Brain Machine Interface Control of an Robotic Exoskeleton in Training Upper Extremity Functions in Stroke

The purpose of this study is:

1. To augment the MAHI Exo-II, a physical human exoskeleton, with a non-invasive brain machine interface (BMI) to actively include patient in the control loop and thereby making the therapy 'active'.
2. To determine appropriate robotic (kinematic data acquired through sensors on robotic device ) and electrophysiological ( electroencephalography- EEG based) measures of arm motor impairment and recovery after stroke.
3. To demonstrate that the BMI controlled MAHI Exo-II robotic arm training is feasible and effective in improving arm motor functions in sub-acute and chronic stroke population.

This study aims to provide an adjunct to accelerate neurorehabilitation for stroke patients. The MAHI EXO-II, a physical human-robot interface, will be combined with a non-invasive brain-machine interface (BMI) to actively include the patient in the training of upper extremity motor functions.

Eligibility Criteria:
Inclusion Criteria:

1. Diagnosis of unilateral cortical and subcortical stroke confirmed by brain CT or MRI scan;
2. Subacute or chronic stroke; interval of at least 3month and interval of at least 6 months from stroke to time of enrollment, respectively;
3. No previous clinically defined stroke;
4. Age between 18-75 years;
5. Upper-extremity hemiparesis associated with stroke (manual muscle testing score of at least 2, but no more than 4/5 in the elbow and wrist flexors);
6. No joint contracture or severe spasticity in the affected upper extremity: i.e., significant increase in muscle tone against passive ROM is no more than ½ of full range for given joint e.g., elbow, wrist and forearm movements.
7. Sitting balance sufficient to participate with robotic activities;
8. No neglect that would preclude participation in the therapy protocol;
9. Upper limb proprioception present ( as tested by joint position sense of wrist);
10. No history of neurolytic procedure to the affected limb in the past four months and no planned alteration in upper-extremity therapy or medication for muscle tone during the course of the study;
11. No medical or surgical condition that will preclude participation in an occupational therapy program, that includes among others, strengthening, motor control and functional re-training of the upper limbs;
12. No contraindication to MRI;
13. No condition (e.g., severe arthritis, central pain) that would interfere with valid administration of the motor function tests;
14. English-language comprehension and cognitive ability sufficient to give informed consent and to cooperate with the intervention.-

Exclusion Criteria:

1. Orthopedic limitations of either upper extremity that would affect performance on the study;
2. Untreated depression that may affect motivation to participate in the study;
3. Subjects who cannot provide self-transportation to the study location.

Inclusion and Exclusion Criteria for Health Subjects:

Inclusion criteria:

* able to understand and sign the consent form
* age 18-65

Exclusion criteria: - Previous history of or MRI findings consistent with brain tumors, strokes, trauma or arterial venous malformations - Contraindication to MRI - Pregnancy