Radiopaque Inner-Coil Guidewire With Gradual Distal Stiffness
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional guidewires lack sufficient distal support and steerability, particularly in navigating tortuous vasculature, and often cause vessel damage due to stiffness issues and abrupt resistance changes during advancement.
Innovation Solution
A guidewire design featuring a radiopaque inner coil and a non-radiopaque outer coil, with a solder distal tip formed using a mold or laser dimpling, and varying cross-section shapes such as I-beam and parabolic grind profiles to enhance torque response and flexibility, while maintaining distal tip integrity and reducing kink resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional guidewires use tapered distal core sections to improve steerability, then the guidewire can navigate tortuous vasculature more easily, but the guidewire experiences abrupt resistance changes that hinder controlled advancement
Solution Approach 1:
The patent applies local quality by creating a gradual taper of the core member diameter along its length, rather than abrupt changes. This gradual transition in the local geometry of the core member provides continuous, smooth resistance changes that improve steerability while eliminating harmful abrupt resistance transitions during advancement through tortuous vasculature.
2Strength
If guidewires are made stiffer to provide improved distal support in challenging anatomy, then the guidewire can navigate severe angulation and tortuosities, but the guidewire becomes less steerable and may damage vessel linings
Solution Approach 1:
The patent segments the guidewire into functionally distinct zones: a stiffer proximal core member for distal support and pushability, a gradually tapering transition zone for smooth flexibility changes, and a more flexible distal section for steerability. This segmentation allows each section to optimize its mechanical properties for its specific function, providing both distal support and steerability simultaneously.
Solution Approach 2:
The patent employs parameter changes by gradually varying the core member diameter along its length rather than maintaining uniform dimensions. This continuous parameter change creates a gradient in stiffness that allows the guidewire to provide strong distal support where needed while maintaining steerability in the distal sections, eliminating the need to choose between support and flexibility.
3Strength
If guidewires use abrupt tapered sections to reduce stiffness, then the guidewire becomes more flexible for navigating tortuous vessels, but the guidewire creates discontinuous resistance that reduces tactile feedback
Solution Approach 1:
The patent applies local quality by creating a gradual taper of the core member diameter along its length, rather than abrupt changes. This gradual transition in the local geometry of the core member provides continuous, smooth resistance changes that improve steerability while eliminating harmful abrupt resistance transitions during advancement through tortuous vasculature.
Data Source
AI summary
A guidewire for use in intravascular procedures has an inner coil that is radiopaque and an outer coil that is non-radiopaque at the distal end of the guidewire. The radiopaque inner coil is visible under fluoroscopy so that the physician can monitor the location of the distal end of the guidewire during a procedure. The inner coil and the outer coil can be formed from a single wire or a multi-filar wire. The inner coil and the outer coil can have any of the following cross-sections for enhanced torquability: I-beam; vertical rectangular; vertical ellipse; square; peanut shape; vertical hexagonal; horizontal hexagonal; and horizontal ellipse.