View Full Version : Kinemetrix

Dr David Michael Hooper
09-24-1996, 02:00 AM
I have recently taken a position at the University of
East London and am being charged with bringing a motion
analysis laboratory into full swing. My question (or query
in the UK) concerns the collection of data using a Kinemetrix
camera system and infrared reflective markers. My dissertation
work involved the Selspot II system which utilizes infrared LEDs,
active versus passive markers and I am encountering some problems
which I am am unfamiliar with.
I am trying to construct an experiment to look simulataneously at
both legs during gait. My idea is to have markers on the back of the
lower limb segments and the three cameras located symmetrically
behind the subject, who is walking upon a treadmill. Since each
marker must be seen by at least two cameras at each instant in time, I
had intended to have a central camera looking at all markers...while
cameras on the left and right sides looked at markers on the left and
right sides, respectively. The problem arises when the markers of the
left leg are intermittently visible to the camera on the right side
(due to interference from the right leg). Since the system is passive
it has no way of knowing which marker is which, and this is causing
problems in reconstructing the 3d coordinates appropriately.
Does anyone know of a way to clean up the individual cameral views
and *then* use those cleaned views to construct 3d coordinates. As far as
I am concerned, I just want to be able to =93erase=94 the markers on the
left leg from the view of the camera on the right, and similarly on
the left.
If anyone has encountered this problem, or would like to bounce
ideas concerning the Kinemetrix system, please contact me. I would be qu=
interested in discussing this with you. Naturally, I will post a
summary of replies.

Thank you.

David Hooper
Department of Health Sciences
University of East London