Instrumentation and Control Techniques for Dynamic Response Experiments in Living Tissue
The development of Polarographic micro oxygen electrodes with tips less than 10μ has allowed the study of cellular and tissue oxygen levels in response to dynamic changes. Several investigators have recorded the in vivo behavior of pO2 in the cerebral cortex tissue when arterial pO2 was made to vary by a step change in the respired O2 concentration. Of particular note are the reports by Bicher (1) in the cat cerebral cortex and Metzger in the cortex of rats (2). A transient overshoot in tissue pO2 was observed during recovery from a one-minute induced hypoxia. This behavior is not predicted directly from first order models with constant metabolism (3). Subsequent analysis ascribed this behavior to delayed brain blood flow transients (4), but instantaneous flow rates were not recorded during the cited experiments.
KeywordsBlood Flow Rate Controller Gain Pump Flow Rate Instantaneous Flow Rate Tissue Oxygen Level
Unable to display preview. Download preview PDF.
- 3.Reneau, D. D., Jr., D. F. Bruley and M. H. Knisely, “A mathematical simulation of oxygen release, diffusion, and consumption in the capillaries and tissue of the human brain,” in Chemical Engineering in Medicine and Biology, ed. by D. Hershey, p. 135–241, Plenum Press, New York, 1967.Google Scholar
- 4.Reneau, D. D., Jr., H. I. Bicher, D. F. Bruley and M. H. Knisely, “A mathematical analysis predicting cerebral tissue reoxygenation time as a function of the rate of change of effective cerebral blood flow,” Blood Oxygenation, ed. by D. Hershey, p. 175–200, Plenum Press, New York, 1970.Google Scholar