HF Surgery Generator Feedback Discharge Circuit

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

HF surgical generators face challenges in achieving precise and efficient control of the coagulation zone depth and efficiency, particularly due to low efficiency in forming short pulses and energy dissipation, which requires complex cooling measures and limits their performance in the operating room.

Innovation Solution

An HF surgical generator with a power pack, controllable switching device, and feedback mechanism that temporarily discharges energy from the output transformer into a storage capacitor, allowing for quick reduction of the HF output signal and increasing efficiency by reusing stored energy, along with a discharge device to convert residual energy into heat, ensuring reliable oscillation and improved signal controllability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If conventional DC voltage supply operates in two operating modes with energy transfer back to input, then efficiency is improved, but significant improvements in formation of short pulses cannot be achieved

Engineering Contradiction:
ImproveefficiencyVSAvoidformation of short pulses
Core Design Contradiction:
Loss of energyVSProductivity

Solution Approach 1:

The patent divides the energy management into two distinct circuits: a feedback circuit for energy recovery to the DC supply, and a separate discharge circuit for rapid pulse termination. This segmentation allows the feedback circuit to improve efficiency while the discharge circuit enables fast pulse formation and termination without interfering with the energy recovery process.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a discharge circuit with a discharge switch and discharge resistor as an intermediary mechanism between the energy store and ground. This intermediary allows rapid dissipation of stored energy when pulse termination is needed, enabling short pulse formation without compromising the efficiency improvements from the feedback circuit.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Ease of operation

If HF output signal is terminated by withdrawing energy through ohmic resistor in parallel with load, then signal termination is achieved, but efficiency is low

Engineering Contradiction:
Improvesignal terminationVSAvoidefficiency
Core Design Contradiction:
Ease of operationVSLoss of energy

Solution Approach 1:

The patent extracts the energy termination function from the load circuit by introducing a separate discharge circuit with a discharge switch. When termination is needed, the discharge switch connects the energy store directly to ground through a discharge resistor, bypassing the load and enabling rapid energy withdrawal without affecting the main operational efficiency.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The discharge circuit is pre-configured and ready to act immediately when pulse termination is required. The discharge switch can be activated to rapidly connect the energy store to ground, ensuring fast signal termination before the energy is dissipated, thus maintaining operational efficiency.

Inventive Principle:
Principle #10Preliminary action

3Loss of energy

If complex cooling measures are implemented to eliminate heat losses, then heat loss elimination is achieved, but device complexity increases

Engineering Contradiction:
Improveheat lossesVSAvoidcooling measures
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The patent converts the harmful heat losses into beneficial reused energy through the feedback circuit. The feedback circuit captures energy that would otherwise be lost and returns it to the DC voltage supply, transforming waste heat into useful energy and reducing the need for cooling measures without adding complex cooling systems.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

4Measurement precision

If amplitude-modulated HF voltages with single oscillation period are used, then coagulation zone depth control is improved, but energy efficiency decreases

Engineering Contradiction:
Improvecoagulation zone depthVSAvoidenergy efficiency
Core Design Contradiction:
Measurement precisionVSLoss of energy

Solution Approach 1:

The patent ensures continuity of useful action by implementing a feedback circuit that continuously recovers energy from the energy store and returns it to the DC supply during both active and idle periods. This continuous energy recovery maintains high efficiency even when the HF output is terminated or during single oscillation periods, preventing energy waste while preserving precise coagulation control.

Inventive Principle:
Principle #20Continuity of useful action

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 solution enhances the efficiency and controllability of the HF output signal, reducing heat losses and simplifying cooling requirements, while allowing for precise adjustment of voltage ratios and efficient energy regeneration.

Implementation Method 1

a feedback device between the energy store and the storage capacitor... the energy store is at least partially discharged into the storage capacitor

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

conversion into heat by means of an ohmic load

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Data Source

PatentEP2424458B1Hf surgery generator and method for operating an hf surgery generator
Publication Date: 2019.06.05 ERBE ELEKTROMEDIZIN GMBH
  • EP2424458B1 patent drawingFigure 1~2
  • EP2424458B1 patent drawingFigure 3~4
  • EP2424458B1 patent drawingFigure 5~6

AI summary

In order to be able to abruptly terminate the output signal of an HF surgery generator, ohmic loads have been previously used. The invention relates to an HF surgery generator having a power supply having at least one storage capacitor, a controllable switching device having at least one energy store, such as a transformer, by means of which an HF output signal that can be fed to an HF surgery instrument is generated, wherein a feedback device is provided between the energy store and the storage capacitor and a controller is further used, controlling the switching device and the feedback device such that whenever the HF output signal is to be terminated, the feedback device allows current flow at least part of the time and the energy store in the storage capacitor is at least partially discharged.