Design of a PDA-based stethoscope for pulmonary sound parametrization and classification

Abstract

Technological developments made in the near past, gave us a chance to analyze respiratory sounds quantitatively. Digitization of respiratory sounds, obviously, was the key in the analysis of respiratory sounds. Although the stethoscope is still the most practical tool, some of its drawbacks may be eliminated with a digital hand-held tool designed for the same purposes. In this thesis, a one-channel respiratory sound acquisition and analysis system has been designed and implemented. Respiratory sounds are captured via a microphone placed on the chest wall. They are then amplified and filtered by a hardware system, designed for the purposes of this thesis. Finally, they are digitized and processed in a hand-held device. A user interface program is written to process digitized respiratory sounds in LabVIEW, which classifies the subject as healthy or pathological. This hand-held device designed as a digital stethoscope eliminates the need of a physician during recording and is very useful as a first stage screening device. Moreover, it records data over a wider bandwidth than that of a stethoscope, where most of the useful information is contained.