A needle stick resistant intravenous catheter

Abstract

This invention relates to the field of medical device technology and discloses a needle-proof indwelling intravenous catheter, comprising a metal puncture needle, a pressure-sealed frame mechanism, and a controllable elastic needle withdrawal mechanism. Its structure includes a sealing tube detachably mounted on the top of a three-way catheter holder, a piston body placed inside the sealing tube and fixed to a specific area by magnetic adsorption, capable of driving the movement of the puncture needle, a helical spring that generates an upward pulling force on the piston body, and a drive rod that drives the piston body. This needle-proof indwelling intravenous catheter utilizes the elastic energy storage of the helical spring to achieve semi-automatic needle withdrawal, allowing medical personnel to focus more on controlling the stability of the device. Furthermore, after needle withdrawal, the puncture needle can be completely locked inside the housing, preventing exposure by any external force, thereby improving the safety of the device during retrieval.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, specifically to an anti-needle-puncture intravenous indwelling needle. Background Technology

[0002] In recent years, the application of indwelling intravenous catheters has been continuously expanding, and they are now widely used in various departments of clinical practice. The use of indwelling intravenous catheters can reduce the pain and fear of injections caused by repeated venipunctures, alleviate the anxiety of family members, facilitate clinical medication administration, reduce the workload of nurses, and reduce patient pain. However, with existing indwelling intravenous catheters, the needle tip becomes contaminated with the patient's blood after withdrawal. Healthcare staff are easily pricked by the needle tip when removing or disposing of the catheter, increasing the risk of infection. Furthermore, the exposed needle tip can cause environmental pollution and poses a serious safety hazard. Studies have shown that nurses are a high-risk occupational group for bloodborne diseases. To prevent nurses from contracting needlestick injuries during intravenous punctures, some indwelling intravenous catheters utilize telescopic designs with special devices to wrap the needle tip, or use stainless steel springs, cards, clips, etc., to reduce the risk of needlestick injuries. Another structure directly uses an irregular object in the middle with a non-concentric axis to prevent the needle tip from passing through. However, current technology cannot completely guarantee zero needlestick injury risk.

[0003] For example, Chinese patent publication number "CN109646761A" discloses "Anti-Needle-Prick Indwelling Vein Needle," whose main structure includes a puncture needle, a three-way catheter seat, a cannula, and a needle hub. The puncture needle is movably inserted into the front end of the three-way catheter seat, and the rear end of the three-way catheter seat is detachably connected to the cannula. The other end of the cannula opposite the three-way catheter seat is connected to the needle hub. The cannula is designed as a segmented fishing rod shape, with the most distal segment of the fishing rod-shaped cannula being held inside the three-way catheter seat. The rear section is secured in the needle hub. When this needle-proof indwelling intravenous catheter is in operation, the puncture needle punctures the human body. After successful puncture, the needle is pulled out. The section secured to the three-way catheter hub remains fixed. The fishing rod sheath is opened and extended section by section from that point until it is fully extended. The bloody needle tip retracts into the frontmost section of the fishing rod sheath. With a little force, the frontmost section is pulled out from the three-way catheter hub. The puncture needle passes through the gap and retracts into the sheath, making it impossible for it to pass through the small gap again, thus protecting the needle tip from being exposed and achieving the needle-proof principle.

[0004] However, the aforementioned needle-proof indwelling intravenous catheter requires two-hand operation when withdrawing the needle. One hand needs to stabilize the three-way catheter hub, while the other hand needs to slowly move the needle hub to withdraw the needle. The stability during manual withdrawal is relatively poor. Furthermore, the withdrawn needle can still be exposed to the external environment under external force, posing a puncture risk during retrieval. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides an anti-needle-puncture indwelling intravenous catheter. Utilizing the elastic energy storage of a spiral spring, it enables automatic needle withdrawal, allowing medical staff to focus more on controlling the stability of the device. Furthermore, after withdrawal, the needle is completely locked inside the housing, preventing any external force from exposing it, thus improving the safety of the device during retrieval and solving the aforementioned technical problems.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a needle-proof indwelling intravenous catheter, comprising a metal puncture needle and a pressure-sealed frame mechanism, the structure of which includes a three-way catheter seat with a hollow interior, an insertion tube located directly below the three-way catheter seat and capable of being inserted into the patient's body, an infusion tube injection channel for connecting to an external infusion tube and injecting medication into the insertion tube, and an elastic bladder embedded inside the three-way catheter seat and capable of clamping and sealing the puncture needle; and a controllable elastic needle withdrawal mechanism, the structure of which includes a sealing tube detachably installed on the top of the three-way catheter seat, a piston body placed inside the sealing tube and capable of being fixed to a specific area by magnetic adsorption and capable of driving the movement of the puncture needle, a helical spring that generates an upward pulling force on the piston body, and a drive rod capable of driving the movement of the piston body.

[0007] Preferably, the pressure-sealed frame mechanism further includes a conical guide seat integrally disposed at the bottom end of the three-way catheter seat. The bottom opening end of the conical guide seat is equipped with a downward-pointing insertion hose. One side of the three-way catheter seat is provided with an infusion tube injection channel communicating with the inner cavity of the three-way catheter seat. The top outer circumferential surface of the three-way catheter seat is provided with three lower fan-shaped limiting wings integrally formed therewith. An elastic bladder is embedded in the inner circumferential wall of the three-way catheter seat. A deformation pinhole is formed around the center of the elastic bladder. The closed area formed by the outer circumferential surface of the elastic bladder and the inner circumferential wall of the three-way catheter seat forms a liquid compression chamber. The outer circumferential surface of the three-way catheter seat is provided with a buffer injection valve for injecting buffer solution into the liquid compression chamber.

[0008] Preferably, the insertion tube is made of polyurethane and its length is the length required to be left in the patient's body after puncture.

[0009] Preferably, during operation, the open end of the infusion tube injection channel is connected to the flexible end of the infusion tube used for discharging the drug solution.

[0010] Preferably, the three lower fan-shaped limiting wings are arranged in a ring array on the top outer circumference of the three-way conduit seat.

[0011] Preferably, an appropriate amount of buffer solution is injected into the buffer solution injection valve through a liquid injection device, and the amount of buffer solution is sufficient to keep the deformed needle hole closed after the puncture needle is withdrawn.

[0012] Preferably, the controllable elastic needle withdrawal mechanism further includes three integrated upper fan-shaped retaining wings at the bottom of the sealing tube. The sealing tube has a limiting perforation in its cavity near its bottom end, an upper rod perforation at its top end, and a flow-limiting orifice on one side of the top end of the sealing tube to limit the outward flow of gas. Three lower fan-shaped permanent magnets arranged in a ring array are embedded around the upper surface of the limiting perforation in the sealing tube. A piston body capable of moving along its axial direction is placed inside the sealing tube. A needle mounting groove for mounting a puncture needle is provided at the bottom of the piston body, and a sleeve is fitted on the circumferential side of the piston body. The piston body has a sealing ring, and three upper fan-shaped permanent magnets arranged in a ring array are embedded at the bottom. A rod mounting groove for mounting the drive rod is provided at the center of the upper surface of the piston body. A rod locking ring that generates a rated locking force for the drive rod is embedded around the rod mounting groove. A rotatable movable disk is mounted on the top of the piston body through a bearing. A lower rod through hole for mounting the drive rod is provided at the center of the movable disk. A helical spring in a stretched state is fixedly installed between the top end of the inner cavity of the sealing tube and the top end of the movable disk. After the helical spring is fully contracted, the puncture needle can be completely inserted into the interior of the sealing tube.

[0013] Preferably, the upper sector-shaped permanent magnet and the lower sector-shaped permanent magnet are adapted to each other, and the upper sector-shaped permanent magnet and the lower sector-shaped permanent magnet have opposite magnetic properties on opposite sides.

[0014] Preferably, the upper fan-shaped locking wing and the lower fan-shaped limiting wing are adapted to each other and can separate or engage after relative rotation at a rated angle.

[0015] Preferably, the locking force of the rod locking ring on the drive rod is sufficient to cause the drive rod to rotate the piston body, and the locking strength between the two is five Newtons.

[0016] Compared with the prior art, the present invention provides an anti-needle-puncture indwelling intravenous needle, which has the following beneficial effects:

[0017] This invention provides a needle-proof indwelling intravenous catheter that utilizes the elastic energy storage of a spiral spring to achieve semi-automatic needle withdrawal, allowing medical staff to focus more on controlling the stability of the device. Furthermore, after needle withdrawal, the puncture needle can be completely locked inside the housing, preventing any external force from exposing the needle and thus improving the safety of the device during retrieval. Attached Figure Description

[0018] Figure 1 This is a perspective view of the present invention;

[0019] Figure 2 This is a three-dimensional cross-sectional view of the present invention;

[0020] Figure 3 This is a perspective view of the pressure-sealing frame mechanism in this invention;

[0021] Figure 4 This is a three-dimensional cross-sectional view of the pressure-sealing frame mechanism in this invention;

[0022] Figure 5 This is a perspective view of the elastic capsule in this invention;

[0023] Figure 6 This is a perspective view of the controllable elastic needle withdrawal mechanism in this invention;

[0024] Figure 7 This is a three-dimensional cross-sectional view of the controllable elastic needle retraction mechanism in this invention;

[0025] Figure 8 This is a three-dimensional cross-sectional view of the piston body region of the present invention.

[0026] The components include: 1. Puncture needle; 2. Pressure-sealed frame mechanism; 21. Three-way catheter seat; 22. Conical flow guide seat; 23. Insertion tubing; 24. Infusion tube injection channel; 25. Lower fan-shaped limiting wing; 26. Elastic bladder; 27. Liquid compression chamber; 28. Buffer injection valve; 29. ​​Deformation needle hole; 3. Controllable elastic needle withdrawal mechanism; 31. Sealing tube; 32. Upper fan-shaped retaining wing; 33. Limiting perforation; 34. Upper rod perforation; 35. Flow limiting orifice; 36. Lower fan-shaped permanent magnet; 37. Piston body; 38. Needle mounting groove; 39. Upper fan-shaped permanent magnet; 310. Sealing ring; 311. Rod placement groove; 312. Rod locking ring; 313. Movable disc; 314. Lower rod perforation; 315. Drive rod; 316. Helical spring. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Please see Figure 1 and Figure 2 A needle-proof indwelling intravenous catheter includes a metal puncture needle 1. In operation, the open end of the infusion tube injection channel 24 is connected to the soft end of the infusion tube used for discharging medication, and then a venous puncture operation is performed.

[0029] To achieve the closure of blood flow and the directional guidance of the medication, please refer to... Figure 1 , Figure 2 , Figure 3, Figure 4 and Figure 5 A pressure-sealed frame mechanism 2 is required, comprising a hollow three-way catheter base 21, an insertion tube 23 located directly below the three-way catheter base 21 and capable of being inserted into the patient's body, an infusion tube injection channel 24 for connecting to an external infusion tube and injecting medication into the insertion tube 23, and an elastic bladder 26 embedded inside the three-way catheter base 21 that provides a clamping seal for the puncture needle 1. During puncture, the needle body of the puncture needle 1 is surrounded by the inwardly bulging elastic bladder 26. The deformable needle hole 29 in 26 changes with the radius of the puncture needle 1, thereby preventing blood from flowing out through the gap of the puncture needle 1 during the puncture process. After the puncture needle 1 is withdrawn, the deformable needle hole 29 is completely closed under liquid pressure, and the blood will not flow out. At the same time, the drug solution flows through the infusion tube injection channel 24 and the insertion tube 23. Since the insertion tube 23 is inserted into the patient's blood vessel, the drug solution can enter the patient's blood vessel to achieve the sealing of blood flow and the directional guidance of the drug solution.

[0030] For details regarding the specific structure of the pressure-sealing frame mechanism 2, please refer to [link / reference]. Figure 3 , Figure 4 and Figure 5 It also includes a conical guide seat 22 integrally disposed at the bottom end of the three-way catheter seat 21. The bottom opening end of the conical guide seat 22 is fitted with a downward-facing insertion tube 23. One side of the three-way catheter seat 21 is provided with an infusion tube injection channel 24 communicating with the inner cavity of the three-way catheter seat 21. The top outer circumferential surface of the three-way catheter seat 21 is provided with three lower fan-shaped limiting wings 25 integrally formed therewith. An elastic bladder 26 is embedded in the inner circumferential wall of the three-way catheter seat 21. The center of the elastic bladder 26 forms a deformation pinhole 29. The closed area formed by the outer circumferential surface of the elastic bladder 26 and the inner circumferential wall of the three-way catheter seat 21 forms a liquid compression chamber 27. The outer circumferential surface of the three-way catheter seat 21 is provided with a buffer injection valve 28 for injecting buffer solution into the liquid compression chamber 27. The insertion tubing 23 is made of polyurethane material and its length is consistent with the length required to be left in the patient's body after puncture. During operation, the open end of the infusion tube injection channel 24 is connected to the soft end of the infusion tube for discharging the drug solution. The three lower fan-shaped limiting wings 25 are arranged in a ring array on the top outer circumferential surface of the three-way catheter seat 21. An appropriate amount of buffer solution is injected into the buffer injection valve 28 through the liquid injection device, and the amount of buffer solution is sufficient to keep the deformable needle hole 29 closed after the puncture needle 1 is pulled out.

[0031] To achieve semi-automatic needle withdrawal and complete closure of puncture needle 1, please refer to... Figure 1 , Figure 2 , Figure 6 , Figure 7 and Figure 8 A controllable elastic needle withdrawal mechanism 3 needs to be set up. Its structure includes a sealing tube 31 detachably mounted on the top of the three-way catheter seat 21, a piston body 37 placed inside the sealing tube 31 and fixed to a specific area by magnetic adsorption, capable of driving the movement of the puncture needle 1, a helical spring 316 that generates an upward pulling force on the piston body 37, and a drive rod 315 that drives the piston body 37. After puncture, the drive rod 315 is rotated in a directional manner. When the upper sector-shaped permanent magnet 39 and the lower sector-shaped permanent magnet 36 are completely misaligned, the attraction between them disappears. At this time, the elastic pulling force of the helical spring 316 causes the piston body 37 to move upward. The piston body 37 then drives the puncture needle 1 upward, achieving needle withdrawal. During the upward movement of the piston body 37, the needle retracts from the piston body 37. The gas in the piston is compressed and flows outward through the flow-limiting orifice 35. The flow-limiting orifice 35 itself has a gas flow-limiting function, which dampens the piston body 37 during movement, allowing the puncture needle 1 to slowly retract until it is fully inserted into the sealing tube 31. Then, the sealing tube 31 is rotated in a directional manner. When the upper fan-shaped retaining fin 32 and the lower fan-shaped limiting fin 25 are misaligned, the sealing tube 31 can be removed. Then, the drive rod 315 is pulled outward until its body is pulled out of the rod locking ring 312. Finally, the drive rod 315 is completely pulled out. At this time, under the tension of the helical spring 316, no external force can act on the piston body 37, ensuring that the puncture needle 1 is stably locked inside the sealing tube 31, so that it can be thrown into the recycling bin. This achieves semi-automatic retraction and complete sealing of the puncture needle 1.

[0032] For details regarding the specific structure of the controllable elastic needle withdrawal mechanism 3, please refer to [link / reference needed]. Figure 6 , Figure 7 and Figure 8It also includes three integrated upper fan-shaped retaining wings 32 disposed at the bottom of the sealing tube 31. The sealing tube 31 has a limiting perforation 33 in the cavity near its bottom end. The top end of the sealing tube 31 has an upper rod perforation 34. One side of the top end of the sealing tube 31 has a flow-limiting hole 35 that can limit the outward flow of gas. The sealing tube 31 has three lower fan-shaped permanent magnets 36 arranged in a ring array embedded around the upper surface of the limiting perforation 33. A piston body 37 capable of axial movement is placed inside the inner cavity of the sealing tube 31. The bottom of the piston body 37 has a needle mounting groove 38 for mounting the puncture needle 1. A sealing ring 310 is fitted onto the circumferential side of the piston body 37. Three upper fan-shaped permanent magnets 39 arranged in a ring array are embedded in the bottom of the piston body 37. A rod mounting groove 311 for mounting the drive rod 315 is provided at the center of the upper surface of the piston body 37. A rod locking ring 312 that generates a rated locking force for the drive rod 315 is embedded around the rod mounting groove 311. A rotatable movable disk 313 is mounted on the top of the piston body 37 via a bearing. A lower rod through hole 314 for mounting the drive rod 315 is provided at the center of the movable disk 313. A coil spring 316 in a stretched state is fixedly installed between the top end of the inner cavity of the sealing tube 31 and the top end of the movable disk 313. After the coil spring 316 is fully contracted, the puncture needle 1 can... Completely entering the interior of the sealed tube 31, the upper sector-shaped permanent magnet 39 and the lower sector-shaped permanent magnet 36 are adapted to each other, and the magnetic properties of the upper sector-shaped permanent magnet 39 and the lower sector-shaped permanent magnet 36 are opposite on opposite sides. The upper sector-shaped locking wing 32 and the lower sector-shaped limiting wing 25 are adapted to each other. After relative rotation at a rated included angle, they can separate or engage with each other. The locking force of the rod locking ring 312 on the drive rod 315 is sufficient to make the drive rod 315 drive the piston body 37 to rotate, and the locking strength between the two is five Newtons.

[0033] In use, during operation, the open end of the infusion tube injection channel 24 is connected to the flexible end of the infusion tube used for discharging the medication, and then a venous puncture operation is performed. During the puncture, the needle body of the puncture needle 1 is surrounded by the inwardly bulging elastic bladder 26, and the deformation needle hole 29 in the elastic bladder 26 changes with the radius of the puncture needle 1, thereby preventing blood from flowing outward through the gap of the puncture needle 1 during the puncture. The directional rotation drive rod 315, when the upper fan-shaped permanent magnet 39 and the lower fan-shaped permanent magnet 315 are in motion, the puncture needle 1 is punctured. When magnet 36 is completely misaligned, the attraction between the upper sector permanent magnet 39 and the lower sector permanent magnet 36 no longer exists. At this time, the elastic tension of the helical spring 316 will cause the piston body 37 to move upward. The piston body 37 will then drive the puncture needle 1 to move upward, thus achieving needle retraction. During the upward movement of the piston body 37, the gas above the piston body 37 will be compressed. The compressed gas will then flow outward through the flow-limiting orifice 35, which itself has a gas... The flow-limiting function of the piston body 37 dampens the piston body 37 during movement, allowing the puncture needle 1 to slowly retract until it is fully inserted into the sealing tube 31. Then, the sealing tube 31 is rotated in a directional manner. When the upper fan-shaped retaining fin 32 and the lower fan-shaped limiting fin 25 are misaligned, the sealing tube 31 can be removed. Next, the drive rod 315 is pulled outwards until its body is pulled out of the rod locking ring 312. Finally, the drive rod 315 is completely pulled out. At this point, the screw... Under the tension of the spring 316, no external force can act on the piston body 37, ensuring that the puncture needle 1 is stably locked inside the sealing tube 31, thus allowing it to be disposed of in the waste recycling bin. After the puncture needle 1 is removed from the work, the deformable needle hole 29 is completely closed under liquid pressure, preventing blood from flowing out. At the same time, the medication flows through the infusion tube injection channel 24 and the insertion tube 23. Since the insertion tube 23 is inserted into the patient's blood vessel, the medication can enter the patient's blood vessel.

[0034] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A needle-proof indwelling intravenous catheter, comprising a metal puncture needle (1), characterized in that: It also includes, The pressure-sealed frame mechanism (2) includes a three-way catheter seat (21) with a hollow interior, an insertion tube (23) located directly below the three-way catheter seat (21) and capable of being inserted into the patient's body, an infusion tube injection channel (24) for connecting to an external infusion tube and injecting medication into the insertion tube (23), and an elastic bladder (26) embedded inside the three-way catheter seat (21) and capable of clamping and sealing the puncture needle (1). And a controllable elastic needle withdrawal mechanism (3), the structure of which includes a sealing tube (31) that can be detachably installed on the top of the three-way catheter seat (21), a piston body (37) placed inside the sealing tube (31) and fixed to a specific area by magnetic adsorption and capable of driving the puncture needle (1) to move, a helical spring (316) that generates an upward pulling force on the piston body (37), and a drive rod (315) that can drive the piston body (37) to move.

2. The anti-needle-puncture indwelling intravenous catheter according to claim 1, characterized in that: The pressure-sealed frame mechanism (2) also includes a conical guide seat (22) integrally disposed at the bottom end of the three-way catheter seat (21). The bottom opening end of the conical guide seat (22) is equipped with a downward-facing insertion hose (23). One side of the three-way catheter seat (21) is provided with an infusion tube injection channel (24) that connects to the inner cavity of the three-way catheter seat (21). The top outer circumferential surface of the three-way catheter seat (21) is provided with three lower fan-shaped limiting wings (25) integrally disposed with it. An elastic bladder (26) is embedded in the inner circumferential wall of the three-way catheter seat (21). The center of the elastic bladder (26) forms a deformation pinhole (29). The closed area formed by the outer circumferential surface of the elastic bladder (26) and the inner circumferential wall of the three-way catheter seat (21) forms a liquid compression chamber (27). The outer circumferential surface of the three-way catheter seat (21) is provided with a buffer injection valve (28) for injecting buffer solution into the liquid compression chamber (27).

3. The anti-needle-puncture indwelling intravenous catheter according to claim 2, characterized in that: The insertion tube (23) is made of polyurethane and its length is the length required to be left in the patient's body after puncture.

4. The anti-needle-puncture indwelling intravenous catheter according to claim 3, characterized in that: During operation, the open end of the infusion tube injection channel (24) is connected to the soft end of the infusion tube used for discharging the medicine.

5. The anti-needle-puncture indwelling intravenous catheter according to claim 4, characterized in that: The three lower fan-shaped limiting wings (25) are arranged in a ring array on the top outer circumference of the three-way conduit seat (21).

6. The anti-needle-puncture indwelling intravenous catheter according to claim 5, characterized in that: An appropriate amount of buffer solution is injected into the buffer injection valve (28) through a liquid injection device, and the amount of buffer solution is sufficient to keep the deformable needle hole (29) closed after the puncture needle (1) is pulled out.

7. A needle-proof indwelling intravenous catheter according to claim 6, characterized in that: The controllable elastic needle withdrawal mechanism (3) further includes three integrated upper fan-shaped retaining wings (32) disposed at the bottom of the sealing tube (31). The sealing tube (31) has a limiting perforation (33) in the cavity near its bottom end. The top end of the sealing tube (31) has an upper rod perforation (34). One side of the top end of the sealing tube (31) has a flow-limiting hole (35) that can limit the outward flow of gas. The sealing tube (31) has three lower fan-shaped permanent magnets (36) arranged in a ring array embedded around the upper surface of the limiting perforation (33). A piston body (37) that can move along its axial direction is placed in the inner cavity of the sealing tube (31). The bottom of the piston body (37) has a needle mounting groove (38) for installing the puncture needle (1). A sealing ring (310) is sleeved on the circumferential side of the piston body (37). The bottom of the piston body (37) is embedded with three upper fan-shaped permanent magnets (39) arranged in a ring array. The center of the upper surface of the piston body (37) is provided with a rod mounting groove (311) for mounting the drive rod (315). The periphery of the rod mounting groove (311) is embedded with a rod locking ring (312) that generates a rated strength locking force for the drive rod (315). The top of the piston body (37) is mounted with a rotatable movable disk (313) through a bearing. The center of the movable disk (313) is provided with a lower rod through hole (314) for mounting the rod of the drive rod (315). A coil spring (316) in a stretched state is fixedly installed between the top of the inner cavity of the sealing tube (31) and the top of the movable disk (313). After the coil spring (316) is fully contracted, the puncture needle (1) can completely enter the interior of the sealing tube (31).

8. The anti-needle-puncture indwelling intravenous catheter according to claim 7, characterized in that: The upper sector permanent magnet (39) and the lower sector permanent magnet (36) are adapted to each other, and the upper sector permanent magnet (39) and the lower sector permanent magnet (36) have opposite magnetic properties on opposite sides.

9. A needle-proof indwelling intravenous catheter according to claim 8, characterized in that: The upper fan-shaped locking wing (32) and the lower fan-shaped limiting wing (25) are adapted to each other and can separate or engage after relative rotation at a rated angle.

10. A needle-proof indwelling intravenous catheter according to claim 9, characterized in that: The locking force of the rod locking ring (312) on the drive rod (315) is sufficient to make the drive rod (315) drive the piston body (37) to rotate, and the locking strength between the two is five Newtons.

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