Design method of artificial aortic valve and artificial aortic valve

Abstract

The invention provides a design method of an artificial aortic valve and the artificial aortic valve. The artificial aortic valve comprises a valve support and three valve leaflets. And the three valve leaflets are fixed on the valve bracket. The design method comprises the following steps: forming a shape curve of the valve stent, and generating the valve stent according to the shape curve of the valve stent. Based on the shape curve of the valve stent, a parameterization method of a power equation is adopted, and free boundary curves of the Tai Chi-like shape of the three valve leaflets are formed respectively. Based on the shape curve of the valve stent and the free boundary curve corresponding to the valve leaflets, abdomen curves of the three valve leaflets are respectively formed. And according to the shape curve of the valve stent, the free boundary curves of the three valve leaflets and the abdomen curves of the three valve leaflets, generating the three valve leaflets in a closed state. The obtained artificial aortic valve is better in performance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical devices, in particular to a design method of an artificial aortic valve and an artificial aortic valve. BACKGROUND

[0002] There are mainly two treatment methods for aortic valve disease patients, namely aortic valve repair and aortic valve replacement. The aortic valve repair can only be used for patients with good leaflet elasticity, and is basically ineffective for patients with calcified valve lesions. In addition, the open chest surgery has a large incision and high risk. The aortic valve replacement has a wider indication and relatively high safety, and therefore is gradually popularized. The effect of aortic valve replacement surgery mainly depends on the performance of the artificial aortic valve. The high-molecular artificial aortic valve has good configuration plasticity, and the good configuration design can greatly improve the performance of the artificial aortic valve.

[0003] In the related art, the configuration of the high-molecular artificial aortic valve is limited to the "elliptical" configuration which imitates the shape of the natural aortic valve. However, the aortic valve with this configuration has certain deficiencies in the kinematic performance and stress performance of the valve. SUMMARY

[0004] The present application provides a design method of an artificial aortic valve and an artificial aortic valve. The performance of the artificial aortic valve obtained by the design method is better.

[0005] The present application provides a design method of an artificial aortic valve, the artificial aortic valve comprising a valve stent and three leaflets; the three leaflets are fixed to the valve stent; the design method comprises: forming a shape curve of the valve stent, and generating the valve stent according to the shape curve of the valve stent; forming free boundary curves of the three leaflets in the shape of a Tai Chi according to the shape curve of the valve stent by using a parameterization method of a power equation; forming abdominal curves of the three leaflets based on the shape curve of the valve stent and the corresponding free boundary curves of the leaflets; generating the three leaflets in a closed state according to the shape curve of the valve stent, the free boundary curves of the three leaflets, and the abdominal curves of the three leaflets.

[0006] Further, the shape curve comprises a stent boundary curve and a circular curve; the forming of the shape curve of the valve stent comprises: establishing a space rectangular coordinate system with an x-axis, a y-axis, and a z-axis; Using the origin of the spatial rectangular coordinate system as the center, the circular curve is formed according to the first preset formula; According to the second preset formula, each point on the circumference of the circular curve is mapped to a different height to form the support boundary curve.

[0007] Furthermore, the first preset formula is: in, The coordinates of the points on the circular curve along the x-axis are represented. The coordinates of a point on the circular curve along the y-axis are represented. The radius of the circular curve is represented by [the symbol]. It is determined based on the radius of the aortic valve annulus in the human body.

[0008] Furthermore, the second preset formula is: in, This represents the coordinate value of a point on the boundary curve of the support along the z-axis. This represents the angle between each point on the circumference of the circular curve and the positive x-axis; This indicates the height of the lowest point of the valve stent; This indicates the height of the highest point of the valve stent; This indicates the degree of curvature of the boundary curve of the support.

[0009] Furthermore, the height of the lowest point of the valve stent The height of the lowest point of the valve stent is determined according to the suturing technique used to fabricate the artificial aortic valve. Less than or equal to 3mm and greater than or equal to 1mm; and / or The height of the highest point of the valve stent Determined based on the height of the aortic sinus in the human body; and / or The curvature of the support boundary curve Less than or equal to 1.4 and greater than or equal to 0.6.

[0010] Furthermore, based on the shape curve of the valve stent, a power-law equation parameterization method is used to form the free boundary curves of the three leaflets in a tai chi-like shape, including: Based on the shape curve of the valve stent, a power equation parameterization method is used to form the free boundary curve of a Taiji-like shape of one of the three leaflets. Rotating the free boundary curve of the leaflet in the two opposite directions by 120° respectively with the z-axis as the rotation axis to obtain the free boundary curves of the other two leaflets in the three leaflets.

[0011] Further, the stent boundary curve of the valve stent is as a fixed boundary curve of the leaflet; and based on the shape curve of the valve stent, a parameterization method of a power equation is adopted to form the free boundary curve of one of the three leaflets in a taiji-like shape, including: based on the shape curve of the valve stent, a third preset formula is adopted to form the free boundary curve of one of the three leaflets in the area of , and a fourth preset formula is adopted to form the free boundary curve of one of the three leaflets in the area of ; wherein, the third preset formula is: the fourth preset formula is: and the relationship between wherein, represents a coordinate value of a point on the free boundary curve along the x-axis direction; represents a coordinate value of a point on the free boundary curve along the y-axis direction; ; ; represents a radius of the circle curve; represents a shortest distance between the free boundary curve and the z-axis in the horizontal plane; represents a maximum distance between a line connecting a highest point of the fixed boundary curve and a center of the circle and an arc of the free boundary curve.

[0012] Further, the radius of the circle curve is determined according to the radius of the aortic valve annulus in the human body; and / or the shortest distance between the free boundary curve and the z-axis in the horizontal plane is less than or equal to 0.5 mm and greater than or equal to 0.1 mm; and / or the maximum distance between the line connecting the highest point of the fixed boundary curve and the center of the circle and the arc of the free boundary curve is less than or equal to 1.4 mm and greater than or equal to 0.4 mm.

[0013] ​Further, before the free boundary curve of the one of the three leaflets is rotated by 120° in the opposite direction respectively with the z-axis as the rotation axis to obtain the free boundary curve of the other two of the three leaflets, the design method further comprises: performing smoothing processing on the free boundary curve of the leaflet in the interval according to a fifth preset formula to form a smoothed curve in the interval; the fifth preset formula is: wherein, a point when is determined according to the third preset formula and the fourth preset formula, and the coordinates of the point are marked as ; represents the coordinate value of a point on the smoothed curve along the x-axis direction; represents the coordinate value of a point on the smoothed curve along the y-axis direction.

[0014] Further, the forming of the belly curve of each of the three leaflets based on the shape curve of the valve stent and the free boundary curve corresponding to the leaflet respectively comprises: forming the belly curve of one of the three leaflets according to a sixth preset formula based on the shape curve of the valve stent and the free boundary curve corresponding to the leaflet; the sixth preset formula is: wherein, represents the coordinate value of a point on the belly curve along the z-axis direction; represents the coordinate value of a point on the belly curve along the x-axis direction; represents the highest height of the belly curve, ; represents the height of the lowest point of the valve stent; represents the height of the highest point of the valve stent; represents the radius of the circular curve; represents the shortest distance between the free boundary curve and the z-axis in the horizontal plane; represents the bending degree of the belly curve; rotating the belly curve of the one of the three leaflets by 120° in the opposite direction respectively with the z-axis as the rotation axis to obtain the belly curve of the other two of the three leaflets.

[0015] Further, the height of the lowest point of the valve stent determined according to the sewing method of the artificial aortic valve; wherein the height of the lowest point of the valve support is less than or equal to 3 mm and greater than or equal to 1 mm; and / or the height of the highest point of the valve support determined according to the height of the aortic sinus in the human body; and / or the radius of the circle curve determined according to the radius of the aortic valve ring in the human body; and / or the shortest distance between the free boundary curve and the horizontal plane of the z-axis is less than or equal to 0.5 mm and greater than or equal to 0.1 mm; and / or the degree of bending of the abdominal curve is less than or equal to 1.5 and greater than or equal to 0.9.

[0016] The present application provides an artificial aortic valve, which comprises a valve support and three valve leaves fixed to the valve support; the artificial aortic valve is designed according to the design method of the artificial aortic valve as in any one of the above embodiments.

[0017] The present application provides an artificial aortic valve, which comprises a valve support and three valve leaves fixed to the valve support and arranged in rotational symmetry around the central axis of the valve support. The three valve leaves comprise a closed state and an open state; when the three valve leaves are in the closed state, the three valve leaves are close to the central axis of the valve support; when the three valve leaves are in the open state, the three valve leaves are away from the central axis of the valve support. Each of the valve leaves comprises a free boundary curve; the free boundary curve of the valve leaf is the shape curve of the top end of the valve leaf when the three valve leaves are in the closed state; wherein the free boundary curve is in a shape similar to a Tai Chi.

[0018] Further, the valve support comprises a support base and a support top, the support base is connected to the support top, and the shape of the support base is a hollow cylinder; the top end of the support top is concave downward to form three axially symmetric U-shaped openings.

[0019] Further, in a spatial rectangular coordinate system, the center of the support base of the valve support coincides with the coordinate origin; the bottom surface of the inner wall of the support base of the valve support is a circle curve, and the parametric expression of the circle curve of the valve support is a first preset formula; The first preset formula is: wherein, represents a coordinate value of a point on the circle along the x-axis direction; represents a coordinate value of a point on the circle along the y-axis direction; represents a radius of the circle, the radius of the circle being determined according to a radius of an aortic annulus in a human body.

[0020] Further, the spatial U-shaped opening is a stent boundary curve of the valve stent; in a spatial rectangular coordinate system with a center of a stent base of the valve stent as a coordinate origin, a parameter expression of the stent boundary curve of the valve stent is a second preset formula. The second preset formula is: wherein, represents a coordinate value of a point on the stent boundary curve along the z-axis direction; represents an included angle between each point on the circle and a positive direction of the x-axis; represents a height of a lowest point of the valve stent; represents a height of a highest point of the valve stent; represents a bending degree of the stent boundary curve.

[0021] Further, each of the valve leaflets comprises a fixed boundary curve, and the stent boundary curve of the valve stent serves as the fixed boundary curve of the valve leaflet.

[0022] Further, in the spatial rectangular coordinate system with the center of the stent base of the valve stent as the coordinate origin, a parameter expression of the free boundary curve of the valve leaflet in a region of is a third preset formula; and a parameter expression of the free boundary curve of the valve leaflet in a region of is a fourth preset formula. The third preset formula is: The fourth preset formula is: and a relationship between wherein, represents a coordinate value of a point on the free boundary curve along the x-axis direction; represents a coordinate value of a point on the free boundary curve along the y-axis direction; ​​​​a radius of the circle curve; a shortest distance between the free boundary curve and the z-axis in a horizontal plane; a maximum distance between a line connecting the highest point of the fixed boundary curve and the center of the circle and an arc of the free boundary curve.

[0023] Further, each of the three leaflets further comprises an abdominal curve; in a spatial rectangular coordinate system with the center of the stent base of the valve stent as the coordinate origin, a parameter expression of the abdominal curve of the leaflet is a sixth preset formula; The sixth preset formula is: wherein, a coordinate value of a point on the abdominal curve along the z-axis direction; a coordinate value of a point on the abdominal curve along the x-axis direction; a highest height of the abdominal curve, ; a height of the lowest point of the valve stent; a height of the highest point of the valve stent; a radius of the circle curve; a shortest distance between the free boundary curve and the z-axis in a horizontal plane; a bending degree of the abdominal curve.

[0024] The design method of the artificial aortic valve provided in the present application, the artificial aortic valve comprises a valve stent and three leaflets, the three leaflets are fixed to the valve stent, and the design method comprises: based on a shape curve of the valve stent, a parameterization method of a power equation is adopted to form a free boundary curve of a class-taijitu shape of each of the three leaflets. So that the obtained leaflet comprises a free boundary curve of a class-taijitu shape, which moderates the stress received by the leaflet and optimizes the stress distribution, thereby improving the performance of the valve and prolonging the service life of the valve. In this way, the performance of the artificial aortic valve obtained by the design method is better, so as to improve the clinical effect of the artificial aortic valve.

[0025] It should be understood that the above general description and the following detailed description are only exemplary and explanatory, and cannot limit the present application. BRIEF DESCRIPTION OF DRAWINGS

[0026] The accompanying drawings incorporated in and forming a part of the specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the application.

[0027] Figure 1 Shown is a structural schematic diagram of an artificial aortic valve according to an exemplary embodiment of the present application; Figure 2 The diagram shows a flowchart of a design method for an artificial aortic valve according to an exemplary embodiment of the application. Figure 3 As shown Figure 2 The flowchart shown is a sub-flowchart of the design method for artificial aortic valves; Figure 4 As shown Figure 1 The diagram shows the configuration of the valve stent for an artificial aortic valve. Figure 5 As shown Figure 2 Another sub-flowchart of the design method for artificial aortic valves is shown; Figure 6 As shown Figure 1 A schematic diagram showing the characteristic curves of the three leaflets of an artificial aortic valve; Figure 7 As shown Figure 6 A top view of the three leaflets shown; Figure 8 As shown Figure 6 A planar schematic diagram of the ventral curve of one of the three leaflets shown. Figure 9 The diagram shown is a schematic diagram of a mold with three leaflets according to an exemplary embodiment of this application. Detailed Implementation

[0028] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0029] To better understand the technical solution of this application, the design method of the artificial aortic valve and the artificial aortic valve of this application will be described in detail below with reference to the accompanying drawings. Unless otherwise specified, the features in the following embodiments and implementations can be combined with each other.

[0030] Figure 1 The diagram shown is a structural schematic of an artificial aortic valve 10 according to an exemplary embodiment of this application. See also... Figure 1 As shown, this application provides an artificial aortic valve 10, which includes a valve stent 11 and three leaflets 12. The three leaflets 12 are fixed to the valve stent 11 and are arranged symmetrically about the central axis of the valve stent 11, so that the three leaflets 12 have the same shape.

[0031] The valve stent 11 is used to be sewn in the root of the aorta in the valve replacement surgery. The base of the valve stent 11 is used to be fixed to the aortic valve annulus in the human body. The diameter of the valve stent 11 is determined according to the diameter of the aortic valve annulus in the human body. The height of the highest point of the valve stent 11 can be determined according to the height of the aortic sinus in the human body. In the embodiment, the height of the highest point of the valve stent 11 is 11 mm. The height of the lowest point of the valve stent 11 is 1 mm to 3 mm. In the embodiment, the height of the lowest point of the valve stent 11 is 2 mm. In an embodiment, the material of the valve stent 11 can be PEEK (Polyether Ether Ketone, polyether ether ketone). The thickness of the valve stent 11 can be 1 mm.

[0032] In an embodiment, the valve stent 11 comprises a stent base and a stent top, the stent base is connected to the stent top, wherein the stent base can be integrally arranged with the stent top. The shape of the stent base can be a hollow cylinder, and the thickness of the hollow cylinder is 1 mm. The top end of the stent top is recessed downward to form three axisymmetric space U-shaped openings, wherein the opening of the space U-shaped opening faces upward, and the curve of the space U-shaped opening is the stent boundary curve of the valve stent 11.

[0033] In an embodiment, in the space rectangular coordinate system, the center of the stent base of the valve stent 11 coincides with the coordinate origin. The bottom surface of the inner wall of the stent base of the valve stent 11 is a circular curve, and the parametric expression of the circular curve of the valve stent 11 is a first preset formula.

[0034] The first preset formula is: wherein, represents the coordinate value of the point of the circular curve along the x-axis direction; represents the coordinate value of the point of the circular curve 13 along the y-axis direction; represents the radius of the circular curve, and the radius of the circular curve is determined according to the radius of the aortic valve annulus in the human body.

[0035] In an embodiment, in the space rectangular coordinate system with the center of the stent base of the valve stent 11 as the coordinate origin, the parametric expression of the stent boundary curve of the valve stent 11 is a second preset formula.

[0036] The second preset formula is: wherein, represents the coordinate value of the point on the stent boundary curve along the z-axis direction; represents the included angle between each point on the circumference of the circular curve and the positive direction of the x-axis. represents the height of the lowest point of the valve stent 11; represents the height of the highest point of the valve stent 11; represents the bending degree of the stent boundary curve.

[0037] The three leaflets 12 include a closed state and an open state. The three leaflets 12 are used to move under the driving of pressure and blood flow to switch between the closed state and the open state. When the three leaflets 12 are in the closed state, the three leaflets 12 are close to the central axis of the valve stent 11. When the three leaflets 12 are in the open state, the three leaflets 12 are away from the central axis of the valve stent 11. When the artificial aortic valve 10 is applied in the human body, during the ventricular diastole, the three leaflets 12 can be closed under the action of pressure difference in the direction close to the axis of the aorta in the human body, that is, the three leaflets 12 will be in the closed state. During the ventricular ejection period, the three leaflets 12 can move in the direction of the aortic wall under the action of blood flow force, that is, the three leaflets 12 will be in the open state to achieve the effect of the aortic valve in the human body. In this embodiment, the material of the leaflet 12 can be polyurethane, and the thickness can be 0.3 mm. In an embodiment, each leaflet 12 can include three characteristic curves, namely a fixed boundary curve, an abdominal curve and a free boundary curve.

[0038] Each leaflet 12 includes a free boundary curve. The free boundary curve of the leaflet 12 is the shape curve of the top end of the leaflet 12 when the three leaflets 12 are in the closed state. Among them, the free boundary curve is in the shape of a Tai Chi.

[0039] In an embodiment, each leaflet 12 includes a fixed boundary curve, and the stent boundary curve of the valve stent 11 can be used as the fixed boundary curve of the leaflet 12. The fixed boundary curve is a spatial U-shaped opening curve.

[0040] In an embodiment, in a spatial rectangular coordinate system with the center of the stent base of the valve stent 11 as the coordinate origin, the parameter expression of the free boundary curve of the leaflet 12 in the area of is a third preset formula. The parameter expression of the free boundary curve of the leaflet 12 in the area of is a fourth preset formula.

[0041] The third preset formula is: The fourth preset formula is: The relationship between is: Among them, represents the coordinate value of a point on the free boundary curve along the x-axis direction; represents the coordinate value of a point on the free boundary curve along the y-axis direction; In the present embodiment, represents the radius of the circular curve; represents the shortest distance between the free boundary curve and the z-axis in the horizontal plane; represents the maximum distance between the arc of the free boundary curve and the line connecting the highest point of the fixed boundary curve and the center of the circle.

[0042] In one embodiment, the shortest distance between the free boundary curve and the central axis of the valve stent 11 is 0.1mm-0.5mm. In the present embodiment, the shortest distance between the free boundary curve and the central axis of the valve stent 11 is 0.3mm.

[0043] In one embodiment, the maximum deflection caused by the bending of the free boundary curve is 0.8mm.

[0044] In one embodiment, each leaflet 12 further comprises an abdominal curve. The abdominal curve of the leaflet 12 is the line connecting the center point of the spatial U-shaped opening of the fixed boundary curve of the leaflet 12 and the center point of the free boundary curve of the leaflet 12. The abdominal curve is an exponential curve with a positive coefficient, and the exponent is 0.9-1.5. In the present embodiment, the exponent is 1.25.

[0045] In one embodiment, in the spatial rectangular coordinate system with the center of the stent base of the valve stent 11 as the coordinate origin, the parameter expression of the abdominal curve of the leaflet 12 is the sixth preset formula.

[0046] The sixth preset formula is: wherein, represents the coordinate value of a point on the abdominal curve along the z-axis direction; represents the coordinate value of a point on the abdominal curve along the x-axis direction; represents the highest height of the abdominal curve, In the present embodiment, the highest height of the abdominal curve is 9mm, i.e. represents the radius of the circular curve; represents the shortest distance between the free boundary curve 16 and the z-axis in the horizontal plane; represents the bending degree of the abdominal curve.

[0047] The present application provides an artificial aortic valve 10, which is designed according to the design method of the artificial aortic valve 10 according to any one of the embodiments.​​​

[0048] Figure 2 A flow chart of a design method of the artificial aortic valve 10 according to an exemplary embodiment is shown. Referring to Figure 2 As shown, the present application provides a design method of an artificial aortic valve 10, the design method comprising steps S10-S13.

[0049] In step S10, a shape curve of the valve stent 11 is formed, and the valve stent 11 is generated according to the shape curve of the valve stent 11. The shape curve of the valve stent 11 comprises a stent boundary curve 14 and a circle curve 13. The stent boundary curve 14 is located above the circle curve 13.

[0050] In step S11, based on the shape curve of the valve stent 11, a parameterization method of a power equation is used to form a free boundary curve 16 of a Tai Chi shape of each of the three leaflets 12. The leaflets 12 are designed based on the fixed boundary curve 15, the free boundary curve 16 and the belly curve 17.

[0051] In step S12, based on the shape curve of the valve stent 11 and the free boundary curve of the leaflets 12, the belly curve 17 of each of the three leaflets 12 is formed.

[0052] In step S13, according to the shape curve of the valve stent 11, the free boundary curve 16 of each of the three leaflets 12 and the belly curve 17 of each of the three leaflets 12, the three leaflets 12 in a closed state are generated. The three leaflets 12 in a closed state can be generated according to the fixed boundary curve 15, the free boundary curve 16 and the belly curve 17.

[0053] The design method of the artificial aortic valve provided by the present application, the artificial aortic valve 10 comprises a valve stent 11 and three leaflets 12, the three leaflets 12 are fixed to the valve stent 11, and the design method comprises: based on the shape curve of the valve stent 11, a parameterization method of a power equation is used to form a free boundary curve 16 of a Tai Chi shape of each of the three leaflets 12. So that the obtained leaflets 12 comprise a free boundary curve 16 of a Tai Chi shape, which moderates the stress on the leaflets 12 and optimizes the stress distribution, thereby improving the performance of the valve and prolonging the service life of the valve. In this way, the performance of the artificial aortic valve 10 obtained by the design method is better, so as to improve the clinical effect of the artificial aortic valve 10.

[0054] Figure 3 A flow chart of a design method of the artificial aortic valve 10 according to an exemplary embodiment is shown. Referring to Figure 2 A sub-flow chart of the design method of the artificial aortic valve 10 is shown. Figure 4 A flow chart of a design method of the artificial aortic valve 10 according to an exemplary embodiment is shown. Referring to Figure 1 A configuration diagram of the valve stent 11 of the artificial aortic valve 10 is shown. Referring toFigure 3 and Figure 4 As shown, in one embodiment, forming the shape curve of the valve stent 11 includes steps S101 to S103.

[0055] In step S101, a spatial rectangular coordinate system with x-axis, y-axis and z-axis is established.

[0056] In step S102, a circular curve 13 is formed with the origin of the spatial rectangular coordinate system as the center O and according to the first preset formula.

[0057] In one embodiment, the first preset formula is: in, This represents the coordinates of a point on the circular curve 13 along the x-axis. This represents the coordinates of a point on the circular curve 13 along the y-axis. This represents the radius of the circular curve 13. It is determined based on the radius of the aortic valve annulus in the human body. The inner diameter of the valve stent 11 can be used. Thus, the resulting circular curve 13 can serve as the base of the valve stent 11 for fixing to the aortic valve annulus.

[0058] In step S103, according to the second preset formula, each point on the circumference of the circular curve 13 is mapped to a different height to form the support boundary curve 14. There are three support boundary curves 14, and the three support boundary curves 14 are arranged symmetrically about the z-axis.

[0059] In one embodiment, the second preset formula is: in, This represents the coordinate value of a point on the support boundary curve 14 along the z-axis. This represents the angle between each point on the circumference of the circular curve 13 and the positive x-axis; This indicates the height of the lowest point of the valve stent 11; This indicates the height of the highest point of the valve stent 11; This indicates the degree of curvature of the support boundary curve 14.

[0060] In one embodiment, the height of the lowest point of the valve stent 11 The method of suturing the artificial aortic valve is determined based on the surgical technique used to fix the artificial aortic valve to the aortic valve annulus within the body. The suturing technique refers to the surgical procedure used to fix the artificial aortic valve to the aortic valve annulus using sutures. The height of the lowest point of the valve stent 11 is also considered. less than or equal to 3mm, and greater than or equal to 1mm, i.e. In the embodiment, the height of the lowest point of the valve stent 11 is 2mm, i.e. .

[0061] In one embodiment, the height of the highest point of the valve stent 11 is According to the height of the aortic sinus in the human body, the height of the highest point of the valve stent 11 can be selected according to the height of the aortic sinus of different users. In the embodiment, the height of the highest point of the valve stent 11 is 11mm, i.e. .

[0062] In one embodiment, the bending degree of the stent boundary curve is less than or equal to 1.4, and greater than or equal to 0.6, i.e. In the embodiment, the bending degree of the stent boundary curve is 0.8, i.e. .

[0063] In this way, the stent boundary curve 14 obtained can be a spatial U-shaped open curve, and the opening of the U-shaped open curve faces upward. The way of forming the shape curve of the valve stent 11 is simple.

[0064] Wherein, the shape of the stent boundary curve 14 of the valve stent 11 is the same as that of the fixed boundary curve 15 of the valve leaflet 12, and the same formula is adopted.

[0065] Figure 5 Another sub-flowchart of the design method of the artificial aortic valve 10 is shown in Figure 2 Another sub-flowchart of the design method of the artificial aortic valve 10 is shown in Figure 6 The characteristic curve diagram of the three valve leaflets 12 of the artificial aortic valve 10 is shown in Figure 1 The characteristic curve diagram of the three valve leaflets 12 of the artificial aortic valve 10 is shown in Figure 7 The top view of the three valve leaflets 12 is shown in Figure 6 The top view of the three valve leaflets 12 is shown in Figure 5 , Figure 6 and Figure 7 In one embodiment, step S11 includes steps S111-S112.

[0066] In step S111, based on the shape curve of the valve stent 11, the parametric method of the power equation is adopted to form the free boundary curve 16 of the Taiji-shaped one of the three valve leaflets 12.

[0067] In one embodiment, step S111 includes: based on the shape curve of the valve stent 11, forming the free boundary curve 16 of the one of the three valve leaflets 12 in the area of according to a third preset formula, and forming the free boundary curve 16 of the one of the three valve leaflets 12 in the area of the free boundary curve 16 within the region.

[0068] wherein the third preset formula is: the fourth preset formula is: and the relationship formula between them is: wherein, represents the coordinate value of the point on the free boundary curve 16 along the x-axis direction; represents the coordinate value of the point on the free boundary curve 16 along the y-axis direction; In the embodiment, the free boundary curve 16 is a circular arc. represents the radius of the circular arc; represents the shortest distance between the free boundary curve 16 and the z-axis in the horizontal plane; represents the maximum distance between the line connecting the highest point of the fixed boundary curve 15 and the center of the circle and the arc of the free boundary curve 16.

[0069] In one embodiment, the shortest distance between the free boundary curve 16 and the z-axis in the horizontal plane is less than or equal to 0.5 mm and greater than or equal to 0.1 mm, that is, In the embodiment, the shortest distance between the free boundary curve and the center axis is 0.3 mm, that is,

[0070] In one embodiment, the maximum distance between the line connecting the highest point of the fixed boundary curve 15 and the center of the circle and the arc of the free boundary curve 16 is less than or equal to 1.4 mm and greater than or equal to 0.4 mm. That is, In the embodiment, the maximum distance between the line connecting the highest point of the fixed boundary curve 15 and the center of the circle and the arc of the free boundary curve 16 is 0.8 mm, that is,

[0071] ​​​​​​​​Thus, this design method yields a Tai Chi-like free boundary curve 16 for the leaflet 12, resulting in a smaller opening area when the three leaflets 12 are closed, effectively preventing incomplete closure of the artificial aortic valve 10. Simultaneously, the helical free boundary curve 16 design of the three leaflets 12, which are coupled together, prevents folding deformation of the leaflets 12 during opening, ensuring full opening of the leaflets 12. It also optimizes the stress distribution of the leaflets 12, reduces maximum stress, improves the performance of the leaflets 12, and increases their service life.

[0072] In step S112, the free boundary curve 16 of the leaflet 12 is rotated 120° in opposite directions around the z-axis to obtain the free boundary curves of the other two leaflets 12 out of the three leaflets 12. This method of forming the free boundary curves of the other two leaflets 12 is simple and more efficient.

[0073] In one embodiment, prior to step S112, the design method further includes: According to the fifth preset formula, the leaflet 12 of the formed free boundary curve 16 is in the interval The local area is smoothed to form a smooth curve within that range; The fifth preset formula is: in, Based on the third and fourth preset formulas, determine when The point at time, the coordinates of that point are defined as ; This represents the coordinates of a point on the smoothed curve along the x-axis. This represents the coordinates of a point on the smoothed curve along the y-axis. The leaflet 12, whose free boundary curve 16 has already been formed, is smoothed near the z-axis to avoid sharp angles near the aortic central axis.

[0074] Figure 8 As shown Figure 6 A planar schematic diagram of the ventral curve of one of the three leaflets 12 shown. See also... Figure 6 and Figure 8 As shown, in one embodiment, step S12 includes: based on the shape curve of the valve stent 11 and the free boundary curve corresponding to the leaflet 12, forming the ventral curve 17 of one of the three leaflets 12 according to the sixth preset formula. The sixth preset formula is: in, This represents the coordinates of a point on the abdominal curve 17 along the z-axis. represents the coordinate value of the point on the abdominal curve 17 along the x-axis direction; represents the highest height of the abdominal curve 17, In the embodiment, the highest height of the abdominal curve is 9mm, i.e. ; represents the radius of the circular curve 13; represents the shortest distance between the free boundary curve 16 and the z-axis in the horizontal plane; represents the bending degree of the abdominal curve 17.

[0075] The abdominal curve of the leaflet 12 is rotated by 120° in two opposite directions respectively with the z-axis as the rotation axis, so as to obtain the abdominal curves of the other two leaflets 12.

[0076] In an embodiment, the bending degree of the abdominal curve 17 is less than or equal to 1.5 and greater than or equal to 0.9. That is In the embodiment, the bending degree of the abdominal curve 17 is 1.25, i.e. . In this way, the abdominal curve 17 of the leaflet 12 can be obtained by the design method, and the abdominal curve 17 can be an exponential spatial curve. The distance between the leaflet 12 and the z-axis gradually decreases with the height, and the change rate gradually decreases with the height.

[0077] Figure 9 Fig. 8 shows a mold 18 for three leaflets according to an exemplary embodiment of the present application. As shown in Figure 9 In the manufacturing process of the artificial aortic valve, the three leaflets 12 and the valve support 11 can be produced by integral molding or separately. The integral molding is taken as an example for description. The mold 18 for the three leaflets 12 as shown in Figure 9 is embedded into the valve support 11, so that the top end of the mold 18 is flush with the top end of the valve support 11. The polymer material, such as polyurethane, is attached to the top of the mold and the valve support 11 by spraying method with a certain thickness. After the polymer material is solidified and shaped, the mold is removed, and an integrated polymer artificial aortic valve is obtained.

[0078] The application does not limit the sewing connection mode of the valve support 11 and the aortic sinus, and appropriate sewing means can be selected according to the actual situation of the aortic valve replacement surgery. And appropriate structures required for sewing are added on the valve support 11. The design method of the artificial aortic valve 10 can design appropriate high-molecular artificial aortic valve 10 according to the height of the aortic sinus in the human body, the diameter of the aortic annulus, and the sewing means. In the configuration design of the valve leaflet 12 based on the fixed boundary curve, the free boundary curve and the abdominal curve, each parameter in the parameter equation of each curve can be adjusted within a certain range according to the actual situation.

[0079] It should be understood that the application is not limited to the precise structures which have been described herein and shown in the accompanying drawings, and that various modifications and changes can be made without departing from its scope. The scope of the application is limited only by the appended claims.

Claims

1. A method for designing an artificial aortic valve, characterized in that, The artificial aortic valve includes a valve stent and three leaflets; the three leaflets are fixed to the valve stent; the design method includes: The shape curve of the valve stent is formed, and the valve stent is generated according to the shape curve of the valve stent; Based on the shape curve of the valve stent, a power equation parameterization method is used to form the free boundary curves of the three leaflets in a Taiji-like shape. Based on the shape curve of the valve stent and the free boundary curve corresponding to the leaflet, the ventral curves of the three leaflets are formed respectively. Based on the shape curve of the valve stent, the free boundary curve of the three leaflets, and the ventral curve of the three leaflets, the three leaflets in a closed state are generated.

2. The method for designing an artificial aortic valve according to claim 1, characterized in that, The shape curve includes a stent boundary curve and a circular curve; the shape curve forming the valve stent includes: Establish a spatial rectangular coordinate system with x-axis, y-axis, and z-axis; Using the origin of the spatial rectangular coordinate system as the center, the circular curve is formed according to the first preset formula; According to the second preset formula, each point on the circumference of the circular curve is mapped to a different height to form the support boundary curve.

3. The method for designing an artificial aortic valve according to claim 2, characterized in that, The first preset formula is: ， in, The coordinates of the points on the circular curve along the x-axis are represented. The coordinates of a point on the circular curve along the y-axis are represented. The radius of the circular curve is represented by [the symbol]. It is determined based on the radius of the aortic valve annulus in the human body.

4. The method for designing an artificial aortic valve according to claim 2, characterized in that, The second preset formula is: ， in, This represents the coordinate value of a point on the boundary curve of the support along the z-axis. This represents the angle between each point on the circumference of the circular curve and the positive x-axis; This indicates the height of the lowest point of the valve stent; This indicates the height of the highest point of the valve stent; This indicates the degree of curvature of the support boundary curve.

5. The method for designing an artificial aortic valve according to claim 4, characterized in that, The height of the lowest point of the valve stent The height of the lowest point of the valve stent is determined according to the suturing technique used to fabricate the artificial aortic valve. Less than or equal to 3 mm and greater than or equal to 1 mm; and / or, The height of the highest point of the valve stent Determined based on the height of the aortic sinus in the human body; and / or, The curvature of the support boundary curve Less than or equal to 1.4 and greater than or equal to 0.

6.

6. The method for designing an artificial aortic valve according to claim 2, characterized in that, The shape curve based on the valve stent is parameterized using a power equation method to form the free boundary curves of the three leaflets in a Tai Chi-like shape, including: Based on the shape curve of the valve stent, a power equation parameterization method is used to form the free boundary curve of a Taiji-like shape of one of the three leaflets. The free boundary curve of the leaflet is rotated 120° in opposite directions around the z-axis to obtain the free boundary curves of the other two leaflets among the three leaflets.

7. The method for designing an artificial aortic valve according to claim 6, characterized in that, The stent boundary curve of the valve stent serves as the fixed boundary curve of the leaflet; based on the shape curve of the valve stent, a power equation parameterization method is used to form a free boundary curve of a tai chi-like shape for one of the three leaflets, including: Based on the shape curve of the valve stent, and according to the third preset formula, one of the three leaflets is formed in... The free boundary curve within the region; and according to the fourth preset formula, forming one of the three leaflets in... The free boundary curve within the region; The third preset formula is as follows: ， The fourth preset formula is: ， and Relationship: ， in, This represents the coordinate value of a point on the free boundary curve along the x-axis. This represents the coordinate value of a point on the free boundary curve along the y-axis. ; ; This represents the radius of the circular curve; This represents the shortest distance between the free boundary curve and the z-axis on the horizontal plane; This represents the maximum distance between the line connecting the highest point of the fixed boundary curve and the center of the circle, and the arc of the free boundary curve.

8. The method for designing an artificial aortic valve according to claim 7, characterized in that, The radius of the circular curve Determined based on the radius of the aortic valve annulus in the human body; and / or, The shortest distance between the free boundary curve and the z-axis on the horizontal plane Less than or equal to 0.5 mm and greater than or equal to 0.1 mm; and / or, The maximum distance between the line connecting the highest point and the center of the fixed boundary curve and the arc of the free boundary curve. Less than or equal to 1.4 mm and greater than or equal to 0.4 mm.

9. The method for designing an artificial aortic valve according to claim 7, characterized in that, Before rotating the free boundary curve of the leaflet by 120° in opposite directions around the z-axis to obtain the free boundary curves of the other two leaflets of the three leaflets, the design method further includes: According to the fifth preset formula, the leaflet with the formed free boundary curve is in the interval The local area is smoothed to form a smooth curve within that range; The fifth preset formula is: ， in, Based on the third preset formula and the fourth preset formula, determine when The point at time, the coordinates of that point are defined as ; This represents the coordinate value of a point on the smoothed curve along the x-axis. This represents the coordinate value of a point on the smoothed curve along the y-axis.

10. The method for designing an artificial aortic valve according to claim 2, characterized in that, The ventral curves of the three leaflets are formed based on the shape curve of the valve stent and the free boundary curve corresponding to the leaflet, including: Based on the shape curve of the valve stent and the free boundary curve corresponding to the leaflet, the ventral curve of one of the three leaflets is formed according to the sixth preset formula. The sixth preset formula is: ， in, This represents the coordinate value of a point on the abdominal curve along the z-axis. This represents the coordinate value of a point on the abdominal curve along the x-axis. This indicates the highest height of the abdominal curve. ; This indicates the height of the lowest point of the valve stent; This indicates the height of the highest point of the valve stent; This represents the radius of the circular curve; This represents the shortest distance between the free boundary curve and the z-axis on the horizontal plane; This indicates the degree of curvature of the abdominal curve; The ventral curve of the leaflet is rotated 120° in opposite directions around the z-axis to obtain the ventral curves of the other two leaflets of the three leaflets.

11. The method for designing an artificial aortic valve according to claim 10, characterized in that, The height of the lowest point of the valve stent The height of the lowest point of the valve stent is determined according to the suturing technique used to fabricate the artificial aortic valve. Less than or equal to 3 mm and greater than or equal to 1 mm; and / or, The height of the highest point of the valve stent Determined based on the height of the aortic sinus in the human body; and / or, The radius of the circular curve Determined based on the radius of the aortic valve annulus in the human body; and / or, The shortest distance between the free boundary curve and the z-axis on the horizontal plane Less than or equal to 0.5 mm and greater than or equal to 0.1 mm; and / or, The curvature of the abdominal curve Less than or equal to 1.5 and greater than or equal to 0.

9.

12. An artificial aortic valve, characterized in that, The artificial aortic valve includes a valve stent and three leaflets, the three leaflets being fixed to the valve stent; the artificial aortic valve is designed according to the design method of the artificial aortic valve according to any one of claims 1-11.

13. An artificial aortic valve, characterized in that, The artificial aortic valve includes a valve stent and three leaflets, the three leaflets being fixed to the valve stent and arranged symmetrically about the central axis of the valve stent. The three leaflets include a closed state and an open state. When the three leaflets are in the closed state, they are close to the central axis of the valve stent. When the three leaflets are in the open state, they are far away from the central axis of the valve stent. Each of the three leaflets includes a free boundary curve; the free boundary curve of the leaflet is the shape curve of the tip of the leaflet when the three leaflets are in the closed state; wherein, the free boundary curve is in the shape of a tai chi symbol.

14. The artificial aortic valve according to claim 13, characterized in that, The valve stent includes a stent base and a stent top. The stent base is connected to the stent top and is shaped as a hollow cylinder. The top of the stent top is recessed downward to form three axially symmetrical U-shaped openings.

15. The artificial aortic valve according to claim 14, characterized in that, In a spatial rectangular coordinate system, the center of the base of the valve stent coincides with the origin of the coordinate system; The bottom surface of the inner wall of the base of the valve stent is a circular curve, and the parametric expression of the circular curve of the valve stent is a first preset formula. The first preset formula is: ， in, The coordinates of the points on the circular curve along the x-axis are represented. The coordinates of a point on the circular curve along the y-axis are represented. The radius of the circular curve is represented by [the symbol]. It is determined based on the radius of the aortic valve annulus in the human body.

16. The artificial aortic valve according to claim 15, characterized in that, The U-shaped opening in the space is the stent boundary curve of the valve stent; in the spatial rectangular coordinate system with the center of the stent base of the valve stent as the origin, the parametric expression of the stent boundary curve of the valve stent is the second preset formula. The second preset formula is: ， in, This represents the coordinate value of a point on the boundary curve of the support along the z-axis. This represents the angle between each point on the circumference of the circular curve and the positive x-axis; This indicates the height of the lowest point of the valve stent; This indicates the height of the highest point of the valve stent; This indicates the degree of curvature of the support boundary curve.

17. The artificial aortic valve according to claim 16, characterized in that, Each of the leaflets includes a fixed boundary curve, and the stent boundary curve of the valve stent serves as the fixed boundary curve of the leaflet.

18. The artificial aortic valve according to claim 17, characterized in that, In a Cartesian coordinate system with the center of the base of the valve stent as the origin, the free boundary curve of the leaflet is... The parameter expression within the region is the third preset formula; the free boundary curve of the leaflet is in The parameter expression within the region is the fourth preset formula; The third preset formula is as follows: ， The fourth preset formula is: ， and Relationship: ， in, This represents the coordinate value of a point on the free boundary curve along the x-axis. This represents the coordinate value of a point on the free boundary curve along the y-axis. ; ; This represents the radius of the circular curve; This represents the shortest distance between the free boundary curve and the z-axis on the horizontal plane; This represents the maximum distance between the line connecting the highest point of the fixed boundary curve and the center of the circle, and the arc of the free boundary curve.

19. The artificial aortic valve according to claim 18, characterized in that, Each leaflet also includes a ventral curve; in a spatial rectangular coordinate system with the center of the base of the valve stent as the origin, the parametric expression of the ventral curve of the leaflet is the sixth preset formula. The sixth preset formula is: ， in, This represents the coordinate value of a point on the abdominal curve along the z-axis. This represents the coordinate value of a point on the abdominal curve along the x-axis. This indicates the highest height of the abdominal curve. ; This indicates the height of the lowest point of the valve stent; This indicates the height of the highest point of the valve stent; This represents the radius of the circular curve; This represents the shortest distance between the free boundary curve and the z-axis on the horizontal plane; This indicates the degree of curvature of the abdominal curve.

Images