Tuesday, October 1, 2013

Rewired nerves control robotic leg



“Mind over matter” has been a saying that was left for mystics and believers of supernatural phenomena. However, with a new break through in bio medical technology, thoughts now have a direct causal reaction to physical objects.

A team of biomedical engineers led by Levi Hargrove at the Rehabilitation Institute of Chicago in Illinois reported a noteworthy break through in the New England Journal of Medicine. The patient that you see in the video above is a 32 year-old man whose knee and lower leg were amputated in 2009 after a motorcycle accident. The prosthetic leg that you see, isn’t the standard grade prosthetic, but is wired directly into the patient’s muscles giving him full control over his prosthetic simply by thinking about moving his leg. In a sense, hijacking the signal that would be sent down the hamstring and to the missing foot.

The major advancement in this technology is that the patient no longer requires a remote-control switch or exaggerated movements to tell the robotic leg to execute a certain movement.

“To our knowledge, this is the first time that neural signals have been used to control both a motorized knee and ankle prosthesis,” According to Hargrove.

In past experiments of robotic prosthetics researchers have shown that individuals that were paralyzed could move a robotic arm using their thoughts such as Matt Nagle, the first person to control an artificial handusing a BCI as part of the first nine-month human trial of Cyberkinestic’s BrainGate chip-implant. What separates the technology that Matt used and our current prosthetic user is that instead of using a typical BCI, it uses the muscle signals to amplify the messages sent by the brain when the person wants to move.

“In order to use muscles as amplifiers to surgeons redirect the nerves that previously controlled a part of the patient’s lower leg muscles so that they would cause the muscles in his thigh to contract in a technique called targeted muscle reinnervation. “ – Nature

They then used the sensors that were embedded in the robotic leg to calculate the electrical pulse created by the reinnervated muscle contraction and the existing thigh muscles. When researchers combined all of this data with the additional information from the sensors, the patient was able to use the prostatic more accurately than when attempting to control the leg with its sensor alone.


Researchers hope that within the next three to five years this technology should be available to the public to help give mobility back to people who have lost a limb.


Citation
http://www.nature.com/news/rewired-nerves-control-robotic-leg-1.13818