Earl Howard Wood (January 1, 1912 – March 18, 2009) was an American cardiopulmonary physiologist who helped invent the G-suit, brought heart catheterization into a clinical reality and introduced dynamic volumetric computed tomography for the study of the heart and lungs. Career G-Suit Shortly after receiving an M.D. and PhD in physiology from the University of Minnesota medical school under the mentorship of Professor Maurice B. Visscher, MD, Wood became a key member of a team, working in a laboratory at the Mayo Clinic, tasked with helping military pilots and flight crew survive and function in high G-force environments. Based upon extensive physiologic testing via use of the human centrifuge installed at the Mayo Clinic, it was determined that blackout and then unconsciousness was caused by reduction of blood flow to the eyes first and then the brain. The solutions the team arrived at were the M-1 breath hold maneuver and the G-suit. The M-1 maneuver consisted of a strained exhalation effort against a closed glottis designed to increase left ventricular pressure. (Although the references given are dated 1946-7, the work was performed much before then. In, see the acknowledgments section explaining the closed nature of the research with restrictions placed on publication during the war. During the war effort the Mayo Clinic laboratory was operating with government Confidential secrecy.) The G suit was a garment, produced by the David Clark Company, which has air bladders situated at the calves, thighs, and abdomen of the wearer. The bladders inflate as the G-force acting on the aircraft increase, constricting the wearer's arteries, hence increasing blood pressure and blood flow to the brain. The G-suit was a superior solution to another alternative (a water-filled suit) being tested at the time, which was considered impractically heavy and cumbersome. The water-filled, pulsatile pressure suits were developed to effect venous return. However, Wood and colleagues' detailed physiologic measurements demonstrated that what was required was augmentation of arterial pressure. Wood himself regularly tested the flight suits, taking many turns in a human centrifuge and plane dubbed the "G-wiz." He calculated that during more than a thousand rides, he had lost consciousness for an aggregate of at least fifteen minutes (without any observed lasting damage). Wood was awarded a Presidential Certificate of Merit by Harry Truman in 1947. The G-suit was adopted in the 1940s. The current models are based on the pattern Wood and his colleagues