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Watson W
02-03-1995, 08:33 AM
A reponse to my angle measurement query.
------------------------------- Original Message -------------------------------
Dear Warren,
we have had same problems just 1 year ago, when we had to collect data
about the 6 DOF of upper limb in order to evaluate frequency content
of human tremor from neurological patients by means of a stereophoto-
grammetric system.
We have implemented the CAST experiment protocol (Cappozzo et al. Clin.
Biomec. in Press) to the total body movements acquisition. It means that
plate with 3 markers are mounted on the body segments under analysis using
elastic bands. Then a number of useful anatomical landmarks are calibrated
with respect to the relevant plate-coordinate system. In this way, for each
body segment, it is possible to determine an anatomical coordinate system
the position and orientation of which are estimated starting from plate-
mounted markers coordinate collected with stereophotogrammetry.
In summary it seemed a complete method for the determination of movements
with respect to anatomical frames. No disturbs are encountered from the
patients (total weight of upper limb sut-up was 0.6 Kg), great accuracy
was found also for small displacements and rotation. For instrumentation
you need a stereophotogrammetric system with 2 cameras, the cost of which
is approximately 40.000 dollars (but you should find this better). Of course
this not reasonable for upper limb movements only, but it may be shared
with other movement analyis projects.
Do not hesitate to contact me for any question.
REFERENCES:
A stereophotogrammetric approach for the study of total body kinematics of
human tremor. Benedetti, Liguori, leardini, Catani,Cappello, Zanna, Giannini
In Proceedings of III Int.Symp.on 3D Analysis of Human Movement. Stoccolm
July 5-8 1994
Alberto Leardini
Biomechanics Lab
ISTITUTI ORTOPEDICI RIZZOLI
Bologna - ITALY