  Bone surface mapping technique is proposed on the bases of two kinds of
uniqueness of bone in vivo, (i) magnitude of the principal moments of inertia,
(ii) the direction cosines of principal axes of inertia relative to inertia
reference frame. We choose the principal axes of inertia as the bone coordinate
system axes. The geographical marks such as the prime meridian of the bone in
vivo are defined and methods such as tomographic reconstruction and boundary
development are employed so that the surface of bone in vivo can be mapped.
Experimental results show that the surface mapping technique can both reflect
the shape and help study the surface changes of bone in vivo. The prospect of
such research into the surface shape and changing laws of organ, tissue or cell
will be promising.
