Reinforced Sheath Wire Assembly for Small Diameter Vascular Delivery
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Solution Overview
Problem
Existing vascular intervention device delivery systems face challenges in achieving smaller diameters, particularly with systems 5 Fr. or less, due to difficulties in the welded attachment between the pull wire and retractable sheath, which hinders deployment of stents to remote locations like below the knee.
Innovation Solution
A reinforced sheath/wire assembly featuring a reinforcement braid with a pull wire interwoven into it, mechanically attached without welding, and an outer polymer jacket laminating the braid and wire, providing a consistent and repeatable attachment that reduces the overall diameter and enhances deployment efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a welded attachment between pull wire and retractable sheath is used, then the attachment strength is improved, but the device complexity and manufacturing difficulty increase for small diameter systems (5 Fr. or less)
Solution Approach 1:
The patent replaces the welded mechanical attachment system with a braided mechanical attachment system. The pull wire is integrated into the braid structure of the retractable sheath, eliminating the need for welding operations. This substitution maintains attachment strength while significantly reducing manufacturing complexity and enabling small diameter configurations (5 Fr. or less) that were previously difficult to achieve with welded attachments.
2Volume of moving object
If the overall diameter of the delivery system is reduced to 5 Fr. or less, then the ability to reach remote locations is improved, but the attachment between pull wire and sheath becomes more difficult
Solution Approach 1:
The patent merges the pull wire and retractable sheath into a single integrated braided structure. The pull wire is incorporated within the braid strands, creating a unified component rather than separate parts requiring assembly. This merging eliminates attachment manufacturing challenges and enables consistent production of small diameter (5 Fr. or less) delivery systems capable of reaching remote vascular locations.
Solution Approach 2:
The patent employs a composite braided structure combining the pull wire with the sheath braid. This composite construction integrates multiple functional elements (pull wire, sheath, reinforcement) into a single multifunctional component, achieving small diameter while maintaining structural integrity and manufacturability.
3Stability of the object's composition
If a reinforced braid structure with interwoven wire is used, then the mechanical stability is improved, but the device complexity increases
Solution Approach 1:
The patent creates a universal braided structure where the braid simultaneously serves multiple functions: providing sheath coverage, reinforcing the structure, and mechanically attaching the pull wire. This multi-functional design achieves high mechanical stability while avoiding the need for separate reinforcement components, thereby reducing overall structural complexity despite the enhanced functionality.
Data Source
AI summary
A reinforced cardiovascular sheath and wire assembly includes an inner tube with an external surface extending between a proximal end and a distal end. A reinforcement braid is in contact with the external surface of the inner tube. A wire with a distal segment is interwoven into, and in contact with, the reinforcement braid. A proximal segment of the wire extends proximally from the proximal end of the inner tube out of contact with the reinforcement braid. An outer tube receives, and is in contact with, the reinforcement braid and the inner tube. A vascular intervention device delivery system utilizes the sheath/wire assembly as a retractable sheath and pull wire.