Balloon catheter and method of manufacturing the same

Abstract

The application discloses a balloon catheter and a manufacturing method thereof. In the balloon catheter structure, the proximal end of the metal mesh extends to between the welding sleeve and the proximal end tube foot, welding heat when welding the proximal end of the metal mesh can make at least part of the outer cover, the proximal end tube foot and at least part of the welding sleeve fuse to form a fusion body, and the proximal end of the metal mesh is embedded in the fusion body to realize welding fixation. At the same time, since the inner layer tube body of the connecting tube is made of thermosetting material, it will not be deformed or collapsed by heat during welding, therefore, the inner layer tube body can provide radial support to the fusion of the outer cover, the proximal end tube foot and the welding sleeve on the inner side, so as to obtain the same support effect as the inserted mandrel.

Description

Technical Field

[0001] The present application relates to the field of interventional medical devices, and in particular to a balloon catheter and a method for manufacturing the same. Background Art

[0002] Balloon catheters, one of the most commonly used interventional medical devices in interventional therapy, are often used to treat plaques formed by calcified structures at the target location. Simply expanding the balloon at the designated location may not achieve the desired expansion effect, or the balloon may deform under stress within the vessel wall, resulting in a "dogbone effect." Therefore, newer balloon catheter designs often incorporate a metal mesh structure on the outside of the balloon to constrain deformation and cut calcified tissue. This allows the metal mesh on the outside of the balloon to squeeze and cut the plaque under the pressure of the balloon's expansion, achieving a more effective expansion effect. Furthermore, because the metal mesh constrains the balloon and disperses stress, it not only eliminates the "dogbone effect," but also effectively reduces vascular damage caused by uneven balloon deformation and vascular rebound caused by inadequate expansion, significantly reducing the occurrence of dissections.

[0003] While the introduction of metal mesh can significantly improve the effectiveness of interventional treatments, unlike stents, which are delivered to a predetermined location via a balloon and then remain in the body, the metal mesh must be removed along with the balloon at the end of the intervention. Therefore, the ends of the metal mesh must remain securely fixed relative to the ends of the balloon to ensure that the mesh can expand and withdraw with the balloon. To achieve this secure fixation, the mesh is typically welded to the ends of the balloon.

[0004] When welding the two ends of the metal mesh, the heat generated by the welding inevitably causes a partial collapse of the balloon catheter tube. For the proximal end of the balloon, this collapse can prevent the inflation medium used to fill the balloon from flowing properly into the balloon. To address this issue, two welding processes are commonly used for welding the metal mesh to the proximal end of the balloon: one involves cutting off the weld at the distal end of the balloon, removing the inner tube, and inserting a supporting mandrel instead. Using this mandrel as internal support, after welding the proximal end of the balloon to the metal mesh, the mandrel is removed, the inner tube is reinserted, and the distal end of the balloon to the metal mesh is welded again. Another process, as described in patent CN117618753B, previously filed by the inventor himself, involves placing a metal coil spring inside the proximal end of the balloon as a support tube. Because this support tube can elastically bend and deform along the axial direction of the inner tube, it does not need to be removed after welding the proximal end of the metal mesh.

[0005] For some specialized balloon catheters, such as those with perfusion holes, the inner tube cannot be removed during the metal mesh welding process, making the first welding process impractical. While the second welding process, which eliminates the need to remove the inner tube and satisfies the proximal metal mesh welding requirements for these specialized balloon catheters, does not require thermal fusion of the support tube with the corresponding section of the balloon catheter due to the different material of the support tube. Consequently, damage to the weld is likely to occur, potentially rendering the entire balloon catheter inoperable. Summary of the Invention

[0006] The present application provides a balloon catheter and a manufacturing method thereof, which can ensure that the proximal end of the metal mesh has good welding quality while meeting the requirements of opening an infusion hole and / or a rapid exchange port on the balloon catheter.

[0007] According to a first aspect of the present application, a balloon catheter is provided, comprising an inner tube, an outer tube, a balloon, and a metal mesh, wherein the outer tube is sleeved outside the inner tube, the balloon is sleeved outside the inner tube, and the distal pin and the proximal pin of the balloon are sealed and fixed to the outer circumference of the inner tube and the outer tube, respectively. The balloon catheter also includes a welding tube group for welding the proximal end of the metal mesh to the proximal pin, the welding tube group including a connecting tube sandwiched between the inner tube and the proximal pin, and a welding sleeve sleeve sleeved outside the proximal pin. , wherein: the tube ends of the connecting tube and the outer tube are docked and fixed through the proximal tube pin; the connecting tube includes an inner tube body made of thermosetting material and an outer covering layer wrapped around the inner tube body; the metal mesh is sleeved on the outside of the balloon, and the proximal end of the metal mesh is clamped between the welding sleeve and the proximal tube pin. When welding is performed at the welding sleeve, at least part of the outer covering layer can be heated and melted with the proximal tube pin and at least part of the welding sleeve to form a fusion body, and the proximal end of the metal mesh is embedded in the fusion body.

[0008] In some embodiments, the outer cover, the welding sleeve, and the proximal pin are made of the same material.

[0009] In some embodiments, the inner tube body is made of PI material, and the outer covering layer is configured as a nylon layer coated on the outer tube body of the PI material.

[0010] In some embodiments, the balloon catheter also includes a first reinforcing tube that is sleeved on the outside of the outer tube. Within the tube section where the first reinforcing tube is sleeved, part of the circumferential wall of the inner tube is hot-melt-bonded to the tube wall of the outer tube and the first reinforcing tube to form a thickened tube wall for opening an infusion hole. A flow space is reserved between the other part of the circumferential wall of the inner tube and the tube wall of the outer tube for the expansion medium for filling the balloon to pass through.

[0011] In some embodiments, the tube end of the first reinforcing tube is spaced apart from the proximal tube pin, and / or a first developing ring is crimped and fixed on the inner tube at a location corresponding to the opening of the perfusion hole.

[0012] In some embodiments, the balloon catheter also includes a second reinforcing tube that is sleeved outside the outer tube, and the second reinforcing tube is spaced apart from the first reinforcing tube at the proximal end of the first reinforcing tube. Within the tube section where the second reinforcing tube is sleeved, part of the circumferential wall of the inner tube is hot-melt-bonded to the tube wall of the outer tube and the second reinforcing tube to form a thickened tube wall for opening a quick exchange port, and a flow space is reserved between the other part of the circumferential wall of the inner tube and the tube wall of the outer tube for the expansion medium for filling the balloon to pass through.

[0013] In some embodiments, the balloon catheter also includes a hypotube and a catheter seat fixed to the proximal end of the hypotube, the distal end of the hypotube is welded and fixed to the outer tube on the proximal side of the rapid exchange port, and the proximal end of the inner tube stops at the rapid exchange port.

[0014] In some embodiments, the outer surface of the balloon is spray-coated with a drug coating.

[0015] According to the second aspect of the present application, there is also provided a method for manufacturing the above-mentioned balloon catheter, the method comprising the following steps:

[0016] S1: Insert the distal end of the outer tube and the proximal end of the connecting tube into the proximal pin of the balloon and align them, then perform laser welding to fix them.

[0017] S2: insert the inner tube from the proximal end of the outer tube, and pass through the connecting tube and the balloon in the distal direction in sequence, install a first reinforcement tube on the outer tube, and insert a D-shaped core shaft into the inner tube;

[0018] S3: Using the curved surface of the D-shaped mandrel as support, a portion of the circumferential wall of the inner tube is bonded to the wall of the outer tube and the first reinforcement tube by hot air welding. A flow-through space is left between the wall of the inner tube corresponding to the flat surface of the D-shaped mandrel and the wall of the outer tube. After welding, the D-shaped mandrel is removed.

[0019] S4: a second reinforcing tube is disposed outside the outer tube, a circular core shaft is inserted into the inner tube, and a flat core shaft is inserted into the gap between the inner tube and the outer tube, with ends of the circular core shaft and the flat core shaft both extending beyond the second reinforcing tube;

[0020] S5: Fixing the inner tube wall, the outer tube wall, and the second reinforcement tube on the other side of the flat mandrel insertion position by hot air welding, and removing the circular mandrel and the flat mandrel after welding;

[0021] S6: Opening a filling hole at the hot air welding position in step S3, and opening a quick exchange port at the hot air welding position in step S5;

[0022] S7: sealing and fixing the distal pin of the balloon to the inner tube, and fixing the distal end of the metal mesh relative to the distal pin;

[0023] S8: A welding sleeve is disposed outside the proximal end of the metal mesh, and a laser welding process is used to heat and fuse at least a portion of the outer covering of the connecting tube with the proximal tube pin and at least a portion of the welding sleeve to form a fusion body, and the proximal end of the metal mesh is embedded in the fusion body.

[0024] In some embodiments, the method further comprises the following steps independent of steps S1-S8:

[0025] S100 fixes the hypotube to the catheter seat through a dispensing process and fixes the catheter reinforcement at the connection between the two;

[0026] S200 A third reinforcing tube is provided outside the semi-finished product formed in step S7 and the semi-finished product formed in step S100. The portion of the outer tube extending beyond the quick exchange port is aligned with the hypotube in the third reinforcing tube and fixed by welding.

[0027] The technical solutions provided by the embodiments of the present application may have the following beneficial effects:

[0028] The proximal end of the metal mesh extends between the welding sleeve and the proximal pin. When the proximal end of the metal mesh is welded, the welding heat causes at least a portion of the outer covering, the proximal pin, and at least a portion of the welding sleeve to fuse together to form a fusion body. The proximal end of the metal mesh is embedded within the fusion body, thereby achieving weld fixation. Simultaneously, because the inner tube body of the connecting tube is made of a thermosetting material, it does not deform or collapse due to heat during welding. Therefore, the inner tube body can provide radial support to the outer covering, the proximal pin, and the welding sleeve at the weld, achieving the same support effect as an inserted mandrel. Because the inner and outer layers of the connecting tube are made of different materials, the need for supporting the local pipe section during welding is met, as well as the need for integration with other pipe structures to reliably secure the proximal end of the metal mesh. Furthermore, the fusion of the outer covering and the proximal pin increases the thickness of the inner tube wall to a certain extent, and the proximal end embedding effect of the metal mesh is also superior to existing welding processes.

[0029] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 This is a schematic diagram of the overall structure of a balloon catheter according to one embodiment of the present application;

[0031] Figure 2 It is around Figure 1 A schematic diagram of a local pipe section structure of a welded pipe group is shown in FIG;

[0032] Figure 3 It is around Figure 1 FIG. 7 is a schematic diagram of a local pipe section structure of a quick exchange port;

[0033] Figure 4 This is a schematic diagram of the structure of a local pipe section when welding the pipe section where the quick exchange port is located. In the figure, a round core shaft is inserted into the inner pipe, and a flat core shaft is inserted between the inner and outer pipes;

[0034] Figure 5 yes Figure 1 , which is a schematic diagram of a partial structure of the proximal end of a balloon catheter, shows a structure in which the proximal semi-finished product and the distal semi-finished product are butted together by welding a protective tube or the like.

[0035] Description of reference numerals:

[0036] 1. Tip tube; 2. Balloon; 21. Proximal tube pin; 3. Second developing ring; 4. Metal mesh; 5. Perfusion hole; 6. First developing ring; 7. Inner tube; 8. Welding tube assembly; 81. Connecting tube; 811. Inner tube body; 812. Outer covering; 82. Welding sleeve; 9. Outer tube; 10. Quick exchange port; 11. Hypotube; 12. Marking band; 13. Catheter reinforcement; 14. Catheter seat; 15. Welding protection tube; 16. Round mandrel; 17. Flat mandrel. DETAILED DESCRIPTION

[0037] The exemplary embodiments will be described in detail here, and examples thereof are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The methods described in the following exemplary embodiments do not represent all methods consistent with the present application, but are only preferred embodiments of the present application. Those skilled in the art can make some changes or modify the technical contents disclosed above into equivalent embodiments with equivalent changes without departing from the scope of the technical solution of the present application. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application are still within the scope of the technical solution of the present application.

[0038] Furthermore, in the description of this application, the proximal and distal ends are defined with reference to the operator's position during use of the balloon catheter. That is, the distal end refers to the end of the device or component relatively farthest from the operator, while the proximal end refers to the end of the device or component relatively close to the operator. Throughout the drawings of this application, the left end is considered the distal end, and the right end is considered the proximal end. The following detailed description of various embodiments of this application will be provided in conjunction with the drawings.

[0039] like Figure 1 As shown in FIG, a balloon catheter according to an embodiment of the present application comprises an inner tube 7, an outer tube 9, a balloon 2, and a metal mesh 4. The outer tube 9 is sheathed over the inner tube 7, with a certain gap left between the two to allow the expansion medium used to fill the balloon 2 to flow through.

[0040] The balloon 2 is generally positioned at the distal end of the overall balloon catheter structure. It comprises a body portion, which actually dilates the blood vessel, and proximal and distal pins 21 and 21 (not labeled in the figure) connected to the proximal and distal ends of the body portion. A second developing ring 3 is provided on the inner tube 7 at each end of the body, corresponding to the actual working length of the balloon 2.

[0041] The distal pin of the balloon 2 is sealed and fixed outside the inner tube 7, and the proximal pin 21 is sealed and fixed relative to the outer tube 9. In this way, the expansion medium flowing into the balloon 2 from the gap between the outer tube 9 and the inner tube 7 can inflate the balloon 2 to a preset level to meet the needs of vascular dilation.

[0042] In order to facilitate the shuttle of the front end of the balloon catheter in the blood vessel, Figure 1 In the illustrated embodiment, a tip tube 1 is fixedly disposed in the distal pin of the balloon 2 , and the lumen of the tip tube 1 is communicated with the lumen of the inner tube 7 , so that a guide wire can pass through the inner tube 7 and the lumen of the tip tube 1 .

[0043] A metal mesh 4 is positioned over the outside of the balloon 2 and fixed relative to the balloon 2. The metal mesh 4 functions as follows: as the balloon 2 inflates, the metal mesh 4 expands and constrains the balloon 2's expansion, preventing substantial axial and radial elongation. In some embodiments, the expanded metal mesh 4 has a structure similar to a grid. The upper portion of the inflated balloon 2 extends from the mesh opening to form a pillow. This allows the stress caused by the balloon 2's expansion to be radially distributed, thereby evenly supporting the vessel wall. Furthermore, during the inflation process of the balloon 2, the metal mesh 4, under the influence of the balloon 2's filling pressure, can incise plaque on the vessel wall to a certain extent, thereby forming a wound with a predetermined shape (based on the expanded shape of the metal mesh 4) and a controllable depth at the intravascular plaque. Consequently, as the balloon 2 further inflates, the tearing shape and extent of the wound can be controlled, ultimately reducing intimal damage, hoop stress, and elastic retraction of the vessel lumen after balloon 2 withdrawal.

[0044] Unlike stents implanted within a blood vessel using the delivery function of a balloon 2, the metal mesh 4 must be withdrawn along with the balloon 2 when the balloon catheter is withdrawn. Therefore, after the inflation medium within the balloon 2 flows back and deflates, the metal mesh 4 elastically recovers to its pre-expansion state, allowing it to be withdrawn along with the balloon 2.

[0045] In order to ensure that the metal mesh 4 can be withdrawn with the balloon 2, it is necessary to ensure that the distal and proximal ends of the metal mesh 4 are reliably connected to the balloon 2. Usually, the distal and proximal ends of the metal mesh 4 need to be welded and fixed to the distal and proximal pins 21 of the balloon 2.

[0046] During welding at the distal pin, since the inner tube 7 and the distal pin of the balloon 2 must be sealed, and this is essentially the most distal point of the balloon catheter, the distal welding of the metal mesh 4 can be performed using an appropriate welding process. However, at the proximal pin 21 of the balloon 2, the heat from welding often causes the proximal pin 21 to collapse, and the flow gap between the inner tube 7 and the outer tube 9 must be maintained to ensure that it is not blocked to meet the flow requirements of the inflation medium. Therefore, the welding at this end requires a certain support structure within the pipe section to prevent the proximal pin 21 from collapsing due to heat.

[0047] Previous practices included: first, sealing and connecting the two ends of the balloon 2 to perform a filling test on the balloon 2; then, cutting the weld at the distal pin of the balloon 2 to remove the inner tube 7, and instead inserting a core shaft to provide support during welding at the position where the inner tube 7 was originally inserted. In this way, with the core shaft as the inner support, welding is performed between the proximal pin 21 and the proximal end of the metal mesh 4. During welding, the support of the core shaft suppresses the thermal collapse of the proximal pin 21, and since the inner tube 7 has been removed at this time, the welding heat will not affect the flow gap between the inner and outer tubes. After welding is completed, the core shaft is removed, and the inner tube 7 is reinserted into its original position, and the welding steps at the distal pin are repeated.

[0048] Although this approach can avoid the collapse of the proximal pin 21 caused by welding heat. However, with the emergence of some new interventional operation requirements, for example, it is necessary to open an infusion hole and a rapid exchange port on the balloon catheter. Among them: the opening of the infusion hole can effectively reduce the risk of myocardial infarction caused by long-term blockage of blood flow, and prolong the balloon expansion time as much as possible, so as to increase the diffusion of anti-proliferative drugs such as paclitaxel sprayed on the outside of the balloon to the lesion site and thus reduce the diffusion of drugs in the blood, while enhancing the shaping effect of the blood vessels at the lesion site and reducing vascular rebound and restenosis. The rapid exchange port allows the guide wire to pass directly into the inner tube 7 from there without entering through the catheter seat.

[0049] Whether it is the perfusion hole or the quick exchange port, it needs to be connected to the inner cavity of the inner tube 7. Therefore, when these holes are opened, the relative position relationship between the inner tube 7 and the outer tube 9 must be maintained at the state when the assembly is completed. This makes it impossible to apply the process of pulling out the inner tube 7 and welding the proximal end of the metal mesh. In the inventor's prior application, in order to take into account the support during welding and the local bending performance of the balloon catheter product when in use, a coil spring was set on the inner side of the proximal tube pin of the balloon. It not only does not deform when heated and provides reliable support, but it can also bend relatively flexibly, so as not to affect the bending performance of the product.

[0050] However, the coil spring is made of a different material than the corresponding section of the balloon catheter. During welding, the melted balloon catheter material is not compatible with the coil spring. Consequently, the coil spring is a vulnerable part of the balloon catheter. If this part breaks, the entire balloon catheter loses its intended function.

[0051] To this end, Figure 1 Based on the combination Figure 2 As shown in , the balloon catheter also includes a welding tube assembly 8 for welding and fixing the proximal end of the metal mesh 4 to the proximal pin 21. The welding tube assembly 8 includes a connecting tube 81 arranged on the outside of the inner tube 7 and the inside of the proximal pin 21, and a welding sleeve 82 sleeved on the outside of the proximal pin 21.

[0052] The proximal end of the connecting tube 81 is fixed to the distal end of the outer tube 9 by the proximal end pin 21. The connecting tube 81 further includes an inner tube body 811 made of thermosetting material and an outer coating 812 covering the outer side of the inner tube body 811.

[0053] The proximal end of the metal mesh 4 extends between the welding sleeve 82 and the proximal tube pin 21. When the proximal end of the metal mesh 4 is welded, the welding heat causes at least part of the outer covering 812, the proximal tube pin 21 and at least part of the welding sleeve 82 to fuse to form a fusion body, and the proximal end of the metal mesh 4 is embedded in the fusion body to achieve welding fixation.

[0054] At the same time, since the inner tube body 811 of the connecting tube 81 is made of thermosetting material, it will not be deformed or collapsed by heat during welding. Therefore, the inner tube body 811 can provide radial support to the outer covering 812, the proximal tube pin 21 and the welding sleeve 82 on the inner side to achieve the same support effect as the embedded core shaft.

[0055] The inner and outer layers of connecting tube 81 are made of different materials to balance the need for supporting a localized section during welding and integrating with the rest of the tube structure to reliably secure the proximal end of metal mesh 4. Furthermore, the integration of outer covering 812 with proximal tube pin 21 increases the thickness of the inner tube wall to a certain extent. Assuming the same thickness as welding sleeve 82, the proximal end of metal mesh 4 is more effectively embedded than in the previously described welding process using a mandrel.

[0056] In some embodiments, the outer covering 812, the welding sleeve 82, and the proximal pin 21 are made of the same material. This allows for optimal compatibility between the three, allowing for better fusion under the action of welding heat, thereby increasing the bonding strength between the metal mesh 4 and the weld body.

[0057] Typically, the balloon 2 is integrally formed by stretching and inflation from a predetermined tubular material. Therefore, the material of the proximal pin 21 is determined by the raw material of the balloon 2. Therefore, the materials of the outer covering 812 and the welding sleeve 82 can be selected based on the material of the balloon 2. In some embodiments, the inner tube 811 is made of PI material, while the outer covering 812 is provided as a nylon layer coated on the outer surface of the PI tube.

[0058] The balloon catheter may also include a first reinforcement tube and a second reinforcement tube sleeved on the outer tube 9. The first reinforcement tube is arranged corresponding to the opening position of the perfusion hole 5, and the second reinforcement tube is arranged corresponding to the opening position of the quick exchange port 10. In the balloon catheter, the wall thickness of each tube section is not large, and the opening of the perfusion hole 5 and the quick exchange port will have a great impact on the strength of the local tube section. Therefore, in order to reduce the weakening of the strength caused by these orifice structures and ensure that the orifice structure can maintain the preset shape and position, the first reinforcement tube and the second reinforcement tube are arranged at the corresponding positions. In this way, after hot air welding, the first reinforcement tube and the second reinforcement tube are fused and bonded to the outer tube 9 at the corresponding positions, which is equivalent to pre-thickening the wall of the corresponding tube section of the outer tube 9.

[0059] As previously mentioned, the perfusion hole 5 needs to be connected to the lumen of the inner tube 7 to allow blood to flow from one end of the balloon 2 to the other. Therefore, within the section of the tube where the first reinforcing tube is sheathed, a portion of the circumferential wall of the inner tube 7 is heat-fused to the wall of the outer tube 9 and the first reinforcing tube, thus forming a thickened tube wall for the perfusion hole 5. The remaining portion of the circumferential wall of the inner tube 7 is not bonded to the outer tube 9, but leaves a flow space for the inflation medium used to fill the balloon 2.

[0060] In the manufacturing method to be mentioned later, the D-shaped core shaft is used as an internal support in the inner tube 7, and the tube walls of the inner tube 7, outer tube 9 and first reinforcement tube corresponding to the curved surface of the D-shaped core shaft can be hot-melt-bonded by a hot air welding process. In this way, the remaining inner and outer tube walls corresponding to the flat surface of the D-shaped core shaft are kept spaced apart.

[0061] Continue to refer Figure 1 As shown in FIG, to facilitate the operator's determination of the location of the perfusion hole 5 under X-ray during surgery, a first developing ring 6 is crimped and fixed to the inner tube 7 at the location corresponding to the perfusion hole 5. Furthermore, two perfusion holes 5 can be provided, spaced apart in the proximal-to-distal direction, thereby fully ensuring distal blood supply requirements.

[0062] Similarly, in Figure 1 Based on the combination Figure 3 As shown in the figure, to minimize local tube diameter enlargement, a second reinforcing tube is spaced apart from the proximal end of the first reinforcing tube. Within the scope of this second reinforcing tube, a portion of the circumferential wall of the inner tube 7 is heat-fused to the wall of the outer tube 9 and the second reinforcing tube to form a thickened tube wall for providing the rapid exchange port 10. A flow space is left between the remaining circumferential wall of the inner tube 7 and the wall of the outer tube 9 to allow the inflation medium used to fill the balloon 2 to pass through.

[0063] In some embodiments, the outer surface of the balloon 2 is sprayed with a drug coating to form a drug balloon. The drug can be paclitaxel or rapamycin. With the help of the cutting effect of the metal mesh 4 on the corresponding part of the blood vessel, the drug sprayed on the outside of the balloon 2 can be accurately transferred to the corresponding part of the inner wall of the blood vessel, while reducing the risk of the drug being washed into the blood by the blood. At the same time, since the balloon catheter in this application is provided with a perfusion hole 5, the balloon 2 can stay in the patient's body for a relatively long time without worrying about distal blood supply problems. Therefore, it can also give the drug coating sufficient time to transfer to the corresponding part of the blood vessel wall.

[0064] exist Figure 1 Based on the combination Figure 5 As shown in FIG, the balloon catheter further includes a hypotube 11 and a catheter seat 14 fixed to the proximal end of the hypotube 11. The distal end of the hypotube 11 is welded and fixed to the outer tube 9 at the proximal side of the rapid exchange port 10 by means of a third reinforcing tube and a welding protection tube 15 shown in the figure. Figure 3 As shown in FIG, only the outer tube 9 extends proximally beyond the rapid exchange port 10 for a portion thereof to be docked and fixed with the hypotube 11. In some embodiments, the hypotube 11 may also be provided with a marking band 12, which is used to facilitate the doctor to observe the working length of the entire balloon catheter into the human body during the operation, providing a reference for the doctor.

[0065] According to another aspect of the present application, there is also provided a method for manufacturing the balloon catheter according to any one of the above embodiments, the method comprising the following steps:

[0066] S1 Insert the distal end of the outer tube 9 and the proximal end of the connecting tube 81 into the proximal pin 21 of the balloon 2 and align them, and perform laser welding to fix them;

[0067] S2: Insert the inner tube 7 from the proximal end of the outer tube 9 and pass it through the connecting tube 81 and the balloon 2 in the distal direction. Install a first reinforcement tube on the outer tube 9 and insert a D-shaped mandrel into the inner tube 7.

[0068] S3: Using the arcuate surface of the inserted D-shaped mandrel as support, the circumferential wall of the inner tube 7 is fixed to the wall of the outer tube 9 and the first reinforcement tube by hot air welding. A flow space is left between the wall of the inner tube 7 and the wall of the outer tube 9 corresponding to the flat surface of the D-shaped mandrel. After hot air welding, the D-shaped mandrel is removed.

[0069] S4 References Figure 4 As shown in , a second reinforcing tube is disposed outside the outer tube 9, a circular core shaft 16 is inserted into the inner tube 7, and a flat core shaft 17 is inserted into the gap between the inner tube 7 and the outer tube 9. The ends of the circular core shaft 16 and the flat core shaft 17 both extend beyond the second reinforcing tube;

[0070] S5. Insert the flat mandrel 17 into the inner tube 7 wall, the outer tube 9 wall and the second reinforcement tube on the other side of the position and fix them together by hot air welding. After welding, remove the circular mandrel 16 and the flat mandrel 17.

[0071] S6: Opening a perfusion hole 5 at the hot air welding position in step S3, and opening a quick exchange port 10 at the hot air welding position in step S5;

[0072] S7: Seal and fix the distal pin of the balloon 2 to the inner tube 7 and the tip tube 1, and fix the distal end of the metal mesh 4 relatively to the distal pin;

[0073] S8 A welding sleeve 82 is disposed outside the proximal end of the metal mesh 4, and a laser welding process is used to heat and fuse at least a portion of the outer covering 812 of the connecting tube 81 with the proximal tube pin 21 and at least a portion of the welding sleeve 82 to form a fusion body, so that the proximal end of the metal mesh 4 is embedded in the fusion body.

[0074] like Figure 4 As shown, since the flat mandrel 17 is inserted into one side of the outer portion of the inner tube 7, the flat mandrel 17 supports the inner tube 7 and the outer tube 9 during hot air welding, thereby preventing the two parts of the tube wall from adhering to each other under the action of welding heat, thereby keeping the flow space between the inner and outer tubes at the location where the quick exchange port 10 is opened unaffected.

[0075] In addition, in the hot air welding process of steps S3 and S5, Figure 4 The welding protection tube 15 shown protects the welding part. After the welding is completed, the welding protection tube 15 can be torn off and removed from the balloon catheter. Figure 1 The output product does not have the protective tube 15 welded on it.

[0076] Combine Figure 3 and Figure 4 As shown in the figure, the proximal end of the inner tube 7 roughly stops at the opening of the quick exchange port 10. In this way, when the hot air welding operation in step S5 is performed, part of the tube wall near the proximal tube opening of the inner tube 7 is hot-air bonded and fixed to the tube wall on the outer tube 9, which is located on the distal side of the quick exchange port 10, while another part of the tube wall near the proximal tube opening of the inner tube 7 is hot-air bonded and fixed to the tube wall on the outer tube 9, which is located on the proximal side of the quick exchange port 10. In this way, the proximal tube opening of the inner tube 7 overlaps and is connected to the quick exchange port 10.

[0077] The pouring hole 5 and the quick exchange port 10 can be formed by a dedicated punching device or by other general tooling.

[0078] Furthermore, the method further comprises the following steps independent of steps S1-S8:

[0079] S100 Fix the hypotube 11 and the catheter seat 14 by glue dispensing process, and fix the catheter reinforcement 13 at the connection between the two;

[0080] S200 A third reinforcing tube is provided outside the semi-finished product formed in step S7 and the semi-finished product formed in step S100. The portion of the outer tube 9 extending beyond the quick exchange port 10 is aligned with the hypotube 11 in the third reinforcing tube and fixed by welding.

[0081] Similarly, during the welding and fixing process of step S200, the aforementioned welding protection tube 15 can also be used to protect the local pipe section at the welding location. In addition, when a marker band 12 is provided in the balloon catheter structure, the above-mentioned step S100 can also include the operation of fixing the marker band 12 to the hypotube 11.

[0082] It can be seen that during manufacturing, with the proximal end of the outer tube 9 and the distal end of the hypotube 11 as the boundary, the corresponding parts such as the balloon 2, the outer tube 9, the inner tube 7 can be assembled separately from the corresponding parts on one side of the hypotube 11, thereby forming a semi-finished product, while the corresponding parts such as the hypotube 11 and the catheter seat 14 are assembled separately to form another semi-finished product. Finally, the two semi-finished products are fixedly assembled through the above step S200 to obtain Figure 1 The balloon catheter shown in FIG. This manufacturing process of assembling two parts separately and then docking the two semi-finished parts can greatly improve assembly efficiency.

[0083] The above is merely a preferred embodiment of the present application and does not constitute any form of limitation to the present application. Although the present application has been disclosed as above with preferred embodiments, it is not intended to limit the present application. Any technician familiar with this profession can make slight changes or modifications to equivalent embodiments with equivalent changes using the technical contents disclosed above without departing from the scope of the technical solution of the present application. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application are still within the scope of the technical solution of the present application.

Claims

1. A balloon catheter comprising an inner tube (7), an outer tube (9), a balloon (2) and a metal mesh (4), wherein the outer tube (9) is sleeved on the outer side of the inner tube (7), the balloon (2) is sleeved on the outer side of the inner tube (7), and the distal pin and the proximal pin (21) of the balloon (2) are sealed and fixed to the outer peripheral sides of the inner tube (7) and the outer tube (9), respectively, characterized in that: The balloon catheter further comprises a welding tube assembly (8) for welding and fixing the proximal end of the metal mesh (4) to the proximal tube pin (21), wherein the welding tube assembly (8) comprises a connecting tube (81) sandwiched between the inner tube (7) and the proximal tube pin (21), and a welding sleeve (82) sleeved outside the proximal tube pin (21), wherein: The connecting tube (81) and the outer tube (9) are butted and fixed together via the proximal tube pin (21); The connecting pipe (81) comprises an inner pipe body (811) made of a thermosetting material and an outer covering layer (812) covering the inner pipe body (811); The metal mesh (4) is sleeved on the outside of the balloon (2), and the proximal end of the metal mesh (4) is clamped between the welding sleeve (82) and the proximal tube pin (21). When welding is performed at the welding sleeve (82), at least a portion of the outer covering (812) can be heated and melted with the proximal tube pin (21) and at least a portion of the welding sleeve (82) to form a fusion body, and the proximal end of the metal mesh (4) is embedded in the fusion body.

2. The balloon catheter according to claim 1, characterized in that The outer covering layer (812), the welding sleeve (82) and the proximal tube pin (21) are made of the same material.

3. The balloon catheter according to claim 1, characterized in that The inner tube body (811) is made of PI material, and the outer coating (812) is configured as a nylon layer coated on the outer surface of the tube body made of PI material.

4. The balloon catheter according to claim 1, characterized in that The balloon catheter further comprises a first reinforcing tube sheathed outside the outer tube (9). Within the range of the tube section sheathed by the first reinforcing tube, a portion of the circumferential wall of the inner tube (7) is thermally melted to the tube wall of the outer tube (9) and the first reinforcing tube to form a thickened tube wall for opening the perfusion hole (5). A flow space for the expansion medium for filling the balloon (2) is reserved between the other portion of the circumferential wall of the inner tube (7) and the tube wall of the outer tube (9).

5. The balloon catheter according to claim 4, characterized in that The tube end of the first reinforcing tube is spaced apart from the proximal tube pin (21), and / or a first developing ring (6) is fixedly pressed and gripped on the inner tube (7) at a position corresponding to the opening of the perfusion hole (5). The balloon catheter according to claim 4 , wherein: The balloon catheter also includes a second reinforcing tube sleeved outside the outer tube (9), and the second reinforcing tube is spaced apart from the first reinforcing tube at the proximal end of the first reinforcing tube. Within the tube section where the second reinforcing tube is sleeved, part of the circumferential wall of the inner tube (7) is hot-melt-bonded with the tube wall of the outer tube (9) and the second reinforcing tube to form a thickened tube wall for opening a quick exchange port (10). A flow space is reserved between the other part of the circumferential wall of the inner tube (7) and the tube wall of the outer tube (9) for the expansion medium for filling the balloon (2) to pass through.

7. The balloon catheter according to claim 6, characterized in that The balloon catheter further comprises a hypotube (11) and a catheter seat (14) fixed to the proximal end of the hypotube (11); the distal end of the hypotube (11) is welded and fixed to the outer tube (9) on the proximal side of the rapid exchange port (10); and the proximal end of the inner tube (7) is terminated at the rapid exchange port (10).

8. The balloon catheter according to claim 1, characterized in that The outer surface of the balloon (2) is sprayed with a drug coating.

9. A method for manufacturing a balloon catheter according to any one of claims 1 to 8, characterized in that: The method comprises the following steps: S1 Insert the distal end of the outer tube (9) and the proximal end of the connecting tube (81) into the proximal tube pin (21) of the balloon (2) and align them, and perform laser welding to fix them; S2 Insert the inner tube (7) from the proximal end of the outer tube (9), and pass through the connecting tube (81) and the balloon (2) in the distal direction, arrange a first reinforcing tube on the outer tube (9), and insert a D-shaped core shaft into the inner tube (7); S3 Using the arc surface of the D-shaped mandrel as support, a portion of the circumferential wall of the inner tube (7) is bonded and fixed to the wall of the outer tube (9) and the first reinforcement tube by a hot air welding process, and a flow-allowing space is left between the wall of the inner tube (7) and the wall of the outer tube (9) corresponding to the straight surface of the D-shaped mandrel, and the D-shaped mandrel is removed after welding; S4: a second reinforcing tube is disposed outside the outer tube (9), a circular core shaft (16) is inserted into the inner tube (7), and a flat core shaft (17) is inserted into the gap between the inner tube (7) and the outer tube (9), with the ends of the circular core shaft (16) and the flat core shaft (17) both extending beyond the second reinforcing tube; S5. Insert the flat mandrel (17) into the wall of the inner tube (7), the wall of the outer tube (9) and the second reinforcement tube on the other side of the position and fix them together through a hot air welding process. After welding, remove the circular mandrel (16) and the flat mandrel (17); S6. Opening a filling hole (5) at the hot air welding position in step S3, and opening a quick exchange port (10) at the hot air welding position in step S5; S7: sealing and fixing the distal end pin of the balloon (2) to the inner tube (7), and fixing the distal end of the metal mesh (4) relative to the distal end pin; S8 A welding sleeve (82) is provided on the proximal outer surface of the metal mesh (4), and a laser welding process is used to heat and fuse at least a portion of the outer covering layer (812) of the connecting tube (81) with the proximal tube pin (21) and at least a portion of the welding sleeve (82) to form a fusion body, and the proximal end of the metal mesh (4) is embedded in the fusion body.

10. The method according to claim 9, characterized in that The method further comprises the following steps independent of steps S1-S8: S100 fixes the hypotube (11) and the catheter seat (14) by a dispensing process, and fixes the catheter reinforcement (13) at the connection between the two; S200 A third reinforcing tube is provided outside the semi-finished product formed in step S7 and the semi-finished product formed in step S100, and the portion of the outer tube (9) extending beyond the quick exchange port (10) is aligned with the hypotube (11) in the third reinforcing tube and fixed by welding.

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