METHOD OF DETECTING NOISE IN AUSCULTATORY SOUND SIGNALS OF A CORONARY-ARTERY-DISEASE DETECTION SYSTEM

摘要

A time-series array of noise data is generated from an inverse frequency transform of the product of the frequency spectrum of an auscultatory sound signal with an associated noise filter generated responsive to a cross-correlation of frequency spectra of auscultatory sound signals from adjacent auscultatory sound-or-vibration sensors on the torso of a test subject. Noise power within at least one range of frequencies of average of frequency spectra from a plurality of windows of the time-series array of noise data is compared with a threshold to determine whether or not the associated auscultatory sound-or-vibration sensor is excessively noisy. In one embodiment, the noise filter is generated by subtracting from unity, a unity-normalized cross-correlation of frequency spectra of the auscultatory sound signals, wherein the resulting values are clipped so as to be no less than an associated noise floor.