Reliability evaluation of an wearable consumer optical heart rate monitor

Abstract

Motivation: Over the past few years, activity trackers which can measure everyday steps, energy expenditures, and sleeping time are getting popular. Especially these days, some activity trackers use not only accelerometers but also optical heart rate monitors based on photopletysmography. In this study, we evaluated reliability of an optical heart rate activity tracker during running. Method and Results: Several subjects(n=11, all male) ran 1km on a flat road and we analyzed heart rate errors to check if there was a difference between subjects. We found that some subjects had significantly higher Mean Absolute Error than others(highest MAE,20.54±13.64; average MAE, 8.41±6.47), and there was a strong correlation between each subject’s MAE and the standard deviation of running speed(Pearson’s r=0.87, p<0.001). Conclusion: Optical HR monitors lead to errors when users change their pace of running.