Teflon-Lined Braid Wire Catheter for Lower Track Forces
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current catheters used in neurovascular interventions face challenges in reducing friction and track forces due to the nature of the vasculature, with existing lubricious coatings having poor integrity and being expensive, leading to the need for improved catheter designs that minimize friction.
Innovation Solution
A catheter design featuring a central polymer liner, a braided metal wire jacket with partially exposed metal wires coated in polymer material, and additional polymer layers, which form contact surfaces with the vessel wall, enhancing adhesion and reducing the need for external lubricious coatings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If lubricious coating is applied to the outer surface of the catheter, then friction is reduced and trackability is improved, but the coating integrity deteriorates and can rub off along the vasculature
Solution Approach 1:
The catheter surface is segmented into multiple functional layers: an inner lubricious coating layer for friction reduction, a middle adhesive promoter layer to prevent coating delamination, and an outer structural layer for mechanical support. This segmentation allows each layer to perform its specific function optimally while maintaining overall coating integrity during vascular navigation.
Solution Approach 2:
The catheter employs a composite material structure combining multiple polymer layers with different properties. The inner layer uses lubricious materials (e.g., PTFE, silicone) for low friction, the middle layer uses adhesive materials (e.g., polyurethane, acrylic) for strong bonding, and the outer layer uses structurally sound materials. This composite approach resolves the contradiction by integrating both low-friction and high-integrity requirements into a single multi-layer system.
2Ease of operation
If lubricious coating is applied to reduce friction, then track forces are reduced, but the cost of the catheter increases
Solution Approach 1:
Instead of coating the entire catheter surface with expensive lubricious materials, the invention applies the lubricious coating only to the portion of the outer surface that contacts the vasculature during navigation. The middle and outer layers provide structural support and adhesive function, allowing the lubricious material to be used more sparingly and efficiently, thereby reducing overall material costs while maintaining low friction where needed.
Solution Approach 2:
The catheter surface exhibits local quality variations with different layers having different properties at different locations. The inner layer provides lubricious properties where friction reduction is critical, the middle layer provides adhesive properties for bonding, and the outer layer provides structural properties. This localized functional differentiation allows cost-effective material selection for each specific function and location.
3Strength
If metal wire jacket is used to provide structural support, then catheter strength is improved, but friction with the vessel wall increases
Solution Approach 1:
The metal wire jacket is covered with a flexible polymer outer layer that conforms to the vessel wall geometry. This thin film layer provides a smooth, low-friction interface between the rigid metal structure and the soft vascular tissue, allowing the metal jacket to maintain its structural support function while the flexible polymer layer handles the friction interaction with the vasculature.
Solution Approach 2:
The polymer outer layer acts as an intermediary between the metal wire jacket and the vessel wall. It mediates the interaction by providing a biocompatible, low-friction surface that prevents direct contact between the metal structure and the vascular tissue, thereby reducing friction and improving trackability while allowing the metal jacket to maintain catheter strength.
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
The design achieves reduced friction and improved trackability through the vasculature by utilizing a braided metal wire jacket with polymer-coated metal wires that adhere to the vessel wall, maintaining integrity and reducing the risk of coating loss during navigation.
Implementation Method 1
polymer-coated metal wires that adhere to the vessel wall
Data Source
AI summary
A catheter that includes an inner lumen liner comprising a first polymer material, a braided metal wire jacket comprising a plurality of metal wires coated in the first polymer material, and an outer liner comprising a second polymer material different from the first polymer material. A portion of the plurality of metal wires are partially exposed on an outer surface of the outer liner and the coating on the exposed portion of the plurality of metal wires forms a contact surface.