Biomedical Engineering Reference
In-Depth Information
Fig. 8.6
Wall shear stress contour plots of carotid bifurcation with different degrees of stenosis.
The simulation pertains to an atherosclerotic artery are presented for the 0 % or healthy case (
a
);
10 % blockage (
b
); 25 % blockage (
c
) and 50 % blockage (
d
). The wall shear stress scale is in Pa
small and has negative value for the large part of the heart cycle as demonstrated
earlier in Fig.
8.4b
. The results also show that at the beginning of each cycle, the
recirculation zone disappears for a short period of time
(at /
tT
=
since the
sign is positive in this period. Figure.
8.5b
and
c
show that as the stenosis becomes
more aggravated, two recirculation zones at the proximal and distal ends of the
plaque are formed.
Figure
8.6
presents the wall shear stress spatial variation on the arterial surface
of the carotid bifurcation. Based on the different degrees of stenosis, the wall shear
stress variation of the healthy artery can be used for comparisons with reference
Fig.
8.4
and the flow patterns in Fig.
8.5
.
The FSI simulations allow examination of vessel deformation, and maximum
principal stress distribution of the artery. Figure
8.7
are contour plots of vessel de-
formation to highlight high deformation regions in the carotid bifurcation. For the
healthy carotid (Fig.
8.7a
) maximum deformation occurs just upstream of the bi-
furcation point. For the stenosed arteries, high deformation occurs at the stenosis
and upstream of the bifurcation (Figs.
8.7b
-
d
). The deformation pattern does not
change with the degree of stenosis. However, the deformation magnitude changes
0 to 0.1)
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