Journal of Applied Physiology, Vol 40, Issue 3 425-433, Copyright © 1976 by American Physiological Society
A square-pulse flow method for measuring characteristics of the arterial bed
M. G. Bottomley and G. W. Mainwood
A device was designed to provide a "square" pulse of blood flow into the
arterial system. Pulses were injected into the carotid artery of the rabbit
during transient cardiac arrest. Analysis of pressure response curves
generated by the flow provides information as to the state of the arterial
tree. With certain assumptions it is possible to estimate from these curves
lumped values of peripheral resistance, critical closing pressure, and
arterial compliance. In a series of 12 rabbits the mean value of peripheral
resistance was found to be 0.21 +/- 0.7 mmHg-ml-1-min and critical closing
pressure was estimated to be 23.6 +/- 3.8 mmHg. This method gives two
possible values for arterial compliance 0.036 +/- 0.010 and 0.055 +/- 0.010
ml-mm-1 based, respectively, on the rise and decay curves of the pressure
response. The theory and limitations of the method are discussed. The use
of the method is illustrated in following the response to increased PCO2
and hemorrhage.
