Pipette device

Abstract

To provide a pipette device which has high dispensation accuracy in a wide dispensation range.SOLUTION: A pipette device includes: a first plunger including a first syringe part, and a first piston located in the first syringe part; a second plunger including a second syringe part, and a second piston located in the second syringe part; a drive mechanism which is attached to the first plunger and the second plunger, and moves the first piston and the second piston relatively to the first syringe part and the second syringe part, respectively; a flow channel which is connected to the first syringe part and the second syringe part, and is so configured that a pipette tip is attached to an opening end thereof; and a first changeover part which performs changeover between a first state that the first syringe part is communicated with the flow channel and a second state that the first syringe part is opened to atmosphere without communicating with the flow channel.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a pipetting device, and more particularly, to a pipetting device for aspirating and dispensing samples. [Background technology]

[0002] A pipette device is used to measure and dispense liquid samples. A pipette device has a structure that allows air to be let in and out of a cylinder by moving a piston up and down inside a syringe, and sucks in and expels liquid by letting air in and out.

[0003] Known pipette devices include a manual pipette device disclosed in JP 2023-015210 A (Patent Document 1) and an electric pipette device disclosed in JP 2020-138198 A (Patent Document 2). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2023-015210 A [Patent Document 2] JP 2020-138198 A Summary of the Invention [Problem to be solved by the invention]

[0005] In both manual and electronic pipette devices, the piston moves up and down in the syringe to increase or decrease the air volume in the syringe, thereby aspirating or dispensing the sample. In other words, the amount of dispensed is calculated by multiplying the cross-sectional area of ​​the cylinder by the amount of movement of the piston.

[0006] For example, consider the case where a single pipette device is used to dispense 10 μL and the case where a single pipette device is used to dispense 100 μL. If the positioning error of the piston in the single pipette device is assumed to be the same, the relative error obtained by dividing the positioning error by the amount of movement will be larger for 10 μL, which is a smaller amount of dispensed, than for 100 μL. For this reason, it has been necessary to use multiple types of pipette devices according to the amount of dispensed.

[0007] An object of the present disclosure is to provide a pipette device that has high dispensing accuracy over a wide dispensing range. [Means for solving the problem]

[0008] The pipette device of the present disclosure is a pipette device for aspirating and discharging a liquid sample. The pipette device includes a first plunger including a first syringe part and a first piston arranged inside the first syringe part, a second plunger including a second syringe part and a second piston arranged inside the second syringe part, a drive mechanism attached to the first plunger and the second plunger and moving the first piston and the second piston relative to the first syringe part and the second syringe part, respectively, a flow path connected to the first syringe part and the second syringe part and configured to allow a pipette tip to be attached to an open end, and a first switching part that switches between a first state in which the first syringe part is connected to the flow path and a second state in which the first syringe part is opened to the atmosphere without being connected to the flow path. Effect of the Invention

[0009] According to the present disclosure, by switching between a first state in which the first syringe part is connected to a flow path to which a pipette tip is attached and a second state in which the first syringe part is not connected to the flow path and is open to the atmosphere by a first switching part, it is possible to change the amount of aspirated liquid relative to the amount of movement of the piston between the first state and the second state. This makes it possible to provide a pipette device with high dispensing accuracy over a wide range of dispensing. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram showing an overall configuration of a pipette device. [Diagram 2] 4 is a flowchart of a process executed by a control device. [Diagram 3] FIG. 13 is a diagram showing the aspirating operation when a dispensing amount equal to or less than a first threshold is set. [Figure 4] 13A and 13B are diagrams illustrating the aspirating operation when a dispensing amount is set to be greater than a first threshold value and equal to or less than a second threshold value. [Diagram 5] FIG. 13 is a schematic diagram showing an overall configuration of a pipette device according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are designated by the same reference characters and their description will not be repeated.

[0012] [Overall configuration of pipette device] 1 is a schematic diagram showing the overall configuration of a pipette device 100. The pipette device 100 includes plungers 10 and 20, a drive mechanism 30 for the plungers 10 and 20, switching units 40 and 50, a flow channel 60, and a control device 80.

[0013] Plunger 10 includes a syringe portion 12 and a piston 14 movably disposed within syringe portion 12. Similarly, plunger 20 includes a syringe portion 22 and a piston 24 movably disposed within syringe portion 22. Piston 14 and piston 24 are each attached to a connection portion 32 of a drive mechanism 30.

[0014] In the following, the direction of movement of pistons 14 and 24 is defined as the Z-axis direction, and the plane perpendicular to the Z-axis is defined as the XY plane. In the following, the positive direction of the Z-axis is defined as "up" and the negative direction of the Z-axis is defined as "down." Although it is preferable that pipette device 100 is used with pistons 14, 24 arranged to move in the vertical direction, it may also be used with pistons 14, 24 arranged to move obliquely with respect to the vertical direction.

[0015] The drive mechanism 30 includes a connection part 32 to which the pistons 14 and 24 are attached, and a drive part 34 for moving the connection part 32 in the Z-axis direction. The mechanism of the drive part 34 for moving the connection part 32 in the Z-axis direction is not particularly limited. The drive part 34 includes, for example, a pinion, a linear rack that can be engaged with the pinion, and a motor that rotates the pinion. The connection part 32 is attached to the rack, and the drive part 34 moves the rack by driving the motor to rotate the pinion, so that the connection part 32 moves in the Z-axis direction and the pistons 14 and 24 also move in the Z-axis direction. The drive part 34 can change the moving direction of the rack by changing the rotation direction of the motor, and as a result, the moving direction of the pistons 14 and 24 can also be changed.

[0016] In this embodiment, the pistons 14 and 24 are attached to one connection portion 32 (drive mechanism 30), so that the pistons 14 and 24 move together, rather than moving separately.

[0017] In this embodiment, when comparing the cross-sectional areas A1 and A2 when syringe portions 12 and 22 are cut perpendicular to the Z axis, the cross-sectional area A1 of syringe portion 12 is smaller than the cross-sectional area A2 of syringe portion 22. Therefore, the amount of change in the air volume in syringe portion 12 when pistons 14 and 24 are moved is smaller than the amount of change in the air volume in syringe portion 22.

[0018] A flow path 60 configured to allow a pipette tip to be attached to an open end 65 is connected to the syringe portion 12 and the syringe portion 22. The flow path 60 includes a first flow path 61 including an open end 65, and a second flow path 62 and a third flow path 63 branching in two directions from the first flow path 61. The second flow path 62 and the third flow path 63 are connected to the syringe portions 12 and 22, respectively.

[0019] A switching unit 40 is provided between the syringe portion 12 and the second flow path 62. The syringe portion 12 is connected to an open portion 72, the end of which is open to the atmosphere, and the second flow path 62 via the switching unit 40. The switching unit 40 switches the connection destination of the syringe portion 12 between the open portion 72 and the second flow path 62. The syringe portion 12 is connected to the second flow path 62, resulting in a first state in which the syringe portion 12 is connected to the flow path 60. On the other hand, the syringe portion 12 is connected to the open portion 72, resulting in a second state in which the syringe portion 12 is open to the atmosphere without being connected to the flow path 60. That is, the switching unit 40 switches between the first state and the second state.

[0020] A switching unit 50 is provided between the syringe portion 22 and the third flow path 63. The syringe portion 22 is connected to an open portion 74, the end of which is open to the atmosphere, and the third flow path 63 via the switching unit 50. The switching unit 50 switches the connection destination of the syringe portion 22 between the open portion 74 and the third flow path 63. The syringe portion 22 is connected to the third flow path 63, resulting in a third state in which the syringe portion 22 is connected to the flow path 60. On the other hand, the syringe portion 22 is connected to the open portion 74, resulting in a fourth state in which the syringe portion 22 is open to the atmosphere without being connected to the flow path 60. That is, the switching unit 50 switches between the third state and the fourth state.

[0021] The switching units 40, 50 include a valve for switching the connection destination of the syringe units 12, 22, and a drive unit for driving the valve. The valve is not particularly limited, and can be arbitrarily selected by a person skilled in the art, for example, a diaphragm valve, a rotary valve, etc. The drive unit is not particularly limited, and can be arbitrarily selected by a person skilled in the art, for example, a solenoid, a motor, etc. depending on the type of valve.

[0022] A first attachment portion 66 having an outer periphery of a first diameter C1 and a second attachment portion 67 having an outer periphery of a second diameter C2 smaller than the first diameter C1 are formed at the tip portion of the flow channel 60 on the side of the open end 65. The second attachment portion 67 is formed closer to the open end 65 than the first attachment portion 66. Therefore, the pipette device 100 is configured to be capable of attaching two types of pipette tips: a pipette tip whose inner diameter is the first diameter C1, and a pipette tip whose inner diameter is the second diameter C2.

[0023] The control device 80 controls the entire pipette device 100. The pipette device 100 includes a processor 82 and a memory 84. The processor 82 is, for example, a central processing unit (CPU) and is an arithmetic circuit that executes predetermined arithmetic processing described in a program stored in the memory 84. The memory 84 includes a non-volatile memory or a volatile memory such as a read only memory (ROM) or a random access memory (RAM), and / or a large-capacity storage device such as a hard disc drive (HDD) or a solid state drive (SSD).

[0024] The processor 82 reads out the programs and data stored in the memory 84, and controls each part (e.g., the drive mechanism 30, the switching parts 40, 50, etc.) that make up the pipette device 100, thereby controlling the pipette device 100 to perform a dispensing operation to dispense a predetermined amount of liquid sample.

[0025] An input device 86 is connected to the control device 80. The input device 86 is a button or the like for receiving input of the dispensing amount and input of starting and stopping dispensing, and receives input of user operations. The control device 80 controls the pipette device 100 in accordance with the user operations received by the input device 86.

[0026] The control device 80 may be connected to a processing device based on a personal computer. For example, the pipette device 100 may be attached to a fully automatic testing device. In this case, the processing device controls each device constituting the testing device including the pipette device 100 according to the experimental conditions set by the user or the like. The control device 80 of the pipette device 100 may control the entire pipette device 100 according to the control signal indicating the dispensing amount, dispensing timing, etc., transmitted by the processing device.

[0027] [Dispensing method] Fig. 2 is a flowchart of the process performed by the control device. Each process step (hereinafter abbreviated as "S") shown in Fig. 2 is realized by the processor 82 executing a program stored in the memory 84. The process shown in Fig. 2 is started, for example, when the input device 86 receives a dispensing amount. It is also assumed that, when the process shown in Fig. 2 is started, the lower ends of the pistons 14, 24 are located at the initial positions at the start of suction.

[0028] In S101, the processor 82 determines whether the received dispensing amount X is equal to or less than the first threshold a1. If the processor 82 determines that the dispensing amount X is equal to or less than the first threshold a1 (YES in S101), the processor 82 advances the process to S102, executes the processes of S102 to S104, and starts the processes of S120 and after. On the other hand, if the processor 82 determines that the dispensing amount X is greater than the first threshold a1 (NO in S101), the processor 82 advances the process to S105.

[0029] The first threshold value a1 corresponds to a volume that can be measured using only the plunger 10, and is determined in advance according to the volume of the syringe portion 12 and the range of movement of the piston 14. As an example, the first threshold value a1 is calculated by multiplying the maximum amount of movement of the piston 14 by the cross-sectional area A1 of the syringe portion 12.

[0030] In S102, processor 82 determines the movement amount of piston 14 based on dispensing amount X. For example, processor 82 determines the movement amount by dividing dispensing amount X by cross-sectional area A1. Processor 82 may also determine the movement amount taking into consideration the processing error of syringe portion 12 and the accuracy of drive mechanism 30. Processor 82 may also correct the movement amount depending on the viscosity of the target liquid.

[0031] In S103, processor 82 controls switching unit 40 to enter a first state in which syringe portion 12 is connected to flow path 60. That is, processor 82 controls switching unit 40 to connect syringe portion 12 to second flow path 62 without connecting syringe portion 12 to open portion 72.

[0032] In S104, processor 82 controls switching unit 50 to enter a fourth state in which syringe portion 22 is open to the atmosphere without communicating syringe portion 22 with flow path 60. That is, processor 82 controls switching unit 50 to connect syringe portion 22 to release portion 74 without connecting syringe portion 22 to third flow path 63.

[0033] If the dispensing amount X is greater than the first threshold a1 (NO in S101), the processor 82 determines in S105 whether the received dispensing amount X is equal to or less than the second threshold a2. If the dispensing amount X is equal to or less than the second threshold a2 (YES in S105), the processor 82 advances the process to S106, executes the processes of S106 to S108, and starts the processes of S120 and after. On the other hand, if the dispensing amount X is greater than the second threshold a2 (NO in S105), the processor 82 advances the process to S109.

[0034] The second threshold a2 corresponds to a volume that can be measured using only the plunger 20, and is determined in advance according to the volume of the syringe portion 22 and the range of movement of the piston 24. As an example, the second threshold a2 is calculated by multiplying the maximum amount of movement of the piston 24 by the cross-sectional area A2 of the syringe portion 22.

[0035] In S106, processor 82 determines the movement amount of piston 24 based on dispensing amount X. For example, processor 82 determines the movement amount by dividing dispensing amount X by cross-sectional area A2. Processor 82 may also determine the movement amount taking into consideration the processing error of syringe portion 22 and the accuracy of drive mechanism 30. Processor 82 may also correct the movement amount depending on the viscosity of the target liquid.

[0036] In S107, processor 82 controls switching unit 40 to set syringe portion 12 to the second state in which syringe portion 12 is open to the atmosphere without communicating syringe portion 12 with flow path 60. That is, processor 82 controls switching unit 40 to connect syringe portion 12 to release portion 72 without connecting syringe portion 12 to second flow path 62.

[0037] In S108, processor 82 controls switching unit 50 to enter a third state in which syringe portion 22 is connected to flow path 60. That is, processor 82 controls switching unit 50 to connect syringe portion 22 to third flow path 63 without connecting syringe portion 22 to open portion 74.

[0038] If the dispensing amount X is greater than the second threshold a2 (NO in S105), the processor 82 determines in S109 whether the received dispensing amount X is equal to or less than the third threshold a3. If the dispensing amount X is equal to or less than the third threshold a3 (YES in S109), the processor 82 advances the process to S110, executes the processes of S110 to S112, and starts the processes of S120 and after. On the other hand, if the dispensing amount X is greater than the third threshold a3 (NO in S109), the processor 82 ends the process.

[0039] The third threshold a3 corresponds to a volume that can be measured using both plungers 10 and 20, and is determined in advance according to the volumes of syringe portions 12 and 22 and the ranges of movement of pistons 14 and 24. As an example, the third threshold a3 is calculated by multiplying the maximum movement amount of pistons 14 and 24 by a total cross-sectional area A3 (=A1+A2) obtained by adding up the cross-sectional area A1 of syringe portion 12 and the cross-sectional area A2 of syringe portion 22.

[0040] In S110, processor 82 determines the movement amount of pistons 14, 24 based on dispensing amount X. For example, processor 82 determines the movement amount by dividing dispensing amount X by total cross-sectional area A3. Processor 82 may also determine the movement amount taking into consideration the processing error of syringe portions 12, 22 and the accuracy of drive mechanism 30. Processor 82 may also correct the movement amount depending on the viscosity of the target liquid.

[0041] In S111, processor 82 controls switching unit 40 to enter a first state in which syringe portion 12 is connected to flow path 60. That is, processor 82 controls switching unit 40 to connect syringe portion 12 to second flow path 62 without connecting syringe portion 12 to open portion 72.

[0042] In S112, processor 82 controls switching unit 50 to enter a third state in which syringe portion 22 is connected to flow path 60. That is, processor 82 controls switching unit 50 to connect syringe portion 22 to third flow path 63 without connecting syringe portion 22 to open portion 74.

[0043] After executing the process of S104, S108, or S112, in S120, the processor 82 determines whether or not an instruction to start suction has been received, and puts the process on hold until the instruction to start suction is received. If the instruction to start suction has been received (YES in S120), the processor 82 advances the process to S121 and onward. For example, after the user attaches the pipette tip 200 (see FIGS. 3 and 4) to the first attachment portion 66 or the second attachment portion 67, the user inputs an instruction to start suction via the input device 86 at the timing when the pipette tip 200 is placed in the liquid sample.

[0044] Typically, when the dispensing amount X is set to be equal to or less than the first threshold a1, the user attaches a pipette tip 200a (see FIG. 3) having an inner diameter of a first diameter C1 to the second attachment portion 67. On the other hand, when the dispensing amount X is set to be greater than the first threshold a1, the user attaches a pipette tip 200b (see FIG. 4) having an inner diameter of a second diameter C2 to the first attachment portion 66. Note that, in this embodiment, the pipette device 100 is provided with two types of first attachment portion 66 and second attachment portion 67, but it may be provided with three or more attachment portions to which different types of pipette tips can be attached, or may be provided with only one attachment portion.

[0045] In S121, processor 82 controls drive mechanism 30 to move pistons 14, 24. At this time, processor 82 controls drive mechanism 30 to move pistons 14, 24 in the positive direction of the Z axis from the initial position by the movement amount determined in S102, S106, or S110. As a result, the air volume in syringe portion 12 and / or syringe portion 22 increases by the received dispensed amount X, and as a result, the liquid sample of dispensed amount X is aspirated into pipette tip ¥200.

[0046] In S122, the processor 82 determines whether or not a discharge start instruction has been received, and puts the process on hold until the start instruction is received. If the start instruction has been received (YES in S122), the processor 82 advances the process to S123. For example, after the user aspirates the liquid sample into the pipette tip 200, the user inputs a discharge start instruction via the input device 86 at the timing when the pipette tip 200 is placed in a sample container to which the liquid sample is to be dispensed.

[0047] In S123, the processor 82 controls the drive mechanism 30 to move the pistons 14, 24, and ends the process. At this time, the processor 82 may lower the pistons 14, 24 to the initial position, and then further lower them to a second position that is lower than the initial position. This allows the liquid sample in the pipette tip 200 to be completely discharged by air pressure.

[0048] As described above, the pipette device 100 changes the connection destination of the syringe parts 12, 22 according to the dispensing amount X, and performs the aspirating operation and the dispensing operation.

[0049] Fig. 3 is a diagram showing the suction operation when a dispensing amount equal to or less than a first threshold is set, and Fig. 4 is a diagram showing the suction operation when a dispensing amount greater than the first threshold and equal to or less than a second threshold is set.

[0050] As shown in FIG. 3, when a small dispensing amount equal to or less than the first threshold a1 is set, the flow path 60 to which the pipette tip 200a is attached is connected to the syringe unit 12 but is not connected to the syringe unit 22. When the suction operation is started and the pistons 14, 24 move from the initial position Pi by the determined movement amount M to the set position Ps, the volume of the flow path connected to the pipette tip 200a increases by a volume obtained by multiplying the movement amount M by the cross-sectional area A1 of the syringe unit 12. As a result, the liquid sample of the increased volume is sucked into the pipette tip 200. Meanwhile, since the syringe unit 22 is connected to the open portion 74, air of a volume obtained by multiplying the cross-sectional area A2 of the syringe unit 22 by the movement amount M is taken into the syringe unit 22 from the open portion 74.

[0051] As shown in FIG. 4, when a large dispensing amount is set that is greater than the first threshold a1 and equal to or less than the second threshold a2, the flow path 60 to which the pipette tip 200b is attached is connected to the syringe portion 22 but is not connected to the syringe portion 12. When the suction operation is started and the pistons 14, 24 move from the initial position Pi by the determined movement amount M to the set position Ps, the volume of the flow path connected to the pipette tip 200b increases by a volume obtained by multiplying the movement amount M by the cross-sectional area A2 of the syringe portion 22. As a result, the liquid sample of the increased volume is sucked into the pipette tip 200b. Meanwhile, since the syringe portion 12 is connected to the open portion 72, air of a volume obtained by multiplying the cross-sectional area A1 of the syringe portion 12 by the movement amount M is taken into the syringe portion 12 from the open portion 72.

[0052] A driving error of the driving mechanism 30 causes a positioning error m regardless of the amount of movement M. For example, when 10 μL and 100 μL are measured using the same syringe unit, the amount of movement M for 10 μL is smaller than that for 100 μL, but a positioning error m occurs in either case. Therefore, the relative error obtained by dividing the positioning error m by the amount of movement M is larger for 10 μL than for 100 μL, and the smaller amount of dispensed 10 μL is more susceptible to the influence of the positioning error m than the larger amount of dispensed 100 μL.

[0053] In this embodiment, when a small dispensing amount equal to or less than the first threshold a1 is set, the syringe portion 12 having a small cross-sectional area is connected to the flow path 60 to reduce the suction amount (volume change) relative to the movement amount and increase the movement amount M. This makes it possible to reduce the relative error obtained by dividing the positioning error m by the movement amount M, and allows dispensing with high accuracy even when the dispensing amount is small.

[0054] In this manner, in this embodiment, by providing two plungers 10, 20 and switching units 40, 50 for switching the connection state between the syringe units 12, 22 and the flow path 60, the amount of suction relative to the amount of movement can be changed according to the amount of dispensing, and high dispensing accuracy can be maintained over a wide range of dispensing.

[0055] In addition, in this embodiment, the pipette device 100 includes two types of plungers 10, 20 with different cross-sectional areas of the syringe portions 12, 22. This allows a wider variation in the amount of aspirated liquid relative to the amount of movement compared to when one type of plunger is used. This allows for an aspirating operation that is more in line with the amount of dispensing.

[0056] Furthermore, by providing switching unit 50 in addition to switching unit 40, multiple connection patterns can be realized compared to when only one switching unit is provided, so the range of variation in the suction volume relative to the movement amount can be expanded, and suction operation that is more in line with the dispensing volume can be realized.

[0057] Furthermore, the control device controls the switching units 40, 50 so that the connection state corresponds to the dispensing amount, thereby reducing the burden on the user.

[0058] Furthermore, the pipette device 100 is configured to be able to mount two types of pipette tips 200 (200a, 200b), so that the pipette tip 200 according to the amount of dispensing can be used, thereby further improving dispensing accuracy.

[0059] [Variations] Fig. 5 is a schematic diagram showing the overall configuration of a pipette device according to a modified example. Referring to Fig. 5, pipette device 100a differs from pipette device 100 in that it includes plunger 20a, drive mechanism 30a, and switch unit 40a instead of plunger 20, drive mechanism 30, and switch unit 40, and does not include switch unit 50, opening unit 74, and control device 80. Hereinafter, a description of the configuration common to pipette device 100 will be omitted.

[0060] The pipette device 100a is not automatically controlled by the control device 80 to perform dispensing operations as in the pipette device 100, but is manually used by a user. For example, the user operates the drive mechanism 30a to aspirate and dispense a liquid sample.

[0061] Incidentally, drive mechanism 30a is a push button, and further includes a spring (not shown) for returning connection part 32a of drive mechanism 30a to its original position and returning pistons 14, 24a to initial positions Pi. When connection part 32a of drive mechanism 30a is pressed, pistons 14, 24a are pushed down to predetermined positions in syringe parts 12, 22a, and when the force on connection part 32a is removed, pistons 14, 24a return to initial positions Pi due to the force of the spring.

[0062] The plunger 20a includes a syringe portion 22a and a piston 24a, similar to the plunger 20. The plunger 20a differs from the plunger 20 in that the cross-sectional area A2 of the syringe portion 22a is the same as the cross-sectional area A1 of the syringe portion 12.

[0063] Plunger 20a also differs from plunger 20a in that syringe portion 22a is directly connected to third flow path 63 without going through switching portion 50, and syringe portion 22a is not connected to open portion 74.

[0064] The switching unit 40a is different from the switching unit 40 in that it is manually operated. For example, the switching unit 40a is a three-way valve.

[0065] In the pipette device 100a, the syringe portion 22a and the flow path 60 are always connected, and the syringe portion 12 and the flow path 60 are connected or disconnected by the switching portion 40a.

[0066] When a suction operation is performed in a first state in which syringe portion 12 is connected to flow path 60, the suction amount (volume change) relative to the movement amount of pistons 14, 24a is proportional to the total cross-sectional area A3 obtained by adding cross-sectional area A1 and cross-sectional area A2 together. On the other hand, when a suction operation is performed in a second state in which syringe portion 12 is not connected to flow path 60 and is open to the atmosphere, the suction amount (volume change) relative to the movement amount of pistons 14, 24a is proportional to cross-sectional area A2.

[0067] As described above, the pipette device may be manually operated. The volumes of the plungers included in the pipette device may be the same. The pipette device may include at least one switching unit. By including multiple plungers and at least one switching unit, the pipette device can change the amount of suction relative to the amount of movement, and can maintain high dispensing accuracy over a wide range of dispensing.

[0068] [Other variations] In the above embodiment, the processor 82 proceeds with the process taking into consideration the upper limit of the dispensing amount that can be measured by the plunger. Note that, in order to further improve the dispensing accuracy, the processor 82 may proceed with the process by setting a lower limit of the dispensing amount that can be measured by the plunger so that the movement amount M of the pistons 14, 24 is equal to or greater than a predetermined value. As an example, the lower limit of the dispensing amount that can be measured by the plunger is predetermined according to the accuracy of the drive mechanism 30, is the minimum drive amount that can be realized by the drive mechanism 30, and is obtained by multiplying the minimum movement amount of the piston by the cross-sectional area of ​​the syringe.

[0069] 2, the processor 82 may determine whether the received dispensing amount X is less than a fourth threshold value, which is the lower limit of the dispensing amount that can be measured by the plunger 10, and terminate the process if the received dispensing amount X is less than the fourth threshold value. The fourth threshold value may be calculated, for example, by multiplying the minimum movement amount by the cross-sectional area A1 of the syringe portion 12.

[0070] 2, the processor 82 may determine whether the received dispensing amount X is less than a fifth threshold, which is the lower limit of the dispensing amount that can be measured by the plunger 20, and terminate the process if the received dispensing amount X is less than the fifth threshold. The fifth threshold is calculated, for example, by multiplying the minimum movement amount by the cross-sectional area A2 of the syringe portion 22.

[0071] 2, the processor 82 may determine whether the received dispensing amount X is less than a sixth threshold value, which is the lower limit of the dispensing amount that can be measured by the plungers 10 and 20, and terminate the process if the received dispensing amount X is less than the sixth threshold value. The sixth threshold value may be calculated, for example, by multiplying the minimum movement amount by the total cross-sectional area A3.

[0072] By setting a lower limit value for the dispensing amount in this manner, the movement amount M of the pistons 14, 24 can be made to be equal to or greater than a predetermined value, and dispensing accuracy can be further improved.

[0073] In the above embodiment, the processor 82 ends the process in S109 when the dispensing amount is greater than the third threshold a3. The processor 82 may control a display device or a notification unit such as an error lamp (not shown) to notify that the dispensing amount is outside the dispensing range.

[0074] In the above embodiment, the pipette tip 200 is attached and detached and the pipette device 100 is moved by a user. The pipette device 100 may be incorporated into an inspection system for fully automatic inspection. The inspection system includes the pipette device 100 and a drive device for moving the tip portion of the pipette device 100 provided with the first mounting portion 66 and the second mounting portion 67 relative to a rack in which pipette tips or samples are stored. The drive device may be a drive device that moves the pipette device 100 relative to the rack in the XYZ axial directions, or may be a robot arm that moves the pipette device 100 relative to the rack in the XYZ axial directions and can change the attitude of the pipette device 100 relative to the rack.

[0075] When incorporating the pipette device 100 into an inspection system, the pipette device 100 is fixed to a drive device or held by a robot arm or the like, and tasks such as changing or re-holding the pipette device 100 in order to change the type of pipette device 100 are time-consuming tasks.

[0076] The pipette device 100 according to the present embodiment can perform dispensing over a wide range while maintaining high dispensing accuracy with a single pipette device 100, thereby reducing the need for work such as replacing the drive device.

[0077] In the above embodiment, the pipette device 100 includes two plungers, but may include three or more plungers.

[0078] In the above embodiment, drive mechanism 30 moves pistons 14, 24. However, it is sufficient if drive mechanism 30 can move pistons 14, 24 relatively to syringe portions 12, 22, and drive mechanism 30 may move syringe portions 12, 22.

[0079] [Aspects] It will be understood by those skilled in the art that the above-described embodiments and modifications are specific examples of the following aspects.

[0080] (Item 1) A pipette device according to one embodiment is a pipette device for aspirating and discharging a liquid sample. The pipette device includes a first plunger including a first syringe part and a first piston disposed inside the first syringe part, a second plunger including a second syringe part and a second piston disposed inside the second syringe part, a drive mechanism attached to the first plunger and the second plunger and moving the first piston and the second piston relative to the first syringe part and the second syringe part, respectively, a flow path connected to the first syringe part and the second syringe part and configured to allow a pipette tip to be attached to an open end, and a first switching part that switches between a first state in which the first syringe part is connected to the flow path and a second state in which the first syringe part is opened to the atmosphere without being connected to the flow path.

[0081] According to the pipette device described in paragraph 1, the first switching unit switches between a first state in which the first syringe unit is connected to a flow path to which a pipette tip is attached, and a second state in which the first syringe unit is not connected to the flow path and is open to the atmosphere, thereby changing the amount of suction relative to the amount of movement of the piston between the first state and the second state. This ensures a sufficient amount of movement even when the amount of dispensing is small, and reduces the effect of positioning errors caused by drive errors of the drive mechanism. As a result, high dispensing accuracy can be maintained even when the amount of dispensing is small, and high dispensing accuracy can be maintained over a wide range of dispensing.

[0082] (Item 2) In the pipette device according to item 1, the cross-sectional area of ​​the first syringe portion is different from the cross-sectional area of ​​the second syringe portion.

[0083] According to the pipette device described in paragraph 2, the variation range of the aspirated amount relative to the movement amount can be widened, so that an aspirating operation more suited to the dispensed amount can be realized.

[0084] (Item 3) The pipette device according to item 1 or 2 further includes a second switching unit that switches between a third state in which the second syringe unit is connected to the flow path and a fourth state in which the second syringe unit is open to the atmosphere without being connected to the flow path.

[0085] The pipette device described in paragraph 3 can realize multiple connection patterns compared to a system equipped with only one switching unit, thereby making it possible to widen the range of variation in the amount of aspirated fluid relative to the amount of movement, thereby enabling an aspirating operation that is more in line with the amount of dispensing.

[0086] (4) The pipette device according to any one of paragraphs 1 to 3 further includes a control device that controls the drive mechanism and the first switching unit. The control device controls the first switching unit to be in the first state when the dispensing amount is smaller than the first amount, and controls the first switching unit to be in the second state when the dispensing amount is larger than the first amount.

[0087] According to the pipette device described in paragraph 4, the control device controls the switching unit to a connection state according to the dispensing amount, thereby reducing the burden on the user.

[0088] (Item 5) The pipette device described in item 1 further includes a second switching unit that switches between a third state in which the second syringe unit is connected to the flow path and a fourth state in which the second syringe unit is not connected to the flow path and is open to the atmosphere, and a control device that controls the drive mechanism, the first switching unit, and the second switching unit. The cross-sectional area of ​​the first syringe unit is smaller than the cross-sectional area of ​​the second syringe unit. The control device controls the first switching unit to the first state and the second switching unit to the fourth state when the dispensing amount is smaller than the first amount, and controls the first switching unit to the second state and the second switching unit to the third state when the dispensing amount is larger than the first amount.

[0089] According to the pipette device described in paragraph 5, the control device controls the switching unit to a connection state according to the dispensing amount, thereby reducing the burden on the user.

[0090] (Item 6) In the pipette device according to any one of items 1 to 5, a first attachment part having a first diameter and a second attachment part having a second diameter smaller than the first diameter are formed on the outer periphery of the tip part on the open end side of the flow channel. The second attachment part is formed closer to the open end than the first attachment part.

[0091] According to the pipette device described in paragraph 6, pipette tips with different inner diameters can be attached, so that a pipette tip according to the amount of dispensing can be used, and dispensing accuracy can be further improved.

[0092] The embodiments disclosed herein are also intended to be combined as appropriate within the scope of technical inconsistency. The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is indicated by the claims, not the description of the above embodiments, and is intended to include all modifications within the scope and meaning equivalent to the claims. [Explanation of symbols]

[0093] 10, 20, 20a plunger, 12, 22, 22a syringe portion, 14, 24, 24a piston, 30, 30a drive mechanism, 32, 32a connection portion, 34 drive portion, 40, 40a, 50 switching portion, 60 flow path, 61 first flow path, 62 second flow path, 63 third flow path, 65 opening end, 66 first mounting portion, 67 second mounting portion, 72, 74 opening portion, 80 control device, 82 processor, 84 memory, 86 input device, 100, 100a pipette device, 200, 200a, 200b pipette tip.

Claims

1. 1. A pipette device for aspirating and dispensing a liquid sample, comprising: a first plunger including a first syringe portion and a first piston disposed within the first syringe portion; a second plunger including a second syringe portion and a second piston disposed within the second syringe portion; a drive mechanism attached to the first plunger and the second plunger, for moving the first piston and the second piston relative to the first syringe portion and the second syringe portion, respectively; a flow channel connected to the first syringe portion and the second syringe portion and configured to allow a pipette tip to be attached to an open end; a first switching unit that switches between a first state in which the first syringe unit is connected to the flow path and a second state in which the first syringe unit is open to the atmosphere without being connected to the flow path.

2. 2. The pipette device of claim 1, wherein a cross-sectional area of ​​the first syringe portion and a cross-sectional area of ​​the second syringe portion are different.

3. 3. The pipette device according to claim 1, further comprising a second switching unit configured to switch between a third state in which the second syringe unit is connected to the flow path and a fourth state in which the second syringe unit is open to the atmosphere without being connected to the flow path.

4. A control device for controlling the drive mechanism and the first switching unit is further provided. The control device includes: When the dispensing amount is smaller than a first amount, the first switching unit is controlled to be in the first state; The pipette device according to claim 1 or 2, wherein the first switching unit is controlled to switch to the second state when the dispensing amount is greater than the first amount.

5. a second switching unit that switches between a third state in which the second syringe unit is connected to the flow path and a fourth state in which the second syringe unit is opened to the atmosphere without being connected to the flow path; a control device that controls the drive mechanism, the first switching unit, and the second switching unit, a cross-sectional area of ​​the first syringe portion is smaller than a cross-sectional area of ​​the second syringe portion; The control device includes: When the dispensing amount is smaller than a first amount, the first switching unit is controlled to be in the first state, and the second switching unit is controlled to be in the fourth state; The pipette device according to claim 1 , wherein when the dispensing amount is greater than the first amount, the pipette device controls the first switching unit to enter the second state and controls the second switching unit to enter the third state.

6. a first attachment portion having a first diameter on an outer periphery of a tip portion on the opening end side of the flow path, and a second attachment portion having a second diameter on the outer periphery that is smaller than the first diameter, The pipette device according to claim 1 , wherein the second attachment portion is formed closer to the opening end than the first attachment portion.

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