Preparation method of the bracket

Abstract

The present invention belongs to the technical field of medical devices, and particularly relates to a preparation method of a stent, comprising the following steps: sleeving a framework structure on a strut, placing a developing material in a developing hole, and sleeving a kit on the outer surface of the framework structure; the kit continuously applies pressure to the developing material, and a laser beam irradiates the developing material through the kit, so that the developing material is combined with the framework structure to obtain a stent. This preparation method can make the shedding rate of the developing structure on the stent low and does not damage the stent.

Description

Technical Field

[0001] The present invention belongs to the technical field of medical devices, and particularly relates to a preparation method of a stent. Background Art

[0002] Stent implantation is to place a stent into the diseased part of a blood vessel to expand the narrowed blood vessel and restore normal blood supply, so as to achieve the purpose of revascularization. It is currently the most effective way to treat diseases (such as coronary heart disease) caused by blood vessel stenosis and insufficient blood supply. Digital Subtraction Angiography (DSA) is a commonly used auxiliary positioning device in stent implantation. Its principle is that when the radiation density of the stent material is greater than that of the organs or tissues around the implantation position, it can be imaged under the action of X-rays and can be used for doctors' diagnosis and clinical treatment. In the market, the materials used to prepare stents are mainly metal materials and polymer materials. When the material for preparing the stent is a material with a relatively high radiation density, such as cobalt-chromium alloy, nickel-titanium alloy, ferroalloy or medical stainless steel material, and the thickness of the stent rod is greater than 70 microns, it can be clearly imaged under DSA. When the stent material is a material with a relatively low radiation density, such as polylactic acid, magnesium alloy, although the thickness of the stent rod reaches more than 120 microns, it is still not clearly imaged under DSA. In addition, for materials with a relatively high radiation density, when the thickness of the stent rod is less than 70 microns, there are also cases where some positions (such as coronary arteries) are not clearly imaged. Therefore, it is necessary to improve the imaging property of the above two types of stents in vivo.

[0003] Currently, the main method to improve the imaging property of stents is to design an imaging hole structure on the stent, and then place the imaging material in the imaging hole by mechanical riveting. During subsequent processes and when the stent expands in vivo, it is ensured that the imaging material does not fall off into the blood vessel to avoid embolism, and at the same time, the position and shape of the stent can be clearly imaged, which is convenient for doctors' diagnosis and clinical treatment. Therefore, this imaging material is required to have good imaging property under X-rays, and at the same time, this riveting structure is required to have good bonding force.

[0004] Currently, mechanical press riveting is mostly adopted to rivet the bracket and the imaging material. In this method, the imaging material with a specific shape is placed in the imaging hole, and mechanical force is used to extrude and fully spread the imaging material (such as pure gold) in the imaging hole. And this method often requires an interference fit to fully expand the imaging material, even overflow, to achieve a riveted structure and ensure no detachment during subsequent use. However, it is not difficult to find that the above method has several disadvantages: 1. The fluidity of solid metal is poor, and the imaging material cannot fully expand in the imaging hole, and there will ultimately be a high risk of detachment in this riveting method; 2. This mechanical method is prone to deforming the bracket matrix and scratching the bracket matrix during the processing, resulting in scratches and reducing the mechanical properties of the bracket; 3. Since the imaging structure is generally relatively small and usually operates under a microscope, the work efficiency is low. Summary of the Invention

[0005] The object of the present invention is to solve at least the problems of low detachment rate of the imaging structure and no damage to the bracket.

[0006] The first aspect of the present invention provides a method for preparing a bracket. The bracket includes a framework structure having a lumen structure, and the framework structure has imaging holes, and the method includes the following steps:

[0007] The framework structure is sleeved on a support rod, the imaging material is placed in the imaging holes, and a kit is sleeved on the outer surface of the framework structure;

[0008] The kit applies pressure to the imaging material, and a laser beam passes through the kit and irradiates the imaging material to cause the imaging material to expand in the imaging holes, and the imaging material combines with the framework structure to obtain the bracket.

[0009] In one embodiment, the diameter of the laser beam ranges from 20 μm to 200 μm.

[0010] In one embodiment, the material of the support rod is selected from at least one of tungsten, tantalum, molybdenum or niobium.

[0011] In one embodiment, the laser beam passes through the kit and irradiates the imaging material, specifically, the laser beam passes through the kit and irradiates the center of the imaging material.

[0012] In one embodiment, the inner diameter of the lumen structure of the framework structure is slightly larger than the outer diameter of the support rod.

[0013] In one embodiment, the light transmittance of at least part of the material of the kit is above 85%.

[0014] In one embodiment, the cross-section of the kit is arc-shaped, or the kit is a tubular structure.

[0015] In one embodiment, the pressure applied by the kit to the developing material ranges from 0.1 N to 10 N, and the pressure is maintained for 0.1 s to 10 s.

[0016] In one embodiment, the developing material includes at least one of gold, silver, platinum, rhodium, cobalt, or chromium.

[0017] In one embodiment, the stent should include a cobalt-chromium alloy stent, a nickel-titanium alloy stent, a pure iron stent, an iron alloy stent, a medical stainless steel material stent, a magnesium alloy stent, and a polylactic acid stent.

[0018] The preparation method of the above stent melts the developing material by a laser beam and applies pressure to the developing material through a kit, so that the developing material unfolds in the developing holes and fuses with the stent skeleton structure, which can greatly enhance the bonding force between the developing material and the stent skeleton structure, avoid the developing material falling into the body and causing embolism, and has no mechanical damage to the stent skeleton structure, and is convenient to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] By reading the following detailed description of the preferred embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present invention. Moreover, throughout the drawings, the same reference numerals are used to represent the same components. Among them:

[0020] Figure 1 Schematic diagram of the stent preparation method provided for one embodiment.

[0021] Figure 2 For Figure 1 Schematic diagram of the cross-section of.

[0022] Figure 3 Schematic diagram of the process before and after the developing material is acted on by a laser beam and a kit in one embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] The exemplary embodiments of the present invention will be described in more detail below with reference to the drawings. Although the exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided so that the present invention can be more thoroughly understood and the scope of the present invention can be fully conveyed to those skilled in the art.

[0024] It should be understood that the terms used herein are for the purpose of describing particular example embodiments only and are not intended to be limiting. Unless the context clearly dictates otherwise, the singular forms "a", "an", and "the" as used herein may also include the plural forms. The terms "comprising", "including", "containing", and "having" are inclusive and thus specify the presence of stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order described or illustrated, unless an execution order is explicitly stated. It should also be understood that additional or alternative steps may be used.

[0025] Although the terms first, second, third, etc. may be used herein to describe multiple elements, components, regions, layers, and / or sections, these elements, components, regions, layers, and / or sections should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or section from another. Unless the context clearly indicates otherwise, terms such as "first", "second", and other numerical terms when used herein do not imply an order or sequence. Thus, the first element, component, region, layer, or section discussed below may be referred to as the second element, component, region, layer, or section without departing from the teachings of the example embodiments.

[0026] For ease of description, spatial relative relationship terms may be used herein to describe the relationship of one element or feature shown in the figures to another element or feature, such as "inner", "outer", "inner side", "outer side", "below", "beneath", "above", "over", etc. Such spatial relative relationship terms are intended to include different orientations of the device in use or operation in addition to the orientations depicted in the figures. For example, if the device in the figures is flipped, an element described as "below" or "beneath" another element or feature will then be oriented "above" or "over" the other element or feature. Thus, the example term "below" can include both an upper and a lower orientation. The device may be otherwise oriented (rotated 90 degrees or in other directions) and the spatial relative relationship descriptors used herein are to be interpreted accordingly.

[0027] Referring to Figures 1 to 3 , this embodiment provides a method for preparing a stent 100, wherein the stent 100 includes a skeleton structure 1 having a lumen structure, and the skeleton structure 1 has a developing hole 11. The method for preparing the stent includes the following steps:

[0028] S101: Slip the skeleton structure 1 over the support rod 2, place the imaging material 4 in the imaging hole 11, and slip the kit 3 over the outer surface of the skeleton structure 1.

[0029] S102: The kit 3 applies pressure to the imaging material 4, and a laser beam irradiates the imaging material 4 through the kit 3, causing the imaging material 4 to bond with the skeleton structure 1 to obtain a stent.

[0030] In step S101, slipping the skeleton structure 1 over the support rod 2 can fix the skeleton structure 1, making it less likely to move during operation and preventing the imaging material from flowing randomly after melting. The outer diameter of the support rod 2 is close to or slightly larger than the inner diameter of the stent, which can better support the skeleton structure 1. In this embodiment, the material of the support rod 2 is selected from at least one of tungsten, tantalum, molybdenum, or niobium.

[0031] Cut the imaging material 4 with a shearing tool to obtain an imaging material of appropriate size and place it in the imaging hole 11. It can be understood that the support rod 2 is located at the position where the imaging hole 11 is located to facilitate supporting the imaging material 4. The thickness of the imaging material is greater than the wall thickness of the skeleton structure 1, and the bottom area of the imaging material is smaller than the area of the imaging hole 11. The shape of the imaging hole 11 can be various shapes such as plum blossom shape, oval shape, circular shape, square shape, double circular shape, etc. The sizes of the imaging holes 11 on the same skeleton structure 1 can be the same or different. The imaging material 4 can be at least one of imaging metal materials such as gold, silver, platinum, rhodium, cobalt, or chromium. The number of imaging holes 11 can be one or more.

[0032] Slipping the kit 3 over the outer surface of the skeleton structure 1 actually makes the imaging hole 11 surrounded by the support rod 2 and the kit 3 from above and below, making it easier for the imaging material 4 to unfold and fill in the imaging hole 11 and preventing the imaging material 4 from flowing randomly after melting. In this embodiment, the cross-section of the kit 3 is arc-shaped, or the kit 3 can be a tubular structure. It can be understood that the kit with an arc-shaped cross-section is more convenient for loading and unloading and more convenient for realizing automation. When the cross-section of the kit 3 is arc-shaped, the kit 3 looks similar to a tile shape as a whole, and the inner and outer surfaces of the kit 3 are arc-shaped, which can better fit the surface of the skeleton structure 1, and the kit 3 can move on the surface of the skeleton structure 1 and act on imaging holes at different positions.

[0033] In step S102, the kit 3 applies pressure to the developing material 4. Specifically, an external force can be used to apply pressure to both ends of the kit 3, and this pressure acts on the developing material 4. In other embodiments, any part of the kit 3 can be pressured as long as the pressure can act on the developing material through the kit 3. In this embodiment, the pressure applied by the kit 3 to the developing material 4 ranges from 0.1 N to 10 N, and the pressure is maintained for 0.1 s to 10 s, which can enable the developing material 4 to be better distributed in the developing holes and at the same time avoid damaging the skeleton structure 1 of the stent.

[0034] The laser beam irradiates the developing material 4 through the kit 3. Among them, the light transmittance of at least part of the material of the kit 3 is above 85%. This at least part of the material can be quartz glass material, organic resin material or crystal material. Specifically, at least the position of the kit 3 that is irradiated by the laser beam and corresponds to the developing hole 11 can be set to quartz glass, organic resin material or crystal material, which can have less or no blocking effect on the laser beam, thereby increasing the visibility of the kit and having heat resistance. In other embodiments, the material of the kit 3 can be any material that can be penetrated by the laser beam and transfer heat, and it does not have to have visibility.

[0035] In this embodiment, the laser beam irradiates the developing material 4 through the kit 3. Specifically, the laser beam irradiates the center of the developing material 4 through the kit 3, which can make the laser beam concentrated in the central part of the developing material, make the initially molten developing material concentrated in the central part, and then slowly spread to the surroundings, which can make the developing material more evenly distributed in the developing holes. At the same time, it can avoid the problems that the molten developing material irradiated by the laser beam at the peripheral part of the developing material is likely to overflow the developing holes and is likely to be unevenly distributed. In other embodiments, the laser beam can also irradiate the peripheral position of the developing material 4 through the kit 3.

[0036] Among them, the diameter of the laser beam ranges from 20 μm to 200 μm, preferably 50 μm to 100 μm. If the size of the laser beam is too small, the energy is too concentrated, and the position where the laser beam acts on the developing material is too small, so that the developing material cannot fill the developing hole quickly; if the size of the laser beam is too large, the energy spreads to the periphery of the developing hole, causing damage to the stent matrix.

[0037] The energy of the laser beam ranges from 0.1 J to 4.0 J. Below this range, it is easy to have insufficient fluidity of the developed material 4 after irradiation, and the binding force between the developed material 4 and the skeleton structure 1 in the developing hole 11 is insufficient; above this range, it is easy to have too strong laser beam energy, and the developed material 4 overflows from the developing hole 11. Within this range, the developed material is partially melted to increase the fluidity of the developed material. It should be noted that in this embodiment, the developed material does not necessarily have to be irradiated by the laser to the molten state, as long as the developed material has a certain fluidity. The temperature at which the fluidity starts is the starting temperature, which is much lower than the melting point of the metal.

[0038] The laser beam used in this embodiment has the characteristics of a small spot, concentrated energy, and a small heat-affected zone, so that the energy is concentrated on the developed material, avoiding damage to the skeleton structure of the stent.

[0039] In this embodiment, the area of the developing hole 11 ranges from 0.03 mm 2 to 0.35 mm 2 . In one embodiment, the developing hole 11 includes a first developing hole and a second developing hole. The area of the first developing hole is larger than that of the second developing hole. The first developing material is placed in the first developing hole, and the second developing material is placed in the second developing hole. The energy range of the laser beam irradiating the first developing material is from 0.3 J to 1.0 J, and the energy range of the laser beam irradiating the second developing material is from 0.2 J to 0.8 J.

[0040] In step S102, first apply pressure to the developed material 4 using the kit 3, and then irradiate the developed material 4 with the laser beam through the kit 3. With this sequence, the laser beam can be irradiated while maintaining the pressure, and the developed material 4 is more likely to spread. If the laser beam is irradiated first and then the pressure is applied, it may occur that the pressure is not applied in time, and the developed material 4 cools down, resulting in a situation where it is not easy to spread.

[0041] In this embodiment, the principle of using the laser beam to irradiate the developed material is that the developed material (such as pure gold) tends to agglomerate into spheres under the action of the laser due to the surface energy. Therefore, when it is under the action of the laser, a small amount of force needs to be applied to it to make it fully spread when it has a certain fluidity, that is, to spread out at the moment when the developed material melts and fill the developing hole, thereby improving the binding force between the developed material and the skeleton structure 1.

[0042] The preparation method of the stent 100 further includes step S103. In step S103, after turning off the laser beam and removing the kit 3, further cooling can be performed, and this cooling process can further improve the binding force between the developed material and the skeleton structure 1.

[0043] In this embodiment, the stent can be made of various materials. The stent can include a high-density thin-walled metal stent and a low-density metal stent or polymer stent. Among them, the high-density thin-walled metal stent includes, but is not limited to, a cobalt-chromium alloy stent, a nickel-titanium alloy stent, a pure iron stent, an iron alloy stent, and a medical stainless steel material stent, and the wall thickness range of the high-density thin-walled metal stent is 40-70 μm; the low-density metal stent or polymer stent includes, but is not limited to, a magnesium alloy and a polylactic acid material. The method adopted in this embodiment can be applied to the relatively thin stent or the stent with relatively low density, and can achieve good results. Specifically, the imaging material can be well combined with the skeleton structure of the stent, the shedding rate is low, and it is not easy to damage the skeleton structure. The operation is convenient and fast, and industrial automated production can be realized.

[0044] Among them, the shedding rate of the imaging structure = the number of stents with the imaging structure shed / the number of stents cleaned. It should be noted that the imaging structure refers to the final structure formed in the imaging hole after the imaging material is processed through steps S101 and S102 (or steps S101, S102, and S103). See the following embodiments for details.

[0045] Embodiment 1

[0046] In this example, an iron-based stent is used as an example.

[0047] An iron-based stent with imaging hole structures at both ends (the wall thickness of the stent rod is 40 μm, and the area of each imaging hole at both ends of the stent is 0.340 mm 2 ) is sleeved on a tungsten support rod;

[0048] A 70-μm-thick gold foil is taken out, and an imaging material with a size of 0.19 mm is cut out with a shearing tool 2 to prepare a cylindrical gold imaging material. The gold imaging material is placed at the corresponding imaging hole position, and a transparent quartz glass kit is sleeved;

[0049] The laser irradiation parameters are set (the diameter of the laser beam is 100 μm, and the laser energy is 4.0 J);

[0050] The laser beam is aligned with the center of the imaging material, and a pressure of 5 N is applied to both ends of the quartz glass kit for laser beam irradiation;

[0051] After static pressure for 5 seconds, the laser beam is turned off, the pressure is removed, and the quartz glass kit is removed;

[0052] The above steps are repeated to press the corresponding-sized imaging material on the imaging hole at the other end.

[0053] Observed with a Keyence three-dimensional microscope, the imaging hole position of the stent is well filled, there are a small number of voids, and there is no damage near the imaging hole structure. After ultrasonic cleaning, the shedding rate of the imaging structure is 1%.

[0054] Example 2

[0055] This example uses an iron-based stent as an example.

[0056] Put an iron-based stent with imaging holes at both ends (the wall thickness of the stent rod is 58μm, the imaging holes of the stent are in the shape of plum blossoms, with two large and two small elliptical imaging holes, the area of the large imaging hole is 0.085mm 2 ; the area of the small imaging hole is 0.039mm 2 ) on the molybdenum support rod;

[0057] Take out a 70μm thick gold sheet, and use a cutting tool to cut out imaging materials of 0.070mm 2 and 0.032mm 2 (corresponding to the imaging materials for the large and small imaging holes respectively), prepare cylindrical gold imaging materials, place the gold imaging materials at the corresponding imaging hole positions, and put on a transparent quartz glass kit;

[0058] Set the laser irradiation parameters (the diameter of the laser beam is 100μm, the laser energy for the large hole is 0.5J, and the laser energy for the small hole is 0.3J);

[0059] Align the laser beam with the center of the imaging material, apply a pressure of 5N to both ends of the quartz glass kit, and perform laser beam irradiation;

[0060] After static pressure for 5 seconds, turn off the laser beam, remove the pressure, and remove the quartz glass kit;

[0061] Repeat the above steps to press the corresponding-sized imaging materials onto all imaging holes.

[0062] Observed with a Keyence three-dimensional microscope, the imaging hole positions of the stent are perfectly filled, there are no obvious gaps, and there is no damage near the imaging hole structure. After ultrasonic cleaning, the shedding rate of the imaging structure is 0.01%.

[0063] Example 3

[0064] This example uses an iron-based stent as an example.

[0065] Put an iron-based stent with imaging holes at both ends (the wall thickness of the stent rod is 70μm, and the area of each imaging hole at both ends of the stent is 0.156mm 2 ) on the tantalum support rod;

[0066] Take out a 100μm thick gold sheet, and use a cutting tool to cut out an imaging material of 0.109mm 2 , prepare a cylindrical gold imaging material, place the gold imaging material at the corresponding imaging hole position, and put on a transparent quartz glass kit;

[0067] Set the laser irradiation parameters (the diameter of the laser beam is 100 μm, and the laser energy for the large hole is 3.2 J);

[0068] Align the laser beam with the center of the developing material, apply a pressure of 5 N to both ends of the quartz glass kit, and perform laser beam irradiation;

[0069] After static pressure for 5 seconds, turn off the laser beam, remove the pressure, and remove the quartz glass kit;

[0070] Repeat the above steps and press the corresponding sized developing material onto the developing holes at the other end.

[0071] Observe with a Keyence three-dimensional microscope. There is a slight overflow of gold at the position of the developing holes of the stent, the middle of the developing structure is slightly uneven, and there is no damage near the developing hole structure. After ultrasonic cleaning, the shedding rate of the developing structure is 0.05%.

[0072] Example 4

[0073] This example uses an iron-based stent as an example.

[0074] An iron-based stent with developing hole structures at both ends (the wall thickness of the stent rod is 58 μm, the developing holes of the stent are in a plum blossom shape structure, with two large and two small elliptical developing holes, the area of the large developing hole is 0.085 mm 2 ; the area of the small developing hole is 0.039 mm 2 ) is sleeved on the niobium support rod;

[0075] Take out a 70-μm thick gold foil, and use a cutting tool to cut out developing materials of 0.070 mm 2 and 0.032 mm 2 (corresponding to the developing materials for the large and small developing holes respectively), prepare cylindrical gold developing materials, place the gold developing materials at the corresponding positions of the developing holes, and put on a transparent quartz glass kit;

[0076] Set the laser irradiation parameters (the diameter of the laser beam is 50 μm, the laser energy for the large hole is 0.5 J, and the laser energy for the small hole is 0.3 J);

[0077] Align the laser beam with the center of the developing material, apply a pressure of 5 N to both ends of the quartz glass kit, and perform laser beam irradiation;

[0078] After static pressure for 5 seconds, turn off the laser beam, remove the pressure, and remove the quartz glass kit;

[0079] Repeat the above steps and press the corresponding sized developing materials onto all the developing holes.

[0080] Observe with a Keyence three-dimensional microscope. The developing holes of the stent are well filled, there are a small number of voids in some areas, there is no damage near the developing hole structure, and after ultrasonic cleaning, the shedding rate of the developing structure is 1%.

[0081] Example 5

[0082] This example uses an iron-based stent as an example.

[0083] Put an iron-based stent with imaging holes at both ends (the wall thickness of the stent rod is 58 μm, the imaging holes of the stent are in the shape of a plum blossom, with two large and two small elliptical imaging holes, the area of the large imaging hole is 0.085 mm 2 ; the area of the small imaging hole is 0.039 mm 2 ) over the tantalum strut;

[0084] Take out a 70-μm-thick gold foil, and use a cutting tool to cut out imaging materials of 0.070 mm 2 and 0.032 mm 2 (corresponding to the imaging materials for the large and small imaging holes respectively), prepare cylindrical gold imaging materials, place the gold imaging materials at the corresponding imaging hole positions, and put on a transparent quartz glass kit;

[0085] Set the laser irradiation parameters (the diameter of the laser beam is 200 μm, the laser energy for the large hole is 0.5 J, and the laser energy for the small hole is 0.3 J);

[0086] Align the laser beam with the center of the imaging material, apply a pressure of 5 N to both ends of the quartz glass kit, and perform laser beam irradiation;

[0087] After static pressure for 5 seconds, turn off the laser beam, remove the pressure, and remove the quartz glass kit;

[0088] Repeat the above steps to press the corresponding-sized imaging materials onto all the imaging holes.

[0089] Observed with a Keyence three-dimensional microscope, the imaging hole positions of the stent are well filled without obvious gaps, but there are slight burn marks near the imaging hole structure. After ultrasonic cleaning, the shedding rate of the imaging structure is 0.02%.

[0090] Example 6

[0091] This example uses a magnesium alloy stent.

[0092] Put a magnesium alloy stent with imaging holes at both ends (the wall thickness of the stent rod is 150 μm, and the area of each imaging hole at both ends of the stent is 0.090 mm 2 ) over the tungsten strut;

[0093] Take out a 200-μm-thick tantalum foil, and use a cutting tool to cut out an imaging material of 0.068 mm 2 of the imaging material, prepare a cylindrical tantalum imaging material, place the tantalum imaging material at the corresponding imaging hole position, and put on a transparent quartz glass kit;

[0094] Set the laser irradiation parameters (laser beam diameter size is 100 μm, laser energy is 2.0 J);

[0095] Align the laser beam with the center of the developing material, apply a pressure of 5 N to both ends of the quartz glass kit, and perform laser beam irradiation;

[0096] After static pressure for 5 seconds, turn off the laser beam, remove the pressure, and remove the quartz glass kit;

[0097] Repeat the above steps to press the corresponding size of developing material onto all developing holes.

[0098] Observe with a Keyence three-dimensional microscope. The positions of the developing holes on the stent are perfectly filled, there are no obvious gaps, and there is no damage near the developing hole structure. After ultrasonic cleaning, the shedding rate of the developing structure is 0.02%.

[0099] Example 7

[0100] This example uses an absorbable polylactic acid stent.

[0101] Put the polylactic acid stent with developing hole structures at both ends (the wall thickness of the stent rod is 156 μm, and the area of each developing hole at both ends of the stent is 0.087 mm 2 ) on the molybdenum support rod;

[0102] Take out a 200-μm-thick gold foil, cut out a developing material with a size of 0.068 mm using a shearing tool 2 , prepare a cylindrical gold developing material, place the gold developing material at the corresponding developing hole position, and put on a transparent quartz glass kit;

[0103] Set the laser irradiation parameters (laser beam diameter size is 100 μm, laser energy is 1.0 J);

[0104] Align the laser beam with the center of the developing material, apply a pressure of 5 N to both ends of the quartz glass kit, and perform laser beam irradiation;

[0105] After static pressure for 5 seconds, turn off the laser beam, remove the pressure, and remove the quartz glass kit;

[0106] Repeat the above steps to press the corresponding size of developing material onto all developing holes.

[0107] Observe with a Keyence three-dimensional microscope. The positions of the developing holes on the stent are perfectly filled, there are no obvious gaps, and there is no damage near the developing hole structure. After ultrasonic cleaning, the shedding rate of the developing structure is 0.02%.

[0108] Comparative example

[0109] This example uses an iron-based stent as an example.

[0110] Put an iron-based stent with developing hole structures at both ends (the wall thickness of the stent rod is 58 μm, the stent developing holes are in the shape of plum blossoms, with two large and two small elliptical developing holes, and the area of the large developing hole is 0.085 mm 2 ; the area of the small developing hole is 0.039 mm 2 ) over the support rod;

[0111] Take out a 70-μm-thick gold foil and cut out developing materials of 0.070 mm 2 and 0.032 mm 2 (corresponding to the developing materials for the large and small developing holes respectively) with a shearing tool to prepare cylindrical gold developing materials, place the gold developing materials at the corresponding positions of the developing holes, and put on a transparent quartz glass kit;

[0112] Apply a pressure of 15 N to the quartz glass kit above the developing materials and keep it for 5 s to make the developing materials spread preliminarily in the developing holes;

[0113] Remove the quartz glass kit and gently press the developing materials with a riveting needle to make them spread fully;

[0114] Repeat the above steps to press corresponding-sized developing materials onto all the developing holes.

[0115] Observed with a Keyence three-dimensional microscope, the surface of the developing structure is uneven, there are voids or overflows in some areas, there are scratch marks near the developing hole structure, and the shedding rate of the developing structure is 5%.

[0116] As mentioned above, it is only a preferred specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be subject to the protection scope of the claims.

Claims

1. Method for preparing a stent, the stent comprising a framework structure having a lumen structure, and the framework structure having a radiopaque hole, characterized in that, Comprising the following steps: Sheathe the framework structure on the strut, place the developing material in the developing hole, and sheathe the kit on the outer surface of the framework structure; The kit applies pressure to the developing material, and a laser beam irradiates the developing material through the kit, causing the developing material to expand in the developing hole, and the developing material combines with the framework structure to obtain the stent; The diameter of the laser beam ranges from 20 μm to 200 μm; the area of the developing hole ranges from 0.03 mm 2 to 0.35 mm 2 .

2. The preparation method of the bracket according to claim 1, characterized in that The energy of the laser beam ranges from 0.1 J to 4.0 J.

3. The preparation method of the bracket according to claim 1, characterized in that, The material of the strut is selected from at least one of tungsten, tantalum, molybdenum or niobium.

4. The preparation method of the bracket according to claim 1, characterized in that, The laser beam irradiates the center of the developing material through the kit.

5. The preparation method of the bracket according to claim 1, characterized in that, The inner diameter of the lumen structure of the framework structure is slightly larger than the outer diameter of the strut.

6. The preparation method of the bracket according to claim 1, characterized in that, The light transmittance of at least part of the material of the kit is above 85%.

7. The preparation method of the bracket according to claim 1, characterized in that, The cross-section of the kit is arc-shaped, or the kit is a tubular structure.

8. The preparation method of the bracket according to claim 1, characterized in that, The pressure applied by the kit to the developing material ranges from 0.1 N to 10 N, and the pressure is maintained for 0.1 s to 10 s.

9. The preparation method of the bracket according to claim 1, characterized in that, The developing material includes at least one of gold, silver, platinum, rhodium, cobalt or chromium.

10. The preparation method of the bracket according to claim 1, characterized in that, The stent includes a cobalt-chromium alloy stent, a nickel-titanium alloy stent, a pure iron stent, an iron alloy stent, a medical stainless steel material stent, a magnesium alloy stent and a polylactic acid stent.

Images