Personalized human factor and ergonomics: Usability design of 3D printed patient-specific fracture external fixator

External fixation is an old and well-established method widely used in the treatment of skeletal muscle trauma or fractures. By taking the advantages of 3D printing, we have designed a patient-specific 3D printed fracture external fixator and fabricated successfully with the automatic reduction function and successful applied in the clinic. The fixator had the advantages of accurate reduction, minimally invasion, easy manipulation, aesthetical, and experience-independence. This paper thinks fundamentally to the potential improvement in function, usability and user experience of connected health systems of the personalized external fixation. Through the summarize and analyze of usability in external fixator, compared with traditional usability principles we conducted necessary evaluations and items relate to the design and usability of customized medical devices, efficacy evaluation in satisfying surgical requirements by experts and summative evaluation for user experience by patients. Framework of the technology-pushed medical additive manufacture personalization was established. Meanwhile, usability design process of the customized product enabled by 3D printing was analyzed. In addition, combined with the principle of design for additive manufacture and application, taking patient-specific external fixator design as an example, this paper also analyzed and summarized the patient-specific design process which initializes design from the perspective of functionality achievement of patient specific customized human factor and ergonomics such as safety and effective. Specifically, this study provides a theoretical support for the improvement and design of patient-specific 3D printed products, combing theory and practice. Simultaneously, it provides suggestions for the future customized medical devices.