Steerable Catheter Handle with Offset Gears

Solution Overview

Problem

Existing lever-style control handles for steerable catheters require wrapping control wires around pulleys, leading to high bending strain and potential structural integrity issues due to compressive forces on the wires.

Innovation Solution

A handle assembly with a lever assembly that includes offset gear assemblies allowing individual pulling of control wires, reducing non-tension forces and preventing compressive forces, thus enhancing the structural integrity of the control wires.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If control wires are wrapped around pulleys to effectuate deflection, then deflection of the distal tip is achieved, but the control wires undergo high bending strain and compressive forces leading to structural integrity loss

Engineering Contradiction:

Improvedeflection controlVSAvoidcontrol wire structural integrity

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent inverts the traditional pushing action by implementing a pulling mechanism. Instead of pushing control wires through pulleys which creates compression and bending, the lever assembly directly pulls the control wires in tension, eliminating compressive forces and reducing bending strain while maintaining deflection control capability

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent extracts and eliminates the pulley component from the control mechanism. By removing the pulleys that cause wire wrapping and bending, the design directly connects the lever assembly to the control wires, allowing them to be pulled in tension without undergoing bending strain or compressive forces

Inventive Principle:

Principle #2Taking out (Extraction)

2Ease of operation

If control wires are pushed through pulleys, then deflection is achieved, but material choices are limited due to low bending radius requirements

Engineering Contradiction:

Improvedeflection controlVSAvoidmaterial selection flexibility

Core Design Contradiction:

Ease of operationVSAdaptability or versatility

Solution Approach 1:

The patent inverts the traditional pushing action by implementing a pulling mechanism. Instead of pushing control wires through pulleys which creates compression and bending, the lever assembly directly pulls the control wires in tension, eliminating compressive forces and reducing bending strain while maintaining deflection control capability

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent extracts and eliminates the pulley component from the control mechanism. By removing the pulleys that cause wire wrapping and bending, the design directly connects the lever assembly to the control wires, allowing them to be pulled in tension without undergoing bending strain or compressive forces

Inventive Principle:

Principle #2Taking out (Extraction)

3Device complexity

If both control wires are connected directly to the lever, then deflection control is simplified, but compressive force is applied to one wire requiring highly elastic material

Engineering Contradiction:

Improvecontrol mechanism simplicityVSAvoidmaterial selection flexibility

Core Design Contradiction:

Device complexityVSAdaptability or versatility

Solution Approach 1:

The patent inverts the traditional pushing action by implementing a pulling mechanism. Instead of pushing control wires through pulleys which creates compression and bending, the lever assembly directly pulls the control wires in tension, eliminating compressive forces and reducing bending strain while maintaining deflection control capability

Inventive Principle:

Principle #13The other way round (Inversion)

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 reduces stress on the control wires, preventing bending and potential breakage, while allowing for the use of materials with higher bending yield radius, thereby extending the life of the handle assembly and reducing costs.

Implementation Method 1

The lever assembly includes a first gear assembly and a second gear assembly each disposed in opposing relationship to one another and offset relative to the longitudinal axis for allowing the lumen to pass therebetween. Each of the first and second gear assemblies are interconnected to a respective one of the pair of control wires for individually pulling the control wires in response to rotation of the lever.

Methodology Applied

Scientific EffectMechanical Advantage: Mechanical Advantage

Data Source

PatentEP3970776B1A handle assembly for controlling a steerable catheter

Publication Date: 2025.06.18 FREUDENBERG MEDICAL LLC

Figure 1~2
Figure 3
Figure 4

AI summary

A handle assembly (20) for controlling a steerable catheter (22) includes a handle (24) extending about a longitudinal axis from a proximal end (26) to a distal end (28). A lumen (34) extends through the handle to a distal tip extending outwardly from the distal end of the handle and a pair of control wires (42,44) are interconnected to the distal end of extend the lumen,. A lever assembly (50) is disposed within the handle and includes a lever (52) rotatable about a lever axis to control deflection of the distal end of the lumen. The lever assembly includes a first (54) and second (56) gear assembly disposed in opposing relationship to one another and offset relative to the longitudinal axis (A1) for allowing the lumen to pass therebetween. Each of the gear assemblies are interconnected to one of the pair of control wires to individually pull a respective one of the control wires in response to rotation of the lever.