Application Of 3D Printing And Numerical Simulation Technique In Plantar Orthosis

With the continuous maturation of medical technology and 3D printing technology,especially the continuous innovation in the field of medicine and engineering,the protection of the human foot has gradually progressed from the simple and single planar insole to the sole with special functions.In the thesis,we use the powerful advantages of 3D printing technology in the manufacture of personalized and special-shaped structures to produce a plantar orthosis with a honeycomb structure and a fully-fitted arch support structure,the plantar orthosis acts as a cushioning and decompression effect on the human foot at the structural level.Based on the image of the plantar pressure output from the gait analyzer,the features of the image are extracted to obtain the contour edges of the large pressure region,and a contour curve smoothing algorithm based on the curvature feature is proposed to achieve personalized modeling.Combining the current mature honeycomb structure theory and finite element analysis technology,the finite element analysis method based on the minimum structure potential energy is concluded,the design goal of maximizing stiffness is determined,and the honeycomb foot pad is designed through three-dimensional modeling and numerical simulation analysis technology.Because the arch support structure and the full-fit profile have an important role in the decompression of the foot,the arch support structure was introduced into the design of the plantar orthosis.The fully-fitting design based on the honeycomb structure and the arch support structure provides cushioning and provides support.The cushioning and damping function can be achieved with a 3D printed honeycomb foot pad based on TPU material,and the function of providing support can be achieved by a full-fitting plantar pad with the arch support.This article establishes the foot orthosis model design flow with image feature extraction,three-dimensional modeling,numerical simulation,3D printing,and engineering validation.In the dissertation,a three-dimensional printing of a honeycomb foot pad using a fused deposition 3D printer is performed.The material is a flexible TPU material.Three-dimensional printing of a fully-fitted arch support structure using selected area laser sintering(SLS)technology is made of nylon.The experimental results show that,honeycomb structure of the foot pad is easy to produce displacement deformation,and it has strong shock absorption capacity.After engineering mechanics testing,the loadbearing capacity of the foot pad with honeycomb structure loading can reach 96.59%of the original structure.The peak pressure of the plantar cushion under the fully-fitted arch support is significantly lower than the peak pressure of the plantar-type plantar cushion.The decompression effect can reach 18.09% of the original plantar pressure value.