Finite Element Modeling and Analysis of Ventricular Septal Defect Occluders / 医用生物力学

ABSTRACT

Objective To analyze influences of the braiding angle and material on performance of ventricular septal defect (VSD) occluders, so as to provide theoretical basis and guidance for their design. Methods The finite element models of occluders with different braiding angles (30°, 45° and 60°) were developed respectively. The radial supporting and axial bending performances of nickel titanium (NiTi) occlude and poly-p-dioxanone (PPDO) occlude were then compared. Results Under 5 kPa radial loading, radial stiffness of the 30°, 45° and 60° NiTi occluder waists were 8.60, 1.51 and 0.99 mN/mm3,respectively, while that of 45° PPDO occluder waist was 7.35 mN/mm3. Under axial bending of 0.5 rad, the maximum radial deformation of the 30°, 45°, 60° NiTi occluder waists were 1.17, 1.24 and 0.22 mm, while that of the 45° PPDO was 0.54 mm. Conclusions Under the condition of using the same material, occluders with braiding angle of 60° show the lowest radial stiffness, indicating they have the best radial supporting ability. Furthermore, they also show the smallest maximum radial deformation, indicating they have the best axial bending ability and the compliance. On the other hand, under the condition of using the same braiding angle, NiTi occluders show lower radial stiffness, indicating they have better radial supporting ability. However, PPDO occluders show lower maximum radial deformation, indicating they have better axial bending ability and compliance.