Catheter Control Handle Dynamic Friction Mechanism
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Solution Overview
Problem
Catheter ablation procedures face challenges in navigating through complex biological lumens due to the need for precise tip deflection control, which can lead to operator fatigue and discomfort due to varying restorative forces in steering spines and the reliance on auditory cues in noisy operating rooms.
Innovation Solution
An adjustable friction mechanism within the control handle that dynamically matches the restorative force of the steering spine across the range of tip deflection, allowing for customizable tactile feedback through vibration or auditory stimuli to assist operators in maintaining precise control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a standardized frictional force is used in the control handle, then the device structure is simple, but operator fatigue increases and control precision decreases due to high force requirements near neutral orientation
Solution Approach 1:
The friction mechanism transitions from a static, standardized frictional force to a dynamic system where frictional force varies with pull wire tension. The frictional force is proportional to the tension in the pull wire, automatically adjusting to match the restorative force of the steering spine at different deflection positions. This dynamic adjustment reduces operator fatigue especially near neutral orientation without requiring complex manual intervention.
Solution Approach 2:
The frictional force parameter is changed from a constant value to a variable value that depends on pull wire tension. By making the frictional force proportional to tension, the system adapts its mechanical properties based on operational conditions, allowing lower frictional resistance when the catheter is near neutral orientation and higher resistance when fully deflected.
2Manufacturing precision
If high frictional force is applied to counter maximum restorative force, then tip deflection control is achieved at maximum deflection, but operator fatigue increases and positional resolution decreases near neutral orientation
Solution Approach 1:
The friction mechanism incorporates feedback through the tension-dependent frictional force. As the operator deflects the catheter tip, the pull wire tension increases, which automatically increases the frictional force to counter the restorative force. This feedback loop ensures that the frictional force is always appropriately matched to the current deflection position, providing precise control without excessive force requirements.
Solution Approach 2:
The frictional force acts as a preliminary counterbalancing force that anticipates the restorative force of the steering spine. By making the frictional force proportional to pull wire tension, the system pre-establishes the necessary counterbalancing force at each deflection position, reducing the additional force the operator must apply and thereby reducing fatigue.
3Stability of the object's composition
If a continuous steering spine is used, then the restorative force naturally returns the tip to neutral position, but the frictional force must be high enough to counter maximum restorative force causing discomfort
Solution Approach 1:
The friction mechanism dynamically adapts to the restorative force of the continuous steering spine by making frictional force proportional to pull wire tension. This ensures that the frictional force automatically matches the restorative force at any given deflection position, allowing the steering spine to maintain its natural restorative property without requiring excessively high frictional force that would cause operator discomfort.
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
Reduces operator fatigue by requiring less force to deflect the catheter tip, especially near neutral orientations, and provides effective tactile feedback to enhance precision and comfort during procedures.
Implementation Method 1
a deformable gasket disposed within the housing assembly and compressible against the glide surface of the piston assembly
Implementation Method 2
an elastic member disposed within the housing assembly and coupled to the piston assembly, the elastic member storing and releasing mechanical energy to restore the piston assembly to an initial position
Data Source
AI summary
A control handle for a steerable catheter body for navigation of the catheter body through a biological lumen and manipulation at a treatment site. The control handle includes a housing assembly that houses a piston assembly and a resistance adjusting assembly. The resistance adjusting assembly can be adjusted to provide the desired frictional characteristics of the user for control of the resistance between the piston assembly and the housing assembly. In one embodiment, the piston assembly is configured to provide a frictional resistance that varies dynamically to substantially match the restorative force across the range of catheter tip deflection. Other embodiments include a vibrating member that provides tactile feedback to the operator to indicate conditions at the distal end of the catheter, such as contact force.