I think, therefore I move - 'brain cap' turns thought into motion


August 1, 2011

Harsha Agashe, a Ph.D. student in Contreras-Vidal's lab at UMD wears the Brain Cap, a non-invasive, sensor-lined cap (Image: John Consoli, University of Maryland)

Harsha Agashe, a Ph.D. student in Contreras-Vidal's lab at UMD wears the Brain Cap, a non-invasive, sensor-lined cap (Image: John Consoli, University of Maryland)

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Researchers at the University of Maryland (UMD) continue to advance the development of their "brain cap" technology that allows users to turn their thoughts into motion. The team has already had success in using EEG brain signals captured from the cap's 64 electrodes attached to users' scalps to reconstruct 3D hand movements and to control a computer cursor with their thoughts, and now the team has successfully reconstructed the complex 3D-movements of the ankle, knee and hip joints during treadmill walking. The aim is to provide a non-invasive technology that can return motor function to victims of paralysis, injury or stroke.

For more than a year, the researchers have been matching specific brain activity recorded in real time with exact lower-limb movements by tracking the neural activity of people on a treadmill doing precise tasks, such as stepping over dotted lines. The data gathered could be used in a prosthetic device, called an "anklebot," that stores data from a normal human gait and assists partially paralyzed people. Larry Forrester, an associate professor of physical therapy and rehabilitation science at the University of Maryland School of Medicine, says that getting people, such as stroke survivors, up and moving could also help combat other health issues such as obesity, diabetes or cardiovascular problems.

The EEG data could also be used to "retrain" the healthy areas of stroke victims' brains in what is known ad neuroplasty.

"By decoding the motion of a normal gait, we can then try and teach stroke victims to think in certain ways and match their own EEG signals with the normal signals," says José 'Pepe' L. Contreras-Vidal, Associate Professor of Kinesiology at UMD.

One potential method of retraining envisioned by first-year bioengineering doctoral student, Steve Graff, is a virtual reality game that matches real EEG data with on-screen characters.

"It gives us a way to train someone to think the right thoughts to generate movement from digital avatars. If they can do that, then they can generate thoughts to move a device," says Graff, who has congenital muscular dystrophy and uses a motorized wheelchair. The advances he's working on could allow him to use both hands - to put on a jacket, dial his mobile phone or throw a football while operating his chair with his mind.

While there are a number of brain computer interface (BCI) technologies under development, Contreras-Vidal says these competing technologies either require electrodes to be implanted directly in the brain or, in the case of other non-invasive technologies, require much more training to use than the EEG-based, brain cap technology. The UMD researchers say their non-invasive interface is the only one to have demonstrated decoding results comparable to those achieved with implanted electrodes.

Multiple projects underway

The team is collaborating with researchers at a number of institutions to develop thought-controlled robotic prosthetics. Under a US$1.2 million grant from the National Science Foundation (NSF), the UMD team is collaborating with researchers at Rice University, the University of Michigan and Drexel University in a four-year project to design a prosthetic arm that amputees can control directly with their brains, and which will allow users to feel what their robotic arm touches.

In another National Institutes of Health (NIH)-supported project, the UMD team is pairing the brain cap's EEG-based technology with a DARPA-funded next-generation robotic arm designed by researchers at the Johns Hopkins Applied Physics Laboratory to function like a normal limb.

They also have partnerships with the University of Maryland School of Medicine in Baltimore and the Veterans Affairs Medical Center in Baltimore focusing on the use of the brain cap technology to help stroke victims whose brain injuries affect their motor-sensory control.

The UMD team is also developing a new collaboration with New Zealand start-up Rexbionics, the developer of the Rex robotic exoskelton that could be used to restore gait after spinal cord injury.

The latest of three papers the UMD team has published on their brain cap technology over the last 18 months appears in the Journal of Neurophysiology.

About the Author
Darren Quick Darren's love of technology started in primary school with a Nintendo Game & Watch Donkey Kong (still functioning) and a Commodore VIC 20 computer (not still functioning). In high school he upgraded to a 286 PC, and he's been following Moore's law ever since. This love of technology continued through a number of university courses and crappy jobs until 2008, when his interests found a home at Gizmag. All articles by Darren Quick

Ultimately the system is lacking one vital component. Until you can complete the system by providing feedback you essentially have a person who has no feeling in their limbs and has all the problems similar to that of a person with leprosy.

What is needed is a non-invasive delivery system that can deliver targeted electrical impulses to the relevant locations of the brain to provide the feedback necessary to avoid damaging the limbs. Until this is developed you have to use inferior systems that stimulate an area of the skin that still has feeling and use that as a way of delivering warnings about the limbs that have no feeling. Very inferior and I hope that developers will not settle for this poor solution when they could do so much more.


I always had assumed that sorting the brain signals from outside the skull would be imposable.

Wear that sensor net and one over the body and after a period of training, such as boot-camp, restoring motion after nerve injury or commanding a prosthesis would almost be plug and play.

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