Liquid surface detection apparatus and method for liquid surface detection

Abstract

The purpose of the present invention is to provide a liquid surface detection apparatus for determining, even in a non-contact manner, a liquid surface position with higher accuracy. For this purpose, the liquid surface detection apparatus of the present invention is provided with: a first liquid surface detection mechanism that detects, in a non-contact manner, the upper surface of a liquid in a container; a second liquid surface detection mechanism that detects, in a contact manner, the upper surface of the liquid in the container; and a control device that uses the detection result from the second liquid surface detection mechanism to correct the detection result from the first liquid surface detection mechanism. Preferably, the control device has a storage unit for storing a correction value for correcting the detection result from the first liquid surface detection mechanism. The correction value is calculated on the basis of a difference between a liquid surface position detected by the first liquid surface detection mechanism and a liquid surface position detected by the second liquid surface detection mechanism.

Description

Liquid level detection device and liquid level detection method

[0001] The present invention relates to a liquid level detection device and a liquid level detection method.

[0002] Automated analyzers are used to perform qualitative and quantitative analysis of specimens such as blood and urine. Sample testing automation systems are also used to automatically perform pre-treatment processes such as centrifuging specimens and transporting specimens to each automated analyzer.

[0003] The pretreatment process may involve centrifuging the specimen and detecting the specimen's liquid level after centrifugation. For example, if the specimen is blood, the blood is separated into serum (or plasma) and blood clots by centrifugation. After this centrifugation, the liquid level detection device in the specimen testing automation system non-contactly measures the interface between the layers and the liquid volume in the specimen container.

[0004] Patent document 1 discloses a liquid level detection device that detects the liquid level in a specimen container by controlling the relative positions of the irradiation unit and the detection unit so that the detection unit moves to a position where transmitted light can be detected in conjunction with moving an irradiation unit that irradiates light onto a part of a specimen container containing a liquid substance in a direction parallel to the axis of the specimen container, and detecting transmitted light over the entire length of the specimen container.

[0005] Special Publication No. 2005-516212

[0006] However, Patent Document 1 does not consider the meniscus, and therefore, due to the meniscus, a position higher than the actual liquid level is determined to be the liquid upper surface, resulting in a problem with the accuracy of liquid level detection.

[0007] In view of the above-mentioned problems, an object of the present invention is to provide a liquid level detection device that determines the liquid level position with higher accuracy even if it is a non-contact type.

[0008] In order to solve the above-mentioned problems, the liquid level detection device of the present invention comprises a first liquid level detection mechanism that detects the top surface of the liquid in a container using a non-contact method, a second liquid level detection mechanism that detects the top surface of the liquid in the container using a contact method, and a control device that corrects the detection result by the first liquid level detection mechanism using the detection result by the second liquid level detection mechanism.

[0009] The liquid level detection device of the present invention is capable of detecting the liquid level with high accuracy even though it is a non-contact type.

[0010] A diagram showing the overall configuration of a specimen testing automation system. An overall configuration diagram of a liquid volume determination processing unit including a first liquid level detection mechanism. A flowchart showing the process of liquid volume determination by the first liquid level detection mechanism. Examples of first transmitted light data and second transmitted light data. An explanatory diagram of a specimen container with a meniscus formed. An overall configuration diagram of a dispensing processing unit including a second liquid level detection mechanism. A flowchart showing a method in which a control device corrects the detection result by the first liquid level detection mechanism.

[0011] An embodiment of the present invention will be described with reference to the drawings.

[0012] FIG. 1 shows the overall configuration of a sample testing automation system. The sample testing automation system includes a pretreatment device 800, a transport path 802, multiple sample transfer units 803, and a control device 804, and is connected to multiple analyzers 801. The pretreatment device 800 performs various pretreatments on samples contained in sample containers 120. The transport path 802 transports a holder 810 carrying a sample container 120 between the pretreatment device 800 and the analyzers 801. The sample transfer unit 803 is provided between the transport path 802 and each of the multiple analyzers 801, and transfers the sample container 120 between the holder 810 transported by the transport path 802 and a rack used to transport the sample container 120 in each analyzer 801. The control device 804 controls the operation of the entire sample testing automation system. The samples in the sample containers 120 that have undergone pretreatment are then analyzed in the analyzers 801 connected to the sample testing automation system.

[0013] The control device 804 has an operation control unit that controls operations, an operation unit that accepts operations from the user, a display unit that displays analysis results, setting contents, etc., and a memory unit that stores analysis results, setting contents, etc. The memory unit also stores sample information such as analysis items and priority information for samples contained in sample containers 120 that are input into the sample testing automation system, the relationship between each identifier and the sample, and a correction value ΔH for correcting the detection results by the first liquid level detection mechanism described below.

[0014] The pre-treatment device 800 is configured by connecting a plurality of units having various functions, and includes, for example, a sample input unit 800a, a sample storage unit 800b, a centrifugal separation unit 800c, a liquid volume determination processing unit 800d, an uncapping processing unit 800e, a daughter sample container production processing unit 800f, an aliquot processing unit 800g, and a capping processing unit 800h.

[0015] The specimen introduction unit 800a is a unit for introducing specimen containers 120 containing specimens into the specimen testing automation system. The specimen introduction unit 800a is also provided with a liquid (specimen) recognition unit, a container recognition unit, and a specimen holder recognition unit (not shown), which recognize the type of specimen container 120 to be transported, the shape of the container stopper, and ID information attached to the holder 810 in which the specimen container 120 is mounted, thereby obtaining information for identifying the specimen container 120 to be transported. Specimen holder recognition units (not shown) are provided at various locations within the specimen testing automation system, allowing the specimen holder recognition units at various locations to confirm the location of the specimen container 120.

[0016] The centrifugal separation unit 800c is a unit for centrifuging the sample containers 120 that have been placed therein.

[0017] The liquid volume determination processing unit 800d is a unit for measuring and determining the volume and color of the specimen contained in the transported specimen container 120 using the first liquid level detection mechanism 100 and image recognition unit described below.

[0018] The uncapping unit 800e is a unit for uncapping a cap (not shown) from an inserted specimen container 120.

[0019] The child specimen container production processing unit 800f is a unit for preparing another specimen container 120 required for dispensing the specimen contained in the input specimen container 120 in the next dispensing processing unit 800g, and for attaching a barcode or the like.

[0020] The dispensing processing unit 800g is a unit for dividing samples that have not been centrifuged or have been centrifuged in the centrifugation unit 800c into separate sample containers 120 prepared in the child sample container generation processing unit 800f for analysis by an analytical device 801 or the like.

[0021] The capping unit 800h is a unit for capping the specimen containers 120 that have been opened or that have been subdivided. Depending on the type of cap used to cap the specimen containers 120, the specimen testing automation system may be configured with two or more capping units 800h.

[0022] The sample storage unit 800b is a unit that stores the sample containers 120 that have been capped by the capping processing unit 800h.

[0023] It should be noted that this configuration is merely an example, and other functional units may be provided in the pretreatment device 800. The units of the pretreatment device 800 are connected by a transport path 802, and the sample containers 120 loaded in holders 810 are transported by the transport path 802.

[0024] The transport path 802 is a mechanism for transporting the specimen containers 120 loaded from the specimen loading unit 800a and the subdivided specimen containers 120 dispensed in the dispensing unit 800g to each part of the specimen testing automation system, such as the centrifugation unit 800c and the dispensing unit 800g. The transport path 802 is also used for transporting specimens to each mechanism that performs a predetermined operation within each part, such as the centrifugation unit 800c and the dispensing unit 800g.

[0025] The control device 804 controls the operation of each part and each mechanism within the sample testing automation system. The control device 804 communicates with each of the above-mentioned parts and mechanisms and is able to confirm the location of the sample within the sample testing automation system from the ID information of the holder 810. Note that while this embodiment shows an example in which one control device 804 controls the entire sample testing automation system, each part may have its own individual control device. Furthermore, although not shown, each analyzer 801 may also have its own individual control PC that analyzes measurement data, etc.

[0026] The analyzer 801 is a unit for performing qualitative and quantitative analysis of the components of the transported sample. Depending on the application, various automatic analyzers that analyze the components of a sample that has been subjected to pretreatment, such as a biochemical analyzer, an immunoanalyzer, or a coagulation analyzer, can be used as the analyzer 801.

[0027] In this embodiment, a liquid level detection device consisting of a first liquid level detection mechanism 100, a second liquid level detection mechanism 200, and a control device 804 is implemented as part of a sample testing automation system (the control device 804 is also used for other devices). The first liquid level detection mechanism 100 is incorporated into a liquid volume determination processing unit 800d located between the sample input unit 800a and the dispensing processing unit 800g. Therefore, if the liquid volume determination processing unit 800d determines that the amount of sample contained in a sample container 120 is insufficient, the control device 804 can transport the sample container 120 to the dispensing processing unit 800g and instead export the sample as an error sample. Furthermore, because the first liquid level detection mechanism 100 can detect the liquid level position (top surface height) of the sample without contact, direct stimulation of the sample before dispensing is also suppressed. Meanwhile, the second liquid level detection mechanism 200 is incorporated into the dispensing processing unit 800g. The second liquid level detection mechanism 200 is a contact type, and therefore can detect the liquid level position more accurately than a non-contact type, thereby improving the accuracy of dispensing. The first liquid level detection mechanism 100 and the second liquid level detection mechanism 200 will be described in detail below.

[0028] FIG. 2 is an overall configuration diagram of a liquid volume determination processing unit including a first liquid level detection mechanism. The sample to be detected by the first liquid level detection mechanism 100 is contained in a sample container 120. There are various types of sample containers 120, and users use different types depending on their respective applications. For example, the sample container 120 may be made of various resin materials or glass materials, and the sample container 120 is substantially transparent. The sample container 120 has a cylindrical or tapered shape with a bottom that is elongated in the vertical direction. A mixture of sample containers with different diameters, heights, and stoppers is used. FIG. 2 shows an example in which a test tube is used as the sample container 120.

[0029] A specimen contained in a specimen container 120 is separated by centrifugation into a layer of substances with a relatively high specific gravity and a layer of substances with a relatively low specific gravity. The specimen container 120 may contain a separator 121 having a specific gravity intermediate between these substances. In this embodiment, a blood specimen collected from a patient is used as the specimen. The blood specimen is separated by centrifugation into a blood clot 122 with a relatively high specific gravity and serum 123 (or plasma) with a relatively low specific gravity. The specimen container 120 also contains the separator 121, and after centrifugation, the blood clot 122 and serum 123 are separated by the separator 121.

[0030] The specimen may be a biological specimen such as urine, a mixture of a biological specimen and a reagent, or a reaction liquid resulting from a reaction between these specimens, in addition to a blood specimen. Separation may also be performed without using a separator.

[0031] As shown in Figure 2, the liquid volume determination processing unit 800d mainly comprises a gripping unit 106, a first driving unit 107, a first irradiation unit 101, a second irradiation unit 102, a first light receiving unit 103, a second light receiving unit 104, a first analysis unit 105, and a first control unit 108.

[0032] The gripper 106 grips the specimen container 120. The gripper 106 is moved up and down by a first drive unit 107. The first drive unit 107 moves the specimen container 120 gripped by the gripper 106 up and down.

[0033] The first irradiating unit 101, the second irradiating unit 102, the first light receiving unit 103, the second light receiving unit 104, and the first analyzing unit 105 constitute the first liquid level detection mechanism 100. The first irradiating unit 101 irradiates the specimen container 120 with light of a first wavelength component (e.g., 1550±100 nm) from the side of the specimen container 120. The light of the first wavelength component is absorbed by the liquid and therefore is not transmitted through the liquid. In other words, the light of the first wavelength component has different transmittance when passing through the liquid and when passing through the air. The second irradiating unit 102 irradiates the specimen container 120 with light of a second wavelength component (e.g., 830±100 nm) different from the first wavelength component from the side of the specimen container 120. The light of the second wavelength component transmits through the liquid. The first light receiving unit 103 receives first transmitted light, which is the light of the first wavelength component that has passed through the specimen container 120. The second light receiving unit 104 receives second transmitted light, which is light of a second wavelength component that has passed through the specimen container 120. The first analyzing unit 105 analyzes transmitted light data at different positions in the vertical direction. Specifically, the first analyzing unit 105 determines, for example, an interface between different liquids (layers), an interface between a separator and a liquid, or an interface between a liquid and gas (air), from the first transmitted light data acquired by the first light receiving unit 103 and the second transmitted light data acquired by the second light receiving unit 104. How the interface is determined will be described later.

[0034] Although there may be only one light receiving unit and one irradiating unit, by providing one for each wavelength, it is possible to acquire the first transmitted light data and the second transmitted light data with a single vertical movement of the specimen container 120. When there is only one light receiving unit and one irradiating unit, it is possible to acquire the first transmitted light data and the second transmitted light data by acquiring the first transmitted light data, changing the wavelength of the irradiating unit to the second wavelength, and acquiring the second transmitted light data.

[0035] The first control unit 108 controls the operations of the first irradiation unit 101, the second irradiation unit 102, the first light receiving unit 103, the second light receiving unit 104, the first analysis unit 105, the gripping unit 106, and the first drive unit 107. The first control unit 108 may have the function of the first analysis unit 105. Furthermore, the functions of the first analysis unit 105 and the first control unit 108 may be performed by a control device provided outside the first liquid level detection mechanism 100.

[0036] 3 is a flowchart showing the procedure for determining the liquid volume by the first liquid level detection mechanism. When the specimen container 120 arrives at a predetermined liquid level detection position, the first liquid level detection mechanism 100 starts the detection operation, and the first control unit 108 performs control as follows.

[0037] The first control unit 108 grips the sample container 120 that has arrived with the gripping unit 106 and lifts it with the first driving unit 107 (step S301).

[0038] Furthermore, the first control unit 108 controls the first driving unit 107 to move the specimen container 120 to a transmitted light measurement start position (step S302). The transmitted light measurement start position may be either above or below the specimen container 120.

[0039] Next, the first control unit 108 causes the first driving unit 107 to move the specimen container 120 vertically from the transmitted light measurement start position, while irradiating light from the first irradiating unit 101 and the second irradiating unit 102. At this time, the first light receiving unit 103 and the second light receiving unit 104 receive the transmitted light that has passed through the specimen container 120, and acquire transmitted light data at different vertical positions (step S303).

[0040] Because light transmittance varies depending on the type of liquid and separator, the amount of transmitted light received (amount of transmitted light) changes significantly when the light irradiation position is an interface between different liquids, an interface between a liquid and a separator, or an interface between a liquid and gas. Therefore, it is possible to determine the position where the amount of transmitted light changes significantly as the interface. That is, the first control unit 108 scans the specimen container 120 in the vertical direction at a predetermined position (irradiation angle) in the circumferential direction to acquire the amount of transmitted light, and the first analysis unit 105 analyzes the change. Note that data on the amount of transmitted light may be acquired as brightness data.

[0041] After the measurement of the transmitted light is completed, the specimen container 120 is returned to the position before it was lifted by the first drive unit 107, and the gripper 106 stops gripping the specimen container 120 (step S304). Thereafter, the specimen container 120 is transported for the next process.

[0042] Fig. 4 shows examples of the first transmitted light data and the second transmitted light data acquired in step S303 of Fig. 3. The first analysis unit 105 detects the boundary surface based on the difference between the first transmitted light data 401 (the transmitted light amount of the first transmitted light) and the second transmitted light data 402 (the transmitted light amount of the second transmitted light).

[0043] The blood clot 122 blocks almost all of the light of the first wavelength component irradiated by the first irradiating unit 101 and the light of the second wavelength component irradiated by the second irradiating unit 102. Therefore, when the blood clot 122 is irradiated with light of the first wavelength component and light of the second wavelength component, the amount of transmitted light is almost the same and low. Compared to the blood clot 122, the separator 121 more easily transmits light of the first wavelength component and light of the second wavelength component, and therefore the amount of transmitted light is higher.

[0044] In contrast, the serum 123 has a significantly different transmittance for light of the first wavelength component and light of the second wavelength component. As described above, the light of the first wavelength component is absorbed by the liquid and becomes opaque, so the amount of transmitted light (first transmitted light data 401) when irradiated onto the serum 123 is low. On the other hand, the light of the second wavelength component passes through the liquid, so the amount of transmitted light (second transmitted light data 402) when irradiated onto the serum 123 remains relatively high.

[0045] Because the air above the serum 123 easily transmits both light of the first wavelength component and light of the second wavelength component, the amount of transmitted light when both light of the first wavelength component and light of the second wavelength component are irradiated onto the air is relatively high. Furthermore, the label 124 attached to the specimen container 120 so as to straddle each layer of the specimen does not easily transmit light of the first wavelength component and light of the second wavelength component compared to air, so the amount of transmitted light is reduced. The amount of transmitted light that is reduced at this time varies depending on the material and number of labels 124, etc.

[0046] As described above, the second transmitted light data 402 also provides a relatively high amount of transmitted light when irradiated onto the separator 121, serum 123, and air. On the other hand, the first transmitted light data 401 provides a lower amount of transmitted light when irradiated onto serum 123 than when irradiated onto the separator 121, and provides a high amount of transmitted light when irradiated onto air, equivalent to that when irradiated onto the separator 121. That is, the first transmitted light data 401 varies significantly at the interface between the separator 121 and serum 123 and the interface between the serum 123 and gas. Furthermore, the amount of transmitted light when irradiated onto the separator 121 and air is higher for the first transmitted light data 401 than for the second transmitted light data 402, and the amount of transmitted light when irradiated onto serum 123 is higher for the second transmitted light data 402 than for the first transmitted light data 401. Therefore, the first analysis unit 105 can detect the position where the first transmitted light data 401 and the second transmitted light data 402 in Figure 4 intersect as the boundary surface. Specifically, of the positions where the difference between the first transmitted light data 401 and the second transmitted light data 402 is zero, the lower position can be detected as the boundary surface between the separator 121 and the serum 123, and the upper position can be detected as the boundary surface between the serum 123 and the gas. Furthermore, the first analysis unit 105 calculates the amount of serum in the specimen container 120 based on the detected boundary surface. The calculated amount of serum is used in planning for dispensing the serum.

[0047] However, the upper surface of the serum in the sample container 120 is not actually horizontal. As shown in FIG. 5 , a meniscus forms, causing the liquid level to rise toward the container wall. Therefore, using only the first liquid level detection mechanism described above can result in a problem: the upper surface of the meniscus, which is higher than the intended detection position, being determined to be the interface between the serum 123 and air. If the upper surface of the meniscus is determined to be higher than the upper surface of the serum, the amount of serum 123 will be overestimated. Overestimating the serum amount could result in insufficient serum 123 when dispensing the serum 123, causing the dispensing probe to reach the separator 121 or blood clot 122 below the serum 123 and potentially clog the dispensing probe. If the dispensing probe is clogged, the sample being aspirated at the time of the clog becomes unusable, resulting in sample waste. This can also cause the device to shut down, resulting in delayed test results. Furthermore, if disposable dispensing tips are used for the dispensing probe, the used tips will also be wasted.

[0048] Therefore, in this embodiment, the detection result by the first liquid level detection mechanism 100 is corrected using the detection result by the second liquid level detection mechanism 200. This improves the detection accuracy of the first liquid level detection mechanism 100, which is a non-contact type, and makes it possible to prevent the above-mentioned problems that are a concern after the dispensing process.

[0049] 6 is a diagram showing the overall configuration of a dispensing processing unit including a second liquid level detection mechanism. As shown in FIG. 6, the dispensing processing unit 800g mainly includes a dispensing probe 201, a second driving unit 202, a dispensing tip 203, a syringe 204, a pump 205, a valve 206, a pressure sensor 207, a second analysis unit 208, and a second control unit 209.

[0050] The dispensing probe 201 aspirates and dispenses the sample from the sample container 120. The second drive unit 202 moves the dispensing probe 201 up and down. The dispensing tip 203 is attached to the tip of the dispensing probe 201 as needed. The syringe 204 is connected to the dispensing probe 201 and aspirates and dispenses the sample. The pump 205 supplies system water to the syringe 204. The valve 206 opens and closes the flow path connecting the syringe 204 and the pump 205.

[0051] The pressure sensor 207 and the second analysis unit 208 constitute the second liquid level detection mechanism 200. The pressure sensor 207 is provided midway through the flow path connecting the dispensing probe 201 and the syringe 204, measures the pressure within the flow path, and outputs the measurement data to the second analysis unit 208. The second analysis unit 208 detects the height of the upper surface of the sample based on the measurement data output from the pressure sensor 207, and outputs the detection result to the second control unit 209.

[0052] The second control unit 209 controls the operations of the second drive unit 202, the syringe 204, and the second analysis unit 208. The second control unit 209 may have the functions of the second analysis unit 208. Furthermore, the functions of the second analysis unit 208 and the second control unit 209 may be provided by a control device provided outside the second liquid level detection mechanism 200.

[0053] When the dispensing processing unit 800g aspirates a sample from a sample container 120, the second control unit 209 first controls the second drive unit 202 to lower the dispensing probe 201. When the second control unit 209 detects that the sample has come into contact with the tip of the dispensing tip 203 based on a change in the measurement data of the pressure sensor 207, the second control unit 209 stores this position in the memory as the height of the upper surface of the sample and further lowers the dispensing probe 201 by a predetermined height. The second control unit 209 then operates the syringe 204 to aspirate the sample through the system water filled in the flow path. When the dispensing processing unit 800g dispenses a sample into another sample container 120, the second control unit 209 operates the syringe 204 in the opposite direction to dispense the sample through the system water.

[0054] Next, a method for correcting the detection result by the first liquid level detection mechanism 100 using the detection result by the second liquid level detection mechanism 200 will be described with reference to Fig. 7. In the following, an example will be described in which this correction is performed by the control device 804, but this correction may also be performed by the first control unit 108. Fig. 7 is a flowchart showing a method in which the control device corrects the detection result by the first liquid level detection mechanism.

[0055] First, the control device controls the liquid volume determination processing unit 800d including the first liquid level detection mechanism 100 to non-contactly detect the top surface height H1 of the sample in the sample container 120 (step S701). Here, a predetermined position on the upper side of the sample container 120 is used as a height reference, and the distance from this reference to the top surface of the sample below is set as the top surface height H1.

[0056] Next, the control device reads a correction value ΔH for correcting the sample top surface height H1 from the memory unit (step S702). Here, the memory unit stores different correction values ​​ΔH depending on the type of sample container 120 and / or the type of sample to achieve more accurate correction. The type of sample container 120 includes the material and shape, and if these factors differ, the size of the meniscus changes. The type of sample container 120 is determined by a container recognition unit in the sample insertion unit 800a. Furthermore, the type of sample includes whether it is blood or urine, or even if it is blood, whether it is serum or whole blood, and whether it contains an anticoagulant, and if these factors differ, the size of the meniscus changes. The type of sample is determined by a liquid (sample) recognition unit in the sample insertion unit 800a. The correction value ΔH is calculated in advance by the control device based on the difference between the top surface height of the sample previously detected by the first liquid level detection mechanism 100 and the top surface height of the sample detected by the second liquid level detection mechanism 200.

[0057] The control device then corrects the top surface height H1 detected in step S701 using the correction value ΔH read out in step S702 (step S703). The corrected top surface height is H1 + ΔH. This correction improves the detection accuracy of the first liquid level detection mechanism 100, which is a non-contact method, and can prevent clogging of the dispensing probe 201 in later processes. Note that, as described above, a typical meniscus causes the liquid level to rise high toward the container wall, resulting in a positive ΔH. However, depending on the specimen or specimen container, a meniscus may occur in which the liquid level drops toward the container wall, in which case ΔH becomes negative.

[0058] Next, when the control device dispenses the sample in the sample container 120 into another sample container 120 in the dispensing processing unit 800g, it controls the second liquid level detection mechanism 200 to detect the top surface height H2 of the sample in the sample container 120 using a contact method (step S704).

[0059] Thereafter, the control device compares the corrected upper surface height (H1+ΔH) in step S703 with the upper surface height H2 detected in step S704 (step S705). If it is determined in step S705 that (H1+ΔH)=H2, the control device does not update ΔH and ends the process.

[0060] On the other hand, if it is determined in step S705 that (H1+ΔH)≠H2, the control device updates ΔH and stores the updated ΔH in the storage unit (step S706), and then ends the process.

[0061] Here, there are two methods for updating ΔH, for example: The first is a method in which (ΔH before update + difference between H1 and H2 detected this time) ÷ 2 = updated ΔH. The second is a method in which (difference between H1 and H2 for the past 10 times) ÷ 2 = updated ΔH.

[0062] Furthermore, the determination of whether ΔH needs to be updated and the update process in steps S705 and S706 may be performed each time a sample is dispensed by the dispensing processing unit, or each time calibration is performed. In the former mode, in which ΔH is updated each time a sample is dispensed, it is expected that ΔH will converge to a more optimal ΔH by repeatedly analyzing the sample components. On the other hand, in the latter mode, in which ΔH is updated each time calibration is performed, the ΔH is fixed to the ΔH calculated when the calibrator sample was dispensed, and the detection results of subsequent samples can be corrected, thereby reducing the calculation load. Furthermore, the former mode and the latter mode may be selectable by the user via the operation unit.

[0063] According to this embodiment, the liquid volume determination processing unit 800d can more accurately determine the upper surface of the sample, improving the accuracy of liquid level detection. Furthermore, by accurately determining the sample volume, it is possible to set more appropriate request items for the sample volume.

[0064] Although the first liquid level detection mechanism 100 in the above-described embodiment detects the liquid level position (the height H1 of the upper surface of the specimen) based on the first transmitted light data 401 and the second transmitted light data 402, it may alternatively be detected by other non-contact methods, for example, by image analysis using a camera. Furthermore, although the second liquid level detection mechanism 200 in the above-described embodiment detects the liquid level position (the height H2 of the upper surface of the specimen) based on measurement data from the pressure sensor 207, it may alternatively be detected by other contact methods, for example, by measurement data from a capacitance sensor.

[0065] Furthermore, the above-described embodiment describes a case in which a liquid level detection device consisting of a first liquid level detection mechanism 100, a second liquid level detection mechanism 200, and a control device 804 is implemented as part of a sample testing automation system (the control device 804 is also used for devices other than the liquid level detection device). However, the above-described liquid level detection device may be used as a standalone device, or may be used as an automatic analyzer or a sample pretreatment device that automatically performs sample pretreatment. Furthermore, the object to be detected by the liquid level detection device is not limited to samples, and may be other liquids such as reagents.

[0066] 100...first liquid level detection mechanism, 101...first irradiation unit, 102...second irradiation unit, 103...first light receiving unit, 104...second light receiving unit, 105...first analysis unit, 106...gripping unit, 107...first driving unit, 108...first control unit, 120...specimen container, 121...separator, 122...blood clot, 123...serum, 124...label, 201...dispensing probe, 202...second driving unit, 203...dispensing tip, 204...syringe, 205...pump, 206...valve, 207...pressure sensor, 208...second analysis unit, 2 09...Second control unit, 401...First transmitted light data, 402...Second transmitted light data, 800...Pretreatment device, 800a...Sample input unit, 800b...Sample storage unit, 800c...Centrifugation unit, 800d...Liquid volume determination processing unit, 800e...Uncap processing unit, 800f...Daughter sample container generation processing unit, 800g...Dispensing processing unit, 800h...Capping processing unit, 801...Analyzer, 802...Transport path, 803...Sample transfer unit, 804...Control device, 810...Holder

Claims

1. A liquid level detection device comprising: a first liquid level detection mechanism that detects the top surface of a liquid in a container using a non-contact method; a second liquid level detection mechanism that detects the top surface of the liquid in the container using a contact method; and a control device that corrects the detection result by the first liquid level detection mechanism using the detection result by the second liquid level detection mechanism.

2. A liquid level detection device as described in claim 1, wherein the control device has a memory unit which stores a correction value for correcting the detection result by the first liquid level detection mechanism, and the correction value is calculated based on the difference between the liquid level position detected by the first liquid level detection mechanism and the liquid level position detected by the second liquid level detection mechanism.

3. A liquid level detection device as described in claim 2, further comprising a container recognition unit that determines the type of the container, and wherein the memory unit stores different correction values ​​depending on the type of the container.

4. A liquid level detection device as described in claim 2, further comprising a liquid recognition unit that determines the type of liquid, and wherein the memory unit stores different correction values ​​depending on the type of liquid.

5. A liquid level detection device according to claim 4, wherein the memory unit stores the correction value which differs between when the liquid is blood and when the liquid is urine.

6. A liquid level detection device as described in claim 5, wherein the memory unit stores the correction value which differs between blood containing an anticoagulant and blood not containing an anticoagulant.

7. A liquid level detection device as described in claim 2, characterized in that the liquid is a sample, the second liquid level detection mechanism is provided in a dispensing processing unit that dispenses the sample from the container to another container, and the first liquid level detection mechanism is provided between a sample input unit for inputting the container containing the sample and the dispensing processing unit.

8. A liquid level detection device as described in claim 7, characterized in that the control device further has an operation unit that accepts operations from a user, and the operation unit can select between a mode in which the correction value is updated each time the sample is dispensed by the dispensing processing unit and a mode in which the correction value is updated each time calibration is performed.

9. A liquid level detection method comprising: a step of a first liquid level detection mechanism detecting the top surface of the liquid in a container in a non-contact manner; a step of a second liquid level detection mechanism detecting the top surface of the liquid in the container in a contact manner; and a step of a control device correcting the detection result by the first liquid level detection mechanism using the detection result by the second liquid level detection mechanism.