Pulmonary and Critical Care Medicine specialist and a former Associate Professor and Chief of the Critical Care Service at the University of Wisconsin. Prior to COVID-19, he was an internationally renowned pioneer in the field of critical care ultrasonography, having served as Senior Editor of an award-winning textbook in its 2nd edition, translated into 7 languages. During COVID-19, he co-founded and serves as the President and Chief Medical Officer of the Front Line COVID-19 Critical Care Alliance (FLCCC).