Expandable Tissue Dissector Shaft for Electrosurgical Isolation

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Solution Overview

Problem

Existing electrosurgical procedures face challenges in protecting adjacent tissue from heat during thermal ablation, as fluid-based dissection techniques are difficult to control and require frequent replenishment, prolonging surgical procedures.

Innovation Solution

A deployable tissue dissector with a shaft that transitions from a non-expanded to an expanded configuration, forming a Faraday cage to separate target tissue from neighboring tissue, using materials like shape memory alloy and elastomeric materials, and featuring slits or rings for expansion, allowing precise separation without fluid introduction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If fluid injection technique is used to dissect adjacent tissue, then tissue separation is achieved, but fluid control becomes difficult and requires frequent replenishment

Engineering Contradiction:
Improvetissue separation effectivenessVSAvoidsurgical procedure time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent extracts the dissection function from fluid injection and transfers it to a deployable shaft structure. The shaft is deployed into the tissue space and expanded to physically separate target tissue from adjacent tissue, eliminating the need for fluid replenishment and providing reliable, continuous tissue separation throughout the surgical procedure.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the fluid-based dissection system with a mechanical shaft-based system. The deployable shaft with expandable distal end provides mechanical tissue separation through its physical presence and expansion, substituting the fluid injection mechanism and eliminating the time loss associated with fluid replenishment.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If CO2 gas is used for tissue dissection, then tissue separation is achieved, but CO2 dissolves into tissue requiring frequent replenishment

Engineering Contradiction:
Improvetissue separation effectivenessVSAvoidCO2 retention time
Core Design Contradiction:
ReliabilityVSDuration of action of moving object

Solution Approach 1:

The patent extracts the dissection function from gas injection and transfers it to a deployable shaft structure. The shaft remains in place throughout the procedure, providing continuous tissue separation without the need for gas replenishment, thereby extending the duration of effective tissue separation.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The deployable shaft provides continuous, uninterrupted tissue separation throughout the surgical procedure. Unlike CO2 gas that dissolves and requires replenishment, the shaft maintains constant physical separation, ensuring continuous protective action for adjacent tissue during the entire electrosurgical procedure.

Inventive Principle:
Principle #20Continuity of useful action

3Object-affected harmful factors

If fluid injection is used to protect adjacent tissue, then tissue protection is achieved, but fluid location control becomes difficult

Engineering Contradiction:
Improveheat protection of adjacent tissueVSAvoidfluid location control
Core Design Contradiction:
Object-affected harmful factorsVSMeasurement precision

Solution Approach 1:

The patent replaces the fluid-based protection system with a mechanical shaft structure that can be precisely positioned and deployed. The shaft's location and expansion are mechanically controlled, providing precise spatial control over the protected zone and eliminating the difficulty of controlling fluid location.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The deployable shaft provides localized tissue protection at the specific site where it is deployed. The expandable distal end creates a focused protective barrier exactly where needed, allowing precise control over the location and extent of tissue protection, unlike diffuse fluid injection.

Inventive Principle:
Principle #3Local quality

4Manufacturing precision

If expandable shaft is deployed to separate tissue, then tissue separation precision is improved, but device complexity increases

Engineering Contradiction:
Improvetissue separation precisionVSAvoiddissector structure complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent employs a nested structure where the distal end of the shaft is expandable from a compact configuration to an expanded configuration. The shaft segments nest within each other during delivery, then expand at the target site to provide precise tissue separation. This nesting principle allows the complex expandable structure to be delivered through a simple catheter while providing sophisticated separation capability at the destination.

Inventive Principle:
Principle #7Nested doll (Nesting)

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

Effectively isolates neighboring tissue from the target tissue during electrosurgical procedures, reducing the risk of adjacent tissue damage and eliminating the need for fluid replenishment, thereby shortening surgical times.

Implementation Method 1

The distal end of the shaft may form a Faraday cage in the expanded configuration for stopping or impeding propagation of electrosurgical energy

Methodology Applied
Scientific EffectFaraday cage: Faraday Cage

Implementation Method 2

The wire is made from a material selected from the group consisting of shape memory alloy and elastomeric material

Methodology Applied
Scientific EffectShape memory alloy: Shape Memory Alloy

Data Source

PatentEP2526873B1Tissue dissectors
Publication Date: 2019.08.28 COVIDIEN LP
  • EP2526873B1 patent drawingFigure 1
  • EP2526873B1 patent drawingFigure 2A~2B
  • EP2526873B1 patent drawingFigure 2C~2D

AI summary

A tissue dissector is provided. The tissue dissector includes an introducer including a lumen extending along a length thereof and defining a longitudinal axis therethrough. The introducer configured for placement adjacent target tissue. A shaft operably coupled to the introducer is deployable from a distal end thereof and includes a proximal end for approximating the distal end of the shaft adjacent target tissue. The distal end of the shaft is movable from a non-expanded configuration to an expanded configuration for separating target tissue from neighboring tissue.