Stranded Wire Catheter Coil for Torque and Flexibility
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Solution Overview
Problem
Conventional catheters face issues with reduced torque transmissivity and flexibility, leading to difficulty in inserting into blocked blood vessels, deformation, and increased risk of breakage at the connection between the catheter main body and distal end tip, as well as resistance with guide wires due to their coil structure and separate metal distal end tip.
Innovation Solution
A catheter with a coil body formed by winding stranded wires into a hollow helical coil structure, where the stranded wires are made of multiple twisted wires, improving torque transmissivity and flexibility, allowing easy insertion and restoration of shape, and preventing breakage by fusing the distal end wires to prevent separation and reduce stress concentration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a single line coil body is used, then torque transmissivity is improved, but flexibility is reduced
Solution Approach 1:
The coil body is segmented into multiple independent wires (plurality of wires) instead of using a single wire. Each wire contributes to torque transmission while the multiple wires collectively provide enhanced flexibility. The wires are arranged in a multi-line configuration where they work together to maintain structural integrity while allowing greater adaptability to curved paths in blood vessels.
2Adaptability or versatility
If a multi-line coil body is used, then flexibility is improved, but torque transmissivity is reduced
Solution Approach 1:
Multiple wires are merged into a unified multi-line coil body structure where they are wound together in parallel. This combining approach allows the individual flexibility benefits of multiple thin wires to be realized while collectively providing sufficient torque transmissivity through their combined structural support and coordinated mechanical action.
3Adaptability or versatility
If the catheter is inserted into a blocked portion of a blood vessel, then treatment capability is improved, but insertion resistance increases
Solution Approach 1:
The coil body exhibits different mechanical properties at different locations and orientations. The multi-line wire construction allows local adaptation where the coil can compress and deform more easily in the direction of insertion while maintaining radial strength for torque transmission. This local quality differentiation reduces insertion resistance while preserving the ability to deliver therapeutic devices.
4Strength
If a separate metal distal end tip is used, then structural integrity is improved, but stress concentration at the border part increases
Solution Approach 1:
The distal end tip is merged with the coil body through fusion of the wires, creating a continuous integrated structure without sharp discontinuities. This merging eliminates the separate connection interface that would otherwise concentrate stress, allowing the transition from coil body to distal end tip to occur gradually through the fused wire structure, thereby preventing breakage at the border part.
5Device complexity
If the wire is inclined relative to the long axis direction, then coil structure is simplified, but insertion resistance increases
Solution Approach 1:
The wire arrangement in the multi-line coil body creates local variations in orientation and spacing that optimize insertion characteristics. While maintaining an overall inclined configuration for structural simplicity, the multiple wires provide local adjustments in angle and positioning that reduce the effective insertion resistance by distributing contact forces more favorably during catheter advancement.
Data Source
AI summary
A catheter has excellent torque transmissivity and excellent flexibility, thus enabling easy insertion of the catheter into a blocked portion of a blood vessel. Additionally, the catheter easily restores to its original form even when the catheter is curved and deformed a large amount. Thus, a break at a border area between a catheter main body part and a distal end tip is prevented when the catheter is bent and deformed. This improves the operability of the catheter with a combination device such as a guide wire. The catheter includes a hollow coil body formed of at least one helically wound stranded wire. The at least stranded wire includes a plurality of wires wound into a helical structure.