<unk>  <unk> , or intracranial electroencephalography (iEEG), is a type of electrophysiological monitoring that uses electrodes placed directly on the exposed surface of the brain to record electrical activity from the cerebral cortex. In contrast, conventional electroencephalography (EEG) electrodes monitor this activity from outside the skull.<unk>  may be performed either in the operating room during surgery (intraoperative<unk>  or outside of surgery (extraoperative<unk> . Because a craniotomy (a surgical incision into the skull) is required to implant the electrode grid,<unk>  is an invasive procedure.
Electrocorticography
Ballistocardiography
Magnetocardiography
Electrocochleography
Phonocardiogram
Electrocardiography
Vectorcardiography
Elastography