MotionTherapy@Home - A robotic device for automated locomotion therapy at home

Lesions of the central nervous system often lead to walking impairments. Primary rehabilitation aims at the improvement of the gait capacity by application of task oriented training regimes utilizing the inherent capability of neural networks for reorganization. However, a sufficient training intensity for enhancement of this neuroplasticity can only be achieved during the inpatient phase, which - due to economical restrictions - is getting shorter and shorter. In the clinical environment complex and expensive robotic devices have been introduced to maintain the duration and the intensity of the training, but up to now only a few exist for continuation of an automated locomotion training at home. Hence this project aims at the development of a compact, modular, individually adaptable motor driven orthosis for home based gait training. In contrast to ergometer or continuous passive motion devices the novel ldquoMoreGaitrdquo system is capable of generating the proprioceptive and sensory stimuli in particular the gait-phase dependent loading of the foot soles, which have been identified recently also in humans as key afferent inputs of the spinal gait pattern generator. Artificial pneumatic muscles with excellent weight-to-force ratio have been integrated as actuators for ankle joint and combined hip-knee movements. Their inherent low stiffness efficiently supports the safety concept of the device, which is intended to be operated by the handicapped users completely on their own including transfers from the wheelchair. A nonlinear observer based controller has been implemented for the knee joint and a model based feedback controller for the ankle to compensate the highly nonlinear behavior of the mechanical system. For safety reasons a semi-recumbent position of the user has been foreseen, in which a foot loading cannot be achieved by the users´ own body weight. Therefore the Stimulative Shoe has been developed on the basis of pneumatically actuated medio-lateral bar- s mimicking the physiological foot loading pattern. The users operate the device via an intuitive user interface and receive feedback about their training activities through a graphical representation of model-based derived joint torques.