A sleeve type structure artificial heart valve and a preparation method thereof

Abstract

An artificial heart valve with a sleeve structure and a preparation method thereof, comprising a first valve seat body, a second valve seat body and artificial valve leaflets; the second valve seat body is sleeved outside the first valve seat body, the artificial valve leaflets are arranged between the first valve seat body and the second valve seat body, the artificial valve leaflets are composed of three equal and same valve leaflets and one covering film, and free end edges of the three valve leaflets are in a wave shape and gradually change in thickness from roots to edges. The sleeve structure improves overall stability and assembly precision, the wave-shaped valve leaflet edges optimize the sealing performance and anti-reflux effect of the artificial valve leaflets, the gradually changing valve leaflet thickness balances the structural strength and flexibility, the bionic microtexture improves the hemodynamics and antithrombotic performance, and when the artificial heart valve is prepared, the femtosecond laser direct writing is adopted to ensure the precision and consistency of the bionic microtexture.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of artificial heart valve, more particularly, it is a kind of sleeve structure artificial heart valve and preparation method thereof. BACKGROUND

[0002] Artificial heart valve is an important implant device for treating heart valve lesions, such as stenosis or dysfunction, and its core function is to replace the damaged valve and reconstruct the structure that meets the physiological blood flow dynamics.

[0003] The current common artificial valve includes mechanical valve and biological valve, each of which still has obvious shortcomings.

[0004] Mechanical valve is usually made of metal material or carbon material, which has good durability and can be used for more than 20 years, but the implanters must take anticoagulant drugs for a long time to prevent thrombosis, which not only increases the probability of bleeding, but also brings the burden of continuous medication.

[0005] Biological valve is mainly derived from porcine or bovine pericardial tissue, which is fixed by glutaraldehyde and has blood flow characteristics closer to human natural valve, and the anticoagulation time after operation is shorter. However, biological valve is prone to calcification, damage or degradation, and has poor durability, so many patients may face reoperation, especially for young patients.

[0006] In recent years, artificial heart valve made of polymer material has attracted wide research interest due to its flexibility and potential anti-thrombosis properties, but there are still problems such as manual sewing and coating uniformity in the manufacturing process, which affect the blood flow performance and durability of the final product, and may cause material wear or structural deformation after long-term repeated stress.

[0007] Therefore, it is urgent to develop a new type of artificial heart valve structure to further optimize its hemodynamic performance, reduce the risk of thrombosis and calcification, and improve the production efficiency on the basis of improving the long-term durability. At the same time, the manufacturing process should be simplified to ensure the function of the valve and improve the production efficiency to realize repeatable and standardized mass production. SUMMARY

[0008] (I) Invention purpose: in order to solve the problems existing in the prior art, the purpose of the present application is to provide a sleeve structure artificial heart valve and a preparation method thereof.

[0009] (II) Technical scheme: in order to solve the above technical problems, the present technical scheme provides a sleeve structure artificial heart valve, which comprises a first valve seat body, a second valve seat body and an artificial valve leaflet; the second valve seat body is sleeved on the outside of the first valve seat body, and the artificial valve leaflet is arranged between the first valve seat body and the second valve seat body,

[0010] The artificial valve leaflet is composed of three equal and identical valve leaflets and one covering film, and the free end edges of the three valve leaflets are wavy and gradually change in thickness from the root to the edge.

[0011] The sleeve type artificial heart valve, wherein the lower parts of the first valve seat body and the second valve seat body are smooth arc structures, and the upper parts are provided with three convex column peaks uniformly distributed in the circumferential direction.

[0012] The sleeve type artificial heart valve, wherein the shapes and sizes of the three convex column peaks are consistent, and the highest points of adjacent convex column peaks are 120° apart.

[0013] The sleeve type artificial heart valve, wherein the wavelength of the wavy free edge of the three valve leaflets is 2-3 mm, the wave height is 0.3-0.5 mm, and the wave peaks and troughs of the edges of adjacent valve leaflets are distributed in a staggered manner.

[0014] The sleeve type artificial heart valve, wherein the thickness of the root of the artificial valve leaflet is twice the thickness of the edge.

[0015] The sleeve type artificial heart valve, wherein the surface of the artificial valve leaflet and / or the inner wall of the first valve seat body are provided with biomimetic microtexture.

[0016] The sleeve type artificial heart valve, wherein the biomimetic microtexture includes parallel primary shallow grooves extending in the opening and closing direction of the valve leaflet.

[0017] The sleeve type artificial heart valve, wherein the width of the primary shallow groove is 80-120 μm, the depth is 20-50 μm, and the spacing between two adjacent primary shallow grooves is 150-200 μm.

[0018] The sleeve type artificial heart valve, wherein the biomimetic microtexture includes parallel secondary shallow grooves perpendicular to the primary shallow grooves.

[0019] The sleeve type artificial heart valve, wherein the primary shallow grooves and the secondary shallow grooves form a grid-like texture.

[0020] The sleeve type artificial heart valve, wherein the cross sections of the primary shallow grooves and the secondary shallow grooves are U-shaped.

[0021] The sleeve type artificial heart valve, wherein the width of the secondary shallow groove is 30-50 μm, the depth is 10-20 μm, and the spacing between two adjacent primary shallow grooves is 50-100 μm.

[0022] The sleeve type artificial heart valve, wherein the biomimetic microtexture adopts a multi-level gradient shallow groove structure.

[0023] A preparation method of a sleeve structure artificial heart valve, for preparing the above-mentioned artificial heart valve, comprising the following steps,

[0024] Step one, respectively preparing a first valve seat body and a second valve seat body by injection molding;

[0025] Step two, preparing an artificial valve leaflet composed of three equal valve leaflets and one covering film by mold pressing, and opening a biomimetic microtexture on the surface of the artificial valve leaflet by femtosecond laser direct writing;

[0026] Step three, embedding the artificial valve leaflet between the first valve seat body and the second valve seat body to form a sleeve structure as a whole, thereby obtaining a sleeve structure artificial heart valve.

[0027] The preparation method of the sleeve structure artificial heart valve, wherein the biomimetic microtexture on the surface of the artificial valve leaflet is opened by femtosecond laser direct writing, comprising the following steps,

[0028] Step A, pretreating the artificial valve leaflet and modeling the artificial valve leaflet in three dimensions to obtain an artificial valve leaflet model;

[0029] Step B, configuring femtosecond laser direct writing parameters according to the artificial valve leaflet model;

[0030] Step C, generating an initial texture path of femtosecond laser direct writing based on the artificial valve leaflet model;

[0031] Step D, opening the biomimetic microtexture on the surface of the artificial valve leaflet according to the texture path by femtosecond laser direct writing, modifying the initial texture path of femtosecond laser direct writing according to the biomimetic microtexture opened in real time, and opening the biomimetic microtexture on the surface of the artificial valve leaflet according to the modified texture path of femtosecond laser direct writing;

[0032] Step E, cleaning the artificial valve leaflet with the completed biomimetic microtexture to obtain a target artificial valve leaflet.

[0033] (Three) beneficial effects: the present application provides a sleeve structure artificial heart valve and a preparation method thereof, the sleeve structure improves the overall stability and assembly precision, the wavy valve leaflet edge optimizes the sealing performance and anti-reflux effect of the artificial valve leaflet, the gradual change of the valve leaflet thickness balances the structural strength and flexibility, the biomimetic microtexture improves the hemodynamics and antithrombotic performance, and when preparing the artificial heart valve, femtosecond laser direct writing is used to ensure the precision and consistency of the biomimetic microtexture. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 is a structural schematic diagram of one embodiment of the sleeve structure artificial heart valve of the present application;

[0035] Figure 2is a structural schematic view of a first valve base body of a sleeve type artificial heart valve embodiment one of the present application;

[0036] Figure 3 is a structural schematic view of a second valve base body of a sleeve type artificial heart valve embodiment one of the present application;

[0037] Figure 4 is a sectional structural schematic view of a first valve base body and a second valve base body of a sleeve type artificial heart valve embodiment one of the present application after combination;

[0038] Figure 5 is a structural schematic view of an artificial valve leaflet of a sleeve type artificial heart valve embodiment one of the present application;

[0039] Figure 6 is a structural schematic view of an artificial valve leaflet of a sleeve type artificial heart valve embodiment two of the present application;

[0040] Figure 7 is a step schematic view of a sleeve type artificial heart valve preparation method of the present application;

[0041] Figure 8 is a step schematic view of a sleeve type artificial heart valve preparation method of the present application adopting femtosecond laser direct writing to open a biomimetic microtexture on the surface of an artificial valve leaflet;

[0042] 100-first valve base body; 200-second valve base body; 300-artificial valve leaflet. DETAILED DESCRIPTION

[0043] The present application will be further described below in conjunction with preferred embodiments, and more details are set forth in the following description in order to fully understand the present application, however, the present application can be implemented in various other ways different from the description, and those skilled in the art can make similar generalization and deduction according to actual application conditions without departing from the connotation of the present application, therefore, the protection scope of the present application should not be limited by the content of the specific embodiments.

[0044] The accompanying drawings are schematic views of the embodiments of the present application, it should be noted that the drawings are only as examples, not drawn according to the condition of the same scale, and should not be used as a limitation to the actual claimed protection scope of the present application.

[0045] Embodiment one

[0046] As Figures 1-5As shown, a sleeve type structure artificial heart valve includes a first valve seat body, a second valve seat body and an artificial valve leaflet. The second valve seat body is sleeved on the outside of the first valve seat body, and the artificial valve leaflet is arranged between the first valve seat body and the second valve seat body, and the first valve seat body, the second valve seat body and the artificial valve leaflet are combined together in a sleeve type structure.

[0047] The first valve seat body and the second valve seat body are in a columnar structure, the second valve seat body is sleeved on the radial outside of the first valve seat body, the base of the second valve seat body is placed on the base of the first valve seat body, and the first valve seat body and the second valve seat body are combined together by superposition. The artificial valve leaflet is composed of three equal and same valve leaflets and one covering film covering the outer surface of the first valve leaflet body. The artificial valve leaflet is attached to the outer surface of the first valve seat body and fixed between the first valve seat body and the second valve seat body, and the three are combined together in a sleeve form.

[0048] The valve leaflets are spaced along the circumference of the first valve seat body. The size of the artificial valve leaflet is an inner diameter of 21 mm, an outer diameter of 23 mm, a height of 9.5 mm, a thickness of 0.2 mm, and the covering film covering the outer surface of the first valve seat body has an inner diameter of 23 mm, an outer diameter of 23.2 mm, a height of 11.5 mm, and a thickness of 0.2 mm.

[0049] The lower part of the first valve seat body and the lower part of the second valve seat body are both smooth arc structures, and the upper part of each is provided with three convex column peaks uniformly distributed in the circumference. The shape and size of each convex column peak are consistent.

[0050] The lower end, i.e. the lower part, of the first valve seat body and the second valve seat body is in a circular ring shape, and the upper end, i.e. the upper part, is composed of three convex column peak structures. The angle of each convex column peak structure is 120°, i.e. the included angle between the highest points of adjacent convex column peaks is 120°, and the height is 9.5 mm, which is treated by rounding. The geometric shape of each convex column peak structure is the same. The second valve seat body is located 0.2 mm radially outside the first valve seat body, the lower part of the second valve seat body is located above the lower part of the first valve seat body, and there is a gap of 0.2 mm between the first valve seat body and the second valve seat body, which is used to fix the artificial valve leaflet.

[0051] When artificial valve leaflets with different thicknesses are used, the inner diameter and the outer diameter of the second valve seat body are adjusted so that the distance between the first valve seat body and the second valve seat body matches the thickness of the artificial valve leaflet.

[0052] The first and second valve seat bodies each comprise at least two structural segments of upper and lower parts. The upper parts of the first and second valve seat bodies are adapted in shape and size, and the lower parts of the first and second valve seat bodies are adapted in shape and size, and form the fitting base of the sleeve structure.

[0053] The upper part of the first valve seat body is a columnar structure, the shape and size of the cross section of which are consistent along the axial direction, that is, the shape and size of the inner diameter of the upper part of the first valve seat body are consistent along the axial direction. The lower part of the first valve seat body is a circular ring base structure; the inner diameter of the upper part is equal to the inner diameter of the lower part, and the outer diameter of the lower part is greater than the outer diameter of the upper part. Specifically, the inner diameter of the cross section of the upper part of the first valve seat body is 21 mm, the outer diameter is 23 mm, the wall thickness is 1 mm, and the height is 9.5 mm; the inner diameter of the lower part of the first valve seat body is 21 mm, the outer diameter is 26.3 mm, and the height is 0.3 mm; the overall height of the first valve seat is 11.8 mm.

[0054] The upper part of the second valve seat body is a columnar structure, and the lower part of the second valve seat body is a circular ring base structure. Specifically, the inner diameter of each cross section of the upper part of the second valve seat body is 23.4 mm, the outer diameter of the cross section is 24.2 mm, the wall thickness is 0.4 mm, and the height is 9.5 mm; the inner diameter of the lower part of the second valve seat body is 23.4 mm, the outer diameter is 26.3 mm, and the height is 1.0 mm; the overall height of the second valve seat is 11.5 mm.

[0055] The upper part and the lower part of the first and second valve seat bodies are respectively provided with a plurality of valve leaf fixing holes at one end, the valve leaf fixing holes are uniformly distributed at the same horizontal position of the upper part of the first and second valve seat bodies, and the valve leaf fixing holes of the first valve seat body correspond to the valve leaf fixing holes of the second valve seat body, that is, each valve leaf fixing hole of the first valve seat body corresponds to a valve leaf fixing hole of the second valve seat body. The first and second valve seat bodies and the artificial valve leaf are fixed through the valve leaf fixing holes, and specifically, the first and second valve seat bodies and the artificial valve leaf can be sewn through the valve leaf fixing holes, so as to realize the fixation of the artificial valve leaf.

[0056] The first and second annulus bodies are made of biocompatible hard material, and the artificial valve leaflets are made of biocompatible flexible material. Specifically, the first and second annulus bodies are made of medical implant-grade PEEK material, which needs to meet the standards of YY / T 0660-2008 and ASTM F2026; the artificial valve leaflets are made of high-molecular polymer material, which meets the requirements of biocompatibility, safety, super durability, blood compatibility, and chemical stability.

[0057] A sleeve structure artificial heart valve, artificial valve leaflets are embedded between the first and second annulus; the first and second annulus and the valve leaflets are combined together to present a sleeve structure function, realizing the preparation of the artificial heart valve, which not only ensures that the shape of the valve leaflets is not disturbed by the processing method, but also reduces / avoids the stress on the damaged area of the valve leaflets during movement after the chamfering, avoiding the interference of the sewing method on the valve leaflet part in the preparation process of the existing artificial heart valve, the error of the symmetry of the overall structure of the artificial valve, the poor tear resistance, and the problems of difficult to reproduce finished products and low production efficiency.

[0058] Embodiment two

[0059] A sleeve structure artificial heart valve, comprising a first annulus body, a second annulus body and an artificial valve leaflet. The second annulus body is sleeved on the outside of the first annulus body, the artificial valve leaflet is arranged between the first annulus body and the second annulus body, and the first annulus body, the second annulus body and the artificial valve leaflet are combined together to present a sleeve structure.

[0060] The first and second annulus bodies are in a columnar structure, the second annulus body is sleeved on the radial outside of the first annulus body, the base of the second annulus body is placed on the base of the first annulus body, and the first and second annulus bodies are combined together by superposition. The artificial valve leaflet is composed of 3 equal and identical valve leaflets and 1 covering film covering the outer surface of the first valve leaflet body. The artificial valve leaflet is attached to the outer surface of the first annulus body and fixed between the first and second annulus bodies, and the three are combined together in the form of a sleeve.

[0061] As shown in Figure 6 The 3 valve leaflets are distributed along the circumference of the first annulus body, and the free end edge of the artificial valve leaflet is wavy and the thickness gradually changes from the root to the edge of the artificial valve leaflet. Specifically, the thickness of the root of the artificial valve leaflet is 2 times the thickness of the edge, for example, the thickness of the root is 0.3mm and the thickness of the edge is 0.15mm.

[0062] The wavelength of the wavy free edge of the 3-petal leaf is 2-3 mm, the wave height is 0.3-0.5 mm, and the edge wave peaks and troughs of adjacent petal leaves are distributed in staggered positions.

[0063] A sleeve type structure artificial heart valve avoids the following problems:

[0064] The flat edge petal leaf has a limited contact area when closed, and is prone to blood reflux due to poor coaptation, which can cause heart failure in the long term;

[0065] The artificial leaf is prone to stress concentration at the root or edge during repeated opening and closing, resulting in tearing or calcification, shortening the service life of the valve;

[0066] It is easy to cause blood flow turbulence, induce platelet deposition and thrombosis, and increase the dependence on anticoagulant therapy.

[0067] The staggered coaptation of the wavy edge prolongs the coaptation line length of the leaf, increases the actual contact area of the leaf by 40% when closed, forms a labyrinth sealing structure, reduces the risk of paravalvular leakage, and significantly improves the recovery effect of heart function; the wavy structure can absorb the impact force of diastolic blood flow reflux through elastic deformation, reduce the collision damage of the leaf edge, and reduce the vortex dead zone of thrombosis; the thickening of the root of the artificial leaf ensures the structural strength of the connection between the artificial leaf and the valve body, resists the fatigue stress generated by repeated opening and closing, the edge is thinned to improve flexibility, ensures close fitting when closed, reduces the risk of calcification caused by rigid collision, and the gradient design of the thickness gradually transfers the stress from the edge to the root, avoiding stress concentration at the junction of the root and the edge of the artificial leaf; the thickness gradient design combined with the wavy buffer structure improves the fatigue resistance.

[0068] Example three

[0069] A sleeve type structure artificial heart valve, comprising a first valve body, a second valve body and an artificial leaf. The second valve body is sleeved on the outside of the first valve body, the artificial leaf is arranged between the first valve body and the second valve body, and the first valve body, the second valve body and the artificial leaf are combined together in a sleeve type structure.

[0070] The first valve body and the second valve body are in a columnar structure, the second valve body is sleeved on the radial outside of the first valve body, the base of the second valve body is placed on the base of the first valve body, and the first valve body and the second valve body are combined together by superposition. The artificial leaf is composed of 3 equal and identical petal leaves and 1 covering film covering the outer surface of the first petal leaf body, the artificial leaf is attached to the outer surface of the first valve body and fixed between the first valve body and the second valve body, and the three are combined together in the form of a sleeve.

[0071] The three leaflets are distributed along the circumference of the first valve body. The covering film is an elastic film material, the inner wall of which is in contact with the outer surface of the first valve body, the outer wall of which is in contact with the inner wall of the second valve body, and the upper end of the covering film extends to the root of the leaflet to form an integrated wrapping structure.

[0072] The artificial leaflet is provided with a biomimetic microtexture on the surface through which blood flows, and the inner wall of the first valve body is provided with a biomimetic microtexture matching the biomimetic microtexture of the artificial leaflet.

[0073] The biomimetic microtexture is a shallow groove extending along the opening and closing direction of the leaflet, the width of the shallow groove is 0.5-1 μm, the depth is 0.2-0.3 μm, and the distance between two adjacent shallow grooves is 1-2 μm. The biomimetic microtexture can be specifically provided on the entire surface of the artificial leaflet or the local area prone to thrombosis, including the coaptation edge and the root of the leaflet, the blood compatibility is optimized by the micro-surface modification of the biomimetic microtexture, and the platelet adhesion and thrombosis are reduced. The shallow groove size is close to the size of the platelet diameter 2-3 μm and the red blood cell diameter 7-8 μm in blood, the boundary layer blood flow is disturbed by the shallow groove capture effect, and the platelets are prevented from staying on the surface of the leaflet for a long time. The distance between two adjacent shallow grooves is 1-2 μm, which can form a micro-channel to guide the plasma laminar flow and reduce the adsorption and deposition of proteins such as fibrinogen.

[0074] The biomimetic microtexture can also be a parallel main shallow groove extending along the opening and closing direction of the leaflet, and the cross section of the main shallow groove is U-shaped. The width of the main shallow groove is 80-120 μm, the depth is 20-50 μm, and the distance between two adjacent main shallow grooves is 150-200 μm. The width and depth of the main shallow groove match the main flow velocity 1-2 m / s when the leaflet is opened, a guide groove is formed by the U-shaped cross section, the blood is smoothly guided from the root to the edge of the artificial leaflet, and vortex is avoided. The depth of the main shallow groove is 20-50 μm, which can reduce stress concentration and prevent the leaflet from tearing due to too deep grooves. The distance between the main shallow grooves is 150-200 μm, which can balance the structural strength and blood flow resistance, too dense will increase the stiffness of the leaflet, and too sparse will not effectively guide the blood flow.

[0075] The biomimetic microtexture can also be a parallel main shallow groove and a parallel secondary shallow groove perpendicular to the main shallow groove, which form a grid-like texture. The cross sections of the main shallow groove and the secondary shallow groove are both U-shaped.

[0076] The cross section of the main shallow groove is U-shaped. The width of the main shallow groove is 80-120 μm, the depth is 20-50 μm, and the distance between two adjacent main shallow grooves is 150-200 μm. The width of the secondary shallow groove is 30-50 μm, the depth is 10-20 μm, and the distance between two adjacent main shallow grooves is 50-100 μm. The edges of the main shallow groove and the secondary shallow groove are rounded with a radius of 0.5 μm to avoid stress concentration.

[0077] The coverage rate of the biomimetic microtexture on the surface of the leaflet is 60%-80% of the surface area of the leaflet, and the texture depth gradually decreases from the root of the leaflet to the edge. The coverage area of the main shallow groove and the secondary shallow groove includes a continuous distribution from the root to the free edge of the artificial leaflet surface at a height of 30% of the valve seat, with a coverage rate of 80%. The first valve seat body inner wall is covered all around from the blood inlet to the blood outlet, and the texture depth gradually decreases along the blood flow direction, for example, the depth of the main shallow groove at the blood inlet is 50 μm, and the depth of the main shallow groove at the blood outlet is 20 μm.

[0078] By guiding the blood flow direction through the main shallow groove and disturbing the boundary layer through the secondary shallow groove, the blood flow shear force fluctuation is reduced, the platelet adhesion is reduced, and the thromboresistance of the whole surface is realized. The texture depth gradually decreases along the blood flow direction, which reduces the transvalvular pressure difference and improves the effective opening area.

[0079] When the artificial valve is in the aortic valve, the three leaflets are distributed in a radial manner, the main shallow groove extends from the fixed point at the root of the artificial valve leaflet and the valve seat body to the coaptation edge direction of the free edge of the artificial valve leaflet, forming a parallel groove array with an angle ≤5° with the radial central axis of the artificial valve leaflet. There is slight bending deformation of the artificial valve leaflet during opening and closing, i.e. the middle part of the leaflet protrudes towards the center during diastole, and the main shallow groove in the middle part of the leaflet will gradually deflect by 0.5°-1° / mm along with the curvature of the surface, ensuring that the direction of the main shallow groove is always consistent with the local blood flow streamline, avoiding the formation of turbulent dead zones due to the large angle between the main shallow groove and the blood flow.

[0080] The biomimetic microtexture adopts a multi-level gradient shallow groove structure, as shown in the following table.

[0081]

[0082] The main shallow groove and the secondary shallow groove perpendicular to the main shallow groove form a grid-like texture, wherein the main shallow groove realizes macro blood flow guidance, and the secondary shallow groove realizes micro boundary layer disturbance, thereby cooperatively realizing: the main shallow groove drains blood flow from the root to the edge, reducing the blood flow stagnation area on the surface of the leaflet; the secondary shallow groove forms a micro-turbulence generator between the main shallow grooves, further breaking the boundary layer, reducing the deposition probability of platelets at the bottom of the main shallow groove, and making the deposition rate ≤0.1 μg / cm²·h.

[0083] Example Four

[0084] The sleeve type structure artificial heart valve further comprises a locking mechanism for locking or unlocking the first valve seat body and the second valve seat body. The locking mechanism comprises an elastic buckle arranged on the outer wall of the first valve seat body and a corresponding clamping groove arranged on the inner wall of the second valve seat body.

[0085] The opposite side of the first valve seat body and the second valve seat body is respectively provided with a guide positioning member for realizing accurate centering of the valve seat and avoiding installation deviation.

[0086] Embodiment five

[0087] A sleeve type structure artificial heart valve preparation method is used to prepare the sleeve type structure artificial heart valve described above, as shown in the drawings, comprising the following steps, Figure 7

[0088] Step one, the first valve seat body and the second valve seat body are respectively prepared by injection molding;

[0089] Step two, an artificial valve leaflet composed of three equal valve leaflets and one covering film is prepared by mold pressing;

[0090] Step three, the artificial valve leaflet is embedded between the first valve seat body and the second valve seat body to form a sleeve type overall structure, and a sleeve type structure artificial heart valve is obtained.

[0091] In the step one, the lower part of the first valve seat body and the second valve seat body is a smooth arc structure, and the upper part is provided with three convex column peaks uniformly distributed in the circumferential direction, the highest point of adjacent column peaks is 120°, and the edge of the column peak is treated by rounding, and the rounding radius is 0.5mm.

[0092] An elastic buckle is arranged on the outer wall of the first valve seat body, and a corresponding clamping groove is arranged on the inner wall of the second valve seat body to form a locking mechanism; guide positioning members are respectively machined on the opposite sides to realize accurate centering during assembly.

[0093] In the step two, an artificial valve leaflet composed of three equal valve leaflets and one covering film is prepared by mold pressing using a biocompatible high molecular polymer material, the free end edge of the valve leaflet is wave-shaped, the wavelength is 2-3mm, the wave height is 0.3-0.5mm, and the wave peaks and wave troughs of adjacent valve leaflet edges are distributed in a staggered manner. The thickness of the valve leaflet gradually changes from the root to the edge, and the root thickness is 2 times the edge thickness.

[0094] ​The step two further comprises opening the bionic microtexture on the surface of the artificial valve leaflet by femtosecond laser direct writing, specifically comprising opening of the main shallow groove and the secondary shallow groove. The main shallow groove: extending along the opening and closing direction of the valve leaflet, with a width of 80-120 μm, a depth of 20-50 μm, and an adjacent interval of 150-200 μm, and the depth is gradiently distributed from 50 μm at the root of the valve leaflet to 20 μm at the edge. The secondary shallow groove: perpendicular to the main shallow groove, with a width of 30-50 μm, a depth of 10-20 μm, and an adjacent interval of 50-100 μm.

[0095] The bionic microtexture is opened on the surface of the artificial valve leaflet by femtosecond laser direct writing, as shown in FIG. 1, comprising the following steps, Figure 8

[0096] Step A: The artificial valve leaflet is pretreated and three-dimensional modeling is performed according to the artificial valve leaflet to obtain an artificial valve leaflet model.

[0097] Step B: The femtosecond laser direct writing parameters are configured according to the artificial valve leaflet model.

[0098] Step C: The initial texture path of femtosecond laser direct writing is generated based on the artificial valve leaflet model.

[0099] Step D: The bionic microtexture is opened on the surface of the artificial valve leaflet according to the texture path by femtosecond laser direct writing, and the initial texture path of femtosecond laser direct writing is modified according to the bionic microtexture opened in real time, and the bionic microtexture is opened on the surface of the artificial valve leaflet according to the modified texture path of femtosecond laser direct writing.

[0100] Step E: The artificial valve leaflet with completed bionic microtexture opening is cleaned to obtain a target artificial valve leaflet.

[0101] In the step A, the artificial valve leaflet is fixed on a vacuum suction clamp, the first data acquisition unit white light interferometer is used to scan the surface of the valve leaflet to obtain three-dimensional point cloud data of the artificial valve leaflet, and three-dimensional modeling is performed according to the three-dimensional point cloud data to obtain the artificial valve leaflet model. The first data acquisition unit can be a white light interferometer.

[0102] In the artificial valve leaflet model, the root region, the middle region and the free edge region are divided, and the microtexture parameters of each region are set according to the multi-stage gradient shallow groove structure of the bionic microtexture: the main shallow groove of the root region is 50 μm deep, 120 μm wide, and 200 μm apart, the main shallow groove of the free edge region is 20 μm deep, 80 μm wide, and 150 μm apart, and the secondary shallow groove is 30-50 μm wide and 10-20 μm deep.

[0103] ​In the step B, the femtosecond laser direct writing parameters are as follows: a femtosecond laser with a wavelength of 1064 nm, a pulse width of 50 fs, a repetition frequency of 50-200 kHz, a three-dimensional piezoelectric translation stage with a positioning accuracy of ±0.05 μm, and a scanning range of the galvanometer scanning system of 30 mm×30 mm.

[0104] According to the region division result, the laser energy is adjusted to 1-5 μJ and the scanning speed is adjusted to 50-200 mm / s, so that the energy linearly decreases from 5 μJ to 1 μJ and the speed linearly increases from 50 mm / s to 200 mm / s from the root region to the free edge region.

[0105] In the step C, based on the artificial valve leaflet model, the initial texture path for femtosecond laser direct writing is generated according to the principle that the main shallow groove extends along the blood flow direction and has an angle of ≤5° with the radial central axis, and the secondary shallow groove is perpendicular to the main shallow groove.

[0106] In the step D, the biomimetic microtexture is opened on the surface of the artificial valve leaflet, including,

[0107] The main shallow groove is scanned in sequence from the root region, the middle region and the free edge region by using the femtosecond laser cold processing mode, and the focal point diameter is controlled to be 0.5-2 μm, so that the groove depth gradient error is ≤±2 μm;

[0108] When the secondary shallow groove is processed, the galvanometer is rotated by 90°, and the secondary shallow groove perpendicular to the main shallow groove is processed by the same method to form a grid-shaped texture, and the intersection is lowered by 10% through energy fine adjustment to avoid excessive depth at the intersection.

[0109] In the step D, according to the real-time opened biomimetic microtexture, the initial texture path for femtosecond laser direct writing is modified, specifically, the second data acquisition unit captures the processing region image in real time to obtain a real-time acquisition image, calculates the deviation of the depth and width of the main shallow groove or the secondary shallow groove in the real-time acquisition image from the preset value, and adjusts the laser energy according to the calculation result. The angle between the main shallow groove in the real-time acquisition image and the radial central axis of the artificial valve leaflet is calculated, and when the angle is greater than 5°, the deflection angle of the galvanometer scanning system is adjusted to correct the scanning direction. The second data acquisition unit can specifically use a high-speed camera, which is matched with the femtosecond laser direct writing to realize closed-loop control in the processing process. Specifically, when the femtosecond laser direct writing is started according to the texture path to open the biomimetic microtexture on the surface of the artificial valve leaflet, the high-speed camera captures the processing region image in real time, the curvature change of the artificial valve leaflet surface is obtained according to the real-time acquisition image, when the middle region of the artificial valve leaflet surface is convex, the deflection angle of the galvanometer scanning system is adjusted by 0.5°-1° / mm, so that the main shallow groove direction is consistent with the local blood flow streamline.

[0110] In the step E, the artificial valve leaflet with the bionic micro-texture is cleaned to remove burrs, and the machining debris can be removed by supercritical CO2 cleaning to ensure that the texture edge smoothness Ra≤0.1 μm, the pressure is 8 MPa, and the temperature is 40°C.

[0111] In the step three, the artificial valve leaflet is embedded between the first valve seat body and the second valve seat body, and is centered by the guide positioning member, and then the elastic buckle is pressed into the clamping groove to complete the locking, thereby forming a sleeve type overall structure.

[0112] In the step A, the first data acquisition unit scans the artificial valve leaflet to obtain three-dimensional point cloud data of the artificial valve leaflet, establishes a virtual space coordinate system (X, Y, Z) with the center point of the valve root area as the origin (O), and records the valve structure parameters: the wavy edge wavelength is 2-3 mm, the wave height is 0.3-0.5 mm, the thickness gradually changes from 0.3 mm at the root to 0.15 mm at the edge. The Z axis is the blood flow direction.

[0113] The artificial valve leaflet model is divided into a root area within 30% of the height of the valve seat, a middle area from 30% to 70% of the height of the valve seat, and a free edge area from 70% to 100% of the height of the valve seat, and an independent local coordinate system (X', Y', Z') is established for each area, and the virtual space coordinates are mapped to the local coordinate system through coordinate conversion parameters.

[0114] The mapping from the virtual space to the local space is realized through the following coordinate conversion parameters:

[0115] Root area: Since the texture of the main shallow groove required in this area is deep and wide, in order to facilitate the clarity of the bionic micro-texture, the Z axis scaling factor is 1.2, the X / Y axis scaling factor is 1.0, and the rotation around the Z axis is 0°;

[0116] Middle area: Since the curved surface of this area is warped, in order to avoid bending when the bionic micro-texture is opened, the Z axis scaling factor is 1.0, the X / Y axis scaling factor is 0.9, and the rotation around the X axis is 3° to correct the curved surface warping, thereby preventing the bionic micro-texture from being distorted;

[0117] Free edge area: the Z axis scaling factor is 0.8, the X / Y axis scaling factor is 0.8, the rotation around the X axis is 5°, and the rotation around the Y axis is 2°, so that the local coordinate system matches the wavy edge curvature.

[0118] The rotation angle of the local coordinate system is corrected through the following formula: θ = θ0 + 0.01 × H, θ0 is the initial rotation angle, for example, the middle area is 3°, and H is the height from the valve seat, when H = 10 mm, the middle area rotates θ = 3.1° around the X axis.

[0119] Based on the local coordinate system, the parameters of the multi-stage gradient shallow groove structure are set as follows: the root region has a main shallow groove with a depth of 50 μm, a width of 120 μm and a pitch of 200 μm; the middle region has a shallow groove with a depth of 30-40 μm, a width of 100 μm and a pitch of 180 μm; and the free edge region has a shallow groove with a depth of 20 μm, a width of 80 μm and a pitch of 150 μm.

[0120] In the step B,

[0121] The parameters of the femtosecond laser direct writing are configured as follows: a wavelength of 1064 nm, a pulse width of 50 fs, a repetition frequency of 50-200 kHz, a positioning accuracy of a three-dimensional piezoelectric translation stage of ±0.05 μm, and a galvanometer scanning range of 30 mm×30 mm.

[0122] In the step C, based on the artificial leaflet model of the local coordinate system in the step A, an initial texture path is generated: the main shallow groove extends along the blood flow direction and has an angle of ≤5° with the radial mid-axis of the leaflet, and the secondary shallow groove is perpendicular to the main shallow groove.

[0123] In the step D, the initial texture path of the femtosecond laser direct writing is modified according to the real-time opened biomimetic microtexture, and the modification can include:

[0124] The second data acquisition unit acquires an image of the processing region, and obtains a current processing point coordinate (Px, Py, Pz) and a surface normal vector (Nx, Ny, Nz);

[0125] A spatial attenuation factor Atten S is calculated:

[0126] Atten S=RadialAtten((Px-Cx) / R,K1)

[0127] wherein Px is the coordinate of the current carving point, (Cx, Cy, Cz) is the center coordinate of the region, R is the radius of the region, K1 is the curvature index, the greater the value, the faster the attenuation, RadialAtten(x, y) is a core attenuation function, RadialAtten(x, y)=pow(1-saturate(dot(x, x)), y); the curvature index of the root region is 2.0, the curvature index of the middle region is 1.5, and the curvature index of the free edge region is 1.0.

[0128] dot(x, x) is the dot product of the distance vector, which equals the square of the vector length: x is the normalized distance vector, which is the direction vector from the region center to the processing point, scaled to a length between 0 and 1. For a two-dimensional vector x = (a, b), dot(x, x) = a² + b²; for a three-dimensional vector x = (a, b, c), dot(x, x) = a² + b² + c². For example, if the actual distance from the processing point to the region center is 5 mm and the region radius is 10 mm, then the normalized distance vector x has a length of 5 / 10 = 0.5, and a three-dimensional vector can be represented as (0.3, 0.4, 0), with a length of .

[0129] Saturate() is a saturation function that limits the value range, specifically, it forces the input value to be between 0 and 1, avoiding the influence of abnormal values on subsequent calculations. Its calculation rule is: if the input value ≥ 1, return 1; if the input value ≤ 0, return 0; otherwise, return the input value directly. Saturate() is used to ensure that the result is strictly between 0 and 1.

[0130] 1 - saturate(dot(x, x)) is the calculation of the attenuation base, which represents the linear attenuation base from 1 at the center to 0 at the edge by subtracting the "saturated distance square" from 1. For example:

[0131] Center point: x length = 0, dot(x, x) = 0, saturate(0) = 0, 1 - 0 = 1, no attenuation at this time;

[0132] Edge point: x length = 1, dot(x, x) = 1, saturate(1) = 1, 1 - 1 = 0, complete attenuation at this time;

[0133] Intermediate point: x length = 0.5, dot(x, x) = 0.25, saturate(0.25) = 0.25, 1 - 0.25 = 0.75, the attenuation base is 0.75 at this time.

[0134] pow(... y) is a power function used to control the attenuation rate, y is the attenuation exponent, used to control the speed of attenuation, the larger y is, the faster the attenuation.

[0135] Calculation logic: pow(a, b) represents a raised to the power of b, here a = 1 - saturate(dot(x, x)), b = y.

[0136] For example, a = 0.75:

[0137] y = 1, linear attenuation at this time: pow(0.75, 1) = 0.75, slow attenuation;

[0138] y=2, which is square attenuation: pow(0.75, 2) = 0.56, attenuation is faster;

[0139] y=3, which is cubic attenuation: pow(0.75, 3) = 0.42, attenuation is even faster.

[0140] Here, take the region center as C, the processing point as P, the region radius as R, the attenuation exponent y=2, and take the calculation of the spatial attenuation factor Atten S as an example for illustration,

[0141] Calculate the normalized distance vector x

[0142] Actual distance vector: d = P - C, such as (3mm, 4mm, 0), the length is 5mm;

[0143] Normalized vector: x = d / R, if R=10mm, then x=(0.3, 0.4, 0), the length is 0.5.

[0144] Calculate dot(x, x)

[0145] dot(x, x) = 0.3² + 0.4² + 0² = 0.09 + 0.16 = 0.25.

[0146] Calculate saturate(dot(x, x))

[0147] 0.25 is between 0~1, saturate(dot(x, x))=0.25.

[0148] Calculate 1 - saturate(...)

[0149] 1 - 0.25 = 0.75.

[0150] Calculate pow(0.75, y)

[0151] y=2, pow(0.75, 2) = 0.5625, the final spatial attenuation factor Atten S is 0.5625.

[0152] Calculate the directional attenuation factor Atten_D:

[0153] Atten_D = RadialAtten( dot(N, F), K2 )

[0154] Wherein, N is the normal vector of the processing point, F is the preset blood flow direction vector, that is, along the Z axis, K2 is the direction index, the value is 1.2, dot(N, F) is the vector dot product, which represents the direction coincidence degree, the range is -1~1, 1 represents complete coincidence, 0 represents perpendicular, and -1 represents complete opposite; the preset blood flow direction vector F is dynamically adjusted along with the convexity of the curved surface in the middle region, and when the convexity of the curved surface is >0.1mm, F deflects 0.5° / mm along the X axis;

[0155] The laser energy E=5μJ×Atten_S×Atten_D and the galvanometer deflection angle θ=0.5° / mm×convexity of the curved surface are adjusted according to Atten_S and Atten_D, so as to ensure that the angle between the main shallow groove and the local blood flow streamline is ≤3°; the convexity of the curved surface depends on the offline modeling before processing and the real-time feedback during processing, specifically, before the bionic microtexture is opened on the surface of the artificial valve leaflet, the convexity of the curved surface is obtained according to the artificial valve leaflet model; when the bionic microtexture is opened on the surface of the artificial valve leaflet, the actual Z coordinate height of the processing point is obtained in real time, compared with the artificial valve leaflet model, the convexity deviation of the curved surface is calculated, if the deviation ≤5μm, the preset convexity of the curved surface is directly used, if the deviation >5μm, the convexity of the curved surface is recalculated, the measured convexity of the curved surface=theoretical convexity+ΔZ / L, L is the sampling interval. The laser energy adjustment range is 1-5μJ, and the scanning speed linearly increases with the energy: when E=5μJ, the speed is 50mm / s, and when E=1μJ, the speed is 200mm / s.

[0156] When the secondary shallow groove of the bionic microtexture is processed, the galvanometer is rotated by 90°, and the energy is adjusted according to the attenuation coefficient algorithm of the initial texture path of the femtosecond laser direct writing in step D, and the cross region energy is reduced by 10% to avoid over-deepening.

[0157] A sleeve type structure artificial heart valve and a preparation method thereof:

[0158] By means of bionic microtexture and blood flow optimization design, the risk of thrombosis is reduced, and the long-term anticoagulant therapy requirement of the patient is reduced; a high polymer polymer material is used, combined with thickness gradient and wave-shaped buffer structure, to resist calcification, wear and degradation, and prolong the service life;

[0159] The wave-shaped staggered opposite valve leaflets increase the contact area by 40%, and significantly reduce the regurgitation rate; the elastic deformation can absorb the diastolic blood flow impact force, reduce the collision damage of the valve leaflet edge, and reduce the vortex dead zone of thrombosis;

[0160] The region with multi-stage gradient micro-texture: the root region is a deep main shallow groove to enhance blood flow guidance and reduce the impact of vortex on the root; the middle region is a main shallow groove with a groove depth of 30-40 μm and a slight deflection along the curved surface, ensuring smooth blood flow along the texture; the free edge region is a relatively shallow main shallow groove with a groove depth of 20 μm, which reduces the influence on the sealing of the edge and maintains the edge antithrombotic performance;

[0161] The valve seat is injection molded, the valve leaflet is integrally prepared by molding and femtosecond laser processing, and the embedded assembly avoids the symmetry error caused by manual sewing, improves the production efficiency, and is convenient for standardized adaptation of valve leaflets with different thicknesses, simplifies the preparation process and assembly precision;

[0162] The valve seat is made of medical implant-grade PEEK material, and the valve leaflet is made of biocompatible polymer, and the surface smoothness is ensured by supercritical CO2 cleaning, which reduces the risk of inflammation and calcification and shortens the postoperative anticoagulation time.

[0163] The above is a description of the preferred embodiments of the present application, which can help those skilled in the art to more fully understand the technical solutions of the present application. However, these embodiments are only illustrative and cannot be construed as limiting the specific embodiments of the present application to these illustrative embodiments. For those skilled in the art to which the present application belongs, without departing from the concept of the present application, a number of simple deductions and transformations can be made, which should be regarded as falling within the scope of protection of the present application.

Claims

1. A sleeve-type structural prosthetic heart valve, characterized in that, The application relates to a sleeve type structure artificial heart valve, which comprises a first valve seat body, a second valve seat body and artificial valve leaves. The artificial valve leaves are composed of three equal and same valve leaves and one covering film, the free end edges of the three valve leaves are in a wave shape and the thickness gradually changes from the root to the edge. The surface of the artificial valve leaves and / or the inner wall of the first valve seat body is provided with a bionic microtexture; the bionic microtexture comprises parallel main shallow grooves extending along the opening and closing direction of the valve leaves; the cross section of the main shallow grooves is in a U shape; the bionic microtexture adopts a multi-stage gradient shallow groove structure, and the depth of the bionic microtexture gradually decreases from the root to the edge of the valve leaves.

2. The sleeve-type structural prosthetic heart valve of claim 1, wherein, The lower parts of the first valve seat body and the second valve seat body are in a smooth arc shape, and the upper parts are provided with three convex column peaks which are uniformly distributed in the circumferential direction.

3. The sleeve-type structural prosthetic heart valve of claim 1, wherein, The wavelength of the wave-shaped free edge of the three valve leaves is 2-3 mm, the wave height is 0.3-0.5 mm, and the edge wave peaks and wave valleys of adjacent valve leaves are distributed in a staggered mode.

4. The sleeve-type structural prosthetic heart valve of claim 1, wherein, The thickness of the root of the artificial valve leaves is 2 times the thickness of the edge.

5. The sleeve-type structural prosthetic heart valve of claim 1, wherein, The width of the main shallow groove is 80-120 mu m, the depth is 20-50 mu m, and the interval between two adjacent main shallow grooves is 150-200 mu m.

6. The sleeve-type structural prosthetic heart valve of claim 1, wherein, The bionic microtexture comprises parallel secondary shallow grooves which are perpendicular to the main shallow grooves.

7. The sleeve-type structural prosthetic heart valve of claim 1, wherein, The main shallow grooves and the secondary shallow grooves of the bionic microtexture form a grid-shaped texture, and the cross section of the secondary shallow grooves is in a U shape.

8. The sleeve-type structural prosthetic heart valve of claim 6, wherein, The width of the secondary shallow groove is 30-50 mu m, the depth is 10-20 mu m, and the interval between two adjacent main shallow grooves is 50-100 mu m.

9. A method of manufacturing a sleeve-type structural prosthetic heart valve for use in the prosthetic heart valve of any one of claims 1-8, the method comprising: providing a plurality of leaflets; providing a plurality of commissure posts; providing a plurality of coaptation assist members; and coupling the plurality of commissure posts to the plurality of leaflets and the plurality of coaptation assist members. The application further discloses a preparation method of the sleeve type structure artificial heart valve. Step one: the first valve seat body and the second valve seat body are respectively prepared through injection molding; Step two: the artificial valve leaves composed of three equal valve leaves and one covering film are prepared through mold pressing, and the bionic microtexture is opened on the surface of the artificial valve leaves through femtosecond laser direct writing; Step three: the artificial valve leaves are embedded between the first valve seat body and the second valve seat body to form a sleeve type overall structure, thereby obtaining the sleeve type structure artificial heart valve.

10. The method of claim 9, wherein the sleeve-type structural prosthetic heart valve is prepared by the steps of: The bionic microtexture is opened on the surface of the artificial valve leaves through femtosecond laser direct writing, and the method comprises the following steps. Step A: the artificial valve leaves are pretreated and three-dimensional modeling is carried out according to the artificial valve leaves, thereby obtaining an artificial valve leaf model; Step B: femtosecond laser direct writing parameters are configured according to the artificial valve leaf model; Step C: an initial texture path of femtosecond laser direct writing is generated based on the artificial valve leaf model; Step D: the bionic microtexture is opened on the surface of the artificial valve leaves according to the texture path, the initial texture path of femtosecond laser direct writing is modified according to the bionic microtexture which is opened in real time, and the bionic microtexture is opened on the surface of the artificial valve leaves according to the modified texture path of femtosecond laser direct writing; Step E: the artificial valve leaves on which the bionic microtexture is opened are cleaned, thereby obtaining target artificial valve leaves.

Images