论文标题
激发媒体中的螺旋波动力学:动态模式分解的见解
Spiral-wave dynamics in excitable media: Insights from dynamic mode decomposition
论文作者
论文摘要
螺旋波是在各种兴奋系统中出现的无处不在的时空模式。在心脏组织中,这些螺旋波的形成与威胁生命的心律不齐有关,因此,研究这些波的动力学很重要。跟踪螺旋波尖端的轨迹可以揭示螺旋波的重要动力学特征,例如其周期性及其对不稳定性的脆弱性。我们展示了如何采用数据驱动的光谱分解方法,称为动态模式分解(DMD),以在三种设置中检测螺旋尖端轨迹(TT):(1)均质介质; (2)异质培养基; (3)带有外部噪音。我们证明,在(1) - (1) - (3)中,基于DMD的TT(DMDTT)的性能与称为等电位交流方法(IIM)的传统尖端跟踪方法相当或更好。但是,IIM比DMDTT对$τ$的更改更敏感。 (2)在异质介质中,IIM产生TT模式,但具有散射噪声的背景,该点在DMDTT中得到了支持。 (3)与IIM相比,DMDTT对外部噪声更强大。最后,我们证明了DMD可用于重建,因此可以预测我们研究的模型中螺旋波的时空演化。
Spiral waves are ubiquitous spatiotemporal patterns that occur in various excitable systems. In cardiac tissue, the formation of these spiral waves is associated with life-threatening arrhythmias, and, therefore, it is important to study the dynamics of these waves. Tracking the trajectory of a spiral-wave tip can reveal important dynamical features of a spiral wave, such as its periodicity, and its vulnerability to instabilities. We show how to employ the data-driven spectral-decomposition method, called dynamic mode decomposition (DMD), to detect a spiral tip trajectory (TT) in three settings: (1) a homogeneous medium; (2) a heterogeneous medium; and (3) with external noise. We demonstrate that the performance of DMD-based TT (DMDTT) is either comparable to or better than the conventional tip-tracking method called the isopotential-intersection method (IIM) in the cases (1)-(3): (1) Both IIM and DMDTT capture TT patterns at small values of the image-sampling interval $τ$; however, IIM is more sensitive than DMDTT to the changes in $τ$. (2) In a heterogeneous medium, IIM yields TT patterns, but with a background of scattered noisy points, which is suppresed in DMDTT. (3) DMDTT is more robust to external noise than IIM. We show, finally, that DMD can be used to reconstruct, and hence predict, the spatiotemporal evolution of spiral waves in the models we study.