Vascular Stent Struts with Tapering Profile for Radial Force
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Solution Overview
Problem
Existing coronary stents face complications such as restenosis and thrombosis due to neointimal formation and elastic recoil, with current materials being brittle and difficult to design into compliant expanding mechanisms.
Innovation Solution
A vascular stent assembly with struts featuring a tapering profile and constant depth, made from biocompatible materials like carbon-infiltrated carbon nanotubes, which allows for uniform stress distribution and reduced clashing, enhancing radial force and biocompatibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If conventional stent designs are used, then manufacturing is simpler, but radial force is insufficient and stress distribution is non-uniform
Solution Approach 1:
The patent applies local quality by implementing a tapering profile specifically on the strut thickness rather than uniform modification throughout the stent. The strut thickness transitions from a first value at the proximal end to a second value at the distal end, creating localized geometric variation that optimizes stress distribution and radial force at critical locations while maintaining overall structural integrity
Solution Approach 2:
The patent employs parameter changes by systematically varying the strut thickness parameter along the length of the stent. The tapering profile continuously modifies the thickness parameter from proximal to distal ends, transforming the stent's mechanical properties to achieve uniform stress distribution and enhanced radial force without requiring complete redesign of the entire stent architecture
2Stability of the object's composition
If stent struts have non-tapered geometry, then manufacturing is easier, but stress distribution is non-uniform leading to restenosis
Solution Approach 1:
The tapering profile applies local quality by concentrating geometric modification at the strut level while maintaining constant depth. This localized variation in thickness along the strut length creates favorable stress distribution patterns at the implantation site, reducing stress concentration points that would otherwise lead to restenosis
Solution Approach 2:
The continuous tapering profile introduces curvature to the otherwise linear strut geometry. This gradual curvature in the thickness variation creates smooth stress transitions along the strut length, eliminating abrupt geometric discontinuities that would cause stress concentration and subsequent tissue hyperplasia
3Strength
If brittle materials are used for stents, then structural strength is achieved, but compliance and expanding mechanism design become difficult
Solution Approach 1:
The patent utilizes parameter changes in the strut thickness to optimize the balance between strength and compliance. By tapering the thickness from proximal to distal ends, the stent achieves varying mechanical properties along its length, with thicker sections providing structural strength and thinner sections allowing for compliance and expansion
Data Source
AI summary
A vascular stent assembly includes at least a first and a second strut, each including a thickness and a depth. The assembly includes a pair of end radii, with each of the first and second struts extending from one of the pair of end radii. A thickness of at least one of the first and second struts includes a tapering profile extending from one of the end radii to another of the end radii, the tapering profile following a continuously increasing or decreasing function through at least half a length of the at least one strut.