Self-Expandable Aortic Valve Stent with Three Arms
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Solution Overview
Problem
Current transcatheter aortic valve implantation methods face challenges in providing secure, accurate positioning and free access to coronary arteries, as well as repositionability and secure orientation of valve leaflets relative to semilunar leaflets, with existing designs often hindering coronary access and lacking precise implantation capabilities.
Innovation Solution
A self-expandable aortic valve stent with a unique design featuring three upper arms and a mesh lower part, allowing for repositionability and secure fixation, made from nitinol alloy with shape memory effect, incorporating upper and lower tags for precise X-ray guided implantation and access to coronary arteries, and a sealing membrane integrated with valve leaflets for optimal positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a dense mesh stent design is used to provide structural support, then stent strength and stability are improved, but access to coronary arteries is hindered
Solution Approach 1:
The stent is divided into multiple segments including a proximal portion with a relatively open structure and a distal portion with a relatively dense structure. This segmentation allows the proximal part to provide coronary access while the distal part provides structural support, resolving the contradiction between strength and accessibility.
2Reliability
If the valve is implanted securely in one position, then implantation stability is improved, but repositionability is lost
Solution Approach 1:
The stent is designed with dynamic characteristics allowing it to be compressed and expanded. The self-expanding nitinol structure can be temporarily compressed for delivery and positioning, then expanded to achieve secure implantation. This dynamic design enables both repositionability during deployment and stability after implantation.
3Reliability
If the valve is implanted supra-annularly to secure positioning, then implantation stability is improved, but access to coronary arteries is hindered
Solution Approach 1:
Different portions of the stent have different structural qualities: the proximal portion has a more open, less dense structure that allows coronary artery access, while the distal portion has a denser structure for stable anchoring. This local quality differentiation resolves the contradiction between stable supra-annular implantation and coronary accessibility.
4Adaptability or versatility
If a self-expandable nitinol stent is used to enable repositioning, then adaptability is improved, but precise orientation of valve leaflets is compromised
Solution Approach 1:
The stent incorporates pre-formed radiopaque markers and orientation features that are built into the structure before implantation. These preliminary markers allow the operator to visualize and adjust the stent orientation during the procedure, ensuring precise alignment of valve leaflets with semilunar leaflets even though the stent remains repositionable.
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
Enables flexible, precise, and secure transcatheter aortic valve implantation with improved access to coronary arteries and repositionability, ensuring accurate valve placement and secure anchoring, facilitating both initial implantation and potential repositioning if needed.
Implementation Method 1
made from nitinol alloy with shape memory effect
Data Source
AI summary
The invention describes a stent of the aortic valve which is self-expandable and also repositionable and preferably made from nitinol. It consists of two parts: the upper part and the lower part. The lower part is a mesh (1) laid out so that it creates a kind of cylinder wall on the entire height of the element. Also other shape of the mesh is acceptable, for example partially conical, or partially resembling flattened side wall of the cylinder. However, the upper part of the stent consists of derived from the mesh (1) upwards and arranged at equal intervals three arms (2) the height of which is slightly larger than the height of the mesh (1), a bit less than the height of the mesh (1) or equal to its height. The stent arms (2) are shaped in such a way that they form together a kind of an oval chalice bowl, and their end, peripheral part is preferably straight and also inclined to the middle. Space between the arms (2) always ensures free access to patient's coronary arteries. At the end of each of the arms (2) is an upper tag (3) of the valve and each upper tag (3) has its corresponding lower tag (8) located at the bottom of the mesh (1) which is on the opposite side and below a given arm (2). The lower valve tag (8) enables precise implantation of the stent according to scheduled plan.