This study explored issues encountered when developing an assistive device for cerebral palsy children and applied the HAAT model for assistive device development to assess assistive device requirements from people, activities, and contexts. The assessment results were incorporated into the assistive device design. There were two main stages in this study. The first stage is the design and development of an assistive device for cerebral palsy children. The second stage is the expert evaluation, in which three designers and special education teachers specializing in assistive device development were invited to provide user feedback. The design parameters acquired from this study are useful for special education teachers for assistive devices and families of children with cerebral palsy. The study results can also be referred to for designing special education assistive devices in the future.