Volumetric Visualization Techniques of Rigid and Deformable Models for Surgery Simulation.

Abstract

Virtual reality computer simulation is nowadays widely used in various fields, such as aviation, military or medicine. However, the current simulators do not completely fulfil the necessary requirements for some fields. For example, in medicine many requirements have to be met in order to allow a really meaningful simulation. However most current medical simulators do not adequately meet them, reducing the usability of these simulators for certain aspects. One of these requirements is the visualization, which in the case of medicine has to deal with unusual data sets, i.e. volume datasets. Additionally, training simulation for medicine needs to calculate and visualize the physical deformations of tissue which adds an additional challenge to the visualization in these type of simulators. In order to overcome this limitations, a prototype of a patient specific neurosurgery simulator has been developed. This simulator features a fully volumetric visualization of patient data, physical interaction with the models through the use of haptic devices and realistic physical simulation for the tissues. This thesis presents a study about the visualization methods necessary to achieve high quality visualization in such simulator. The different possibilities for rigid volumetric visualization have been studied. As a result, improvements on the current volumetric visualization frameworks have been done. Additionally, the use of direct volumetric isosurfaces for certain cases have been studied. The resulting visualization scheme has been demonstrated by an intermediate craniotomy simulator. Furthermore, the use of deformable volumetric models has been studied. The necessary algorithms for this type of visualization have been developed and the different rendering options have been experimentally studied. This study gives the necessary information to make informed decisions about the visualization in the neurosurgery simulator prototype.