Physiological Vibration and Resonance of LFS on the Respiratory System
Abstract
Model predictions of the effects of LFS on the human respiratory system suggested that pressures within airways can be greater than pressures applied to the body surface. In the current study, more physiologically and anatomically accurate human and rat lung models were developed to further study the consequences of LFS as well as to infer human lung behavior from measurements made in rats. The human model was also used to predict whether pressure amplification would be more significant in asthmatics by incorporating airway heterogeneity and broncho-constriction into the model. Pressure amplification was predicted to be reduced in asthmatics. A comparison between human and rat lung behavior indicated that resonances in rat lungs occur in human lungs at about one-tenth the frequency. Thus, the resonances predicted to occur in rat lungs at higher frequencies, i.e., 5,000 and 11,000 Hz, could produce pressure amplification in humans at much lower frequencies (i.e., 50-100 Hz). We are confident in the human model predictions since they compared very well with physiological measurements over a wide frequency range (2-2000 Hz). However, we have less confidence in the rat model since ft could be validated only for a limited frequency range (20-80 Hz) due to the paucity of published rat data.
Document Details
- Document Type
- Technical Report
- Publication Date
- Nov 29, 1999
- Accession Number
- ADA373523
Entities
People
- Andrew C. Jackson