Sound transmission in human thorax through airway insonification: an experimental and computational study with diagnosti
- PDF / 4,511,553 Bytes
- 20 Pages / 595.276 x 790.866 pts Page_size
- 108 Downloads / 178 Views
ORIGINAL ARTICLE
Sound transmission in human thorax through airway insonification: an experimental and computational study with diagnostic applications Harish Palnitkar 1 & Brian M. Henry 2 & Zoujun Dai 2 & Ying Peng 1 & Hansen A. Mansy 3 & Richard H. Sandler 3 & Robert A. Balk 4 & Thomas J. Royston 1,2 Received: 8 February 2019 / Accepted: 25 June 2020 # International Federation for Medical and Biological Engineering 2020
Abstract Pulmonary diseases and injury lead to structural and functional changes in the lung parenchyma and airways, often resulting in measurable sound transmission changes on the chest wall surface. Additionally, noninvasive imaging of externally driven mechanical wave motion in the chest (e.g., using magnetic resonance elastography) can provide information about lung stiffness and other structural property changes which may be of diagnostic value. In the present study, a comprehensive computational simulation (in silico) model was developed to simulate sound wave propagation in the airways, parenchyma, and chest wall under normal and pathological conditions that create distributed structural (e.g., pneumothoraces) and diffuse material (e.g., fibrosis) changes, as well as a localized structural and material changes as may be seen with a neoplasm. Experiments were carried out in normal subjects to validate the baseline model. Sound waves with frequency content from 50 to 600 Hz were introduced into the airways of three healthy human subjects through the mouth, and transthoracic transmitted waves were measured by scanning laser Doppler vibrometry at the chest wall surface. The computational model predictions of a frequency-dependent decreased sound transmission due to pneumothorax were consistent with experimental measurements reported in previous work. Predictions for the case of fibrosis show that while shear wave motion is altered, changes to compression wave propagation are negligible, and thus, insonification, which primarily drives compression waves, is not ideal to detect the presence of fibrosis. Results from the numerical simulation of a tumor show an increase in the wavelength of propagating waves in the immediate vicinity of the tumor region. Keywords Computational modeling . Finite element analysis . Lung acoustics . Pneumothorax . Fibrosis . Tumor
1 Introduction 1.1 Motivation The lungs are comprised of soft tissue, airways, alveoli, and vasculature structures, acoustically behaving as a poroviscoelastic material over a broad frequency range [1]. * Harish Palnitkar [email protected] 1
Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, 842 W. Taylor St, Chicago, IL 60607, USA
2
Richard and Loan Hill Department of Bioengineering, University of Illinois at Chicago, Chicago, IL 60607, USA
3
University of Central Florida, Orlando, FL 32816, USA
4
Rush University Medical Center, Chicago, IL 60612, USA
Due to this fine-structure heterogeneity, conventional imaging modalities such as magnetic resonance imaging (MRI), ultrasound (US), and X-ray co
Data Loading...
