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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.

A computer tool, based on an acoustic transmission line model, was developed for modeling and predicting sound propagation and reflections in cascaded tube segments. This subroutine considered the number of interconnected tubes, their dimensions and wall properties, as well as medium properties to create a network of cascaded transmission line model segments, from which the impulse response of the network was estimated. Acoustic propagation was examined in air-filled cascaded tube networks and model predictions were compared to measured acoustic pulse responses. The model was able to accurately predict the location and morphology of reflections. The developed code proved to be a useful design tool for applications such as the guidance of catheters through compliant air-filled biological conduits.