Biomedical Engineering Reference
In-Depth Information
Fig. 10.6
The
left graph
shows the force measured in the rod during an experiment, for a segment
that was previously clamped with the device described in Sect.
10.3
to a level of 5 mN and for
a segment that was undamaged, both normalized to the width of the numerical model. The
right
graph
shows the force in the rod of the myograph as a function of time calculated from the finite
element simulation, for a previously undamaged segment (
solid line
), for a segment that was pre-
viously clamped at 5 mN with a smooth clamp (
dashed
) and for a segment that was previously
clamped at 5 mN with a mosquito clamp (
dotted
). The
letters along the curve
correspond to the
snapshots shown in Fig.
10.5
6 of the simulation, i.e., the pulling of the rod to the passive state. After 2 seconds,
the smooth muscle cells are activated, corresponding to step 7.
The left graph of Fig.
10.6
shows the force measured in the rod for a segment
that was previously clamped with the device described in Sect.
10.3
to a level of
5 mN, normalized to the width of the numerical model, and for a segment that was
undamaged. The force in the rod was also normalized to the width of the numerical
model. Again, in the first section of the graph, the rod is gradually pulled to reach
the passive preload state. At the point indicated with the arrow, PE is added to the
Krebs solution, triggering the activation of the smooth muscle cells. Note that the
time scales in the two graphs do not agree. To calibrate the model appropriately, an
additional time parameter would have to be included into the model. Here, however,
we were only interested in the end result of the curve, rather than in calibrating the
model to real physical times.
10.7 Discussion
This chapter outlined a framework to experimentally quantify and numerically sim-
ulate damage to cardiovascular tissue due to mechanical loading. Different experi-
mental methods were described for the damage quantification of the different con-
stituents of the tissue and explicit attention was given to the myograph setup, a de-
vice to test the vasoregulating capability of the artery. Next, it was shown how
in
vivo
mechanical experiments can be performed to determine the experimental rela-
tion between a certain mechanical load and the induced damage.
