Interrupted-Spiral Cannula Openings for Pushability and Flexibility
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing delivery systems for implanting intraluminal medical devices face challenges in achieving both pushability and flexibility, which are crucial for navigating through body vessels effectively.
Innovation Solution
The development of cannulae with strategically designed patterns of openings along their axial lengths, allowing for localized stiffness adjustments, enhances pushability and flexibility by manipulating parameters such as spiral gap, opening size, and angle relative to the longitudinal axis, ensuring effective delivery of intraluminal medical devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the cannula is made with a solid circumferential wall to provide structural integrity and pushability, then the strength and stiffness are improved, but the flexibility and ability to navigate through body vessels deteriorates
Solution Approach 1:
The cannula applies local quality by creating a pattern of openings in specific axial regions while maintaining solid wall sections in other regions. This allows different portions of the cannula to have different mechanical properties - the opened regions provide flexibility for navigation while solid regions maintain pushability and structural integrity.
Solution Approach 2:
The circumferential wall is segmented by introducing a pattern of openings that divide the continuous wall structure into distinct sections. This segmentation reduces overall stiffness in controlled regions, enabling the cannula to bend and flex as needed for vascular navigation while maintaining sufficient strength through the remaining solid wall portions.
2Adaptability or versatility
If the pattern of openings extends along the entire axial length of the cannula to maximize flexibility, then the flexibility is improved, but the pushability and structural integrity deteriorates
Solution Approach 1:
The pattern of openings is applied locally to specific axial portions of the cannula rather than uniformly across the entire length. This selective application maintains flexibility where needed while preserving pushability in regions that require structural support, resolving the contradiction between these two opposing requirements.
3Strength
If the cannula wall thickness is increased to improve pushability and structural integrity, then the strength is improved, but the flexibility and ability to conform to vessel geometry deteriorates
Solution Approach 1:
The cannula incorporates a porous or perforated wall structure through the pattern of openings. This creates an effective reduction in wall thickness and stiffness in the opened regions, allowing the cannula to flex and conform to vessel geometry while the overall structural integrity is maintained through the remaining solid wall material and the support provided by the delivery system.
Data Source
AI summary
The disclosure relates to cannulae, delivery systems, methods of making cannulae, and methods of making delivery systems. A delivery system comprises an elongate outer tubular member defining an outer tubular member lumen, a cannula having a circumferential wall extending between a proximal end and a distal end and defining an interior lumen, and an intraluminal medical device disposed within the outer tubular member lumen distal to the cannula and not about the cannula. A pattern of openings arranged in an interrupted spiral extends circumferentially along the cannula.