Restraint stent for balloon catheter and balloon catheter system

Abstract

The application provides a restraint support for a balloon catheter and a balloon catheter system, the restraint support comprising a restraint part and one or more connecting parts, the connecting parts being arranged at axial ends of the restraint part, the connecting parts comprising first axial ends and second axial ends, the first axial ends being farther away from the restraint part than the second axial ends, the second axial ends being connected to the restraint part, and the first axial end of at least one connecting part being a circumferential non-closed structure.The first axial end of the connecting part of the restraint support can be expanded and / or shrunk in size as required, so that the risk of the first axial end scratching the outer surface of the balloon during the manufacturing process of the balloon catheter system can be reduced, and the first axial end can well match the size of the tubular member of the balloon catheter, so that the advancing performance and safety performance of the balloon catheter system can be improved.

Description

Technical Field

[0001] This invention relates to the field of interventional medical device technology, and in particular to a balloon catheter restraint stent and balloon catheter system. Background Technology

[0002] From the 1970s to the present, interventional vascular treatment technology has experienced rapid and vigorous development. Balloon angioplasty is one of the fundamental procedures in the endovascular treatment of lower extremity arteriosclerosis obliterans. Common balloons include notched balloons, standard balloons (POBA), and drug-coated peripheral balloons (DCB).

[0003] The principle of balloon angioplasty is as follows: When an artery is narrowed, the location, diameter, and length of the narrowing are confirmed by angiography. Then, a balloon catheter of appropriate size is selected. A sheath is first inserted to establish a channel, and a guidewire is inserted to establish a track. The balloon dilation catheter then advances externally along this channel and track until the distal end of the catheter passes the narrowed segment (aligning the balloon with the narrowed segment). An additional pressure dilation device is used to apply pressure to the balloon catheter, causing the balloon to inflate. The balloon dilation compresses the narrowed segment, converting its internal pressure into expansion force, causing atherosclerotic material and plaque in the narrowed segment to be deformed and adhere to the inner wall of the blood vessel. Further inflation of the balloon causes appropriate tearing of the smooth muscle in the vessel wall, further widening the vessel and its lumen. After maintaining this position for a period of time (approximately tens of seconds to several minutes), the balloon pressure is released and the balloon is withdrawn along the guidewire and channel. Finally, the lumen of the narrowed segment of the blood vessel is widened, restoring good blood supply.

[0004] Currently available balloon catheters have a problem: during expansion, the balloon's flaps expand first, causing uneven stress on the vessel wall and increasing the risk of tearing and flow-limiting dissection. A restraining stent is installed over the balloon, expanding as the balloon expands to control its overall expansion and ensure more even stress on the vessel wall. The stent's ends are connected to the tubular components (e.g., inner or outer tubing) of the balloon catheter via connecting rings and then securely fixed using heat fusion. A larger connecting ring diameter reduces the risk of abrasion on the balloon's outer surface during assembly. However, a larger connecting ring diameter often results in a poor fit against the tubular component, creating a large step that can abrade the catheter or vessel wall during delivery. Conversely, a smaller connecting ring diameter that matches the tubular component size can still abrade the balloon's outer surface during assembly. Summary of the Invention

[0005] This invention provides a restraint stent for balloon catheters and a balloon catheter system to reduce the risk of the connecting end of the restraint stent scraping the outer surface of the balloon during the manufacturing process of the balloon catheter system, and the connecting end of the restraint stent can well match the size of the tubular part of the balloon catheter.

[0006] This invention provides a constraint stent for balloon catheters, used to be fitted over the balloon of a balloon catheter, comprising:

[0007] The constraint part has an axial end;

[0008] One or more connecting portions are disposed at the axial ends of the constraint portion. The connecting portion includes a first axial end and a second axial end. The first axial end is further away from the constraint portion than the second axial end. The second axial end is connected to the constraint portion. At least one of the first axial ends of the connecting portion is a circumferentially non-closed structure.

[0009] In one embodiment, the circumferential non-closed structure includes at least one end connection unit in the circumferential direction, and the end connection unit has a circumferential gap on both sides along the circumferential direction of the constraint bracket.

[0010] In one embodiment, the circumferential non-closed structure includes at least two end connecting units that are evenly spaced apart in the circumferential direction and are arranged opposite each other in the radial direction.

[0011] In one embodiment, the shape of the end connection unit includes one or more of the following: circular, elliptical, teardrop-shaped, triangular, T-shaped, and fork-shaped.

[0012] In one embodiment, the end connection unit includes a closed or open annular connector and a connection hole disposed within the annular connector.

[0013] In one embodiment, the constraint bracket includes two connecting parts, namely a first connecting part and a second connecting part. The first connecting part is connected to the proximal end of the constraint part, and the second connecting part is connected to the distal end of the constraint part. The first axial ends of both connecting parts include end connecting units. The shape of the end connecting unit of the first connecting part is different from the shape of the end connecting unit of the second connecting part, and the surface area of ​​the end connecting unit of the first connecting part is larger than the surface area of ​​the end connecting unit of the second connecting part.

[0014] In one embodiment, the first axial end further includes an intermediate connecting unit disposed between the constraint portion and the end connecting unit. The end connecting unit is connected to the constraint portion through the corresponding intermediate connecting unit, and circumferential spacing is provided on both sides of the intermediate connecting unit along the circumferential direction of the constraint bracket.

[0015] In one embodiment, the intermediate connecting unit includes a connecting rod, one end of which is connected to the constraint part, and the other end of which is connected to a corresponding end connecting unit. The shape of the connecting rod includes one or more of straight, curved, and polygonal shapes, wherein the curved shape includes one or more of arc, wave, and sawtooth shapes.

[0016] In one embodiment, the intermediate connecting unit includes a connecting rod, the two axial ends of which are located on the same axial plane as the central axis of the constraint bracket; or, one axial end of the connecting rod is located on a first axial plane with the central axis of the constraint bracket, and the other axial end of the connecting rod is located on a second axial plane with the central axis of the constraint bracket, wherein the first axial plane and the second axial plane intersect.

[0017] In one embodiment, the end of the intermediate connecting unit directly connected to the constraint part is defined as the first end, and the end of the intermediate connecting unit directly connected to the end connecting unit is defined as the second end. The deflection direction of the second end of the intermediate connecting unit relative to the first end in the circumferential direction of the constraint bracket is opposite to the folding direction of the balloon.

[0018] The present invention also provides a constraint stent for balloon catheters, for being fitted over the balloon of a balloon catheter, including a constraint portion, the constraint portion including a mesh structure, the mesh structure including at least one row of mesh holes, each row of mesh holes including at least one first mesh hole and at least one second mesh hole, the first mesh hole and the second mesh hole being alternately arranged in the circumferential direction of the constraint portion, and when the constraint portion is in a first state, the area of ​​the first mesh hole is larger than the area of ​​the second mesh hole.

[0019] By setting a first mesh and a second mesh in the circumferential direction of the restraint section, the flexibility of the restraint section is improved, allowing the area where the restraint section is located to better adapt to the tortuous vascular morphology. On the other hand, it is beneficial to improve the recovery performance of the restraint section (i.e., the ability of the restraint section to return to its initial contracted state after balloon contraction). This allows the balloon catheter system to repeatedly expand and contract in vivo while still maintaining good therapeutic effects. Therefore, it is possible to treat multiple narrowed vascular segments in the body without having to repeatedly release and retract the same balloon catheter for different treatment areas, or to change the balloon catheter multiple times for different treatment areas.

[0020] In one embodiment, the ratio of the area of ​​the first mesh to the area of ​​the second mesh ranges from 1.5 to 2.5.

[0021] In one embodiment, when the constraint portion is in the second state, the area of ​​the first mesh and the area of ​​the second mesh are substantially equal.

[0022] In one embodiment, the constraint portion includes a plurality of circumferential constraint rings spaced apart along the axial direction of the constraint portion and a plurality of axial struts spaced apart along the circumferential direction of the constraint portion. The axial struts divide the space between two adjacent circumferential constraint rings into a plurality of first mesh holes and a plurality of second mesh holes.

[0023] In one embodiment, the constraint portion includes a circumferential constraint ring, which includes a plurality of first vertices and second vertices arranged alternately along the circumference of the circumferential constraint ring. The first vertices are closer to the far end of the constraint portion than the second vertices. The circumferentially adjacent first vertices and second vertices are connected by a wave rod. The wave rod includes a first end bend connected to the first vertices, a second end bend connected to the second vertices, and an intermediate segment whose two ends are respectively connected to the first end bend and the second end bend. When the constraint portion is in a first state, the proximal endpoint of the intermediate segment is farther from the generatrix of the constraint portion where the first vertex is located than the distal endpoint of the intermediate segment.

[0024] In one embodiment, the intermediate segment includes a straight rod segment and / or a mid-bend segment.

[0025] In one embodiment, the intermediate segment includes a central bending sub-segment. When the constraint portion is in the first state, the central bending sub-segment includes an even number of bending points, and the bending directions at two adjacent bending points are opposite.

[0026] In one embodiment, the middle bending segment bends at its bending point closest to the first vertex toward the generatrix of the constraint portion where the first vertex is located, and the bending segment bends at its bending point closest to the second vertex toward the generatrix of the constraint portion where the second vertex is located.

[0027] In one embodiment, the constraint portion includes a circumferential constraint ring, which includes a plurality of vertices arranged sequentially and spaced apart in the circumferential direction. The circumferential constraint ring also includes a wave rod connecting two adjacent vertices. The wave rod includes an end bend segment connected to the vertex. The end bend segment includes an end transition sub-segment and an end bend segment. The end transition sub-segment is closer to the vertex than the end bend segment. The end transition sub-segment is a straight line segment or an arc segment. When the end transition sub-segment is an arc segment, the arc of the end transition sub-segment is smaller than the arc of the end bend segment.

[0028] In one embodiment, the constraint portion includes a circumferential constraint ring, and when in the second state, the circumference of the circumferential constraint ring and the nominal diameter of the balloon satisfy the following expression:

[0029] L1∈[π(D-1),π(D-0.2)]

[0030] Wherein, L1 represents the circumference of the circumferential constraint ring in mm, and D represents the nominal diameter of the balloon in mm.

[0031] In one embodiment, the balloon includes two imaging sections spaced apart in the axial direction, and when the restraint section is in a second state, the restraint section completely covers the space between the two imaging sections in the axial direction.

[0032] The balloon catheter restraint stent of the present invention includes a restraint portion and a connecting portion. The connecting portion is disposed at the axial end of the restraint portion and includes a first axial end and a second axial end. The first axial end is further away from the restraint portion than the second axial end, and the second axial end is connected to the restraint portion. At least one of the first axial ends of the connecting portion has a circumferentially non-closed structure. By providing a circumferentially non-closed structure at the first axial end of the connecting portion, the radial dimension of the first axial end of the connecting portion can be enlarged and / or reduced as needed, thereby reducing the risk of the first axial end scraping against the outer surface of the balloon during the fabrication of the balloon catheter system. Furthermore, the first axial end can well match the size of the tubular component of the balloon catheter, which is beneficial to improving the propulsion performance and safety performance of the balloon catheter system. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the balloon catheter system in one embodiment of the present invention;

[0034] Figure 2 This is a partial structural schematic diagram of the balloon catheter in one embodiment of the present invention;

[0035] Figure 3 This is a partial structural diagram of the balloon catheter system when the balloon is inflated, according to one embodiment of the present invention.

[0036] Figure 4 This is a planar unfolded schematic diagram of the constraint bracket in one embodiment of the present invention;

[0037] Figures 5a-5e This is a schematic diagram of the structure of the end connection unit in one embodiment of the present invention;

[0038] Figure 6 This is a planar unfolded schematic diagram of the constraint bracket in one embodiment of the present invention;

[0039] Figure 7This is a planar unfolded schematic diagram of the constraint bracket in another embodiment of the present invention;

[0040] Figure 8 This is a schematic diagram of the folding of the balloon in one embodiment of the present invention;

[0041] Figure 9 This is a planar unfolded schematic diagram of the constraint bracket in one embodiment of the present invention (the black filled part is only used to identify the first mesh and the second mesh);

[0042] Figure 10 for Figure 9 Enlarged view of region A (the black filled area is only used to identify the first and second meshes);

[0043] Figure 11 This is a schematic diagram of the planar unfolding of the constraint stent following the inflation of the balloon in one embodiment of the present invention;

[0044] Figure 12 for Figure 9 Enlarged view of region A in the middle;

[0045] Figure 13 This is a partial structural schematic diagram of the constraint bracket in one embodiment of the present invention;

[0046] Figure 14 This is a planar unfolded schematic diagram of the constraint bracket in one embodiment of the present invention;

[0047] Figure 15 for Figure 14 Enlarged view of region B in the middle;

[0048] Figure 16 This is a planar unfolded schematic diagram of the constraint bracket in another embodiment of the present invention;

[0049] Figure 17 This is a planar unfolded schematic diagram of the constraint bracket in another embodiment of the present invention;

[0050] Figure 18 This is a schematic diagram of the structure of the additional part in one embodiment of the present invention;

[0051] Figure 19 This is a schematic diagram of the balloon catheter system in one embodiment of the present invention;

[0052] Figure 20 This is a planar unfolded schematic diagram of the constraint bracket in one embodiment of the present invention;

[0053] Figure 21 This is a partial structural diagram of the balloon catheter system when the balloon is inflated, according to one embodiment of the present invention.

[0054] Figure 22This is a schematic diagram of the balloon in an inflated state according to one embodiment of the present invention;

[0055] Figure 23 This is a planar unfolded schematic diagram of the constraint bracket in one embodiment of the present invention;

[0056] Figure 24 This is a partial structural diagram of the balloon catheter system when the balloon is inflated, according to one embodiment of the present invention.

[0057] Figure 25 This is a schematic diagram of the traction unit in one embodiment of the present invention;

[0058] Figure 26 This is a schematic diagram of the limiting part in one embodiment of the present invention. Detailed Implementation

[0059] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0060] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0061] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0062] In the field of interventional medical devices, the end of a medical device implanted in the human or animal body that is closer to the operator is generally called the "proximal end," and the end that is farther from the operator is called the "distal end." Based on this principle, the "proximal end" and "distal end" of any component of a medical device are defined.

[0063] Example 1

[0064] Reference Figure 1 and Figure 2This embodiment provides a balloon catheter system 100, which includes a balloon catheter 10 and a restraint stent 20. The balloon catheter 10 may include a balloon 11 and a tubular assembly 12. The balloon 11 is covered with a restraint stent 20 for limiting the inflation of the balloon 11.

[0065] The balloon 11 can expand and contract radially under the operator's control. The balloon 11 has an inner cavity, and its radial expansion and contraction can be controlled by injecting a medium (liquid or gas, etc.) into and withdrawing the medium. When the balloon 11 is inflated, it includes a proximal segment 111, a distal segment 113, and a middle segment 112 connecting the proximal segment 111 and the distal segment 113 at both ends. The middle segment 112 is the therapeutic area (also called the effective area) of the balloon 11. In this embodiment, the cross-sectional shape of the balloon 11 is approximately circular; in other embodiments, the cross-section of the balloon 11 can be elliptical, crescent-shaped, semi-circular, or any other suitable shape. The proximal segment 111 and distal segment 113 are generally conical, and the middle segment 112 is generally cylindrical. The cross-sectional area of ​​the proximal end of the proximal segment 111 is smaller than that of the distal end, the cross-sectional areas of the middle segment 112 are approximately equal, and the cross-sectional area of ​​the proximal end of the distal segment 113 is larger than that of the distal end. In other embodiments, the shapes of the proximal segment 111, distal segment 113, and middle segment 112 of the balloon 11 can be any suitable shape. The balloon 11 can be a semi-compliant balloon or a compliant balloon, for example, it can be made of one or more materials selected from nylon, Pebax, polyurethane, latex, polyethylene phthalate, and polyethylene.

[0066] The tubular assembly 12 includes at least one tubular member. For example, the tubular assembly 12 includes two tubular members: an inner tube 121 and an outer tube 122. The inner tube 121 passes through the outer tube 122 and axially penetrates the inner lumen of the balloon 11, and is fixedly connected to the distal end of the balloon 11. The distal end of the outer tube 122 is fixedly connected to the proximal end of the balloon 11. A delivery channel is formed between the inner tube 121 and the outer tube 122, which communicates with the inner lumen of the balloon 11. Media can be injected into or withdrawn from the inner lumen of the balloon 11 through this delivery channel. The inner tube 121 also has a guidewire channel, through which a guidewire can axially pass.

[0067] The restraint stent 20 is fitted over the balloon 11 and restricts the inflation shape of the balloon 11. (See reference...) Figure 2 , Figure 3 , Figure 4The restraint support 20 includes a restraint portion 21 and a connecting portion 27. In this embodiment, the restraint portion 21 is only provided on the middle section 112 of the balloon 11, that is, the restraint portion 21 does not extend to the proximal section 111 and the distal section 113 of the balloon 11. The restraint portion 21 is provided with a plurality of restraint holes (or gaps). When the pressure inside the balloon 11 reaches a preset pressure (for example, the nominal pressure inside the balloon 11) and is in an inflated state, since the restraint portion 21 and part of the outer surface of the balloon 11 are in contact and the radial expansion of the balloon 11 is restricted in the contact area with the outer surface of the balloon 11, the unrestrained area of ​​the balloon 11 protrudes outward through the plurality of restraint holes on the restraint portion 21 to form a plurality of protrusions 115. The protrusions 115 protrude relative to the restraint portion 21 toward the inner cavity of the balloon 11. The multiple protrusions 115 can compress the narrowed segment of the blood vessel, causing the atherosclerotic material and arterial plaque in the narrowed segment to be compressed and deformed, adhering to the inner wall of the blood vessel, thus achieving a good vasodilatory effect. At the same time, because the multiple protrusions 115 form a concave area, the compressed atherosclerotic material and arterial plaque can move into the concave area between the protrusions 115, releasing some of the compressive force and preventing excessive tearing of the smooth muscle of the blood vessel wall, which would damage the blood vessel.

[0068] Reference Figure 1 and Figure 4 The connecting part 27 is used to connect the restraint part 21 to other components. For example, the connecting part 27 fixes the restraint part 21 to the tubular assembly 12, so that the restraint bracket 20 is fixed on the balloon catheter 10.

[0069] Exemplarily, the connecting portion 27 is disposed at the axial end of the constraint portion 21 and connected to the constraint portion 21. In this embodiment, both ends of the constraint portion 21 are provided with connecting portions 27, wherein the connecting portion 27 located at the distal end of the constraint portion 21 is fixedly connected to the inner tube 121, and the connecting portion 27 located at the proximal end of the constraint portion 21 is fixedly connected to the outer tube 122, while the constraint portion 21 is not directly connected to the balloon 11. In other embodiments, the constraint portion 21 may only have a connecting portion 27 at one end. The connecting portion 27 includes a first axial end and a second axial end, the first axial end being further away from the constraint portion 21 than the second axial end, and the second axial end being connected to the constraint portion 21. At least one first axial end of the connecting portion 27 is a circumferentially non-closed structure. A circumferentially non-closed structure means that the outline of the structure in the circumferential direction is not closed, and there is a circumferential interval (or circumferential gap, circumferential notch). Because the first axial end is not closed in the circumferential direction, it can deform radially before being connected to the tubular component, thereby changing its radial dimension. By providing a circumferentially non-closed structure at the first axial end of the connecting portion 27, the radial dimension of the first axial end of the connecting portion 27 can be enlarged and / or reduced as needed. This reduces the risk of the first axial end scraping against the outer surface of the balloon 11 during the fabrication of the balloon catheter system 100. Furthermore, the first axial end can well match the dimensions of the tubular component of the balloon catheter 10, which is beneficial for improving the propulsion performance and safety performance of the balloon catheter system 100. Exemplarily, in some embodiments, the first axial end has an end opening, and in its natural state (i.e., without external force), its radial dimension matches the outer diameter of the tubular component to be fitted. This reduces the probability of a large step forming after the first axial end and the tubular component are connected. Additionally, during the fitting process with the balloon 11, the first axial end can undergo radial deformation, thereby enlarging its end opening, allowing the balloon 11 to enter the restraint bracket 20 from this end opening, thus reducing the risk of the first axial end scraping against the surface of the balloon 11. In some embodiments, the radial dimension of the first axial end in its natural state is sufficiently large (e.g., its end opening is larger than the maximum radial dimension of the restraint bracket 20). This reduces the risk of the first axial end rubbing against the surface of the balloon 11 during assembly. Conversely, during connection with the tubular component, the radial dimension of the first axial end can be reduced, for example, by reducing its end opening to match the outer diameter of the tubular component. This reduces the probability of a large step forming after the first axial end connects with the tubular component. In some embodiments, the radial dimension of the first axial end in its natural state can be any other suitable size. During assembly with the balloon catheter 10, expanding or shrinking its radial dimension can similarly reduce the probability of a large step forming after the first axial end connects with the tubular component and also reduce the risk of the first axial end rubbing against the surface of the balloon 11.

[0070] In this embodiment, the first axial ends of the connecting portions 27 connected to both axial ends of the constraint portion 21 are circumferentially non-closed structures. This allows both axial ends of the constraint bracket 20 to be well-suited for tubular components of different diameters (in this embodiment, the outer diameter of the inner tube 121 is smaller than the inner diameter of the outer tube 122). Furthermore, when the balloon 11 is inserted into the inner cavity of the constraint bracket 20, either end can be inserted. In other embodiments, only the first axial end of the connecting portion 27 at one axial end of the constraint portion 21 can be a circumferentially non-closed structure, which also solves the technical problem of this invention.

[0071] In this embodiment, the circumferentially non-closed structure includes one or more end connection units 271 and circumferential spacing 273 disposed on both sides of the end connection units 271. The end connection units 271 can be connected to the tubular component. When multiple end connection units 271 exist, the multiple end connection units 271 are arranged circumferentially along the tubular component, wherein at least two of the end connection units 271 form a spacing in the circumferential direction of the constraint support 20. Before the end connection unit 271 is connected to the tubular component, the end connection unit 271 can move relative to the constraint portion 21 in the radial direction of the constraint support 20. Before being connected to the tubular component, pushing any one end connection unit 271 can change the radial dimension of the end opening of the first axial end, which is simple to operate and highly efficient. It can reduce the risk of the first axial end scraping the outer surface of the balloon 11 during the manufacturing process of the balloon catheter system 100, and the first axial end can match the size of the tubular component of the balloon catheter 10 well. Furthermore, due to the presence of the circumferential spacing 273, the end connecting unit 271 can move more easily relative to the constraint part 21 and has a larger range of motion. Therefore, the circumferential non-closed structure can undergo radial deformation more conveniently and flexibly, thereby making its radial dimension change space large enough to meet a wider range of needs during assembly.

[0072] For example, the circumferentially non-closed structure includes at least two end connecting units 271 evenly spaced circumferentially from the constraint bracket 20, and the two end connecting units 271 are arranged opposite each other in the radial direction of the constraint bracket 20. This arrangement facilitates uniform force distribution on the end connecting units 271 and improves the connection strength between the connecting portion 27 and the tubular member, while not excessively increasing the radial dimension at the connection between the end connecting units 271 and the tubular member. In other embodiments, the number of end connecting units 271 may be one or more.

[0073] Reference Figure 4 and Figures 5a-5e In this embodiment, the shape of the end connection unit 271 includes a circle (see reference). Figure 5b ), oval (refer to) Figure 4 (271b) Teardrop shape (refer to) Figure 4(271a) Triangle (refer to) Figure 5a , Figure 5c ), T-shape (refer to) Figure 5d ), fork (refer to Figure 5e One or more of the following. In other embodiments, the end connection unit 271 may be any other suitable shape. Exemplarily, the end connection unit 271 may include a closed or open annular connector 2711 and a connection hole 2712 disposed within the annular connector 2711. When it is necessary to connect the end connection unit 271 to the tubular component, the end connection unit 271 can be fully fitted to the outer surface of the tubular component first, and then a heat shrink tubing can be placed over it. By heat treatment, the diameter of the heat shrink tubing can be reduced, and the end connection unit 271 and the tubular component can be firmly wrapped and fixed together. The provision of the annular connector and the connection hole 2712 allows the end connection unit 271 to better fit the surface of the tubular component, making the surface after the two are connected smoother, further reducing the probability of the formation of large steps, which is beneficial to improving the propulsion performance and safety performance of the balloon catheter system 100. In addition, during the heat treatment process, the polymer material on the heat shrink tubing and / or tubular parts can enter the connection hole 2712 and be thermally fused together, which is beneficial to improving the connection strength between the end connection unit 271 and the tubular parts. In particular, when the annular connector 2711 is a closed annular structure, the connection strength between the end connection unit 271 and the tubular parts can be further improved.

[0074] In this embodiment, the constraint bracket 20 includes two connecting portions 27, namely a first connecting portion 27a and a second connecting portion 27b. The first connecting portion 27a connects to the proximal end of the constraint portion 21, and the second connecting portion 27b connects to the distal end of the constraint portion 21. The first axial ends of both connecting portions 27 include end connecting units 271 that are radially movable relative to the constraint portion 21 of the constraint bracket 20. Exemplarily, the end connecting unit 271 of the first connecting portion 27a is referred to as the first end connecting unit 271a, and the end connecting unit 271 of the second connecting portion 27b is referred to as the second end connecting unit 271b. The shapes of the first end connecting unit 271a and the second end connecting unit 271b may differ, which helps the operator better distinguish the proximal and distal ends of the constraint bracket 20. Alternatively, an end connecting unit 271 of a suitable shape can be selected as the proximal or distal end of the constraint bracket 20 for connection with other components according to actual needs. For example, the first end connecting unit 271a is roughly teardrop-shaped, and the second end connecting unit 271b is roughly elliptical. Both can fit well against the outer surface of the tubular component, and have a large contact area with the tubular component, which is conducive to a stable connection with the tubular component, and the connected surface is relatively flat. The first end connecting unit 271a is connected to the outer tube 122, and the second end connecting unit 271b is connected to the inner tube 121. Since the outer diameter of the outer tube 122 is larger than the outer diameter of the inner tube 121, the connection stability requirements between it and the end connecting unit 271 are higher. The teardrop shape of the first end connecting unit 271a can fit better against the surface of the tubular component than other shapes. Therefore, the teardrop shape of the first end connecting unit 271a is conducive to improving the connection stability between it and the outer tube 122. Furthermore, the surface area of ​​the first end connecting unit 271a is larger than that of the second end connecting unit 271b, which helps to increase the contact area between the first end connecting unit 271a and the outer tube 122, thereby further improving the connection stability between the first end connecting unit 271a and the outer tube 122. The teardrop-shaped tip connects to other components and points towards the constraint part 21, which helps to improve its flexibility in relative movement with other components and helps to reduce stress concentration at the connection between the teardrop-shaped tip and other components.

[0075] Furthermore, the connecting portion 27 may also include an intermediate connecting unit 272 disposed between the constraint portion 21 and the end connecting unit 271, with the end connecting unit 271 connected to the constraint portion 21 via the corresponding intermediate connecting unit 272. Along the circumferential direction of the constraint bracket 20, circumferential spacing 273 is provided on both sides of the intermediate connecting unit 272. This arrangement allows the intermediate connecting unit 272 to move relative to the constraint portion 21 at least radially from the constraint bracket 20, thereby further increasing the movable space of the connected end connecting unit 271 relative to the constraint portion 21, and further increasing the variation space of the radial dimension of the circumferentially non-closed structure, thus meeting a wider range of needs during assembly. In this embodiment, each end connecting unit 271 is connected to the constraint portion 21 via a corresponding intermediate connecting unit 272. In other embodiments, some or all of the end connecting units 271 may also be directly connected to the constraint portion 21.

[0076] The aforementioned intermediate connecting unit 272 may not be directly connected to the balloon 11, thereby allowing the intermediate connecting unit 272 to move relative to the balloon 11. This not only facilitates better sheathing during the sheathing process, but also allows the intermediate connecting unit 272 to follow the length changes of the restraint part 21 during expansion and contraction to a certain extent, preventing excessive pulling on the balloon 11 and causing damage to the balloon 11.

[0077] For example, the intermediate connecting unit 272 includes a connecting rod 2721, one end of which is connected to the constraint part 21, and the other end is connected to the corresponding end connecting unit 271. The shape of the connecting rod 2721 includes one or more of straight, curved, and polygonal shapes, wherein the curved shape includes one or more of arc, wavy, and sawtooth shapes. (Refer to...) Figure 4 and Figure 6 In this embodiment, the connecting rod 2721 is straight. (Refer to...) Figure 7 In another embodiment, the connecting rod 2721 may be wavy. When the length of the constraint part 21 changes, the curved or zigzag-shaped connecting rod 2721 itself can also change in length to a certain extent, thereby providing room for the length change of the constraint part 21, which helps to reduce the risk of the intermediate connecting unit 272 breaking due to the expansion and contraction of the constraint part 21.

[0078] Reference Figure 4 In this embodiment, the two axial ends of the connecting rod 2721 and the central axis of the constraint bracket 20 can be located on the same axial plane. (Refer to...) Figure 6 and Figure 7In other embodiments, one axial end of the connecting rod 2721 is located in a first axial plane with the central axis of the constraint bracket 20, and the other axial end of the connecting rod 2721 is located in a second axial plane with the central axis of the constraint bracket 20. The first and second axial planes intersect. This arrangement allows the connecting rod 2721 (even if it is straight) to change its length to a certain extent when the length of the constraint portion 21 changes, thus providing room for the length change of the constraint portion 21 and reducing the risk of the intermediate connecting unit 272 breaking due to the expansion and contraction of the constraint portion 21. For curved or broken-line connecting rods 2721, having the two axial ends of the connecting rod 2721 located in different axial planes can further reduce the risk of the intermediate connecting unit 272 breaking due to the expansion and contraction of the constraint portion 21.

[0079] Reference Figure 8 In its initial contracted state (i.e., the initial contracted state before treatment), the balloon 11 folds to form a plurality of flaps 114, and the plurality of flaps 114 fold circumferentially in a predetermined folding direction (e.g., clockwise or counterclockwise). Further, referring to… Figure 6 and Figure 7 In other embodiments, the end of the intermediate connecting unit 272 directly connected to the constraint part 21 is defined as the first end 2722, and the end of the intermediate connecting unit 272 directly connected to the end connecting unit 271 is defined as the second end 2723. The deflection direction of the second end 2723 of the intermediate connecting unit 272 relative to the first end 2722 in the circumferential direction of the constraint bracket 20 is opposite to the folding direction of the balloon 11. When the balloon 11 begins to inflate, the balloon 11 will exert a force on the constraint part 21 opposite to its folding direction due to the expansion. When the deflection direction of the intermediate connecting unit 272 in the circumferential direction is opposite to the folding direction of the balloon 11, it can effectively buffer the circumferential deflection force on the constraint part 21, thereby reducing the degree of deflection of the constraint part 21 and thus reducing the risk of damage and breakage at both ends of the intermediate connecting unit 272 due to the deflection of the constraint part 21.

[0080] The structure of the constraint part 21 in this embodiment can be varied, and examples are given below with reference to the accompanying drawings.

[0081] Reference Figure 9 and Figure 10In this embodiment, the constraint portion 21 includes a mesh structure 21a. The mesh structure 21a includes one or more rows of mesh openings 22. Each row of mesh openings 22 includes multiple mesh openings 22 arranged circumferentially along the constraint portion 21. Each multiple mesh opening 22 includes one or more first mesh openings 22a and one or more second mesh openings 22b. The first mesh openings 22a and second mesh openings 22b are alternately arranged circumferentially in the constraint portion 21. For example, in this embodiment, each row of mesh openings 22 is formed by alternating arrangements of first mesh openings 22a and second mesh openings 22b. When the constraint portion 21 is in a first state, the area of ​​the first mesh opening 22a is larger than the area of ​​the second mesh opening 22b. The first state can be the initial natural radial contraction state of the constraint portion 21, that is, the state when the balloon 11 inside the constraint portion 21 is in a contracted state and the constraint portion 21 is not subjected to any external force. By providing a first mesh 22a and a second mesh 22b circumferentially on the restraint portion 21, the flexibility of the restraint portion 21 is improved, allowing the area where the restraint portion 21 is located to better adapt to the tortuous morphology of blood vessels. Furthermore, the recovery performance of the restraint portion 21 (i.e., the ability of the restraint portion 21 to return to its initial contracted state after the balloon 11 contracts) is improved. This allows the balloon catheter system 100 to repeatedly expand and contract in vivo while maintaining good therapeutic effects. Therefore, it is possible to treat multiple narrowed blood vessel segments in the body without repeatedly releasing and retracting the same balloon catheter 10 for different treatment areas, or repeatedly changing the balloon catheter 10 for different treatment areas. For example, when the restraint portion 21 is in the first state, the ratio R of the area of ​​the first mesh 22a to the area of ​​the second mesh 22b ranges from 1.5 to 2.5. When R is greater than 2.5, the radial expansion of the constraint part 21 becomes more difficult. When R is less than 1.5, the clamping performance of the constraint bracket 20 is poor. Therefore, by setting R within the above range, the constraint part 21 can not only expand radially but also have excellent clamping performance.

[0082] Furthermore, the mesh structure 21a includes one or more rows of mesh holes 22. Each row of mesh holes 22 includes a plurality of mesh holes 22 arranged circumferentially along the constraint portion 21. The plurality of mesh holes 22 includes one or more of the first mesh holes 22a and one or more of the second mesh holes 22b. The first mesh holes 22a and the second mesh holes 22b are arranged alternately in the axial direction of the constraint portion 21. For example, in this embodiment, each row of mesh holes 22 is formed by the alternating arrangement of the first mesh holes 22a and the second mesh holes 22b.

[0083] Reference Figure 11In this embodiment, when the constraint part 21 is in the second state, the area of ​​the first mesh 22a and the area of ​​the second mesh 22b are substantially equal. For example, when the constraint part 21 is in the second state, the areas of all meshes 22 are substantially equal, forming a quadrilateral-like shape. The aforementioned second state refers to the radial expansion state of the constraint part 21 when the pressure inside the balloon 11 reaches a preset pressure (for example, the nominal pressure inside the balloon 11). Since the constraint part 21 has uniform meshes 22 when it is in the second state, protrusions 115 (refer to...) formed from the plurality of meshes 22 can be made to... Figure 3 The size of the protrusions is also relatively uniform, so that the multiple protrusions 115 can fit well into the narrow section of the blood vessel, achieving a good vasodilatory effect. At the same time, the multiple uniform protrusions 115 can apply a relatively uniform squeezing force to the inner wall of the blood vessel, which can avoid excessive tearing of the smooth muscle of the blood vessel wall and damage to the blood vessel.

[0084] Reference Figure 9 , Figure 10 and Figure 12 For example, the constraint portion 21 includes a plurality of circumferential constraint rings 23 spaced apart along the axial direction of the constraint portion 21 and a plurality of axial struts 26 spaced apart along the circumferential direction of the constraint portion 21. The axial struts 26 divide the space between two adjacent circumferential constraint rings 23 into a plurality of first meshes 22a and second meshes 22b. When the constraint portion 21 is in the second state, the axial struts 26 are approximately parallel to the central axis of the constraint portion 21 (i.e., the angle between the line connecting the two axial ends of the axial struts 26 and the central axis of the constraint portion 21 does not exceed 15°). In this embodiment, the circumferential constraint rings 23 are closed ring structures in the circumferential direction (or closed-loop structures in the circumferential direction). In other embodiments, the circumferential constraint rings 23 may be open-loop structures in the circumferential direction (or open-loop structures in the circumferential direction).

[0085] The circumferential constraint ring 23 includes a plurality of vertices 24 spaced apart along the circumference of the circumferential constraint ring 23. These vertices 24 include a first vertex 24a (or crest) and a second vertex 24b (or trough), which are alternately spaced along the circumferential direction of the circumferential constraint ring 23. Exemplarily, the first vertex 24a is closer to the distal end of the constraint portion 21 than the second vertex 24b. In other embodiments, the vertex 24 closer to the proximal end of the constraint portion 21 may also be designated as the first vertex 24a.

[0086] The first vertices 24a and 24b, which are circumferentially adjacent, are connected by wave rods 25, thereby forming multiple waves arranged sequentially in the circumferential direction. Each vertex 24 is connected to two wave rods 25, which are located on both sides of the vertex 24 in the circumferential direction of the constraint portion 21. The wave rods 25 can extend and contract relative to the vertex 24 through deformation. When the constraint portion 21 is in the first state, the wave rods 25 on both sides of the vertex 24 are close to each other. When the constraint portion 21 is in the second state, the wave rods 25 on both sides of the vertex 24 are flipped in a direction away from each other and extended in the circumferential direction of the constraint portion 21, and are generally located on the same radial plane (cross-section) of the constraint portion 21 as the whole with the wave rods 25 they are connected to.

[0087] Reference Figure 13 The wave rod 25 includes an end bend 251 connected to the vertex 24. For example, when the constraint part 21 is in the first state, the wave rod 25 includes a first end bend 251a connected to the first vertex 24a and a second end bend 251b connected to the second vertex 24b. By providing the end bend 251 connected to the vertex 24, the stress at the connection between the end of the wave rod 25 and the vertex 24 during deformation can be reduced, thereby reducing the risk of breakage at the connection between the wave rod 25 and the vertex 24.

[0088] To further reduce the stress at the connection between the wave rod 25 and the vertex 24 during deformation, when the constraint part 21 is in the first state, the end bending section 251 may include an end transition section 2511 and an end bending section 2512, with the end transition section 2511 being closer to the vertex 24 than the end bending section 2512. Figure 13 As shown, in one embodiment, the end transition segment 2511 can be a straight segment. For example... Figure 14 , Figure 15 As shown, the end transition segment 2511 can also be an arc segment, the curvature of which is smaller than that of the end bending segment 2512, in order to achieve a better transition connection effect. It is understood that in other embodiments, the end transition segment 2511 may be omitted, and the end bending segment 251 can still reduce the risk of stress concentration at the connection between the wave rod 25 and the apex 24 to a certain extent.

[0089] Reference Figure 13In this embodiment, when the constraint part 21 is in the first state, the wave rod 25 may further include an intermediate section 252 that connects the first end bend section 251a and the second end bend section 251b at both ends. The proximal end of the intermediate section 252 is farther from the generatrix 21b of the constraint part 21 where the first vertex 24a is located than the distal end of the intermediate section 252. That is, the distal end of the intermediate section 252 is farther from the generatrix 21b of the constraint part 21 where the second vertex 24b is located than the proximal end of the intermediate section 252. This configuration reduces the amount of rotation required for the wave rod 25 as a whole towards the connected vertex 24 during the transition of the constraint part 21 from the first state to the second state, thereby further reducing the probability of stress concentration inside the end bend section 251 and at the connection between the end bend section 251 and the vertex 24. This helps to further reduce the risk of breakage of the end bend section 251 itself or at the connection between the end bend section 251 and the vertex 24.

[0090] For example, refer to Figure 13 and Figure 16 In this embodiment, when the constraint part 21 is in the first state, the intermediate section 252 includes a straight rod segment 2521. The included angle between the straight rod segments 2521 of two adjacent wave rods 25 is in the range of 8° to 35°. For example, the included angle between the straight rod segments 2521 of two adjacent wave rods 25 can be 8°, 10°, 15°, 20°, 25°, 30°, 25°, etc.

[0091] Reference Figure 14 In another embodiment, when the constraint portion 21 is in the first state, the intermediate segment 252 includes a central bending segment 2522. This central bending segment 2522 may be curved, including arc shapes, wavy shapes, etc. The central bending segment 2522 includes at least one bending point 2523 (or bending apex), and at its bending point 2523, the central bending segment 2522 may bend or protrude towards one circumferential direction of the constraint portion 21 or bend towards another circumferential direction of the constraint portion 21. The provision of the central bending segment 2522 is beneficial for further improving the retaining performance of the constraint portion 21.

[0092] The aforementioned bending segment may include an even number of bending points 2523, with adjacent bending points 2523 bending in opposite directions. The purpose of this arrangement is to make the wave shape at the first vertex 24a and the wave shape at the second vertex 24b more consistent, resulting in more uniform force on the wave rod 25 and better containment performance of the constraint part 21.

[0093] For example, Figure 15The middle bending segment 2522 includes two bending points 2523. The bending point 2523 closer to the first vertex 24a is designated as the first bending point 2523a, and the bending point 2523 closer to the second vertex 24b is designated as the second bending point 2523b. At the first bending point 2523a, the middle bending segment 2522 bends convexly in the direction away from the generatrix 21b of the constraint portion 21 where the first vertex 24a is located (i.e., it bends convexly in the direction outward from the wave where the first vertex 24a is located). At the second bending point 2523b, the middle bending segment 2522 bends convexly in the direction away from the generatrix 21b of the constraint portion 21 where the second vertex 24b is located (i.e., it bends convexly in the direction outward from the wave where the second vertex 24b is located). This arrangement helps reduce the risk of stress concentration in the area where the end bending segment 251 is located. In other embodiments, the middle bending segment 2522 may include two or more even-numbered bending points 2523. As long as the middle bending segment 2522 bends in the direction of the generatrix 21b of the constraint portion 21 where the first vertex 24a is located at its bending point 2523 closest to the first vertex 24a, and the middle bending segment 2522 bends in the direction of the generatrix 21b of the constraint portion 21 where the second vertex 24b is located at its bending point 2523 closest to the second vertex 24b, the risk of stress concentration in the area where the end bending segment 251 is located can be reduced to a certain extent.

[0094] Furthermore, the intermediate section 252 may also include straight rod segments 2521 disposed at both ends of the intermediate bent sub-section 2522. This arrangement allows for a smooth transition between the intermediate bent sub-section 2522 and the end bent section 251, which helps to improve the degree of freedom of movement of the intermediate bent sub-section 2522 relative to the end bent section 251, making it easier for the constraint part 21 to expand radially. In other embodiments, the straight rod segments 2521 connecting the intermediate bent sub-section 2522 may be omitted.

[0095] Reference Figure 9 , Figure 12 and Figure 15 In this embodiment, each vertex 24 is fixedly connected to a corresponding axial support 26. The axial supports 26 intersect at their connected vertices 24 within the circumferential constraint ring 23, such that each wave rod 25 is connected between two adjacent axial supports 26 in the circumferential direction. The axial supports 26 and wave rods 25 together form a mesh 22. The axial supports 26 arranged along the axial direction form a circle, and the circumferential constraint ring 23 arranged along the axial direction is fixedly connected to each axial support 26, constraining the axial supports 26 in the circumferential direction and simultaneously forming the mesh 22. In other embodiments, it is not necessarily true that each vertex 24 is connected to an axial support 26.

[0096] In this embodiment, the axial support 26 extends from the proximal end of the constraint portion 21 to the distal end of the constraint portion 21. The axial support 26 includes a plurality of axially bent segments 261 evenly arranged along the axial direction. The axially bent segments 261 can expand and contract through deformation to buffer the axial tension of the axial constraint ring during the unfolding process. Exemplarily, the axially bent segment 261 includes two or more bending points 2523, and the bending directions of adjacent bending points 2523 are opposite to form a wave shape. Further, the axial support 26 may also include a straight reinforcing segment 262 connecting two adjacent axially bent segments 261. The straight reinforcing segment is located at the apex 24 of the circumferential constraint ring 23 to enhance the connection strength at the connection between the axial support 26 and the circumferential constraint ring 23. In other embodiments, the above-mentioned straight reinforcing segment 262 may be omitted.

[0097] In this embodiment, when in the second state, the circumference of the circumferential constraint ring 23 and the nominal diameter of the balloon 11 can satisfy the following expression:

[0098] L1∈[π(D-1),π(D-0.2)]

[0099] Wherein, L1 represents the circumference of the circumferential constraint ring 23 in mm, and D represents the nominal diameter of the balloon 11 in mm. This arrangement causes the protrusion 115 formed from the mesh 22 (refer to...) Figure 3 The height of the protrusion 115 (i.e., the height relative to the protrusion of the constraint part 21) is suitable. The protrusion 115 can effectively dilate blood vessels without easily causing vascular damage, and at the same time, it can also avoid excessive constraint force of the constraint part 21 on the surface of the balloon 11, which could damage the balloon 11. In other embodiments, the circumference of the circumferential constraint ring 23 and the nominal diameter of the balloon 11 do not necessarily satisfy the above expression, and appropriate parameters can be selected according to actual needs.

[0100] Furthermore, referring to Figure 3 In this embodiment, the balloon 11 includes two imaging sections 123 spaced apart in the axial direction (for example, the imaging sections 123 are spaced apart on the inner tube 121). When the restraint section 21 is in the second state, the restraint section 21 completely covers the space between the two imaging sections 123 in the axial direction. This arrangement of the restraint section 21 can effectively cover the entire effective area of ​​the balloon 11, so that the balloon catheter system 100 can more comprehensively and effectively expand the entire narrow area, avoiding the situation where the restraint section 21 cannot cover the entire effective area of ​​the balloon 11 due to shortening during the transition from the first state to the second state.

[0101] Furthermore, referring to Figure 17In this embodiment, at least one axial end of the constraint portion 21 is provided with an additional portion 28, which is located between the connecting portion 27 and the constraint portion 21. The two axial ends of the additional portion 28 are connected to the connecting portion 27 and the constraint portion 21, respectively. When the balloon 11 inflates, the additional portion 28 can expand radially with the balloon 11 before the constraint portion 21. The provision of the additional portion 28 is beneficial in sharing some of the force with the connecting portion 27 during the inflation of the balloon 11. On the other hand, since it expands radially with the balloon 11 before the constraint portion 21, a circumferential relative constraint is formed between the surface of the inflated balloon 11 and the additional portion 28 after inflation. This reduces the risk that the constraint portion 21 will cause the connecting portion 27 to deflect relative to the balloon 11 during inflation, thereby reducing the risk of breakage of the connecting portion 27.

[0102] For example, the additional portion 28 includes one or more additional circumferential rings 281 and additional axial posts 282. The radial support force of the additional circumferential rings 281 is less than the radial support force of the circumferential constraint rings 23, which allows the additional portion 28 to expand faster than the constraint portion 21. The additional circumferential rings 281 and additional axial posts 282 enclose to form at least one row of additional mesh holes 283. Each row of additional mesh holes 283 includes at least one first additional mesh hole 283a and at least one second additional mesh hole 283b. The first additional mesh holes 283a and the second additional mesh holes 283b are alternately arranged in the circumferential direction of the additional portion 28. For example, in this embodiment, each row of additional mesh holes 283 is formed by alternating arrangements of the first additional mesh holes 283a and the second additional mesh holes 283b. When the additional part 28 is in the first state (i.e., the initial natural radial contraction state), the ratio of the area of ​​the first additional mesh 283a to the area of ​​the second additional mesh 283b is less than the ratio of the area of ​​the first mesh 22a to the area of ​​the second mesh 22b. For example, the ratio of the area of ​​the first additional mesh 283a to the area of ​​the second additional mesh 283b can be in the range of 1.0 to 1.4. This arrangement also allows the additional part 28 to expand faster than the constraint part 21. (Refer to...) Figure 18 Furthermore, the additional portion 28 may be in the form of a frustum-shaped structure. For example, the cross-sectional area of ​​the axial end further away from the constraint portion 21 is smaller than that of the axial end closer to the constraint portion 21, so as to better match the shape of the end of the balloon 11 and thus better respond to the expansion of the end of the balloon 11. For example, the additional portion 28 located at the far end of the constraint portion 21 and / or the additional portion 28 located at the near end of the constraint portion 21 are generally in the form of a frustum-shaped structure, and the cross-sectional area of ​​the axial end further away from the constraint portion 21 is smaller than that of the axial end closer to the constraint portion 21.

[0103] Reference Figure 1In this embodiment, a catheter seat 13 may be provided at the proximal end of the tubular assembly 12 for communicating with the outside. The catheter seat 13 may be provided with interfaces 131 corresponding to the delivery channel and guidewire channel of the tubular assembly 12. It should be noted that the above description of the structure of the catheter seat 13 and the tubular assembly 12 is merely illustrative. In other embodiments, the structure of the tubular assembly 12 and the catheter seat 13 may differ from this embodiment; in other embodiments, the catheter seat 13 may be omitted.

[0104] The aforementioned constraint bracket 20 can be cut or woven from one or more elastic materials such as nickel-titanium alloy, stainless steel, and polymer materials. The various components of the constraint bracket 20 can be an integral structure or can be made separately and then spliced ​​together.

[0105] Understandably, the structures of the connecting part 27, the constraint part 21, and the additional part 28 exemplified in this embodiment can be implemented individually and can exert their respective beneficial effects, or they can be implemented in combination to exert their respective beneficial effects.

[0106] Example 2

[0107] Reference Figure 19 , Figure 20 This embodiment provides a balloon catheter system 100, which includes a balloon catheter 10 and a restraint stent 20. The balloon catheter 10 may include a balloon 11 and a tubular assembly 12. The balloon 11 is covered with a restraint stent 20 for limiting the inflation of the balloon 11.

[0108] Reference Figure 21The balloon 11 can expand and contract radially under the operator's control. The balloon 11 has an inner cavity, and its radial expansion and contraction can be controlled by injecting a medium (liquid or gas, etc.) into and withdrawing the medium. When the balloon 11 is inflated, it includes a proximal segment 111, a distal segment 113, and a middle segment 112 connecting the proximal segment 111 and the distal segment 113 at both ends. The middle segment 112 is the therapeutic area (also called the effective area) of the balloon 11. In this embodiment, the cross-sectional shape of the balloon 11 is approximately circular. In other embodiments, the cross-section of the balloon 11 can also be elliptical, crescent-shaped, semi-circular, or any other suitable shape. The proximal segment 111 and distal segment 113 are generally conical, and the middle segment 112 is generally cylindrical. The cross-sectional area of ​​the proximal end of the proximal segment 111 is smaller than that of the distal end, and the cross-sectional area of ​​the proximal end of the distal segment 113 is larger than that of the distal end. In other embodiments, the shapes of the proximal segment 111, distal segment 113, and middle segment 112 of the balloon 11 can be any suitable shape. The balloon 11 can be a semi-compliant balloon 11 or a compliant balloon 11, and can be made of one or more of the following materials: nylon, Pebax, polyurethane, latex, polyethylene phthalate, and polyethylene. The specific structure of the tubular component 12 can be referred to the description in Embodiment 1, and will not be repeated here.

[0109] Reference Figure 20 and Figure 21The outer surface of the balloon 11 has a recess 116. A restraint bracket 20 is disposed outside the balloon 11 and can restrict the inflation shape of the balloon 11. The restraint bracket 20 includes a restraint portion 21, the axial ends of which can be directly connected to the axial ends of the balloon 11, or connected to the axial ends of the balloon 11 through a connecting portion 27 (the specific structure of the connecting portion 27 can be referred to in Embodiment 1, and will not be repeated here). In other embodiments, only one end of the restraint portion 21 may be fixed to the axial end of the balloon 11, and the restraint bracket 20 as a whole may not be connected to the balloon 11, but only be sleeved on the outside of the balloon 11. When the balloon 11 reaches a preset pressure (e.g., the nominal pressure inside the balloon 11) and is in an inflated state, the restraint portion 21 contacts the outer surface of the balloon 11 and restricts the radial expansion of the balloon 11 in the contact area with the outer surface of the balloon 11. The recessed portion 116 and the restraining portion 21 cooperate to form multiple protrusions 115 on the surface of the balloon 11. These protrusions 115 protrude relative to the restraining portion 21 and the recessed portion 116 towards the interior of the balloon 11. These multiple protrusions 115 can compress the narrowed segment of the blood vessel, causing the atherosclerotic material and arterial plaque in the narrowed segment to be deformed and adhere to the inner wall of the blood vessel, resulting in a good vasodilatory effect. Simultaneously, because a recessed area is formed between the multiple protrusions 115, the compressed atherosclerotic material and arterial plaque can move into the recessed area between the protrusions 115, releasing some of the compressive force and preventing excessive tearing of the smooth muscle of the blood vessel wall, thus avoiding damage to the blood vessel. Furthermore, compared to the solution that simply constrains the surface of the balloon 11 to form multiple protrusions 115 by the constraint part 21, the solution of this embodiment can reduce the coverage of the constraint part 21 on the surface of the balloon 11, which is beneficial to improve the flexibility of the area where the balloon 11 is located, so that the balloon catheter 10 can better conform to the curvature of the blood vessel. Compared to the solution that simply sets the recess 116 on the surface of the balloon 11, the constraint part 21 of this embodiment can constrain and support the protrusions 115 to a certain extent, which can prevent the protrusions 115 from being greatly deformed due to the compression of the narrow section of the blood vessel, which is beneficial to stabilizing the protrusion shape of the protrusions 115, thereby ensuring that the protrusions 115 can achieve the desired vasodilatory effect.

[0110] Exemplarily, the balloon 11 includes at least two balloon bodies 112a arranged sequentially along the axial direction of the balloon catheter 10. For example, the middle section 112 of the balloon 11 includes two balloon bodies 112a arranged sequentially along the axial direction of the balloon catheter 10. The recessed portion 116 includes a circumferential recessed unit 116a located between two adjacent balloon bodies 112a. The circumferential recessed unit 116a extends circumferentially in the balloon 11, and when the balloon 11 inflates to its nominal diameter, the diameter of the circumferential recessed unit 116a is smaller than the nominal diameter of the balloon 11. In this embodiment, each balloon body 112a has circumferential recessed units 116a at both ends of its axial direction. The restraint portion 21 includes axial struts 26 extending along the axial direction of the balloon 11. The number of axial struts 26 can be one or more. When there are multiple axial struts 26, the multiple axial struts 26 can be arranged at uniform intervals along the circumference of the balloon 11. When the balloon 11 reaches a preset pressure and is inflated, the axial strut 26 restricts the radial expansion of the balloon 11. The axial strut 26 and the circumferential recessed unit 116a cooperate to form multiple protrusions 115 on the surface of the balloon 11. The axial ends of the axial strut 26 can be directly connected to the axial ends of the balloon 11, or connected to the axial ends of the balloon 11 via a connecting part 27 (the specific structure of the connecting part 27 can be referred to in Embodiment 1, and will not be repeated here). Through the cooperation of the circumferential recessed unit 116a and the axial strut 26, the balloon 11 can uniformly form multiple protrusions 115 when it reaches the preset pressure. These multiple protrusions 115 can fit well into the narrowed segment of the blood vessel, achieving a good vascular dilation effect. At the same time, the multiple uniform protrusions 115 can apply a relatively uniform compressive force to the inner wall of the blood vessel, preventing excessive tearing of the smooth muscle of the blood vessel wall and damage to the blood vessel. Furthermore, the axial strut 26 easily expands with the balloon 11 and can effectively restrain it when the preset pressure is reached inside the balloon 11.

[0111] Furthermore, please also refer to Figure 22 In this embodiment, the recessed portion 116 may further include an axial recessed unit 116b, which extends axially in the balloon 11 and intersects with the circumferential recessed unit 116a. When the balloon 11 inflates to its nominal diameter, the axial recessed unit 116b recesses towards the inner cavity of the balloon 11. The axial recessed unit 116b and the circumferential recessed unit 116a cooperate to form an array of protrusions 115 on the surface of the balloon 11, for example, forming a crisscrossing grid-like array of protrusions 115. Please also refer to... Figure 23 and Figure 24The restraint portion 21 may further include a circumferential restraint ring 23 extending along the circumferential direction of the balloon 11. The number of circumferential restraint rings 23 may be one or more. When there are multiple circumferential restraint rings 23, they may be evenly spaced along the axial direction of the balloon 11. The specific structure of the restraint portion 21 can be referred to the description in Embodiment 1. This arrangement makes it easier to form the protrusion 115. When a relatively low preset pressure is reached inside the balloon 11, a protrusion 115 of a predetermined height can be formed, which helps to reduce the restraining force of the restraint portion 21 on the surface of the balloon 11, thereby reducing the risk of damage to the surface of the balloon 11 caused by the restraint portion 21. The addition of the circumferential restraint ring 23 also helps to better maintain the shape of the protrusion 115, which is beneficial to improving the vasodilatory effect. For a balloon catheter system 100 with a drug layer (e.g., drug coating) on ​​the surface of the balloon 11, when the balloon catheter system 100 is in the delivery state, the restraint portion 21 can effectively protect the drug layer and reduce the risk of drug detachment caused by the drug layer rubbing against the delivery sheath. In addition, the recessed portion 116 can further increase the outer surface area of ​​the balloon 11, which can increase the drug loading on the surface of the balloon 11 and is beneficial to improving the therapeutic effect.

[0112] Understandably, in other embodiments, the recess 116 may only include the circumferential recess unit 116a, and the constraint part 21 may only include the axial support 26; or, in other embodiments, the recess 116 may only include the axial recess unit 116b, and the constraint part 21 may only include the circumferential constraint ring 23; of course, in other embodiments, recess units and constraint parts 21 of other shapes or structures may be included.

[0113] In this embodiment, the restraint stent 20 is fixedly connected to the balloon 11 via its axial ends. For example, both axial ends of the restraint stent 20 are fixedly connected to both axial ends of the balloon 11, and the restraint portion 21 can move relative to the surface of the balloon 11. When the balloon 11 reaches a preset pressure and is in an inflated state, part or all of the restraint portion 21 is located within the recessed portion 116. This arrangement facilitates better cooperation with the recessed portion 116 to form a regular protrusion 115 and increases the contact area between the surface of the balloon 11 and the inner wall of the blood vessel, thus improving the vasodilatory effect. For balloons 11 with a drug layer on their surface, this arrangement is beneficial for improving the drug delivery effect. Furthermore, when the outer surface of the recessed portion 116 has a drug layer, the restraint portion 21, upon entering the recessed portion 116, can promote the fragmentation and release of the drug layer.

[0114] Furthermore, referring to Figure 25The balloon catheter system 100 of this embodiment may further include a traction section 117, which is connected to both the restraint section 21 and the recessed section 116. The traction section 117 is used to pull the restraint section 21 during balloon 11 inflation, so that the restraint section 21 is located within the recessed section 116 when the balloon 11 reaches a preset pressure and is inflated. By providing the traction section 117, the probability of the restraint section 21 entering the recessed section 116 after balloon 11 inflation can be increased. Exemplarily, the traction section 117 includes one or more of a flexible traction unit and an adhesion unit. The flexible traction unit includes a traction rope, traction line, traction wire, etc., with one end connected to the recessed section 116 and the other end connected to the restraint section 21. The flexible traction unit may or may not be elastic. During balloon 11 inflation, the flexible traction unit can pull the restraint section 21 into the recessed section 116 region connected to it. The adhesion unit may include an adhesion point. By adhering the constraint portion 21 and the recessed portion 116 at a certain adhesion point, for example, adhering the axial end of the constraint portion 21 and the corresponding region of the recessed portion 116 at one adhesion point, the relative position of the constraint portion 21 and the recessed portion 116 at the adhesion point remains unchanged during the inflation of the balloon 11, thereby prompting other unadheded parts of the constraint portion 21 to also enter the corresponding region of the recessed portion 116. In other embodiments, different traction portion 117 structures may be used to increase the probability that the constraint portion 21 enters the recessed portion 116 after the balloon 11 is inflated. In other embodiments, the traction portion 117 may be omitted.

[0115] In other embodiments, refer to Figure 26 The balloon catheter system 100 may include at least one limiting part 118, which is disposed on the restraint part 21 (see reference). Figure 25 On one side of the axial direction, the constraint part 21 is used to limit the circumferential deflection of the constraint part 21 relative to the balloon 11 during the inflation process, thereby increasing the probability that the constraint part 21 enters the recess 116 after the balloon 11 is inflated.

[0116] For example, refer to Figure 25 , Figure 26 The constraint part 21 is provided on the middle section 112, and the proximal section 111 and the distal section 113 are located outside the constraint part 21. The proximal section 111 and / or the distal section 113 can be provided with a limiting part 118. The limiting part 118 includes a limiting groove 1181 provided on the balloon 11 and a limiting member 1182 provided in conjunction with the limiting groove 1181. The limiting member 1182 is provided at the axial end of the constraint part 21 and is connected to the constraint part 21. During the inflation of the balloon 11, the limiting member 1182 is located in the limiting groove 1181 to limit the circumferential deflection of the constraint part 21 relative to the balloon 11.

[0117] In other embodiments, refer to Figure 17The balloon catheter system 100 may also be provided with an additional part 28 as described in Embodiment 1. The specific structure and description of Embodiment 1 are not repeated here. The additional part 28 helps to share some of the force with the connecting part 27 during balloon 11 inflation. Furthermore, since it expands radially with the balloon 11 before the restraint part 21, a circumferential relative constraint is formed between the inflated balloon 11 surface and the additional part 28 after inflation. This reduces the risk of the restraint part 21 causing the connecting part 27 to deflect relative to the balloon 11 during inflation, further increasing the probability that the restraint part 21 will enter the recess 116 after balloon 11 inflation. It also helps to reduce the risk of the connecting part 27 breaking. Understandably, the additional part 28 can be omitted.

[0118] In this embodiment, refer to Figure 22 The conformability of the protrusion 115 can be set to be greater than that of the recess 116, thereby allowing the recess 116 to better maintain its recessed shape when a predetermined pressure is reached inside the balloon 11. For example, when the protrusion 115 and the recess 116 are made of the same material, the conformability of the recess 116 can be reduced by making the sidewall thickness of the recess 116 greater than that of the protrusion 115. Alternatively, a low-modulus layer can be provided within the recess 116, the elastic modulus of which is less than that of the material used in the protrusion 115, to reduce the conformability of the recess 116.

[0119] The aforementioned constraint bracket 20 can be cut or woven from one or more elastic materials such as nickel-titanium alloy, stainless steel, and polymer materials. The various components of the constraint bracket 20 can be an integral structure or can be made separately and then spliced ​​together.

[0120] In this embodiment, refer to Figure 1 The proximal end of the tubular component 12 may also be provided with a catheter seat 13. The specific structure of the catheter seat 13 and the connection method of the tubular component 12 can be referred to the description in Embodiment 1, and will not be repeated here. In other embodiments, the catheter seat 13 may be omitted.

[0121] Understandably, the structures of the connecting part 27, the restraining part 21, the traction part 117, and the additional part 28 exemplified in this embodiment can all be implemented individually and can exert their respective beneficial effects, or they can be implemented in combination to exert their respective beneficial effects.

[0122] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

Claims

1. A constraint stent for balloon catheters, used to be fitted over the balloon of a balloon catheter, characterized in that, include: The constraint part has an axial end; Two connecting portions are disposed at the axial ends of the constraint portion. Each connecting portion includes a first axial end and a second axial end. The first axial end is further away from the constraint portion than the second axial end. The second axial end is connected to the constraint portion. At least one of the first axial ends of the connecting portion is a circumferentially non-closed structure. The circumferential non-closed structure includes at least one end connecting unit in the circumferential direction. The first axial end also includes an intermediate connecting unit disposed between the constraint part and the end connecting unit. The intermediate connecting unit includes a connecting rod. One axial end of the connecting rod is located in a first axial plane with the central axis of the constraint bracket, and the other axial end of the connecting rod is located in a second axial plane with the central axis of the constraint bracket. The first axial plane and the second axial plane intersect. The constraint part includes a circumferential constraint ring, which includes a plurality of first vertices and second vertices arranged alternately along the circumference of the circumferential constraint ring. The first vertices are closer to the far end of the constraint part than the second vertices. The circumferentially adjacent first vertices and second vertices are connected by a wave rod. The wave rod includes a first end bend connected to the first vertices, a second end bend connected to the second vertices, and an intermediate section whose two ends are respectively connected to the first end bend and the second end bend. When the constraint part is in a first state, the proximal end of the intermediate section is farther away from the generatrix of the constraint part where the first vertex is located than the far end of the intermediate section.

2. The balloon catheter restraint stent according to claim 1, characterized in that, Along the circumferential direction of the constraint bracket, the two sides of the end connecting unit are provided with circumferential spacing.

3. The balloon catheter restraint stent according to claim 1, characterized in that, The circumferential non-closed structure includes at least two end connecting units that are evenly spaced in the circumferential direction and are arranged opposite each other in the radial direction.

4. The balloon catheter restraint stent according to claim 2 or 3, characterized in that, The shape of the end connection unit includes one or more of the following: circular, elliptical, teardrop-shaped, triangular, T-shaped, and fork-shaped.

5. The balloon catheter restraint stent according to claim 2 or 3, characterized in that, The end connection unit includes a closed or open annular connector and a connection hole provided in the annular connector.

6. The balloon catheter restraint stent according to any one of claims 1 to 3, characterized in that, The constraint bracket includes two connecting parts, namely a first connecting part and a second connecting part. The first connecting part is connected to the proximal end of the constraint part, and the second connecting part is connected to the distal end of the constraint part. The first axial ends of both connecting parts include end connecting units. The shape of the end connecting unit of the first connecting part is different from that of the end connecting unit of the second connecting part, and the surface area of ​​the end connecting unit of the first connecting part is larger than that of the end connecting unit of the second connecting part.

7. The balloon catheter restraint stent according to claim 2 or 3, characterized in that, The end connection unit is connected to the constraint part through the corresponding intermediate connection unit, and circumferential spacing is provided on both sides of the intermediate connection unit along the circumferential direction of the constraint bracket.

8. The balloon catheter restraint stent according to claim 7, characterized in that, One end of the connecting rod is connected to the constraint part, and the other end of the connecting rod is connected to the corresponding end connecting unit. The shape of the connecting rod includes one or more of straight, curved, and polygonal shapes, wherein the curved shape includes one or more of arc, wave, and sawtooth shapes.

9. The balloon catheter restraint stent according to claim 1, characterized in that, The constraint portion includes a mesh structure, the mesh structure includes at least one row of mesh holes, each row of mesh holes includes at least one first mesh hole and at least one second mesh hole, the first mesh hole and the second mesh hole are alternately arranged in the circumferential direction of the constraint portion, and when the constraint portion is in a first state, the area of ​​the first mesh hole is larger than the area of ​​the second mesh hole.

10. The balloon catheter restraint stent according to claim 9, characterized in that, The ratio of the area of ​​the first mesh to the area of ​​the second mesh is in the range of 1.5 to 2.

5.

11. The balloon catheter restraint stent according to claim 9, characterized in that, When the constraint part is in the second state, the area of ​​the first mesh and the area of ​​the second mesh are basically equal.

12. The balloon catheter restraint stent according to claim 1, characterized in that, The intermediate section includes straight rod segments and / or a mid-section bent segment.

13. The balloon catheter restraint stent according to claim 1, characterized in that, The intermediate segment includes a central bending sub-segment. When the constraint part is in the first state, the central bending sub-segment includes an even number of bending points, and the bending directions of two adjacent bending points are opposite.

14. The balloon catheter restraint stent according to claim 13, characterized in that, The middle bending segment bends and protrudes in the direction away from the generatrix of the constraint part where the first vertex is located at the bending point closest to the first vertex, and the bending segment bends and protrudes and protrudes in the direction away from the generatrix of the constraint part where the second vertex is located at the bending point closest to the second vertex.

15. The balloon catheter restraint stent according to claim 1, characterized in that, The constraint part includes a circumferential constraint ring, which includes a plurality of vertices arranged sequentially and spaced apart in the circumferential direction. The circumferential constraint ring also includes a wave rod connecting two adjacent vertices. The wave rod includes an end bend segment connected to the vertex. The end bend segment includes an end transition sub-segment and an end bend segment. The end transition sub-segment is closer to the vertex than the end bend segment. The end transition sub-segment is a straight segment or an arc segment. When the end transition sub-segment is an arc segment, the arc of the end transition sub-segment is smaller than the arc of the end bend segment.

16. A balloon catheter system, characterized in that, Includes balloon catheters and restraint stents as described in any one of claims 1 to 15.

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