Professional activities as a staff member of Mayo Clinic was in the field of pulmonary medicine including interventional bronchoscopy, critical care, with special interests in early and advanced stage lung cancer, liver and lung transplantation. Activities in education included the medical school and director of the pulmonary-fellowship training program. Research was focused on NIH funded endoscopic laser photodynamic therapy for early stage lung cancer and on NdYAG-laser phototherapy of advanced stage airway obstructing cancer.

In addition to his current ASU academic position, he currently serves on the board of trustees of Dartmouth-Hitchcock, and the boards of directors for Cerner Corporation, Essence Global Holding Corporation, and Pinnacle West.