Design method of self-expanding stents suitable for the patient's condition

Abstract

Abstract

A medical device of mesh-shaped tubular structure, called a stent, is frequently used to expand the stenosis of a blood vessel. The stent normally has the structure of longitudinally repeated wavy wire parts and strut parts, and its mechanical properties, such as bending flexibility and rigidity in the radial direction, mainly depend on the shape of the wavy wire and the construction of the strut. This paper presents, a design support system for self-expanding stents that can design stent shape and evaluate stent performance as routine flow. A two-stage method for designing suitable stent shapes is built into this system. The mechanical properties of self-expandable stents are evaluated using a non-linear finite element method. The wire length of the stent and the wire width are adopted as design parameters, and the sensitivity of the mechanical properties to these parameters is obtained. When the patient's conditions, such as blood vessel type and the diameter of the blood vessel with stenosis, are given by medical examination, the performance of the stent in restoring blood flow has to be determined. Finally, a method is proposed for designing suitable stents with the desired performance on the basis of mechanical properties.