Intravascular lung assist devices (ILADs) must transfer sufficient amounts of oxygen and carbon dioxide to and from limited surface areas. It has become apparent that passive devices, i.e., those without an active means for enhancing transfer, cannot achieve sufficient transfer within the space available. High speed rotation or oscillation of fiber sheets can increase transfer rates up to 800% over the rates achieved by a stationary device, judiciously configured fiber sheets cause an additional benefit when rotated: reduced resistance to blood flow across the device. The authors have developed a series of device prototypes based on these principles of transfer augmentation and minimization of flow resistance. The prototypes are small enough to fit inside the vena cava, with transfer surface areas ranging from 0.1 m2 to 0.5 m2. Transfer rates of O2 up to 53 ml/min and CO2 up to 51 ml/min and fluxes of 208 ml (min/m2) for O2 and 310 ml (min/m2) for CO2 have been achieved.
Artificial Organs Biomedical Engineering