Usability of assistive technology: User interface design guidelines for powered wheelchairs

Abstract

Background The usability of assistive devices indicates the users' level of participation in various roles. Powered wheelchairs allow users with severe disabilities to operate wheelchairs using their remaining functions, because of which, the user interface of a powered wheelchair is as complex and varied as the degree of user disability. However, compared to manual wheelchairs, types of powered wheelchairs that can reflect the needs of individual users are limited. Methods User research was conducted on 15 people with high-level spinal cord injuries. The results of the user research were analyzed using the thematic analysis method. Based on the analysis results, user interface design guidelines were developed to ensure the usability of powered wheelchairs. In addition, these guidelines were verified by five assistive technology and wheelchair experts. Results Thematic analysis resulted in five themes: wheel movements, use controller, component adjustments, sitting posture adjustments, and physical characteristics. User interface design guidelines for powered wheelchair components such as wheels, controllers, power seat functions (PSFs), and armrests are derived according to the various usage characteristics of powered wheelchairs. Conclusions It is expected that products developed based on the guidelines derived from this study will minimize the heterogeneity of development and consumer choice. The results of this study deal only with the initial stages of user interface design (use and user interface design specification). Therefore, further research is needed to address the later stages of user interface design (formative and summative evaluation).