Original waveform of lung sound crackles: a case study of the effect of high-pass filtration.
In lung sound research, low-frequency noise usually disturbs the sound signal being recorded. Some researchers therefore use high-pass filtration before the final analysis. In this study, the effect of digital and analog high-pass filtration on the morphology of the lung sound crackles is evaluated. The original nonprefiltered crackle waveform is presented, and the effect of the high-pass filtration on the crackle waveform characteristics is elucidated in one patient with silicoasbestosis.
Katila
T
T
Helsinki University of Technology, Helsinki University Hospital, Finland.
Piirilä
P
P
Kallio
K
K
Paajanen
E
E
Rosqvist
T
T
Sovijärvi
A R
AR
D000162:Acoustics; D001195:Asbestosis / Q000503:physiopathology; D055592:Biophysical Phenomena; D001703:Biophysics; D006801:Humans; D008297:Male; D008875:Middle Aged; D015656:Respiratory Mechanics / Q000502:physiology; D012135:Respiratory Sounds / Q000503:physiopathology*; D012829:Silicosis / Q000503:physiopathology