Comparison of commercial smart watch and universal pulse oximeter on heart rate, oxygen saturation, and distance covered using the 6-minute walk test: A cross-sectional study

Abstract

Commercial smartwatches offer the ability to measure vital signs such as heart rate (HR) and oxygen saturation (SpO2), and track physical activity, including distance covered. However, the accuracy of these devices compared to clinical tools, such as pulse oximeters, remains in question. This study aims to find correlation between commercial smartwatches against universal pulse oximeters in measuring HR, SpO2, and distance covered during the 6-minute walk test (6MWT). A total of 35 healthy subjects aged 18-25 years participated in the study. HR and SpO2 were measured using both a universal pulse oximeter and a commercial smartwatch, which were worn on the same side of the body. Measurements were taken both before and after the 6MWT. Distance covered during the 6MWT was measured manually and compared with the smartwatch reading. As the data did not follow a normal distribution, non-parametric tests were employed for statistical analysis. The intra-class correlation coefficient (ICC) was calculated to determine the level of agreement between the devices for each parameter. The results indicated that the ICC for heart rate measurements between the smartwatch and pulse oximeter was above 0.70, suggesting good agreement. However, the ICC for SpO2 and distance measurements was less than 0.70, indicating poor reliability of the smartwatch in measuring these parameters compared to the pulse oximeter and manual distance measurement. The findings suggest that while commercial smartwatches can be a reliable tool for measuring heart rate during activities such as the 6MWT, their accuracy in measuring SpO2 and distance covered is limited.