A comparison of wearable and stationary sensors for stress detection

Abstract

To test the stress detection performance of a wearable sensor system, the signals related to heart activity and electrodermal activity of the Empatica E4 wristband have been compared to stationary electrocardiogram and finger skin conductivity electrodes of high sampling rates during the classical laboratory stress protocol Trier Social Stress Test. The comparison has been done on both signal level and in terms of features for stress detection on a total of seven subjects. The main results point out that the Empatica E4 wristband had a significant loss in terms of detected interbeat intervals, but that time-domain features such as the mean heart rate and standard deviation of the heart rate were still well estimated, with good stress discrimination power. Furthermore, the skin conductivity signals measured at different locations (wrist versus finger) show no visual resemblance and it appears that the signal from the Empatica E4 wristband yielded higher stress discrimination power than the signal measured at the fingers.