Annalsof Biomedical Engineering, Vol. 10, pp. 1-33, 1982 0090-6964/82/010001-33503.00/0 Printed in the USA. All rights reserved. Copyright 9 1982Pergamon Press Ltd. A COMPREHENSIVE ELEMENTARY MODEL OF THE MAMMALIAN CIRCULATORY SYSTEM Gary M. Sandquist Donald B. Olsen Willem J. Kolff Institute of Biomedical Engineering University of Utah Salt Lake City, Utah Beginning with a set of simplifying assumptions and the statements for the hydrody- namic and thermodynamic processes involved, a comprehensive mathematical model for the mammalian circulatory system is developed and evaluated. Analytical relation- ships are derived and examined for the circulatory component pressures, flow rates, blood volumes, flow resistances, pumping power and pumping rate. The essential circu- latory model parameters are identified and inspected for their influence upon circula- tory behavior. A complete and consistent set of circulatory model parameters is given for the adult human male and the model response is examined. In general, agreement of the model predictions for man with experimental data is good. Keywords -- Circulatory, Model, Hydrodynamic, Blood flow, Mammalian. INTRODUCTION It would seem likely that a biological system as important to man and as wide- ly distributed throughout the biosphere as the hematological circulatory system would be well understood and accurately described. In fact, however, compre- hensive analytical models of the entire circulatory system, particularly quantita- tive mathematical descriptions, are surprisingly scarce and command rather limited attention in basic biological education. As a consequence of this limited resource of analytical models much of the accumulated data relative to the mammalian circulatory system is qualitative and without mathematical basis for quantitative description and analysis. There are several studies (8,9,17,21) directed at developing quantitative models of the entire circulatory system, but these models have proved to be Address correspondence to Gary M Sandquist, Mechanical Engineering Department, University of Utah, Salt Lake City, Utah 84112.