Guiding Catheter Braid Containment Ring for Pull Wire Integrity
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Solution Overview
Problem
Existing deflectable guiding catheters face issues such as braid exposure leading to sharp edges and pull wire separation due to the cutting and reflow process, which compromises the integrity and functionality of the catheter shaft.
Innovation Solution
A containment ring made from the same material as the braid and anchor ring is positioned over the cut end of the braid, laser welded to the braided sleeve and anchor ring, covering the cut end and encapsulating the pull wire to prevent exposure and separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If the stainless steel braid is cut and terminated during assembly, then the braid can be positioned correctly, but the braid may expand during reflow and expose sharp edges on the shaft surface
Solution Approach 1:
A containment ring is introduced as an intermediary component between the cut braid end and the shaft surface. This ring captures and contains the potentially expanding braid, preventing it from exposing sharp edges while allowing the braid to be properly positioned and terminated during assembly.
Solution Approach 2:
The containment ring is positioned beforehand to anticipate and prevent the harmful effect of braid expansion. By placing the ring before the reflow process, it creates a protective barrier that cushions against the potential sharp edge exposure, ensuring safety even if expansion occurs.
2Reliability
If the pull wire anchor ring is reflowed into the distal softer sheath tip section, then the anchor ring is secured, but the anchor ring may deform or dislodge under extreme pull force
Solution Approach 1:
The containment ring is nested over the anchor ring, creating a layered protective structure. This nested configuration allows the anchor ring to be securely reflowed into the softer sheath section while the outer containment ring provides additional structural support to prevent deformation and dislodgement under extreme forces.
Solution Approach 2:
The structure combines multiple materials and components (anchor ring, containment ring, softer sheath section) into a composite assembly. This composite structure leverages the properties of each component to achieve both secure anchoring and enhanced resistance to deformation, with the containment ring providing additional mechanical strength.
3Strength
If the braid reinforcement is extended to the proximal end of the anchor ring, then kink resistance is improved, but the assembly process becomes more complex and risky
Solution Approach 1:
The braid reinforcement is segmented into two parts: the main braid extending to the anchor ring, and the containment ring as a separate protective component. This segmentation allows the braid to provide kink resistance while the separate containment ring simplifies the assembly process by preventing complications during reflow, making the overall process more manageable despite the extended braid length.
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 enhances the catheter's structural integrity by preventing sharp edges and ensuring the pull wire remains connected to the anchor ring, improving kink resistance and durability under deflection.
Implementation Method 1
A containment ring is positioned over a distal end portion of the braided sleeve at the proximal end of the anchor ring and preferably laser welded to the braided sleeve and the anchor ring
Data Source
AI summary
A deflectable guiding catheter that includes a proximal handle assembly, an elongated catheter shaft extending distally from the proximal handle assembly and including a deflectable distal end portion, a drive mechanism within the proximal handle assembly for steering the deflectable distal end portion of the catheter shaft, an anchor ring positioned adjacent a distal end of the catheter shaft, an elongated pull wire extending from the drive mechanism and connected to the anchor ring, a braided sleeve extending from a proximal end of the catheter shaft to a proximal end of the anchor ring, and a containment ring positioned over a distal end portion of the braided sleeve at the proximal end of the anchor ring.