Stent With Starry Cell Structure For Flexible Bending
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional stents exhibit poor bending characteristics when used in vessels with sharply curved portions, and the coating process further degrades this flexibility, making them unsuitable for vessels with complex curvatures.
Innovation Solution
A method of manufacturing a stent by alternating obtuse and acute angles to form starry cells, allowing wires to freely move in both diametrical and lengthwise directions, using a specialized jig to bend and cross wires in a zigzag pattern, resulting in a stent with improved flexibility and resistance to folding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the stent is manufactured by bending wires in right-angled directions using a basic jig, then the manufacturing process is simple, but the bending characteristic is poor when used in sharply curved vessels
Solution Approach 1:
The stent structure transitions from fixed right-angled intersections to dynamic intersections that can freely move relative to each other. The wire crossing points are designed to allow sliding movement, enabling the stent to adapt its shape dynamically when bent, thus improving bending characteristics while maintaining manufacturing simplicity
Solution Approach 2:
The invention changes the geometric parameters of the cell intersections from fixed right angles to variable angles. The intersecting wires form cells with angles that can change during bending, allowing the stent to accommodate sharply curved vessel geometries while preserving the basic manufacturing approach
2Reliability
If the stent is coated with PTFE or silicone to prevent cell penetration, then the biocompatibility is improved, but the bending characteristic is further degraded
Solution Approach 1:
The dynamic intersection design allows the coated stent to maintain flexibility by enabling wire movement at intersections. This dynamic structure compensates for the rigidity introduced by the coating, preserving bending characteristics while maintaining the biocompatibility benefits of PTFE or silicone coating
Solution Approach 2:
The coating is applied as a thin flexible layer that conforms to the dynamic structure of the stent. The flexible coating follows the wire movements at intersections, maintaining the bending capability even though the coating itself adds some rigidity
3Stability of the object's composition
If the wires are tightly woven to form a stable cylindrical structure, then the structural stability is improved, but the flexibility in diametrical and lengthwise directions is reduced
Solution Approach 1:
The stent structure incorporates dynamic elements at the wire intersections that allow controlled movement. This enables the tightly woven structure to maintain overall stability while allowing local flexibility through wire sliding at intersections, resolving the contradiction between structural integrity and adaptability
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 maintains flexibility and prevents folding even when sharply bent, ensuring reliable performance and maintaining wire integrity after coating, with the unique starry cell structure allowing for rapid expansion and contraction.
Implementation Method 1
a strand of wire, which has a predetermined length and is formed of a superelastic shape memory alloy or stainless steel
Implementation Method 2
the wire constituting the stent provides a superior bending characteristic and is prevented from being twisted after being coated
Data Source
AI summary
Provided is a method for manufacturing a stent having a superior bending characteristic, in which a basic jig is employed to weave wires by alternating an obtuse angle and an acute angle so as to repetitively form starry cells in left and right portions and upper and lower portions of the stent, and in which the wires intersecting each other in the starry cells are allowed to freely move to provide the superior bending characteristic caused by flexibility in both the diametrical direction and lengthwise direction thereof, and the stent manufactured thereby. Thus, the stent can have a flexible bending characteristic and is prevented from being folded even when sharply bent after being coated.