Varying Cell Density Stent for Heart Valve Anchoring
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Solution Overview
Problem
Prosthetic heart valves with existing stent designs often experience inaccurate deployment and anchoring, leading to paravalvular leakage and reduced cardiac efficiency due to calcification and anatomical variations, which current technologies fail to adequately address.
Innovation Solution
A collapsible and expandable stent with varying cell density, featuring a higher cell density in the annulus section for secure anchoring and a lower cell density in the aortic section to minimize interference with blood flow, along with a transition section to facilitate proper expansion and sealing, is used to improve the positioning and sealing of prosthetic heart valves.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a uniform cell density stent design is used, then the manufacturing process is simple, but the deployment accuracy and sealing performance are poor due to inability to address calcification and anatomical variations
Solution Approach 1:
The stent employs varying cell densities in different sections: a first cell density in the annulus section for secure anchoring, a second cell density in the aortic section for minimal blood flow interference, and a third cell density in the transition section for proper expansion. This local differentiation resolves the contradiction by optimizing deployment accuracy in specific regions without requiring complete structural redesign throughout the entire stent.
Solution Approach 2:
The stent is divided into three distinct sections (annulus section, transition section, aortic section) with different cell densities. This segmentation allows each section to perform its specific function independently, improving overall deployment accuracy while managing complexity through modular design principles.
2Reliability
If a high cell density is used throughout the stent, then the anchoring security is improved, but the interference with blood flow and coronary access increases
Solution Approach 1:
The stent applies high cell density (first cell density) specifically in the annulus section where anchoring security is critical, while using lower cell density (second cell density) in the aortic section where blood flow interference would be problematic. This localized application resolves the contradiction by providing high reliability only where needed without generating harmful effects in other regions.
3Object-generated harmful factors
If a low cell density is used throughout the stent, then the interference with blood flow is minimized, but the anchoring security and sealing performance deteriorate
Solution Approach 1:
The stent uses low cell density (second cell density) in the aortic section to minimize blood flow interference, while maintaining high cell density (first cell density) in the annulus section to ensure sealing performance. This spatial differentiation resolves the contradiction by allowing low harmful effects in the aortic region while maintaining high reliability in the annulus region.
4Stability of the object's composition
If the entire valve is released for expansion, then the expansion is uniform, but the control over deployment positioning is reduced
Solution Approach 1:
The stent's varying cell density structure provides different mechanical properties in different sections, allowing the annulus section to anchor first and provide positioning control, while the aortic section expands subsequently with uniformity. The transition section with intermediate cell density facilitates this controlled sequential expansion, resolving the contradiction between uniform expansion and deployment control.
Data Source
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Figure 3A
AI summary
A prosthetic heart valve for replacing a native valve includes a collapsible and expandable stent extending between a proximal end and a distal end, the stent including an annulus section adjacent the proximal end and an aortic section adjacent the distal end. The annulus section has cells arranged in at least one annulus row, each annulus row having a same first number of cells, the first number defining a first cell density. The aortic section has cells arranged in at least one aortic row, each aortic row having a same second number of cells, the second number defining a second cell density, the first cell density and the second cell density being different. A valve assembly is disposed within the stent.