System and method for guidance of anesthesia, analgesia and amnesia

Abstract

A method for monitoring anesthetization of a patient, includes the steps of removably connecting a plurality of electrodes to the scalp of the patient and administering sufficient anesthesia to the patient so that the patient attains a plane of anesthesia selected by an operator. The brain waves of the patient are then amplified and digitized after the patient has been anesthetized, before beginning the medical procedure, to obtain a first set of digital data. The brain waves of the patient are then amplified and digitized during the medical procedure to provide a second set of digital data and the first and second sets of digital data are analyzed in at least one of a time domain and a frequency domain. Separate trajectories are then computed from the data analysis trajectories for at least two different indices of an anesthetic state of the patient during the medical procedure, the indices being selected from a group including a Depth Index (DI), a Memory Index (MI) and a Pain Index (PI). A system for providing anesthesia to a patient, includes a plurality of electrodes, a first arrangement allowing an operator to administer anesthesia to the patient until the patient has attained a selected plane of anesthesia and a second arrangement coupled to the electrodes for amplifying and digitizing brain waves of the patient after the patient has been anesthetized, before the medical procedure has been begun to obtain a first set of digital data, the second arrangement amplifying and digitizing ongoing brain waves of the patient during the medical procedure to provide a second set of digital data in combination with a third arrangement analyzing the first and second sets of digital data in at least one of a time domain and a frequency domain, a fourth arrangement computing from the data analysis separate trajectories for at least two different indices of a state of the patient during the medical procedure, the indices being selected from a group including a Depth Index (DI), a Memory Index (MI) and a Pain Index (PI), a fifth arrangement providing control signals when any of the trajectories indicates that the patient is deviating from the selected plane of anesthesia and a sixth arrangement automatically adjusting two different anesthetic agents administered to the patient based on the control signal to restore the patient to the selected plane of anesthesia.