Sound Propagation in Liquid-Filled Arterial Segments: Measurements and Model Predictions

The efficacy of an acoustic transmission line model (TLM) for predicting distortion that occurs with axial propagation in liquid-filled arterial segments was assessed. Water-filled segments of excised bovine aorta were excited with acoustic pulses and noise to evaluate if velocities, attenuation, and transverse resonance frequencies could be accurately predicted using the TLM. Regions of low acoustic power that were attributed to transverse wall resonance effects were evident in all vessels, but the model generally under-predicted upper frequency limit of the high loss regions. Model-predicted velocities were in fair agreement with measured velocities both in trend and values, however, the energy losses were under-predicted. These preliminary results indicate that the TLM can forecast the general distortion of longitudinal acoustic propagation in liquid-filled arterial segments, yet it requires further refinement to accurately predict dispersive characteristics.