by David Geer
Contact the author at geercom@windstream.net
Simple Spine of Lamprey Leads to Complex
Robot Limbs and Neuroprostheses
Researchers from Tulane and the University of Maryland along with Dr. Avis
Cohen are working with a computational model of the Lamprey fish. The
model consists of a system that solves several sets of equations around fluid
motion and how the fish’s muscles operate. “This is running on a cluster
system at Tulane. It runs simulations,” states Dr. Eric Tytell of Johns Hopkins.
Using this model, the researchers intend to study the Lamprey’s simple spinal cord, in order to better
understand the human spinal cord — which is not so
simple.
Muscles are capable of a certain amount of force
depending on how long the muscle is and how fast it is
trying to contract. This creates mechanical feedback
before the connection to the nervous system is made,
according to Dr. Tytell.
A study of this force supplied by the Lamprey’s
muscles as it works with and against the force of the water
10 SERVO 02.2011
(fluid dynamics) is a large part of the research which
should contribute to improved neuroprostheses and
robotic limbs.
The Lamprey
The structure of the Lamprey nervous system,
including the spinal cord, is basically the same as our
human spinal cord, explains Dr. Eric Tytell, assistant
research scientist on mechanical engineering at Johns
Hopkins. “But, it is much simpler, so we can look at
specific cells in detail to understand the changes that
occur in an injured spinal cord in the Lamprey,” comments
Dr. Tytell.
“With the Lamprey, we know the cells that make up
the neural circuit that controls the swimming and we
know the first connections those cells make,” Dr. Tytell
continues.
With the information gained from this research, the
scientists can focus on mechanical feedback instead of the
sensory feedback which may not be available in a human
being with spinal cord damage who needs a quality
neuroprosthetic. By tailoring mechanical feedback, a
prosthetic could do a lot of the things a normal limb can
do even without all the sensory feedback.
As an example, a car’s mechanics respond well to
potholes even though there is no brain or sensory
feedback available to the mechanics, Dr. Tytell explains.
Images of the Lamprey — the type of fish selected to
create the computational model and framework for
furthering research and development of neuroprostheses
and robotic limbs.
