Early Detection of Intra Operative Hypotension (IOH) During the Induction of General Anaesthesia

Dicpleth and PI are obtained a posteriori from the PPG waveform reconstruction and blindly from ABP values. Dicpleth is defined as the ratio of the height of the dicrotic notch (from nadir point of the complex to the notch) to the height of the systolic peak (from nadir point of the complex to the pic), measured at end-expiratory time (average of 3 consecutive complex). PI is calculated as the ratio of the pulsatile component of the PPG signal and the continuous component.