Liquid management device and dispensing device

Abstract

In a dispensing device provided with a weight sensor that measures the weight of a liquid container in which a liquid to be dispensed is stored, zero-point correction of the weight sensor is reliably performed. A liquid management device (5) provided in a dispensing device (1) includes a placement portion (11) in which a liquid container is placed, a weight sensor (12) that measures the weight of the placement portion, a weight measurement value acquisition portion (21) that continuously acquires measurement values of the weight sensor, and a zero-point correction execution portion (22) that performs zero-point correction of the weight sensor based on a plurality of measurement values acquired by the weight measurement value acquisition portion between a first time that is a first predetermined time earlier than a load-exceeding measurement value acquisition time at which a measurement value acquired by the weight measurement value acquisition portion exceeds a predetermined threshold value and a second time that is a second predetermined time earlier than the first time.

Description

Technical Field

[0001] The present invention relates to a liquid management device used in a liquid dispensing apparatus, and a dispensing apparatus having the liquid management device. Background Technology

[0002] In the treatment of infectious diseases, identifying the type of bacteria causing the infection is crucial; therefore, bacterial tests are performed to identify the types of bacteria present in the blood collected from patients with infectious diseases. For example, Patent Document 1 describes the analysis of blood culture samples (blood culture samples) after bacterial proliferation has been achieved through matrix-assisted laser desorption / ionization (MALDI) mass spectrometry to identify bacterial species. When analyzing blood culture samples using MALDI-MS, a pretreatment is performed by adding a hemolyzing reagent to the blood culture sample to lyse blood cells.

[0003] Such pretreatment typically uses a pretreatment apparatus. This apparatus includes a dispensing device that performs the dispensing action, i.e., collecting a predetermined amount of reagent from a reagent container and injecting it into a sample container. As an example of such a dispensing apparatus, Patent Document 2 describes a device having a sample container holding section and a reagent container holding section that respectively hold the sample container and the reagent container, a pipette tip mechanism that draws reagent from the reagent container and dispenses it into the sample container, and a pipette tip moving mechanism that moves the pipette tip between the reagent container and the sample container.

[0004] In order for the reagent container to be drawn through the pipette tip, the container needs to contain a sufficient amount of reagent. Therefore, a weight sensor is provided in the reagent container holding section, which will notify the user when the weight of the reagent container held in the holding section drops below a predetermined value. Upon receiving the notification, the user removes the reagent container from the holding section, replenishes the reagent, and then returns the reagent container to the holding section.

[0005] Existing technical documents Patent documents Patent Document 1: Japanese Patent Application Publication No. 2024-104883 Patent Document 2: Japanese Patent Application Publication No. 2014-235076 Summary of the Invention The technical problem that the invention aims to solve In the above-described dispensing device, zero-point calibration of the weight sensor is performed when the reagent container is returned to the reagent container holding section. This allows for accurate measurement of the remaining reagent volume. Zero-point calibration of the weight sensor is performed by a pre-defined operation by the user. Therefore, if the user forgets to perform zero-point calibration, the preprocessing process may restart without zero-point calibration of the weight sensor, resulting in inaccurate measurement of the reagent container's weight.

[0006] The technical problem to be solved by the present invention is to enable the zero-point calibration of the weight sensor to be reliably performed in a liquid management device for a dispensing device, which is equipped with a weight sensor that measures the weight of a liquid container containing liquid to be dispensed.

[0007] Solution to the above technical problems The liquid management device of the present invention, made to solve the above-mentioned technical problems, comprises: Placement section for storing liquid containers; A weight sensor measures the weight of the placement part; The weight measurement acquisition unit continuously acquires the measurement values ​​from the weight sensor; and The zero-point calibration execution unit performs zero-point calibration of the weight sensor based on multiple measurement values ​​acquired by the weight measurement acquisition unit between a first time that is a first predetermined time earlier than the time when the load over-limit measurement value is acquired and a second time that is a second predetermined time earlier than the first time. The time when the load over-limit measurement value is acquired is the time when the measurement value acquired by the weight measurement acquisition unit exceeds a predetermined threshold.

[0008] Invention Effects In the liquid management device of the present invention, by placing a liquid container on the placement unit, the weight sensor measurement value acquired by the weight measurement value acquisition unit rises. Based on the moment when this measurement value exceeds a predetermined threshold, i.e., the moment when the load over-limit measurement value is acquired, the zero-point correction execution unit performs zero-point correction of the weight sensor based on multiple measurement values ​​acquired between a first moment and a second moment prior to this point. Furthermore, measurement values ​​acquired between the first moment and the moment when the load over-limit measurement value is acquired are excluded from the measurement values ​​used for zero-point correction. The first predetermined time corresponds to the period from when the user begins placing the liquid container on the placement unit until the placement operation ends, during which the placement unit is in an unstable state. By not using the weight sensor measurement values ​​obtained during such a period for zero-point correction processing, the zero-point correction of the weight sensor can be performed accurately. In summary, in the liquid management device of the present invention, zero-point correction can be performed reliably and accurately without user operation, thus preventing the measurement of the liquid container's weight in a state of zero-point offset. Attached Figure Description

[0009] 【 Figure 1 The diagram shows a schematic configuration of a first embodiment of the dispensing device according to the present invention.

[0010] 【 Figure 2 The flowchart shows the zero-point calibration operation in the dispensing device of the first embodiment.

[0011] 【 Figure 3The graph showing the variation of measured values ​​during zero-point calibration is marked with the threshold, the time of measurement acquisition for overload, the first time, the second time, and the zero-point calibration value.

[0012] 【 Figure 4 This diagram shows a schematic configuration of a second embodiment of the dispensing apparatus according to the present invention.

[0013] 【 Figure 5 This diagram shows a schematic configuration of the pipette tip height detection mechanism in a second embodiment of the dispensing device of the present invention.

[0014] 【 Figure 6 [Image showing the operation of the pipette tip height detection mechanism]

[0015] 【 Figure 7 The diagram shows the difference in the lower height of the pipette tip caused by the difference in the inner diameter of the mounting part. Detailed Implementation

[0016] use Figures 1 to 7 This invention describes an embodiment of the dispensing device involved in the present invention.

[0017] (1) First implementation method (1-1) Configuration of the liquid management device and the dispensing device having the first embodiment Figure 1 The liquid management device 5 and the dispensing device 1 equipped with it are schematically shown. The dispensing device 1 includes a placement section 11, a weight sensor 12, a sample container holding section 13, an unused pipette tip holding section 14, a used pipette tip receiving container 141, a sample processing section after reagent addition 15, a robotic arm 16, a liquid reagent aspiration and dispensing mechanism 17, a control / information processing section 20, a storage section 30, an input section 40, and a display section 50. The liquid management device 5 is composed of the placement section 11 and the weight sensor 12, as well as a portion of the control / information processing section 20 (described later), which are components of the dispensing device 1.

[0018] The placement section 11 is used to place a liquid container 91, which is a container for holding the liquid described later. Figure 1 The example shown has 8 placement parts 11, but the number of placement parts 11 is not limited to this example.

[0019] Weight sensors 12 are sensors that measure the weight of placement sections 11, and one is provided for each placement section 11. Each weight sensor 12 measures the weight of the placement section 11 itself when the liquid container 91 is not placed in the placement section 11, and measures the total weight of the placement section 11 and the liquid container 91 when the liquid container 91 is placed in the placement section 11. The weight sensors 12 can be known sensors such as load cells or capacitive sensors. In addition, each weight sensor 12 has the function of sending the weight measurement value and a unique identification code (information used to distinguish it from other weight sensors 12) to the control / information processing unit 20. The weight measurement values ​​are continuously sent at predetermined time intervals.

[0020] The sample container holding section 13 is used to hold a plurality of (e.g., 192) sample containers 92, which are containers for holding samples that are to be examined / analyzed, such as for bacterial testing. The liquid contained in the aforementioned liquid container 91 is a reagent added to the sample as a pretreatment for analysis. Figure 1 The example shown illustrates a sample container 92 that holds multiple samples, each containing one sample. However, the sample container 92 can also hold one or more microplates with multiple (e.g., 192) pores.

[0021] The unused pipette tip holder 14 is used to hold multiple unused pipette tips 93. The pipette tip 93 is a cylindrical component with a narrowed inner diameter near its lower end when in use. It is mounted on the liquid reagent aspiration and dispensing mechanism 17 by inserting the probe of the liquid reagent aspiration and dispensing mechanism 17 into its upper end during use, and liquid is drawn / dispensed from the lower end. In the unused pipette tip holder 14, the pipette tips 93 are held with their upper ends facing upwards.

[0022] The used pipette tip container 141 is a container for holding used pipette tips 93 removed from the liquid reagent aspiration and dispensing mechanism 17. The used pipette tip container 141 can be removed from the dispensing device 1 when the used pipette tips 93 are discarded.

[0023] After reagent addition, the sample processing unit 15 performs processes such as shaking or centrifugation on the sample containing the reagent. Since the sample processing unit 15 is not a critical component of this invention, a detailed description is omitted.

[0024] The robotic arm 16 is positioned above the placement section 11, the weight sensor 12, the sample container holding section 13, the unused pipette tip holding section 14, the used pipette tip receiving container 141, and the sample processing section 15 after reagent addition. It has a clamping section 161 for holding the sample container 92 or the liquid reagent aspiration / dispensing mechanism 17, a planar movement mechanism 162 for two-dimensional movement of the clamping section 161, and a lifting mechanism (not shown) for moving the clamping section 161 up and down. Figure 1 In the example shown, the clamping part 161 has two types: one type that always clamps the liquid reagent aspiration and dispensing mechanism 17, and another type that clamps the sample container 92 when it is moved. Alternatively, only one clamping part 161 may be provided, which clamps the liquid reagent aspiration and dispensing mechanism 17 when the liquid reagent is aspirated and dispensed, and clamps the sample container 92 when it is moved. The planar movement mechanism 162 may be a mechanism consisting of a linear first track arranged along the direction that causes the clamping part 161 to move one dimension, a second track arranged along the direction that causes the first track to move in a plane in a direction perpendicular to it, and a drive source that moves the clamping part 161 and the first track.

[0025] The liquid reagent aspiration and dispensing mechanism 17 includes a probe on which a pipette tip 93 is mounted, and a gas aspiration and dispensing device for drawing gas from the probe and dispensing gas from the probe. When the pipette tip 93 is mounted on the probe, the liquid reagent aspiration and dispensing mechanism 17 draws liquid from the tip of the pipette tip 93 into the pipette tip 93 by drawing a smaller amount of gas than the volume inside the pipette tip 93. Furthermore, the liquid reagent aspiration and dispensing mechanism 17 dispenses the liquid from the pipette tip 93 by dispensing gas into the pipette tip 93 after it has drawn liquid.

[0026] The control / information processing unit 20 controls the various parts of the dispensing device 1 and performs predetermined information processing. It is implemented by a CPU, a storage device such as memory or a hard disk, other hardware, and software running this hardware. The control / information processing unit 20 includes, as a functional module, a weight measurement acquisition unit 21, a zero-point calibration execution unit 22, a weight measurement display and processing unit 23, a reagent residual warning notification unit 24, a suction and dispensing mechanism control unit 25, a robotic arm control unit 26, and a reagent addition post-processing control unit 27. Among these functional modules, the weight measurement acquisition unit 21, the zero-point calibration execution unit 22, the weight measurement display and processing unit 23, and the reagent residual warning notification unit 24 are constituent elements of the liquid management device 5.

[0027] The weight measurement acquisition unit 21 has the following functions: continuously acquiring the weight measurement value and identification code of the placement unit 11 sent from each weight sensor 12, and storing the measurement value of the weight sensor identified by each identification code in the storage unit 30.

[0028] The zero-point calibration execution unit 22 has the function of performing zero-point calibration of the weight sensor 12 when the liquid container 91 is placed on the placement unit 11. The specific data processing during zero-point calibration will be described later.

[0029] The weight measurement value display processing unit 23 has the function of performing a process to make the display unit 50 display the weight measurement values ​​obtained by the weight measurement value acquisition unit 21 from each placement unit 11. The weight measurement values ​​are displayed not only when performing zero-point calibration, which is a feature of the present invention, but also continuously over time during the repeated execution of the process of dispensing liquid reagent from the liquid container 91.

[0030] In addition, when the weight measurement value obtained by the weight measurement value acquisition unit 21 is reduced to the level where the reagent needs to be replenished due to repeated dispensing processes, the reagent residual warning notification unit 24 performs the process of issuing a warning sound and displaying a warning on the display unit 50.

[0031] Users can determine when to replenish liquid reagents in liquid container 91 by viewing these weight measurements and hearing warning sounds / warning displays.

[0032] The suction and discharge mechanism control unit 25 controls the operation of the liquid reagent suction and discharge mechanism 17, the robotic arm control unit 26 controls the operation of the robotic arm 16, and the reagent addition post-processing control unit 27 controls the operation of the reagent addition post-sample processing unit 15.

[0033] The storage unit 30 is a storage medium that stores the measurement values ​​acquired by the weight measurement value acquisition unit 21 for each weight sensor as described above. The storage unit 30 can be a computer-equipped memory, hard disk, SSD (Solid State Drive), etc.

[0034] The input unit 40 is a device for allowing the user to input predetermined information. The input unit 40 can be equipped with a keyboard, mouse, touch screen, etc. The display unit 50 is a display that shows the weight measurement results and other information about the operation of the dispensing device 1.

[0035] (1-2) Operation of the liquid management device and the dispensing device equipped therewith according to the first embodiment The operation of the liquid management device 5 and the dispensing device 1 equipped with it according to the first embodiment will be explained. In the following text, the dispensing operation, that is, the operation of dispensing liquid reagent from liquid container 91 and supplying it to sample container 92, is the same as that of a normal dispensing device, so it will only be briefly explained. The focus will be on the zero-point calibration operation of the weight sensor when replenishing liquid reagent to liquid container 91.

[0036] (1-2-1) Note dispensing action Before starting the dispensing device 1, the user places the liquid container 91 containing the liquid reagent on the placement section 11, the sample container holding section 13 holds the sample container 92 containing the sample, and the unused pipette tip holding section 14 holds the unused pipette tip. Based on this, the user performs a predetermined setting operation using the input section 40 and then starts the operation, after which the dispensing device 1 begins to operate.

[0037] First, the robotic arm 16 moves the liquid reagent aspiration and dispensing mechanism 17 (the clamping part 161 holding it) above the unused pipette tip holding part 14 and then lowers it, thereby installing the unused pipette tip 93 on the liquid reagent aspiration and dispensing mechanism 17. Next, the robotic arm 16 raises the liquid reagent aspiration and dispensing mechanism 17, moves it above a liquid container 91 placed on one of the plurality of holding parts 11, and lowers it, thereby immersing the lower end of the pipette tip 93 into the liquid in the liquid container 91. In this state, the liquid reagent aspiration and dispensing mechanism 17 aspirates a predetermined amount of liquid. Next, the robotic arm 16 raises the liquid reagent aspiration and dispensing mechanism 17, moves it above one of the plurality of sample containers 92 held in the sample container holding part 13, and lowers it, thereby inserting the lower end of the pipette tip 93 into the sample container 92. In this state, the liquid reagent aspiration and dispensing mechanism 17 dispenses the liquid from the pipette tip 93. Then, the robotic arm 16 raises the liquid reagent aspiration and dispensing mechanism 17 and moves it above the used pipette tip receiving container 141, removes the pipette tip 93 mounted on the liquid reagent aspiration and dispensing mechanism 17 and stores it in the used pipette tip receiving container 141.

[0038] The above process completes the dispensing of liquid reagents into one sample container 92. Then, by repeating the above steps, liquid reagent dispensing is performed into multiple sample containers 92 sequentially.

[0039] Furthermore, the robotic arm 16 moves the other gripping part 161 of the liquid reagent suction and discharge mechanism 17, which is not holding the liquid reagent, above the sample container 92 that has been supplied with liquid reagent and lowers it, gripping the sample container 92 and moving it to the reagent addition sample processing unit 15. The predetermined reagent addition sample processing is performed in the reagent addition sample processing unit 15.

[0040] (1-2-2) Zero-point calibration of the weight sensor As the dispensing process described above is repeated, the liquid reagent in the liquid container 91 gradually decreases. Therefore, when the weight measurement value obtained by the weight measurement unit 21 is lower than a predetermined value, the reagent residual warning unit 24 will notify that the liquid reagent residual in the liquid container 91 placed on a certain placement section 11 has decreased. Upon receiving this notification, the user performs an operation to replenish the liquid reagent in the liquid container 91. It should be noted that replenishing the liquid reagent can be done by injecting liquid reagent into a previously used liquid container 91, or by replacing it with a new liquid container 91 that already contains liquid reagent (in this specification, both are collectively referred to as "liquid reagent replenishment operation"). In conjunction with this liquid reagent replenishment operation performed by the user, the liquid management device 5 performs a zero-point calibration operation on the weight sensor 12 of the placement section 11 where the liquid container 91 to be replenished is placed, as described below. Hereinafter, refer to... Figure 2 Flowchart and Figure 3 The diagram illustrates the zero-point correction action.

[0041] First, the user performs a predetermined operation using the input unit 40, thereby stopping the dispensing process. When the dispensing process stops, the zero-point calibration operation begins. The user removes the liquid container 91 to be replenished from the placement unit 11, thereby reducing the measurement value of the weight sensor 12 of the placement unit 11 to below a predetermined threshold. Figure 3 (as in "when removed"). Here, the threshold is set to be higher than the range expected for measurements taken without the liquid container 91 after zero-point calibration.

[0042] When the zero-point calibration operation begins as described above, the weight measurement acquisition unit 21 acquires the measurement value of the weight sensor 12 on the placement unit 11 where the liquid container 91 to be replenished is placed (step 1). During the period when the acquired measurement value exceeds the threshold (step 2 is "No"), it means that the load of the liquid container 91 before replenishment is still on the weight sensor 12, therefore the acquired measurement value is not used for zero-point calibration, and the process returns to step 1 to continue acquiring measurement values. Then, when the measurement value falls below the threshold (step 2 is "Yes"), the weight measurement acquisition unit 21 stores the acquired measurement value in the storage unit 30 (step 3).

[0043] After performing step 3, the weight measurement acquisition unit 21 acquires a measurement value again (step 4). When the acquired measurement value is below the threshold (step 5 is "No"), the weight measurement acquisition unit 21 returns to step 3 to store the measurement value in the storage unit 30, and then acquires a measurement value again (step 4). Thus, the acquisition of measurement values ​​and storage in the storage unit 30 are repeated while the measurement value is below the threshold.

[0044] When the user places the liquid container 91, which has been replenished with a liquid sample, on the placement section 11, the measured value increases. However, during the period from when the user begins placing the liquid container 91 on the placement section 11 until the placement operation ends, the measured value of the weight sensor 12 becomes unstable. During this unstable period, the measured value is higher than when the liquid container 91 is not placed, but lower than a threshold value. Figure 3 The measurement value indicated by the arrow within the "first time" (in the text). If such unstable measurement values ​​are used for zero-point correction as described later, an error will occur at the zero point. Therefore, in this embodiment, the measurement values ​​obtained during the period when the measurement value is below the threshold ( Figure 3 Measurements within the range marked as "not used" are not used for zero-point calibration, and measurement values ​​continue to be acquired (step 5 is "No"). Then, when the measured value exceeds the threshold (step 5 is "Yes"), proceed to step 6 to perform data processing for zero-point calibration.

[0045] In step 6, the zero-point correction execution unit 22 retrieves from the storage unit 30 the measurement value obtained between a first time earlier than the time when the measured value exceeds the threshold (referred to as the "load over-limit measurement value acquisition time") and a second time earlier than the first time. Figure 3 (Measurements recorded as "data usage" range). Further, the zero-point calibration execution unit 22 calculates the average of the acquired measurements (step 7). Alternatively, the median can be used instead of the average. Here, the first predetermined time is preset to be a sufficiently long time longer than the time it takes for the measurement values ​​to become unstable when the liquid container 91 is placed on the placement unit 11. Furthermore, the second predetermined time is set to a time length sufficient to obtain a number of measurements for averaging. However, if the second predetermined time is too long, unstable measurement values ​​may be obtained immediately after the liquid container 91 is removed from the placement unit 11 before replenishment of the liquid reagent; therefore, the second predetermined time is preset to avoid including such measurement values. The first and second predetermined times can also be set by the user through a separately configured settings screen.

[0046] The average value (or median) calculated as described above is used as the measurement value of the weight sensor at the zero point (the state where the liquid container 91 is not placed in the placement section 11). The value obtained by subtracting the measurement value at the zero point from the measurement value of the weight sensor 12 when the liquid container 91 with the replenished liquid sample is placed is the weight of the liquid container 91 with the replenished liquid sample.

[0047] According to the liquid management device of this embodiment, since zero-point calibration is performed without user intervention, inaccurate weight measurement of the liquid container 91 can be prevented due to the user forgetting to perform zero-point calibration. Furthermore, since the measurement values ​​obtained during the unstable period immediately after the liquid container 91 is placed, from the first moment to the moment the overload measurement value is acquired, are not used for zero-point calibration, accurate zero-point calibration can be performed. For these reasons, the liquid management device of this embodiment prevents the measurement of the liquid container weight from being performed while the zero point is offset.

[0048] (2) Second implementation method The liquid management device 6 of the second embodiment, in addition to having all the constituent elements of the liquid management device 5 of the first embodiment, such as Figure 4 As shown, the control / information processing unit 20 also includes a sample residual initial value calculation unit 28 and a reagent residual calculation unit 29 as functional modules. The purpose of setting up the sample residual initial value calculation unit 28 and the reagent residual calculation unit 29 is as follows: when the reagent residual warning notification unit 24 notifies that the reagent residual is reduced, it does not base its notification on the measurement value of the weight sensor 12, that is, the weight of the liquid container 91 containing the liquid reagent (more precisely, the weight after adding the weight of the placement unit 11), but rather calculates the residual amount of the liquid reagent more directly and notifies at a more appropriate time. The configuration of the dispensing device 2 in the second embodiment is the same as that of the dispensing device 1 in the first embodiment, except that the liquid management device 5 in the first embodiment is replaced with the liquid management device 6 in the second embodiment.

[0049] The initial value calculation unit 28 calculates the initial value of the sample residual volume using the measurement value acquired by the weight measurement value acquisition unit 21 as the initial value of the measurement after the load over-limit measurement value is acquired during zero-point calibration and before the first dispensing from the liquid container 91 replenished with liquid reagent. Simultaneously, the initial value calculation unit 28 acquires the weight of the empty liquid container as information on the empty liquid container's weight from the storage unit 30. Based on this, the initial value calculation unit 28 calculates the initial value of the liquid weight, which is the initial value of the liquid reagent weight contained in the liquid container 91 replenished with liquid reagent, by subtracting the empty container weight from the initial measurement value. Furthermore, the empty container weight is pre-input by the user using the input unit 40, or pre-stored in the storage unit 30 after measuring the empty liquid container 91 with a weight sensor.

[0050] The reagent residual calculation unit 29 obtains the unit dispensing weight, which is the weight of liquid dispensed from the liquid container 91 in a single dispensing operation, from the storage unit 30. This unit dispensing weight is pre-input by the user using the input unit 40 when setting dispensing conditions. Furthermore, the reagent residual calculation unit 29 receives a signal each time the suction / dispensing mechanism control unit performs control of the suction of reagent solution, and based on the number of times this signal is received, obtains information about the number of dispensing operations performed after zero-point calibration in the liquid container 91. Based on this, the reagent residual calculation unit 29 calculates the reagent residual in the liquid container 91, which is subject to zero-point calibration, by subtracting the value obtained by multiplying the unit dispensing weight by the dispensing count information from the initial liquid weight value.

[0051] When the liquid reagent residual amount calculated by the reagent residual amount calculation unit 29 is lower than a predetermined value, the reagent residual amount warning notification unit 24 issues a warning. Afterwards, the user's operation to replenish the liquid reagent and the zero-point calibration operation are the same as in the first embodiment.

[0052] According to the liquid management device 6 of the second embodiment, since the remaining liquid level in the liquid container 91 placed on the placement section 11 can be monitored, the user can replenish the liquid container 91 at an appropriate time. Therefore, it is possible to prevent the situation where dispensing cannot be performed due to the liquid container 91 becoming empty.

[0053] (3) Third implementation method The dispensing device in the third embodiment is an addition to the dispensing device 1 in the first embodiment or the dispensing device 2 in the second embodiment. Figure 5 The device shown is a pipette tip height detection mechanism 60. All components except the pipette tip height detection mechanism 60, including the liquid management device 5 or 6, are the same as in the first or second embodiment, and therefore detailed descriptions are omitted.

[0054] (3-1) Composition of the pipette tip height detection mechanism 60 like Figure 5 As shown, the pipette tip height detection mechanism 60 includes a lifting part 61, a probe 62, a force-applying component holding part 63, a force-applying component 64, a sensor 65, a movable rod 66, a probe fixing part 67, and a pipette tip height calculation part 68.

[0055] The lifting unit 61 is a component fixed to the lifting mechanism of the robotic arm 16. The lifting unit 61 moves up and down by the action of the lifting mechanism.

[0056] The probe 62 is mounted by inserting its lower end into the opening of the pipette tip 93 (see reference). Figure 6It has a gas outlet for drawing gas from and discharging gas into the pipette tip 93. The probe 62 is held vertically relative to the lifting part 61 by means of a movable rod 66.

[0057] The force-applying component holding part 63 is provided on the upper side of the probe 62 and fixed to the lifting part 61. The force-applying component 64 is composed of an elastic member provided between the probe 62 and the force-applying component holding part 63, which extends to apply force to the probe 62 in a direction away from the force-applying component holding part 63, i.e., downward. In this embodiment, a helical spring is used as the force-applying component 64, but other springs or elastic members other than springs may also be used.

[0058] The sensor 65 is composed of a detection unit 651 fixed on the lifting unit 61 and a detected unit 652 fixed on the probe 62 by the probe fixing member 67. The detection unit 651 detects when the distance between itself and the detected unit 652 becomes a predetermined value (e.g., 0, i.e., a state of contact with the detected unit 652) and sends a detection signal.

[0059] The pipette tip height calculation unit 68 is part of the functional modules of the control / information processing unit 20. Furthermore, although... Figure 5 The image only shows the pipette tip height calculation unit 68, one of the functional modules of the control / information processing unit 20. However, in reality, the control / information processing unit 20 has, in addition to the pipette tip height calculation unit 68, also... Figure 1 or Figure 4 The functional modules shown are as follows. The pipette tip height calculation unit 68 obtains the distance the lifting unit 61 descends from the start of its descent until it receives the detection signal from the sensor 65 from the robotic arm control unit 26, and calculates the height of the lower end of the pipette tip 93 mounted on the probe 62 based on this distance. The principle of this height calculation will be described later in conjunction with the operation of the pipette tip height detection mechanism 60.

[0060] (3-2) Action of the pipette tip height detection mechanism 60 Reference Figure 6 This describes the operation of the pipette tip height detection mechanism 60. With the probe 62 not fitted with the pipette tip 93, the robotic arm 16 moves the lifting unit 61 directly above the unused pipette tip holding unit 14. Figure 6 (Left figure), then the lifting part 61 is lowered. After the probe 62 has descended to the height of the mounting part of the pipette tip 93, the force-applying part 64 initially remains in the extended state, and the probe 62 enters the mounting part ( Figure 6(See middle image). As the lifting unit 61 further descends, the force-applying component 64 is gradually compressed, increasing the force exerted on the probe 62 from the force-applying component 64. Consequently, the probe 62 is inserted deeper into the mounting portion. Then, when the lifting unit 61 descends to the point where the sensor 65 enters the detection state and sends a detection signal (…), Figure 6 (See right figure) A predetermined force is applied to the pipette tip 93. Then, the lifting section 61 is raised. Through this action, the pipette tip 93 is mounted on the probe 62 with a predetermined force.

[0061] The inner diameter of the mounting portion of each pipette tip 93 varies within tolerance. Therefore, even when the pipette tip 93 is mounted on the probe 62 with the same force, the larger the inner diameter of the mounting portion, the easier it is for the probe 62 to be inserted deeper from the upper end 931 of the pipette tip 93. As a result, based on the height of the probe 62, the height of the lower end 932 of the pipette tip 93, i.e., the aspiration and dispensing port, will vary from pipette tip 93 to pipette tip 93 (see reference). Figure 7 (The height of probe 62 in the figure is shown to be consistent). Suppose that when attempting to dispense liquid from liquid container 91 without correcting for the height difference of the lower end 932, the lower end 932 of the pipette tip may not actually reach the liquid surface in liquid container 91 but instead draws in gas, which may result in the inability to dispense the liquid sample correctly, or cause the lower end 932 to mistakenly hit the bottom of liquid container 91.

[0062] Therefore, the pipette tip height calculation unit 68 obtains from the robotic arm control unit 26 the distance the lifting unit 61 descends before the sensor 65 enters the detection state, and calculates the height of the lower end 932 of the installed pipette tip 93 based on this distance. Specifically, a reference distance is determined in advance through preliminary experiments. This reference distance is the distance the lifting unit 61 descends when the pipette tip 93 is installed on the probe with the lower end 932 at a predetermined reference height. Then, when actually installing the pipette tip 93, the distance difference (positive or negative) obtained by subtracting the reference distance from the distance the lifting unit 61 moves is calculated. By adding the distance difference to the reference height, the position of the lower end 932 of the pipette tip 93 after installation can be determined.

[0063] It should be noted that the aforementioned preliminary experiment can also be conducted by placing a positioning component that simulates the shape of the mounted portion of the pipette tip 93 at a predetermined height instead of the pipette tip 93 itself.

[0064] The above describes the embodiments of the dispensing device involved in the present invention, but the present invention is not limited to the above embodiments, and various modifications can obviously be made.

[0065] [plan] The above exemplary implementations are specific examples of the following solutions, which will be obvious to those skilled in the art.

[0066] (Item 1) A liquid management device according to one aspect of the present invention comprises: Placement section for storing liquid containers; A weight sensor measures the weight of the placement part; The weight measurement acquisition unit continuously acquires the measurement values ​​from the weight sensor; and The zero-point calibration execution unit performs zero-point calibration of the weight sensor based on multiple measurement values ​​acquired by the weight measurement acquisition unit between a first time that is a first predetermined time earlier than the time when the load over-limit measurement value is acquired and a second time that is a second predetermined time earlier than the first time. The time when the load over-limit measurement value is acquired is the time when the measurement value acquired by the weight measurement acquisition unit exceeds a predetermined threshold.

[0067] In the liquid management device according to the first claim, by placing the liquid container on the placement section, the measurement value of the weight sensor acquired by the weight measurement acquisition section rises. Based on the moment when this measurement value exceeds a predetermined threshold, i.e., the moment when the load over-limit measurement value is acquired, the zero-point correction execution section performs zero-point correction of the weight sensor based on multiple measurement values ​​acquired between a first moment and a second moment prior to this point. Furthermore, measurement values ​​acquired between the first moment and the moment when the load over-limit measurement value is acquired are excluded from the measurement values ​​used for zero-point correction. The first predetermined time corresponds to the period from when the user begins placing the liquid container on the placement section until the placement operation ends, during which the placement section is in an unstable state. By not using the weight sensor measurement values ​​obtained during such a period for zero-point correction processing, the zero-point correction of the weight sensor can be performed accurately. In summary, in the dispensing device of the present invention, zero-point correction can be performed reliably and accurately without user operation, thus preventing the measurement of the liquid container weight in a state of zero-point offset.

[0068] (Item 2) The liquid management device involved in Item 2 is the device involved in Item 1, wherein the zero-point calibration execution unit calculates the average value of the plurality of measurements that are the objects of calibration processing as the measurement value of the weight sensor at the zero point.

[0069] According to the liquid management device involved in item 2, a highly reasonable zero-point calibration can be performed by calculating the measurement value of the weight sensor at zero point using the average of multiple measurement values ​​as the object of calibration processing.

[0070] Furthermore, in the liquid management device involved in item 1, the median or the like may be used instead of the average value of the measured values ​​of the calibration processing object used in the liquid management device involved in item 2.

[0071] (Item 3) The liquid management device according to item 3 is a device according to item 1 or item 2, further comprising: The liquid weight initial value calculation unit calculates an initial liquid weight value, which is the initial value of the liquid contained in the liquid container placed on the placement unit, based on the initial measurement value obtained by the weight measurement value acquisition unit after the load over-limit measurement value acquisition time and before the first dispensing, and information about the weight of the empty liquid container; and The liquid residual calculation unit calculates the liquid residual in the liquid container based on the initial value of the liquid weight, the weight of the liquid dispensed from the liquid container in one dispensing operation, and the number of dispensing operations performed from the liquid container.

[0072] According to the liquid management device involved in item 3, since the liquid level in the liquid container placed on the placement unit can be measured, the user can replenish the liquid container at the appropriate time.

[0073] Information about the weight of an empty (no liquid-containing) liquid container can be input by the user via an input device such as a keyboard on the dispensing device, or it can be obtained by a weight sensor after the empty liquid container has been placed on the placement section. Information about the weight of the liquid dispensed in a single dispensing operation can be obtained by the user inputting a value via an input device, or by a value preset by the hardware or software of the dispensing device.

[0074] (Item 4) The dispensing device involved in Item 4 has the following features: The liquid management device as described in any one of items 1 to 3; The lifting unit moves up and down above the pipette tip holding part, which holds the unused pipette tip in a manner that holds the mounted part upward; The probe is held vertically relative to the lifting part, and the mounting part of the pipette tip is mounted on its lower end. A force-applying component holding part is provided above the probe and fixed on the lifting part; A force-applying component is disposed between the probe and the force-applying component holding part, and applies force downward to the probe; The sensor sends a detection signal when it detects that the vertical distance between the lifting unit and the probe has become below a predetermined value; and The pipette tip height calculation unit calculates the height of the lower end of the pipette tip based on the distance the lifting unit descends before the sensor sends the detection signal, at the pipette tip mounting position, when the pipette tip is installed onto the probe.

[0075] In the dispensing device described in item 4, the pipette tip is mounted on the probe mounting section by lowering the lifting unit from above the pipette tip holding section. During the descent of the lifting unit, after the lower end of the probe reaches the pipette tip mounting section, further descent of the probe gradually presses the lower end of the probe into the pipette tip by the force of the force-applying member. Then, when the sensor detects that the height distance between the lifting unit and the probe has fallen below a predetermined value, the force-applying member is compressed by a predetermined length between the force-applying member holding section fixed to the lifting unit and the probe. Thus, the pipette tip is mounted on the probe with a predetermined force.

[0076] The inner diameter of the mounting portion of the pipette tip has a tolerance. Due to this tolerance, even when the probe is pressed into the mounting portion with a predetermined force, the larger the inner diameter of the mounting portion, the longer the probe penetrates into the pipette tip. As a result, the height of the lower end of the pipette tip mounted on the probe varies depending on the inner diameter of the mounting portion, and it may be impossible to position the lower end of the pipette tip at the correct height when dispensing liquid from a liquid container. Therefore, in the dispensing device according to item 4, the pipette tip height calculation unit calculates the height of the lower end of the pipette tip based on the distance the probe descends due to the moving mechanism until the maximum force of a predetermined magnitude is applied. Based on the height of the lower end of the pipette tip calculated thereby, the lower end of the pipette tip can be positioned at the correct height during dispensing.

[0077] Explanation of reference numerals in the attached figures 1, 2...dispensing device 5, 6… Liquid Management Devices 11… Placement Section 12…weight sensors 13…Sample container holding section 14…Unused pipette tip retainer 141… Pipette tip containment container used 15…Sample processing section after reagent addition 16…robotic arm 161…Clamping section 162…Planar Moving Mechanism 17…Liquid reagent suction and discharge mechanism 20…Control / Information Processing Department 21…Weight Measurement Acquisition Department 22…Zero-point calibration execution department 23…Weight Measurement Value Display and Processing Unit 24…Reagent Residue Warning Notification Department 25…Suction and Ejection Mechanism Control Section 26…Robotic Arm Control Unit 27…Reagent Addition Post-Processing Control Department 28… Sample Residual Initial Value Calculation Section 29…Reagent Residual Calculation Department 30… Storage Department 40… Input Section 50… Display Department 60… Pipette tip height detection mechanism 61… Lifting section 62… probe 63…Force application component holding part 64…Force-applying components 65…sensor 651… Testing Department 652…Department under inspection 66…Modular lever 67…Probe Fixture 68… Pipette tip height calculation unit 91…Liquid Container 92…sample container 93…pipette tip 931… The upper end of the pipette tip 932…the lower end of the pipette tip.

Claims

1. A liquid management device, characterized in that, have: Placement section for storing liquid containers; A weight sensor measures the weight of the placement part; The weight measurement acquisition unit continuously acquires the measurement values ​​from the weight sensor; and The zero-point calibration execution unit performs zero-point calibration of the weight sensor based on multiple measurement values ​​acquired by the weight measurement acquisition unit between a first time that is a first predetermined time earlier than the time when the load over-limit measurement value is acquired and a second time that is a second predetermined time earlier than the first time. The time when the load over-limit measurement value is acquired is the time when the measurement value acquired by the weight measurement acquisition unit exceeds a predetermined threshold.

2. The liquid management device according to claim 1, characterized in that, The zero-point calibration execution unit calculates the average of the multiple measured values ​​that are the objects of calibration processing as the measured value of the weight sensor at zero point.

3. The liquid management device according to claim 1, characterized in that, Further features include: The liquid weight initial value calculation unit calculates the initial value of the liquid contained in the liquid container placed on the placement unit, based on the initial value of the measurement value obtained by the weight measurement value acquisition unit before the first dispensing is performed after the load over-limit measurement value acquisition time, and the weight of the empty liquid container. as well as The liquid residual calculation unit calculates the liquid residual in the liquid container based on the initial value of the liquid weight, the weight of the liquid dispensed from the liquid container in one dispensing operation, and the number of dispensing operations performed from the liquid container.

4. A dispensing device, characterized in that, have: The liquid management device according to any one of claims 1 to 3; The lifting unit moves up and down above the pipette tip holding part, which holds the unused pipette tip in a manner that holds the mounted part upward; The probe is held vertically relative to the lifting part, and the mounting part of the pipette tip is mounted on its lower end. A force-applying component holding part is provided above the probe and fixed on the lifting part; A force-applying component is disposed between the probe and the force-applying component holding part, and applies force downward to the probe; The sensor sends a detection signal when it detects that the vertical distance between the lifting unit and the probe has become below a predetermined value; as well as The pipette tip height calculation unit calculates the height of the lower end of the pipette tip based on the distance the lifting unit descends before the sensor sends the detection signal, at the pipette tip mounting position, when the pipette tip is installed onto the probe.

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