Dispensing device and dispensing method
The dispensing device addresses liquid dripping by measuring container mass to estimate liquid surface position and control pipette operations, achieving efficient and clean liquid transfer.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- ENEOS CORP
- Filing Date
- 2022-08-22
- Publication Date
- 2026-06-01
AI Technical Summary
Existing dispensing devices struggle with liquid dripping during the dispensing process, which can lead to inefficiencies and increased cleaning burdens.
A dispensing device that measures the mass of a specimen container to estimate the liquid surface position, controls the pipette insertion based on this position, and determines the timing of pipette movements to minimize liquid adherence and dripping, utilizing a processor to manage these operations.
The device effectively suppresses liquid dripping by accurately controlling pipette insertion and movement, reducing cleaning burdens and ensuring precise liquid transfer.
Smart Images
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Abstract
Description
Technical Field
[0001] One aspect of the present disclosure relates to a dispensing device and a dispensing method.
Background Art
[0002] Patent Document 1 describes a dispensing device that can determine a dispensing abnormality by a simple configuration and data processing. This device compares the peak value of the suction pressure applied from the pump to the pipette with the average value of the suction pressure calculated within a predetermined period after the start of suction by the pump to determine a dispensing abnormality. Patent Document 2 describes a liquid dispensing device including a nozzle moving mechanism that moves a suction nozzle up and down and a control unit that controls the nozzle moving mechanism. The control unit stops the movement of the suction nozzle by the nozzle moving mechanism and then moves the suction nozzle upward and stops it.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Patent Document 2
Summary of the Invention
Problems to be Solved by the Invention
[0004] A dispensing device and a dispensing method capable of suppressing liquid dripping are desired.
Means for Solving the Problems
[0005] A dispensing device according to one aspect of the present disclosure includes a scale that measures the mass of a specimen container that stores a liquid, a pipette that sucks and discharges the liquid in the specimen container, and a processor that estimates the position of the liquid surface based on the measured mass and controls the insertion of the pipette into the liquid based on the estimated position.
[0006] In this respect, the position of the liquid level inside the sample container is estimated based on the mass of the sample container, and the pipette is inserted into the liquid based on that position. This mechanism controls the amount of liquid that adheres to the tip of the pipette and drips out. As a result, dripping in the dispensing device can be suppressed. [Effects of the Invention]
[0007] According to one aspect of this disclosure, it is possible to suppress liquid dripping in a dispensing device. [Brief explanation of the drawing]
[0008] [Figure 1] This figure shows an example of the configuration of a dispensing device. [Figure 2] This flowchart shows an example of how a dispensing device works. [Modes for carrying out the invention]
[0009] The embodiments of this disclosure will be described in detail below with reference to the attached drawings. In the description of the drawings, the same or equivalent elements will be denoted by the same reference numeral, and redundant descriptions will be omitted.
[0010] The dispensing device 1 according to this embodiment is a device that transfers (dispenses) the liquid in the sample container 81 into the measuring container 82. The dispensing device 1 may be part of an analytical device that analyzes the liquid. The sample container 81 is a device that contains the liquid, and the measuring container 82 is a device that receives the liquid from the sample container 81. The measuring container 82 may be a container with sides, or it may be a plate without sides, such as a microscope slide.
[0011] Figure 1 shows an example of the configuration of the dispensing device 1. In this example, the dispensing device 1 comprises a first balance 11, a second balance 12, a pipette 20, a drive mechanism 30 for the pipette 20, a drain port 40, a processor 50, and a memory 60. The sample container 81 is placed on the first balance 11 from the tray 90, either automatically or manually. The measurement container 82 is placed on the second balance 12, either automatically or manually. After the dispensing process is complete, the sample container 81 is returned to the tray 90, either automatically or manually, and the measurement container 82 is transported to a designated analyzer, either automatically or manually, for liquid analysis. The liquid to be analyzed may be an oil such as lubricating oil, or an aqueous solution.
[0012] The first balance 11 is a device for measuring the mass of the sample container 81. In one example, the first balance 11 has the accuracy to measure the change in mass of a single drop of liquid. The first balance 11 is connected to the processor 50 and outputs the measured value to the processor 50.
[0013] The second balance 12 is a device for measuring the mass of the measuring container 82. In one example, the second balance 12 has the accuracy to measure the change in mass of a single drop of liquid. The second balance 12 is connected to the processor 50 and outputs the measured value to the processor 50.
[0014] The pipette 20 is a device that draws liquid from the sample container 81 and dispenses that liquid into the measurement container 82. The pipette 20 may be, for example, a volumetric pipette or a volumetric pipette.
[0015] The drive mechanism 30 is a device that holds and manipulates the pipette 20. The drive mechanism 30 is connected to the processor 50 and operates according to control signals from the processor 50. In one example, the drive mechanism 30 moves the pipette 20 between the sample container 81 and the measurement container 82, and inserts and removes the pipette 20 into and out of the sample container 81 and the measurement container 82, respectively.
[0016] The drain port 40 is a component for receiving any liquid remaining in the pipette 20 as drainage. The drain port 40 is located on the movement path of the pipette 20 between the first balance 11 and the second balance 12.
[0017] The processor 50 is a computing device that controls the pipette 20. Examples of the processor 50 include a CPU (Central Processing Unit) and a GPU (Graphics Processing Unit). In one example, the processor 50 has a mass acquisition unit 51, a determination unit 52, and a control unit 53. The mass acquisition unit 51 is a functional module that acquires the mass of the sample container 81 from the first balance 11 and the mass of the measuring container 82 from the second balance 12. The determination unit 52 is a functional module that performs determinations related to various controls of the pipette 20 based on the acquired masses. The control unit 53 is a functional module that controls the pipette 20 based on the determination results.
[0018] Memory 60 is a device that stores various data used to control the dispensing device 1. Memory 60 is composed of a non-volatile storage medium such as a hard disk or flash memory. In one example, memory 60 pre-stores reference information regarding the sample container 81 and the liquid. For example, the reference information may include the three-dimensional dimensions of the sample container 81, the density of the liquid, the mass of the sample container 81 when it is full of liquid (hereinafter also referred to as "maximum mass"), and the position of the liquid level inside the sample container 81 when it is full (hereinafter also referred to as "highest position"). Alternatively, the reference information may include a correspondence table or function that defines the relationship between the mass of the sample container 81 and the position of the liquid level. Memory 60 may store reference information for each type of sample container 81 and liquid that can be processed by the dispensing device 1.
[0019] The operation of the dispensing device 1 will be explained with reference to Figure 2. Figure 2 is a flowchart showing an example of the operation of the dispensing device 1 as the processing flow S1.
[0020] In step S11, the mass acquisition unit 51 acquires the mass of the specimen container 81 measured by the first scale 11.
[0021] In step S12, the determination unit 52 estimates the position of the liquid level in the specimen container 81 based on that mass. In one example, the determination unit 52 estimates the position of the liquid level based on the acquired mass and the reference information in the memory 60. For example, the determination unit 52 calculates a mass difference, which is the difference between the maximum mass and the acquired mass, and calculates the amount of decrease in the liquid level from the highest position based on that mass difference, the density of the liquid, and the three-dimensional dimensions of the specimen container 81. Then, the determination unit 52 calculates the position of the liquid level based on that highest position and the amount of decrease. Alternatively, the determination unit 52 may directly obtain the position of the liquid level from the measured mass using a correspondence table or a function.
[0022] In step S13, the determination unit 52 determines the insertion length of the pipette 20 with respect to the specimen container 81 based on the estimated position of the liquid level. The "insertion length of the pipette with respect to the specimen container" refers to the distance from the opening of the specimen container to the tip of the pipette inserted into the specimen container. The immersion length, which is the length of the pipette that enters the liquid, is preset based on the dispensing amount of the liquid. For example, that immersion length is set so that a predetermined dispensing amount of liquid can be aspirated while minimizing the entry of the pipette into the liquid. In one example, the immersion length is a fixed value, but the insertion length changes according to the position of the liquid level. The determination unit 52 calculates the distance from the opening of the specimen container 81 to the liquid level based on the three-dimensional dimensions of the specimen container 81, and calculates the sum of that distance and the immersion length as the insertion length.
[0023] In step S14, the control unit 53 controls the drive mechanism 30 to insert the pipette 20 into the specimen container 81 based on the determined insertion length of the pipette 20. The drive mechanism 30 moves the pipette 20 onto the opening of the specimen container 81, lowers the pipette 20 toward that opening, and inserts the portion of the pipette corresponding to the insertion length into the specimen container 81. The "portion of the pipette corresponding to the insertion length" refers to the range of the insertion length with the tip of the pipette as the starting point. By this control, the tip of the pipette 20 enters the liquid by the amount of the immersion length.
[0024] In step S15, the pipette 20 draws a predetermined amount of liquid from the sample container 81. After the pipette 20 has drawn the predetermined amount of liquid, the drive mechanism 30 raises the pipette 20 and withdraws it from the sample container 81.
[0025] In step S16, the mass acquisition unit 51 acquires the history of the measurement values of the first balance 11. The mass acquisition unit 51 acquires the history from the moment the drive mechanism 30 pulls the pipette 20 out of the sample container 81.
[0026] In step S17, the determination unit 52 determines the timing to move the pipette 20 to the measuring container 82 based on the history. In one example, the determination unit 52 refers to the history and determines to move the pipette 20 to the measuring container 82 if the measured value has not changed for a predetermined time (e.g., a few seconds). A change in the measured value means that the mass of the sample container 81 has changed because liquid has dripped from the pipette 20 into the sample container 81. If the measured value does not change for a predetermined time, it means that no liquid has dripped from the pipette 20, and it can be expected that no liquid will drip from the pipette 20 even if the pipette 20 is moved.
[0027] In step S18, the drive mechanism 30 moves the pipette 20 onto the opening of the measuring container 82 at a predetermined timing. In this operation, the drive mechanism 30 pauses the pipette 20 for a predetermined time at a transit point above the drain port 40 before moving the pipette 20 onto the measuring container 82. While the pipette 20 is paused at that transit point, liquid may drip from the pipette 20 and be collected through the drain port 40.
[0028] In step S19, the pipette 20 dispenses liquid into the measuring container 82. The drive mechanism 30 lowers the pipette 20 toward the opening of the measuring container 82, inserting the tip of the pipette 20 into the measuring container 82, and the pipette 20 dispenses liquid into the measuring container 82. Subsequently, the drive mechanism 30 raises the pipette 20 and withdraws it from the measuring container 82.
[0029] In step S20, the mass acquisition unit 51 acquires the history of the measurement values of the second balance 12. The mass acquisition unit 51 acquires the history from the moment the drive mechanism 30 pulls the pipette 20 out of the measuring container 82.
[0030] In step S21, the determination unit 52 determines the timing to move the pipette 20 to the sample container 81 based on the history. In one example, the determination unit 52 refers to the history and determines to move the pipette 20 to the sample container 81 if the measured value does not change within a predetermined time (e.g., a few seconds). A change in the measured value means that the mass of the measuring container 82 has changed because liquid has dripped from the pipette 20 into the measuring container 82. Similar to step S17, if the measured value does not change within a predetermined time, it is expected that no liquid will drip from the pipette 20 even if the pipette 20 is moved.
[0031] In step S22, the drive mechanism 30 moves the pipette 20 onto the opening of the sample container 81 at a predetermined timing. In this operation, the drive mechanism 30 pauses the pipette 20 for a predetermined time at a transit point above the drain port 40 before moving the pipette 20 onto the sample container 81. Similar to step S18, while the pipette 20 is paused at that transit point, liquid may drip from the pipette 20 and be collected through the drain port 40.
[0032] The dispensing device 1 may repeat the processing flow S1 to dispense a predetermined amount of liquid from the sample container 81 to the measurement container 82. The dispensing device 1 may continuously dispense a predetermined amount of liquid from multiple sample containers 81 to multiple measurement containers 82. The dispensing device 1 may dispense a predetermined amount of liquid from one sample container 81 to multiple measurement containers 82.
[0033] [Differentiation] The present disclosure has been described in detail above based on its embodiments. However, the present disclosure is not limited to the embodiments described above. The present disclosure can be modified in various ways without departing from its essence.
[0034] In the above example, the determination unit 52 estimates the liquid surface position based on the mass difference, which is the difference between the maximum mass and the acquired mass, the density of the liquid, and the three-dimensional dimensions of the sample container 81. However, the determination unit 52 may also estimate the liquid surface position by so-called tare. In this case, the reference information in the memory 60 may include the three-dimensional dimensions of the sample container 81, the density of the liquid, and the mass of the empty sample container 81 (hereinafter also referred to as "container mass"). The determination unit 52 may calculate the mass difference, which is the difference between the acquired mass and the container mass, and estimate the liquid surface position based on that mass difference, the density of the liquid, and the three-dimensional dimensions of the sample container 81.
[0035] In the example above, the mass of the measuring container 82 is also measured. However, the measurement of the mass of the container that receives the dispensed liquid may be omitted, and accordingly, the determination of the timing for moving the pipette from the container may also be omitted.
[0036] In the example above, the timing of moving the pipette 20 from the sample container 81 is determined based on the history of the first balance's measurements. However, this timing determination may be omitted. That is, the processor may move the pipette to the desired location immediately after it has drawn the liquid from the sample container.
[0037] In the example above, the timing for moving the pipette 20 from the sample container 81 is determined based on the history of the first balance's measurement; however, the timing may be determined based on other information. For example, the determination unit 52 may determine the timing based on a correspondence table between liquid type and timing. The correspondence table may be prepared in advance, or it may be based on information compiled from timings determined in past dispensing operations. The reference information may be a machine learning model trained using information compiled from timings determined in past dispensing operations as training data.
[0038] In the example above, after the tip of the pipette 20 is inserted into the liquid by the specified insertion length (step S14), the pipette 20 draws a predetermined amount of liquid from the sample container 81 (step S15). However, the control unit 53 may also insert the tip of the pipette 20 slightly into the liquid, gradually lower the pipette 20 while drawing liquid from the sample container 81, and finally lower the pipette 20 to the determined insertion length.
[0039] The dispensing device 1 may repeat the process in steps S14 to S22 based on the determined insertion length. The insertion length of the pipette 20 into the measuring container 82 during repetition may be the sum of the previous insertion length and the immersion length.
[0040] The dispensing device does not need to have a drain port. Accordingly, the procedure of temporarily pausing the pipette over the drain port may also be omitted.
[0041] The processing steps of the method executed by the processor are not limited to the examples in the above embodiments. For example, some of the steps (processes) described above may be omitted, or each step may be executed in a different order. Also, any two or more of the steps described above may be combined, or some of the steps may be modified or deleted. Alternatively, other steps may be executed in addition to each of the above steps.
[0042] When comparing the relative magnitudes of two numbers in a computer system or within a computer, either the two criteria "greater than or equal to" and "greater than" may be used, or either the two criteria "less than or equal to" and "less than" may be used.
[0043] The dispensing apparatus relating to this disclosure may be defined as follows: (Item 1) A scale for measuring the mass of a sample container holding liquid, A pipette for aspirating and dispensing the liquid in the sample container, A processor that estimates the position of the liquid level in the sample container based on the measured mass, and controls the insertion of the pipette into the liquid based on the estimated position, A dispensing device equipped with the following features. (Item 2) The aforementioned processor, Based on the estimated position, the insertion length of the pipette into the sample container is determined. The portion of the pipette corresponding to the insertion length is inserted into the sample container. The dispensing device described in item 1. (Item 3) The aforementioned processor, Based on the history of mass measured after the pipette aspirates the liquid, the timing for moving the pipette from the sample container to the measuring container containing the liquid dispensed from the pipette is determined. At the aforementioned timing, the pipette is moved away from the sample container. A dispensing device as described in item 1 or 2. (Item 4) The pipette further comprises a drain port located on the movement path between the sample container and the measurement container, The processor pauses the pipette that has drawn in or dispensed the liquid over the drain port for a predetermined time. The dispensing device described in item 3. (Item 5) The system further includes an additional scale for measuring the mass of the measuring container, The aforementioned processor, Based on the history of mass measured by the additional scale after the pipette has dispensed the liquid, the timing for moving the pipette from the measuring container to the sample container is determined. At the aforementioned timing, the pipette is moved away from the measuring container. Dispensing device as described in item 3 or 4. (Item 6) A step of measuring the mass of the sample container that holds the liquid, The steps include preparing a pipette for aspirating and dispensing the liquid in the sample container, The processor estimates the position of the liquid level in the sample container based on the measured mass, and controls the insertion of the pipette into the liquid based on the estimated position. The pipette performs the steps of drawing the liquid from the sample container and discharging the liquid into the measuring container, A dispensing method comprising:
[0044] According to items 1 and 6, the position of the liquid level in the sample container is estimated based on the mass of the sample container, and the pipette is inserted into the liquid based on that position. This mechanism controls the amount of liquid that adheres to the tip of the pipette and drips out. As a result, dripping in the dispensing device can be suppressed. For example, if the liquid is an oil such as lubricant, the oil has a viscosity above a certain level, so it may drip onto the floor of the dispensing device at an unintended time while the pipette is being controlled. In addition, removing the dripped oil is troublesome. By adopting the dispensing device according to this disclosure, oil dripping is suppressed, so oil can be dispensed while eliminating or reducing the burden of troublesome cleaning.
[0045] One possible method involves photographing the sample container from the side with a camera and determining the liquid level from the resulting image (photograph or video). However, this method may fail to accurately determine the liquid level from the image due to factors such as the liquid's transparency and the shooting environment. According to item 1, the liquid level can be estimated from the mass of the sample container without photographing it, and the insertion of a pipette into the liquid can be controlled based on that position.
[0046] According to item 2, based on the estimated liquid level, the range of the pipette to be inserted into the sample container is determined as the insertion length, and the pipette is inserted into the sample container according to that insertion length. By determining the insertion length in this way, the pipette can be accurately inserted into the sample container.
[0047] According to item 3, the timing of pipette movement is determined based on the change in mass of the sample container, which indicates the dripping of liquid from the pipette. Therefore, dripping during pipette movement can be suppressed.
[0048] According to item 4, the pipette pauses at the drain port, allowing any liquid that might drip from the pipette during movement to fall off at that port. This mechanism prevents liquid from dripping into unintended locations along the pipette's path. As a result, dripping in the analytical instrument can be suppressed.
[0049] According to item 5, the timing of pipette movement is determined based on the change in mass of the measuring container, which indicates the dripping of liquid from the pipette. Therefore, dripping during pipette movement can be suppressed.
[0050] 1…Dispensing device, 11…First balance, 12…Second balance, 20…Pipette, 30…Drive unit, 40…Drain port, 50…Processor, 51…Mass acquisition unit, 52…Determination unit, 53…Control unit, 60…Memory, 81…Sample container, 82…Measurement container, 90…Tray.
Claims
1. A scale for measuring the mass of a sample container holding liquid, A pipette for aspirating and dispensing the liquid in the sample container, A processor that estimates the position of the liquid level in the sample container based on the measured mass, and controls the insertion of the pipette into the liquid based on the estimated position, Equipped with, The aforementioned processor, Based on the history of mass measured after the pipette aspirates the liquid, the timing for moving the pipette from the sample container to the measuring container containing the liquid dispensed from the pipette is determined. At the aforementioned timing, the pipette is moved away from the sample container. Dispensing device.
2. The aforementioned processor, Based on the estimated position, the insertion length of the pipette into the sample container is determined. The portion of the pipette corresponding to the insertion length is inserted into the sample container. The dispensing apparatus according to claim 1.
3. The pipette further comprises a drain port located on the movement path between the sample container and the measurement container, The processor pauses the pipette that has drawn in or dispensed the liquid over the drain port for a predetermined time. The dispensing apparatus according to claim 1 or 2.
4. The system further includes an additional scale for measuring the mass of the measuring container, The aforementioned processor, Based on the history of mass measured by the additional balance after the pipette has dispensed the liquid, the timing for moving the pipette from the measuring container to the sample container is determined. At the aforementioned timing, the pipette is moved away from the measuring container. The dispensing apparatus according to claim 1 or 2.
5. A step of measuring the mass of the sample container that holds the liquid, The steps include preparing a pipette for aspirating and dispensing the liquid in the sample container, The processor estimates the position of the liquid level in the sample container based on the measured mass, and controls the insertion of the pipette into the liquid based on the estimated position. The pipette performs the step of drawing up the liquid in the sample container, The processor determines the timing for moving the pipette from the sample container to a measuring container containing the liquid dispensed from the pipette, based on the history of mass measured after the pipette has drawn up the liquid. The processor moves the pipette away from the sample container at the timing, The pipette dispenses the aspirated liquid into the measuring container, A dispensing method comprising the following features.