The present invention disclosed a device and method for assessing in real time the hypnotic and analgesic effect in a subject during wakefulness, sedation and general anaesthesia via drug interactions and physiological signals. In a preferred embodiment of the present invention, the analgesic and hypnotic effect of drug(s) infused in a subject could be accurately assessed in real time through the device and method disclosed in the present invention, comprising steps of receiving data from electroencephalography (EEG) device, receiving data from brain impedance tomography device, obtaining pharmacodynamic and pharmacokinetic parameters of drug(s) infused in the subject, defining initial indices of consciousness and nociception as a function of said EEG and brain impedance tomography data, and generating output of final indices of consciousness and nociception in real time from processing input of EEG, brain tomography and drug interaction data using established mathematical manipulation.
