Temperature Simulator for RF Ablation Signal Separation

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Solution Overview

Problem

Current tissue ablation systems face challenges in accurately simulating and calibrating the temperature responses to RF energy delivery, which affects the precision of lesion formation and safety monitoring during cardiac arrhythmia treatments.

Innovation Solution

An apparatus and method utilizing an emulation circuitry with a temperature simulator connected to an ablator module, allowing for the separation of RF and DC currents, and an adjustable voltage source to simulate temperature-dependent responses, enabling the calibration and verification of the ablation system's power output and temperature monitoring.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a thermocouple is used to measure temperature during RF ablation, then temperature monitoring capability is improved, but the system cannot accurately distinguish between RF-induced voltage and DC thermocouple signal

Engineering Contradiction:
Improvetemperature monitoring accuracyVSAvoidsignal separation capability
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The patent segments the voltage signal into two distinct components: RF-induced voltage and DC thermocouple signal. By using a DC blocking capacitor, the system separates these signals in the frequency domain, allowing the DC thermocouple signal to be extracted and measured independently from the RF interference. This segmentation enables accurate temperature monitoring without contamination from RF voltage.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a DC blocking capacitor as an intermediary element in the signal path. This capacitor acts as a frequency-selective mediator that blocks DC thermocouple signals from reaching the RF amplifier while allowing RF-induced voltages to pass through. This intermediary component enables the system to handle both signal types without mutual interference.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If RF power is delivered during temperature simulation, then realistic testing conditions are improved, but DC voltage measurements become inaccurate due to RF interference

Engineering Contradiction:
Improvetesting accuracyVSAvoidDC voltage measurement accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent segments the measurement circuit into two parallel paths: one for RF power delivery and one for DC voltage measurement. The DC measurement path includes a DC blocking capacitor that isolates it from RF interference, while the RF delivery path operates independently. This segmentation allows both functions to operate simultaneously without compromising measurement accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements a feedback mechanism where the DC thermocouple signal is continuously monitored and fed back to the control system. This feedback loop allows the system to adjust RF power delivery based on real-time temperature measurements, ensuring safe and effective ablation while maintaining accurate DC voltage measurements despite the presence of RF interference.

Inventive Principle:
Principle #23Feedback

3Object-affected harmful factors

If the system monitors temperature to prevent overheating, then safety is improved, but the complexity of signal processing and control increases

Engineering Contradiction:
Improveoverheating preventionVSAvoidsignal processing complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent uses a DC blocking capacitor as an intermediary that simplifies the signal processing architecture. By placing this capacitor in the signal path, the system automatically separates DC thermocouple signals from RF-induced voltages in the frequency domain. This passive frequency-selective separation reduces the need for complex active signal processing circuits while maintaining effective temperature monitoring for safety.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 allows for precise simulation and calibration of the ablation system's response to temperature variations, improving the accuracy of lesion formation and safety monitoring during cardiac arrhythmia treatments by independently controlling RF and DC currents, thereby enhancing treatment efficacy and safety.

Implementation Method 1

The return pathway includes a DC blocking capacitor

Methodology Applied
Scientific EffectCapacitive coupling: Capacitance

Implementation Method 2

the output circuit includes a chain of resistors connected in series with an inductor

Methodology Applied
Scientific EffectInductive reactance: Inductor

Implementation Method 3

a first arm of a first thermocouple metallic material linked to the power output of the ablator module, and a second arm of a second thermocouple metallic material connected to the monitor display

Methodology Applied
Scientific EffectSeebeck effect: Seebeck Effect

Data Source

PatentEP2712566B1Temperature simulator for thermocouple-based rf ablation system
Publication Date: 2021.03.31 BIOSENSE WEBSTER (ISRAEL) LTD
  • EP2712566B1 patent drawingFigure 1
  • EP2712566B1 patent drawingFigure 2~3
  • EP2712566B1 patent drawingFigure 4~5

AI summary

Testing a thermocouple-based RF ablation system is carried out by connecting a temperature simulator to an ablator module. The ablator module is operative to vary a radiofrequency power output thereof in a predefined manner in response to predefined variations in a temperature signal from the simulator. The method is further carried out by delivering RF power from the ablator module to the temperature simulator, and while delivering RF power, performing the steps of: communicating temperature signals from the temperature simulator to the ablator module, varying the communicated temperature signals, and verifying that a variation in the power output of the ablator module in response to varying the temperature signals conforms to the predefined manner.