Biomedical Engineering Reference
In-Depth Information
tensile triangles is appropriate to reduce stresses in bending structures. Therefore,
this method is used as a simple tool for shape improvements.
3.1.4 Improvement of Standard Scaffolds
For previously tested scaffolds, high stresses and strains were observed in narrow
radii. Therefore, these radii were enlarged with respect to the design requirements.
The junctions between the inner oval and protruding arms were shaped with tensile
triangles. Further, the position of the protruding arms was varied. After these changes,
the previously presented scaffold was referred to as the 'standard scaffold'.
3.1.5 New Designs
The method of tensile triangles gives an idea of an optimized shape, but makes no
predictions about its sizing. A scaffold in the shape of a snowflake was designed and
tensile triangles were used to round off its corners. In several calculation steps, the
tensile triangles were adjusted to decrease resultant stresses.
New shape ideas were developed through consideration of previously explored
characteristics. Therefore, tight radii were avoided, large arcs were used where it
was possible, and tensile triangles were applied where seemed it useful. All shapes
were designed with a thickness of 1mm and simulated with the previously described
modeling approach.
One-piece scaffolds were presented previously. Additionally, one scaffold was
designed consisting of several segments as shown in Fig.
9
. The segments can be
linked by degradable polymers, e.g. resorbable sutures.
Fig. 9
Myocardial scaffold
consisting of segments that
are linked by degradable
sutures
