Analog chip could be Rx for spinal cord injury
From: EETimes - 09/17/2007 - page 1
By: Sunny Bains

There's a reason that a broken neck or back is considered to be one of the
most tragic of injuries. If the spinal cord snaps, the brain loses its
ability to communicate with the rest of the body, and the limbs to talk to
each other. What most people don't realize is that when it comes to
locomotion, the second problem is actually worse than the first. The chicken
with its head cut off can still run around, thanks to its spinal cord: The
brain gave the signal to get going, then became superfluous to requirements.
But if the limbs can't "speak" to each other to coordinate, then walking is
impossible. 

Researchers at Johns Hopkins University (JHU; Baltimore) saw a way of getting
around the problem. It turns out that the coordinated movements of limbs in
all sorts of animals (including chickens) are produced by a central pattern
generator (CPG). Sensors and actuators feed signals into the neurons of the
spinal cord and then respond to the output. Because of the cyclical nature of
walking, the spinal cord neurons learn to coordinate the inputs and outputs
to produce a regular pattern: they become a CPG as the creature learns to
walk. So, to give locomotion to an animal with a severed spinal cord, you
need to reproduce this neural process. 

If you could do so with an embedded chip, the researchers reasoned, you could
enable walking at the flip of a switch. 

Now they've shown that it really works. In a recent experiment with
colleagues at the University of Alberta, Edmonton, they used a chip with
analog neurons to control the walking of a temporarily paralyzed cat. Not
only were signals from the chip used to stimulate the muscles, but the
movement of the limbs was detected and fed back into the artificial neural
network. The resulting movement might not have been completely natural, but
it proved the concept. And this solution, unlike a more brute-force digital
approach, has the potential of actually being implantable in the medium term. 

Read the entire article at:
http://www.eetimes.com/showArticle.jhtml;jsessionid=KNKSIMVYJBXYQQSNDLPCKHSCJUNN2JVN?articleID=201806940

Links:
Reggie Edgerton
http://www.bmc.org/rehab/redgerton_bio.htm
http://www.physci.ucla.edu/physcifacultyindiv.php?FacultyKey=82
http://www.physci.ucla.edu/research/edgerton/

Francesco Tenore
http://etienne.ece.jhu.edu/labweb/people/fran/index.html

Jacob Vogelstein
http://etienne.ece.jhu.edu/labweb/people/jacob/index.html

Bidirectional Neuroprostheses
http://etienne.ece.jhu.edu/labweb/projects/bnp/index.html

Iguana Robotics, Inc.
http://iguana-robotics.com/

Ralph Etienne-Cummings
http://etienne.ece.jhu.edu/~etienne/

Replicating an Eel's Nerve Circuitry May Aid Paralyzed People
http://www.jhu.edu/news_info/news/home04/dec04/spine.html

Vivian Mushahwar
http://www.ualberta.ca/~vmushahw/
http://www.ualberta.ca/CELLBIOLOGY/mushahwar.html
http://www.boneandjoint-training.ca/mushahwar.htm

Prof earns big grant to reverse spinal paralysis
http://www.expressnews.ualberta.ca/article.cfm?id=3388