Resin Stent with Treated Layer for Bile Duct Locking
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Solution Overview
Problem
Conventional medical stents for bile ducts face challenges in securely locking to the narrowed area due to material differences and temperature limitations during the welding process, which can lead to deformation, melting, or fracture of the flaps, affecting long-term stability and reliability.
Innovation Solution
A medical stent design featuring a tubular main body made of polyurethane resin and elastic members formed from fluororesin, with a treated layer having functional groups for enhanced adhesion, and a production method involving surface treatment and heat pressing to connect the end portions of the main body and elastic members at specific temperature ranges, ensuring strong bonding without deformation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If flaps are locked to the main body using conventional welding methods, then the stent can be fixed to the narrowed area, but the flaps may deform, melt, or fracture due to temperature limitations and material differences
Solution Approach 1:
The invention changes the welding parameters by controlling the temperature to be within a specific range (above the glass transition temperature of the resin material but below the decomposition temperature) and limiting the welding time. This parameter optimization allows reliable locking while preventing deformation, melting, or fracture of the flaps.
Solution Approach 2:
The invention applies preliminary surface treatment to the flaps and main body before welding to enhance adhesion. This preliminary action ensures better bonding strength and prevents separation during the welding process, thereby improving locking reliability without compromising structural integrity.
2Reliability
If the stent is designed with flaps for locking to the narrowed area, then fixation capability is improved, but the complexity of the structure increases
Solution Approach 1:
The invention segments the elastic member into distinct functional portions: a tubular portion that locks to the narrowed area and a flap portion that provides additional fixation. This segmentation allows each portion to perform its specific function efficiently while maintaining overall structural simplicity through the integrated design.
3Adaptability or versatility
If different resin materials are used for the main body and flaps, then functional requirements are met, but adhesion between components becomes difficult
Solution Approach 1:
The invention changes the surface properties of the resin materials through surface treatment (such as plasma treatment or chemical treatment) to introduce functional groups that enhance adhesion. This allows different resin materials to be used for functional adaptability while achieving strong bonding through improved surface compatibility.
Solution Approach 2:
The invention introduces a primer layer or adhesive promoter as an intermediary between the main body and flaps made of different resin materials. This intermediary enhances the bonding strength by creating compatible interfaces between dissimilar materials, allowing each component to maintain its functional properties while achieving reliable adhesion.
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 stent achieves reliable locking to the bile duct narrowed area with improved durability and reduced risk of movement, allowing for longer-term indwelling without deformation or fracture, while maintaining biocompatibility and ease of insertion.
Implementation Method 1
a treated layer which is formed between an end portion of the main body and the one end portion of the elastic member and which has a functional group for joining the end portion of the main body and the one end portion of the elastic member to each other
Implementation Method 2
the end portion of the main body and the one end portion of the elastic member are connected to each other at a temperature equal to or higher than the melting temperature of the first resin material and lower than the melting temperature of the second resin material
Data Source
AI summary
The medical stent includes: a main body formed into an approximately tubular shape along a longitudinal axis with a first resin material; an elastic member formed of a second resin material which is larger in flexural modulus than the first resin material, and configured to have one end portion connected to an end portion of the main body and the other end portion formed to extend to the central portion side of the main body along the longitudinal axis and also to direct to the radial direction of the main body; and a treated layer formed between the end portion of the main body and the one end portion of the elastic member and configured to have a functional group for joining the end portion of the main body and the one end portion of the elastic member to each other.