Characterization and valuation of a five-fingered hand exoskeleton for assistance in activities of daily living

This paper presents a comprehensive evaluation of the BRAIL hand exoskeleton, a five-fingered hand exoskeleton, focusing on its mechanical and functional characteristics. The BRAIL hand exoskeleton assist individuals with hand impairments by supporting all the fingers and enabling them to regain dexterity while performing activities of daily living (ADLs). The mechanical characterization of the exoskeleton include determining its weight, joint stiffness and ease of fixation. Functional characterization is through a series of experiments conducted on five subjects to evaluate the performance and effectiveness of the device in accomplishing the requirements for ADLs. The usability of the hand exoskeleton is measured through a customized System Usability Scale (SUS) questionnaire. Finally, a performance metric based on six parameters is used to evaluate the device's wearability. The exoskeleton is compact and lightweight with the wearable part weighing 496 g and can generate a maximum pinch force of 30 N. The exoskeleton can perform five functional grasps: Power, Precision, Cylindrical, Palmar and Lumbrical. The usability test indicates that users can operate the hand exoskeleton with ease. The system was evaluated with individuals without disabilities, achieving a wearability score of 83.3%. Mechanical and functional characterization of the BRAIL hand exoskeleton confirms the potential of the hand exoskeleton as a practical tool for mechanical support and functional rehabilitation.