Experimental and Numerical Investigations on Hemodynamic Characteristics in an Internal Cerebral Artery Sidewall Aneurysm Model using Non-Newtonian Blood Analogue Fluids*

This study aimed to develop an experimentally validated computational fluid dynamics (CFD) model to study the hemodynamic characteristics in cerebral aneurysms (CAs) using non-Newtonian blood analogue fluids. Firstly, a pilot study was employed to compare the hemodynamic characteristics between Newtonian and non-Newtonian fluids in an internal cerebral artery sidewall aneurysm model. The simulation results showed that relatively significant differences can be observed between Newtonian and non-Newtonian fluids, with respect to instantaneous wall shear stress, time averaged wall shear stress and oscillatory shear index distributions on the aneurysmal wall. The different performances of hemodynamic parameters on the aneurysms can further affect the evaluations of the growth and rupture of existing aneurysms, and the generation probability and locations of small/secondary aneurysms. To validate abovementioned findings, several non-Newtonian blood analogue fluids were prepared to conduct particle image velocimetry measurements to quantify the flow filed characteristics in CAs. In our following study, the agreements between PIV measurements and numerical simulations in flow field quantifications will be compared to build an experimental validated CFD model with non-Newtonian blood analogue fluids. The developed model can be further employed to investigate the hemodynamic factors on the pathophysiology of cerebral aneurysms statistically.