Duchenne muscular dystrophy leaves patients with severe dependency on health care. In an effort to increase independence and quality of life, active exoskeletons are developed to support activities of daily living. This study is dedicated to the development and assessment of three different admittance control algorithms for a trunk supporting robot; a law with constant parameters, a law with added feed-forward force, and a law with variable parameters. A Fitts'-like experiment with 12 healthy subjects was performed to compare the control laws. The results show decreased movement times for the feedforward and variable admittance controllers with respect to the standard admittance.

In this study, we present the implementation of the controller for adapting the energy storage capacity of the WalkMECH according to the different walking speeds and gait characteristics of an amputee. Since the main aim is to keep the design both mechanically and metabolically energy-efficient, the actuation system is designed based on the minimal actuation principle. The overall system, called WalkMECHadapt, is evaluated with the experimental test set-up with a healthy subject. Test results show that the system is working sufficiently for adapting the energy storage capacity of the WalkMECHadapt thanks to the simple nature of the controller architecture.

In this study, we present the conceptual design of a fully-passive transfemoral prosthesis. The design is inspired by the power flow in human gait in order to have an energy efficient device. The working principle of the conceptual mechanism is based on three storage elements, which are responsible of the energetic coupling between the knee and the ankle joints. Design parameters of the prosthesis have been determined according to the energy absorption intervals of the human gait. Simulation results shows that the power flow of the system is comparable with human data. Finally, an initial prototype is presented as proof of concept.