Biased Release Capture Assembly for Prosthetic Heart Valve Deployment
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Solution Overview
Problem
Current percutaneous transcatheter prosthetic heart valve delivery systems face challenges in consistently achieving partial and full deployment of stented prosthetic heart valves due to issues with retaining the valve during partial deployment and avoiding damage during full deployment, while also ensuring accurate positioning and preventing leakage or dislodgment.
Innovation Solution
A delivery device with a delivery sheath assembly, inner shaft, and capture assembly that includes a spindle and biasing members, allowing for selective coupling and release of the prosthetic heart valve, enabling precise control over the deployment process through self-transitioning biasing members that facilitate both partial and full deployment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the delivery device uses a robust engagement structure to securely retain the prosthetic heart valve during partial deployment, then the valve retention reliability is improved, but the device complexity increases and the valve may catch on the engagement structure during full deployment
Solution Approach 1:
The engagement structure is divided into multiple discrete radial projections distributed around the circumference of the inner shaft, each independently engaging with corresponding features on the valve frame. This segmentation allows the structure to provide robust retention through multiple contact points while reducing overall complexity compared to a single complex engagement mechanism.
Solution Approach 2:
The radial projections are designed to be flexible and deformable, allowing them to dynamically adapt during deployment. During partial deployment, the projections engage and retain the valve securely. During full deployment, the projections can deform or retract to prevent catching, enabling smooth transition from retention to release without requiring complex additional mechanisms.
2Manufacturing precision
If the delivery device allows partial deployment for positioning evaluation, then the implantation precision is improved, but the risk of incomplete deployment or damage increases
Solution Approach 1:
The delivery device employs a dynamic release mechanism where the radial projections can transition from an engaged state during partial deployment to a disengaged state for full deployment. This dynamic behavior allows the system to safely support partial deployment for positioning evaluation while ensuring complete and damage-free deployment when the projections retract or deform to release the valve.
Solution Approach 2:
The flexible radial projections are designed to anticipate potential catching or damage during deployment transitions. By incorporating inherent flexibility and deformability into the engagement structure, the device provides a cushioning effect that prevents damage during both partial and full deployment phases, ensuring deployment completeness while allowing positioning evaluation.
3Reliability
If the biasing member is forced to deflected condition during delivery, then the valve retention is improved, but the stress on the biasing member increases
Solution Approach 1:
The biasing member is designed with specific material and geometric parameters that allow it to withstand the deflected condition during delivery. By optimizing the wire diameter, length, and material properties of the biasing member, the system achieves adequate retention force in the deflected state while maintaining sufficient strength to prevent failure. The parameters are selected to balance retention requirements with stress limitations.
Solution Approach 2:
The delivery device incorporates features that distribute and cushion the stress on the biasing member during the deflected condition. The radial projections and engagement structure are designed to share the load, preventing excessive stress concentration on the biasing member while maintaining reliable valve retention throughout the delivery process.
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 ensures consistent and controlled deployment of the prosthetic heart valve, allowing for accurate positioning and minimizing the risk of leakage or dislodgment, while enabling evaluation and potential repositioning before full release, thus improving the safety and efficacy of the implantation process.
Implementation Method 1
the biasing member is configured to self-transition from a deflected condition to a normal condition. With this in mind, a radial projection of the biasing member relative to a centerline of the inner shaft is greater in the normal condition than in the deflected condition
Data Source
Figure 1A~1B
Figure 2
Figure 3
AI summary
A delivery system (50) for percutaneously delivering and deploying a stented prosthetic heart valve (20). The delivery device includes a delivery sheath (52) slidably disposed over an inner shaft (54), and a capture assembly (56). The capture assembly includes a spindle (100) and a biasing member (102). The spindle is attached to the inner shaft and defines slot (130). The biasing member is disposed within the slot and self - transitions from a deflected condition to a normal condition. In a delivery state, the delivery sheath retains the prosthesis over the inner shaft and coupled to the spindle via the capture slot, including a portion of the prosthetic valve being engaged within the slot and the biasing member forced to the deflected condition. In a deployment state, the delivery sheath is proximally withdrawn and the biasing member self - transitions toward the normal condition to eject the prosthetic valve from the capture slot.