A Coupled CFD-FEA study of the Sound Generated in a Stenosed Artery and Transmitted Through Tissue Layers

Khalili, Fardin; Gamage, Peshala T.; Meguid, Ibrahim A.; Mansy, Hansen A.

doi:10.1109/secon.2018.8478873

Cited by 6 publications

(8 citation statements)

References 42 publications

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“…CFD may also provide valuable information to speed up the design of implantable devices during the prototype development [ 29 ] and reduce the costs and risks associated with new heart valve designs [ 30 ]. Hence, analysis of flow dynamics and the resulting turbulence [ 31 , 32 , 33 , 34 ] and sounds [ 35 , 36 , 37 , 38 , 39 , 40 ] has been an active area of research.…”

Section: Introductionmentioning

confidence: 99%

Adverse Hemodynamic Conditions Associated with Mechanical Heart Valve Leaflet Immobility

et al. 2018

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Artificial heart valves may dysfunction, leading to thrombus and/or pannus formations. Computational fluid dynamics is a promising tool for improved understanding of heart valve hemodynamics that quantify detailed flow velocities and turbulent stresses to complement Doppler measurements. This combined information can assist in choosing optimal prosthesis for individual patients, aiding in the development of improved valve designs, and illuminating subtle changes to help guide more timely early intervention of valve dysfunction. In this computational study, flow characteristics around a bileaflet mechanical heart valve were investigated. The study focused on the hemodynamic effects of leaflet immobility, specifically, where one leaflet does not fully open. Results showed that leaflet immobility increased the principal turbulent stresses (up to 400%), and increased forces and moments on both leaflets (up to 600% and 4000%, respectively). These unfavorable conditions elevate the risk of blood cell damage and platelet activation, which are known to cascade to more severe leaflet dysfunction. Leaflet immobility appeared to cause maximal velocity within the lateral orifices. This points to the possible importance of measuring maximal velocity at the lateral orifices by Doppler ultrasound (in addition to the central orifice, which is current practice) to determine accurate pressure gradients as markers of valve dysfunction.

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Section: Introductionmentioning

confidence: 99%

Adverse Hemodynamic Conditions Associated with Mechanical Heart Valve Leaflet Immobility

et al. 2018

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“…They concluded that the amplitude of acoustic pressure fluctuations increased significantly with a richer frequency content for the 75% case. A similar analysis was performed by Khalili et al [ 18 ]. Salman and Yazicioglu numerically and experimentally investigated the vibrations of constricted arteries.…”

Section: Introductionmentioning

confidence: 75%

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

et al. 2021

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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.

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“…In another study, the acoustic radiation analysis in the 2D vessel model with 50% and 75% severities showed a significant increase in radiated acoustic power with an increase in severity [ 18 ]. Khalili et al [ 11 ] performed a similar numerical study employing different numerical methods and reported comparable results.…”

Section: Introductionmentioning

confidence: 88%

“…This will lead to high-frequency turbulent pressure fluctuations downstream of the stenosis generating vascular sounds, often referred to as murmurs [ 8 , 9 ]. Subsequently, the induced pressure fluctuations can transmit through the surrounding soft tissues to the epidermal surface [ 10 , 11 ]. In 1970, Lees and Dewey proposed the diagnosis technique, Phonocardiography, which utilized vibro-acoustics on the epidermal surface caused by the flow fluctuations inside an artery in the presence of stenosis [ 12 ].…”

Section: Introductionmentioning

confidence: 99%

“…The study of frequency contents of flow structures in unhealthy arteries has recently been an active research area in biomechanics. In some similar studies done by the authors of this paper, the wall pressure spectra measured downstream of the stenosis were analyzed using spectral decomposition techniques [ 11 , 19 , 20 ]. These studies explored the coherent flow structures related to the peak frequencies.…”

Section: Introductionmentioning

confidence: 99%

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Spectral Decomposition of the Flow and Characterization of the Sound Signals through Stenoses with Different Levels of Severity

et al. 2021

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Treatments of atherosclerosis depend on the severity of the disease at the diagnosis time. Non-invasive diagnosis techniques, capable of detecting stenosis at early stages, are essential to reduce associated costs and mortality rates. We used computational fluid dynamics and acoustics analysis to extensively investigate the sound sources arising from high-turbulent fluctuating flow through stenosis. The frequency spectral analysis and proper orthogonal decomposition unveiled the frequency contents of the fluctuations for different severities and decomposed the flow into several frequency bandwidths. Results showed that high-intensity turbulent pressure fluctuations appeared inside the stenosis for severities above 70%, concentrated at plaque surface, and immediately in the post-stenotic region. Analysis of these fluctuations with the progression of the stenosis indicated that (a) there was a distinct break frequency for each severity level, ranging from 40 to 230 Hz, (b) acoustic spatial-frequency maps demonstrated the variation of the frequency content with respect to the distance from the stenosis, and (c) high-energy, high-frequency fluctuations existed inside the stenosis only for severe cases. This information can be essential for predicting the severity level of progressive stenosis, comprehending the nature of the sound sources, and determining the location of the stenosis with respect to the point of measurements.

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A Coupled CFD-FEA study of the Sound Generated in a Stenosed Artery and Transmitted Through Tissue Layers

Cited by 6 publications

References 42 publications

Adverse Hemodynamic Conditions Associated with Mechanical Heart Valve Leaflet Immobility

Adverse Hemodynamic Conditions Associated with Mechanical Heart Valve Leaflet Immobility

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

Spectral Decomposition of the Flow and Characterization of the Sound Signals through Stenoses with Different Levels of Severity

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