0
Research Papers

Experimental and Computational Models for Simulating Sound Propagation Within the Lungs

[+] Author and Article Information
S. Acikgoz, M. B. Ozer

 Baxter Healthcare Corporation, Deerfield, IL, 60015

T. J. Royston1

 University of Illinois at Chicago, Chicago, IL 60607troyston@uic.edu

H. A. Mansy, R. H. Sandler

 Rush Medical University, Chicago, IL 60612

1

Corresponding author.

J. Vib. Acoust 130(2), 021010 (Mar 17, 2008) (10 pages) doi:10.1115/1.2827358 History: Received March 26, 2007; Revised August 10, 2007; Published March 17, 2008

An acoustic boundary element model is used to simulate sound propagation in the lung parenchyma and surrounding chest wall. It is validated theoretically and numerically and then compared with experimental studies on lung-chest phantom models that simulate the lung pathology of pneumothorax. Studies quantify the effect of the simulated lung pathology on the resulting acoustic field measured at the phantom chest surface. This work is relevant to the development of advanced auscultatory techniques for lung, vascular, and cardiac sounds within the torso that utilize multiple noninvasive sensors to create acoustic images of the sound generation and transmission to identify certain pathologies.

FIGURES IN THIS ARTICLE
<>
Copyright © 2008 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Real and imaginary parts of complex wave number for (—) lung parenchyma (16), (– –) soft tissue (15), (- - -) air, and (– - –) polyurethane foam (Flex Foam-IT X)

Grahic Jump Location
Figure 2

Comparison of theoretical solution with BE results for a finite monopole centered in a spherical volume. Key: (—) theory and (× × ×) BE results for velocity potential at sphere surface with fixed boundary (m2∕s); (– – –) theory and (○ ○ ○) BE results for radial velocity at sphere surface with free boundary (m/s); (- - -) theory and (+ + +) BE results for radial velocity at sphere surface with “soft” tissue boundary condition (m/s); (– - –) theory and (● ● ●) BE results for radial velocity at sphere surface with “stiff” tissue boundary condition (m/s).

Grahic Jump Location
Figure 3

Axisymmetric FE model of spherical parenchymal region with centered monopole source, PTX air pocket, and outer shell (not shown)

Grahic Jump Location
Figure 4

Comparison of FE and BE results for a finite monopole centered in a spherical volume of parenchymal tissue encased in a “chest wall” with a PTX air pocket as depicted in Fig. 3. Key: (—) theory for radial velocity at sphere surface with “soft” tissue boundary condition and no PTX (m/s); (- - -) BE and (× × ×) FE results for radial velocity at outer shell surface directly over PTX location; (— —) BE and (+ + +) FE results for radial velocity at outer shell surface 90deg away from PTX location.

Grahic Jump Location
Figure 5

Schematic of lung and chest wall mechanical phantom. Top and side views. All dimensions in millimeters. Garalite “ribs” are 6×12×250mm3.

Grahic Jump Location
Figure 6

Photograph of lung and chest wall mechanical phantom. Top and side views. Images show syringes that are used for inputting air into the bladders.

Grahic Jump Location
Figure 7

Experimental measurement of frequency response of conical surface normal velocity (color scale dB ref: 1mm∕sPa) to “trachea” acoustic pressure excitation at three vertical heights indicated in Fig. 5 of (a) 160mm, (b) 120mm, and (c) 80mm measured from the bottom of the phantom model

Grahic Jump Location
Figure 8

Calculated frequency response of conical surface normal velocity (color scale dB ref: 1mm∕sPa) to “trachea” acoustic pressure excitation at three vertical heights indicated in Fig. 5 of (a) 160mm, (b) 120mm, and (c) 80mm measured from the bottom of the phantom model

Grahic Jump Location
Figure 9

Calculated frequency response of conical surface normal velocity (color scale dB ref: 1mm∕sPa) to “trachea” acoustic pressure excitation at three vertical heights indicated in Fig. 5 of (a) 160mm, (b) 120mm, and (c) 80mm measured from the bottom of the phantom model using a simplified “ray acoustics” assumption.

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In