NeuroExo is a device which includes a robotic exoskeleton that you were in your affected arm to assist you with arm movements, a headset that you wear on your head to measure your brain activity and detect your intention to move, and a graphical user interface that allows you to initiate and stop neurotherapy, and track your motor performance.

In this longitudinal study, adult subjects with hemiparesis due to chronic stroke will receive robotic-assisted upper-arm training through an EEG-based BMI control of robotic exoskeleton to study the changes in upper extremity motor function, cortical plasticity (using the EEG). After one screening visit, two baseline visits for EEG signal screens, six onsite training sessions will be provided with the NeuroExo system, followed by 60 home therapy sessions (2 sessions per day, 5 days per week for 6 weeks). If the participant have completed at least 50 sessions of neurotherapy at home, the participant will complete a set of measurements to assess function of the affected upper arm and brain activity within 3 days after the last session for post-assessment visit, and one-month post follow-up session. The total amount of time for this study is 16-20 weeks.

FMA is a stroke-specific, performance based impairment index. It quantitatively measures impairment based on Twitchell and Brunnstrom's concept of sequential stages of motor return in hemiplegic stroke patients. It uses an ordinal scale for scoring of 33 items for the upper limb component of the F-M scale (0:can not perform; 1:can perform partially; 2:can perform fully). Total range is 0-66, 0 being poor and 66 normal.

EEG activity in the delta, theta, alpha, beta and gamma bands will be assessed. Scalp EEG electrodes will be located over the motor cortex, specifically, central (Cz, C1- C4), fronto- central (FCz, FC1 - FC4) and centro-parietal electrodes (CPz, CP1 - CP4). Further, to account for left hand vs. right hand impairment, the electrode locations will be flipped for individuals with right hand impairment. Increased MRCP amplitude indicates increased activation of the ipsi-lesional hemisphere or inhibition of competing contra-lesional hemisphere, following motor relearning.

EEG activity in the low-frequency delta band will be assessed. Scalp EEG electrodes will be located over the motor cortex, specifically, central (Cz, C1- C4), fronto- central (FCz, FC1 - FC4) and centro-parietal electrodes (CPz, CP1 - CP4). Further, to account for left hand vs. right hand impairment, the electrode locations will be flipped for individuals with right hand impairment. MRCP latency is the duration of MRCP prior to movement onset, and is defined as time difference starting from 50% of peak amplitude until the time of movement onset. Increased MRCP latency indicates increased activation of the ipsi-lesional hemisphere or inhibition of competing contra-lesional hemisphere, following motor relearning.

The ARAT is used to assess subject's ability to manipulate-lift-release objects horizontally and vertically, which differs in size, weight and shape. The test consists of 19 items divided into 4 sub-tests (grasp, grip, pinch, gross arm movement) and each item is rated on a 4-point scale. The possible total score ranges between 0-57. Higher scores indicate better performance.