1 Department of Individualized Program, Concordia University, Montreal, Canada.
2 Design Department, Ontario College of Art & Design University, Toronto, Canada.

Purpose: Wheelchairs should support not only safe and intuitive navigation but also positive social presence without reinforcing disability-related stereotypes. This study introduces a user-centred external communication framework (ECF) to guide the design of wheelchair external human-machine interfaces and their perceptual dimensions.Materials and methods: A two-phase mixed-methods approach was employed. In phase 1, focus groups with wheelchair users (WUs) and domain experts identified four key themes through thematic analysis. In phase 2, WUs evaluated multiple wheelchair designs, and their socio-emotional responses were analysed using principal component (PC) analysis.Results: In developing the ECF, phase 1 identified four themes - Streamlined Information in Interaction; User-Centric Safety Feedback; Harmonious & Minimalist Interaction Design; and Effortless Integration & Production - which form the foundational layer addressing functional and interactional requirements. In phase 2, PCs were positioned as second-layer perceptual elements, with the first three explaining over 70% of the variance. Manual wheelchairs were associated with Safety, Stability and Comfort, whereas powered designs emphasised Independence, Trustworthiness and Futuristic design; Communicative and Stylish qualities were valued across both.Conclusion: Although not mechanically functional, these PCs exert a circular influence by shaping user perceptions before interaction. Applying the ECF in wheelchair development can potentially improve wheelchair acceptance, sustained use and social presence.