A Health Belief Model- and TRIZ-Based Design Method for Transfer Assistive Equipment for Individuals with Lower-Limb Mobility Impairment

Individuals with lower-limb mobility impairment often experience fear of falling and difficulty coordinating with caregivers during transfer tasks. Therefore, safe, stable, and easy-to-operate collaborative transfer assistive equipment is urgently needed. This study proposes a Health Belief Model-driven design method for transfer assistive equipment, aiming to translate users’ risk perceptions and behavioral needs into implementable structural design strategies. First, transfer-related behavioral characteristics were analyzed according to the six constructs of the Health Belief Model. Second, the KJ method was used to classify original user requirements and establish a hierarchical requirement model, while the Fuzzy Analytic Hierarchy Process was applied to calculate requirement weights. Third, Quality Function Deployment and the House of Quality were used to transform user requirements into technical characteristics, through which four key technical contradictions were identified: anti-tipping stability versus lightweight design, status feedback versus process simplification, assistance and effort reduction versus lightweight design, and support-bearing capacity versus human–machine adaptability. Finally, structural optimization strategies were generated using TRIZ, and the proposed concept was preliminarily assessed through JACK digital human simulation and multi-stakeholder assessment at the conceptual design stage. The multi-stakeholder assessment further indicated that the proposed concept responded to requirements related to fall risk mitigation, injury protection, and perceived benefits, while adaptability for small-sized users, distal lower-limb support, and status-feedback mechanisms require further optimization. This study provides a traceable design process for incorporating users’ psychological and behavioral factors into structural innovation for assistive devices, thereby offering a methodological reference for the design of transfer assistive equipment.