"This is
a tremendous step forward in the utilization of this type of
technology for opthamology."
Dr. Keith Green, Regents Professor, Medical
College of Georgia
Researchers at the Medical College of Georgia and IMTC at Georgia
Tech created a device incorporating virtual reality to simulate
the look and feel of eye surgery. A primary benefit of the simulator
is to provide an environment for recursive and time-critical training
for medical students and practicing surgeons. By using this system,
surgeons can practice coping with emergencies and the unpredictable,
as do pilots with flight simulators. Beside photo-realistic images
of the anterior segment of the eye derived from photographs of
bank
eyes, the simulator has linear tactile feedback for real-time "feel" of
tool-tissue interaction. The haptic information was based on data
gathered by monitoring surgical tool forces during procedures performed
on a bank eye at the Medical College of Georgia.
The operating
station for the simulator allows the viewer to interact with a
3D virtual eye using a virtual surgical instrument controlled
by a handheld 6D tracking stylus. The stylus “understands” the
user’s hand position and orientation, and reports this information
to the computer. The tip of the stylus is connected by thin rigid
bars to three magnetic particle clutches that generate a passive
component force feedback in response to the instrument's interaction
with virtual tissue. In other words, the stylus, in the hand of
the user “reacts” and allows the user to feel the sensation
of cutting into the sclera, without an actual sclera being present,
except as a video representation.
As the knife makes contact, the
sclera (white of the eye) slightly deforms until the blade penetrates
and starts to cut. The force feedback
system produces a compliant or "springy" resistance as
the sclera deforms and then allows the blade to slice through the
sclera with a small viscous resistance in the cutting direction after
penetration. As the blade is cutting, a strong compliant force is
generated in the direction perpendicular to the cutting axis to produce
the same type of resistance that would be experienced if the surgeon
tried to move the blade in the wrong or non-cutting direction. With
the tactile recorder, the procedure can be recorded during a procedure
on say, a cadaver eye, quantified and parametrically defined for
playback on the simulator for increased fidelity in the tactile domain.
Patent number: 5766016 click on a thumnail below for a larger view (JPG: 640 x 480)
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Examples from the 3-D Scanner
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