Sound transmission in the lung as a function of lung volume
| Autor: | J. Shane, D. Ofengeim, Raymond L. H. Murphy, Andrey Vyshedskiy, T. Bergstresser |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
Adult
Male medicine.medical_specialty Physiology Sound transmission class Models Biological Physiology (medical) Speed of sound Humans Medicine Computer Simulation Lung volumes Respiratory system Lung Lung function Aged Sound (medical instrument) business.industry Acoustics Middle Aged respiratory system Surgery Sound medicine.anatomical_structure Air content Female Lung Volume Measurements business Biomedical engineering |
| Zdroj: | Scopus-Elsevier |
| ISSN: | 1522-1601 8750-7587 |
| DOI: | 10.1152/japplphysiol.00050.2002 |
| Popis: | We were interested in how the transmission of sound through the lung was affected by varying air content in intact humans as a method of monitoring tissue properties noninvasively. To study this, we developed a method of measuring transthoracic sound transit time accurately. We introduced a “coded” sound at the mouth and measured the transit time at multiple microphones placed over the chest wall by using a 16-channel lung sound analyzer (Stethographics). We used a microphone placed over the neck near the trachea as our reference and utilized cross-correlation analysis to calculate the transit times. The use of the coded sound, composed of a mix of frequencies from 130 to 150 Hz, greatly reduced the ambiguity of the cross-correlation function. The measured transit time varied from 1 ms at the central locations to 5 ms at the lung bases. Our results also indicated that transit time at all locations decreased with increasing lung volume. We found that these results can be described in terms of a model in which sound transmission through the lung is treated as a combination of free-space propagation through the trachea and a propagation through a two-phase system in the parenchyma. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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