An asymmetric double balloon

Abstract

The utility model relates to an asymmetric double-layer balloon, including first balloon group, second balloon group and catheter, and the catheter contains the inflation cavity of guide wire cavity and inner and outer balloon, first balloon group and second balloon group are all fan -shaped double -layer balloon and correspondingly arrange on the outside wall of catheter, the centre of circle of first balloon group is fixed on the outside wall of catheter and is communicated with catheter, the centre of circle of second balloon group is fixed on the outside wall of catheter and is communicated with catheter, first balloon group occupies the angle in the direction of catheter circumference and is greater than the angle that second balloon group occupies in the direction of catheter circumference. The utility model relates to an asymmetric double-layer balloon, adopts the first balloon group and second balloon group of different angles, solves the problem that the balloon is used to expand the stent and other grafts in the thoracic aorta.

Description

Technical Field

[0001] This utility model relates to the field of medical device technology, specifically to an asymmetric double-layer balloon. Background Technology

[0002] Currently, balloon dilation is generally difficult to perform during thoracic aortic stent implantation. This means that the stent typically only has one deployment opportunity, and once deployed, it's difficult to adjust the stent's shape and apposition to the aorta using balloon dilation. Because blood flow in the thoracic aorta is rapid, balloon dilation would block blood flow, causing the balloon to shift downwards under the force of the blood flow, potentially dragging the stent and other implants downwards as well. This could lead to surgical failure or even serious complications. Therefore, many thoracic aortic grafts, even those with unsatisfactory post-implantation morphology, cannot be repositioned using balloon dilation. Summary of the Invention

[0003] In order to solve one or more technical problems existing in the prior art, this utility model provides an asymmetric double-layer balloon.

[0004] The technical solution of this utility model to solve the above-mentioned technical problems is as follows: an asymmetric double-layer balloon, including a first balloon group, a second balloon group, and a catheter. The first balloon group and the second balloon group are both fan-shaped double-layer balloons and are correspondingly arranged on the outer side wall of the catheter. The center of the first balloon group is fixed on the outer side wall of the catheter and communicates with the inflation chamber inside the catheter. The center of the second balloon group is fixed on the outer side wall of the catheter and communicates with the inflation chamber inside the catheter. The angle occupied by the first balloon group in the circumferential direction of the catheter is greater than the angle occupied by the second balloon group in the circumferential direction of the catheter.

[0005] The beneficial effects of this invention are as follows: This invention provides an asymmetric double-layer balloon, employing a first balloon group and a second balloon group at different angles, which solves the problem of using a balloon to expand stents and other grafts within the thoracic aorta. It can maintain unobstructed blood flow within the aorta while fully expanding the target area using the balloon, avoiding potential complications caused by blood flow obstruction, such as balloon displacement due to blood flow impact and associated graft displacement.

[0006] Based on the above technical solution, the present invention can be further improved as follows.

[0007] Furthermore, the first balloon group includes a first balloon, and the second balloon group includes a second balloon, wherein the angle occupied by the first balloon in the circumferential direction of the catheter is greater than the angle occupied by the second balloon in the circumferential direction of the catheter.

[0008] The advantages of adopting the above-mentioned further solution are: using two balloons at different angles results in a simple structure and ease of manufacturing.

[0009] Furthermore, the first balloon includes a first inner balloon and a first outer balloon, both with a fan-shaped cross-section. The first inner balloon is located inside the first outer balloon. The first inner balloon and the first outer balloon are independent and not connected to each other. The first inner balloon and the first outer balloon are respectively connected to the inflation chamber in the catheter. The axial length of the first inner balloon is not greater than the axial length of the first outer balloon. The second balloon includes a second inner balloon and a second outer balloon, both with a fan-shaped cross-section. The second inner balloon is located inside the second outer balloon. The second inner balloon and the second outer balloon are independent and not connected to each other. The second inner balloon and the second outer balloon are respectively connected to the inflation chamber in the catheter. The axial length of the second inner balloon is not greater than the axial length of the second outer balloon. The angle occupied by the first inner balloon in the circumferential direction of the catheter is greater than the angle occupied by the second inner balloon in the circumferential direction of the catheter, and the angle occupied by the first outer balloon in the circumferential direction of the catheter is greater than the angle occupied by the second outer balloon in the circumferential direction of the catheter.

[0010] The advantages of this further approach are: the inner and outer balloons are independent and not connected, allowing for separate inflation using different chambers. During use, the inner balloon is inflated first. Due to its small size, the inner balloon only occupies a portion of the blood vessel lumen and therefore does not completely block blood flow. This allows sufficient time to adjust the inner balloon's position under fluoroscopy, based on markers on the inner balloon, ensuring the overall balloon is properly positioned and at the desired inflation location. Once alignment is confirmed, the outer balloon can then be inflated for further expansion.

[0011] Furthermore, the radius of the first inner balloon is equal to the radius of the second inner balloon, and the radius of the first outer balloon is equal to the radius of the second outer balloon; The axial length of the first inner balloon is equal to the axial length of the second inner balloon, and the axial length of the first outer balloon is equal to the axial length of the second outer balloon.

[0012] The beneficial effects of adopting the above-mentioned further scheme are: using an outer balloon and an inner balloon with the same radius and axial length, the structure becomes more stable and the support effect is more stable.

[0013] Furthermore, the first balloon group includes a plurality of first balloons, and the second balloon group includes a second balloon, wherein the sum of the angles occupied by the plurality of first balloons in the circumferential direction of the catheter is greater than the angle occupied by the second balloon in the circumferential direction of the catheter.

[0014] The advantages of adopting the above-mentioned further scheme are: the eccentric structure obtained by using multiple first balloons and one second balloon has a simple structural design and is convenient for production and manufacturing.

[0015] Furthermore, the first balloon includes a first inner balloon and a first outer balloon, both with a fan-shaped cross-section. The first inner balloon is located inside the first outer balloon. The first inner balloon and the first outer balloon are independent and not connected to each other. The first inner balloon and the first outer balloon are respectively connected to the inflation chamber in the catheter. The axial length of the first inner balloon is not greater than the axial length of the first outer balloon. The second balloon includes a second inner balloon and a second outer balloon, both with a fan-shaped cross-section. The second inner balloon is located inside the second outer balloon. The second inner balloon and the second outer balloon are independent and not connected to each other. The second inner balloon and the second outer balloon are respectively connected to the inflation chamber in the catheter. The axial length of the second inner balloon is not greater than the axial length of the second outer balloon. The sum of the angles occupied by the multiple first inner balloons in the circumferential direction of the catheter is greater than the angle occupied by the second inner balloon in the circumferential direction of the catheter, and the sum of the angles occupied by the multiple first outer balloons in the circumferential direction of the catheter is greater than the angle occupied by the second outer balloon in the circumferential direction of the catheter.

[0016] The advantages of this further approach are: the inner and outer balloons are independent and not interconnected, allowing for separate inflation using different inflatable chambers within the catheter. During use, the inner balloon is inflated first. Due to its small size, the inner balloon only occupies a portion of the vessel lumen and therefore does not completely block blood flow. This provides ample time to adjust the inner balloon's position under fluoroscopy, based on markers on the inner balloon, ensuring a proper overall balloon placement and positioning it at the desired inflation point. Once alignment is confirmed, the outer balloon can then be inflated for further expansion.

[0017] Furthermore, the radius of the first inner balloon is equal to the radius of the second inner balloon, and the radius of the first outer balloon is equal to the radius of the second outer balloon; The axial length of the first inner balloon is equal to the axial length of the second inner balloon, and the axial length of the first outer balloon is equal to the axial length of the second outer balloon.

[0018] The beneficial effects of adopting the above-mentioned further scheme are: using an outer balloon and an inner balloon with the same radius and axial length, the structure becomes more stable and the support effect is more stable.

[0019] Furthermore, the center line of the fan-shaped structure of the first balloon group coincides with the center line of the fan-shaped structure of the second balloon group.

[0020] The beneficial effect of adopting the above-mentioned further scheme is that it makes the entire first balloon group and the second balloon group symmetrical on both sides of the centerline, resulting in good structural stability.

[0021] Furthermore, the catheter has an outer balloon branch and an inner balloon branch on a section of its structure located axially outside the first balloon group and the second balloon group. The outer balloon branch contains an outer balloon inflation chamber and extends into the catheter, communicating with the first outer balloon of the first balloon group and the second outer balloon of the second balloon group, respectively. The inner balloon branch contains an inner balloon inflation chamber and extends into the catheter, communicating with the first inner balloon of the first balloon group and the second inner balloon of the second balloon group, respectively. Attached Figure Description

[0022] Figure 1 This is a cross-sectional structural diagram of Embodiment 1 of the present invention; Figure 2 This is a cross-sectional structural diagram of Embodiment 2 of the present invention; Figure 3 This is a side view of the asymmetric double-layer balloon structure of this utility model.

[0023] The attached diagram lists the components represented by each number as follows: 1. Catheter; 11. Guidewire lumen; 12. External balloon branch; 13. Internal balloon branch; 14. External balloon inflation chamber; 15. Internal balloon inflation chamber; 2. First internal balloon; 21. First external balloon; 3. Second internal balloon; 31. Second external balloon. Detailed Implementation

[0024] The principles and features of this utility model are described below with reference to the accompanying drawings. The examples given are only for explaining this utility model and are not intended to limit the scope of this utility model. Example 1

[0025] like Figure 1 and Figure 3 As shown, an asymmetric double-layer balloon of this embodiment includes a first balloon group, a second balloon group, and a catheter 1. The first balloon group and the second balloon group are both fan-shaped double-layer balloons and are correspondingly arranged on the outer side wall of the catheter 1. The center of the first balloon group is fixed on the outer side wall of the catheter 1 and communicates with the inflation chamber inside the catheter 1. The center of the second balloon group is fixed on the outer side wall of the catheter 1 and communicates with the inflation chamber inside the catheter 1. The angle occupied by the first balloon group in the circumferential direction of the catheter 1 is greater than the angle occupied by the second balloon group in the circumferential direction of the catheter 1.

[0026] Specifically, the catheter contains a guidewire lumen and an inflation chamber for both inner and outer balloons.

[0027] like Figure 1As shown, the first balloon assembly in this embodiment includes a first balloon, and the second balloon assembly includes a second balloon. The angle occupied by the first balloon in the circumferential direction of catheter 1 is greater than the angle occupied by the second balloon in the circumferential direction of catheter 1. Using two balloons with different angles results in a simple structure and ease of fabrication.

[0028] like Figure 1 As shown, the first balloon in this embodiment includes a first inner balloon 2 and a first outer balloon 21, both with a fan-shaped cross-section. The first inner balloon 2 is located inside the first outer balloon 21. The first inner balloon 2 and the first outer balloon 21 are independent and not connected to each other. The first inner balloon 2 and the first outer balloon 21 are respectively connected to the inflation chamber in the catheter 1. The axial length of the first inner balloon 2 is not greater than the axial length of the first outer balloon 21. like Figure 1 As shown, the second balloon in this embodiment includes a second inner balloon 3 and a second outer balloon 31, both with a fan-shaped cross-section. The second inner balloon 3 is located inside the second outer balloon 31. The second inner balloon 3 and the second outer balloon 31 are independent and not connected to each other. The second inner balloon 3 and the second outer balloon 31 are respectively connected to the inflation chamber in the catheter 1. The axial length of the second inner balloon 3 is not greater than the axial length of the second outer balloon 31. like Figure 1 As shown, in this embodiment, the angle occupied by the first inner balloon 2 in the circumferential direction of the catheter 1 is greater than the angle occupied by the second inner balloon 3 in the circumferential direction of the catheter 1, and the angle occupied by the first outer balloon 21 in the circumferential direction of the catheter 1 is greater than the angle occupied by the second outer balloon 31 in the circumferential direction of the catheter 1.

[0029] The inner and outer balloons are independent and not connected. They can be inflated separately using catheters. When using the balloon, the inner balloon is inflated first. Because of its small size, the inner balloon only occupies a portion of the blood vessel lumen and therefore does not completely block blood flow. This allows sufficient time to adjust the position of the inner balloon under fluoroscopy, based on the markers on it, ensuring the overall balloon is properly positioned and at the desired inflation location. Once the alignment is confirmed, the outer balloon can be inflated for further expansion.

[0030] like Figure 1 As shown, in this embodiment, the radius of the first inner balloon 2 is equal to the radius of the second inner balloon 3, and the radius of the first outer balloon 21 is equal to the radius of the second outer balloon 31; the axial length of the first inner balloon 2 is equal to the axial length of the second inner balloon 3, and the axial length of the first outer balloon 21 is equal to the axial length of the second outer balloon 31. Using outer and inner balloons with the same radius and axial length improves structural stability and enhances support effectiveness.

[0031] like Figure 1As shown, in this embodiment, the center line of the fan-shaped structure of the first balloon group coincides with the center line of the fan-shaped structure of the second balloon group. This makes the entire first and second balloon groups symmetrical on both sides of the center line, resulting in good structural stability.

[0032] like Figure 3 As shown, in this embodiment, the catheter 1 is provided with an outer balloon branch 12 and an inner balloon branch 13 on a section of the structure located axially outside the first balloon group and the second balloon group. The outer balloon branch 12 contains an outer balloon inflation chamber 14 and extends into the catheter 1, and is connected to the first outer balloon 21 of the first balloon group and the second outer balloon 31 of the second balloon group, respectively. The inner balloon branch 13 contains an inner balloon inflation chamber 15 and extends into the catheter 1, and is connected to the first inner balloon 2 of the first balloon group and the second inner balloon 3 of the second balloon group, respectively.

[0033] This embodiment presents an asymmetric double-layer balloon, where the first and second balloons serve as the main support balloon and the contralateral support balloon, respectively. The balloons can be asymmetrically structured with one large and one small. The balloons can be non-compliant, semi-compliant, or compliant, and can be made of suitable materials depending on the specific application. Different markings can be set on the inner balloon. During use, the inner balloon can be inflated first using a high-pressure pump. Due to its small size, the inner balloon only occupies a portion of the lumen within the blood vessel, thus not completely blocking blood flow. Sufficient time is allowed to adjust the orientation of the inner balloon under fluoroscopy based on the markings, ensuring the overall balloon position is appropriate, while the main support balloon (the larger balloon) is positioned at the desired expansion location. Once alignment is confirmed, the outer balloon is inflated using a pressure pump for full balloon dilation. Because the entire balloon has an eccentric design with ample space, sufficient dilation time can be achieved while maintaining unobstructed blood flow. The balloon can be inflated using a pressure pump or a hand-operated syringe. The catheter can consist of multiple tubes inside a single catheter, used to connect the inner balloon, the outer balloon, and to form the guidewire lumen 11.

[0034] This embodiment presents an asymmetric double-layer balloon, employing a first balloon group and a second balloon group at different angles, to address the problem of balloon dilation of stents and other grafts within the thoracic aorta. It can maintain unobstructed blood flow within the aorta while fully dilating the target area using the balloon, avoiding potential complications caused by blood flow obstruction, such as balloon displacement due to blood flow impact and associated graft displacement. Example 2

[0035] like Figure 2As shown, an asymmetric double-layer balloon of this embodiment includes a first balloon group, a second balloon group, and a catheter 1. The first balloon group and the second balloon group are both fan-shaped double-layer balloons and are correspondingly arranged on the outer side wall of the catheter 1. The center of the first balloon group is fixed on the outer side wall of the catheter 1 and communicates with the catheter 1. The center of the second balloon group is fixed on the outer side wall of the catheter 1 and communicates with the catheter 1. The angle occupied by the first balloon group in the circumferential direction of the catheter 1 is greater than the angle occupied by the second balloon group in the circumferential direction of the catheter 1.

[0036] Specifically, the catheter contains a guidewire lumen and an inflation chamber for both inner and outer balloons.

[0037] like Figure 2 As shown, the first balloon group in this embodiment includes multiple first balloons (e.g., 2, 3, 4, etc.), and the second balloon group includes one second balloon. The sum of the angles occupied by the multiple first balloons in the circumferential direction of catheter 1 is greater than the angle occupied by the second balloon in the circumferential direction of catheter 1. The eccentric structure obtained by using multiple first balloons and one second balloon has a simple structural design and is convenient for manufacturing.

[0038] like Figure 2 As shown, in this embodiment, the angle occupied by a single first balloon in the circumferential direction of catheter 1 is equal to the angle occupied by a single second balloon in the circumferential direction of catheter 1.

[0039] like Figure 2 As shown, the first balloon in this embodiment includes a first inner balloon 2 and a first outer balloon 21, both with a fan-shaped cross-section. The first inner balloon 2 is located inside the first outer balloon 21. The first inner balloon 2 and the first outer balloon 21 are independent and not connected to each other. The first inner balloon 2 and the first outer balloon 21 are respectively connected to the inflation chamber in the catheter 1. The axial length of the first inner balloon 2 is not greater than the axial length of the first outer balloon 21. like Figure 2 As shown, the second balloon in this embodiment includes a second inner balloon 3 and a second outer balloon 31, both with a fan-shaped cross-section. The second inner balloon 3 is located inside the second outer balloon 31. The second inner balloon 3 and the second outer balloon 31 are independent and not connected to each other. The second inner balloon 3 and the second outer balloon 31 are respectively connected to the inflation chamber in the catheter 1. The axial length of the second inner balloon 3 is not greater than the axial length of the second outer balloon 31. like Figure 2 As shown, in this embodiment, the sum of the angles occupied by the plurality of first inner balloons 2 in the circumferential direction of the catheter 1 is greater than the angle occupied by the second inner balloon 3 in the circumferential direction of the catheter 1, and the sum of the angles occupied by the plurality of first outer balloons 21 in the circumferential direction of the catheter 1 is greater than the angle occupied by the second outer balloon 31 in the circumferential direction of the catheter 1.

[0040] The inner and outer balloons are independent and not connected. They can be inflated separately using catheters. When using the balloon, the inner balloon is inflated first. Because of its small size, the inner balloon only occupies a portion of the blood vessel lumen and therefore does not completely block blood flow. This allows sufficient time to adjust the position of the inner balloon under fluoroscopy, based on the markers on it, ensuring the overall balloon is properly positioned and at the desired inflation location. Once the alignment is confirmed, the outer balloon can be inflated for further expansion.

[0041] like Figure 2 As shown, in this embodiment, the radius of the first inner balloon 2 is equal to the radius of the second inner balloon 3, and the radius of the first outer balloon 21 is equal to the radius of the second outer balloon 31; the axial length of the first inner balloon 2 is equal to the axial length of the second inner balloon 3, and the axial length of the first outer balloon 21 is equal to the axial length of the second outer balloon 31. Using outer and inner balloons with the same radius and axial length improves structural stability and enhances support effectiveness.

[0042] like Figure 2 As shown, in this embodiment, the center line of the fan-shaped structure of the first balloon group coincides with the center line of the fan-shaped structure of the second balloon group. This makes the entire first and second balloon groups symmetrical on both sides of the center line, resulting in good structural stability.

[0043] like Figure 3 As shown, in this embodiment, the catheter 1 is provided with an outer balloon branch 12 and an inner balloon branch 13 on a section of the structure located axially outside the first balloon group and the second balloon group. The outer balloon branch 12 contains an outer balloon inflation chamber 14 and extends into the catheter 1, and is connected to the first outer balloon 21 of the first balloon group and the second outer balloon 31 of the second balloon group, respectively. The inner balloon branch 13 contains an inner balloon inflation chamber 15 and extends into the catheter 1, and is connected to the first inner balloon 2 of the first balloon group and the second inner balloon 3 of the second balloon group, respectively.

[0044] This embodiment presents an asymmetric double-layer balloon, where the first and second balloons serve as the main support balloon and the contralateral support balloon, respectively. The balloons can be asymmetrically structured with one large and one small. The balloons can be non-compliant, semi-compliant, or compliant, and can be made of suitable materials depending on the specific application. Different markings can be set on the inner balloon. During use, the inner balloon can be inflated first using a high-pressure pump. Due to its small size, the inner balloon only occupies a portion of the lumen within the blood vessel, thus not completely blocking blood flow. Sufficient time is allowed to adjust the orientation of the inner balloon under fluoroscopy based on the markings, ensuring the overall balloon position is appropriate, while the main support balloon (the larger balloon) is positioned at the desired expansion location. Once alignment is confirmed, the outer balloon is inflated using a pressure pump for full balloon dilation. Because the entire balloon has an eccentric design with ample space, sufficient dilation time can be achieved while maintaining unobstructed blood flow. The balloon can be inflated using a pressure pump or a hand-operated syringe. The catheter can consist of multiple tubes inside a single catheter, used to connect the inner balloon, the outer balloon, and to form the guidewire lumen 11.

[0045] This embodiment presents an asymmetric double-layer balloon, employing a first balloon group and a second balloon group at different angles, to address the problem of balloon dilation of stents and other grafts within the thoracic aorta. It can maintain unobstructed blood flow within the aorta while fully dilating the target area using the balloon, avoiding potential complications caused by blood flow obstruction, such as balloon displacement due to blood flow impact and associated graft displacement. Example 3

[0046] Based on Example 1, in this example, the center line of the fan-shaped structure of the first balloon group does not coincide with the center line of the fan-shaped structure of the second balloon group. Example 4

[0047] Based on Example 2, in this example, the center line of the fan-shaped structure of the first balloon group does not coincide with the center line of the fan-shaped structure of the second balloon group.

[0048] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0049] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this utility model, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0050] In this utility model, unless otherwise explicitly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0051] In this utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0052] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0053] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. An asymmetric double-layered balloon, characterized in that, The device includes a first balloon assembly, a second balloon assembly, and a catheter. Both the first and second balloon assemblies are fan-shaped double-layered balloons and are correspondingly arranged on the outer wall of the catheter. The center of the first balloon assembly is fixed to the outer wall of the catheter and communicates with the inflation chamber inside the catheter. The center of the second balloon assembly is fixed to the outer wall of the catheter and communicates with the inflation chamber inside the catheter. The angle occupied by the first balloon assembly in the circumferential direction of the catheter is greater than the angle occupied by the second balloon assembly in the circumferential direction of the catheter.

2. The asymmetric double-layered balloon according to claim 1, characterized in that, The first balloon group includes a first balloon, and the second balloon group includes a second balloon, wherein the angle occupied by the first balloon in the circumferential direction of the catheter is greater than the angle occupied by the second balloon in the circumferential direction of the catheter.

3. The asymmetric double-layered balloon according to claim 2, characterized in that, The first balloon includes a first inner balloon and a first outer balloon, both with a fan-shaped cross-section. The first inner balloon is located inside the first outer balloon. The first inner balloon and the first outer balloon are independent and not connected to each other. The first inner balloon and the first outer balloon are respectively connected to the inflation chamber in the catheter. The axial length of the first inner balloon is not greater than the axial length of the first outer balloon. The second balloon includes a second inner balloon and a second outer balloon, both with a fan-shaped cross-section. The second inner balloon is located inside the second outer balloon. The second inner balloon and the second outer balloon are independent and not connected to each other. The second inner balloon and the second outer balloon are respectively connected to the inflation chamber in the catheter. The axial length of the second inner balloon is not greater than the axial length of the second outer balloon. The angle occupied by the first inner balloon in the circumferential direction of the catheter is greater than the angle occupied by the second inner balloon in the circumferential direction of the catheter, and the angle occupied by the first outer balloon in the circumferential direction of the catheter is greater than the angle occupied by the second outer balloon in the circumferential direction of the catheter.

4. The asymmetric double-layered balloon according to claim 3, characterized in that, The radius of the first inner balloon is equal to the radius of the second inner balloon, and the radius of the first outer balloon is equal to the radius of the second outer balloon; The axial length of the first inner balloon is equal to the axial length of the second inner balloon, and the axial length of the first outer balloon is equal to the axial length of the second outer balloon.

5. The asymmetric double-layered balloon according to claim 1, characterized in that, The first balloon group includes multiple first balloons, and the second balloon group includes a second balloon. The sum of the angles occupied by the multiple first balloons in the circumferential direction of the catheter is greater than the angle occupied by the second balloon in the circumferential direction of the catheter.

6. The asymmetric double-layered balloon according to claim 5, characterized in that, The first balloon includes a first inner balloon and a first outer balloon, both with a fan-shaped cross-section. The first inner balloon is located inside the first outer balloon. The first inner balloon and the first outer balloon are independent and not connected to each other. The first inner balloon and the first outer balloon are respectively connected to the inflation chamber in the catheter. The axial length of the first inner balloon is not greater than the axial length of the first outer balloon. The second balloon includes a second inner balloon and a second outer balloon, both with a fan-shaped cross-section. The second inner balloon is located inside the second outer balloon. The second inner balloon and the second outer balloon are independent and not connected to each other. The second inner balloon and the second outer balloon are respectively connected to the inflation chamber in the catheter. The axial length of the second inner balloon is not greater than the axial length of the second outer balloon. The sum of the angles occupied by the multiple first inner balloons in the circumferential direction of the catheter is greater than the angle occupied by the second inner balloon in the circumferential direction of the catheter, and the sum of the angles occupied by the multiple first outer balloons in the circumferential direction of the catheter is greater than the angle occupied by the second outer balloon in the circumferential direction of the catheter.

7. The asymmetric double-layered balloon according to claim 6, characterized in that, The radius of the first inner balloon is equal to the radius of the second inner balloon, and the radius of the first outer balloon is equal to the radius of the second outer balloon; The axial length of the first inner balloon is equal to the axial length of the second inner balloon, and the axial length of the first outer balloon is equal to the axial length of the second outer balloon.

8. The asymmetric double-layered balloon according to claim 1, characterized in that, The center line of the fan-shaped structure of the first balloon group coincides with the center line of the fan-shaped structure of the second balloon group.

9. The asymmetric double-layered balloon according to claim 1, characterized in that, The catheter has an outer balloon branch and an inner balloon branch on a section of its structure located axially outside the first balloon group and the second balloon group. The outer balloon branch contains an outer balloon inflation chamber and extends into the catheter, communicating with the first outer balloon of the first balloon group and the second outer balloon of the second balloon group, respectively. The inner balloon branch contains an inner balloon inflation chamber and extends into the catheter, communicating with the first inner balloon of the first balloon group and the second inner balloon of the second balloon group, respectively.

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