Deflectable RF Electrode Support for Ultrasonic Tissue Sealing

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Solution Overview

Problem

Existing surgical instruments struggle to effectively control and customize single or multiple energy modalities depending on the type of tissue being treated, limiting the quality of tissue treatment, sealing, or cutting.

Innovation Solution

A surgical instrument with an end-effector that can deliver multiple energy modalities, including ultrasonic, bipolar RF, microwave, or irreversible electroporation, simultaneously or sequentially, using a generator to supply energy to the end-effector, with a bipolar RF electrode, and ultrasonic transducer stack, and a movable clamp jaw, a compliant polymeric pad, and a deflectable electrode, allowing for customizable tissue interaction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a fixed electrode is used in combination with ultrasonic blade, then the structure is simple, but the electrode cannot adapt to tissue variations and pad wear

Engineering Contradiction:
Improveelectrode adaptability to tissue variationsVSAvoidelectrode structure complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The electrode is designed as deflectable rather than fixed, allowing it to dynamically adjust its position and orientation in response to tissue variations and pad wear. The electrode can deflect toward or away from the ultrasonic blade to maintain optimal engagement with tissue throughout the procedure.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The deflectable electrode serves itself by automatically adjusting its position based on mechanical forces applied during tissue engagement. As the clamp jaw closes or tissue thickness varies, the electrode deflects accordingly without requiring external control mechanisms, maintaining consistent electrical contact.

Inventive Principle:
Principle #25Self-service

2Manufacturing precision

If high blade pressure is applied for precise cutting, then cutting precision is improved, but the risk of electrode-blade contact increases

Engineering Contradiction:
Improvecutting precisionVSAvoidelectrode-blade contact risk
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The deflectable electrode design allows it to yield to blade pressure rather than maintaining rigid contact. When high pressure is applied for precise cutting, the electrode can deflect away from the blade path, reducing the risk of harmful contact while still maintaining electrical engagement with the tissue.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The electrode's deflectability acts as a built-in safety mechanism that cushions against potential blade contact. Before harmful contact can occur, the electrode naturally deflects under pressure, providing a mechanical buffer that prevents the harmful event.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Adaptability or versatility

If multiple energy modalities are integrated, then treatment versatility is improved, but the control complexity increases

Engineering Contradiction:
Improvetreatment modality versatilityVSAvoidenergy modality control complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

Multiple energy modalities (ultrasonic, bipolar RF, microwave, irreversible electroporation) are merged into a single end-effector assembly. The shared mechanical structure and tissue engagement mechanism simplify control compared to separate instruments, while the generator provides integrated control of all energy types.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The end-effector is designed as a universal platform capable of delivering multiple energy modalities through a single interface. The deflectable electrode serves all energy types (RF and electroporation), while the clamp jaw mechanism supports both ultrasonic and electrical energy delivery.

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

4Reliability

If the electrode is made deflectable to prevent contact, then safety is improved, but the mechanical stability decreases

Engineering Contradiction:
Improveelectrode-blade contact preventionVSAvoidelectrode mechanical stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The electrode is constructed as a flexible, thin-walled structure that can deflect without compromising structural integrity. This flexibility allows safety deflection while maintaining sufficient mechanical stability to transmit electrical energy and maintain form factor during normal operation.

Inventive Principle:
Principle #30Flexible shells and thin films

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 instrument provides precise and customizable tissue treatment by adjusting energy density, preventing damage, and minimizing tissue sticking and charring, enhancing the quality of tissue sealing and cutting.

Implementation Method 1

Vibrating at high frequencies (e.g., 55,500 times per second), the ultrasonic blade denatures protein in the tissue to form a sticky coagulum

Methodology Applied
Scientific EffectUltrasonic vibration: Ultrasonic Vibration

Implementation Method 2

the at least one electrode is configured to be deflectable with respect to the clamp arm

Methodology Applied
Scientific EffectElastic deflection: Elasticity

Implementation Method 3

Heat generated by the current flowing through the tissue may form hemostatic seals within the tissue and/or between tissues

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP3854336B1Deflectable support of RF energy electrode with respect to opposing ultrasonic blade
Publication Date: 2025.12.10 ETHICON INC
  • EP3854336B1 patent drawingFigure 1
  • EP3854336B1 patent drawingFigure 2
  • EP3854336B1 patent drawingFigure 3~4

AI summary

An end-effector is disclosed. The end-effector includes a clamp arm and an ultrasonic blade configured to acoustically couple to an ultrasonic transducer and electrically couple to a pole of an electrical generator. The clamp arm includes a clamp jaw, a clamp arm pad, and a cantilever electrode that is free to deflect. The cantilever electrode is configured to electrically couple to an opposite pole of the electrical generator. Also disclosed are configurations where the clamp arm includes a peripheral cantilever electrode and a clamp arm pad extending beyond the electrode, a floating cantilever electrode and a resilient clamp arm pad, an interlocked cantilever electrode plate and a camp arm pad configured to receive the plate, a laterally deflectable cantilever electrode and a clamp arm pad extending beyond the electrode, and a flexible cantilever electrode and a clamp arm pad extending beyond the electrode.