A stereo-triplet of a rat portal vein
helical "screw" which demonstrates how
closely it conforms to a "best fit"
mathematical helix.Note:Stereopsis of any
two adjecent members yields two spatial
images with reversed depth.The
stereoscopic effect can easily be
achieved either by viewing the triplet
with the naked eye using the parallel eye
method or by the cross-eye method, in
which case the "depth" will be reversed.
For the stereoscopically "uninformed" a
simple hand stereoscope should be used to
achieve stereoscopy.
3.1.1.2 Ihe quantification of wear of
denture teeth.
The attrition of denture teeth hae been
a concern to prosthetists for a long
time. With the advent of acrylic resin
however, the problem has become more
acute, although in recent times, acrylic
resin technology has progressed
significantly in producing harder resins
which are more suited to withstanding
occlusal wear. To quantify
comprehensively the extent of wear and to
display the volumetric loess of material
under clinical conditions, has proved
difficult in the past. A method using a
reflex microscope to undertake direct and
highly precise three-dimensional
measurement of denture casts, for the
purpose of mapping and determining the
volumetric loss of material over a period
of time, has been developed jointly by
University of Cape town biostereometric
researchers and dental researchers from
the University of Stellenbosch (Adams et
al, 1989).
Examples of graphical computer outputs,
demonstrating the loss of material, are
shown here:
Tooth 46 before wear
Tooth 46 after one year of wear
Difference plot demonstrates loss of
material.
3.1.2. STEREO VIDEO TECHNOLOGY.
A stereometric video camera system has
been established and numerous motion
study projects have been undertaken using
the system, or modifications of the
system.
T
Ol ec mes S ©
TIMAGE
MIXER
IBM PC |
Fn
| MONITOR
VIDEO
CASSETTE
| RECORDER
FRAME GRABBER
A near real-time stereometric system
Two of the studies are described briefly
here:
