A lumped parameter physical model of the human vascular system is proposed, which consists of four components— two elastic chambers joined by an inertance and followed by a pure resistance (grossly approximating, respectively, large and small arterial systems joined by long columns of blood and followed by the capillary bed). Equations of this model are presented in both mechanical and electrical equivalents and normal modes of response are derived. These normal modes of the model determine a descriptive equation for the contour of the actual arterial pressure pulse. Particular values of model components can be calculated for specific human subjects under varying conditions of stress or disease through a least squares fit of the descriptive equation to the clinically measured pressure pulse contour. Copyright © 1967 by The Institute of Electrical Engineers, Inc.