Expansion balloon catheter
By employing a double-layer balloon structure and a limiting design, the problem of vascular damage during carotid artery plaque dilation in existing technologies has been solved, achieving a safe and efficient dilation effect.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANGHAI ACHIEVA MEDICAL SUZHOU CO LTD
- Filing Date
- 2024-12-25
- Publication Date
- 2026-04-10
AI Technical Summary
Existing technologies, when dilating carotid artery plaques, require repeated balloon replacements, leading to damage to the vascular intima. Furthermore, the balloon is prone to slippage, making it difficult to effectively dilate stenotic areas with high rigidity.
It adopts a double-layer balloon structure. The outer compliant balloon performs initial expansion, while the inner, more rigid and movable balloon performs precise expansion. Combined with a limiting structure, it prevents balloon slippage, ensuring the safety and accuracy of expansion.
It reduces damage to the vascular endothelium, improves the safety and precision of dilation, and can effectively dilate harder plaque areas.
Smart Images
Figure CN224099804U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The utility model relates to the technical field of medical apparatus and instruments, in particular to a dilatation balloon catheter. BACKGROUND
[0002] Percutaneous transluminal angioplasty is a relatively mature recanalization technology, which mainly extrudes the stenosis segment of the blood vessel from the inside to the outside by using a dilatation balloon, so that the blood vessel wall is damaged and the dilatation purpose is achieved. The dilatation process of the balloon catheter on the stenosis segment of the blood vessel is particularly crucial in the treatment process.
[0003] Due to the congenital structural characteristics of the carotid artery, the plaque part is often very long and has high hardness, and the stenosis part cannot be easily dilated by the balloon, which makes it necessary to replace the balloon of different specifications for secondary or even multiple dilations during the balloon dilatation process. Multiple dilations are accompanied by multiple balloon exchange processes, which will inevitably cause damage to the blood vessel intima. Due to the high hardness of the stenosis part of the balloon carotid artery, the balloon is very easy to slip during the dilatation process, which will cause greater damage to the blood vessel intima. However, the current technology still has problems in the balloon dilatation stage, so a new instrument is needed. SUMMARY
[0004] The utility model aims at providing a dilatation balloon catheter to solve the problems in the prior art.
[0005] In order to achieve one of the above purposes, the utility model provides a dilatation balloon catheter, which comprises:
[0006] An inner catheter has a guide wire channel exposed outward from the proximal end of the inner catheter;
[0007] An inner inflation tube is arranged outside the inner catheter, the inner inflation tube comprises an intermediate inner tube and an intermediate outer tube, and a first balloon and a first inflation channel are formed between at least part of the outer side wall of the intermediate inner tube and at least part of the inner side wall of the intermediate outer tube;
[0008] An outer catheter is arranged outside the inner inflation tube, a second inflation channel is formed between at least part of the inner side wall of the outer catheter and at least part of the outer side wall of the intermediate outer tube, and the outer catheter further has a second balloon in communication with the second inflation channel;
[0009] The inner inflation tube is movably arranged between the inner catheter and the outer catheter, and the dilatation balloon catheter further comprises a movement structure for limiting the movement of the inner inflation tube from the proximal end of the inner catheter to the distal end;
[0010] The first balloon is arranged in the second balloon, and the length of the first balloon is less than the length of the second balloon in the axial direction of the dilatation balloon catheter.
[0011] As a further improvement of an embodiment of the present application, the ratio of the length of the first balloon to the length of the second balloon ranges from 1:2 to 1:4.
[0012] As a further improvement of an embodiment of the present application, the hardness of the first balloon is greater than the hardness of the second balloon.
[0013] As a further improvement of an embodiment of the present application, the outer sidewall of the first balloon is provided with a plurality of stress strips.
[0014] As a further improvement of an embodiment of the present application, the outer sidewall of the stress strip is provided with a curved surface, and the ratio of the maximum size of the stress strip to the diameter of the first balloon ranges from 1:10 to 1:20 along the radial direction of the first balloon.
[0015] As a further improvement of an embodiment of the present application, the stress strip extends along the generatrix direction of the first balloon.
[0016] As a further improvement of an embodiment of the present application, the moving structure comprises:
[0017] A limiting step is arranged outside the inner catheter, and a plurality of limiting steps are arranged along the axial direction.
[0018] A clamping rod is rotatably arranged on the inner filling tube, and the clamping rod has a first end on one side of the rotation center and a second end on the other side of the rotation center. The second end is clamped with the limiting step, and a step groove is arranged on the inner filling tube to limit the rotation of the first end towards the proximal end.
[0019] As a further improvement of an embodiment of the present application, the second end gradually inclines towards the side close to the proximal end from the inner filling tube to the inner catheter.
[0020] As a further improvement of an embodiment of the present application, the clamping rod is rotatably connected to the step groove, and when the clamping rod is perpendicular to the inner catheter, the first end towards the side of the proximal end is fitted with the sidewall of the step groove.
[0021] As a further improvement of an embodiment of the present application, the limiting step has a first wall towards the proximal end and a second wall towards the distal end. The first wall gradually inclines towards the side away from the inner catheter from the proximal end to the distal end, and the second wall is perpendicular to the inner catheter.
[0022] As further improvement of the embodiment of the utility model, two first developing rings are arranged on the inner guide pipe, the first balloon is located between the two first developing rings, and two second developing rings are arranged at two ends of the first balloon.
[0023] Compared with the prior art, the utility model adopts the cooperation of the external second balloon and the movable first balloon inside, after the dilation balloon guide pipe moves to the lesion position in the arterial blood vessel, the second balloon is used for preliminary dilation, and the first balloon is used for further dilation. The length of the first balloon is smaller than that of the second balloon, and the hardness of the first balloon is greater than that of the second balloon, so the stress of the second balloon after expansion is greater than that of the second balloon, and the hard block part that the second balloon cannot expand can be accurately and smoothly expanded through the first balloon. Moreover, the second balloon can only move to the distal end of the guide pipe, so the second balloon is not easy to slide back and forth in the arterial blood vessel, so as to reduce the damage to the blood vessel intima, make the dilation of the balloon more safe and accurate operation. BRIEF DESCRIPTION OF DRAWINGS
[0024] Figure 1 It is a structure schematic view of the dilation balloon guide pipe provided by the utility model;
[0025] Figure 2 It is a structure schematic view of the proximal end of the dilation balloon guide pipe provided by the utility model;
[0026] Figure 3 It is a part structure schematic view of the inner guide pipe and the inner filling pipe in the utility model along the axial direction;
[0027] Figure 4 It is a cross-sectional schematic view of the inner guide pipe and the inner filling pipe along the radial direction in the utility model;
[0028] Figure 5 It is a cross-sectional schematic view of the first balloon along the radial direction in the utility model;
[0029] Figure 6 It is a part structure schematic view in Figure 1 ;
[0030] Figure 7 It is a structure schematic view of the moving structure in the utility model, mainly showing the state of the inner filling pipe during the movement to the distal end;
[0031] Figure 8 It is a structure enlarged schematic view of part A in Figure 7 ;
[0032] Figure 9 It is a structure schematic view of the moving structure in the utility model, mainly showing the state when the clamping rod is clamped with the limiting step;
[0033] Figure 10 is a schematic view of a moving structure in an optional embodiment.
[0034] Reference signs:
[0035] 10, inner catheter; 11, guide wire channel; 12, anti-kinking guide wire; 13, guide wire channel opening; 14, first visualization ring; 20, inner inflation tube; 21, intermediate inner tube; 22, intermediate outer tube; 23, first balloon; 231, stress strip; 24, first inflation channel; 25, first inflation port; 26, second visualization ring; 30, outer catheter; 31, second inflation channel; 32, second inflation port; 33, second balloon; 40, moving structure; 41, limiting step; 411, first wall; 412, second wall; 42, clamping rod; 421, first end; 422, second end. DETAILED DESCRIPTION
[0036] The embodiments described below are exemplary only, and are not to be construed as limiting the present application.
[0037] It should be understood that, in the description of the present application, the terms "inner", "outer", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be construed as limiting the present application. In addition, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance. In addition, it should be noted that, unless otherwise explicitly specified and limited, the term "connection" should be understood broadly, for example, the connection can be direct connection or indirect connection through an intermediate medium, and can be fixed connection or movable connection or detachable connection or integral connection. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.
[0038] It should be noted that in the present application, the terms "distal end" and "proximal end" should be understood as being observed from the direction of the instrument operator, the proximal end being the end close to the instrument operator, and the distal end being the end relatively far away from the instrument operator. The instrument operator can be a syringe or a pneumatic delivery device, etc.
[0039] In order for those skilled in the art to better understand the technical solutions in the present application, the following will combine the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Figure 1 -10, to clearly and completely describe the technical solutions in the embodiments of the present application.
[0040] The utility model discloses an embodiment provides a kind of expansion balloon catheter, refer to Figure 1 And Figure 2 Including by inside sequentially arranged inner catheter 10, inner filling pipe 20 and outer catheter 30, inner filling pipe 20 movably arranged between inner catheter 10 and outer catheter 30.Expansion balloon catheter also includes the movement structure 40 that the movement of inner filling pipe 20 is limited, ensure that inner filling pipe 20 does not slide back and forth during intervention treatment.Expansion balloon catheter is overall for the slender structure, and expansion balloon catheter has the proximal end close to instrument operator and the distal end away from instrument operator.
[0041] Inner catheter 10 has the guide wire channel 11 being arranged along the axial direction, and the anti-bending guide wire 12 is arranged in the guide wire channel 11, and the guide wire channel 11 is connected with atmosphere to form guide wire channel opening 13 in one end of the proximal end of inner catheter 10, and the anti-bending guide wire 12 is inserted into the guide wire channel 11 through the guide wire channel opening 13 and extends to the distal end of inner catheter 10 along the guide wire channel 11.
[0042] Inner filling pipe 20 is arranged on the outside of inner catheter 10, and outer catheter 30 is arranged on the outside of inner filling pipe 20.In the direction of catheter axis, the part of inner filling pipe 20 towards the proximal end is located on the outside of outer catheter 30, facilitating the displacement of inner filling pipe 20.Specifically, the one end of outer catheter 30 and inner catheter 10 towards the distal end is fixedly connected, inner filling pipe 20 is slidably connected with inner catheter 10, and a sliding gap for the movement of inner filling pipe 20 is formed between the outer side wall of at least part of outer catheter 30 and the inner side wall of at least part of outer catheter 30.In the axial direction of catheter, inner filling pipe 20 can linearly move relative to inner catheter 10 and outer catheter 30.
[0043] The sliding gap should not be too small or too large, to ensure that inner filling pipe 20 can slide between inner catheter 10 and outer catheter 30, and inner filling pipe 20 cannot be displaced when being accidentally touched, to ensure the accuracy and reliability of operation.
[0044] Refer to Figure 3 And Figure 4 Inner filling pipe 20 includes intermediate inner tube 21 and intermediate outer tube 22 connected with each other, and a first balloon 23 and a first filling channel 24 in communication with each other are formed between the outer side wall of at least part of intermediate inner tube 21 and the inner side wall of at least part of intermediate outer tube 22.The part of intermediate outer tube 22 located on the outside of outer catheter 30 is provided with a first filling port 25 in communication with the first filling channel 24.The first filling port 25 is arranged at a position closer to the proximal end of inner filling pipe 20, and the first balloon 23 is arranged at a position closer to the distal end of inner filling pipe 20.
[0045] The second inflation passage 31 is formed between at least part of the inner side wall of the outer catheter 30 and at least part of the outer side wall of the intermediate outer tube 22. The outer catheter 30 is provided with a second inflation port 32 at one end thereof toward the proximal end, which communicates with the second inflation passage 31. The outer catheter 30 further has a second balloon 33 which communicates with the second inflation passage 31. After the catheter is moved to the lesion position in the artery, the operator passes air flow into the second inflation port 32, the air flow flows into the second inflation passage 31 through the second inflation port 32, and then flows into the second balloon 33 through the second inflation passage 31, so that the second balloon 33 is expanded at the lesion position.
[0046] The second balloon 33 is a compliant balloon, and is made of a polymer material such as silicone or thermoplastic polyurethane. When the second balloon 33 is expanded in the artery, it can rapidly swell and adhere to the inner wall of the blood vessel as the expansion pressure increases.
[0047] The first balloon 23 is located in the second balloon 33. In the present embodiment, the diameter of the first balloon 23 is equal to the diameter of the second balloon 33. Of course, in alternative embodiments, the diameter of the first balloon 23 can be slightly larger or slightly smaller than the diameter of the second balloon 33. The first balloon 23 is at least capable of exerting a certain expansion force on the stenosis position in the artery, and the present embodiment does not make specific limitations thereon. It should be noted that the diameter of the first balloon 23 is at most 110% of the diameter of the second balloon 33, and the maximum diameter of the first balloon 23 and the second balloon 33 is at most 8 mm.
[0048] In the axial direction of the expansion balloon catheter, the length of the first balloon 23 is less than the length of the second balloon 33, and the ratio of the length of the first balloon 23 to the length of the second balloon 33 is in the range of 1:2-4. As an example, the length of the first balloon 23 is in the range of 1-4 cm, and the length of the second balloon 33 is in the range of 5-8 cm.
[0049] The first balloon 23 is also a compliant balloon, and is made of polyurethane. The hardness of the first balloon 23 is greater than the hardness of the second balloon 33, and the hardness of the first balloon 23 and the second balloon 33 is in the range of Shore 60A-90A.
[0050] The initial position of the first balloon 23 is located on the side of the second balloon 33 close to the proximal end. When the first balloon 23 needs to be expanded, a gas flow is introduced into the first filling port 25. The gas flow flows into the first filling channel 24 through the first filling port 25, and then flows into the first balloon 23 through the first filling channel 24, so that the first balloon 23 expands at the lesion position and can be targeted to expand the longer and harder part in the arterial blood vessel. Because the second balloon 33 is longer, it may not be able to fully and effectively expand the harder part in the arterial blood vessel. The length of the first balloon 23 is smaller than that of the second balloon 33, and the hardness of the first balloon 23 is greater than that of the second balloon 33. Therefore, the stress of the second balloon 33 after expansion is greater than that of the second balloon 33. For the hard block part that the second balloon 33 cannot expand, the first balloon 23 can accurately and smoothly expand.
[0051] Referring to Figure 5 The outer side wall of the first balloon 23 is provided with a plurality of stress strips 231. The stress strips 231 extend along the generatrix direction of the first balloon 23. The plurality of stress strips 231 are uniformly arranged on the outer side of the first balloon 23, that is, the spacing between adjacent stress strips 231 is substantially the same. Along the radial direction of the first balloon 23, the ratio of the maximum size of the stress strip 231 to the diameter of the first balloon 23 is in the range of 1:10-20. As an example, the size of the stress strip 231 is in the range of 1mm-3mm.
[0052] The connection between the stress strip 231 and the first balloon 23 can be integrally formed or bonded. Of course, the materials of the stress strip 231 and the first balloon 23 can be the same or different. When the materials of the stress strip 231 and the first balloon 23 are the same, the stress strip 231 and the first balloon 23 are integrally formed. When the materials of the stress strip 231 and the first balloon 23 are different, the stress strip 231 and the first balloon 23 are bonded.
[0053] The plurality of equidistantly arranged stress strips 231 can increase the hardness of the entire first balloon 23, so that the first balloon 23 has more prominent expansion effect and can more smoothly and fully expand the hard block in the arterial blood vessel.
[0054] Referring to Figure 6 The moving structure 40 is arranged between the inner filling tube 20 and the inner catheter 10. The moving structure 40 can limit the moving direction of the first balloon 23, so that the first balloon 23 can only slide towards the distal end and cannot slide towards the proximal end.
[0055] Referring to Figure 7In the embodiment, the moving structure 40 comprises a limiting step 41 arranged outside the inner catheter 10 and a clamping rod 42 rotatably connected to the inner filling tube 20. The limiting step 41 can be formed along the radial direction outwardly from the outer periphery of the inner catheter 10 or formed on the sidewall of the inner catheter 10, i.e. the limiting step 41 is located within the wall thickness of the inner catheter 10.
[0056] With reference to Figure 7 and Figure 8 , the intermediate inner tube 21 is provided with a step groove, and the clamping rod 42 is rotatably connected in the step groove. The clamping rod 42 can be rotatably connected with the step groove through a rotating shaft, and the rotating connection between the clamping rod 42 and the step groove is the rotating center of the clamping rod 42. The clamping rod 42 has a first end 421 located on one side of the rotating center and a second end 422 located on the other side of the rotating center. The second end 422 is clamped with the limiting step 41. Specifically, when the clamping rod 42 is perpendicular to the inner catheter 10, the first end 421 is attached to the sidewall of the step groove on the side of the proximal end, and the side of the step groove on the distal end has a space for the rotation of the clamping rod 42.
[0057] With reference to Figure 8 and Figure 9 , the limiting step 41 is arranged in an array along the catheter axis direction, and the limiting step 41 has a first wall 411 facing the proximal end and a second wall 412 facing the distal end. The first wall 411 gradually inclines away from the side of the inner catheter 10 from the proximal end to the distal end, and the second wall 412 is perpendicular to the inner catheter 10, i.e. the cross section of the limiting step 41 along the catheter axis direction is triangular. The second end 422 of the clamping rod 42 extends to one side of the limiting step 41 and is clamped with the limiting step 41. Specifically, the second end 422 is clamped with the second wall 412.
[0058] The operator pushes the inner filling tube 20 to the distal end, and the clamping rod 42 is deflected under the guidance of the inclined surface of the limiting step 41. Therefore, the first balloon 23 moves to the distal end with the inner filling tube 20, and when the inner filling tube 20 moves to the proximal end, the clamping rod 42 cannot rotate under the limiting action of the second wall 412 of the limiting step 41 and the step groove on the clamping rod 42. The clamping rod 42 cooperates with the limiting step 41 to limit the inner filling tube 20, so that the inner filling tube 20 can only move to the distal end under the action of external force and cannot move to the proximal end. Therefore, the second balloon 33 is not easy to slide back and forth in the arterial blood vessel, so as to reduce the damage to the blood vessel intima and make the expansion of the balloon more secure and accurate. It should be noted that since there is a certain gap between adjacent limiting steps 41, the inner filling tube 20 and the first balloon 23 can move to the proximal end within a small range. This small range of movement will not have adverse effects in use and can be ignored.
[0059] The limiting steps 41 and the clamping rods 42 can be arranged in several groups along the circumference of the catheter, of course, the limiting steps 41 can also be arranged around the inner catheter 10, and the clamping rods 42 are arranged in several groups along the circumference of the catheter. It is relatively easy to understand that the limiting steps 41 and the clamping rods 42 are both made of polyurethane material to ensure the safety of the operation of the balloon dilatation catheter.
[0060] In optional embodiments, the moving structure 40 can also be implemented by other structures. As an example, as shown in Figure 10 , a thread structure matched with each other can be arranged between the inner catheter 10 and the inner inflation tube 20, the first thread structure is spirally arranged along the circumference of the outer wall of the inner catheter 10, and the second thread structure is spirally arranged along the circumference of the inner wall of the intermediate inner tube 22, the first thread structure and the second thread structure are matched with each other. When the first balloon 23 needs to be moved, the inner inflation tube 20 can be rotated to move to the distal end, and the cooperation between the inner inflation tube 20 and the inner catheter 10 in this structure is relatively stable, and the limiting effect on the inner inflation tube 20 is also good.
[0061] The operation method of the dilatation balloon catheter provided by the utility model is as follows: when the catheter enters the lesion position in the arterial blood vessel, the airflow is introduced into the second balloon 33 through the second inflation port 32, the second balloon 33 can press the narrow position in the artery to make the arterial blood vessel preliminarily dilate. The airflow is introduced into the first balloon 23 through the first inflation port 25, the hardness of the first balloon 23 is greater than that of the second balloon 33, and because the first balloon 23 is smaller than the second balloon 33, under the same air pressure, the stress of the first balloon 23 is greater than that of the second balloon 33. The inner inflation tube 20 can be pushed to the distal end or rotated, so that the first balloon 23 moves in the second balloon 33, the first balloon 23 can dilate the larger hard block in the arterial blood vessel again, and the moving structure 40 can limit the first balloon 23, therefore, the structure of the catheter in the utility model can dilate the plaque in the arterial blood vessel more safely and smoothly.
[0062] In order to observe the position of the catheter in the artery, referring to Figure 6 , two first developing rings 14 are arranged on the inner catheter 10 at intervals, one of the first developing rings 14 is arranged on one side of all the limiting steps 41, and the other first developing ring 14 is arranged on the other side of all the limiting steps 41. The first balloon 23 is located between the two first developing rings 14, and two second developing rings 26 are arranged on the inner inflation tube 20 at intervals, and the two second developing rings 26 are located at the two ends of the first balloon 23 respectively.
[0063] Thus the position of the second balloon 33 can be clearly shown by the two first marker rings 14, and the position of the first balloon 23 within the second balloon 33 can be clearly shown by the second marker ring 26, so that the first balloon 23 can be moved more accurately during operation.
[0064] The above detailed description of the embodiments shown in the drawings explains the structure, features and effects of the present application, and the above description is only the preferred embodiments of the present application, but the present application is not limited by the drawings, and any changes or modifications made in accordance with the concept of the present application, or equivalent embodiments with equivalent changes, are still within the scope of the present application.
Claims
1. A dilatation balloon catheter, characterized by, The application relates to a dilatation balloon catheter, which comprises: an inner catheter (10) with a guide wire channel (11) exposed outside the proximal end of the inner catheter (10); an inner inflation tube (20) arranged outside the inner catheter (10), the inner inflation tube (20) comprising an intermediate inner tube (21) and an intermediate outer tube (22), at least part of the outer side wall of the intermediate inner tube (21) and at least part of the inner side wall of the intermediate outer tube (22) forming a first balloon (23) and a first inflation channel (24) in communication with each other; an outer catheter (30) arranged outside the inner inflation tube (20), at least part of the inner side wall of the outer catheter (30) and at least part of the outer side wall of the intermediate outer tube (22) forming a second inflation channel (31), the outer catheter (30) further having a second balloon (33) in communication with the second inflation channel (31); the inner inflation tube (20) is movably arranged between the inner catheter (10) and the outer catheter (30), and the dilatation balloon catheter further comprises a moving structure (40) for limiting the movement of the inner inflation tube (20) from the proximal end of the inner catheter (10) to the distal end; the first balloon (23) is arranged inside the second balloon (33) along the axial direction of the dilatation balloon catheter, and the length of the first balloon (23) is smaller than the length of the second balloon (33).
2. The dilation balloon catheter of claim 1, wherein: The ratio of the length of the first balloon (23) to the length of the second balloon (33) ranges from 1:2 to 1:
4.
3. The dilation balloon catheter of claim 2, wherein: The hardness of the first balloon (23) is greater than the hardness of the second balloon (33).
4. The dilation balloon catheter of any of claims 1-3, wherein: The outer side wall of the first balloon (23) is provided with a plurality of stress strips (231).
5. The dilation balloon catheter of claim 4, wherein: The outer side wall of the stress strip (231) is provided with a curved surface, and the ratio of the maximum size of the stress strip (231) to the diameter of the first balloon (23) ranges from 1:10 to 1:20 along the radial direction of the first balloon (23).
6. The dilation balloon catheter of claim 4, wherein: The stress strip (231) extends along the generatrix direction of the first balloon (23).
7. The dilation balloon catheter of claim 4, wherein, The moving structure (40) comprises: a limiting step (41) arranged outside the inner catheter (10), the limiting step (41) being provided with a plurality of steps along the axial direction; a clamping rod (42) rotatably arranged on the inner inflation tube (20), the clamping rod (42) having a first end (421) on one side of the rotation center and a second end (422) on the other side of the rotation center, the second end (422) being clamped with the limiting step (41), and the inner inflation tube (20) being provided with a step groove for limiting the rotation of the first end (421) towards the proximal end.
8. The dilation balloon catheter of claim 7, wherein: The second end (422) gradually inclines towards the side close to the proximal end from the inner inflation tube (20) to the inner catheter (10).
9. The dilation balloon catheter of claim 7, wherein: The clamping rod (42) is rotationally connected to the step groove, and when the clamping rod (42) is perpendicular to the inner catheter (10), the side of the first end (421) towards the proximal end is fitted with the side wall of the step groove.
10. The dilation balloon catheter of claim 9, wherein: The limiting step (41) has a first wall (411) towards the proximal end, a second wall (412) towards the distal end, the first wall (411) gradually inclines away from the side of the inner catheter (10) from the proximal end to the distal end, and the second wall (412) is perpendicular to the inner catheter (10).
11. The dilation balloon catheter of claim 1, wherein: Two first developing rings (14) are arranged on the inner catheter (10) at intervals, and the first balloon (23) is located between the two first developing rings (14), and two second developing rings (26) are arranged at two ends of the first balloon (23) respectively.