Usually, the brain and body follow what's known as a contralateral model, where the right side of the brain controls the left side of the body. But Leuthardt's team had discovered that control signals were also present on the ipsilateral side – the same side of the brain as the limb being controlled.
Leuthardt's team built a system that could detect and decode those ipsilateral signals. Then they connected it to a device that would open and close a patient's disabled hand for them when they imagined the action.
But a mechanical hand wasn't Leuthardt's ultimate goal. He wanted to help his patients regain the ability to move their hand without assistance. And that meant answering a question:
"If somebody can generate a brain signal that's associated with their desire to move, and the exoskeleton moves it, so they're getting feedback, can we use this device that controls their affected limb to essentially encourage the brain to rewire?"
Early experiments suggested the approach worked. A video of one man with a disabled hand showed him initially trying and failing to grasp a marble and place it on a shelf.
"Then after six weeks of training, he can pick up that marble and he can move it on top of the shelf," Leuthardt says.
NeuroLutions tested the device on 40 patients for 12 weeks. All of them got better, and the results persuaded the FDA to authorize marketing of the device.
Now the company is gearing up to manufacture the system, says NeuroLutions CEO Leo Petrossian, a brain scientist with a business degree.
"I got involved specifically to help take something that was great in clinical studies and figure out how we can now bring this out to the million-plus people in the U.S. living with disability post stroke," Petrossian says.
The IpsiHand system consists of a headset that analyzes brain signals, a tablet computer, and a robotic exoskeleton worn over the wrist and hand. Unlike many rehabilitation aids, it can be used at home.
And it appears to help people who are no longer getting better with traditional rehabilitation.
The conventional wisdom is that most recovery from a stroke takes place in the first 90 days or so, says Petrossian. "So if it's day 100 and a person can't move their arm very well, that's how their arm's going to be for the rest of their life."
The IpsiHand study showed that doesn't have to be the case.
"If you spend an hour a day doing this exercise of thinking and visualizing opening and closing the hand, five days a week for 12 weeks, you retrain a different part of the brain to drive that previously disabled appendage," Petrossian says.
You just know that he'd have some strong opinions on fiat currency
www.businessinsider.com