Variable Density Braided Stent for Aneurysm Occlusion
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Solution Overview
Problem
Current stents lack variability in porosity, which is essential for effective diffusion of body fluids in small vessels while occluding aneurysms, particularly in neuro-vascular applications, where they need to balance fluid flow and occlusion requirements.
Innovation Solution
A braided stent with variable porosity achieved by selectively distributing and weaving fibers or wires into strands, altering the number and distribution of members and strands to modify the size and shape of openings, allowing for different porosity characteristics in various regions to accommodate fluid flow and occlusion needs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a stent has uniform porosity throughout, then manufacturing is simple, but it cannot simultaneously allow fluid diffusion in healthy vessels and occlude aneurysms
Solution Approach 1:
The stent implements local quality by varying the braid pattern density in different longitudinal sections. The first section has a first braid pattern with a first porosity suitable for fluid diffusion in healthy vessels, while the second section has a second braid pattern with a second porosity for occluding aneurysms. This allows each section to have optimized properties for its specific function.
Solution Approach 2:
The stent is segmented into multiple longitudinal sections, each with distinct braid patterns and porosity characteristics. This segmentation enables different functional zones within a single stent structure, allowing simultaneous fulfillment of fluid diffusion requirements in healthy vessels and occlusion requirements in aneurysmal regions.
2Quantity of substance
If the stent porosity is increased to allow fluid diffusion, then body fluids can reach small vessels, but the stent cannot effectively occlude aneurysms
Solution Approach 1:
The stent applies local quality by creating regions with different porosity levels. In sections where fluid diffusion is needed (adjacent to healthy vessels), the braid pattern is more open with higher porosity. In sections where occlusion is needed (at aneurysm necks), the braid pattern is denser with lower porosity, ensuring reliable sealing while maintaining fluid flow in appropriate regions.
3Reliability
If the stent porosity is decreased to occlude aneurysms, then aneurysm flow is restricted, but fluid diffusion to adjacent small vessels is impaired
Solution Approach 1:
The stent implements local quality by spatially differentiating porosity across its length. Denser braid patterns with lower porosity are positioned at aneurysm necks to ensure effective occlusion, while more open braid patterns with higher porosity are positioned in regions adjacent to healthy vessels to maintain fluid diffusion and prevent impairment of flow to small vessels.
Data Source
AI summary
A stent comprises at least one stent member woven to form a substantially tubular body that defines a flow path. The tubular body comprises a first region and a second region. In the first region the at least one stent member defines a plurality of first region openings and in the second region at least one first portion of the at least one member and at least one second portion of the at least one member are engaged together to form at least one primary strand. The at least one primary strand defines a plurality of second region openings. The at least one of the plurality of second region openings is in fluid communication with the flow path. The plurality of second region openings provide the second region with a greater porosity than the first region.