Single Cell Stent Design for Heart Valve Fixation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing replacement heart valve prostheses face challenges in achieving precise positioning, sufficient fixation, and reduced interference with soft endogenous tissues like the mitral or tricuspid heart valves, particularly in the tricuspid context, where the valve diameter is large and the surrounding tissue is sensitive or anatomically challenging.
Innovation Solution
A stent-based replacement heart valve prosthesis with a single cell structure from proximal to distal ends, composed of predefined strut dimensions and a combination of inner and outer stents, featuring atrial and ventricular intermediate struts, longitudinal struts, and fixation means, designed to provide optimal radial force, reduced interference, and improved sealing characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a replacement heart valve prosthesis is designed with traditional multi-cell stent structure, then the structural strength is sufficient, but the positioning precision and fixation capability in soft endogenous tissue are insufficient
Solution Approach 1:
The stent structure is divided into distinct functional segments: a first stent portion for positioning in the annulus with a first cell structure, and a second stent portion for engagement with endogenous tissue with a second cell structure. This segmentation allows each portion to be optimized independently for its specific function, improving positioning precision while managing overall complexity.
Solution Approach 2:
Different cell structures are applied to different portions of the stent based on local requirements. The first cell structure in the annular portion provides positioning stability, while the second cell structure in the ventricular portion enhances fixation capability in soft tissue. This local differentiation resolves the contradiction by tailoring structural complexity to functional needs.
2Reliability
If the stent structure is made more complex to improve fixation in soft tissue, then the fixation capability improves, but the interference with endogenous tissue increases
Solution Approach 1:
The stent is segmented into a first portion that interfaces with the annulus and a second portion that interfaces with endogenous tissue. Each portion has a specifically designed cell structure optimized for its interaction mode, allowing reliable fixation while minimizing unnecessary interference with surrounding tissues.
Solution Approach 2:
The cell structure geometry is locally optimized: the first cell structure provides stable anchoring in the annular region, while the second cell structure is designed to engage soft tissue with minimal disruption. This local quality differentiation achieves reliable fixation without excessive interference.
3Reliability
If the strut dimensions are increased to improve radial force for fixation, then the fixation capability improves, but the compliance with soft endogenous tissue decreases
Solution Approach 1:
Different strut dimensions and cell geometries are applied locally to different stent portions. The first stent portion has strut dimensions optimized for generating radial force in the annulus, while the second stent portion has smaller, more flexible struts that comply with soft endogenous tissue. This resolves the contradiction by allowing high fixation force where needed while maintaining compliance where flexibility is required.
Solution Approach 2:
The stent is divided into segments with different mechanical properties. The first segment provides rigid support and radial force for fixation, while the second segment provides flexibility and compliance with surrounding tissue. This segmentation allows simultaneous achievement of fixation capability and tissue compliance.
4Device complexity
If a single cell structure is used from proximal to distal end, then the device complexity is reduced, but the positioning and fixation performance in challenging anatomy is insufficient
Solution Approach 1:
The stent is segmented into a first portion with a first cell structure optimized for annular positioning and a second portion with a second cell structure optimized for tissue fixation. This segmentation maintains relatively simple overall construction while achieving superior positioning accuracy through functional differentiation of the cell structures in different anatomical regions.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The present invention relates to a novel stent and a replacement heart valve prosthesis.