Wed Sep 7, 11-12, 4750 Boelter Hall Efficient Modeling of Excitable Cells Using Hybrid Automata Scott Smolka SUNY Stony Brook We present an approach to modeling complex biological systems based on Hybrid Automata (HA). HA combine discrete transition graphs with continuous dynamics. Our goal is to efficiently capture the behavior of excitable cells previously modeled by systems of nonlinear differential equations. Our much simpler HA models are able to successfully capture the action-potential morphology of the different cells, as well as reproduce typical excitable cell characteristics, such as refractoriness (period of non-responsiveness to external stimulation) and restitution (adaptation to pacing rates). To model electrical wave propagation in a cell network, the single-cell HA models are linked to a classical 2D spatial model. The resulting simulation framework exhibits significantly improved computational efficiency in modeling complex wave patterns, including the spiral waves underlying pathological conditions in the heart. Joint work with Emilia Entcheva, Radu Grosu, Pei Ye. Scott Smolka is a Professor of Computer Science at SUNY Stony Brook. His research interests include model checking, process algebra and the application of Hybrid automata to the modeling of complex biological systems. He is also president and co-founder of Reactive Systems, Inc., which makes automated testing and validation tools for models of embedded control software. Host: Jens Palsberg