Expandable Stent With Diamond and Flex Cell Modules
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Solution Overview
Problem
Conventional stents face challenges in maintaining radial strength in the expanded state while minimizing longitudinal contraction during radial expansion, which complicates navigation through vessel turns and bends, and often result in an increased collapsed length that hinders deployment.
Innovation Solution
The design incorporates a main body with ring structures and connector segments that form diamond and flex cell modules, allowing for rotation and orientation changes during expansion to maintain axial flexibility and constant length, utilizing undulating patterns and connector segments that adjust from non-parallel to parallel configurations between the collapsed and expanded states.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a stent is formed from larger tubing to increase radial strength, then radial strength in expanded state is improved, but collapsed diameter increases making navigation difficult
Solution Approach 1:
The stent is divided into multiple cell modules (diamond cells and flex cells) that are interconnected. This segmentation allows the stent to achieve high radial strength through the diamond-shaped support structures while maintaining a compact collapsed profile through the modular arrangement that can nest efficiently.
2Length of stationary object
If a stent is designed to minimize longitudinal contraction during expansion, then constant length is improved, but axial flexibility may be reduced
Solution Approach 1:
The stent incorporates flex cells with connector segments that can dynamically adjust their configuration during expansion. These connectors allow controlled longitudinal contraction in specific regions while maintaining overall length stability, and provide axial flexibility when needed for navigation through vessel bends.
Solution Approach 2:
Different cell modules have different properties: diamond cells provide radial strength and resistance to longitudinal contraction, while flex cells with angled connectors provide axial flexibility. This local differentiation allows the stent to simultaneously achieve constant length and navigability.
3Length of stationary object
If a stent has a longer collapsed length to maintain constant expanded length, then length stability is improved, but difficulty in advancing through turns increases
Solution Approach 1:
The connector segments between cell modules are designed to be flexible and capable of angular adjustment during navigation. This allows the stent to bend and conform to vessel geometry during advancement, then stabilize into its configured shape once deployed, maintaining the desired expanded length.
Data Source
AI summary
An expandable stent radially adjustable between a collapsed state and an expanded state. The stent generally includes a main body and a plurality of connector segments. The main body has first and second ends, a longitudinal axis extending from the first end to the second end, and a plurality of ring structures. Each of the plurality of connector segments joins adjacent ring structures. Some ring structures may be connected by a pair of diamond connector segments that define a diamond-shaped portion when the stent is in the expanded state. Some ring structures may be connected by flex connector segments oriented to permit rotation of the second ring structure about the longitudinal axis during radial expansion of the stent.