A micro-injection needle device

Abstract

The utility model discloses a kind of micro injection needle devices, it is related to medical instrument technical field.The device includes: plastic needle seat, multiple micro injection needles and needle sheath, the inside of one end of plastic needle seat is provided with injection cavity, the other end is equipped with the injection needle slot adjacent to injection cavity, the entrance at close injection cavity is equipped with the connecting structure for connecting injector, the fit surface of injection needle slot and skin is set as inclined plane;Multiple micro injection needles are fixed in injection needle slot, and are communicated with injection cavity;Needle sheath is the cap-shaped structure of one end opening, for covering and protecting micro injection needle outside plastic needle seat is set.The utility model exposes length accurate control in 0.1-2mm with needle tip, can penetrate stratum corneum and reach superficial layer of dermis, effectively avoid nerve ending, ensure stab angle stability simultaneously in combination with fit inclined plane, expand drug permeation area by multiple needle independent channel design, to realize painless injection while significantly promote drug efficient absorption.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, and in particular to a miniature injection needle device. Background Technology

[0002] Drug injection technology is a cornerstone of the modern medical system, with its core purpose being to minimize patient pain and discomfort while achieving effective treatment. Subcutaneous injection, as one of the most commonly used routes of drug administration, plays an irreplaceable role in areas such as vaccine immunization, insulin injection, and delivery of biological agents.

[0003] Currently, the length of subcutaneous injection needles widely used in clinical practice is typically between 25 and 40 millimeters. This length is designed to ensure that medication can penetrate the epidermis and dermis and be delivered to the subcutaneous tissue layer. However, the subcutaneous tissue layer is rich in nerve endings and capillaries, and a longer needle tip can easily irritate or even damage nerve endings, causing significant sharp and burning pain. This painful experience is a major cause of injection anxiety, fear, and even decreased treatment adherence in patients (especially diabetic patients who require long-term, frequent injections, and women undergoing fertility treatment). Furthermore, traditional injection procedures require professional medical personnel, making self-administration by patients in various scenarios inconvenient.

[0004] To overcome the pain associated with traditional injections, painless microneedling technology (primarily patch-type microneedle arrays) has emerged. This technology uses microneedles hundreds of micrometers long to penetrate the stratum corneum and reach the superficial dermis, effectively avoiding nerve endings and achieving painless or minimally painful drug delivery. In pursuit of a painless experience, this technology abandons the core function of "active infusion." Its drug delivery relies entirely on the principle of passive diffusion, where the drug dissolves or is released from the microneedle matrix and then slowly diffuses based on its concentration gradient. This mechanism results in extremely low delivery efficiency, slow onset of action, and is severely limited by the molecular weight and physicochemical properties of the drug.

[0005] Therefore, there is an urgent need in this field for an innovative drug delivery method that combines the advantages of "painless penetration" and "active and controllable infusion" to provide a truly efficient and humane way of drug delivery for a wider range of drugs and patients. Utility Model Content

[0006] This invention proposes a micro-injection needle device to solve the problems of significant pain and inability to achieve active infusion into the dermis in existing technologies. This micro-injection needle device can avoid nerve endings to achieve painlessness. Its independent channel design expands the drug penetration area, forming a drug delivery channel on the skin surface. The drug reaches a designated depth in the skin and is absorbed into the subcutaneous capillary network, promoting drug penetration without causing pain or skin damage.

[0007] To achieve the above objectives, this utility model proposes a miniature injection needle device, the specific technical solution of which is as follows:

[0008] A miniature injection needle device, comprising:

[0009] A plastic needle hub has an injection chamber at one end and an injection needle groove adjacent to the injection chamber at the other end. A connecting structure for connecting a syringe is provided near the entrance of the injection chamber. The injection needle groove has a contact surface for conforming to the skin. The contact surface is configured as at least one inclined surface, and the angle between the at least one inclined surface and the axis of the injection needle is 10° to 22°.

[0010] Multiple micro-injection needles are fixedly installed in the injection needle groove and communicate with the injection cavity. The cutting edge direction of the needle tip of the micro-injection needle is consistent, and the length of the needle tip of the micro-injection needle protruding from the axial outer wall of the injection needle groove is consistent.

[0011] The needle sheath, a cap-like structure with an open end, is used to cover and protect the micro-injection needle by fitting it over the plastic needle hub.

[0012] Furthermore, the bonding surface is a single-angled slope, with an angle of 10° to 22° between it and the axis of the injection needle.

[0013] Furthermore, the bonding surface is a double-sloped surface, including a first slope near the tip of the micro-injection needle and a second slope near the injection cavity. The angle between the first slope and the axial direction of the injection needle is 10° to 22°, and the angle between the second slope and the axial direction of the injection needle is greater than 2° and less than 10°.

[0014] Furthermore, the injection cavity and the injection needle groove are connected by a tapered solid frustum section, and the connection between the injection cavity and the solid frustum section is an arc surface.

[0015] Furthermore, the solid frustum section and the axial outer wall of the injection needle groove are provided with a plurality of corresponding positioning holes to form a channel through which the micro injection needle passes, and the diameter of the positioning hole is adapted to the outer diameter of the micro injection needle.

[0016] Furthermore, the cutting edge of the needle tip faces the bonding surface.

[0017] Furthermore, the cutting edge of the needle tip faces the opposite side of the bonding surface.

[0018] Furthermore, the length of the tip of the micro-injection needle protruding from the axial outer wall of the injection needle groove is 0.1-2 mm.

[0019] Furthermore, the length of the tip of the micro-injection needle protruding from the axial outer wall of the injection needle groove is 0.1-1 mm.

[0020] Furthermore, medical-grade sealant is filled between the positioning hole and the micro-injection needle.

[0021] Furthermore, the internal cavity of the injection needle groove is filled with medical-grade sealant, forming a smooth sealing surface.

[0022] Furthermore, the connection structure is a Luer inner cone locking connector, used for assembly with the Luer outer cone locking connector on the pre-filled syringe.

[0023] Furthermore, the root of the Luer inner cone locking joint is provided with an annular flange, and the annular flange is provided with at least one protrusion.

[0024] Furthermore, the two side walls of the injection needle groove are provided with lateral ribs, and the lateral ribs have the same width.

[0025] Furthermore, the open end of the needle sheath is provided with an annular snap rib that mates with the annular flange, and the annular snap rib is provided with at least one notch for mates with the protrusion.

[0026] Furthermore, the inner wall of the needle sheath is provided with a locking groove for engaging with the lateral rib and the mating surface.

[0027] By applying the above-described technical solution of this utility model, at least the following technical effects are achieved:

[0028] 1. The present invention proposes a micro-injection needle device, which strictly controls the exposed length of the micro-injection needle tip within the range of 0.1-2mm, and can accurately penetrate the epidermal layer rich in nerve endings to reach the superficial dermis, thereby effectively avoiding the main nerves and blood vessels in the subcutaneous tissue layer and significantly reducing the pain during injection.

[0029] 2. This invention proposes a micro-injection needle device that employs a design of multiple independent micro-injection needles, forming a parallel multi-channel drug delivery pathway. This design not only greatly promotes the transdermal absorption efficiency of biological macromolecular drugs (such as insulin, monoclonal antibodies, etc.), enabling them to rapidly diffuse into the dermal capillary network, but also significantly improves the accuracy of the drug dosage and the uniformity of distribution within the skin.

[0030] 3. This utility model proposes a miniature injection needle device with a highly integrated structure, few parts, and a simple design. The UV curing sealing process ensures the airtightness of the drug delivery channel, resulting in high safety. The concise overall design significantly reduces the complexity of the production process and manufacturing costs, giving it both excellent safety and significant economic advantages.

[0031] 4. The miniature injection needle device proposed in this utility model can be directly connected to a universal pre-filled syringe via a standard Luerne conical locking connector to form a complete drug delivery system without any additional adapters, making operation extremely simple. Furthermore, the uniquely designed beveled contact surface ensures stable contact with the skin during injection, guaranteeing consistent and stable needle tip insertion depth and greatly reducing the risk of ineffective drug delivery due to differences in operating techniques. Attached Figure Description

[0032] The accompanying drawings, which form part of this specification, are used to provide a further understanding of this utility model. The illustrative embodiments and descriptions of this utility model are used to explain this utility model and do not constitute an undue limitation thereof. In the drawings:

[0033] Figure 1 A schematic diagram of the overall structure of a micro-injection needle device proposed in this utility model is shown.

[0034] Figure 2 A partial structural schematic diagram of a micro-injection needle device proposed in this utility model is shown;

[0035] Figure 3 A partial structural schematic diagram of a micro-injection needle device proposed in this utility model is shown;

[0036] Figure 4 A partial structural schematic diagram of a micro-injection needle device proposed in this utility model is shown;

[0037] Figure 5 A partial structural schematic diagram of a micro-injection needle device proposed in this utility model is shown.

[0038] Reference numerals: 10-Plastic needle hub, 20-Micro injection needle, 30-Needle sheath, 11-Injection chamber, 12-Luer inner cone locking connector, 121-Annular flange, 122-Protrusion, 13-Injection needle groove, 131-Lateral rib, 132-Limiting surface, 133-Mating surface, 14-Positioning hole, 31-Annular snap rib, 32-Notch. Detailed Implementation

[0039] It should be noted that, where there is no conflict, the embodiments and features in the embodiments of this utility model can be combined with each other. The present utility model will now be described in detail with reference to the accompanying drawings and embodiments.

[0040] The present invention will be further described in detail below with reference to specific embodiments. These embodiments should not be construed as limiting the scope of protection claimed by the present invention.

[0041] Example

[0042] See Figures 1-5 As shown, this embodiment provides a miniature injection needle device. (See also...) Figure 1 As shown, the micro-injection needle device includes a plastic needle hub 10, multiple micro-injection needles 20 fixed on the plastic needle hub 10, and a needle sheath 30 detachably fitted over the plastic needle hub 10. (See reference...) Figure 2 As shown, one end of the plastic needle hub 10 has an injection chamber 11, and the other end has an injection needle groove 13 adjacent to the injection chamber 11. A Luer inner cone locking connector 12 is located at the end of the plastic needle hub 10 near the inlet of the injection chamber 11. The Luer inner cone locking connector 12 is used for assembly with a standard Luer outer cone locking connector of a pre-filled syringe. Multiple micro-injection needles 20 are fixed in the injection needle groove 13 and communicate with the injection chamber 11. The cutting edges of the tips of the multiple micro-injection needles 20 are aligned, and the distance from the needle tips protruding from the injection needle groove 13 is consistent. A needle sheath 30 is fitted over the plastic needle hub 10, and one end has a locking structure for engaging with a corresponding structure on the plastic needle hub 10, thereby completely covering the end where the micro-injection needles 20 are located. This protects the needle tips of the micro-injection needles 20 from damage and ensures that the device remains sterile from sterilization until use.

[0043] In one specific embodiment of the plastic needle hub 10, the end of the plastic needle hub 10 with the injection chamber 11 is cylindrical. The inlet end of the injection chamber 11 is connected to the base of the Luer inner cone locking connector 12, forming an integral structure. The interior of the Luer inner cone locking connector 12 is a conical hole conforming to ISO standards, used for assembly with the standard Luer outer cone locking connector on the pre-filled syringe. Axial preload is generated through threaded engagement, ensuring a tight fit between the conical surfaces of the two, achieving a leak-free seal. The outer side of the root of the Luer inner cone locking connector 12 has a radially protruding annular flange 121, and at least one protrusion 122 is also provided on this annular flange 121. Both the annular flange 121 and the protrusion 122 are used to engage with the needle sheath 30 to restrict the relative rotation of the plastic needle hub 10 and the needle sheath 30, preventing the needle sheath from loosening due to accidental rotation during transportation or handling, thereby ensuring the integrity of the sterile barrier of the micro-injection needle 20.

[0044] The solid substrate at the other end of the injection cavity 11 is transitionally connected to the solid substrate of the injection needle groove 13 via a tapered solid frustum section. The connection between the injection cavity 11 and the solid frustum section is smoothly formed by an arc surface. This design effectively eliminates stress concentration, ensures structural reliability, and minimizes drug residue by creating smooth inner corners. Multiple sets of positioning holes 14 are provided on the axial outer walls of the solid frustum section and the injection needle groove 13, forming channels for the micro-injection needles 20 to pass through. Multiple micro-injection needles 20 are inserted from the outer wall of the injection needle groove 13, sequentially passing through the positioning hole 14, the cavity of the injection needle groove 13, and the positioning hole 14 of the solid frustum section, thereby being fixedly mounted on the plastic needle holder 10. The number of micro-injection needles 20 is the same as the number of positioning holes 14; in this embodiment, there are three of each. The outer diameter of all micro-injection needles 20 is adapted to the diameter of the corresponding positioning hole 14, and all micro-injection needles 20 are connected to the injection cavity 11. The aforementioned micro-injection needles 20 are assembled using an assembly machine. During assembly, the cutting direction of the needle tips of multiple micro-injection needles 20 is kept consistent, and the length of the needle tips protruding from the injection needle groove 13 is also kept consistent. Furthermore, each positioning hole 14 is filled with medical-grade sealant outside the micro-injection needle 20 for initial fixation and sealing. To ensure absolute sealing reliability and structural integrity, the internal cavity of the injection needle groove 13 is further filled with medical-grade sealant until it is completely filled, forming a smooth, continuous, transparent plane. This process is not only simple and reliable but also creates an excellent "inspection window": through the transparent sealant above, operators or quality inspectors can visually inspect the base of each needle for bending, cracks, or assembly defects, and can clearly confirm the quality of the sealant filling (such as whether there are air bubbles or insufficient sealant), thus greatly simplifying the production and quality inspection process and ensuring 100% reliability of the products leaving the factory. All these sealing measures together ensure that the liquid medicine in the injection chamber 11 can only flow out to the outside through the micro-injection needles 20. In this embodiment, the tip of the micro-injection needle 20 protrudes at a length of 0.1–2 mm. This length is designed to allow the needle tip to penetrate the stratum corneum and epidermis, delivering the medication to the superficial dermis. This puncture depth effectively reduces pain by avoiding the densely distributed nerve endings in the dermis. As a preferred embodiment, the tip of the micro-injection needle 20 protrudes at a length of 0.1–1 mm from the injection needle groove 13. This optimized design further precisely limits the puncture depth to the epidermal layer where nerve endings are sparser, reaching just the superficial part of the epidermal-dermal junction or the papillary dermal layer. This achieves both effective drug delivery and a synergistic effect of stronger pain relief and a lower risk of bleeding.

[0045] Optionally, the number of micro-injection needles 20 and positioning holes 14 is not limited to the three in this embodiment, but may also be two, four, five or more.

[0046] Optionally, medical-grade sealants may be ultraviolet (UV) curing adhesives to meet the requirements for biocompatibility, curing speed, and sealing strength.

[0047] See Figure 3 and Figure 4 As shown, the injection needle groove 13 has raised structures on both sides extending from the cylindrical end of the plastic needle holder 10 to the needle tip. These structures can be called lateral ribs 131, and the width of the lateral ribs 131 on both sides is the same. Near the needle tip, the raised structures on both sides gradually taper and form a concave, smooth limiting surface 132 at the end. The back side of the injection needle groove 13 is configured as a contact surface 133 for adhering to the skin. In this embodiment, the needle tip of the micro-injection needle 20 faces the contact surface 133. In other embodiments, the needle tip of the micro-injection needle 20 faces the opposite side of the contact surface 133, that is, the side with the opening direction of the injection needle groove 13. This allows for a shallower insertion depth while avoiding leakage, suitable for the needs of superficial injection. The contact surface 133 is configured as a slope extending from the cylindrical end to the needle tip, with an angle of 10° to 22° with the axial direction of the injection needle.

[0048] As one embodiment of this utility model, see [link / reference]. Figure 3 As shown, the bonding surface 133 is a single-angled inclined surface, and the angle between it and the axis of the injection needle is 10° to 22°.

[0049] As another preferred embodiment of this utility model, see [reference]. Figure 4As shown, the contact surface 133 is a composite double-sloped surface, including a first slope near the tip of the micro-injection needle 20 and a second slope near the injection cavity 11. The angle α between the first slope and the axis of the injection needle is between 10° and 22°, and the angle b between the second slope and the axis of the injection needle is greater than 2° and less than 10°. The angle range of the first segment ensures that the micro-injection needle has the best insertion efficiency and accuracy when piercing the skin. An angle less than 10° will result in an excessively long insertion stroke, increasing skin deformation and patient discomfort; while an angle greater than 22° will bring multiple drawbacks: firstly, it will make the slope too steep, affecting the stability of the device and increasing the insertion resistance; secondly, an excessively large angle will cause the slope of this device to converge with or even form a reverse angle with the cutting edge angle of conventional injection needles on the market, resulting in an inability to form an effective seal with the skin surface during injection, thereby significantly increasing the risk of drug leakage. The angle of the second segment provides a supporting platform for the device during the initial injection stage, allowing it to smoothly adhere to and stabilize on the skin surface, effectively preventing wobbling. An angle less than 2° would make this bevel almost horizontal, losing its purpose as a guiding surface; while an angle greater than 10° would weaken its stabilizing effect, making it approach the insertion function of the first bevel, failing to achieve the design purpose of phased operation. In this embodiment, the two bevels are tangent at the connection point, achieving a smooth transition. During injection, by keeping this composite double-angled bevel close to the skin, the smaller-angled stabilizing bevel first achieves initial stability and positioning of the device, while the larger-angle insertion bevel ensures that the needle tip inserts smoothly at a more precise and stable predetermined angle, effectively preventing needle wobbling and improving the smoothness of the injection process and user experience. In this embodiment, the axial length ratio of the first and second bevels is 1:1 to 1:3.

[0050] As one specific embodiment of the needle sheath 30, see [reference]. Figure 5 As shown, it is a cap-shaped structure with one open end. The open end has a double-locking structure: first, an annular locking rib 31 is provided inside the open end to engage with the annular flange 121 of the Luer conical locking connector 12, providing the main axial locking force; second, the annular locking rib 31 has at least one notch 32 for engaging with the protrusion 122 of the Luer conical locking connector 12. This double structure ensures that the needle sheath 30 and the plastic needle seat 10 are reliably fixed in both the axial and circumferential directions.

[0051] The cap of the needle sheath 30 is adapted to the plastic needle hub 10. The diameter of the end near the injection chamber 11 is larger than the diameter of the end near the injection needle groove 13. Symmetrical engaging grooves are provided in four directions (front, back, left, and right) inside the cap near the injection needle groove 13. The layout and width of these engaging grooves match the contours of the lateral ribs 131 and the mating surface 133 on the plastic needle hub 10. When the needle sheath 30 is fitted, the lateral ribs 131 and the mating surface 133 on the plastic needle hub 10 are precisely embedded in these engaging grooves. This embedded fit ensures the axial engagement and disengagement of the needle sheath 30, providing extremely high assembly stability and guiding accuracy. The needle sheath 30 prevents the needle tip from bending and being damaged during movement, and after the needle tip is sterilized with ethylene oxide, it ensures that the needle tip of the micro-injection needle 20 and the plastic needle hub 10 remain in a clean and sterile environment throughout their service life.

[0052] Optionally, the needle sheath 30 may be made of polypropylene (PP), polyethylene (PE), or other plastic materials that meet medical requirements.

[0053] The product usage process of the miniature injection needle device proposed in this embodiment is as follows: Pinch the needle sheath 30 of the device, assemble it together with the Luer inner cone locking connector 12 of the plastic needle seat 10 and the Luer outer cone locking connector of the pre-filled syringe, remove the needle sheath 30, and press the contact surface of the injection needle groove 13 tightly against the skin to perform the injection.

[0054] By applying the above-described technical solution of this utility model, at least the following technical effects are achieved:

[0055] 1. This utility model proposes a micro-injection needle device, which, through a base integrated with a precision injection groove, strictly controls the exposed length of the micro-injection needle tip within the range of 0.1-2mm. This length is scientifically designed to ensure that the needle tip accurately penetrates the stratum corneum and epidermis, reaching the superficial dermis, thereby effectively avoiding the densely distributed nerve endings in the epidermis and significantly reducing pain during injection. This painless experience greatly improves patient acceptance and treatment compliance, making it particularly suitable for chronic disease treatments requiring frequent medication.

[0056] 2. This invention proposes a micro-injection needle device that employs a design of multiple independent micro-injection needles, forming a parallel multi-channel drug delivery pathway. Compared to single-needle injection, this design can instantly create multiple tiny drug delivery channels on the skin surface, significantly increasing the drug penetration area and overcoming skin barrier resistance. This not only promotes the transdermal absorption of macromolecular drugs (such as insulin and antibodies), enabling the drug to quickly reach the subcutaneous capillary network, but also improves the accuracy and uniformity of drug dosage, ultimately achieving a significant improvement in drug bioavailability and efficacy.

[0057] 3. This utility model proposes a miniature injection needle device, in which the core components are highly integrated into a single plastic needle hub, resulting in fewer parts and a simpler structure. Automated assembly machines control the cutting direction and protrusion distance of the needle body, ensuring product consistency and precision. Key sealing areas utilize UV-cured sealing technology, reliably sealing the assembly gap between the needle hub and the needle body, ensuring that the medication is delivered through the pre-set needle path without exception, eliminating the risk of leakage. This simple and reliable design not only guarantees a safe and sealed injection process but also significantly reduces the complexity of the production process and production costs, demonstrating excellent economic efficiency.

[0058] 4. This utility model proposes a miniature injection needle device that connects directly to a universal pre-filled syringe via a standard Luerne conical locking connector, forming a complete drug delivery system. This design eliminates the need for any additional adapters, significantly lowering the barrier to drug administration for hospitals and patients. Simultaneously, the device's uniquely designed contact surface automatically assists the user in maintaining the optimal puncture angle, ensuring stable injection depth and reducing the risk of ineffective drug delivery due to improper operation. This makes it highly suitable for widespread adoption in home and clinical settings.

[0059] The above are merely several specific embodiments of this utility model, but the protection scope of this utility model is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the technical scope disclosed in this utility model, based on the technical solution and inventive concept of this utility model, should be included within the protection scope of this utility model.

[0060] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0061] It should be noted that, in the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this utility model. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

Claims

1. A micro-injection needle device, characterized in that, include: A plastic needle hub has an injection chamber at one end and an injection needle groove adjacent to the injection chamber at the other end. A connecting structure for connecting a syringe is provided near the entrance of the injection chamber. The injection needle groove has a contact surface for conforming to the skin. The contact surface is configured as at least one inclined surface, and the angle between the at least one inclined surface and the axis of the injection needle is 10° to 22°. Multiple micro-injection needles are fixedly installed in the injection needle groove and communicate with the injection cavity. The cutting edge direction of the needle tip of the micro-injection needle is consistent, and the length of the needle tip of the micro-injection needle protruding from the axial outer wall of the injection needle groove is consistent. The needle sheath, a cap-like structure with an open end, is used to cover and protect the micro-injection needle by fitting it over the plastic needle hub.

2. The micro-injection needle device according to claim 1, characterized in that: The bonding surface is a single-angled slope, with an angle of 10° to 22° between it and the axis of the injection needle.

3. The micro-injection needle device of claim 1, wherein: The bonding surface is a double-sloped surface, including a first slope near the tip of the micro-injection needle and a second slope near the injection cavity. The angle between the first slope and the axis of the injection needle is 10° to 22°, and the angle between the second slope and the axis of the injection needle is greater than 2° and less than 10°.

4. The micro-injection needle device of claim 1, wherein: The injection cavity and the injection needle groove are connected by a tapering solid frustum section, and the connection between the injection cavity and the solid frustum section is an arc surface.

5. The micro-injection needle device according to claim 4, characterized in that: The solid frustum section and the axial outer wall of the injection needle groove are provided with a plurality of corresponding positioning holes to form a channel through which the micro injection needle passes. The diameter of the positioning hole is adapted to the outer diameter of the micro injection needle.

6. The micro-needle injection device of claim 1, wherein: The direction of the needle tip's cutting edge is towards the bonding surface.

7. The micro-needle injection device of claim 1, wherein: The direction of the needle tip cutting edge is towards the opposite side of the bonding surface.

8. The micro-injection needle device of claim 1, wherein: The length of the tip of the micro-injection needle protruding from the outer axial wall of the injection needle groove is 0.1-2 mm.

9. The micro-injection needle device of claim 1, wherein: The length of the tip of the micro-injection needle protruding from the outer axial wall of the injection needle groove is 0.1-1 mm.

10. The micro-needle injection device of claim 5, wherein: The positioning hole and the micro-injection needle are filled with medical-grade sealant.

11. The micro-injection needle device of claim 10, wherein: The internal cavity of the injection needle groove is filled with medical-grade sealant, forming a smooth sealing surface.

12. The micro-needle injection device of claim 1, wherein: The connection structure is a Luer inner cone locking connector, used for assembly with the Luer outer cone locking connector on the pre-filled syringe.

13. The micro-injection needle device of claim 12, wherein: The root of the Luer inner conical locking joint is provided with an annular flange, and at least one protrusion is provided on the annular flange.

14. The micro-needle injection device of claim 1, wherein: The two side walls of the injection needle groove are provided with lateral ribs, and the lateral ribs are of the same width.

15. The micro-needle injection device of claim 13, wherein: The open end of the needle sheath is provided with an annular snap rib that mates with the annular flange. The annular snap rib has at least one notch for mates with the protrusion.

16. The micro-needle injection device of claim 14, wherein: The inner wall of the needle sheath is provided with a locking groove for engaging with the lateral rib and the mating surface.

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