Integrated Pull Ring Marker Band for Steerable Catheters
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Solution Overview
Problem
Existing steerable catheters and introducer sheaths face challenges in navigating tortuous vascular paths due to the rigidity of the distal end, which is compounded by the susceptibility of pull rings to stress fractures and detachment from the catheter shaft.
Innovation Solution
A pull ring that serves as both a marker band and a steering mechanism, made from radiopaque materials like tantalum or molybdenum alloys, is integrated into the distal end of the catheter or sheath. This design reduces the number of components, enhances flexibility, and prevents delamination through asymmetric aperture distribution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a separate marker band and pull ring are used, then visualization and steering functions are achieved, but device complexity and rigidity increase
Solution Approach 1:
The patent combines the marker band and pull ring into a single integrated component made from radiopaque material. This merged structure eliminates the need for separate marker band and pull ring components, reducing device complexity while maintaining both visualization (marker band function) and steering (pull ring function) capabilities.
Solution Approach 2:
The integrated pull ring marker band serves multiple functions simultaneously: it provides radiopaque visualization like a traditional marker band, acts as a pull ring for steering control, and serves as an anchor point for pull wire attachment. This multi-functionality resolves the contradiction by achieving multiple objectives with a single component.
2Strength
If traditional welding is used to attach pull wire to pull ring, then connection is achieved, but stress fractures and detachment occur under repeated pull force
Solution Approach 1:
The patent employs a composite construction where the integrated pull ring marker band is made from radiopaque material that provides both structural integrity and radiopacity. The pull wire is embedded within or attached to this composite structure, creating a unified assembly that distributes stress more effectively than traditional welding, thereby reducing stress fractures and detachment under repeated pull force.
3Ease of operation
If pull ring is placed distally for steering, then steering control is improved, but heat-sink effect prevents homogeneous reflow during assembly
Solution Approach 1:
By merging the marker band and pull ring into a single integrated component positioned at the distal end, the patent eliminates the heat-sink effect that occurs when two separate metal rings are placed close together during assembly. The integrated structure allows for more uniform heat distribution during the reflow process, enabling homogeneous bonding while maintaining optimal steering control positioning.
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 integrated pull ring marker band improves navigation by increasing the flexibility of the distal end, reduces manufacturing costs, and maintains tensile strength comparable to traditional systems, while minimizing the risk of stress fractures and detachment.
Implementation Method 1
made from radiopaque materials like tantalum or molybdenum alloys
Data Source
AI summary
A pull wire assembly for integrating into and anchoring an end of a steerable catheter or introducer sheath used in medical procedures; it has a pull ring made at least in part from a radiopaque material that, when integrated into the end of the steerable catheter or the introducer sheath, allows for visualizing the end of the steerable catheter or the introducer sheath during a medical procedure; and one or more pull wires with a different material composition from that of the pull ring, wherein the one or more pull wires are each fused to the pull ring, wherein the fusion results in an amalgam of the radiopaque material and the pull wire material composition.