Stent structure and expandable catheter sheath

Abstract

A stent structure and an expandable catheter sheath, the stent structure comprising a plurality of support skeletons and support beams, the support skeletons being annular or arc-shaped, and the plurality of support skeletons being arranged in sequence along an axis; the support beams being used for connecting the plurality of support skeletons. The support skeleton comprises an expansion part, which expands radially under the action of an external force, and drives the support skeleton to expand along the radial direction; after the external force is removed, the expansion part retracts, and drives the support skeleton to contract along the radial direction. By setting the expansion part, and by utilizing the characteristics that the expansion part expands under stress and retracts after the external force disappears, the expansion and retraction of the stent structure are realized, so that the expandable catheter sheath can be expanded by a smaller external force, and the surgical process is more convenient. In addition, the support beams are also provided, so that the axial length of the stent structure is not easy to change during the expansion and retraction process, and the structure is more stable and reliable; and the support beams can also provide certain radial support for the expandable catheter sheath, so that the expandable catheter sheath is not easy to bend during the surgical process.

Description

Technical Field

[0001] This application relates to the field of medical device technology, and more particularly to a stent structure and an expandable catheter sheath. Background Technology

[0002] The main characteristic of heart failure is that the heart cannot function properly, resulting in insufficient blood pumping from veins and insufficient blood supply to arteries. Left ventricular failure is more common under normal circumstances. Heart failure can occur as a complication or as an acute symptom. Common situations include: high-risk coronary artery disease patients requiring percutaneous coronary intervention (PCI) often have heart failure, and the procedure may cause myocardial ischemia or arrhythmias that are difficult to tolerate, posing a risk of malignant hemodynamics. Therefore, cardiac assist devices are needed during treatment to restore ventricular function, with restoration of left ventricular function being particularly urgent. These procedures typically require cardiac assist devices with larger outer diameters, necessitating larger catheter sheaths. Larger catheter sheaths often result in larger incisions during insertion, making suturing or hemostasis more difficult, and increasing the risk of vascular injury during insertion and withdrawal.

[0003] An expandable catheter sheath exists that can assist in the insertion of medical devices into the human body. Compared to traditional catheter sheaths, it is both expandable and retractable, allowing insertion into blood vessels through smaller incisions during surgery. Its expandable nature allows for the insertion of medical devices of varying sizes. The expansion method of the expandable catheter sheath is its key technological focus; it needs to possess both expandability and retraction capability. Therefore, its internal stent structure and the method of fusion with the membrane are crucial to achieving this effect. Existing stent structures and membrane fusion methods experience significant resistance during expansion, making it difficult to achieve a large outer diameter with relatively small force.

[0004] Therefore, improvements are needed in the stent structure and its membrane welding method to further enhance the expansion and retraction capabilities of the expandable catheter sheath. Utility Model Content

[0005] The purpose of this application is to provide a stent structure and an expandable catheter sheath, which have good expandability and retraction capabilities, can be opened with a small amount of external force, making the surgical procedure more convenient, and the stent structure is not easily bent during the operation.

[0006] The technical solution provided by this utility model is as follows:

[0007] A stent structure suitable for an expandable catheter sheath, comprising:

[0008] Multiple support frames, the support frames being ring-shaped or arc-shaped, and the multiple support frames being arranged sequentially along an axis;

[0009] A support beam, wherein there is at least one support beam, used to connect multiple support frames;

[0010] The supporting frame includes an expansion portion adapted to expand radially under the action of an external force, thereby causing the supporting frame to expand radially; and the expansion portion is configured to retract after the external force is removed, causing the supporting frame to contract radially.

[0011] In some embodiments, the expansion portion includes an expansion arm and a connecting arm, the number of expansion arms being two, the connecting arm connecting the two expansion arms, and the two expansion arms undergoing radial deformation and moving away from each other under the action of external force.

[0012] In some embodiments, the connecting arm is arc-shaped, and the two ends of the connecting arm in the arc length direction are respectively connected to the ends of the two expansion arms;

[0013] Wherein, the arc shape of the connecting arm is a superior arc, and both of the expansion arms are arc-shaped with convex surfaces, and the convex surfaces of the two expansion arms are arranged facing each other to form an inwardly contracting neck at the connection between the connecting arm and the expansion arm; or, the arc shape of the connecting arm is a semi-circular arc or a inferior arc, and the two expansion arms are linear.

[0014] In some embodiments, there are multiple expansion portions, and the multiple expansion portions are sequentially connected to form a ring-shaped support frame; and there are multiple support beams, and each expansion portion is connected to at most two support beams;

[0015] The support beam is fixed to the end of the expansion arm away from the connecting arm and is axially connected to a plurality of the support frames, which are adapted to limit the relative position between two adjacent support frames.

[0016] In some embodiments, the support structure further includes:

[0017] Inner membrane and outer membrane;

[0018] The inner walls of the plurality of support frames are covered with the inner layer membrane, and the outer walls of the plurality of support frames are covered with the outer layer membrane. The projection of the outer layer membrane on the inner layer membrane overlaps with the inner layer membrane. A fusion zone is provided between the inner layer membrane and the outer layer membrane, and the fusion zone is partially located at the overlapping area to allow the inner layer membrane and the outer layer membrane to be fused together.

[0019] In some embodiments, the molten zone is linear, including one or more of the following: straight, arc-shaped, wave-shaped, zigzag, S-shaped, and spiral-shaped.

[0020] In some embodiments, the molten zone includes a first molten zone;

[0021] The first melting zone is located on the convex side of the connecting arm, and the shape of the first melting zone is arc-shaped, adapted to the shape of the connecting arm.

[0022] In some embodiments, each of the expansion portions is connected to two of the support beams, and the two support beams are respectively located at the ends of the two expansion arms away from the connecting arm;

[0023] Wherein, the first melting zone extends circumferentially from both ends of the support frame to the support beams located on both sides of the connecting arm.

[0024] In some embodiments, the melting zone further includes a second melting zone;

[0025] The second melting zone is located on the concave side of the connecting arm and between the two expanding arms connected by the connecting arm;

[0026] The second melting zone is linear and extends axially along the support frame.

[0027] This application also provides an expandable catheter sheath, comprising:

[0028] The sheath and the support structure disposed on the sheath, wherein the support structure is the support structure provided in any of the above embodiments;

[0029] The sheath is adapted to allow external instruments to pass through, and when an external instrument is inserted into the sheath, the support structure expands radially under the force of the external instrument, thereby causing the sheath to expand radially.

[0030] The technical advantages of this application are as follows:

[0031] 1. In this application, the supporting skeleton includes an expansion portion. This expansion portion can radially expand when external instruments enter the supporting skeleton, using the delivery force of the external instruments to allow the external instruments to pass smoothly. After the external instruments have passed, the expansion portion can immediately retract to its original size. By providing an expansion portion, this application enables the stent structure and expandable catheter sheath to have better expandability and retraction capabilities, thereby making the surgical procedure more convenient.

[0032] 2. In this application, by setting a support beam to connect multiple support frames, the scaffold structure is less prone to axial length changes during expansion and retraction, making the structure more stable and reliable. Furthermore, the support beam also provides radial support for the expandable catheter sheath, making it less prone to bending during surgery.

[0033] 3. In this application, the expansion section includes an arc-shaped connecting arm and expansion arms located at both ends along the arc length of the connecting arm, forming an overall "U" shape, which improves expansion and retraction performance. When an external instrument enters the support frame, the two expansion arms of the expansion section move away from each other, thereby expanding the support frame. The longer the two expansion arms are, the greater the expansion distance they can extend. After the external instrument passes through, the two expansion arms spring back and return to their original state.

[0034] 4. In this application, the inner and outer sides of the support frame are covered with an inner membrane and an outer membrane, respectively. The inner membrane and the outer membrane are fused together in the melting zone, while the area outside the melting zone is not fused together. This provides room for the deformation of the expansion part, reduces the resistance encountered by the expansion part when it expands, and allows the support structure to be opened with a smaller external force.

[0035] 5. In this application, the melting zone includes a first melting zone, which is located on the convex side of the connecting arm and is adapted to the shape of the connecting arm. When the external instrument enters the support frame, the part where the inner and outer films are fused in the first melting zone can apply a uniform axial thrust to the connecting arm, causing the connecting arm to drive the expansion arms on both sides to open. At this time, the support frame no longer relies solely on the expansion force of the conveying to expand, and its expansion capacity is stronger. Attached Figure Description

[0036] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0037] Figure 1 This is a side view of the support structure provided in one embodiment of this application;

[0038] Figure 2 This is a front view of the support structure provided in one embodiment of this application;

[0039] Figure 3 This is a partial perspective view of the support structure provided in one embodiment of this application;

[0040] Figure 4 This is a partial perspective view of an external instrument penetrating a support structure, as provided in one embodiment of this application.

[0041] Explanation of icon numbers:

[0042] 100. Support frame; 110. Expansion section; 111. Expansion arm; 112. Connecting arm; 113. Neck;

[0043] 200. Support beam;

[0044] 310. Outer membrane; 320. Inner membrane;

[0045] 410, First melting zone; 420, Second melting zone; 430, Cavity;

[0046] 500. External instruments. Detailed Implementation

[0047] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application can also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0048] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the specific implementation methods of this application will be described below with reference to the accompanying drawings. Obviously, the drawings described below are merely some embodiments of this application. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without any creative effort.

[0049] To keep the drawings concise, each drawing only schematically shows the parts relevant to this application, and they do not represent the actual structure of the product. Furthermore, for ease of understanding, in some drawings, only one of the components with the same structure or function is schematically shown, or only one is labeled. In this document, "one" not only means "only one," but can also mean "more than one."

[0050] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0051] In this document, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0052] In the embodiments shown in the accompanying drawings, the directional indications (such as up, down, left, right, front, and back) used to explain the structure and movement of the various components of this application are relative rather than absolute. These descriptions are appropriate when these components are in the positions shown in the drawings. If the description of the positions of these components changes, these directional indications also change accordingly.

[0053] Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0054] According to a specific embodiment provided in this application, see [link to specific embodiment]. Figure 1 A stent structure suitable for expandable catheter sheaths includes a support frame 100 and a support beam 200. There are multiple support frames 100 arranged sequentially along an axis; and at least one support beam 200 is used to connect the multiple support frames 100.

[0055] The support frame 100 includes an expansion portion 110, which is adapted to expand radially under the action of an external force, thereby causing the support frame 100 to expand radially. Specifically, when an external instrument 500 enters the support frame 100, the expansion portion 110 can expand radially with the help of the conveying force of the external instrument 500, allowing the external instrument 500 to pass smoothly inside the support frame 100. In addition, the expansion portion 110 is also configured to retract after the external force is removed, that is, after the external instrument 500 has passed, the expansion portion 110 can immediately retract to its original size, thereby causing the support frame 100 to contract radially.

[0056] This embodiment, by providing the expansion portion 110, enables the support structure and expandable catheter sheath to have better expandability and retraction capabilities, thereby making the surgical procedure more convenient. The supporting skeleton 100 is annular or arc-shaped and is located within the sheath wall of the expandable catheter sheath, which is more conducive to the even distribution of force on the supporting skeleton 100 and the sheath, preventing it from becoming intermittently tight or loose when the external instrument 500 passes through.

[0057] This embodiment also includes a support beam 200, which connects multiple support frames 100, enabling simultaneous expansion of the multiple support frames 100. This facilitates the passage of external instruments 500 and makes the surgical procedure more convenient. Furthermore, the support beam 200 effectively restricts the axial position of the support frames 100, preventing axial length changes during expansion and retraction, resulting in a more stable and reliable structure. In addition, the support beam 200 provides radial support to the expandable catheter sheath, preventing it from bending during surgery.

[0058] In an exemplary embodiment, the expansion part 110 includes expansion arms 111 and a connecting arm 112. The number of expansion arms 111 is two. The connecting arm 112 is used to connect the two expansion arms 111, and the two expansion arms 111 can undergo radial deformation under an external force and move away from each other.

[0059] Specifically, the connecting arm 112 is arc-shaped, and both ends of the connecting arm 112 in the arc length direction are respectively connected to the ends of the two expansion arms 111, making the overall structure of the expansion part 110 similar to a "ji" character shape, with good expansion and retraction performance. For example, refer to Figure 1 , when the arc formed by the connecting arm 112 is a major arc (the arc is larger than a semi-circular arc), the two expansion arms 111 are also preferably arc-shaped, with convex surfaces, and the convex surfaces of the two expansion arms 111 are arranged facing each other to form an inwardly contracting neck 113 at the connection between the connecting arm 112 and the expansion arms 111. When the arc formed by the connecting arm 112 is a semi-circular arc or a minor arc (the arc is smaller than a semi-circular arc), the two expansion arms 111 are preferably linear.

[0060] For the expansion part 110 provided in the above two embodiments, when the external instrument 500 enters the support framework 100, the two expansion arms 111 thereon can move away from each other, thereby realizing the expansion of the support framework 100. Among them, the longer the lengths of the two expansion arms 111 of the expansion part 110, the greater the distance that the expansion part 110 can expand. Therefore, when the arc formed by the connecting arm 112 is a major arc and the two expansion arms 111 are arc-shaped, the expansion ability of the stent structure and the expandable catheter sheath is better, further improving the convenience of the surgical process. After the external instrument 500 passes through, the two expansion arms 111 of the expansion part 110 rebound and return to the original state, driving the stent structure to retract.

[0061] In actual production, the overall structure of the expansion part 110 can also be in an "S" shape or a snake shape, which will not be elaborated here one by one, and all are within the protection scope of this application.

[0062] Preferably, the number of expansion parts 110 is multiple, and the multiple expansion parts 110 are sequentially connected and surrounded to form a ring-shaped support framework 100. Taking the expansion part 110 in the shape of a "ji" character as an example, the end of each expansion arm 111 of each expansion part 110 away from the connecting arm 112 is connected to the end of the expansion arm 111 of the adjacent expansion part 110 away from the connecting arm 112, and the openings of the arcs formed by the connecting arms 112 of each expansion part 110 face the same direction.

[0063] In this embodiment, by setting multiple expansion portions 110 and having the multiple expansion portions 110 together form a ring-shaped support frame 100, compared with a support frame 100 in which multiple expansion portions 110 are connected to form an arc-shaped support frame 100 or where expansion portions 110 are only set in a part of the area, its expansion performance is better, it can adapt to external instruments 500 of more sizes, and its application range is wider.

[0064] In this embodiment, the number of support beams 200 is preferably multiple, which is beneficial for the synchronous and stable expansion of multiple support frames 100. Each expansion portion 110 is connected to at most two support beams 200, and the support beam 200 is preferably fixed to the end of the expansion arm 111 away from the connecting arm 112, and is axially connected to multiple support frames 100. This can limit the relative position between adjacent support frames 100, making the support structure less prone to axial length changes during expansion and retraction, resulting in a stable and reliable structure.

[0065] In one example embodiment, see Figure 1 and Figure 2 Each expansion section 110 is connected to two support beams 200, and the two support beams 200 are respectively located at the ends of the two expansion arms 111 away from the connecting arm 112. That is, multiple support beams 200 are spaced apart along the circumference of the annular support frame 100 and are simultaneously connected to the multiple support frames 100. The support frame 100 is divided into multiple sub-sections by the multiple support beams 200 connected in the circumferential direction, and each sub-section is exactly one expansion section 110.

[0066] Preferably, there are four support beams 200, and the four support beams 200 are evenly spaced along the periphery of the ring-shaped support frame 100, dividing the support frame 100 into four sub-parts in the circumferential direction to ensure that the support structure is subjected to uniform force.

[0067] Furthermore, the support beam 200 and the support frame 100 are an integral structure, formed by laser cutting on a circular nickel-titanium tube.

[0068] In actual production, see Figure 2 and Figure 3 The outer surfaces of the support frame 100 and the support beam 200 are also covered with a membrane, which can form a hierarchical structure within the sheath of the expandable catheter sheath. Specifically, taking an annular support frame 100 as an example, the support structure also includes an inner membrane 320 and an outer membrane 310. The inner walls of multiple support frames 100 are covered with the inner membrane 320, and the outer walls of multiple support frames 100 are covered with the outer membrane 310. In this case, the inner membrane 320 can form the inner layer structure of the sheath, the outer membrane 310 can form the outer layer structure of the sheath, and the support frame 100 and the support beam 200 are disposed as an intermediate layer structure between the inner membrane 320 and the outer membrane 310.

[0069] Specifically, a melting zone is provided between the inner membrane 320 and the outer membrane 310 to allow the inner membrane 320 and the outer membrane 310 to be fused together. Thus, when the support frame 100 expands radially, the outer membrane 310 expands under the force of the support frame 100, simultaneously causing the inner membrane 320 to expand as well. Both the inner membrane 320 and the outer membrane 310 are made of highly elastic polymer materials, such as TPU, PTFE, EPTFE, and PU, so that when the support frame 100 expands radially, the inner membrane 320 and the outer membrane 310 can expand radially along with the support frame 100.

[0070] In this embodiment, the melting zone should be located outside the active area where the support frame 100 and support beam 200 deform, so as not to create resistance to the radial expansion of the support frame 100 and support beam 200, which is beneficial to the radial expansion of the support structure.

[0071] In one specific embodiment, the projection of the outer membrane 310 onto the inner membrane 320 overlaps with the inner membrane 320, and the molten zone is locally located in the overlapping area. This arrangement differs from having the molten zone formed over the entire area between the outer membrane 310 and the inner membrane 320, providing more deformation space and improving the deformability of the support structure. Preferably, the molten zone is distributed circumferentially along the support frame 100 between the inner membrane 320 and the outer membrane 310, and each support frame 100 has the molten zone at the same position at the expansion portion 110.

[0072] The molten zone can be dot-shaped, block-shaped, or linear. If the molten zone is block-shaped, it can include one or more of regular block shapes (e.g., circles, rectangles, etc.) and irregular block shapes. If the molten zone is linear, it can include one or more of straight lines, arcs, waves, broken lines, S-shapes, and spiral lines.

[0073] Specifically, see Figure 3 and Figure 4The melting zone includes a first melting zone 410, located on the convex side of the connecting arm 112, and the first melting zone 410 is arc-shaped to fit the shape of the connecting arm 112. When the external instrument 500 enters the support frame 100, the expansion arm 111 expands with the help of the delivery force of the external instrument 500, thereby causing the support frame 100 and the inner membrane 320 and outer membrane 310 to expand together. The expanded inner membrane 320 and outer membrane 310 can apply a uniform axial thrust to the connecting arm 112 at the fusion point of the first melting zone 410, thereby causing the connecting arm 112 to drive the expansion arms 111 on both sides to open. At this time, the expansion arm 111 expands not only by the delivery expansion force, but also by the thrust at the first melting zone 410, resulting in a stronger expansion capacity. This is beneficial for the stent structure to be opened with a smaller thrust of the external instrument 500, making the surgical process more convenient.

[0074] See Figure 4 Especially when the external instrument 500 enters the support structure from one side of the convex surface of the connecting arm 112, the auxiliary effect of the fusion joint of the inner layer film 320 and the outer layer film 310 in the first melting zone 410 on the expansion of the expansion arm 111 is better.

[0075] Furthermore, the first melting zone 410 preferably extends along the circumferential direction of the support frame 100 to the support beams 200 located on both sides of the connecting arm 112 at both ends of the first melting zone 410. In this case, the first melting zone 410 is a linear shape similar to "Ω", which can be simply regarded as a combination of straight lines and arcs.

[0076] In this embodiment, the inner membrane 320 and the outer membrane 310 can form an unfused interlayer at the expansion portion 110, providing a cavity 430 for the expansion portion 110. When the expansion portion 110 expands radially, the expansion arm 111 undergoes a large radial deformation, which corresponds precisely to the aforementioned cavity 430. This ensures that the expansion arm 111 is not constrained by the inner membrane 320 and the outer membrane 310 during expansion, thereby reducing the force required to expand the expansion portion 110 and facilitating the operator's operation.

[0077] Furthermore, see Figure 2 and Figure 3 The molten zone also includes a second molten zone 420, which is located on the concave side of the connecting arm 112 and between the two expansion arms 111 connected by the connecting arm 112. The second molten zone 420 is not directly subjected to force and in contact with the support structure. It is located between the gaps in the support structure and its main function is to increase the additional welding area, thereby strengthening the welding strength between the inner layer film 320 and the outer layer film 310.

[0078] Specifically, the second melting zone 420 is linear and extends axially along the support frame 100, and the circumferential width of the second melting zone 420 is 0.2mm-0.6mm, and the axial length is 1mm-2mm.

[0079] This application also provides an expandable catheter sheath, including a sheath tube and a support structure disposed on the sheath tube, wherein the support structure is the support structure provided in any of the above embodiments. When an external instrument 500 is inserted into the sheath tube, the support structure expands radially under the external force of the external instrument 500, thereby driving the sheath tube to expand radially. This embodiment, by utilizing the expansion portion 110 provided in the support structure, enables the expandable catheter sheath to have good expandability and retraction capability, thereby making the surgical procedure more convenient and practical.

[0080] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0081] It should be noted that the above embodiments can be freely combined as needed. The above are merely preferred embodiments of this application. It should be pointed out that for those skilled in the art, several improvements and modifications can be made without departing from the principles of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A stent structure suitable for expandable catheter sheaths, characterized in that, include: Multiple support frames, the support frames being ring-shaped or arc-shaped, and the multiple support frames being arranged sequentially along an axis; A support beam, wherein there is at least one support beam, used to connect multiple support frames; The supporting frame includes an expansion portion adapted to expand radially under the action of an external force, thereby causing the supporting frame to expand radially; and the expansion portion is configured to retract after the external force is removed, causing the supporting frame to contract radially.

2. The support structure according to claim 1, characterized in that, The expansion section includes an expansion arm and a connecting arm. There are two expansion arms, and the connecting arm connects the two expansion arms. Under the action of external force, the two expansion arms undergo radial deformation and move away from each other.

3. The support structure according to claim 2, characterized in that, The connecting arm is arc-shaped, and its two ends in the arc length direction are respectively connected to the ends of the two expansion arms; Wherein, the arc shape of the connecting arm is a superior arc, and both of the expansion arms are arc-shaped with convex surfaces, and the convex surfaces of the two expansion arms are arranged facing each other to form an inwardly contracting neck at the connection between the connecting arm and the expansion arm; or, the arc shape of the connecting arm is a semi-circular arc or a inferior arc, and the two expansion arms are linear.

4. The support structure according to claim 3, characterized in that, The number of expansion portions is multiple, and the multiple expansion portions are sequentially connected to form a ring-shaped support frame; and the number of support beams is multiple, and each expansion portion is connected to at most two support beams; The support beam is fixed to the end of the expansion arm away from the connecting arm and is axially connected to a plurality of the support frames, which are adapted to limit the relative position between two adjacent support frames.

5. The support structure according to claim 4, characterized in that, Also includes: Inner membrane and outer membrane; The inner walls of the plurality of support frames are covered with the inner layer membrane, and the outer walls of the plurality of support frames are covered with the outer layer membrane. The projection of the outer layer membrane on the inner layer membrane overlaps with the inner layer membrane. A fusion zone is provided between the inner layer membrane and the outer layer membrane, and the fusion zone is partially located at the overlapping area to allow the inner layer membrane and the outer layer membrane to be fused together.

6. The support structure according to claim 5, characterized in that, The molten zone is linear, including one or more of the following: straight line, arc, wave, broken line, S-shape, and spiral line.

7. The support structure according to claim 6, characterized in that, The molten zone includes a first molten zone; The first melting zone is located on the convex side of the connecting arm, and the shape of the first melting zone is arc-shaped, adapted to the shape of the connecting arm.

8. The support structure according to claim 7, characterized in that, Each of the expansion portions is connected to two of the support beams, and the two support beams are respectively located at the ends of the two expansion arms away from the connecting arm; Wherein, the first melting zone extends circumferentially from both ends of the support frame to the support beams located on both sides of the connecting arm.

9. The support structure according to claim 7 or 8, characterized in that, The melting zone further includes a second melting zone; The second melting zone is located on the concave side of the connecting arm and between the two expanding arms connected by the connecting arm; The second melting zone is linear and extends axially along the support frame.

10. An expandable catheter sheath, characterized in that, include: A sheath and a support structure disposed on the sheath, wherein the support structure is the support structure according to any one of claims 1-9; The sheath is adapted to allow external instruments to pass through, and when an external instrument is inserted into the sheath, the support structure expands radially under the force of the external instrument, thereby causing the sheath to expand radially.

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