Rotatable Stent Delivery Sheath for Kink-Resistant Deployment
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Solution Overview
Problem
Existing intracorporeal medical devices, such as stent delivery systems, face challenges in efficiently deploying stents while maintaining guidewire position and reducing the likelihood of kinking, especially when navigating tortuous anatomies.
Innovation Solution
A stent delivery system with a deployment sheath coupled to a flexible rack that shifts between configurations, allowing for proximal retraction and rotation, and includes a rotatable linkage with coupling members and a sleeve to manage translation and torsional forces, ensuring smooth deployment and guidewire stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional stent delivery system is used, then stent deployment can be achieved, but guidewire kinking and force buildup occur when navigating tortuous anatomies
Solution Approach 1:
The delivery system is divided into multiple independent components: an inner member for guidewire support, a deployment sheath for stent containment, and an outer shaft for structural support. This segmentation allows each component to independently manage forces and movements, preventing guidewire kinking while maintaining stability during navigation through tortuous anatomies.
Solution Approach 2:
The system employs a nested configuration where the inner member with guidewire support is positioned within the deployment sheath, which is itself contained within the outer shaft. This nested structure provides concentric support layers that prevent guidewire kinking while allowing controlled deployment through tortuous pathways.
2Manufacturing precision
If the deployment sheath is made rigid for stable stent delivery, then delivery precision is improved, but the system cannot accommodate tortuous anatomical pathways
Solution Approach 1:
Different sections of the delivery system have different mechanical properties: the inner member and deployment sheath are designed with controlled flexibility to navigate tortuous pathways, while the distal tip and stent receiving region maintain sufficient rigidity for precise positioning and deployment. This local differentiation of mechanical properties resolves the contradiction between flexibility and precision.
Solution Approach 2:
The delivery system transitions from a flexible configuration during navigation to a more rigid configuration during deployment. The deployment sheath and inner member can be positioned and stabilized to provide precise control at the target site while maintaining overall system flexibility for navigating anatomical pathways.
3Reliability
If a complex coupling mechanism is used to prevent guidewire kinking, then guidewire stability is improved, but device complexity increases
Solution Approach 1:
A coupling member serves as an intermediary element between the inner member and deployment sheath, providing a simple yet effective mechanism to coordinate their relative movements. This intermediary component prevents guidewire kinking by ensuring synchronized motion without requiring a complex multi-component coupling mechanism.
Data Source
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AI summary
The present invention discloses a stent delivery system, comprising: an inner member having a stent receiving region configured to have a stent disposed thereon; a deployment sheath axially slidable relative to the inner member, the deployment sheath having a proximal end region; wherein the deployment sheath is rotatable relative to the inner member; a handle coupled to the deployment sheath; a rack track formed in the handle; a flexible rack coupled to the proximal end region of the deployment sheath; wherein the rack track is configured to allow the flexible rack to be moved therealong while being contained within the handle.