Liquid path system and automatic needle changing structure for micromanipulation

Abstract

The invention discloses a liquid path system and an automatic needle changing structure for micromanipulation, and relates to the technical field of micromanipulation. The liquid suction and spitting structure aims to solve the problem that gas in an air cavity of an existing liquid suction and spitting structure is prone to being compressed, and the deviation between liquid relief precision and expectation is too large. The liquid path system comprises a liquid driving unit, the liquid driving unit is detachably connected with a liquid inlet of a micromanipulation needle of a micromanipulation automatic needle changing unit, and incompressible liquid is injected into the micromanipulation needle, so that a continuous liquid column without an air cavity is formed between the liquid driving unit and the micromanipulation needle; liquid is used as a medium to suck and spit cells or tissue fragments, and perfusion or cleaning is carried out; the automatic needle changing structure comprises a liquid path system and a micromanipulation automatic needle changing unit, and the liquid path system is connected with the micromanipulation automatic needle changing structure and used for transferring cells or tissue fragments with liquid as a medium in micromanipulation. The method is used for cell culture and organoid culture.

Description

Technical Field

[0001] This application relates to the field of micromanipulation technology, specifically to a fluid circuit system and an automatic needle changing structure for micromanipulation. Background Technology

[0002] In cell culture and organoid culture, the transfer of cells or tissue fragments is often required. The cells being manipulated are typically around 10 μm in size, while tissue fragments are generally between 20 and 100 μm in size. Therefore, manipulation of cells and tissue fragments usually requires the use of micromanipulation glass needles. By pulling the needle, the diameter of the needle tip can be reduced to the micrometer level to meet the experimental requirements.

[0003] Micromanipulation systems for cell preparation include cell movement, drug delivery, and injection. Different glass needles of varying shapes and diameters are required depending on the target. Automating the changing of these micromanipulation needles is an essential step in building an automated micromanipulation system.

[0004] Micromanipulation is used for liquid handling in microliters, especially when the volume of liquid to be handled is 0.1 μL or nanoliters. The accuracy requirements for liquid handling are very high. However, the existing automatic needle-changing liquid aspiration and dispensing structures have air chambers in the liquid handling structure, and the gas is easily compressed, resulting in a large deviation between the liquid handling accuracy and the expected accuracy. Summary of the Invention

[0005] The purpose of this application is to address the issue of excessive deviation between the expected and actual pipetting accuracy in existing aspiration and dispensing structures. Therefore, it provides a fluid circuit system and an automatic needle-changing structure for microscopic manipulation.

[0006] The technical solution of this application is as follows: This application provides a liquid circuit system, including a liquid driving unit, which is detachably connected to the liquid inlet of the micromanipulation needle of the micromanipulation automatic needle changing unit, and injects incompressible liquid into the micromanipulation needle, so that a continuous liquid column without air cavity is formed between the liquid driving unit and the micromanipulation needle, so as to use the liquid as a medium to aspirate or expel cells or tissue fragments, perfuse or wash.

[0007] Furthermore, the liquid driving unit includes a bidirectional pumping module, which is connected to an external liquid. The outlet of the bidirectional pumping module is detachably connected to the inlet of the micromanipulation needle. The bidirectional pumping module drives incompressible liquid to flow back and forth in a continuous liquid column to achieve the aspiration or discharge of cells or tissue fragments.

[0008] Furthermore, the bidirectional pumping module includes a drive motor and a micro-plunger oil pump. The drive motor is connected to the micro-plunger oil pump, and the pumping side of the micro-plunger oil pump is machined with a filling port and a liquid outlet.

[0009] Preferably, the micro-plunger oil pump is equipped with a volume indicator element for displaying or providing feedback on the plunger displacement of the micro-plunger oil pump.

[0010] Furthermore, the bidirectional pumping module also includes a platform on which the drive motor and the micro-plunger oil pump are mounted.

[0011] Furthermore, the liquid drive unit also includes a switching valve module, which is installed upstream of the bidirectional pumping module and connected in series with the bidirectional pumping module to control the flow direction of the liquid path.

[0012] Furthermore, the liquid drive unit also includes a fluid conductor, which is located at the fluid path node between the switching valve module, the bidirectional pumping module, and the micromanipulation needle to form a continuous sealed channel.

[0013] Preferably, the fluid conduction element has the same initial internal cross-section as the micromanipulation needle.

[0014] Preferably, the fluid conduction element has a deformation-resistant wall.

[0015] This application also provides an automatic needle-changing structure for micromanipulation, including the above-mentioned liquid circuit system and an automatic needle-changing unit for micromanipulation. The liquid circuit system is connected to the liquid port of the automatic needle-changing unit for micromanipulation, and is used to transfer cells or tissue fragments in liquid as a medium during micromanipulation.

[0016] Compared with the prior art, this application has the following advantages:

[0017] 1. This application completely replaces the air chamber in traditional automatic needle-changing structures by using a fluid system with incompressible liquids such as mineral oil as the transmission medium. Because the volume change of the liquid medium is minimal under pressure, its displacement can be precisely transmitted and controlled, thus overcoming the inherent defects of pipetting endpoint lag and volume inaccuracy caused by the compressibility of gases. This allows the system to maintain excellent precision and accuracy even in microliter and nanoliter ranges, meeting the extreme liquid volume requirements of micromanipulations such as cell injection and tissue fragment transfer.

[0018] 2. The stopper of the needle-changing structure in this application is connected to the downstream liquid system via a liquid line connector, ensuring sealing after loading. This allows a single system to automatically change glass needles of different specifications to meet diverse experimental needs, and to perform precise perfusion, cleaning, pipetting, and cell manipulation on each needle. It achieves full automation and high precision from needle changing to operation, resolving the contradiction between automatic needle changing and precise liquid manipulation that existing technologies could not simultaneously address. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the liquid circuit system of this application. Figure 2This is a structural schematic diagram of the bidirectional pumping module A-2. Figure 3 This is a schematic diagram of the structure of fluid conduction component A-1. Figure 4 This is a schematic diagram of the structure of the automatic needle changing unit B for micromanipulation. Figure 5 This is a cross-sectional view of the micromanipulation automatic needle changing structure.

[0020] In the diagram: A-1, fluid conduction component; A-1-1, PTFE rigid tubing; A-1-2, PEEK rigid tubing connector; A-1-3, anti-clogging port; A-2, bidirectional pumping module; A-2-1, drive motor; A-2-2, micro-plunger oil pump; A-2-3, filling port; A-2-4, outlet; A-2-5, platform; A-2-6, volume indicator element; A-3, switching valve module; A-4, mineral oil.

[0021] B. Automatic needle changing unit for micromanipulation, B-1. Micromanipulation needle, B-2. Clamping motor, B-3. Transmission assembly, B-4. Plug, B-5. Sensor, B-6. Cutter, B-7. Positioning block, B-8. Rotary seat, B-9. Elastic block, B-10. Buckle.

[0022] C. Needle holder; D. Needle assembly. Detailed Implementation

[0023] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.

[0024] For example, patent application number 202311747619.4, entitled "An Automatic Needle Changing Structure and Micromanipulation Device for Microscopy," discloses a needle changing structure that automates the replacement of glass needles in micromanipulation experiments. In liquid handling during micromanipulation, this structure effectively handles microliter-level liquids by transferring cells or tissue fragments through a liquid aspiration / extraction mechanism.

[0025] This liquid suction and discharge structure uses a motor-driven plunger to move within a stopper cylinder, achieving the suction and discharge function by changing the air pressure inside the cylinder. Therefore, the structure utilizes piston movement to cause a change in the volume of the air chamber, thereby propelling the liquid in and out of the glass needle. This solution performs reasonably well with larger volumes of liquid. However, when handling liquid volumes in the range of 0.1 microliters or nanoliters, the presence of an air chamber in the pipetting structure leads to significant deviations in pipetting accuracy from expectations due to the compressibility of the gas within the air chamber.

[0026] Specific implementation method one: Combining Figures 1 to 3This embodiment describes a liquid circuit system including a liquid drive unit, which is detachably connected to the liquid inlet of the micromanipulation needle B-1 of the micromanipulation automatic needle changing unit B, and injecting incompressible liquid into the micromanipulation needle B-1, so that a continuous liquid column without air cavity is formed between the liquid drive unit and the micromanipulation needle B-1, so as to use the liquid as a medium to aspirate or expel cells or tissue fragments, perfuse or wash.

[0027] With the aforementioned fluid system, during micromanipulation, the liquid drive unit injects incompressible liquid into the micromanipulation needle B-1 through a rigid channel (specifically, the fluid conduction component A-1 between the bidirectional pumping module A-2 and the micromanipulation needle B-1), forming a continuous liquid column without air chambers between the liquid drive unit and the micromanipulation needle B-1. Thus, there are no compressible air chambers within the entire fluid path, avoiding the displacement-volume nonlinearity problem caused by the compressibility of air, significantly improving the accuracy and repeatability of micro-liquid manipulation. Simultaneously, this continuous liquid column structure allows for faster liquid response, enabling rapid aspiration, discharge, irrigation, or rinsing, meeting the demands of high-speed continuous operation.

[0028] Furthermore, since there are no air bubbles trapped in the liquid path, the risk of cross-contamination is reduced, ensuring the cleanliness and integrity of cells or tissue fragments during the transfer process, thereby effectively improving the overall efficiency and reliability of micromanipulation.

[0029] Specific Implementation Method Two: Combining Figure 1 and Figure 2 This embodiment describes a liquid driving unit that includes a bidirectional pumping module A-2. The bidirectional pumping module A-2 is connected to an external liquid, and its outlet is detachably connected to the inlet of the micromanipulation needle B-1. The bidirectional pumping module A-2 drives incompressible liquid to flow back and forth in a continuous liquid column to achieve the aspiration or discharge of cells or tissue fragments.

[0030] The bidirectional pumping module A-2 used in this embodiment can simultaneously complete the liquid intake and discharge process through the forward and reverse operation of the drive motor, thereby achieving high-precision bidirectional "suction-discharge" operation within the same needle path. This operation method eliminates the need for switching valves or additional piping systems, greatly simplifying the operation process and significantly shortening the liquid circulation time. This not only improves the convenience and efficiency of experimental operations but also provides a more efficient and accurate solution for laboratory work.

[0031] Specific implementation method three: Combining Figure 2This embodiment describes a bidirectional pumping module A-2, which includes a drive motor A-2-1 and a micro-plunger oil pump A-2-2. The drive motor A-2-1 is connected to the micro-plunger oil pump A-2-2, and the pumping side of the micro-plunger oil pump A-2-2 is machined with a filling port A-2-3 and a liquid outlet A-2-4.

[0032] In this embodiment, the inlet A-2-3 is used to quickly draw in oil and fill the entire pipeline, realizing the initial filling and air bubble flushing of the pipeline; the outlet A-2-4 is used to directly send the mineral oil in the micro plunger oil pump into the downstream rigid channel and the micro-manipulation needle B-1 to complete micro-suction, perfusion or cleaning.

[0033] Furthermore, with the bidirectional pumping module A-2, mineral oil is first drawn into the micro-plunger pump via a rotary valve injection pump, and then rapidly fills the entire fluid conduction component A-1 (preferably a Teflon rigid tube) through the infusion port A-2-3, forming a continuous liquid column free of air bubbles. Subsequently, the drive motor A-2-1 drives the micro-plunger pump A-2-2 to rotate in both directions, and the mineral oil flows back and forth within the rigid channel of the same inner diameter and the micromanipulation needle B-1. Because the liquid is incompressible and there is no air cavity throughout the process, the piston displacement is linearly related to the liquid volume, resulting in a fast system response and continuous nano-level aspiration and expulsion, meeting the requirements of high-speed and high-precision operations such as single-cell injection. At the same time, the oil column completely encapsulates the cells or tissue fragments, avoiding aerosol residue at the gas-liquid interface, resulting in an extremely low cross-contamination rate and achieving clean transfer.

[0034] Specific implementation method four: Combination Figure 2 This embodiment describes a micro-plunger oil pump A-2-2 equipped with a volume indicator element A-2-6, used to display or provide feedback on the plunger displacement of the micro-plunger oil pump A-2-2.

[0035] In this embodiment, the vernier scale volume indicator element A-2-6 configured on the micro-plunger oil pump enables direct display or precise feedback of piston displacement. This provides operators with a clear and intuitive volume reference, simplifies the initial setup process, and significantly improves the convenience and accuracy of process monitoring. Through this indicator element, operators can monitor the precise position of the piston in real time.

[0036] Furthermore, during perfusion experiments, operators can choose to manually observe and precisely control the termination of perfusion under imaging conditions to adapt to specific experimental needs; alternatively, they can preset perfusion flow parameters to allow the system to automatically complete the entire perfusion process, thus achieving efficient and precise automated operation. This flexible configuration of dual control modes enables the system to perfectly adapt to different experimental habits and complex and ever-changing operating scenarios, providing researchers with great convenience and operational freedom.

[0037] Specific Implementation Method Five: Combining Figure 2 To illustrate this embodiment, the bidirectional pumping module A-2 of this embodiment also includes a platform A-2-5, and the drive motor A-2-1 and the micro plunger oil pump A-2-2 are both mounted on the platform A-2-5.

[0038] This implementation utilizes platform A-2-5, which effectively reduces the operating error of the micro-plunger pump A-2-2, facilitating high-speed, high-precision parallel operation. Platform A-2-5, manufactured with precision machining and high-rigidity materials, effectively suppresses vibration and deformation, ensuring coaxial alignment between the drive motor A-2-1 and the micro-plunger pump A-2-2, reducing motion misalignment and transmission errors. During high-speed reciprocating operation, the platform maintains system structural stability, significantly improving the repeatability and positioning accuracy of the piston movement, ensuring the continuity and consistency of nanoliter-level liquid delivery. Simultaneously, the modular design facilitates multi-channel parallel integration, supporting synchronous or independent control of multiple pumping units to meet high-throughput experimental requirements.

[0039] Specific Implementation Method Six: Combination Figure 1 To illustrate this embodiment, the liquid drive unit of this embodiment also includes a switching valve module A-3. The switching valve module A-3 is installed upstream of the bidirectional pumping module A-2 and connected in series with the bidirectional pumping module A-2 to control the flow direction of the liquid path.

[0040] The liquid drive unit of this application integrates a perfusion and cleaning mechanism that works in concert with a switching valve module A-3 (preferably a rotary valve injection pump) and a bidirectional pumping module A-2 (referring to a micro plunger oil pump A-2-2).

[0041] Specific implementation method seven: Combining Figure 1 and Figure 3 In this embodiment, the liquid drive unit further includes a fluid conductor A-1, which is disposed at the fluid path node between the switching valve module A-3, the bidirectional pumping module A-2, and the micromanipulation needle B-1 to form a continuous sealed channel.

[0042] The fluid conduction component A-1 in this embodiment includes a polytetrafluoroethylene (PTFE) rigid tube A-1-1 and a polyetheretherketone (PEEK) rigid tube connector A-1-2. The outer diameter of the PTFE rigid tube A-1-1 is 1.6 mm. One end of the PTFE rigid tube A-1-1 is connected to the PEEK rigid tube connector A-1-2. The other end of the PTFE rigid tube A-1-1 is provided with an anti-clogging port A-1-3 at the lower part. The PEEK rigid tube connector A-1-2 is provided with external threads, and "the inner diameter of the PTFE rigid tube A-1-1 is the same as that of the micromanipulation needle B-1".

[0043] In this structure, the function of the fluid transmission component A-1 is to tightly connect the three fluid circuits of the switching valve module A-3, the bidirectional pumping module A-2, and the micromanipulation needle B-1, forming a continuous sealed channel without bubbles, dead space, or deformation. This ensures that the mineral oil maintains the same inner diameter from the micro-plunger pump to the needle tip, avoiding abrupt changes in cross-section that cause bubble retention. At the same time, it can withstand positive and negative pressure without leakage, thereby achieving high-precision and high-cleanliness micro-liquid transmission.

[0044] Specific implementation method eight: Combination Figure 1 and Figure 3 In this embodiment, the fluid conduction element A-1 and the micromanipulation needle B-1 have the same initial internal cavity cross-section, which is preferably 0.7 mm.

[0045] The constant-diameter design of this embodiment minimizes fluid flow resistance and dead space in the pipeline, resulting in smoother fluid flow, reducing the probability of residual air bubbles during injection, and ensuring greater consistency between the piston displacement of the micro-plunger pump and the displacement of the liquid at the needle tip. This leads to a faster system response and more direct control. Furthermore, this constant-diameter structure plays a crucial role in the cleaning phase, preventing sudden changes in flow rate due to changes in pipe diameter, thereby improving residue removal efficiency. Combined with forward and reverse flushing by a rotary valve injection pump, cross-contamination can be effectively prevented, ensuring the stability and repeatability of continuous operation.

[0046] Specific Implementation Method Nine: Combining Figure 3 This embodiment describes a fluid conduction component A-1 with a deformation-resistant wall.

[0047] As a preferred approach, this embodiment employs a hard fluid conductor A-1 made of polyetheretherketone (PEEK) and uses a Teflon tube, whose hardness effectively prevents changes in internal volume caused by tube wall deformation. This anti-deformation characteristic ensures that the internal geometry of the fluid conductor A-1 remains stable under alternating positive and negative pressure, avoiding liquid rebound or pressure hysteresis caused by elastic deformation, thereby ensuring the accuracy and repeatability of micro-liquid delivery.

[0048] Specific Implementation Method Ten: Combining Figure 1 and Figure 2 This embodiment describes an automatic needle-changing structure for micromanipulation, which includes the aforementioned liquid path system and an automatic needle-changing unit B for micromanipulation. The liquid path system is connected to the liquid path port of the automatic needle-changing unit B for transferring cells or tissue fragments using liquid as a medium during micromanipulation.

[0049] In this embodiment, glass needles are pre-assembled onto a needle fixing block as needle assembly D, and a needle holder C is used to hold a certain number of needle assemblies D. Figure 5As shown, the automatic needle-changing unit B for micromanipulation in this embodiment includes a micromanipulation needle B-1, a clamping motor B-2, a transmission assembly B-3, a plug cylinder B-4, a sensor B-5, a chopper B-6, a positioning block B-7, a rotating seat B-8, an elastic block B-9, and a latching block B-10. The front end of the plug cylinder B-4 is fixedly connected to the positioning block B-7; the elastic block B-9 is fitted on the outer circumference of the positioning block B-7, and the elastic block B-9 can extend and retract radially. The rotating seat B-8 is coaxially sleeved on the outside of the plug cylinder B-4 through a pair of bearings, and can rotate freely relative to the plug cylinder B-4; the latching block B-10 is fixed to the inner wall of the rotating seat B-8 and rotates together with the rotating seat B-8. The clamping motor B-2 drives the rotating seat B-8 to rotate forward / reverse via the transmission assembly B-3 (gear or synchronous belt), realizing the clamping or releasing of the latching block B-10 on the protrusion of the needle assembly. Sensor B-5 is fixed to the outer wall of plug cylinder B-4, and a chopper B-6 is fixed to the rotating seat B-8. When rotating, the chopper B-6 blocks sensor B-5 and provides a zero-position signal for initial loading position detection and homing.

[0050] Combination Figures 1 to 5 Explanation of how this application works:

[0051] 1. Loading process:

[0052] When the needle changing module moves above the needle assembly D and the positioning block B-7 aligns with the positioning hole on the needle assembly D, the entire needle changing module moves downward under external drive, compressing the elastic block B-9. After moving to a certain position, the clamping motor B-2 drives the rotating seat B-8, and the latching block B-10 on the rotating seat B-8 rotates synchronously at a certain angle, pressing the protrusion on the outer periphery of the base of the needle assembly D, thus fixing the needle assembly D on the needle changing module.

[0053] 2. Uninstallation process:

[0054] The needle changing module moves above the needle holder C, aligning the positioning structure on the base of the needle assembly D with the positioning port on the needle holder C. The needle changing module is lowered to a certain height, and when the needle assembly D approaches or has already touched the needle holder C, the clamping motor B-2 drives the rotating seat B-8. The latching block B-10 on the rotating seat B-8 rotates synchronously at a certain angle, releasing the latching block B-10 from pressing and fixing the protrusion on the base of the needle assembly D. Subsequently, the needle changing module rises, and the needle assembly D is unloaded from the needle changing module under the pushing force of the elastic block B-9.

[0055] Although this application has been disclosed above with reference to preferred embodiments, it is not intended to limit this application. Those skilled in the art can make other changes within the spirit of this application and apply it to fields not mentioned in this application. Of course, all such changes made in accordance with the spirit of this application should be included within the scope of protection claimed in this application.

Claims

1. A fluid circuit system, characterized in that: It includes a liquid drive unit, which is detachably connected to the inlet of the micromanipulation needle (B-1) of the micromanipulation automatic needle changing unit (B), and injects incompressible liquid into the micromanipulation needle (B-1) so that a continuous liquid column without air cavity is formed between the liquid drive unit and the micromanipulation needle (B-1) to aspirate or expel cells or tissue fragments, perfuse or wash them using liquid as a medium.

2. The hydraulic system according to claim 1, characterized in that: The liquid drive unit includes a bidirectional pumping module (A-2), which is connected to an external liquid. The outlet of the bidirectional pumping module (A-2) is detachably connected to the inlet of the micromanipulation needle (B-1). The bidirectional pumping module (A-2) drives incompressible liquid to flow back and forth in a continuous liquid column to achieve the aspiration and expulsion of cells or tissue fragments.

3. A hydraulic system according to claim 2, characterized in that: The bidirectional pumping module (A-2) includes a drive motor (A-2-1) and a micro plunger oil pump (A-2-2). The drive motor (A-2-1) is connected to the micro plunger oil pump (A-2-2). The pumping side of the micro plunger oil pump (A-2-2) is provided with a filling port (A-2-3) and a liquid outlet (A-2-4).

4. A hydraulic system according to claim 3, characterized in that: The micro-plunger oil pump (A-2-2) is equipped with a volume indicator element (A-2-6) to display or provide feedback on the plunger displacement of the micro-plunger oil pump (A-2-2).

5. A hydraulic system according to claim 3, characterized in that: The bidirectional pumping module (A-2) also includes a platform (A-2-5), and the drive motor (A-2-1) and the micro plunger oil pump (A-2-2) are all mounted on the platform (A-2-5).

6. A hydraulic system according to claim 2, characterized in that: The liquid drive unit also includes a switching valve module (A-3), which is installed upstream of the bidirectional pumping module (A-2) and connected in series with the bidirectional pumping module (A-2) to control the flow direction of the liquid path.

7. A hydraulic system according to claim 6, characterized in that: The liquid drive unit also includes a fluid conductor (A-1), which is located at the fluid path node between the switching valve module (A-3), the bidirectional pumping module (A-2), and the micromanipulation needle (B-1) to form a continuous sealed channel.

8. A hydraulic system according to claim 7, characterized in that: The fluid conduction element (A-1) has the same initial internal cross-section as the micromanipulation needle (B-1).

9. A hydraulic system according to claim 8, characterized in that: The fluid conduction component (A-1) has a deformation-resistant wall.

10. An automatic needle-changing structure for microscopic manipulation, characterized in that: Includes the fluid system as described in any one of claims 1-9, and the automatic needle changing unit (B) for micromanipulation, wherein the fluid system is connected to the fluid port of the automatic needle changing unit (B) for transferring cells or tissue fragments in a liquid medium during micromanipulation.

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