Folded Double-Wall Mitral Valve Stent for Sealing and Anchoring
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Solution Overview
Problem
Transcatheter mitral valve therapies face challenges due to the difficulty in balancing sealing and anchoring properties of replacement valves, leading to high delivery failure rates and anatomical incompatibilities, particularly with non-circular valve annulus shapes and ventricular contraction forces.
Innovation Solution
A unibody, folded double-wall stent structure with a stent cover and leaflet valve attached to the inner lumen, decoupling the valve support geometry from the retention structure, allowing for independent expansion and contraction of the outer and inner walls, facilitating transcatheter delivery and reducing outflow track obstruction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a two-part replacement valve structure is used to address sealing and anchoring challenges, then the sealing and anchoring properties may be improved, but the delivery failure rate increases and the device becomes too large for transcatheter delivery
Solution Approach 1:
The patent merges the inner and outer walls into a single unibody structure formed from one continuous piece of material. This integration eliminates the complexity of assembling and coordinating two separate components during delivery, thereby reducing delivery failure rates while maintaining the functional benefits of both sealing and anchoring structures
Solution Approach 2:
The patent employs a nested configuration where the inner wall is positioned within the outer wall, with both walls collapsing concentrically during delivery. This nesting allows the complex double-wall structure to be compressed into a compact form suitable for transcatheter delivery through small access vessels
2Reliability
If the outer wall is designed to conform to native anatomy for sealing, then sealing properties improve, but outflow track obstruction may occur due to ventricular contraction forces
Solution Approach 1:
The patent segments the stent structure into two functional walls: an outer wall designed to seal against the native annulus and an inner wall that maintains a stable geometry for valve support. This segmentation allows each wall to be optimized for its specific function, with the outer wall conforming to anatomy for sealing while the inner wall resists deformation from ventricular contraction
Solution Approach 2:
The patent applies different geometric properties to different parts of the structure. The outer wall has a geometry optimized for conforming to the native annulus shape, while the inner wall has a geometry optimized for maintaining structural stability and preventing outflow track obstruction. This local differentiation of properties resolves the conflict between sealing and obstruction prevention
3Strength
If multiple joined support components are used to build the stent, then structural integrity may be improved, but force concentrations at connection points cause complications
Solution Approach 1:
The patent combines multiple support components into a single unibody structure formed from one continuous piece of material. This eliminates all welded or mechanically connected joints that would create stress concentration points, while maintaining structural integrity through the continuous material geometry and distributed load paths
4Stability of the object's composition
If the stent is designed with fixed geometry to provide stable support, then valve support stability improves, but adaptability to non-circular valve annulus shapes decreases
Solution Approach 1:
The patent segments the stent into an outer wall and inner wall that can deform independently. The outer wall is designed to conform to non-circular annulus shapes, while the inner wall maintains a more stable geometry for valve support. This segmentation allows the structure to adapt to anatomical variations while preserving functional stability
Solution Approach 2:
The patent employs asymmetric geometries in the outer wall to match the non-circular shape of the native valve annulus. This asymmetric design allows the outer wall to conform to the specific anatomical shape while the inner wall maintains sufficient stability for valve support, resolving the conflict between adaptability and stability
Data Source
AI summary
A replacement heart valve comprises a unibody, folded, double-wall stent, with a stent cover and a leaflet valve attached to the inner lumen of the stent. The heart valve is delivered using a multi-pulley, suture-based stent restraint assembly provided by fixed guide openings or structures along the distal end of the delivery system that independently permits expansion of the distal and proximal ends of the outer wall of the stent, and control of the inner wall expansion simultaneously with or separately from the expansion of the outer wall.