Variable Stiffness Guide Wire Using Phase Change Material

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Solution Overview

Problem

Current FEVAR procedures require multiple guide wires and catheters with different stiffnesses, increasing procedural steps, patient exposure to X-rays and contrast agents, and risk of errors.

Innovation Solution

An elongated device with a phase change material and optical fiber, featuring tilted or blazed gratings, allows for controlled stiffness changes along its length by transmitting light, enabling a single guide wire or catheter to adapt from soft to stiff, reducing the number of procedural steps and eliminating the need for multiple devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If multiple guide wires and catheters with different stiffnesses are used, then the procedural steps increase and patient exposure to X-rays and contrast agents increases, but the ability to navigate and guide the stent is improved

Engineering Contradiction:
Improvenavigation capabilityVSAvoidnumber of devices
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent combines multiple guide wires with different stiffnesses into a single guide wire by integrating a phase change material that can transform the guide wire's stiffness along its length. This merging eliminates the need to use multiple separate guide wires and catheters, reducing procedural complexity while maintaining the ability to navigate and guide the stent effectively.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The guide wire incorporates a phase change material that can dynamically change its stiffness properties in response to optical heating. This dynamic capability allows the guide wire to transition from a soft state for navigation to a stiff state for guiding the stent, replacing the need for multiple static devices with different stiffnesses.

Inventive Principle:
Principle #15Dynamics

2Ease of operation

If multiple guide wires and catheters are used, then the ability to guide the stent is improved, but the patient exposure to harmful X-rays and contrast agents increases

Engineering Contradiction:
Improveguiding capabilityVSAvoidpatient exposure to harmful agents
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent merges the functions of multiple guide wires and catheters into a single guide wire with variable stiffness. This reduction in the number of devices directly reduces the time patients are exposed to X-rays and contrast agents during the procedure, while the phase change material ensures the guiding capability is maintained through controlled stiffness changes.

Inventive Principle:
Principle #5Merging (Combining)

3Productivity

If a single guide wire with variable stiffness is used, then the number of procedural steps is reduced, but the control precision for stiffness adjustment is required

Engineering Contradiction:
Improveprocedural efficiencyVSAvoidstiffness control precision
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The patent uses optical heating to change the physical state (phase) of the phase change material, which directly alters the stiffness parameter of the guide wire. By controlling the amount and distribution of optical energy applied, precise control over the stiffness of different sections of the guide wire is achieved, enabling efficient procedures with accurate stiffness adjustment.

Inventive Principle:
Principle #35Parameter changes

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

This solution reduces the number of procedural steps, minimizes patient exposure to harmful agents, and ensures MR compatibility by allowing controlled stiffness adjustment of the guide wire or catheter during FEVAR procedures.

Implementation Method 1

transmitting light from a proximal end of the optical fiber to at least part of the phase change material for optically providing heat to said at least part of the phase change material

Methodology Applied
Scientific EffectOptical heating: Absorption (EM radiation)

Implementation Method 2

cause said at least part of the phase change material to change its stiffness from one stiffness value to a different stiffness value

Methodology Applied
Scientific EffectPhase change: Phase Change

Implementation Method 3

the optical fiber comprises a plurality of longitudinal portions with tilted or blazed gratings arranged for guiding light in a direction away from the longitudinal extension of the optical fiber

Methodology Applied
Scientific EffectDiffraction grating: Diffraction Grating

Data Source

PatentEP3157406B1Elongated interventional device with variable stiffness
Publication Date: 2019.12.11 KONINKLIJKE PHILIPS NV
  • EP3157406B1 patent drawingFigure 1~3
  • EP3157406B1 patent drawingFigure 4~5
  • EP3157406B1 patent drawingFigure 6

AI summary

An elongated device, e.g. an interventional guide wire or catheter, comprises an optical fiber (OF) arranged to allow transmission of light to phase change material (PCM) arranged long the elongated device, for optically heating the phase change material (PCM) to change its stiffness from one stiffness value to a different stiffness value. Using distributed tilted or blazed Bragg gratings with light wavelength dependent unique grating periods along the optical fiber, it is possible to provide a guide wire or catheter which can be stiffness controlled at selected longitudinal portions. Especially, it may be preferred to be able to control the behavior of the tip of a guide wire or catheter for optimal navigation, e.g. during a FEVAR procedure. Portions of phase change material (PCM-1, PCM 2) arranged inside a tube material T_M can be activated at selected longitudinal parts of the elongated device.