Commissure Patch Stress Isolation for Prosthetic Heart Valves
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing collapsible/expandable prosthetic heart valves face challenges with mechanical stress on leaflet tissue due to continuous opening and closing, particularly with harder materials like cobalt-chromium, where stress isolation at commissure regions is limited.
Innovation Solution
Incorporating commissure attachment features with patches, such as inner patches and billowing patches, to allow for deflection and stress absorption between leaflets and the stent, reducing mechanical stress on the leaflet material.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If harder materials like cobalt-chromium are used for stents, then stent strength and durability are improved, but mechanical stress on leaflet tissue increases
Solution Approach 1:
A compliant commissure attachment feature is introduced as an intermediary element between the rigid stent and the leaflet. This compliant feature acts as a stress-absorbing mediator that decouples the rigid stent structure from the flexible leaflet, preventing direct transmission of mechanical stress while maintaining structural integrity.
Solution Approach 2:
The commissure attachment feature utilizes material compliance parameter changes through deflection and deformation. The compliant material allows controlled deflection under mechanical load, changing its physical state to absorb stress peaks and reduce force transmission to the leaflet tissue.
2Duration of action of moving object
If continuous opening and closing occurs during valve operation, then valve function is maintained, but mechanical stress on leaflet tissue accumulates
Solution Approach 1:
The compliant commissure attachment feature provides beforehand cushioning by absorbing mechanical stress during each valve cycle before it can be transmitted to the leaflet. This preemptive stress absorption protects the leaflet from cumulative damage over time, extending its operational lifespan.
Solution Approach 2:
The design converts the potentially harmful continuous mechanical stress into a beneficial stress-absorption mechanism. The compliant feature deliberately deforms and deflects under load, transforming harmful stress transmission into useful stress dissipation that protects the leaflet while maintaining valve functionality.
3Stability of the object's composition
If rigid stent structures are used, then structural stability is improved, but stress isolation at commissure regions is reduced
Solution Approach 1:
The stent structure employs local quality differentiation by maintaining rigid structures in most areas for overall stability while introducing a locally compliant commissure attachment feature. This localized compliance specifically at the commissure region provides stress isolation where needed without compromising the global structural integrity of the stent.
Solution Approach 2:
The commissure attachment feature is segmented as a distinct, separable component between the stent and leaflet. This segmentation allows the compliant feature to independently deflect and absorb stress, isolating the stress concentration from both the rigid stent structure and the leaflet tissue.
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
The solution effectively reduces mechanical stress on leaflet tissue by enabling movement and deflection in high-stress regions, enhancing the durability and performance of prosthetic heart valves, especially with cobalt-chromium stents.
Implementation Method 1
a billowing patch coupled to a selected one of the plurality of commissure attachment features... enabling movement and deflection in high-stress regions
Data Source
AI summary
In some embodiments, a prosthetic heart valve system, includes a stent having a plurality of commissure attachment features, a cuff coupled to the stent, a plurality of leaflets, the cuff and the plurality of leaflets forming a valve assembly, and a plurality of patches, each of the plurality of patches being disposed about a selected one of the plurality of commissure attachment features and coupled thereto, the plurality of leaflets being coupled to plurality of patches.