| The increasing prevalence of stroke coupled with the cost of rehabilitation is creating a need for technology that allows stroke patients to retrain arm movement with minimal help from therapists. Initial attempts to meet this need have focused on robotic devices that actively assist in arm movement. Although initial results are promising, this work can be criticized from both ends of the range of possible design complexity. From the lower end, the technology can be criticized for being too sophisticated: it may be possible to automate therapy with non-robotic devices that do not require powered actuation but still provide assistance to arm movement. On the upper end of design complexity, the developed devices may be criticized for not being sophisticated enough: they have limited ranges of motion and force. The goal of this dissertation is to develop and evaluate technology that expands the performance of robotic therapy devices at both ends of the design complexity spectrum.; The first device developed is an instrumented version of a passive upper extremity gravity-balancing orthosis named Wilmington Robotic Exoskeleton (WREX). We named the new device Training-WREX (T-WREX), which functions as a three-dimensional input device to a simple virtual reality environment that allows severely weakened stroke subjects to practice simulated functional movements. In a pilot study with nine chronic hemiparetic subjects, we found that the subjects could significantly improve their movement ability while wearing the device, making functional movement practice possible. In a subsequent eight-week pilot study with five chronic hemiparetic subjects, we found that regular practice with the T-WREX system can improve unassisted movement ability. These results indicate that motor therapy following stroke can be automated with a non-powered device that is simpler and safer than current robotic approaches.; The second device is a pneumatically actuated version of T-WREX named Pneumatic-WREX (Pneu-WREX). Pneu-WREX will be a tool in the development of advanced, interactive, sensory motor training techniques. Pneu-WREX can assist arm movement across an estimated 70% of the arms workspace, is capable of generating up to 15 lbs of assistive force, and counterbalances the arm for all positions within the workspace. |
