Frangible Pull Wire for Embolic Coil Detachment
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Solution Overview
Problem
Current embolic coil delivery systems face challenges in manufacturing ease and reliability, particularly in the detachment mechanism, which can be complex and prone to errors.
Innovation Solution
A flexible elongate delivery shaft with a detachable embolic coil device and a pull wire featuring a frangible segment that breaks predictably under tensile force, allowing for reliable detachment of the coil from the shaft, and a breakable section in the shaft for additional separation, facilitating easy deployment and retraction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a mechanical detachment arrangement with a pull wire is used, then the embolic coil device can be detached from the delivery shaft, but the detachment mechanism becomes complex and prone to errors
Solution Approach 1:
The pull wire is segmented into a frangible segment with a predictable separation region, allowing the wire to break at a specific location under tensile force. This segmentation simplifies the detachment mechanism by eliminating the need for complex mechanical interfaces while ensuring reliable coil release from the delivery shaft.
2Reliability
If the frangible segment has a smaller cross-sectional dimension, then the pull wire breaks predictably under tensile force, but the structural strength of the pull wire is reduced
Solution Approach 1:
The pull wire exhibits local quality variation through its frangible segment, which has a smaller cross-sectional dimension compared to the proximal and distal segments. This localized reduction in strength allows the wire to break predictably at the frangible segment when tensile force is applied, while the stronger proximal and distal segments maintain sufficient structural integrity for delivery and detachment operations.
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 ensures a reliable, predictable, and easy-to-use detachment mechanism for embolic coil devices, enhancing manufacturing efficiency and reducing the risk of unintended release during deployment, while maintaining the coil's integrity within the vascular system.
Implementation Method 1
The frangible segment of the pull wire may have a cross-sectional dimension that is smaller than a cross-sectional dimension of the proximal segment of the pull wire immediately proximal of the frangible segment. The frangible segment of the pull wire may define a predictable region of separation of the pull wire in response to tensile force
Data Source
AI summary
An embolic coil delivery system includes a delivery shaft that defines a delivery shaft lumen and an embolic coil device that is detachably connected to a distal region of the delivery shaft. The embolic coil device includes coil windings that define a coil lumen. A pull wire is positioned at least partially within the delivery shaft lumen and at least partially within the coil lumen. The pull wire includes a frangible segment that is positioned within the coil lumen. The frangible segment of the pull wire defines a predictable region of separation of the pull wire in response to tensile force so as to detach said embolic coil device from said delivery shaft.