Study of Cerebrospinal Fluid Flow and Mixing that Accounts for Non-Uniform Orientation of Cilia

Cerebrospinal fluid (CSF) within the brain ventricles serves an important physiological function of both a nutrient delivery and a waste removal. Complex CSF flow patterns created within the brain ventricles are generated by a synchronized motion of microscopic cilia. However, as opposed to conventional models of cilia carpets, where all cilia beat in the same direction, the ventricular walls display a complex anatomy with non-uniform cilia clustering and orientations. In order to understand the role of such physiologically-derived non-uniformities in cilia organization, we have developed a CSF flow model that takes non-uniform clustering and orientation of cilia into account. Flow patterns and mixing properties within the CSF fluid are studied, depending on several control parameters within the model, which include polarization properties of the ependymal cells, distribution in the deviation angles, and a percentage of dysfunctional cells. To study the effects of these parameters on the transport properties within the CSF flow, we introduce non-inertial Lagrangian particles into the simulations and track their motion within the fluid.