Patent ID: 6999905

Claim:
A method for extracting a signal of interest from a signal generated from at least one subject, comprising the steps of: (A) obtaining a time-series signal generated from the subject as a data group consisting of a plurality of pieces of data; (B) obtaining a plurality of extracted data groups from the data group, wherein each extracted data group comprises a predetermined number of pieces of data selected from the data group; (C) calculating standard deviations of the plurality of extracted data groups to obtain a standard deviation group; and (D) referencing each standard deviation included in the standard deviation group and selecting the signal of interest, wherein the referencing in the step (D) is to divide the standard deviations into a plurality of classes having a predetermined width of standard deviation as a unit, plot each standard deviation on a coordinate system having an axis representing the class and another axis representing the number of the standard deviations present in each class, approximate a resultant graph to a normal distribution, and calculate an average, half-width and variance, or standard deviation of the resultant normal distribution.