Motion Control And Collision Detection Of Instruments In Visual Arthroscopic Surgery

With the development of computer technology, virtual reality technology gets a large advancement. In medical science field, the suppositional human body being structure by virtual reality technology, and carry out suppositional operation of all kinds on it. This has provided a ideal method for the doctor carries out operation exercise, and we call this method suppositional operation.Virtual surgery system refers to many fields such as Computer Graphics, Digital Image Processing, Computer Vision, Dynamics, Biomechanics, Medicine, etc, it is a challenging subject.Purpose of virtual surgery system is to imitate actual operation process, so require that it must have very high emulation degree. Be then in a circumstances, not only require that the model simulates on outward appearance, but also require that make a user felling like due with the true object when control the motion of the model. While existence more models we have to think about the collision of them. So motion control and collision detection of instruments is quite important in medical VR.In control of model moving, this thesis analyses the principle of 3-D model for moving from graphics, namely use matrix for altering to carry out the alternation of strategic point on the model. According to the characteristic of the alternation, break up motion for two parts, translate motion and revolution motion, suggested a method for realizing the moving of model of surgical equipment in the environment of using OpenGL, and realized 6DOF motion of the model.Now hierarchical bounding volume algorithm is one kind of common algorithms collision detection. The aim of the algorithm is to reduce the number of geometry that need to be checked for contact, and as far as possible changed them into simplicity, using the fewest times of calculation and lowest degree of difficulty to realize the collision detection of two models.In this thesis the hierarchical bounding volume algorithm be composed of specially external bounding boxes and AABB. According to one of surgical equipment, have given out structuring, renewing and algorithm flow of bounding boxes tree. And have explained the intersect checking method of the fundamental geometry (triangle) that compose the model.In the last, this thesis sums up the work in this thesis, and gives out what I should do in the future based on those problems in my work.