At 16.20 16/09/96 +0200, you wrote:

Dear biomch-l subscribers,

Some times ago i have send this mail
> I work in the Biomechanics Laboratory of Rizzoli Orthopedic Institute,
>Bologna, Italy and I am interested in the possibility of using an Acoustic
>Transducer in knee kinematics investigations. Such a device has been used by
>Quinn and Mote in 1990 (ASME J. Biomech. Eng., Vol 112, pp. 371-378) and by
>Hart et al. in 1991 (ASME J. Biomech. Eng., Vol. 113, pp. 215-221).
> I used a 6DOF electromagnetic sensor (Flock of Birds) for similar
>purposes, but unfortunately its performances are strongly affected by the
>presence of metal in the surroundings.
> I would be therefore very grateful if somebody could give me some
>information on acoustic 6DOF sensors. More in detail:
>1) In which conditions does the sensor ensure the precisions reported in the
>paper by Quinn and Mote (distance and environment constraints)?
>2) Which is the weight of each component of the instrumentation?
>3) Is it easy to use (mounting, setup configuration, interfacing, available
>software etc.)?
> Any other information about its use in kinematic data collection will of
>course be valuable. I will post a summary of the responses.

I have not reiceived much informations on the use of such kind of sensor for
kinematic investigations.
If you visit for 3D sensors built by Science
Accesories Corporation Digitizer you can see that the limit of such
instruments is accuracy in a large environment (+/-0.05 inches). In order to
have a better accuracy you probably need to reduce the range of motion.
I have not obtained informations, yet, concerning a manufacturer of 6DOF
accoustic transducer sensor.

Luigi Nizzi Grifi

Lab. Biomeccanica
via di Barbiano 1/10 fax: (+39).51.583 789
I-40136 Bologna