Accuracy of Heart Rate Measurements by a Smartwatch in Low Intensity Activities

Wearable technologies to measure heart rate have improved remarkably in the last few years, making it possible for the users to find low-cost commercially available devices for easy and unobtrusive daily use. Despite the technological advancements, however, the accuracy provided by these devices in measuring the heart rate remains questionable, especially in scenarios not involving fitness or physical exercise monitoring. This paper concerns the metrological characterization of a Samsung Gear FIT SM-R350 smartwatch in measuring the user's heart rate, focusing on the accuracy provided in low-intensity activities, by designing a suitable measurement protocol. The results obtained show an acceptable correlation of the smartwatch measurements with a certified pulse-oximeter, which suggest future activities aimed at testing the device's accuracy in uncontrolled operative conditions and indoor/outdoor environments.