Collapsible Nose Cone for Non-Circular Stent Retrieval
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Solution Overview
Problem
Existing implant delivery systems face challenges in efficiently deploying and retrieving non-circular stents due to issues with the profile and diameter of the distal nose cone, which can get caught on the implant during withdrawal, and traditional systems struggle with advancing and retrieving non-circular stents.
Innovation Solution
The development of delivery systems with non-circular axial cross-sectional shapes and low-profile distal nose cones, featuring deflatable designs, proximal tapers, and flexible covers, to facilitate the introduction, advancement, and retrieval of non-circular stents without interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional distal nose cone with larger diameter is used in the delivery system, then the nose cone provides adequate structural support and protection during delivery, but the nose cone gets caught on the implant device during retrieval through the deployed stent
Solution Approach 1:
The nose cone transitions from a rigid structure to a flexible, collapsible structure that can dynamically change its diameter. During delivery, the nose cone maintains its structural integrity, but during retrieval, it can be collapsed to a smaller diameter to pass through the deployed stent, eliminating the retrieval problem while maintaining delivery reliability
Solution Approach 2:
The nose cone's diameter parameter is made variable rather than fixed. By incorporating flexible materials and collapsible结构设计, the nose cone can change its diameter from a larger value during delivery to a smaller value during retrieval, resolving the contradiction between needing structural support and avoiding entanglement
2Ease of manufacture
If a delivery system with circular cross-section is used, then the system is simple to manufacture and assemble, but it cannot effectively accommodate and deliver non-circular stents with optimized compliance
Solution Approach 1:
The delivery system abandons the traditional circular cross-section in favor of a non-circular cross-section that matches the geometry of the stent being delivered. This asymmetric design allows the system to effectively accommodate and deliver non-circular stents with optimized compliance while maintaining manufacturability through standard forming processes
3Ease of operation
If the nose cone diameter is reduced to facilitate retrieval through the implant, then the nose cone can pass through the deployed stent, but the nose cone loses structural support and protection capabilities during delivery
Solution Approach 1:
The nose cone is designed with dynamic flexibility allowing it to maintain a larger diameter during delivery for structural support, then collapse to a smaller diameter during retrieval to pass through the stent. This dynamic behavior resolves the contradiction by providing the needed structural integrity when large and enabling easy retrieval when small
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 efficient deployment and retrieval of non-circular stents, reducing the risk of interference and enhancing compliance in blood vessels by reshaping them to improve perfusion and reduce pulsatile load.
Implementation Method 1
Nose cone examples presented herein further include nose cones having, or configured to assume, a low-profile diameter that is less than a diameter of a delivery shaft/lumen of the delivery system associated with the nose cone
Implementation Method 2
Some nose cones disclosed herein include proximal taper features to guide the nose cone back into/through a lumen of a deployed implant device with reduced risk of catching on the implant
Data Source
AI summary
An implant delivery system includes an elongate sheath having an inner diameter at a distal end thereof, a nose cone shaft dimensioned for advancement within the elongate sheath, and a collapsible nose cone associated with a distal end of the nose cone shaft and positionable at least partially beyond the distal end of the elongate sheath, the collapsible nose cone being transitionable between an expanded state having a first maximum diameter and a compressed state having a second maximum diameter that is less than the inner diameter of the elongate sheath.