Disposable long cannula indwelling trocar

Abstract

The invention relates to the technical field of manufacturing of medical instruments, in particular to a disposable long-cannula indwelling trocar which is beneficial to recycling of tiny parts and improvement of pushing stability of a puncture needle or a guide wire and is provided with a puncture assembly, a cannula assembly and an outer protective sleeve assembly, and the outer protective sleeve assembly comprises an outer protective sleeve and a supporting sleeve. The supporting sleeve is located in the outer protective sleeve, the supporting sleeve is connected to the sleeve assembly in a sleeved mode, and a guide groove used for pushing is formed in the side face of the outer protective sleeve. One side of the left supporting sleeve is connected with one side of the right supporting sleeve, the recycling connecting belt extends in the length direction of the outer protective sleeve, and a positioning component is arranged at the tail end of the recycling connecting belt. Compared with the prior art, the medical instrument pushing device has the remarkable advantages that the structure is reasonable, pushing is stable and smooth, tiny parts are easy to recycle, and the implantation success rate of medical instruments can be increased.

Description

Technical Field

[0001] This invention relates to the field of medical device manufacturing technology, specifically to a disposable long cannula indwelling needle with a reasonable structure, smooth delivery, and facilitates the recovery of small parts and improves the stability of puncture needle or guidewire delivery. Background Technology

[0002] Medium-length cannulas are medical devices primarily used for peripheral vascular infusion of drugs, with a cannula length of 8-25 cm. The adoption and usage rate of medium-length cannulas in China is very low, indicating they are still in the early stages of development. However, they are used effectively in many clinical departments abroad, such as gastroenterology, respiratory medicine, oncology, internal medicine, surgery, and even emergency medicine. Medium-length cannulas can be left in place for up to 30 days, reducing patient discomfort from repeated punctures, leakage, the incidence of phlebitis, and discomfort during infusion.

[0003] Existing medium-length cannulas have two main support components. One is a detachable sheath structure that detaches after support is provided, but this has the disadvantage of being small and easily lost, posing a risk of being swallowed by children. The other is an integrated design where the cannula seat is pushed to the middle position and the protective sheath separates at the front end; however, this design offers poor support after separation. To address these issues, a connecting strap structure with an invisible design is adopted, ensuring the component remains intact after use. For medium-length cannulas, the cannula and guidewire push angles are typically designed to be horizontal or vertical, with the push groove designed at a reasonable angle. This design conforms to ergonomics and avoids contact between medical staff and the patient's skin during operation. Medium-length cannulas are typically 10 cm long and generally designed for guidewire insertion. Through a reasonable design, medical staff can feel the push process and the point of insertion with different sensations, allowing them to confirm placement by touch without visual inspection. A rigid bushing with a supporting effect is added to the front end of the soft cannula to ensure that the front end of the cannula does not deform.

[0004] Existing products of this kind, such as the disposable long cannula needle placement device described in patent document CN115252958A, include multiple components, including a support sleeve for supporting the cannula seat. To facilitate the smooth disengagement of the cannula seat, the support sleeve is composed of a left support sleeve and a right support sleeve fastened together. During use, the left / right support sleeves and the cannula seat are pushed out of the outer protective sleeve. When the left / right support sleeves lose the fastening pressure of the outer protective sleeve, they naturally detach from the outside of the cannula seat. The detached left / right support sleeves are small in size, requiring special collection by medical staff, which reduces the efficiency of clinical operations. In addition, when the support sleeve is pressed against the surface of the cannula seat and pushed along the axial direction of the outer protective sleeve, the push should be smooth. In the prior art, since the support sleeve is formed by two separate parts fastening together, the pressing force of the outer protective sleeve is required to ensure that the two parts fasten smoothly and accurately. This results in the outer wall of the support sleeve being in close contact with the inner wall of the outer protective sleeve, causing greater resistance during the push process. Summary of the Invention

[0005] This invention addresses the shortcomings and deficiencies of existing technologies by proposing a disposable long cannula indwelling needle that has a reasonable structure, smooth delivery, facilitates the recovery of small parts, and improves the stability of puncture needle or guide wire delivery.

[0006] This invention achieves its purpose through the following measures: A disposable long-cannula indwelling needle includes a puncture assembly, a cannula assembly, and an outer protective sleeve assembly. The outer protective sleeve assembly includes an outer protective sleeve and a support sleeve, with the support sleeve located inside the outer protective sleeve and fitted onto the cannula assembly. A guide groove for pushing is formed on the side of the outer protective sleeve. The support sleeve comprises a left support sleeve, a right support sleeve, and a retrieval connecting band connected to either the left or right support sleeve. The left and right support sleeves are connected on one side. The retrieval connecting band extends along the length of the outer protective sleeve, and a positioning component is provided at the end of the retrieval connecting band. A guide groove for accommodating the retrieval connecting band is formed on the inner wall of the outer protective sleeve, and a protrusion or groove for engaging with the positioning component is provided at the front end of the guide groove. The guide groove for pushing is formed on the upper side of the outer protective sleeve, and in the cross-section of the outer protective sleeve, the line connecting the center line of the guide groove and the center point forms an angle of 20°-70° with the horizontal direction.

[0007] The puncture assembly of this invention comprises a puncture needle tube and a needle handle. The cannula assembly includes a cannula and a cannula seat. The end of the cannula is connected to the cannula seat. The cannula seat has a cavity communicating with the cannula. The cannula seat has a sealing plug for sealing the rear end of the cannula seat. An incision is made on the sealing plug. The puncture needle tube passes through the incision on the sealing plug along the rear end of the cannula seat and extends into the cannula. The side of the cannula seat also has an infusion bypass tube communicating with the cavity inside the cannula seat. The left and right support sleeves of the support sleeve are respectively pressed onto the cannula seat and the left and right sides of the rear end of the cannula, and the left and right support sleeves are interlocked. The contact surfaces of the left and right support sleeves have matching fittings. The groove and the fitting protrusion ensure accurate engagement between the two. The outer wall of the support sleeve partially contacts the inner wall of the outer protective sleeve, meaning the outer surface of the support sleeve is not completely fitted to the inner wall of the outer protective sleeve, thus reducing resistance during the pushing process. Furthermore, the cross-section of the outer protective sleeve is elliptical, olive-shaped, or circular, while the cross-section of the support sleeve only partially conforms to the cross-section of the outer protective sleeve, meaning only a portion of its arc segments fit the curvature of the cross-section of the outer protective sleeve. Preferably, the cross-section of the outer protective sleeve is elliptical or olive-shaped, and the cross-section of the support sleeve is rhomboid, with convex arc segments at the four corners of the rhombus that fit against the inner wall of the outer protective sleeve, thereby effectively reducing pushing resistance.

[0008] The outer protective sleeve of the present invention is provided with a needle-holding wing on the outside. The needle-holding wing is horizontally arranged. The needle-holding wing and the guide groove are respectively located on both sides of the central axis of the outer protective sleeve, that is, on the cross-section of the outer protective sleeve. The line connecting the guide groove and the center point is at an angle of 110°-160° with the needle-holding wing. This structure can ensure that the operator's hand will not touch the patient's arm when pushing the needle, avoid the fluctuation when pushing the guide wire, and improve the pushing stability.

[0009] The present invention also includes a guidewire pushing mechanism, which is located at the rear of the outer protective sleeve. The guidewire extends along the cannula / puncture needle tube. A guidewire pushing guide groove is formed on the rear outer wall of the outer protective sleeve. The guidewire pushing guide groove is coaxially arranged with the guide groove. A guidewire seat is built into the rear end of the outer protective sleeve. A push handle is connected to the guidewire seat. A countersunk hole for fixing the rear end of the guidewire is formed on the guidewire seat. The guidewire seat is set inside the outer protective sleeve and connected to the push handle. The push handle extends out of the outer protective sleeve along the guidewire pushing guide groove. The width of the beginning and end of the guidewire pushing guide groove is slightly larger than the thickness of the push handle to form a clearance fit with the push handle, while the guide groove at other positions forms a transition fit with the push handle. This allows the operator to obtain a damping feeling during the pushing process and to estimate the pushing distance of the guidewire by hand to determine whether it is in place.

[0010] The present invention further includes a locking needle tip assembly inside the outer protective sleeve. Specifically, a locking needle tip assembly is provided between the guide wire pushing mechanism and the sheath assembly. The locking needle tip assembly uses two overlapping Z-shaped spring pieces. The two Z-shaped spring pieces share a straight section at the front end. Corresponding needle tube through holes are opened on the straight sections at the front and rear ends of the spring pieces. During and before puncture, the needle tube extends towards the front end of the outer protective sleeve along the needle tube through hole. After puncture, the puncture needle retracts to the rear side of the locking needle tip assembly, and the two Z-shaped spring pieces overlap to seal the needle tube through hole, thereby locking the puncture needle inside the outer protective sleeve and preventing injury to the retrieval operator.

[0011] The outer protective sleeve of this invention has an elliptical or olive-shaped cross-section, forming a flat outer protective sleeve body, making it easier to hold and facilitating the creation of a wider outer wall space for setting guide grooves. The support sleeve has a rhomboid cross-section, with convex arc segments at each of the four corners. The support sleeve is divided into a snap-fit ​​left support sleeve and a right support sleeve along the short axis of the cross-section. The left and right support sleeves snap together to form a sleeve body that adapts to the sleeve seat. The left and right support sleeves open and close at one end along the short axis of the cross-section, and are connected at the other end by a snap-fit ​​connecting band. The snap-fit ​​connecting band is convex arc-shaped, with its two ends connected to the upper side of the left / right support sleeves respectively. The left / right support sleeves have hollowed-out portions near the snap-fit ​​connecting band, allowing the snap-fit ​​connecting band to be partially open. The remaining portion of the outer end has a gap with the support sleeve. The fastening connecting strip is adapted to the contour of the support sleeve. When the support sleeve is placed inside the outer protective sleeve, the outer side of the fastening connecting strip fits against the inner wall of the outer protective sleeve. This structure allows for adjustment when the left and right support sleeves are not properly fastened, using the gap between the fastening connecting strip and the left / right support sleeves. The fitting grooves and protrusions on the mating surfaces of the left and right support sleeves can be used for quick alignment. After alignment, the fastening connecting strip acts as a point of contact between the support sleeve and the outer protective sleeve, ensuring effective contact area during the pushing process to improve pushing stability. Furthermore, the connection point between the fastening connecting strip and the upper side of the left / right support sleeve is located at approximately half the length of the left / right support sleeve. Correspondingly, the cross-section of the guide wire seat is also elliptical or olive-shaped.

[0012] The recycling connecting strip of the present invention is set at the rear end of the side of the support sleeve. The end of the recycling connecting strip is provided with an anchor-shaped or arrow-shaped hook component, and a guide groove is correspondingly opened on the inner wall of the outer protective sleeve. The front end of the guide groove is provided with a groove or a stop protrusion for engaging with the hook component. The outer protective sleeve adopts a tubular body with an elliptical or olive-shaped cross section. The guide groove is opened on one side of its long axis. Compared with the existing circular cross section tube, its side space can be effectively utilized without affecting the thickness and strength of the outer protective sleeve.

[0013] The cannula assembly of this invention is made of soft material, meaning that both the cannula and the cannula seat can deform to a certain extent with human movement. This allows the cannula inserted into the human body to twist with the blood vessels, ensuring the stability of the device insertion. However, in order to avoid the flow rate from decreasing due to deformation at the cannula tip, a cylindrical support frame is built into the cannula tip to enhance the strength of the cannula tip.

[0014] In this invention, the puncture component, guide component, and guidewire pushing component are sequentially assembled and placed inside the outer protective sleeve. The pushing handle of the pushing component extends along the guidewire guide groove of the outer protective sleeve, and the pushing handle is located at the starting end of the guidewire guide groove. During use, the pushing handle is pushed along the guide groove. Because the fit between the guide groove and the pushing handle changes from a clearance fit to a transition fit, the operator will feel resistance during the pushing process until it reaches the end of the guide groove. At this point, the push handle and the guide groove change from a transition fit to a clearance fit, and the operator can confirm that the pushing is in place by feel. At the same time, because the guidewire guide groove is located on the upper side of the outer protective sleeve and forms an angle of 20°-70° with the long axis of the cross-section of the outer protective sleeve, the operator's hand will not touch the patient's arm during the pushing process, which can further ensure the smoothness and stability of the pushing. During puncture, the infusion tube connected to the cannula seat is pushed along the guide groove. Similarly, due to the 20-70° opening angle of the guide groove, the pushing process does not... Touching the patient's arm may cause puncture blockage or instability. The cannula seat and its outer support sleeve are gradually pushed out of the outer protective sleeve. When the left and right support sleeve bodies are fully exposed outside the outer protective sleeve, the left and right support sleeve bodies can be gently pulled apart from the cannula seat. At this time, the puncture needle continues to perform puncture and withdrawal. The cannula and cannula seat are left in place. The outer protective sleeve and support sleeve are connected by a recycling strap and can be disposed of as a whole as a disposable part, without worrying about leaving small parts behind. During the product assembly process, the support sleeve is fastened to the outside of the cannula seat and then inserted into the outer protective sleeve together. Through the gap between the fastening strap and the support sleeve body in this solution, it can be ensured that the support sleeve is quickly aligned inside the outer protective sleeve during insertion, and the left and right parts are stably fastened. The outward convex arc design of the support sleeve effectively reduces the contact area between its outer wall and the inner wall of the outer protective sleeve, making the operation easier and smoother, and making it easier for the operator to find the feel.

[0015] Compared with existing technologies, this invention has significant advantages such as reasonable structure, stable and smooth pushing, easy recycling of small parts, and improved success rate of medical device placement. Attached Figure Description Appendix Figure 1 This is a schematic diagram of the structure of the present invention.

[0016] Appendix Figure 2 This is the present invention. Figure 1 A partial sectional view.

[0017] Appendix Figure 3This is a schematic diagram of one possible structural configuration of the support sleeve and the outer protective sleeve in this invention. Figure 3 In diagram 'a', the overall assembly drawing of the support sleeve and the outer protective sleeve is shown; 'b' is a cross-sectional view; and 'c' is a sectional view along line AA.

[0018] Appendix Figure 4 This is a schematic diagram of the support sleeve in this invention, wherein... Figure 4 In diagram a, the support sleeve is shown in its engaged state; in diagram b, the sleeve is shown in its engaged state; and in diagram c, the sleeve is shown in its unfolded state.

[0019] Appendix Figure 5 This is a schematic diagram of the sleeve and the built-in cylindrical support frame in this invention.

[0020] Appendix Figure 6 This is a schematic diagram of the structure of Embodiment 2 of the present invention.

[0021] Reference numerals: 1. Outer protective sleeve; 2. Support sleeve; 3. Left support sleeve; 4. Right support sleeve; 5. Recycling connecting strap; 6. Guide groove; 7. Needle holding wing; 8. Pushing component; 9. Starting end; 10. End; 11. Fastening connecting strap; 12. Hollowed-out part; 13. Cylindrical support frame; 14. Guide wire; 15. Guide wire pushing guide groove; 16. Guide wire seat; 17. Push handle; 18. Locking needle tip assembly; 19. Protective cap; 20. Sleeve; 21. Sleeve seat; 22. Puncture needle; 23. Infusion side tube; 24. Fitting groove / fitting protrusion; 25. Detailed Implementation The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0022] Example 1: As attached Figure 1 As shown, this example provides a disposable long-cannula indwelling needle, comprising a puncture assembly, a cannula assembly, an outer protective sleeve assembly, and a pushing component 9. The outer protective sleeve assembly includes an outer protective sleeve 1 and a support sleeve 2, with the support sleeve 2 located inside the outer protective sleeve 1 and fitted onto the cannula assembly. A guide groove 7 for pushing is formed on the side of the outer protective sleeve 1. The support sleeve 2 includes a left support sleeve 3 and a right support sleeve 4 that interlock, and a recovery connecting strap 5 connected to either the left or right support sleeve 3. The left... The support sleeve 3 is connected to the right support sleeve 4 on one side. The recycling connecting strip 5 extends along the length of the outer protective sleeve 1, and the end of the recycling connecting strip 5 is provided with a positioning component. The inner wall of the outer protective sleeve 1 is provided with a guide groove 6 for accommodating the recycling connecting strip 5. The front end of the guide groove 6 is provided with a protrusion or groove for engaging with the positioning component. The guide groove 7 for pushing is provided on the upper side of the outer protective sleeve 1. In the cross-section of the outer protective sleeve 1, the line connecting the center line of the guide groove 7 and the center point is at an angle of 20°-70° with the horizontal direction, preferably 45°. The puncture assembly described in this example consists of a puncture needle tube and a needle handle. The cannula assembly includes a cannula 21 and a cannula seat 22. The end of the cannula 21 is connected to the cannula seat 22. The cannula seat 22 has a cavity that communicates with the cannula 21. The cannula seat 22 has a sealing plug for sealing the rear end of the cannula seat 22. An incision is made on the sealing plug. The puncture needle 23 passes through the incision on the sealing plug along the rear end of the cannula seat 22 and extends into the cannula 21. The side of the cannula seat 22 also has an infusion bypass tube 24 that communicates with the cavity inside the cannula seat. The left support sleeve 3 and the right support sleeve 4 of the support sleeve 2 are respectively pressed onto the left and right sides of the sleeve seat 22 and the rear end of the sleeve 21, and the left support sleeve 3 and the right support sleeve 4 are fastened to each other. The contact surfaces of the left support sleeve 3 and the right support sleeve 4 are provided with matching grooves and protrusions to ensure that the two are accurately fastened. The outer wall of the support sleeve 2 is in partial contact with the inner wall of the outer protective sleeve 1, that is, the outer surface of the support sleeve 2 is not completely attached to the inner wall of the outer protective sleeve 1 to reduce the resistance during the pushing process. The outer protective sleeve 1 is provided with a needle holding wing 8 on its outer side. The needle holding wing 8 is horizontally arranged. The needle holding wing 8 and the guide groove 7 are located on both sides of the central axis of the outer protective sleeve 1, that is, on the cross-section of the outer protective sleeve 1. The line connecting the guide groove 7 and the center point is at an angle of 110°-160° with the needle holding wing 8. This structure can ensure that the operator's hand will not touch the patient's arm when the needle is pushed, avoid the undulation when the puncture needle is pushed, and improve the pushing stability. This example also includes a guidewire pushing mechanism, which is located at the rear of the outer protective sleeve 1. The guidewire 15 extends along the cannula / puncture needle tube. A guidewire pushing guide groove 16 is formed on the outer wall of the rear part of the outer protective sleeve 1. The guidewire pushing guide groove 16 is coaxially arranged with the guide groove 7. A countersunk hole for fixing the rear end of the guidewire is formed on the guidewire seat 17. The guidewire seat 17 is set inside the outer protective sleeve 1 and is connected to the push handle 18. The push handle 18 extends out of the outer protective sleeve 1 along the guidewire pushing guide groove 16. The width of the beginning and end of the guidewire pushing guide groove 16 is slightly larger than the thickness of the push handle to form a clearance fit with the push handle, while the guidewire pushing guide grooves at other positions form a transition fit with the push handle, so that the operator can obtain a damping feeling during the pushing process and estimate the pushing distance of the guidewire by hand to determine whether it is in place.

[0023] Example 2: As attached Figure 3As shown, this example retains the structural components of Embodiment 1, but compared to Embodiment 1, the cross-section of the outer protective sleeve 1 in this example is elliptical, olive-shaped, or circular, while the cross-section of the support sleeve 2 is only partially conformal to the cross-section of the outer protective sleeve, that is, only a portion of the arc segment fits the arc of the cross-section of the outer protective sleeve 1. The cross-section of the outer protective sleeve 1 is elliptical or olive-shaped, and the cross-section of the support sleeve 2 is rhomboid, with convex arc segments at the four corners of the rhombus that fit against the inner wall of the outer protective sleeve 1, thereby effectively reducing the pushing resistance. In this example, the outer protective sleeve 1 has an elliptical or olive-shaped cross-section, forming a flat outer protective sleeve 1 body, making it easier to hold and facilitating the formation of a wider outer wall space for setting the guide groove 7. The support sleeve 2 has a rhomboid cross-section, and each of the four corners of the cross-section of the support sleeve 2 has an outwardly convex arc segment. The support sleeve 2 is divided into a snap-fit ​​left support sleeve 3 and a right support sleeve 4 along the short axis of the cross-section. The left support sleeve 3 and the right support sleeve 4 snap together to form a sleeve body that adapts to the sleeve seat. The left support sleeve 3 and the right support sleeve 4 open and close at one end along the short axis of the cross-section, and are connected at the other end of the short axis of the cross-section by a snap-fit ​​connecting band 12. The snap-fit ​​connecting band 12 is an outwardly convex arc shape, and its two ends are respectively connected to the upper side of the left / right support sleeve. The left / right support sleeve has a hollowed-out portion 1 near the snap-fit ​​connecting band 12. 3. The fastening connecting strip 12, except for the two ends, has a gap with the support sleeve 2. The fastening connecting strip 12 is adapted to the contour of the support sleeve 2. When the support sleeve 2 is placed inside the outer protective sleeve 1, the outer side of the fastening connecting strip 12 fits against the inner wall of the outer protective sleeve 1. This structure allows for adjustment when the left support sleeve 3 and the right support sleeve 4 are not properly fastened, using the gap between the fastening connecting strip 12 and the left / right support sleeve. The matching groove / protrusion 25 on the contact surface of the left support sleeve 3 and the right support sleeve 4 can be used to quickly align the connection. After alignment, the fastening connecting strip acts as a point of contact between the support sleeve 2 and the outer protective sleeve 1. During the pushing process, the effective contact area can be used to improve the pushing stability. The connection point between the fastening connecting strip 12 and the upper side of the left / right support sleeve 2 is located at approximately half the length of the left / right support sleeve. As attached Figure 4 As shown, the recycling connecting strip 5 in this example is set at the rear end of the side of the support sleeve 2. The end of the recycling connecting strip 5 is provided with an anchor-shaped or arrow-shaped hook component, and a corresponding guide groove is opened on the inner wall of the outer protective sleeve 1. The front end of the guide groove is provided with a groove or a stop protrusion for fitting with the hook component. The outer protective sleeve 1 adopts a tubular body with an elliptical or olive-shaped cross section. The guide groove is opened on one side of its cross section major axis. Compared with the existing circular cross section tube cavity, its side space can be effectively utilized, and it will not affect the thickness and strength of the outer protective sleeve.

[0024] In this example, the cannula assembly is made of soft material, meaning that both the cannula and the cannula seat can deform to a certain extent with the movement of the human body. This allows the cannula to twist with the blood vessels after being inserted into the human body, ensuring the stability of the device insertion. However, in order to avoid the flow rate from decreasing due to deformation at the front end of the cannula, a cylindrical support frame 14 is built into the front end of the cannula to enhance the strength of the front end of the cannula.

[0025] In this example, a locking needle tip assembly 19 is also provided inside the outer protective sleeve. Specifically, a locking needle tip assembly 19 is provided between the guide wire pushing mechanism and the sheath assembly. The locking needle tip assembly 19 uses two overlapping Z-shaped spring pieces. The two Z-shaped spring pieces share a straight section at the front end. Corresponding needle tube through holes are opened on the straight sections at the front and rear ends of the spring pieces. During and before puncture, the needle tube extends towards the front end of the outer protective sleeve along the needle tube through hole. After puncture, the puncture needle retracts to the rear side of the locking needle tip assembly, and the two Z-shaped spring pieces overlap to seal the needle tube through hole, thereby locking the puncture needle inside the outer protective sleeve and preventing injury to the retrieval operator.

[0026] In this invention, a protective cap 20 is provided at the front end, which is fastened to the front end of the outer protective sleeve 1. The puncture component, guide component, and push component are assembled sequentially and placed into the outer protective sleeve. The push handle of the push component extends along the guide groove of the outer protective sleeve, and the push handle is located at the push start end of the guide groove. During use, the push handle is pushed along the guide groove. Because the fit between the guide groove and the push handle changes from a clearance fit to a transition fit, the operator will feel resistance during the push process until it reaches the end of the guide groove. At this point, the push handle and the guide groove change from a transition fit to a clearance fit, and the operator can confirm that the push is in place by feel. At the same time, because the guide groove is opened on the upper side of the outer protective sleeve and forms an angle of 20°-70° with the long axis of the cross-section of the outer protective sleeve, the operator's hand will not touch the patient's arm during the push process, which can further ensure the smoothness and stability of the push. During puncture, the push component connected to the cannula seat is pushed along the guide groove. As the components are inserted, the cannula seat and its outer support sleeve are gradually pushed out of the outer protective sleeve. When the left and right support sleeve bodies are fully exposed outside the outer protective sleeve, the left and right support sleeve bodies can be gently pulled apart from the cannula seat. At this time, the puncture needle continues to perform puncture and withdrawal, and the cannula and cannula seat are left in place. The outer protective sleeve and support sleeve are connected by a recycling connecting strap and can be disposed of as a whole as a disposable part, without worrying about leaving small parts behind. During the product assembly process, the support sleeve is fastened to the outside of the cannula seat and then inserted into the outer protective sleeve together. Through the gap between the fastening connecting strap and the support sleeve body in this solution, it can be ensured that the support sleeve is quickly aligned inside the outer protective sleeve when inserted, and the left and right parts are stably fastened. The outward convex arc surface design of the support sleeve effectively reduces the contact area between its outer wall and the inner wall of the outer protective sleeve, making the push effortless and smoother during operation, and making it easier for the operator to find the feel.

[0027] Compared with existing technologies, this invention has significant advantages such as reasonable structure, stable and smooth pushing, easy recycling of small parts, and improved success rate of medical device placement.

Claims

1. A disposable long-cannula indwelling needle, comprising a puncture assembly, a cannula assembly, and an outer protective sleeve assembly, wherein the outer protective sleeve assembly includes an outer protective sleeve and a support sleeve, the support sleeve being located inside the outer protective sleeve and sleeved on the cannula assembly, and a guide groove for pushing is formed on the side of the outer protective sleeve, characterized in that, The support sleeve includes a left support sleeve and a right support sleeve that interlock, and a recycling connecting strip connected to the left support sleeve or the right support sleeve. The left support sleeve is connected to the right support sleeve on one side. The recycling connecting strip extends along the length of the outer protective sleeve, and a positioning component is provided at the end of the recycling connecting strip. A guide groove for accommodating the recycling connecting strip is opened on the inner wall of the outer protective sleeve. A protrusion or groove for engaging with the positioning component is provided at the front end of the guide groove. The guide groove for pushing is opened on the upper side of the outer protective sleeve, and in the cross-section of the outer protective sleeve, the line connecting the center line of the guide groove and the center point is at an angle of 20°-70° with the horizontal direction.

2. The disposable long-cannula indwelling needle according to claim 1, characterized in that, The puncture assembly consists of a puncture needle tube and a needle handle. The cannula assembly includes a cannula and a cannula seat. The end of the cannula is connected to the cannula seat. The cannula seat has a cavity communicating with the cannula. The cannula seat has a sealing plug for sealing the rear end of the cannula seat. An incision is made on the sealing plug. The puncture needle tube passes through the incision on the sealing plug along the rear end of the cannula seat and extends into the cannula. The side of the cannula seat also has an infusion bypass tube communicating with the cavity inside the cannula seat. The left and right support sleeves of the support sleeve are respectively pressed onto the cannula seat and the left and right sides of the rear end of the cannula, and the left and right support sleeves are interlocked. The contact surfaces of the left and right support sleeves have matching grooves. The outer wall of the support sleeve partially contacts the inner wall of the outer protective sleeve, meaning the outer surface of the support sleeve is not completely fitted to the inner wall of the outer protective sleeve, thus reducing resistance during the pushing process. Furthermore, the cross-section of the outer protective sleeve is elliptical, olive-shaped, or circular, while the cross-section of the support sleeve only partially conforms to the cross-section of the outer protective sleeve, meaning only a portion of its arc segments fit the curvature of the cross-section of the outer protective sleeve. Preferably, the cross-section of the outer protective sleeve is elliptical or olive-shaped, and the cross-section of the support sleeve is rhomboid, with convex arc segments at the four corners of the rhombus that fit against the inner wall of the outer protective sleeve, thereby effectively reducing pushing resistance.

3. The disposable long-cannula indwelling needle according to claim 1, characterized in that, The outer protective sleeve is provided with a needle-holding wing on its outer side. The needle-holding wing is horizontally set and the needle-holding wing and the guide groove are respectively located on both sides of the central axis of the outer protective sleeve, that is, on the cross-section of the outer protective sleeve. The line connecting the guide groove and the center point is at an angle of 110°-160° with the needle-holding wing. This structure can ensure that the operator's hand will not touch the patient's arm when pushing the needle, avoid the undulation when pushing the guide wire, and improve the pushing stability.

4. The disposable long-cannula indwelling needle according to claim 1, characterized in that, It also includes a guidewire pushing mechanism located at the rear of the outer protective sleeve. The guidewire extends along the cannula / puncture needle tube. A guidewire pushing guide groove is formed on the rear outer wall of the outer protective sleeve. The guidewire pushing guide groove is coaxially arranged with the guide groove. A guidewire seat is built into the rear end of the outer protective sleeve. A push handle is connected to the guidewire seat. A countersunk hole for fixing the rear end of the guidewire is formed on the guidewire seat. The guidewire seat is set inside the outer protective sleeve and connected to the push handle. The push handle extends out of the outer protective sleeve along the guidewire pushing guide groove. The width of the beginning and end of the guidewire pushing guide groove is slightly larger than the thickness of the push handle to form a clearance fit with the push handle, while the guide groove at other positions forms a transition fit with the push handle. This allows the operator to obtain a damping feel during the pushing process and estimate the pushing distance of the guidewire by hand to determine whether it is in place.

5. A disposable long-cannula indwelling needle according to claim 1, characterized in that, A locking needle tip assembly is provided inside the outer protective sleeve. Specifically, a locking needle tip assembly is provided between the guide wire pushing mechanism and the sheath assembly. The locking needle tip assembly uses two overlapping Z-shaped spring pieces. The two Z-shaped spring pieces share a straight section at the front end. Corresponding needle tube through holes are opened on the straight sections at the front and rear ends of the spring pieces. During and before puncture, the needle tube extends towards the front end of the outer protective sleeve along the needle tube through hole. After puncture, the puncture needle retracts to the rear side of the locking needle tip assembly, and the two Z-shaped spring pieces overlap to seal the needle tube through hole, thereby locking the puncture needle inside the outer protective sleeve and preventing injury to the retrieval operator.

6. The disposable long-cannula indwelling needle according to claim 1, characterized in that, The outer protective sleeve has an elliptical or olive-shaped cross-section, forming a flat outer protective sleeve body, making it easier to hold and facilitating the creation of a wider outer wall space for setting guide grooves. The support sleeve has a rhomboid cross-section, with convex arc segments at each of the four corners. The support sleeve is divided into a snap-fit ​​left support sleeve and a right support sleeve along the short axis of the cross-section. The left and right support sleeves snap together to form a sleeve body that adapts to the tube seat. The left and right support sleeves open and close at one end along the short axis of the cross-section, and are connected at the other end by a snap-fit ​​connecting band. The snap-fit ​​connecting band is convex arc-shaped, with its two ends connected to the upper side of the left / right support sleeves respectively. The left / right support sleeves have cutouts near the snap-fit ​​connecting band, so that the snap-fit ​​connecting band, except for the two ends, has cutouts. The remaining portion has a gap with the support sleeve. The fastening connecting strip is adapted to the contour of the support sleeve. When the support sleeve is placed inside the outer protective sleeve, the outer side of the fastening connecting strip fits against the inner wall of the outer protective sleeve. This structure allows for adjustment when the left and right support sleeves are not properly fastened, using the gap between the fastening connecting strip and the left / right support sleeves. The fitting grooves and protrusions on the mating surfaces of the left and right support sleeves can be used for quick alignment. After alignment, the fastening connecting strip acts as a point of contact between the support sleeve and the outer protective sleeve, ensuring effective contact area during the pushing process to improve pushing stability. Furthermore, the connection point between the fastening connecting strip and the upper side of the left / right support sleeve is located at approximately half the length of the left / right support sleeve. Correspondingly, the cross-section of the guide wire seat is also elliptical or olive-shaped.

7. The disposable long-cannula indwelling needle according to claim 1, characterized in that, The recycling connecting strip is located at the rear end of the side of the support sleeve. The end of the recycling connecting strip is provided with an anchor-shaped or arrow-shaped hook component, and a corresponding guide groove is opened on the inner wall of the outer protective sleeve. The front end of the guide groove is provided with a groove or stop protrusion for engaging with the hook component. The outer protective sleeve adopts a tubular body with an elliptical or olive-shaped cross section. The guide groove is opened on one side of its long axis. Compared with the existing circular cross section tube, its side space can be effectively utilized without affecting the thickness and strength of the outer protective sleeve.

8. A disposable long-cannula indwelling needle according to claim 1, characterized in that, The cannula assembly is made of soft materials, meaning that both the cannula and the cannula seat can deform to a certain extent with human movement. This allows the cannula to twist with the blood vessels after being inserted into the body, ensuring the stability of the device insertion. However, in order to prevent the flow rate from decreasing due to deformation at the cannula tip, a cylindrical support frame is built into the cannula tip to enhance the strength of the cannula tip.

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