A model of the carotid vascular system with stenosis at the carotid bifurcation

Stroke is one of the major diseases leading to human death and may be caused by arterial stenosis, possibly combined with arterial spasm. Carotid stenosis can be detected through ocular pulse caused by the blood flow in the choroid which, in turn, is influenced by the blood flow in the carotid vascular system (CVS). This paper presents a mathematical model of the stenosis, usually located at the carotid bifurcation into the external and internal carotid arteries. The model is based on experimental data from in vitro studies. The stenosis is modelled as a nonlinear resistive element, causing a pressure drop in the blood flow over a local constriction. Such a pressure change affects the spectral contents of peripheral pressure waveforms, particularly the ocular blood pressure (OBP) waveform. The dynamics of the CVS with stenosis is determined by the haemodynamic and geometric properties of the stenosis. Computer implementation and simulation of the composite model shows how the OBP waveform dynamics is affected by the level of the stenosis. These unique results are being used in our research on a method for early detection of stroke, glaucoma, and elevated intracranial pressure.