A Simulation Study of Wave Transformation Using a Nonlinear Model of Artery and a Physical Model of Intracranial Vascular Bed

Abstract

If hydrodynamic changes in the pressure pulse waveform depend on the condition of the cerebrospinal fluid (CSF) system, we should be able to evaluate that condition by measuring the pattern of the intracranial pressure (ICP) pulse waveform. Although the dependence of the ICP pulse amplitude on the mean ICP can be explained by the nonlinear pressure-volume relationship in the CSF system, changes in the monotonous wave in the ICP pulse waveform, with elevated mean ICP, have not yet been clearly explained. There are some doubts that the deformation of ICP pulse is affected by the pressure-volume relationship. We don’t believe that deformation of the ICP pulse (except for pulse amplitude) is related to the CSF pressure-volume relationship. In order to identify the part where the deformation of the ICP pulse waveform occurs, we constructed a cerebrovascular physical model without a venous circulation system. We also designed a nonlinear mathematical model simulating the artery, in order to investigate the genesis and morphology of the ICP pulse waveform.