Composite Wire with Powder Core for Radiopacity
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Minimally invasive medical devices face challenges in achieving sufficient radiopacity, mechanical strength, and biocompatibility, particularly in thin sections where material selection is critical, and existing composite wires have limitations in mechanical performance and electrochemical behavior.
Innovation Solution
A composite wire design featuring a powder core made of highly radiopaque materials like tantalum and platinum integrated within a hollow shell, allowing for enhanced radiopacity while maintaining mechanical properties and electrochemical compatibility, with the powder core being 'mechanically invisible' to the shell material, enabling higher core ratios without compromising superelastic performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a solid metal core is used in composite wire to enhance radiopacity, then radiopacity is improved, but mechanical performance deteriorates
Solution Approach 1:
The patent employs a powder core instead of a solid metal core, creating a porous-like structure within the wire. The powder core consists of numerous small particles that provide radiopacity while maintaining mechanical compatibility with the shell material, thus resolving the contradiction between radiopacity enhancement and mechanical performance preservation.
Solution Approach 2:
The patent uses a composite structure combining a shell material (e.g., nitinol, magnesium, zinc) with a powder core material (e.g., tantalum, platinum, barium sulfate). This composite approach allows the shell to provide mechanical strength and the powder core to provide radiopacity, eliminating the need for a solid metal core that would compromise mechanical performance.
2Illumination intensity
If radiopaque materials are used in composite wire to improve radiopacity, then radiopacity is improved, but electrochemical behavior deteriorates
Solution Approach 1:
The powder core structure reduces the surface area contact between dissimilar metals compared to a solid core, thereby minimizing galvanic corrosion. The powder particles are dispersed within the shell material, creating a more favorable electrochemical interface that maintains reliability while providing the necessary radiopacity.
Solution Approach 2:
The patent changes the physical state of the radiopaque material from solid (in a solid core) to powder form. This parameter change allows for better control over the electrochemical interface between the core and shell materials, reducing galvanic interaction and maintaining electrochemical behavior while achieving the required radiopacity.
3Illumination intensity
If higher core ratios are used to enhance radiopacity, then radiopacity is improved, but mechanical performance deteriorates
Solution Approach 1:
The powder core structure allows for higher core ratios without compromising mechanical performance because the powder particles do not create the same mechanical constraints as a solid core. The porous-like arrangement of powder particles maintains flexibility and mechanical compatibility even at high core ratios, enabling enhanced radiopacity while preserving mechanical properties.
Solution Approach 2:
The composite structure with powder core allows for optimized core-to-shell ratios that balance radiopacity and mechanical performance. The powder core material can be selected to have different densities and mechanical properties, enabling higher radiopacity through increased core ratio without the mechanical penalties associated with solid metal cores.
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 composite wire achieves radiopacity at least 100% greater than equivalent solid wires, maintains mechanical performance identical to solid wires, and reduces costs by using lower-cost materials for the core, while ensuring biocompatibility and minimal galvanic interaction, facilitating improved deployment and durability of medical devices.
Implementation Method 1
Radiopacity is thus an important property and can be challenging to achieve in thin material sections. The non-metallic powder of the core has a higher radiopacity than the metallic material of the shell such that the wire has a radiopacity at least 100% greater than an equivalent solid wire made of the shell material only.
Data Source
AI summary
A composite wire uses a powder core to offer radiopaque enhancements without the drawbacks of a solid metal core. For example, composite wires may include highly radiopaque materials, such as tantalum and platinum, integrated into the wire core in powder form. The powder core provides high radiopacity to the finished wire while preserving mechanical properties of the shell material. The powder form of the core material also enables a wider range of candidate materials for the composite wire core, such that a desirable electrochemical profile may be maintained between the core and shell materials, including bioabsorbable shell materials.