In the present work, the difference between arrival times of photoplethysmographic (PPG) pulses from two different sites of the arterial tree (PTTD) is calculated. As the PTTD is considered to be related with arterial pulse wave velocity, an evaluation of it’s usefulness to identify states of acute mental stress is performed.
A subset of fourteen healthy volunteers undergoing a stress protocol was analysed and a statistical test was carried out to evaluate the validity of the proposed method. The results showed that the standard deviation of the PTTD had sufficient statistical capacity to discern between states of stress and relaxation. Furthermore, a generalised descending trend of the mean PTTD can be seen from relaxation to stress.