Fig. 4From: Hydrocephalus and the neuro-intensivist: CSF hydrodynamics at the bedsideExample of a constant rate infusion test in post-SAH HCP with B (slow) waves. The same patient as in Fig. 3 where a RAP index close to + 1 is associated with an increased power of B (slow) waves during infusion test. A fast Fourier transformation (FFT) was performed to evaluate the energy (power) of B waves within the ICP signalBack to article page