Hydrodynamic Characteristics of Artificial Lungs

An artificial lung is used during cardiopulmonary bypass to oxygenate blood and to control blood temperature. The pressure drop–flow rate characteristics of the membrane compartment in three hollow fiber membrane oxygenators were determined in vitro to characterize design features. Results are presented in a unique dimensionless relationship between Euler number, NEu (ratio of pressure drop to kinetic energy), and Reynolds number, NRe (ratio of inertial to viscous forces), and are a function of the device porosity, ε, and a characteristic device length, ξ, defined as the ratio of the mean blood path and manifold lengthThis dimensionless approach allows us (1) to compare oxygenators independently, and (2) to relate water tests to blood.