PRESSURE PEAKING IN PULSATILE FLOW-THROUGH ARTERIAL TREE-STRUCTURES

An analytical iterative scheme is presented for computing the local ch aracteristics of pressure and flow waves as they progress along a tree structure and become modified by wave reflections. Results are obtain ed to illustrate the phenomenon of pressure peaking under two differen t sets of circumstances. In the first case, the propagation of a singl e harmonic wave along a simple tree is considered, where wave reflecti ons modify the amplitude of the pressure wave as it travels. In the se cond case, the propagation of a composite wave along a tree with multi ple branches is considered, where wave reflections modify the shape of the wave as it travels and cause it to peak. The results demonstrate unambiguously that the root cause of this phenomenon is wave reflectio ns caused by stepwise decreases in admittance, as has been previously suggested, rather than due to nonlinear interactions, as has also been previously suggested. It is shown clearly that even when wave reflect ions combine linearly, they lead to considerable peaking in the pressu re waveform.