Estimation of Heart Rate Variability Measures Using Apple Watch and Evaluating Their Accuracy

Abstract

In a pandemic crisis such as the one that the world has been experiencing since January 2020, utilizing remote mobile health monitoring can help monitor the cardiac health of healthy individuals as well as chronically ill patients. Apple Watch is a fitness tracker that measures heart rate and can facilitate this need due to its availability worldwide and relative affordability. Hence, it has the potential of being useful in assessing and monitoring one's cardiac health. This paper reports the preliminary results from an ongoing study aimed at assessing the accuracy of the Apple Watch in measuring heart rate variability. To achieve the goal of the study, concurrent measurements of electrocardiogram (ECG), as a gold standard, and instantaneous Apple Watch heartrate values were made in six (4 male) age 26.4±3.2 years old volunteer healthy subjects. Both time and frequency domain measures of heartrate variability (HRV) were obtained from the recorded ECG and estimated from the Apple Watch instantaneous heartrate values. The results indicate that it may be possible to obtain a reasonable estimate of HRV time-domain and frequency-domain metrics using Apple Watch in healthy subjects.