Patient-cooperative strategies for robot-aided treadmill training: first experimental results

Abstract

Task-oriented repetitive movements can improve motor performance in patients with neurological or orthopaedic lesions. The application of robotics and automation technology can serve to assist, enhance, evaluate, and document neurological and orthopedic rehabilitation. This paper deals with the application of "patient-cooperative" techniques to robot-aided gait rehabilitation of neurological disorders. We define patient-cooperative to mean that, during movement, the technical system takes into account the patient's intention and voluntary efforts rather than imposing any predefined movements or inflexible strategies. It is hypothesized that such cooperative robotic approaches can improve the therapeutic outcome compared to classical rehabilitation strategies. New cooperative strategies are presented that detect the patient's voluntary efforts. First, this enables the patient increased freedom of movement by a certain amount of robot compliance. Second, the robot behavior adapts to the existing voluntary motor abilities. And third, the robotic system displays and improves the patient contribution by visual biofeedback. Initial experimental results are presented to evaluate the basic principle and technical function of proposed approaches. Further improvements of the technical design and additional clinical testing is required to prove whether the therapeutic outcome can be enhanced by such cooperative strategies.

Therapeutic Robotics: A Technology Push

“…This robot action (which we dubbed "sensorimotor" therapy) was similar to the "hand-over-hand" assistance that a therapist often provides during conventional therapy. It is interesting to note that this form of "assistance as needed," which has been a central feature of our approach from the outset (and a challenge for our robot designs) has recently been adopted and promoted by other groups [5], [6].…”

Development of Exoskeletons and Applications on Rehabilitation

“…Compared to the over-ground exoskeletons, Hocoma AG developed an immobile exoskeleton Lokomat consisting of an over-ground exoskeleton, an advanced body weight support system (BWS) and a treadmill in 2000 at Switzerland [18,19]. The Lokomat with repetitive walking on one hand help to improve circulation, strengthen bones and muscles and gain a natural walking pattern [20], on the other hand decrease the physical effort and constraint of the therapists [19].…”

“…The Lokomat with repetitive walking on one hand help to improve circulation, strengthen bones and muscles and gain a natural walking pattern [20], on the other hand decrease the physical effort and constraint of the therapists [19]. …”

Learning a Locomotor Task: With or without Errors?

“…Recent work in robotic assistance has focused on developing sophisticated robotic mechanisms in order to support movement training of more complex movements such as walking [1][2][3][4]. Although robotic locomotor training has been proposed as a promising technique to improve rehabilitation in patients with severe gait impairments, the functional gains obtained after robotic training are still limited [5,6].…”