Improved geometry and metallic material for controlled recoil stent

摘要

A biocompatible material may be configured into any number of implantable medical devices including intraluminal stents. The biocompatible material may comprise metallic and non-metallic materials. These materials maybe designed with a microstructure that facilitates or enables the design of devices with a wide range of geometries adaptable to various loading conditions. An embodiment is described in which an intraluminal scaffold comprises at least one load bearing element which has a luminal surface and an abluminal surface. The load bearing element has a predetermined wall thickness. The wall thickness is defined by the radial distance between the luminal surface and the abluminal surface, and a predetermined feature width. An area bounded by the wall thickness and the feature width comprises three zones, a first zone undergoing a change in compressive and/or tensile stress due to an external load, a second zone undergoing a change in tensile and/or compressive stress due to the external load and a neutral zone between the first and second zones. The feature width is the linear distance across the first, neutral and second zones in a direction substantially orthogonal to the wall thickness. The load bearing element is fabricated from a metallic material processed to have a microstructure with a granularity of about 32 microns or less and at least one internal grain boundary within the bounded area.