National Institutes of Health U.S. researchers have developed a hand-exercising robotic device that appears to help stroke victims recover motor skills, even more than six months after a stroke. Brain scans suggested that the device, which patients squeeze with their stroke-afflicted hands, boosted activity in the part of the brain that handles use of the hands. Stroke is the third leading cause of death in the United States, trailing only heart disease and cancer, and a leading cause of severe long-term disability. An estimated 700,000 cases of stroke are diagnosed in the country annually.