Prosthetic Heart Valve Outer Cuff Axial Stretching
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Solution Overview
Problem
Existing methods for loading collapsible prosthetic heart valves into delivery devices often result in the outer cuff snagging, leading to peak loading and resheathing forces, which complicates the crimping and loading process.
Innovation Solution
A collapsible and expandable stent with an outer cuff featuring axially projecting arms that form a parachute configuration, allowing for easier gathering and loading by axially stretching the stent to minimize snagging during the loading process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the outer cuff is made larger to improve paravalvular leakage performance, then sealing performance is improved, but loading forces increase due to snagging on delivery device edges
Solution Approach 1:
The outer cuff is segmented into multiple regions with different properties: a billowing region for sealing and a gathered region for easy loading. The cuff includes multiple folds or segments that can be independently configured to billow outward for sealing while maintaining a compact form factor for loading into the delivery device.
Solution Approach 2:
The outer cuff is designed to be dynamically configurable between a billowed state during implantation for sealing and a gathered state during loading for ease of manipulation. The cuff can transition between these states through controlled deformation of the stent and cuff material.
2Ease of operation
If the stent is compressed to a smaller diameter for loading, then ease of delivery is improved, but the outer cuff may snag on delivery device edges
Solution Approach 1:
The outer cuff is pre-configured with folds and segments that are designed to gather together before loading into the delivery device. This preliminary configuration ensures that the cuff maintains a compact form factor during loading while minimizing the risk of snagging on delivery device edges.
Solution Approach 2:
The outer cuff is constructed from flexible material that can deform and conform to the stent structure during loading. The flexible nature of the cuff allows it to be compressed and manipulated within the delivery device without creating harmful snagging forces.
3Force
If the outer cuff is gathered closer to the stent for loading, then loading forces are reduced, but the cuff may not provide sufficient sealing surface
Solution Approach 1:
The outer cuff is divided into distinct functional segments: a gathered region that loads easily and a billowing region that provides sealing. The segmentation allows each region to perform its specific function optimally without compromising the other.
Solution Approach 2:
The outer cuff utilizes three-dimensional configuration where the billowing region extends radially outward to provide sealing surface area, while the gathered region maintains a compact axial profile for easy loading. The cuff transitions from a two-dimensional approximation to a three-dimensional structure that optimizes both loading and sealing.
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
This solution reduces loading forces and improves the efficiency of loading and resheathing the prosthetic heart valve, enabling successful and efficient deployment with reduced paravalvular leakage performance.
Implementation Method 1
axially stretching the collapsible and expandable stent so that the plurality of projecting arms gathers the outer cuff closer to the stent
Data Source
AI summary
A prosthetic heart valve includes a collapsible and expandable stent having a plurality of cells including a lowermost row of cells, a valve including an inner cuff, and a plurality of leaflets secured to the stent, and an outer cuff at least partially covering the lowermost row of cells, the outer cuff having a bottom edge, a top edge, and a plurality of axially projecting arms extending from the top edge, the outer cuff being attached to at least one cell at two side vertices and a bottom vertex to form at least one parachute, and to an upper vertex of the at least one cell via at least one of the plurality of axially projecting arms.