Steerable Guiding Sheath With Ring Electrodes and Anti-Kink Shaft
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Solution Overview
Problem
Guiding sheaths used for catheterization often suffer from limited space, kinking, and undesirable deflection characteristics, lack electrical sensing capabilities, and introduce air when holding catheters, compromising catheter positioning and visualization.
Innovation Solution
A guiding sheath with an elongated shaft featuring a braided member, lumened tubing, and a hemostatic valve with air vents, enabling improved pushability, deflection, and electrical sensing, while protecting lead wires and securely holding catheters without introducing air.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the lumen size is increased to accommodate puller wires and provide space for deflection, then steerability is improved, but kinking and undesirable deflection characteristics worsen
Solution Approach 1:
The shaft is divided into multiple functional segments: a proximal section with a first braid density for pushability, and a distal section with a second braid density for flexibility and deflection. The puller wire is segmented into multiple strands that can move independently through the lumen, allowing deflection without kinking. This segmentation allows each region to optimize its properties for its specific function while working together as a unified structure.
2Adaptability or versatility
If ring electrodes and lead wires are added to the shaft, then electrical sensing capability is improved, but space for puller wires and catheter pathway is reduced
Solution Approach 1:
The lead wires for the ring electrodes are nested within the lumen of the shaft, running parallel to and alongside the puller wire. The ring electrodes are mounted on the outer surface of the shaft, utilizing the radial space rather than consuming longitudinal lumen space. This nesting arrangement allows multiple functions (electrical sensing, puller wire transmission, and catheter guidance) to coexist within the same shaft volume without significantly reducing the catheter pathway space.
3Reliability
If the hemostatic valve uses a friction ring to hold catheter in place, then catheter positioning is improved, but air may be introduced into the lumen
Solution Approach 1:
The air venting function is extracted from the friction ring assembly and integrated into the hemostatic valve mechanism itself. The valve includes a one-way valve design with a valve member that can open to allow air to escape from the lumen while maintaining the friction seal for catheter positioning. This separation of functions allows the friction ring to focus on positioning stability while the valve mechanism independently handles air management.
4Volume of moving object
If a sizable lumen is used in the shaft, then space for puller wires is improved, but pushability and deflection characteristics worsen
Solution Approach 1:
The braid density is varied locally along the length of the shaft: the proximal section has a first braid density that provides rigidity and pushability, while the distal section has a second braid density that provides flexibility and deflection characteristics. This local variation in braid density allows different regions of the shaft to have optimized properties for their specific functions, with the proximal region resisting compression during insertion and the distal region allowing smooth deflection during navigation.
Data Source
AI summary
A guiding sheath has a braided layer for improved deflection characteristics and ring electrodes for electrical sensing, mapping and visualization, wherein lead wires for the ring electrodes are passed through lumened tubing position under the braided layer in a proximal portion of the guiding sheath shaft and above the braided layer in a distal portion of the guiding sheath shaft. Moreover, the hemostatic valve includes an improved friction ring with air vents to reduce the risk of air being introduced into the valve.