Microwave Thermometry Network for Ablation Temperature Control

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Solution Overview

Problem

Current microwave ablation systems face challenges in achieving precise temperature control during tissue ablation due to the small temperature difference between malignant and healthy cells, requiring accurate temperature measurements to minimize damage to healthy tissue while effectively treating tumors.

Innovation Solution

Incorporating a microwave thermometry network within the cable of the microwave ablation system, which includes a radiometer and a microwave coupling network to measure noise temperature signals, allowing for real-time monitoring and feedback of tissue temperature and system component temperatures, thereby enhancing procedural outcomes and preventing device failures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If implantable thermoprobes such as thermocouples or optical fibers are used to measure tissue temperature, then temperature measurement capability is provided, but the measurement is limited to a small volume of tissue surrounding the measuring point

Engineering Contradiction:
Improvetemperature measurement capabilityVSAvoidmeasurement volume coverage
Core Design Contradiction:
Measurement precisionVSArea of stationary object

Solution Approach 1:

The microwave transmission line is designed to perform multiple functions: delivering microwave energy for ablation and simultaneously serving as an antenna for radiometric temperature measurement. This eliminates the need for separate thermoprobes and provides temperature information from a larger tissue volume through the microwave radiation detection capability of the transmission line structure.

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

2Measurement precision

If a radiometer and microwave coupling network are integrated within the cable, then real-time temperature monitoring capability is enhanced, but the device complexity increases

Engineering Contradiction:
Improvereal-time temperature monitoring capabilityVSAvoidcable structure complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The radiometer and microwave coupling network are integrated directly within the cable structure, merging the temperature measurement functionality with the existing microwave energy delivery system. This consolidation provides real-time temperature monitoring while utilizing the existing cable infrastructure, thereby enhancing monitoring capability without proportionally increasing overall system complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The microwave transmission line serves dual purposes: delivering microwave energy for ablation and simultaneously functioning as an antenna for the radiometer to detect tissue temperature. This multi-functionality reduces the need for separate dedicated temperature measurement components, thereby enhancing monitoring capability while controlling the increase in device complexity.

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

3Object-affected harmful factors

If precise temperature control is implemented to minimize damage to healthy tissue, then safety is improved, but the system complexity increases due to additional monitoring and control mechanisms

Engineering Contradiction:
Improvedamage to healthy tissueVSAvoidtemperature control system complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The system implements feedback control by continuously monitoring tissue temperature through radiometric measurement and using this information to control the microwave energy delivery. This feedback mechanism enables precise temperature control to minimize damage to healthy tissue while the integration within the existing cable structure helps manage the complexity of the control system.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The microwave transmission line simultaneously delivers ablation energy and provides temperature measurement feedback, eliminating the need for separate dedicated temperature sensing components. This multi-functionality enables precise temperature control for safety while reducing the overall complexity compared to systems with separate energy delivery and temperature monitoring subsystems.

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

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 enables precise temperature control and real-time monitoring, ensuring effective tumor treatment while minimizing damage to healthy tissue and preventing system failures, thus improving the safety and efficacy of the microwave ablation procedure.

Implementation Method 1

a radiometer and a microwave coupling network configured to couple a portion of the signals propagating through the microwave transmission line to the radiometer. The radiometer may process the portion of the signals to determine a noise temperature signal.

Methodology Applied
Scientific EffectThermal radiation: Thermal Radiation

Data Source

PatentEP2863825B1Microwave thermometry for microwave ablation systems
Publication Date: 2018.02.21 COVIDIEN LP
  • EP2863825B1 patent drawingFigure 1~2
  • EP2863825B1 patent drawingFigure 3A~3C
  • EP2863825B1 patent drawingFigure 4A~4B

AI summary

A microwave ablation system incorporates a microwave thermometer that couples to a microwave transmission network connecting a microwave generator to a microwave applicator to measure noise temperature. The noise temperature is processed to separate out components the noise temperature including the noise temperature of the tissue being treated and the noise temperature of the microwave transmission network. The noise temperature may be measured by a radiometer while the microwave generator is generating the microwave signal or during a period when the microwave signal is turned off. The microwave ablation system may be configured as a modular system having one or more thermometry network modules that are connectable between a microwave applicator and a microwave generator. Alternatively, the modular system includes a microwave generator, a microwave applicator, and a microwave cable that incorporate a microwave thermometry network module.