Unipolar atrial fibrillation (AF) electrograms (EGMs) require far-field ventricle cancellation to recover hidden atrial activations. Current methods cannot achieve real-time cancellation because of the temporal delay they introduce. We propose a new real-time ventricular cancellation (RVC) method based on causal implementation optimized for real-time functioning. The method is similar to the classical average beat subtraction (ABS) method but it computes the ventricular contribution before the ventricular activation finishes. We compare the proposed method to the ABS on synthetic and real EGM databases for the time and frequency domains. All parameters and their optimal values are analyzed and validated. The RVC method provides a good reconstruction of the unipolar EGMs and a better local activation time detection than the classical approach with average F1scores 0.7307 and 0.7125, respectively. The spectral analysis shows that the average power after ventricular cancellation is reduced for frequency bands between 3 and 5.5 Hz, demonstrating that the proposed method removes the ventricular component present in the unipolar EGM signals compared to the ABS method. The phase mapping analysis on the RVC method presented lower error when comparing the annotated EGM cycles with the phase inversion intervals. In terms of performance ABS and RVC behave similarly, but the real-time capability of the latter justifies its preference over the offline implementations. In the clinical environment other online investigations, e.g., rotational activity assessment, dominant frequency or local activation time mapping, might benefit from the real-time potential of the proposed cancellation method.

中文翻译：

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单极心房颤动电图中的实时心室消除

单极心房颤动 (AF) 电图 (EGM) 需要远场心室消除以恢复隐藏的心房激活。由于它们引入的时间延迟，当前的方法无法实现实时消除。我们提出了一种新的实时心室消除 (RVC) 方法，该方法基于针对实时功能优化的因果实现。该方法类似于经典的平均搏动减法 (ABS) 方法，但它在心室激活完成之前计算心室贡献。我们在时域和频域的合成和真实 EGM 数据库上将所提出的方法与 ABS 进行比较。分析和验证所有参数及其最佳值。与平均 F1scores 分别为 0.7307 和 0.7125 的经典方法相比，RVC 方法提供了单极 EGM 的良好重建和更好的局部激活时间检测。频谱分析表明，在 3 到 5.5 Hz 之间的频带内，心室消除后的平均功率降低，这表明与 ABS 方法相比，所提出的方法消除了单极 EGM 信号中存在的心室成分。当将带注释的 EGM 周期与相位反转间隔进行比较时，对 RVC 方法的相位映射分析显示出较低的误差。就性能而言，ABS 和 RVC 的行为相似，但后者的实时能力证明其优先于离线实现。在临床环境中，其他在线调查，例如，