Guidewire Polymer Jacket Reflow for Vasculature Navigation
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Solution Overview
Problem
Conventional guidewires face difficulties navigating through narrow, tortuous, or plaque-built vasculature due to their large distal ends, which can delay and complicate medical procedures, increase costs, and pose risks to patients.
Innovation Solution
A guidewire with a small distal tip profile and a flexible polymer jacket that closely follows the shape of a core wire, allowing for increased maneuverability and reduced risk of rupture when navigating through tight spaces and lesions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional guidewires with larger distal ends are used, then longitudinal stiffness and force response are maintained, but the guidewire cannot navigate through narrow, tortuous, or plaque-built vasculature
Solution Approach 1:
The guidewire is divided into distinct segments: a distal portion with smaller profile for navigation through tight spaces, and a proximal portion with larger profile for operator control and force transmission. This segmentation allows each portion to perform its specific function optimally without compromising the other.
Solution Approach 2:
Different portions of the guidewire have different structural properties tailored to their specific functions. The distal portion has a smaller profile and increased flexibility for navigating vasculature, while the proximal portion maintains larger dimensions and higher stiffness for operator control, creating local quality variations along the wire length.
2Ease of operation
If the distal tip profile is reduced to access smaller vasculature, then maneuverability improves, but the polymer jacket thickness becomes non-uniform affecting performance
Solution Approach 1:
The polymer jacket is pre-formed with a uniform thickness before being crimped onto the tapered core wire. This preliminary formation ensures manufacturing precision is maintained during the jacket creation process, and the subsequent crimping operation preserves this uniformity while achieving the desired profile reduction.
Solution Approach 2:
The traditional mechanical trimming or cutting method for achieving profile reduction is replaced with a thermal crimping process. This substitution allows the polymer jacket to be conformally reduced in thickness through controlled heating and compression, maintaining uniformity without the need for mechanical removal that would create non-uniform edges.
3Reliability
If heat is applied to reflow the polymer jacket, then the jacket fuses to the core wire improving reliability, but the jacket thickness may become non-uniform
Solution Approach 1:
A release agent or barrier layer is introduced between the polymer jacket and the heating surface during the reflow process. This intermediary prevents direct contact between the jacket and the heat source, controlling the thermal transfer to ensure uniform reflow and thickness maintenance while still achieving adequate fusion to the core wire.
Solution Approach 2:
The thermal processing parameters are precisely controlled, including temperature, heating rate, and dwell time. By optimizing these parameters, the polymer jacket achieves complete fusion to the core wire for reliability while maintaining uniform thickness through controlled thermal diffusion that prevents localized thinning or thickening.
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
Enables easier access to branched vasculature and calcified vessels with reduced risk of rupture, maintaining longitudinal stiffness and force response, thus improving procedure efficiency and patient safety.
Implementation Method 1
Heat is applied to the polymer jacket and the core wire to reflow the polymer jacket and fuse the polymer jacket to the core wire
Implementation Method 2
Heat is applied to the polymer jacket and the core wire to reflow the polymer jacket
Implementation Method 3
the heat shrink tubing constrains the polymer jacket with application of the heat to the polymer jacket and the core wire
Data Source
AI summary
In various examples, a method of making a guidewire is described. The method includes placing a polymer jacket over a core wire. The core wire includes a first portion having a first profile and a second portion having a second profile. The first profile is smaller than the second profile. Heat is applied to the polymer jacket and the core wire to reflow the polymer jacket and fuse the polymer jacket to the core wire, wherein the polymer jacket forms a layer of substantially uniform thickness along a length of the core wire. In some examples, a guidewire made using the method is also described.