Kirk Shelley is boarded in Anesthesia and Internal Medicine. He is a Professor of Anesthesia at Yale University where he heads the Ambulatory Surgical Division. Dr. Shelley obtained MD and PhD degrees (biochemistry) from Penn State University. His research focuses on developing tools for the noninvasive measurement of physiologic parameters. The photoplethysmograph (PPG) has been his study focus for twenty years. His primary goal has been to understand the physiology that underlies the PPG components associated with respiratory and venous signals. His secondary goal is the utilization of this understanding to develop new methods of patient monitoring. He has numerous awards for his work and is a past President of the Society for Technology in Anesthesia (STA).