Flexible Helical Stent with Opposing Winding and Ring Section
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing stent designs face challenges such as instability, non-uniform expansion, difficulty in accurate placement, and excessive material strain due to thin-walled materials and complex geometries, leading to issues like buckling, thrombosis, and inadequate lumen support.
Innovation Solution
A flexible stent design featuring a cylindrical shape with proximal and distal helical sections and an intermediate ring section, utilizing ductile hinges and connectors for structural stability, allowing for uniform expansion and drug delivery while maintaining radial strength and flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If thin-walled materials are used to reduce expansion forces, then expansion forces are within acceptable levels, but the stent is not visible on fluoroscopic equipment and accurate placement becomes difficult
Solution Approach 1:
The stent incorporates radiopaque markers at specific locations (ends and intermediate positions) while maintaining thin-walled construction throughout. This local addition of radiopaque material improves visibility on fluoroscopic equipment without significantly increasing the overall wall thickness or expansion forces required.
2Force
If thin-walled materials are used to reduce expansion forces, then expansion forces are within acceptable levels, but the stent lacks structural stability and exhibits buckling
Solution Approach 1:
The stent is divided into multiple segments or cells formed by struts and connectors. This segmented structure provides structural stability and resistance to buckling while maintaining thin-walled construction, as the distributed geometry rather than continuous thick walls provides the necessary rigidity.
Solution Approach 2:
The stent combines thin-walled material with strategically placed radiopaque markers and optimized strut-connector geometries. This composite approach maintains low expansion forces while improving structural stability and visibility.
3Adaptability or versatility
If complex geometries are used to improve flexibility, then the stent can navigate body lumens, but the struts become unstable and buckle
Solution Approach 1:
The stent employs dynamic hinge connectors that allow controlled movement between struts during navigation, providing flexibility to navigate body lumens. Once deployed, the hinge geometry locks into a stable configuration that prevents buckling while maintaining the ability to adapt to vessel shapes.
4Ease of manufacture
If uniform strut geometry is used to simplify manufacturing, then manufacturing is easier, but expansion becomes non-uniform causing inadequate lumen support
Solution Approach 1:
The stent incorporates struts and connectors with locally optimized geometries at different positions along the stent length. This allows uniform expansion during deployment while maintaining ease of manufacture through standardized connection mechanisms and modular design elements.
Data Source
AI summary
The present invention relates to tubular stents that are implanted within a body lumen. The stent has a cylindrical shape defining a longitudinal axis and includes a proximal helical section, a distal helical section and an intermediate ring section there between. Each of the proximal and distal helical sections has of a plurality of longitudinally oriented strut members and a plurality of circumferentially oriented hinge members connecting circumferentially adjacent strut members to form a band, the band being wrapped about the longitudinal axis in a substantially helical manner to form a plurality of helical windings, wherein the distal helical section is wound about the longitudinal axis in the opposite direction from the proximal helical section. The intermediate ring section includes a plurality of longitudinally oriented strut members and a plurality of circumferentially oriented hinge members connecting circumferentially adjacent strut members to form an endless ring.