Spectrum analysis of lung sounds

The power spectra of vesicular breathing, rale and wheeze from 40 people (including normal people and people with lung diseases) were analysed by BSFA (zoom fast Fourier transform). The distribution of spectrum peak frequencies was estimated. It is noted that the vesicular breathing of normal people and abnormal breathing (rale and wheeze) are significantly different in their distribution of spectrum peak frequencies. The power spectrum of rale and wheeze contain more high-frequency components, and that of rale has more low-frequency components. This difference could provide a basis for automatic classification and diagnosis