Computer-Assisted Assay of Respiratory Sounds of Children Suffering from Bronchial Asthma

The aim of the investigation was to develop a computer processing technique of respiratory sounds and determine their spectral characteristics for bronchial asthma diagnosis.

Materials and Methods. The proposed method is based on analysis of fast Fourier transform (FFT) parameters of respiratory sound spectrum and their comparison in asthmatic children and healthy volunteers. The technique was applied to study respiratory sounds in 5 children with incomplete control of bronchial asthma, aged 10.9±2.1 years, and in 5 healthy schoolchildren (12.0±2.2 years). Respiratory sounds were recorded at three points: anterior thoracic surface, above trachea to the right, and inside oral cavity. A signal recorded by microphone Sony (ECM-77B) was amplified and digitalized using a Sound Blaster (Singapore). A recorded signal was computer processed. A computer-assisted assay was performed using software developed on the basis of a standard software package MATLAB.

Results. Breath sounds of patients with bronchial asthma are characterized by a specific wheezing presented as harmonic amplitude increase with frequency near to 400 Hz; wheezing period ranges from 80 to 250 ms. These peculiar properties of wheezing made it possible to suggest a computer processing method of respiratory sounds based on the analysis of approximation function for harmonic amplitude-frequency relationship. Approximation function was chosen as superposition of two functions: the first function characterizing natural attenuation of sounds with increasing frequency; the second one describing typical of asthmatic breathing pathological increase of harmonic amplitudes with frequency near to 400 Hz.

The program developed self-diagnoses wheezing typical for asthmatic children.

Conclusion. A computer-assisted assay of respiratory sounds can be the basic to an objective, independent of a doctor’s subjective opinions, automated computer-assisted diagnostic technique of respiratory sounds typical of bronchial asthma.

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Furman Е.G., Yakovleva Е.V., Malinin S.V., Furman G., Sokolovsky V. Computer-Assisted Assay of Respiratory Sounds of Children Suffering from Bronchial Asthma. Sovremennye tehnologii v medicine 2014; 6(1): 83