TITLE:
Impacts of waveforms on the fluid flow, wall shear stress, and flow distribution in cerebral aneurysms and the development of a universal reduced pressure
AUTHORS:
Noel M. Naughton, Brian D. Plourde, John R. Stark, Simona Hodis, John P. Abraham
KEYWORDS:
Aneurysm; Hemodynamics; Blood Flow; Computational Fluid Dynamics
JOURNAL NAME:
Journal of Biomedical Science and Engineering,
Vol.7 No.1,
January
2,
2014
ABSTRACT:
The hydrodynamics of aneurysm blood flow is thought
to be a critical factor in the evolution and potential rupture of blood vessel
walls. The ability to predict which aneurysms may grow or rupture has eluded
researchers and practicing clinicians. On the other hand, it is expected that
local flow patterns, pressures, and wall shear stress play a role in the
aneurysm life. In this study, the impact of waveform on these parameters was
studied. A baseline waveform, taken from a patient, was applied to an aneurysm geometry.
Then the waveform was modified by increasing and decreasing both the flowrates
and the cardiac rate. In total, seven cases were investigated. It was found
that there were remarkable similarities in the patterns of flow and wall
stresses for the cases. These similarities existed throughout the cardiac
cycle. It was also found that there was a reduced pressure variable that provides
a universal relationship that characterizes all of the cases. It was seen that
the maximum wall shear occurs at the neck of the aneurysm and scales with the
peak systolic velocity. Finally, it is shown that the flow distribution to the
multiple outlets does not appreciably depend on the details of the inlet
waveform. All cases had a flow distribution that was within 2%.