A novel technique for denoising explosive lung sounds emnpirmical mode decompiosition and fractal dimension foilte

A novel technique for denoising explosive lung sounds (ELSs), such as fine/coarse crackles and squawks (SQs), is presented here. A combination of empirical mode decomposition (EMD) and fractal dimension (FD) analysis is proposed to form a denoising EMD-FD filter. The latter decomposes the data into a number of intrinsic mode functions and automatically selects their important and unimportant portions, which lead to the estimation of the denoised ELS signal and the background noise, respectively. Experimental results prove efficient performance of the EMD-FD filter (mean detectability 98.4%; sensitivity 98.1%; specificity 97.7%) in sustaining both time location and structural characteristics of ELS.