Fatigue life optimization for coronary stent under the effect of blood flow / 医用生物力学

ABSTRACT

Objective To evaluate the fatigue life of coronary stent under the effect of blood flow and thus optimize the stent design.MethodsA simplified model of the stent, blood, plaque and artery was established using Pro/Engineering, and the periodic blood flow impact on the vascular stent was simulated by finite element method via ANSYS. The result on hemodynamics from such stent was then used to evaluate its fatigue life. The geometric parameters of the stent were chosen as design variables for optimization. By using Latin Hypercubic sampling and ANSYS program, responses of the sample points could be obtained and the Kriging surrogate model was then constructed to optimize the fatigue life of the coronary stent.Results Goodman’s method showed that the optimized stent was safe. The cumulative damage method indicated that the largest damage occurred at the second cross-section of the bridge struts. The fatigue life of the optimized stent could be enhanced by 30.55%. Conclusions The finite element method can be used to evaluate the fatigue life of the coronary stent, and the optimization of stent by establishing Kriging model can effectively enhance the fatigue life of the stent.