This NSF-FDA Scholar-In-Residence award supports translational research in modeling to inform future medical device design and approval processes. It is supported by the NSF Cyber-Physical Systems program in the Division of Computer and Network Systems in the Directorate for Computer and Information Science and Engineering. Sudden cardiac death is the leading cause of fatalities in the industrialized world. One in five people in the United States is affected by some sort of heart disease and one third of all deaths are due to cardiac diseases with an economic impact of about $200 billion a year. Most of these deaths result from arrhythmias, particularly fibrillation, which is rapid, disorganized electrical activity. The classification of arrhythmias as either reentrant or focal is of clinical significance, yet is difficult to assess. The FDA is responsible for regulating the systems and algorithms that aim to make this important differentiation. Such differentiation is a complex task involving the analysis of complex spatio-temporal patterns of electrical activity. The objectives of this project are to identify the key features of fibrillation that models should represent, to compare how well (or poorly) existing models correspond to measured values of these features, and to develop models that better represent fibrillation. The project develops and extends cell and tissue models and explores the analysis of clinical, experimental and simulation data from the perspective of regulatory science at the FDA, including verification, validation, and uncertainty quantification (VVUQ). The project seeks to 1) validate and create new models that reproduce not only single-cell dynamics, but also experimental and clinically relevant physiological dynamics in tissue and 2) initiate a new developmental framework that the FDA can use not only to test cardiac electrophysiology devices but also to characterize and verify massive submissions of therapeutic compounds obtained by computer-aided drug design methods. The research is conducted in collaboration with the Center for Devices and Radiological Health at FDA, and is aimed at developing tools that can characterize and evaluate real-world performance of devices. This will help the FDA to better regulate and verify the safety and effectiveness of devices that are developed to treat and terminate cardiac arrhythmias. All results from this project will be made freely available to the research community and to the general public.