View Full Version : Measuring tissue displacements using "gait" analysis systems

Matt Silva 314-362-8585
02-19-1997, 04:21 AM

I am looking for an automated system for measuring tissue displacements
during mechanical testing. The first application of this will be to measure
linear displacement at several points (to be converted to a 1D strain field)
of tendons during ex vivo tension testing. I am soliciting comments and
sage advice from individuals who have experience in using "gait analysis"
systems to measure tissue motions during mechanical tests, or from anyone
who has developed a successful "in house" method for doing this. After
reviewing some of the literature, I am inclined toward using a video-based,
single camera system with high contrast markers attached at several places
along the tendon. I am looking for software solutions for tracking marker
positions "automatically".

I have looked into a Motion Analysis Corp. HiRES system (PC-based, single
camera, $39,000) after seeing a Motion Analysis system at the Mayo Clinic
used for tendon testing, and also because the gait lab on campus here uses
one of their 6 camera systems (alas, borrowing their system is not an option).
The cost of the HiRES system inspired me to see what other options might
be out there.

I would appreciate hearing comments and suggestions from those of you
who have used Motion Analysis or other "gait" systems to measure tissue
displacements. We will not use the system to measure gait/locomotion,
but will probably use it in a variety of tests on soft and hard tissues.
Are gait systems worth the cost? Are there other, lower cost but equally
versatile alternatives?

Thanks for any comments.

Matt Silva
Orthopaedic Research Lab
Washington University St. Louis, MO