Three-Dimensional Quantitative Pulsatile Flow Analysis in a Physiologically Accurate Collapsible Jugular Vein Model

The flow physics inside the cerebral veins is more complicated than in the arteries as they are prone to self-excitation. Furthermore, these veins experience unique flow dynamics as the mean flow and the first generation of the wave (generated by the right heart) are in opposite directions. Despite the extensive research on self-oscillating and collapsing tubes on steady flows, the pulsatile flow dynamics and its interaction with dominated backward pressure waves remain unexplored. To address this gap, we developed a physiologically relevant hydro-mechanical setup to investigate the three-dimensional pulsatile velocity field in the internal jugular vein (IJV). The complex three-dimensional velocity fields in collapsible tube models of IJV were obtained using volumetric 3-component Particle Image Velocimetry (PIV) system (TSI Inc., V3V-9000). We conducted quantitative 3D velocity measurements under various pulsatile flow conditions such as tube stiffness, flow rate, and heart rate (frequency of excitation). We analyzed IJV collapsing modes/motions and flow patterns by evaluating the changes in vortex formation and backflow propagation. Our results showed unique wave propagations and three-dimensional flow structures due to the excitation of the collapsible tube. This study may provide crucial insights into the flow dynamics in the cerebral venous circulation and cerebrovascular system.