Electromedics, Inc. and the University of Pittsburgh Medical Center have joined forces to develop an innovative, intravenous membrane oxygenator which is intended to augment the incomplete respiration of patients with adult respiratory distress syndrome. We have been developing an oxygenator that can be introduced into the venous system and positioned in the superior vena cava, right atrium and inferior vena cava. It is made of microporous hollow membrane fibers through which oxygen is vacuum aspirated. What distinguishes our device from other designs is that the hollow fibers are arranged around a centrally positioned balloon, which pulsates rhythmically and thereby enhances convective mixing to maximize O2/CO2 transport. In initial animal trials, our intravenous oxygenator has shown to be safe, provide highly efficient gas exchange, and not compromise hemodynamics in the host animal. These encouraging results have prompted us to continue our systematic development of our intravenous oxygenator through the SBIR mechanism. Our research goals for this program include: 10 Optimize balloon pulsation rate with respect to maximum gas exchange efficiency; 2) Demonstrate the long term mechanical integrity of an operating prototype, including the durability of the hollow fibers; 3) Examine hemolysis generation as a preliminary measure of blood compatibility; 4) Characterize pressure drop across the device as a function of the frequency of balloon pulsation.