CN115554578A

CN115554578A - Restraint device for balloon, preparation method of restraint device and blood vessel dilator

Info

Publication number: CN115554578A
Application number: CN202211545279.2A
Authority: CN
Inventors: 关丽鹃; 王永刚
Original assignee: Suzhou Venmed Technology Co ltd
Current assignee: Suzhou Venmed Technology Co ltd
Priority date: 2022-12-05
Filing date: 2022-12-05
Publication date: 2023-01-03
Anticipated expiration: 2042-12-05
Also published as: CN115554578B

Abstract

The invention discloses a restraining device for a balloon, a preparation method thereof and a vessel dilatation apparatus. The restraint device comprises an axial strip, a first connecting strip and a second connecting strip; the plurality of axial strips are arranged at intervals along the circumferential direction of the constraint device; the axial strip can elastically deform and is provided with a plurality of first connecting parts and a plurality of second connecting parts which are arranged at intervals along the length direction, and at least one second connecting part is arranged between every two adjacent first connecting parts; the first connecting part of any axial strip is connected with the first connecting part of one adjacent axial strip through a first connecting strip, and the second connecting part of any axial strip is connected with the second connecting part of the other adjacent axial strip through a second connecting strip; each first connecting portion is connected with only one first connecting strip, and each second connecting portion is connected with only one second connecting strip. The restraining device has larger elastic deformation amount, increases the specification range of the balloon which can be adapted, and is suitable for expanding plaques in narrow blood vessels.

Description

Restraint device for balloon, preparation method thereof and vascular dilation instrument

Technical Field

The invention belongs to the field of medical instruments, and particularly relates to a restraining device for a balloon, a preparation method of the restraining device and a blood vessel dilatation instrument.

Background

Occlusion of body lumens is a common Disease, such as Peripheral Artery Disease (PAD), which is commonly referred to as a Disease of various arteries other than the coronary and intracranial arteries. One of the main methods for treating PAD diseases is angioplasty, the used device is a balloon catheter, and angioplasty is performed through the balloon catheter to form a vascular access, or the balloon catheter is used for pre-dilatation, post-dilatation and the like when the vascular access is ensured by releasing a stent.

The balloon catheter mainly comprises a balloon and a catheter for conveying and pressurizing the balloon. The size of the balloon can vary significantly with inflation pressure. The sacculus reduces the size through folding before reaching pathological change position, and the folding sacculus of in-process that pressurizes after reaching pathological change position can rotary-cut formula open, can form the shearing force to the vascular wall, and the damage vascular wall probably appears the diameter at sacculus both ends in addition in the intravascular of having the plaque and is greater than the diameter that has the plaque region, and "dog bone effect" promptly, this kind of phenomenon can cause the injury to blood vessel. The conventional balloon has a phenomenon of slipping off when expanding a blood vessel with plaque due to smooth appearance, which reduces the expansion effect of the balloon.

In order to solve the above problems, there is proposed a conventional balloon catheter provided with a constraining structure for reducing damage to a vessel wall and preventing the balloon from slipping. The design requirement of the scheme on the constraint structure is very high, and the scheme at least comprises the following steps: first, it is desirable that the constraining structure not only expand in compliance with the inflation of the balloon, but also ensure that there is little or no risk of fracture during the expansion process and the post-expansion function; second, considering that balloons of the same size in the industry often have tolerances as high as ± 10% due to uncontrollable factors of the equipment and the manufacturing process, the matched constraint structure must have good balloon adaptability to ensure good consistency of the product as a whole in use, thereby facilitating improvement of the accuracy of the operation and reduction of the damage to the vessel wall. However, the prior art constraint structure has not yet achieved the aforementioned requirements.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provides a novel balloon restraint device and a preparation method thereof. The invention also provides a vascular dilation instrument adopting the novel restraining device for the balloon.

The invention provides a restraining device for a balloon, which is provided with an inner space capable of accommodating the balloon, wherein the restraining device is provided with an expansion state capable of expanding along with the balloon and a contraction state capable of contracting along with the balloon, and the restraining device comprises a plurality of axial strips, a plurality of first connecting strips and a plurality of second connecting strips;

the plurality of axial strips are arranged at intervals along the circumferential direction of the restraining device; each axial strip can be elastically deformed and is provided with a plurality of first connecting parts and a plurality of second connecting parts which are arranged at intervals along the length direction, and at least one second connecting part is arranged between every two adjacent first connecting parts;

the first connecting part of any axial strip is connected with the first connecting part of one adjacent axial strip through the first connecting strip, and the second connecting part of any axial strip is connected with the second connecting part of the other adjacent axial strip through the second connecting strip;

each first connecting part is connected with only one first connecting strip, and each second connecting part is connected with only one second connecting strip;

two adjacent axial strips and two adjacent first connecting strips or two adjacent second connecting strips between the two axial strips form an expansion outlet for the balloon to expand outwards; when the restraining device is in a contraction state, the axial strips extend along the length direction of the restraining device for the saccule; when the restraint device is in the expansion state, the axial strips are bent at the first connecting part and the second connecting part, and the outline shape of the expansion port is a polygon with the number of sides being more than or equal to 6.

Preferably, the plurality of first connecting strips and the plurality of second connecting strips are arranged in a staggered manner, one second connecting portion is arranged between two adjacent first connecting portions, and one first connecting portion is arranged between two adjacent second connecting portions.

Preferably, the axial bar and the first connecting bar and the second connecting bar are integrally arranged, and the axial bar and the first connecting bar or the second connecting bar are in circular arc transition.

More preferably, the first connection portion has a transition angle protruding toward a side where the first connection bar is located, the first connection bar being connected to the transition angle; the second connecting portion has a transition corner protruding toward a side where the second connecting bar is located, and the second connecting bar is connected to the transition corner.

Further, the width of the first connection portion and the second connection portion is the sum of the width of the portion of the axial strip located between the first connection portion and the second connection portion and the chamfer radius of the transition angle.

Preferably, when the restriction device is in a contracted state, the axial strips linearly extend along the length direction of the restriction device for the balloon.

More preferably, when said restriction device is in said expanded state, either of said expansion outlets has a hexagonal shape, wherein one of said axial strips forms two sides of the hexagon, the other axial strip forms the other two sides of the hexagon, and two of said first connecting strips or two of said second connecting strips form the remaining two sides.

More preferably, the length of the first connecting strip, the length of the second connecting strip, and the distance between the adjacent first connecting portions and the second connecting portions are equal.

Preferably, when the restriction device is in the inflated state, the first connecting strips and the second connecting strips are perpendicular to the length direction of the restriction device for the balloon.

Preferably, the first and second connecting strips comprise one or more arcuate portions when the restraining means is in the retracted state.

More preferably, the first and second connector strips are sinusoidal when the restraining means is in a retracted state.

Preferably, the first and second connection bars have elasticity.

Preferably, the restraining device further comprises a proximal connecting bracket and a distal connecting bracket for connecting the balloon catheter, wherein the proximal end parts of the axial strips are connected between the proximal connecting brackets, and the distal end parts of the other axial strips are connected to the distal connecting brackets.

Preferably, the restriction device is integrally formed of nitinol, and the axial bar, the first connecting bar and the second connecting bar are nitinol wires.

Preferably, when the restriction device is in the expansion state, the outline shape of the expansion port is a polygon with the number of sides being 6 to 10.

The second aspect of the present invention provides a method for preparing the restriction device for balloon, comprising the following steps: providing a thin-wall nickel-titanium alloy tube, cutting the nickel-titanium alloy tube to form an axial strip, and connecting a first connecting strip with the axial strip and a second connecting strip with the axial strip.

The invention provides a vessel dilator, which comprises a balloon and a catheter for pushing the balloon, wherein the balloon device further comprises a restraining device for the balloon, the restraining device for the balloon is fixedly connected to the catheter, the balloon is arranged in the restraining device, the restraining device is in an expansion state after the balloon is expanded, a plurality of balloon walls of the balloon expand from the expansion outlet to form a plurality of pillows which protrude outwards and are arranged in a staggered manner, and a concave part is arranged between every two adjacent pillows.

Preferably, the surface of the balloon and/or the surface of the restriction device is loaded with a drug. More preferably, the drug is one or more of a drug that inhibits proliferation of mesodermal smooth muscle cells and/or a drug that eliminates inflammation. Specifically, the drug is paclitaxel which inhibits the proliferation of mesodermal smooth muscle cells.

Compared with the prior art, the invention has the following advantages by adopting the scheme:

according to the restraining device for the saccule, through the integral structure design, particularly, the first connecting parts and the second connecting parts of the axial strips are arranged in a staggered mode, and each connecting part is connected with only one first connecting strip or one second connecting strip; on the other hand, the structural design has more uniform stress distribution, and compared with the structure in the prior art, the structure has the advantages that the fracture risk is obviously reduced, and the safety is better.

The blood vessel expansion device has the advantages that by adopting the restraining device for the saccule, when the restraining device is used for expanding the angiostenosis, the fracture risk is small, the safety is good, the damage of the saccule to the blood vessel wall can be effectively reduced, and the saccule is not easy to slip. For doctors, the vascular dilation device has good consistency, so that the vascular dilation can be performed more accurately, and the damage to the blood vessel is reduced to the maximum extent. The control requirements for the tolerance of the ball are reduced for the manufacturer, so that the production costs can be reduced.

Drawings

In order to more clearly illustrate the technical solution of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.

FIG. 1 is a schematic structural view of a vasodilator device according to an embodiment of the present invention, in which the balloon is uninflated and the constraining scaffold is in a contracted state;

FIG. 2 is a schematic structural view of a vasodilator device according to an embodiment of the present invention, wherein the balloon is inflated and the constraining scaffold is in an inflated state;

fig. 3 is a schematic view of a collapsed deployment of a restraint device according to an embodiment of the invention.

Figure 4 is an enlarged partial schematic view of the restriction device in a contracted state.

FIG. 5 is a schematic view of a flat deployment of a restraint device in an inflated state according to an embodiment of the invention.

Fig. 6a is a schematic view of a variant of an axial strip according to an embodiment of the invention.

FIG. 6b is a force analysis diagram of an axial strip according to an embodiment of the present invention.

Detailed Description

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings so that the advantages and features of the invention may be more readily understood by those skilled in the art. It should be noted that the description of the embodiments is provided to help understanding of the present invention, but the present invention is not limited thereto. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

The embodiment provides a restraining device for a balloon and a vessel dilator with the restraining device. Referring to fig. 1 and 2, the vessel dilator with the restriction device 1 further comprises a balloon 2 and a catheter 3 for pushing the balloon 2 to a part to be treated of a vessel. The saccule 2 can be expanded and contracted, and after a certain amount of gas or liquid is introduced into the saccule 2 through the catheter 3, the saccule 2 is expanded; the restraint device 1 is sleeved outside the balloon 2, and the surface of the balloon 2 and/or the surface of the restraint device 1 can be loaded with medicines; the restriction device 1 is fixedly attached to the catheter 3. The restriction device 1 can also assist the retraction of the balloon 2 under the condition of pressure relief, the diameter of the restriction device 1 after being expanded is smaller than that of the balloon 2 in an unrestrained state, so that the over-expansion of the balloon 2 can be limited, and the restriction device 1 is withdrawn out of the body along with the catheter 3 of the balloon 2 after the blood vessel expansion is finished and cannot be left in the body.

Referring to fig. 1 to 5, the restriction device 1 has an inner space for accommodating the balloon 2, and the balloon 2 is located in the inner space. The restriction device 1 has an expanded state in which it is expandable with the balloon 2 and a contracted state in which it is contracted with the balloon 2. Specifically, the main body of the restriction device 1 is fitted over the balloon 2, and includes a plurality of axial bars 11 (e.g., 6), a plurality of first connection bars 12, and a plurality of second connection bars 13. The plurality of axial strips 11 are arranged at intervals along the circumferential direction of the restriction device, and in the embodiment, the plurality of axial strips 11 are distributed at equal intervals along the circumferential direction of the restriction device. Each axial strip 11 is elastically deformable and has a plurality of first connection portions 111 and a plurality of second connection portions 112 arranged at intervals along the length direction of the restraining device. The first connection portions 111 and the second connection portions 112 are distributed in an alternating manner, and at least one second connection portion 112 is arranged between two adjacent first connection portions 111. The first connecting portion 111 of any one axial strip 11 and the first connecting portion 111 of one axial strip 11 adjacent thereto are connected by a first connecting strip 12, and the second connecting portion 112 of any one axial strip 11 and the second connecting portion 112 of another axial strip 11 adjacent thereto are connected by a second connecting strip 13.

The connection will be described in detail below by taking the specific axial strips 11b in fig. 3 and 5 as an example. The axial bar 11b is connected with the axial bar 11a on the left side thereof through a plurality of first connecting bars 12, the first connecting bars 12 being connected with the first connecting portions 111 of the axial bar 11 b; the axial bar 11b is connected to the right-hand axial bar 11c via a plurality of second connecting bars 13, the second connecting bars 13 being connected to the second connecting portions 112 of the axial bar 11 b. It should be noted that each first connecting portion 111 is connected to only one first connecting bar 12, and each second connecting portion 112 is connected to only one second connecting bar 13.

The two adjacent axial strips 11 and the two adjacent first connecting strips 12 or the two adjacent second connecting strips 13 between the two adjacent axial strips enclose an expansion opening 10 for the balloon 2 to expand outwards, and when the restraining device 1 is in an expansion state, the shape of the expansion opening 10 is a polygon with the number of sides being more than or equal to 6. The number of edges satisfies the following conditions: 2N, N is a positive integer greater than or equal to 3; further, the number of sides is 6 or more and 10 or less. Specifically, in the present embodiment, the plurality of first connecting strips 12 and the plurality of second connecting strips 13 are arranged in a staggered manner, one second connecting portion 112 is arranged between two adjacent first connecting portions 111, and one first connecting portion 111 is arranged between two adjacent second connecting portions 112; thus, in the expanded state of the restriction device 1, the expansion opening 10 has a hexagonal shape, wherein one axial stripe 11 forms two sides of the hexagon, the other axial stripe 11 forms the other two sides of the hexagon, and the two first connecting stripes 12 or the two second connecting stripes 13 form the remaining two sides. For example, with reference to figure 4, the axial strips 11a form two sides of the hexagonal puff port 10, the axial strips 11b form the other two sides of the hexagonal puff port 10, and the two first connecting strips 12 form the remaining two sides of the hexagonal puff port 10. Further, the first connecting portions 111 and the second connecting portions 112 on the same axial strip 11 are arranged at equal intervals, the shape of the expansion port 10 when the restriction device 1 is in the expanded state is a regular hexagon, and the length of the first connecting strip 12, the length of the second connecting strip 13, and the distance between the adjacent first connecting portions 111 and the second connecting portions 112 are equal.

The axial strips 11 and the first connecting strips 12 and the second connecting strips 13 are integrally arranged, and the axial strips 11 and the first connecting strips 12 or the second connecting strips 13 are in circular arc transition, as shown in fig. 3. The first connecting portion 111 has a transition angle protruding to a side where the first connecting bar 12 is located, and the first connecting bar 12 is connected to the transition angle; the second connection portion 112 has a transition angle protruding toward a side where the second connection bar 13 is located, and the second connection bar 13 is connected to the transition angle. The width of the first and

second connection portions

111, 112 is the sum of the width of the portion of the axial strip 11 between said first and second connection portions and the chamfer radius of the transition angle. In the present embodiment, the width of the axial strips 11 is 50% greater than the width of the first and second connecting

strips

12, 13.

The axial strips 11 have elasticity and can be elastically bent and deformed, and when the balloon 2 is expanded, the first connecting parts 111 of the axial strips 11 are pulled to one side from the first connecting strips 12 so as to be bent to one side; the second connection portion 112 is pulled toward the other side from the second connection bar 13, and is thus bent toward the other side. In the deflated state of the restriction device 1, the axial strips 11 extend linearly along the balloon 2 in the longitudinal direction (axial direction) of the restriction device 1. When the restraint device 1 is in the expanded state, the axial strips 11 are bent into a zigzag shape at the first connection portion 111 and the second connection portion 112, respectively. Further, the axial strips 11 can also elastically stretch and deform, and when the stress is large, the axial strips 11 are stretched.

The first and

second links

12, 13 comprise one or more arcuate portions when the restriction device 1 is in the retracted state. Further, the first and second connecting

strips

12 and 13 are shaped as sine waves, i.e., are formed by a combination of a plurality of circular arc portions. When the restriction device 1 is in the inflated state, the first connecting strips 12 and the second connecting strips 13 are perpendicular to the axial direction of the restriction device 1 for the balloon 2. The first connecting strip 12 and the second connecting strip 13 have elasticity and are capable of bending deformation and also capable of telescopic deformation.

The restriction device 1 further comprises a proximal connecting stent 14 and a distal connecting stent 15 for connecting the catheter 3, wherein the proximal ends of some of the axial strips 11 are connected to the proximal connecting stent 14, and the distal ends of other axial strips 11 are connected to the distal connecting stent 15. The proximal connecting bracket 14 and the distal connecting bracket 15 are fixed to the catheter 3 by heat fusion or adhesion. Herein, "proximal end" and "distal end" are defined as states of the medical staff when operating the vasodilator device, and the end closer to the hand of the medical staff operating the device is the proximal end, and the end farther away is the distal end.

The restraint device 1 is formed by nickel-titanium alloy in a whole, and the axial strips 11, the first connecting strips 12 and the second connecting strips 13 are respectively nickel-titanium alloy wires formed by cutting.

The preparation method of the restraint device 1 for the sacculus 2 comprises the following steps: providing a thin-wall nickel-titanium alloy tube, and cutting the nickel-titanium alloy tube to form an axial strip 11, a first connecting strip 12 connected with the axial strip 11 and a second connecting strip 13 connected with the axial strip 11. The proximal connecting stent 14 and the distal connecting stent 15 are also nickel-titanium alloy wires cut from the nickel-titanium alloy tube.

As shown in fig. 2, in the above-described vasodilator, the restriction device 1 is in the inflated state after the balloon 2 is inflated, a plurality of balloon walls of the balloon 2 are inflated from the inflation port 10 to form a plurality of pillows 21 which are protruded outward and are arranged alternately, and the adjacent pillows 21 have the concave portions 22 therebetween. The plurality of convex pillows 21 contact the wall of the blood vessel to expand the blood vessel. As shown in fig. 1, after the balloon 2 is decompressed, the pillow 21 disappears, and the restraining device 1 retracts to contract with the balloon 2, so as to be separated from the contact with the vessel wall, and to be withdrawn out of the body along with the balloon 2. Taking the axial strips 11 with a width of 0.08mm as an example, the inflated inner diameter of the restriction device 1 at nominal pressure is 0.13-0.23 mm smaller than the inner diameter of the adaptation balloon 2.

The vasodilator device may further comprise a tip tube attached to the distal end of the catheter 3 and a visualization ring. The catheter 3 comprises an inner tube and an outer tube which are sleeved with each other, and a developing ring is arranged on the inner tube and used for indicating the position of the saccule 2. The proximal 14 and distal 15 attachment brackets of the restriction device 1 are fixed to the outer tube.

The surface of the balloon 2 and/or the surface of the restriction device 1 are loaded with a drug. The medicine is one or more of medicine for inhibiting proliferation of mesodermal smooth muscle cells and/or medicine for eliminating inflammation. Specifically, the drug is paclitaxel which inhibits the proliferation of mesodermal smooth muscle cells.

Adopt above-mentioned structure restraint device and vascular dilator instrument to have following advantage:

1. the first connecting portion 111/the second connecting portion 112 of the axial bar 11 only needs to be connected with the first connecting bar 12/the second connecting bar 13 on one side, the width of the connecting portion of the axial bar 11 and the connecting bars is controlled (the maximum width is reduced by 15 to 40 percent compared with other possible structures), so that the whole restraint device has a large deformation amount, stress concentration is reduced, and the risk of product fracture is small.

For example: the width of the main portion of the connecting strip (except for the first connecting portion 111/the second connecting portion 112) is 0.15mm, the transition angle is formed at the first connecting portion 111/the second connecting portion 112 by rounding, and the radius of the rounding is 0.08mm, so that the maximum width of the axial strip 11 is 0.23mm. And if the following structure is adopted: both sides of same connecting portion of axial strip all are connected with the connecting strip, so the both sides of the connecting portion of axial strip all need the chamfer, then the maximum width of axial strip is 0.31mm, comparatively speaking, the maximum width of axial strip 11 has reduced 25% in the structure of this embodiment.

The reduction of the width at the connection may improve the radial linear elastic variation of the whole constraint device 1. If the expanded diameter of the restriction device 1 is 6mm, the circumference of the restriction device 1 is 6 pi, wherein there are 6 axial strips 11, and three sets of first connecting strips 12 and three sets of second connecting strips 13 as seen in the circumferential direction, so that there are 6 sets of joints, and the total width (6 x 0.23mm) of the joints accounts for 7.3% of the circumference of the restriction device 1, compared with 9.8% of the conventional structure (the total width of the joints is 6 x 0.31mm), the amount of deformation of the entire restriction device 1 of the present embodiment is larger. Assuming that the elastic deformation of the nickel titanium is 7%, the deformation amount of the restriction device 1 of this embodiment is closer to 7% than the connection mechanism in which the connection strips are connected to both sides of the same connection portion of the axial strip, and the elastic deformation of the instrument can be increased by reducing the ratio of the rod width at the connection portion.

2. The axial strips 11 can adapt to the size of the saccule 2 to generate corresponding deformation so as to make up the problem of poor pillow expansion effect caused by the tolerance of the saccule 2, namely, the specification range of the saccule 2 capable of being adapted is enlarged, the method is more suitable for industrial production, and the assembly cost of the blood vessel expansion instrument is reduced.

Referring to fig. 6a, the restriction device 1 of the present embodiment may generate different deformation amounts according to the size of the balloon 2. The axial strips 11 are subjected to an upward pulling force from the first connecting strips 12 and to a downward pulling force from the second connecting strips 13. When the balloon 2 is deflated, the axial strips 11 remain horizontal, as shown at P1 in fig. 6 a. When the balloon 2 starts to be inflated, the first connecting strips 12 and the second connecting strips 13 are unfolded and gradually straightened; referring to fig. 6b, at this time, the tensile force F1 of the first connecting bar 12 increases, the direction of the component force F2 of the tensile force from the second connecting bar 13 is inclined downward, and the axial bar 11 is bent and deformed, thereby forming a mechanical balance. When the diameter of the balloon 2 is larger, F1 is larger, so that the connecting rod is deformed more, and the corresponding F2 is increased to achieve mechanical balance. Referring to fig. 6a, P2 is the position where the small diameter balloon 2 is fitted and the axial strips 11 are deformed after the balloon 2 is inflated; p3 is the position after the deformation of the axial strips 11 after the balloon 2 is inflated and fitted to the large-diameter balloon 2. Therefore, the structural design can make up the problem that the inflated pillow part is not obvious due to the dimensional tolerance of the balloon 2, so that the balloon 2 with a larger specification range can be adapted, and the use consistency of products is ensured.

3. The distance between pillows formed by the expansion of the balloon 2 when the restraint device 1 is in an expansion state is small, and a plurality of pillows are arranged in unit length, so that the blood vessel plaque is easy to expand, and the restraint device is suitable for being applied to narrow blood vessels.

In the embodiment, the staggered arrangement is adopted, and the distance between the highest points of the adjacent pillows is smaller, so that the stricture blood vessel can be expanded more favorably.

As used in this specification and the appended claims, the terms "comprises" and "comprising" are intended to only encompass the explicitly identified steps and elements, which do not constitute an exclusive list, and that a method or apparatus may include other steps or elements. As used herein, the term "and/or" includes any combination of one or more of the associated listed items.

It should be noted that, unless otherwise specified, when a feature is referred to as being "fixed" or "connected" to another feature, it may be directly fixed or connected to the other feature or indirectly fixed or connected to the other feature. Further, the description of the upper, lower, left, right, etc. used in the present invention is only with respect to the positional relationship of the respective components of the present invention with respect to each other in the drawings.

The above-mentioned embodiments are merely illustrative of the technical concepts and features of the present invention, and are preferred embodiments, which are intended to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and not to limit the scope of the present invention. All equivalent changes or modifications made according to the principles of the present invention should be covered within the protection scope of the present invention.

Claims

1. A restraining device for a balloon, which has an inner space capable of accommodating the balloon, and which has an expanded state capable of expanding with the balloon and a contracted state capable of contracting with the balloon, characterized in that the restraining device comprises a plurality of axial strips, a plurality of first connecting strips and a plurality of second connecting strips;

2. A balloon constraining apparatus according to claim 1, wherein the plurality of first connecting strips and the plurality of second connecting strips are arranged alternately, one second connecting portion is provided between two adjacent first connecting portions, and one first connecting portion is provided between two adjacent second connecting portions.

3. A constraining device for a balloon according to claim 1 or 2, wherein the axial strips and the first and second connecting strips are integrally provided, and the axial strips and the first or second connecting strips are in arc transition.

4. A balloon-restraining device according to claim 3, wherein the first connecting portion has a transition angle protruding to a side where the first connecting strip is located, the first connecting strip being connected to the transition angle; the second connecting portion has a transition corner protruding toward a side where the second connecting bar is located, and the second connecting bar is connected to the transition corner.

5. A balloon restraint device according to claim 4, wherein the widths of the first and second connection portions are the sum of the width of the portion of the axial strip between the first and second connection portions and the chamfer radius of the transition angle.

6. A balloon restraint device according to claim 1 or 2, wherein the axial strips extend linearly in a longitudinal direction of the balloon restraint device when the restraint device is in a contracted state.

7. A restraining device for a balloon according to claim 6, wherein in the inflated state of the restraining device, any one of the inflation ports has a hexagonal shape, wherein one axial strip forms two sides of the hexagonal shape, the other axial strip forms the other two sides of the hexagonal shape, and two first connecting strips or two second connecting strips form the remaining two sides.

8. A balloon restraint device according to claim 1 or 7, wherein the length of the first connecting strip, the length of the second connecting strip, and the pitch between the adjacent first connecting portion and second connecting portion are equal.

9. A balloon-restraining device according to claim 1, wherein the first and second connecting strips are perpendicular to a longitudinal direction of the balloon-restraining device when the restraining device is in the inflated state.

10. A constraining device for a balloon according to claim 1, wherein the first and second connecting strips comprise one or more arcuate portions when the constraining device is in a collapsed state.

11. A balloon constraining apparatus according to claim 10, wherein the first and second connecting strips are sinusoidal in shape when the constraining apparatus is in a deflated state.

12. The restriction device for a balloon according to claim 1, wherein the first connection strip and the second connection strip have elasticity.

13. A balloon catheter according to claim 1, wherein the balloon catheter further comprises a proximal connecting stent and a distal connecting stent for connecting the balloon catheter, wherein a proximal portion of one of the axial strips is connected between the proximal connections, and a distal portion of the other axial strip is connected to the distal connecting stent.

14. A balloon restraint device according to claim 1, wherein the restraint device is integrally formed of nitinol, and the axial strips, the first connecting strips, and the second connecting strips are each nitinol wires.

15. A balloon restraint device according to claim 1, wherein the outline shape of the inflation port is a polygon having 6 to 10 sides when the restraint device is in the inflated state.

16. A method of making a restriction device for a balloon according to any of claims 1 to 15, comprising the steps of: providing a thin-wall nickel-titanium alloy tube, cutting the nickel-titanium alloy tube to form an axial strip, and connecting a first connecting strip with the axial strip and a second connecting strip with the axial strip.

17. A vessel dilator comprising a balloon and a catheter for pushing the balloon, wherein the balloon device further comprises the restraining device for balloon as defined in any one of claims 1 to 15, the restraining device for balloon is fixedly connected to the catheter, the balloon is arranged in the restraining device, the restraining device is in an inflated state after the balloon is inflated, a plurality of balloon walls of the balloon are inflated from the inflation outlet to form a plurality of pillows protruding outwards and arranged in a staggered manner, and a concave part is arranged between adjacent pillows.

18. The vessel dilator of claim 17 wherein a surface of the balloon and/or a surface of the constraining means is loaded with a drug.