing a specimen is carried and a measurement mechanism that measures the specimen contained in the specimen container transferred from the specimen transfer mechanism, The automatic analyzer includes a liquid level height detection device that is disposed in the specimen transfer mechanism and detects the liquid level height of the specimen contained in the carried-in specimen container, and is disposed in the measurement mechanism and transferred from the specimen transfer mechanism. A dispensing device that dispenses the specimen contained in the specimen container by a dispensing probe, a liquid level detection unit that outputs a liquid level detection signal indicating that the dispensing probe is in contact with the specimen based on a change in 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 liquid level detection unit includes a liquid level detection circuit whose output voltage changes according to the capacitance between the dispensing probe and the specimen contained in the specimen container. The dispensing control unit lowers the dispensing probe toward the specimen 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 descent of the dispensing probe. The threshold value when performing the first dispensing from the specimen container is set by the dispensing control unit based on at least the liquid level height of the specimen contained in the specimen container detected by the liquid level height detection device. A specimen dispensing method.

10. In claim 9, When dispensing a sample from the sample container multiple times, the dispensing control unit resets the threshold value based on the liquid level height of the sample contained in the sample container detected by the liquid level height detection device and the liquid level height of the sample contained in the sample container calculated based on the amount of the sample already dispensed. A sample dispensing method.

11. In claim 10, the dispensing control unit compares the required descent amount of the dispensing probe estimated based on the liquid level height of the sample contained in the sample container with the actual descent amount of the dispensing probe stopped upon receiving the liquid level detection signal, and when the error between the required descent amount and the actual descent amount exceeds the allowable range, the dispensing device is caused to lower the dispensing probe toward the sample container again. When dispensing a sample from the sample container multiple times, the dispensing control unit updates the required descent amount based on the liquid level height of the sample contained in the sample container detected by the liquid level height detection device or the liquid level height of the sample contained in the sample container calculated based on the actual descent amount and the amount of the sample already dispensed. A sample dispensing method.

12. A sample dispensing method in an automatic analyzer, comprising: a liquid level height detection device that detects the liquid level height of a sample contained in a sample container; a dispensing device that dispenses the sample contained in the sample container by a dispensing probe; a liquid level detection unit that outputs a liquid level detection signal indicating that the dispensing probe is in contact with the sample based on a change in capacitance between the dispensing probe and the sample contained in the sample container; and a dispensing control unit that controls the operation of the dispensing device. The liquid level detection unit includes a liquid level detection circuit in which an output voltage changes according to the capacitance between the dispensing probe and the sample contained in the sample container. The dispensing control unit causes the dispensing device to lower the dispensing probe toward the sample container. 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 stops the descent of the dispensing probe upon receiving the liquid level detection signal from the liquid level detection unit. The threshold value is set by the dispensing control unit based on at least the liquid level height of the sample contained in the sample container detected by the liquid level height detection device. When the dispensing device sucks the sample contained in the sample 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. When the dispensing control unit does not receive the liquid level detection signal and the aspiration from the sample container is the first time, the sample dispensing method is to lower the dispensing probe toward the sample container again to the dispensing device.

13. In claim 12, When the liquid level detection unit does not generate the liquid level detection signal and the aspiration from the sample container is after the second time, the liquid level height detection device detects the liquid level height of the sample contained in the sample container again. The sample dispensing method.