Figure 5. Typical waveforms and spectral analysis of haemodynamic responses observed during spontaneous (A) and repeated squat‐stand manoeuvres (B, C) in a representative patient with chronic mountain sickness.

BP, blood pressure; MCAv, middle cerebral artery velocity; PSD, power spectral density; V/LF, very/low frequency. Note the markedly amplified and coherent oscillations in MAP and MCAv during the repeated squat‐stand manoeuvres compared to resting (spontaneous) measures, leading to improved estimation of transfer function of dynamic cerebral autoregulation at the frequency of interest.