Abstract:
:Measurements were made of exchange rates of oxygen, carbon dioxide, and krypton-85 with blood at 37.5 degrees C. Gas transfer took place across a 1 mil silicone rubber membrane. The blood was in a rotating disk boundary layer flow, and the controlling resistance to transfer was the concentration boundary layer. Measured rates were compared with rates predicted from the equation of convective diffusion using velocities derived from the Navier-Stokes equations and diffusivities calculated from the theory for conduction in a heterogeneous medium. The measured absorption rate of krypton-85 was closely predicted by this model. Significant deposition of material onto the membrane surface, resulting in an increased transfer resistance, occurred in one experiment with blood previously used in a nonmembrane type artificial lung. The desorption rate of oxygen from blood at low P(o2)(1) was up to four times the corresponding transfer rate of inert gas. This effect is described somewhat conservatively by a local equilibrium form of the convective diffusion equation. The carbon dioxide transfer rate in blood near venous conditions was about twice that of inert gas, a rate significantly greater than predicted by the local equilibrium theory. It should be possible to apply these theoretical methods to predict exchange rates with blood flowing in systems of other geometries.
journal_name
Biophys Jjournal_title
Biophysical journalauthors
Spaeth EE,Friedlander SKdoi
10.1016/S0006-3495(67)86624-4subject
Has Abstractpub_date
1967-11-01 00:00:00pages
827-51issue
6eissn
0006-3495issn
1542-0086pii
S0006-3495(67)86624-4journal_volume
7pub_type
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