Catheter Braid Structure for Stress Distribution and Torque Transmission
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Catheters with a coil body and resin-coated tapered tips face issues with stress concentration and reduced torque transmission performance at the boundary between the tip and the catheter body, especially when navigating acute branching angles in vessels, leading to potential damage and inefficiency in procedures like CART approaches.
Innovation Solution
Incorporating a braid structure that extends axially from the tip to the catheter body, positioned between the inner and outer resin layers, to distribute stress and enhance torque transmission by embedding the braid between the inner resin layer and the coil, thereby increasing flexibility and strength at the boundary.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a resin tip is provided at the distal end of the catheter body including the coil, then the catheter can enter branches at acute angles without damaging the vessel, but stress concentration occurs at the boundary between the tip and the catheter body
Solution Approach 1:
The patent applies composite materials by combining the resin tip with a coil structure at the boundary region. The coil provides structural reinforcement while the resin tip maintains its softness for navigating acute angles. This composite construction eliminates stress concentration by distributing mechanical loads across both materials, preventing tip displacement while preserving the ability to enter branches at acute angles.
Solution Approach 2:
The patent implements local quality by providing the coil structure specifically at the boundary between the tip and catheter body, rather than uniformly throughout the entire catheter. This localized reinforcement addresses the stress concentration issue only where needed, maintaining the softness and flexibility of the tip for acute angle navigation while strengthening the boundary region.
2Ease of operation
If the tip is made sufficiently soft to navigate acute angles, then the catheter can smoothly pass through collateral channels, but torque transmission performance decreases
Solution Approach 1:
The patent segments the catheter into distinct functional regions: a soft resin tip for navigating acute angles and a coil-reinforced boundary region for torque transmission. The coil structure acts as a separate mechanical element that provides torsional rigidity independently from the soft tip, allowing each segment to perform its specialized function without compromising the other.
Solution Approach 2:
The patent uses composite materials to achieve both softness and torque transmission. The resin tip provides the necessary softness for smooth passage through collateral channels, while the embedded coil structure provides the mechanical strength for torque transmission. The combination allows the catheter to exhibit both compliant and rigid characteristics in different regions.
3Ease of operation
If the tip is rotated while reaching stenosis, then the catheter can be positioned accurately, but torsional stress concentrates at the boundary between the tip and the catheter body
Solution Approach 1:
The patent applies composite materials to resolve torsional stress concentration during rotation. The coil structure embedded in the boundary region provides a rigid framework that resists torsional deformation, while the resin tip allows for controlled rotation. This composite construction distributes torsional stresses across the coil structure rather than concentrating them at the tip-catheter interface, enabling accurate positioning without excessive stress.
Solution Approach 2:
The patent implements local quality by providing enhanced structural properties specifically at the boundary region where torsional stress occurs during rotation. The coil structure is strategically placed at this location to provide localized torsional resistance, allowing the tip to rotate for positioning while the boundary region absorbs the resulting stresses.
Data Source
AI summary
A catheter body includes a hollow coil whose outer and inner surfaces are coated with outer and inner resin layers. A resin tip is provided at a distal end of the catheter body. The tip has a tapered section at a distal end of the tip. Also, an axially extending braid is embedded in the catheter body and the tip to extend from the catheter body to the tip.