Helical Reinforcement Element for Graft Creep Rupture
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Solution Overview
Problem
Endoluminal devices used for vascular interventions face issues with graft creep due to material fatigue under blood pressure pulsations and vessel movements, leading to potential graft creep rupture, which can result in endoleaks, aneurysms, and other complications.
Innovation Solution
A medical device with a radially expandable stent frame structure and a reinforcement element featuring a plurality of bends disposed helically along the graft material, providing hoop strength and tensile support to inhibit creep rupture while maintaining longitudinal flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the graft material is made flexible to allow navigation through vessels, then the ease of operation is improved, but the strength and resistance to creep rupture deteriorate
Solution Approach 1:
The graft prosthesis combines flexible graft material with a reinforcement element featuring a helical pattern with bends. This composite structure allows the graft to maintain navigation flexibility while the reinforcement element provides creep rupture resistance through its geometric configuration that resists radial expansion forces.
Solution Approach 2:
The reinforcement element incorporates a helical pattern with bends that creates curved geometries along the graft. These bends are specifically configured to resist radial expansion forces while allowing axial flexibility, addressing both the flexibility and strength requirements simultaneously.
2Strength
If the graft material is made stronger to prevent creep rupture, then the strength is improved, but the longitudinal flexibility and bending capability deteriorate
Solution Approach 1:
The reinforcement element features bends in its helical pattern that are strategically designed to allow longitudinal bending while resisting radial expansion. The curved geometry enables the structure to flex along the length of the graft while maintaining strength against creep forces.
Solution Approach 2:
The reinforcement element is not uniformly distributed but is placed at specific locations along the graft where creep resistance is most needed. The helical pattern with bends provides localized reinforcement that maintains overall graft flexibility while preventing creep rupture at critical points.
3Productivity
If the graft diameter is expanded to maximum to prevent narrowing, then the blood flow is improved, but the graft becomes more susceptible to creep rupture
Solution Approach 1:
The combination of graft material and reinforcement element with helical bends creates a composite structure that can maintain expanded diameter for optimal blood flow while the reinforcement provides continuous resistance to creep forces that would otherwise cause rupture in a maximally expanded graft.
Data Source
AI summary
A medical device, such as a prosthesis, and method of forming the same are disclosed. The medical device includes a cover material and a reinforcement element, and may include a stent frame structure. The reinforcement element includes a plurality of bends disposed about a pattern axis. The pattern axis is arranged helically along the cover material.