Variable Density Catheter Support Resists Kinking at Segment Junctions
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Solution Overview
Problem
Medical catheters face challenges in navigating tortuous blood vessels due to kinking and buckling, particularly at junctions between segments with different properties, which can lead to delamination and reduced structural integrity.
Innovation Solution
The catheter design incorporates a structural support member with variable density, particularly increased density at junctions between outer jacket segments with different materials, durometers, or thicknesses, and surface treatments to enhance adhesion between the support member and the inner liner and outer jacket, thereby resisting compression and bending forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the outer jacket is made from multiple segments with different properties (materials, durometers, thicknesses) to optimize flexibility and pushability in different vascular regions, then the catheter's adaptability and ease of operation are improved, but the structural integrity at junctions deteriorates, making the catheter more prone to buckling and kinking
Solution Approach 1:
The structural support member is designed with variable density along its length, with higher density specifically at the junctions between outer jacket segments. This local variation in density provides targeted reinforcement exactly where the structural integrity is most compromised, without affecting the overall flexibility of the catheter in other regions.
Solution Approach 2:
The structural support member is constructed as a composite structure combining materials or configurations with different densities. The high-density sections at junctions provide enhanced structural support, while lower-density sections in other regions maintain catheter flexibility, creating a composite structure that addresses both contradictory requirements.
2Strength
If the structural support member has high density throughout to prevent buckling and kinking, then the catheter's structural integrity is improved, but the catheter's flexibility and ease of navigation through tortuous vessels deteriorates
Solution Approach 1:
Rather than uniformly increasing the density of the structural support member throughout, the invention applies high density only at specific locations (junctions between outer jacket segments) where buckling and kinking are most likely to occur. This localized approach provides necessary strength exactly where needed while preserving flexibility in other regions.
Solution Approach 2:
The invention applies the principle of partial action by providing structural reinforcement only at the specific locations where it is most needed (the junctions), rather than throughout the entire length of the catheter. This partial reinforcement is sufficient to prevent buckling and kinking at critical points without unnecessarily compromising overall flexibility.
3Reliability
If surface treatments are applied to the structural support member to enhance adhesion between layers, then the reliability of the catheter structure is improved, but the manufacturing complexity increases
Solution Approach 1:
The invention modifies the surface properties of the structural support member by applying surface treatments that change parameters such as surface roughness, energy, or chemistry. These parameter changes enhance the adhesion between the structural support member and adjacent layers (inner liner and outer jacket), improving the reliability of the multi-layer construction.
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
This design enhances the catheter's ability to maintain structural integrity and resist kinking and buckling, allowing for more effective navigation through complex vascular pathways while maintaining flexibility and pushability.
Implementation Method 1
The relatively high density section may enable the catheter body to resist compression at the junction between the two outer jacket segments, such that the structural support member may be less likely to collapse at the junction response to compression or bending forces
Implementation Method 2
surface treatments to enhance adhesion between the support member and the inner liner and outer jacket
Data Source
AI summary
In some examples, a catheter includes an elongated body that includes an inner liner, and outer jacket, and a structural support member positioned between at least a portion of the inner liner and the outer jacket. The outer jacket includes a plurality of outer jacket segments in which each outer jacket segment of the plurality is longitudinally adjacent to another outer jacket segment of the plurality. The structural support member includes a first section having a first density, a second section distal to the first section and having a second density, and a third section distal to the second section and having a third density, such that the second density being higher than the first and third densities. The second section of the structural support member is longitudinally aligned with a junction between two outer jacket segments of the plurality of outer jacket segments.