CN109663200B

CN109663200B - Sheath device

Info

Publication number: CN109663200B
Application number: CN201811544397.5A
Authority: CN
Inventors: 张�雄; 龙汉; 吴星宇; 房金锋
Original assignee: Lifetech Scientific Shenzhen Co Ltd
Current assignee: Lifetech Scientific Shenzhen Co Ltd
Priority date: 2018-12-17
Filing date: 2018-12-17
Publication date: 2021-10-19
Anticipated expiration: 2038-12-17
Also published as: CN109663200A

Abstract

The invention discloses a sheath device which is sleeved outside a catheter assembly and comprises an elastic sheath assembly, wherein the elastic sheath assembly comprises a first sleeve and an elastic piece connected to the first sleeve, the first sleeve can be in a bent state under the action of a constraint force, and after the constraint force disappears, the elastic piece enables the first sleeve to rebound from the bent state to a straight state. The invention has the beneficial effects that: under the constraining force effect, this application sheath device's first sleeve can be in the bending state, and after the constraining force disappeared, the elastic component made first sleeve kick-backs to the straight state by the bending state automatically, avoided manual straightening first sleeve.

Description

Sheath device

Technical Field

The invention relates to the technical field of interventional medical instruments, in particular to a sheath device.

Background

This section provides background information related to the present disclosure only and is not necessarily prior art.

As shown in fig. 1-a, the balloon catheter 12 'includes a catheter and a balloon connected to the catheter, and since the balloon is easily broken, a protective sheath 11' is usually provided on the balloon when the balloon catheter 12 'is assembled, so as to protect the balloon of the balloon catheter 12' from being damaged during assembly and handling.

As shown in fig. 1-b, the balloon catheter 12 'covered with the protective sheath 11' is often stored in the spiral coil 20 'during packaging, but if the balloon catheter 12' is stored in the spiral coil 20 'for too long, the balloon catheter 12' and the protective sheath 11 'covered thereon are easily bent irreversibly after the balloon catheter 12' is taken out from the coil 20 ', and at this time, the balloon catheter 12' and the protective sheath 11 'thereof are easily damaged if the balloon catheter 12' is straightened manually. In addition, the protective sheath 11 ' of the prior art is easily detached from the balloon catheter 12 ' when being installed in the coil 20 ' and removed from the coil 20 ', and the exposed balloon catheter 12 ' is easily damaged and contaminated.

Therefore, it is necessary to provide a new sheath device for solving the technical problem that the existing protective sheath does not play a good role in protecting the balloon catheter when the balloon catheter is restored from a bent state to a straight state.

Disclosure of Invention

The invention provides a sheath device which can effectively protect a catheter assembly when the catheter assembly is restored to a straight state from a bending state based on the problems of the sheath device in the prior art, and the sheath device is mainly realized by the following technical scheme.

The invention provides a sheath device which is sleeved outside a catheter assembly and comprises an elastic sheath assembly, wherein the elastic sheath assembly comprises a first sleeve and an elastic part connected to the first sleeve, the first sleeve can be in a bending state under the action of a constraint force, and after the constraint force disappears, the elastic part enables the first sleeve to rebound from the bending state to a straight state.

In the sheath device according to the present invention, the sheath device further includes a resilient clamp, one end of the resilient clamp is connected to the resilient sheath assembly, and the other end of the resilient clamp is a free end and is adapted to be detachably connected to the catheter assembly.

In the sheath device of the present invention, the sheath device further includes a second sleeve, the second sleeve is detachably sleeved outside the elastic sheath assembly, and when the second sleeve is sleeved outside the elastic sheath assembly, the second sleeve radially compresses the elastic sheath assembly.

In the sheath device according to the present invention, the sheath device further includes a resilient clamp, one end of the resilient clamp is connected to the second sleeve or the resilient sheath assembly, and the other end of the resilient clamp is a free end and is adapted to be detachably connected to the catheter assembly.

In the sheath device of the present invention, the sheath device further includes a third sleeve, a pressing member, and a flexible member, the third sleeve is detachably sleeved outside the elastic sheath assembly, the pressing member is connected to the third sleeve, the flexible member is connected to the elastic sheath assembly, and when the third sleeve is sleeved outside the elastic sheath assembly, the pressing member radially compresses the flexible member.

In the sheath apparatus of the present invention, when the third sheath is sheathed outside the elastic sheath assembly, the third sheath radially compresses the elastic sheath assembly.

In the sheath device, an included angle between a connecting line at two ends of the pressing piece and a longitudinal central shaft of the third sleeve is 30-70 degrees.

In the sheath device, the length of the flexible member along the longitudinal central axis direction of the elastic sheath component is 2 mm-6 mm.

In the sheath device of the present invention, the elastic force of the two ends of the elastic member is different.

In the sheath device of the present invention, the elastic member is fixed to an outer wall of the first sleeve, and an inner wall of the first sleeve is provided with a protective layer.

In summary, the sheath device of the present invention has the following advantages: under the constraining force effect, this application sheath device's first sleeve can be in the bending state, and after the constraining force disappeared, the elastic component made first sleeve kick-backs to the straight state by the bending state automatically, avoided manual straightening first sleeve.

Drawings

Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The drawings are only for purposes of illustrating the preferred embodiments and are not to be construed as limiting the invention. Also, like reference numerals are used to refer to like parts throughout the drawings. In the drawings:

FIG. 1-a is a schematic view of a prior art balloon catheter and its protective sheath;

FIG. 1-b is a schematic view of a coil for storing the balloon catheter and protective sheath of FIG. 1-a;

FIG. 2-a is a schematic view of a sheath apparatus according to a first embodiment of the present invention;

FIG. 2-b is a schematic view of the sheath device shown in FIG. 2-a being disposed over a balloon catheter;

fig. 3-a is a schematic view of a sheath device according to a second embodiment of the invention, in which the elastic member is a first elastic sheet structure;

fig. 3-b is a schematic view of a second elastic piece structure of the sheath device according to the second embodiment of the invention;

FIG. 4-a is a schematic view of a sheath device disposed outside a balloon catheter according to a third embodiment of the present invention;

FIG. 4-b is a schematic illustration of the elastomeric sheath assembly of the sheath apparatus of FIG. 4-a having a maximum outer diameter;

FIG. 4-c is a schematic view of the elastomeric sheath assembly of the sheath apparatus of FIG. 4-a having a minimum outer diameter;

FIG. 4-d is a schematic view of the elastic member of the sheath apparatus shown in FIG. 4-a in a natural state;

FIG. 4-e is a schematic view of the resilient member of the sheath apparatus of FIG. 4-a in a compressed state;

FIG. 4-f is a schematic view of a second cannula of the sheath apparatus shown in FIG. 4-a;

FIG. 4-g is a schematic view of the sheath apparatus and balloon catheter shown in FIG. 4-a, shown in flexion;

FIG. 5-a is a schematic view of a sheath device disposed outside a balloon catheter according to a fourth embodiment of the present invention;

FIG. 5-b is a schematic view of a second cannula of the sheath apparatus shown in FIG. 5-a;

FIG. 5-c is a schematic view of the elastic sheathing assembly of the sheathing apparatus shown in FIG. 5-a;

fig. 6 is a schematic view of an elastic member of a sheath apparatus according to a fifth embodiment of the present invention.

Detailed Description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

It is to be understood that the terminology used herein is for the purpose of describing particular example embodiments only, and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises," "comprising," "including," and "having" are inclusive and therefore specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order described or illustrated, unless specifically identified as an order of performance. It should also be understood that additional or alternative steps may be used.

Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as "first," "second," and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.

For ease of description, spatially relative terms, such as "outer", "inner", "end", "inclined", "distal", "outer wall", "axial", "radial", and the like, may be used herein to describe one element or feature's relationship to another element or feature as illustrated in the figures. Such spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" or "over" the other elements or features. Thus, the example term "below … …" can include both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.

In the field of interventional medicine, it is generally defined that the end of the instrument proximal to the operator is the proximal end and the end distal to the operator is the distal end. "axial" generally refers to the length of the instrument as it is being delivered, and "radial" generally refers to the direction of the instrument perpendicular to its "axial" direction, and defines both "axial" and "radial" directions for any component of the instrument in accordance with this principle.

In order to describe in detail the technical features and technical effects of the sheath device of the present invention, the sheath device of the present invention is described below by way of specific embodiments.

The first embodiment is as follows: as shown in fig. 2-a and 2-b, a first embodiment of the present invention provides a sheath device 100 that is sleeved outside a catheter assembly 200. The sheath apparatus 100 comprises an elastic sheath assembly 10, the elastic sheath assembly 10 comprising a first sleeve 20 and an elastic member 30 connected to the first sleeve 20, the first sleeve 20 being capable of being in a bent state under a constraint force, the elastic member 30 causing the first sleeve 20 to rebound from the bent state to a straight state when the constraint force acting thereon disappears.

When first sleeve 20 is in the straight state, elastic component 30 is in the natural state, elastic component 30 does not take place elastic deformation this moment, when first sleeve 20 is receiving constraining force and is in the bending state, if first sleeve 20 deposits to take place when crooked in the coil pipe, elastic component 30 bends and takes place elastic deformation along with first sleeve 20 together, after first sleeve 20 takes out from the coil pipe, the constraining force that is used in first sleeve 20 disappears, this moment, elastic component 30 automatic recovery to the natural state, simultaneously, under elastic component 30's resilience effect, first sleeve 20 can resume to the straight state by the bending state.

Further, the sheath apparatus 100 further includes a resilient clamp 40, one end of the resilient clamp 40 is connected to the resilient sheath assembly 10, and the other end of the resilient clamp 40 is detachably abutted to the outer wall of the catheter assembly 200. When the first sleeve 20 is sleeved outside the catheter assembly 200, the other end of the elastic clamping member 40 can abut against the outer wall of the catheter assembly 200, so that the clamping operation is completed, and the sheath device 100 is prevented from falling off from the catheter assembly 200.

In the embodiment of fig. 2-b, catheter assembly 200 is a balloon catheter that includes a catheter 201 and a balloon (not shown) attached to catheter 201, with first cannula 20 being disposed over the balloon. The elastic member 30 is a spiral spring structure, the spiral spring structure includes but is not limited to a compression spring, a torsion spring, a tension spring, a tower spring, etc., the elastic member 30 is sleeved on the outer surface of the first sleeve 20, and two ends of the elastic member 30 can be fixed on the first sleeve 20 by glue bonding, hot melt welding, laser welding, etc. The number of the elastic clamping members 40 is two, one end of the elastic clamping member 40 is provided with a first connection ring (not shown), and the elastic member 30 is provided with a second connection ring (not shown) matched with the first connection ring, and the first connection ring is hooked on the second connection ring, so that the elastic clamping member 40 and the elastic member 30 are rotatably connected. The other end of the elastic clamping member 40 is a free end, and when the first sleeve 20 is sleeved outside the balloon, the user can rotate the elastic clamping member 40 to enable the free end to abut against the outer wall of the catheter 201, so that the clamping operation is completed.

In order to increase the contact area of the resilient clamping member 40 with the guide tube 201, to improve the strength of the connection between the two, and to avoid the resilient clamping member 40 damaging the surface of the guide tube 201, the free end of the resilient clamping member 40 is provided with an open slot (not shown) adapted to the outer diameter of the guide tube 201, the slot wall of which slot can be applied against the outer wall of the guide tube 201.

Since the resilient clamping member 40 acts directly on the surface of the conduit 201, in order to avoid the resilient clamping member 40 damaging the surface of the conduit 201, the free end of the resilient clamping member 40 is equipped with a flexible member (not shown), and the user can rotate the resilient clamping member 40 to abut the flexible member of the free end against the outer wall of the conduit 201. The flexible member can be made of high polymer materials with good elasticity, such as polyurethane, nitrile rubber and the like.

Because the first sleeve 20 is sleeved outside the balloon of the balloon catheter, in order to prevent the first sleeve 20 from damaging the balloon, the inner wall of the first sleeve 20 is provided with a protective layer, and the protective layer is a coating made of a high polymer material with high strength and good elasticity, such as a high-strength polyurethane coating, a nitrile rubber coating, and the like.

It is understood that the present embodiment does not limit the specific connection relationship between the elastic member 30 and the first sleeve 20, as long as the elastic member 30 can restore the first sleeve 20 from the bent state to the straight state. For example, in other embodiments, the elastic element 30 may be fixed on the inner wall of the first sleeve 20, and in order to avoid the elastic element 30 damaging the balloon, the inner wall of the first sleeve 20 is provided with a receiving groove (not shown) in which the elastic element 30 is mounted, and the surface of the elastic element 30 away from the bottom of the receiving groove is located on the same circumferential surface as the inner wall of the first sleeve 20. It should also be understood that the present embodiment is not limited to the specific structure of the elastic member 30, and the elastic member 30 may also be a spring or other elastically deformable component.

It will also be appreciated that the present embodiment is not limited to the specific connection of the resilient clamping member 40 to the first sleeve 20 or the resilient member 30, as long as the free end of the resilient clamping member 40 is detachably engaged with the outer wall of the conduit 201 to complete the clamping operation. For example, in other embodiments, the resilient clamping member 40 may be rotatably connected to the first sleeve 20 or the resilient member 30 by a hinge or a shaft; alternatively, the elastic clamping member 40 is fixed to the first sleeve 20 or the elastic member 30, and the elastic clamping member 40 abuts its free end to the outer wall of the guide pipe 201 by its own elastic deformation. It will also be appreciated that the present embodiment is not limited to the number of spring clamps 40, and that in other embodiments, the number of spring clamps 40 may be one or more.

During assembly, the first sleeve 20 is firstly sleeved outside the balloon of the balloon catheter, and then the elastic clamping members 40 are rotated to enable the free ends of the two elastic clamping members 40 to respectively abut against the outer wall of the balloon catheter, and at this time, the sheath device 100 is fixedly connected with the balloon catheter through the elastic clamping members 40. Then the balloon catheter sleeved with the protection device 10 is put into the coil. Because the coil is helical, both the balloon catheter and the sheath device 100 are in a curved state within the coil. During removal of the balloon catheter and sheath device 100 from the coil, the sheath device 100 will not separate from the balloon catheter due to the gripping action of the resilient clamp 40. After the balloon catheter and sheath device 100 is taken out of the coil, the first sleeve 20 and the balloon catheter can be rapidly restored to a natural straight state from a bent state under the action of the resilience force of the elastic member 30 because the constraint force of the coil on the balloon catheter and sheath device 100 disappears.

As will be understood by those skilled in the art, the elastic member 30 of the sheath device 100 of the present invention can restore the balloon catheter from the curved state to the straight state by its own resilience, thereby reducing the occurrence of irreversible bending of the balloon catheter stored in the coil for a long time and reducing the occurrence of damage to the balloon catheter when the balloon catheter is straightened manually. Furthermore, the sheath device 100 is sleeved outside the balloon catheter through the clamping device 40, so that the phenomenon that the sheath device 100 falls off from the balloon catheter when the sheath device 100 and the balloon catheter are stored in the coil pipe or taken out from the coil pipe can be reduced.

It should be noted that the application of the sheath device 100 to the balloon catheter is only a preferred embodiment of the present invention, and is not intended to limit the application scope of the sheath device 100 of the present invention, for example, the sheath device of the present invention can also be used to protect other medical devices having similar tubular structures, and such an adjustment belongs to the protection scope of the sheath device of the present invention.

It should be noted that the present invention is described by storing the sheath device and catheter assembly 200 in a coiled tube, but the storage manner of the sheath device and catheter assembly 200 is not limited thereto, for example, the sheath device and catheter assembly 200 may be folded in a binding manner, and such an adjustment still falls within the protection scope of the storage manner of the sheath device and catheter assembly 200.

Example two: as shown in fig. 3-a and 3-b, a second embodiment of the present invention provides a sheath device 100, which is substantially the same as the sheath device of the first embodiment except that the elastic member 30 includes at least one elastic piece fixed to the first sleeve 20.

In the embodiment shown in fig. 3-a, the elastic member 30 includes two elastic sheets, the two elastic sheets are symmetrically disposed along the radial direction of the first sleeve 20, each elastic sheet is in a strip shape and has a flat surface, the elastic sheet is attached to the outer wall of the first sleeve 20 and extends along a direction parallel to the longitudinal central axis of the first sleeve 20, and the elastic sheet can be integrally fixed on the first sleeve 20 by glue bonding, hot melt welding, laser welding, or the like.

Because the elastic sheet is integrally fixed on the outer wall of the first sleeve 20, when the elastic sheet is bent with the first sleeve 20, the elastic sheet cannot be separated from the first sleeve 20, so that the overall outer diameter of the sheath device 100 can be kept unchanged, and the smoothness of the sheath device 100 when being assembled to a coil pipe is improved.

It is understood that the present embodiment does not limit the specific structure of the elastic sheet, and the elastic sheet may be a unitary structure or a combination structure of a plurality of elastic sheet units, for example, in the embodiment shown in fig. 3-b, the elastic sheet is an elastic sheet having a corrugated structure. It should be further understood that the specific number of the elastic pieces is not limited in this embodiment, in other embodiments, the number of the elastic pieces may be one or more, and when the number of the elastic pieces is multiple, the multiple elastic pieces are uniformly distributed on the outer surface of the first sleeve 20 along the circumferential direction. It can also be understood that, in other embodiments, the elastic sheet can be fixed on the inner wall of the first sleeve 20, specifically, the inner wall of the first sleeve 20 is provided with a receiving groove (not shown), the elastic sheet is fixed in the receiving groove, and the surface of the elastic sheet away from the bottom of the receiving groove is located on the same circumferential surface as the inner wall surface of the first sleeve 20.

When first sleeve 20 was in straight state, the shell fragment was in nature straight state, and elastic deformation did not take place for the shell fragment this moment, and when first sleeve 20 took place the bending, the shell fragment was crooked and taken place elastic deformation along with first sleeve 20 together, and when the external binding power disappearance back, the shell fragment resumes to straight state, and first sleeve 20 can become straight state by the bending state under the resilience force effect of shell fragment. The method for using the sheath device in the second embodiment is similar to that of the sheath device in the first embodiment, and therefore, the method for using the sheath device in the second embodiment is not described herein again.

Example three: referring to fig. 4-a, a third embodiment of the present invention provides a sheath apparatus 100, which is substantially the same as the sheath apparatus of the first embodiment, the sheath apparatus 100 includes an elastic sheath assembly 10, and the elastic sheath assembly 10 includes a first sleeve 20 and an elastic member 30 connected to the first sleeve 20.

The third embodiment is different from the first embodiment in that the sheath device 100 further includes a second sleeve 50, the second sleeve 50 is detachably sleeved outside the elastic sheath assembly 10, and when the second sleeve 50 is sleeved outside the elastic sheath assembly 10, the second sleeve 50 radially compresses the elastic sheath assembly 10 to enable the elastic sheath assembly 10 to be tightly attached to the balloon catheter, so as to improve the connection strength between the elastic sheath assembly 10 and the balloon catheter and prevent the elastic sheath assembly 10 from falling off from the balloon catheter.

Referring to fig. 4-b, the circumscribed circle of the cross-section of the elastic sheath assembly 10 has a maximum outer diameter Dmax when the elastic member 30 is in the natural state. Referring to fig. 4-c, when a radial force F is applied to the elastic member 30, the circumscribed circle of the cross-section of the elastic sheath assembly 10 has a minimum outer diameter Dmin when the elastic member 30 is at a maximum radial deformation, i.e., when the elastic member 30 cannot continue to be radially compressed. The inner diameter C of the second sleeve 50 meets the requirement that Dmin is less than C and less than Dmax, so that the second sleeve 50 can be sleeved outside the elastic part 30, and when the second sleeve 50 is sleeved outside the elastic part 30, the second sleeve 50 can radially compress the elastic part 30, so that the first sleeve 20 is tightly attached to the balloon catheter.

Further, in order to reduce the overall outer diameter of the sheath device 100 and improve the smoothness when the sheath device 100 is assembled to the coil, C-Dmin is less than 1 mm. Preferably, C-Dmin < 0.5 mm.

In the present embodiment, the elastic member 30 is fixed to the outer surface of the second sleeve 50, and the elastic member 30 has a coil spring structure including a plurality of coils of the spring unit 31 connected to each other. Fig. 4-d is a schematic view of the spring in a natural state where the spring has a maximum outer diameter, and fig. 4-e is a schematic view of the spring after being radially compressed, the spring having a minimum outer diameter when the spring cannot be elastically deformed continuously, the outer diameter of the spring being gradually reduced during the radial compression. Referring to fig. 4-d, the pitch of the spring is L1, and the diameter of each coil of spring unit 31 is L2, which increases the radial deformation of the spring to facilitate the insertion into the second sleeve 50, and when the spring is in a natural state, the pitch L1 of the spring is greater than the diameter L2 of the spring unit 31, i.e. when the spring is in a natural state, there is a gap between adjacent spring units 31.

It is understood that the present embodiment does not limit the specific position of the elastic member 30 fixed on the second sleeve 50, and in other embodiments, the elastic member 30 can be fixed on the inner wall of the second sleeve 50 as long as the second sleeve 50 can radially compress the elastic sheath assembly 10 when the second sleeve 50 is sleeved on the outer side of the elastic sheath assembly 10.

It is further understood that the present embodiment does not limit the specific structure of the elastic element 30, for example, in other embodiments, the elastic element 30 is a spring sheet with a corrugated structure (as shown in fig. 3-b), since the spring sheet has a corrugated structure, when a radial force acts on the spring sheet, the spring sheet will be compressed radially and extended axially, so as to ensure that the second sleeve 50 can be sleeved on the spring sheet, and when the second sleeve 50 is sleeved on the spring sheet, the second sleeve 50 can radially press the spring sheet to make the first sleeve 20 tightly fit with the balloon catheter.

Referring again to fig. 4-a, the sheath apparatus 100 further includes a resilient clamping member 40, one end of the resilient clamping member 40 is connected to the second sheath 50 or the resilient sheath assembly 10, and the other end of the resilient clamping member 40 is a free end. When the first sheath 20 is sleeved outside the balloon catheter, the user can rotate the elastic clamping member 40 to enable the free end of the elastic clamping member 40 to abut against the outer wall of the catheter 201, so that the clamping operation is completed, and the sheath device 100 is prevented from falling off from the balloon catheter.

In order to increase the contact area of the resilient clamping member 40 with the conduit 201, to improve the strength of the connection between the two, and to avoid the resilient clamping member 40 damaging the surface of the conduit 201, the free end of the resilient clamping member 40 is provided with a groove and/or a flexible member (neither shown).

Referring to fig. 4-f, the number of the elastic clamping members 40 is two, one end of the elastic clamping member 40 is connected to the second sleeve 20, and the other end is a free end. It will be appreciated that in other embodiments, one end of the resilient clamp member 40 may also be attached to the first sleeve 20 or the resilient member 30, with the other end of the resilient clamp member 40 being a free end.

During assembly, the second sleeve 50 is firstly sleeved outside the balloon of the balloon catheter, then the elastic member 30 is radially pressed, and the first sleeve 20 connected with the elastic member 30 is arranged between the second sleeve 50 and the balloon, so that the first sleeve 20 is tightly attached to the balloon catheter. Then, the elastic clamping members 40 are rotated to enable the free ends of the two elastic clamping members 40 to respectively press against the outer wall of the balloon catheter, and at the same time, the sheath device 100 is fixedly connected with the balloon catheter through the elastic clamping members 40. Finally, the balloon catheter covered with the protector 10 is put into the coil, and both the balloon catheter and the sheath device 100 are in a bent state in the coil due to the spiral shape of the coil (as shown in fig. 4-g).

Example four: as shown in fig. 5-a, a fourth embodiment of the present invention provides a sheath apparatus 100, which is substantially the same as the sheath apparatus of the third embodiment, the sheath apparatus 100 includes an elastic sheath assembly 10, and the elastic sheath assembly 10 includes a first sleeve 20 and an elastic member 30 connected to the first sleeve 20.

The fourth embodiment is different from the first embodiment in that the sheath apparatus 100 further includes a third sleeve 60, a flexible member 61, and a pressing member 62, the third sleeve 60 is detachably sleeved outside the sheath assembly 10, the pressing member 62 is connected to the third sleeve 60, and the flexible member 61 is connected to the elastic sheath assembly 10. When the third sleeve 60 is sleeved outside the elastic sheath assembly 10, the pressing piece 62 radially compresses the flexible piece 61, so that the flexible piece 61 is tightly attached to the balloon catheter, the connection strength of the elastic sheath assembly 10 and the balloon catheter is improved, and the elastic sheath assembly 10 is prevented from falling off from the balloon catheter.

The flexible member 61 is made of a high polymer material with good elasticity, such as polyurethane, nitrile rubber, etc., and can be connected to the elastic sheath assembly 10 by bonding, welding, or integral molding. Referring to fig. 5-c, the flexible member 61 is generally a circular ring structure that is secured to the end of the first sleeve 20.

Referring to fig. 5-b, the compressing member 62 is substantially a plate-shaped structure, one end of the compressing member 62 is fixedly connected to the end of the third sleeve 60, and the other end of the compressing member 62 extends toward a side away from the third sleeve 60 and inclines toward a side of the balloon catheter.

Because the pressing member 62 is obliquely arranged, it has a component force in the radial direction and a component force in the axial direction to the flexible member 61, and if an included angle θ between a connecting line at two ends of the pressing member 62 and the longitudinal central axis of the third sleeve 60 is too large, the component force in the axial direction is too large, which is not favorable for sleeving the elastic sheath assembly 10 in the third sleeve 60. However, if the angle θ between the connecting line of the two ends of the pressing member 62 and the longitudinal central axis of the third sleeve 60 is too small, the axial length of the flexible member 61 needs to be increased to ensure that the pressing member 62 clamps the flexible member 61. Therefore, the included angle theta between the connecting line of the two ends of the pressing piece 62 and the longitudinal central axis of the third sleeve 60 satisfies the condition that theta is more than 30 degrees and less than 70 degrees.

In order to ensure that the flexible member 61 has a sufficient clamping force and also facilitate the pressing member 62 to radially press the flexible member 61, the length of the flexible member 61 along the longitudinal central axis of the elastic sheath assembly 10 is 2mm to 6 mm. When the length of the flexible member 61 in the longitudinal central axis direction of the elastic sheath assembly 10 is greater than 6mm, the contact area between the flexible member 61 and the pressing member 62 is too large, so that the clamping force acting on the balloon catheter becomes small, which is not favorable for clamping, and the elastic sheath assembly 10 is easily separated from the balloon catheter. When the length of the flexible member 61 in the longitudinal central axis direction of the elastic sheath assembly 10 is less than 2mm, the contact area between the flexible member 61 and the pressing member 62 is too small to facilitate the pressing member 62 to radially compress the flexible member 61.

In a cross section passing through a longitudinal central axis of the sheath device 100, a ratio of the radial heights of the flexible part 61 and the elastic sheath component 10 on the same side of the longitudinal central axis of the elastic sheath component 10 is 0.8-1.2, preferably 1. When the above ratio is less than 0.8, that is, the radial height of the flexible member 61 is much smaller than the radial height of the elastic sheath assembly 10, if the pressing member 62 is to radially compress the flexible member 61, the included angle θ between the pressing member 62 and the axial direction of the third sleeve 60 is too large. When the above ratio is greater than 1.2, that is, the radial height of the flexible member 61 is much greater than the radial height of the elastic sheath assembly 10, it is not favorable for the third sleeve 60 to be sleeved outside the elastic sheath assembly 10.

Further, the inner wall of the flexible member 61 is subjected to a special process including plasma treatment, coating, etc., thereby increasing the frictional force between the inner wall of the flexible member 61 and the balloon catheter 10.

In this embodiment, when the third sleeve 60 is sleeved outside the elastic sheath assembly 10, the third sleeve 60 also radially compresses the elastic sheath assembly 10, so that the elastic sheath assembly 10 is tightly attached to the balloon catheter, so as to further improve the connection strength between the elastic sheath assembly 10 and the balloon catheter. Specifically, when the elastic member 30 is in a natural state, the circumcircle of the cross section of the elastic sheath assembly 10 has a maximum outer diameter Dmax, and when the elastic member 30 is in a maximum radial deformation, that is, when the elastic member 30 cannot continue to be radially compressed, the circumcircle of the cross section of the elastic sheath assembly 10 has a minimum outer diameter Dmin, the inner diameter C of the second sleeve 50 is satisfied, and Dmin < C < Dmax. In order to reduce the overall outer diameter of the sheath device 100 and improve the smoothness when the sheath device 100 is assembled to a coil, C-Dmin is less than 1 mm. Preferably, C-Dmin < 0.5 mm.

It is understood that in other embodiments, when the third sleeve 60 is sleeved outside the elastic sheath assembly 10, the third sleeve 60 may not radially compress the elastic sheath assembly 10 as long as the pressing member 62 is ensured to radially compress the flexible member 61.

Example five: a fifth embodiment of the present invention provides a sheath apparatus substantially identical to the sheath apparatus of the first embodiment, the sheath apparatus comprising an elastomeric sheath assembly including a first sleeve and an elastomeric member attached to the first sleeve. The difference from the first embodiment is that the elastic force at the two ends of the elastic member is different.

During assembly, the tip of the balloon catheter is inserted from the inlet 20 a' (as shown in fig. 1-b) outside the coil, and since the inside radius of curvature of the coil is smaller than the outside radius of curvature, the tip of the balloon catheter gradually decreases in radius and increases in angle of curvature as the balloon catheter moves within the coil. When the balloon catheter is completely installed in the coil, the bending angle of the balloon catheter gradually decreases from the head end to the tail end, and accordingly, the bending angle of the sheath device 100 also gradually decreases in the direction from the head end to the tail end of the balloon catheter. In consideration of the above, the end of the elastic member 30 with stronger elasticity may be fixed to the first sleeve 20 near the head end of the balloon catheter, and the end of the elastic member 30 with weaker elasticity may be fixed to the first sleeve 20 far from the head end of the balloon catheter.

As shown in fig. 6, the elastic member 30 is a coil spring structure including a plurality of connected spring units 31, and the diameters of the plurality of spring units 31 are increased from one end to the other end, i.e., L3> L4. In the embodiment, the thickness of the spring unit 31 at the two ends of the spring is changed, so that the two ends of the spring 30 can bear constraint forces with different sizes and different angles.

It is understood that the present embodiment is not limited to the specific structure of the elastic member 30, and in other embodiments, the elastic member 30 may also be a spring structure, and the thicknesses of the two ends of the spring structure are changed to make the elastic forces at the two ends of the elastic member 30 different.

It should be noted that, the structures of the sheath devices described in the first embodiment, the second embodiment, the third embodiment, the fourth embodiment and the fifth embodiment of the present invention may be reasonably combined according to an actual application environment, the combined sheath device may include one or more technical features described above, and has the technical effects of the technical features, and the combined sheath device belongs to the protection range of the sheath device of the present invention, and the specific combination manner of the structures in the sheath device is not described herein again.

The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.

Claims

1. A sheath device is sleeved outside a catheter assembly and is characterized by comprising an elastic sheath assembly, wherein the elastic sheath assembly comprises a first sleeve and an elastic piece connected to the first sleeve, the first sleeve can be in a bending state under the action of a constraint force, after the constraint force disappears, the elastic piece enables the first sleeve to rebound from the bending state to a straight state, the sheath device further comprises an elastic clamping piece, one end of the elastic clamping piece is connected to the elastic sheath assembly, and the other end of the elastic clamping piece is a free end and is used for being detachably connected with the catheter assembly.

2. A sheath apparatus according to claim 1, further comprising a second sleeve detachably disposed over the resilient sheath assembly, the second sleeve radially compressing the resilient sheath assembly when the second sleeve is disposed over the resilient sheath assembly.

3. A sheath assembly according to claim 2 wherein one end of the resilient clamp is replaced by attachment to the resilient sheath assembly to the second sleeve, and the other end of the resilient clamp is free and is adapted for detachable attachment to the catheter assembly.

4. A sheath device is sleeved outside a catheter assembly and is characterized by comprising an elastic sheath assembly, wherein the elastic sheath assembly comprises a first sleeve and an elastic piece connected to the first sleeve, the first sleeve can be in a bending state under the action of a constraint force, when the constraint force disappears, the elastic piece enables the first sleeve to rebound from the bending state to a straight state, the sheath device further comprises a third sleeve, a pressing piece and a flexible piece, the third sleeve is detachably sleeved outside the elastic sheath assembly, the pressing piece is connected to the third sleeve, the flexible piece is connected to the elastic sheath assembly, and when the third sleeve is sleeved outside the elastic sheath assembly, the pressing piece radially compresses the flexible piece.

5. A sheath apparatus according to claim 4 wherein the third sheath radially compresses the resilient sheath assembly when the third sheath is sheathed outside the resilient sheath assembly.

6. The sheath apparatus according to claim 4, wherein an angle between a line connecting both ends of the pressing member and a longitudinal central axis of the third sleeve is 30 ° to 70 °.

7. A sheath device according to claim 4, wherein the length of the flexible member in the direction of the longitudinal central axis of the elastic sheath assembly is 2mm to 6 mm.

8. A sheath device according to claim 1 wherein the resilient member has different resilience at each end.

9. A sheath device according to claim 1 wherein the resilient member is secured to an outer wall of the first sleeve, the inner wall of the first sleeve being provided with a protective layer.