People recovering from a stroke will soon have access to a device that can help restore a disabled hand. The Food And Drug Administration has authorized a device called IpsiHand, which uses signals from the uninjured side of a patient's brain to help rewire circuits controlling the hand, wrist and arm. NeuroLutions ... was founded by Dr. Eric Leuthardt. Leuthardt had been puzzled by something he often heard from patients who'd lost the use of hand after a stroke. "If you talk to a stroke patient, they can imagine moving their hand," he says. "They can try to move their hand. But they just can't actually move it." So Leuthardt had been looking for the source of those thoughts. Usually ... the right side of the brain controls the left side of the body. But ... control signals [are] 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: "Can we use this device that controls their affected limb to essentially encourage the brain to rewire?" Early experiments suggested the approach worked. NeuroLutions tested the device on 40 patients for 12 weeks. All of them got better.