Deflectable Catheter Shaft With Variable Coil Stiffness
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing catheters face issues with unwanted displacement and deformation during manipulation due to the operation of actuation wires, affecting precise control and positioning of electrodes at treatment sites.
Innovation Solution
A catheter shaft design featuring a first coil with increased rigidity and a second coil with greater flexibility, supported by a flexible coupler, to stabilize the shaft and enable precise deflection and adjustment of the electrode loop assembly, reducing shaft nodding and ensuring consistent planarity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a loop actuation wire extends through the catheter shaft to adjust the electrode loop assembly, then the loop diameter can be selectively adjusted, but unwanted displacement and deformation of the catheter shaft occurs
Solution Approach 1:
The catheter shaft is divided into multiple discrete coils (first coil, second coil, third coil) along its length. Each coil segment provides localized support and flexibility, allowing the shaft to maintain overall stability while permitting controlled movement at specific segments during loop actuation.
Solution Approach 2:
Different coils are positioned at specific locations along the catheter shaft (proximal, middle, and distal segments). Each coil provides localized mechanical support properties tailored to its position, with the first coil near the handle providing stability, the second coil in the middle providing transition flexibility, and the third coil at the distal end allowing loop assembly movement without compromising overall shaft stability.
2Stability of the object's composition
If the catheter shaft is made rigid to maintain stability during manipulation, then precise positioning is improved, but the ability to deflect and adjust the electrode loop assembly is reduced
Solution Approach 1:
The catheter shaft transitions from a static rigid structure to a dynamic system with variable flexibility. The multiple coils enable the shaft to change its mechanical properties along its length, providing rigidity where stability is needed and flexibility where deflection is required, allowing the shaft to adapt its characteristics based on operational requirements.
Solution Approach 2:
The catheter shaft incorporates coil structures that function as flexible elements within the shaft construction. These coils act as controlled flexibility zones that allow bending and deflection at specific locations while maintaining structural integrity and stability in other regions, enabling both rigid and flexible behaviors in a single shaft design.
Data Source
AI summary
A catheter shaft includes an elongate body extending from a proximal end to a distal end and including a proximal portion and a deflectable distal portion. The distal portion is selectively deflectable in at least one direction by actuation of a shaft actuator assembly. The elongate body defines at least one lumen extending from the proximal end to the distal end. The catheter shaft also includes a loop actuation wire extending through the at least one lumen and being operable to selectively adjust a diameter of an electrode loop assembly coupled at the distal end of the elongate body. The catheter shaft further includes a first coil wound around the loop actuation wire along the proximal portion of the elongate body and a second coil wound around the loop actuation wire along the distal portion of the elongate body. The second coil has a more flexible construction than the first coil.