For the last decade, many medical researchers are interested in the region in cerebral artery where process of atherosclerosis initiates. There are many methods to study the progression of atherosclerosis. We depends on hemodynamic method to find progression region in cerebral artery. We proposed vessel model which can describe vibrating motion of a vessel which can make relationships between blood pressure and cross-section area of a vessel. The model can consider not only vessel but also the overall system. Determining exact outlet pressure boundary condition is very important because wall shear stress which take an important role in progression of atherosclerosis changes sensitively with the condition. So we consider slight change of flow rate because of vessel wall vibration induced by pulsatile pressure. MOSFET transistor model can change the flow rate with change of the cross section area like small AC signal changes the trans-conductance of MOSFET to change current.
With checking flow rate ratio of inlet to outlet, we can determine the outlet pressure using trial and error so that outlet flow rate can match the inlet flow rate. Determining more exact boundary conditions, we can locate significant regions which can initiate the process of atherosclerosis. By simulation it can be shown that curvature of a vessel take an important role in decreasing the shear stress inducing vortex.