Biomedical Engineering Reference
In-Depth Information
Fig. 7.35 a normal stress S
33
along path 5 (see Fig.
7.34
)
and b shear stress S
13
along
path 6, both resulting from
interaction of BoMo2 with
system LS2 at membrane
internal air pressures of 10
and 20 mbar
Figure
7.35
depicts the normal and shear stress along path 5 and path 6 based
on the interaction of BoMo2 and LS2 at minimum (10 mbar) and maximum
(20 mbar) membrane pressure. Simulated pressure at skin level indirectly
verified the measured contact pressure values since they were nearly equal in
both cases. In addition, in both cases, internal tissue stress values also match.
Doubling the membrane internal air pressure from 10 to 20 mbar shows, once
again, that the maximum shear stress at the bone only slightly increased by 7.7 %
(Fig.
7.35
b).
Conclusion
In summary, reasonable agreement of measurement and simulation results could
be shown. This verifies the use of simulation tools, in particular human body
model and the Boss-Procedure in the process of design and material optimization.
The bedding system optimized with help of simulation is characterized by a net
mass of 20 kg and a mattress of 30 cm height as well as a metal-free frame support
and is intended for subjects with a body mass in the range of 50-150 kg.
