Anti-backflow venous indwelling needle

Abstract

The utility model provides an anti-backflow venous indwelling needle. The anti-backflow venous indwelling needle comprises a sleeve seat, a sleeve body, a needle core assembly and an outer extension tube. The sleeve seat is provided with an infusion channel, and the sleeve body is connected with the sleeve seat and communicated with the infusion channel. The needle core assembly is provided with a puncture needle which can penetrate through the infusion channel and the sleeve body. One end of the outer extending pipe is connected to the sleeve seat, the other end of the outer extending pipe is connected with the three-way connector, the outer extending pipe is communicated with the infusion channel, a check valve is arranged on the outer extending pipe, and the check valve conducts liquid flowing in the direction from the three-way connector to the sleeve seat and stops liquid flowing in the direction from the sleeve seat to the three-way connector. The anti-backflow valve of the anti-backflow venous indwelling needle limits the flowing direction of liquid in the indwelling needle, and it is guaranteed that in the using process of the indwelling needle, it can be avoided that blood flows back into the indwelling needle after infusion, thrombus is formed, and an infusion channel is blocked; thrombus formed in the indwelling needle is prevented from rushing into veins of a patient to cause hidden dangers to health of the patient.

Description

Technical Field

[0001] This application relates to the field of medical device technology, specifically to an anti-reflux venous indwelling needle. Background Technology

[0002] Indwelling needles are commonly used medical devices in nursing work. They are convenient to use, reduce the number of punctures for patients, reduce the number of repeated punctures during clinical infusion, reduce the pain of punctures for patients, and reduce the workload of clinical nursing staff. Therefore, indwelling needles have been widely used in clinical practice.

[0003] Existing indwelling needles generally consist of a base, a cannula body, a needle core assembly, and an external extension tube. One end of the external extension tube connects to the infusion tubing, and the other end connects to the infusion channel within the base. The end of the base furthest from the external extension tube connects to the cannula body. The needle core assembly runs through both the base and the cannula body. In use, the puncture needle from the needle core assembly is first inserted into the patient's injection site. Then, guided by the puncture needle, the cannula body is inserted into the patient's blood vessel. The puncture needle is then withdrawn, leaving the cannula body in the patient's blood vessel, which is then secured with a dressing. Connecting the infusion tubing to the external extension tube allows the medication to flow sequentially into the patient's blood vessel through the external extension tube, base, and cannula body.

[0004] However, in clinical nursing practice, backflow of blood can easily occur when intravenous catheters run dry during infusion. It can also happen that after the infusion is complete, limb movement can cause blood to flow back into the extension catheter. If this backflow causes a thrombus to form in the catheter, it can not only block the catheter and affect subsequent infusions, but smaller thrombi may also be flushed into the vein. If these small thrombi adhere to the inner wall of a vein elsewhere in the body, they can narrow the vessel or even cause a blockage, seriously impacting the patient's health.

[0005] In view of the above, this utility model is hereby proposed. Utility Model Content

[0006] To address one of the aforementioned technical deficiencies, this application provides an anti-reflux venous indwelling needle.

[0007] The present invention adopts the following technical solution:

[0008] An anti-reflux venous catheter includes:

[0009] A cannula seat, wherein the cannula seat has an infusion channel;

[0010] The cannula body is connected to the cannula seat and is connected to the infusion channel;

[0011] A needle core assembly, wherein the needle core assembly has a puncture needle that can penetrate the infusion channel and the cannula body;

[0012] An external extension tube is provided, with one end connected to the sleeve seat and the other end connected to a tee connector. The external extension tube connects to the infusion channel and is equipped with an anti-backflow valve. The anti-backflow valve allows the liquid flow from the tee connector to the sleeve seat and blocks the liquid flow from the sleeve seat to the tee connector.

[0013] Optionally, the outer extension tube has a first tube body and a second tube body;

[0014] One end of the first tube is connected to the sleeve seat, and the other end is connected to the anti-backflow valve;

[0015] One end of the second pipe is connected to the tee connector, and the other end is connected to the anti-backflow valve;

[0016] The anti-reverse valve allows liquid flow from the second pipe to the first pipe, and the anti-reverse valve blocks liquid flow from the first pipe to the second pipe.

[0017] Optionally, the length of the first tube is less than the length of the second tube.

[0018] Optionally, the anti-reverse valve has a main body, a first connecting nozzle, and a second connecting nozzle. The main body has a one-way fluid cavity. The first connecting nozzle and the second connecting nozzle are both connected to the main body. The first connecting nozzle and the second connecting nozzle are disposed on opposite sides of the main body. The first connecting nozzle and the second connecting nozzle are both connected to the one-way fluid cavity. The first connecting nozzle is connected to the first pipe body, and the second connecting nozzle is connected to the second pipe body.

[0019] Optionally, the first connector and the second connector are located on the same straight line.

[0020] Optionally, the anti-backflow venous catheter includes a one-way valve.

[0021] The main body includes an upper cover and a lower cover, the upper cover and the lower cover are connected, and a one-way fluid cavity is formed between the upper cover and the lower cover. The first connecting nozzle is connected to the lower cover, and the second connecting nozzle is connected to the upper cover.

[0022] The upper cover has a mating cavity that connects the unidirectional fluid cavity and the second connecting nozzle;

[0023] The one-way valve plate is movably disposed within the one-way fluid cavity;

[0024] When the fluid pressure inside the second connecting nozzle is greater than the fluid pressure inside the first connecting nozzle, the one-way valve plate is at least partially disengaged from the upper cover, and the mating cavity, the one-way fluid cavity, and the first connecting nozzle are connected.

[0025] When the fluid pressure inside the first connector is greater than the fluid pressure inside the second connector, the one-way valve plate adheres to the upper cover and closes the mating cavity.

[0026] Optionally, the upper cover has an annular stepped surface, which encloses an opening in which the unidirectional fluid cavity communicates with the mating cavity;

[0027] The surface of the one-way valve plate is attached to the annular stepped surface;

[0028] When the fluid pressure inside the second connecting nozzle is greater than the fluid pressure inside the first connecting nozzle, at least a portion of the surface of the one-way valve plate disengages from the annular stepped surface, and the mating cavity, the one-way fluid cavity, and the first connecting nozzle are connected.

[0029] When the fluid pressure inside the first connecting nozzle is greater than the fluid pressure inside the second connecting nozzle, the one-way valve plate is entirely fitted to the annular stepped surface to close the opening of the mating cavity.

[0030] Optionally, a top tube is provided on the inner side of the lower cover. The top tube is located in the one-way fluid cavity and extends toward the mating cavity. The top tube has a cavity, and a connecting portion connecting the cavity and the one-way fluid cavity is provided on the peripheral sidewall of the top tube.

[0031] The one-way valve plate is located between the mating cavity and the top pipe;

[0032] When the fluid pressure inside the second connecting nozzle is greater than the fluid pressure inside the first connecting nozzle, the one-way valve plate is attached to the end of the top pipe, and the connecting part remains connected to the pipe cavity and the one-way fluid cavity.

[0033] Optionally, the end of the jacking pipe near the mating cavity is provided with a pipe opening, and the connecting portion includes a plurality of notches provided around the edge of the pipe opening;

[0034] When the fluid pressure inside the second connector is greater than the fluid pressure inside the first connector, the one-way valve plate closes the pipe opening, and each of the notches remains connected to the pipe cavity and the one-way fluid cavity.

[0035] Optionally, the upper cover has a first peripheral sidewall, and the lower cover has a second peripheral sidewall;

[0036] The first peripheral sidewall includes an outer sidewall and an inner sidewall, the outer sidewall and the inner sidewall are connected, and an annular slot is formed between the outer sidewall and the inner sidewall;

[0037] The second circumferential sidewall is inserted into the annular slot;

[0038] The inner sides of the first and second peripheral sidewalls have the unidirectional fluid cavity.

[0039] By adopting the above technical solution, this application has the following beneficial effects:

[0040] The anti-backflow indwelling venous catheter provided in this application is equipped with an anti-backflow valve on its external extension tube. The anti-backflow valve ensures that the fluid flowing through the indwelling catheter can only flow in the direction of flowing into the patient's blood vessels, and cannot flow outward from the patient's blood vessels in the opposite direction. This ensures that during the use of the indwelling catheter of this application, it can prevent blood from flowing back into the indwelling catheter after infusion, forming a thrombus that blocks the infusion channel, and further prevents the thrombus formed in the indwelling catheter from rushing into the patient's vein and causing potential health risks to the patient. Attached Figure Description

[0041] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0042] Figure 1 This diagram illustrates the exploded structure of the anti-backflow venous indwelling needle provided in an embodiment of this application.

[0043] Figure 2 This diagram illustrates the structure of the anti-backflow valve of the anti-backflow venous indwelling needle provided in an embodiment of this application.

[0044] Figure 3 This diagram shows a cross-sectional view of the anti-backflow valve of the anti-backflow venous indwelling needle provided in an embodiment of this application.

[0045] Figure 4 This is a cross-sectional view of the anti-backflow valve of the anti-backflow venous indwelling needle provided in an embodiment of this application, with the one-way valve plate removed.

[0046] Figure 5 This diagram shows the structure of the top cover of the anti-backflow valve of the anti-backflow indwelling venous needle provided in an embodiment of this application;

[0047] Figure 6 This diagram shows the structure of the lower cover of the anti-backflow valve of the anti-backflow venous indwelling needle provided in an embodiment of this application.

[0048] In the diagram: 1. Cannula seat; 2. Cannula body; 3. Needle core assembly; 31. Rubber stopper; 32. Puncture needle; 33. Safety clip; 34. L-shaped safety plate; 35. Safety sleeve; 36. Puncture needle seat; 4. Outer extension tube; 41. First tube body; 42. Second tube body; 5. T-connector; 6. Anti-backflow valve; 61. Main body; 611. One-way fluid cavity; 612. Upper cover; 612. Mating cavity; 6121. Annular stepped surface; 6122. First peripheral sidewall; 6123. Outer sidewall; 61231. Inner sidewall; 61232. Lower cover; 613. Second peripheral sidewall; 6131. ​​Top tube; 62. Lumen; 621. Notch; 622. First connecting nozzle; 63. Second connecting nozzle; 64. One-way valve plate; 65. End cap; 7. Heparin cap; 8. Rivet; 9. Detailed Implementation

[0049] To make the technical solutions and advantages of the embodiments of this application clearer, the exemplary embodiments of this application will be described in further detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not an exhaustive list of all embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of this application can be combined with each other.

[0050] In the description of this application and its embodiments, it should be understood that the terms "top", "bottom", "height", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0051] In this application and its embodiments, unless otherwise expressly specified and limited, the terms "set," "install," "connect," "link," "fix," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a communication connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0052] In this application and its embodiments, unless otherwise expressly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature being directly above or diagonally above the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0053] See Figures 1 to 6 As shown in the illustration, this application provides an anti-backflow indwelling venous catheter, including a cannula seat 1, a cannula body 2, a needle core assembly 3, and an external extension tube 4. The cannula seat 1 has an infusion channel, and the cannula body 2 is connected to the cannula seat 1 and communicates with the infusion channel. The needle core assembly 3 has a puncture needle 32 that can penetrate the infusion channel and the cannula body 2. One end of the external extension tube 4 is connected to the cannula seat 1, and the other end is connected to a three-way connector 5. The external extension tube 4 communicates with the infusion channel, and an anti-backflow valve 6 is provided on the external extension tube 4. The anti-backflow valve 6 allows liquid flow from the three-way connector 5 to the cannula seat 1 and blocks liquid flow from the cannula seat 1 to the three-way connector 5.

[0054] The anti-backflow indwelling venous catheter provided in this application is equipped with an anti-backflow valve 6 on the outer extension tube 4. The anti-backflow valve 6 ensures that the fluid flowing through the indwelling catheter can only flow in the direction of flowing into the patient's blood vessels, and cannot flow outward from the patient's blood vessels in the opposite direction. This ensures that during the use of the indwelling catheter of this application, blood can be prevented from flowing back into the indwelling catheter after infusion to form a thrombus that blocks the infusion channel, and also prevents the thrombus formed in the indwelling catheter from rushing into the patient's vein and causing potential health risks to the patient.

[0055] The tee connector 5 has a first interface connected to the outer extension tube 4, one interface is equipped with an end cap 7, and the other interface is equipped with a heparin cap 8. The sleeve body 2 is connected to the sleeve seat 1 by a rivet 9.

[0056] In some possible implementations, the external extension pipe 4 has a first pipe body 41 and a second pipe body 42. One end of the first pipe body 41 is connected to the sleeve seat 1, and the other end is connected to the anti-backflow valve 6; one end of the second pipe body 42 is connected to the tee connector 5, and the other end is connected to the anti-backflow valve 6. The anti-backflow valve 6 allows liquid flow from the second pipe body 42 to the first pipe body 41, and blocks liquid flow from the first pipe body 41 to the second pipe body 42. Dividing the external extension pipe 4 into two sections, the first pipe body 41 and the second pipe body 42, and placing the anti-backflow valve 6 between the first pipe body 41 and the second pipe body 42, does not affect the connection method between the external extension pipe 4 and the tee connector 5 and the sleeve seat 1. This results in fewer process changes and less modification to the production equipment required during production.

[0057] In some possible implementations, the length of the first tube 41 is less than the length of the second tube 42. The shorter the length of the first tube 41, the closer the anti-reverse valve 6 is to the patient's blood vessel, and the less likely there is to be fluid depletion or backflow of blood during limb movement.

[0058] In some possible implementations, the anti-backflow valve 6 has a body 61, a first connecting nozzle 63, and a second connecting nozzle 64. The body 61 includes a one-way fluid chamber 611. Both the first connecting nozzle 63 and the second connecting nozzle 64 are connected to the body 61, located on opposite sides of the body 61, and both communicate with the one-way fluid chamber 611. The first connecting nozzle 63 is connected to the first tube 41, and the second connecting nozzle 64 is connected to the second tube 42. The outer extension tube 4 is a relatively flexible tube. The anti-backflow valve 6 has the first connecting nozzle 63 and the second connecting nozzle 64 at both ends to connect to the first tube 41 and the second tube 42 respectively, making the production connection process easier to operate and improving production efficiency. The first connecting nozzle 63 and the second connecting nozzle 64 are located on both sides of the body 61, making the outer extension tube 4 smoother after connecting to the first tube 41 and the second tube 42, and easier to use. Preferably, the first connecting nozzle 63 and the second connecting nozzle 64 can be made of rigid material, and the first connecting nozzle 63 and the second connecting nozzle 64 can be tapered tubes with a smaller diameter as they are farther away from the column. This makes the assembly process more convenient and faster when the first connecting nozzle 63 and the second connecting nozzle 64 are connected to the first tube body 41 and the second tube body 42, respectively.

[0059] In some possible implementations, the first connecting nozzle 63 and the second connecting nozzle 64 are located on the same straight line. This arrangement eliminates bends in the flow path, resulting in less resistance and smoother flow of the liquid as it passes through the anti-backflow valve 6. Furthermore, this arrangement allows the first connecting nozzle 63 and the second connecting nozzle 64 to connect to the first tube body 41 and the second tube body 42 respectively, creating a high degree of integration between the outer extension tube 4 and the backflow valve, making them appear as a single tube and thus more convenient to use.

[0060] In some possible implementations, the anti-backflow valve 6 includes a one-way valve plate 65. The main body 61 includes an upper cover 612 and a lower cover 613 connected together, forming the one-way fluid cavity 611 between the upper cover 612 and the lower cover 613. A first connecting nozzle 63 is connected to the lower cover 613, and a second connecting nozzle 64 is connected to the upper cover 612. The upper cover 612 has a mating cavity 6121 communicating with the one-way fluid cavity 611 and the second connecting nozzle 64, and the one-way valve plate 65 is movably disposed within the one-way fluid cavity 611. When the fluid pressure inside the second connecting nozzle 64 is greater than the fluid pressure inside the first connecting nozzle 63, the one-way valve plate 65 at least partially disengages from the upper cover 612, and the mating cavity 6121, the one-way fluid cavity 611, and the first connecting nozzle 63 are connected. When the fluid pressure inside the first connecting nozzle 63 is greater than the fluid pressure inside the second connecting nozzle 64, the one-way valve plate 65 adheres to the upper cover 612 and closes the mating cavity 6121. The one-way valve plate 65 is movably disposed within the one-way fluid cavity 611, ensuring that the liquid can only flow from the second connecting nozzle 64 to the first connecting nozzle 63 under the impact of the liquid. If the liquid tends to flow from the first connecting nozzle 63 to the second connecting nozzle 64, the one-way valve plate 65 adheres to the upper cover 612 to prevent the liquid from flowing. The upper cover 612 and the lower cover 613 can be interference-fitted to ensure that the liquid will not leak from the connection seal after the upper cover 612 and lower cover 613 are fastened together. The main body 61 is configured with two covers, an upper cover 612 and a lower cover 613, which facilitates the installation of the one-way valve plate 65 into the main body 61. The one-way fluid cavity 611 is partially located inside the upper cover 612 and partially inside the lower cover 613. When the upper cover 612 and the lower cover 613 are fastened together, a complete one-way fluid cavity 611 is formed.

[0061] In some possible implementations, the upper cover 612 has an annular stepped surface 6122, which encloses the opening of the one-way fluid cavity 611 that connects to the mating cavity 6121. A portion of the surface of the one-way valve plate 65 is attached to the annular stepped surface 6122. When the fluid pressure inside the second connecting nozzle 64 is greater than the fluid pressure inside the first connecting nozzle 63, at least a portion of the surface of the one-way valve plate 65 detaches from the annular stepped surface 6122, and the mating cavity 6121, the one-way fluid cavity 611, and the first connecting nozzle 63 become connected. When the fluid pressure inside the first connecting nozzle 63 is greater than the fluid pressure inside the second connecting nozzle, the entire one-way valve plate 65 is attached to the annular stepped surface 6122 to close the opening of the mating cavity 6121. The partial attachment of the one-way valve plate 65 to the annular stepped surface 6122 can fix the position of the one-way valve plate 65 and prevent it from flipping or curling due to liquid impact. The one-way valve plate 65 can be circular, adapting to the shape of the annular stepped surface 6122. When the one-way valve plate 65 is attached to the annular stepped surface 6122, it completely covers the opening of the mating cavity 6121 without any gaps.

[0062] In some possible implementations, a top tube 62 is provided inside the lower cover 613. The top tube 62 is located in the one-way fluid cavity 611 and extends toward the mating cavity 6121. The top tube 62 has a cavity 621, and a connecting portion is provided on the peripheral sidewall of the top tube 62, connecting the cavity 621 and the one-way fluid cavity 611. The one-way valve plate 65 is located between the mating cavity 6121 and the top tube 62. When the fluid pressure inside the second connecting nozzle 64 is greater than the fluid pressure inside the first connecting nozzle 63, the one-way valve plate 65 is attached to the end of the top tube 62, and the connecting portion maintains communication between the cavity 621 and the one-way fluid cavity 611. The top tube 62 further limits the position of the one-way valve plate 65 to prevent the one-way valve plate 65 from being excessively bent and difficult to reset due to the impact of the liquid, thereby causing the anti-reverse valve 6 to fail. The cavity 621 of the jacking pipe 62 is connected to the first connecting nozzle 63. When the liquid medicine impacts the one-way valve plate 65 and flips towards the first connecting nozzle 63, the one-way valve plate 65 will cover the top surface of the jacking pipe 62. In order to prevent the liquid medicine from being cut off, a connecting part is provided on the side wall of the jacking pipe 62. The one-way valve plate 65 will not cover the side wall of the jacking pipe 62, and the liquid medicine can flow into the cavity 621 through the connecting part.

[0063] In some possible implementations, the end of the jacking tube 62 near the mating cavity 6121 is provided with an opening, and the connecting portion includes a plurality of notches 622 disposed around the edge of the opening. When the fluid pressure inside the second connecting nozzle 64 is greater than the fluid pressure inside the first connecting nozzle 63, the one-way valve plate 65 closes the opening, and each of the notches 622 maintains communication between the cavity 621 and the one-way fluid cavity 611. The opening abuts against the one-way valve plate 65, allowing the liquid medicine to flow into the cavity 621 through the notches 622.

[0064] In some possible implementations, the upper cover 612 has a first peripheral sidewall 6123, and the lower cover 613 has a second peripheral sidewall 6131. ​​The first peripheral sidewall 6123 includes an outer sidewall 61231 and an inner sidewall 61232, which are connected to form an annular slot. The second peripheral sidewall 6131 is inserted into the annular slot. The inner sides of the first peripheral sidewall 6123 and the second peripheral sidewall 6131 have the unidirectional fluid cavity 611. The first peripheral sidewall 6123 and the second peripheral sidewall 6131 are interference-fitted to ensure that no medicine leaks from the connection seal after the upper cover 612 and the lower cover 613 are fastened together. The second side wall 6131 is interference-fitted between the inner side wall 61232 and the outer side wall 61231. A connecting bottom wall is also provided between the inner side wall 61232 and the outer side wall 61231. The connecting bottom wall plays a positioning role for the second side wall 6131, limiting the depth of the lower cover inserted into the upper cover, and preventing the lower cover 613 from being over-inserted and affecting the position of the one-way valve plate 65.

[0065] In some possible implementations, the needle core assembly 3 includes a rubber stopper 31, a puncture needle 32, a safety clip 33, an L-shaped safety plate 34, a safety sleeve 35, and a puncture needle hub 36. The puncture needle 32, safety clip 33, L-shaped safety plate 34, safety sleeve 35, and puncture needle hub 36 are integrated as a single unit. When using this indwelling needle, the puncture needle hub 36 is held to guide the puncture needle 32 into the patient's injection site. Then, the cannula body 2 is guided into the patient's blood vessel through the puncture needle 32. The puncture needle 32 is then withdrawn, leaving the cannula body 2 in the patient's blood vessel. Simultaneously with the withdrawal of the puncture needle 32, the safety clip 33, L-shaped safety plate 34, safety sleeve 35, and puncture needle hub 36 detach from the other structures of the indwelling needle. The rubber stopper 31 seals the side of the cannula hub 1 from which the puncture needle 32 is withdrawn, ensuring that the medication flows only towards the cannula body 2.

[0066] It should be noted that the embodiments of this application merely add an anti-reverse valve (or one-way valve) to the outer extension tube of the existing indwelling needle. This application does not improve other parts of the indwelling needle. For example, the structure of the needle core assembly 3 in this application is mature prior art, and its internal structural components, such as the rubber stopper 31, puncture needle 32, safety clip 33, L-shaped safety plate 34, safety sleeve 35, and puncture needle seat 36, as well as their mating structure with the cannula seat 1, are all mature prior art. This application will not elaborate on its structural principles. This application does not limit its specific structure; the needle core assembly 3 can directly adopt mature products of the prior art.

[0067] The foregoing disclosure provides many different embodiments or examples for implementing different structures of this application. To simplify the disclosure, specific examples of components and arrangements are described above. Of course, these are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this application, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0068] Although preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0069] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. An anti-reflux venous indwelling needle, characterized in that, include: A cannula seat, wherein the cannula seat has an infusion channel; The cannula body is connected to the cannula seat and is connected to the infusion channel; A needle core assembly, wherein the needle core assembly has a puncture needle that can penetrate the infusion channel and the cannula body; An external extension tube is provided, with one end connected to the sleeve seat and the other end connected to a tee connector. The external extension tube connects to the infusion channel and is equipped with an anti-backflow valve. The anti-backflow valve allows the liquid flow from the tee connector to the sleeve seat and blocks the liquid flow from the sleeve seat to the tee connector.

2. The anti-reflux venous indwelling needle according to claim 1, characterized in that, The outer extension tube has a first tube body and a second tube body; One end of the first tube is connected to the sleeve seat, and the other end is connected to the anti-backflow valve; One end of the second pipe is connected to the tee connector, and the other end is connected to the anti-backflow valve; The anti-reverse valve allows liquid flow from the second pipe to the first pipe, and the anti-reverse valve blocks liquid flow from the first pipe to the second pipe.

3. The anti-reflux venous indwelling needle according to claim 2, characterized in that, The length of the first tube is less than the length of the second tube.

4. The anti-reflux venous indwelling needle according to claim 2, characterized in that, The anti-reverse valve has a main body, a first connecting nozzle, and a second connecting nozzle. The main body has a one-way fluid cavity. The first connecting nozzle and the second connecting nozzle are both connected to the main body. The first connecting nozzle and the second connecting nozzle are disposed on opposite sides of the main body. The first connecting nozzle and the second connecting nozzle are both connected to the one-way fluid cavity. The first connecting nozzle is connected to the first tube body, and the second connecting nozzle is connected to the second tube body.

5. The anti-reflux venous indwelling needle according to claim 4, characterized in that, The first connector and the second connector are located on the same straight line.

6. The anti-reflux venous indwelling needle according to claim 4, characterized in that, Including one-way valve plates; The main body includes an upper cover and a lower cover, the upper cover and the lower cover are connected, and a one-way fluid cavity is formed between the upper cover and the lower cover. The first connecting nozzle is connected to the lower cover, and the second connecting nozzle is connected to the upper cover. The upper cover has a mating cavity that connects the unidirectional fluid cavity and the second connecting nozzle; The one-way valve plate is movably disposed within the one-way fluid cavity; When the fluid pressure inside the second connecting nozzle is greater than the fluid pressure inside the first connecting nozzle, the one-way valve plate is at least partially disengaged from the upper cover, and the mating cavity, the one-way fluid cavity, and the first connecting nozzle are connected. When the fluid pressure inside the first connector is greater than the fluid pressure inside the second connector, the one-way valve plate adheres to the upper cover and closes the mating cavity.

7. The anti-reflux venous indwelling needle according to claim 6, characterized in that, The upper cover has an annular stepped surface, which encloses and forms an opening for the unidirectional fluid cavity to communicate with the mating cavity; The surface of the one-way valve plate is attached to the annular stepped surface; When the fluid pressure inside the second connecting nozzle is greater than the fluid pressure inside the first connecting nozzle, at least a portion of the surface of the one-way valve plate disengages from the annular stepped surface, and the mating cavity, the one-way fluid cavity, and the first connecting nozzle are connected. When the fluid pressure inside the first connector is greater than the fluid pressure inside the second connector, the one-way valve plate is fully fitted to the annular stepped surface to close the opening of the mating cavity.

8. The anti-reflux venous indwelling needle according to claim 6, characterized in that, A top tube is provided on the inner side of the lower cover. The top tube is located in the one-way fluid cavity and extends toward the mating cavity. The top tube has a cavity, and a connecting part is provided on the peripheral side wall of the top tube to connect the cavity and the one-way fluid cavity. The one-way valve plate is located between the mating cavity and the top pipe; When the fluid pressure inside the second connecting nozzle is greater than the fluid pressure inside the first connecting nozzle, the one-way valve plate is attached to the end of the top pipe, and the connecting part remains connected to the pipe cavity and the one-way fluid cavity.

9. The anti-reflux venous indwelling needle according to claim 8, characterized in that, The top pipe is provided with a pipe opening at one end near the mating cavity, and the connecting part includes a plurality of notches provided around the edge of the pipe opening; When the fluid pressure inside the second connector is greater than the fluid pressure inside the first connector, the one-way valve plate closes the pipe opening, and each of the notches remains connected to the pipe cavity and the one-way fluid cavity.

10. The anti-reflux venous indwelling needle according to claim 6, characterized in that, The upper cover has a first peripheral sidewall, and the lower cover has a second peripheral sidewall; The first peripheral sidewall includes an outer sidewall and an inner sidewall, the outer sidewall and the inner sidewall are connected, and an annular slot is formed between the outer sidewall and the inner sidewall; The second circumferential sidewall is inserted into the annular slot; The inner sides of the first and second peripheral sidewalls have the unidirectional fluid cavity.

Images