Evaluation of the Suitability of Digital Devices for Measuring Heart Rate Variability : A Comparative Analysis with ECG

Purpose: The purpose of this study is to investigate the reliability of heart rate variability (HRV) measurements obtained through wearable devices and applications in comparison to those obtained from a medical-grade electrocardiogram (ECG) device.<br/> Method: A total of 42 participants (14 males and 28 females; mean age: 32.19±12.07 years) were included in the study. The devices used in this study were the Polar H10, EliteHRV application, and the medical-grade ECG device SA-3000New. HRV parameters (heart rate, RMSSD, SDNN, TP, LF, and HF) were measured under three conditions (Rest, Stress, and Breathing), each for 5 minutes. To evaluate the agreement between HRV measurements from the ECG device and Polar+Elite HRV combination, correlation and Bland-Altman (BA) ratio analyses were conducted.<br/> Results: The correlation coefficients between the two devices for heart rate, SDNN, RMSSD, TP, LF, and HF were 0.998, 0.991, 0.978, 0.850, 0.951, and 0.954, respectively. The BA ratio analysis showed BA ratios of 0.005, 0.077, 0.110, 0.407, 0.317, and 0.634 for heart rate, SDNN, RMSSD, TP, LF, and HF, respectively. <br/> Conclusion: The study concluded that heart rate and time-domain HRV measurements calculated through the wearable device and application provided accurate and reliable signals comparable to those from the medical-grade ECG device. However, frequency-domain HRV measurements showed lower agreement and higher variability, indicating the need for caution when using these data for research purposes.