Tapered Catheter with Variable Durometer Jacket
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current medical catheters face challenges in navigating tortuous vasculature while maintaining structural integrity and preventing kinking, which hinders access to distal tissue sites such as the middle cerebral artery and Circle of Willis.
Innovation Solution
A catheter design featuring a flexible, thin-walled construction with a tapered outer diameter and a distal section with increased durometer to resist geometric deformation, combined with a structural support member and inner liner, allows for navigation through tortuous paths while maintaining shape and preventing kinking.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a catheter has a flexible, thin-walled construction to navigate tortuous vasculature, then flexibility and navigability are improved, but structural integrity and resistance to geometric deformation deteriorate
Solution Approach 1:
The catheter incorporates an outer jacket with varying durometer along its length - a first section with lower durometer for flexibility and a second distal section with higher durometer for structural support. This local variation in material property allows the catheter to be flexible where needed while maintaining structural integrity at the distal end.
Solution Approach 2:
The catheter uses a composite structure combining an inner liner, structural support member, and outer jacket with different material properties. The outer jacket itself is a composite of sections with different durometers, creating a multi-material system that achieves both flexibility and strength simultaneously.
2Adaptability or versatility
If a catheter has a tapered outer diameter to improve navigation through tortuous paths, then flexibility is improved, but resistance to geometric deformation at the distal end deteriorates
Solution Approach 1:
The outer jacket has a tapered outer diameter that decreases toward the distal end, but incorporates a second section with higher durometer at the distal portion. This local increase in stiffness compensates for the reduced diameter, maintaining resistance to geometric deformation despite the tapered configuration.
Solution Approach 2:
The catheter changes physical parameters along its length - the outer diameter decreases (tapering) while the durometer increases in the distal section. These parameter changes allow the catheter to be more navigable due to tapering while maintaining structural resistance through increased hardness at the critical distal end.
3Strength
If a catheter has a distal section with higher durometer to resist geometric deformation, then structural integrity is improved, but flexibility and pushability deteriorate
Solution Approach 1:
The outer jacket is divided into a first section with lower durometer for flexibility and pushability, and a second distal section with higher durometer for structural integrity. This local differentiation allows each section to optimize its function without compromising the other.
Solution Approach 2:
The outer jacket is segmented into multiple sections with different durometers - the first section proximal to the distal end and the second section at the distal end. This segmentation allows independent optimization of flexibility in the proximal section and structural support in the distal section.
Data Source
Figure 1~2
Figure 3~5
Figure 6~7
AI summary
In some examples, a catheter comprises an inner liner, an outer jacket, and a structural support member positioned between at least a portion of the inner liner and the outer jacket. The inner liner, the outer jacket, and the structural support member define a catheter body that comprises a proximal portion having a first outer diameter, a distal portion having a second outer diameter less than the first outer diameter, the distal portion including a distal end of the catheter body, and a medial portion positioned between the proximal portion and the distal portion, the medial portion tapering from the first outer diameter to the second outer diameter.