Medical device, balloon structure and its manufacturing method

Abstract

The present invention provides a medical device, a balloon structure and a preparation method thereof, which can effectively form protrusions on the balloon structure, and at the same time will not affect the use performance of the balloon, and improve the anti-deployment ability of the stent to prevent the stent from falling off the balloon during the pushing process. The preparation method of the balloon structure includes: heating the initial structure of the balloon structure in the forming cavity of a pretreatment mold and receiving the perfusion of a fluid, so that the initial structure forms protrusions and is shaped in the forming cavity to obtain the formed structure of the balloon structure; wherein both the initial structure and the formed structure are in a folded state, the stent is crimped on the formed structure and is located on one side of the protrusion, and the height of the protrusion is at least higher than the height of the inner surface after the stent is crimped.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and particularly relates to a medical device, a balloon structure and a preparation method thereof. Background Art

[0002] The polymer stent product consists of a polymer stent, a drug coating and a balloon delivery system, and is applicable to the treatment of ischemic heart disease caused by coronary primary lesions and to improve the diameter of the coronary artery lumen.

[0003] In many therapeutic applications, the polymer stent must be present in the body for a limited time until its intended function is achieved. Compared with metal stents, polymer stents have lower mechanical properties. Therefore, the thickness and width of polymer stents are relatively large so that the stent has the strength required to support the blood vessel wall.

[0004] Relatively speaking, polymer stents have a larger circumferential diameter. Therefore, they have a greater tendency of radial springback before use. During the operation, the polymer stent is simply press-fitted onto a traditional balloon by the press-fitting force. Therefore, its larger radial diameter and radial springback may cause the polymer stent to be unloaded when pushing it distally in the human body and passing through a slightly blocked, curved or tortuous blood vessel section, thereby increasing the risk of the operation. Summary of the Invention

[0005] In view of this, the present invention provides a medical device, a balloon structure and a preparation method thereof, which can effectively form the protrusions on the balloon structure, and at the same time will not affect the use performance of the balloon, and improve the anti-unloading ability of the stent to prevent the stent from falling off the balloon during the pushing process.

[0006] According to one aspect of the present invention, a preparation method of a balloon structure is provided, including:

[0007] Heating the initial structure of the balloon structure in the forming cavity of a pretreatment mold and receiving the perfusion of a fluid, so that the initial structure forms a protrusion in the forming cavity and is shaped to obtain the formed structure of the balloon structure;

[0008] Wherein, both the initial structure and the formed structure are in a folded state, a stent is press-fitted on the formed structure and is located on one side of the protrusion, and the height of the protrusion is at least higher than the height of the inner surface after the stent is press-fitted.

[0009] Preferably, in the above preparation method, the protrusions are respectively located at both ends of the formed structure, and the stent is press-fitted on the formed structure and is located between the protrusions.

[0010] Preferably, in the preparation method, before heating the initial structure of the balloon structure in the forming cavity of the pretreatment mold and receiving the perfusion of fluid, it further includes:

[0011] Providing the initial structure in a folded state;

[0012] Installing the pretreatment mold on the initial structure, placing the initial structure in the forming cavity, and fixing the pretreatment mold.

[0013] Preferably, in the preparation method, before heating the initial structure of the balloon structure in the forming cavity of the pretreatment mold and receiving the perfusion of fluid, it further includes:

[0014] Providing the initial structure in a folded state;

[0015] Pressing and holding the stent on the initial structure;

[0016] Installing the pretreatment mold on the initial structure with the stent pressed and held, placing the initial structure with the stent pressed and held in the forming cavity, and fixing the pretreatment mold.

[0017] Preferably, in the preparation method, when obtaining the formed structure, making one surface of the protrusion fit the outer surface after the stent is pressed and held, so that the protrusion covers the stent.

[0018] Preferably, in the preparation method, the protrusion is in an inverted L shape.

[0019] Preferably, in the preparation method, after the protrusion is formed and shaped in the forming cavity of the initial structure, first stop heating the pretreatment mold and continue to receive fluid perfusion, and after the pretreatment mold cools down, stop perfusion of fluid into the initial structure.

[0020] Preferably, in the preparation method, the heating temperature of the initial structure is 40°C to 80°C, the fluid is compressed gas and the conveying pressure is 2.0 atm to 10.0 atm.

[0021] Furthermore, according to another aspect of the present invention, there is provided a balloon structure for loading and transporting a stent, which is prepared by the above preparation method, wherein the stent is used to be pressed and held on the balloon structure and is located on one side of the protrusion, and the height of the protrusion is at least higher than the height of the inner surface after the stent is pressed and held.

[0022] Preferably, in the balloon structure, the protrusions are respectively located at both ends of the balloon structure, and the stent is used to be pressed and held between the protrusions.

[0023] Preferably, in the balloon structure, the protrusion is a continuous ring of protrusions, or at least one end of the balloon structure is provided with a plurality of protrusions, and the plurality of protrusions are arranged at intervals in the circumferential direction of the balloon structure.

[0024] Preferably, in the balloon structure, the height of the protrusion is 50 μm to 200 μm, and more preferably, the height of the protrusion is 50 μm to 150 μm.

[0025] Preferably, in the balloon structure, the axial clearance between the protrusion and the stent is 0 mm to 5.0 mm, and more preferably the axial clearance is 0 mm to 2.0 mm.

[0026] Preferably, in the balloon structure, the protrusion has an opening facing the stent, and the opening is used to accommodate the end of the stent.

[0027] Preferably, in the balloon structure, one surface of the protrusion is used to fit the outer surface of the stent after being crimped, so that the protrusions at both ends cover the stent.

[0028] Preferably, in the balloon structure, 0 to 1.0 wave nodes in the axial direction of the stent are covered by the protrusions at both ends.

[0029] Preferably, in the balloon structure, the protrusion is in an inverted L shape.

[0030] According to another aspect of the present invention, a medical device is further provided, including a stent and a balloon structure, and the stent is crimped on the balloon structure and located on one side of the protrusion.

[0031] According to the technical solution provided by the present invention, the medical device, the balloon structure and its preparation method have the following beneficial effects:

[0032] First, based on the original folded balloon, the present invention uses a pre-treatment mold to perform protrusion shaping on the balloon under a certain temperature and a certain fluid pressure, thereby obtaining a balloon with protrusions at least at one end in the folded state. Here, since the protrusions are formed on the folded balloon, the use of the protrusions will not be affected by the folding of the balloon, thus ensuring that the protrusions will not decrease in size or disappear after the balloon is folded. Therefore, this method can effectively prepare a balloon with protrusions; in particular, the protrusions prepared in this way only exist in the folded balloon. When the balloon is inflated and expanded, the protrusions will disappear. Therefore, it will not cause any impact on the performance of the balloon;

[0033] Second, when the stent is pressed and held on the balloon and located on one side of the protrusion, the protrusion can axially restrain the stent, preventing the stent from falling off the balloon during the pushing process, thereby enhancing the anti-disengagement ability of the stent and reducing the surgical risk; preferably, in addition to axially restraining the stent, it can also radially restrain the stent, such as an inverted L-shaped protrusion, and the anti-disengagement ability of the stent is stronger; more preferably, there are protrusions at both ends of the balloon, so that the stent is pressed and held on the balloon and located between the protrusions, and this structure can further enhance the anti-disengagement ability of the stent. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The drawings are used to better understand the present invention and do not constitute an improper limitation to the present invention. Among them:

[0035] Figure 1a is a schematic diagram of the balloon structure provided by the first embodiment of the present invention;

[0036] Figure 1b is a schematic diagram of the stent pressed and held on the balloon structure provided by the first embodiment of the present invention;

[0037] Figure 2a is a schematic diagram of the balloon structure provided by the second embodiment of the present invention;

[0038] Figure 2b is a schematic diagram of the stent pressed and held on the balloon structure provided by the second embodiment of the present invention;

[0039] Figure 3 is a schematic diagram of the stent pressed and held on the balloon structure provided by the third embodiment of the present invention;

[0040] Figure 4a is an axial schematic diagram of the initial structure provided in the preparation of the balloon structure according to an embodiment of the present invention;

[0041] Figure 4b is an end face view of the initial structure when it is folded and compressed in the preparation of the balloon structure according to an embodiment of the present invention;

[0042] Figure 5a is an exploded view of the pretreatment mold provided by an embodiment of the present invention;

[0043] Figure 5b is a schematic diagram of the fixing member provided by an embodiment of the present invention;

[0044] Figure 5c is a schematic diagram of the fixing member sleeved on the pretreatment mold provided by an embodiment of the present invention;

[0045] Figure 5d is a preparation principle diagram provided in the preparation of the balloon structure according to an embodiment of the present invention;

[0046] Figure 6It is a schematic diagram of another embodiment of the present invention in which a stent is pre-crimped onto an initial structure when preparing a balloon structure;

[0047] Figure 7 It is an axial sectional view of a pre-treatment mold provided by another embodiment of the present invention;

[0048] Figure 8 It is a preparation principle diagram provided by another embodiment of the present invention when preparing a balloon structure.

[0049] In the figure:

[0050] Balloon structures - 10, 20, 30; Initial structure - 101; Protrusions - 11, 21, 31; Stent - 100; Pre-treatment molds - 410, 510; First mold body - 411, First cavity - 413, Second mold body - 412, Second cavity - 414, Fixing parts - 420, 520, Forming cavity - 511. Detailed implementation manners

[0051] To make the objectives, advantages and features of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. It should be noted that the drawings are all in a very simplified form and use non-precise scales, and are only used to conveniently and clearly assist in explaining the objectives of the embodiments of the present invention.

[0052] As used in this specification and the appended claims, the singular forms "a", "an" and "the" include plural objects unless the context clearly indicates otherwise. As used in this specification and the appended claims, the term "or" is generally used in the sense of including "and / or" unless the context clearly indicates otherwise.

[0053] As used in this specification and the appended claims, the term "inner" generally refers to the direction close to the axis of the corresponding component, and the term "outer" generally refers to the direction away from the axis of the corresponding component. The term "axial" generally refers to the direction of the central axis of the corresponding component, "radial" generally refers to the direction perpendicular to the central axis of the corresponding component, "circumferential" generally refers to the circumferential direction centered on the axis of the balloon structure, "length" generally refers to the distance along the axis of the stent, and "height" generally refers to the distance in the radial direction of the balloon structure relative to the outer surface of the balloon in the folded state. The "folded state" generally refers to the state where the balloon is in an unfilled state or a contracted state, and the folded state includes but is not limited to single-wing folding, double-wing folding, and triple-wing folding.

[0054] As Figure 1a and Figure 1bAs shown in the figure, the first embodiment of the present invention provides a balloon structure 10, which includes a body and protrusions 11 provided at both ends of the body, so that the stent 100 is located between the protrusions 11 at both ends, and the height of the protrusions 11 is at least higher than the height of the inner surface of the stent 100 after being crimped, so as to limit the stent 100 axially at least in the balloon structure 10, prevent the stent 100 from falling off the balloon structure 10, and improve the anti-disengagement ability of the stent. It should also be understood that the height of the protrusions 11 can be further higher than the height of the outer surface of the stent 100 after being crimped, but in order not to overly increase the diameter of the balloon structure 10, it is preferably that the height of the protrusions 11 is less than the height of the outer surface of the stent 100 after being crimped. Here, the balloon structure 10 is in a folded state, and a stent 100 that can be expanded by the balloon structure 10 is externally crimped thereon. The stent 100 is in a radially inwardly contracted state in the crimped state. In addition, the height of the inner surface of the stent 100 after being crimped refers to the radial distance of this inner surface relative to the outer surface of the body. The height of the protrusions 11 refers to the height of the outer surface of the body bulging radially outward.

[0055] In the first embodiment, the distance L between the protrusions 11 at both ends on the body is greater than the length of the stent 100 to crimp the stent 100 between the protrusions 11 at both ends. Preferably, the axial gap d between the protrusions 11 and the stent 100 is between 0 mm and 5.0 mm, and more preferably the protrusions 11 at both ends are symmetric about the axis of symmetry of the stent 100. The protrusions 11 may be rectangular in the axial section of the balloon structure 10, and the protrusions 11 are integrally connected to the body of the balloon structure 10. In this embodiment, the height h of the protrusions 11 is between 50 μm and 200 μm, and more preferably between 50 μm and 150 μm.

[0056] Furthermore, the protrusions 11 are not limited to a continuous circle of protrusions (i.e., surrounding the balloon in a circle), and may also be that a plurality of the protrusions 11 are distributed at intervals in the circumferential direction around the body, such as two symmetric protrusions, or three protrusions distributed at 120°. Therefore, a plurality of protrusions 11 arranged in the circumferential direction can be provided at any end of the balloon structure 10, or a continuous circle of protrusions 11 can be provided. The number and arrangement of the protrusions can be set according to actual needs.

[0057] Such as Figure 2a and Figure 2bAs shown in the figure, the second embodiment of the present invention provides another balloon structure 20. Both ends of the body of the balloon structure 20 are provided with protrusions 21, so that the stent 100 is located between the two end protrusions 21, and the protrusions 21 have openings facing the stent 100 to accommodate the ends of the stent 100. At this time, the minimum distance L between the two end protrusions 21 is also greater than the length of the stent 100, and one surface of the protrusion 21 is close to and higher than the outer surface of the stent 100 after being crimped, so that the stent 100 can enter the opening. Therefore, when the stent 100 is crimped on the body, it can be restricted by the protrusions 21 in both its axial and radial directions, thereby further improving the anti-disengagement ability of the stent. The protrusion 21 can be in an inverted L shape in this embodiment, and is not limited to a continuous circle of protrusions 21, and can also be a plurality of protrusions 21 arranged at intervals in the circumferential direction. In addition, the height of the protrusion 21 should not be too large. Optionally, the opening height h' of the protrusion 21 is greater than or equal to the thickness of the stent after being crimped, and the total height h of the protrusion 21 is greater than the height of the outer surface of the stent after being crimped. Optionally, in this embodiment, the total height h of the protrusion 21 is between 50 μm and 200 μm, and more preferably between 50 μm and 150 μm. In addition, the axial clearance d between the protrusion 21 and the stent 100 is between 0 mm and 5.0 mm, and more preferably the two end protrusions 21 are symmetric about the symmetry axis of the stent 100.

[0058] As Figure 3 shown in the figure, the third embodiment of the present invention also provides a balloon structure 30. The balloon structure 30 is similar to the second embodiment, but the difference is that the stent 100 is covered by the two end protrusions 31 of the balloon structure 30. Preferably, 0 to 1.0 wave nodes on the axial direction of the stent are covered by the protrusions 31, which can effectively improve the anti-disengagement ability of the stent. Here, the wave node is the maximum width of a wave band of the stent in the axial direction. When covering the stent, one surface of the protrusion 31 preferably fits with the outer surface of the stent 100 after being crimped (that is, the height of the opening is equal to the thickness of the stent after being crimped). Therefore, the protrusion 31 is also in an inverted L shape, but the structure can be a continuous circle or a plurality of protrusions 31 arranged at intervals.

[0059] Moreover, in the third embodiment, the minimum distance L between the two end protrusions 31 is less than the length of the stent 100, and preferably the axial clearance between the protrusion 31 and the stent 100 is between 0 mm and 5.0 mm, and more preferably the two end protrusions 31 are symmetric about the symmetry axis of the stent 100. Optionally, in this embodiment, the total height h of the protrusion 31 is between 50 μm and 200 μm, and more preferably between 50 μm and 150 μm.

[0060] Finally, it should be added that the present invention is not limited to the case where both ends of the balloon structure are provided with protrusions. It is also possible to provide a protrusion only at one end, such that the stent is crimped onto the balloon structure and located on one side of the protrusion. Therefore, the stent is limited by the protrusion at one end to prevent the stent from falling off the balloon structure during the pushing process. Similarly, compared with the balloon structure with protrusions at both ends, the balloon structure with a protrusion at one end can also constrain the stent at least axially, and preferably can also constrain the stent radially, such as a protrusion in an inverted L shape.

[0061] To obtain the balloon structure provided by the embodiments of the present invention, the embodiments of the present invention also provide a method for preparing a balloon structure, including:

[0062] heating the initial structure of the balloon structure in the forming cavity of a pre-treatment mold and receiving the perfusion of a fluid, so that the initial structure forms protrusions and is shaped in the forming cavity to obtain the formed structure of the balloon structure. Wherein, both the initial structure and the formed structure are in a folded state, the stent is crimped onto the formed structure and located on one side of the protrusion, and the height of the protrusion is at least higher than the height of the inner surface after the stent is crimped.

[0063] Here, since the forming principles of the protrusions at both ends are the same as those of the protrusion at one end, the forming method of the protrusions at both ends will be used as an example hereinafter to further elaborate on the preparation process of balloon structures with different configurations.

[0064] First, taking the preparation of the balloon structure 10 as an example, the specific preparation method includes steps 11 to 13.

[0065] Step 11 is: providing an initial structure 101 in a folded state.

[0066] The structure of the initial structure 101 is as Figure 4a and Figure 4b shown. Obviously, the initial structure 101 is in a folded state, but it is not limited to three-wing folding, and can also be single-wing folding or two-wing folding, or the state where the balloon is not inflated. The material of the initial structure 101 is a polymer material, preferably polyamide.

[0067] Step 12 is: installing the pre-treatment mold 410 on the initial structure 101, placing the initial structure 101 in the forming cavity of the pre-treatment mold 410, and fixing the pre-treatment mold 410. The shape of the forming cavity here matches the outer contour of the balloon structure 10.

[0068] As Figure 5aAs shown, an embodiment of the present invention provides a preprocessing mold 410. The preprocessing mold 410 preferably includes a first mold body 411 and a second mold body 412. A first cavity 413 is provided inside the first mold body 411, and a second cavity 413 is provided inside the second mold body 412. After the first mold body 411 and the second mold body 412 are closed, the first cavity 413 and the second cavity 414 enclose to form the molding cavity, and the shape of the molding cavity is designed to be the same as the shape of the preformed balloon structure 10. Among them, at the cavity corresponding to the protrusion, preferably, a plurality of small holes (preferably evenly arranged) are provided on the cavity wall to facilitate the discharge of gas in the cavity, so that the balloon fits the cavity better and the forming effect of the protrusion is better.

[0069] The step 1-3 is: heating the initial structure 101 in the molding cavity of the preprocessing mold 410 and injecting compressed gas, so that the initial structure 101 forms protrusions 11 at both ends in the molding cavity and is shaped to obtain the formed structure of the balloon structure 10.

[0070] As Figure 5d shown, a heat source can be provided outside the preprocessing mold 410 to heat the preprocessing mold 410 as a whole, and the compressed gas is injected into the initial structure 101 through a connecting pipe, so that the initial structure 101 forms protrusions 11 at both ends in the molding cavity and is shaped.

[0071] Furthermore, after obtaining the formed structure of the balloon structure 10, the stent 100 can be crimped on the formed structure and located between the protrusions 11 at both ends, as Figure 1b shown.

[0072] In addition, for the balloon structure 20, since its usage mode is basically the same as that of the balloon structure 10, that is, the axial gap between the protrusions at both ends is greater than the length of the stent, therefore, the preparation method of the balloon structure 10 can be referred to for preparing the balloon structure 20, and the specific preparation process will not be elaborated here one by one.

[0073] Preferably, after heating and ventilating for a period of time, the heat source can be removed (that is, stop heating the preprocessing mold 410) and continue to receive the injection of compressed gas, and preferably, after the mold cools down, the supply of compressed gas to the initial structure is stopped to ensure the forming effect. Here, it should be known that after obtaining the formed structure, there is no compressed gas inside the initial structure 101, that is, the formed structure is in an un-inflated and contracted state. In addition, during the process of forming the protrusions 11, the heating temperature and the conveying pressure of the compressed gas also need to be controlled. The heating temperature is preferably 40°C to 80°C in this embodiment, and the conveying pressure of the gas is preferably 2.0 atm to 10.0 atm.

[0074] Next, refer to Figure 5bThe embodiment of the present invention further provides a fixing member 420 for fixing the pretreatment mold 410. Figure 5c As shown, the fixing part 420 is a hollow structure with both ends open, which is used to be placed on the pretreatment mold 410 after mold closing, but is not limited to this socketing method. The fixing part 420 can also fix the pretreatment mold 410 in a clamping manner, such as using a multi-jaw chuck for fixing. Therefore, the present invention does not impose specific restrictions on the way in which the fixing part 420 fixes the pretreatment mold 410.

[0075] Furthermore, since the balloon structure 30 needs to cover the stent, its preparation process is different from the preparation process of the above-mentioned two balloon structures 10 and 20. Specifically, the preparation process of the balloon structure 30 includes steps 21 to 24.

[0076] The step 21 is: providing an initial structure 101 in a folded state, such as Figure 4a and Figure 4b As shown, but not limited to three-wing folding, it can also be single-wing or double-wing folding, or in an uninflated state.

[0077] The step 22 is: press and hold the support 100 onto the initial structure 101, such as Figure 6 As shown;

[0078] The second and third steps are: installing the pre-processing mold 510 on the initial structure 101 with the bracket 100 pressed, so that the initial structure 101 with the bracket 100 pressed is accommodated in the molding cavity of the pre-processing mold 510, and fixing the pre-processing mold 510, as shown in FIG. Figure 8 shown.

[0079] Here, first refer to Figure 7 , and combined with Figure 8 The embodiment of the present invention provides another pretreatment mold 510, which includes a molding cavity 511, and the molding cavity 511 matches the outer contour of the balloon structure 30, and preferably the pretreatment mold 510 includes two mold bodies, and the molding cavity 511 is formed by the mold closing of the two mold bodies, and when the mold is closed, the pretreatment mold 510 can also be fixed by a fixing member 520. The structure of the fixing member 520 is specifically the same as the above-mentioned fixing member 420, which will not be repeated here.

[0080] Furthermore, the step 24 is: the initial structure 101 with the stent 100 is heated in the molding cavity 511 of the pretreatment mold 510 and receives the infusion of compressed gas, so that the initial structure 101 forms protrusions 31 at both ends in the molding cavity and is shaped to obtain the molding structure of the balloon structure 30.

[0081] like Figure 8As shown, a heat source can be set outside the preprocessing mold 510 to locally heat the preprocessing mold 510, mainly heating the area where the protrusions 31 need to be formed, and introducing compressed gas into the initial structure 101 to form the respective protrusions 31. Therefore, different from the aforementioned two balloon structures, before obtaining the formed structure of the balloon structure 30, the stent 100 is pressed and held on the initial structure 101. Thus, the formed structure itself carries the stent 100, eliminating the subsequent process of pressing and holding the stent, and the preparation is more convenient.

[0082] However, the preparation method of the balloon structure 30 can also be applied to the preparation of the aforementioned two balloon structures 10 and 20, that is, before forming the protrusions, the stent is compressed on the initial structure in a folded state. In addition, the present invention does not specifically limit the structure of the preprocessing mold, as long as it can provide a forming cavity.

[0083] Therefore, in the embodiment of the present invention, on the basis of the original balloon in a folded state, a preprocessing mold is used to perform protrusion shaping treatment on the balloon under a certain temperature and a certain fluid pressure, thereby obtaining a balloon with protrusions at least at one end in the folded state. Here, since the protrusions are formed on the folded balloon, the use of the protrusions will not be affected by the folding of the balloon, thus ensuring that the protrusions will not decrease in size or disappear after the balloon is folded. Therefore, this method can effectively prepare a balloon with protrusions. In particular, the protrusions prepared in this way only exist in the balloon in the folded state. When the balloon is inflated and expanded, the protrusions will disappear. Therefore, it will not cause any impact on the performance of the balloon. Furthermore, when the distal catheter passes through a slightly blocked, curved or tortuous blood vessel section, by loading and transporting the stent 100 through the balloon structure of this embodiment, the stent 100 can be prevented from falling off the balloon structure, reducing the surgical risk.

[0084] Furthermore, the embodiment of the present invention provides a medical device, including a stent and the balloon structure of this embodiment, and the stent is pressed and held on the balloon structure and is located on one side of the protrusion.

[0085] Next, the embodiment of the present invention also provides some comparison data. First, the offloading forces borne by the initial structure 101 and the balloon structure 10 are provided, as shown in Table 1, where:

[0086] The material of the balloon structure is polyamide, and the material of the stent 100 is cobalt-chromium alloy; the protrusion 11 is a continuous structure, the total height of the protrusion 11 is 150 μm, and the axial gap between the protrusion 11 and the stent is 0.1 mm; the test equipment is a tensile tester. One clamp of the tensile tester clamps the proximal end of the metal stent, and the other clamp clamps the distal end of the balloon, and the metal stent is moved towards the distal end of the balloon, and the offloading force of the metal stent is recorded when the clamp moves 0 - 5 mm and throughout the process.

[0087] Table 1: The offloading forces borne by the initial structure 101 and the balloon structure 10

[0088]

[0089] As can be seen from Table 1, the offloading force of the balloon structure 10 in this embodiment is about 1.6 times that of the existing offloading force. Therefore, the balloon structure 10 of the present invention has a better effect in preventing the stent from falling off.

[0090] Secondly, the relationship between the offloading forces borne by the initial structure 101 and the balloon structure 30 is also provided, as shown in Table 2, where:

[0091] The material of the balloon structure is polyamide, and the material of the stent 100 is cobalt-chromium alloy; the protrusion 31 is a continuous structure, and the protrusion 31 wraps 0.5 wave nodes axially on the stent 100, and the total height of the protrusion 31 is 120 μm; the test equipment is a tensile tester, one end of the tensile tester clamps the proximal end of the metal stent, and the other end clamps the distal end of the balloon, so that the metal stent moves towards the distal end of the balloon, and the offloading force of the metal stent is recorded when the clamp moves 0-5 mm and the whole process.

[0092] Table 2: The offloading forces borne by the initial structure 101 and the balloon structure 30

[0093]

[0094] As can be seen from Table 2, the offloading force of the balloon structure 30 in this embodiment has increased by 60% and 61% compared with the existing one. Therefore, the balloon structure 30 of the present invention can also better prevent the stent from falling off.

[0095] Furthermore, the relationship between the burst pressures borne by the initial structure 101 and the balloon structure 20 is also provided, as shown in Table 3, where:

[0096] The material of the balloon structure is polyamide, and the material of the stent 100 is cobalt-chromium alloy; the total height of the protrusion 21 is 130 μm, and the axial gap between the protrusion 21 and the stent 100 is 1.0 mm; the test condition is a 37°C water bath, starting from 0 atm, increasing the pressure by 1 atm for each cycle and maintaining it for 10 s, and then entering the next cycle until the balloon bursts.

[0097] Table 3: The burst pressures borne by the initial structure 101 and the balloon structure 20

[0098]

[0099] As can be seen from Table 3, compared with the prior art, the performance of the balloon structure 20 of the present invention remains basically unchanged. Therefore, the pretreatment process will not reduce the service performance of the balloon structure and can ensure its structural strength.

[0100] In summary, the balloon structure provided by the embodiments of the present invention is used to load and transport a stent, and the stent is preferably a polymer stent or a metal stent, and more preferably a degradable stent.

[0101] The above description is only a description of the preferred embodiments of the present invention and does not limit the scope of the present invention in any way. Any changes and modifications made by those of ordinary skill in the art of the present invention based on the above disclosure fall within the scope of protection of the claims.

Claims

1. A method for preparing a balloon structure, characterized in that, on the basis of the original folded balloon, a pre-treatment mold is used to perform a convex shaping treatment on the balloon under heating and fluid pressure to obtain a balloon with convexities at both ends in the folded state, and the convexities only exist in the balloon in the folded state. The preparation method includes: heating the initial structure of the balloon structure in the forming cavity of the pre-treatment mold and receiving the perfusion of fluid, so that the initial structure forms a convexity in the forming cavity and is shaped to obtain the formed structure of the balloon structure; the convexities are respectively located at both ends of the formed structure; wherein, both the initial structure and the formed structure are in a folded state, a stent is press-gripped on the formed structure and is located between the convexities, and the height of the convexities is at least higher than the height of the inner surface after the stent is press-gripped.

2. The method for preparing a balloon structure according to claim 1, characterized in that, before heating the initial structure of the balloon structure in the forming cavity of the pre-treatment mold and receiving the perfusion of fluid, it further includes: providing the initial structure in a folded state; installing the pre-treatment mold on the initial structure, placing the initial structure in the forming cavity, and fixing the pre-treatment mold.

3. The method for preparing a balloon structure according to claim 2, characterized in that, the convexity is in an inverted L shape.

4. The method for preparing a balloon structure according to claim 1, characterized in that, before heating the initial structure of the balloon structure in the forming cavity of the pre-treatment mold and receiving the perfusion of fluid, it further includes: providing the initial structure in a folded state; press-gripping the stent on the initial structure; installing the pre-treatment mold on the initial structure with the stent press-gripped thereon, placing the initial structure with the stent press-gripped in the forming cavity, and fixing the pre-treatment mold.

5. The method for preparing a balloon structure according to claim 4, characterized in that, when obtaining the formed structure, one surface of the convexity is attached to the outer surface after the stent is press-gripped, so that the convexity covers the stent.

6. The method for preparing a balloon structure according to claim 1, characterized in that, after the initial structure forms the convexity in the forming cavity and is shaped, stop heating the pre-treatment mold and continue to receive fluid perfusion, and after the pre-treatment mold cools down, stop perfusion of fluid to the initial structure.

7. The method for preparing a balloon structure according to claim 1, characterized in that, the heating temperature of the initial structure is 40°C to 80°C, the fluid is compressed gas and the conveying pressure is 2.0 atm to 10.0 atm.

8. A balloon structure for loading and transporting a stent, characterized in that, it is prepared by using the preparation method according to any one of claims 1-7, wherein the stent is used to be press-gripped on the balloon structure and is located between the convexities, and the height of the convexities is at least higher than the height of the inner surface after the stent is press-gripped.

9. The balloon structure according to claim 8, characterized in that, The protrusion is a continuous ring of protrusions, or at least one end of the balloon structure is provided with a plurality of protrusions, and the plurality of protrusions are arranged at intervals in the circumferential direction of the balloon structure.

10. The balloon structure according to claim 8 or 9, characterized in that the height of the protrusion is 50 μm to 200 μm.

11. The balloon structure according to claim 8 or 9, characterized in that the axial clearance between the protrusion and the stent is 0.0 mm to 5.0 mm.

12. The balloon structure according to claim 8 or 9, characterized in that the protrusion has an opening facing the stent, and the opening is used to accommodate the end of the stent.

13. The balloon structure according to claim 8 or 9, characterized in that one surface of the protrusion is used to fit the outer surface of the stent after being crimped, so that the protrusion covers the stent.

14. The balloon structure according to claim 13, characterized in that 0 to 1.0 wave nodes in the axial direction of the stent are covered by the protrusion.

15. The balloon structure according to claim 8 or 9, characterized in that the protrusion is in an inverted L shape.

16. A medical device, characterized in that it includes a stent and the balloon structure according to any one of claims 8-15, and the stent is crimped on the balloon structure and located between the protrusions.

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