Spectral Decomposition and Sound Source Localization of Highly Disturbed Flow through a Severe Arterial Stenosis

Fardin Khalili; Peshala T Gamage; Amirtahà Taebi; Mark E Johnson; Randal B Roberts; John Mitchel

doi:10.3390/bioengineering8030034

Spectral Decomposition and Sound Source Localization of Highly Disturbed Flow through a Severe Arterial Stenosis

Bioengineering (Basel). 2021 Mar 4;8(3):34. doi: 10.3390/bioengineering8030034.

Authors

Fardin Khalili¹, Peshala T Gamage², Amirtahà Taebi³, Mark E Johnson⁴, Randal B Roberts⁴, John Mitchel⁵

Affiliations

¹ Department of Mechanical Engineering, Embry-Riddle Aeronautical University, 1 Aerospace Boulevard, Daytona Beach, FL 32114, USA.
² Department of Biomedical and Chemical Engineering and Sciences, Florida Institute of Technology, 2930 Science Cir., Melbourne, FL 32901, USA.
³ Department of Biomedical Engineering, University of California Davis, One Shields Avenue, Davis, CA 95616, USA.
⁴ Telecraft Engineering Inc., 1254 Mount Carmel Church Lane, Canton, GA 30114, USA.
⁵ Infrasonix Inc., 1665 Lakes Parkway, Suite 102, Lawrenceville, GA 30043, USA.

Abstract

For the early detection of atherosclerosis, it is imperative to explore the capabilities of new, effective noninvasive diagnosis techniques to significantly reduce the associated treatment costs and mortality rates. In this study, a multifaceted comprehensive approach involving advanced computational fluid dynamics combined with signal processing techniques was exploited to investigate the highly turbulent fluctuating flow through arterial stenosis. The focus was on localizing high-energy mechano-acoustic source potential to transmit to the epidermal surface. The flow analysis results showed the existence of turbulent pressure fluctuations inside the stenosis and in the post-stenotic region. After analyzing the turbulent kinetic energy and pressure fluctuations on the flow centerline and the vessel wall, the point of maximum excitation in the flow was observed around two diameters downstream of the stenosis within the fluctuating zone. It was also found that the concentration of pressure fluctuation closer to the wall was higher inside the stenosis compared to the post-stenotic region. Additionally, the visualization of the most energetic proper orthogonal decomposition (POD) mode and spectral decomposition of the flow indicated that the break frequencies ranged from 80 to 220 Hz and were correlated to the eddies generated within these regions.

Keywords: atherosclerosis; cardiovascular diseases; fluid dynamics; noninvasive diagnostics; signal processing; sound localization; spectral decomposition; stenosis; turbulent pressure fluctuations.