Software Open Access

ECG-Derived Respiration

Lewis Lipsitz George Moody

Published: March 19, 2000. Version: 1.0.0

When using this resource, please cite the original publication:

Lipsitz LA, Hashimoto F, Lubowsky LP, Mietus J, Moody GB, Appenzeller O, and Goldberger AL. Heart rate and respiratory rhythm dynamics on ascent to high altitude. British Heart Journal 74(4):390-396 (October 1995).

Please include the standard citation for PhysioNet: (show more options)
Goldberger, A., Amaral, L., Glass, L., Hausdorff, J., Ivanov, P. C., Mark, R., ... & Stanley, H. E. (2000). PhysioBank, PhysioToolkit, and PhysioNet: Components of a new research resource for complex physiologic signals. Circulation [Online]. 101 (23), pp. e215–e220.


Several techniques can be used to obtain a respiration signal from an ECG. A popular technique used in bedside patient monitors involves measuring transthoracic impedance using the ECG electrodes. Unlike those described below, this method obtains the respiration signal from the ECG electrodes rather than from the ECG signal. It requires special-purpose hardware and is not suited to recovering respiration from a recorded ECG, but it has the significant advantage (relative to the other methods mentioned here) that a continuous respiration-related waveform can be obtained.

Another well-known method is based on observing the beat-to-beat variations in RR intervals or their reciprocals, which are primarily due to respiratory sinus arrhythmia (RSA) in most individuals. This method works best in young, healthy subjects, in whom RSA is most pronounced.

The EDR (ECG-Derived Respiration) technique is a third approach. It is based on the observation that the positions of ECG electrodes on the chest surface move relative to the heart, and transthoracic impedance varies, as the lungs fill and empty. Thus the lead axes vary at different points in the respiratory cycle, and any sufficiently precise measurement of the mean cardiac electrical axis shows variations that are correlated with respiration. This method is particularly effective if two or more ECG signals are available, but a single lead is sufficient. The EDR can be obtained even in the context of congestive heart failure, in which RSA may be absent.

None of these methods supplies a calibrated respiration signal; for tidal volume and air flow measurements, other techniques (spirometry, measurements from nasal thermistors, and plethysmography) are best. Nevertheless, any of these methods can provide a basis for estimating respiration rate and for detecting apneas.


Software Description

This project contains:

  • A short C program implementing the EDR, which can be used to derive a respiration-related signal from one or two ECG signals (precompiled binaries for Linux and MS-Windows are also available).
  • The paper that introduced the technique.
  • A second paper that describes applications for the EDR.


Access Policy:
Anyone can access the files, as long as they conform to the terms of the specified license.

License (for files):
Open Data Commons Attribution License v1.0



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