Development of an intravenous membrane oxygenator: Enhanced:Intravenous gas exchange through convective mixing of blood around Hollow-Fiber membranes

In vitro testing of a new prototype intravenous membrane oxygenator (IMO) is reported. The new IMO design consists of matted hollow fiber membranes arranged around a centrally positioned tripartite balloon. Short gas flow paths and consistent, reproducible fiber geometry after insertion of the device result in an augmented oxygenflux of up to 800% with balloon activation compared with the static mode (balloon off). Operation of the new IMO device with the balloon on versus the balloon off results in a 400% increase in carbon dioxide flux. Gas flow rates of up to 9.5 L/min through the 14-cm-long hollow fibers have been achieved with vacuum pressures of 250 mm Hg. Gas exchange efficiency for intravenous membrane oxygenators can be increased by emphasizing the following design features. short gas flaw paths, consistent and reproducible fiber geometry, and most importantly, an active means of enhancing convective mixing of blood around the hollow fiber membranes.