Looped Core Wire Steering for Consistent Intraluminal Bending
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Solution Overview
Problem
Intravascular and intraluminal medical devices, such as guide wires and microcatheters, often face challenges with poor steerability and inconsistent bending, making it difficult to navigate through tortuous anatomy, especially when the anatomy is small and complex.
Innovation Solution
The intraluminal device features a flexible elongated sheath with a core wire that includes a looped distal end and a movement restrictor to allow for consistent directional flexing, enhancing steerability and torquability while maintaining a soft and atraumatic tip.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a pull wire is used as a steering mechanism, then the device can be steered through tortuous anatomy, but the device exhibits poor steerability requiring large force application for small bends
Solution Approach 1:
The core wire is divided into multiple segments with different flexibility characteristics. The distal portion includes a first segment with a loop configuration that provides high flexibility for steering, while proximal segments maintain structural support. This segmentation allows the device to bend easily at the distal tip while maintaining overall stability.
Solution Approach 2:
Different portions of the core wire are assigned different mechanical properties. The distal segment is designed with a loop configuration and greater flexibility to enable steering, while proximal segments maintain higher rigidity for support. This local differentiation of mechanical properties allows the device to achieve both ease of steering and structural integrity.
2Object-affected harmful factors
If the distal tip is made pliable to avoid complications, then patient safety is improved, but steering consistency deteriorates
Solution Approach 1:
The core wire is segmented into distinct regions with the distal portion forming a loop that provides controlled flexibility. This segmentation allows the tip to be pliable for patient safety while the proximal segments maintain consistent mechanical properties for reliable steering.
Solution Approach 2:
The loop configuration in the distal portion allows the core wire to dynamically adjust its bending characteristics. The loop can buckle and flex in a controlled manner to provide consistent directional bending while maintaining tip pliability, enabling both patient safety and steering reliability.
3Measurement precision
If the core wire is made rigid for consistent bending, then steering precision is improved, but navigation through small tortuous anatomy becomes difficult
Solution Approach 1:
The core wire is divided into segments with different flexibility characteristics. The distal segment with the loop configuration provides high adaptability for navigating small tortuous anatomy, while proximal segments maintain rigidity for precise bending control.
Solution Approach 2:
Different portions of the core wire have different mechanical properties tailored to their functions. The distal portion has local flexibility for navigation adaptability, while proximal portions maintain rigidity for bending precision, resolving the contradiction between these two requirements.
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 device provides improved and consistent steering capabilities, allowing for easier navigation through complex anatomies by ensuring repeatable and controlled bending of the distal tip, reducing the risk of complications during delivery to a treatment site.
Implementation Method 1
The movement restrictor may be configured to permit the loop of the core wire to buckle, resulting in a bend in the distal section of the sheath, when an axial force is exerted on the core wire.
Implementation Method 2
At least some of the windings forming the distal portion of the sheath may be configured to have spaces therebetween
Data Source
AI summary
Intraluminal and endovascular devices and methods of manufacturing intraluminal and endovascular devices may be provided. In one implementation, an intraluminal device may include a sheath having a flexible distal bending segment and a core wire arranged within the sheath. The core wire may include a distal end portion doubled back in a loop within the sheath such that the distal tip of the core wire is situated proximally from the loop. The intraluminal device may also include a movement restrictor within the sheath that is configured to limit axial movement of the distal tip of the core wire. Limiting the axial movement of the core wire distal tip may cause the loop of the core wire to buckle, resulting in a bend in the distal bending segment of the sheath, when a force is exerted on the core wire.