Parametric Design And Customization Of Ankle-foot Orthosis For Patients With Hemiplegia

Ankle-foot Orthosis(AFO)is an important tool to correct abnormal gait and improve the walking ability of hemiplegia patients.Its application in clinical treatment played an important role in restoring patients' independent living ability.However,the investigation found that the existing AFO products had poor wearing comfort,low customization efficiency and complicated process,which affected the treatment and rehabilitation of patients.Therefore,improving the wearing comfort and customization efficiency of AFO products has become the research focus and purpose of the subject.3D scanning technology is fast,accurate and convenient in data acquisition,and its application in the field of medicine has gradually received attention at home and abroad.In this paper,an innovative design scheme was proposed to provide accurate data acquisition and measurement for patient customization by using 3D scanning,and applied it to AFO digital modeling.The main contents of the study were as follows:Firstly,a scanning method that suitable for collecting data of a patient's foot and lower leg was proposed,and created a scanning bracket consisting of a stainless steel frame and a transparent glass panel,the complete point cloud data for the patient's foot and lower leg was quickly and accurately captured by using a hand-held scanner in a prescriptive scanning sequence.Then,the collected point cloud data was processed and optimized by using Geomagic Studio reverse engineering software.Based on the digital model of foot and lower leg that generated by point cloud data fitting,two kinds of AFO customization design schemes were proposed by using parametric design,surface reconstruction and Rhinoceros software modeling.Finally,the AFO physical model was made by 3D printing and provided to patients for trial wearing.According to the feedback information of patients,fuzzy evaluation method was used to comprehensively evaluate the design scheme.The results proved that the customized design scheme of AFO based on parametric modeling had better customization efficiency and patients' satisfaction with wearing.In this study,reverse engineering and Grasshopper parametric modeling were applied to AFO design to achieve rapid and accurate customization of AFO products and improved patient wearing comfort.The AFO parametric modeling program was easy for physicians to use without CAD software experience,providing a better solution for ergonomic orthotic design.