Model Representation And Cutting Simulation Of Virtual Cruciate Ligament Surgery

Virtual surgery simulation system is the combination of modern medical operation and virtual reality. The virtual surgery simulation system ask for high technology in the aspect of real-time, stability, precision and skills about3D visualization of medical digital images.Cruciate ligament is the most important organizational structure to keep the normal motion of knee, as it provide knee with energy stability. Cruciate ligament injury is the a common damage compared with other knee injuries, the mar is usually treated by doctor with arthroscopic surgery, but arthroscopic surgery must be operated with high hand-eye coordination ability that can’t be predominated easily by surgeon. This paper give analysis of physical properties for cruciate ligament, study the basic operations of cruciate ligament surgery and build a virtual cruciate ligament cutting simulation arthroscopic surgery with emphasis on visual and tactile.Related work of this paper is as follows:(1)3D reconstruction of soft tissue anterior cruciate ligament based on medical digital images. This article studies2D medical image sequences against low accuracy and poor fidelity of virtual model in traditional surgical simulation system. Analysis the raw CT data extracted from patient, remove the noise of raw data and then process CT images with the help of open source software tool VTK. Carry out3D reconstruction of soft tissue for higher accuracy of geometric model. Study the physical properties of cruciate ligament to provide foundation for the creation of physical model.(2) The study of soft tissue cutting algorithm. Give analysis of cutting algorithm of soft tissue combined with virtual surgery simulation system’s requirements of real-time. Firstly, create visual model, collision model and physical model for cruciate ligament model to improve computational efficiency. Implement multi-model expression for soft tissue to realize the synchronous of different models. Define the topology and topology updating algorithms and use tetrahedron removal method for the simulation of cutting, taking the stability of virtual surgical system into account.(3) Give analysis of tactile feedback in virtual surgery. Study the tactile feedback process of anterior cruciate ligament surgery. Classify express feedback force generated in the course of surgical operation into surface force and friction force, creating physical model respectively for each of them. Calculate the size of the force of the two kinds of force respectively.(4) Exploitation of the surgical system. Design functional framework for the cruciate ligament system with the tool of open source software SOFA which mostly used to do the work of medical simulation. This system achieved the goal of surgical simulation, evaluation of surgical operation and knowledge learning.