Studies on Improved Model for Cerebrovascular Blood Circulation

For the elastic cavity model adopted in the existing cerebrovascular hemodynamics analyzers was too simple, we developed the improved model for cerebrovascular blood circulation to describe more exactly the physiologic nature of both sides cerebrovascular blood circulation and the relation between them (Willis Circle). It was a network consisting of 2 inputs, 9 arteries and 4 terminal flow resistances. For two cases, constantflow and pulsating flow, the further improved models for calculability were analyzed and the mathematical equations describing the model was obtained; some algorithms were given to solve the positive and negative problems to the mathematical functions; the physiologic means to parameters in the model were defined; at last, the possible applications of the models in basic research and clinic about cerebrovascular disease were stated as well. In the paper, we compared our portable cerebrovascular hemodynamics analyzer with the improved model to other analyzers with the elastic cavity model, and concluded that because of providing additional M-style ultrasonic detector for measuring the diameters of blood vessels and improving the Doppler ultrasonic detector for measuring the velocity of blood flow of the internal carotid artery we could accept the improved model to obtain more exact and more details and the relation about cerebrovascular blood circulation and hemodynamics.