Ablation Current Profiling for Steam Pop-Free Tissue Heating
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Solution Overview
Problem
Ablation procedures face challenges in safely delivering high power to tissue within a short interval, risking steam pops due to excessive subsurface temperature increases.
Innovation Solution
A predetermined ablation-current profile is used, where a processor simulates and controls the current amplitude to quickly reach and maintain a safe maximum subsurface temperature, adjusting based on tissue conditions and feedback.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high power is delivered to tissue quickly, then ablation productivity is improved, but subsurface temperature increases excessively causing steam pops
Solution Approach 1:
The patent applies a time-varying current amplitude profile that dynamically adjusts the ablation current over time. The current amplitude starts at an initial value and increases to a maximum value according to a predefined function, allowing the system to deliver high power quickly while controlling subsurface temperature rise to prevent steam pops.
Solution Approach 2:
The patent changes the parameter of current amplitude over time using a predefined function that describes the temporal variation. By controlling the current amplitude to follow this predefined function, the system achieves rapid power delivery while maintaining safe temperature thresholds through parameter optimization.
2Power
If current amplitude increases rapidly to maximize power delivery, then ablation efficiency is improved, but subsurface temperature exceeds safe thresholds
Solution Approach 1:
The system dynamically controls current amplitude over time rather than applying constant high power. The predefined function of time governs the temporal profile of current amplitude, enabling the system to deliver maximum power at the optimal moment while preventing excessive temperature accumulation through controlled ramp-up.
Solution Approach 2:
The system performs preliminary simulation to determine the optimal current amplitude profile before actual ablation. The predefined function of time is derived from simulations that predict tissue temperature response, allowing safe power delivery parameters to be established in advance.
3Reliability
If a predefined current profile is used to control temperature, then safety is improved, but system complexity increases
Solution Approach 1:
The system performs preliminary simulations to pre-determine the optimal current amplitude profile and stores it as a predefined function of time. During actual ablation, the system simply retrieves and applies this pre-computed profile, significantly reducing real-time computational complexity while maintaining safe temperature control.
Solution Approach 2:
The system uses a simplified mathematical model (predefined function of time) that copies the essential characteristics of optimal current delivery without requiring complex real-time simulations. This approximation maintains safety while reducing computational burden during the ablation procedure.
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
Ensures rapid and controlled tissue ablation without exceeding safe temperature thresholds, preventing steam pops and ensuring consistent lesion formation.
Implementation Method 1
electric currents are then passed through the tissue, causing a lesion to be formed in the tissue
Data Source
AI summary
Described embodiments include a system that includes a current source generator and a processor. The processor is configured to drive the current source generator to supply, for application to tissue of a subject, an electric current having an amplitude that varies in accordance with a predefined function of time, such that the amplitude initially monotonically increases to a maximum value. Other embodiments are also described.