Fig. 4

Quantification of steady-streaming velocities. Steady-streaming within the spinal SAS increases with Neurapheresis therapy compared to lumbar drain. a Coronal view of cyclic mean z-velocity profiles, \(U_{z{\text{-}}mean}\), in the cranial SAS is nearly identical for Neurapheresis therapy and lumbar drain. b Sagittal view of cyclic mean z-velocity profiles, \(U_{z{\text{-}}mean}\), simulated by CFD for lumbar drain (left) and Neurapheresis therapy (right). c Steady-streaming velocity magnitude, \(U_{ss}\), and d non-dimensional fraction of flow rate amplitude, \(Q_{ss}\)