Nested Radiofrequency Electrode Array for Minimizing Cannula Profile

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Solution Overview

Problem

Existing radiofrequency ablation devices face limitations in creating larger ablation areas due to the natural constraints of individual tine size, requiring a greater number of tines that increase the cannula profile and cause collateral tissue damage.

Innovation Solution

The design includes a delivery cannula with an electrode array of tines that are secured to a mandrel, allowing them to be nested in offset, circumferential layers when retracted, reducing the overall diameter and minimizing collateral damage while maintaining the ability to deploy for effective ablation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If more tines are added to create larger ablation areas, then the ablation area increases, but the cannula profile increases causing collateral tissue damage

Engineering Contradiction:
Improveablation areaVSAvoidcollateral tissue damage
Core Design Contradiction:
Area of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The electrode tines are arranged in nested circumferential layers around the mandrel when retracted into the cannula. This nesting configuration allows multiple tines to be housed within a compact diameter, enabling a greater number of tines without increasing the cannula profile, thus avoiding collateral tissue damage while maintaining the capability for large ablation areas

Inventive Principle:
Principle #7Nested doll (Nesting)

2Area of stationary object

If more tines are added to create larger ablation areas, then the ablation area increases, but the device complexity increases

Engineering Contradiction:
Improveablation areaVSAvoiddevice complexity
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The electrode array is segmented into multiple circumferential layers of tines arranged around the mandrel. This segmentation allows the tines to be organized in a systematic pattern that simplifies the deployment mechanism while accommodating a greater total number of tines, thereby increasing ablation area without proportionally increasing device complexity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The tines are arranged in multiple circumferential layers around the mandrel, transitioning from a single-plane arrangement to a three-dimensional radial configuration. This dimensional change allows more tines to be packed into the same linear space within the cannula, increasing ablation capability without adding linear complexity to the deployment structure

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 configuration enables the use of a greater number of tines on a smaller mandrel, allowing for larger ablation areas without increasing the cannula profile, thereby reducing tissue damage and enhancing treatment efficacy.

Implementation Method 1

radiofrequency energy into a targeted tissue area, e.g., a tumor, causing heating and eventual ablation of the tissue area

Methodology Applied
Scientific EffectRadiofrequency energy heating: Dielectric Heating

Data Source

PatentEP1895925B1Low profile radiofrequency electrode array
Publication Date: 2015.10.14 BOSTON SCI LTD
  • EP1895925B1 patent drawingFigure 1~2
  • EP1895925B1 patent drawingFigure 3~5

AI summary

An electrosurgical device for tissue ablation includes a delivery cannula having a lumen and an open distal end in communication with the lumen, wherein an electrode array comprising a plurality of tines is deployable from, and retractable into, the cannula lumen through the open distal end. The electrode array tines have proximal ends secured to a mandrel carried in the cannula lumen, the mandrel being movable axially relative to the cannula, wherein the tines, when the electrode array is retracted into the cannula lumen, are nested in offset, circumferential layers about the mandrel.