计算机辅助活体足建模生物力学方法研究

随着计算机断层(CT,computed tomography)和MRI(nuclear magnetic resonance imaging)技术的发展,困扰着活体足建模的问题得到了解决,特别是DICOM(digital imaging and communications in medicine)标准的建立为计算机辅助足生物力学的研究开辟了一条新的途径。探讨了一种集CT扫描技术、Mimics(Materiaise’s interactive medical imagecontrol system)和ANSYS软件为一体的活体足研究的生物力学方法。利用PHILIPS 64排螺旋CT扫描仪获得了足部骨组织的DICOM图像;在工作站上用三维重建软件Mimics分别对足部骨、皮肤等建模,利用Mimics的逆向工程模块对模型去噪、平滑处理和点云运算,之后进行模型面网格的划分;在ANSYS中建立约束、加载载荷并求解,从而实现足的生物力学研究。CT扫描的足部断层图像通过Mimics能够实现对足的外型和骨的三维重建,在逆向工程软件中可以实现模型的体网格划分,用ANSYS实现有限元分析。根据运动中足的动力学规律(如通过压力分布测量平台),能够实现足的表面和骨的动力学和应力应变的计算机仿真研究,为运动损伤或运动鞋的评价等提供了依据。

Computer-assisted biomechanical method to the foot

The development of CT and MRI technologies has helped resolve the problem of setting up a model for the in vivo foot.The approval of DICOM standards has pioneered a new method to do the computer-assisted foot biomechanical research.The scanning techniques of CT,MRI,and gait analysis are studied by pressure distribution measuring platform and Mimics and ANSYS software. The foot three-dimensional data are obtained by a three-dimensional laser scanner,and a foot bone tissue DICOM is generated by a Philips 64-channel CT scanner.The foot fattiness and lean tissue DICOM is obtained by GE 1.5T MRI Scanner.At the workstation,a three-dimensional remodel software,Mimics,is employed to model the bone,lean tissue and fattiness of the foot.The function of reverse engineering of Mimics can operate the denoising,smoothening,and scattered point cloud data and the planetary mesh can be distributed.Models can be assembled,rigid body can be defined and restraint can be established by ANSYS.The volume mesh is distributed to the models according to various tissue intensities,modulus of elasticity,and Poisson's ratio.The human body motion data taken from the gait analysis of pressure distribution measuring platform test can be exercised to define the boundaries,load,and work out the solution——a study by a foot biomechanical method. The Mimics software has been employed to study the foot tomographic image scanned by CT/MRI to remodel three-dimensional models of the shape,fattiness,lean tissue and bone.The reverse engineering software can distribute the volume mesh of the models and the meshed model can be processed with finite element analysis in ANSYS.According to the foot dynamical laws(e.g.by the pressure distribution measuring platform),the computer simulation research can be carried out to the foot surface and the bone dynamics and the stress strain,which can be applied to the evaluation of motion injuries or sports shoes.