@article {, title = {Interactive 3D Human Heart Simulations on Segmented Human MRI Hearts}, year = {2021}, url = {https://www.cinc.org/2021/Program/accepted/261.pdf}, author = {John P. Berman and FLAVIO H. FENTON and ELIZABETH M. CHERRY and Tinen Iles and Paul A. Iaizzo and Abouzar Kaboudian} } @article {, title = {Large-scale interactive numerical experiments of chaos, solitons and fractals in real time via GPU in a web browser}, journal = {Chaos, Solitons \& Fractals}, volume = {121}, year = {2019}, pages = {6{\textendash}29}, doi = {10.1016/j.chaos.2019.01.005}, url = {https://doi.org/10.1016/j.chaos.2019.01.005}, author = {Abouzar Kaboudian and ELIZABETH M. CHERRY and FLAVIO H. FENTON} } @article {, title = {Real-time interactive simulations of large-scale systems on personal computers and cell phones: Toward patient-specific heart modeling and other applications}, journal = {Science Advances}, volume = {5}, year = {2019}, pages = {eaav6019}, doi = {10.1126/sciadv.aav6019}, url = {https://doi.org/10.1126/sciadv.aav6019}, author = {Abouzar Kaboudian and ELIZABETH M. CHERRY and FLAVIO H. FENTON} } @article {, title = {Spatiotemporal correlation uncovers characteristic lengths in cardiac tissue}, journal = {Physical Review E}, volume = {100}, year = {2019}, doi = {10.1103/physreve.100.020201}, url = {https://doi.org/10.1103/physreve.100.020201}, author = {Alessandro Loppini and Alessio Gizzi and Christian Cherubini and ELIZABETH M. CHERRY and FLAVIO H. FENTON and Simonetta Filippi} } @article {, title = {Electromechanical vortex filaments during cardiac fibrillation}, journal = {Nature}, volume = {555}, year = {2018}, pages = {667+}, abstract = {

The self-organized dynamics of vortex-like rotating waves, which are also known as scroll waves, are the basis of the formation of complex spatiotemporal patterns in many excitable chemical and biological systems. In the heart, filament-like phase singularities5,6\ that are associated with three-dimensional scroll waves7\ are considered to be the organizing centres of life-threatening cardiac arrhythmias. The mechanisms that underlie the onset, maintenance and control14,15,16\ of electromechanical turbulence in the heart are inherently three-dimensional phenomena. However, it has not previously been possible to visualize the three-dimensional spatiotemporal dynamics of scroll waves inside cardiac tissues. Here we show that three-dimensional mechanical scroll waves and filament-like phase singularities can be observed deep inside the contracting heart wall using high-resolution four-dimensional ultrasound-based strain imaging. We found that mechanical phase singularities co-exist with electrical phase singularities during cardiac fibrillation. We investigated the dynamics of electrical and mechanical phase singularities by simultaneously measuring the membrane potential, intracellular calcium concentration and mechanical contractions of the heart. We show that cardiac fibrillation can be characterized using the three-dimensional spatiotemporal dynamics of mechanical phase singularities, which arise inside the fibrillating contracting ventricular wall. We demonstrate that electrical and mechanical phase singularities show complex interactions and we characterize their dynamics in terms of trajectories, topological charge and lifetime. We anticipate that our findings will provide novel perspectives for non-invasive diagnostic imaging and therapeutic applications.

}, doi = {https://doi.org/10.1038/nature26001}, author = {Jan Christoph and M. Chebbok and Carl Richter and Johannes Schr{\"o}der-Schetelig and Philip Bittihn and Seth Stein and Ilija Uzelac and FLAVIO H. FENTON and Gerd Hasenfuss and Robert F. Gilmour and Stefan Luther} } @article {, title = {Probabilistic reachability for multi-parameter bifurcation analysis of cardiac alternans}, journal = {Theoretical Computer Science}, year = {2018}, month = {02/2018}, abstract = {

Using a probabilistic reachability-based approach, we present a multi-parameter bifurcation analysis of electrical alternans in the two-current Mitchell{\textendash}Schaeffer (MS) cardiac-cell model. Electrical alternans is a phenomenon characterized by a variation in successive Action Potential Durations generated by a cardiac cell or tissue. Alternans are known to initiate re-entrant waves and are an important physiological indicator of an impending life-threatening arrhythmia such as ventricular fibrillation. The multi-parameter bifurcation analysis we perform identifies a bifurcation hypersurface in the MS model parameter space, such that a small perturbation to this region results in a transition from highly likely alternans to highly likely non-alternans behavior. Our approach to this problem rests on encoding alternans-like behavior in the MS model as a five-mode, multinomial hybrid automaton. To perform multi-parameter bifurcation analysis of cardiac alternans, we first treat the parameters in question as bounded random variables. We then apply a sophisticated guided-search-based probabilistic reachability analysis to compute a bounded bifurcation region (possibly very tight) that contains the bifurcation hypersurface (BH). Our probabilistic reachability analysis uses a technique that combines a δ-decision procedure with statistical tests. In the process of computing the bifurcation region, we further partition the parameter space into two more regions such that any valuation chosen from one of the regions will either produce alternans or non-alternans behavior with a probability greater than a user-defined threshold.

}, keywords = {Bifurcation analysis, Cardiac alternans, Cardiac modeling, Formal methods, Hybrid systems, Probabilistic reachability}, issn = {0304-3975}, doi = {https://doi.org/10.1016/j.tcs.2018.02.005}, url = {http://www.sciencedirect.com/science/article/pii/S0304397518300823}, author = {Md. Ariful Islam and Rance Cleaveland and FLAVIO H. FENTON and Radu Grosu and Paul L. Jones and Scott A. Smolka} } @article {, title = {Simultaneous Quantification of Spatially Discordant Alternans in Voltage and Intracellular Calcium in Langendorff-Perfused Rabbit Hearts and Inconsistencies with Models of Cardiac Action Potentials and Ca Transients}, journal = {Frontiers in Physiology}, volume = {8}, year = {2017}, doi = {10.3389/fphys.2017.00819}, url = {https://doi.org/10.3389/fphys.2017.00819}, author = {Ilija Uzelac and Yanyan C. Ji and Daniel Hornung and Johannes Schr{\"o}der-Scheteling and Stefan Luther and Richard A. Gray and ELIZABETH M. CHERRY and FLAVIO H. FENTON} } @article {, title = {SHARP BOUNDARY ELECTROCARDIAC SIMULATIONS}, year = {2016}, address = {Stony Brook}, abstract = {

We present a sharp boundary electrocardiac simulation model based on the finite volume embedded boundary method for the solution of voltage dynamics in irregular domains with anisotropy and a high degree of anatomical detail. This method is second order accurate uniformly up to boundaries and is able to resolve small features without the use of fine meshes. This capability is necessary to enable the repeated simulations required for future verification and validation and uncertainty quantification studies of defibrillation, where fine-scale heterogeneities, such as those formed by small blood vessels, play an important role and require resolution.

}, keywords = {cardiac electrophysiology, embedded boundary method, tensor diffusion}, doi = {10.1137/15M1019283}, author = {SHUAI XUE and HYUNKYUNG LIM and JAMES GLIMM and FLAVIO H. FENTON and ELIZABETH M. CHERRY} }