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Jeff Walker
09-12-1997, 03:48 AM
>Our research group at the Veterinary Orthopedic Reseach Laboratory at UC
>Davis is investigating the use of helical computed tomography images in a
>study of the knematics, morphometry, and biomechanics of the elbow joint.
>We would like to develop a Cartesian coordinate system that can be applied
>consistantly to the elbow joint of every specimen or patient. The purpose
>is for the subsequent comparison of measurments between samples or patients.
>
>We have not been able to find a reference to this this type of system in
>any joint or guidance as to how Cartesian coordinate systems should be set
>up in biological specimens with three dimensional images.

Kurt, shape differences among configurations of Cartesian coordinates of
homologous landmarks (in 2D or 3D) can be analyzed using either
superimposition analysis or a thin-plate spline analysis and its
decomposition. The best place to start is the Stony Brook morphometrics www
site:

http://life.bio.sunysb.edu/morph/

The Stony Brook site has a glossary, bibliography, all the software,
addresses of morphometricians, etc.

I have Power Macintosh software to do most of the basic geometric
morphometrics (in 2D) on my WWW site:

http://jaw.fmnh.org/Morphometrics.html

and there is also Dennis Slice's software that runs on about every OS and
analyzes 3D data:

http://life.bio.sunysb.edu/morph/morpheus/

Joint shape has often been measured as an outline. For outline data the
software is not as well developed. At the Stony Brook site there is an
Elliptic Fourier analysis package to describe and compare outlines and a
macintosh program that uses Eigenshape analysis. As far as I can tell these
only analyze 2D data.

Good luck.

Jeff



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Jeff Walker
Dept. of Zoology
Field Museum of Natural History
Roosevelt Rd. at Lake Shore Dr.
Chicago, IL 60605, USA
phone: 312-922-9410 x537 fax: 312-427-7269
email: walker@fmppr.fmnh.org
web: http://jaw.fmnh.org/Home.html

"I like practical applications in mathematics, rather than speculating
about the first ten to the minus something seconds of the universe.
Cosmology seems to be almost too close to theology to be interesting.
To me, it is not quite science, but more like creation myth."

- Sir James Lighthill
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