Balloon catheter and method for manufacturing the same

Abstract

The present application discloses a balloon catheter and a manufacturing method thereof, the balloon catheter comprises an inner tube, a balloon, a metal mesh, an outer tube and a welding sleeve, wherein: the outer tube is sleeved outside the inner tube, the balloon is sleeved outside the inner tube, and its two ends are respectively sealed and fixed to the outer peripheral sides of the inner tube and the outer tube; the outer tube comprises a tube body and a braided wire layer embedded in the tube body, along the length direction of the tube body, the distal end of the tube body extends beyond the braided wire layer to form a welded connection part in one piece; the welding sleeve is sleeved outside the welded connection part; the metal mesh is sleeved outside the balloon, the proximal end of the metal mesh extends between the welding sleeve and the welding connection part, and is welded and fixed between the welding connection part and the welding sleeve. The balloon catheter can reliably fix the metal mesh and the braided tube under the premise of ensuring the pushing performance.

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] One of the commonly used interventional devices in interventional treatment is the balloon catheter. Its basic structure is to configure an inflatable balloon at the distal end of the catheter. During the operation, the balloon follows the catheter to the target position under the guidance of the guidewire; by introducing an expansion medium, such as saline, into the balloon, the balloon is inflated and expanded to a preset degree to perform local expansion treatment on the target position. However, when there are plaques formed by calcified structures at the target position, the expected expansion effect cannot be achieved by balloon expansion alone. Therefore, in some balloon catheters, a metal mesh structure is set outside the balloon. When the balloon is inflated, the metal mesh squeezes and cuts the plaque under the pushing action of the balloon, thereby achieving the preset expansion effect.

[0003] Although adding a metal mesh outside the balloon can improve the expansion effect, it will also increase the diameter of the balloon, and the pushing performance requirements are higher than those of balloon catheters without metal mesh. In order to obtain better pushing performance, an outer tube with braided wire inside is usually connected to the outside of the catheter. Unlike stents implanted in the human body, the metal mesh needs to be withdrawn from the body with the catheter and outer tube before the end of the interventional operation. Therefore, the end of the metal mesh usually needs to be reliably welded and fixed to the outer tube.

[0004] However, although the above outer tube structure can improve the pushing performance, when the metal mesh is fixed thereto, the metal mesh is difficult to be reliably welded to the outer tube due to the presence of the braided wire. Summary of the invention

[0005] The present application provides a balloon catheter and a manufacturing method thereof, wherein the balloon catheter can reliably fix a metal mesh and a braided tube while ensuring pushing performance.

[0006] According to a first aspect of the present application, a balloon catheter is provided, which includes an inner tube, a balloon, a metal mesh, an outer tube and a welding sleeve, wherein: the outer tube is sleeved outside the inner tube, the balloon is sleeved outside the inner tube, and both ends thereof are sealed and fixed to the outer peripheral sides of the inner tube and the outer tube respectively; the outer tube includes a tube body and a braided wire layer embedded in the tube body, and along the length direction of the tube body, the distal end of the tube body extends beyond the braided wire layer to form a welded connection portion in one piece; the welding sleeve is sleeved outside the welded connection portion; the metal mesh is sleeved outside the balloon, and the proximal end of the metal mesh extends between the welding sleeve and the welding connection portion, and is welded and fixed between the welding connection portion and the welding sleeve.

[0007] Furthermore, the welding sleeve and the tube body are configured to be tubes of the same material.

[0008] Furthermore, the proximal end of the metal mesh is interference-sleeved outside the welding connection portion, and / or the welding sleeve and the welding connection portion are clearance-matched before welding.

[0009] Furthermore, the welding sleeve is configured to be able to radially shrink under the action of welding heat to apply radial pressure to the proximal end of the metal mesh.

[0010] Furthermore, the length of the welding connection portion is set to 7mm-10mm.

[0011] Furthermore, the tube body is made of polymer material.

[0012] Furthermore, the balloon includes a balloon body, and a first pin and a second pin respectively arranged at both ends of the balloon body, wherein: the first pin sealing sleeve is arranged on the outside of the inner tube and fixed thereto; the second pin extends to the outside of the tube section on the outer tube in which the braided silk layer is embedded and is sealed and fixed to the tube body.

[0013] Furthermore, the proximal end of the metal mesh is embedded into the welding connection portion and fixed by a laser welding process.

[0014] According to a second aspect of the present application, a method for manufacturing the above-mentioned balloon catheter is also provided, the method comprising the following steps:

[0015] S1. Providing an outer tube, wherein the outer tube comprises a tube body and a braided wire layer embedded in the tube body, wherein along the length direction of the tube body, a distal end of the tube body extends beyond the braided wire layer to integrally form a welding connection portion;

[0016] S2 inserting the inner tube into the outer tube, and making one end of the inner tube extend out from the end where the welding connection portion is located;

[0017] S3: sealing and fixing the first tube pin and the second tube pin of the balloon to the outer circumference of the inner tube and the outer tube respectively;

[0018] S4: placing a metal mesh on the outside of the folded balloon;

[0019] S5: disposing a welding sleeve outside the welding connection portion, and making the proximal end of the metal mesh extend between the welding sleeve and the welding connection portion;

[0020] S6: Welding is performed between the welding sleeve, the welding connection part and the proximal end of the metal mesh.

[0021] Furthermore, the proximal end of the metal mesh is interference-sleeved on the outside of the welding connection. In step S6, laser welding is performed between the welding sleeve, the welding connection and the proximal end of the metal mesh. The heat generated by the laser welding can cause the welding sleeve to radially shrink so as to radially press the proximal end of the metal mesh into the heated and molten welding connection.

[0022] The technical solution provided by the embodiments of the present application may have the following beneficial effects:

[0023] The braided wire layer embedded in the tube body enables the outer tube to obtain a suitable hardness, thereby meeting the requirements of the metal mesh for pushability of the balloon outer casing. Since both ends of the metal mesh need to be reliably fixed, in the present application, a welding connection portion is integrally formed at the distal end of the tube body in the outer tube, and there is no braided wire layer in the welding connection portion. Therefore, the welding sleeve that is sleeved outside the welding connection portion and clamps the proximal end of the metal mesh together can be reliably welded and fixed to the outer tube without being affected by the braided wire layer. In this way, not only the reliability of the proximal welding of the metal mesh is improved, but also, when welding is performed between the welding sleeve, the welding connection portion and the metal mesh, the welding heat can cause the welding connection portion to melt to a certain extent, so that the proximal end of the metal mesh is radially embedded in the welding connection portion of the outer tube, and the local part of the balloon catheter will not be excessively enlarged in radial size due to the welding of the metal mesh, and the passability of the balloon catheter at this location is basically unaffected. Furthermore, since the welding connection portion is integrally formed with the tube body, it is not easy for the portion to break when bent, and the overall product reliability of the balloon catheter is greatly improved.

[0024] 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

[0025] Figure 1 It is a schematic diagram of the overall structure of a balloon catheter according to an embodiment of the present application;

[0026] Figure 2 yes Figure 1 A schematic diagram of the local structure of the proximal welding portion of the metal mesh of the balloon catheter shown in FIG.

[0027] Figure 3 yes Figure 1 A schematic diagram of a partial structure of an outer tube of a balloon catheter shown in FIG.

[0028] Figure 4 yes Figure 1 Schematic diagram of the local structure of the distal welding part of the metal mesh of the balloon catheter shown in.

[0029] Explanation of the reference numerals: 1. inner tube; 2. balloon; 21. first tube pin; 22. second tube pin; 3. metal mesh; 31. proximal end; 32. distal end; 4. outer tube; 41. tube body; 411. welding connection; 42. braided wire layer; 5. welding sleeve; 6. tip tube; 7. developing ring; 8. catheter seat. DETAILED DESCRIPTION

[0030] Here, exemplary embodiments will be described in detail, 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 them into equivalent embodiments of 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.

[0031] In addition, in the description of this application, the proximal end and the distal end are defined with reference to the position of the operator when the balloon catheter is used, that is, the distal end refers to the end of the instrument or component itself that is relatively far away from the operator, and the proximal end refers to the end of the instrument or component itself that is relatively close to the operator. In all the drawings of this application, the left end is the distal end and the right end is the proximal end. The embodiments of this application will be described in detail below in conjunction with the drawings.

[0032] like Figure 1 As shown in , a balloon catheter according to one embodiment of the present application includes an inner tube 1, a balloon 2, a metal mesh 3, an outer tube 4 and a welding sleeve 5, wherein: the outer tube 4 is sleeved outside the inner tube 1, and an annular gap is formed between the inner and outer tubes; the balloon 2 is sleeved outside the inner tube 1, and its two ends are respectively sealed and fixed to the outer circumference of the inner tube 1 and the outer tube 4, so that the balloon 2 forms a relatively closed chamber outside the inner tube 1, and the chamber is connected to the annular gap formed between the inner and outer tubes, and an expansion medium such as saline can enter the balloon 2 through the annular gap to fill and expand it to a preset degree.

[0033] The metal mesh 3 is sleeved on the outside of the balloon 2 and fixed relative to the balloon 2. As the balloon 2 is filled and expanded, the metal mesh 3 is fully unfolded to constrain the balloon 2, preventing the balloon 2 from substantially extending in the axial and radial directions; at the same time, in the process of the balloon 2 expanding and stretching the intravascular plaque, the metal mesh 3 can produce a certain cutting effect on the plaque under the filling pressure of the balloon 2, so that the metal mesh 3 can form a wound with regular shape and controllable depth at the intravascular plaque. As the balloon 2 further expands, a tear with regular shape can be formed at the wound to reduce the damage to the intima, reduce the annular stress, and the elastic retraction of the vascular lumen after the balloon 2 is withdrawn.

[0034] The metal mesh 3 outside the balloon 2 will increase the radial size of the balloon 2 and make it more difficult to advance in the blood vessel. Therefore, when pushing the distal end of the balloon catheter to the target position, a more reliable pushing force is required. Figure 2 and Figure 3 As shown in , the outer tube 4 in the present application includes a tube body 41 and a braided wire layer 42 embedded in the tube body 41. In particular, during the molding process, the braided wire layer 42 and the tube body 41 can be integrally molded, and the material forming the tube body 41 is coated on both the inner and outer sides of the braided wire layer 42 in the shape of a ring tube, thereby forming the structure of the outer tube 4. In the final molded structure, the tube body thickness inside the braided wire layer 42 is roughly equivalent to the outer tube body thickness.

[0035] The distal end of the tube body 41 extends beyond the braided wire layer 42 to form a welded connection portion 411. The welded connection portion 411 does not have the braided wire layer 42, so the portion can be used as a welded fixing position for the proximal end of the metal mesh 3.

[0036] As mentioned above, the outer tube 4 is configured as a tube structure with a braided wire layer 42, which can improve the pushability of the balloon catheter and ensure that the balloon 2 with the metal mesh 3 can be reliably pushed to the target position. However, when the proximal end 31 of the metal mesh 3 is fixed to the outer tube 4, the braided wire layer 42 will hinder the fixation of the proximal end 31 of the metal mesh 3. Figure 2 and Figure 3 As shown in the figure, in the solution of the present application, there is no braided wire layer 42 in the welding connection part 411, so the proximal end 31 of the metal mesh 3 can be conveniently welded and fixed thereon.

[0037] The welding sleeve 5 is sleeved on the outside of the welding connection part 411 and covers the proximal end 31 of the metal mesh 3. In other words, the proximal end 31 of the metal mesh 3 is sandwiched between the welding connection part 411 and the welding sleeve 5. When welding is performed here, the heat of welding will cause the welding connection part 411 to melt to a certain extent, and the proximal end 31 of the metal mesh 3 can be at least partially embedded in the melted welding connection part 411 in the radial direction. In addition, the size of the balloon catheter at this position will not be significantly affected by the heat shrinkage of the welding sleeve 5, so the overall passability can be guaranteed.

[0038] Laser welding can be selected for welding here. Compared with other welding processes, laser welding can minimize thermal deformation and avoid unexpected thermal deformation of the balloon catheter caused by welding heat.

[0039] In some embodiments, the welding sleeve 5 and the pipe body 41 are made of the same material. In this way, when the welding heat causes the welding sleeve 5 and the welding connection portion 411 to melt, the same materials are more easily fused with each other, so that the proximal end 31 of the metal mesh 3 is more reliably embedded between the two fused pipes.

[0040] The tube body 41 and the welding sleeve 5 can both be configured as tubes made of polymer materials. Thus, at the overlapping position of the two, the local bending resistance of the balloon catheter is better, which can improve the ability of the balloon catheter to resist bending deformation.

[0041] Furthermore, the proximal end 31 of the metal mesh 3 is interference fit outside the welding connection 411. The metal mesh 3 is usually made of nickel-titanium alloy, which has super memory and super elasticity. The interference fit state of the proximal end 31 of the metal mesh 3 can ensure that the proximal end 31 will not slip relative to the welding connection 411; and when the metal mesh 3 is welded, the temperature of the proximal end 31 increases under the action of welding heat. Since there is an interference fit between the proximal end 31 and the welding connection 411, the contact between the proximal end 31 and the welding connection 411 is closer, so the welding heat can be conducted to the welding connection 411 through the proximal end 31, thereby causing the welding connection 411 to melt. At the same time, the interference fit also makes the proximal end 31 have a tendency to be radially pressed into the welding connection 411, so that once the welding connection 411 melts to an appropriate degree, the proximal end 31 can be quickly and smoothly embedded therein.

[0042] In some embodiments, the welding sleeve 5 is configured to be able to contract radially under the action of welding heat to apply radial pressure to the proximal end 31. In this way, in addition to the radial pressure caused by the interference fit of the proximal end 31, the welding sleeve 5 can also radially press the proximal end 31 inward after being heated to cause it to be embedded in the molten welding connection portion 411.

[0043] In some embodiments, the welding sleeve 5 and the welding connection part 411 are clearance-fitted before welding. In other words, when the welding sleeve 5 is assembled, the inner diameter is slightly larger than the outer diameter of the welding connection part 411. In this way, during assembly, due to the interference fit between the proximal end 31 and the welding connection part 411, the relative position of the proximal end 31 on the outer tube 4 is reliably determined, and the welding sleeve 5 is clearance-fitted with the welding connection part 411 during assembly, and its sleeve installation will not affect the sleeve position of the proximal end 31 on the outer tube 4. During welding, the welding sleeve 5 shrinks due to heat, and the proximal end 31 is radially squeezed inward to cause it to be embedded in the welding connection part 411. Not only is the relative position between several structural parts easy to ensure during the assembly process, but the effect after welding is also better.

[0044] Furthermore, the length of the welding connection 411 is set to 7mm-10mm. Usually, the length of the proximal end 31 of the metal mesh 3 is 2mm-3mm. In order to completely cover the proximal end 31 to ensure the welding fixing effect, the length of the welding sleeve 5 needs to be set to 3mm-4mm. Considering the energy radiation range of welding, in order to prevent the residual heat radiated during welding from affecting the balloon body of the balloon 2, the welding connection 411 should be at least 2mm away from the balloon body end of the balloon 2. The welding connection 411 needs to be integrally formed with other parts of the outer tube 4 by mold splicing during manufacturing, so its excessive length will also affect the manufacturing process. In the present application, the length of the welding connection 411 is selected to be 7mm-10mm, which can ensure that the proximal end 31 of the metal mesh 3 is reliably fixed and prevent the balloon 2 from being affected by welding heat radiation. At the same time, the length will not be too long to affect the manufacture of the outer tube 4.

[0045] like Figure 2 and Figure 4 As shown in , the balloon 2 includes a balloon body and a first pin 21 and a second pin 22 disposed at both ends of the balloon body, wherein: the first pin 21 is sealed and sleeved on the outside of the inner tube 1 and fixed thereto, and the second pin 22 extends to the outside of the tube section of the outer tube 4 embedded with the braided silk layer 42 and is sealed and fixed thereto. In one embodiment, the overlapping distance between the second pin 22 and the braided silk layer 42 is more than 3 mm, so that the second pin 22 can cross the tube section of the outer tube 4 without the braided silk layer 42 (i.e., the welding connection portion 411) and the tube section with the braided silk layer 42, thereby better avoiding the local stress concentration on the outer tube 4.

[0046] Return to reference Figure 1, and combined with what is shown in 4, the proximal ends of the outer tube 4 and the inner tube 1 are fixed to the catheter seat 8 by UV glue. A section of welding sleeve 5 is also sleeved on the outside of the first pin 21, and the distal end 32 of the metal mesh 3 extends between the first pin 21 and the section of welding sleeve 5, and is welded and fixed. The distal end of the first pin 21 extends beyond the corresponding welding sleeve 5, and a tip tube 6 is also inserted and fixed in the first pin 21, and the lumen of the tip tube 6 is connected to the inner lumen of the inner tube 1 to allow the guide wire to pass through. The setting of the tip tube 6 is conducive to the shuttle of the balloon catheter in the blood vessel. In addition, two spaced developing rings 7 are also fixed on the outside of the inner tube 1, and the spacing between the two developing rings 7 is used to mark the effective working length of the balloon 2.

[0047] The present application also discloses a method for manufacturing a balloon catheter in any of the above embodiments, the method comprising the following steps:

[0048] S1: Provide an outer tube 4, the outer tube 4 comprising a tube body 41 and a braided wire layer 42 embedded in the tube body 41, and along the length direction of the tube body 41, the distal end of the outer tube 41 extends beyond the braided wire layer 42 by a distance to form an integral welding connection portion 411 at one end of the tube body 41;

[0049] S2 Insert the inner tube 1 into the outer tube 4, and make one end of the inner tube 1 extend out from the end where the welding connection part 411 is located;

[0050] S3: The first pin 21 and the second pin 22 of the balloon 2 are sealed and fixed to the outer circumference of the inner tube 1 and the outer tube 4 respectively;

[0051] S4: Cover the metal mesh 3 on the outside of the folded balloon 2;

[0052] S5: a welding sleeve 5 is disposed outside the welding connection portion 411, and the proximal end 31 of the metal mesh 3 extends between the welding sleeve 5 and the welding connection portion 411;

[0053] S6 Welding is performed between the welding sleeve 5 , the welding connection portion 411 and the proximal end 31 of the metal mesh 3 .

[0054] In one embodiment, in step S5, a welding sleeve 5 is also sleeved on the outer side of the first pin 21, and the distal end 32 of the metal mesh 3 is extended between the first pin 21 and the welding sleeve 5. Then, in step S6, welding is also attempted between the first pin 21, the welding sleeve 5 and the distal end 32 of the metal mesh 3.

[0055] Furthermore, the proximal end of the metal mesh 3 is interference-sleeved on the outside of the welding connection 411. In step S6, laser welding is performed between the welding sleeve 5, the welding connection 411 and the proximal end 31 of the metal mesh 3. The heat generated by the laser welding can cause the welding sleeve 5 to shrink radially, so as to radially press the proximal end of the metal mesh 3 into the heated and molten welding connection 411.

Claims

1. A balloon catheter, characterized in that: The balloon catheter comprises an inner tube (1), a balloon (2), a metal mesh (3), an outer tube (4) and a welding sleeve (5), wherein: The outer tube (4) is sleeved outside the inner tube (1), the balloon (2) is sleeved outside the inner tube (1), and both ends thereof are sealed and fixed to the outer circumference of the inner tube (1) and the outer tube (4) respectively; The outer tube (4) comprises a tube body (41) and a braided wire layer (42) embedded in the tube body (41); along the length direction of the tube body (41), the distal end of the tube body (41) extends beyond the braided wire layer (42) to integrally form a welded connection portion (411); The welding sleeve (5) is sleeved on the outside of the welding connection portion (411); The metal mesh (3) is sleeved on the outside of the balloon (2), and the proximal end of the metal mesh (3) extends between the welding sleeve (5) and the welding connection part (411). The proximal end (31) of the metal mesh (3) is embedded into the welding connection part (411) by a laser welding process and is fixed between the welding connection part (411) and the welding sleeve (5).

2. The balloon catheter according to claim 1, characterized in that: The welding sleeve (5) and the tube body (41) are configured to be tubes made of the same material.

3. The balloon catheter according to claim 1, characterized in that: The proximal end of the metal mesh (3) is interference-fitted outside the welding connection portion (411), and / or the welding sleeve (5) and the welding connection portion (411) are clearance-matched before welding.

4. The balloon catheter according to claim 3, characterized in that: The welding sleeve (5) is configured to be able to radially shrink under the action of welding heat, so as to apply radial pressure to the proximal end of the metal mesh (3).

5. The balloon catheter according to claim 1, characterized in that: The length of the welding connection portion (411) is set to 7 mm-10 mm.

6. The balloon catheter according to claim 1, characterized in that: The tube body (41) is made of polymer material.

7. The balloon catheter according to claim 1, characterized in that: The balloon (2) comprises a balloon body, and a first tube pin (21) and a second tube pin (22) respectively arranged at two ends of the balloon body, wherein: the first tube pin (21) is sealingly sleeved on the outside of the inner tube (1) and fixed thereto; The second tube pin (22) extends to the outside of the tube section on the outer tube (4) in which the braided wire layer (42) is embedded, and is sealed and fixed to the tube body (41).

8. A method for manufacturing a balloon catheter as claimed in any one of claims 1 to 7, characterized in that: The method comprises the following steps: S1. An outer tube (4) is provided, wherein the outer tube (4) comprises a tube body (41) and a braided wire layer (42) embedded in the tube body (41); along the length direction of the tube body (41), the distal end of the tube body (41) extends beyond the braided wire layer (42) to integrally form a welded connection portion (411); and the proximal end of the metal mesh (3) is interference-fittedly sleeved outside the welded connection portion (411); S2 inserting the inner tube (1) into the outer tube (4) so ​​that one end of the inner tube (1) extends out from the end where the welding connection portion (411) is located; S3: sealing and fixing the first tube pin (21) and the second tube pin (22) of the balloon (2) to the outer circumference of the inner tube (1) and the outer tube (4), respectively; S4: placing the metal mesh (3) on the outside of the folded balloon (2); S5: a welding sleeve (5) is disposed outside the welding connection portion (411), and the proximal end of the metal mesh (3) is extended to between the welding sleeve (5) and the welding connection portion (411); S6: Laser welding is performed between the welding sleeve (5), the welding connection portion (411) and the proximal end of the metal mesh (3). The heat generated by the laser welding can cause the welding sleeve (5) to shrink radially, so as to radially press the proximal end of the metal mesh (3) into the heated and molten welding connection portion (411).

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