3-D Modeling And Finite Element Analysis Applying To Ophthalmology And Orthopaedics

In the 21st century, the engineering field of medical imaging methods,computer image processing, 3D modeling, finite element analysis(FEA), andthe medical field of ophthalmology and orthopaedics have been developingvery fast. The task of this paper was to generate geometry models of someorgans from high resolution medical image data, and bring them into FEAsoftware to do some analysis, applying the engineering methods to theapplication of ophthalmology and orthopaedics.In the aspect of 3D modeling, this paper emphasized on the constructionof the whole processing procedure of generating 3D geometry models oforgans based on medical images, including the steps of image acquisition,preprocessing, segmentation, registration and 3D visualization. Wegenerated a model of eyeball-extraocular muscles and a model of proximalfemur, which accorded with their status in vivo, and well expressed theiranatomical characters.In the aspect of FEA, this paper used two softwares - Ansys and Marc tocarry out a series of analysis of eyeball-extraocular muscles model andfemoral model. In the study of visual organs, we got two sets of results.One was the change caused by the eyeball rotation and the other was thechange caused by the contraction of the extraocular muscles. Theycorresponded with the basic theory of ophthalmology. In the study of femur,we exerted different conditions on three models of entire or proximal femurand concluded many rules, which also verified the clinical orthopaedicsknowledge. We used the method of converting the gray value of the imagesto the relative biomaterial data, which made the computational model moreaccurate. We also did some simulations to predict the collapse of thefemoral head. We compared our simulation results with the mechanicalexperiments to show that the calculated results were reasonable, and try tomake them more exact.This paper also settled the problem of interface to combine 3D modelingwith FEA, and studied the 2D shell structure and the modeling of muscles toput forward some advice of using the whole modeling-to-computation methodin more sophisticated and refined situation.In general, this paper established a system of analysis, which combinedcomputer tomography, methods of image processing, 3D reconstruction, CADmodeling and FEA, to discuss the whole process of segmenting originalimages, reconstructing the organs, putting them into FEA software andsimulating their loads and movements according to their normal or abnormalstatus. By the combination of 3D reconstruction and FEA, we provided aspecific method of applying medical image data to the domain ofbiomechanical analysis.