Energy Equivalent Pressure

THE OBJECT of this paper is to describe, quantitatively, differences in steady and pulsatile blood flow in terms of an<i>energy equivalent pressure</i>, which is obtained by calculation from phasic flow and pressure measurements. Any project to develop an artificial heart or to aid the failing heart by surgical methods involves consideration of the nature of blood flow in the arterial system. The pulsatile properties of arterial flow and pressure have been thought by some investigators to be important and by others unimportant. It has been suggested that these properties influence the exchange rate between interstitial fluid and lymph, help maintain normal capillary flow and normal kidney function, and have an effect on cellular metabolism by aiding in the propulsion of lymph and in the exchange of cerebrospinal fluid.¹The arterial pressure pulse has been found by numerous investigators to undergo characteristic changes in vascular disease. Its quantitative measurement,