Woven Self-Expanding Stent Locking Structure Against Migration
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Solution Overview
Problem
Self-expanding stents used for treating constricted body lumens face issues with positional deviation (migration) due to lack of effective anchoring, leading to reduced functionality and potential complications.
Innovation Solution
A stent design featuring a tubular portion and locking portions formed by weaving wire, with linear bodies protruding outward to act as anchors, restricting movement and enhancing stability, while maintaining structural integrity and reducing stress concentration on the body wall.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If locking portions are provided by intentionally not entwining a wire in a part of the stent, then the stent can anchor to suppress positional deviation, but the strength and durability of the stent decrease
Solution Approach 1:
The stent is divided into two functional regions: entwined portions that provide strength and durability, and locking portions that provide anchoring function. This segmentation allows each region to optimize its specific function without compromising the other, resolving the contradiction between strength and positional stability.
Solution Approach 2:
Different portions of the stent have different structural characteristics: the tubular portion has full entwining for maximum strength, while the locking portions have intentional non-entwining for maximum anchoring capability. This local differentiation of quality allows the stent to simultaneously achieve both strength and positional stability.
2Reliability
If locking portions protrude to the outside of the tubular portion, then anchoring function is enhanced, but stress concentration on the body wall increases
Solution Approach 1:
The locking portions are designed with curved shapes rather than sharp protrusions. This curvature distributes the stress more evenly across the contact area with the body wall, reducing stress concentration while maintaining the anchoring function. The curved geometry allows gradual stress transition into the body wall.
3Reliability
If the stent is made with a configuration that provides strong anchoring, then positional deviation is suppressed, but the complexity of the stent structure increases
Solution Approach 1:
The locking portions are formed using the same wire and weaving process as the tubular portion, merging the anchoring function into the existing stent structure rather than adding separate components. This integration maintains structural simplicity while providing effective anchoring through the natural geometry of the locking portions.
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 design effectively suppresses stent migration, maintains placement position, reduces stress on the body wall, and minimizes complications such as bleeding or perforation, while allowing for easy removal and improved accommodation in delivery systems.
Implementation Method 1
The self-expanding stent is a stent that contracts in the radial direction due to elasticity when a compressive force is applied, and expands in the radial direction when the compressive force is released
Data Source
AI summary
A stent includes a tubular portion and a locking portion. The tubular portion is formed by weaving a wire, has a plurality of entwined portions, and is configured to be expandable. The wire intersects with itself in a hook shape and is entwined with itself at each of the entwined portions. The locking portion is configured to protrude to the outside of the tubular portion when the tubular portion is expanded. The locking portion has a first linear body that passes through a first hole formed in a first entwined portion of the plurality of entwined portions.