Fig. 2
Median (thick lines) of the time-averaged wavelet transforms of signals recorded in all 30 subjects: a BP, b HR/ECG, c HbO2 RIGHT and d SASLEFT obtained from the 30 min continuous recordings. Shaded areas indicate the inter-quartile range (25th, 75th percentiles). Red (blue) lines and shade areas correspond to breathing a gas mixture with 19.8% (14.8%) O2. *p < 0.05; **p < 0.01; ***p < 0.001