Back in 2008, scientists from the University of Pittsburgh
published in Nature some amazing results – a monkey could feed itself with a prosthetic
arm entirely under the control of the monkey’s motor cortex! The scientists implanted a grid about the
size of a large freckle just under the skull. It sat on the motor cortex, in an
area known to control hand and arm movements. The grid held 100 tiny
electrodes, each connecting to a single neuron, its wires running out of the
brain and to a computer. The computer
was programmed to analyze the collective firing of these 100 motor neurons,
translate that sum into an electronic command and send it instantaneously to
the arm, which was mounted flush with the left shoulder. Check out the video below that
shows the monkey in action! If the video doesn't work below, here's the link. The
researchers believe that the monkey adopted the prosthetic similarly to a
real arm because it was more natural and intuitive than a normal prosthetic.
You can imagine how these findings could potentially impact
the lives of patients with spinal cord injuries in the future and allow them to
control a prosthetic naturally and intuitively.
However, one major kink in the study published in Nature was
that the monkey received no sensory input from the prosthetic, making biofeedback
impossible. In a more recent study
published in 2011 by researchers from Duke University (also in Nature),
scientists implanted electrodes in both the motor cortex and sensory cortex of
monkeys. Using a computer program, the
monkeys were able to detect different textures and control a virtual arm to “select”
a desired texture. This research builds
on the 2008 Nature study and shows progress toward the ultimate development of prosthesis controlled by the motor cortex that can also detect subtle
differences in texture using sensory input.
Link to the 2008 Nature article: http://www.nature.com/nature/journal/v453/n7198/abs/nature06996.html
Link to the 2011 Nature article: http://www.nature.com/nature/journal/v479/n7372/full/nature10489.html
Have you seen this video yet? There is a group in Chile called "Think Thinkers" that has developed a technology that allows the scientists to move a cockroach leg with their mind. They initially use sound waves to determine the wavelength needed to move the leg. The computer learns this wavelength and recognizes when you emit a similar wavelength with your thoughts. It's super interesting and I've included a link to a MIT technology review article about it!
ReplyDeletehttp://www.technologyreview.com/view/507756/human-brainwaves-move-a-cockroach-leg/
My reason for posting this, is that this group of scientists hopes to apply the same technology to prosthetics.
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