Sleeve type dosing syringe

Abstract

The utility model relates to an injector, in particular to a sleeve type dosing injector which comprises a needle cylinder and a sleeve type needle body. According to the sleeve type needle body, the first end of a flexible inner tube is connected with a needle cylinder injection connector; the first end of the needle-type outer tube is sleeved outside the second end of the flexible inner tube, and the second end of the needle-type outer tube is provided with a needle tip; a slidable structure is arranged between the needle head type outer tube and the flexible inner tube; the first end of the flexible inner tube is sleeved with the clamping limiting piece, the first end of the clamping limiting piece abuts against the needle cylinder, and the second end of the clamping limiting piece abuts against the first end of the needle type outer tube; a detachable structure is formed among the clamping limiting piece, the flexible inner tube and the needle head type outer tube. Compared with the prior art, the utility model solves the problem that the conventional syringe easily punctures the tracheal wall or causes the short and strong cough reaction of a mouse to cause the needle head to slip off. According to the scheme, after the tracheal cartilage is punctured, the outer-layer hard tube body is retracted, and the inner-layer hose is used for dosing, so that the tracheal wall cannot be punctured or the needle cannot slide off.

Description

Technical Field

[0001] This utility model relates to a syringe, specifically a cannula-type drug delivery syringe. Background Technology

[0002] Animal models are one of the core tools for elucidating pathological mechanisms and validating drugs. Among them, the bleomycin (BLM)-induced mouse model accounts for more than 80% of basic research applications due to its high similarity to human idiopathic pulmonary fibrosis (IPF) and controllable cost. However, in this classic model, the key operational step—intratracheal administration—still has significant defects, which directly affect the reliability and reproducibility of experimental data.

[0003] Specifically, in the BLM induction model, intratracheal administration is one of the core steps in establishing pulmonary fibrosis, but its success rate is limited by the unique physiological structure of mice and the complexity of the procedure: 1) The diameter of the mouse trachea is only 1.2-1.5 mm, and the distance between the cartilage rings is less than 0.3 mm. Using a traditional 26-30G needle, it is very easy to puncture the tracheal wall due to angle deviation. Studies have shown that 15-25% of the procedures result in drug extravasation into the mediastinum or pleural cavity, causing non-specific inflammation that interferes with experimental results. 2) Even when using anesthetics such as tribromoethanol, needle stimulation can still trigger a cough reflex, leading to spasmodic contraction of the tracheal muscle layer. At this time, the needle slippage rate can be as high as 30%, and the dosage fluctuation range can reach ±20%, which seriously affects the consistency of the model.

[0004] Currently, most research and improvements to syringes focus on reusable and adjustable applications. For example, CN114028653B discloses a split-type syringe and protective needle. Through a diaphragm design, it isolates the rear syringe barrel and plunger from contact with the medication. Since the rear syringe barrel and plunger do not come into contact with the medication or the patient, they can be reused or recycled instead of being treated as medical waste. Another example is CN219071596U, which discloses a syringe with an adjustable telescopic needle length. This allows for subcutaneous, intradermal, intramuscular, and intra-articular injections. However, these improvements to syringes still cannot overcome the aforementioned problems: easy puncture of the tracheal wall, or needle slippage during strong coughing and wheezing in mice, leading to inaccurate dosage and potentially unreliable results or experimental failures in mice.

[0005] Based on the problems and shortcomings of the existing technology, this solution proposes a syringe suitable for intratracheal injection in mice to improve the accuracy of the dosage and thus ensure the reliability of the results and the success rate of the mouse experiment. Utility Model Content

[0006] The purpose of this invention is to provide a cannula-type drug delivery syringe to solve at least one of the aforementioned problems. This addresses the issue that in existing technologies using conventional syringes for establishing pulmonary fibrosis in mice, the needle is prone to puncturing the tracheal wall or causing a brief, intense coughing reaction, leading to needle slippage. This solution utilizes a cannula-type drug delivery syringe, specifically a cannula-type needle body. After the syringe needle is inserted into the tracheal cartilage, the outer rigid tube can be retracted, and the inner flexible tube allows for position adjustment and drug delivery. The flexible tube will not puncture the tracheal wall or cause the needle to slip.

[0007] The objective of this utility model is achieved through the following technical solution:

[0008] A cannula-type drug delivery injector includes a syringe barrel and a cannula-type needle body;

[0009] The cannulated needle body includes a needle-shaped outer tube, a snap-fit ​​limiting component, and a flexible inner tube;

[0010] The first end of the flexible inner tube is connected to the injection port of the syringe;

[0011] The first end of the needle-type outer tube is sleeved outside the second end of the flexible inner tube, and the second end of the needle-type outer tube is provided with a needle tip; the needle-type outer tube and the flexible inner tube have a sliding structure.

[0012] The locking and limiting component is sleeved on the outside of the first end of the flexible inner tube. The first end of the locking and limiting component abuts against the syringe, and the second end of the locking and limiting component abuts against the first end of the needle-type outer tube. The locking and limiting component, the flexible inner tube, and the needle-type outer tube are all detachable.

[0013] Preferably, the flexible inner tube is made of polytetrafluoroethylene, silicone, or polyurethane.

[0014] Preferably, the length of the flexible inner tube is 50-100 mm;

[0015] The length of the needle-type outer tube is not less than half the length of the flexible inner tube, and the length of the needle-type outer tube is less than the length of the flexible inner tube.

[0016] The length of the snap-fit ​​limiting member is not greater than the difference between the length of the flexible inner tube and the length of the needle-type outer tube, and the length of the snap-fit ​​limiting member is not less than half of the difference between the length of the flexible inner tube and the length of the needle-type outer tube.

[0017] Preferably, the snap-fit ​​limiting member is a semi-tubular structure.

[0018] Preferably, the inner side of the first end of the snap-fit ​​limiting member is provided with a first stepped structure that matches the syringe, and the inner side of the second end of the snap-fit ​​limiting member is provided with a second stepped structure that matches the first end of the needle-type outer tube.

[0019] Preferably, the first end of the snap-fit ​​limiting member is provided with a first stepped structure that matches the injection interface of the syringe.

[0020] Preferably, the outer side of the second end of the snap-fit ​​limiting member is provided with a third step structure that is symmetrical to the second step structure.

[0021] Preferably, the outer side of the first end of the snap-fit ​​limiting member is provided with a radially extending protruding ring.

[0022] Preferably, the flexible inner tube has a groove on its outer surface near the first end, and the needle-type outer tube has a slider on its inner surface near the first end. The slider and the groove are slidably connected, so that the needle-type outer tube and the flexible inner tube form a slidable structure.

[0023] Preferably, the syringe is a 2mL syringe or a 5mL syringe; the size of the flexible inner tube matches the injection port of the syringe; and the needle-type outer tube and the flexible inner tube are arranged in a concentric structure.

[0024] The working principle of this utility model is as follows:

[0025] In use, reliably connect the flexible inner tube of the cannula-type needle body to the injection port of the syringe. Then, push the needle-type outer tube to the distal end of the flexible inner tube (away from the syringe). Next, place the locking stop on the outside of the flexible inner tube between the needle-type outer tube and the syringe, so that the syringe, the locking stop, and the needle-type outer tube are sequentially abutted and positioned, completing the assembly of the cannula-type drug delivery syringe. Then, insert the cannula-type needle (through the needle-type outer tube) of the cannula-type drug delivery syringe into the tracheal cartilage of the mouse. Remove the locking stop to release the abutment and position, and retract the needle-type outer tube backward, leaving the flexible inner tube in the trachea. Finally, adjust the position of the flexible inner tube according to the actual insertion situation (such as pushing the flexible inner tube further inward) before administering the drug, or administer the drug directly through the flexible inner tube.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The proposed cannula-type drug delivery injector employs a cannula-type needle structure, consisting of a rigid outer needle tube and a flexible inner tube. In use, the rigid outer needle tube is first inserted into the tracheal cartilage, ensuring reliable penetration. The outer needle tube can then be withdrawn, leaving only the flexible inner tube inside the trachea. The flexible inner tube, even with repositioning within the trachea, will not cause further damage to the tracheal wall, thus preventing tracheal wall puncture or a brief, intense coughing response in mice. Finally, the drug is administered through the flexible inner tube at the target location, ensuring complete entry of the injected medication into the trachea for reliable, quantitative delivery.

[0028] In the cannulated needle, a locking and limiting component is used to achieve abutment and positioning between the needle outer tube and the syringe barrel, which can prevent slippage during insertion and thus avoid insertion failure. The stepped structure designed at both ends of the locking and limiting component can easily achieve mutual abutment between adjacent components, and the stepped structure on its outer side can also serve as an indicator, allowing the user to quickly locate the abutment position. The protruding ring on the outer side of the locking and limiting component also facilitates the user to hold the locking and limiting component against the syringe barrel during insertion, ensuring that the overall structure of the cannulated needle remains relatively stationary during insertion. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of a cannula-type drug delivery syringe.

[0030] Figure 2 This is a schematic diagram of the structure of a cannula-type needle;

[0031] Figure 3 This is an exploded view of the structure of a cannula-type needle.

[0032] Figure 4 This is a partially enlarged schematic diagram of the locking and limiting component in a sleeve-type needle.

[0033] Figure 5 This is a schematic diagram of the structure of a cannula-type needle when the locking and limiting component is removed and the needle-type outer tube is retracted.

[0034] In the diagram: 1-syringe; 11-injection interface; 2-cannula-type needle body; 21-needle-type outer tube; 211-needle tip; 22-clamping limiting component; 221-first step structure; 222-second step structure; 223-third step structure; 224-convex ring; 23-flexible inner tube. Detailed Implementation

[0035] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0036] Example 1

[0037] A cannula-type drug delivery syringe, such as Figure 1-5 As shown, it includes a syringe 1 and a cannula-type needle body 2;

[0038] The cannulated needle body 2 includes a needle-type outer tube 21, a snap-fit ​​limiting member 22, and a flexible inner tube 23;

[0039] The first end of the flexible inner tube 23 is connected to the injection port 11 of the syringe 1;

[0040] The first end of the needle-type outer tube 21 is sleeved outside the second end of the flexible inner tube 23, and the second end of the needle-type outer tube 21 is provided with a needle tip 211; the needle-type outer tube 21 and the flexible inner tube 23 have a sliding structure.

[0041] The snap-fit ​​limiting member 22 is sleeved outside the first end of the flexible inner tube 23. The first end of the snap-fit ​​limiting member 22 abuts against the syringe 1, and the second end of the snap-fit ​​limiting member 22 abuts against the first end of the needle-type outer tube 21. The snap-fit ​​limiting member 22, the flexible inner tube 23, and the needle-type outer tube 21 are all detachable structures.

[0042] More specifically, in this embodiment:

[0043] This cannula-type drug delivery syringe, such as Figure 1 As shown, it consists of two parts: a syringe 1 and a cannula-type needle body 2. The syringe 1 can adopt existing technology, and the main structural improvement of this solution lies in the cannula-type needle body 2.

[0044] The cannulated needle body 2 is composed of... Figure 2-5 As shown, it specifically includes three parts: a needle-type outer tube 21, a snap-fit ​​limiting member 22, and a flexible inner tube 23. One end of the flexible inner tube 23 is directly connected to the injection port 11 at the front end of the syringe 1. The needle-type outer tube 21 is sleeved on the outside of the flexible inner tube 23 and can slide along the flexible inner tube 23. The snap-fit ​​limiting member 22 abuts against the needle-type outer tube 21 and the syringe 1 so that the needle-type outer tube 21 can abut and limit.

[0045] The flexible inner tube 23 is a tubular structure with a flat front end (the end furthest from the syringe 1). It can be made of polytetrafluoroethylene, silicone, or polyurethane, possessing a certain degree of flexibility and meeting the biocompatibility standards for medical devices, while also being able to withstand the sterilization process. The length of the flexible inner tube 23 should be controlled between 50-100 mm to ensure that it remains stably within the trachea after the outer needle-type outer tube 21 is retracted. The outer diameter of the flexible inner tube 23 is controlled between 0.5-1.0 mm to ensure the safety and effectiveness of insertion. Simultaneously, its inner diameter can typically be designed to be 0.1 to 0.2 mm smaller than the outer diameter to meet the requirements of drug delivery flow rate and viscosity.

[0046] The needle-type outer tube 21 has a needle tip 211 at its front end (the end furthest from the syringe 1) to facilitate the insertion of the cannulated needle body 2 into the mouse. The length of the needle-type outer tube 21 should be less than the length of the flexible inner tube 23 and not less than half the length of the flexible inner tube 23, to ensure that the cannulated needle body 2 has a certain structural strength during use, while also having a certain sliding space for retracting the needle-type outer tube 21 after insertion. It should be noted that the length of the needle-type outer tube 21 should satisfy the following condition: when the needle-type outer tube 21 slides to the farthest end of the flexible inner tube 23, its needle tip 211 can completely cover the flexible inner tube 23 inside it. Preferably, the flexible inner tube 23 covers the rear side of the needle tip 211, that is, the flexible inner tube 23 is set so that it does not protrude from the needle-type outer tube 21. The needle-type outer tube 21 and the flexible inner tube 23 are concentrically arranged, and their central axes coincide.

[0047] In some embodiments, a slider is provided on the inner wall of the needle-type outer tube 21, and correspondingly, a groove is provided on the outer wall of the flexible inner tube 23. The slider is slidably fitted into the groove to achieve a sliding connection between the needle-type outer tube 21 and the flexible inner tube 23 (forming a slidable structure). If the needle-type outer tube 21 is configured as a non-removable structure, the groove on the flexible inner tube 23 can be configured to extend from the end of the syringe 1 to its middle position, so that the needle-type outer tube 21 can only slide within the range defined by the groove. In this case, the length of the locking and limiting member 22 should match the length of the groove, so that when the needle-type outer tube 21 slides to the farthest end of the flexible inner tube 23, the locking and limiting member 22 can be inserted between the syringe 1 and the needle-type outer tube 21 and achieve abutment with the syringe 1 and the needle-type outer tube 21 respectively, completing the limiting of the three. If the needle-type outer tube 21 is designed as a detachable structure, a bending structure should be provided in the middle of the flexible inner tube 23, preferably an acute-angle bending structure. In this way, the needle-type outer tube 21 can be blocked at the bending structure during use and will not slide arbitrarily in the axial direction. At the same time, the needle-type outer tube 21 can be removed from the flexible inner tube 23 according to the specific structural direction of the groove.

[0048] The snap-fit ​​limiting member 22 is a semi-circular tubular structure with stepped structures at both ends to abut against the syringe 1 and the needle-type outer tube 21, respectively. It can also be removed from the flexible inner tube 23. Specifically, the rear end of the snap-fit ​​limiting member 22 (the end closer to the syringe 1) has a first stepped structure 221 on its inner side, which matches the outer wall surface of the syringe 1, specifically the injection port 11, so that when the snap-fit ​​limiting member 22 is placed against the outside of the flexible inner tube 23, its rear end can abut against the injection port 11. A convex ring 224 is radially provided on the outer side of the same end to facilitate positioning and gripping of the first stepped structure 221. The snap-fit ​​limiting member 22 has a second stepped structure 222 on its inner front end, which matches the rear end of the needle-type outer tube 21, so that when the snap-fit ​​limiting member 22 is placed against the outside of the flexible inner tube 23, its front end can fit against the injection interface 11. A third stepped structure 223, symmetrical to the second stepped structure 222, is provided on the outer side of the same end for easy observation and positioning from the outside. The length of the snap-fit ​​limiting member 22 should be set to match the distance between the needle-type outer tube 21 and the syringe 1 when the needle-type outer tube 21 slides to its farthest point, thereby enabling the snap-fit ​​limiting member 22 to achieve contact and positioning with both the needle-type outer tube 21 and the syringe 1.

[0049] In some embodiments, the front end of the snap-fit ​​limiting member 22 and the rear end of the needle-type outer tube 21 can be configured as radially inclined slopes; specifically, the needle-type outer tube 21 can be configured as a slope with the center higher than the outer side, and the snap-fit ​​limiting member 22 can be configured as a slope with the center covering the outer side. The two match and abut against each other, so that the snap-fit ​​limiting member 22 can slide smoothly into the flexible inner tube 23 when it is assembled, reducing friction and structural obstruction.

[0050] The cannula-type drug delivery syringe in this embodiment is used for drug delivery through the trachea of ​​mice. The syringe 1 can be a 2mL or 5mL syringe 1, and the flexible inner tube 23 is designed with a suitable structure to match the syringe 1.

[0051] In use, the flexible inner tube 23 in the cannula-type needle body 2 is reliably connected to the injection port 11 of the syringe 1. Then, the needle-type outer tube 21 is pushed to the far end of the flexible inner tube 23 (away from the syringe 1). Then, the locking and limiting member 22 is placed on the outside of the flexible inner tube 23 between the needle-type outer tube 21 and the syringe 1, so that the syringe 1, the locking and limiting member 22 and the needle-type outer tube 21 are sequentially abutted and positioned, thus completing the assembly of the cannula-type drug delivery syringe. Subsequently, the cannula-type needle of the syringe (through the needle-type outer tube 21) is inserted into the tracheal cartilage of the mouse. The locking and limiting member 22 is removed to release the contact and positioning of the needle-type outer tube 21, and the needle-type outer tube 21 is retracted backward (towards the syringe 1) to expose the flexible inner tube 23 and leave the flexible inner tube 23 in the trachea. Finally, depending on the actual insertion situation, the position of the flexible inner tube 23 is adjusted (such as pushing the flexible inner tube 23 further inward) before administering the drug, or the drug is administered directly through the flexible inner tube 23.

[0052] The above description of the embodiments is provided to enable those skilled in the art to understand and use the utility model. It will be apparent to those skilled in the art that various modifications can be easily made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present utility model is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present utility model without departing from its scope should be within the protection scope of the present utility model.

Claims

1. A cannula-type drug delivery syringe, characterized in that, It includes a syringe (1) and a cannula-type needle body (2); The cannulated needle body (2) includes a needle-type outer tube (21), a snap-fit ​​limiting member (22), and a flexible inner tube (23); The first end of the flexible inner tube (23) is connected to the injection port (11) of the syringe (1); The first end of the needle-type outer tube (21) is sleeved outside the second end of the flexible inner tube (23), and the second end of the needle-type outer tube (21) is provided with a needle tip (211); the needle-type outer tube (21) and the flexible inner tube (23) are slidable. The snap-fit ​​limiting member (22) is sleeved on the outside of the first end of the flexible inner tube (23). The first end of the snap-fit ​​limiting member (22) abuts against the syringe (1), and the second end of the snap-fit ​​limiting member (22) abuts against the first end of the needle-type outer tube (21). The snap-fit ​​limiting member (22) is detachable from both the flexible inner tube (23) and the needle-type outer tube (21).

2. The cannula-type drug delivery syringe according to claim 1, characterized in that, The flexible inner tube (23) is made of polytetrafluoroethylene, silicone or polyurethane.

3. The cannula-type drug delivery syringe according to claim 1, characterized in that, The length of the flexible inner tube (23) is 50-100 mm; The length of the needle-type outer tube (21) is not less than half the length of the flexible inner tube (23), and the length of the needle-type outer tube (21) is less than the length of the flexible inner tube (23). The length of the snap-fit ​​limiting member (22) is not greater than the difference between the length of the flexible inner tube (23) and the length of the needle-type outer tube (21), and the length of the snap-fit ​​limiting member (22) is not less than half the difference between the length of the flexible inner tube (23) and the length of the needle-type outer tube (21).

4. A cannula-type drug delivery syringe according to claim 1, characterized in that, The snap-fit ​​limiting member (22) is a semi-tubular structure.

5. A cannula-type drug delivery syringe according to claim 1, characterized in that, The inner side of the first end of the snap-fit ​​limiting member (22) is provided with a first stepped structure (221) that matches the syringe (1), and the inner side of the second end of the snap-fit ​​limiting member (22) is provided with a second stepped structure (222) that matches the first end of the needle-type outer tube (21).

6. A cannula-type drug delivery syringe according to claim 5, characterized in that, The first end of the snap-fit ​​limiting member (22) is provided with a first stepped structure (221) that matches the injection interface (11) of the syringe (1).

7. A cannula-type drug delivery syringe according to claim 5, characterized in that, The outer side of the second end of the snap-fit ​​limiting member (22) is provided with a third step structure (223) that is symmetrical to the second step structure (222).

8. A cannula-type drug delivery syringe according to claim 1, characterized in that, The outer side of the first end of the snap-fit ​​limiting member (22) is provided with a radially extending protruding ring (224).

9. A cannula-type drug delivery syringe according to claim 1, characterized in that, The flexible inner tube (23) has a groove on its outer surface near the first end, and the needle-type outer tube (21) has a slider on its inner surface near the first end. The slider and the groove are slidably connected so that the needle-type outer tube (21) and the flexible inner tube (23) form a slidable structure.

10. A cannula-type drug delivery syringe according to claim 1, characterized in that, The syringe (1) is a 2mL syringe or a 5mL syringe; the size of the flexible inner tube (23) matches the injection port (11) of the syringe (1); the needle-type outer tube (21) and the flexible inner tube (23) are arranged in a concentric structure.

Images