An interventional polymer heart valve integrated injection molding method

Abstract

This invention relates to a heart valve manufacturing technology, specifically providing a method for integral injection molding of an interventional polymer heart valve, comprising the following steps: S1: providing a stent and a mold, wherein the stent has multiple grid units composed of support rods, and the grid units have multiple positioning mating parts at the connection points of the support rods; the mold includes a main mold and a support mold; S2: setting the support mold at the positioning mating parts; setting the main mold at the non-positioning mating parts of the stent, and the main mold and the stent are spaced apart; S3: injecting molding material, flowing to the space to encapsulate the stent, forming a valve frame with the stent as its interior. The innovation of this invention lies in designing corresponding features at the positioning mating parts of the stent grid, controlling deformation by constraining each grid positioning mating part, thereby achieving the goal of manufacturing interventional polymer heart valves through integral injection molding.

Description

Technical Field

[0001] This invention relates to a technique for preparing heart valves, specifically to an interventional method for integral injection molding of polymer heart valves. Background Technology

[0002] Valvular heart disease is a common type of structural heart disease, and heart valve replacement through surgery or minimally invasive interventional procedures is a common treatment. Currently, the most commonly used valves in clinical practice are mechanical valves and bioprosthetic valves. Both types have their advantages and disadvantages. Mechanical valves are prone to causing blood clots, requiring patients to take anticoagulants for life, but they have a long lifespan. Bioprosthetic valves do not require long-term anticoagulant medication, but they are prone to tissue calcification and have a shorter lifespan.

[0003] Polymer valves combine the advantages of both biological and mechanical valves, making them a hot topic in future valve development. Current manufacturing methods for polymer valves include dip coating and injection molding.

[0004] Dip-coating molding involves a slow drying process of the polymer solution, and molding a single valve can take several hours, resulting in low efficiency. The existing dip-coating molding process for an interventional polymeric heart valve (WO2020190855A1) is as follows: the valve leaflets are molded by repeatedly dipping them in the polymer solution, then the molded leaflets are trimmed, and then assembled with a stent coated with polymer material. A second dip-coating process is then used to bond the leaflets and stent together, ultimately forming the interventional polymeric heart valve. First, this method requires multiple dip-coatings in the polymer solution and the removal of excess polymer material. This removal process can easily lead to defects such as irregular gaps on the free edges of the leaflets, affecting the valve's fatigue life. Second, because the polymer solution is highly fluid, it is difficult to control the molding thickness in a specific area during dip-coating. For example, at the junction of the leaflet root and the stent, tensile stress is generated during leaflet movement, which can easily cause tearing at the junction. Therefore, an appropriate amount of polymer material needs to be added to this area to increase strength and resist tearing. However, it is difficult to control the flow direction of a flowing polymer solution during dip-coating, which is not conducive to adding polymer material individually to a designated area. Furthermore, due to the easy flow of polymer solutions, it is difficult to control the uniformity of the polymer material thickness attached to the stent during dip-coating. Too thick a polymer material on the stent affects stent contraction, while too thin a material weakens the connection with the stent, affecting valve performance. Finally, the leaflet material of polymer valves is usually harder than that of biological valves. When the leaflet thickness of the same polymer valve is inconsistent, with a difference exceeding 0.02 mm, pulsatile flow simulation in vivo environment tests revealed asynchronous leaflet opening and closing, affecting the performance of the polymer heart valve. Dip-coating makes it difficult to control the leaflet thickness uniformity within 0.02 mm.

[0005] Injection molding can complete the molding of a single valve within minutes, and its efficiency is far superior to dip-coating. Injection molding the leaflets, frame, and stent of a polymer valve into a single unit is currently the most common method. Polymer valves include surgical valves used in surgical procedures and interventional valves used in minimally invasive transcatheter interventional procedures. Polymer surgical valves typically do not require radial contraction, and their internal stents or inserts can be designed with high strength, making them less prone to deformation during one-piece injection molding. However, unlike polymer surgical valves, the stents of interventional polymer heart valves require contraction and deformation to enter the catheter. This characteristic makes the stent susceptible to deformation under external forces. Especially when the stent of an interventional polymer heart valve is placed in a mold for one-piece injection molding, the stent is easily deformed by the injection pressure, leading to abnormal relative positions between the leaflets and stent, affecting the performance of the interventional polymer heart valve. This is one of the reasons why it is currently difficult to integrally injection mold interventional polymer heart valves. Therefore, developing a novel interventional polymeric heart valve and its molding method to solve the problems existing in the current technology and improve production efficiency is of great clinical significance. Summary of the Invention

[0006] To address the problems existing in the above-mentioned technologies, the present invention provides a technology that designs corresponding features at the position of the stent grid positioning mating part, controls deformation by constraining each grid positioning mating part, and enables the interventional polymer heart valve to be manufactured by integral injection molding.

[0007] This invention provides a method for integral injection molding of an interventional polymer heart valve, comprising the following steps:

[0008] S1: The bracket has multiple grid units, and each grid unit has a positioning and mating part; a support mold is provided at the positioning and mating part; the bracket has a main body mold at a position other than the positioning and mating part, and the main body mold is spaced apart from the bracket;

[0009] S2: A support mold is provided at the positioning and mating part; a main mold is provided at a non-positioning and mating part position of the bracket, and the main mold is spaced apart from the bracket;

[0010] S3: Injection-molded material flows to the interval to wrap the support, forming a petal frame with an internal support.

[0011] Preferably, the main mold has an L-shaped channel with an injection hole, the main mold has a sidewall, and the molding material coming out of the injection hole diffuses in a circular manner along the sidewall.

[0012] Preferably, the support is a metal support, which is arranged around the integral leaflet, and the molding material used for injection molding is a polymer material.

[0013] Preferably, the metal bracket has four layers of grid units, and each grid unit has one or more of a top positioning mating part, a bottom positioning mating part, a left positioning mating part, and a right positioning mating part; the four sets of grid units are arranged from top to bottom as a first layer of grid units, a second layer of grid units, a third layer of grid units, and a fourth layer of grid units.

[0014] Preferably, the supporting mold is a supporting rod, which is supported and fixed to the top positioning mating part and the left and right positioning mating parts on both sides of the first layer grid unit; or, the supporting mold is a feature part of the main body mold, which is supported and fixed to the left and right positioning mating parts of the second layer grid unit.

[0015] Preferably, the positioning mating part forms a transition feature, which has an arc-shaped protrusion structure, that is, it forms a distance L1 and a distance L2 in the left and right X direction. The distance L2 is the distance between the start and end points of the arc-shaped protrusion structure, and L1 is the maximum distance between the arc-shaped protrusion structures; the distance L is greater than the distance L2.

[0016] Preferably, the transition feature is an elliptical transition arc, or an arc transition arc, or a triangular transition arc.

[0017] Preferably, the main mold of the first layer of grid unit has three feeding positions distributed at 120°.

[0018] The interventional polymeric heart valve, manufactured by the integral injection molding method of the present invention, comprises:

[0019] A valve frame has an outer valve frame membrane and a support structure. The outer valve frame membrane wraps around the outside of the support structure, which has multiple grid units. Each grid unit has a positioning and mating part. The support structure has four layers of grid units, each grid unit having one or more of a top positioning and mating part, a bottom positioning and mating part, a left side positioning and mating part, and a right side positioning and mating part. The four sets of grid units are, from top to bottom, a first layer of grid units, a second layer of grid units, a third layer of grid units, and a fourth layer of grid units.

[0020] An integral leaflet is located within the internal space of the support.

[0021] Preferably, the positioning mating part forms a transition feature, which has an arc-shaped protrusion structure, that is, it forms a distance L1 and a distance L2 in the left and right X direction. The distance L2 is the distance between the start and end points of the arc-shaped protrusion structure, and L1 is the maximum distance between the arc-shaped protrusion structures; the distance L is greater than the distance L2.

[0022] The transition features are elliptical transition arcs, or arcs transitioning to arcs, or triangles transitioning to arcs.

[0023] The advantages of the technical solution of the present invention are as follows:

[0024] The innovation of this invention lies in designing corresponding features at the position of the stent grid positioning and mating part, and controlling the deformation by constraining each grid positioning and mating part, so as to achieve the purpose of manufacturing interventional polymer heart valves through integral injection molding.

[0025] The basic idea of ​​this invention is to pre-embed a bracket in the injection mold and position the bracket by means of a support mold in the mold and a positioning part on the bracket, so as to cope with the deformation of the bracket caused by the impact of injection pressure.

[0026] In the preferred embodiment, the injection pressure acting on the stent is further dispersed by a side-diffusion feeding method, so that the stent is subjected to uniform stress, the degree of stent deformation is reduced, and the fatigue resistance of the high-stress area of ​​the polymer leaflet is guaranteed; thus solving the technical problem that interventional polymer heart valves cannot be prepared by injection molding.

[0027] The entire structure of the interventional polymer heart valve, including the valve frame (including the stent) and leaflets, is fabricated through a single injection molding process. This eliminates the need for trimming or other methods to remove excess material, avoiding defects such as notches and cracks caused during material removal and thus ensuring valve performance. This method of injection molding the polymer material into a precision mold not only facilitates the individual addition of polymer material in designated areas to resist tearing but also allows for easy control of the leaflet thickness and the thickness of the polymer material attached to the stent, ensuring optimal valve performance.

[0028] This invention, which completes the interventional polymer heart valve through a single injection molding process, differs from the traditional method of manually sewing the leaflets for interventional artificial biological heart valves, and also from the aforementioned (WO_2020190855_A1) method of multiple dip-coating for interventional polymer heart valves. This fundamentally improves the manufacturing efficiency of interventional artificial heart valves and makes it possible to significantly reduce the cost of using interventional artificial heart valves.

[0029] Corresponding features are designed at the positions of each grid positioning and mating part on the interventional polymeric valve stent. The mold positioning structure mates with these stent features to reduce stent deformation under injection molding pressure. This reduces the degree of misalignment between the leaflet and the stent frame; ensures the consistency of the thickness of the polymer material coating on the stent surface, thereby guaranteeing the strength of the overall leaflet-stent connection and further ensuring the valve's fatigue resistance; simultaneously ensures the consistency of valve dimensions during radial compression contraction; and ultimately ensures the compatibility of the overall structural features of the interventional heart valve with the valve product design. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the integrated valve leaflet and valve frame structure.

[0031] Figure 2 This is a magnified view of a portion of the support structure wrapped by the outer membrane of the petiole frame, used to demonstrate the petiole frame.

[0032] Figure 3 This is a magnified view of the valve frame from another angle, showing the outer membrane of the valve frame wrapping around the support.

[0033] Figure 4 This is a schematic diagram showing the valve leaflets and stent in their working order without the outer membrane of the stent covering them.

[0034] Figure 5 Is Figure 4 The diagram shows the structure after multiple molds have been set up.

[0035] Figure 6 This is a magnified structural diagram of multiple molds.

[0036] Figure 7 yes Figure 4 A structural diagram from another angle.

[0037] Figure 8 This is a magnified view of the mold and support working together.

[0038] Figure 9 This is a magnified view of the mold and support assembly from a top-down perspective.

[0039] Figure 10 yes Figure 4 A schematic diagram with the X and Y axes marked in the middle.

[0040] Figure 11 yes Figure 4 A magnified structural diagram of the positioning and mating parts.

[0041] Figure 12 This is a magnified view of the second and third grid cells.

[0042] Figure 13 This is a magnified view of a portion of the support structure.

[0043] Figure 14 This is a magnified view of a local grid cell. Detailed Implementation

[0044] like Figures 1 to 3 As shown, this invention provides an interventional polymeric heart valve and its molding method. The interventional polymeric heart valve includes a valve frame and an integral leaflet 2. The valve frame has an outer valve frame membrane 3 and a support 1. The outer valve frame membrane 3 wraps around the outside of the support 1, and the support 1 has multiple grid units. Each grid unit has a positioning and fitting part, which plays a supporting and fixing role during the injection molding of the outer valve frame membrane 3. The integral leaflet 2 is located within the internal space of the support 1. The support 1, located inside the outer valve frame membrane 3, provides excellent support strength, preventing deformation of the overall valve structure. Furthermore, positioning and fitting parts are provided at multiple locations within the grid units, which cooperate with the supporting mold during injection molding, thereby improving the structural stability of the grid units and preventing deformation of the support 1 due to injection pressure.

[0045] The support 1 provides support for the integrated leaflet 2, therefore it needs to be made of a material with sufficient strength, typically metal or polymer, preferably a metal support. The metal support surrounds the integrated leaflet 2. The molding material used for the integrated leaflet 2 and the outer membrane 3 during injection molding is a polymer. This polymer can be polyether block amide (PEBA), polylactic acid (PLA), or copolymers (such as PLGA), etc., which possess biocompatibility and mechanical properties suitable for valves; further details are omitted here. Figure 4 As shown, the bracket 1 has four layers of grid units, namely, the first layer grid unit 101, the second layer grid unit 102, the third layer grid unit 103, and the fourth layer grid unit 104. The grid unit has multiple positioning mating parts, such as the top positioning mating part 1012, the bottom positioning mating part 1021, the left side positioning mating part 1031, and the right side positioning mating part 1011.

[0046] This invention provides a method for integral injection molding of an interventional polymer heart valve, comprising the following steps:

[0047] S1: A support (1) and a mold are provided, wherein the support has multiple grid units composed of support rods, and the grid units have multiple positioning mating parts (1012, 1011, 1021, 1031) at the connection of the support rods; the mold includes a main mold and a supporting mold (111-1, 1111-1, 112-1, 113-1). The main mold includes a mold for forming the leaflet 2 (not shown in the figure) and a mold for forming the outer membrane of the petiole 3 (at least including 111, 112, 113). The mold for forming the leaflet 2 and the mold for forming the outer membrane of the petiole 3 can share the same feed port, and the two are connected by the side wall of the inner diameter of the support, so the side wall of the inner diameter of the support has a layer of polymer with a certain thickness.

[0048] S2: Assemble the bracket in the mold, wherein the positioning mating part in the grid unit of the bracket matches the supporting mold of the mold and the two are in direct contact; the other spaces in the grid unit of the bracket match the main mold of the mold, but there is a gap between the two.

[0049] A support mold is provided at the positioning and mating part; such as Figure 5 As shown, the bracket 1 has main body molds 111, 112, 113 at non-positioning mating parts, and the main body molds 111, 112, 113 are spaced apart from the bracket 1;

[0050] S3: The injection molding material flows to the interval to wrap the support 1, forming a petiole with the support 1 inside and the petiole outer membrane 3 wrapped outside.

[0051] The basic idea of ​​this invention is to use the support mold of the mold to cooperate with the positioning part of the bracket 1 to position the bracket 1 and thus cope with the deformation of the bracket 1 caused by the impact of injection molding pressure.

[0052] It should be noted that the positioning and fitting part of the stent 1 is positioned by the support mold, while other positions can be set with the main mold as needed. The main mold and the stent 1 are all separated. After the polymer material is injected, it can wrap the stent 1 to form the valve outer membrane 3. Since the positioning and fitting part is supported and fixed, it plays a good role in stabilizing the support during injection molding and avoids the problem of the stent 1 being deformed by the injection pressure.

[0053] This invention focuses on how to wrap the outer membrane 3 of the valve frame 1 around the stent 1, and ensure that the stent 1 does not deform during the injection molding process. The integral leaflet 2 can be formed independently or integrally injection molded with the outer membrane 3; both are embodiments of this invention.

[0054] like Figure 5As shown, the main mold specifically includes a first-layer main mold 111, a second-layer main mold 112, and a third-layer main mold 113. Since the fourth-layer grid unit 104 experiences relatively low pressure during material injection molding, no additional support mold is needed for support and fixation. That is, during material injection molding, the process begins from the top of the first-layer grid unit 101, where the pressure is greatest, decreasing sequentially from top to bottom. Therefore, no special support mold is needed at the lower positions. It should be noted that other positions still require existing ordinary blocking-type molds, such as a main mold, to form a gap with the support 1 and deform the outer membrane 3 of the petiole surrounding the support 1.

[0055] The aforementioned support mold is designed to form a stable support by engaging the feature parts with the positioning and mating parts (which will be explained in detail below).

[0056] like Figures 4-6 As shown, the first layer main mold 111 is fitted to the inner ring of the first layer grid unit 101, the second layer main mold 112 is fitted to the second layer grid unit 102, and the third layer main mold 113 is fitted to the third layer grid unit 103.

[0057] The supporting mold is a supporting rod 111-1, which is supported and fixed to the top positioning mating part of the first layer grid unit 101. The supporting rod 111-1 at the top position is fixed together with the first layer main mold 111, while the left and right positioning mating parts are supported and fixed by the supporting rods 1111-1 independently set on both sides of the first layer main mold 111.

[0058] In other words, the support rod 111-1 or 1111-1 of the present invention can be an independent structure or integrated into the main body mold; in the following description, the support mold and the main body mold are set independently.

[0059] The positioning mating parts on both sides of the first layer grid unit 101 are characterized by a hole structure 105. Figure 10 The hole structure 105 is positioned in conjunction with the support rod 1111-1.

[0060] Specifically, the supporting mold consists of feature parts 112-1 on both sides of the second-layer main mold 112. Feature parts 112-1 are fixed to the left and right positioning mating parts of the second-layer grid unit 102. Specifically, feature parts 112-1 are positioned with the left and right positioning mating parts of the grid in the second-layer grid unit 102; simultaneously, the positioning of the bottom positioning mating part of the grid in the first-layer grid unit 101 is completed, and the positioning of the top positioning mating part of the grid in the third-layer grid unit 103 is also completed simultaneously. Only feature parts 112-1 contact the metal bracket 1, and the second-layer main mold 112 maintains a distance from the side wall 1-1 of the bracket 1. Figure 8 ), ensuring that the polymer material uniformly encapsulates the metal scaffold 1 to form the outer membrane 3 of the scaffold.

[0061] Specifically, the supporting mold is the feature part 113-1 set on both sides of the third layer main mold 113. Figure 6 The feature 113-1 matches the positioning mating parts 1031 on both sides of the support 1, completing the positioning of the left and right positioning mating parts of the third layer grid unit 103. Only the feature 113-1 contacts the support 1, and the third layer main body mold 113 maintains a distance from the side wall 1-1 of the metal support 1. Figure 8 This ensures that the polymer material uniformly encapsulates the scaffold.

[0062] The positioning and mating parts on the left and right sides of the second-layer grid unit 102 and the third-layer grid unit 103 are both inner protrusions formed inside the perimeter of the grid unit.

[0063] The interaction between the feature portion and the positioning mating portion is, for example, a protrusion and a recess, or the contact and abutment of two parts. For example, feature portion 112-1 and feature portion 113-1 are protruding structures that fit with the shape of the positioning mating portion.

[0064] In some embodiments, a transition feature is formed at the positioning and mating portion of the grid cell, and the transition feature has an arc-shaped protrusion structure, such as... Figure 10 and Figure 11 As shown, distances L1 and L2 are formed in the left and right X directions. L2 is the distance between the start and end points of the arc-shaped protrusion, and L1 is the maximum distance between the arc-shaped protrusions; distance L1 is greater than distance L2. This arc-shaped protrusion structure is formed at the positioning and mating part of the first-layer grid unit 101, specifically forming an arc-to-arc transition structure. In the X-axis direction, the connection distance between the two arcs is L1 > L2, thus constraining the positioning and mating part of the first-layer grid unit 101 in the aforementioned X and Y-axis directions; that is, the structural strength is improved through this structural design.

[0065] Specifically, such as Figure 11As shown, the arc-shaped protrusion structure is provided at the top positioning and fitting part 1012 as a transition feature. On the one hand, it facilitates the feature fitting with the support mold; and on the other hand, when the bracket 1 is subjected to external force, the force is transmitted to the positioning and fitting part through the arc-shaped protrusion structure. The pressure is buffered by the deformation of the arc-shaped protrusion structure in the lateral direction (X) or longitudinal direction (Y) at the positioning and fitting part. That is, the support and fixing effect of the support mold is further enhanced by the arc-shaped protrusion structure.

[0066] In some embodiments, such as Figure 12 As shown, features 1021 are symmetrically arranged on the left and right sides of the positioning and mating parts of the second-layer grid unit 102. Features 1021 are transition features with arc-shaped protrusion structures. Features 1021 can simultaneously constrain the left and right positioning and mating parts and the bottom positioning and mating parts of the first-layer grid unit 101, as well as the top positioning and mating parts of the third-layer grid unit 103 along the X and Y axes. Because in this structure, the arc-shaped protrusion structure in an extended manner increases the structural strength and makes it less prone to deformation, that is, the convex-concave transition feature achieves the purpose of constraint. More specifically, an arc-shaped protrusion structure with an inward concave shape is formed at the connection position of the support. Through this arc-shaped protrusion structure with an inward concave shape, the structural strength is strengthened. When subjected to forces from the X-axis or Y-axis direction, this arc-shaped protrusion structure can play a buffering and reinforcing role, thereby improving the structural strength.

[0067] In some embodiments, the left and right positioning mating parts of the third layer grid unit 103 are symmetrically provided with features 1031, which are contained within the third layer grid unit 103. Features 1031 are transition features with arc-shaped protrusions. Such a structure can simultaneously constrain the left and right positioning mating parts of the third layer grid unit 103 and the lower positioning mating part of the second layer grid unit 102 along the X and Y axes as described above.

[0068] In some embodiments, the arcuate protrusion in the transition feature is an elliptical arcuate structure or a circular arcuate structure.

[0069] In some embodiments, a feeding position 101-1 is provided on the first layer main body mold 111 located on the first layer grid unit 101.

[0070] In some embodiments, the main mold has an L-shaped channel inside, such as... Figure 14As shown, taking the first layer main mold 111 as an example, its L-shaped channel 1116 opens from the top end face 1117 of the first layer main mold 111, first extends a certain distance to the bottom end face 1118 of the first layer main mold 111, and then extends a certain distance to the side wall 111-3 of the first layer main mold 111. Finally, an injection hole 111-2 is opened on the side wall 111-3 of the first layer main mold 111, which is used to send the injection material at the feeding position 101-1 into the gap between the main mold and the leaf 2.

[0071] In some embodiments, molding material is injected into the feeding position 101-1 in the middle of the first layer of grid unit 101 above the support 1. The feeding position 101-1 corresponds to the high stress area of ​​the leaflet 2. During integral injection molding, the injection pressure loss in the high stress area of ​​the leaflet 2 is small.

[0072] Furthermore, the injection pressure acting on the stent is dispersed by a side-diffusion feeding method, so that the stent is subjected to uniform stress, reducing the degree of stent deformation, while ensuring the fatigue resistance of the high-stress area of ​​the polymer leaflet; thus solving the technical problem that interventional polymer heart valves cannot be prepared by injection molding.

[0073] like Figure 4 Three feeding positions 101-1 at a 120-degree angle are set at the center of the first layer grid unit 101. By setting an L-shaped channel on the main mold 111, the polymer material enters the mold cavity from the L-shaped channel and extends along the side wall 111-3 of the mold 111 during integral injection molding. Figure 3 Circular diffusion. During one-piece injection molding, the polymer material diffuses in a circular pattern along 111-3. At this time, the injection pressure mainly acts on the inner sidewall 1-1 of the support. Figure 5 Since the positioning and mating parts of the first layer grid unit 101, the second layer grid unit 102, and the third layer grid unit 103 are fixed, the degree of deformation of the bracket is reduced.

[0074] Stress changes of polymer leaflet 2 during opening and closing ( Figure 7 From the positioning mating part A on the first layer grid unit 101 to the left and right positioning mating parts B and C on the third layer grid unit 103, the stress gradually decreases from large to small.

[0075] The selection of the feeding position 101-1 is based on the following reasons: Feeding position 101-1 is close to the high-stress area of ​​the leaflet 2. During integral injection molding, the injection pressure loss in the high-stress area of ​​the leaflet 2 is small, avoiding defects such as polymer material weld lines, bubbles, and missing polymer material in the high-stress area. This ensures a high density of the material in the high-stress area, thereby guaranteeing the connection strength between the polymer material in the high-stress area and the support 1, and further ensuring the fatigue resistance of the high-stress area. During operation, the high-stress area of ​​the polymer valve bears high stress, and the polymer layer in the high-stress area is prone to friction and wear with the support. Therefore, it is necessary to ensure the injection density of the polymer layer material in the high-stress area. During feeding, the polymer material density is more uniform near the feed inlet, and defects such as bubbles are more likely to appear in locations further away from the feed inlet. Therefore, this invention sets the feed inlet close to the high-stress area to ensure uniform injection density of the polymer layer material in the high-stress area, thus improving the service life of the valve.

[0076] In some embodiments, the main mold 111 has an L-shaped channel with an injection hole 111-2, and the main molds 111, 112, and 113 have sidewalls 111-3. The molding material coming out of the injection hole 111-2 diffuses in a circular manner along the sidewall.

[0077] Although specific embodiments have been described above, these embodiments are not intended to limit the scope of the invention, even when only a single embodiment is described with respect to a particular feature. The feature examples provided in this disclosure are intended to be illustrative and not limiting, unless otherwise stated. In practice, one or more technical features of the dependent claims may be combined with the technical features of the independent claims as needed and where technically feasible, and the technical features from the respective independent claims may be combined in any suitable manner rather than solely by the specific combinations listed in the claims.

[0078] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A method for integral injection molding of an interventional polymer heart valve, characterized in that, Includes the following steps: S1: A bracket and a mold are provided, wherein the bracket has multiple grid units composed of support rods, and the grid units have multiple positioning and mating parts at the connection of the support rods; the mold includes a main mold and a supporting mold; the main mold has an L-shaped channel with an injection hole, and the main mold has a side wall, and the molding material coming out of the injection hole diffuses in a circular manner along the side wall; the main mold includes a mold for forming petals and a mold for forming the outer membrane of the petal frame; the L-shaped channel is opened from the top end face of the main mold, extends a certain distance to the bottom end face of the main mold, and then extends a certain distance to the side wall of the main mold, finally opening an injection hole in the side wall of the main mold to feed the injection material at the feeding position into the gap between the main mold and the petals; S2: A support mold is provided at the positioning and mating part; a main mold is provided at a non-positioning and mating part position of the bracket, and the main mold is spaced apart from the bracket; S3: Injection-molded material flows to the interval to wrap the support, forming a petal frame with an internal support.

2. The method for integral injection molding of interventional polymer heart valves according to claim 1, characterized in that, The support is a metal support, which is arranged around an integral leaflet, and the molding material used for injection molding is a polymer material.

3. The method for integral injection molding of interventional polymer heart valves according to claim 2, characterized in that, The metal bracket has four layers of grid units, and each grid unit has one or more of the following: a top positioning fit part, a bottom positioning fit part, a left positioning fit part, and a right positioning fit part; the four sets of grid units are arranged from top to bottom as the first layer grid unit, the second layer grid unit, the third layer grid unit, and the fourth layer grid unit.

4. The method for integral injection molding of interventional polymer heart valves according to claim 3, characterized in that, The supporting mold is a supporting rod, which is supported and fixed to the top positioning mating part and the left and right positioning mating parts on both sides of the first layer grid unit; or, the supporting mold is a feature part of the main body mold, which is supported and fixed to the left and right positioning mating parts of the second layer grid unit.

5. The method for integral injection molding of interventional polymer heart valves according to claim 1, characterized in that, The positioning mating part forms a transition feature, which has an arc-shaped protrusion structure, that is, it forms a distance L1 and a distance L2 in the left and right X direction. The distance L2 is the distance between the start and end points of the arc-shaped protrusion structure, and L1 is the maximum distance between the arc-shaped protrusion structures; the distance L1 is greater than the distance L2.

6. The method for integral injection molding of interventional polymer heart valves according to claim 1, characterized in that... The transition features are elliptical transition arcs, or arcs transitioning to arcs, or triangles transitioning to arcs.

7. The method for integral injection molding of interventional polymer heart valves according to claim 4, characterized in that, The main mold of the first layer of grid unit has three feeding positions distributed at 120°.

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