Needle head positioning mechanism and micro-droplet generating device
By designing a needle positioning mechanism, the problem of uneven mixing of water-in-oil microdroplets was solved, achieving a consistent proportion of the original solution in the water-in-oil microdroplets and improving the accuracy of nucleic acid detection.
Patent Information
- Application Number
- CN202520025958.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-06
- Publication Date
- 2026-01-27
- Estimated Expiration
- 2035-01-06
AI Technical Summary
Existing methods for preparing water-in-oil microdroplets can easily lead to uneven mixing of the original solution, affecting the accuracy of nucleic acid detection.
A needle positioning mechanism is adopted. By setting a first positioning rib on the outer wall of the needle and cooperating with the outer tube, the alignment accuracy of the outer tube and the needle is improved, ensuring that the original solution has the same proportion in each water-in-oil microdroplet.
This improved the uniformity of water-in-oil microdroplets and enhanced the accuracy of nucleic acid detection.
Smart Images
Figure CN223832352U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of nucleic acid detection technology, specifically to a needle positioning mechanism and a microdroplet generating device. Background Technology
[0002] Droplet digital PCR is an absolute quantitative PCR technique that primarily employs a dropletization method to disperse a solution containing the target nucleic acid into a large number of water-in-oil microdroplets, forming tens of thousands of independent microreaction systems of equal volume. Each droplet initially contains 0, 1, or more target nucleic acid templates. After PCR cycles, droplets initially containing one target nucleic acid will emit a fluorescent signal, while droplets without a target nucleic acid will not emit a fluorescent signal. Based on the relative proportions of the two types of droplets and Poisson distribution mathematical corrections, the concentration of the target nucleic acid in the original solution can be calculated.
[0003] Currently, the general method for preparing water-in-oil microdroplets involves mixing the original solution and oil in a certain ratio, then helically stirring the mixture before dripping it out at a specific flow rate to form water-in-oil microdroplets. However, this helical stirring method easily leads to uneven mixing of the original solution and oil, resulting in inconsistent proportions of the original solution in each water-in-oil microdroplet. This poor uniformity of the water-in-oil microdroplets directly affects the accuracy of nucleic acid detection.
[0004] In view of this, designing and manufacturing a needle positioning mechanism with high accuracy and uniformity, as well as a microdroplet generation device, is particularly important, especially in nucleic acid detection. Utility Model Content
[0005] The purpose of this invention is to provide a needle positioning mechanism that can improve the alignment accuracy of the outer catheter and the needle, ensure that the proportion of the original solution in each water-in-oil microdroplet is the same, improve the uniformity of the water-in-oil microdroplets, and improve the accuracy of nucleic acid detection.
[0006] Another objective of this invention is to provide a microdroplet generation device that can improve the alignment accuracy of the external catheter and needle, ensure that the proportion of the original solution in each water-in-oil microdroplet is the same, improve the uniformity of the water-in-oil microdroplets, and improve the accuracy of nucleic acid detection.
[0007] This utility model is achieved by the following technical solution.
[0008] A needle positioning mechanism includes a needle tube, a sleeve, a needle, and an outer guide tube. The sleeve is connected to the needle tube and is fitted over the needle tube, forming an oil inlet channel between the sleeve and the needle tube. The needle is installed at the end of the needle tube, and the outer guide tube is installed at the end of the sleeve and is fitted over the needle. An oil outlet channel is formed between the outer guide tube and the needle, and the oil outlet channel communicates with the oil inlet channel. A first positioning rib is provided on the outer wall of the needle, extending along the length of the needle. The first positioning rib is used to limit the outer guide tube during installation.
[0009] Optionally, the outer guide tube includes an assembly section, a connecting section, and a constricted section connected in sequence. The assembly section is sleeved outside the sleeve and snaps into the sleeve. The needle is simultaneously located inside the connecting section and the constricted section. The first positioning rib cooperates with the connecting section.
[0010] Optionally, the needle includes a mating section, a connecting section, and a tapering section connected in sequence. The mating section is sleeved outside the needle tube and is engaged with the needle tube. The first positioning rib is simultaneously provided on the mating section and the connecting section. The tapering section extends into the constricted section.
[0011] Optionally, a second positioning rib is provided in the constricted section. The second positioning rib extends along the length of the outer conduit and is used to limit the constricted section during the installation of the outer conduit.
[0012] Optionally, a constricted inner wall and a straight inner wall are sequentially provided in the constricted section. A capillary tube extends from the end of the constricted section away from the connecting section. A second positioning rib is provided on the constricted inner wall. The capillary tube extends into the straight inner wall and is coaxially spaced with the straight inner wall.
[0013] Optionally, there may be multiple second positioning ribs, which are arranged in a circular array.
[0014] Optionally, a limiting platform is provided in the connecting section, and a stepped part is provided at the end of the mating section away from the connecting section, with the stepped part abutting against the limiting platform.
[0015] Optionally, an oil leakage hole is provided in the step portion, which is offset from the first positioning rib, and the oil leakage hole is used for oil supply.
[0016] Optionally, there may be multiple first positioning ribs, which are arranged in a circular array.
[0017] A microdroplet generating device includes the aforementioned needle positioning mechanism. The needle positioning mechanism includes a needle tube, a sleeve, a needle, and an outer guide tube. The sleeve is connected to the needle tube and is fitted over the needle tube, forming an oil inlet channel between the sleeve and the needle tube. The needle is installed at the end of the needle tube, and the outer guide tube is installed at the end of the sleeve and is fitted over the needle. An oil outlet channel is formed between the outer guide tube and the needle, and the oil outlet channel communicates with the oil inlet channel. A first positioning rib is provided on the outer wall of the needle, extending along the length of the needle. The first positioning rib is used to limit the outer guide tube during installation.
[0018] The needle positioning mechanism and microdroplet generating device provided by this utility model have the following characteristics:
[0019] Beneficial effects:
[0020] The needle positioning mechanism provided by this utility model has a sleeve connected to the needle tube and fitted over the needle tube, forming an oil inlet channel between the sleeve and the needle tube. The needle is installed at the end of the needle tube, and an outer guide tube is installed at the end of the sleeve and fitted over the needle, forming an oil outlet channel between the outer guide tube and the needle. The oil outlet channel communicates with the oil inlet channel. A first positioning rib is provided on the outer wall of the needle, extending along the length of the needle. The first positioning rib is used to limit the outer guide tube during installation. Compared with the prior art, the needle positioning mechanism provided by this utility model, due to the use of the first positioning rib on the outer wall of the needle and the outer guide tube that cooperates with the first positioning rib, can improve the alignment accuracy of the outer guide tube and the needle, ensure that the proportion of the original solution in each water-in-oil microdroplet is the same, improve the uniformity of the water-in-oil microdroplets, and improve the accuracy of nucleic acid detection.
[0021] The microdroplet generation device provided by this utility model includes a needle positioning mechanism, which can improve the alignment accuracy of the outer catheter and the needle, ensure that the proportion of the original solution in each water-in-oil microdroplet is the same, improve the uniformity of the water-in-oil microdroplets, and improve the accuracy of nucleic acid detection. Attached Figure Description
[0022] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0023] Figure 1 A schematic diagram of the microdroplet generation device provided in this embodiment of the utility model;
[0024] Figure 2 A cross-sectional view of the needle positioning mechanism provided in an embodiment of this utility model;
[0025] Figure 3 A cross-sectional view of the needle positioning mechanism provided in an embodiment of this utility model;
[0026] Figure 4 A cross-sectional view of the outer guide tube and the needle in the needle positioning mechanism provided in this embodiment of the utility model;
[0027] Figure 5 A cross-sectional view of the outer guide tube and the needle in the needle positioning mechanism provided in this embodiment of the utility model;
[0028] Figure 6 A cross-sectional view of the outer guide tube in the needle positioning mechanism provided in this embodiment of the utility model;
[0029] Figure 7 A cross-sectional view of the needle and the outer guide tube placed on the support plate in the needle positioning mechanism provided in this embodiment of the utility model.
[0030] Icons: 10-Microdroplet generating device; 100-Needle positioning mechanism; 110-Needle tube; 120-Sleeve; 130-Needle; 131-First positioning rib; 132-First gap; 133-Matching section; 134-Connecting section; 135-Gradual narrowing section; 136-Capillary tube; 137-Step section; 138-Oil leakage hole; 140-Outer guide tube; 141-Assembly section; 142-Connecting section; 143-Narrowing section; 1431-Narrowing inner wall; 1432-Straight inner wall; 144-Second positioning rib; 146-Second gap; 147-Limiting platform; 148-Hanging lug; 150-Oil inlet channel; 160-Oil outlet channel; 200-Drive mechanism; 300-Push rod; 400-Bearing plate; 410-Through hole. Detailed Implementation
[0031] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0032] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.
[0033] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0034] In the description of this utility model, it should be noted that the terms "inner," "outer," "upper," "lower," "horizontal," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the utility model product is in use. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first," "second," "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.
[0035] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "connected," "installed," and "connected" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0036] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the features in the following embodiments can be combined with each other.
[0037] Please refer to the reference. Figures 1 to 3 This invention provides a microdroplet generating device 10 for generating water-in-oil microdroplets for nucleic acid detection. It improves the alignment accuracy of the external catheter 140 and the needle 130, ensures that the proportion of the original solution in each water-in-oil microdroplet is the same, improves the uniformity of the water-in-oil microdroplets, and enhances the accuracy of nucleic acid detection.
[0038] It should be noted that the microdroplet generation device 10 is used in a digital PCR detection device (not shown in the figure). The digital PCR detection device also includes a temperature control device (not shown in the figure) and a microscopic imaging device (not shown in the figure). The microdroplet generation device 10 is used to generate a large number of water-in-oil microdroplets from the original solution of a sample, and these water-in-oil microdroplets are injected into a reaction pan placed on the temperature control device. The temperature control device is used to cycle the water-in-oil microdroplets through the reaction pan, doubling the number of target nucleic acids in each water-in-oil microdroplet with each cycle. This process is repeated to significantly increase the amount of target nucleic acids from a small quantity. The microscopic imaging device is used to photograph and measure all the water-in-oil microdroplets after the temperature cycle is completed. Water-in-oil microdroplets initially containing target nucleic acids will emit a fluorescent signal, while those without target nucleic acids will not. Based on the relative proportions of the two types of water-in-oil microdroplets and a Poisson distribution mathematical correction, the concentration of the target nucleic acid in the original solution of the corresponding sample can be calculated.
[0039] The microdroplet generating device 10 includes a drive mechanism 200, a push rod 300, an oil pump mechanism (not shown), and a needle positioning mechanism 100. The push rod 300 is slidably disposed within the needle positioning mechanism 100, and can slide relative to the needle positioning mechanism 100 to create negative or positive pressure within the needle positioning mechanism 100, thereby achieving liquid aspiration and dripping functions. The needle positioning mechanism 100 guides and limits the push rod 300. The drive mechanism 200 is connected to the push rod 300 and is used to drive the push rod 300 to slide relative to the needle positioning mechanism 100, thereby achieving automated control of the push rod 300. The oil pump mechanism is connected to the needle positioning mechanism 100 and is used to introduce flushing oil into the needle positioning mechanism 100 to facilitate the formation of water-in-oil microdroplets.
[0040] The needle positioning mechanism 100 includes a needle tube 110, a sleeve 120, a needle 130, and an outer guide tube 140. The sleeve 120 is connected to the needle tube 110 and is sleeved over the needle tube 110. An oil inlet channel 150 is formed between the sleeve 120 and the needle tube 110. The oil inlet channel 150 is coaxial with and separated from the inner cavity of the needle tube 110, so that the oil inlet channel 150 and the inner cavity of the needle tube 110 are independent and do not affect each other. The oil inlet channel 150 is used to supply flushing oil. A push rod 300 is slidably disposed inside the needle tube 110. The push rod 300 can slide relative to the needle tube 110 to create negative or positive pressure inside the needle tube 110, thereby realizing the liquid aspiration and dripping functions. The needle tube 110 can guide and limit the push rod 300. The needle 130 is installed at the end of the needle tube 110 and is connected to the inner cavity of the needle tube 110. The outer guide tube 140 is installed at the end of the sleeve 120 and is sleeved over the needle 130. An oil outlet channel 160 is formed between the outer guide tube 140 and the needle 130. The oil outlet channel 160 is connected to the oil inlet channel 150, and the flushing oil in the oil inlet channel 150 can flow smoothly to the oil outlet channel 160. Specifically, the needle 130 is used to expel the original solution when the push rod 300 slides towards the needle 130, and the oil outlet channel 160 is used to output flushing oil while the original solution is expelled to form water-in-oil microdroplets. Through the limiting effect of the needle 130 and the outer conduit 140, and by reasonably controlling the flow rate of the original solution and the flushing oil, the original solution and the flushing oil can undergo coaxial sheath flow (the original solution flows out from the needle 130, and the flushing oil flows out from the oil outlet channel 160) and form water-in-oil microdroplets, thereby ensuring that the proportion of the original solution in each water-in-oil microdroplet is the same, improving the uniformity of the water-in-oil microdroplets, and improving the accuracy of nucleic acid detection.
[0041] During the use of the microdroplet generating device 10, the air inside the syringe 110 and the needle 130 is first removed; then a certain amount of the original solution is drawn through the needle 130; next, the original solution flows out from the needle 130 under the pressure of the push rod 300, forming microdroplets. During this process, the flushing oil enters the oil inlet channel 150 evenly under the action of external force and flows out through the oil outlet channel 160 to flush the microdroplets located at the end of the needle 130; when the force of the flushing oil (flushing force) is greater than the surface tension of the microdroplet, the microdroplet falls off from the end of the needle 130 and flows into the reaction plate below with the flushing oil, thus forming microdroplets of the original solution (i.e., water-in-oil microdroplets) wrapped in flushing oil. Specifically, as long as the flow rates of the original solution and the flushing oil are uniform (the two liquids have different flow rates), uniform water-in-oil microdroplets can be formed. The size of the water-in-oil microdroplets is affected by the flow rates and physical properties (viscosity and density, etc.) of the two liquids. If water-in-oil microdroplets of different sizes are to be generated, the flow rates and composition ratios of the two liquids need to be adjusted.
[0042] It should be noted that both the needle 130 and the outer cannula 140 are consumables. During the dripping process, the needle 130 must first be installed onto the syringe 110; then the needle 130 is inserted into the sample solution storage tube to draw the original solution from the sample solution storage tube into the needle 130 (the amount drawn is very small, about 20 μL, so the original solution will not enter the syringe 110); next, the outer cannula 140 is installed onto the sleeve 120 so that the outer cannula 140 is spaced around the needle 130, forming an oil outlet channel 160 between the outer cannula 140 and the needle 130; then the original solution is dripped out, and simultaneously flushing oil is introduced into the oil inlet channel 150 so that the flushing oil flows out from the oil outlet channel 160 and coats the original solution droplets, forming water-in-oil microdroplets. In this way, during each drip, only the needle 130 and the outer catheter 140 come into contact with the original solution of the sample. To avoid cross-contamination of multiple samples, after each drip, the used needle 130 and outer catheter 140 need to be removed and replaced with new needle 130 and outer catheter 140 to facilitate the next drip.
[0043] Please refer to the reference. Figures 4 to 7 It is worth noting that the outer wall of the needle 130 is provided with a first positioning rib 131. The first positioning rib 131 extends along the length of the needle 130. The first positioning rib 131 is used to limit the outer conduit 140 during installation, so as to fine-tune the position of the outer conduit 140, improve the alignment accuracy of the outer conduit 140 and the needle 130, and ensure that the outer conduit 140 is aligned with the needle 130 after installation. This improves the coaxiality of the oil outlet channel 160 and the needle 130, thereby improving the coaxial sheath flow effect of the original solution and the flushing oil, and ensuring that the water-in-oil microdroplets are evenly dripped out.
[0044] Specifically, there are multiple first positioning ribs 131, which are arranged in a ring array. There is a first gap 132 between two adjacent first positioning ribs 131. The first gap 132 is used to allow flushing oil to flow, so as to prevent the first positioning ribs 131 from affecting the flow of flushing oil in the oil outlet channel 160. Multiple first gaps 132 work together to ensure that the flow rate of flushing oil can meet the dripping requirements.
[0045] The outer conduit 140 includes an assembly section 141, a connecting section 142, and a constricted section 143 connected in sequence. In this embodiment, the assembly section 141, the connecting section 142, and the constricted section 143 are integrally formed to improve the connection strength. The assembly section 141 is sleeved outside the sleeve 120 and snaps into the sleeve 120 to achieve a detachable connection between the outer conduit 140 and the sleeve 120, facilitating disassembly and assembly, and ensuring the sealing of the oil outlet channel 160 and the oil inlet channel 150. The needle 130 is simultaneously disposed within the connecting section 142 and the constricted section 143. The first positioning rib 131 cooperates with the connecting section 142 and is used to limit the connecting section 142, thereby limiting the entire outer conduit 140 and ensuring the alignment accuracy of the outer conduit 140 and the needle 130.
[0046] The needle 130 includes a mating section 133, a connecting section 134, and a tapering section 135 connected in sequence. In this embodiment, the mating section 133, the connecting section 134, and the tapering section 135 are integrally formed to improve the connection strength. The mating section 133 is sleeved on the outside of the needle tube 110 and snaps into the needle tube 110 to achieve a detachable connection between the needle 130 and the needle tube 110, which facilitates disassembly and assembly and ensures the airtightness of the connection between the needle 130 and the needle tube 110. The first positioning rib 131 is simultaneously provided on the mating section 133 and the connecting section 134. The tapering section 135 extends into the constriction section 143. The tapering section 135 is used to gradually limit the cross-sectional area of the original solution. The tapering section 135 and the constriction section 143 are used together to gradually limit the cross-sectional area of the flushing oil to ensure the stability of the flow of the original solution and the flushing oil.
[0047] Preferably, a second positioning rib 144 is provided within the constricted section 143. The second positioning rib 144 extends along the length of the outer conduit 140 and is used to limit the constricted section 135 during the installation of the outer conduit 140, so that the outer conduit 140 is displaced under the reaction force, thereby fine-tuning the position of the outer conduit 140 again, further improving the alignment accuracy of the outer conduit 140 and the needle 130, thereby improving the coaxial sheath flow effect of the original solution and the flushing oil, and ensuring that the water-in-oil microdroplets are dripped out evenly.
[0048] Preferably, the constricted section 143 is provided with a constricted inner wall 1431 and a straight inner wall 1432 in sequence. During the outflow process, the flushing oil in the oil outlet channel 160 passes sequentially through the constricted inner wall 1431 and the straight inner wall 1432. The constricted inner wall 1431 gradually narrows the cross-sectional area of the flushing oil, allowing it to flow out stably and uniformly from the straight inner wall 1432. Specifically, a second positioning rib 144 is disposed on the constricted inner wall 1431. The second positioning rib 144 cooperates with the tapered section 135 and limits the tapered section 135, thereby limiting the entire outer guide tube 140 under the reaction force, ensuring the alignment accuracy of the outer guide tube 140 and the needle 130.
[0049] Furthermore, a capillary tube 136 is provided at the end of the tapered section 135 away from the connecting section 134. The capillary tube 136 is a straight tube, and part of the capillary tube 136 extends into the inner wall 1432 of the straight cylinder and is coaxially spaced from the inner wall 1432 of the straight cylinder. The capillary tube 136 is used to supply the original solution to flow out, and the inner wall 1432 of the straight cylinder is used to supply the flushing oil to flow out, so that the original solution and the flushing oil form a coaxial sheath flow. When the force of the flushing oil is greater than the surface tension of the tiny droplets formed by the original solution, the tiny droplets fall off from the free end of the capillary tube 136 to form individual water-in-oil microdroplets. Specifically, during the process of the second positioning rib 144 cooperating with the tapered section 135, on the one hand, the second positioning rib 144 can limit the tapered section 135 to make high-precision fine-tuning of the position of the outer guide tube 140, further improving the alignment accuracy of the outer guide tube 140 and the needle 130; on the other hand, the second positioning rib 144 can effectively protect the capillary tube 136, improve the coaxiality of the capillary tube 136 and the inner wall 1432 of the straight cylinder, thereby improving the coaxial sheath flow effect of the original solution and the flushing oil, and ensuring that the water-in-oil microdroplets are evenly dripped out.
[0050] Specifically, there are multiple second positioning ribs 144, which are arranged in a ring array. There is a second gap 146 between two adjacent second positioning ribs 144. The second gap 146 is used to allow flushing oil to flow, so as to prevent the second positioning ribs 144 from affecting the flow of flushing oil in the oil outlet channel 160. Multiple second gaps 146 work together to ensure that the flow rate of flushing oil can meet the dripping requirements.
[0051] Preferably, a limiting platform 147 is provided within the connecting section 142, and a stepped portion 137 is provided at the end of the mating section 133 away from the connecting section 134. The stepped portion 137 abuts against the limiting platform 147, and the limiting platform 147 can limit the stepped portion 137 to limit the entire needle 130, preventing the needle 130 from disengaging from the needle tube 110 and ensuring the stability of the engagement between the needle 130 and the needle tube 110. Specifically, both the limiting platform 147 and the stepped portion 137 are annularly arranged, and the inner diameter of the limiting platform 147 is smaller than the outer diameter of the stepped portion 137 to ensure that the limiting platform 147 can effectively support and limit the stepped portion 137, thereby improving the limiting effect.
[0052] Furthermore, the needle 130 is integrally disposed within the oil outlet channel 160. An oil leakage hole 138 is provided on the stepped portion 137. The oil leakage hole 138 is offset from the first positioning rib 131 and communicates with the first gap 132. The oil leakage hole 138 allows flushing oil to flow through, ensuring smooth flow of the flushing oil within the oil outlet channel 160 and preventing the engagement of the limiting platform 147 and the stepped portion 137 from affecting the flow of the flushing oil. Specifically, there are multiple oil leakage holes 138, the same number as the number of first gaps 132. These multiple oil leakage holes 138 are arranged in a circular array on the stepped portion 137. The multiple oil leakage holes 138 work together to allow flushing oil to pass through simultaneously, ensuring that the flow rate of the flushing oil flowing out of the oil outlet channel 160 meets the requirements.
[0053] It should be noted that the outer guide tube 140 is placed on the support plate 400, which has a through hole 410. The outer guide tube 140 extends into the through hole 410. Specifically, the outer guide tube 140 is provided with a hook 148, which is annular and located at the end of the assembly section 141 away from the connecting section 142. The diameter of the through hole 410 is larger than the outer diameter of the assembly section 141 but smaller than the outer diameter of the hook 148. The outer guide tube 140 can be hooked onto the support plate 400 through the hook 148. Because the diameter of the through hole 410 is larger than the outer diameter of the assembly section 141, the outer guide tube 140 can undergo a certain amount of radial displacement within the through hole 410 to achieve fine-tuning of the position of the outer guide tube 140 and improve the alignment accuracy between the outer guide tube 140 and the needle 130.
[0054] During the installation of the outer conduit 140, the position of the needle 130 is first aligned with the position of the outer conduit 140 on the support plate 400. Then, the needle tube 110, sleeve 120, and needle 130 are controlled to descend vertically in sync, so that the needle 130 extends into the outer conduit 140. During this process, the first positioning rib 131 on the outer wall of the needle 130 initially limits the outer conduit 140 to achieve initial fine-tuning of the position of the outer conduit 140. Then, the needle tube 110, sleeve 120, and needle 130 are controlled to continue descending vertically, so that the second positioning rib 144 in the constricted section 143 engages with the tapered section 135, thereby limiting the outer conduit 140 again under the reaction force to achieve further fine-tuning of the position of the outer conduit 140. When the needle 130 moves to the limit position, the outer conduit 140 and sleeve 120 are engaged, and the installation of the outer conduit 140 is completed.
[0055] The needle positioning mechanism 100 provided in this embodiment of the utility model has a sleeve 120 connected to a needle tube 110 and sleeved outside the needle tube 110. An oil inlet channel 150 is formed between the sleeve 120 and the needle tube 110. The needle 130 is installed at the end of the needle tube 110. An outer guide tube 140 is installed at the end of the sleeve 120 and sleeved outside the needle 130. An oil outlet channel 160 is formed between the outer guide tube 140 and the needle 130. The oil outlet channel 160 communicates with the oil inlet channel 150. A first positioning rib 131 is provided on the outer wall of the needle 130. The first positioning rib 131 extends along the length direction of the needle 130 and is used to limit the outer guide tube 140 when it is installed. Compared with the prior art, the needle positioning mechanism 100 provided by this utility model, by employing a first positioning rib 131 disposed on the outer wall of the needle 130 and an outer conduit 140 that cooperates with the first positioning rib 131, can improve the alignment accuracy of the outer conduit 140 and the needle 130, ensure that the proportion of the original solution in each water-in-oil microdroplet is the same, improve the uniformity of the water-in-oil microdroplets, and improve the accuracy of nucleic acid detection. This results in high generation efficiency and good generation effect of the microdroplet generation device 10.
[0056] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.
Claims
1. A needle positioning mechanism, characterized in that, The device includes a needle tube, a sleeve, a needle tip, and an outer guide tube. The sleeve is connected to the needle tube and is fitted over the needle tube, forming an oil inlet channel between the sleeve and the needle tube. The needle tip is installed at the end of the needle tube, and the outer guide tube is installed at the end of the sleeve and is fitted over the needle tip, forming an oil outlet channel between the outer guide tube and the needle tip. The oil outlet channel communicates with the oil inlet channel. A first positioning rib is provided on the outer wall of the needle tip, extending along the length of the needle tip. The first positioning rib is used to limit the position of the outer guide tube during installation.
2. The needle positioning mechanism according to claim 1, characterized in that, The external conduit includes an assembly section, a connecting section, and a constricted section connected in sequence. The assembly section is sleeved outside the sleeve and engages with the sleeve. The needle is simultaneously disposed within the connecting section and the constricted section. The first positioning rib cooperates with the connecting section.
3. The needle positioning mechanism according to claim 2, characterized in that, The needle includes a mating section, a connecting section, and a tapering section connected in sequence. The mating section is sleeved on the outside of the needle tube and is engaged with the needle tube. The first positioning rib is simultaneously disposed on the mating section and the connecting section. The tapering section extends into the constricted section.
4. The needle positioning mechanism according to claim 3, characterized in that, A second positioning rib is provided inside the constricted section. The second positioning rib extends along the length of the outer conduit and is used to limit the constricted section during the installation of the outer conduit.
5. The needle positioning mechanism according to claim 4, characterized in that, The constricted section is provided with a constricted inner wall and a straight inner wall in sequence. A capillary tube extends from the end of the constricted section away from the connecting section. The second positioning rib is provided on the constricted inner wall. The capillary tube extends into the straight inner wall and is coaxially spaced with the straight inner wall.
6. The needle positioning mechanism according to claim 4, characterized in that, The number of the second positioning ribs is multiple, and the multiple second positioning ribs are distributed in a ring array.
7. The needle positioning mechanism according to claim 3, characterized in that, A limiting platform is provided in the connecting section, and a step is provided at the end of the mating section away from the connecting section, and the step abuts against the limiting platform.
8. The needle positioning mechanism according to claim 7, characterized in that, The stepped portion is provided with an oil leakage hole, which is offset from the first positioning rib and is used for oil supply.
9. The needle positioning mechanism according to claim 1, characterized in that, There are multiple first positioning ribs, and the multiple first positioning ribs are distributed in a ring array.
10. A microdroplet generation device, characterized in that, Includes the needle positioning mechanism as described in any one of claims 1-9.