Variable Stiffness Fiber Optic Guidewire for Vascular Lesion Crossing

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Solution Overview

Problem

Current mechanical guidewires are limited in their ability to consistently penetrate and cross chronic total occlusions in the mammalian vasculature due to their mechanical forces and lack of laser energy, making it difficult to position laser catheters effectively for ablation in vascular procedures.

Innovation Solution

A fiber optic guidewire system with a hypotube and adhesive plug, featuring optical fibers that extend through the hypotube and a mandrel for shaping, providing variable stiffness and tracking characteristics, allowing for the transmission of laser energy to ablate vascular obstructions and facilitate the passage of larger treatment catheters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If a laser catheter is used to ablate vascular occlusions, then the ablation capability is improved, but the device diameter increases making it difficult to position within vessels

Engineering Contradiction:

Improveablation capabilityVSAvoiddevice diameter

Core Design Contradiction:

PowerVSVolume of moving object

Solution Approach 1:

The device is divided into two separate components: a thin guidewire with optical fibers for laser delivery and a separate laser catheter. The guidewire can navigate through vessels due to its small diameter, while the laser catheter can be advanced over the guidewire to perform ablation when needed.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The laser catheter is designed to be advanced over the guidewire, with the guidewire serving as a rail or track. This nested configuration allows the larger laser catheter to be delivered through the smaller guidewire, solving the diameter problem while maintaining both navigation and ablation capabilities.

Inventive Principle:

Principle #7Nested doll (Nesting)

2Force

If mechanical forces are used to penetrate chronic total occlusions, then the guidewire can cross lesions, but the penetration capability is insufficient for highly calcified occlusions

Engineering Contradiction:

Improvepenetration capabilityVSAvoidconsistency of crossing

Core Design Contradiction:

ForceVSReliability

Solution Approach 1:

The device replaces purely mechanical penetration methods with laser energy delivery. Optical fibers transmit laser energy through the guidewire to ablate highly calcified occlusions, providing consistent penetration capability where mechanical forces alone are insufficient.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The guidewire incorporates optical fibers that enable delivery of laser energy with specific wavelengths and power levels. This changes the interaction mechanism from mechanical force to photothermal ablation, allowing reliable crossing of chronic total occlusions with varying calcification levels.

Inventive Principle:

Principle #35Parameter changes

3Strength

If a solid hypotube structure is used, then the guidewire has adequate stiffness for torque transmission, but the flexibility and tracking characteristics are reduced

Engineering Contradiction:

Improvetorque transmissionVSAvoidflexibility and tracking

Core Design Contradiction:

StrengthVSEase of operation

Solution Approach 1:

The hypotube is designed with non-uniform wall thickness, having thicker walls in proximal sections for stiffness and torque transmission, and thinner walls in distal sections for flexibility and tracking. This local variation in structural quality optimizes both contradictory requirements along the length of the guidewire.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The guidewire combines the hypotube structure with optical fibers and adhesive plugs to create a composite construction. This composite design allows the hypotube to provide structural support and torque transmission while the optical fibers and adhesive materials contribute to flexibility and positioning capabilities.

Inventive Principle:

Principle #40Composite materials

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

Enables safe, reliable, and consistent crossing of vascular lesions, providing both the handling characteristics of a guidewire and the ablation capabilities of a laser delivery device, effectively addressing chronic total occlusions that standard guidewires cannot penetrate or cross.

Implementation Method 1

optical fibers that extend through the hypotube... transmission of laser energy to ablate vascular obstructions

Methodology Applied

Scientific EffectLaser energy transmission: Laser

Implementation Method 2

transmission of laser energy to ablate vascular obstructions

Methodology Applied

Scientific EffectLaser ablation: Laser Ablation

Implementation Method 3

an adhesive plug within the distal end of the hypotube... The adhesive plug surrounds the optical fibers and fixes the fibers within the distal end of the hypotube

Methodology Applied

Scientific EffectAdhesion: Adhesive

Data Source

PatentUS11445892B2Laser-assisted guidewire having a variable stiffness shaft

Publication Date: 2022.09.20 SPECTRANETICS CORP

AI summary

Embodiments of the present invention comprise a fiber optic guidewire having a hypotube with a plurality of openings that provide variable stiffness and tracking characteristics between at least one proximal segment and one distal segment of the guidewire. In some embodiments, the guidewire further comprises a mandrel disposed within the hypotube, the mandrel cooperating with the optical fibers to permit the distal end of the hypotube to be shaped as desired by a user. Methods of manufacturing and using the guidewire are also disclosed.