3D-Printing-Oriented Mechanical Redesign of a Hand Exoskeleton System for Rehabilitative Tasks

The number of Years Lived with Disability (YLDs) is growing at an impressive pace under the aging global population's push. Consequently, the demand for innovative therapies and solutions to improve the quality of life of disabled people is rising. Robots are making their way into the clinical sector to provide high-intensity rehabilitation exercises or assistance while monitoring quantitative metrics for tracking the patients' status evolution. Exoskeletons are among the most studied and most interesting embodiments of today's robotic technologies. This paper investigates an innovative design concept for a rehabilitative Hand Exoskeleton System (HES) driven by a Remote Actuation System (RAS). The discussion starts from the characteristics of a previously built prototype and focuses on using finite element analysis, topological optimization techniques, and 3D-printing-oriented design to minimize the system's weight and complexity while assuring adequate performance to be effective in rehabilitation. The text will present, in sequence: the main features of the starting prototype; the preliminary design of the new exoskeleton; a detailed dynamic analysis of the finger mechanisms composing it; the final topologically optimized design; and, finally, the evaluation of the result of the redesign process.