Research On The Method For 3D Finite Element Modeling Of Human Stomach

Gastric disease is one of most common gastrointestinal diseases in the world,which threatens human healthy and life badly. Getting the biopsy and pathology studyof gastric mucosa is the most important and effective clinical method to detect,diagnose gastric diseases. When clinicians manipulate the biopsy clamp under theendoscope with their experience, the wall of stomach would be deforming under theirforce. However, if the force is too large, the biopsy clamp would injury normal tissue.Therefore, if doctors could exercise in a gastric surgery simulation system before thereal surgery, this would help. The surgery simulation system is an important andvaluable research task.The stomach model in the surgery simulation system need simulate humanstomach realistically and precisely both in the geometrical and physical characteristics.Not only it is the absolutely similar to human stomach in the geometrical shape, butalso it can deform and react to the outside force. Finite element model (FEM), whichis built based on the accurate organ prototype, is famous for its fine geometric andphysical similarities. As a result, the 3D finite element model of human stomach canbecome a good base to realize the human gastric simulation system.It is just on the threshold of the gastric finite element model research till now, andthere are some default in other soft tissue modeling methods. The aim of thisdissertation is based on the CT images of human stomach, building gastricgeometrical model by automatic or semi-automatic methods, and then building a 3DFEM. The contents in the dissertation are listed below:●The relative academic base knowledge of CT imaging field and finiteelement analyze and model field are introduced firstly. Specially analyze thecharacteristics of gastric CT images.●An overall architecture of human gastric FEM system is established, which isdescribed in two view ports: technological hierarchy and functional modules. And important techniques and toolkits, including the visual toolkit(VTK) andthe insights toolkit(ITK), are introduced.●According to the characteristics of gastric CT images, design and realize aneffective method based on region grow algorithm, which can select and setthe seed point automatically, to segment the serial CT images.●3D surface render gastric geometric model based on marching cubesalgorithm.●The method of triangular mesh smoothing and simplification for gastricsurface is researched and compared. Implemented the Laplacian smoothingalgorithm and QEM simplifying algorithm.●Based on the study of physical characteristics of human stomach, aftertransforming the context data format, make use of ANSYS to model andanalyze the mechanics of the gastric FME.The result of the physical analyse of 3D FEM shows that the model has geometricand physical similarities.