Apparatus for the Assessment of the Level of Pain and Nociception During General Anesthesia Using Electroencephalogram, Plethysmographic Impedance Cardiography, Heart Rate Variability and the Concentration or Biophase of the Analgesics
Means and methods for measuring pain and adapted for calculating the level of nociception during general anesthesia or sedation from data including electroencephalogram (EEG), facial electromyogram (EMG), heart rate variability (HRV) by electrocardiogram (ECG) and plethysmography by impedance cardiography (ICG). In a preferred embodiment of this invention the parameters derived from the EEG, the HRV, the plethysmographic curve and the analgetics concentrations are either combined into one index on a scale from 0 to 100, where a high number is associated with high probability of response to noxious stimuli, while a decreasing index is associated with decreasing probability of response to noxious stimuli. Zero (0) indicates extremely low probability of response to noxious stimuli. In an alternative embodiment, only features from the EEG and ECG will be used or only features from EEG, ECG and ICG, to define the fmal index.
