Variable-Rigidity Coil Structure for Catheter Torque Transmission
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Solution Overview
Problem
Existing rotation transmission structures in medical devices lack the ability to adjust rigidity while maintaining effective torque transmission, particularly in the distal end regions of catheters and guide wires.
Innovation Solution
A rotation transmission structure with a reinforcing body that connects adjacent wires, featuring varying densities and pitches of connection portions, materials with different Young's moduli, and helical orientations to adjust rigidity, ensuring flexibility and improved torque transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a reinforcing body connects adjacent wires uniformly throughout the coil, then rotation transmission properties are improved, but the rigidity of the entire structure increases uniformly making the distal end less flexible
Solution Approach 1:
The reinforcing body is designed with non-uniform connection density where connection portions are arranged more densely in the proximal end region and more sparsely in the distal end region. This local variation in connection density allows the proximal end to have higher rigidity for stable torque transmission while the distal end maintains lower rigidity for flexibility and ease of navigation through vessels.
2Strength
If the reinforcing body uses material with high Young's modulus, then strength and torque transmission are improved, but the overall rigidity becomes too high reducing operational flexibility
Solution Approach 1:
The reinforcing body employs material with high Young's modulus but implements it with spatially varying connection density. The high-strength material provides adequate torque transmission capability throughout the structure, while the non-uniform distribution of connection portions (denser proximally, sparser distally) creates regions of different effective rigidity, allowing the distal end to remain flexible for navigation while maintaining overall structural strength.
3Reliability
If connection portions are arranged densely throughout the entire coil, then rotation transmission is enhanced, but manufacturing complexity and time increase
Solution Approach 1:
The reinforcing body is manufactured with non-uniform connection density where connection portions are densely arranged only in the proximal end region and sparsely arranged in the distal end region. This localized approach concentrates manufacturing effort where it is most needed for torque transmission stability, while reducing connection density in regions where flexibility is prioritized, thereby decreasing overall manufacturing complexity and time compared to uniform dense connection throughout.
Data Source
AI summary
A rotation transmission structure includes a coil body formed by winding wires, and a reinforcing body for connecting adjacent wires of the coil body. When the wires of the coil body are connected to one another by the reinforcing body, the rigidity of a predetermined region of the rotation transmission structure in the longitudinal direction is lower than the rigidity of another region of the rotation transmission structure.