Self-Expanding Valve Prosthesis Tab Geometry for Leaflet Engagement
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Solution Overview
Problem
Current medical devices for treating mitral regurgitation face challenges in accurately positioning and securely anchoring prosthetic valves, particularly due to difficulties in engaging moving valve leaflets and varying clinical results across different surgical and minimally invasive methods.
Innovation Solution
A self-expanding prosthetic valve system with an atrial skirt, ventricular skirt, and tabs that deploy via a delivery system to anchor securely to the heart's anatomy, utilizing a sequence of expansion to maximize window size for leaflet engagement and minimize it for secure anchoring, facilitated by a cam mechanism and pusher element for controlled deployment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional surgical or percutaneous catheter methods are used to implant prosthetic valves, then valve replacement can be achieved, but the devices are difficult to deliver, expensive to manufacture, and may not be indicated for all patients
Solution Approach 1:
The prosthetic valve assembly is divided into separate components including a valve prosthesis, a delivery catheter, and a tissue engaging element that can be delivered independently through the catheter. This segmentation allows for simplified delivery through peripheral vessels while maintaining reliable valve replacement function.
Solution Approach 2:
The tissue engaging element and valve prosthesis are nested within the delivery catheter in a collapsed state during delivery, then deployed in sequence at the implantation site. This nesting enables complex devices to be delivered through simple catheter-based approaches, reducing delivery difficulty while maintaining reliability.
2Reliability
If prosthetic valves are anchored by engaging tissue such as native valve leaflets, then secure anchoring can be achieved, but capturing a moving valve leaflet is challenging
Solution Approach 1:
The delivery catheter is positioned and the tissue engaging element is prepared for deployment before the valve leaflet movement becomes a problem. The element is then deployed to engage the leaflet in a controlled manner, securing the prosthesis before leaflet motion can cause displacement.
Solution Approach 2:
A tissue engaging element with specific geometric features acts as an intermediary between the prosthetic valve and the native valve leaflet. This intermediary component facilitates reliable engagement by providing a mechanical interface that can capture and hold the moving leaflet, translating leaflet motion into secure anchoring.
3Measurement precision
If a self-expanding prosthetic valve system with tabs is used to anchor securely, then placement accuracy is improved, but the device complexity increases
Solution Approach 1:
The tabs are designed to dynamically change their configuration from a collapsed state during delivery to an expanded state at implantation. This dynamic transformation allows the tabs to provide precise anchoring features only when needed, maintaining placement accuracy while reducing complexity during the delivery phase.
Solution Approach 2:
The geometric parameters of the tabs (such as their angle and position) are changed from a compressed configuration during delivery to an expanded configuration at implantation. This parameter change enables the tabs to engage tissue features at specific angles for accurate positioning, while the same tabs remain compact during delivery to simplify the overall device.
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 system enables precise and secure anchoring of the prosthetic valve, improving the accuracy and stability of valve placement, thereby enhancing treatment efficacy for mitral regurgitation while accommodating the dynamic nature of heart valve leaflets.
Implementation Method 1
a self-expanding frame having a superior end, an inferior end, and a midsection therebetween. The frame has an expanded configuration and a collapsed configuration. The collapsed configuration is adapted to be delivered to a patient's heart, and the expanded configuration is adapted to anchor the self-expanding frame in the patient's heart.
Data Source
AI summary
A prosthetic valve comprises a self-expanding frame which includes a self-expanding atrial skirt that forms a flanged region, a self-expanding ventricular skirt, and a first self-expanding tab coupled with the ventricular skirt. A receptacle for receiving a valve leaflet is formed by the area bounded by an outer surface of the atrial skirt, an outer surface of the ventricular skirt, and an inner surface of the first tab. The receptacle has a window for receiving the valve leaflet that is defined by a gap between an edge of the flange and a tip of the first tab. The gap is maximized when the tip of the first tab is unconstrained and a base of the first tab is at least partially constrained. The gap is minimized when the tip of the first tab and its base are unconstrained.