MECHANICAL BEHAVIOR OF A NEW STENT WITH NEGATIVE POISSON’S RATIO: THE INFLUENCE OF GEOMETRIC PARAMETERS

For the proposed new negative Poisson’s ratio vascular stent, the effects of stent parameters on radial resilience, axial shortening rate, and radial support stiffness were compared and analyzed based on finite element methods and orthogonal tests, considering the complete compression-grip expansion process of the stent. It was concluded that decreasing the wall width of the cell structure or increasing the length of the cell structure could improve the radial resilience performance of the stent; decreasing the number of axial cell structures, decreasing the pinch angle, and increasing the wall width of the cell structure could reduce the axial shortening rate and could improve the axial shortening performance of the stent; increasing the wall width of the cell structure, the wall thickness of the cell structure and the number of axial cell structure could improve the radial support stiffness of the stent. In Vitro tests were conducted to study the effects of compression rate, circumferential compression position, and number of axial cells on the radial support performance of the stent. The geometric parameters of vascular stents have a significant influence on the mechanical properties of stents and should be given significant consideration in the clinical selection and optimal design of stents.