This project compares different techniques for assisting individuals with stroke-related mobility impairments using a robotic ankle orthosis. Several promising assistance techniques have been developed for robotic prostheses and rehabilitation platforms, which have been extended to exoskeletons - worn at the ankle joint, and adapted for individuals with stroke. An ankle exoskeleton test bed is used to emulate each assistance technique, allowing comparisons of efficiency and effectiveness within the same platform. Each technique is first programmed and verified in pilot tests with this emulator, followed by multi-dimensional parameter studies, conducted first on subjects without neurological impairment and then on subjects with hemiparesis following stroke. The results for each technique are used to identify ideal parameters and their settings, which facilitates across-technique comparisons and development of a standardized set of quantitative performance metrics, including measures of effort, preferred speed, and stability. These studies will contribute to a scientific foundation for the design and prescription of robotic ankle-foot orthoses that will benefit the millions of impaired individuals.
