Telescoping Guide Wire Stiffness Control for Calcified Lesions
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Solution Overview
Problem
Conventional guide wires face challenges in crossing calcified segments of coronary vessels due to limited stiffness control and maneuverability, leading to potential vessel damage and the need for additional tools and radiation exposure during PCI procedures.
Innovation Solution
A guide wire with an internal shaft slidably received within an external shaft, featuring a high elasticity coiled wire distal portion and a conically tapered tip, allowing for adjustable stiffness and precise steering through manual control, enabling safe penetration and navigation through calcified segments without additional microcatheters or stiffer wires.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a floppy guide wire is used to pass through tortuous coronary vessels, then the guide wire can be inserted without damage, but it cannot penetrate calcified occlusions
Solution Approach 1:
The guide wire is divided into multiple segments with different stiffness characteristics: a floppy distal tip for navigation, a intermediate section for flexibility, and a stiffer proximal section for penetration. This segmentation allows each portion to perform its specific function optimally.
Solution Approach 2:
The guide wire incorporates a dynamic stiffness adjustment mechanism that allows the operator to change the stiffness of the wire by applying rotational force or axial tension, transforming it from a floppy state for insertion to a stiffer state for penetration.
2Strength
If a stiff guide wire is used to penetrate calcified occlusions, then penetration power is sufficient, but the guide wire cannot be maneuvered and steered
Solution Approach 1:
The guide wire is divided into multiple segments with different stiffness characteristics: a floppy distal tip for navigation, a intermediate section for flexibility, and a stiffer proximal section for penetration. This segmentation allows each portion to perform its specific function optimally.
Solution Approach 2:
The guide wire incorporates a dynamic stiffness adjustment mechanism that allows the operator to change the stiffness of the wire by applying rotational force or axial tension, transforming it from a floppy state for insertion to a stiffer state for penetration.
3Strength
If additional microcatheters are used to increase guide wire stiffness, then tip load and shaft support increase, but device complexity and radiation exposure increase
Solution Approach 1:
The guide wire integrates multiple functions into a single device: navigation capability, stiffness adjustment, and penetration power. This eliminates the need for separate microcatheters and reduces procedural complexity.
Solution Approach 2:
The guide wire serves multiple purposes: it acts as both a navigation wire and a penetration wire, and can be adjusted to provide different levels of support. This multi-functionality replaces the need for multiple specialized devices.
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 guide wire provides precise maneuverability and controlled stiffness, reducing the risk of vessel damage and radiation exposure, allowing for efficient and safe passage through calcified segments and facilitating the installation of PTCA balloons and stents.
Implementation Method 1
The distal portion of the external shaft is made of a high elasticity coiled wire
Implementation Method 2
a conically tapered tip, allowing for adjustable stiffness and precise steering through manual control, enabling safe penetration and navigation through calcified segments
Data Source
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AI summary
A guide wire includes elements in a telescoping arrangement which impart stiffness to the guide wire for maneuverability in the tortious cardiac vessels. This arrangement also creates engagements between an inner shaft and the tip, that when released, result in a tip which can move outward with forces sufficient to penetrate a lesion in the coronary vessels.