Coaxial Ablation Needle Assembly for Single-Entry Tissue Ablation

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Solution Overview

Problem

Existing radio frequency ablation needles require multiple punctures for biopsy and can cause ablation damage to normal tissues outside the target area due to interfering currents, and they lack flexibility in adapting to lesions of varying sizes.

Innovation Solution

An ablation needle assembly with a detachable insulated coaxial outer tube that serves as a re-entry needle channel, forming a single electrode with the ablation needle body, and an adjustable handle to adapt to different lesion sizes, while preventing interference currents and minimizing tissue damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If multiple punctures are performed for biopsy and ablation operations, then diagnostic and treatment functions can be achieved, but tissue damage is aggravated and procedural complexity increases

Engineering Contradiction:
Improvefunctional versatilityVSAvoidtissue damage
Core Design Contradiction:
Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The patent combines biopsy needle and ablation needle into a single integrated needle assembly. The biopsy needle can pass through the ablation needle, allowing both diagnostic sampling and therapeutic ablation to be performed through one puncture site, thereby eliminating the need for multiple separate punctures and reducing cumulative tissue damage.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The needle assembly is designed to perform multiple functions: the outer ablation needle delivers radiofrequency energy for tissue ablation, while the inner biopsy needle enables tissue sampling. This multi-functional design allows a single needle system to accomplish both diagnostic and therapeutic objectives without requiring separate intervention procedures.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Manufacturing precision

If the ablation needle is integrated with insulation, then ablation precision is improved, but interference currents are generated outside the target area causing damage to normal tissues

Engineering Contradiction:
Improveablation precisionVSAvoidinterference current
Core Design Contradiction:
Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The ablation needle features selective insulation where only specific portions are covered with insulating material. The insulation layer is applied to the proximal portion of the needle body but deliberately excludes the distal tip region, creating localized electrical properties that confine current flow to the intended ablation zone while preventing parasitic currents on insulated sections.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

Instead of insulating the entire needle and creating separate electrode structures, the invention inverts the approach by leaving the distal tip uninsulated to serve as the active electrode, while insulating all other portions. This reverse insulation strategy simplifies the structure and eliminates interference currents by ensuring only the target area conducts radiofrequency energy.

Inventive Principle:
Principle #13The other way round (Inversion)

3Device complexity

If a fixed-length ablation needle is used, then device simplicity is maintained, but adaptability to lesions of varying sizes is reduced

Engineering Contradiction:
Improvedevice simplicityVSAvoidlesion size adaptability
Core Design Contradiction:
Device complexityVSAdaptability or versatility

Solution Approach 1:

The ablation needle incorporates an adjustable-length handle that can be extended or retracted to match the required ablation depth. This dynamic adjustment mechanism allows the needle to adapt to lesions of varying sizes and depths while maintaining a compact storage configuration, providing both versatility and ease of use without requiring multiple fixed-length needles.

Inventive Principle:
Principle #15Dynamics

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

The design allows for single-entry procedures, reduces tissue damage, and enables precise ablation of lesions of varying sizes with enhanced safety and efficiency by avoiding secondary punctures and controlling the ablation area accurately.

Implementation Method 1

use radio frequency energy to generate high temperature in the local tissue of the lesion

Methodology Applied
Scientific EffectRadio frequency energy: Electromagnetic Induction

Implementation Method 2

prevents interfering radio frequency currents from being generated outside the lesion area

Methodology Applied
Scientific EffectRadio frequency current confinement: Electromagnetic Induction

Implementation Method 3

the cutting edge is arranged to effectively reduce the puncture force of the ablation needle body when it is punctured

Methodology Applied
Scientific EffectMechanical cutting: Fracture Mechanics

Data Source

PatentEP4681668A1Ablation needle assembly and ablation system
Publication Date: 2026.01.21 ZHEJIANG JIANAIWEI MEDICAL TECH
  • EP4681668A1 patent drawingFigure 1~3
  • EP4681668A1 patent drawingFigure 4~7
  • EP4681668A1 patent drawingFigure 8~10

AI summary

The present invention discloses an ablation needle assembly and an ablation system. The ablation needle assembly includes a hollow insulated coaxial outer tube and an ablation needle, the ablation needle including an ablation needle body and an ablation handle connected to the proximal end of the ablation needle body. The ablation needle body movably passes through the interior of the insulated coaxial outer tube, the proximal end of the insulated coaxial outer tube being detachably connected to the distal end of the ablation handle; and a portion of the distal end of the ablation needle body extending out of the insulated coaxial outer tube is tightly fitted with the uninsulated portion at the distal end of the insulated coaxial outer tube to form a single electrode. By providing a detachable connection between the ablation handle and the insulated coaxial outer tube, after the initial needle insertion, the insulated coaxial outer tube serves as a re-entry needle channel, avoiding secondary injury to tissue during secondary needle insertion. By tightly fitting the portion of the ablation needle body extending out of the insulated coaxial outer tube with the uninsulated portion of the insulated coaxial outer tube to form a single electrode, interference current generated outside the lesion is avoided, thereby preventing ablation damage to normal tissues.