Trans Thoracic Manipulation of Ventilation/Perfusion: the V/Q System

With the patient supine, sedated, and hemodynamically stable, the Vest is placed upon the patient and secured by clinicians and staff. All chambers of the Vest will be inflated simultaneously. First inflation will be for one hour to a pressure of 0.4 psi. Subsequent inflations at 0.8 and finally 1.2 psi will be performed for one hour each. Participants will be treated for up to four hours and then will be observed for an additional hour.