Catheter sheath assembly

Abstract

The catheter sheath assembly comprises an inner sheath tube and an outer sheath tube, the inner sheath tube and the outer sheath tube are accommodated in the outer sheath tube in a relative sliding mode in the extending direction of the inner sheath tube, and when the catheter sheath assembly is in butt joint with a catheter seat, an insertion section is inserted into an insertion cavity of the catheter seat until the insertion section abuts against the catheter seat, and the insertion section is inserted into the insertion cavity of the catheter seat. And the outer sheath tube continues to move towards the catheter seat until the outer sheath tube also abuts against the catheter seat. In this way, after the insertion section of the inner sheath tube makes contact with the catheter base, the outer sheath tube can continue to advance, so that the abutting force of the inner sheath tube and the catheter base is not too large, and when a doctor feels relative displacement of the inner catheter and the outer catheter, the inner catheter is already abutted against the catheter base, so that the doctor has expectations on the applied force and the abutting time; deformation of the catheter sheath assembly caused by excessive force is avoided, so that the implant can be smoothly pushed into the inner cavity of the micro catheter, and the operation safety and the conveying efficiency of the catheter sheath assembly are improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of medical apparatus and instruments, especially to a catheter sheath assembly. BACKGROUND

[0002] In interventional therapy, catheter sheath assemblies are widely used to assist stents, spring coils or other implants to enter the lumen of a microcatheter through a catheter hub. When a conventional catheter sheath assembly is connected to a catheter hub, the following two factors may cause excessive force:

[0003] On the one hand, in order to prevent a thin stent from escaping from the gap between the catheter sheath assembly and the catheter hub, the catheter sheath assembly needs to be tightly abutted against the catheter hub, and a large force is usually applied to ensure the tightness of the connection.

[0004] On the other hand, once the catheter sheath assembly abuts against the catheter hub, the abutting force is large or small depending on the operating experience of the doctor, and may be excessive, and is affected by inertia and the reaction time of the person, so the abutting force may continue to increase after the catheter sheath assembly abuts against the catheter hub.

[0005] Excessive force will cause the end of the catheter sheath that abuts against the catheter hub to deform greatly, making it difficult or even impossible for the stent or spring coil to be pushed into the lumen of the microcatheter, which not only affects the efficiency of the operation, but also increases the risk of the operation and endangers the safety of the patient. SUMMARY

[0006] To solve the problem of deformation of the catheter sheath assembly in the prior art during use, the purpose of the utility model is to provide a catheter sheath assembly that is not easy to deform during use and improves the efficiency of the operation.

[0007] To achieve the above purpose of the utility model, one embodiment of the utility model provides a catheter sheath assembly, which comprises:

[0008] an inner sheath tube, which is provided in the form of a hollow tubular structure that fits a microcatheter, and comprises a plug-in section provided at one end;

[0009] an outer sheath tube, which is provided in the form of a hollow tubular structure that fits the inner sheath tube, and is slidably accommodated in the outer sheath tube along the extension direction of the inner sheath tube, and the plug-in section is exposed from the outer sheath tube;

[0010] The positional relationship between the inner sheath tube and the outer sheath tube satisfies the following conditions: when the catheter sheath assembly is connected to a catheter hub, the plug-in section is inserted into the plug-in cavity of the catheter hub, and after abutting against the catheter hub, the outer sheath tube continues to move towards the catheter hub.

[0011] As a further improvement of the utility model, the first sliding part and the second sliding part are one sliding convex and the other is a sliding groove, and the sliding convex slides along the sliding groove.

[0012] As a further improvement of the utility model, the projection of the sliding path of the sliding convex along the sliding groove on the plane passing through the axis of the inner sheath forms an angle with the axis of the inner sheath, and when the sliding convex slides along the sliding groove, the inner sheath rotates relative to the outer sheath.

[0013] As a further improvement of the utility model, the sliding groove is in the shape of a spiral with the axis of the inner sheath as the axis.

[0014] When the sliding convex slides along the sliding groove, the inner sheath abuts against the catheter seat, and the outer sheath rotates relative to the inner sheath while moving towards the catheter seat until the outer sheath abuts against the catheter seat.

[0015] As a further improvement of the utility model, the sliding convex is symmetrically arranged on the outer wall of the inner sheath, and the sliding groove is arranged on the outer sheath in a corresponding position and corresponding number of groups corresponding to the sliding convex.

[0016] As a further improvement of the utility model, the outer wall of the inner sheath and / or the inner wall of the outer sheath is provided with a friction section, and the friction coefficient between the inner sheath and the outer sheath at the friction section is greater than the friction coefficient at other connection positions between the inner sheath and the outer sheath.

[0017] As a further improvement of the utility model, after the sliding convex slides along the sliding groove, the hemostasis valve clamps the outer sheath at the clamping position of the outer wall of the outer sheath, and the friction section covers the clamping position in the extension direction of the inner sheath.

[0018] As a further improvement of the utility model, the outer sheath comprises an outer main body and an outer insertion section, the outer insertion section is connected to the end of the outer main body close to the catheter seat, the outer insertion section is in the shape of a circular truncated cone, and the outer diameter of the outer insertion section gradually increases towards the outer main body.

[0019] The outer sheath continues to move towards the catheter seat until the outer insertion section abuts against the catheter seat.

[0020] As a further improvement of the utility model, the inner sheath comprises an inner main body, the insertion section is connected to the end of the inner main body close to the catheter seat, the outer surface of the inner main body is in the shape of a circular cylinder, the insertion section is in the shape of a circular truncated cone, and the outer diameter of the insertion section gradually increases towards the inner main body.

[0021] As a further improvement of the utility model, when the outer plug-in section abuts against the catheter seat, the outer plug-in section is still within the outer surface range of the inner main body and does not coincide with the plug-in section part.

[0022] As a further improvement of the utility model, along the extension direction of the inner sheath tube, the length of the outer sheath tube is shorter than the length of the inner sheath tube.

[0023] Compared with the common technology, the utility model has the following beneficial effects: the catheter sheath assembly is provided with an inner sheath tube and an outer sheath tube and their relative position relationship, when the plug-in section of the inner sheath tube contacts the catheter seat, the outer sheath tube can continue to advance, which makes the force applied by the doctor to the catheter seat in one aspect, the force applied by the doctor to the catheter seat is not all changed into the resistance between the inner sheath tube and the catheter seat, but changed into the force for continuing to move the outer catheter, which makes the force of the inner sheath tube abutting against the catheter seat not too large; on the other hand, the butt joint between the catheter sheath assembly and the catheter seat is a gradual abutting relationship, that is, when the doctor feels the relative displacement of the inner catheter and the outer catheter, it means that the inner catheter has abutted against the catheter seat at this time, which makes the doctor continue to push the outer catheter to the catheter seat with a relatively small force and a slower speed, thereby avoiding continuing to apply too large a force to the catheter sheath assembly after abutting, avoiding the deformation of the catheter sheath assembly caused by the application of too large a force, so that the implant can be smoothly pushed into the microcatheter lumen, the operation safety and the conveying efficiency of the catheter sheath assembly are improved, and the intraoperative risk is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 is the structure schematic view of the catheter sheath assembly of an embodiment of the utility model;

[0025] Figure 2 is Figure 1 the sectional view of A-A direction in it;

[0026] Figure 3 is the sectional view of the catheter sheath assembly of an embodiment of the utility model when starting to insert the catheter seat;

[0027] Figure 4 is the sectional view of the catheter sheath assembly of an embodiment of the utility model when completely inserting the catheter seat;

[0028] Figure 5 is the structure schematic view of the outer sheath tube of an embodiment of the utility model;

[0029] Figure 6 is Figure 5 the sectional view of B-B direction in it;

[0030] Figure 7 is the structure schematic view of the inner sheath tube of an embodiment of the utility model;

[0031] Figure 8 is Figure 7 a sectional view along the C-C direction in the figure;

[0032] Figure 9 is another embodiment of the inner sheath of the utility model sectional view;

[0033] Figure 10 is a structure schematic view of the hemostatic valve locking catheter sheath assembly of an embodiment of the utility model;

[0034] Wherein, 100, catheter sheath assembly;10, inner sheath;11, inner main body;12, plug-in section;121, conical section;122, straight section;13, sliding protrusion;14, friction section;20, outer sheath;21, outer main body;22, outer plug-in section;23, sliding slot;200, hemostatic valve;210, clamping position;300, catheter seat;310, plug-in cavity;T1, extension direction. DETAILED DESCRIPTION

[0035] The utility model will be described in detail in the following with specific embodiments shown in the drawings. But these embodiments do not limit the utility model, the structural, method or functional change made by the ordinary skill in the art according to these embodiments is included in the protection scope of the utility model.

[0036] An embodiment of the utility model provides a catheter sheath assembly that is not easy to deform when in use and improves surgical efficiency.

[0037] The catheter sheath assembly 100 of the embodiment, as shown in Figure 1 and 2 , includes an inner sheath 10 and an outer sheath 20. The inner sheath 10 is provided as a hollow tubular structure that is adapted to a microcatheter. The inner sheath 10 includes a plug-in section 12 provided at one end. The outer sheath 20 is provided as a hollow tubular structure that is adapted to the inner sheath 10. The inner sheath 10 is relatively slidably accommodated in the outer sheath 20 along the extension direction T1 of the inner sheath 10, and the plug-in section 12 is exposed from the outer sheath 20.

[0038] The inner sheath 10 is used to adapt to the microcatheter to deliver an implant, such as a spring coil and a stent, which are in a contracted or crimped state inside the inner sheath 10. The outer sheath 20 is used to support and fix the inner sheath 10. The extension directions T1 of the inner sheath 10 and the outer sheath 20 are both along the same direction, as shown in Figure 1 .

[0039] The outer diameter of the inner sheath 10 and the inner diameter of the outer sheath 20 can be matched, i.e. the outer diameter of the inner sheath 10 can be equal to or slightly smaller than the inner diameter of the outer sheath 20. This matching relationship makes the inner sheath 10 unable to shuttle through the inner sheath 10 at will, but when the doctor holds the outer sheath 20, the friction between the inner sheath 10 and the outer sheath 20 will make the inner sheath 10 move synchronously with the outer sheath 20. Only when a force greater than the friction between the inner sheath 10 and the outer sheath 20 is applied to the inner sheath 10 or the outer sheath 20 alone can the relative movement occur. When the hemostatic valve 200 clamps the outer sheath 20, the friction between the inner sheath 10 and the outer sheath 20 will be further increased, and the relative movement of the two will be further limited.

[0040] In addition, the hollow structures of the inner sheath 10 and the outer sheath 20 can be cylindrical, i.e. their inner diameters remain unchanged in the extension direction T1 of the inner sheath 10, i.e. the inner diameters remain unchanged even at the location of the splicing part. The outer diameter of the splicing part can adopt a tapered structure, and various possible structures thereof are discussed below.

[0041] The positional relationship between the inner sheath 10 and the outer sheath 20 satisfies: when the catheter sheath assembly 100 is docked with the catheter seat 300, the splicing section 12 is inserted into the splicing cavity 310 of the catheter seat 300, and after abutting against the catheter seat 300, the outer sheath 20 continues to move towards the catheter seat 300.

[0042] As described in the background, the conventional catheter sheath assembly can be deformed when it abuts against the catheter seat, and in addition, the distal end of the catheter sheath assembly abuts against the catheter seat to deform, wherein the end close to the doctor is the proximal end, and the end away from the doctor is the distal end. The proximal end and the distal end of the catheter sheath assembly have a certain length, and it is difficult to control the degree of deformation. Even if the distal end is replaced with a hard alloy material, the harder material or the complex processing, or the risk of damaging the surface coating of the stent, are not convenient for popularization.

[0043] In the present scheme, by setting the relative sliding relationship between the inner sheath 10 and the outer sheath 20, this problem is eliminated. When the catheter sheath assembly 100 is inserted into the catheter seat 300, since the splicing section 12 is exposed from the outer sheath 20, as shown in Figure 3 When the splicing section 12 of the inner sheath 10 contacts the catheter seat 300, the outer sheath 20 can continue to move forward, as shown in Figures 3 to 4The design not only provides the outer sheath tube 20 with space for further movement when the inner sheath tube 10 is in close contact with the catheter seat 300, but also allows the doctor to accurately determine the degree of close contact by the frictional resistance between the outer sheath tube 20 and the inner sheath tube 10 when the outer sheath tube 20 continues to move, thereby avoiding excessive force that may deform the sheath tube and facilitate the smooth advancement of the implant into the microcatheter lumen, improving the operation safety of the catheter sheath assembly 100 and the delivery efficiency of the implant, and reducing the risk during the operation.

[0044] In addition, after the outer sheath tube 20 continues to move towards the catheter seat 300, the hemostatic valve 200 can be fixed on the outer sheath tube 20, as shown in Figure 10 , the hemostatic valve 200 clamps the outer sheath tube 20. When the hemostatic valve 200 is fixed, the outer sheath tube 20 can move a certain distance, or be in contact with the catheter seat 300, that is, after the insertion section 12 is inserted into the insertion cavity 310 of the catheter seat 300 until it is in contact with the catheter seat 300, the outer sheath tube 20 continues to move towards the catheter seat 300 until the outer sheath tube 20 is also in contact with the catheter seat 300.

[0045] When hospitals purchase medical devices, they may require different manufacturers and different matching models, which may make the catheter sheath assembly 100 incompatible with the catheter seat 300. However, the double-layer sliding nested structure of the inner sheath tube 10 and the outer sheath tube 20 of the catheter sheath assembly 100 does not require the shape of the inner catheter to be completely matched with the shape of the catheter seat 300, which can make the catheter sheath assembly 100 compatible with more shape specifications of the catheter seat 300, and has stronger compatibility, thereby facilitating the hospital's procurement.

[0046] More specifically, the insertion cavity 310 of the catheter seat 300 is generally provided with a tapered opening, as shown in Figure 3 and 4 , the tapered opening angles of the insertion cavities 310 of different manufacturers and different specifications are different. In the embodiment, when the inner sheath tube 10 is in contact with the catheter seat 300, even if the shapes of the inner sheath tube 10 and the catheter seat 300 are not compatible, that is, the taper of the inner sheath tube 10 is different from the taper of the insertion cavity 310, by moving the outer sheath tube 20 to different positions and being in contact with different parts of the catheter seat 300 of different shapes, the contact between the two layers of tubes and the catheter seat 300 can also form a stable contact relationship, that is, a stable connection between the catheter sheath assembly 100 and the catheter seat 300. Therefore, the flexible positional relationship between the outer sheath tube 20 and the inner sheath tube 10 can make the catheter sheath assembly 100 compatible with more tapered opening angle specifications of the catheter seat 300.

[0047] The inner sheath tube 10 and the outer sheath tube 20 can be made of materials such as PTFE (polytetrafluoroethylene), PEEK (polyether ether ketone), and Pebax (polyether block polyamide).

[0048] Further, as shown in Figure 5 and 6 The outer sheath tube 20 includes an outer body 21 and an outer insertion segment 22 connected to the end of the outer body 21, the outer insertion segment 22 is designed as a circular truncated cone, and the outer diameter of the outer insertion segment 22 gradually increases in the direction of the outer body 21; when the outer sheath tube 20 abuts against the catheter seat 300, the outer insertion segment 22 abuts against the catheter seat 300.

[0049] By designing the outer insertion segment 22 as a circular truncated cone and gradually increasing the outer diameter in the direction of the outer body 21, on the one hand, the outer sheath tube 20 can be inserted into the catheter seat 300 with a smaller conical opening angle of the insertion cavity 310, and on the other hand, in combination with the structure of the multiple sliding grooves 23 openings below, it also better guarantees the centration of the inner sheath tube 10, avoids deformation, and improves the safety and reliability of operation.

[0050] As shown in Figures 7 to 9 The inner sheath tube 10 includes an inner body 11, and an insertion segment 12 connected to the end of the inner body 11, the insertion segment 12 is designed as a circular truncated cone, and the diameter of the insertion segment 12 gradually increases in the direction of the inner body 11.

[0051] By designing the insertion segment 12 as a circular truncated cone and gradually increasing the diameter in the direction of the inner body 11, on the one hand, the insertion segment 12 is more adaptable to the insertion cavity 310 of the catheter seat 300, and on the other hand, it also guarantees that the inner sheath tube 10 is more closely connected to the catheter seat 300. Since the insertion cavity 310 is generally conical, the circular truncated cone-shaped insertion segment 12 can better butt joint with the insertion cavity 310, and the conical insertion cavity 310 and the conical insertion segment 12 are in abutting relationship, which not only guarantees the centration, but also enhances the tightness of the connection, ensures the close contact between the insertion segment 12 and the catheter seat 300, and reduces the instability of the connection caused by the gap between the insertion segment 12 and the catheter seat 300.

[0052] When the outer insertion segment 22 abuts against the catheter seat 300, the outer insertion segment 22 is still within the outer surface range of the inner body 11 and does not partially coincide with the insertion segment 12, so that when the outer sheath tube 20 moves to the limit position, it can only contact the inner body 11, but not move to the position of the insertion segment 12, avoiding the gap between the circular truncated cone-shaped insertion segment 12 and the outer sheath tube 20, and the inner sheath tube 10 can provide stable support for the outer sheath tube 20, preventing the deformation of the outer sheath tube 20 at the gap, thereby on the one hand, improving the reliability and maneuverability of the catheter sheath assembly 100 in actual application, and on the other hand, because of the least deformation, it also ensures the reusability of the catheter sheath assembly 100, prolonging the service life of the assembly.

[0053] To ensure that the outer insertion segment 22 remains within the outer surface area of ​​the inner body 11 and does not partially overlap with the insertion segment 12, the position of the sliding protrusion 13, the length of the groove 23, and the starting position of the sliding protrusion 13 can be defined to ensure that the outer insertion segment 22 remains within the outer surface area of ​​the inner body 11 when the sliding protrusion 13 finishes moving. For example, in one distance relationship, if the sliding protrusion 13 can move to one end of the groove 23, then along the extension direction T1 of the inner sheath 10, the distance from the sliding protrusion 13 to the junction of the insertion segment 12 and the inner body 11 is greater than the distance from the end of the groove 23 away from the outer insertion segment 22 to the end of the outer insertion segment 22. In this way, no matter how the sliding protrusion 13 slides within the groove 23, the insertion segment 12 is always entirely within the outer surface area of ​​the inner body 11.

[0054] In addition, along the extension direction T1 of the inner sheath 10, the length of the outer sheath 20 is shorter than that of the inner sheath 10, ensuring that the outer sheath 20 will not obscure or cover both ends of the inner sheath 10 when it slides. The sliding of the outer sheath 20 does not affect the operation of the inner sheath 10, thereby improving the flexibility and maneuverability of the catheter sheath assembly 100 and making it easier to achieve precise positioning and control in clinical applications.

[0055] Furthermore, the shape of the insertion segment 12 is adapted to the inner wall of the insertion cavity 310.

[0056] If a specially matched catheter sheath assembly 100 and catheter seat 300 are required, the shape of the inner sheath 10 can be designed according to the inner wall shape of the catheter seat 300 at the mating position with the insertion section 12. The insertion section 12 can then be designed as follows: Figure 8 As shown, it can also be as follows Figure 9 As shown, in Figure 8 In the middle, the plug section 12 only has a conical section 121, in Figure 9 In the middle, the insertion segment 12 is provided with two conical segments 121 and a straight segment 122 between the two conical segments 121. That is, the inner wall of the insertion cavity 310 at the docking position with the insertion segment 12 is also in the shape of two conical segments plus a straight segment. Alternatively, it can be set as a structure of a straight segment 122 plus a conical segment 121, or other quantitative relationships.

[0057] The shape of the insertion segment 12 adapts to the inner wall of the insertion cavity 310, enhancing the fit between the insertion segment 12 of the inner sheath 10 and the insertion cavity 310 of the catheter seat 300. This ensures tightness and stability during insertion, allowing the insertion segment 12 to form a good seal and mechanical connection with the insertion cavity 310, thus preventing loosening or detachment during insertion. This highly adaptable design also effectively reduces the force required during insertion, lowers the difficulty of operation, and improves the success of the surgery.

[0058] Further, the inner sheath 10 comprises a first sliding part, and the outer sheath 20 comprises a second sliding part, one of the first sliding part and the second sliding part is arranged as the sliding protrusion 13, and the other is arranged as the sliding groove 23, and the sliding protrusion 13 slides along the sliding groove 23. Preferably, as shown in Figure 5 and 7 the sliding protrusion 13 is arranged on the inner sheath 10, and the sliding groove 23 is arranged on the outer sheath 20.

[0059] The cooperation of the sliding protrusion 13 and the sliding groove 23 avoids accidental rotation between the inner sheath 10 and the outer sheath 20, forms a stable sliding fit between the inner sheath 10 and the outer sheath 20, ensures that the inner and outer sheaths can move or rotate smoothly and controllably during operation, and also avoids operation difficulty caused by sliding disorder or jamming, enhances the smoothness of the catheter sheath assembly 100 when it is docked with the catheter seat 300, and ensures that the delivery process of the implant is stable and reliable.

[0060] Continuing as shown in Figure 1 and 5 the projection of the sliding path of the sliding protrusion 13 along the sliding groove 23 on the plane passing through the axis of the inner sheath 10 forms an angle with the axis of the inner sheath 10; when the sliding protrusion 13 slides along the sliding groove 23, the inner sheath 10 rotates relative to the outer sheath 20.

[0061] By arranging the angle, when the sliding protrusion 13 slides along the sliding groove 23, relative rotation between the inner sheath 10 and the outer sheath 20 occurs. This rotation helps the doctor to intuitively determine whether the inner sheath 10 has moved into place, because when the inner sheath 10 has not reached the catheter seat 300, no rotation occurs, and when rotation occurs, the sliding protrusion 13 must stop moving, and the sliding groove 23 needs to move along the sliding protrusion 13, so that the relative rotation between the inner sheath 10 and the outer sheath 20 can indicate whether the catheter sheath assembly 100 has reached the best connection state, avoiding operation errors caused by excessive force. Through this design, the accuracy and operability of the catheter sheath assembly 100 are further improved.

[0062] That is, this rotation serves as an indication signal, prompting the doctor that the sheath has been in close contact with the catheter seat 300, and there is no need to apply excessive force, so that the doctor can better control the force, avoiding the risk of deformation of the end of the sheath.

[0063] The sliding path of the sliding protrusion 13 along the sliding groove 23 can be a straight line with an angle between the axis in space, or can be a wave shape or a spiral shape, and the spiral shape is taken as an example. The sliding groove 23 is arranged in a spiral shape with the axis of the inner sheath 10 as the axis. When the sliding protrusion 13 slides along the sliding groove 23, the inner sheath 10 abuts against the catheter seat 300, and the outer sheath 20 rotates relative to the inner sheath 10 while moving towards the catheter seat 300.

[0064] The technical effect of the spiral chute 23 is embodied in two aspects: on the one hand, the spiral chute 23 enables the sliding protrusion 13 to produce a smoother rotating action when sliding, and the sliding of the sliding protrusion 13 in the chute 23, the rotation of the outer sheath 20 is smoother, and the spiral has good centering; on the other hand, the design of the spiral chute 23 enables the outer sheath 20 to rotate while moving forward, and this rotating action sends a more obvious signal to the doctor that once the outer sheath 20 starts to rotate, it means that the inner sheath 10 has been abutted in place, facilitating the doctor to grasp the specific movement state of the catheter sheath assembly 100.

[0065] Further, the sliding protrusions 13 are circumferentially symmetrically arranged in several groups on the outer wall of the inner sheath 10, and the chute 23 is arranged on the outer sheath 20 in corresponding positions and corresponding numbers of several groups corresponding to the sliding protrusions 13.

[0066] The stability of the sliding and rotation of the inner and outer tubes is enhanced. When the sliding protrusions 13 and the chutes 23 are symmetrically arranged in groups, the inner and outer tubes can maintain good balance during sliding or rotating, avoiding the deviation or instability caused by a single chute 23 or sliding protrusion 13. This symmetric arrangement also improves the overall strength and durability of the catheter sheath assembly 100, ensuring consistent operation performance over a long period or multiple uses, and reducing the difficulty of operation caused by wear or aging.

[0067] As shown in Figure 2 or Figure 5 , the number of sliding protrusions 13 is set to two, and the two sliding protrusions 13 are symmetrically arranged at 180° along the circumference of the inner sheath 10. Correspondingly, two chutes 23 are also symmetrically arranged at 180° along the circumference of the outer sheath 20.

[0068] In addition, the number of sliding protrusions 13 can also be other, for example, four sliding protrusions 13, four chutes 23 symmetrically arranged at 90°, five sliding protrusions 13, five chutes 23 symmetrically arranged at 72°, six sliding protrusions 13, six chutes 23 symmetrically arranged at 60°, and so on.

[0069] The cooperation between the sliding protrusions 13 and the chutes 23, and the friction between the outer sheath 20 and the inner sheath 10, ensures that the inner sheath 10 will not slip out of the outer sheath 20 during transportation or other vibration processes.

[0070] The chute 23 can penetrate the wall of the outer sheath 20, or it can not penetrate, for example, as shown in Figure 3 .

[0071] Especially when this penetration is combined with other features, a more significant effect is produced. In combination with the two grooves 23 arranged symmetrically 180° on the outer sheath tube 20, the two grooves 23 divide the end of the outer sheath tube 20 into two petals. When the two-petal structure is in abutment with the catheter seat 300, especially when the two grooves 23 are arranged on the outer insertion section 22 and in abutment with the catheter seat 300, the two-petal structure will be subjected to a pressing force in the direction of the axis of the outer sheath tube 20. This pressing force has good centering properties and can uniformly deform inwardly, better fixing the inner sheath tube 10 and changing the force in the extension direction T1 into a protective force that avoids deformation of the inner sheath tube 10.

[0072] Further, as shown in Figures 7 to 10 , the outer wall of the inner sheath tube 10 and / or the inner wall of the outer sheath tube 20 is provided with a friction section 14. The friction coefficient between the inner sheath tube 10 and the outer sheath tube 20 at the friction section 14 is greater than the friction coefficient between the two at other connection positions.

[0073] The friction section 14 can be provided on the outer wall of the inner sheath tube 10 or on the inner wall of the outer sheath tube 20. The process of providing the friction section 14 on the outer wall of the inner sheath tube 10 is relatively simple. The friction section 14 can be designed with concave-convex particles, spots, sprayed non-slip material, micro-abrasion, etc., and can be marked with different colors for easy identification of the position of the friction section 14. The provision of the friction section 14 can increase the friction between the inner sheath tube 10 and the outer sheath tube 20, thereby achieving the effect of stabilizing the relative position of the inner sheath tube 10 and the outer sheath tube 20 and effectively preventing accidental relative sliding between the inner sheath tube 10 and the outer sheath tube 20. Especially when locked and pressed by the hemostatic valve 200, the design of the friction section 14 can further enhance the locking effect. The friction at the friction section 14 is further increased, making it difficult for the outer sheath tube 20 to move at the locked position. This not only increases the stability of the operation of the catheter sheath assembly 100, but also effectively avoids operation errors caused by relative sliding between the inner and outer tubes.

[0074] The position of the friction section 14 can be determined according to the clamping position 210 of most of the hemostatic valves 200 on the market. Specifically, when the outer sheath tube 20 is in abutment with the catheter seat 300, the clamping position 210 of the hemostatic valve 200 clamps the outer sheath tube 20 on the outer wall of the outer sheath tube 20. In the extension direction T1 of the inner sheath tube 10, the friction section 14 covers the clamping position 210.

[0075] For example, the clamping position 210 of most of the hemostatic valves 200 on the market is within a distance of 120mm-160mm from the end. The setting range of the friction section 14 can be a length range of 110mm-170mm from the end, thereby covering the clamping position 210, as shown in Figure 10 .

[0076] The design of the friction section 14, in combination with the locking effect of the hemostatic valve 200, further improves the stability of the catheter sheath assembly 100. By covering the friction section 14 at the contact position of the inner sheath tube 10 and the outer sheath tube 20, when the hemostatic valve 200 locks the outer sheath tube 20, it is just clamped at the position of the friction section 14, so that the friction between the inner and outer tubes increases significantly, preventing the relative sliding and rotation of the inner and outer tubes. This design ensures that the inner sheath tube 10 does not slide backward due to external force during the delivery of the implant, thereby avoiding instability during the implant delivery process. In addition, this design can also prevent the sheath tube from loosening or shifting during the delivery process due to improper operation, thereby improving the safety and reliability of the entire operation.

[0077] In particular, the relative movement of the inner sheath tube 10 and the outer sheath tube 20 is accompanied by sliding and rotating design. After the hemostatic valve 200 is locked, because the hemostatic valve 200 is locked at the position of the friction section 14, the presence of the friction section 14 makes it more difficult to rotate than to slide. When there is a tendency for relative movement between the inner sheath tube 10 and the outer sheath tube 20, it must be accompanied by relative rotation. Because the friction section 14 is difficult to move, rotation is more difficult. If it cannot rotate, it means it cannot move. Therefore, the relative rotation of the inner sheath tube 10 and the outer sheath tube 20, in combination with the clamping position 210 of the friction section 14 and the hemostatic valve 200, ensures that the inner sheath tube 10 and the outer sheath tube 20 do not move relative to each other after being clamped.

[0078] Compared with the prior art, the embodiment has the following beneficial effects:

[0079] (1) The catheter sheath assembly 100 is provided with the inner sheath tube 10 and the outer sheath tube 20 and their relative position relationship. When the insertion section 12 of the inner sheath tube 10 contacts the catheter seat 300, the outer sheath tube 20 can continue to advance. This makes it so that, on the one hand, the force exerted by the doctor on the catheter sheath assembly 100 in the direction of the catheter seat 300 will not all become the resistance between the inner sheath tube 10 and the catheter seat 300, but will become the force that makes the outer catheter continue to move. This makes the force between the inner sheath tube 10 and the catheter seat 300 not too large. On the other hand, the interface between the catheter sheath assembly 100 and the catheter seat 300 is a gradual abutting relationship. That is, when the doctor feels the relative displacement of the inner catheter and the outer catheter, it means that the inner catheter has abutted with the catheter seat 300. This allows the doctor to continue to push the outer catheter to the catheter seat 300 at a relatively small force and a slower speed, thereby avoiding the application of excessive force on the catheter sheath assembly 100 after abutting, and avoiding the deformation of the catheter sheath assembly 100 caused by the application of excessive force, so that the implant can be smoothly pushed into the microcatheter lumen. In this way, the operation safety and delivery efficiency of the catheter sheath assembly 100 are improved, and the intraoperative risk is reduced.

[0080] (2) The double-layer sliding nested structure of the inner sheath tube 10 and the outer sheath tube 20 of the catheter sheath assembly 100, by moving the outer sheath tube 20 to different positions, abutting against different parts of the catheter seat 300 of different shapes, the abutting of the two layers of tubes with the catheter seat 300 can also form a stable abutting relationship, that is, a stable connection between the catheter sheath assembly 100 and the catheter seat 300. Therefore, the flexible positional relationship between the outer sheath tube 20 and the inner sheath tube 10 can make the catheter sheath assembly 100 adapt to more specifications of the catheter seat 300 with different taper angles, and have stronger compatibility, which facilitates the hospital procurement.

[0081] (3) Two sliding grooves 23 are symmetrically arranged on the outer sheath tube 20 at 180°, or other corresponding number of even sliding grooves 23 at 90°, 60°, etc. At this time, the end of the outer sheath tube 20 is divided into multiple petals by the multiple sliding grooves 23. When the multi-petal structure abuts against the catheter seat 300, the multi-petal structure will be subjected to extrusion force in the axial direction of the outer sheath tube 20. This extrusion force has good centering property and can uniformly deform inward, which better fixes the inner sheath tube 10 and changes the force in the extension direction T1 into a protective force to avoid deformation of the inner sheath tube 10.

[0082] (4) The relative movement of the inner sheath tube 10 and the outer sheath tube 20 is accompanied by sliding relative rotation through the design of the sliding protrusion 13 and the sliding groove 23. This rotation helps the doctor to intuitively judge whether the inner sheath tube 10 has moved into place, avoiding operation errors caused by excessive force. Through this design, the accuracy and operability of the catheter sheath assembly 100 are further improved.

[0083] (5) The relative movement of the inner sheath tube 10 and the outer sheath tube 20 is accompanied by sliding relative rotation. After the hemostatic valve 200 is locked, because the hemostatic valve 200 is locked at the position of the friction section 14, the presence of the friction section 14 makes the relative rotation more difficult than the relative sliding. When there is a tendency of relative movement between the inner sheath tube 10 and the outer sheath tube 20, it must be accompanied by relative rotation. Because the friction section 14 is difficult to move, rotation is more difficult. If it cannot rotate, it means that it cannot move. Therefore, the relative rotation of the inner sheath tube 10 and the outer sheath tube 20 and the design of the clamping position 210 of the hemostatic valve 200 and the friction section 14 ensure that the inner sheath tube 10 and the outer sheath tube 20 will not move relative to each other after being clamped.

[0084] It should be understood that although the present specification is described in terms of embodiments, not every embodiment contains only one independent technical solution, and the description of the specification is only for the sake of clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that those skilled in the art can understand.

[0085] The series of detailed descriptions listed above are only specific descriptions for the feasible implementation manners of the present application, and are not used to limit the protection scope of the present application. Any equivalent implementation manners or changes made without departing from the spirit of the present application should be included in the protection scope of the present application.

Claims

1. A catheter sheath assembly, characterized in that, include: An inner sheath, configured as a hollow tubular structure adapted to a microcatheter, the inner sheath including an insertion section at one end; An outer sheath is configured as a hollow tubular structure adapted to the inner sheath, the inner sheath being slidably accommodated within the outer sheath along the extension direction of the inner sheath, and the insertion section protruding from the outer sheath. The positional relationship between the inner sheath and the outer sheath satisfies the following condition: when the catheter sheath assembly is docked with the catheter seat, the insertion segment is inserted into the insertion cavity of the catheter seat until it abuts against the catheter seat, and the outer sheath continues to move toward the catheter seat.

2. The catheter sheath assembly according to claim 1, characterized in that, The inner sheath includes a first sliding portion, and the outer sheath includes a second sliding portion. One of the first sliding portion and the second sliding portion is configured as a sliding protrusion and the other is configured as a sliding groove. The sliding protrusion slides along the sliding groove.

3. The catheter sheath assembly according to claim 2, characterized in that, The projection of the sliding protrusion along the sliding path of the groove onto the plane passing through the axis of the inner sheath tube forms an angle with the axis of the inner sheath tube; when the sliding protrusion slides along the groove, the inner sheath tube and the outer sheath tube rotate relative to each other.

4. The catheter sheath assembly according to claim 2, characterized in that, The groove is configured as a spiral with the axis of the inner sheath as the axis; When the sliding protrusion slides along the groove, the inner sheath abuts against the catheter seat, and the outer sheath rotates relative to the inner sheath while moving toward the catheter seat until the outer sheath abuts against the catheter seat.

5. The catheter sheath assembly according to claim 2, characterized in that, The sliding protrusions are arranged symmetrically in several groups around the outer wall of the inner sheath, and the sliding grooves are arranged in several groups on the outer sheath at positions and in corresponding numbers to the sliding protrusions.

6. The catheter sheath assembly according to claim 2, characterized in that, The outer wall of the inner sheath and / or the inner wall of the outer sheath are provided with friction sections, and the coefficient of friction at the friction sections between the inner sheath and the outer sheath is greater than the coefficient of friction at other connection points between them.

7. The catheter sheath assembly according to claim 6, characterized in that, After the sliding protrusion slides along the groove, the hemostatic valve clamps the outer sheath at the clamping position on the outer wall of the outer sheath, and the friction section covers the clamping position in the extending direction of the inner sheath.

8. The catheter sheath assembly according to claim 1, characterized in that, The outer sheath includes an outer body and an outer insertion section. The outer insertion section is connected to the end of the outer body near the catheter seat. The outer insertion section is frustum-shaped, and its outer diameter gradually increases towards the outer body. The outer sheath continues to move toward the catheter seat until the external insertion segment abuts against the catheter seat.

9. The catheter sheath assembly according to claim 8, characterized in that, The inner sheath includes an inner body, and the insertion segment is connected to the end of the inner body near the catheter seat. The outer surface of the inner body is cylindrical, and the insertion segment is frustum-shaped. The outer diameter of the insertion segment gradually increases towards the inner body.

10. The catheter sheath assembly according to claim 9, characterized in that, When the external insertion segment abuts against the catheter seat, the external insertion segment is still within the outer surface range of the inner body and does not overlap with the insertion segment.

11. The catheter sheath assembly according to claim 1, characterized in that, Along the extension direction of the inner sheath, the length of the outer sheath is shorter than the length of the inner sheath.

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