Biomedical Engineering Reference
In-Depth Information
(a)
(b)
FIgure 19.2
Great spotted woodpecker's (a) head and (b) hyoid bone.
Apart from the possible neurophysiological implications of this interesting arrangement, this
muscular sling might function as an isometric shock absorber and distributor by limiting movement
around the anterior-posterior axis (Figure 19.2).
19.2.2 G
eometry
of
tHe
m
odel
The geometry of the human head was developed based on CT scan images of a female corpse
(37 years old, dead from a car accident without head injury). The images were transverse sections
scanned at 1-mm intervals along the vertical axis of the body. The head model simulated all essen-
tial anatomical features of the human head, including skull, brain, maxillary, and mandibular bone
(Figure 19.3a). Due to the irregularity and complexity of the skull's bony structures, the geometry
of some of the bones, such as the orbital and nasal bones, were simplified and smoothed, but the
structural features of the head were preserved. The architecture of the skull bone resembles a sand-
wich structure containing cortical and cancellous bone layers. The cortical layer of the cranial bone
is generally thinner. Thus, the thin layer is modeled with shell elements with a thickness of 1 mm
while the cancellous bone is modeled as solid elements of varying thicknesses at different regions.
The temporo-mandibular articulation was included by ligaments.
The great spotted woodpecker (
Dendrocopos major
) was selected for its wide distribution in
northern China. It was fed with yellow mealworm (
Tenebriomolitor L.
) in separate metal cages.
Then, the morphology of the woodpecker's cranial bone was obtained based on image process-
ing of microcomputed tomography (micro-CT, Skyscan1076, Skyscan, Belgium). To investigate
the dynamic response of the woodpecker's head, a geometrically accurate three-dimensional FE
model of the woodpecker's head, including the upper/lower beak, skull, brain, and hyoid bone,
was developed based on the actual geometry and anatomic detail from micro-CT scanning
(Figure 19.3b).
(a)
(b)
FIgure 19.3
The finite element models of (a) human head and (b) woodpecker head.
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