Research Of Heterogeneous Femoral 3d Reconstruction And Biomechanical Finite Element Analysis

Femur is the important support structure of human body, Femur damage and necrosis are dreaddisease of human, so the mechanical property and replacement technology of femur are hotspots ofbone study. Traditional femoral replacement technology can replace the damaged femur, but itsclinical application still have some problems such as immune rejection, replacement fall off andindividual difference. As the Tissue engineering gradually developing, it brings new theory andtechnique for the tissue repair and replace. Fabrication tissue engineering scaffold to repair andreplace bone tissue becomes a new methods for bone defect. In this study, we used computer aiddesign (CAD), finite element analysis and Low-temperature deposition manufacturing (LDM) tofabricate tissue scaffolds for individual femur repair.Firstly, we studied the advantages and disadvantages of Direct Modeling, Points Modeling,Tissue slicing Modeling and Modeling based on Medical Images. Finally, we chose Modeling basedon Medical Images technology for the 3D femur modeling. By the CT scan, we got normal humanfemoral DICOM images. Then, we used Mimics (for 3d reconstruction) to separate pelvis, patellaand femur. Finally, we got the human body femoral CAD model. Based on this model, weoptimized model grid, provided a femoral model that macroscopic structure and internal structuresimilar with real femoral for the later finite element analysis.Secondly, we used finite element analysis technology for biomechanical simulation analysisand chose solid10node92 units for body grid, because of the heterogeneity of femoral material; wetook gray divided method and used material function of Mimics10.0 FEA module for materialassignment. Then we simulated the results of normal human under different loads, we fixed thefemoral ends and applied the vertical load in the direction of femoral head, Results showed femoralfracture ranges and heterogeneous fabrication parameters.Finally, follow the 3D femoral model research, we used the low temperature depositionmanufacturing to fabricate scaffold for femur. By controlling the scanning density and scanningdirection, we got different parameters of femoral scaffold, then we evaluated the porosity of femoralscaffold, and the results met the porosity requirements of bone tissue engineering. In addition, weevaluated the mechanical properties of femoral scaffold, and the results are consistent withbiomechanical simulation analysis results. Finally based on the finite element analysis results, wedesigned and fabricated different knitting density for femoral fracture parts and got theheterogeneous femoral scaffold.