Virtual Systems For Laryngeal Surgery With Laryngoscope

Virtual surgery system is an application of virtual reality in modern medicine technology. The object of virtual surgery simulation system research and development is to provide a reusable environment for surgery training, planning, rehearsal and protection in operation. Based on laryngeal surgery with laryngoscope, a virtual surgery system is established and it can realize the simulation of vocal cord tumor cutting with force feedback.Firstly, the virtual surgery system is established. It can be divided into the hardware parts and the software. The hardware is composed of a haptic device named PHANToM, a computer and a display device, and the haptic interface is set up by Visual C++ and GHOST SDK.Secondly, for geometrical modeling, a three-dimensional model of main tissue such as vocal of throat is set up using 3D reconstruct from CT segments. The three-dimensional model is made by a set of 2D contour which is created after filtering and amplification of CT slices. The geometric model of vocal cord and its tumor is built by blocking partition because of the requirement of real-time. In the aspect of physical modeling, through analysis of biomechanics property of soft tissue and different physical models, we apply the mass-spring-damp model of vocal cord deformation in surgery simulation. The deformation of a cube composed with triangular mesh demonstrates the model is correct.In the end, the simulation of vocal cord tumor cutting is realized by program. Actual soft tissue deformation of vocal cord is obtained when cutting tumor from it and simultaneously the manipulator can feel the interactive force. The force of vocal cord composed of triangle mesh and the collision detect of this process are considered. Adopted virtual force potential field, an experiment of cutting a part of vocal cord in a swine was done successfully.