Balloon, balloon dilatation catheter and stent system

Abstract

The invention provides a balloon, a balloon dilatation catheter and a stent system, and particularly provides a balloon, a balloon dilatation catheter and a stent system suitable for bifurcated vascular lesion areas. The balloon comprises a balloon body, a far-end body and a near-end body, the far-end body comprises a first cone part, the near-end body comprises a second cone part, and at least the size of the cone angle alpha 1 of the first cone part and the size of the diameter d of the balloon in the expansion state meet the following relational expression: alpha 1 = k1ld + b1; wherein k1 belongs to [11.009, 21.478], b1 belongs to [7.98, 20.8], d is more than or equal to 5 and less than or equal to 16, and d is a positive integer. The balloon dilatation catheter comprises the balloon, a pushing tube and a catheter seat. According to the balloon, the balloon dilatation catheter and the stent system, the structure of the balloon is improved and optimized, and the balloon, the balloon dilatation catheter and the stent system are simple in structure, easy to produce, capable of achieving industrialization, low in cost, easy to operate clinically and capable of accurately releasing and positioning the stent. Therefore, the positioning accuracy of the stent in a bifurcated vascular lesion area and the success rate of an operation are greatly improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and in particular relates to a balloon, a balloon dilatation catheter and a corresponding stent system. Background Art

[0002] Among vascular diseases, arteriovenous stenosis can directly endanger the patient's life safety. The treatment methods for arteriovenous stenosis include surgery and interventional therapy. Among them, interventional therapy has been favored in recent years because it is simple, minimally invasive, can be performed repeatedly, and can maximize the preservation of vascular resources in hemodialysis patients. Interventional therapy refers to percutaneous transluminal angioplasty (PTA), which uses a balloon dilatation catheter to dilate the narrowed target blood vessel, or delivers a stent to be implanted, and expands the stent to support the narrowed target blood vessel, thereby restoring the vascular access. Compared with traditional surgical operations, this method has the advantages of less bleeding, less trauma, fewer complications, faster postoperative recovery, and safety and reliability, which can greatly reduce the pain suffered by patients.

[0003] Although interventional therapy has been developed relatively maturely, and some related products have been launched and implanted in large quantities, in actual clinical practice, since many arteriovenous stenosis occurs at the junction of the main blood vessel and the branch blood vessel, that is, the bifurcation, due to the presence of the branch blood vessel at the bifurcation, after the stent is delivered to the vascular lesion area through the balloon dilatation catheter, it is difficult to avoid the distal end of the stent system from not being inserted into the branch blood vessel. Since the branch blood vessel is thin, it is bound to have a certain negative impact on the clinical operation of the stent system. Therefore, the presence of the branch blood vessel brings many challenges to the implementation of percutaneous angioplasty, one of which is how to accurately position the stent to the lesion area at the bifurcation to improve the success rate of PTA surgery. In recent years, some related research results have been published one after another, but it can be seen from the currently disclosed existing technologies that these studies are usually based on adding some new components / devices to the stent delivery system to improve the accuracy of stent positioning. However, the newly added components often bring new technical problems, such as causing the outline of the stent system to become larger and the operation to be too complicated, which increases the risk of surgery to a certain extent.

[0004] For example, patent application US20030055483A discloses a balloon catheter, which is made to have a rotating performance by adding hollow hypotubes and other components, thereby optimizing the positioning performance of the stent at the bifurcated blood vessel, but this feature also leads to an increase in the total diameter of the stent system, a complex structure, and higher requirements for the production process, production cost and clinical implantation. Patent application WO2019156560A1 discloses a stent delivery system, which is a delivery system in which an elastic sleeve is wrapped on a part of the inflatable balloon. Therefore, compared with another part of the inflatable balloon opposite to the stent, the elastic sleeve can be configured to at least partially prevent or delay the inflation of the inflatable balloon at the wrapped part. By preventing the proximal part of the balloon from expanding prematurely, the position displacement of the stent during the inflation process can be avoided, and the anchor cable is combined to determine the anchor position relative to the branch position, thereby improving the positioning accuracy of the stent. However, the delivery system has added both an elastic sleeve and an anchor cable, and has the disadvantages of complex structure, relatively high cost, large total profile diameter, and clinically difficult operation.

[0005] Therefore, it is very necessary to provide a stent delivery device suitable for the lesion area of ​​the bifurcation site, which has a simple structure, low cost, easy processing and production, simple clinical operation, small overall profile, low surgical risk and high positioning accuracy. Summary of the invention

[0006] In view of this, the present invention provides a technical solution that can improve the positioning accuracy of the stent in the lesion area of ​​the bifurcation site without adding new components / devices, but only by improving / optimizing the existing structure of the balloon or balloon dilatation catheter. This solution not only has a simple structure, low cost, and easy processing and production, but also has the advantages of convenient clinical operation, small overall contour, low surgical risk and high stent positioning accuracy.

[0007] On one hand, the present invention provides a balloon, comprising a balloon body and a distal body and a proximal body respectively connected to both ends of the balloon body, wherein the interior of the balloon body, the distal body and the proximal body are combined to form an inner cavity, wherein the inner cavity is used to accommodate a medium for expanding the balloon, wherein the distal body comprises a first cone portion, and the proximal body comprises a second cone portion, wherein at least the cone angle α1 of the first cone portion and the diameter d of the balloon in the expanded state satisfy the relationship:

[0008] α1=k1lnd+b1; wherein: k1∈[11,42.421], and b1∈[6.8,31.8], 5≤d≤16, and d is a positive integer.

[0009] Further, the balloon includes a balloon body and a distal body and a proximal body respectively connected to both ends of the balloon body, the balloon body, the distal body and the proximal body are combined to form an inner cavity, the inner cavity is used to accommodate a medium for expanding the balloon, the distal body includes a first cone, the proximal body includes a second cone, at least the cone angle α1 of the first cone and the diameter d of the balloon body in the expanded state satisfy the relationship:

[0010] α1=k1lnd+b1; wherein: k1∈[11.009, 27.4], and b1∈[7.98, 14.2], 5≤d≤16, and d is a positive integer.

[0011] Furthermore, the cone angle α1 of the first cone portion and / or the cone angle α2 of the second cone portion and the diameter d of the balloon body in the expanded state satisfy the following relationship:

[0012] α1=k1lnd+b1; wherein: k1∈[12,20], and b1∈[9,25.8], 5≤d≤16, and d is a positive integer;

[0013] α2=k2lnd+b2;wherein: k2∈[12,20], and b2∈[9,25.8], 5≤d≤16, and d is a positive integer;

[0014] The roughness Ra of the capsule surface is 0.03 μm-0.2 μm, and the roughness Ra of the first cone surface is 0.05 μm-0.2 μm.

[0015] Furthermore, the length L1 of the first cone portion and / or the length L2 of the second cone portion satisfy the following relationship:

[0016] Where k∈[0.6, 2.1].

[0017] Furthermore, the length L1 of the first cone portion and / or the length L2 of the second cone portion satisfy the following relationship:

[0018] Where k∈[0.6, 2.1].

[0019] Furthermore, the first cone portion and / or the second cone portion includes at least one protrusion, and at least a portion of the protrusion has a distance D relative to the central axis of the balloon that is 1.05-1.5 times the radius d / 2 of the balloon body.

[0020] Furthermore, the horizontal distance between at least part of the protrusion and the adjacent end on the capsule is less than 2 mm; the total length of the protrusion accounts for 5%-35% of the total length of the first cone or the second cone; the protrusion or its tangent forms a "V" shape with the capsule lying flat and the opening facing the capsule.

[0021] Furthermore, the included angle of the "V" shape is 30°-150°.

[0022] Further, at least the first cone portion includes a stepped structure, the stepped structure includes at least a first cone segment, a second cone segment and a straight segment, the straight segment is connected between the first cone segment and the second cone segment, and the other end of the first cone segment is connected to the capsule;

[0023] The cone angle α3 of the first cone section is 30°-150°, the cone angle α4 of the second cone section is 40°-178°, and the diameter of the straight section is smaller than the diameter of the capsule.

[0024] Furthermore, the magnitude of the cone angle α1 of the first cone portion and the cone angle α2 of the second cone portion and the magnitude of the diameter d of the balloon body in the expanded state satisfy the following relationship:

[0025] α1=k1lnd+b1; where: k1∈[11.51,21.52], d∈[5,9], b1∈[10.2,21.4]; or k1∈[21,

[0026] 27.87], and d∈[10,16], b1∈[-11.6,3.85];

[0027] α2=k2lnd+b2;where: k2∈[11.51,21.52],d∈[5,9],b2∈[10.2,21.4];or k2∈[21,

[0028] 27.87], and d∈[10,16], b2∈[-11.6,3.85].

[0029] Furthermore, the ratio of the wall thickness of the balloon to the diameter of the balloon in the expanded state is 0.0015-0.010.

[0030] Another aspect of the present invention provides a balloon dilatation catheter, comprising:

[0031] The push tube comprises a guidewire cavity for the guidewire to pass through and a filling cavity for the medium to pass through, wherein the guidewire cavity and the filling cavity are axially arranged in parallel and isolated from each other by a partition;

[0032] A balloon, which is the balloon described in the present invention, the balloon is connected to one end of the push tube, and the inner cavity of the balloon is connected to the filling cavity;

[0033] A catheter seat connected to the other end of the push tube, the catheter seat comprising a first interface and a second interface, the first interface being communicated with the guidewire cavity, and the second interface being communicated with the filling cavity;

[0034] Among them, the distal body also includes a distal joint, and the proximal body also includes a proximal joint. At least the proximal joint and the push tube are sealed to form a first connecting part, and the diameter of the first connecting part is less than or equal to the diameter of the proximal joint.

[0035] Furthermore, the inner diameter of the proximal joint is 1.78 mm-2.2 mm, the gap between the push tube and the proximal joint is no more than 0.2 mm, and the ratio of the wall thickness of the proximal joint to the wall thickness of the push tube is 0.2-2.0.

[0036] Furthermore, the ratio of the radial cross-sectional area of ​​the filling cavity to the radial cross-sectional area of ​​the pushing tube is 0.1-0.3, or the maximum width of the filling cavity along the radial direction of the pushing tube is 0.3mm-0.55mm.

[0037] Furthermore, the balloon dilatation catheter also includes:

[0038] An inner tube is inserted into the inner cavity of the balloon, one end of the inner tube is connected to the push tube, and the other end of the inner tube is connected to the distal connector;

[0039] A developing ring, arranged on the inner tube;

[0040] Wherein, the guide wire cavity is communicated with the inner tube, and the diameter of the inner tube is smaller than the diameter of the push tube.

[0041] Furthermore, the distal end connector is connected to the inner tube to form a second connecting portion, and the diameter of the second connecting portion is smaller than the diameter of the distal end connector.

[0042] Furthermore, the balloon dilatation catheter also includes:

[0043] A guide tube, arranged in front of the distal body along the pushing direction of the pushing tube, and connected to the inner tube;

[0044] Wherein, the ratio of the diameter of the front end of the guide tube to the diameter of the front end of the second connecting part is 0.75-0.94.

[0045] Furthermore, the minimum wall thickness of the guidewire cavity is 0.08 mm-0.12 mm; and / or the minimum wall thickness of the filling cavity is 0.08 mm-0.15 mm.

[0046] The technical solution of the present invention further provides a stent system, comprising a stent and the balloon dilatation catheter as described in the present invention, wherein the stent is sleeved on the balloon of the balloon dilatation catheter.

[0047] Furthermore, the roughness Ra of the inner surface of the stent is 0.05 μm-0.4 μm; and the maximum static friction force on the surface of the balloon in the stent system is 2.8N-7.9N.

[0048] The present invention determines a certain intrinsic relationship between the size of the balloon diameter d and the cone angle α1 in the balloon expansion state and the positioning accuracy of the stent based on the clinical performance of the stent system when used in branch vessels, the size of the cone angle α1 of the first cone, the balloon diameter d in the balloon expansion state, and the length L1 of the first cone and the volume of the cavity determined by the two, and combines the force characteristics of the fluid inside the balloon such as direction and size, the balloon expansion method, and the size of the friction coefficient of the blood vessel wall, and finally fits a relationship, which determines the range of cone angles adapted to each balloon diameter. Within this range, a stent system formed by a balloon catheter with the above characteristics and loaded with a stent will neither cause the stent system to move backward during the expansion process due to an excessively small cone angle of the balloon cone, nor will the stent slip out during the balloon expansion process due to an excessively large cone angle of the balloon cone, thereby making the entire stent system more clinically positioned; at the same time, the present invention is also combined with the performance of the balloon in the recovery and withdrawal process after the stent is released, Further, a more optimized cone angle interval corresponding to each balloon specification is obtained. Within this interval, the stent not only has a more accurate positioning in the bifurcation lesion area, but also is conducive to the recovery and withdrawal of the balloon, so that the balloon will not cause vascular damage and other problems during the withdrawal process, and will not even cause the final stent system to have a larger profile in the gripping state due to unreasonable balloon structure design, thereby increasing the difficulty of stent system delivery; in addition, the present invention further combines the structure and inner surface roughness of the stent itself, the surface roughness of the balloon, the structure of the balloon, and the mutual force between the balloon and the stent to further improve the positioning accuracy of the stent in the branch vessel; finally, the present invention further combines the balloon thickness and the setting and optimization of various parameters of the balloon catheter to ensure that the balloon not only has better positioning performance in the bifurcation lesion area while meeting the corresponding performance requirements, but also has a smaller profile, safe bursting pressure and pressure relief time, etc., thereby improving the overall performance of the balloon, which is conducive to the delivery and safe implantation of the stent system. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0050] Figure 1 is a cross-sectional schematic diagram of a first balloon provided by an embodiment of the present invention;

[0051] Figure 2 is a cross-sectional schematic diagram of a second balloon provided by an embodiment of the present invention;

[0052] Figure 3 is a cross-sectional schematic diagram of a third balloon provided by an embodiment of the present invention;

[0053] Figure 4 is a cross-sectional schematic diagram of a fourth balloon provided by an embodiment of the present invention;

[0054] Figure 5 is a cross-sectional schematic diagram of a balloon dilatation catheter provided by an embodiment of the present invention;

[0055] Figure 6 yes Figure 5 A local enlarged schematic diagram of the middle A;

[0056] Figure 7 yes Figure 5 A partial enlarged schematic diagram of point B in the middle;

[0057] Figure 8 yes Figure 5 Schematic diagram of the cross section at CC. Description of the drawings:

[0059] 1. Balloon; 10. Inner cavity; d. Diameter of balloon expansion; W1. Thickness of balloon wall on one side; 12. Distal body; 120. First connection part; 121. First cone; 1211. First cone section; 1212. Second cone section; 1213. Straight section; 122. Distal joint; L1. Length of first cone; D2. Diameter of distal joint; 13. Proximal body; 130. Second connection part; 131. Second cone; 132. Proximal joint; L2. Length of second cone; W3. Thickness of proximal joint wall; D3. Diameter of proximal joint; D. Distance between protrusion and central axis of balloon; 14. Protrusion; 15. "V" shape;

[0060] 2. Balloon dilatation catheter; 21. Push tube; 211. Guidewire cavity; W6. Guidewire cavity wall thickness; 212. Filling cavity; W4. Maximum width of filling cavity; W7. Filling cavity wall thickness; 213. Separator; W5. Diaphragm thickness; 22. Catheter seat; 221. First interface; 222. Second interface; 23. Inner tube; 24. Development ring; 25. Guide tube. DETAILED DESCRIPTION

[0061] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0062] It should be noted that the terms “setting” and “connection” should be understood in a broad sense. For example, it can be directly setting or connecting, or it can be indirectly setting or connecting through a central component or a central structure.

[0063] In addition, in the embodiments of the present invention, if there are terms such as "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicating orientation or positional relationship, they are based on the orientation or positional relationship or conventional placement state or use state shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the structure, feature, device or element referred to must have a specific orientation or positional relationship, nor must it be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0064] The various specific technical features and embodiments described in the specific implementation methods can be combined in any suitable manner unless there is any contradiction. For example, different implementation methods can be formed by combining different specific technical features / embodiments. In order to avoid unnecessary repetition, the various possible combinations of the specific technical features / embodiments in the present invention will not be described separately.

[0065] In this article, the terms "proximal" and "distal" are relative positions from the perspective of a doctor using the medical device. The "proximal" usually refers to the end of the medical device that is close to the doctor during normal operation, while the "distal" usually refers to the end that first enters the patient's body.

[0066] like Figure 1As shown, an embodiment of the present invention provides a balloon 1, which has the property of being elastically expandable or contractible, so that when the balloon 1 is pushed to a target blood vessel where stenosis occurs, the expansion of the balloon 1 can expand the stent attached to the balloon 1, and then the blood vessel is no longer narrowed due to the support of the stent, thereby restoring normal blood circulation in the target blood vessel.

[0067] like Figure 1 As shown, in one embodiment, the balloon 1 includes a balloon body 11 and a distal body 12 and a proximal body 13 respectively connected to the two ends of the balloon body 11. The internal combination of the balloon body 11, the distal body 12 and the proximal body 13 forms an inner cavity 10, and the inner cavity 10 is used to accommodate a medium for expanding the balloon 1. Specifically, the balloon body 11 is a hollow cylinder with openings at both ends, and the distal body 12 and the proximal body 13 are respectively connected to the openings at the two ends of the balloon body 11. The distal body 12 and the proximal body 13 can be integrally formed with the balloon body 11, or they can be independent parts that are connected as a whole by welding. The balloon body 11, the distal body 12 and the proximal body 13 can undergo elastic deformation, so that they can increase in volume after swelling. The materials constituting the capsule 11, the distal body 12 and the proximal body 13 can be materials that meet the medical use standards, such as the capsule 11 is made of nylon or nylon composite materials or polyurethane or polyethylene, so that the capsule 11 can expand to meet the required diameter under the working pressure. The materials made of the distal body 12 and the proximal body 13 can be the same as the capsule 11, or other materials that meet the medical use standards and are preferably capable of elastic deformation. After the distal body 12 and the proximal body 13 are respectively connected to the two ends of the capsule 11, the entire interior of the formed balloon 1 is a hollow structure, thereby forming the inner cavity 10 of the balloon 1. Then, by passing a medium that meets the pressure requirements, such as gas or liquid, into the inner cavity 10, the capsule 11 can be elastically expanded, thereby achieving the purpose of expanding the stent attached thereto. After the stent is expanded, the balloon can be removed / withdrawn from the blood vessel by depressurizing and shrinking the balloon, and then performing a removal / withdrawal operation.

[0068] Specifically, in the operation of pushing the balloon 1 into the body, the distal body 12 is the end that first enters the body, and when the balloon 1 is withdrawn from the body after expansion is completed, the proximal body 13 is the end that first withdraws from the body. Therefore, the distal body 12 is provided with a first cone 121, and the proximal body 13 is provided with a second cone 131. The diameter of the end connected to the balloon 11 on the first cone 121 and the second cone 131 is larger than the diameter of the end away from the balloon 11, forming a cone angle of corresponding numerical value, so that the balloon has a better guiding effect. In this way, the first cone 121 and the second cone 131 both have a guiding function, so that in the process of pushing the balloon 1 into the body or withdrawing it from the body, the first cone 121 and the second cone 131 can respectively provide a guiding effect for the corresponding movement, so that the balloon can be pushed into the body or withdrawn from the body more smoothly.

[0069] In the embodiment of the present invention, Figure 1As shown, when the diameter of the balloon 1 after expansion is constant, if the cone angle α1 is smaller, the length of the shoulder of the first cone 121 is longer, and the volume of the inner cavity formed by the first cone 121 is larger; the larger the cone angle α1 is, the shorter the length of the shoulder of the first cone 121 is, and the volume of the inner cavity formed by the first cone 121 is smaller. As the first cone 121 is longer, when the stent system is delivered to the lesion area near the bifurcation, the depth and probability of the first cone 121 entering the branch blood vessel are greatly increased. As the fluid flows to the cavity formed by the first cone 121, the first cone 121 will exert a force on the blood vessel wall under the action of the fluid, and the blood vessel wall will also exert an opposite force on the first cone, thereby driving the entire stent system to move backward, resulting in the problem of inaccurate positioning. Therefore, the present invention determines a certain intrinsic relationship between the size of the balloon diameter d and the cone angle α1 in the expanded state of the balloon and the positioning accuracy of the stent based on the size of the cone angle α1 corresponding to the first cone 121, the balloon diameter d in the expanded state of the balloon, the length L1 of the first cone 121 determined by the two, and the volume of the cavity, and combines the force characteristics of the fluid inside the balloon such as direction and size, and the size of the friction coefficient of the blood vessel wall and other factors, and determines a reasonable interval based on the relationship, and finally fits a relationship. Within the range determined by the relationship, the comprehensive force exerted on the balloon and its stent system by the branch blood vessels in the direction of the blood vessel is relatively small or even zero, thereby avoiding the overall backward movement of the stent system during the expansion process. The backward movement here refers to the movement of the entire stent system relatively away from the bifurcation of the blood vessel, that is, the entire stent system moves toward the proximal direction of the balloon under the action of the bifurcated blood vessel. The technical solution of the present invention adopts that the size of the cone angle α1 of at least the first cone portion 121 and the size of the diameter d of the balloon body in the expanded state of the balloon 1 satisfy the following relationship: α1=k1lnd+b1; wherein: k1∈[11, 42.421], and b1∈[6.8, 31.8], 5≤d≤16, and d is a positive integer. Specifically, at least the size of the cone angle α1 of the first cone portion 121 and the size of the diameter d of the balloon body in the expanded state of the balloon 1 satisfy the above relationship.According to the fitted relationship, under the corresponding balloon expansion state and the diameter specification of the balloon, there will be a suitable value range of the cone angle α1. Within this value range, there will be a good match between the balloon and the stent. When the stent system is applied to the lesion at the bifurcation of the blood vessel, the stent system will not be subjected to the force of the branch blood vessel in the direction of the blood vessel on the distal end of the stent system greater than the friction force in the opposite direction generated by the movement of the stent system relative to the blood vessel wall due to the cone angle of the balloon being too small or the shoulder being too long, thereby avoiding the situation where the entire stent will move backward as the balloon expands, resulting in inaccurate positioning of the stent; in addition, within the range determined by the relationship, the cone angle of the balloon is too large and the length of the first cone 121 is too short, resulting in the stent shifting forward and backward or detaching from the balloon as the balloon expands, thereby greatly improving the positioning accuracy of the stent in the area with branch blood vessel lesions, thereby greatly improving the success rate of PTA surgery. In summary, the present invention achieves the purposes of guided insertion, safe pushing, and accurate positioning of the stent in the target blood vessel by adopting a suitable cone angle design for the balloon 1. The design is ingenious and greatly improves the performance of the balloon 1.

[0070] Furthermore, in some embodiments, the present invention adopts a method that at least the cone angle α1 of the first cone portion 121 of the balloon and the diameter d of the balloon body in the expanded state of the balloon 1 satisfy the following relationship: α1=k1lnd+b1; wherein: k1∈[11.009, 27.4], and b1∈[7.98, 14.2], 5≤d≤16, and d is a positive integer. According to the above relationship, the balloon 1 not only satisfies the requirement that the stent will not be displaced or detached during expansion, but also avoids the problem that the balloon has an excessively large retraction diameter due to an excessively large cone angle, which makes it difficult to recover the balloon, and thus causes damage to the blood vessel or requires the use of a larger sheath. At the same time, it can also avoid the problem that the stent is displaced forward and backward relative to the balloon or detaches from the balloon due to an excessively large cone angle. Therefore, when the size of the cone angle α1 of the first cone 121 of the balloon and the size of the diameter d of the balloon body in the expanded state of the balloon 1 satisfy the above-mentioned relationship, it can not only ensure that the stent has a more precise positioning, but also ensure that the balloon can be better recovered and withdrawn after the stent is expanded, so that the balloon causes as little damage to the human blood vessels as possible during the recovery and withdrawal process.

[0071] Furthermore, in some embodiments of the present invention, the cone angle α1 on the first cone 121 and / or the cone angle α2 on the second cone 131 and the diameter d of the balloon 1 in the expanded state satisfy the following relationship: α1 = k1lnd + b1; wherein: k1∈[12, 20], and b1∈[9, 25.8], 5≤d≤16, and d is a positive integer; α2 = k2lnd + b2; wherein: k2∈[12, 20], and b2∈[9, 25.8], 5≤d≤16, and d is a positive integer. That is, the cone angle α1 on the first cone 121 and the cone angle α2 on the second cone 131 both satisfy the above relationship, and the cone angle α1 and / or α2 are set to meet the above range of values. In this way, within the range of the diameter of the balloon body and the corresponding cone angle of the first cone 121 and / or the second cone 131 in the balloon expansion state determined by the above relationship, not only can the problem of stent displacement or detachment and inaccurate positioning caused by the cone angle of the first cone 121 and / or the second cone 131 being too large or too small be avoided. Moreover, the size of the cone angle α1 and / or α2 within the above value range can also make the balloon and the corresponding stent system easier to recover after expansion, thereby making it have a smaller outline size in the compressed / recovered state, which is conducive to the delivery and withdrawal of the balloon and its stent system in the body, and also makes the balloon and its stent system cause less damage to human blood vessels during the delivery or withdrawal process in the body. In the above technical solution of the present invention, the numerical values ​​of α1 and α2 can be the same or different, so that the lengths of the first cone 121 and the second cone 131 formed can be the same or different, and can be selected according to different application requirements, with good flexibility.

[0072] After the stent is delivered to the diseased area, as the balloon expands, the stent system will be subject to the pressure of the blood vessels, the outward force of the fluid inside the balloon on the stent, and the friction in the opposite direction of the relative movement of the stent relative to the balloon. If the friction factor between the balloon and the stent is small, that is, the surface roughness of the balloon or the stent is small, then under the external combined force, the stent is easy to slide relative to the balloon, so that the stent cannot be accurately positioned in the diseased area. If the roughness of the balloon cone is high, the static friction between the cone and the bifurcated blood vessel wall can be appropriately increased, which is conducive to preventing the stent system from moving backward. Therefore, the present invention further combines the roughness of the balloon body and the cone surface to improve the positioning accuracy of the stent in the diseased area near the bifurcation.

[0073] In some embodiments, in order to improve the reliability of stent delivery, the roughness Ra of the surface of the capsule 11 is set to 0.03 μm-0.2 μm. Further, the roughness Ra of the surface of the capsule 11 can also be set to 0.05 μm-0.18 μm, and further, the roughness Ra of the surface of the capsule 11 can also be set to 0.08 μm-0.15 μm. The specific value of Ra can be selected according to actual use requirements. In this arrangement, since the stent is mainly pressed and gripped on the balloon body 11 for transportation, by setting the roughness Ra of the surface of the balloon body 11 within the above-mentioned range and coordinating it with the size of the cone angle of the balloon cone and the diameter d of the balloon body in the expanded state, when the stent system is pushed, there is a relatively appropriate maximum static friction force between the balloon and the stent, thereby effectively preventing the stent from shifting or falling off on the balloon body 11 during transportation or expansion, so that the stent can be accurately delivered to the target blood vessel position to improve the success rate of the operation; and it also avoids excessive roughness of the balloon surface, thereby increasing the difficulty and safety risks in the subsequent recovery and withdrawal process.

[0074] In some embodiments, the roughness Ra of the surface of the first cone 121 can also be set to 0.05 μm-0.2 μm. Further, the roughness Ra of the surface of the first cone 121 can also be set to 0.1 μm-0.2 μm, and further, the roughness Ra of the surface of the first cone 121 can also be set to 0.1 μm-0.18 μm. By setting the roughness of the balloon cone, especially the surface of the first cone 121, within the above range, the static friction between the branch vessel wall and the stent system can be effectively increased, thereby effectively preventing the stent from shifting forward or backward or detaching during the balloon expansion process, and avoiding the displacement of the stent during the balloon withdrawal process due to excessive roughness of the balloon surface, thereby further improving the positioning accuracy of the stent.

[0075] In some embodiments, the length L1 of the first cone 121 and / or the length L2 of the second cone 131 satisfy the following relationship: Among them, k∈[0.6, 2.1], where d refers to the diameter of the balloon in the expanded state, and k is the inner diameter of the distal end of the balloon. Figure 1In the above, "the length of L1" refers to the total length of the hypotenuse of the first cone 121 when the balloon 1 is in an expanded state; "the length of L2" refers to the total length of the hypotenuse of the second cone 131 when the balloon 1 is in an expanded state. The present invention sets the length of the balloon cone so that when the balloon 1 is expanded, the first cone 121 or the second cone 131 has sufficient deformation margin, the fluid is first rushed into the balloon cone and expands, and the middle part expands subsequently, and combined with the back pressure generated by the stent on the balloon body of the balloon 1 during the expansion process, in the process of the stent system expanding with the balloon, at least one portion whose height is higher than the outer surface of the balloon body 11 can be formed on the expanded first cone 121 or the second cone 131, so that it can play a limiting role, that is, the raised portion formed during expansion can limit the stent attached to the balloon body 11, and can avoid the problem of displacement caused by relative movement between the stent and the balloon 1 during the expansion of the cone, or even detachment from the balloon body 11. The present invention can further achieve precise positioning of the stent by controlling the lengths of the balloon cones L1 and L2, combined with the appropriate cone angle of the balloon.

[0076] Further, the length L1 of the first cone portion 121 and / or the length L2 of the second cone portion 131 satisfy the following relationship: Among them, k∈[0.6, 2.1], where d refers to the diameter of the balloon body in the balloon expansion state, and k is the inner diameter of the distal end of the balloon. In this way, the value range of L1 or L2 is set according to the above relationship, so that the length of the first cone 121 or the second cone 131 has a suitable setting range. Within this range, not only can the cone of the balloon form a convex surface relative to the balloon body during the balloon expansion process, thereby achieving a limiting effect on the stent and preventing the stent from moving or detaching relative to the balloon during the balloon expansion process, but also the cone length L1 and L2 can be prevented from being too large, so that the diameter of the cone in the gripping state is too large to be convenient for transportation, or it is not convenient for recovery and withdrawal after balloon expansion. At the same time, if the cone length L1 and L2 are too large, the positioning accuracy of the stent will be deteriorated to a certain extent. That is, the present invention can improve the accurate positioning of the stent through the reasonable design of the cone length of the balloon cone, and at the same time will not affect the transportation of the stent system or the recovery and withdrawal of the balloon.

[0077] like Figure 2As shown, in some embodiments, the first cone 121 and / or the second cone 131 include at least one protrusion 14, and at least a portion of the protrusion 14 has a distance D relative to the central axis of the balloon 1 that is 1.05-1.5 times the radius d / 2 of the balloon 1. That is, the protrusion 14 has at least a portion that is farthest from the central axis of the balloon, and the distance D between the farthest portion and the central axis of the balloon 1 is 1.05-1.5 times the radius d / 2 of the balloon 1. Further, at least a portion of the protrusion 14 has a distance D relative to the central axis of the balloon 1 that is 1.1-1.5 times the radius d / 2 of the balloon 1, and further, at least a portion of the protrusion 14 has a distance D relative to the central axis of the balloon 1 that is 1.15-1.5 times the radius d / 2 of the balloon 1. With such an arrangement, the highest part of the protrusion 14 formed after the balloon 1 is inflated is slightly higher than the outer surface of the balloon body 11, which can play a limiting role without hindering the delivery of the stent system in the blood vessel. As a result, the first cone 121 and / or the second cone 131 can have good smoothness and can be smoothly delivered in the blood vessel. At the same time, the protrusion 14 can also be used to limit the stent attached to the balloon 1, thereby reducing the possibility of displacement of the stent during the expansion of the balloon 1, thereby further improving the accuracy of stent positioning.

[0078] It should be noted that the "radius of the balloon" or "diameter of the balloon" in the present invention refers to the radius or diameter of the balloon body when the balloon is in an expanded state.

[0079] In some embodiments, a plurality of protrusions 14 are provided on the first cone 121 and / or the second cone 131. Each protrusion 14 can be provided circumferentially around the first cone 121 and / or the second cone 131 near one end of the capsule 11, and each protrusion 14 can be spaced or continuously distributed. When each protrusion 14 is continuously distributed, it can also be regarded as a circle of protrusions circumferentially provided on the first cone 121 and / or the second cone 131. In this way, the stent can be limited at various positions around the stent, thereby improving the reliability of the stent limiting effect. The present invention can avoid the relative movement of the stent on the balloon surface, and the number of protrusions and the size or area of ​​the protrusions are adjusted by combining the length of the balloon cone and the roughness of the respective surfaces of the balloon and the stent, so as to achieve a good limiting effect, thereby avoiding the relative movement of the stent and the balloon.

[0080] Specifically, in order to improve the effectiveness of the protrusion 14 in limiting the position of the stent, the horizontal distance between at least part of the protrusion 14 and the end adjacent to the capsule 11 can be set to be less than 2 mm. The "end adjacent to the capsule" refers to the part of the capsule 11 that is closest to the protrusion 14 in horizontal distance, that is, if the protrusion 14 is set on the first cone 121, it is the part of the capsule 11 that is used to connect with the first cone 121; if the protrusion 14 is set on the second cone 131, it is the part of the capsule 11 that is used to connect with the second cone 131. Since the stent is mainly attached to the capsule 11, by adopting this setting method, the position of the protrusion 14 can be closer to the capsule 11, so that when expanding, the protrusion 14 formed can limit the position of the stent in time, avoiding the problem that the stent has been partially displaced when the protrusion 14 contacts the stent due to the long distance between the protrusion 14 and the stent, thereby causing the stent to still have obvious positioning inaccuracy. The present invention limits the position between the protrusion 14 and the capsule 11, so that the position between the protrusion 14 and the stent is maintained within a suitable range, thereby improving the timeliness and effectiveness of the stent limitation by the protrusion 11.

[0081] In some embodiments, the total length of the protrusion 14 accounts for 5%-35% of the total length of the first cone 121 or the second cone 131. Further, the total length of the protrusion 14 accounts for 10%-30% of the total length of the first cone 121 or the second cone 131. The present invention achieves that the protrusion 14 formed on the first cone 121 or the second cone 131 will not affect the smoothness of the first cone 121 or the second cone 131 passing through the blood vessel due to being too large, nor will it affect the effectiveness of the stent limiting function due to being too small. Moreover, referring to Figure 3 , it is also possible to make the protrusion 14 or its tangent and the capsule 11 form a "V" shape 15 lying flat and with its opening facing the capsule. That is, a "V" shape 15 is formed between the protrusion 14 and the capsule 11; or a "V" shape 15 is formed between the tangent of the protrusion 14 facing one side of the capsule 11 and the capsule 11. One side of the "V" shape 15 formed by the two methods is horizontally arranged, flush with or parallel to one side of the capsule 11, and the other side is obliquely upward or obliquely downward toward the capsule 11, and the two sides together form a "V" shape 15 lying flat and with its opening facing the capsule. In this way, by forming the structure of the "V" shape 15, one end of the stent can be located in the structure of the "V" shape 15, so that the position of the stent can be limited. When the cone expands, the stent can be prevented from shifting or detaching, and has a reliable position limiting function.

[0082] Further, the angle of the formed "V" shape 15 is 30°-150°. Exemplary are 30°, 40°, 45°, 52°, 60°, 65°, 70°, 80°, 100°, 120°, 130°, 140° or 150°. Other values ​​between 30°-150° may also be used. Setting the angle of the "V" shape 15 within this value range can not only achieve the positioning of the stent, but also prevent the shape of the protrusion 14 from hindering the pushing of the cone in the blood vessel.

[0083] like Figure 4 As shown, in some embodiments, at least the first cone portion 121 is configured to include a stepped structure, and the stepped structure includes at least a first cone section 1211, a second cone section 1212, and a straight section 1213, the straight section 1213 is connected between the first cone section 1211 and the second cone section 1212, the other end of the first cone section 1211 is connected to the capsule 11, and the other end of the second cone section 1212 is connected to other objects (such as a push tube or an inner tube). The cone angle α3 of the first cone section 1211 is set between 30°-150°, the cone angle α4 of the second cone section 1212 is set between 40°-178°, and the diameter of the straight section 1213 is smaller than the diameter of the capsule 11. Specifically, the number of cone sections and straight sections on the stepped structure can be set according to actual design requirements, and the stepped structure includes at least two cone sections and one straight section, wherein the straight section is used to connect between two adjacent cone sections. For example, if a certain step structure has three cone sections, then there are two straight sections, and the three cone sections are arranged in sequence, and the two straight sections are respectively connected between two adjacent cone sections; and if another step structure has four cone sections, then there are three straight sections, and the four cone sections are arranged in sequence, and the three straight sections are respectively connected between two adjacent cone sections, and so on. The diameter size of the formed step structure decreases in the pushing direction, such as in the step structure with two straight sections, the diameter of the straight section closer to the capsule 11 is greater than the diameter of the straight section farther from the capsule 11. With this arrangement, since the cone angle of the first cone section 1211 is small, the stent is not likely to be relatively displaced on the balloon surface. At the same time, since the diameter of the straight section farthest from the balloon body 11 is small, even if it is placed in a branch vessel, the pressure of the branch vessel on the first cone section is difficult to cause the stent system to move backward as a whole. Therefore, when the balloon 1 is expanded, the first cone section 121 can be prevented from being squeezed by the branch vessel, causing the balloon 1 and the stent system to move in the proximal direction as a whole, thereby improving the accuracy of the stent positioning at the target vessel. In addition, this design can also reduce the outline size of the front end of the first cone section 121 after expansion, so that its diameter after expansion is significantly smaller than the diameter of the branch vessel, thereby effectively preventing the stent system from being significantly moved backward due to squeezing by the branch vessel during the expansion process, thereby improving the accuracy of the stent positioning.

[0084] Furthermore, in one embodiment, when the roughness Ra of the surface of the first cone 121 is set to 0.05μm-0.2μm, it may refer to the roughness of the surface of the entire stepped structure, or it may refer to the roughness of the surface of the portion of the stepped structure inserted into the branch blood vessel, so as to increase the friction with the branch blood vessel. When the balloon 1 is expanded, when there is a portion of the first cone 121 in contact with the branch blood vessel, due to the large friction coefficient between the portion of the first cone 121 in contact with the branch blood vessel, the stent system will not shift backward as a whole under the drive of the first cone 121, and will not push the balloon 1 and the stent to move backward as a whole, and the stent will not shift, so that the stent can be accurately positioned at the target blood vessel. Specifically, the roughness Ra of the surface of the first cone 121 can be any value in the above-mentioned value range, such as 0.05μm, 0.08μm, 0.10μm, 0.12μm, 0.15μm, 0.18μm or 0.20μm, etc., so as to meet the premise of not affecting the smooth pushing in the blood vessel and improving the friction between the branch blood vessels.

[0085] like Figure 4 As shown, when the stepped structure is set to have two cone sections and one straight section, the extension line of the second cone section 1212 intersects with the central axis of the balloon 1 to form an intersection E, and the opposite sides of the balloon body 11 are respectively connected to the intersection E, and the angle between the two connections is defined as the cone angle α1 of the first cone portion 121.

[0086] In another embodiment, when the first cone 121 is configured to include the above-mentioned first cone section 1211, the second cone section 1212 and the straight section 1213, and the protrusion 14 is also provided, the protrusion 14 can be arranged on the first cone section 1211 so that the position of the protrusion 14 and the balloon body 11 are closer, so that when the balloon 1 is expanded, the protrusion 14 can effectively limit the position of the stent to prevent the stent from shifting or falling off, thereby improving the accuracy of the stent positioning.

[0087] In some embodiments, the size of the cone angle α1 on the first cone 121 and / or the cone angle α2 of the second cone 131 and the size of the diameter d of the balloon in the expanded state satisfy the following relationship: α1=k1lnd+b1; wherein: k1∈[11.51, 21.52], and d∈[5, 9], b1∈[10.2, 21.4]; or k1∈[21, 27.87], and d∈[10, 16], b1∈[-11.6, 3.85]; α2=k2lnd+b2; wherein: k2∈[11.51, 21.52], and d∈[5, 9], b2∈[10.2, 21.4]; or k2∈[21, 27.87], and d∈[10, 16], b2∈[-11.6, 3.85]. In this way, balloons 1 of different specifications correspond to different ranges of cone angles. Within the corresponding range of cone angles, the stent used in combination can be accurately positioned in the lesion area without deviation, and the size of the formed cone can still meet the requirements of smooth pushing of the balloon 1 in the blood vessel.

[0088] Specifically, the greater the ratio of the wall thickness W1 of the capsule 11 to the diameter d of the capsule 11 in the expanded state, the higher the bursting pressure of the balloon 1; conversely, the smaller the ratio of the wall thickness W1 of the capsule 11 to the diameter d of the capsule 11 in the expanded state, the lower the bursting pressure of the balloon 1. Figure 1 As shown, the ratio of the wall thickness W1 of the balloon 11 to the diameter d of the balloon 11 in the expanded state is set to 0.0015-0.010. If the diameter d of the balloon 1 is 5mm, the unilateral wall thickness W1 of the balloon 11 is 0.0075mm-0.05mm, or if the diameter d of the balloon 1 is 10mm, the unilateral wall thickness W1 of the balloon 11 is 0.015mm-0.1mm. In this way, the relationship between the wall thickness of the balloon 11 and the balloon diameter size in the expanded state of the balloon 1 is maintained within a suitable value range, so that the balloon 1 can have a bursting pressure performance of a suitable size, and the diameter that can be expanded also meets the use requirements, and will not burst when it is not expanded to the required diameter. Under the design of the ratio of the wall thickness W1 to the diameter d, the balloon 1 can reliably realize the expansion of the stent to the rated diameter, and has a smaller outline size, which is more conducive to transportation in the blood vessel.

[0089] The balloon diameter d of the balloon 1 in the expanded state mainly refers to the maximum diameter that the balloon 11 can expand to. For example, if the balloon diameter of the balloon 1 in the expanded state is 5 mm, then the maximum diameter that the balloon 11 can expand to is 5 mm.

[0090] In some embodiments, the bursting pressure of the balloon 1 is adjusted according to the diameter of the balloon 1, and the bursting pressures of balloons 1 of different diameters may be the same or different. In the embodiment of the present invention, the diameter of the balloon 1 is in the range of 5 mm to 16 mm, and the bursting pressure of the capsule 11 is in the range of 10-30 atm (atm is a common unit for atmospheric pressure, and the value of 1 standard atmospheric pressure is recorded as 1 atm).

[0091] like Figure 1 As shown, in some embodiments, the cone angle α1 of the first cone 121 and the cone angle α2 of the second cone 131 are equal or unequal in value. When the cone angle α1 of the first cone 121 and the cone angle α2 of the second cone 131 are equal in value, the cone angles at both ends of the balloon 1 are equal, which is convenient for production and manufacturing. Moreover, when the balloon 1 is connected to other objects (such as a push tube), there is no need to distinguish the positions of the two ends, which is convenient for welding. When the cone angle α1 of the first cone 121 and the cone angle α2 of the second cone 131 are not equal in value, the angle value of the cone angle α2 of the second cone 131 can be set to be smaller than the angle value of the cone angle α1 of the first cone 121, such as the cone angle α1 of the first cone 121 is 50°, 60°, 65° or 75°, and the cone angle α1 of the second cone 131 corresponds to 28°, 34°, 40° or 45°. In this way, the head of the proximal body 13 is smaller, and when the balloon 1 is withdrawn from the body, the guiding effect is good, and the withdrawal of the balloon 1 is convenient. Of course, the angle value of the cone angle α2 of the second cone 131 can also be set to be greater than the angle value of the cone angle α1 of the first cone 121. At this time, the head of the second cone 131 in the contracted state is larger, and when a stent is attached to the balloon 1, it can play a role in positioning the stent to prevent the stent from shifting.

[0092] like Figures 5 to 8 As shown, the present invention also provides a balloon dilatation catheter 2, comprising a push tube 21, a balloon and a catheter seat 22. The push tube 21 comprises a guidewire cavity 211 for a guidewire to pass through and a filling cavity 212 for a medium to pass through. The guidewire cavity 211 and the filling cavity 212 are axially arranged in parallel and separated from each other by a partition 213. The balloon is the balloon 1 mentioned above, and the balloon 1 is connected to one end of the push tube 21. The inner cavity 10 (refer to Figure 1) is connected to the filling cavity 212; the catheter seat 22 is connected to the other end of the push tube 21, and the catheter seat 22 includes a first interface 221 and a second interface 222, the first interface 221 is connected to the guidewire cavity 211, and the second interface 222 is connected to the filling cavity 212. Specifically, the push tube 21 has at least two mutually isolated and unconnected cavities, usually including at least the guidewire cavity 211 and the filling cavity 212. Since the push tube 21 is made of a relatively soft material, when the balloon 1 is pushed into the body, it is necessary to insert a guidewire into the guidewire cavity 211. The guidewire is usually made of a relatively hard metal material to increase the relative hardness of the push tube 21, so that the balloon 1 can pass smoothly in the blood vessel. The filling cavity 212 is used to pass a medium such as gas or liquid into the inner cavity 10 of the balloon 1 through the filling cavity 212 after the balloon 1 is pushed to the corresponding part, so as to expand the balloon 1. The setting of the catheter seat 22 is used for holding during operation to facilitate the application of force for the corresponding surgical operation. The catheter seat 22 is correspondingly provided with a first interface 221 connected to the guidewire cavity 211 and a second interface 222 connected to the filling cavity 212. The openings of the first interface 221 and the second interface 222 are relatively large, which is convenient for inserting the guidewire through the first interface 221 to enter the guidewire cavity 211 and for passing the medium through the second interface 222 to inflate the balloon 1.

[0093] Specifically, due to the balloon 1 (reference Figure 1 ) needs to be sealed and connected to the outer surface of the push tube 21, usually by sleeve-mounting the end of the balloon 1 for connection on the push tube 21 for welding. Figures 5 to 7As shown, the distal body 12 is also provided with a distal connector 122, and the proximal body 13 is also provided with a proximal connector 132. Moreover, at least the proximal connector 132 is sealedly connected with the push tube 21 to form a first connection portion 130. In this way, the proximal connector 132 is a hollow structure, and the proximal connector 132 is sleeved on the push tube 21, and then the proximal connector 132 and the push tube 21 are sealedly connected by a method such as laser welding, and a first connection portion 130 is formed at the connection between the two, and the purpose of effective sealing connection is achieved through the formed first connection portion 130. At the same time, it is necessary to make the filling cavity 212 in the push tube 21 communicate with the inner cavity 10 of the balloon 1, so that the medium can be introduced into the inner cavity 10 of the balloon 1 through the filling cavity 212 or the medium can be extracted to achieve the expansion or retraction of the balloon 1. In the embodiment of the present invention, the first connection part 130 is formed between the proximal connector 132 and the push tube 21 by laser welding. The first connection part 130 is continuously distributed around the outer surface of the push tube 21 in the circumferential direction, and the sealing connection reliability is good. Moreover, the diameter of the highest position of the formed first connection part 130 is less than or equal to the diameter D3 of the proximal connector 132. That is, the first connection part 130 does not increase the diameter of the proximal connector 132, so that it will not become an obstacle point during intravascular delivery, and has good passability, which is conducive to intravascular delivery.

[0094] In other embodiments, the connection between the balloon 1 and the push tube 21 may also be: one end of the push tube 21 is inserted through the proximal connector 132, then passes through the inner cavity 10 of the balloon 1, and passes out through the distal connector 122. The connection between the proximal connector 132 and the distal connector 122 and the push tube 21 is sealed by laser welding, and the filling cavity 212 of the push tube 21 is connected to the inner cavity 10 of the balloon 1. The formed balloon dilatation catheter can also meet the requirements of the case where the blood vessel diameter is large and the distal body 12 can be inserted.

[0095] The balloon dilatation catheter 2 provided in the embodiment of the present invention uses the balloon 1 of the above structure. Since the first cone 121 of the balloon 1 is of appropriate length, the balloon dilatation catheter 2 is used to implant the stent into a narrow target blood vessel. During the balloon dilatation process, the stent will not be displaced or detached, and the stent can be accurately positioned at the target blood vessel, thereby improving the effectiveness and safety of the operation. At the same time, the balloon dilatation catheter 2 provided in the embodiment of the present invention is suitable for the delivery and expansion of any type of stent, including degradable stents and non-degradable stents, and the material types of the stent include but are not limited to iron-based, magnesium-based, zinc-based, polylactic acid, cobalt-chromium alloy, nickel-titanium alloy and other materials. That is, the balloon dilatation catheter 2 can be widely used and has a good market prospect.

[0096] In the embodiment of the present invention, since the balloon 1 needs to be of different sizes after expansion, such as a diameter of 5mm, 8mm or 14mm, etc., the sizes of the proximal joints 132 on the balloons 1 of different sizes are also different. In order to meet the reliable sealing connection between the balloon 1 and the push tube 21, the inner diameter of the proximal joint 132 is set to 1.78mm-2.2mm, and the gap between the push tube 21 and the proximal joint 132 is not greater than 0.2mm. Specifically, the gap between the proximal joint 132 and the push tube 21 needs to be maintained within a suitable range. A too large gap is not convenient for welding between the two, and poor welding (such as holes due to welding) is likely to occur, resulting in failure to seal the connection; while a too small gap is likely to cause the push tube 21 to be difficult to insert into the proximal joint 132 and the connection is prone to damage. Therefore, according to the gap requirements between the push tube 21 and the proximal joint 132, selecting a proximal joint 132 with a suitable inner diameter size is conducive to improving the effectiveness of the connection between the push tube 21 and the proximal joint 132.

[0097] like Figure 1 and Figure 6 As shown, in an embodiment of the present invention, the ratio of the wall thickness W3 of the proximal joint 132 to the wall thickness of the push tube 21 is 0.2-2.0. In other embodiments, the ratio of the wall thickness W3 of the proximal joint 132 to the wall thickness of the push tube 21 is 0.6-2.0. Specifically, since a guide wire cavity 211 and a filling cavity 212 are formed in the push tube 21, and during welding, the proximal joint 132 will be connected to the side wall of the guide wire cavity 211 and the side wall of the filling cavity 212 at the same time. Therefore, the wall thickness of the push tube 21 mentioned here refers to the smallest wall thickness value in the guide wire cavity 211 or the filling cavity 212. Both the proximal joint 132 and the push tube 21 need to have a certain wall thickness to ensure reliable welding. If the wall thickness of the proximal joint 132 or the pushing tube 21 is too small, welding cracks are likely to occur; and if the wall thickness of the proximal joint 132 or the pushing tube 21 is too large, it is easy for the first connection part 130 to form a bulge, causing the local diameter of the first connection part 130 to be too large, thus affecting the smoothness of pushing. Therefore, the ratio between the wall thickness W3 of the proximal joint 132 and the wall thickness of the pushing tube 21 is set within the above numerical range, so that the two can be reliably welded with good sealing, and the diameter size of the local first connection part 130 will not be enlarged, and the diameter size of the proximal joint 132 will not be increased. Exemplarily, the balloon 1 has specifications of different diameters, but the diameter of the push tube 21 connected to the balloon 1 remains consistent. For example, when welding the push tube 21 with a wall thickness of 0.08 mm, when the diameter of the balloon 1 is 5 mm, the corresponding wall thickness W3 of the proximal joint 132 is 0.05 mm, and when the diameter of the balloon 1 is 16 mm, the corresponding wall thickness W3 of the proximal joint 132 is 0.4 mm.

[0098] like Figure 5 and Figure 6 As shown, in an embodiment of the present invention, in order to improve the smoothness of the guidewire being inserted into the guidewire cavity 211 and pushed, the position of the first interface 221 set on the catheter seat 22 is maintained flush with the position of the guidewire cavity 211. Furthermore, the axis of the first interface 221 is made colinear with the axis of the guidewire cavity 211, so that the guidewire can smoothly pass through the first interface 221 and extend into the guidewire cavity 211, and can be smoothly pulled and slid in the guidewire cavity 211 without jamming, thereby improving the operability of the operation.

[0099] like Figures 5 to 7 As shown, in one embodiment, the balloon dilatation catheter 2 also includes an inner tube 23 and a developing ring 24. The inner tube 23 is a single-lumen structure, and the diameter of the inner tube 23 is smaller than the diameter of the push tube 21. Specifically, in order to allow a guide wire to be inserted into the distal body 12 so as to enhance the passability of the distal body 12 in the blood vessel through the guide wire, the inner tube 23 is provided, and the inner tube 23 is passed through the inner cavity 10 of the balloon 1, and one end of the inner tube 23 is connected to the push tube 21, and the other end of the inner tube 23 is connected to the distal joint 122. In this way, the guide wire can pass through the inner tube 23 without destroying the sealing of the inner cavity 10 of the balloon 1. Moreover, the diameter of the inner tube 23 is smaller than the diameter of the push tube 21, so that the inner tube 23 with a smaller diameter will not cause the overall outline size to be too large when the balloon is compressed, and the balloon 1 as a whole when it is not expanded has a smaller outline size as much as possible, so as to facilitate smooth pushing in the blood vessel.

[0100] Specifically, the developing ring 24 is arranged on the inner tube 23, and at least two developing rings 24 are usually arranged. The developing rings 24 are sleeved on the inner tube 23 at a preset distance interval, and are used to display the position of the balloon 1 in the body during surgery, so as to accurately position the balloon 1. The specific structure and material of the developing ring 24 adopt the existing conventional design, which will not be described in detail here.

[0101] like Figure 1 , Figure 5 and Figure 7As shown, in the embodiment of the present invention, the distal joint 122 is connected to the inner tube 23 to form a second connection portion 120, and the diameter of the second connection portion 120 is smaller than the diameter D2 of the distal joint 122. Specifically, the distal joint 122 is sleeved on the inner tube 23, and a sealed connection is achieved between the distal joint 122 and the inner tube 23 by laser welding or the like, thereby ensuring the sealing of the inner cavity 10 of the balloon 1. The distal joint 122 and the inner tube 23 are sealed to form the second connection portion 120, and the diameter of the second connection portion 120 is smaller than the diameter D2 of the distal joint 122. At the same time, the diameter D2 of the distal joint 122 itself is relatively small. Therefore, the second connection portion 120 formed does not additionally increase the diameter D2 size of the distal joint 122, so that when inserted into the body, the second connection portion 120 with a smaller diameter is more conducive to insertion and intravascular delivery. Specifically, the diameter of the second connecting portion 120 is 1.25 mm to 1.47 mm, and the diameter D2 of the distal joint 122 is 1.54 mm to 2.4 mm. The wall thickness of the distal joint 122 is usually the same as that of the proximal joint 132, thereby reducing the difficulty of production and processing.

[0102] Specifically, when the compressed stent is expanded by inflating the balloon 1, it is usually necessary to maintain a certain time after the expansion to stabilize the expansion effect, but the inflated balloon 1 is kept in close contact with the blood vessel wall, which is easy to cause the blood flow in the blood vessel to be blocked, and the blood flow blocking time is too long, which is easy to cause additional risks such as myocardial ischemia or myocardial infarction. Therefore, in the embodiment of the present invention, the ratio of the radial cross-sectional area of ​​the filling cavity 212 to the radial cross-sectional area of ​​the push tube 21 is set to 0.1-0.3. In this way, the filling cavity 212 has a larger radial cross-sectional area per unit area, thereby increasing the flow rate of the medium that can pass through the filling cavity 212 per unit time, and reducing the time required for the medium to be input into the balloon 1 and expand to the rated diameter and the time required for the medium to be extracted from the balloon 1. In this way, the time for the blood in the blood vessel to be blocked is shortened, which improves the safety of the operation; or the time for maintaining stable expansion after expansion is guaranteed, which is conducive to improving the stability of the stent expansion effect. In the embodiment of the present invention, according to the design requirements, the radial cross-sectional area of ​​the filling cavity 212 is 50 mm 2 -55 mm 2 The radial cross-sectional area of ​​the push tube 21 is 245 mm 2 -250 mm 2 In one embodiment, the radial cross-sectional area of ​​the filling chamber 212 is 53 mm 2 The radial cross-sectional area of ​​the push tube 21 is 248 mm 2 .

[0103] The above-mentioned “radial cross-sectional area of ​​the filling chamber 212” refers to the shape of the filling chamber 212 obtained along the axial direction perpendicular to the push tube 21, and the area of ​​the filling chamber 212 under this shape; the above-mentioned “radial cross-sectional area of ​​the push tube 21” refers to the cross-sectional shape obtained along the axial direction perpendicular to the push tube 21, and the area of ​​the entire cross-sectional shape.

[0104] like Figure 6 and Figure 8 As shown, in the embodiment of the present invention, the maximum width W4 of the filling chamber 212 along the radial direction of the push tube 21 is set to 0.3mm-0.55mm. Specifically, since the size of the filling chamber 212 in the radial direction is increased when the area of ​​the filling chamber 212 is constant, the diameter of the entire push tube 21 becomes larger. Therefore, in order to reduce the diameter of the push tube 21 and make the filling chamber 212 have the largest possible area, the maximum width W4 of the filling chamber 212 along the radial direction is set between 0.3mm-0.55mm, and the filling chamber 212 has the largest possible area while meeting the use strength requirements. In addition, the shape of the filling chamber 212 can be set as follows Figure 8 The "crescent" shape shown in the figure becomes a part of the filling cavity 212 by utilizing the area between the filling cavity 212 and the guide wire cavity 211, and fully utilizes the internal area of ​​the pushing tube 21 to increase the area of ​​the filling cavity 212, thereby achieving an increase in the inflation speed of the balloon 1 and a reduction in the time required for the balloon 1 to deflate.

[0105] like Figure 5 and Figure 7 As shown, in the embodiment of the present invention, the balloon dilatation catheter 2 also includes a guide tube 25. The guide tube 25 is arranged in front of the distal body 12 along the pushing direction of the pushing tube 21 and is connected to the inner tube 23. The guide tube 25 is made of a material with good flexibility, and is soft and easy to bend as a whole. The guide tube 25 is arranged at the front of the pushing direction. Therefore, it can not only play a guiding role, but also the good softness will not damage the blood vessel. Usually, the radial cross-section of the guide tube 25 is circular. In order to make the guide tube 25 have good guiding performance, the ratio of the diameter of the front end of the guide tube 25 to the diameter of the front end of the second connecting part 120 is set to 0.75-0.94. The diameter of the front end of the guide tube 25 refers to the diameter at the front end of the guide tube 25, and the diameter of the front end of the second connecting part 120 refers to the diameter at the front end of the second connecting part 120 in the direction of the guide tube 25. In this way, along the pushing direction, the diameter of the front end of the guide tube 25 is the smallest, and is not greater than the diameter at the front end of the second connecting part 120. Therefore, toward the pushing direction, the overall shape of the guide tube 25 is gradually reduced, which is conducive to the guidance during pushing.

[0106] like Figures 5 to 8As shown, in some embodiments, the partition 213 used to separate the guidewire cavity 211 and the filling cavity 212 is set as a diaphragm, and the thickness W5 of the diaphragm is set to 0.10mm-0.14mm. The material of the diaphragm is the same as the material of the push tube 21, and is formed synchronously when the guidewire cavity 211 and the filling cavity 212 are formed. In an embodiment of the present invention, the thickness W5 of the diaphragm is set between 0.10mm and 0.14mm, such as 0.1mm or 0.12mm or 0.134mm or 0.14mm. The diaphragm within this thickness range has a strength that not only satisfies the requirement that it will not be punctured when the guidewire is inserted, but also will not burst the diaphragm when a medium with a certain pressure is input into the filling cavity 212. At the same time, the diaphragm within this thickness range will not cause the area of ​​the guidewire cavity 211 or the filling cavity 212 to be reduced.

[0107] like Figure 8 As shown, in some embodiments, the minimum wall thickness W6 of the guidewire cavity 211 is 0.08mm-0.12mm, and / or the minimum wall thickness W7 of the filling cavity 212 is 0.08mm-0.15mm. For example, in some embodiments, the minimum wall thickness W6 of the guidewire cavity 211 is 0.08mm, and the minimum wall thickness W7 of the filling cavity 212 is 0.11mm, or in other embodiments, the minimum wall thickness W6 of the guidewire cavity 211 is 0.11mm, and the minimum wall thickness W7 of the filling cavity 212 is 0.13mm. Of course, in other embodiments, the minimum wall thickness W6 of the guidewire cavity 211 can also be other arbitrary values ​​between 0.08mm-0.12mm, and the minimum wall thickness W7 of the filling cavity 212 can also be other arbitrary values ​​between 0.08mm-0.15mm. In this way, the wall thickness of the guidewire cavity 211 and the filling cavity 212 are respectively set within this range. Under the premise of ensuring the strength requirement for use, the filling cavity 212 and the guidewire cavity 211 can have a sufficiently large cross-sectional area as much as possible to ensure smooth pushing of the guidewire and improve the efficiency of inflation or decompression of the balloon 1.

[0108] In an embodiment of the present invention, a stent system is also provided, comprising a stent and the above-mentioned balloon dilatation catheter 2, wherein the stent is sleeved on the balloon 1 of the balloon dilatation catheter 2. The stent comprises a degradable stent and a non-degradable stent, and the material types of the stent include, but are not limited to, iron-based, magnesium-based, zinc-based, polylactic acid, cobalt-chromium alloy, nickel-titanium alloy and the like. The balloon dilatation catheter 2 is used to deliver the stent to the target blood vessel, so as to achieve the expansion of the narrowed target blood vessel through the stent. Specifically, the stent is pre-pressed on the balloon 1 in a contracted state in an unexpanded state, and the end of the balloon dilatation catheter 2 having the balloon 1 is inserted into the blood vessel, and pushed to the target blood vessel, and then the stent is expanded by inflating the balloon 1, and the purpose of expanding the target blood vessel is achieved under the support provided by the stent. The balloon dilatation catheter 2 can accurately deliver the stent to the target blood vessel, and when the balloon 1 is expanded, the stent will not be displaced or fall off the balloon 1, so that the stent can be accurately positioned at the target blood vessel, thereby improving the effect of the stent system for stent implantation surgery.

[0109] Specifically, the roughness Ra of the inner surface of the stent is 0.05 μm-0.4 μm; the maximum static friction force on the balloon surface in the stent system is 2.8 N-7.9 N. Here, the roughness of the inner surface of the stent refers to the roughness of the inner surface and / or outer surface of the stent; the maximum static friction force on the balloon surface in the stent system refers to the maximum static friction force on the balloon surface in the final expansion state of the stent system.

[0110] This arrangement ensures that the surface finish of the stent is within an appropriate range, and neither the surface of the balloon 1 is scratched or punctured due to excessively high roughness of the inner surface of the stent, nor the inner wall of the blood vessel is injured due to excessively high roughness of the outer surface of the stent, nor relative sliding between the stent and the balloon 1 or between the stent and the blood vessel wall during the expansion process of the stent system due to excessively low roughness of the inner surface of the stent. That is, the present invention further improves the accuracy of positioning the stent in the lesion area near the bifurcation of the blood vessel by controlling the roughness of the inner and outer surfaces of the stent. Furthermore, the maximum static friction between the stent and the surface of the balloon 1 in the stent system is set between 2.8N and 7.9N. Thus, the stent system has suitable anti-slip properties while being able to move smoothly in the blood vessel, so that the stent after being pressed and gripped can be reliably attached to the balloon 1 without loosening. Therefore, when pushing, there will be no relative movement between the stent and the balloon 1, and the stent will not shift or fall off on the balloon 1, ensuring that the stent can be accurately pushed to the target blood vessel. When the stent system is expanded by the balloon, there will be no relative sliding between the stent and the balloon due to the force of the branch blood vessels, thereby avoiding additional surgical risks caused by stent displacement or falling off, and improving the safety of the operation.

[0111] The balloon and the stent system prepared by the balloon dilatation catheter in the present invention can be expanded from the proximal end to the balloon body to the distal end after the stent is delivered to the target bifurcation vascular lesion area. The balloon can be expanded from the proximal end to the balloon body to the distal end, or from the distal end to the balloon body to the proximal end, or first to the balloon body and then to the two ends. Furthermore, the present invention preferably expands the balloon body first and then expands the proximal end and the distal end. By adopting this method, the positioning accuracy of the stent can be improved.

[0112] It should be noted that the "length of the shoulder of the first cone portion 121" in the present invention refers to the length of the shortest line segment formed by the two farthest endpoints of the first cone portion 121; the "length of the first cone portion 121" in the present invention refers to the actual length of the cone portion. Since the cone portion may be uneven or have arc segments, etc., the length of the first cone portion 121 in the present invention should actually be greater than or equal to the length of the shoulder of the first cone portion 121.

[0113] In the present invention, the deviation between the final position of the stent after implantation in the vascular lesion area and the target position before implantation is used to measure the accuracy of stent positioning. For example, if the target position of the stent before implantation corresponds to the segment corresponding to the two points a and b of the lesion vessel, and the final position of the stent after actual implantation is the lesion vessel segment located by the two points a' and b', then the deviation between the position of the stent after implantation and the position before implantation is the distance d between the two points a and a'. 偏离 . General bracket | d 偏离 |The smaller it is, the higher the positioning accuracy of the bracket is, d 偏离 >0 means the stent has shifted to the distal end, d 偏离 <0 indicates that the stent has shifted toward the proximal end. 偏离 | is used to measure the accuracy of the stent positioning. Generally, the stent is displaced within ±3mm, that is, |d 偏离 |≤3 can meet the demand for bracket positioning accuracy to a certain extent.

[0114] The "maximum static friction force" of the balloon surface of the stent system in the present invention refers to the maximum friction force that the stent is subjected to before relative movement occurs between the stent and the balloon, that is, the magnitude of the friction force that the stent is subjected to when it is in a critical state of being about to move relative to the balloon. The maximum static friction force is not only related to the roughness of the inner surface of the stent and the roughness of the outer surface of the balloon, but also closely related to factors such as the structure of the stent, the weight of the stent, the gripping method of the stent system, the balloon expansion method, and the shoulder length or cone length of the balloon cone.

[0115] The "embrace diameter ratio" mentioned in the present invention refers to the ratio of the diameter of the balloon after the stent is released and recovered to the diameter of the balloon in the folded state before the stent is pressed and gripped. The smaller the ratio, the better the balloon is recovered and the easier it is to withdraw, and vice versa. The diameter of the balloon after the stent is released and recovered in the present invention also refers to the embrace diameter of the balloon, which is the distance between the two farthest points on the cross section of the balloon after recovery. DETAILED DESCRIPTION

[0117] In order to facilitate the understanding of the present invention, the design points of the present invention are explained in combination with some specific embodiments below. It can be understood that the relevant embodiments are only some examples of the scheme of the present invention and do not constitute a limitation on the scope of application. That is, what is described below are only some preferred embodiments of the present invention, and the protection of the present invention is not limited to the following preferred embodiments. For example, in order to facilitate understanding, the embodiments of the present invention are all explained using balloon dilatation catheters with the following structure, but it does not mean that the technical scheme of the present invention is only applicable to balloon dilatation catheters with the following structure. It should be pointed out that for those skilled in the art, several deformations and improvements made on the basis of this invention concept all belong to the protection scope of the present invention. The parts used without indicating the manufacturer are all conventional products that can be purchased commercially. The basic structure of the balloon catheter used in the embodiments of the present invention is as follows:

[0118] The balloon dilatation catheter of the present invention includes a push tube, a balloon, a catheter seat, an inner tube, a developing ring and a guide tube. The balloon includes a balloon body and a distal body and a proximal body respectively connected to the two ends of the balloon body, the distal body includes a first cone, and the proximal body includes a second cone; the push tube includes a guide wire cavity and a filling cavity, the proximal body is sleeved on one end of the push tube and connected, the filling cavity is connected to the inner cavity of the balloon, and the catheter seat is connected to the other end of the push tube; the inner tube is inserted into the inner cavity of the balloon, one end of the inner tube is connected to the push tube, and the distal body is sleeved on the other end of the inner tube and connected; the guide tube is arranged in front of the distal body and connected to the inner tube; if the balloon has a developing ring, it is mainly arranged on the inner tube.

[0119] Test method:

[0120] 1. Roughness Ra

[0121] The average roughness Ra defines the average distance from the measurement point on the surface to the average center line of the measured object. The center line intersects the actual contour within the reference distance so that the sum of the contour deviations (relative to the center line) becomes minimum. Therefore, the average roughness Ra corresponds to the arithmetic mean of the deviations from the center line. The present invention measures the roughness of the surface of the stent or balloon with the aid of an optical measuring device and with reference to the ISO25178 standard. For example, with the aid of Keyence's optical microscope VHX100, which has software-supported 3D surface analysis and a resolution of 54M pixels, and is combined with a Zeiss optical magnification lens with a maximum magnification of 2500×. The software allows a virtual section through the surface and calculates the average roughness depth of the measurement area.

[0122] 2. Maximum static friction

[0123] The present invention adopts the following method to measure the maximum static friction force on the balloon surface of the stent system in the expanded state:

[0124] First, simulate the use of the stent in a curved anatomical model in a 37±2℃ water bath environment, and mark the stent in advance. After the simulated use, observe whether the stent is displaced. Then, use adhesive tape to pull the stent off, and use a universal test tensile machine to test. Set the test rate to 50.8mm / min and the gauge length L=15mm to measure the removal force.

[0125] 3. Diameter and other parameters

[0126] In the present invention, the measurements of various parameters such as diameters of the stent, stent system, and support member are all obtained by using a non-contact measuring instrument.

[0127] 4. Accuracy of stent positioning in bifurcation lesions

[0128] The present invention adopts a method to determine the reference point in DSA angiography, and determines the two end points a and b of the diseased blood vessel corresponding to the target implantation position of the stent according to the reference point. After the stent is implanted in the blood vessel, the corresponding points of the two end points a' and b' after the stent is actually implanted are determined by the same reference system method, and then the distance between point a and point a' or between point b and point b' can be obtained. 偏离 |, thereby determining the accuracy of stent positioning in the bifurcation vessel lesion area.

[0129] 5. Balloon embrace diameter ratio N 回抱

[0130] First measure the diameter d of the balloon in the folded state before pressing and gripping the stent. 压握前 , and then measure the diameter d after the balloon releases the stent and recovers it in a simulated environment 回收 , the comparison between the two can get the diameter ratio of the balloon back embrace, that is:

[0131] N 回抱 =d 回收 / d 压握前 .

[0132] 6. Explosion pressure

[0133] The balloon bursting pressure in the present invention is mainly measured with reference to Appendix A of the standard "YY / T0285.4-2017-Intravascular Catheter Disposable Sterile Catheter Part 4 Balloon Dilatation Catheter". The specific operation method is to immerse the balloon in 37±2°C water for 2 minutes, then use a water pressure tester or a balloon pressure pump to inflate the balloon at a fixed rate until it ruptures, and finally measure the corresponding pressure value.

[0134] 7. Pressure relief time

[0135] The balloon decompression time in the present invention is mainly measured with reference to Appendix D of the standard "YY / T0285.4-2017-Intravascular Catheter Disposable Sterile Catheter Part 4 Balloon Dilatation Catheter". The specific operation method is to use a balloon pressure pump to fill the balloon to RBP in a 37±2℃ water bath, maintain the pressure for 30 seconds, and then release the pressure until the balloon is deflated. The time from the start of decompression to the balloon deflation is recorded.

[0136] Examples 1-16

[0137] This group of embodiments provides the rated diameter d of the balloon of each embodiment, the inner diameter value k of the distal end of the balloon, the cone angle α1 of the first cone, the length L1 of the first cone, the cone angle α2 of the second cone, the length L2 of the second cone, and the roughness Ra of the balloon surface. 囊体 , the roughness of the first cone surface Ra 锥部 , the roughness of the inner surface of the bracket Ra 支内 , the roughness of the outer surface of the bracket Ra 支外 , the maximum static friction force f on the balloon surface in the stent system max The stent system loaded by the balloon dilatation catheter with the above specific characteristics was implanted into the bifurcation vessel lesion of the pulmonary artery of the dog, and the measurement parameter of the positioning accuracy of the stent in the bifurcation vessel lesion of the pulmonary artery of the dog in each embodiment was measured according to the above test method. 偏离 |Ratio of the diameter of the balloon to the embrace diameter N 回抱 The specific parameters of each embodiment are as follows (see Table 1):

[0138] Table 1 Specific design parameters of the balloons in each embodiment from Example 1 to Example 16, and performance characterization parameters of the balloon dilatation catheters having these design features

[0139]

[0140] Embodiment 17

[0141] This embodiment is based on the embodiment 3, and a protrusion is provided on the first cone. The distance between the highest part of the protrusion and the central axis of the balloon is 5.0 mm, and the horizontal distance between the highest part of the protrusion and the adjacent end of the balloon body is 1.5 mm. The total length of the protrusion accounts for 10% of the total length of the first cone. The protrusion and the balloon body form a "V" shape lying flat with the opening facing the balloon body, and the angle of the "V" shape is 150°. The positioning accuracy of the stent at the bifurcation vascular lesion of the dog's pulmonary artery |d 偏离 | is 0.35mm, and the balloon's embrace diameter ratio is 2.21.

[0142] Embodiment 18

[0143] This embodiment is based on the embodiment 3, and a protrusion is provided on the first cone. The distance between the highest part of the protrusion and the central axis of the balloon is 9.0 mm, and the horizontal distance between the highest part of the protrusion and the adjacent end of the balloon body is 1.2 mm. The total length of the protrusion accounts for 35% of the total length of the first cone. The protrusion and the balloon body form a "V" shape lying flat with the opening facing the balloon body, and the angle of the "V" shape is 30°. The positioning accuracy of the stent at the bifurcation vascular lesion of the dog's pulmonary artery |d 偏离 | is 0.38mm, and the balloon's embrace diameter ratio is 2.24.

[0144] Examples 19-25

[0145] For the sake of convenience, the present invention adds the relevant parameters of the balloon dilatation catheter on the basis of Example 12 to further illustrate the influence of the various parameters of the balloon dilatation catheter on its related performance, but it does not mean that the parameters of the balloon dilatation catheter have any limiting effect on the parameters of the balloon. Here, the parameters of the balloon and the parameters of the balloon dilatation catheter are independent and do not affect each other. In each embodiment, the inner diameter D of the proximal connector is mainly limited. 近内 , the gap G between the push tube and the proximal joint, the wall thickness W3 of the proximal joint and its thickness W of the push tube 推 The ratio N 壁厚 , the ratio of the radial cross-sectional area of ​​the filling cavity to the radial cross-sectional area of ​​the push tube is S 径 , the maximum width of the filling cavity in the radial direction W 充max , the minimum wall thickness of the guidewire lumen W 导min , the minimum wall thickness W of the filling cavity 充min , the diameter of the front end of the guide tube d 引 and the diameter ratio N of the second connecting part 引直 , and the performance characterization parameters of the balloon dilatation catheter with specific structural features corresponding to each embodiment, such as the pressure relief time T, the balloon bursting pressure Pa, and the profile of the balloon after compression and gripping. The specific parameters of each embodiment are as follows (see Table 2):

[0146] Table 2 Specific design parameters of the balloon and balloon dilatation catheter in each embodiment from Example 19 to Example 25, and performance characterization parameters of the balloon dilatation catheter with these design features

[0147]

[0148] The stent is implanted in the bifurcated vascular lesion of the dog's pulmonary artery by using the balloon dilatation catheter in the above-mentioned embodiments. During the operation, the guide wire can be flexibly pulled in the guide wire cavity, and the guide tube can be smoothly inserted into the blood vessel to guide the balloon into the blood vessel smoothly. In the process of pushing the balloon in the blood vessel, the stent is accurately pushed to the narrow target blood vessel. After the medium is introduced into the filling cavity, the balloon expands smoothly and stretches the stent to the rated diameter. The balloon expands for a period of time without rupture. After that, the balloon completes pressure relief within a certain period of time. After the pressure relief, the process of pulling the balloon out of the body is smooth, and the stent is accurately released at the target blood vessel. At the same time, it can be seen that the narrow target blood vessel is effectively stretched by the stent, meeting the surgical expectations.

[0149] In order to further illustrate the technical effect of the balloon dilatation catheter proposed in the embodiment of the present invention, an exemplary description is now given to supplement the comparative example.

[0150] Comparative Example 1

[0151] The design of the balloon dilatation catheter in this embodiment is basically the same as that in Embodiment 1, except that the cone angle α1 of the first cone on the distal body 12 of the balloon 1 is 10°, the length of the first cone shoulder of the distal body 12 is 20 mm, and the length L1 of the first cone is 30 mm.

[0152] When the balloon dilatation catheter is used to implant a stent in the dog's pulmonary artery, the guidewire can be smoothly inserted into the guidewire cavity 211 and can be flexibly pulled and moved, and the balloon 1 can be smoothly inserted into the body and smoothly pushed in the blood vessel. However, when it is pushed to the lesion area at the bifurcated blood vessel, after the medium is introduced into the filling cavity 212, the balloon 1 can be smoothly expanded to the rated diameter. However, during the dilatation process, under the action of the branch blood vessel, the balloon and the stent move backward together, eventually resulting in|d 偏离 |It reached 4.5mm, the stent was not positioned accurately and did not completely cover the lesion area.

[0153] Comparative Example 2

[0154] The design of the balloon dilatation catheter in this embodiment is basically the same as that in Embodiment 3, except that the cone angle α1 of the first cone on the distal body 12 of the balloon 1 is 120°, and the cone of the distal body 12 is steeper.

[0155] When the balloon dilatation catheter is used to implant a stent in the dog's pulmonary artery, the guidewire can be smoothly inserted into the guidewire cavity 211 and can be pulled and moved flexibly. However, due to the steep cone of the distal body 12, it is difficult to insert the balloon 1 into the body, and the insertion port needs to be enlarged. The process of pushing it into the blood vessel is also relatively slow. In the process of pushing it to the stenotic lesion of the branch vessel, the distal body 12 did not cause damage to the surrounding branch vessels. However, due to the large cone angle α1 of the first cone, the stent moved forward relative to the balloon during the balloon expansion process, which ultimately resulted in |d 偏离 |It reached 4.8mm, the stent was not positioned accurately and did not completely cover the lesion area.

[0156] Comparative Example 3

[0157] The design of the balloon dilatation catheter in this embodiment is basically the same as that in embodiment 21, except that the radial cross-sectional area of ​​the filling cavity 212 is smaller than the radial cross-sectional area of ​​the pushing tube 21. 径 is 0.1.

[0158] When the balloon dilatation catheter is used to implant a stent in the dog's pulmonary artery, the guide wire can be smoothly inserted into the guide wire cavity 211 and can be flexibly pulled and moved. The balloon 1 can be smoothly inserted into the body and pushed to the stenotic lesion of the branch blood vessel. The distal body 12 does not cause damage to the surrounding branch blood vessels. After the medium is introduced into the filling cavity 212, the balloon 1 can be smoothly expanded to the rated diameter and the narrow blood vessel is stretched open, but the time required for expansion is relatively long. The balloon 1 is expanded for a period of time without rupture. Afterwards, the balloon 1 completes the pressure relief within 25 seconds, and the time required for pressure relief is also relatively long, resulting in a long time for the blood flow in the blood vessel to be blocked, posing a safety hazard. Afterwards, the process of extracting the balloon 1 from the body is smooth, and it can be seen that the narrow blood vessel is effectively stretched open.

[0159] It can be seen from the data of the above embodiments and comparative examples that by setting the taper of a balloon of a certain diameter within a certain range, the positioning accuracy of the stent can be significantly improved. In addition, by optimizing the length L of the stent cone, the roughness of the surfaces of the balloon and the stent, the maximum static friction between the balloon and the stent, and setting a protrusion on the balloon cone, the positioning accuracy of the stent can be improved to a certain extent. In particular, when various parameters are combined, the accuracy of the stent at the bifurcated vessel lesions can be significantly improved. That is, the present invention does not need to add other structures to improve the positioning accuracy of the stent at the bifurcated vessel lesions, and the preparation of the balloon and stent delivery system is simple and the production cost is low. At the same time, there is no need to sacrifice the profile of the stent system in exchange for the accuracy of the stent positioning, which provides an excellent technical solution for the implantation of stents at bifurcated vessel lesions.

[0160] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A balloon, characterized in that: The balloon comprises a balloon body and a distal body and a proximal body respectively connected to both ends of the balloon body, the balloon body, the distal body and the proximal body are combined to form an inner cavity, the inner cavity is used to accommodate a medium for expanding the balloon, the distal body comprises a first cone portion, the proximal body comprises a second cone portion, at least the cone angle α1 of the first cone portion and the diameter d of the balloon body in the expanded state of the balloon satisfy the following relationship: α1=k1lnd+b1; Among them: k1∈[11, 42.421], and b1∈[6.8, 31.8], 5≤d≤16, and d is a positive integer.

2. The balloon according to claim 1, characterized in that The balloon comprises a balloon body and a distal body and a proximal body respectively connected to both ends of the balloon body, the balloon body, the distal body and the proximal body are combined to form an inner cavity, the inner cavity is used to accommodate a medium for expanding the balloon, the distal body comprises a first cone portion, the proximal body comprises a second cone portion, at least the cone angle α1 of the first cone portion and the diameter d of the balloon body in the expanded state of the balloon satisfy the following relationship: α1=k1lnd+b1; Among them: k1∈[11.009, 27.4], and b1∈[7.98, 14.2], 5≤d≤16, and d is a positive integer.

3. The balloon according to claim 1, wherein: The size of the cone angle α1 of the first cone portion and / or the cone angle α2 of the second cone portion and the size of the diameter d of the balloon body in the expanded state of the balloon satisfy the following relationship: α1=k1lnd+b1; Where: k1∈[12, 20], and b1∈[9, 25.8], 5≤d≤16, and d is a positive integer; α2=k2lnd+b2;wherein: k2∈[12,20], and b2∈[9,25.8], 5≤d≤16, and d is a positive integer; The roughness Ra of the capsule surface is 0.03 μm-0.2 μm, and the roughness Ra of the first cone surface is 0.05 μm-0.2 μm.

4. The balloon according to claim 1, wherein: The length L1 of the first cone portion and / or the length L2 of the second cone portion satisfy the following relationship: Where k∈[0.6, 2.1].

5. The balloon according to claim 1, characterized in that: The length L1 of the first cone portion and / or the length L2 of the second cone portion satisfy the following relationship: Where k∈[0.6, 2.1].

6. The balloon according to claim 1, characterized in that The first cone portion and / or the second cone portion comprises at least one protrusion, and a distance D of at least a portion of the protrusion relative to the central axis of the balloon is 1.05-1.5 times of the balloon radius d / 2.

7. The balloon according to claim 6, characterized in that The horizontal distance between at least part of the protrusion and the adjacent end of the capsule is less than 2 mm; the total length of the protrusion accounts for 5%-35% of the total length of the first cone or the second cone; the protrusion or its tangent forms a "V" shape lying flat with the opening facing the capsule.

8. The balloon according to claim 7, characterized in that The included angle of the "V" shape is 30°-150°.

9. The balloon according to claim 1, wherein: At least the first cone portion includes a stepped structure, the stepped structure includes at least a first cone segment, a second cone segment and a straight segment, the straight segment is connected between the first cone segment and the second cone segment, and the other end of the first cone segment is connected to the capsule; The cone angle α3 of the first cone section is 30°-150°, the cone angle α4 of the second cone section is 40°-178°, and the diameter of the straight section is smaller than the diameter of the capsule.

10. The balloon according to claim 1, wherein: The taper angle α1 of the first taper portion and the taper angle α2 of the second taper portion satisfy the following relationship with the diameter d of the balloon in the expanded state: α1=k1lnd+b1; where: k1∈[11.51,21.52], d∈[5,9], b1∈[10.2,21.4]; or k1∈[21, 27.87], and d∈[10,16], b1∈[-11.6,3.85]; α2=k2lnd+b2;where: k2∈[11.51,21.52],d∈[5,9],b2∈[10.2,21.4];or k2∈[21, 27.87], and d∈[10,16], b2∈[-11.6,3.85].

11. The balloon according to any one of claims 1 to 10, characterized in that: The ratio of the wall thickness of the balloon to the diameter of the balloon in the expanded state is 0.0015-0.

010.

12. A balloon dilatation catheter, characterized in that: include: The push tube comprises a guidewire cavity for the guidewire to pass through and a filling cavity for the medium to pass through, wherein the guidewire cavity and the filling cavity are axially arranged in parallel and isolated from each other by a partition; A balloon, which is the balloon according to any one of claims 1 to 11, wherein the balloon is connected to one end of the push tube, and the inner cavity of the balloon is connected to the filling cavity; A catheter seat connected to the other end of the push tube, the catheter seat comprising a first interface and a second interface, the first interface being communicated with the guidewire cavity, and the second interface being communicated with the filling cavity; Wherein, the distal body also includes a distal joint, and the proximal body also includes a proximal joint. At least the proximal joint and the push tube are sealed to form a first connecting part, and the diameter of the first connecting part is less than or equal to the diameter of the proximal joint.

13. The balloon dilatation catheter according to claim 12, characterized in that: The inner diameter of the proximal joint is 1.78 mm-2.2 mm, the gap between the push tube and the proximal joint is no more than 0.2 mm, and the ratio of the wall thickness of the proximal joint to the wall thickness of the push tube is 0.2-2.

0.

14. The balloon dilatation catheter according to claim 12, characterized in that: The ratio of the radial cross-sectional area of ​​the filling cavity to the radial cross-sectional area of ​​the pushing tube is 0.1-0.3, or along the radial direction of the pushing tube, the maximum width of the filling cavity is 0.3mm-0.55mm.

15. The balloon dilatation catheter according to claim 12, characterized in that: The balloon dilatation catheter also includes: An inner tube is inserted into the inner cavity of the balloon, one end of the inner tube is connected to the push tube, and the other end of the inner tube is connected to the distal connector; A developing ring, arranged on the inner tube; Wherein, the guide wire cavity is communicated with the inner tube, and the diameter of the inner tube is smaller than the diameter of the push tube.

16. The balloon dilatation catheter according to claim 15, characterized in that: The distal end joint is connected to the inner tube to form a second connection portion, and the diameter of the second connection portion is smaller than the diameter of the distal end joint.

17. The balloon dilatation catheter according to claim 16, characterized in that: The balloon dilatation catheter also includes: A guide tube, arranged in front of the distal body along the pushing direction of the pushing tube, and connected to the inner tube; Wherein, the ratio of the diameter of the front end of the guide tube to the diameter of the front end of the second connecting part is 0.75-0.

94.

18. The balloon dilatation catheter according to any one of claims 12 to 17, characterized in that: The minimum wall thickness of the guidewire cavity is 0.08 mm to 0.12 mm; and / or the minimum wall thickness of the filling cavity is 0.08 mm to 0.15 mm.

19. A stent system, comprising a stent and the balloon dilatation catheter according to any one of claims 12 to 18, wherein the stent is sleeved on a balloon of the balloon dilatation catheter.

20. The support system according to claim 19, wherein: The roughness Ra of the inner surface of the stent is 0.05 μm-0.4 μm; the maximum static friction force on the surface of the balloon in the stent system is 2.8N-7.9N.

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