Effect of time-varying blood flow on oxygen uptake in the pulmonary capillaries.

Abstract
Previous pro-cedures for determingin the blood O2 tension along the pulmonary capillaries assumed that the blood velocity in the capillaries is constant. It is probable, however, that this blood flow is actually pulsatile in nature, although little is known about the specific characteristics of the pulses. In this study, a model was developed which takes into account time-varying pulmonary capillary blood flow, while at the same time including the variations of over-all pulmonary diffusing capacity with blood O2 tension and the nonlinear form of the oxyhemoglobin dissociation curve. Pulsatile blood flow has a detrimental effect on the efficiency of the gas exchange process in the lungs.