Thin-Walled Scaffolds With Modified Marker Structures
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Bioresorbable polymer scaffolds face challenges in maintaining radiopaque markers securely during crimping and balloon expansion due to significant plastic deformation, leading to potential dislodgment and reduced reliability, especially in thin-walled scaffolds with reduced wall thickness.
Innovation Solution
The development of thin-walled scaffolds with modified ring and link structures, including longer marker links and non-linear link struts, to reduce strain energy buildup and prevent marker dislodgment, along with the use of rivet-shaped markers to enhance securement within the scaffold holes, ensuring reliable retention during crimping and deployment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the scaffold wall thickness is reduced to improve deliverability and conformability, then the scaffold can better navigate tortuous anatomy, but the radiopaque markers become prone to dislodgment during crimping and deployment
Solution Approach 1:
The patent applies different structural characteristics to different parts of the scaffold. Specifically, the ring structures at locations holding radiopaque markers have modified geometries (different wavelengths, crown configurations) compared to other rings, creating localized structural reinforcement precisely where marker retention is critical, while maintaining thin walls elsewhere for deliverability
Solution Approach 2:
The scaffold combines thin-walled polymer structure with strategically placed radiopaque markers (such as platinum) and modified ring geometries. This composite approach allows the thin polymer walls to provide flexibility and deliverability while the radiopaque materials and reinforced ring structures provide marker retention and radiopacity for imaging
2Adaptability or versatility
If the scaffold undergoes significant plastic deformation during crimping and balloon expansion to enable delivery and deployment, then the scaffold can be compressed for catheter delivery and expanded at the treatment site, but the radiopaque markers may dislodge from the scaffold
Solution Approach 1:
The ring structures at marker locations are locally modified with different wavelengths and crown configurations to provide enhanced structural support precisely where markers are held, while other parts of the scaffold undergo normal plastic deformation during crimping and deployment
Solution Approach 2:
The modified ring structures with different wavelengths and crown geometries are designed in advance to absorb and distribute the strain energy generated during crimping and balloon expansion, preventing this energy from concentrating at the marker-scaffold interface and causing marker dislodgment
3Shape
If the scaffold is designed with thin walls to reduce profile and improve conformability, then the scaffold can better fit within the catheter and conform to vessel walls, but the structural strength to maintain marker position during deformation is reduced
Solution Approach 1:
The scaffold has non-uniform ring structures where rings at marker locations have different wavelengths and crown configurations compared to other rings, creating localized structural reinforcement precisely where marker holding strength is needed, while maintaining thin walls elsewhere for conformability
Solution Approach 2:
The modified ring structures utilize specific curvature characteristics (different wavelengths, crown angles) to create optimized stress distribution patterns that enhance marker retention while maintaining the overall thin-walled conformable structure
Data Source
AI summary
A thin-walled scaffold includes a radiopaque marker connected to a link. In a first example, the marker is retained on the strut by a head at one or both ends by swaging. In a second example of a thin-walled scaffold the link is modified to avoid interference during crimping. In a third example a distal end of the thin-walled scaffold is modified to improve deliverability of the thin-walled scaffold. These features are combined in a fourth example.