DIY Wrist-Worn Device for Physiological Monitoring: Metrological Evaluation at Different Band Tightening Levels

Wearable devices are currently employed in several application fields, especially in the healthcare context, thanks to the advent of IoT technology in the global market. However, there are few studies focused on the reliability of collected data depending on the best wearing conditions, e.g. the band tightness in the case of wrist-worn devices, necessary to optimise the quality of the measured data. The aim of this study is to evaluate the variability of heart rate (HR) and tightening force data measured with a Do-It-Yourself (DIY) wrist-worn device, considering three different band tightening levels: loose, medium and tight. Results show that the increasing tightening levels produce an increasing tightening force, as expected; interestingly, the coefficient of variation is minimum (i.e., 0.16%) when the band tightening level is medium.