Deflectable Catheter Shaft With Pull Wire Liners
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Solution Overview
Problem
Current catheters used in electrophysiology procedures face challenges in navigating through tortuous vasculature and achieving precise positioning due to limitations in torque application and directional control, particularly in deflecting the distal tip for effective access and manipulation within the heart.
Innovation Solution
A deflectable catheter shaft section with first and second pull wires, each with a pull wire liner, and a bendable stiffening member, allowing for asymmetric or symmetric deflection along a plane, enhanced by polytetrafluoroethylene liners for reduced friction and increased lubricity, enabling improved curve angles and reduced deflection forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional catheter shaft designs are used, then the catheter can be deployed through vasculature, but the catheter cannot achieve precise positioning or effective deflection in tortuous vasculature
Solution Approach 1:
The catheter shaft is divided into multiple sections with different mechanical properties. The deflectable shaft section includes specific structural components (pull wires, liners, stiffening members) that can be independently controlled, allowing precise positioning while maintaining ease of operation through selective deflection capabilities.
Solution Approach 2:
The catheter shaft transitions from a static, uniform structure to a dynamic, variable-geometry structure. The deflectable shaft section can change its curvature and orientation in response to applied forces, enabling real-time adjustment of the distal tip position for precise navigation through tortuous vasculature.
2Ease of operation
If pull wires are added for deflection control, then directional control is improved, but device complexity increases
Solution Approach 1:
The pull wires are nested within the deflectable shaft section, with each pull wire contained within its own pathway. This nesting approach allows multiple control elements to be integrated without proportionally increasing external complexity, as the components are housed within the existing catheter structure.
Solution Approach 2:
The deflectable shaft section with pull wires serves multiple functions: it provides directional control, maintains structural integrity, and enables navigation through tortuous vasculature. By combining these functions into a single integrated component, the overall device complexity is minimized while achieving superior directional control.
3Force
If friction between pull wire and liner is reduced, then deflection forces are decreased, but manufacturing precision requirements increase
Solution Approach 1:
The inner diameter of the pull wire liner is specifically optimized to create a controlled interference fit with the pull wire. This parameter adjustment balances the reduction of frictional forces during deflection while maintaining sufficient engagement to prevent excessive movement or disengagement, thereby managing manufacturing precision requirements.
Solution Approach 2:
The pull wire liner is constructed from materials with specific friction characteristics that reduce deflection forces. By selecting appropriate material combinations for the liner and pull wire, the design achieves low friction while maintaining adequate mechanical engagement, offsetting the need for extremely tight manufacturing tolerances.
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 solution enables more precise and efficient navigation and positioning of the catheter within the heart by reducing deflection forces and improving curve angles, facilitating better access and manipulation during electrophysiology procedures.
Implementation Method 1
enhanced by polytetrafluoroethylene liners for reduced friction and increased lubricity
Data Source
AI summary
A deflectable catheter shaft section is disclosed comprising an elongated body extending along a longitudinal axis with a distal end and a proximal end. First and second pull wires can extend along the elongated body and can have a proximal end and a distal end. First and second pull wire liners can be disposed over a portion of one of the first and second pull wires, respectively. Each of the first and second pull wires can have a proximal end and a distal end. A first gap can exist between the proximal end of the first pull wire liner and the proximal end of the elongated body and a second gap can exist between the proximal end of the second pull wire liner and the proximal end of the elongated body.