Balloon, balloon dilatation catheter and stent system

Abstract

The application provides a balloon, a balloon dilatation catheter and a stent system, in particular a balloon, a balloon dilatation catheter and a stent system suitable for bifurcated vascular lesion area. The balloon comprises a balloon body, a distal end body and a proximal end body, the distal end body comprises a first taper part, and the proximal end body comprises a second taper part, at least the taper angle alpha1 of the first taper part satisfies the following relationship with the diameter d in the balloon dilatation state: alpha1=k1*ln(d)+b1; wherein k1 is in the range of 11.009 to 21.478, b1 is in the range of 7.98 to 20.8, 5<=d<=16, and d is a positive integer. The balloon dilatation catheter comprises the balloon, a push tube and a catheter seat. The application improves and optimizes the structure of the balloon itself, and provides a balloon, a balloon dilatation catheter and a stent system which are simple in structure, easy to produce and realize industrialization, low in cost, easy to operate in clinic, can accurately release and position the stent, and thus greatly improve the positioning accuracy of the stent in the bifurcated vascular lesion area and the success rate of the operation.

Description

Technical Field

[0001] This invention belongs to the field of medical device technology, specifically relating to a balloon, a balloon dilation catheter, and a corresponding stent system. Background Technology

[0002] In vascular diseases, arterial and venous stenosis can directly endanger a patient's life. Treatment options for arterial and venous stenosis include surgery and interventional therapy. Interventional therapy, in particular, has gained increasing popularity in recent years due to its simplicity, minimal invasiveness, repeatability, and ability to preserve vascular resources to the greatest extent possible in hemodialysis patients. Interventional therapy refers to percutaneous transluminal angioplasty (PTA), which uses a balloon dilation catheter to dilate the narrowed target vessel or deliver the necessary stent, then expands the stent to support the narrowed vessel, thereby restoring vascular access. Compared to traditional surgery, this method offers advantages such as less bleeding, less trauma, fewer complications, faster postoperative recovery, and greater safety and reliability, significantly reducing patient suffering.

[0003] Although interventional therapy has become relatively mature, and several related products have been marketed and implanted extensively, in actual clinical practice, many arteriovenous stenosis cases occur at the junction of the main vessel and its branches, i.e., bifurcation points. Due to the presence of branch vessels at these points, after the stent is delivered to the lesion area via a balloon dilation catheter, it is difficult to avoid the distal end of the stent system inserting into the branch vessel. Since the branch vessels are relatively thin, this inevitably has a negative impact on the clinical operation of the stent system. Therefore, the presence of branch vessels presents many challenges to the implementation of percutaneous angioplasty (PTA), one of which is how to accurately position the stent in the lesion area at the bifurcation point to improve the success rate of PTA. In recent years, some related research results have been published. However, from the currently available technologies, these studies are usually based on adding new components / devices to the stent delivery system to improve the accuracy of stent positioning. However, the addition of new components often brings new technical problems, such as increasing the size of the stent system and making the operation too complex, thus increasing the risk of the surgery to some extent.

[0004] For example, patent application US20030055483A discloses a balloon catheter that optimizes stent positioning at bifurcation vessels by adding components such as a hollow hypo tube to enable rotation. However, this feature also increases the overall diameter of the stent system, making the structure more complex and placing higher demands on manufacturing processes, production costs, and clinical implantation. Patent application WO2019156560A1 discloses a stent delivery system in which an elastic sleeve is wrapped around a portion of an inflatable balloon. Therefore, compared to the other portion of the inflatable balloon opposite the stent, the elastic sleeve can be configured to at least partially prevent or delay inflation of the inflatable balloon at the wrapped portion. By preventing premature inflation of the proximal portion of the balloon, stent displacement during inflation can be avoided. Combined with anchor cables to determine the anchoring position relative to the branch location, this improves stent positioning accuracy. However, this delivery system, with its added elastic sleeve and anchor cables, suffers from structural complexity, relatively high cost, large overall diameter, and difficulty in clinical operation.

[0005] Therefore, it is essential to provide a stent delivery device suitable for lesions at bifurcation sites, which is simple in structure, low in cost, easy to manufacture, easy to operate clinically, has a 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 improves the accuracy of stent positioning in the lesion area at the bifurcation site without adding new components / devices, but only by improving / optimizing the existing structure of the balloon or balloon dilation catheter. This solution not only has the advantages of simple structure, low cost, and easy processing and production, but also has the advantages of convenient clinical operation, small overall profile, low surgical risk and high stent positioning accuracy.

[0007] This 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. The balloon body, the distal body, and the proximal body are internally combined to form an inner cavity for containing a medium that inflates the balloon. The distal body includes a first cone portion, and the proximal body includes a second cone portion. At least the cone angle α1 of the first cone portion and the diameter d of the balloon in its inflated state satisfy the following relationship:

[0008] α1 = k1lnd + b1; where: k1 ∈ [11, 42, 421], and b1 ∈ [6.8, 31.8], 5 ≤ d ≤ 16, and d is a positive integer.

[0009] Furthermore, 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 internally combined to form an inner cavity for containing a medium that inflates the balloon. The distal body includes a first cone portion, and the proximal body includes 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 inflated state satisfy the following relationship:

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

[0011] Furthermore, the relationship between the cone angle α1 of the first cone and / or the cone angle α2 of the second cone and the diameter d of the balloon body in the inflated state is as follows:

[0012] α1 = k1lnd + b1; where: k1 ∈ [12, 20], and b1 ∈ [9, 25, 8], 5 ≤ d ≤ 16, and d is a positive integer;

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

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

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

[0016] Where k∈[0.6, 2.1].

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

[0018] Where k∈[0.6, 2.1].

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

[0020] Furthermore, at least a portion of the protrusion is less than 2 mm away from the adjacent end of the bladder body at a horizontal distance; 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 bladder body lying flat and the opening facing the bladder body.

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

[0022] Furthermore, at least the first conical portion includes a stepped structure, the stepped structure including at least a first conical segment, a second conical segment, and a straight segment, the straight segment connecting the first conical segment and the second conical segment, and the other end of the first conical segment connecting to the bladder body;

[0023] Wherein, the cone angle α3 of the first cone segment is 30°-150°, the cone angle α4 of the second cone segment is 40°-178°, and the diameter of the straight segment is smaller than the diameter of the cyst body.

[0024] Furthermore, the relationship between the cone angle α1 of the first cone and the cone angle α2 of the second cone and the diameter d of the balloon body in the inflated state is as follows:

[0025] α1 = k1lnd + b1; where: k1 ∈ [11.51, 21.52], and 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], and 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 cyst to the diameter of the cyst in its expanded state is 0.0015-0.010.

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

[0031] The push tube includes a guide wire cavity for guide wire insertion and a filling cavity for medium passage, wherein the guide wire cavity and the filling cavity are arranged axially parallel and isolated from each other by a separator;

[0032] The balloon, as described in this invention, is connected to one end of the push tube, and the inner cavity of the balloon is connected to the inflation cavity;

[0033] A catheter hub is connected to the other end of the push tube. The catheter hub includes a first interface and a second interface. The first interface is connected to the guidewire lumen, and the second interface is connected to the filling lumen.

[0034] The distal body further includes a distal connector, and the proximal body further includes a proximal connector. At least the proximal connector and the push tube are sealed together to form a first connection portion, and the diameter of the first connection portion is less than or equal to the diameter of the proximal connector.

[0035] Furthermore, the inner diameter of the proximal connector is 1.78mm-2.2mm, the gap between the push tube and the proximal connector is no greater than 0.2mm, and the ratio of the wall thickness of the proximal connector 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 dilation catheter also includes:

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

[0039] A developing ring is disposed on the inner tube;

[0040] The guide wire cavity is connected to the inner tube, and the diameter of the inner tube is smaller than the diameter of the push tube.

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

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

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

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

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

[0046] The present invention also provides a stent system, including a stent and a balloon dilation catheter as described in the present invention, wherein the stent is sleeved on the balloon of the balloon dilation catheter.

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

[0048] This invention, based on the clinical performance of stent systems used in branch vessels, the size of the cone angle α1 of the first cone, the balloon diameter d under balloon expansion, and the length L1 and cavity volume of the first cone determined by these two factors, combined with the force characteristics of the fluid inside the balloon (such as direction and magnitude), the balloon expansion method, and the coefficient of friction of the vessel wall, determines an intrinsic relationship between the balloon diameter d, the cone angle α1 under balloon expansion, and the stent positioning accuracy. A relationship is ultimately fitted, which determines the range of cone angles suitable for each balloon diameter. Within this range, a stent system formed by a balloon catheter with the aforementioned characteristics and a stent loaded with it will not experience posterior displacement of the stent system during expansion due to an excessively small cone angle, nor will it experience stent slippage during balloon expansion due to an excessively large cone angle. This results in more precise clinical positioning of the entire stent system. Furthermore, this invention also considers the performance of the balloon during retrieval and withdrawal after stent deployment. Furthermore, this invention obtains a more optimized cone angle range for each balloon specification. Within this range, the stent not only achieves more precise positioning in the bifurcation lesion area but also facilitates balloon retrieval and withdrawal. This prevents vascular damage during balloon withdrawal and avoids an excessively large profile of the final stent system under pressure due to an inadequate balloon structural design, thus preventing increased difficulty in stent delivery. In addition, this invention further improves the positioning accuracy of the stent at branch vessels by combining the stent's structure and internal surface roughness, the balloon's surface roughness, the balloon's structure, and the interaction forces between the balloon and the stent. Finally, this invention further combines the setting and optimization of balloon thickness and various parameters of the balloon catheter to ensure that the balloon, while meeting the corresponding performance requirements, not only has better positioning performance in the bifurcation lesion area but also a smaller profile, safe burst pressure, and decompression time, thereby improving the overall performance of the balloon and facilitating the delivery and safe implantation of the stent system. Attached Figure Description

[0049] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

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

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

[0052] Figure 3 This is a cross-sectional schematic diagram of the third type of balloon provided in the embodiments of the present invention;

[0053] Figure 4 This is a cross-sectional schematic diagram of the fourth type of balloon provided in the embodiments of the present invention;

[0054] Figure 5 This is a schematic cross-sectional view of the balloon dilation catheter provided in an embodiment of the present invention;

[0055] Figure 6 yes Figure 5 A magnified view of a portion of point A in the middle;

[0056] Figure 7 yes Figure 5 A magnified view of a portion of point B in the middle;

[0057] Figure 8 yes Figure 5 A cross-sectional view at point CC. Attached image description:

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

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

[0061] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0062] It should be noted that the terms "setup" and "connection" should be interpreted broadly. For example, they can refer to direct setup or connection, or indirect setup or connection through centered components or centered structures.

[0063] Furthermore, in embodiments of this invention, terms such as "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer" are used to indicate orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, or in a conventional placement or usage state. These terms are merely for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the structures, features, devices, or elements referred to must have a specific orientation or positional relationship, nor that they must be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0064] The various specific technical features and embodiments described in the detailed embodiments can be combined in any suitable manner without 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 various specific technical features / embodiments in this invention will not be described separately.

[0065] In this article, the terms "proximal" and "distal" refer to the relative positions from the perspective of the physician using the medical device. "Proximal" usually refers to the end of the medical device that is closer to the physician during normal operation, while "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 elastic expansion or contraction. When the balloon 1 is pushed to the target blood vessel where the blood vessel is narrowed, the expansion of the balloon 1 can expand the stent attached to the balloon 1, and then the blood vessel will no longer be narrowed by the support of the stent, so that the target blood vessel can restore normal blood flow.

[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 both ends of the balloon body 11. The balloon body 11, the distal body 12, and the proximal body 13 are combined internally to form an inner cavity 10, which is used to contain the medium that inflates 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 both 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 connected by welding. The balloon body 11, the distal body 12, and the proximal body 13 can undergo elastic deformation, thereby increasing their volume after inflation. The materials constituting the balloon body 11, distal body 12, and proximal body 13 can be materials that meet medical use standards. For example, the balloon body 11 can be made of nylon or nylon composite materials, polyurethane, or polyethylene, etc., so that the balloon body 11 can expand to the required diameter under working pressure. The materials used to make the distal body 12 and proximal body 13 can be the same as those used for the balloon body 11, or other materials that meet medical use standards, preferably those capable of elastic deformation. After the distal body 12 and proximal body 13 are respectively connected to the two ends of the balloon body 11, the resulting balloon 1 has a hollow internal structure, thus forming the inner cavity 10 of the balloon 1. By introducing a medium that meets the pressure requirements, such as gas or liquid, into the inner cavity 10, the balloon body 11 can elastically expand, thereby achieving the purpose of expanding the stent attached to it. After the stent expansion is completed, the balloon can be removed / withdrawn from the blood vessel by depressurizing and contracting the balloon, and then by performing a removal / withdrawal operation.

[0068] Specifically, during the insertion of the balloon 1 into the body, the distal body 12 is the first end to enter the body, and when the balloon 1 is withdrawn from the body after expansion, the proximal body 13 is the first end to exit the body. Therefore, the distal body 12 includes a first cone 121, and the proximal body 13 includes a second cone 131. The diameter of the end of the first cone 121 and the second cone 131 connected to the balloon body 11 is larger than the diameter of the end away from the balloon body 11, forming a cone angle of a corresponding value, thus providing better guidance for the balloon. In this way, both the first cone 121 and the second cone 131 have a guiding function, so that during the insertion or withdrawal of the balloon 1 into or from the body, the first cone 121 and the second cone 131 can provide guidance for the corresponding movements, making the insertion and withdrawal of the balloon smoother.

[0069] In embodiments of the present invention, such as Figure 1As shown, with a fixed diameter of balloon 1 after expansion, a smaller cone angle α1 results in a longer shoulder of the first cone 121 and a larger volume of the lumen formed by the first cone 121; conversely, a larger cone angle α1 results in a shorter shoulder of the first cone 121 and a smaller volume of the lumen formed by the first cone 121. Because a longer first cone 121 increases the depth and probability of its entry into the branch vessel when the stent system is delivered to the lesion area near the bifurcation, as fluid flows into the cavity formed by the first cone 121, the first cone 121 exerts a force on the vessel wall, while the vessel wall exerts a counterforce, causing the entire stent system to move backward, leading to inaccurate positioning. Therefore, based on the size of the cone angle α1 corresponding to the first cone 121, the diameter d of the balloon body under balloon expansion, the length L1 of the first cone 121 determined by the two, and the volume of the cavity, and combined with the force characteristics of the fluid inside the balloon, such as direction and magnitude, and the friction coefficient of the blood vessel wall, the present invention determines a certain intrinsic relationship between the balloon body diameter d and the cone angle α1 under balloon expansion and the stent positioning accuracy. Based on this relationship, a reasonable range is determined, and finally a relationship is fitted. Within the range determined by this relationship, the combined force of the branch blood vessels on the balloon and its stent system in the direction of the blood vessel is relatively small or even zero, thereby avoiding the overall backward movement of the stent system during expansion. Here, backward movement 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 towards the proximal end of the balloon under the action of the bifurcation. The technical solution of the present invention employs a relationship between the cone angle α1 of at least the first cone portion 121 and the diameter d of the balloon body in the expanded state of the balloon 1, which satisfies the following formula: α1=k1lnd+b1; where: k1∈[11, 42.421], and b1∈[6.8, 31.8], 5≤d≤16, and d is a positive integer. Specifically, at least the cone angle α1 of the first cone portion 121 satisfies the above-mentioned relationship with the diameter d of the balloon body in the expanded state of the balloon 1.According to the fitted relationship above, under the corresponding balloon dilation state and balloon diameter specifications, there will be a suitable range of values ​​for the cone angle α1. Within this range, there will be a good match between the balloon and the stent. When the stent system is applied to lesions at the bifurcation of blood vessels, the stent system will not experience a situation where the force exerted by the branch vessel on the distal end of the stent system in the vascular direction is greater than the frictional force generated in the opposite direction by the movement of the stent system relative to the vessel wall due to the balloon's cone angle being too small or the shoulder being too long. This avoids the situation where the entire stent will shift backward as the balloon expands, leading to inaccurate stent positioning. In addition, within the range determined by this relationship, the stent will not shift forward or backward or detach from the balloon as it expands due to the balloon's cone angle being too large or the length of the first cone 121 being too short. This significantly improves the positioning accuracy of the stent in areas with branch vessel lesions, thereby greatly improving the success rate of PTA surgery. In summary, by adopting a suitable cone angle design for the balloon 1, this invention achieves the intended use of guided insertion, safe delivery, and accurate positioning of the stent at the target blood vessel. The design is ingenious and greatly improves the performance of the balloon 1.

[0070] Furthermore, in some embodiments, the present invention employs a method where the cone angle α1 of the first cone portion 121 of the balloon satisfies the following relationship with the diameter d of the balloon body in the inflated state: α1 = k1lnd + b1; where: 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 satisfies the condition that it will not cause stent displacement or detachment during inflation, while also avoiding problems such as an excessively large balloon diameter due to an excessively large cone angle, which would hinder retrieval and potentially damage blood vessels or necessitate the use of a larger sheath. It also avoids stent displacement or detachment from the balloon due to an excessively large cone angle. Therefore, when the size of the cone angle α1 of the first cone portion 121 of the balloon and the size of the diameter d of the balloon body in the balloon 1 under the above relationship are satisfied, it can not only ensure that the stent has more accurate positioning, but also ensure that the balloon can be better retrieved and withdrawn after the stent is expanded, so that the balloon causes the least possible damage to human blood vessels during retrieval and withdrawal.

[0071] Furthermore, in some embodiments of the present invention, the magnitudes of the cone angle α1 on the first cone 121 and / or the cone angle α2 on the second cone 131 are related to the diameter d of the balloon 1 in its expanded state by the following formula: α1 = k1lnd + b1; where: k1 ∈ [12, 20], and b1 ∈ [9, 25.8], 5 ≤ d ≤ 16, and d is a positive integer; α2 = k2lnd + b2; where: k2 ∈ [12, 20], and b2 ∈ [9, 25.8], 5 ≤ d ≤ 16, and d is a positive integer. That is, the magnitudes of the cone angle α1 on the first cone 121 and the cone angle α2 on the second cone 131 both satisfy the above formula, and the magnitudes of the cone angles α1 and / or α2 are set to conform to the above value range. Thus, within the range of the balloon diameter and the corresponding cone angles of the first cone 121 and / or the second cone 131 under the balloon expansion state determined by the above-mentioned relationship, not only can the problem of stent displacement or detachment due to excessively large or small cone angles of the first cone 121 and / or the second cone 131 be avoided, resulting in inaccurate positioning, but also, with the cone angles α1 and / or α2 within the above-mentioned range, the balloon and the corresponding stent system can be more easily retrieved after expansion, thereby having a smaller profile size in the compressed / retrieved state. This facilitates the delivery and withdrawal of the balloon and its stent system within the body, and also reduces damage to human blood vessels during the delivery or withdrawal of the balloon and its stent system within the body. In the above-mentioned technical solution of the present invention, the values ​​of α1 and α2 can be the same or different, and thus the lengths of the first cone 121 and the second cone 131 can be the same or different, which can be selected according to different application requirements, providing good flexibility.

[0072] After the stent is delivered to the lesion area, as the balloon inflates, the stent system is subjected to pressure from the blood vessel, the outward force of the fluid inside the balloon on the stent, and the frictional force in the opposite direction of the relative motion between the stent and the balloon. If the friction factor between the balloon and the stent is low, that is, if the surface roughness of both the balloon and the stent is low, then under the combined external forces, the stent can easily slip relative to the balloon, making it impossible for the stent to be accurately positioned in the lesion area. Conversely, if the roughness of the balloon cone is high, it can appropriately increase the static friction between the cone and the bifurcation vessel wall, thereby helping to prevent the stent system from shifting backward. Therefore, this invention further combines the surface roughness of the balloon body and the cone to improve the positioning accuracy of the stent in the lesion area near the bifurcation.

[0073] In some implementations, to improve the reliability of stent delivery, the surface roughness Ra of the capsule 11 is set to 0.03 μm-0.2 μm. Further, the surface roughness Ra of the capsule 11 can be set to 0.05 μm-0.18 μm, and even further, it can be set to 0.08 μm-0.15 μm. The specific value of Ra can be selected according to the actual application requirements. With this configuration, since the stent is mainly held in place on the balloon body 11 for transport, by setting the surface roughness Ra of the balloon body 11 within the aforementioned 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, the maximum static friction force between the balloon and the stent system is appropriately sized during delivery. This effectively prevents the stent from shifting or falling off the balloon body 11 during delivery or expansion, allowing the stent to be accurately delivered to the target blood vessel location, thereby improving the success rate of the surgery. It also avoids excessive roughness of the balloon surface, which would increase the difficulty and safety risks during subsequent retrieval and withdrawal.

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

[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: Where k∈[0.6, 2.1], d refers to the diameter of the balloon body in its inflated state, and k is the inner diameter of the distal balloon body. (Reference) Figure 1In the above, "L1 length" refers to the total length of the hypotenuse of the first cone 121 when the balloon 1 is in the expanded state; "L2 length" refers to the total length of the hypotenuse of the second cone 131 when the balloon 1 is in the expanded state. This invention, by setting the length of the balloon cone, ensures that the first cone 121 or the second cone 131 has sufficient deformation margin during balloon expansion. Fluid is first injected into the balloon cone and it expands, followed by the middle section. Combined with the back pressure generated by the stent on the balloon body during expansion, at least one portion with a height exceeding the outer surface of the balloon body 11 is formed on the expanded first cone 121 or second cone 131 as the stent system expands with the balloon. This portion serves as a limiting element, restricting the stent attached to the balloon body 11. This prevents displacement or even detachment of the stent from the balloon body 11 due to relative movement between the cone and the balloon body during expansion. By controlling the lengths of the balloon cones L1 and L2, and combining this with a suitable cone angle, this invention further achieves precise stent positioning.

[0076] Furthermore, the length L1 of the first cone 121 and / or the length L2 of the second cone 131 satisfy the following relationship: Where k∈[0.6, 2.1], d refers to the diameter of the balloon body in the balloon expansion state, and k is the inner diameter of the distal balloon body. Thus, by setting the value range of L1 or L2 according to the above relationship, 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 balloon expansion, thereby achieving a limiting effect on the stent and preventing the stent from moving or detaching relative to the balloon during balloon expansion, but it can also prevent the lengths L1 and L2 of the cone from being too large, making the diameter of the cone in the gripping state too large, which would be inconvenient for delivery or for retrieval and withdrawal after balloon expansion. Furthermore, excessively large lengths L1 and L2 of the cone can also deteriorate the stent positioning accuracy to some extent. In other words, this invention, through the reasonable design of the cone length of the balloon cone, can improve the accurate positioning of the stent without affecting the delivery of the stent system or the retrieval and withdrawal of the balloon.

[0077] like Figure 2As shown, in some embodiments, the first cone 121 and / or the second cone 131 includes at least one protrusion 14, on which at least a portion is at 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 furthest from the central axis of the balloon, and the distance D of this furthest portion relative to 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 is at 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 even further, at least a portion of the protrusion 14 is at 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 this configuration, the highest point of the protrusion 14 formed after the balloon 1 expands is slightly higher than the outer surface of the balloon body 11, which can serve as a limiting function without obstructing the delivery of the stent system in the blood vessel. This allows the first cone 121 and / or the second cone 131 to not only have good smoothness and be able to be delivered smoothly in the blood vessel, but also to limit the stent attached to the balloon 1 through the protrusion 14, reducing the possibility of stent displacement during balloon 1 expansion and further improving the accuracy of stent positioning.

[0078] It should be noted that in this invention, "the radius of the balloon" or "the diameter of the balloon" refers to the radius or diameter of the balloon body when the balloon is in the 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 may be arranged circumferentially around the end of the first cone 121 and / or the second cone 131 near the balloon body 11, and the protrusions 14 may be spaced apart or continuously distributed. When the protrusions 14 are continuously distributed, it can also be regarded as a circumferential arrangement of one ring of protrusions around the first cone 121 and / or the second cone 131. In this way, multiple protrusions 14 can limit the stent at various positions in the circumferential direction, improving the reliability of the stent limiting effect. The present invention can avoid relative movement of the stent on the balloon surface. By combining the length of the balloon cone and the roughness of the surfaces of the balloon and the stent, the number, size or area of ​​the protrusions can be adjusted to achieve a good limiting effect, thereby preventing relative movement between the stent and the balloon.

[0080] Specifically, to improve the effectiveness of the protrusion 14 in limiting the support, the horizontal distance between at least a portion of the protrusion 14 and the adjacent end on the bladder body 11 can be set to less than 2 mm. Here, "adjacent end on the bladder body" refers to the part of the bladder body 11 that is horizontally closest to the protrusion 14. That is, if the protrusion 14 is located on the first cone 121, it is the part of the bladder body 11 used to connect with the first cone 121; if the protrusion 14 is located on the second cone 131, it is the part of the bladder body 11 used to connect with the second cone 131. Since the support is mainly attached to the bladder body 11, this arrangement ensures that the protrusion 14 is close to the bladder body 11. Therefore, during expansion, the protrusion 14 can effectively limit the support, preventing the support from partially shifting when the protrusion 14 contacts the support due to an excessively long distance, thus avoiding significant positioning inaccuracies. By limiting the position between the protrusion 14 and the bladder 11, the present invention keeps the position between the protrusion 14 and the stent within a suitable range, thereby improving the timeliness and effectiveness of the protrusion 11 in limiting the stent.

[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. By setting the protrusion length in an appropriate proportion, the present invention achieves that the protrusion 14 formed on the first cone 121 or the second cone 131 is neither too large to affect the smooth passage of the first cone 121 or the second cone 131 within the blood vessel, nor too small to affect the effectiveness of the stent restraint function. Moreover, referring to… Figure 3 Alternatively, the protrusion 14 or its tangent can form a horizontal "V" shape 15 with the opening facing the cyst body 11. That is, a "V" shape 15 can be formed between the protrusion 14 and the cyst body 11; or a "V" shape 15 can be formed between the tangent on the side of the protrusion 14 facing the cyst body 11 and the cyst body 11. In both cases, one side of the "V" shape 15 is horizontally positioned, flush with or parallel to one side of the cyst body 11, while the other side faces the cyst body 11 at an angle upwards or downwards. Together, the two sides form a horizontal "V" shape 15 with the opening facing the cyst body. This "V" shape structure allows one end of the support to be located within the "V" shape, thus limiting the position of the support. During conical expansion, this prevents the support from shifting or detaching, providing a reliable position-limiting function.

[0082] Furthermore, the included angle of the formed "V" shape 15 is between 30° and 150°. Examples include 30°, 40°, 45°, 52°, 60°, 65°, 70°, 80°, 100°, 120°, 130°, 140°, or 150°. Other values ​​between 30° and 150° are also possible. Setting the included angle of the "V" shape 15 within this range not only allows for stent positioning but also prevents the shape of the protrusion 14 from obstructing the movement of the cone within the blood vessel.

[0083] like Figure 4 As shown, in some embodiments, at least the first cone 121 is configured to include a stepped structure, which includes at least a first cone segment 1211, a second cone segment 1212, and a straight segment 1213. The straight segment 1213 connects the first cone segment 1211 and the second cone segment 1212. The other end of the first cone segment 1211 is connected to the capsule 11, and the other end of the second cone segment 1212 is connected to other objects (such as a push tube or inner tube). The cone angle α3 of the first cone segment 1211 is set between 30° and 150°, and the cone angle α4 of the second cone segment 1212 is set between 40° and 178°. The diameter of the straight segment 1213 is smaller than the diameter of the capsule 11. Specifically, the number of cone segments and straight segments on the stepped structure can be set according to actual design requirements, and the stepped structure includes at least two cone segments and one straight segment, wherein the straight segment is used to connect two adjacent cone segments. For example, if a stepped structure has three conical segments, then it has two straight segments. The three conical segments are arranged alternately, and the two straight segments connect to adjacent conical segments. Similarly, if another stepped structure has four conical segments, then it has three straight segments. The four conical segments are arranged alternately, and the three straight segments connect to adjacent conical segments, and so on. The diameter of the resulting stepped structure decreases in the direction of propulsion. For instance, in a stepped structure with two straight segments, the diameter of the straight segment closer to the capsule 11 is larger than the diameter of the straight segment farther from the capsule 11. This design, due to the small cone angle of the first conical segment 1211, makes it less likely for the stent to shift relative to the balloon surface. Simultaneously, because the diameter of the straight segment furthest from the balloon body 11 is small, even when inserted into a branch vessel, the pressure from the branch vessel on the first conical segment is unlikely to cause overall posterior displacement of the stent system. Therefore, during balloon 1 expansion, the first conical segment 121 is prevented from being squeezed against the branch vessel, thus avoiding proximal displacement of the balloon 1 and the stent system. This improves the accuracy of stent positioning at the target vessel. Furthermore, this design reduces the profile size of the first conical segment 121 after expansion, making its expanded diameter significantly smaller than the diameter of the branch vessel. This effectively prevents significant posterior displacement of the stent system due to compression from the branch vessel during expansion, further improving stent positioning accuracy.

[0084] Furthermore, in one embodiment, when the surface roughness Ra of the first cone 121 is set to 0.05μm-0.2μm, it can refer to the roughness of the entire stepped structure surface or the roughness of the surface of the portion of the stepped structure inserted into the branch vessel. This can increase the frictional force between the stent and the branch vessel. Consequently, when the balloon 1 expands, if there is a portion of the first cone 121 in contact with the branch vessel, the friction coefficient between the portion of the first cone 121 and the branch vessel is relatively large, so that the stent system will not shift backward as a whole under the action of the first cone 121. This will prevent the balloon 1 and the stent from moving backward as a whole, and the stent will not shift, allowing the stent to be accurately positioned at the target vessel. Specifically, the roughness Ra of the surface of the first cone 121 can be any value within the above-mentioned 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 smooth delivery in the blood vessel, while improving the friction between the vessel and the branch blood vessel.

[0085] like Figure 4 As shown, when the stepped structure is configured with two conical segments and one straight segment, the extension line of the second conical segment 1212 intersects the central axis of the balloon 1 to form an intersection point E. The opposite sides of the balloon 11 are connected to the intersection point E respectively. The included angle between the two connections is defined as the cone angle α1 of the first conical part 121.

[0086] In another embodiment, when the first cone 121 is configured to include the first cone segment 1211, the second cone segment 1212 and the straight segment 1213, and also has a protrusion 14, the protrusion 14 can be placed on the first cone segment 1211, so that the protrusion 14 is closer to the balloon body 11. Thus, when the balloon 1 expands, the protrusion 14 can effectively limit the position of the stent, prevent the stent from shifting or falling off, and improve the accuracy of stent positioning.

[0087] In some embodiments, the size of the cone angle α1 on the first cone 121 and / or the cone angle α2 on the second cone 131 satisfies the following relationship with the size of the diameter d of the balloon body in the balloon expansion state: α1=k1lnd+b1; where: 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; where: 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 of different sizes 1 correspond to different cone angle ranges. Within the corresponding cone angle range, the stent used can be accurately positioned in the lesion area without displacement, and the size of the formed cone can still meet the requirements for smooth delivery of balloon 1 in the blood vessel.

[0088] Specifically, the larger the ratio of the wall thickness W1 of the balloon 11 to the diameter d of the balloon 11 in its expanded state, the higher the burst pressure of the balloon 1; conversely, the smaller the ratio of the wall thickness W1 of the balloon 11 to the diameter d of the balloon 11 in its expanded state, the lower the burst pressure of the balloon 1. In the embodiments of the present invention, such as Figure 1 As shown, the ratio of the wall thickness W1 of the balloon 11 to the diameter d of the balloon 11 in its expanded state is set to 0.0015-0.010. For example, if the diameter d of the balloon 1 is 5 mm, then the wall thickness W1 of one side of the balloon 11 is 0.0075 mm-0.05 mm; or if the diameter d of the balloon 1 is 10 mm, then the wall thickness W1 of one side of the balloon 11 is 0.015 mm-0.1 mm. This setting keeps the relationship between the wall thickness of the formed balloon 11 and the diameter of the balloon 1 in its expanded state within a suitable range, so that the balloon 1 can have a suitable burst pressure performance and that the diameter that can be inflated also meets the usage requirements, preventing rupture before inflating to the required diameter. With this design of the ratio of wall thickness W1 to diameter d, the balloon 1 can reliably expand the stent to the rated diameter and has a smaller profile size, which is more conducive to delivery in blood vessels.

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

[0090] In some embodiments, the burst pressure of the balloon 1 is adjusted according to the diameter of the balloon 1. Balloons 1 with different diameters may have the same or different burst pressures. In this embodiment of the invention, the diameter of the balloon 1 ranges from 5 mm to 16 mm, and the burst pressure of the balloon body 11 ranges from 10 to 30 atm (atm is a commonly used unit of atmospheric pressure, and the value of 1 standard atmosphere is denoted 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 may be equal or unequal. When the cone angle α1 of the first cone 121 and the cone angle α2 of the second cone 131 are equal, the cone angles at both ends of the balloon 1 are equal, which facilitates manufacturing. Moreover, when connecting the balloon 1 to other objects (such as a push tube), there is no need to distinguish the positions of the two ends, which facilitates welding. When the cone angle α1 of the first cone 121 and the cone angle α2 of the second cone 131 are unequal, 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. For example, the cone angle α1 of the first cone 121 may be 50°, 60°, 65°, or 75°, while the cone angle α1 of the second cone 131 may be 28°, 34°, 40°, or 45°. In this way, the head of the proximal body 13 is relatively small, which provides good guidance when the balloon 1 is withdrawn from the body, facilitating the withdrawal of the balloon 1. Of course, the angle α2 of the second cone 131 can also be set to be greater than the angle α1 of the first cone 121. In this case, the head of the second cone 131 in the contracted state is larger, which can play a role in positioning the stent when it is attached to the balloon 1, preventing the stent from shifting.

[0092] like Figures 5 to 8 As shown, another aspect of the present invention provides a balloon dilation catheter 2, including a push tube 21, a balloon, and a catheter seat 22. The push tube 21 includes a guidewire lumen 211 for guidewire insertion and an inflation lumen 212 for media passage. The guidewire lumen 211 and the inflation lumen 212 are arranged axially parallel and isolated from each other by a separator 213. The balloon is the balloon 1 described above, which is connected to one end of the push tube 21. The inner lumen 10 of the balloon 1 (refer to...) Figure 1The catheter 21 is connected to the filling cavity 212. The catheter hub 22 is connected to the other end of the push tube 21. The catheter hub 22 includes a first interface 221 and a second interface 222. The first interface 221 communicates with the guidewire lumen 211, and the second interface 222 communicates with the filling cavity 212. Specifically, the push tube 21 has at least two mutually isolated and non-communicating cavities, typically including at least the guidewire lumen 211 and the filling cavity 212. Since the push tube 21 is made of a relatively soft material, when pushing the balloon 1 into the body, a guidewire needs to be inserted into the guidewire lumen 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 introduce a medium such as gas or liquid into the inner cavity 10 of the balloon 1 after the balloon 1 is pushed to the corresponding position, so as to inflate the balloon 1. The catheter hub 22 is designed for holding during operation to facilitate the application of force for the corresponding surgical operation. The catheter hub 22 is provided with a first interface 221 that communicates with the guidewire lumen 211 and a second interface 222 that communicates with the filling lumen 212. The openings of the first interface 221 and the second interface 222 are relatively large, which facilitates the insertion of the guidewire through the first interface 221 into the guidewire lumen 211 and the introduction of the medium through the second interface 222 to inflate the balloon 1.

[0093] Specifically, due to balloon 1 (reference) Figure 1 A sealed connection needs to be achieved with the outer surface of the push tube 21, typically by welding one end of the ball bag 1, used for connection, onto the push tube 21. In this embodiment of the invention, as... Figures 5 to 7As shown, the distal body 12 is further provided with a distal connector 122, and the proximal body 13 is further provided with a proximal connector 132. Moreover, at least the proximal connector 132 and the push tube 21 are sealed together by a first connecting portion 130. With this configuration, the proximal connector 132 is a hollow structure. The proximal connector 132 is fitted onto the push tube 21, and then a sealing connection is formed between the proximal connector 132 and the push tube 21 using methods such as laser welding. A first connecting portion 130 is formed at the connection point between the two, achieving an effective sealing connection. Simultaneously, the inflation cavity 212 in the push tube 21 needs to communicate with the inner cavity 10 of the balloon 1, so that a medium can be introduced into or extracted from the inner cavity 10 of the balloon 1 through the inflation cavity 212, thereby achieving the inflation or deflation of the balloon 1. In this embodiment of the invention, a first connecting portion 130 is formed between the proximal connector 132 and the push tube 21 by laser welding. This first connecting portion 130 is continuously distributed circumferentially around the outer surface of the push tube 21, ensuring a reliable sealing connection. Furthermore, the diameter at the highest point of the first connecting portion 130 is less than or equal to the diameter D3 of the proximal connector 132. That is, the first connecting portion 130 does not additionally increase the diameter of the proximal connector 132, thus avoiding becoming an obstacle during intravascular delivery, ensuring good passage, and facilitating intravascular delivery.

[0094] In other embodiments, the connection between the balloon 1 and the push tube 21 can also be as follows: one end of the push tube 21 is inserted through the proximal connector 132, then passes through the inner lumen 10 of the balloon 1, and exits through the distal connector 122. The connection points between the proximal connector 132 and the distal connector 122 and the push tube 21 are respectively sealed by means such as laser welding, and the filling cavity 212 of the push tube 21 is connected to the inner lumen 10 of the balloon 1. The resulting balloon dilation catheter can also meet the needs of use when the blood vessel diameter is large enough to allow for the insertion of the distal body 12.

[0095] The balloon dilation catheter 2 provided in this embodiment of the invention, using a balloon 1 with the aforementioned structure, ensures that the first conical portion 121 of the balloon 1 is of suitable length. When using the balloon dilation catheter 2 to implant a stent into the narrowed target blood vessel, stent displacement or detachment will not occur during balloon dilation, ensuring accurate positioning of the stent at the target blood vessel location, thus improving the effectiveness and safety of the procedure. Furthermore, the balloon dilation catheter 2 provided in this embodiment of the invention is suitable for the delivery and dilation of any type of stent, including biodegradable and non-biodegradable stents. The stent material types include, but are not limited to, iron-based, magnesium-based, zinc-based, polylactic acid, cobalt-chromium alloy, and nickel-titanium alloy. In other words, this balloon dilation catheter 2 has a wide range of applications and good market prospects.

[0096] In embodiments of the present invention, since the balloon 1 needs to be inflated to different sizes, such as 5mm, 8mm, or 14mm in diameter, the size of the proximal connector 132 on balloons of different sizes is also different. To ensure a reliable sealing connection between the balloon 1 and the push tube 21, the inner diameter of the proximal connector 132 is set to 1.78mm-2.2mm, and the gap between the push tube 21 and the proximal connector 132 is no greater than 0.2mm. Specifically, the gap between the proximal connector 132 and the push tube 21 needs to be kept within a suitable range. An excessively large gap makes welding between the two difficult and prone to poor welding (such as weld breaks resulting in holes), leading to an inability to seal the connection. An excessively small gap makes it difficult for the push tube 21 to be inserted into the proximal connector 132 and may cause damage at the connection point. Therefore, selecting a proximal connector 132 with a suitable inner diameter based on the gap requirement between the push tube 21 and the proximal connector 132 is beneficial to improving the effectiveness of the connection between the push tube 21 and the proximal connector 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 connector 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 connector 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 within the push tube 21, and during welding, the proximal connector 132 is simultaneously connected to the sidewall of the guide wire cavity 211 and the sidewall of the filling cavity 212, the wall thickness of the push tube 21 mentioned here refers to the minimum wall thickness value of either the guide wire cavity 211 or the filling cavity 212. Both the proximal connector 132 and the push tube 21 need to have a certain wall thickness to ensure reliable welding. If the wall thickness of the proximal connector 132 or the push tube 21 is too small, weld cracking is likely to occur; conversely, if the wall thickness of the proximal connector 132 or the push tube 21 is too large, the first connecting portion 130 may bulge, resulting in an excessively large local diameter of the first connecting portion 130 and affecting the smoothness of the push. Therefore, the ratio between the wall thickness W3 of the proximal connector 132 and the wall thickness of the push tube 21 is set within the aforementioned range to ensure reliable welding and good sealing, without causing an increase in the local diameter of the first connecting portion 130 and additionally increasing the diameter of the proximal connector 132. For example, the balloon 1 may have different diameters, but the diameter of the push tube 21 used to connect to the balloon 1 remains the same. For instance, when the push tube 21 with a wall thickness of 0.08 mm is used for welding, the wall thickness W3 of the proximal connector 132 is 0.05 mm when the diameter of the balloon 1 is 5 mm, and the wall thickness W3 of the proximal connector 132 is 0.4 mm when the diameter of the balloon 1 is 16 mm.

[0098] like Figure 5 and Figure 6 As shown in this embodiment of the invention, in order to improve the smoothness of the guidewire insertion into the guidewire cavity 211, the position of the first interface 221 on the catheter seat 22 is kept flush with the position of the guidewire cavity 211. Furthermore, the axis of the first interface 221 is collinear with the axis of the guidewire cavity 211, so that the guidewire can be smoothly inserted into the guidewire cavity 211 through the first interface 221 and extended into the guidewire cavity 211, and can be smoothly pulled and slid in the guidewire cavity 211 without jamming, thus improving the operability of the surgery.

[0099] like Figures 5 to 7 As shown, in one embodiment, the balloon dilation catheter 2 further includes an inner tube 23 and a contrast ring 24. The inner tube 23 has a single-lumen structure, and its diameter is smaller than that of the push tube 21. Specifically, in order to allow a guidewire to be inserted into the distal body 12 to enhance the passability of the distal body 12 within the blood vessel, an inner tube 23 is provided. This inner tube 23 passes through the lumen 10 of the balloon 1, with one end connected to the push tube 21 and the other end connected to the distal connector 122. In this way, the guidewire can pass through the inner tube 23 without compromising the seal of the lumen 10 of the balloon 1. Moreover, the diameter of the inner tube 23 is smaller than that of the push tube 21, so that the smaller diameter of the inner tube 23 does not cause the overall profile size to be too large when the balloon is compressed, thus minimizing the overall profile size of the balloon 1 when it is not inflated, facilitating smooth push-through within the blood vessel.

[0100] Specifically, the imaging rings 24 are disposed on the inner tube 23, and there are usually at least two imaging rings 24. The imaging rings 24 are fitted onto the inner tube 23 at predetermined intervals to visualize the position of the balloon 1 within the body during surgery, thereby achieving accurate positioning of the balloon 1. The specific structure and material of the imaging rings 24 adopt existing conventional designs and will not be described in detail here.

[0101] like Figure 1 , Figure 5 and Figure 7As shown, in this embodiment of the invention, the distal connector 122 is connected to the inner tube 23 to form a second connecting portion 120, the diameter of which is smaller than the diameter D2 of the distal connector 122. Specifically, the distal connector 122 is sleeved on the inner tube 23, and a sealed connection is achieved between the distal connector 122 and the inner tube 23 by means of laser welding or the like, thereby ensuring the sealing of the inner cavity 10 of the balloon 1. The sealed connection between the distal connector 122 and the inner tube 23 forms the second connecting portion 120, the diameter of which is smaller than the diameter D2 of the distal connector 122. Simultaneously, the diameter D2 of the distal connector 122 itself is also small. Therefore, the formed second connecting portion 120 does not additionally increase the diameter D2 of the distal connector 122, thus, when inserted into the body, the smaller diameter of the second connecting portion 120 is more conducive to insertion and delivery within the blood vessel. Specifically, the diameter of the second connecting part 120 is 1.25mm to 1.47mm, and the diameter D2 of the distal connector 122 is 1.54mm to 2.4mm. The wall thickness of the distal connector 122 is usually the same as that of the proximal connector 132, thereby reducing the difficulty of manufacturing.

[0102] Specifically, when expanding a compressed stent by inflating balloon 1, a certain period of time is usually required to stabilize the expanded stent. However, if the inflated balloon 1 remains tightly attached to the vessel wall, it can easily obstruct blood flow. Prolonged blood flow obstruction can lead to additional risks such as myocardial ischemia or myocardial infarction. Therefore, in this embodiment of the 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. This allows the filling cavity 212 to have 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. This reduces the time required for the balloon 1 to inflate to its rated diameter and the time required to remove the medium from the balloon 1. This shortens the time of blood flow obstruction, improving the safety of the procedure; or it ensures a longer period of stable expansion after inflation, thus improving the stability of the stent expansion effect. In this embodiment of the invention, according to design requirements, the radial cross-sectional area of ​​the filling cavity 212 is 50 mm². 2 -55 mm 2 The radial cross-sectional area of ​​the push tube 21 is 245 mm². 2 -250 mm 2 In one embodiment, the radial cross-sectional area of ​​the filling cavity 212 is 53 mm². 2 The radial cross-sectional area of ​​the push tube 21 is 248 mm². 2 .

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

[0104] like Figure 6 and Figure 8 As shown, in this embodiment of the invention, the maximum width W4 of the filling cavity 212 is set to 0.3mm-0.55mm along the radial direction of the push tube 21. Specifically, since increasing the radial dimension of the filling cavity 212 will increase the diameter of the entire push tube 21 when the area of ​​the filling cavity 212 is fixed, in order to reduce the diameter of the push tube 21 and make the filling cavity 212 have the largest possible area, the maximum width W4 of the filling cavity 212 along the radial direction is set between 0.3mm and 0.55mm, so that the filling cavity 212 has the largest possible area while meeting the strength requirements. Furthermore, the shape of the filling cavity 212 can also be set as follows... Figure 8 The crescent shape shown is used to make full use of the area between the filling cavity 212 and the guide wire cavity 211 to become part of the filling cavity 212, thereby increasing the area of ​​the filling cavity 212 by making full use of the internal area of ​​the push tube 21, thereby increasing the inflation speed of the balloon 1 and reducing the time required for the balloon 1 to depressurize.

[0105] like Figure 5 and Figure 7 As shown, in this embodiment of the invention, the balloon dilation catheter 2 further includes a guide tube 25. The guide tube 25 is positioned anterior to the distal body 12 along the pushing direction of the push tube 21 and is connected to the inner tube 23. The guide tube 25 is made of a flexible material, making it soft and easily bendable. Positioning the guide tube 25 at the forefront of the pushing direction not only provides guidance but also ensures good flexibility without damaging blood vessels. Typically, the radial cross-section of the guide tube 25 is circular. To improve the guiding ability of the guide tube 25, 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 very 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 very front end of the second connecting part 120 in the direction facing the guide tube 25. Thus, along the pushing direction, the diameter of the very front end of the guide tube 25 is the smallest and does not exceed the diameter at the front end of the second connecting part 120. Consequently, the overall shape of the guide tube 25 gradually decreases in the pushing direction, which is beneficial for guidance during pushing.

[0106] like Figures 5 to 8As shown, in some embodiments, the separator 213 used to separate the guidewire cavity 211 and the filling cavity 212 is configured as a diaphragm, and the thickness W5 of the diaphragm is set to 0.10 mm-0.14 mm. The diaphragm is made of the same material as the push tube 21 and is formed simultaneously when the guidewire cavity 211 and the filling cavity 212 are formed. In this embodiment of the invention, the thickness W5 of the diaphragm is set between 0.10 mm and 0.14 mm, such as 0.1 mm, 0.12 mm, 0.134 mm, or 0.14 mm. A diaphragm within this thickness range has sufficient strength to prevent puncture during guidewire insertion and to prevent bursting when a medium with a certain pressure is introduced into the filling cavity 212. Simultaneously, a diaphragm within this thickness range will not reduce the area of ​​the guidewire cavity 211 or the filling cavity 212.

[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 any other value between 0.08mm and 0.12mm, and the minimum wall thickness W7 of the filling cavity 212 can also be any other value between 0.08mm and 0.15mm. This configuration allows the wall thicknesses of the guidewire cavity 211 and the filling cavity 212 to be set within this range. While ensuring the strength requirements are met, it also allows the filling cavity 212 and the guidewire cavity 211 to have a sufficiently large cross-sectional area, which satisfies the need for smooth guidewire delivery and improves the efficiency of balloon 1 inflation or deflation.

[0108] This invention also provides a stent system, including a stent and the aforementioned balloon dilatation catheter 2, with the stent sleeved on the balloon 1 of the balloon dilatation catheter 2. The stent includes biodegradable and non-biodegradable stents, and the stent material types include, but are not limited to, iron-based, magnesium-based, zinc-based, polylactic acid, cobalt-chromium alloy, and nickel-titanium alloy. The balloon dilatation catheter 2 is used to deliver the stent to the target blood vessel to dilate the narrowed target blood vessel. Specifically, the stent is pre-pressed onto the balloon 1 in a contracted state in an uninflated state. The balloon dilatation catheter 2, with one end containing the balloon 1, is inserted into the blood vessel and pushed to the target blood vessel. Then, the balloon 1 is inflated to dilate the stent, thereby dilating the target blood vessel under the support provided by the stent. This balloon dilatation catheter 2 can accurately deliver the stent to the target blood vessel, and during balloon 1 dilation, the stent will not shift or dislodge from the balloon 1, allowing the stent to be precisely positioned at the target blood vessel, thus improving the effectiveness of the stent system for stent implantation surgery.

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

[0110] This design ensures that the surface smoothness of the stent is within a suitable range. Excessive roughness on the inner surface of the stent will prevent scratching or puncturing the balloon 1 surface, while excessive roughness on the outer surface will prevent injury to the vessel wall. Conversely, insufficient roughness on the inner surface will prevent relative sliding between the stent and balloon 1 or between the stent and the vessel wall during expansion. In other words, this invention further improves the accuracy of stent positioning in the lesion area near the vessel bifurcation by controlling the roughness of the inner and outer surfaces of the stent. Furthermore, by setting the maximum static friction force between the stent and the surface of balloon 1 in the stent system between 2.8N and 7.9N, the stent system not only ensures smooth movement within the blood vessel but also provides adequate anti-slip properties. This allows the stent, once gripped, to reliably adhere to balloon 1 without loosening. Consequently, during delivery, there is no relative movement between the stent and balloon 1, preventing stent displacement or detachment from balloon 1. This ensures accurate delivery of the stent to the target vessel. Moreover, during balloon expansion, the stent and balloon do not slide relative to each other due to the force of branch vessels, thus avoiding additional surgical risks caused by stent displacement or detachment and improving the safety of the procedure.

[0111] The stent system fabricated using the balloon and balloon dilation catheter of this invention allows for balloon dilation in the following manner after the stent is delivered to the target bifurcation vessel lesion area: dilation can be performed proximally-capsule-distal, distally-capsule-proximal, or capsule-capsule-ends first. Furthermore, this invention preferably dilates the capsule first, followed by dilation of the proximal and distal ends, which improves the accuracy of stent positioning.

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

[0113] In this invention, the stent positioning accuracy is measured by the deviation between the final implanted position of the stent in the vascular lesion area and the target position before stent implantation. For example, if the target position of the stent before implantation corresponds to the segment corresponding to points a and b of the lesion vessel, and the final placement of the stent after implantation is the segment of the lesion vessel located by points a' and b', then the deviation between the post-implantation and pre-implantation positions is the distance d between points a and a'. 偏离 The |d of a typical support 偏离 The smaller the value, the higher the positioning accuracy of the stent. 偏离 >0 indicates that the stent has shifted distally, d 偏离 <0 indicates that the stent has shifted proximally. In this application, |d 偏离 | is used to measure the accuracy of stent positioning. Generally, a stent displacement within ±3mm is considered accurate. 偏离 |≤3 can meet the requirements for the accuracy of bracket positioning to a certain extent.

[0114] In this invention, the "maximum static friction force" on the balloon surface of the stent system refers to the maximum frictional force experienced by the stent before relative motion with the balloon occurs, that is, the magnitude of the frictional force experienced by the stent when it is in a critical state about to move relative to the balloon. This 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] In this invention, the "recapture diameter ratio" refers to the ratio of the balloon's diameter after stent deployment and retrieval to its diameter in its folded state before gripping the stent. A smaller ratio indicates better balloon retrieval and easier retraction, and vice versa. The balloon's diameter after stent deployment and retrieval also refers to its recapture diameter, which is the distance between the two furthest points on the balloon's cross-section after retrieval. Detailed Implementation

[0117] To facilitate understanding of the present invention, the design points of the present invention are illustrated below with reference to some specific embodiments. It is understood that the relevant embodiments are merely illustrative examples of the present invention and do not constitute a limitation on the scope of application. That is, the following descriptions are only some preferred embodiments of the present invention, and the present invention is not limited to the following preferred embodiments. For example, for ease of understanding, the embodiments of the present invention are all described using balloon dilation catheters with the following structures, but this does not mean that the technical solution of the present invention is only applicable to balloon dilation catheters with the following structures. It should be noted that for those skilled in the art, any modifications and improvements made based on this inventive concept are within the scope of protection of the present invention. Unless otherwise specified, all components used are conventional products that can be obtained commercially. The basic structure of the balloon catheter used in the embodiments of the present invention is as follows:

[0118] The balloon dilation catheter of this invention includes a push tube, a balloon, a catheter hub, an inner tube, a contrast ring, and a guide tube. The balloon includes a balloon body and a distal body and a proximal body connected to both ends of the balloon body. The distal body includes a first cone portion, and the proximal body includes a second cone portion. The push tube includes a guidewire lumen and an inflation lumen. The proximal body is fitted onto and connected to one end of the push tube, and the inflation lumen communicates with the inner lumen of the balloon. The catheter hub is connected to the other end of the push tube. The inner tube passes through the inner lumen of the balloon. One end of the inner tube is connected to the push tube, and the distal body is fitted onto and connected to the other end of the inner tube. The guide tube is positioned in front of the distal body and connected to the inner tube. If the balloon has a contrast ring, it is primarily located 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 centerline of the object being measured. The centerline intersects the actual profile within the reference distance, minimizing the sum of profile deviations (relative to the centerline). Therefore, the average roughness Ra corresponds to the arithmetic mean of the deviations from the centerline. This invention measures the roughness of a support or balloon surface using an optical measuring device and in accordance with the ISO 25178 standard. For example, a Keyence VHX100 optical microscope with software-supported 3D surface analysis and a 54M pixel resolution, combined with a Zeiss optical magnification lens up to 2500×, is used. The software allows for virtual cross-sections through the surface and calculates the average roughness depth of the measurement area.

[0122] 2. Maximum static friction

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

[0124] First, the stent was simulated in a curved anatomical model under a water bath environment of 37±2℃. The stent was marked in advance. After the simulation was completed, the stent was observed to see if it had shifted. Then, the stent was pulled off by adhesive tape. The tensile strength of the stent was tested using a universal testing machine with a test rate of 50.8 mm / min and a gauge length of L = 15 mm. The magnitude of the removal force was measured.

[0125] 3. Diameter and other parameters

[0126] In this invention, the diameters and other parameters of the bracket, bracket system, and support components are all measured using a non-contact measuring instrument.

[0127] 4. Accuracy of stent positioning in the bifurcation vessel lesion area

[0128] This invention employs a method to first determine reference points during DSA angiography, and then uses these reference points to determine the two endpoints a and b of the diseased blood vessel corresponding to the target stent implantation location. After stent implantation, the same reference system is used to determine the corresponding points between the two actual implanted endpoints a' and b'. The distance between points a and a', or between points b and b', is then measured to obtain |d|. 偏离 This allows us to determine the accuracy of the stent's positioning in the bifurcation vessel lesion area.

[0129] 5. Balloon encirclement diameter ratio N 回抱

[0130] First, measure the diameter d of the balloon in its folded state before it is pressed against the stent. 压握前 Then, the diameter d of the balloon after the stent is deployed and retrieved in a simulated environment is measured. 回收 By comparing the two, we can obtain the ratio of the balloon's encirclement diameter, that is:

[0131] N 回抱 =d 回收 / d 压握前 .

[0132] 6. Explosive pressure

[0133] In this invention, the balloon burst pressure is mainly measured with reference to Appendix A of the standard "YY / T0285.4-2017-Intravascular Catheters - Disposable Sterile Catheters - Part 4 - Balloon Dilatation Catheters". The specific operation method is to immerse the balloon in water at 37±2℃ for 2 minutes, then inflate the balloon to rupture at a fixed rate using a water pressure tester or balloon pressure pump, and finally measure the corresponding pressure value.

[0134] 7. Decompression time

[0135] In this invention, the balloon decompression time is mainly determined according to Appendix D of the standard "YY / T0285.4-2017-Intravascular Catheters - Disposable Sterile Catheters - Part 4: Balloon Dilatation Catheters". The specific procedure is as follows: in a water bath at 37±2℃, the balloon is inflated to RBP using a balloon pressure pump, pressure is maintained for 30 seconds, and then depressurized until the balloon collapses. The time from the start of depressurization to the balloon collapse is recorded.

[0136] Examples 1-16

[0137] This set of embodiments provides the rated diameter d of the balloon, the distal internal diameter k 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 surface roughness Ra of the balloon body for each embodiment. 囊体 The surface roughness Ra of the first cone 锥部 The roughness Ra of the inner surface of the support 支内 The roughness Ra of the outer surface of the support 支外 The maximum static friction force f on the surface of the balloon in the stent system max Using parameters such as [specific parameters], stent systems loaded with balloon dilation catheters possessing the aforementioned specific characteristics were implanted into the bifurcation lesions of the pulmonary artery in dogs. The positioning accuracy of the stents at the bifurcation lesions of the pulmonary artery in each embodiment was measured using the aforementioned testing method, using the parameter |d]. 偏离 | and the ratio of the balloon's encirclement diameter N 回抱 The specific parameters for each embodiment are as follows (see Table 1):

[0138] Table 1 shows the specific design parameters of the balloons in each of Examples 1 to 16, and the performance characterization parameters of the balloon dilation catheters with these design features.

[0139]

[0140] Example 17

[0141] This embodiment is based on Embodiment 3, which has a protrusion on the first cone. The distance between the highest point of the protrusion and the central axis of the balloon is 5.0 mm, and the horizontal distance between the highest point 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 flat "V" shape with the opening facing the balloon body, and the included angle of the "V" shape is 150°. The positioning accuracy of the stent at the bifurcation lesion of the pulmonary artery in dogs is |d 偏离 The diameter is 0.35 mm, and the ratio of the balloon's encirclement diameter to its circumference is 2.21.

[0142] Example 18

[0143] This embodiment is based on Embodiment 3, which has a protrusion on the first cone. The distance between the highest point of the protrusion and the central axis of the balloon is 9.0 mm, and the horizontal distance between the highest point 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 that lies flat and faces the balloon body, with the included angle of the "V" shape being 30°. The positioning accuracy of the stent at the bifurcation lesion of the pulmonary artery in dogs is |d 偏离 The diameter is 0.38 mm, and the ratio of the balloon's encirclement diameter is 2.24.

[0144] Examples 19-25

[0145] For ease of explanation, this invention adds relevant parameters of the balloon dilation catheter to Example 12 to further illustrate the influence of these parameters on the catheter's performance. However, this does not mean that the parameters of the balloon dilation catheter have any limiting effect on the balloon parameters. Here, the balloon parameters and the balloon dilation catheter parameters are independent and do not affect each other. The main limitation in each embodiment is the inner diameter D of the proximal connector. 近内 The gap G between the push tube and the proximal connector, the wall thickness W3 of the proximal connector and its relationship with the wall thickness W of the push tube. 推 The ratio N 壁厚 The ratio S of the radial cross-sectional area of ​​the filling cavity to the radial cross-sectional area of ​​the pushing tube 径 The maximum width W of the filling cavity in the radial direction 充max Minimum wall thickness W of the guidewire cavity 导min The minimum wall thickness W of the filling cavity 充min The diameter d at the front end of the guide tube 引 and the diameter ratio N between it and the second connecting part 引直 The specific parameters for each embodiment are as follows (see Table 2): Decompression time T, balloon burst pressure Pa, and balloon profile after compression, for each embodiment's specific structural features.

[0146] Table 2 shows the specific design parameters of the balloons and balloon dilation catheters in Examples 19 to 25, as well as the performance characterization parameters of the balloon dilation catheters with these design features.

[0147]

[0148] In this procedure, a balloon dilation catheter was used to implant a stent at the bifurcation of the pulmonary artery in a dog. During the procedure, the guidewire could be easily pulled in and out of the guidewire lumen, allowing the guide tube to be smoothly inserted into the blood vessel and guiding the balloon smoothly into the vessel. As the balloon was advanced within the vessel, the stent was accurately advanced to the narrowed target vessel. After the medium was introduced into the filling lumen, the balloon inflated smoothly, expanding the stent to its rated diameter. The balloon remained inflated for a period of time without rupture. The balloon then deflated within a certain time, and the subsequent withdrawal of the balloon was smooth, with the stent precisely released at the target vessel. Simultaneously, the narrowed target vessel was visibly dilated by the stent, achieving the expected surgical outcome.

[0149] To further illustrate the technical effects of the balloon dilation catheter proposed in the embodiments of the present invention, a comparative description is provided below.

[0150] Comparative Example 1

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

[0152] When using this balloon dilation catheter to implant a stent in the dog's pulmonary artery, the guidewire can be smoothly inserted into the guidewire lumen 211 and can be flexibly pulled and moved. The balloon 1 can be smoothly inserted into the body and pushed smoothly within the blood vessel. However, when pushed to the lesion area at the bifurcation vessel, after the medium is introduced into the filling lumen 212, the balloon 1 can be smoothly inflated to the rated diameter. But during the dilation process, under the action of the branch vessel, the balloon and the stent move backward together, ultimately leading to |d 偏离 The diameter reached 4.5mm, indicating inaccurate stent positioning and incomplete coverage of the lesion area.

[0153] Comparative Example 2

[0154] The design of the balloon dilation catheter in this embodiment is basically the same as that in embodiment 3. The difference is 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 using this balloon dilation catheter to implant a stent in the dog's pulmonary artery, the guidewire can be smoothly inserted into the guidewire lumen 211 and can be flexibly pulled and moved. However, due to the steepness of the cone of the distal body 12, the balloon 1 is difficult to insert into the body, requiring enlargement of the insertion port, and the process of pushing it into the blood vessel is also relatively slow. During the process of pushing to the stenotic lesion of the branch vessel, the distal body 12 did not cause damage to the surrounding branch vessel. However, due to the large cone angle α1 of the first cone, the stent moved forward relative to the balloon during balloon dilation, ultimately leading to |d 偏离 The diameter reached 4.8mm, indicating inaccurate stent positioning and incomplete coverage of the lesion area.

[0156] Comparative Example 3

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

[0158] When using this balloon dilation catheter to implant a stent in the dog's pulmonary artery, the guidewire smoothly inserts into the guidewire lumen 211 and can be flexibly pulled and moved. The balloon 1 is successfully inserted into the body and pushed to the stenotic lesion in the branch vessel. The distal body 12 does not damage surrounding branch vessels. After the medium is introduced into the filling lumen 212, the balloon 1 smoothly inflates to its rated diameter and opens the narrowed vessel, but the inflation takes a relatively long time. The balloon 1 remains inflated for a period without rupturing. The balloon 1 then deflates within 25 seconds, which also takes a relatively long time, resulting in a prolonged obstruction of blood flow within the vessel, posing a safety hazard. The subsequent withdrawal of the balloon 1 is smooth, and the narrowed vessel can be seen to have been effectively opened.

[0159] As can be seen from the data in the above embodiments and comparative examples, by setting the taper of a balloon of a specific diameter within a certain range, the positioning accuracy of the stent can be significantly improved. Furthermore, optimizing the length L of the stent's conical portion, the surface roughness of the balloon and stent, the maximum static friction between the balloon and stent, and adding a protrusion to the balloon's conical portion can all improve the positioning accuracy of the stent to a certain extent. Especially when these parameters are combined, the accuracy of the stent at bifurcation vessel lesions can be significantly improved. In other words, this invention can improve the positioning accuracy of the stent at bifurcation vessel lesions without adding any additional structures, and the preparation of the balloon and stent delivery system is simple and has low production costs. It also does not sacrifice the profile of the stent system in exchange for stent positioning accuracy, providing an excellent technical solution for stent implantation at bifurcation 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 within the protection scope of the present invention.

Claims

1. A balloon characterized by, The balloon comprises a balloon body and a distal body and a proximal body connected to two ends of the balloon body respectively, the balloon body, the distal body and the proximal body combine to form an inner cavity, the inner cavity is used for accommodating a medium for inflating the balloon, the distal body comprises a first taper, the proximal body comprises a second taper, the size of the taper angle α1 of at least the first taper and the size of the diameter d of the balloon body in the expanded state of the balloon satisfy the following relationship: ; where: k1 e [11.009, 27.4] and b1 e [7.98, 14.2], 5 < d < 16, and d is a positive integer; Under the diameter specification of the balloon body in the expanded state of the balloon corresponding to the relationship, there is a corresponding value interval of the taper angle α1, and in the value interval, the matching degree between the balloon and the stent can reduce the movement of the stent in the proximal direction of the balloon under the action of the bifurcated blood vessel.

2. A balloon characterized in that, The balloon comprises a balloon body and a distal body and a proximal body connected to two ends of the balloon body respectively, the balloon body, the distal body and the proximal body combine to form an inner cavity, the inner cavity is used for accommodating a medium for inflating the balloon, the distal body comprises a first taper, the proximal body comprises a second taper, the size of the taper angle α1 of the first taper and / or the size of the taper angle α2 of the second taper and the size of the diameter d of the balloon body in the expanded state of the balloon satisfy the following relationship: ; where: k1 e [12, 20], and b1 e [9, 25.8], 5 < d < 16, and d is a positive integer; ; where: k2 e [12, 20], and b2 e [9, 25.8], 5 < d < 16, and d is a positive integer; The roughness Ra of the surface of the balloon body is 0.03 μm-0.2 μm, and the roughness Ra of the surface of the first taper is 0.05 μm-0.2 μm; Under the diameter specification of the balloon body in the expanded state of the balloon corresponding to the relationship, there is a corresponding value interval of the taper angle α1, and in the value interval, the matching degree between the balloon and the stent can reduce the movement of the stent in the proximal direction of the balloon under the action of the bifurcated blood vessel.

3. A balloon characterized by, The balloon comprises a balloon body and a distal body and a proximal body connected to two ends of the balloon body respectively, the balloon body, the distal body and the proximal body combine to form an inner cavity, the inner cavity is used for accommodating a medium for inflating the balloon, the distal body comprises a first taper, the proximal body comprises a second taper, the size of the taper angle α1 of the first taper and the size of the taper angle α2 of the second taper and the size of the diameter d of the balloon body in the expanded state of the balloon satisfy the following relationship: ; where: k1 e [11.51, 21.52] and d e [5, 9], b1 e [10.2, 21.4]; or k1 e [21, 27.87] and d e [10, 16], b1 e [-11.6, 3.85]; ; where: k2 e [11.51, 21.52] and d e [5, 9], b2 e [10.2, 21.4]; or k2 e [21, 27.87] and d e [10, 16], b2 e [-11.6, 3.85]; Under the diameter specification of the balloon body in the expanded state of the balloon corresponding to the relationship, there is a corresponding value interval of the taper angle α1, and in the value interval, the matching degree between the balloon and the stent can reduce the movement of the stent in the proximal direction of the balloon under the action of the bifurcated blood vessel.

4. The balloon of any of claims 1-3, wherein, The length L1 of the first taper and / or the length L2 of the second taper satisfy the following relationship: ≥ , ≥ where k e [0.6, 2.1].

5. The balloon of any of claims 1-3, wherein, The length L1 of the first taper and / or the length L2 of the second taper satisfy the following relationship: ≥ , ≥ where k e [0.6, 2.1].

6. The balloon of any of claims 1-3, wherein, The first taper and / or the second taper comprises at least one protruding part, and at least part of the distance D of the protruding part from the center axis of the balloon is 1.05-1.5 times the radius d / 2 of the balloon body.

7. The balloon of claim 6, wherein, At least part of the protrusion is horizontally spaced apart from the adjacent end of the balloon body by less than 2 mm; the total length of the protrusion is 5%-35% of the total length of the first or second taper; the protrusion or its tangent line forms a "V" shape with the balloon body, which is flat and has an opening facing the balloon body.

8. The balloon of claim 7, wherein, The included angle of the "V" shape is 30°-150°.

9. The balloon of any of claims 1-3, wherein, At least the first taper includes a stepped structure, which includes at least a first taper section, a second taper section, and a straight section connected between the first taper section and the second taper section, and the other end of the first taper section is connected to the balloon body. The taper angle of the first taper section is 30°-150°, the taper angle of the second taper section is 40°-178°, and the diameter of the straight section is less than the diameter of the balloon body.

10. The balloon of any of claims 1-3, wherein, The ratio of the wall thickness of the balloon body to the diameter of the balloon body in the expanded state is 0.0015-0.

010.

11. A balloon dilatation catheter characterized by, It comprises: a push tube comprising a guide wire lumen for a guide wire to pass through and a filling lumen for a medium to pass through, the guide wire lumen and the filling lumen being axially parallel and isolated from each other by a partition; a balloon as claimed in any one of claims 1-10, the balloon being connected to one end of the push tube, and the inner cavity of the balloon being in communication with the filling lumen; 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 in communication with the guide wire lumen, and the second interface being in communication with the filling lumen; wherein the distal end further comprises a distal end connector, and the proximal end further comprises a proximal end connector, and at least the proximal end connector and the push tube are sealingly connected to form a first connecting portion, and the diameter of the first connecting portion is less than or equal to the diameter of the proximal end connector.

12. The balloon dilation catheter of claim 11, wherein, The inner diameter of the proximal end connector is 1.78 mm-2.2 mm, the gap between the push tube and the proximal end connector is not greater than 0.2 mm, and the ratio of the wall thickness of the proximal end connector to the wall thickness of the push tube is 0.2-2.

0.

13. The balloon dilation catheter of claim 11, wherein, The ratio of the radial cross-sectional area of the filling lumen to the radial cross-sectional area of the push tube is 0.1-0.3, or in the radial direction of the push tube, the maximum width of the filling lumen is 0.3 mm-0.55 mm.

14. The balloon dilation catheter of claim 11, wherein, The balloon dilation catheter further comprises: an inner tube arranged in the inner cavity of the balloon, one end of the inner tube being connected to the push tube, and the other end of the inner tube being connected to the distal end connector; a developing ring arranged on the inner tube; wherein the guide wire lumen is in communication with the inner tube, and the diameter of the inner tube is less than the diameter of the push tube.

15. The balloon dilation catheter of claim 14, wherein, 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 less than the diameter of the distal end connector.

16. The balloon dilation catheter of claim 15, wherein, The balloon dilation catheter further comprises: a guide tube arranged in front of the distal end body in the pushing direction of the push 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 portion is 0.75-0.

94.

17. The balloon dilation catheter of any of claims 11-16, wherein, The minimum wall thickness of the guide wire cavity is 0.08mm-0.12mm; and / or the minimum wall thickness of the filling cavity is 0.08mm-0.15mm.

18. A stent system comprising a stent and the balloon expandable catheter according to any one of claims 11-17, the stent being sleeved on the balloon of the balloon expandable catheter.

19. The support system of claim 18, wherein, The roughness Ra of the inner surface of the stent is 0.05μm-0.4μm; the maximum static friction force of the balloon surface in the stent system is 2.8N-7.9N.

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