Patent ID: 6526297
Filing Date: 2003-02-25
Classification: A61B,A61M

Abstract:
Method for non-invasively measuring neurological activity in the brain of a subject to ascertain a state of hypnosis of an anesthetized subject or a state of sedation of the subject, said method comprising the steps of:passing light through a portion of the brain of the subject, the light having a characteristic that subjects it to scattering during passage by tissues of the brain, the light scattering capabilities of the brain tissues varying responsive to their neurological activity; sensing light that has passed through the portion of the brain and that has thereafter become available for sensing; and measuring the sensed light, in the form it became available for sensing, to determine the amount of scattering present in the sensed light and resulting from the passage of the light through the brain tissue as a measurement of the state of hypnosis or sedation of the subject.