fig4
Figure 4. Evolution of sensor signals from an EMFIT QS bed sensor device indicating changes in respiration rate (respiration cycles/min), heart rate (beats/min), high frequency (HF), and low frequency (LF) heart rate variability (HRV-HF refers to the normalized power spectral density between 0.04 and 0.15 Hz; conversely, HRV-LF refers to the same between 0.15 and 0.4 Hz).
