Analysis of vocal breath sounds before and after administering Bronchodilator in Asthmatic patients

TL;DR

This study demonstrates that vocal breath sound analysis can effectively distinguish pre- and post-bronchodilator conditions in asthmatic patients, offering a less effortful alternative to spirometry for clinical assessment.

Contribution

The paper introduces a subject-dependent analysis of vocal breath sounds using LDA, identifying specific frequency ranges that significantly differentiate pre- and post-bronchodilator states.

Findings

LDA features show significant differences in all 30 subjects.

Baseline features only differentiate in 26 subjects.

Frequency ranges 400-500Hz and 1480-1900Hz are most discriminative.

Abstract

Asthma is one of the chronic inflammatory diseases of the airways, which causes chest tightness, wheezing, breathlessness, and cough. Spirometry is an effort-dependent test used to monitor and diagnose lung conditions like Asthma. Vocal breath sound (VBS) based analysis can be an alternative to spirometry as VBS characteristics change depending on the lung condition. VBS test consumes less time, and it also requires less effort, unlike spirometry. In this work, VBS characteristics are analyzed before and after administering bronchodilator in a subject-dependent manner using linear discriminant analysis (LDA). We find that features learned through LDA show a significant difference between VBS recorded before and after administering bronchodilator in all 30 subjects considered in this work, whereas the baseline features could achieve a significant difference between VBS only for 26 subjects. We also observe that all frequency ranges do not contribute equally to the discrimination between pre and post bronchodilator conditions. From experiments, we find that two frequency ranges, namely 400-500Hz and 1480-1900Hz, maximally contribute to the discrimination of all the subjects. The study presented in this paper analyzes the pre and post-bronchodilator effect on the inhalation sound recorded at the mouth in a subject-dependent manner. The findings of this work suggest that, inhalation sound recorded at mouth can be a good stimulus to discriminate pre and post-bronchodilator conditions in asthmatic subjects. Inhale sound-based pre and post-bronchodilator discrimination can be of potential use in clinical settings.