Design and development of a customized 3D-printed assistive device using modular 3D blocks.

Purpose: 3D printing enables the production of customizable, cost-effective, and reproducible items, making it a promising approach for manufacturing assistive devices. This study aims to develop customized 3D-printed assistive devices using 3D blocks.

Methods: A 3D scanner was used to scan the limbs and trunks where the devices would be worn. The study utilized 3D blocks capable of undergoing subdivision surfaces to match the scanned external appearance of limbs and trunks. The mass-spring model and Gauss-Newton method were applied to optimize the subdivision surfaces, ensuring a better fit for users' hand shapes. Additionally, 3D blocks were used as design units for blending-based morphing, generating diverse 3D patterns.

Results: The proposed approach successfully enabled real-time manufacturing of customized external appearances for assistive devices. The resulting designs met usability, functionality, and aesthetic requirements. Usability testing, conducted using the Quebec User Evaluation of Satisfaction with Assistive Technology, demonstrated high satisfaction scores, confirming the effectiveness of 3D blocks in customizing assistive devices.

Conclusions: By integrating 3D scanning and printing technologies, this study highlights the feasibility of using reverse engineering to develop personalized assistive devices. The findings suggest that the proposed method enhances user satisfaction and provides a practical approach to assistive device customization.