Angled HF Electrode for Lateral Tissue Access

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Solution Overview

Problem

Conventional medical instruments for minimally invasive surgery, such as resectoscopes, are limited in their ability to access and remove tissue located laterally to the insertion axis due to their rigid design, making it difficult to precisely target and remove tissue in areas like the bladder neck and prostate without causing damage.

Innovation Solution

A medical instrument with a hollow shaft and an electrically insulated HF electrode that can be adjusted in angular orientation relative to the shaft, allowing it to protrude radially beyond the shaft's circumference, enabling controlled positioning and access to tissue areas distant from the insertion axis through adjustable mechanisms like flexible connecting sections, memory materials, and deflection elements.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stability of the object's composition

If the resectoscope is rigidly constructed to facilitate placement and provide good guidance, then the stability and guidance capability are improved, but the ability to access tissue located laterally to the insertion axis deteriorates

Engineering Contradiction:
Improveguidance capabilityVSAvoidaccess to lateral tissue
Core Design Contradiction:
Stability of the object's compositionVSAdaptability or versatility

Solution Approach 1:

The instrument is divided into a rigid proximal shaft for stable insertion and guidance, and a flexible distal region containing the HF electrode that can be independently angled. This segmentation allows the proximal part to maintain stability while the distal part adapts to access lateral tissue through angular adjustment mechanisms.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The HF electrode assembly is designed with dynamic angular adjustment capability through flexible connecting sections and deflection elements. The electrode can be angled relative to the shaft centerline, transforming the static rigid structure into a dynamic system that adapts to different tissue locations while maintaining overall instrument stability.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If traumatic leveraging or tilting of the resectoscope is used to reach lateral tissue, then the ability to access lateral tissue is improved, but the risk of tissue damage increases

Engineering Contradiction:
Improveaccess to lateral tissueVSAvoidtissue damage
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The HF electrode is designed with controlled angular adjustment capability through flexible connecting sections that allow the electrode to be angled relative to the shaft without requiring traumatic leveraging of the entire instrument. This dynamic adjustment enables safe access to lateral tissue by isolating the angling action to the distal electrode region.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

Flexible connecting sections with controlled flexibility are introduced between the shaft and HF electrode. These flexible elements enable the electrode to be positioned at angles to reach lateral tissue while the flexibility absorbs mechanical stress, preventing transmission of traumatic forces to surrounding healthy tissue.

Inventive Principle:
Principle #30Flexible shells and thin films

3Device complexity

If the RF electrode is fixed along the centerline of the instrument, then the structural simplicity is maintained, but the ability to ablate tissue away from the insertion axis is limited

Engineering Contradiction:
Improvestructural simplicityVSAvoidablacion capability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The instrument is segmented into a rigid shaft and a flexible distal region with the HF electrode. This segmentation allows the electrode to be angled relative to the shaft centerline through the flexible connecting section, enabling ablation of tissue away from the insertion axis while keeping the overall structure relatively simple.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The angular orientation of the HF electrode is made variable through the flexible connecting section, allowing the electrode angle to be adjusted as needed. This parameter change enables the same simple structure to achieve multiple ablation positions by changing only the electrode angle rather than requiring complex mechanical systems.

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

Enables precise and minimally invasive removal of tissue in traditionally difficult-to-reach areas by allowing the HF electrode to be angled and positioned accurately, reducing the risk of damage to healthy tissue and improving surgical precision.

Implementation Method 1

An RF electrode is inserted into the bladder, to which a high-frequency alternating current is applied to remove harmful or damaged tissue

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 2

adjustable mechanisms like flexible connecting sections, memory materials, and deflection elements

Methodology Applied
Scientific EffectShape memory alloy: Shape Memory Alloy

Data Source

PatentEP3453352B1Medical instrument for removing tissue by means of a high frequency (HF) electrode having the function of a controlled distal angular orientation
Publication Date: 2024.09.11 KARL STORZ SE & CO KG
  • EP3453352B1 patent drawingFigure 1
  • EP3453352B1 patent drawingFigure 2
  • EP3453352B1 patent drawingFigure 3a~3b

AI summary

The invention relates to a medical instrument 1 for minimally invasive tissue ablation using a radiofrequency (RF) electrode 10, comprising a hollow shaft 2, 3, wherein the RF electrode 10 is electrically insulated from the hollow shaft, is arranged at a distal end 6 thereof, and projects at least partially axially beyond the hollow shaft 2, 3 for tissue ablation. According to the invention, the angular orientation of the RF electrode 10 relative to the hollow shaft 2, 3 can be adjusted in a controlled manner to a working position in which the RF electrode, viewed from the front of the hollow shaft 2, 3, projects radially beyond an outer circumference of the hollow shaft for tissue ablation. In the working position, a position can always be found by suitable adjustment of the shaft and the RF electrode in which the distal end of the RF electrode sufficiently reaches or touches the tissue sections to be ablated in the region of the bladder neck.One preferred use is as a resectoscope for transurethral resection in the area of ​​the bladder neck or the prostate.