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DoE Spearheads
Collaboration on Retinal Prostheses
by Glenn Cornett, senior financial editor and James Cavuoto,
editor
With the help of the U.S. Department of Energy and other funding
agencies, several national laboratories, universities, and commercial
firms are collaborating on retinal prosthesis technology development.
The U.S. Department of Energys Office of Biological and Environmental
Research recently issued a $9 million, three-year grant for the
development of retinal implant technology. The money was award to
five national laboratories, two universities, and Second
Sight, LLC of Valencia, CA. The goal of the project is to develop
electrode arrays with increased resolution from 100 to 1000 elements
by fiscal year 2004.
The University of Southern Californias Retinal Prosthesis
Group, led by Mark Humayun, will implant the devices and test their
effectiveness. North Carolina State University will develop the
in-situ medical electronics. The five national labs involved are
Argonne, which is investigating diamond-based electrode arrays and
biocompatible coatings, Lawrence Livermore, which is looking into
rubberized arrays, Los Alamos, which is modeling neural pathways
in the visual system, Sandia, which is researching MEMS chips fabricated
with lithography, electroplating, and molding, and Oak Ridge, which
is managing the multilaboratory effort. Second Sight will commercially
produce the finished system.
As part of this effort, DoEs Medical Sciences Division is
planning the
First U.S. Department of Energy International Symposium on Artificial
Sight, to be held in Fort Lauderdale, FL next month. The purpose
of the symposium is to provide a forum for research, discussions,
and clinical advances in the field of artificial vision, especially
multielectrode array retinal prostheses.
Peter Krulevitch, a scientist at Lawrence
Livermore National Laboratory, has been collaborating on the
retinal device with colleagues at Oak Ridge, Argonne, Sandia, and
Los Alamos labs, USC and UC Santa Cruz, and Second Sight. His multidisciplinary
team includes lead engineer Mariam Maghribi, fabrication technician
Julie Hamilton, instrumentation engineer Courtney Davidson, MEMS
guru Dennis Polla, senior engineering associate Bill Benett, and
summer student Armando Tovar. Elias Greenbaum at Oak Ridge is the
principal investigator on the grant. The USC clinical work is funded
by the National Institutes of Health as well as the DOE.
Expertise at LLNL is being tapped to develop a flexible microelectrode
array that is able to conform to the curved shape of the retina
without damaging retinal tissue, and to integrate electronics developed
by UC Santa Cruz. Initial prototypes with nine electrodes were tested
in early durability and ergonomics studies. According to Krulevitch,
the main objective of the DOE project is to try to increase the
number of viable electrodes to 1000 on a square device that measures
4 millimeters on a side. The DOE project is funded for three
years, and is near its half-way point, he says. We hope
to have an approach that is scalable to 1000 electrodes one and
one half years from now.
Krulevitch and colleagues have pioneered the use of a form of silicone
rubber called polydimethylsiloxane (PDMS), in fabricating hybrid
integrated microsystems for biomedical applications. In particular,
the lab has worked on metalization - applying metals
for electronics and electrodes to PDMS for implant devices. Its
our important contribution to this project, Krulevitch says.
Weve developed a technique for fabricating metal lines
that can be stretched.
Krulevitch has been encouraged by early results on the retinal device.
The team did some very preliminary tests at USCs Doheny Eye
Institute, mostly to see how easily the prostheses were handled
in surgery. They now have a second-generation device that they are
about to test at Doheny. We will be testing conformation to
the shape of the retina, device robustness during implantation,
and device ergonomics during surgery, Krulevitch says.
The First U.S.
Department of Energy International Symposium on Artificial Sight
will be held Friday, May 2, 2003 at the Fort Lauderdale Marriott
North, Fort Lauderdale, FL. The Symposium will be held in conjunction
with the annual meeting of the Association for Research in Vision
and Ophthalmology (ARVO). The morning session of the Symposium will
provide an overview of the field. The afternoon session will focus
on in-depth talks on the engineering and scientific hurdles that
need to be addressed. Mark Humayun, of the Doheny Retina Institute,
and Elias Greenbaum, of Oak Ridge National Laboratory, will co-chair
the event.
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