User-Centered and Analytic-Based Approaches to Generate Usable Gestures for Individuals With Quadriplegia

Hand gesture-based interfaces have become increasingly popular as a form to interact with computing devices. Unfortunately, standard gesture interfaces are not very usable by individuals with upper limb motor impairments, including quadriplegics due to spinal cord injury (SCI). The objective of this paper is to convert an existing interface to be usable by users with motor impairments. The key idea is to project existing patterns of gestural behavior to match those exhibited by users with quadriplegia due to common cervical SCIs. Two complementary approaches (a user-centered and an analytic approach) have been developed and validated to provide both subjective and quantitative solutions to interface design. The feasibility of the proposed methodology was validated through user-based experimental paradigms. Through this study, subjects with upper extremity motor impairments preferred (gave a significantly lower Borg scale) the use of alternative constrained gestures generated by the proposed approach rather than the standard gestures.