Multimodal data from one arbitrarily selected subject, with grey bars
indicating subsequent BHs. (a) Aestiva/5 continuous fingertip PPG
pulsations, (b) Aestiva/5 monitor etCO2 signal for
respiration from nasal cannula. For this subject, BH5 was excluded
due to spontaneous inhalation (marked with blue arrow). (c)
Amplitude of preprocessed MREG BOLD signal from anterior cingulate
cortex (x = −6 mm, y = 39 mm, z = 0 mm, 4 mm spherical ROI in MNI
space). (d) Magnified view of preprocessed MREG BOLD signal during
BH2. (e) Band-pass filtered cardiovascular MREG signal during BH2.
Inlay depicts a single pulse amplitude peak-to-peak (red vertical
line) calculation. (f) Red envelope curve of cardiovascular pulse
amplitude peak to peak (PtP) signal derived from (e).