Heart rate variability calculation: a non-conventional approach for saving memory

Abstract
Heart rate variability (HRV) is one of the tools for accessing the status of the autonomic nervous system. For calculating the heart rate variability from an electrocardiogram (ECG), the principle of R-wave detection is widely used. The authors' study focuses on a new method of estimating the heart rate variability which does not need the R-wave detection. With this method, the HRV could be calculated from an ECG signal sampled around 5 Hz with a mean error of 1.2 beats/min, compared to the R-wave detection. This error was smaller for the HRV lower frequencies.