Analysis of Heart Rate Variability Using Photopletismnographic and Electrocardiographic Signals

Heart rate variability (HRV) is a non-invasive marker for monitoring the physiological condition of patients and assisting in the diagnosis of cardiovascular disease. The aim of this study was to investigate the consistency between HRV parameters based on photoplethysmographic (PPG) and electrocardiographic (ECG) signals. Parameters from the linear analysis in the time domain were studied. The time domain indices are standardized and widely used to calculate HRV. These indices are statistical and geometric measurements. The statistical calculations of the successive heart rate intervals (RR interval series) are strictly interrelated (SDNN, SDANN, RMSSD, pNN50), while geometric measurements are based on TINN and HRVTi parameters. The ECG and PPG signals of a healthy individual were examined. The obtained results show a very good agreement between the HRV parameters obtained from the two types of signals. In view of this finding, it can be concluded that the PPG offers an alternative ECG option for HRV analysis without compromising accuracy. The correspondence between the studied parameters applied to the two types of signals provides potential support for the idea of using PPG instead of ECG in the extraction and analysis of HRV in outpatient cardiac monitoring of healthy individuals and patients with cardiovascular disease. A study of two groups of individuals: healthy and with cardiovascular disease based on PPG signals by applying the method: analysis in the time domain. The obtained results show that with the used method the two studied groups of subjects can be distinguished.