Research On Digital Design,material Optimization And Intelligent Manufacturing Of Rehabilitation Aids Based On 3D Printing Technology

Background:For adults and children with limb paralysis,dysfunction and developmental malformations,rehabilitation aids can help improve dysfunction,correct deformity,and promote comprehensive recovery.However,due to the limitations of design level and manufacturing process,there are many deficiencies in the rehabilitation aids made by traditional methods.For example,fabricating a custom-fit orthosis is a time-consuming and laborious work and cannot completely match the patient.More importantly,it is often bulky and unsightly,and the patient is unwilling to wear it.For children with funnel chest and head deformity,there is no effective traditional rehabilitation aid for treatment.Three-Dimensional Printing(3D printing)is a technology where objects are constructed via a series of sub-millimetre layers of substrate material by the use of hot-melt adhesive materials such as powdered metal or plastic,through the layering process.The biggest advantage of 3D printing technology in the application of rehabilitation aids is the of freedom of molding.Combined with computer digitization technology,we can design complex structures and shapes according to patients' needs.Some studies conducted in research institute demonstrated the feasibility of rehabilitation aids fabrication using 3D printing techniques.However,3D printed rehabilitation aids are inaccessible to many patients due to lack in AFO model design,printing material,printing costs and printing manufacturing processes.Objectives:The purpose of the study was to conduct a study of 3D printed rehabilitation aids(ankle foot orthosis,head deformity helmet,funnell chest vacuum suction cup,stroke upper limb brace).Based on 3D printing technology,the researches focus on digital design,material optimization and manufacturing processes,in order to promote the clinical transformation of 3D printing rehabilitation aids,improve patient function and correct malformations.Methods:Bi-directional evolutionary structural optimization(BESO)technique was employed to remove non-essential materials from the initial design in the study of 3D printed patients specific AFO;Subsequently,the study compared the printing effects of the four printed materials,and further explored the impact of 3D printed AFO on functional recovery of stroke patients.In the study of 3D printed head deformity helmet,funnel chest vacuum suction cups,and stroke upper limb brace,the initial computer model was designed,and the printing effects of different materials were tested.Finally,the 3D printing process was developed.Results:The topologically optimized AFO was successfully designed.The volume of the final optimized AFO has been reduced by 17%from the initial design.The AFOs fabricated by 3D printing Somos NeXt have a significant effect on the improvement of velocity and stride length in patients with stroke.Materials PA2200 and Accura Xtreme are not suitable for clinical applications.The AFO printed by PA 12 can improve the walking function and improve activities of daily living.We successfully completed the design and production process of 3D printed helmet,funnel chest vacuum suction cup and upper limb brace.The testing of difterent materials was completed and the phased results were achieved.Conclusions:This researches have successfully completed the digital design,material selection and manufacturing process of 3D printing rehabilitation aids in China.Future researches will focus on material selection and systematic clinical research.