Tonal Index in digital recognition of lung auscultation

In the paper the Tonal Index (TI) as a feature to wheezes detection in lung auscultation is presented. The lungs auscultation is a non invasive test in asthma diagnose. On the basis of such tests, the medical doctors can precise evaluate the stage of the disease. The TI is compared with the other features taken from literature: Kurtosis, Frequency Ratio, Spectral Peaks Entropy and Spectral Flatness. The modified Frequency Ratio called Energy Ratio (ER) is presented as well. The recognition process was taken on artificial and real data.