Inclusion Criteria:  age over 18 years old at the time of enrolment history of cerebrovascular insult verified by computerized tomography or magnetic resonance imaging; stoke occurred not more than 6 months prior to study enrolment; subject need to be medically and neurologically stable determined by medical history and documented neurological examination; ability to understand, communicate and cooperate with the research team; ability to sit for at least 45 minutes and the ability to adhere to the study rehabilitation protocol.  Exclusion Criteria:  any neurologic condition (beyond the stroke) or physical condition that impaired function of the affected arm a substantial cardiopulmonary or metabolic disorder or other major medical complication; history of seizures; moderate to severe hemispatial neglect or anosognosia involving the affected arm; severe sensory deficit; inability to understand, cooperate, and adhere to the study procedures; severe spasticity defined as Ashworth scale score of 4 in the affected arm; contraindication to stimulation system placement; nursing a child; pregnancy.