Fig. 2

Flow chart for quantifying the breathing effects (Δp and Φp) on CSF. Definition of the inspiratory phase (IN, red) and the expiratory phase (EX, blue), using the breathing signal. (A) Reconstruction of Q_t-Inspiration (red curve) and Q_tExpiration (blue curve) from the respective inspiratory Q_t (red) and expiratory Q_t (blue) points extracted from the continuous Q_t. Then, Δp is calculated for each evaluated parameter with Φp = 0. (B) The breathing window is shifted from − 3s to + 3s in steps of 0.1 s. The previous steps are repeated to obtain the Δp(Φp) curves. (C) Represents the Δp values for four parameters at Φp = -9% (0.3 s). At this point, the ΔSV reaches the maximum value