Coated medical device

Abstract

A coated medical device, comprising a main lattice stent (10) and a covering (20). The covering (20) covers at least part of the outer surface of the main lattice stent (10); the covering (20) has a first friction area and a second friction area which are provided axially from a proximal end (101) of the main lattice stent (10) to a distal end (102); the friction coefficient of the first friction area is less than that of the second friction area; and the first friction area extends from the proximal end (101) of the main lattice stent (10) and covers the maximum outer diameter position of the main lattice stent (10). The coated medical device takes into account both the sheathing performance and anchoring performance by means of the first friction area and the second friction area of the covering (20), and realizes the low sheathing force and high anchoring force without sacrificing other performance of the device.

Description

Coated medical devices Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a coated medical device capable of taking into account both sheathing performance and anchoring performance. Background Art

[0002] Occluders and other coated medical devices are implants for interventional therapy and can be used to treat conditions such as atrial septal defect (ASD), patent ductus arteriosus (PDA), ventricular septal defect (VSD), patent foramen ovale (PFO), and left atrial appendage (LAA) occlusion. Currently known occluder products are divided into three categories: wire braided products, tube cut products, and a combination of the first two. To achieve effective occlusion, a polymer coating is generally provided on the outer surface or inside of the main frame (lattice-like stent). For occluders with a coating provided on the outer surface, the friction between the coating and the sheath is relatively large. When inserting and removing the occluder, the coating at the largest outer diameter on the occluder often contributes the greatest insertion force. This large insertion force limits the design of larger occluder products on the one hand, and on the other hand, it limits the design of minimizing the outer diameter of the sheath. Existing methods mainly address this problem by changing the structure of the occluder, using a thinner coating, or increasing the inner diameter of the sheath. However, these solutions sacrifice other performance aspects, thus placing significant constraints on the structural design of the occluder. Moreover, if the insertion force is unilaterally reduced, the stability of the occluder after implantation will also be reduced, increasing safety risks.

[0003] It should be noted that the information disclosed in the background technology section of this application is only intended to deepen the understanding of the general background technology of this application, and should not be regarded as an admission or any form of implication that the information constitutes prior art already known to those skilled in the art.

[0004] Summary of the Invention

[0005] In view of this, the present invention provides a membrane-coated medical device that reduces the sheathing force of the device without sacrificing other performance aspects, while improving the stability of the device after implantation.

[0006] To achieve the above-mentioned objectives, the present invention provides a membrane-coated medical device, comprising a main frame and a covering, wherein the covering covers at least a portion of the outer surface of the main frame, and the covering has a first friction area and a second friction area axially arranged from the proximal end to the distal end of the main frame, the friction coefficient of the first friction area is smaller than the friction coefficient of the second friction area, and the first friction area extends from the proximal end of the main frame and covers the maximum outer diameter position of the main frame.

[0007] Optionally, the covering includes a film and a coating, the film covers the outer surface of the main frame, the coating covers the film, and the coating includes a first friction coefficient coating that forms the first friction area.

[0008] Optionally, the area of ​​the coating other than that covered by the first friction coefficient coating is a non-coating area, and the non-coating area forms the second friction area.

[0009] Optionally, the coating further includes a second friction coefficient coating forming the second friction area, and the area of ​​the coating film other than that covered by the first friction coefficient coating is covered by the second friction coefficient coating.

[0010] Optionally, the first friction coefficient coating is covered on the covering film, or the first friction coefficient coating is covered on at least one first transition coating having a lower or higher friction coefficient than the first transition coating.

[0011] Optionally, the second friction coefficient coating is covered on the covering film, or the second friction coefficient coating is covered on at least one second transition coating having a lower or higher friction coefficient than the second friction coefficient coating.

[0012] Optionally, the first friction coefficient coating includes one or a combination of fluoropolymer, parylene, polyimide, polyvinyl pyrrolidone, polyacrylamide, polyetheramide, gel.

[0013] Optionally, the fluorine-containing polymer includes one or a combination of polytetrafluoroethylene, polyvinylidene fluoride, vinyl fluoride homopolymer and perfluoroethylene propylene copolymer.

[0014] Optionally, the coating has a thickness of no more than 1 μm.

[0015] Optionally, the friction coefficient of the first friction area does not exceed 0.3.

[0016] Optionally, the friction coefficient of the first friction area does not exceed 0.1.

[0017] Optionally, the covering is composed of a coating film, which is composed of a first film body and a second film body with different friction coefficients. The first film body forms the first friction area, and the second film body forms the second friction area.

[0018] In summary, the coated medical device provided by the present invention includes: a main frame and a covering, wherein the covering covers at least part of the outer surface of the main frame, and the covering has a first friction area and a second friction area axially arranged from the proximal end to the distal end of the main frame, the friction coefficient of the first friction area is smaller than the friction coefficient of the second friction area, and the first friction area extends from the proximal end of the main frame and covers the maximum outer diameter position of the main frame.

[0019] With such a configuration, when the coated medical device is inserted into and removed from the sheath, the friction between the cover and the sheath can be reduced through the first friction area, thereby making the cover at the maximum outer diameter position on the main frame have a smaller sheathing force; in addition, after the coated medical device is implanted into the body, the friction between the cover and the target object can be increased through the second friction area, thereby enhancing the stability of the device after implantation; ultimately, the coated medical device of the present invention can take into account both sheathing performance and anchoring performance, and achieve low sheathing force and high anchoring force without sacrificing other aspects of the device's performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Those skilled in the art will appreciate that the accompanying drawings are provided for a better understanding of the present invention and do not constitute any limitation on the scope of the present invention.

[0021] FIG1 is a schematic structural diagram of a film-coated medical device provided in an embodiment of the present invention;

[0022] FIG2 is a schematic structural diagram of a film-coated medical device provided in Example 1 of the present invention;

[0023] FIG3 is a test result of the sheathing force of a comparative example and an embodiment of the present invention;

[0024] FIG4 is a schematic structural diagram of a film-coated medical device provided in Example 4 of the present invention;

[0025] FIG5 is a schematic structural diagram of a film-coated medical device provided in Example 5 of the present invention;

[0026] FIG6 is a schematic structural diagram of a film-coated medical device provided in Example 6 of the present invention;

[0027] FIG7 is a schematic structural diagram of a film-coated medical device provided in Example 7 of the present invention.

[0028] In the accompanying drawings: 10-main body grid; 101-proximal end of the main body grid; 102-distal end of the main body grid; 103-connecting unit; 11-skirt; 20-covering; 21-distal end of the covering; 210-membrane; 211-PTFE knitted membrane; 212-PET knitted membrane; 220-coating; 221-PTFE coating; 222-polyacrylamide coating; 223-PVDF coating. DETAILED DESCRIPTION

[0029] To make the objects, advantages, and features of the present invention more clearly apparent, the present invention is further described below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the drawings are all in a very simplified form and are not drawn to scale. They are only used to conveniently and clearly assist in illustrating the purposes of the embodiments of the present invention. In addition, the structures shown in the drawings are often part of the actual structure. In particular, different drawings may need to illustrate different focuses and sometimes use different scales.

[0030] In this application document, the term "proximal end" generally refers to the end close to the surgical operator, the term "distal end" generally refers to the end away from the surgical operator, "axial" refers to the direction of the central axis of the coated medical device, and "circumferential" refers to the direction around the central axis of the coated medical device.

[0031] The purpose of the present invention is to provide a coated medical device that can treat various diseases, such as atrial septal defect, patent ductus arteriosus, ventricular septal defect, patent foramen ovale, etc. The coated medical device is preferably a left atrial appendage occluder.

[0032] As shown in Figure 1, the membrane-coated medical device provided by the present invention comprises a main frame 10 and a covering 20. The covering 20 covers at least a portion of the outer surface of the main frame 10. For example, the distal end of the main frame 10 is not provided with the covering 20, leaving the skirt 11 exposed. The outer surface of the main frame 10, covered by the covering 20, forms a sealing disk that can be used to isolate blood flow.

[0033] The height of the covering 20 generally does not exceed two-thirds of the total height of the main grid 10, but is not limited thereto. The height refers to the distance from the proximal end 101 to the distal end 102 of the main grid 10, that is, the height is defined with the proximal end 101 of the main grid 10 as the reference. The height of the covering 20 refers to the distance that the covering 20 extends from the proximal end 101 of the main grid 10 toward the distal end 102, that is, the distance from the proximal end of the covering 20 to the distal end 21 of the covering 20. The proximal end of the covering 20 is the proximal end 101 of the main grid 10, and the distal end 102 of the main grid 10 extends beyond the distal end 21 of the covering 20, or the covering 20 covers the distal end 102 of the main grid 10.

[0034] The distal end 102 of the main body grid 10 can be opened or closed, and the present invention does not limit this. Specifically in this embodiment, the distal end 102 of the main body grid 10 is open, similar to a basket, and the distal end 102 is provided with a skirt 11, which is bent inward to prevent the skirt 11 of the main body grid 10 from puncturing internal tissues during and after implantation. The main body grid 10 can be provided with an anchoring structure at a certain position extending from its maximum outer diameter (Dmax) position to the distal end, and the anchoring structure can be used to pierce or hook the tissue in the body to increase stability. The proximal end 101 of the main body grid 10 is provided with a connecting unit 103 for releasably connecting to the delivery system.

[0035] The main frame 10 is a cut stent or a braided stent, preferably a cut stent for better stability. Besides nickel-titanium alloy, the main frame 10 can be made of other biocompatible materials with shape memory properties, or materials that are elastically or plastically deformable, which is not limited by the present invention.

[0036] Specifically, the cover 20 includes a first friction region and a second friction region arranged axially from the proximal end 101 to the distal end 102 of the main grid 10. The first friction region and the second friction region do not overlap and both surround and cover the main grid 10, such that the cover 20 covers the main grid 10 on the circumferential side. The friction coefficient (i.e., static friction coefficient) of the first friction region is smaller than the friction coefficient (i.e., static friction coefficient) of the second friction region.

[0037] The first friction region needs to extend from the proximal end 101 of the main frame 10 and cover the position of the maximum outer diameter of the main frame 10. The coated medical device needs to be inserted into or removed from the delivery sheath during delivery or withdrawal. Therefore, when inserting and removing the sheath, the first friction region can reduce the friction between the cover 20 and the sheath, so that the cover 20 at the position of the maximum outer diameter (Dmax) on the main frame 10 has a smaller insertion force.

[0038] The second friction zone extends from the junction with the first friction zone to the distal end 21 of the covering 20. In other words, the area of ​​the covering 20 excluding the first friction zone constitutes the second friction zone. This allows the second friction zone to increase friction between the covering 20 and the target object after implantation, thereby enhancing the stability of the covered medical device. The target object referred to herein refers to the implanted object, such as a blood vessel, left atrial appendage, or ventricular septal perforation.

[0039] The present invention takes into account both sheathing performance and anchoring performance through the first friction area and the second friction area of ​​the cover 20, and achieves low sheathing force and high anchoring force without sacrificing other aspects of the performance of the device, while also increasing the safety of the device.

[0040] As can be understood, the second friction zone is the anchoring zone, primarily used to ensure the stability of the device after implantation, enabling it to stably and effectively occlude the target object. The first friction zone, on the other hand, is essentially not used for anchoring support and does not affect the device's support and anchoring force. For example, in the case of left atrial appendage occlusion, the second friction zone aligns with the left atrial appendage wall, ensuring support and anchoring force, while the first friction zone, facing the atrial side and positioned at the entrance of the left atrial appendage, is in contact with blood and does not require anchoring.

[0041] In some embodiments, the covering 20 includes a film 210 and a coating 220. The film 210 directly covers the outer surface of the main frame 10, and the coating 220 directly covers the film 210. The coating 220 includes at least a first friction coefficient coating forming a first friction area, and the first friction coefficient coating is made of a material with a lower friction coefficient than that of the film 210.

[0042] In other embodiments, the covering 20 is composed only of the coating 210 and the coating 220 is not provided. In this case, the coating 210 can be composed of a first film body and a second film body with different friction coefficients, the first film body forming a first friction area, and the second film body forming a second friction area.

[0043] In some embodiments, the coating 220 only includes a first friction coefficient coating that forms a first friction area. In this case, the area of ​​the coating 210 other than that covered with the first friction coefficient coating is an uncoated area, and the uncoated area directly forms a second friction area, that is, the coating 210 in the uncoated area forms the second friction area.

[0044] In another embodiment, coating 220 includes a first friction coefficient coating forming a first friction region and a second friction coefficient coating forming a second friction region, and the second friction coefficient coating is covered in the region of coating 210 other than the region covered by the first friction coefficient coating. The first and second friction coefficient coatings do not overlap, and the second friction coefficient coating is made of a material having a higher friction coefficient than the first friction coefficient coating.

[0045] The first friction coefficient coating can be directly coated on the coating 210, or the first friction coefficient coating can be directly coated on at least one first transfer coating having a lower or higher friction coefficient than the first friction coefficient coating. The first transfer coating can increase the bonding force between the first friction coefficient coating and the coating 210 to a certain extent, and reduce the risk of the coating falling off. For example, if the friction coefficient of the first transfer coating is greater than that of the first friction coefficient coating, the first transfer coating can be directly coated on the corresponding area on the coating 210, and then the first friction coefficient coating can be covered on the first transfer coating. For another example, if the friction coefficient of the first transfer coating is smaller than that of the first friction coefficient coating, then, similarly, the first transfer coating can be directly coated on the corresponding area on the coating 210, and then the first friction coefficient coating can be covered on the first transfer coating. In short, it is only necessary to ensure that the upper coating exposed to the outside is the first friction coefficient coating. In practice, the first friction coefficient coating can be loaded by one or more first transfer coatings with different friction coefficients.

[0046] Similar to the arrangement of the first friction coefficient coating, the second friction coefficient coating can be applied directly to the covering film 210, or directly to at least one second transition coating layer with a lower or higher friction coefficient. For example, if the friction coefficient of the second transition coating layer is lower than that of the first friction coefficient coating layer, the second transition coating layer can be applied directly to the corresponding area on the covering film 210, and then the second friction coefficient coating layer can be applied over the second transition coating layer. Alternatively, if the friction coefficient of the second transition coating layer is higher than that of the first friction coefficient coating layer, similarly, the second transition coating layer can be applied directly to the corresponding area on the covering film 210, and then the second friction coefficient coating layer can be applied over the second transition coating layer. In short, it is sufficient to ensure that the uppermost exposed coating layer is the second friction coefficient coating layer. Similarly, the second friction coefficient coating layer can be applied via one or more second transition coating layers with different friction coefficients. Similarly, the second transition coating layer can, to a certain extent, increase the bonding strength between the second friction coefficient coating layer and the covering film 210, reducing the risk of the coating layer peeling off.

[0047] The material of the second friction coefficient coating can be the processing material of the coating 210, such as PET (commonly known as polyester resin), silicone resin, TPU (polyurethane) and other processing materials, or other polymer materials.

[0048] Preferably, the first friction coefficient coating comprises one or a combination of materials such as fluoropolymer, Parylene, polyimide, polyvinyl pyrrolidone, polyacrylamide, polyetheramide, gel, etc. More preferably, the first friction coefficient coating comprises a fluoropolymer to achieve an anti-coagulation effect while reducing friction. More preferably, the first friction coefficient coating comprises only a fluoropolymer.

[0049] The first friction coefficient coating can be made of a single material or a combination of multiple materials having different friction coefficients. Preferably, the first friction coefficient coating is made of a single fluoropolymer or a combination of multiple fluoropolymers. For example, the fluoropolymer includes one or a combination of PTFE (polytetrafluoroethylene), PVDF (polyvinylidene fluoride), PVF (fluoroethylene homopolymer), FEP (fluorinated ethylene propylene copolymer, also known as perfluoroethylene propylene copolymer), or multiple thereof.

[0050] The thickness of the coating on the covering film 210 is preferably no more than 1 μm so as not to affect the sheathing of the device.

[0051] The friction coefficient of the first friction area is preferably not more than 0.3, so as to reduce friction and have an anti-coagulation effect. For example, when using fluoropolymer, the friction coefficient of the fluoropolymer should not exceed 0.1 to achieve the best effect.

[0052] The friction coefficient of the second friction area can basically refer to the friction coefficient of common coating materials. For example, the second friction area can be formed by using some common processing materials of the coating 210.

[0053] The coating 210 may be a knitted or non-knitted film, which is not limited by the present invention. When the coating 220 is provided, the coating 220 may cover the entire filament of the coating 210 or only the outer surface of the coating 210. The coating 220 may be prepared by, for example, dipping, spraying, or other methods.

[0054] The present invention will be further described through the following examples, which are merely illustrative and intended to help those skilled in the art understand the present invention rather than to limit the scope of protection of the present invention.

[0055] Example 1

[0056] 2 , in this embodiment, the outer surface of the main grid 10 is coated with a coating 210. The coating 210 is a PET knitted film. A coating 220 is provided on part of the outer surface of the PET knitted film. The coating 220 only includes a PTFE coating 221 (i.e., a polytetrafluoroethylene coating) that forms a first friction region. The PTFE coating 221 constitutes a first friction coefficient coating. The PTFE coating 221 extends from the proximal end 101 of the main grid 10 and covers the maximum outer diameter of the main grid 10. For example, the PTFE coating 221 extends beyond the maximum outer diameter (Dmax) of the main grid 10 so that the PTFE coating 221 can fully cover the maximum outer diameter of the main grid 10. The distance exceeding the maximum outer diameter can be 5 mm or other dimensions. The area of ​​the coating 210 other than the PTFE coating 221 is an uncoated area. The coating 210 in the uncoated area directly forms the second friction region.

[0057] At the same time, a friction coefficient tester was used to measure the friction coefficient of the PTFE coating 221 and the uncoated area according to the method of GB / T 10006-2021. The measurement results are shown in Table 1.

[0058] Table 1: Friction coefficients of PTFE-coated and uncoated areas

[0059] The sheathing force was further tested. During the test, the coated medical device of Example 1 and the coated medical device of the comparative example were installed in a 12F sheath tube, and the sheathing force (unit: N) required for each coated medical device as the sheath tube moved was measured. The measurement results are shown in Figure 3. It should be noted that the PET knitted film on the coated medical device of the comparative example was uncoated; that is, the entire outer surface of the PET knitted film was an uncoated area. It should also be understood that the maximum sheathing force is the force applied when the device is pulled into the sheath tube at its maximum outer diameter, and the force applied at the maximum outer diameter is recorded as the sheathing force.

[0060] 3 , the maximum sheathing force of Example 1 of the present invention is about 20 N, while the maximum sheathing force of the comparative example is about 28.6 N. As can be seen from the comparison, providing the PTFE coating 221 on the PET knitted film is beneficial for reducing the sheathing force.

[0061] Example 2

[0062] The difference from Example 1 is that the first friction area is formed by a PVDF coating (i.e., a polyvinylidene fluoride coating) instead of the PTFE coating 221 of Example 1. The remaining settings are the same as those of Example 1 and will not be described in detail.

[0063] The same test method was used to measure the friction coefficient of the PVDF coating and the uncoated area. The measurement results are shown in Table 2.

[0064] Table 2: Friction coefficients of PVDF coated and uncoated areas

[0065] According to Table 2, the friction coefficient of the PVDF coating (0.07) is smaller than the friction coefficient of the PTFE coating 221 (0.1), and thus the maximum sheathing force is smaller. More detailed sheathing force measurement results are shown in Table 3.

[0066] Table 3: Maximum insertion force under different experimental conditions

[0067] As can be seen in Table 3, the maximum sheathing force for Example 2 is 18.5 N, while the maximum sheathing force for the comparative example is 28.6 N. Thus, applying a PVDF coating to the PET knitted membrane reduces the maximum sheathing force. Furthermore, the PVDF coating also acts as an anticoagulant, reducing the probability of platelet deposition on the device and lowering the incidence of device thrombosis.

[0068] Example 3

[0069] The difference from Example 1 is that the first friction area is formed by a Parylene coating (i.e., a parylene coating) instead of the PTFE coating 221 of Example 1. In addition, the Parylene coating extends beyond the maximum outer diameter of the main frame 10 by about 3 mm. The remaining settings are the same as in Example 1 and will not be described in detail.

[0070] The friction coefficient tester was used to test the friction coefficient, and the measurement results in Table 4 were obtained.

[0071] Table 4: Friction coefficient of Parylene coated and uncoated areas

[0072] As shown in Table 4 , the friction coefficient of the Parylene coating is smaller than that of the PVDF coating and the PTFE coating 221 . Therefore, the maximum sheathing force is smaller. The measurement results of the sheathing force are shown in Table 5 .

[0073] Table 5: Maximum insertion force under different experimental conditions

[0074] It can be seen that the maximum sheathing force of Example 3 is reduced to 15.0N, so the sheathing difficulty is lower and the sheathing resistance is smaller.

[0075] Example 4

[0076] 4 , in this embodiment, the coating 220 further includes a polyacrylamide coating 222 forming a second friction region. The polyacrylamide coating 222 constitutes a second friction coefficient coating. The PET knitted film is covered with the polyacrylamide coating 222 in areas other than the PTFE coating 221 .

[0077] The friction coefficients of the PTFE coating 221 and the polyacrylamide coating 222 were measured using the same test method as in Example 1. The results are shown in Table 6.

[0078] Table 6: Friction coefficients of PTFE coating and polyacrylamide coating

[0079] Therefore, the friction coefficient of the polyacrylamide coating 222 (0.15) is greater than the friction coefficient of the PTFE coating 221 (0.1), that is, low friction and high friction can be achieved simultaneously by the coating 220. The sheathing force measurement results are shown in Table 7.

[0080] Table 7: Maximum insertion force under different experimental conditions

[0081] Thus, compared with uncoated instruments, by providing the first friction coefficient coating and the second friction coefficient coating on the PET knitted film, the sheathing force can also be reduced.

[0082] Example 5

[0083] Different from the above-mentioned embodiments 1-4, in this embodiment, the covering 20 is only composed of the coating 210 without a coating. At this time, the coating 210 is composed of a first film body and a second film body with different friction coefficients. The first film body constitutes a first friction area, and the second film body constitutes a second friction area.

[0084] Specifically, as shown in Figure 5 , the covering membrane 210 is composed of a PTFE membrane 211 and a PET knitted membrane 212. The PTFE membrane 211 forms the first membrane element, while the PET knitted membrane 212 forms the second membrane element. The PTFE membrane 211 extends from the proximal end 101 of the main mesh frame 10 to the maximum outer diameter of the main mesh frame 10. Preferably, the PTFE membrane 211 extends approximately 5 mm beyond the maximum outer diameter of the main mesh frame 10. The PET knitted membrane 212 covers the entire area of ​​the main mesh frame 10, excluding the PTFE membrane 211.

[0085] At the same time, a friction coefficient tester was used to test the friction coefficients of the PTFE knitted film 211 and the PET knitted film 212, as shown in Table 8.

[0086] Table 8: Friction coefficient of PTFE knitted membrane and PET knitted membrane

[0087] The maximum sheathing force was further tested. During the test, the coated medical device of Example 5 and the coated medical device of the comparative example were placed in a 12F sheath tube, and the maximum sheathing force (unit: N) of each was measured. The measurement results are shown in Table 9.

[0088] Table 9: Sheathing force under different experimental conditions

[0089] As shown in Table 9, after using the coatings 210 with different friction coefficients, the sheathing force of the entire device is reduced, achieving the expected effect.

[0090] Example 6

[0091] The difference from the above embodiment is that, in this embodiment, the first friction coefficient coating covers the first transition coating having a larger friction coefficient than the first transition coating.

[0092] Specifically, as shown in Figure 6 , the outer surface of the main frame 10 is covered with a PET knitted film (i.e., coating 210), the entire surface of which is pre-coated with a PTFE coating 221. Furthermore, a PVDF coating 223 is applied to the PTFE coating 221 where the first friction zone is to be formed. Thus, a combined coating is formed at the location corresponding to the first friction zone. Because the friction coefficient of the PVDF coating 223 is lower than that of the PTFE coating 221, this approach also ensures that the surface covering the first friction zone has a relatively low friction coefficient.

[0093] In this embodiment, although the PVDF coating 223 extends beyond the maximum outer diameter of the main frame 10 by approximately 1 mm, it should be understood that the present invention does not limit the distance that the first friction coefficient coating extends beyond the maximum outer diameter of the main frame 10, as long as the maximum outer diameter position of the main frame 10 can be completely covered by the low friction coefficient coating.

[0094] The area of ​​the PTFE coating 221 other than that covered by the PVDF coating 223 is not further processed, so that the exposed PTFE coating 221 directly forms the second friction area.

[0095] The measurement of the friction coefficient of Example 6 is shown in Table 10, and the measurement of the maximum sheathing force is shown in Table 11.

[0096] Table 10: Friction coefficient of PVDF coating over PTFE coating

[0097] Table 11: Maximum sheathing force under different experimental conditions

[0098] According to Tables 10 and 11, when a combined coating is formed in the low-friction area and a single coating is formed in the high-friction area, the sheathing force can also be reduced to achieve the same or similar effect.

[0099] Example 7

[0100] The difference from Example 6 is that, in this embodiment, the second friction coefficient coating is covered on the second transition coating having a smaller friction coefficient than the second transition coating.

[0101] As shown in Figure 7, the entire surface of the PET knitted film is pre-coated with a PVDF coating 223. Furthermore, a PTFE coating 221 is applied to the PVDF coating 223 where the second friction zone is to be formed, thereby forming a combined coating corresponding to the second friction zone. Because the coefficient of friction of the PTFE coating 221 is greater than that of the PVDF coating 223, the surface of the covering in the second friction zone has a relatively high coefficient of friction.

[0102] The PVDF coating 223 is not further processed except for the area covered by the PTFE coating 221, so that the exposed PVDF coating 223 directly forms the first friction area.

[0103] The measurement results of the friction coefficient of Example 7 are shown in Table 12, and the measurement results of the maximum sheathing force are shown in Table 13.

[0104] Table 12: Friction coefficient of PTFE coating over PVDF coating

[0105] Table 13: Maximum insertion force under different experimental conditions

[0106] According to Tables 12 and 13, when a combined coating is formed in the high-friction area and a single coating is formed in the low-friction area, the sheathing force can also be reduced to achieve the same or similar effect.

[0107] Comparative Example 1

[0108] The PTFE coating 221 in Example 1 is completely covered with the PET knitted film, so that the entire surface of the cover 20 is the first friction area.

[0109] The pull-off force was further measured, and the pull-off force of the devices of Example 1 and Comparative Example 1 was tested in a pull-off force test model made of silicone. The results are shown in Table 14.

[0110] Table 14: Pull-off force under different experimental conditions

[0111] As can be seen from Table 14, although the sheathing force of the device of Comparative Example 1 is expected to be consistent with that of Example 1, the pull-out force is too small. Therefore, there is a risk of the device falling off after being implanted in the human body, and the stability cannot be guaranteed. The device of Example 1 can take into account both the sheathing force and the anchoring performance, and achieve better results.

[0112] In summary, the coated medical device provided by the present invention can match the functions of different areas of the device through high and low area friction design to obtain better clinical effects; the first friction area covering the maximum outer diameter position requires a smaller sheathing force when sheathing, which brings greater freedom to the device design and is also conducive to the design of smaller sheaths and larger specifications of devices; and the area extending from the maximum outer diameter position of the device to the distal end is the anchoring area, and the high friction coefficient in the anchoring area makes the device more stable; especially when the first friction area adopts a fluoropolymer coating, a lower surface friction coefficient can be obtained, the sheathing force can be smaller, and the probability of platelet deposition can be reduced, and the incidence of device-induced thrombosis can be reduced, so the effect is better.

[0113] It should also be noted that in the present invention, although the maximum outer diameter position of the main frame is covered by the low friction area (i.e., the first friction area), because the fixation of the instrument is mainly guaranteed by the anchoring of the high friction area (i.e., the second friction area), the low friction area will not affect the stability of the entire instrument.

[0114] The above description is only a description of the preferred embodiment of the present invention and does not limit the scope of the present invention. Any changes and modifications made by ordinary technicians in the field of the present invention based on the above disclosure are within the scope of protection of the technical solution of the present invention.

Claims

1. A film-coated medical device, characterized in that: It includes a main frame and a covering, wherein the covering covers at least a portion of the outer surface of the main frame, and the covering has a first friction area and a second friction area axially arranged from the proximal end to the distal end of the main frame, the friction coefficient of the first friction area is smaller than the friction coefficient of the second friction area, and the first friction area extends from the proximal end of the main frame and covers the maximum outer diameter position of the main frame.

2. The film-coated medical device according to claim 1, characterized in that: The covering includes a film and a coating, wherein the film covers the outer surface of the main body grid, the coating covers the film, and the coating includes a first friction coefficient coating that forms the first friction area.

3. The film-coated medical device according to claim 2, characterized in that: The area of ​​the coating film other than that covered with the first friction coefficient coating is a non-coating area, and the non-coating area forms the second friction area.

4. The film-coated medical device according to claim 2, characterized in that: The coating layer further includes a second friction coefficient coating layer forming the second friction region, and the coating film is covered with the second friction coefficient coating layer in a region other than that covered with the first friction coefficient coating layer.

5. The film-coated medical device according to claim 2, characterized in that: The first friction coefficient coating covers the covering film, or the first friction coefficient coating covers at least one first transfer coating having a lower or higher friction coefficient than the first transfer coating.

6. The film-coated medical device according to claim 4, characterized in that: The second friction coefficient coating covers the covering film, or the second friction coefficient coating covers at least one second transfer coating having a lower or higher friction coefficient than the second friction coefficient coating.

7. The film-coated medical device according to claim 2, characterized in that: The first friction coefficient coating includes one of fluoropolymer, parylene, polyimide, polyvinyl pyrrolidone, polyacrylamide, polyetheramide, gel or a combination thereof.

8. The film-coated medical device according to claim 7, characterized in that: The fluorine-containing polymer includes one or a combination of polytetrafluoroethylene, polyvinylidene fluoride, vinyl fluoride homopolymer and perfluoroethylene propylene copolymer.

9. The film-coated medical device according to claim 2, characterized in that: The thickness of the coating does not exceed 1 μm.

10. The film-coated medical device according to claim 1, characterized in that: The friction coefficient of the first friction area does not exceed 0.

3.

11. The film-coated medical device according to claim 10, characterized in that: The friction coefficient of the first friction area does not exceed 0.

1.

12. The film-coated medical device according to claim 1, characterized in that: The covering is composed of a coating film, and the coating film is composed of a first film body and a second film body with different friction coefficients. The first film body forms the first friction area, and the second film body forms the second friction area.

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