Microwave Ablation System with Dynamic Thermal Dosage Control

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Solution Overview

Problem

Existing microwave ablation systems lack precise control over thermal dosage delivery, leading to potential damage to healthy tissue due to manual entry of treatment duration and temperature, and do not account for prolonged exposure, which can result in irreversible tissue damage.

Innovation Solution

A microwave ablation system with a computing device that dynamically controls the ablation probe settings based on a temperature accumulation profile, using multiple temperature sensors and the Arrhenius equation to ensure the target tissue temperature follows a predetermined profile, and includes an ultrasound imager for real-time visualization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If manual entry of treatment duration and temperature is used, then ease of operation is improved, but reliability deteriorates due to user error and lack of precise control

Engineering Contradiction:
Improvemanual entry of treatment parametersVSAvoidprecision of thermal dosage delivery
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The system performs self-monitoring and self-adjustment of treatment parameters. Temperature sensors continuously monitor tissue temperature, and the control system automatically adjusts microwave power output based on real-time temperature feedback, eliminating the need for manual parameter entry and reducing human error.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system implements closed-loop feedback control where temperature sensors continuously measure tissue temperature during ablation, and the control system uses this feedback to dynamically adjust microwave power delivery. This ensures precise thermal dosage delivery by maintaining temperature within target ranges while preventing overheating of healthy tissue.

Inventive Principle:
Principle #23Feedback

2Object-affected harmful factors

If temperature threshold monitoring is used to prevent healthy tissue damage, then safety is improved, but productivity deteriorates due to premature shutdown below damaging temperatures

Engineering Contradiction:
Improvedamage to healthy tissueVSAvoidtreatment effectiveness
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The system pre-defines spatial zones with different temperature thresholds: a first zone containing the target lesion with a higher temperature threshold that permits prolonged heating for effective ablation, and a second zone containing healthy tissue with a lower temperature threshold that prevents damage. This preliminary zoning allows the system to maintain temperatures effective for tumor destruction while protecting surrounding healthy tissue.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system applies different temperature control strategies to different spatial locations. The target lesion region allows higher temperatures and longer exposure times for complete ablation, while adjacent healthy tissue regions maintain lower temperature thresholds. This local differentiation enables effective treatment without premature shutdown, improving both safety and productivity.

Inventive Principle:
Principle #3Local quality

3Productivity

If prolonged exposure to sub-threshold temperatures is allowed, then treatment efficacy is improved, but harmful factors worsen due to irreversible tissue damage in healthy tissue

Engineering Contradiction:
Improvetreatment efficacyVSAvoidirreversible tissue damage
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The system pre-establishes spatially differentiated temperature thresholds before treatment begins. The first zone (target lesion) is assigned a higher threshold allowing prolonged exposure for complete ablation, while the second zone (healthy tissue) is assigned a lower threshold to prevent damage. This preliminary configuration prevents the harmful effect of prolonged sub-threshold exposure in healthy tissue while maintaining treatment efficacy in the target.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system transitions from single-point temperature monitoring to multi-point spatial temperature mapping. By monitoring temperature at multiple locations simultaneously (different spatial dimensions), the system can allow prolonged heating in the target lesion while detecting and preventing overheating in adjacent healthy tissue, thus enabling effective treatment without causing damage to surrounding structures.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 and safe thermal dosage delivery, minimizing damage to healthy tissue by dynamically adjusting energy output and ensuring effective ablation of target tissue while preventing overheating, thus improving treatment efficacy and safety.

Implementation Method 1

Treatment may involve inserting ablation probes into or adjacent to tissues where cancerous tumors have been identified. Once the probes are positioned, electromagnetic energy is passed through the probes into surrounding tissue to treat, e.g., heat, ablate and/or coagulate tissue.

Methodology Applied
Scientific EffectDielectric heating: Dielectric Heating

Implementation Method 2

at least one temperature sensor configured to determine a temperature of the target volume of tissue at a plurality of points in time during the ablation procedure

Methodology Applied
Scientific EffectTemperature sensing:

Data Source

PatentEP3451964B1Systems facilitating application of an appropriate thermal dosage in microwave ablation procedures
Publication Date: 2021.06.30 COVIDIEN LP
  • EP3451964B1 patent drawingFigure 1
  • EP3451964B1 patent drawingFigure 2
  • EP3451964B1 patent drawingFigure 3

AI summary

Provided in accordance with the present disclosure is a microwave ablation system including a microwave ablation probe configured to deliver energy to a target volume of tissue during an ablation procedure, at least one temperature sensor configured to determine a temperature of the target volume of tissue at a plurality of points in time during the ablation procedure, and a computing device operably coupled to the microwave ablation probe and the at least one temperature sensor. The computing device includes a processor and a memory storing instructions, which causes the computing device to load a temperature accumulation profile corresponding to the target volume of tissue, and dynamically control the microwave ablation probe in accordance with the temperature of the target volume of tissue at each of the points in time such that the temperature of the target volume of tissue follows the temperature accumulation profile during the ablation procedure.