Stroke survivors with severe upper limb (UL) impairment face years of therapy to recover function. Robot-assisted therapy (RT) is increasingly used in the field for goal-oriented rehabilitation as a means to improve function in ULs. To be used effectively for wrist and hand therapy, the current RT systems require the patient to have a minimal active range of movement in the UL, and those that do not have active voluntary movement cannot use these systems. We have overcome this limitation by harnessing tongue motion to allow patients to control a robot using synchronous tongue and hand movement. This novel RT device combines a commercially available UL exoskeleton, the Hand Mentor, and our custom-designed Tongue Drive System as its controller. We conducted a proof-of-concept study on six nondisabled participants to evaluate the system usability and a case series on three participants with movement limitations from poststroke hemiparesis. Data from two stroke survivors indicate that for patients with chronic, moderate UL impairment following stroke, a 15-session training regimen resulted in modest decreases in impairment, with functional improvement and improved quality of life. The improvement met the standard of minimal clinically important difference for activities of daily living, mobility, and strength assessments.
Keywords: Hand Mentor; Tongue Drive System; assistive technology; exoskeleton; motor cortex; neuroplasticity; robot-assisted therapy; robotic rehabilitation; stroke; upper-limb functional recovery.