基于CT人眶骨三维有限元模型的建立

Establishment of three-dimensional finite element model of human orbital bone based on CT

目的根据逆向工程的原理以及有限元方法,探索利用人头颅CT图像数据,建立人眼眶骨的三维有限元模型的方法。方法利用CT对健康人头颅进行扫描,得到颅骨组织的断层图像资料,保存为DICOM标准文件格式后,利用Mimics软件自动处理并结合人工描绘将数据进行处理,建立单侧人眼眶骨的三维数字模型,然后导入逆向工程软件Geomagic Studio对Mimics生成的模型进一步处理,包括光顺、打磨、生成曲面等操作,在UG软件中对曲面重建实体模型,最后应用Hypermesh和ANSYS软件对几何模型进行有限元网格划分和材料赋值,最终生成人眼眶三维有限元模型,并检验其准确性。结果成功建立了由10000个单元和2885个节点组成的右侧人眶骨三维有限元模型。结论利用螺旋CT技术并联合使用Mimics软件,逆向工程与有限元软件构建的眼眶三维有限元模型,忠实于人体解剖数据,有较高的准确性,能够满足眼眶骨折生物力学分析的需要,为进一步进行眼眶骨折有限元分析研究提供了有效的而快速的建模平台。

Objective To establish a three dimensional（3D） finite element model of human orbital bone based on the method of the reverse engineering and medical images of CT. Methods The image data of cranium in sagittal, coronary and transverse plane were obtained by the CT scan of a healthy subject. The data were saved in standard DICOM format and output into Mimics software. 3D digital model of human orbital bone was established, with the automatic and manual function in Mimics in a personal computer. Based on the reverse engineering method, the model established in Mimics was further modified with Geomagic Studio, including smoothing ,polishing, creating surface,and so on. Then,the 3D geometric model was transported to UG to set up entity model. Finally, the processed model was input to and meshed by Hypermesh, and the 3D finite element model of human orbit bone was constructed in ANSYS, and verified by measurement. Results A 3D finite element model of an unilateral orbit bone was successful constructed with 10 000 units and 2 885 nodes. Conclusion Based on the cranium image data by spiral CT scanning, with the combination of Mimics software, reverse engineering software and finite element analysis software ,the 3D finite element model which is very close to the real anatomical structures of human orbital bone can be established, with great similarity in biomechanical response to real object. The newly completed model could be used for further finite element analysis and may provide effective platform for biomechanical research of orbital fractures.