Patent ID: 7373198

Claim:
A method for extracting information from an observed signal representing measured brain activity of a subject in order to evaluate the level of depression of the CNS of said subject, said method comprising: a) acquiring at least two reference signals, said at least two reference signals corresponding to two distinct CNS states obtained from one or more reference subject or subjects; b) selecting a wavelet transformation function which, when applied to one of said at least two reference signals, yields a set of coefficients; c) selecting a statistical function which, when applied to said set of coefficients derived from one of said at least two reference signals or a subset of said set of coefficients, yields a reference data set which characterizes the distinct CNS state corresponding to said one of at least two reference signals; d) applying said wavelet transformation and statistical function to said at least two reference signals to produce reference data sets which distinguish between the distinct CNS state(s) corresponding to said reference signals; e) observing the brain activity of said subject to produce said observed signal; f) applying said wavelet transformation and statistical function to said observed signal to produce an observed data set; g) comparing the observed data set to said reference data sets; and h) computing a numerical value or values representative of said level of depression of the (INS of said subject which results from said comparison; wherein said at least two reference signals correspond to distinct CNS states which are two extreme states.