METHOD FOR EXTRACTING QUASI-PERIODIC SIGNALS FROM NOISE

摘要

The invention relates to a method for extraction of quasi-periodic signals from noise, intended to be used in processing biomedical signals, such as electrocardiographic signal (ECG), magnetocardiographic signal (MCG) or other quasi-periodic signals of reduced level, recorded in the presence of high-level noise. According to the invention, the method consists in that the waveform of a quasi-periodic signal of very low amplitude recorded in the presence of noise of high amplitude is obtained based on the prior determination (2.2) of duration of all sequences of the quasi-periodic signal, which allows the selection (2.3) of some groups of sequences randomly located in the record, but with the approximately the same value of durations, where, for each so-formed group, a replica of the signal of interest is obtained (2.4) which, together with a replica of the signal for the entire record, obtained by the signal sampling (2.5) and processing (2.6) corresponding to the duration of each sequence, are compared and analyzed (2.7) to permit identification and characterization of specific waves or of changes or evolutions of the signal of interest, even in the conditions in which the records exhibit a very low signal-to-noise ratio.