Patent ID: 6669651
Filing Date: 2003-12-30
Classification: A61B

Abstract:
A brain function examining apparatus for performing an examination of a brain function by detection of a pupillary size of a subject, which apparatus comprises:a) a light source for illuminating a pupil of the subject; b) a pupillary detector for detecting the pupillary size; c) an index calculating unit for calculating a subject index indicative of a characteristic of the pupil based on the pupillary size detected by the pupillary detector, wherein: c1) the characteristic of the pupil is a quality associated with variation of pupillary size; and c2) the subject index includes at least one of: pupillary constricting acceleration, maximum acceleration of pupillary constriction, time required to attain a maximum velocity of pupillary constriction, time required to attain a maximum velocity of pupillary redilation, and time required to attain a maximum acceleration of pupillary constriction; d) a database for storing a base index indicative of a characteristic of a pupil that can be used as a reference; and e) an output unit for outputting the subject index calculated by the index calculating unit, and the base index stored in the database, wherein: (1) the subject index calculated by the index calculating unit includes at least one of: latency, a natural size of the pupil, pupillary redilating time, amplitude of pupillary constriction, pupil constricting rate, pupil constricting velocity, maximum velocity of pupillary constriction, pupil redilating velocity, and maximum velocity of pupillary redilation; (2) the index calculating unit calculates a plurality of subject indexes; (3) the database stores a plurality of base indexes; and (4) the apparatus further comprises a multivalue calculator for calculating a first number of discriminant scores based on a second number of input values that is larger than the first number, the input values including the subject indexes calculated by the index calculating unit and the base indexes stored in the database.