Research On Parametric Three-Dimensional Reverse Engineering Modeling For Ankle-Foot Orthosis Design For Hemiplegia

Sports-related hemiplegia is commonly present in stroke patients.Ankle joint deformity causing gait dysfunction is more frequently observed clinically.Research has shown that early intervention with rehabilitative therapy is necessary when foot drop and foot inversion occur in hemiplegic patients.An ankle-foot orthosis(AFO)is one of the treatment options for improving foot deformities in patients.Currently,thermoplastic manufacturing is the primary method used for AFO production,but it has drawbacks such as poor molding precision and low material utilization.This method fails to meet the individual needs and comfort of patients.The introduction of 3D printing technology into the field of medical rehabilitation offers the potential for optimizing AFOs.However,its clinical adoption is limited mainly because rehabilitation physicians generally lack specialized training in this area,rendering them unable to perform the necessary tasks.Therefore,leveraging digital technology to optimize the design methods and production processes,reducing the learning curve,improving the efficiency of AFO fabrication,and addressing the design and development challenges of clinically 3D printing AFOs is the focus of this research project.The parametric design of the product primarily aims to improve design efficiency,quality,and cost reduction,and its feasibility has been proven in various orthotic products,although there is limited research on AFOs used for hemiplegia.Therefore,this research proposes a customized approach based on three-dimensional reverse modeling to obtain accurate patient data and develop a parametric design platform for AFOs based on that data.The goal is to overcome the clinical design bottlenecks of existing AFOs and assist orthotists in achieving efficient modeling and AFO fabrication.The research involves the development of a transparent support frame that facilitates foot scanning,utilizing a handheld scanner(SENSE)to acquire point cloud data of the patient’s foot and leg.The data is processed and optimized using Geomagic Studio reverse modeling software.A digital design program for AFOs,developed with Grasshopper plugin,is inputted to generate customized AFO models with simple parameter adjustments.Physical prototypes are then produced through 3D printing.Finally,cushioning pads and fastening straps are added according to user needs to complete the product fabrication.The research includes efficiency testing of the parametric design platform,a comparison between parametric and traditional thermoplastic AFO digital models and patient foot models,analysis of matching deviations,and testing of multi-point pressure distribution of the AFOs.The results validate that parametric reverse modeling of AFOs can achieve low-cost and efficient customization in clinical settings.The research outcomes have practical significance in promoting the application of digital design and manufacturing in clinical settings,providing a research pathway and reference for the use of 3D printing technology in the field of medical rehabilitation.