An apparatus for determining the neurological state of a subject, comprising: a set of electrodes configured to be placed on the subject to collect brain electrical signals； a processor； a memory operatively coupled to the processor, wherein the memory stores one or more operating instructions； and an input-output interface having at least one channel operatively coupled to the processor, wherein the input-output interface is configured to receive brain electrical signals through the set of electrodes； and the processor is configured to utilize the one or more operating instructions to perform one or more operations on the signals received through the input-output interface, wherein the one or more operations comprise: de-noising the received signals； extracting features from the de-noised signals； classifying the extracted features； and determining a neurological state of the subject based on the classification, wherein determining the neurological state comprises the steps of: determining if the neurological state is normal or abnormal； and determining if an abnormal neurological state is psychiatric or "functional" in nature, organic in nature, or an emergency or "Alert" condition.
