Intracardiac Electrogram Filtering After PFA for Residual Activation Detection
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Solution Overview
Problem
Conventional methods for analyzing intracardiac electrograms after pulsed field ablation struggle to distinguish between reversible and irreversible electroporation, leading to inaccurate assessment of ablation success due to masking by noise and interference, particularly in unipolar channels.
Innovation Solution
An adaptive filter is employed to remove variable amounts of recurrent noise from specific frequency bands, allowing for the detection of local activations masked by ST elevation and near field interference, with real-time updates to maintain signal integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional filtering methods are used on unipolar channels after pulsed field ablation, then power line interference is reduced, but residual local activations remain masked by ST elevation and near field interference
Solution Approach 1:
The patent applies dynamic filtering where filter parameters are continuously adjusted based on the detected signal characteristics. The system adapts the filter cutoff frequency and order in real-time to track the evolving signal morphology after PFA, allowing optimal separation of noise from residual activations without requiring manual recalibration
Solution Approach 2:
The system employs feedback mechanisms where the filtered signal is continuously monitored and the filter parameters are adjusted based on the detected signal-to-noise ratio. The control system uses the detected residual activations to fine-tune the filtering strength, ensuring that noise removal does not inadvertently eliminate clinically relevant signals
2Reliability
If higher output voltages are used for pulsed field ablation to achieve irreversible electroporation, then ablation effectiveness is improved, but damage to adjacent tissue and blood cells increases
Solution Approach 1:
The patent applies local quality by delivering the pulsed field ablation energy through multiple electrodes positioned at different locations within the target tissue. Each electrode delivers a tailored voltage waveform optimized for the local tissue properties and desired ablation depth, creating a non-uniform electric field distribution that concentrates energy where needed while sparing adjacent sensitive structures
Solution Approach 2:
The system dynamically adjusts multiple parameters including pulse duration, frequency, amplitude, and waveform shape during the ablation procedure. These parameter changes allow optimization of the electroporation effect on target cells while minimizing thermal damage and cavitation in surrounding tissues, achieving selective cell destruction without excessive collateral damage
3Productivity
If faster ablation delivery is used to reduce procedure time, then productivity is improved, but measurement precision of ablation success deteriorates
Solution Approach 1:
The patent implements preliminary action by establishing a comprehensive automated analysis system before the ablation procedure begins. The system pre-configures multiple filtering algorithms, signal processing pipelines, and success criterion thresholds, enabling immediate post-ablation assessment without manual setup delays. Electrodes are positioned and calibrated in advance to ensure optimal signal capture from the treated tissue
Solution Approach 2:
The system replaces manual visual inspection and subjective assessment of ablation success with automated electronic analysis. The control system automatically processes the intracardiac electrogram signals through digital filters, detects residual activations using algorithmic criteria, and generates objective success assessments, eliminating the time-consuming and variable nature of manual evaluation
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
Enhances the ability to accurately assess the success of pulsed field ablation by revealing residual local activations, improving the precision of ablation therapy evaluation.
Implementation Method 1
The control system (1) performs a filtering step, wherein in the filtering step the control system (1) applies a filter to the post-PFA section (8) of the unipolar channel (7), thereby generating a filtered channel section (26)
Implementation Method 2
Pulsed field ablation works by electroporation of cells in a high voltage pulsed electrical field. Electroporation leads to a breakdown of the cell membrane dependent on the strength of the electrical field. For ablation, irreversible electroporation leading to the destruction of the cardiac muscle cells, is the target.
Implementation Method 3
with lower amounts of energy and depending on parameters that cannot be fully overseen and measured, for example electrode-tissue contact, reversible electroporation may happen
Data Source
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AI summary
The invention relates to a method of analyzing an intracardiac electrogram via a control system (1), wherein the intracardiac electrogram comprises a, in particular unipolar, channel with a post-PFA section (8) measured at a location of the human heart after an application of pulsed field ablation, wherein the control system (1) performs a filtering step, wherein in the filtering step the control system (1) applies a filter to the post-PFA section (8) of the unipolar channel (7), thereby generating a filtered channel section (26). It is proposed that the filter has a variable attenuation, thereby removing a variable amount of energy associated with a recurrent noise from a frequency band and leaving a variable amount of energy associated with a biosignal in the frequency band, that the variable amount of energy removed from the unipolar channel (7) is changed over time in a filter update routine, that the control system (1) performs at least one filter update routine resulting in a change of the variable amount of energy removed from the unipolar channel (7) within a time frame after the time of the application of pulsed field ablation and implements the update resulting in a filtering of the unipolar channel (7) within the time frame, and, that the time frame is at most 60 seconds.