Microporous membrane blood oxygenators

Abstract

Abstract Extracorporeal blood oxygenators are used to oxygenate blood during open‐heart surgery. Hydrophobic microporous flat‐sheet or hollow‐fiber membranes are used to separate blood and gas phases. Oxygen diffuses from the gas phase through the gas‐filled membrane pores into the blood. Mass‐transfer and friction‐factor correlations have been developed for flat‐sheet and hollow‐fiber blood oxygenators. Generalized Graetz, Reynolds, and Schmidt numbers are used in these correlations to account for the shear‐thinning behavior of blood. Because oxygen not only dissolves in plasma but also binds to hemoglobin, a mass‐transfer enhancement factor based on film theory has been developed to account for oxygen binding to hemoglobin. Experimental results for oxygen transfer to bovine blood and both non‐Newtonian and Newtonian blood analogue fluids indicate that the correlations developed may be used to predict the performance of a blood oxygenator based on results for an experimentally simple system such as the oxygenation of deionized water. © 2005 American Institute of Chemical Engineers AIChE J, 51: 656–670, 2005