Reconstruction of respiratory patterns from electrocardiographic signals

Presently there is lack of a reliable method for monitoring the respiratory cycles in the ambulatory patients. Knowledge of respiratory pattern is useful in many clinical situations. With the ECG signal being the most frequently monitored biomedical signal, it is essential to extract the respiratory waveform from ordinary ECG tracings. Such a technique permit reliable detection of respiratory efforts in healthy and diseased patients. Here, the authors present the result of a pilot study in which the ECG signals from lead II (LL+:RA-) and a modified chest lead I(V1+:LA-) were used to derive the respiration waveforms from the mean electrical axis of the heart. The ECG derived respiratory patterns compared favorably with those obtained from airflow measurements.