What is my heart rate right now? Comparing data from different devices

The extraordinary development of wearable devices and Internet of Things (IoT) technologies has substantially expanded the opportunities offered to remote healthcare systems, allowing to monitor physiological parameters out of clinical settings. One of the most important parameters is surely a subject's heart rate (HR). A key point in the design of a reliable remote healthcare solution is the proper selection of the devices: here, the focus is on the accuracy of HR data collected by wearable devices, which is still debatable, since rigorous validations are rarely applied. This paper aims at comparing the HR values obtained by different devices, namely smartwatches, chest-strap, pulse-oximeter, and by different methods, like the oscillometric-based one and the palpatory one, using an electrocardiogram as the reference measurement instrument. Results show different accuracy and precision values included in the ranges [-1, 3] bpm and [4], [12] bpm, respectively, thus confirming the importance that manufacturers make these figures available, for a better device selection depending on the target application