1. Division of Pulmonary, Allergy and Critical Care Medicine, Stanford University School of Medicine, Stanford, CA
2. Inova Interventional Pulmonology and Complex Airways Disease Program, Division of Thoracic Surgery, Inova Fairfax Medical Campus, Falls Church, VA
3. Division of Thoracic Surgery and Interventional Pulmonology, Beth Israel Deaconess Medical Center, Boston, MA
4. Department of Respiratory Care Services, Stanford Health Care, Stanford, CA