Sound transmission in the chest under surface excitation: an experimental and computational study with diagnostic applications
Chest physical examination often includes performing chest percussion, which involves introducing sound stimulus to the chest wall and detecting an audible change. This approach relies on observations that underlying acoustic transmission, coupling, and resonance patterns can be altered by chest structure changes due to pathologies. More accurate detection and quantification of these acoustic alterations may provide further useful diagnostic information. To elucidate the physical processes involved, a realistic computer model of sound transmission in the chest is helpful. In the present study, a computational model was developed and validated by comparing its predictions with results from animal and human experiments which involved applying acoustic excitation to the anterior chest, while detecting skin vibrations at the posterior chest. To investigate the effect of pathology on sound transmission, the computational model was used to simulate the effects of pneumothorax on sounds introduced at the anterior chest and detected at the posterior. Model predictions and experimental results showed similar trends. The model also predicted wave patterns inside the chest, which may be used to assess results of elastography measurements. Future animal and human tests may expand the predictive power of the model to include acoustic behavior for a wider range of pulmonary conditions.
KeywordsComputational modeling Lung acoustics Pneumothorax Percussion Human studies
Financial support of the National Institutes of Health (Grant No. EB012142) is acknowledged. The assistance of Mr. Brian Henry in the experiment is appreciated.
- 5.Bourbie T, Coussy O, Zinszner B (1987) Acoustics of porous media. Gulf Publishing Company, Huston, pp 86–87Google Scholar
- 7.Dai Z, Peng Y, Royston TJ, Mansy HA (2013) Experimental comparison of poroviscoelastic models for sound and vibration in the lungs. ASME J Vib Acoust. doi: 10.1115/1.4026436
- 13.Kemper J, Sinkus R, Lorenzen J, Nolte-Ernsting C, Stork A, Adam G (2004) MR elastography of the prostate: initial in vivo application. In RöFo-Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren 176(8):1094–1099. © Georg Thieme Verlag KG Stuttgart, New YorkGoogle Scholar
- 21.Ogata K (2004) System dynamics, vol 4, 4th edn. Pearson/Prentice Hall, New Jersey, p 107Google Scholar
- 24.Rice DA (1983) Sound speed in pulmonary parenchyma. J Appl Physiol 54:1304–1308Google Scholar
- 26.Royston TJ, Ozer MB, Acikgoz S, Mansy HA, Sandler RH (2008) Advances in computational modeling of sound propagation in the lungs and torso with diagnostic applications. In: Biomedical applications of vibration and acoustics in imaging and characterizations, chap 9. ASME Press, pp 217–248Google Scholar
- 29.Visible Human Project (2003) http://www.nlm.nih.gov/research/visible/visible_human.html
- 31.Walker HK, Hall WD Hurst JW (1990) The funduscopic examination-clinical methods: the history, physical, and laboratory examinations, 3rd edn, Chaper 46, ButterworthsGoogle Scholar
- 32.Warner L, Yin M, Ehman RL, Lerman LO (2009) Kidney stiffness measured in an animal model of unilateral renal arterial stenosis using 2-D MR elastography. in: Proceedings of the international society for magnetic resonance in medicine, p 407Google Scholar