Assessment of Baroreflex Sensitivity Using Time-Frequency Analysis during Postural Change and Hypercapnia

Figure 2

Exemplary time (top plots), frequency (left plots), and time-frequency (centre graphs) representations of (a) pulse interval variability (PIV) and (b) systolic arterial pressure variability (SAPV) signals recorded during postural change in normocapnia stage of the experiment. The low (0.04–0.15 Hz) and high (0.15–0.4 Hz) frequency ranges used in baroreflex sensitivity estimation are shown together. Figures below the graphs indicate the subject’s body position during each part of the measurement.

(a)

(b)