The Safety and Effectiveness of Q Therapeutic System, Frequency-tuned Electromagnetic Field Treatment in Facilitating the Recovery of Patients With Chronic Stroke.

Inclusion Criteria: * Be between ages 18-80 * Have an score between 22-50 (inclusive) of impaired limb on the Fugl-Meyer Assessment for the Upper Extremity (FMA-UE), as determined by study staff * Have upper extremity function that is not changing much over time (as determined by study staff based on assessments I complete at screening and before treatment starts) * Have stroke due to ischemia or to intracerebral hemorrhage • Be \>6 months to 5 years from stroke onset * Have a Box \& Block Test score with affected arm is ≥1 block in 60 seconds at Baseline Visit * Be able to sit with the investigational System for 40 consecutive minutes * Be able to follow a 3-step command in English, such as "take the paper, fold it in half, and return it to me", or a non-verbal equivalent * Have the willingness to participate in physical exercises during study intervention sessions. * Be sure of the availability of a relative, friend, or other non-hired caregiver to be able to assist during program sessions and study visits, as needed Exclusion Criteria: * Be younger than 18 years old or older than 80 * Have implanted MR-incompatible devices or MR-incompatible retained objects (like shrapnel) or an implanted life-sustaining MR-compatible devices (such as a pacemaker or internal cardiac defibrillator) * Have conditions other than stroke, such as: A. Severe neglect impairment interfering with assessments or treatments. B. Severe depression, defined as GDS Score \>10/15 C. Active epilepsy or currently taking anti-epileptic medication (indicated for the treatment of a seizure disorder), or any epileptic seizure in the last 5 years. D. Severe upper extremity spasticity, defined as presence of upper extremity contracture or modified Ashworth Scale score ≥3 in either biceps or chest muscles. E. Pre-existing neurological condition (such as Alzheimer's disease, Parkinson's disease, multiple sclerosis, traumatic brain injury, spinal cord injury) or physical limitation that would interfere significantly with my participation in the study and/or confound neurological or functional evaluation F. Unstable serious illness/condition (such as active cancer, severe heart failure, active major psychiatric condition) or life expectancy of less than 12 months. significant visual disturbances, pre-existing or resulting from the index stroke, that cannot be corrected and that would interfere significantly with my participation in the study and/or confoundneurological or functional evaluation * Have alcohol abuse and/or drug abuse in the past 6 months, which is likely to influence ability to fully participate in the trial * Had active participation in an arm rehabilitation program with a therapist in the 4 weeks prior to the screening visit * Plan to have an arm rehabilitation program with a therapist between the screening visit and the assessment visit at 3-months * Be an employee of Kessler Foundation * Be a prisoner * Be pregnant or breastfeeding or planning pregnancy during the study period. * Have other conditions or circumstances that, in the opinion of the investigators, would affect the safety or effectiveness of the training in which I would participate