Criterion Validation of an Open-source Wearable Physiological Sensors Device

Wearable sensors are very popular in monitoring sport performances and increasingly used in scientific research. However, several scientific and ethical issues regarding pricing, raw data accessibility, validity and commercial access to user’s data are linked with these devices. To address these limitations, an open-source device, called Emotibit, was designed through crowdfunding. The aim of this study is to evaluate the criterion validity of this new open-source device’s physiological components in resting position. To this end, heart rate (HR) and heart rate variability (HRV) via photoplethysmography (PPG) and electrodermal activity (EDA) were assessed and compared with a medical grade reference device, the FlexComp Infiniti. The Bland-Altman plot and ratio (BAr) results indicate a good validity for HR estimation with a BAr of 0.02. However, results suggest an insufficient validity for HRV, as well as EDA amplitude and number of activation events estimation. These results are comp arable to other studies using PPG for HRV estimation, but the EDA components need adjustment in regard to the sensitivity of the device. We analyze the validity issues associated with open source technology, and conclude that further improvements are required to qualify its accuracy with statistical significance. This study also contributes to the wearable sensors studies by identifying and describing the many challenges associated with the democratization of access to biosensing technolog