Respiration-guided analysis of pulse and heart rate variabilities for acute emotional stress assessment

Acute Emotional Stress may be assessed through the changes on the autonomic nervous system. Pulse Rate Variability (PRV) and Heart Rate Variability (HRV) are well known and widely used as markers of autonomic nervous system. Pulse photoplethysmographic and electro-cardiographic signals were synchronously recorded during relax and stress stages from 80 young healthy students during an ad hoc experiment. To evaluate the agreement among HRV and PRV, frequency indices were computed over 1-min-length running window on the classical spectral bands [LF:0.04–0.15Hz, HF:0.15–0.4Hz], extended HF band [0.15Hz-halfmean Heart Rate], HF band centered at respiratory frequency with a bandwidth of 0.1 Hz. Between relax and highest stress stage most of the HRV indices show significant changes but most of the PRV indices do not. Most of the indices showed significant differences between PRV and HRV on relax stages. In contrasts, during stress stages they do not show significant differences. These results suggest that pulse arrival time variability is higher during relax.