Design optimization of stent and its dilatation balloon using kriging surrogate model

Area of Science:

• Biomedical Engineering
• Materials Science
• Computational Mechanics

Background:

• Cardiovascular disease treatment with stents is limited by in-stent restenosis and fatigue failure.
• Stent geometry and balloon length significantly impact performance and fatigue life.
• Conventional optimization methods fail to find global optimal designs.

Purpose of the Study:

• To propose an adaptive optimization method based on a Kriging surrogate model.
• To optimize stent structure and dilatation balloon length.
• To enhance stent service life and performance.

Main Methods:

• Finite element simulation combined with Kriging surrogate model for step-by-step optimization.
• Design of experiment and expected improvement function for global optimization.
• Fatigue life prediction using Goodman diagram and expansion performance measurement via dogboning effect.

Main Results:

• Optimized diamond-shaped stent showed a 22.39% increase in fatigue life and eliminated dogboning.
• Optimized sv-shaped stent showed a 15.91% increase in fatigue life and eliminated dogboning.
• Both stent designs exhibited reduced radial elastic recoil and foreshortening, improving overall performance.

Conclusions:

• The Kriging surrogate model-based adaptive optimization method effectively enhances stent fatigue life and expansion performance.
• This method optimizes both stent structure and dilatation balloon length, reducing the dogboning effect.
• Further research is warranted for more design goals and advanced multidisciplinary optimization methods.