title: Automating arm movement training following severe stroke: functional exercises with quantitative feedback in a gravity-reduced environment.
abstract: An important goal in rehabilitation engineering is to develop technology that allows individuals with severe motor impairment to practice arm movement without continuous supervision from a rehabilitation therapist. This paper describes the development of such a system, called Therapy WREX or ("T-WREX"). The system consists of an orthosis that assists in arm movement across a large workspace, a grip sensor that detects hand grip pressure, and software that simulates functional activities. The arm orthosis is an instrumented, adult-sized version of the Wilmington Robotic Exoskeleton (WREX), which is a five degrees-of-freedom mechanism that passively counterbalances the weight of the arm using elastic bands. After providing a detailed design description of T-WREX, this paper describes two pilot studies of the system's capabilities. The first study demonstrated that individuals with chronic stroke whose arm function is compromised in a normal gravity environment can perform reaching and drawing movements while using T-WREX. The second study demonstrated that exercising the affected arm of five people with chronic stroke with T-WREX over an eight week period improved unassisted movement ability (mean change in Fugl-Meyer score was 5 points +/- 2 SD; mean change in range of motion of reaching was 10%, p < 0.001). These results demonstrate the feasibility of automating upper-extremity rehabilitation therapy for people with severe stroke using passive gravity assistance, a grip sensor, and simple virtual reality software.
authors.affiliation: Department of Mechanical and Aerospace Engienering, University of California, Irvine, CA 92697-3975, USA. dreinken@uci.edu
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Sanchez
authors.forename: Jiayin
authors.initials: J
authors.lastname: Liu
authors.forename: Sandhya
authors.initials: S
authors.lastname: Rao
authors.forename: Punit
authors.initials: P
authors.lastname: Shah
authors.forename: Robert
authors.initials: R
authors.lastname: Smith
authors.forename: Tariq
authors.initials: T
authors.lastname: Rahman
authors.forename: Steven C
authors.initials: SC
authors.lastname: Cramer
authors.forename: James E
authors.initials: JE
authors.lastname: Bobrow
authors.forename: David J
authors.initials: DJ
authors.lastname: Reinkensmeyer
mesh_terms: D000328:Adult; D000368:Aged; D001132:Arm / Q000503:physiopathology; D001676:Biofeedback, Psychology / Q000379:methods*; D005081:Exercise Therapy / Q000295:instrumentation* / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015915:Motion Therapy, Continuous Passive / Q000295:instrumentation* / Q000379:methods; D010291:Paresis / Q000209:etiology / Q000503:physiopathology / Q000534:rehabilitation*; D010812:Physical Stimulation / Q000295:instrumentation / Q000379:methods; D012371:Robotics / Q000295:instrumentation* / Q000379:methods; D020521:Stroke / Q000150:complications / Q000503:physiopathology; D000071939:Stroke Rehabilitation; D017216:Telemedicine / Q000295:instrumentation* / Q000379:methods; D013813:Therapy, Computer-Assisted / Q000295:instrumentation / Q000379:methods; D014584:User-Computer Interface; D018474:Weightlessness Simulation