Catheter sheath

Abstract

The utility model relates to the technical field of interventional medical instruments, in particular to a catheter sheath, and aims to solve the problem that the passing resistance is large when the sealing performance of an existing catheter sheath is improved. The catheter sheath provided by the utility model comprises a sheath tube joint and a sheath tube, wherein the sheath tube is connected with the sheath tube joint; the sheath tube joint comprises a joint shell, a guide block, an elastic body and a supporting block; the guide block and the supporting block are located at the two axial ends of the elastic body respectively. The guide block, the supporting block and the elastic body are arranged in the connector shell. The elastic body is provided with a first through hole in the axial direction for an instrument to pass through, and the guide block moves towards the supporting block to extrude the elastic body; a film layer is arranged on the surface of the elastomer, and the friction coefficient of the film layer is lower than that of the elastomer. According to the catheter sheath, sealing is achieved by extruding the elastic body, the thin film layer wraps the surface of the elastic body to reduce friction force, and meanwhile the sealing effect and the passing ability of an instrument are guaranteed.

Description

Technical Field

[0001] The utility model relates to the technical field of interventional medical equipment, in particular to a catheter sheath. Background Art

[0002] As a basic component for establishing channels in minimally invasive vascular interventional surgery, the catheter sheath requires good sealing performance and low resistance to the passage of instruments. With the development of this procedure, there are more and more ways to introduce multiple instruments into the sheath at the same time, such as the "All in one" procedure, which poses a great challenge to the sealing performance of the sheath. The permeability and sealing of the instrument are mutually exclusive and often cannot be achieved at the same time. The valve body with better sealing effect in the catheter sheath often has greater resistance to passage and is inconvenient to use. Utility Model Content

[0003] The utility model aims to provide a catheter sheath to solve the problem of large passing resistance when the sealing performance of the existing catheter sheath is improved.

[0004] In order to solve the above technical problems, the technical solution provided by the utility model is:

[0005] The utility model provides a catheter sheath, comprising a sheath tube joint and a sheath tube, wherein the sheath tube is connected to the sheath tube joint; the sheath tube joint comprises a joint housing, a guide block, an elastomer and a support block; the guide block and the support block are respectively located at two ends of the axial direction of the elastomer, and the guide block, the support block and the elastomer are arranged in the joint housing; the elastomer is provided with a first through hole along its axial direction for the passage of instruments, and the guide block moves toward the support block to squeeze the elastomer; a thin film layer is provided on the surface of the elastomer, and the friction coefficient of the thin film layer is lower than the friction coefficient of the elastomer.

[0006] Furthermore, the diameter of the first through hole along its own axial direction gradually increases from the middle to both ends.

[0007] Furthermore, the sheath tube joint also includes a first fixed joint, a knob and a second fixed joint; the first fixed joint is connected to the joint housing, and the knob is threadedly connected to the first fixed joint; the second fixed joint is connected to an end of the joint housing away from the first fixed joint, and the support block abuts against the second fixed joint; the end of the second fixed joint away from the joint housing is connected to the sheath tube; the knob is rotated to push the guide block to move toward the support block, thereby squeezing the elastomer.

[0008] Furthermore, the material of the film layer includes polytetrafluoroethylene.

[0009] Furthermore, a guide hole is provided on the guide block for the instrument to pass through, and the diameter of the guide hole gradually decreases along the direction in which the instrument enters.

[0010] Furthermore, the guide block and the support block are made of polymer and have a harderness than that of the elastomer.

[0011] Furthermore, the catheter sheath also includes a buffer assembly, which includes a one-way valve assembly and a buffer bag. One end of the one-way valve assembly is connected to the sheath tube connector, and the other end is connected to the buffer bag; the liquid in the sheath tube can enter the buffer bag through the one-way valve assembly.

[0012] Furthermore, the one-way valve assembly includes a one-way valve housing, a spring and a valve core; the valve core is arranged in the one-way valve housing and is slidably connected to the one-way valve housing, the inlet of the one-way valve housing is connected to the sheath tube joint, and the outlet of the one-way valve housing is connected to the buffer bag; the spring is arranged in the one-way valve housing, one end of which is connected to the valve core, and the other end of which is connected to the one-way valve housing, and the spring applies thrust to the valve core so that the valve core closes the outlet of the one-way valve housing.

[0013] Furthermore, the one-way valve assembly also includes a duckbill valve, which is installed at the outlet of the one-way valve housing; a flow channel is provided on the valve core, one end of the flow channel is connected to the inlet of the one-way valve housing, and the other end can be connected to the duckbill valve.

[0014] Furthermore, the buffer assembly also includes a connecting tube and a connecting valve, one end of the connecting tube is connected to the sheath tube joint, and the other end is connected to the connecting valve, and the end of the connecting valve away from the connecting tube is connected to the inlet of the one-way valve housing.

[0015] Based on the above technical solutions, the technical effects that can be achieved by the utility model are:

[0016] The catheter sheath provided by the utility model comprises a sheath tube joint and a sheath tube, wherein the sheath tube is connected to the sheath tube joint; the sheath tube joint comprises a joint housing, a guide block, an elastomer and a support block; the guide block and the support block are respectively located at two ends of the axial direction of the elastomer, and the guide block, the support block and the elastomer are arranged in the joint housing; the elastomer is provided with a first through hole along its axial direction for the passage of instruments, and the guide block moves toward the support block to squeeze the elastomer; a thin film layer is provided on the surface of the elastomer, and the friction coefficient of the thin film layer is lower than the friction coefficient of the elastomer.

[0017] The catheter sheath provided by the utility model realizes sealing by extruding an elastomer, and a thin film layer is provided on the surface of the elastomer to reduce friction, thereby ensuring the sealing effect and the passability of the device. In addition, the sealing method of extruding the elastomer can ensure the reliability of the seal. Compared with the structure of the balloon-like sealing valve body filled with gas or liquid, the seal failure may occur due to damage to the film layer, scratches on the device, etc., while the seal formed by extruding the elastomer will not fail even if it is scratched and damaged, thus ensuring safety. In addition, compared with the balloon, the elastomer can withstand higher pressure, and a better sealing effect can be achieved by applying a greater extrusion force. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the specific implementation methods of the utility model or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 A schematic diagram of the structure of a catheter sheath provided in an embodiment of the utility model;

[0020] Figure 2 It is the front view of the sheath tube connector;

[0021] Figure 3 is a cross-sectional view of a sheath tube connector;

[0022] Figure 4 This is the main view of the buffer assembly;

[0023] Figure 5 is a cross-sectional view of a one-way valve assembly;

[0024] Figure 6 Schematic diagram of the force on the elastic body.

[0025] Icons: 100-sheath connector; 200-sheath; 300-buffer assembly; 110-connector housing; 120-guide block; 130-elastomer; 140-support block; 150-film layer; 160-first fixed connector; 170-knob; 180-second fixed connector; 310-one-way valve assembly; 320-buffer bag; 330-connecting pipe; 340-connecting valve; 311-one-way valve housing; 312-spring; 313-valve core; 314-duckbill valve; 315-sealing ring; 301-flow channel. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical scheme and advantages of the embodiments of the utility model clearer, the technical scheme in the embodiments of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Generally, the components of the embodiments of the utility model described and shown in the drawings here can be arranged and designed in various different configurations.

[0027] In conjunction with the accompanying drawings, some embodiments of the present invention are described in detail below. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0028] As the basic component for establishing the channel in minimally invasive vascular intervention surgery, the catheter sheath needs good sealing performance and low resistance to the passage of the device. However, the permeability and sealing of the device are mutually exclusive and often cannot be achieved at the same time. The valve body with good sealing effect often has large resistance to the passage and is inconvenient to use.

[0029] In view of this, the utility model provides a catheter sheath, including a sheath tube connector 100 and a sheath tube 200, the sheath tube 200 is connected to the sheath tube connector 100; the sheath tube connector 100 includes a connector housing 110, a guide block 120, an elastomer 130 and a support block 140; the guide block 120 and the support block 140 are respectively located at the two ends of the axial direction of the elastomer 130, and the guide block 120, the support block 140 and the elastomer 130 are arranged in the connector housing 110; the elastomer 130 is provided with a first through hole along its axial direction for the passage of instruments, and the guide block 120 moves toward the support block 140 to squeeze the elastomer 130; a thin film layer 150 is provided on the surface of the elastomer 130, and the friction coefficient of the thin film layer 150 is lower than the friction coefficient of the elastomer 130.

[0030] The catheter sheath provided by the utility model realizes sealing by squeezing the elastic body 130, and a thin film layer 150 is provided on the surface of the elastic body 130 to reduce friction, thereby ensuring the sealing effect and the passability of the device. In addition, the sealing method of squeezing the elastic body 130 can ensure the reliability of the seal. Compared with the structure of the balloon-like sealing valve body filled with gas or liquid, the seal failure may be caused by damage to the film layer, scratches on the device, etc., and the seal formed by squeezing the elastic body 130 will not fail even if scratches and damage occur, thereby ensuring safety. In addition, compared with the balloon, the elastic body 130 can withstand higher pressure and achieve a better sealing effect by applying a greater squeezing force.

[0031] The following combination Figure 1-Figure 6 The structure and shape of the catheter sheath provided in this embodiment are described in detail.

[0032] In an optional solution of this embodiment, the sheath tube connector 100 further includes a first fixed connector 160, a knob 170 and a second fixed connector 180. Figure 2 As shown, the first fixed joint 160 and the second fixed joint 180 are respectively connected to the upper and lower ends of the joint housing 110, and the knob 170 is inserted into the first fixed joint 160. Specifically, as Figure 3 As shown, the knob 170 is inserted into the first fixed joint 160 and threadedly connected with the first fixed joint 160, that is, the first fixed joint 160 is provided with an internal thread and the knob 170 is provided with an external thread; the support block 140 abuts against the second fixed joint 180, and the end of the second fixed joint 180 away from the joint housing 110 is connected to the sheath tube 200.

[0033] The sheath connector 100 is provided with a through hole for passing instruments, specifically, Figure 3 As shown, the knob 170 is provided with a through hole along its own axis, the guide block 120 is provided with a guide hole, and the elastomer 130, the support block 140 and the second fixed joint 180 are all provided with through holes. The through hole of the elastomer 130 extends along its own axis, and the through hole of the elastomer 130 is the first through hole. The diameter of the first through hole along its own axis gradually increases from the middle to both ends. Specifically, the cross-sectional profile of the first through hole is in a hyperbolic shape, thereby ensuring that the inner surfaces of the first through hole contact each other after the elastomer 130 is compressed to ensure sealing. In addition, the diameter of the guide hole gradually decreases along the direction in which the instrument enters, so as to guide the instrument, avoid scratching the instrument with other parts, and improve work efficiency. Specifically, the guide hole is set as a tapered hole. In this embodiment, the material of the elastomer 130 is preferably silicone.

[0034] When in use, the knob 170 is turned to push the guide block 120 to move toward the support block 140, thereby squeezing the elastic body 130, so that the diameter of the first through hole on the elastic body 130 is reduced until it becomes zero. Figure 3 becomes Figure 6 To form a seal. Specifically, Figure 6 As shown, the knob 170 moves downward to apply pressure F0 to the elastic body, and the second fixed joint 180 and the joint housing 110 respectively apply an upward supporting force F1 and a radial supporting force F2 to the elastic body 130. After the elastic body 130 forms a seal, the sheath tube 200 is inserted into the blood vessel, and then the interventional instrument enters the human body through the catheter sheath provided in this embodiment. At this time, the elastic body 130 clamps the interventional instrument, thereby eliminating the gap between the elastic body 130 and the interventional instrument to achieve sealing and prevent blood from spilling.

[0035] In order to reduce friction, the film layer 150 is made of a polymer film material, and specifically, can be made of polytetrafluoroethylene material.

[0036] In order to ensure the extrusion effect on the elastomer 130 to ensure the sealing reliability, the guide block 120 and the support block 140 are made of polymer and the hardness is greater than the elastomer 130. Specifically, the polymer can be selected from elastic materials such as rubber, hard silicone, polyurethane, PET, etc., wherein the hard silicone is a silicone with a hardness of Shore A45-65. In this embodiment, the guide block 120 and the support block 140 are both made of hard silicone to avoid damage to the elastomer 130. When the elastomer 130 is compressed and deformed to a certain extent, the guide block 120 and the support block 140 may also be deformed, thereby avoiding the elastomer 130 from generating excessive friction on the instrument as the extrusion force of the guide block 120 on the elastomer 130 increases, thereby causing the instrument to pass through. The deformation of the guide block 120 and the support block 140 can absorb the extrusion energy, avoid excessive pressure on the elastomer 130, and thus avoid excessive friction causing excessive resistance to the passage of the instrument.

[0037] In this embodiment, in order to facilitate the adjustment of the knob 170 and increase the friction, strip ribs extending along the axial direction are provided on the outer surface of the knob 170. Multiple strip ribs are distributed around the axis of the knob 170 to increase the friction between the knob 170 and the hand and prevent slipping when the knob 170 is turned.

[0038] When the interventional device is withdrawn in the sheath tube 200, its "piston movement" will produce a "compression" effect on a section of liquid between the device and the elastic body 130, thereby causing an instantaneous pressure surge at the elastic body 130, and a spray phenomenon may occur due to instantaneous high blood pressure. For this reason, the catheter sheath provided in this embodiment also includes a buffer assembly 300 for releasing excessive pressure and reducing the pressure at the elastic body 130, such as Figure 1 shown.

[0039] Specifically, the buffer assembly 300 includes a one-way valve assembly 310, a buffer bag 320, a connecting pipe 330 and a connecting valve 340. Figure 4 As shown, the connecting tube 330, the connecting valve 340, the one-way valve assembly 310 and the buffer capsule 320 are connected in sequence, and the end of the connecting tube 330 away from the connecting valve 340 is connected to the second fixed joint 180. When the pressure at the elastic body 130 is too high, the one-way valve assembly 310 opens, and the liquid in the second fixed joint 180 and the sheath tube 200 can enter the buffer capsule 320 through the connecting tube 330, the connecting valve 340 and the one-way valve assembly 310 in sequence, so as to reduce the pressure at the elastic body 130 and avoid excessive pressure.

[0040] In an optional solution of this embodiment, the one-way valve assembly 310 includes a one-way valve housing 311, a spring 312, a valve core 313, a duckbill valve 314 and a sealing ring 315. Figure 5As shown, the inlet of the one-way valve housing 311 is connected to the sheath tube connector 100, and the outlet of the one-way valve housing 311 is connected to the buffer bag 320; the valve core 313 is inserted into the one-way valve housing 311 and is slidably connected to the one-way valve housing 311. Specifically, the side wall of the one-way valve housing 311 is provided with a plurality of outlets, the valve core 313 is provided with a central hole and a side hole arranged on the side wall and connected to the central hole, the central hole and the side hole constitute a flow passage 301, one end of the flow passage 301 is connected to the inlet of the one-way valve housing 311, and the other end can be connected to the duckbill valve 314; the sealing ring 315 is installed on the one-way valve housing 311 to strengthen the seal between the valve core 313 and the one-way valve housing 311. The spring 312 is disposed in the one-way valve housing 311 and inserted into the valve core 313, with one end abutting against the valve core 313 and the other end abutting against the one-way valve housing 311, and is configured to apply thrust to the valve core 313 to misalign the side hole of the valve core 313 with the outlet of the one-way valve housing 311. The duckbill valve 314 is installed at the outlet of the one-way valve housing 311 to ensure that blood only flows from the valve core 313 to the buffer bag 320 to prevent contamination caused by blood backflow.

[0041] In order to prevent the one-way valve housing 311 and the valve core 313 from rotating relative to each other, resulting in the duckbill valve 314 being unable to communicate with the side hole of the valve core 313, the inner wall of the one-way valve housing 311 is provided with a slide groove extending along its own axial direction, and the outer wall of the valve core 313 is provided with a guide strip extending along its own axial direction, and the guide strip is clamped in the slide groove and slides along the slide groove.

[0042] When the instrument is withdrawn in the sheath 200, the blood pressure will increase, which can push the valve core 313 and cause the valve core 313 to compress the spring 312. At this time, the flow channel 301 of the valve core 313 is connected with the duckbill valve 314, and the liquid can pass through the one-way valve assembly 310 and enter the buffer bag 320; when the pressure does not reach the set value, the spring 312 can keep the side hole of the valve core 313 and the duckbill valve 314 in an offset state, thereby maintaining the seal and achieving one-way communication.

[0043] In this embodiment, the connecting tube 330 is made of TPU material, and the connecting valve 340 is a three-way valve for switching the on-off state of the connecting tube 330 and the one-way valve assembly 310. When the buffer capsule 320 needs to be cleaned, the connecting tube 330 and the one-way valve assembly 310 can be disconnected by the three-way valve, and then the buffer capsule 320 can be removed for cleaning to avoid contamination.

[0044] The sheath tube connector 100 provided in this embodiment achieves a good gap sealing effect by compressing and deforming the elastomer 130, and can well fill the irregular gap between special-shaped instruments or multiple instruments and the valve body. At the same time, by using the buffer assembly 300 and releasing the pressure by the one-way valve assembly 310, the sealing load of the elastomer 130 and the obstruction to the withdrawal of the instrument are reduced, the elastomer 130 is prevented from being subjected to excessive pressure, and the sealing performance of the sheath tube 200 and the passability of the instrument are improved. In addition, the buffer assembly 300 can prevent excessive pressure in the blood vessel, thereby reducing the sealing requirements for the sheath tube connector 100, thereby taking into account the requirements of sealing and passability.

[0045] In this embodiment, the surface wrapping material of the elastic body 130 is a film layer made of ultra-thin slippery film materials such as polytetrafluoroethylene, which can greatly reduce the friction generated when the device passes through, further improving the passability. The guide block 120 and the support block 140 made of hard silicone can not only squeeze and support the elastic body 130 to form a seal with the device, but also serve as energy storage buffer components. When the elastic body 130 has a large resistance to the passage of the device due to a large deformation, it can absorb part of the pressure to reduce the resistance.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the utility model, rather than to limit it. Although the utility model has been described in detail with reference to the aforementioned embodiments, ordinary technicians in this field should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not make the essence of the corresponding technical solution deviate from the scope of the technical solution of the embodiments of the utility model.

Claims

1. A catheter sheath, characterized in that: It comprises a sheath tube connector and a sheath tube, wherein the sheath tube is connected to the sheath tube connector; The sheath tube joint comprises a joint housing, a guide block, an elastic body and a support block; The guide block and the support block are respectively located at two ends of the elastic body in the axial direction, and the guide block, the support block and the elastic body are arranged in the joint housing; The elastomer is provided with a first through hole along its axial direction for the passage of instruments, and the guide block moves toward the support block to squeeze the elastomer; a film layer is provided on the surface of the elastomer, and the friction coefficient of the film layer is lower than the friction coefficient of the elastomer.

2. The catheter sheath according to claim 1, characterized in that The diameter of the first through hole along its own axial direction gradually increases from the middle to both ends.

3. The catheter sheath according to claim 1, characterized in that: The sheath tube joint also includes a first fixed joint, a knob and a second fixed joint; The first fixed joint is connected to the joint housing, and the knob is threadedly connected to the first fixed joint; the second fixed joint is connected to an end of the joint housing away from the first fixed joint, and the support block abuts against the second fixed joint; One end of the second fixed joint away from the joint housing is connected to the sheath tube; The knob is rotated to push the guide block to move toward the support block, thereby squeezing the elastic body.

4. The catheter sheath according to claim 1, characterized in that: The material of the film layer includes polytetrafluoroethylene.

5. The catheter sheath according to claim 1, characterized in that: The guide block is provided with a guide hole for the passage of an instrument, and the diameter of the guide hole gradually decreases along the direction in which the instrument enters.

6. The catheter sheath according to claim 1, characterized in that: The guide block and the support block are made of polymer and have a harderness greater than that of the elastomer.

7. The catheter sheath according to claim 1, characterized in that: It also includes a buffer assembly, which includes a one-way valve assembly and a buffer bag. One end of the one-way valve assembly is connected to the sheath tube connector, and the other end is connected to the buffer bag. The liquid in the sheath tube can enter the buffer bag through the one-way valve assembly.

8. The catheter sheath according to claim 7, characterized in that: The one-way valve assembly comprises a one-way valve housing, a spring and a valve core; The valve core is arranged in the one-way valve housing and is slidably connected to the one-way valve housing, the inlet of the one-way valve housing is communicated with the sheath tube joint, and the outlet of the one-way valve housing is communicated with the buffer bag; The spring is arranged in the one-way valve housing, one end of which is connected to the valve core and the other end of which is connected to the one-way valve housing. The spring applies thrust to the valve core so that the valve core closes the outlet of the one-way valve housing.

9. The catheter sheath according to claim 8, characterized in that: The one-way valve assembly also includes a duckbill valve, which is installed at the outlet of the one-way valve housing; a flow channel is provided on the valve core, one end of the flow channel is connected to the inlet of the one-way valve housing, and the other end can be connected to the duckbill valve.

10. The catheter sheath according to claim 9, characterized in that: The buffer assembly also includes a connecting tube and a connecting valve, one end of the connecting tube is connected to the sheath tube joint, and the other end is connected to the connecting valve, and the end of the connecting valve away from the connecting tube is connected to the inlet of the one-way valve housing.

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