Helical Stent with Segmented Bridges for Tortuous Vessels
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Solution Overview
Problem
Existing stents face challenges in maintaining vessel patency while adapting to tortuous anatomy and navigating complex ducts or vessels, requiring high flexibility and a small delivery profile.
Innovation Solution
A stent with a continuous helical winding and interconnected struts, featuring bridges that connect circumferential sections and an annular ring with extensions, allowing for differential strut lengths and configurations that enhance flexibility and minimize distortion during expansion and compression.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a stent is designed with rigid structure to maintain vessel patency, then it can provide adequate structural support, but it cannot navigate tortuous ducts or vessels effectively
Solution Approach 1:
The stent is divided into multiple circumferential sections (first, second, third sections) connected by bridges. This segmentation allows each section to move independently, enabling the stent to navigate tortuous anatomy while maintaining structural support. The bridges connect these sections in a way that permits relative movement between them.
Solution Approach 2:
The stent structure incorporates dynamic elements including the bridges that allow relative movement between circumferential sections, and the annular ring with extensions that can deform during expansion. This dynamic design enables the stent to adapt to tortuous vessels while providing adequate support.
2Adaptability or versatility
If a stent is made highly flexible to navigate tortuous anatomy, then it can be delivered through small incisions, but it cannot maintain adequate structural support for vessel patency
Solution Approach 1:
The stent is divided into multiple circumferential sections (first, second, third sections) connected by bridges. This segmentation allows each section to move independently, enabling the stent to navigate tortuous anatomy while maintaining structural support. The bridges connect these sections in a way that permits relative movement between them.
Solution Approach 2:
The stent structure incorporates dynamic elements including the bridges that allow relative movement between circumferential sections, and the annular ring with extensions that can deform during expansion. This dynamic design enables the stent to adapt to tortuous vessels while providing adequate support.
3Ease of manufacture
If a stent uses uniform strut lengths for simplicity of manufacture, then production is easier, but it causes distortion during expansion and compression
Solution Approach 1:
The stent employs different strut lengths in different locations: first struts have a first length, second struts have a second length, and third struts have a third length. This local variation in strut quality allows the stent to expand and compress uniformly without distortion, while still being manufacturable using standard techniques.
4Manufacturing precision
If a stent is designed with complex structure to reduce distortion during expansion, then expansion uniformity improves, but device complexity increases
Solution Approach 1:
The stent is divided into multiple circumferential sections (first, second, third sections) connected by bridges. This segmentation allows each section to move independently, enabling the stent to navigate tortuous anatomy while maintaining structural support. The bridges connect these sections in a way that permits relative movement between them.
Solution Approach 2:
The stent employs different strut lengths in different locations: first struts have a first length, second struts have a second length, and third struts have a third length. This local variation in strut quality allows the stent to expand and compress uniformly without distortion, while still being manufacturable using standard techniques.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The stent achieves uniform expansion, reduced distortion, and improved navigability through tortuous anatomy, requiring less force for deployment and maintaining patency with a smaller profile, facilitating easier delivery and implantation.
Implementation Method 1
Nitinol, which has strong shape memory characteristics so that Nitinol self-expands when placed in the duct or vessel of a mammalian body at normal body temperature
Data Source
AI summary
Preferred embodiments of a stent with a high degree of flexibility are shown and described. The stent can include a continuous helical winding having interconnected struts joined at vertices, and having bridges connecting sections of the helical winding to each other. An annular ring can be provided at one or both ends of the helical winding, and the annular ring can have five extensions extending to connect to the helical winding. One of the extensions can connect to a bridge and another extension can connect to a vertex. The struts at the ends of the helical winding can have strut lengths that differ from the strut lengths of the struts in a central portion of the winding between the ends of the winding.