Metrological characterizationof commercial smartwatches: are these sensors suitable for the assessment of well-being?

Today, an increasing number of wearable devices is equipped with biomedical sensors for monitoring physiological parameters, such as temperature, heart rate (HR), oxygen saturation (SpO 2 ), and blood pressure (BP). Wearable devices offer accurate and continuous data on essential physiological parameters, enabling improved quality of care and more proactive and personalized approaches to healthcare by assessing the subject’s overall well-being in living environments. However, it is crucial to pay attention to the accuracy and precision of the data provided by these devices, particularly when collecting physiological parameters, as their metrological validation is often inadequate despite their widespread use. It is essential to determine the impact of measurement errors on healthcare decision-making and on the development of personal comfort models (PCMs) in a view of improving well-being and quality of life. This study aims to assess the metrological performance of a commercial smartwatch, determining the accuracy and precision of heart rate and blood pressure measurements, given their relevance for well-being assessment. A test population of 20 healthy subjects was enrolled in the test. Results show that that HR and BP can be tracked, with certain precision and accuracy, using a wrist-worn wearable device, evaluated with respect to a medical grade sphygmomanometer. The bias at measuring HR was of 0.2 bpm with a confidence interval of CI95% = [−6.2, 6.6] bpm. Confidence intervals of [−4.6, 7.6] mmHg and [−9.7, 10.9] mmHg were obtained for the diastolic and systolic BP, respectively.