Catheter Multi-Layer Structure for Flexibility and Slidability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Catheters used for injecting contrast media into the body lack flexibility and slidability, leading to potential stimulation of the living body during insertion and decreased guide wire mobility due to insufficient flexibility and adhesion issues with existing materials like PTFE and EFEP copolymers.
Innovation Solution
A catheter design featuring a tubular member with a main body part composed of 60% ethylene-tetrafluoroethylene copolymer and a second layer with 60% polyamide resin, allowing for differential cantilever bending loads between the tip and main body parts, enhancing flexibility and adhesiveness, while improving guide wire slidability and reducing biostimulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a catheter is made of PTFE to ensure chemical inertness and ease of manufacture, then the catheter can be easily produced and maintains chemical stability, but the catheter lacks flexibility and may stimulate the living body during insertion
Solution Approach 1:
The catheter employs a multi-layer composite structure where the inner layer is made of PTFE for chemical inertness and the outer layer is made of a flexible polymer material. This composite construction allows the catheter to maintain the chemical stability of PTFE while gaining the flexibility needed for easy insertion and operation in the living body.
2Shape
If the distal part of the catheter is bent in advance to allow the tip to protrude in a desired direction, then the catheter can be positioned accurately, but the catheter may stimulate the papilla due to contact with the distal end part
Solution Approach 1:
The catheter's outer layer is constructed from a flexible polymer material that allows the distal part to be softly bent and adapted to the anatomical structures. This flexibility reduces the rigidity of the bent tip, minimizing mechanical stimulation and trauma to the papilla during insertion and positioning procedures.
3Stability of the object's composition
If a multi-layered catheter structure is used with reactive polar polymer and end-functionalized EFEP copolymer to improve adhesion, then melt adhesion between layers is excellent, but the catheter still lacks flexibility and guide wire slidability decreases
Solution Approach 1:
The catheter uses a composite material structure where the inner layer is PTFE for chemical inertness and the outer layer is a flexible polymer that provides both adequate layer adhesion and superior guide wire slidability. This composition resolves the contradiction by selecting materials that simultaneously satisfy adhesion requirements while maintaining low friction for smooth guide wire passage.
Data Source
AI summary
A catheter (1) has a distal side and a proximal side and includes a tip part (10) and a main body part (20) disposed proximal to the tip part (10), the main body part (20) includes a first layer (21) and a second layer (22), the first layer (21) contains 60% by mass or more of an ethylene-tetrafluoroethylene copolymer, the second layer (22) is disposed inside of the first layer (21) in a radial direction of the catheter (1) and contains 60% by mass or more of a polyamide resin, and a cantilever bending load of the tip part (10) is smaller than a cantilever bending load of the main body part (20).