Hua Cong

Nonlinear Analysis of Bioprosthetic Heart Valve on Suture Densities

In order to improve long term durability of bioprosthetic heart valve, we analyze and compare stress distribution of bioprosthetic heart valve leaflets with different shapes and suture density under the same load. The finite element analysis results are compared with each valve model. It shows that suture density has a significant effect on the dynamic behavior of the bioprosthetic heart valve, which lead to different stress peak values, different stress distributions and deformation. According to the finite element analysis results, we can conclude that the cylindric and spherical valve leaflet with 50 suture points has better dynamic properties. From the whole loading process, we can find that the dynamic mechanical performance of spherical valve leaflet with 50 suture points is better than the cylindrical valve leaflet with 50 suture points. The finite element analysis on the BHV could provide direct and useful information for the BHV designer.

The Material Nonlinear Analysis of Bioprosthetic Heart Valve on Suture Densities

In order to investigate the effect of suture density on the dynamic behavior of bioprosthetic heart valve with nonlinear material and improve long term durability of bioprosthetic heart valve, we establish the ellipsoidal leaflets and paraboloidal leaflets models via computer aided design. Based on the parametric models of the heart valve, four kinds of suture density (100,70,50 and 35 suture points on the attachment edge of the bioprosthetic heart valve) are analyzed by using finite element method. The finite element analysis results are compared with each valve model. It shows that suture density has a significant effect on the dynamic behavior of the bioprosthetic heart valve, which lead to different stress peak values, different stress distributions and deformation. The finite element analysis of the BHV could provide direct and useful information for the BHV designer.

The Geometric and Material Nonlinear Analysis of the Bioprosthetic Heart Valve

This paper constructs four types of bioprosthetic heart valve’s parametric model via computer aided design, a series of accurate parameters of the bioprosthetic heart valve, such as radius of the sutural ring, height of the supporting stent and inclination of the supporting stent are determined. The finite element method is used to analyze the mechanical properties of the bioprosthetic heart valve in which geometric non-linearity and material non-linearity are all taken into account. The finite element analysis results show that the shape of the bioprosthetic has a significant effect on the mechanical performance of the valve. The stress distribution of ellipsoidal valve leaflets is comparatively reasonable. It has lower peak von-Mises, smaller stress concentration area than the other three types of valve leaflets. This work is very helpful to manufacture valvular leaflets with reasonable shapes and to prolong the lifetime of the bioprosthetic heart valve.

Nonlinear Analysis of Bioprosthetic Heart Valves under Dynamic Loading

In order to investigate the effect of material nonlinearity on the dynamic behavior of bioprosthetic heart valve, we establish the spherical, cylindrical and ellipsoidal leaflets models with the material model of Mooney-Rivlin. The mechanical behavior of bioprosthetic valve leaflet during diastolic phase is analyzed. The finite element analysis results show that the stress distributions of the ellipsoidal and spherical valve leaflets are comparatively reasonable. The ellipsoidal and spherical valve leaflets have the following advantages over the cylindrical leaflet valve, lower peak von-Mises stress, smaller stress concentration area, and relatively uniform stress distribution. This work is very helpful to manufacture reasonable shaped valvular leaflets，thus to prolong the lifetime of the bioprosthetic heart valve.

Influence of Material Thickness to the Dynamic Mechanical Properties of Bioprosthetic Heart Valve

The paper constructs one type of bioprosthetic valve leaflets’ parametric model via computer aided design, a series of accurate parameters of the bioproshtetic heart valve, such as radius of the sutural ring, height of the supporting stent and inclination of the supporting stent, are determined. Numerical simulation is used to determine the effect of one shape design on the mechanical performance of the bioprosthetic valve leaflet. The stress with a shape under the same load is analysed and the thickness of the leaflets 0.5mm and 0.6mm is compared by us. We creat a ellipsoidal surface in accordance with geometrical features. The experimental results of the finite element analysis show that stress distribution of the same bioprosthetic heart valve leaflets with different thickness is different. The maximal primary stress with the thickness of 0.5mm is lower than the others. This work is very helpful to manufacture reasonable shaped valvular leaflets and to prolong the lifetime of the bioprosthetic heart valve.

Stress Analysis on Bioprosthetic Heart Valve Leaflets with Non-Linear Material

The finite element software is often applied to stress analysis, which is also crucial to the design of anti-fatigue and anti-calcification of artificial heart valve. The material properties and the boundary conditions of bioprosthetic valve leaflets are defined and geometrical models are established. The linear material and the non-linear material of leaflets with different shapes are analyzed. After valve leaflets with the finite element models have been loaded, the finite element analysis results can be got .It is showed that the maximal primary stress of the valve leaflets with elliptic sphere is lower than that of the other valve leaflets and the stress distribution of the valve leaflet with elliptic sphere is comparatively reasonable. The work is helpful to make optimization design for the bioprosthetic heart valve and prolongs the lifetime of the synthetic heart valve.

Construction parametric model and stress analysis of the biopresthetic heart valve

In order to improve long-term durability of bioprosthetic heart valve, stress distribution of bioprosthetic heart valve leaflets with different shapes under the same load is analyzed and compared based on finite element method. Combining traditional design theories and modern design methods, we create the cylindrical, spherical, paraboloidal and ellipsoidal curved surfaces in accordance with the geometrical equations in the appropriate frame ordinal. Based on the stress analysis of two kinds of curved surfaces, we take turns to create relative inverse conic curved surfaces which satisfy the actual condition. Meanwhile, the space positions of boundary curves and important points are determined by the intersected curves and axis of revolution. Geometrical design and the finite element analysis could provide direct and useful information for the bioprosthetic heart valve designer. The experimental results of the finite element analysis reveal that stress distribution of different bioprosthetic heart valve leaflets is quite different in diastole time. Ellipsoidal valve leaflets have the following advantages over spherical, paraboloidal and cylindrical valves leaflets: one is that the peak stress area of ellipsoidal valve leaflets is comparatively far from seam position, the other is that the maximal primary stress of ellipsoidal valve leaflets is lower than that of spherical, paraboloidal and cylindrical valves leaflets. Therefore, mechanical properties of ellipsoidal valves leaflets are superior to those of spherical, paraboloidal and cylindrical valves leaflets.