Page 275 - Biomedical Engineering and Design Handbook Volume 1, Fundamentals

252 BIOMECHANICS OF THE HUMAN BODY

1.541e + 007

1.383e + 007

1.225e + 007
1.067e + 007

9.092e + 006
7.513e + 006

5.933e + 006
4.353e + 006

2.773e + 006
1.193e + 006

–3.872e + 005

FIGURE 10.3 Ankle-foot orthosis optimized manually to reduce material in
regions of low stress. Total weight reduction is approximately 30 percent.

The viscoelastic behavior of actual arterial wall may be investigated during the final model or two in
the process.
The fifth version of the model will now seek to address the issues of the red blood cells. Using
software allowing for the addition of user-defined particles, rigid disks may first be used. After
success with this version, deformable cells may be used to better approximate red blood cells.
At each point in the process (each generation of the model), the user should compare the findings
with those of available bench and clinical studies, along with the results from previous model
versions. Little change from previous models may suggest either that there is no need for a more
complex model or that all the modifications have not been taken account of.
It should also be noted that varying the simpler models may encompass the behavior of more
complex models. For example, varying the static flow parameters may account for many of the
behavior modifications seen in the pulsatile model. For similar reasons, varying the elastic properties
of the vessel wall may encompass behavioral changes brought about by viscoelastic modeling at a
great savings of computational time and power.

10.5.1 Other Areas of Computer Modeling
In addition to orthopaedic-based research noted above, modeling research is being performed in all
aspects of biomedicine. Following are a few examples pertaining to some of the major arenas of