Expandable Guidewire Centering Structures for Torque Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing guidewire devices face challenges in centering the core wire within a hypotube, leading to misalignment, reduced torque transmission, and instability in navigating tortuous anatomy, with limited material options and lack of visual stiffness profile indication.
Innovation Solution
The guidewire device incorporates expandable structures like stent-like, cut-tube, and spike crown-like structures to center the core wire, uses a radiopaque marker with plastically deformable materials for improved shapeability and shape retention, and includes a visual indicator for stiffness profile changes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional metal coils or braids are used as guidewire reinforcement, then the guidewire can maintain basic structural integrity, but the core wire becomes difficult to center within the hypotube, leading to misalignment and reduced torque transmission
Solution Approach 1:
The reinforcement structure is divided into discrete elements (multiple struts or spikes) rather than continuous coils or braids. These segmented elements can be independently positioned and configured to provide both centering force and structural support, resolving the conflict between maintaining integrity and enabling easy centering.
Solution Approach 2:
The expandable structure is pre-configured in a compressed state that allows it to be delivered through the catheter, then expanded at the target location to automatically center the core wire within the hypotube. This preliminary configuration enables the centering action to occur before final deployment, improving both ease of operation and reliability.
2Reliability
If the guidewire uses a stiffer profile for better torque transmission, then torque control improves, but the guidewire becomes less adaptable to navigating tortuous and complex pathways
Solution Approach 1:
The guidewire is designed with varying stiffness along its length, with the distal portion being more flexible for navigating tortuous pathways and the proximal portion being stiffer for torque transmission. The expandable reinforcement structure is positioned at specific locations to provide localized support without compromising overall flexibility, allowing the wire to adapt to complex anatomy while maintaining torque control.
Solution Approach 2:
The guidewire transitions from a static stiffness profile to a dynamic one where the expandable reinforcement structure can be deployed or adjusted based on procedural needs. This allows the guidewire to change its mechanical properties in real-time, becoming stiffer when torque control is needed and more flexible when navigating complex pathways.
3Adaptability or versatility
If the guidewire uses a more flexible distal section for better navigation, then adaptability to tortuous anatomy improves, but torque transmission capability deteriorates
Solution Approach 1:
The expandable reinforcement structure is positioned at specific locations along the guidewire, typically in the proximal or mid-sections, leaving the distal tip flexible for navigation. This localized reinforcement provides torque transmission capability where needed while preserving the flexibility of the distal section for trackability through tortuous anatomy.
4Ease of manufacture
If traditional centering methods are used, then manufacturing is simpler, but the guidewire lacks visual indication of stiffness profile changes, making delivery difficult
Solution Approach 1:
The expandable reinforcement structure or associated components are provided with radiopaque materials or visual markers that allow the operator to see the stiffness profile changes and structure deployment under fluoroscopy. This visual indication helps guide the delivery process without significantly complicating the manufacturing of the centering structure itself.
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
Enhances torque control, improves navigation through complex pathways, and provides clear visual cues for stiffness changes, ensuring stable and predictable guidewire performance.
Implementation Method 1
The expandable structure is configured to interference-fit onto the inner surface of the tube member
Implementation Method 2
a radiopaque marker with plastically deformable materials for improved shapeability and shape retention
Data Source
AI summary
A guidewire device employs an expandable structure or a plurality of disks to center a core wire to improve torque transmission control. Also disclosed are a guidewire device including a radiopaque coil or braid constructed of two or more different materials to improve the shapeability and shape retention of the device, and a guidewire device including an indicator to provide a visual indication of changes of the stiffness profile of the device to assist the physician during the clinical use. A guidewire device including a core wire constructed from a metal composite wire to provide for more manufacturing options through various combinations of the metal composite wire inner core and outer sheath and/or through adjusting the metal composite wire inner core fill percentage is also disclosed.