The Research Of Cornea Modeling And Thchnology Of Real-time Interactive Virtual Surgery

With the rapid development of computer technology in recent years,at the end of the 20th century appeared a new technology-the Virtual Reality technology,(Virtual Reality,VR),and the technology is widely used in industrial,medical,entertainment and education,and other fields,among them,in the field of medicine is an important application of Virtual surgery simulation system.Cornea in virtual surgery simulation virtual surgery is a more subtle,so it's necessary to preoperative training of surgeons,cornea virtual surgery simulation system at home and abroad research is less.Cornea,the author of this paper the application requirements of virtual surgery simulation system,focus on the following research.A corneal hybrid deformation model is put forward and deformation calculation method based on the point,the model by the surface of the cornea internal particle model and boundary nodes grid model,based on location of dynamics method to calculate the particle displacement,thus solving the corneal deformation.In order to guarantee the stability of the deformation in the model to join the volume constraint.When virtual surgery tool touch deformation object,calculate the size of the contact force,MLS method is used to calculate each particle displacement gradient,finally according to the geometric mapping relationship between node with the internal particle surface and the surface deformation.The experimental results show that the model not only can well simulate the corneal deformation,and has a good stability under large deformation,does not produce distortion.Design implements a bounding box collision detection method,simplifies the process of collision detection,can quickly find the collision point,calculation model of deformation,accelerate the speed of collision detection.Deformation object to set up a level of binary tree to ensure that the triangles in at least one in each box,traversing the bounding box tree,read the bounding box of the triangles in the information to determine whether the rest the another and surgical tools are at the top of the intersection.The experimental results show that the collision method can quickly calculate the surgical tools and deformation collision intersection point of the object,through the method to realize the force feedback device and corneal model between the real-time interaction.Puts forward an improved cutting simulation algorithm based on vertex copy method,according to the operation in the process of cutting tool movement direction of new node form incision,in order to make more smooth incision in real-time subdividing triangles in cutting process,increasing the number of triangles in the slit.Experimental results show that using this method can generate more smooth,vivid incision,a further sign of hybrid model has good stability and scalability,in the process of deformation can maintain the authenticity of the model.