Related Experiment Video
Updated: Oct 13, 2026

Calculating Heart Rate Variability from ECG Data from Youth with Cerebral Palsy During Active Video Game Sessions
Published on: June 5, 2019
Heart rate variability spectra based on non-equidistant sampling: the spectrum of counts and the instantaneous heart
H G van Steenis1, J H Tulen, L J Mulder
1Department of Clinical Neurophysiology, University Hospital Rotterdam, Dijkzigt, The Neherlands.
Abstract:
This paper compares two methods to estimate heart rate variability spectra, i.e., the spectrum of counts and the instantaneous heart rate spectrum. Contrary to Fourier techniques based on equidistant sampling of the interbeat intervals, the spectrum of counts and the instantaneous heart rate spectrum are based on non-equidistant sampling: the values are determined at R-wave moments. A consequence of the non-equidistant occurrence of the R-peaks in a heart rate signal is the appearance of the sidebands of the harmonic components of the mean heart rate in the spectra. These sidebands contaminate the signal components in the spectrum. The sideband distortion in the instantaneous heart rate spectrum was found to be smaller than in the spectrum of counts. Simulations using the IPFM-model were made to quantify this difference. On the basis of these simulations, sideband distortion appeared to be dependent on the mean heart rate, the modulation depth and the modulation frequency.
Related Concept Videos
Pulse rhythm
Conversely, an irregular pulse pattern is termed dysrhythmia, stemming from disruptions in cardiac muscle...
Factors Influencing Heart Rate
Let us explore the significant factors affecting heart rate, including age, body temperature, posture, acute pain, chemical influences,...
Correlation between ECG and Cardiac Cycle
A cardiac action potential originates in the SA node and spreads throughout the atria and the AV node in approximately 0.03 seconds. This results in the P wave in an ECG and triggers atrial contraction. The action potential is then briefly slowed at the AV node, allowing the atria to contract and fill the ventricles with blood before...
Disturbances in Heart Rhythm
Arrhythmias are categorized by their speed, rhythm, and origin. A slow heart...
ECG Interpretation of Rhythms
Components of the Electrocardiogram
The primary components of a normal ECG waveform in Normal sinus rhythm(NSR) include the P wave, PR interval, QRS complex, ST segment, T wave, and occasionally a U wave.
ECG waveforms are divided by vertical and horizontal lines at standard intervals.
The horizontal axis measures time and rate, and the vertical axis measures amplitude or voltage. When...
Dysrhythmias III: Characteristics of Dysrhythmias

