A method for holding a long tubular implantable medical device in a straight position

Abstract

The present invention belongs to the technical field of medical devices, specifically relates to a method for keeping a long tubular implantable medical device straight, which involves fixing one end of the long tubular implantable medical device and simultaneously applying an external force to the other end to ensure that the device is kept straight. The method provided by the present invention is simple and convenient, and at the same time, can ensure that the angle θ between the most inclined position of the long tubular implantable medical device and the center line of the fixing device is ≦5°, thereby improving the uniformity of the processed workpiece, the pass rate of the processed product and the detection accuracy.

Description

[Technical Field]

[0001] The present invention relates to the field of medical devices, and more particularly to a method for maintaining a long, tubular, implantable medical device in an upright position. [Background technology]

[0002] With the development of medical technology, implantable medical devices have gradually come into the public eye, primarily serving the purpose of supporting the affected area. For example, stent placement, currently commonly used for vascular lesions, involves inserting a stent into the affected area of ​​the blood vessel to re-expand the narrowed blood vessel and restore normal blood supply, thereby achieving the goal of revascularization. This is currently the most effective method for treating diseases caused by vascular stenosis or insufficient blood supply (e.g., coronary heart disease and lower limb arteriosclerosis obliterans). Because implantable medical devices are implanted into the human body, any issues during the production process, such as low device pass rates and unstable quality, can easily lead to numerous safety issues, resulting in significant adverse reactions and distress for patients. Therefore, countries are now setting high standards for the quality and safety of implantable medical devices and strengthening corresponding regulations. Manufacturers must ensure that their products meet applicable standards during production and minimize safety risks after implantation.

[0003] Medical devices often involve processes such as spraying, cutting, and inspection during their production. A commonly used method for these processes is to clamp one end of the medical device with a jig and suspend the other end, then perform the corresponding operations such as spraying, cutting, and inspection. When the length of a medical device is relatively short, the suspended end will not bend or sag due to gravity, so there are few problems during processing, such as instability in the device production process due to gravity and a low product pass rate. When the length of a tubular medical device reaches a certain value, especially for long tubular medical devices with an openwork design, the surface material coverage is low and the entire device is light and thin, so the stent at the suspended portion is likely to bend downward due to gravity. Especially during processes such as spraying, cutting, and inspection, the device must rotate within a certain speed and range, which causes the central axes of the front and rear ends of the device to not overlap, resulting in significant "vibration." The extremely fast swing of the suspended portion causes a series of problems in the production process. For example, the spraying process may not be uniform on the surface of the equipment, the energy may be uneven during laser cutting, resulting in inconsistent cutting or the thickness of the cut rods may not be consistent, or the cutting position may be off, resulting in uneven dimensions and poor processing precision. This may cause a series of problems with the final stent product, such as blood clots, when it is used in the body. Therefore, it is necessary to provide a method to ensure that the stent remains straight during processing, so as to ensure a uniform coating on the stent surface, a uniform cutting pattern, and high-precision detection results. Summary of the Invention

[0004] To address the above technical problems, the technical solution of the present invention provides a method for keeping a long tubular implantable medical device straight, which can ensure that a long tubular implantable medical device, especially an openwork long tubular implantable medical device, is always kept relatively straight during the processing or inspection process, and the angle between the connecting line between the highest or lowest point passed through during the swing and the fixing point of the device fixing end and the straight line on which the center line of the fixing device is located is θ≦5°, or even θ≦3°. At the same time, the pass rate of the workpiece's appearance and dimensions during the processing process and the detection accuracy during the inspection process can reach 90% or even 95% or more.

[0005] The technical solution of the present invention provides a method for keeping a long tubular implantable medical device straight, in which the long tubular implantable medical device includes a fixed end and a suspended end, and an external force is applied to the suspended end to ensure that the device is kept straight.

[0006] The long tubular implantable medical device of the present invention has small specifications, and the longer the tubular device, the longer the suspended portion, and the more severe the vibration phenomenon. In some processing steps, the processed device needs to be constantly rotated, so the device will experience significant vibration due to gravity and its own inertia, and the vibration angle can reach 120°. That is, the highest and lowest points passed by the device during the vibration process form an angle of 2θ with the connecting line between the fixed point of the device and the fixed end of the device, and the value of 2θ can reach a range of 10°-120° during the vibration process. In particular, when the long tubular implantable medical device has an openwork structure, the vibration is more severe, and the vibration angle 2θ can even reach 180°. Therefore, it is necessary to apply sufficient force to the surface of the device to achieve the effect of "pulling the tail of the device straight".

[0007] The above "highest point" and "lowest point" both refer to the center point of the machine end cross section where the machine reaches the highest or lowest position during the swinging process.

[0008] In the above technical solution provided by the present invention, the applied external force is a magnetic field traction force; the magnitude of the magnetic field traction force acting on the implantable medical device is JPEG0007742941000001.jpg16170 where μ0 is the permeability of the magnetic medium in a vacuum state (i.e., vacuum permeability, where μ0=4π×10 -7 N.A. -2 ), where x is the distance from the magnetic source to the outermost working surface of the magnetically permeable material at the suspended end of the device, dx is the integral of the distance from the magnetic source to the working surface of the magnetically permeable material, h is the length of the device in the direction perpendicular to the working surface of the magnetically permeable material, and F 牽 is the total traction force of the device subjected to the magnetic field, B is the magnetic induction strength on the surface of the magnetically permeable material on which the magnetic field acts, and S is the area of ​​the surface on which the magnetic field acts on the magnetically permeable material.

[0009] The implantable long tubular medical device of the present invention can generate a corresponding force when induced by a magnetic field, but the specific manner in which the surface of the device receives the magnetic field pulling force is not limited. In some cases, the long tubular implantable medical device itself is magnetically conductive, for example, the entire suspended portion of the device in some embodiments, and even the entire device, can be magnetically conductive, and both can be subjected to the force of the magnetic field; in other embodiments, some portion of the device is magnetically conductive, for example, the coating or main material of the device is magnetically conductive, or a magnetically conductive substance (such as a development structure) is present on a cross section of the device, ensuring that the device is subjected to the force of the magnetic field and thereby maintains its straight state. In other cases, the device itself is not magnetically conductive, but an external magnetically conductive material, such as a magnetically conductive patch attached to the outer surface of the device, can also be used to further maintain the device in a straight state under the force of the magnetic field.

[0010] If the device itself is magnetically conductive, such as being made of pure iron or iron alloy, and the suspended part or the entire device is capable of conducting magnetic fields, the magnetic field acting on the device of the present invention at this point is JPEG0007742941000002.jpg12170, where μ0 is the magnetic permeability of the magnetic medium in a vacuum state, i.e., the vacuum permeability, μ0=4π×10 -7 N.A. -2 where x is the distance from the magnetic source to the outermost working surface at the suspended end of the equipment, dx is the integral of the distance from the magnetic source to the working surface of the equipment, h is the length of the suspended part of the equipment, and F 牽 is the total magnetic attraction force of the magnetic field acting on the equipment, B is the magnetic induction strength at the surface of the equipment where the magnetic field acts, and S is the area of ​​the magnetic field and the surface of the equipment where the magnetic field acts.

[0011] In the present invention, the "area S of the magnetic field and the equipment acting surface" means the area of ​​the covering material in any circumferential cross section where the equipment is subjected to the action of magnetic force. When the equipment in the present invention has an openwork tubular structure, the "area S of the magnetic field and the equipment acting surface" is the area of ​​the equipment support rod in the cross section, that is, S 支持ロッド断面 The formula is the cross-sectional area S of the outer diameter of the equipment in the circumferential direction. 周方向 The coverage rate S of the material that covers the cross section of the equipment 断面被覆率 Multiply by, i.e.: S 機器ロッド断面 =S 周方向 ×S 断面被覆率 Formula II Here, the coverage rate S of the material covered by the equipment on the cross section 断面被覆率 is the area S of the support rod in the circumferential cross section 支持ロッド断面 and the circumferential cross-sectional area S of the stent outer diameter 周方向 is the ratio of JPEG0007742941000003.jpg11170

[0012] In addition, the above S 断面被覆率 , S 周方向 , S 支持ロッド断面 All of these are average values, and all of these are areas in the processed state / process of the device, not areas when the device is implanted and used inside the body.

[0013] In the present invention, when the device itself has only a portion that is magnetically conductive (internal magnetic conductivity) or when a magnetically permeable material (external magnetic conductivity) is attached to its outer surface, especially when the magnetically permeable material at the internal or external magnetically conductive portion of the device is so short in the longitudinal direction of the device that it can be ignored, the traction force formula may be as follows: B 2 S JPEG0007742941000004.jpg15170In other words, the magnitude of the magnetic field pulling force that the device is subjected to is related only to the area of ​​the magnetic conductive material in the circumferential cross-sectional direction.

[0014] Because a magnetic field gradually weakens with increasing distance, for a constant magnetic field emitted from a magnetic source, the magnetic induction strength of the magnetic field decreases the farther away from the magnetic source. Therefore, when the distance between the magnetic field and the outermost working surface of the suspended end of the implantable medical device is large, the magnetic induction strength emitted by the magnetic source must be increased accordingly to maintain a constant final force acting on the device surface. When the magnetic source is far from the outermost working surface of the suspended end of the implantable medical device, the required magnetic induction strength can reach 1000mT; when the magnetic source is close to the outermost working surface of the suspended end of the implantable medical device, the magnetic induction strength generated by the magnetic source can meet the requirement of 100mT. That is, in the above technical solution provided by the present invention, the magnetic field generated by the magnetic source has a magnetic induction strength B≦1000mT, including, but not limited to, any value below 1000, such as 200mT, 300mT, 400mT, 500mT, 600mT, 700mT, 800mT, 900mT, etc., and further has a magnetic induction strength B≦750mT or B≦600mT, etc.

[0015] In the above technical solution provided by the present invention, the magnetic source generating the magnetic attraction force may be any apparatus and / or device capable of generating a magnetic field, including a natural magnet such as a general permanent magnet, or a device or device capable of generating a magnetic field under the action of an external force, such as a device capable of generating a magnetic field when energized. Furthermore, the magnetic source of the present invention includes, but is not limited to, a permanent magnet and an electromagnet, and may also be a magnet, a magnetic iron, a coil generating a magnetic field, etc. It may be one or more of a constant magnetic field, an alternating magnetic field, a pulsating magnetic field, or a pulsed magnetic field. Furthermore, the number of magnetic field sources is not limited to one, and may be one or a combination of multiple sources.

[0016] In the above technical solution provided by the present invention, the distance x from the magnetic source to the outermost working surface of the suspended end of the implantable medical device can range from 0.1 mm to 100 mm (including 0.5 mm, 1 mm, 3 mm, 5 mm, 7 mm, 9 mm, 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, 50 mm, 55 mm, 60 mm, 65 mm, 70 mm, 75 mm, 80 mm, 85 mm, 90 mm, 95 mm, 98 mm, etc. and are not limited to these); furthermore, the distance x from the magnetic source to the outermost working surface of the suspended end of the implantable medical device may be any two-value interval between 0.1 and 100 mm, such as 0.1 mm-10 mm, 0.1 mm-15 mm, 0.1 mm-25 mm, 0.1 mm-50 mm, 0.1 mm-60 mm, 0.1 mm-70 mm, 0.1 mm-80 mm, 0.15 mm-80 mm, and 0.15 mm-90 mm.

[0017] In the present invention, the outermost working surface of the suspended end of the implantable medical device refers to the circumferential cross section perpendicular to the radial plane of the device at the point on the magnetic conductive material closest to the magnetic source, and when the entire device or the suspended part of the device in the present invention is made of a magnetically permeable material, the outermost working surface of the suspended end of the implantable medical device refers to the circumferential cross section perpendicular to one radial plane where the suspended end of the device comes into contact with the air.

[0018] The present invention is a technical solution provided for the processing of implantable medical devices, especially those that are long and tubular. The longer the length of an implantable medical device, the lower the surface coverage rate, making it more likely for the implantable medical device to bend due to gravity and to vibrate during rotation or vibration. Therefore, the length of the medical device required / applied inside the human body is limited. Therefore, the present invention is suitable for long tubular devices with a suspended part length of 5mm-200mm (the suspended part length can be 10mm, 15mm, 20mm, 25mm, 30mm, 35mm, 40mm, 45mm, 50mm, 55mm, 60mm, 65mm, 70mm, 75mm, 80mm, 85mm, 90mm, 95mm, 100mm, 105mm, 106mm, 107mm, 108mm, 110mm, 115mm, 116mm, 118mm, 120mm, 122mm, 124mm, 126mm, 128mm, 129mm, 130mm, 132mm, 134mm, 136mm, 138mm, 140mm, 142mm, 144mm, 146mm, 148mm, 149mm, 150mm, 152mm, 156mm, 158mm, 158mm, 160mm, 165mm, 170mm, 172mm, 176mm, 180mm, 182mm, 184mm, 186mm, 188mm, 189mm, 200mm, 201mm, 202mm, 203mm, 204mm, 205mm, 206mm, 2 The present invention is applicable to long tubular instruments having a length of 5mm-200mm (including, but not limited to, 38mm, 80mm, 85mm, 90mm, 95mm, 100mm, 110mm, 120mm, 130mm, 140mm, 150mm, 160mm, 170mm, 180mm, 190mm, 200mm, etc.) that is held straight, and further applicable to long tubular instruments having a length of the suspended portion that falls within a new interval range consisting of any two values ​​within the 5mm-200mm interval, such as 38mm-150mm, 38mm-140mm, 15mm-150mm, 15mm-140mm, 20mm-150mm, 20mm-140mm.

[0019] In the above technical solution provided by the present invention, in order to ensure that the equipment basically maintains a straight state, that is, the angle θ between the most tilted position of the equipment and the center line of the fixing device is as small as possible, the value of the angle θ can be controlled to 5° and below 5°, and even 3° and below 3°, thereby ensuring that the pass rate of the appearance and dimensions of the workpiece in the processing process and the detection accuracy in the detection process can reach 90% or more; deviceA sufficient external force or magnetic traction force must be applied to the suspended end of the implantable medical device. However, the magnetic traction force applied to the implantable medical device must not be too large. If it is too large, the device will easily break away from the fixed end and lose stability. That is, the magnitude of the magnetic traction force acting on the implantable medical device must be smaller than the pulling force exerted by the fixed end on the device so that the fixed end does not move left and right or up and down. Furthermore, if the long tubular implantable medical device of the present invention has an openwork structure, if the external force applied is too large, the device will easily be pulled and deformed. Therefore, in the present invention, the magnitude of the magnetic traction force applied to the implantable medical device must be limited so that the magnitude of the magnetic traction force acting on the device is appropriate. In the technical solution provided by the present invention, the magnitude of the magnetic field traction force acting on the device is 1-40 times the gravity force acting on the implantable medical device, including, but not limited to, 2 times, 3 times, 5 times, 7 times, 10 times, 12 times, 15 times, 18 times, 20 times, 23 times, 25 times, 28 times, 30 times, 35 times, 38 times, 40 times, etc. Furthermore, the magnitude of the magnetic field traction force acting on the implantable medical device is 1-28 times, 1-20 times, 5-35 times, 3-35 times, 3-40 times, etc., the gravity force acting on the implantable medical device.

[0020] In the spraying process for long-tubular implantable medical devices, the spray liquid is viscous and the spray liquid is attached to a jig during spraying. device Spraying on the end tends to cause adhesion between the device and the jig, which causes the coating on the device surface to tear during the process of separating from the jig, so currently it is common to spray the device in two or more passes, and even in this case, the length of the jig at the clamping end of the implantable medical device must not exceed the length of the device, that is, the length of the device must be longer than the length of the jig. In the above technical solution provided by the present invention, the length of the jig may be less than 2 / 3, less than 1 / 2, less than 1 / 3, less than 1 / 4, or less than 1 / 5 of the length of the implantable medical device, and even the length of the jig located inside the device may be 0 mm.

[0021] In the above technical solution provided by the present invention, the fixing method of the fixed end of the implantable medical device can be various, such as clamping with a jig, fixing by physical interference fit, and even fixing by magnetic force or chemical means, that is, the fixing method of the device fixed end in the technical solution provided by the present invention includes, but is not limited to, several fixing methods such as clamping, physical interference fit, magnetic force fixing, and chemical fixing.

[0022] The manufacturing method provided by the present invention is applicable to the processing of long tubular implantable medical devices of all outer diameters, wall thicknesses and coverage rates, especially to the processing of openwork long tubular implantable medical devices, ensuring that the long tubular implantable medical devices remain straight during the processing process.

[0023] In the above technical solutions provided by the present invention, the outer diameter of the long tubular implantable medical device is 1.0mm-20.0mm; further, the outer diameter of the long tubular implantable medical device is 1.0mm-15.0mm; further, the outer diameter of the long tubular implantable medical device is 1.0mm-10.0mm.

[0024] In the above technical solution provided by the present invention, the wall thickness of the long tubular implantable medical device is 10 μm-600 μm (20 μm, 30 μm, 40 μm, 50 μm, 80 μm, 100 μm, 120 μm, 150 μm, 175 μm, 200 μm, 225 μm, 250 μm, 280 μm, 300 μm, 320 μm, 350 μm, 380 μm). , 425 μm, 450 μm, 475 μm, 500 μm, 520 μm, 550 μm, 560 μm, 580 μm, 600 μm, etc.); further, the wall thickness of the elongated tubular implantable medical device is 10 μm-500 μm; further, the wall thickness of the elongated tubular implantable medical device is 15 μm-450 μm.

[0025] In the above technical solutions provided by the present invention, the coverage rate of the cross section of the long tubular implantable medical device is 0.1%-35% (including but not limited to 1%, 5%, 8%, 10%, 12%, 14%, 16%, 18%, 20%, 22.5%, 25%, 28%, 30%, 33%, 34.5%, etc.); further, the coverage rate of the cross section of the long tubular implantable medical device is 0.1%-30%; further, the coverage rate of the cross section of the long tubular implantable medical device is 0.1%-25%.

[0026] In the above technical solution provided by the present invention, the long tubular implantable medical device has an openwork design, and the coverage of the device surface is 5%-60% (including but not limited to 6%, 8%, 10%, 12%, 14%, 16%, 18%, 20%, 22.5%, 25%, 28%, 30%, 33%, 36%, 40%, 45%, 50%, 55%, 58%, etc.), and further, the long tubular implantable medical device surface The coverage is 5%-55%; and further, the long tubular implantable medical device surface The coverage is a value within an interval consisting of any two values ​​within the range of 5%-60%, such as 5%-50%, 8%-55%, 8%-50%, 10%-55%, 10%-50%, 8%-45%, 8%-40%, 5%-45%, 5%-40%, 10%-45%, 10%-40%, 8%-35%, or 10%-35%.

[0027] The term "surface coverage of the device" in the present invention refers to the surface coverage of the device material under the device diameter condition during the processing, i.e., the ratio of the surface area covered by the device material to the total cylindrical surface area of ​​the stent covering portion, which is expressed by the following formula: JPEG0007742941000005.jpg8170where: Sr: the area actually filled / occupied on the outer surface of the device pattern during the processing process, the outer surface area of ​​the stent is measured by CAD software; Ss: total cylindrical surface area of ​​the stent coating during processing, Ss = π × D1 × L1 (2) D1: diameter of the stent during processing;

[0028] The terms "outer diameter," "wall thickness," "cross-sectional coverage," and "surface coverage" of the long tubular implantable medical device of the present invention all refer to the corresponding values ​​when the long tubular implantable medical device is in a processed state. That is, they refer to the values ​​of the "outer diameter," "wall thickness," "cross-sectional coverage," and "surface coverage" of the tubular material of the long tubular implantable medical device being processed or being processed.

[0029] In some other embodiments of the technical solution provided by the present invention, the long tubular implantable medical device is a luminal prosthesis, further, the long tubular implantable medical device is a blood flow guide device, and further, the long tubular implantable medical device is a vascular support. In some other embodiments of the present invention, the long tubular implantable medical device is a stent; in some other embodiments, the long tubular implantable medical device is a tubular material that is processed into a stent, and in some other embodiments, the long tubular implantable medical device is a semi-finished product that is processed into a final finished stent; in some other embodiments, the long tubular implantable medical device may be any long and lightweight medical device that can be implanted inside the body; and in some other embodiments, the long tubular implantable medical device is device raw materials, semi-processed products, or device This is the finished product.

[0030] In the above technical solution provided by the present invention, the implantable medical device itself is magnetically conductive; or a magnetic patch is attached to the implantable medical device. The magnetic patch can be attached at any position on the device, but is more effective when attached to a part that is not clamped by a jig and is close to the magnetic source. Examples of magnetic patch attachment include, but are not limited to, adding magnetic conductive development points to both ends of the stent or applying a magnetic conductive coating to the surface of the stent. Furthermore, the shorter the average distance from the magnetic source, the more preferable the magnetic patch. The number of magnetic patches attached in the present invention can be one or more, and the shape of the magnetic patch is not limited, but it can generate sufficient magnetic force to keep the stent in a straight state, depending on the magnetic field strength generated by the magnetic source and the distance from the device's working surface to the magnetic source.

[0031] The method is applicable to multiple steps in the manufacturing process of hollow-out long-tube instruments, including but not limited to spraying, cutting, detecting, coating, etc.

[0032] In the above technical solutions provided by the present invention, in some embodiments, the material of the device may be pure iron-based, iron-based alloy, or any other pure metal or alloy material with magnetic conductivity; in other embodiments, the material of the device may be a material that does not have magnetic conductivity itself, such as polylactic acid.

[0033] "Fixing" in the present invention may mean fixing the fixed end of the equipment in a predetermined position by the force generated by the interaction between the jig and the equipment; or fixing the fixed end of the equipment in a specific position by an external force such as a magnetic force; fixing by interference fit, or fixing by the chemical action of a magnetic field, etc.

[0034] In the present invention, for the sake of convenience, the term "long tubular implantable medical device" is abbreviated, i.e., "device," "medical device," and "implantable medical device" described in the present invention all refer to "long tubular implantable medical device."

[0035] A "long tubular" implantable medical device according to the present invention refers to a device whose length is greater than its outer diameter, particularly a device whose suspended portion has a length of 5 mm or more, and even more particularly a device whose suspended portion has a length of 10 mm or more.

[0036] In this invention, "runout" refers to the device Tip and device This means that the central axes of the rear ends do not overlap.

[0037] "Straight" as used in the present invention means that the angle θ between the most inclined position of the implantable medical device and the center line of the fixation device is ≦5°.

[0038] In the present invention, the symbol " / " means "or", for example, "required / applied in the body" means that it is required or applied in the body.

[0039] It is to be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. As used herein, the singular forms "a," "an," and "said" can also refer to the plural, unless the context clearly indicates otherwise. The terms "comprise," "include," "contain," and "have" are inclusive and thus indicate the presence of described features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The methods, steps, processes, and operations described herein should not be construed as requiring performance in the particular order described or illustrated, unless the order of performance is explicitly indicated. It should also be understood that other or alternative steps may be used. [Brief explanation of the drawings]

[0040] Various other benefits and advantages will become apparent to those skilled in the art upon reading the following detailed description of the preferred embodiments. The drawings are for purposes of illustrating the preferred embodiments only and are not intended to limit the invention. Furthermore, like parts will be designated by like reference numerals throughout the drawings, where: [Figure 1] FIG. 1 is a schematic diagram of the stent spray in Example 1; [Figure 2] FIG. 2 is a schematic diagram of the coupling method between the development hole and the stent in Example 5; [Figure 3] FIG. 3 is a schematic diagram showing the state of the stent cutting process in Example 6. DETAILED DESCRIPTION OF THE INVENTION

[0041] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. While the drawings illustrate exemplary embodiments of the present invention, it should be understood that the present invention is not limited to the embodiments described herein, and can be embodied in various forms. On the contrary, these embodiments are provided to provide a more complete understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0042] Test Method: 1. Coating thickness test The stent is placed under an ultrasonic atomizing nozzle and sprayed to coat the surface with a coating. The thickness of the coating is then measured using a Sensofar non-contact 3D optical profilometer based on white light interference technology. The coating thickness is measured at multiple points across the stent, and the maximum and minimum values ​​are compared. The difference between the two should not exceed 2 μm. 2. Stent rod width test The cut stents were placed under a three-dimensional microscope and observed. All stent levers were visually inspected to find and measure the maximum and minimum rod width levers. Rods with a difference between the maximum and minimum rod widths exceeding 16 μm were defined as male and female rods, and the number of stents cutting male and female rods was counted. In other words, the cut dimension pass rate = 1-100%×( Number of male and female rod stents / number of cut stents )。 3. Measuring the tilt angle Determine the length h of the suspended part of the stent, measure the height b of the center point of the cross section at the farthest end of the stent and the horizontal center line of the clamped part, and use trigonometric functions to calculate JPEG0007742941000006.jpg8170, and the magnitude of the tilt angle θ is obtained. 4. Cutting visual inspection The cut stent is placed under a three-dimensional microscope and observed to see if there are any areas on the surface of the stent that are not completely blanked, and the number of stents that are not completely blanked is counted. That is, the pass rate of cut appearance = number of stents that were not completely blanked / number of cut stents.

[0043] Example 1 One end of a 118 mm long iron-based absorbable drug-eluting peripheral stent (the stent processed outer diameter was 1.58 mm, the stent surface coverage was 30%, the stent wall thickness was 70 μm, the support rod coverage of the circumferential cross section of the stent was 5%, and the stent mass m was 112.53 mg) was fixed by physical interference fit using a 59 mm long jig, and a magnet with a clamped length h of 59 mm and a maximum magnetic induction strength Bmax of 400 mT was used as a magnetic source to apply magnetic traction to the stent. When the magnet was placed 1 mm away from the outermost working surface of the suspended end of the stent, the stent was in a relatively straight state. JPEG0007742941000007.jpg32170The stent was placed under an ultrasonic atomizing nozzle and sprayed. Sensofar, a non-contact 3D optical profilometer, was used to measure the thickness of the stent coating after spraying. The difference between the maximum and minimum coating thicknesses was 0.5 μm.

[0044] Example 2 One end of a 200 mm long iron-based absorbable drug-eluting peripheral stent (the stent processed outer diameter was 1.58 mm, the stent surface coverage was 30%, the stent wall thickness was 60 μm, the support rod coverage of the circumferential cross section of the stent was 4%, and the stent mass m was 152.16 mg) was fixed by physical interference fit using a 100 mm long jig, and a magnet with a clamped length h of 100 mm and a maximum magnetic induction strength Bmax of 600 mT was used as the magnetic source to apply magnetic traction to the stent. When the magnet was placed 1 mm away from the outermost working surface of the suspended end of the stent, the stent was in a relatively straight state. JPEG0007742941000008.jpg32170The stent was placed under an ultrasonic atomizing nozzle and sprayed. Sensofar, a non-contact 3D optical profilometer, was used to measure the thickness of the stent coating after spraying. The difference between the maximum and minimum coating thicknesses was 1 μm.

[0045] Example 3 One end of a 38 mm long iron-based absorbable drug-eluting peripheral stent (the stent processed outer diameter was 1.2 mm, the stent surface coverage was 40%, the stent wall thickness was 80 μm, the support rod coverage of the circumferential cross section of the stent was 10%, and the stent mass m was 22.83 mg) was fixed by physical interference fit using a 15 mm long jig, and the clamped length h was 23 mm.A magnet capable of emitting a maximum magnetic induction strength Bmax of 300 mT was used as the magnetic source to apply magnetic traction to the stent.The magnet was placed 3 mm away from the outermost working surface of the suspended end of the stent, and the stent was in a relatively straight state. The stent was then placed under an ultrasonic atomizing nozzle and sprayed. Sensofar, a non-contact 3D optical profilometer, was used to measure the thickness of the stent coating after spraying, with a difference of 1 μm between the maximum and minimum coating thicknesses.

[0046] Example 4 One end of a 118 mm long cobalt alloy stent (with a processed outer diameter of 2.4 mm, a stent surface coverage of 20%, a stent wall thickness of 100 μm, a support rod coverage of the circumferential cross section of the stent of 4%, and a stent mass m of 98.8 mg) is fixed by physical interference fit using a 50 mm long jig, and a magnet with a clamped length h of 68 mm and capable of emitting a maximum magnetic induction strength Bmax of 300 mT is used as a magnetic source to apply magnetic traction to the stent.The magnet is placed 1 mm away from the outermost working surface of the suspended end of the stent, and the stent is in a relatively straight state. JPEG0007742941000010.jpg32170The stent was placed under the ultrasonic atomizing nozzle and sprayed. Sensofar, a non-contact 3D optical profilometer, was used to measure the thickness of the stent coating after spraying. The difference between the maximum and minimum coating thicknesses was 0.5 μm.

[0047] Example 5 One end of a 58 mm long iron-based absorbable drug-eluting stent (with a processed outer diameter of 8.0 mm, a stent surface coverage of 11%, a stent wall thickness of 150 μm, a circumferential cross-sectional support rod coverage of 0.8%, and a stent mass m of 215.98 mg) was fixed by physical interference fit in a 15 mm long jig, and a magnet with a clamped length h of 43 mm and a maximum magnetic induction strength Bmax of 600 mT was used as a magnetic source to apply magnetic traction to the stent. The magnet was placed 3 mm away from the outermost working surface of the suspended end of the stent, resulting in a relatively straight state. JPEG0007742941000011.jpg27170The stent was placed under an ultrasonic atomizing nozzle and sprayed. Sensofar, a non-contact 3D optical profilometer, was used to measure the thickness of the stent coating after spraying. The difference between the maximum and minimum coating thicknesses was 1 μm.

[0048] Example 6 A magnesium alloy stent with a length of 68 mm (stent mass m is 57.26 mg) is attached to both ends of a 0.5 mm cross-sectional area. 2 The development holes are cut and filled with nickel material (shown in Figure 2) with excellent magnetic conductivity. The length of the jig used is 30 mm, the length of the stent without the clamping part, h, is 38 mm, and a magnet capable of emitting a maximum magnetic induction strength, Bmax, of 300 mT is used as the magnetic source to apply a magnetic traction force to the stent. When the magnet is placed 3 mm away from the development hole, the stent is in a relatively straight state. At this time, the stent receives the traction force only at the development point, and the length, h, of the development point in the radial direction of the stent is too small, so the traction force received by the stent is expressed by the formula: JPEG0007742941000012.jpg9170, and based on the Gaussmeter, the magnetic induction strength B=150mT was measured when the magnet was at x=3, and F 牽 = 0.00447N, and the gravity F acting on the suspended part of this stent is 重 =0.00032N. At this time, F 牽 =14F 重At this point, the height b between the center point of the stent's farthest cross section and the horizontal center line of the clamping section is 2.65 mm, and θ is calculated as 4°<5° based on trigonometric functions. The stent in this state is placed under the ultrasonic atomizing nozzle and sprayed. The stent coating thickness after spraying is measured using Sensofar - a non-contact 3D optical profilometer. The difference between the maximum and minimum coating thicknesses is 0.5 μm.

[0049] Example 7 One end of a 38 mm long iron-based absorbable drug-eluting peripheral stent (the stent processed outer diameter is 1.58 mm, the stent surface coverage is 30%, the stent wall thickness is 70 μm, the support rod coverage of the circumferential cross section of the stent is 5%, and the stent mass m is 36.24 mg) is attracted and fixed with a magnet, and a magnetic traction force is applied to the stent using a magnet with a clamped length h of 38 mm and a maximum magnetic induction strength Bmax of 400 mT as a magnetic source.The magnet is placed 1 mm away from the outermost working surface of the suspended end of the stent, and the stent is in a relatively straight state. JPEG0007742941000013.jpg27170The stent in the above state was placed under the ultrasonic atomizing nozzle and sprayed. A Sensofar non-contact 3D optical profilometer was used to measure the stent coating thickness after spraying, and the difference between the maximum and minimum coating thicknesses was 0.5 μm.

[0050] Example 8 Referring to Figure 3, a 200mm long, 1.6mm diameter metal pipe is clamped in a fixture. The left side rotates the feed material at a constant speed of 6mm / s, while the right side uses a laser to cut the metal into a specific pattern. When cutting a long stent, as in State 1, if only a portion of the stent is cut, the hardness of the metal pipe material itself ensures that the stent maintains a certain straightness, which does not affect the energy of the laser reaching the material surface. When the stent is cut in State 2, the cut length of the stent reaches a certain value. If the suspended, openwork stent is longer, the suspended end of the stent will tilt to a certain extent due to gravity. The tilt angle θ increases as the stent length increases, resulting in a discrepancy between the distance from the laser light source to the cut portion of the stent surface and the original laser cutting distance. The greater the discrepancy, the weaker the laser energy reaching the material surface, resulting in failure to cut or a large dimensional deviation of the stent pattern after cutting. In this case, a variable electromagnetic source of a magnetic field capable of emitting a magnetic induction strength of up to 1000 mT to the suspended end of the stent is added, and the magnitude of the radiated magnetic induction strength can be adjusted by the magnetic source, and / or the magnitude of the magnetic induction strength received by the suspended end of the metal tube can be adjusted by adjusting the distance between the magnetic source and the metal tube. In this embodiment, the magnetic source is placed 5 mm from the end of the stent at the beginning of cutting. As the metal tube moves toward the magnetic source, the openwork stent gradually becomes longer, while the distance of the stent from the magnetic source becomes shorter. At this time, there is no need to adjust the magnetic source. As more of the subsequent metal rod is cut, the length of the suspended end increases. The magnetic field strength is adjusted based on the distance / angle the stent moves away from its original center position, ensuring that the angle of the stent moving away from the central axis is always kept within 5°. After cutting is completed, the height b of the center point of the cross section at the farthest end of the stent and the horizontal center line of the clamping part is calculated to be 13.95 mm, and θ = 4° < 5°. At the same time, the cut stent is placed under a three-dimensional microscope for inspection. The cut appearance pass rate is 97% and the cut dimension pass rate is 95%.

[0051] Comparative Example 1 One end of a 118mm long iron-based absorbable drug-eluting peripheral stent (stent processed outer diameter 1.58mm, stent surface coverage 30%, stent wall thickness 70µm, stent circumferential cross-sectional support rod coverage 5%, stent mass m 112.53mg) was fixed in a 59mm long jig. The clamped length h was 59mm. The height b between the center of the stent's most distal cross-section and the horizontal centerline of the clamped portion was 37.92mm, and θ = 40° was calculated based on trigonometric functions. The stent in this state was placed under an ultrasonic atomization nozzle and sprayed. The stent coating thickness after spraying was measured using a Sensofar non-contact 3D optical profilometer. The difference between the maximum and minimum coating thicknesses was 7µm.

[0052] The above are preferred specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto, and any modifications or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed in the present invention are all included in the scope of protection of the present invention. In this application document, only stents are described as examples, and the method provided in the present invention does not represent an application only to the stent manufacturing process, and any other method for using magnetic force to keep a long tubular implantable device straight is also included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. 1. A method for maintaining an elongated tubular implantable medical device in an upright position, the elongated tubular implantable medical device having a fixed end and a suspended end, wherein an external force is applied to the suspended end of the elongated tubular implantable medical device to maintain the device in an upright position; The external force is a magnetic field traction force, and the magnitude of the magnetic field traction force acting on the implantable medical device is where: μ ０ is the vacuum permeability of the magnetic medium, x is the distance from the magnetic source to the outermost working surface of the magnetic material at the suspended end of the device, dx is the integral of the distance from the magnetic source to the working surface of the magnetic material, h is the length of the magnetic material on the device in the direction perpendicular to the working surface, and F 牽 1. A method for holding a long tubular implantable medical device in a straight position, wherein: ∑ is the total magnetic field attraction force experienced by the device; B is the magnetic induction strength at the interface of the magnetic field and the magnetically permeable material; and S is the area of ​​the interface of the magnetic field and the magnetically permeable material.

2. 2. The method for holding a long tubular implantable medical device straight as claimed in claim 1, wherein the magnetic source for generating the magnetic field traction force is a permanent magnet or an electromagnet.

3. 2. The method for holding a long tubular implantable medical device straight as described in claim 1, wherein the distance x from the magnetic source to the outermost active surface of the suspended end magnetic permeable material of the long tubular implantable medical device can range from 0.1 to 100 mm.

4. 2. The method for holding a long tubular implantable medical device straight as described in claim 1, wherein the magnetic induction strength B of the magnetic field generated by the magnetic source is ≦1000 mT.

5. The method for straightening a long tubular implantable medical device according to claim 1, wherein the length of the hollowed portion of the implantable medical device is 5mm-200mm.

6. The method for holding a long tubular implantable medical device straight, as described in claim 1, characterized in that the magnitude of the magnetic field traction force acting on the implantable medical device is 1-40 times the gravity force experienced by the suspended portion of the implantable medical device.

7. The length of the device fixed to the fixed end of the implantable medical device is L 固定 ≦2 / 3×L 機器 2. The method for holding a long tubular implantable medical device straight according to claim 1, wherein:

8. The method for holding a long tubular implantable medical device straight as described in claim 1, characterized in that the fixing method of the fixed end of the implantable medical device includes clamping, physical interference fit, magnetic link, and chemical fixation.

9. 2. The method for holding a long tubular implantable medical device straight as claimed in claim 1, wherein the outer diameter of the long tubular implantable medical device is 1.0 mm-20.0 mm.

10. 2. The method for keeping a long tubular implantable medical device straight as claimed in claim 1, wherein the wall thickness of the long tubular implantable medical device is 10 μm-600 μm.

11. 2. The method for keeping a long tubular implantable medical device straight as claimed in claim 1, wherein the coverage of the cross section of the long tubular implantable medical device is 0.1%-35%.

12. The method for keeping a long tubular implantable medical device straight as claimed in claim 1, wherein the coverage of the surface of the long tubular implantable medical device is 5%-60%.

13. 2. The method for keeping a long tubular implantable medical device straight as described in claim 1, characterized in that the implantable medical device itself is magnetically conductive or a magnetically conductive patch is added to the implantable medical device.

14. 2. The method for holding a long tubular implantable medical device straight as described in claim 1, wherein the long tubular implantable medical device is a raw material to be processed into a device, a semi-finished product, or a finished product of the device.

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