Perimeter growth of a branched structure: application to crackle sounds in the lung.

Crackle Pitch Rises Progressively during Inspiration in Pneumonia, CHF, and IPF Patients

Objective. It is generally accepted that crackles are due to sudden opening of airways and that larger airways produce crackles of lower pitch than smaller airways do. As larger airways are likely to open earlier in inspiration than smaller airways and the reverse is likely to be true in expiration, we studied crackle pitch as a function of crackle timing in inspiration and expiration. Our goal...

Are crackles an appropriate outcome measure for airway clearance therapy?

BACKGROUND There is an urgent need to develop new outcome measures for respiratory therapy, to evaluate its effectiveness. Adventitious sounds generated from the lungs (crackles and wheezes), can now be quantified and characterized objectively with computer technology. To our knowledge, this is the first reported study designed to assess any change in lung crackles before and after a single se...

Crackle sounds and lung recruitment PhD Thesis

Auditory detection of simulated crackles in breath sounds.

BACKGROUND Computerized analysis of breath sounds has relied on human auditory perception as the reference standard for identifying crackles. In this study, we tested the human audibility of crackles by superimposing artificial clicks on recorded breath sounds and having physicians listen to the recordings to see if they could identify the crackles. OBJECTIVES To establish the audibility of s...

The Relationship Between Crackle Characteristics and Airway Morphology in COPD.

BACKGROUND Crackles in COPD are believed to be generated by the re-opening of collapsed airways, which result from chronic inflammation, secretions, and loss of cartilaginous support through inflammation. However, it is unclear whether crackle characteristics can be used to identify COPD. This is the first study to examine the relationship between specific added lung sounds (crackles) and measu...