Definition of Sleep Apnea Event by One Minute HRV Spectrum Analysis

Obstructive sleep apnea (OSA) is accompanied by a characteristic cyclic variation in heart rate in the waveform of the electrocardiogram (ECG). If sleep apnea could be diagnosed using ECG only, it could be possible to diagnose sleep apnea inexpensively from ECG recordings acquired in the patient's home. The most informative feature is low frequency oscillation at about 0.02 Hz in heart rate variability (HRV) signal. By calculating one minute HRV spectrum, we find the characterized frequency oscillation begins and ends a little early than the corresponding obstructive sleep apnea segment. When the one minute ECG segment contains more than 5 seconds sleep apnea signal, the characterized 0.02 Hz oscillation will apear in HRV spectrum.