Affiliations: [a] Laboratory of Biomedical Engineering, Helsinki University of Technology, P.O. Box 2200, FIN-02015 HUT, Finland | [b] Laboratory of Clinical Physiology, Helsinki University Central Hospital, Helsinki, Finland
Correspondence:
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Correspondence to (current address): P. Helistö, VTT Automation, Measurement Technology, P.O. Box 1304, FIN-02044 VTT, Finland. E-mail: panu.helisto@vtt.fi.
Abstract: A new automatic wheeze detection method which is based on image processing techniques applied to the sonagram was developed here. In the calculation of the sonagram, autoregressive and FFT spectrum estimation methods were compared. The method was validated in four wheezing asthmatic patients by a pulmonary physician. Nine out of ten wheezes longer than 250 ms were detected. Very short wheezes were not detected. The false positive amount of wheezing in control subjects was only about 1%. The method extracts also information about the frequency, duration, flow and volume associated with the wheezes.
