MRI Compatible Steerable Sheath Using Non-Metallic Composite Materials
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional steerable sheaths used in MRI-guided interventional procedures are not compatible with magnetic resonance environments, leading to RF-induced heating, image artifacts, and unwanted device movement due to metallic materials, which pose safety risks and degrade image quality.
Innovation Solution
A steerable sheath and control handle constructed from non-metallic materials, such as reinforced polymer tubes with non-metallic pull-wires and diamagnetic or paramagnetic materials, allowing for safe navigation and precise control within MRI environments while maintaining image quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If metallic materials are used in steerable sheaths, then mechanical strength and torque resistance are improved, but RF-induced heating and image artifacts occur in MRI environments
Solution Approach 1:
The patent employs composite materials consisting of non-conductive polymer matrices reinforced with non-metallic fibers (such as Kevlar, nylon, or glass fibers) to construct the sheath. This composite structure provides the necessary mechanical strength and torque resistance while eliminating the conductive properties that cause RF-induced heating in metallic materials, thereby resolving the contradiction between strength and RF safety in MRI environments.
Solution Approach 2:
The patent replaces metallic pull-wires with non-metallic alternative mechanisms for steerable catheter deflection. This substitution eliminates the interaction between metallic components and RF fields that causes heating, while maintaining the mechanical functionality of wire-driven deflection through non-conductive materials that do not interfere with MRI imaging.
2Stability of the object's composition
If metallic materials are used in steerable sheaths, then structural integrity is improved, but image artifacts and unwanted device movement occur in MRI environments
Solution Approach 1:
The patent utilizes composite materials with non-metallic reinforcement fibers embedded in polymer matrices to construct the sheath. These materials maintain structural integrity and stability throughout the MRI procedure while being completely non-magnetic and non-conductive, thereby eliminating image artifacts and unwanted device movement that occur with metallic components in MRI environments.
3Reliability
If non-metallic materials are used in steerable sheaths, then RF-induced heating and image artifacts are eliminated, but mechanical strength and torque resistance are reduced
Solution Approach 1:
The patent employs composite materials where high-strength non-metallic fibers (such as Kevlar, nylon, or glass fibers) are embedded in a polymer matrix. These composite structures provide mechanical strength and torque resistance comparable to or exceeding metallic materials, while maintaining complete MRI compatibility by eliminating all metallic components that cause RF-induced heating and image artifacts.
Solution Approach 2:
The patent changes the material parameters by selecting polymers and fiber reinforcements with specific mechanical properties that match or exceed the performance requirements of metallic materials. Through careful selection of fiber type, orientation, density, and polymer matrix composition, the composite achieves the necessary strength and torque resistance while maintaining non-conductive properties for MRI safety.
4Ease of operation
If conventional steerable sheaths are used in MRI procedures, then device functionality is maintained, but patient safety is compromised due to RF-induced heating
Solution Approach 1:
The patent replaces metallic pull-wires and control mechanisms with non-metallic alternatives that maintain full device functionality for steerable catheter navigation and tool delivery. The non-metallic construction eliminates RF-induced heating risks to patients while preserving the ability to deflect the catheter tip, deliver tools, and perform interventional procedures under MRI guidance.
Solution Approach 2:
The patent uses composite materials with non-conductive fibers and polymer matrices to construct the entire steerable sheath system, including the control handle and pull-wires. This comprehensive non-metallic construction ensures patient safety by eliminating all sources of RF-induced heating while maintaining complete device functionality for navigation and tool delivery during MRI procedures.
Data Source
AI summary
A method of using a MR compatible deflectable catheter is provided. The MR compatible deflectable catheter includes a steerable sheath having a tubular shaft. The tubular shaft receives first and second longitudinal movement wires at a distal end thereof. A control handle is coupled to a proximal end of the first and second longitudinal movement wires and causes longitudinal movement of the wires. Longitudinal movement of the wires causes the catheter to deflect approximately 180 degrees.