TY - JOUR
T1 - Analysis of factors affecting gas exchange in intravascular blood gas exchanger
AU - Niranjan, S. C.
AU - Clark, J. W.
AU - San, K. Y.
AU - Zwischenberger, J. B.
AU - Bidani, A.
PY - 1994
Y1 - 1994
N2 - A mathematical model of an intravascular hollow-fiber gas-exchange device, called IVOX, has been developed using a Krogh cylinder-like approach with a repeating unit structure comprised of a single fiber with gas flowing through its lumen surrounded by a coaxial cylinder of blood flowing in the opposite direction. Species mass balances on O2 and CO2 result in a nonlinear coupled set of convective-diffusion parabolic partial differential equations that are solved numerically using an alternating-direction implicit finite- difference method. Computed results indicated the presence of a large resistance to gas transport on the external (blood) side of the hollow-fiber exchanger. Increasing gas flow through the device favored CO2 removal from but not O2 addition to blood. Increasing blood flow over the device favored both CO2 removal as well as O2 addition. The rate of CO2 removal increased linearly with the transmural PCO2 gradient imposed across the device. The effect of fiber crimping on blood phase mass transfer resistance was evaluated indirectly by varying species blood diffusivity. Computed results indicated that CO2 excretion by IVOX can be significantly enhanced with improved bulk mixing of vena caval blood around the IVOX fibers.
AB - A mathematical model of an intravascular hollow-fiber gas-exchange device, called IVOX, has been developed using a Krogh cylinder-like approach with a repeating unit structure comprised of a single fiber with gas flowing through its lumen surrounded by a coaxial cylinder of blood flowing in the opposite direction. Species mass balances on O2 and CO2 result in a nonlinear coupled set of convective-diffusion parabolic partial differential equations that are solved numerically using an alternating-direction implicit finite- difference method. Computed results indicated the presence of a large resistance to gas transport on the external (blood) side of the hollow-fiber exchanger. Increasing gas flow through the device favored CO2 removal from but not O2 addition to blood. Increasing blood flow over the device favored both CO2 removal as well as O2 addition. The rate of CO2 removal increased linearly with the transmural PCO2 gradient imposed across the device. The effect of fiber crimping on blood phase mass transfer resistance was evaluated indirectly by varying species blood diffusivity. Computed results indicated that CO2 excretion by IVOX can be significantly enhanced with improved bulk mixing of vena caval blood around the IVOX fibers.
KW - IVOX
KW - mathematical model
KW - membrane oxygenator
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U2 - 10.1152/jappl.1994.77.4.1716
DO - 10.1152/jappl.1994.77.4.1716
M3 - Article
C2 - 7836191
AN - SCOPUS:0028061655
SN - 8750-7587
VL - 77
SP - 1716
EP - 1730
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
IS - 4
ER -