Duration of tracheal sound recorded during forced expiration: From a model to establishing standards

The influence of the bronchodilatation test on the duration of forced expiratory tracheal noises in young men

“…In order to understand the mechanisms of forma tion of some or other type of the response of the forced expiratory noise duration to salbutamol, we have to briefly dwell on the model concepts of noise formation on the trachea during the FE outlined in [7,8,[20][21][22]. According to the qualitative acoustic-biomechanical model [7,8,20], FE noises are produced in the regions of the bronchial tree with increased resistance to the flow due to the turbulence and viscous-elastic inter actions between the flow and the AW walls.…”

Computer Evaluation of Tracheal Forced Expiratory Noise Time for Bronchial Obstruction Diagnostics

“…Conceivably, other factors might influence the forced expiratory time too; including those that can be easily estimated and measured, for example, sex and anthropometric parameters. In general terms, the FET a seems to be specific to every healthy subject [20] .…”

“…Since T 1 , T 2 have been measured automatically or semiautomatically, the program automatically calculates the duration of tracheal noises (FET a ) by the difference of measured times T 2 -T 1 . The maximal individual FET a from 3 well-done attempts was used for further analysis [20] .…”

“…It is evident that computer analysis of respiratory noises provides a precise estimation of time parameters such as FE acoustic noises duration (FET a ), being the object-measured analog of FET as . In studies [20,21] , FET a of FE tracheal noises showed promise in recognizing hidden bronchial obstruction (spirometry negative asthma-like symptoms). However the first step in assessing the diagnostic power of FET a should be evaluating its ability to diagnose bronchial obstruction revealed by spirometry.…”

“…However the first step in assessing the diagnostic power of FET a should be evaluating its ability to diagnose bronchial obstruction revealed by spirometry. Since FET a correlated significantly with FVC, FEV 1 /FVC [20] , being dependent on gender and age [4,7] , we decided to use homogenous in gender and age sample for the first step of FET a diagnostic possibility estimation. Therefore, the objective of our study is a comparative analysis of the computer assessed FET a in FE tracheal noises among a homogenous sample of young healthy males and young male patients with bronchial asthma as a model of bronchial obstruction.…”