Comparing Consumer and Research-Grade Wristbands for Inter-Beat Intervals Monitoring

The aim of the present study is to evaluate the accuracy of a commercially available wristband (Fitbit Sense) and the new research device EmbracePlus (Empatica Inc.) used for heart rate (HR) monitoring. Data were collected from 10 healthy young volunteers who were asked to wear the two devices, one on each arm. The estimated HR, in the form of inter-beat intervals (IBI), was compared with the RR intervals extracted from a simultaneously recorded gold-standard electrocardiogram (ECG) and evaluated during 5 minutes of sitting, 5 minutes of standing, and while typing on a PC keyboard to simulate an everyday office task. The effect of the device position (right /left arm) was also evaluated. Overall, results showed a good agreement between the RR intervals of the gold standard and the estimated IBI measures, averaged in 10-second windows, of both wearable devices in the sitting phase. The agreement of the Fitbit device was also quite strong in standing position and during the typing task, while the EmbracePlus was found more affected by uncontrolled arm movements. Both devices showed a slightly better estimation (i.e., higher correlation with the gold standard) when positioned on the left arm.