DocumentCode :
1252327
Title :
Incorporating O/sub 2/-Hb reaction kinetics and the Fahraeus effect into a microcirculatory O/sub 2/-CO/sub 2/ transport model
Author :
Guo-Fan Ye ; Park, Joung Won ; Buerk, D.G. ; Jaron, D.
Author_Institution :
New Concept Dev. Div., Respironics Inc., Redwood City, CA, USA
Volume :
45
Issue :
1
fYear :
1998
Firstpage :
26
Lastpage :
35
Abstract :
The influence of O 2-Hb reaction kinetics and the Fahraeus effect on steady state O 2 and CO 2 transport in cat brain microcirculation was investigated using the authors´ refined multicompartmental model. The most important model predictions include: (1) capillaries are the sites in the microcirculation where the effect of O 2-Hb kinetics is most pronounced; (2) while there is only a small difference between equilibrium and actual oxygen saturation, this effect is not negligible; (3) O 2-Hb kinetics tends to make the PO 2 level at the venous entrance higher than in venules; (4) the influence of the Fahraeus effect leads to a lower tissue PO 2 level than in venules and the outlet vein. The resultant decline in tissue PO 2 may lead to a decrease in O 2 consumption rate and extraction ratio; (5) although the Fahraeus effect changes the ratio between arteriolar flux and capillary flux, incorporating the Fahraeus effect and O 2-Hb kinetics into the simulation does not change the authors´ previous conclusion that most of the O 2 and CO 2 exchange takes place at the capillary level; (6) in general, influences of O 2-Nb kinetics and Fahraeus effect are synergistic; (7) a model that excludes these two mechanisms might overestimate the tissue oxygenation level especially during severe hypoxia.
Keywords :
biotransport; brain models; carbon compounds; haemorheology; oxygen; reaction kinetics theory; CO/sub 2/; Fahraeus effect; O/sub 2/; O/sub 2/-Hb reaction kinetics; arteriolar flux; capillary flux; capillary level; cat brain microcirculation; microcirculatory O/sub 2/-CO/sub 2/ transport model; outlet vein; oxygen consumption; oxygen delivery; severe hypoxia; venules; Arteries; Biomedical engineering; Blood; Brain modeling; Carbon dioxide; Kinetic theory; Plasmas; Predictive models; Steady-state; Veins; Algorithms; Animals; Arterioles; Biological Transport; Capillaries; Carbon Dioxide; Cats; Cerebrovascular Circulation; Diffusion; Hemoglobins; Models, Cardiovascular; Models, Neurological; Oxygen Consumption; Venules;
fLanguage :
English
Journal_Title :
Biomedical Engineering, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9294
Type :
jour
DOI :
10.1109/10.650348
Filename :
650348
Link To Document :
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