Assessment of Samsung Galaxy Watch4 PPG-Based Heart Rate During Light-to-Vigorous Physical Activities

Lately, there has been a notable increase in the adoption of smartwatches and fitness trackers. These wearables have gained popularity by monitoring vital health parameters, such as heart rate (HR), employing a low-cost and noninvasive technique known as photoplethysmography (PPG). Despite its ease of continuous monitoring the cardiovascular system during daily activities, PPG signal is susceptible to noise, mainly caused by user movement during monitoring, particularly in activities involving vigorous body motion. Therefore, it is crucial that PPG-based devices undergo scientific validation to ensure their reliability and accuracy in real-world conditions. In this letter, we conducted an assessment of the smartwatch Samsung Galaxy Watch4 (SGW4), comparing its performance with the Polar H10: an electrocardiogram device acknowledged as the reference for HR measurement during intense activities with intense body movements. Our research protocol involved 14 participants engaged in activities that induced a range of HR variations, covering light, moderate and vigorous intensities, including stationary cycling and treadmill workouts. We employed five metrics to compare HR measurements obtained from the SGW4 with those from the reference device. In addition, a Bland–Altman analysis was conducted to evaluate the agreement between the two devices. The results of our study indicate that the SGW4 is well-suited for accurately measuring HR during usual exercises, spanning from low to high-intensity physical activities, and considering scenarios in which the SGW4 was either nearly stationary or in free movement.