Catheter with Biased Planar Deflection for Predictable Steering
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Solution Overview
Problem
Existing steerable catheters lack a tubing construction that integrates reinforcement components with a biasing mechanism to promote in-plane bi-directional deflection, leading to unpredictable and imprecise steering of the catheter tip.
Innovation Solution
The development of a steerable catheter with an integrated tubing construction that includes a braided mesh, bias members, and an extruded outer wall, which biases the catheter for in-plane bi-directional deflection, allowing for more predictable and precise steering of the tip section.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a braided mesh reinforcement is added to increase torsional stiffness, then the catheter shaft becomes more resistant to kinking and twisting, but the catheter loses the ability to deflect predictably in a preferred plane
Solution Approach 1:
The patent introduces bias members that create an asymmetric structure within the reinforced tubing. The bias members are positioned to preferentially resist bending in one direction while allowing controlled deflection in a preferred plane, thus resolving the contradiction between torsional stiffness and predictable deflection capability
Solution Approach 2:
The patent combines multiple materials and structures - braided mesh for torsional reinforcement, bias members for planar deflection control, and flexible tubing - into a composite construction that achieves both high torsional stiffness and predictable in-plane deflection characteristics
2Stability of the object's composition
If traditional reinforced tubing is used to provide structural integrity, then the catheter shaft maintains its shape and resists deformation, but the catheter cannot achieve bidirectional deflection with precision
Solution Approach 1:
The patent segments the tubing construction into distinct functional layers: an inner flexible tubing layer for deflection, a braided mesh reinforcement layer for structural integrity, and bias members for directional control. This segmentation allows each layer to perform its specific function without interfering with others
Solution Approach 2:
The bias members act as intermediary elements between the flexible inner tubing and the rigid braided mesh reinforcement. They transmit and control the deflection forces while maintaining the structural integrity provided by the reinforcement, enabling precise steering without compromising structural stability
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 improved catheter design provides greater resistance to out-of-plane deflections, resulting in more predictable and precise steering of the catheter tip, enhancing its usability in medical procedures such as ablation and mapping.
Implementation Method 1
a first pair of bias members integrated between the inner layer and the braided mesh to resist bending of the reinforced tubing in a first plane
Data Source
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AI summary
An improved steerable catheter (10) with biased, in-plane bi-directional deflection has an elongated catheter body (129, a deflectable intermediate section (14) having a tubing with at least a first and a second off-axis opposing lumens (30, 31, 32, 33) for puller wires (42), and a control handle (16) at a proximal end of the catheter body. The deflectable intermediate section includes at least two elongated bias members (54) that extend along the length and lie on a plane perpendicular to the plane of deflection so as to resist flexure outside of the plane of deflection. The deflectable intermediate section has an integrated tubular construction that includes an inner layer (50), a braided mesh (52) surrounding the inner layer and an outer layer (56), where the bias members can be situated between the inner layer and the braided mesh, or between the braided mesh and the outer layer.