Dear Biomch-L readers,

The following note was posted onto Usenet's comp.human-factors newsgroup;
this is the follow-up to my posted reply there.

"There are various systems in the Biomechanics field that may accomodate this
problem, based on video ("gait analysis equipment"), ultrasound, electro-
goniometry ("elgons"), and electromagnetic principles. I'll Xpost your CfH
to / Biomch-L@hearn.bitnet; also, you might look into
the sci.virtual-worlds archives at the University of Washington in Seattle."



Article 2921 in comp.human-factors:
From: (Lindsey Ford)
Subject: 3-D locator device
Date: 24 Sep 92 21:48:52 GMT
Sender: (news admin)
Distribution: comp
Organization: Computer Science Dept. - University of Exeter. UK

Imagine you hold two knitting needles, one in each hand. The one in your left
hand is held steady and, with your eyes closed, you try to move the knitting
needle in your right hand so that the tip of it comes into close proximity to
the tip of the needle in your left hand. It's not easy.

Such is the problem of the surgeon using an arthroscope (left hand) and
another instrument, say a hook probe, in the right hand. The arthroscope,
which in effect has a miniscule camera at its tip, can be inserted into a
shoulder joint from the rear. The camera relays a picture to a TV screen of
the inside of the shoulder joint. The surgeon now inserts the hook probe into
the shoulder joint from the front and attempts to move it into visual scope
of the camera. Until the hook probe comes into the immediate vicinity of the
camera there is no visual feedback for the surgeon. Its a skill that takes
time (and live patients) to acquire and is costly and time-consuming to set
up with a dummy patient.

I'm attempting to provide a simulation of this situation to enable surgeons
to practice the skill. What I need is a device which relays its proximity
(preferably its 3-dimensional position) relative to some fixed point. Does
anyone have suggestions?

Dr Lindsey Ford

UUCP: lindsey@ex-dcs.uucp