A coupled flow-acoustic computational study of bruits from a modeled stenosed artery.

The sound generated by blood flow in stenosed arteries is investigated for a model that consists of a channel with a one-sided constriction. The blood flow-induced arterial "bruits" are computed directly using a hybrid approach wherein the hemodynamic flow field is solved by an immersed boundary, incompressible flow solver, and the sound generation is modeled by a first-principles approach that employs the linearized compressible perturbation equations. The transmission and propagation of the sound through the surrounding biological tissues is also modeled with a simplified, linear structural wave equation. The flow field inside the artery and the bruit sound signal at the epidermal surface are examined to delineate the precise source of the arterial bruit and the correlation between the bruit and the arterial wall pressure fluctuations. It is found that the bruits are related primarily to the time-derivative of the integrated pressure force on the post-stenotic segment of arterial wall. The current study provides a clear perspective on the generation of bruits from stenosed arteries and enables an assessment of the conjectures of previous researchers regarding the source of arterial bruits.