Figure 3
A spectrogram analysis from electrocardiogram (ECG) signal obtained during ventricular fibrillation (VF). The Hanning window function was used with a size of 1.7 sec with 512 sample points. Supplying oxygenated blood started at 10 min after VF induction. To show the original characteristic of the ECG signal, this spectrogram is not preprocessed by a 4–50 Hz band-pass filter. As a result, remarkable harmonic spectral lines with a strong low frequency spectrum observed for a minute due to a mechanical artifact by a pulsatile blood perfusion after ECPR was initiated. The color bar indicates the power in dB with red representing high power and blue low power.