Stent with Acute Loop Connectors for Radial Strength
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Solution Overview
Problem
Existing stents for tubular hollow organs face issues such as buckling, turbulence, and vessel damage due to their structural design, which can lead to restenosis, aneurysm, and embolism, and are prone to fractures and detachment during movement within vessels.
Innovation Solution
A stent with a continuous, tubular structure formed by loops with acute connection points and smooth surfaces, allowing for flexibility and increased radial strength without buckling, and enabling retrieval into a catheter without breaking, using a design with loops that connect via loop heads and valleys with acute angles and smooth, curved surfaces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a rigid closed cell design is used, then radial strength is improved, but the stent buckles when bending causing turbulent flow
Solution Approach 1:
The stent structure is divided into multiple struts connected by connectors, where each connector is designed with bending freedom to allow independent movement. This segmentation enables the stent to maintain radial strength through its structured framework while avoiding buckling by allowing controlled movement at connection points.
Solution Approach 2:
The connector design changes the mechanical parameters at connection points by allowing bending movement, which transforms the overall stent behavior from rigid to flexible. This parameter change enables the stent to adapt to vessel curvature without buckling while maintaining sufficient radial support.
2Stability of the object's composition
If a flexible open cell design is used, then buckling is prevented, but radial strength is reduced
Solution Approach 1:
The stent is segmented into struts and connectors where the connector design provides bending freedom. This segmentation allows the structure to achieve flexibility through controlled movement at joints rather than through overall structural flexibility, thereby maintaining radial strength.
Solution Approach 2:
The connector design introduces dynamic movement capability at connection points, allowing the stent to adapt to vessel curvature. This dynamic feature provides buckling resistance while the overall structured framework maintains radial strength through its geometric configuration.
3Strength
If the stent is expanded radially, then the vessel is held open, but connectors can tear at the rhomboid corner points
Solution Approach 1:
The connector geometry is designed with specific dimensional relationships (side lengths and angles) that optimize stress distribution during radial expansion. The parameters are configured to reduce concentration at corner points, preventing connector tearing while maintaining effective radial support.
Solution Approach 2:
The connector design incorporates curved surfaces and optimized angular configurations that distribute mechanical stresses more evenly during expansion. This curvature-based design reduces stress concentration at connection points, preventing connector failure while achieving adequate radial support.
4Ease of operation
If the stent is pulled back into the catheter, then incorrect placement can be corrected, but the stent breaks in flexible designs
Solution Approach 1:
The connector design with bending freedom provides dynamic flexibility that allows the stent to be compressed and retrieved into the catheter without breaking. This dynamic capability enables correction of placement errors while maintaining structural integrity throughout the retrieval process.
Solution Approach 2:
The connector structure functions as a flexible element that allows the rigid-looking stent framework to be compressed and bent during retrieval. This flexibility enables the stent to be pulled back into the catheter without fracturing, combining the appearance of rigidity with the flexibility needed for retrieval.
Data Source
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AI summary
The invention relates to a stent for use in hollow tubular organs, comprising a continuous tubular or cylindrical inner cavity which is delimited by a wall. The wall is formed in a tubular or cylindrical manner about an axis which runs in a longitudinal direction and has a structure which surrounds the wall. The structure is made of elements (300, 310, 320), and the elements are made of loops which are arranged about the longitudinal axis in the radial direction. The elements are rigidly connected via connection points (200) such that a tubular or cylindrical single-piece wall structure is produced, and the stent has acute angles in the region of the connection points.