Research On Electrotomy Scene In Virtual Surgery Simulation System

Virtual surgery simulation technology can be used for surgery training of junior doctors to avoid mistakes in actual surgery.However,most researchers study virtual surgical systems for traditional surgical procedures,and few people study virtual surgical systems for emerging surgical procedures such as electrotomy.This paper solves some problems in the existing virtual surgery simulation,such as(1)model hole problem;(2)heavy burden of calculation for surgical smoke simulation;(3)Vortex particle smoke is difficult to impose collision boundary conditions;(4)Smoke and virtual surgery system are difficult to combine.This paper developed a virtual surgical system for electrotomy,including cleavage of lung tissue and electrocoagulation of tumor tissue.It solves the problems of virtual surgical electrotomy scene simulation,improves the realism of electrotomy operation simulation,and provides a modern virtual surgical training platform for junior doctors.Firstly,aiming at the problem of holes in the three-dimensional point cloud model of lung tissue reconstructed by CT images and Mimics software,a hole filling algorithm was designed to reconstruct a complete and realistic lung tissue model.The boundary of large holes is obtained by octree collision detection algorithm.The spherical mapping algorithm is used to convert the rectangular coordinates of the boundary points to the spherical coordinates,so as to interpolate a new point set for the large hole area.Compared with the traditional linear interpolation method,the filled area has radian,which can better restore the soft tissue structure.The point cloud augmentation rendering algorithm is used to fill the small holes in the model,and the octree nearest neighbor search method was used to determine the appropriate amplification multiple to fill the small holes.The results showed that the structure of the lung tissue model after the hole filling was complete and the visual effect was realistic,which laid the foundation for the subsequent operation.Secondly,aiming at the heavy computational burden of the traditional vortex particle method for simulating surgical smoke,Vortex Particles in Cube algorithm is proposed.This method can not only better show the vortex details of the smoke rising,but also effectively reduce the computational burden,which was suitable for the realtime simulation system of virtual surgery.Cube grids is used to surround all vortex particles,and the speed and position of vortex particles are updated with the help of volume decentralization and Helmholtz decomposition method.Comparing the Vortex Particles in Cube algorithm with the traditional Biot-Savart integration method,the Vortex Particles in Cube algorithm reduces the time complexity from O(N2)to O(N)+O(M log2 M),especially when the number of vortex particles is large,the calculation loss is reduced more obviously.Thirdly,aiming at the problem that it is difficult to obtain the normal vector information of the collision surface when the vortex particles collide with irregular surface,the auxiliary particles method is proposed to transmit the normal vector and position information of the collision surface to the collision vortex particles to help the collision vortex particles update the position and vorticity in time according to different information.Experiments show that the auxiliary particle method can make the smoke simulated by vortex particles meet the impermeable and non-slip boundary condition during the collision,which effectively solves the vortex particle collision problem.Finally,a virtual surgical platform for electrotomy was built.In this paper,the soft tissue after filling the hole and surgical smoke were incorporated into the system.The experimental results show that the electrotomy virtual surgery system developed in this subject can effectively complete the electrotomy operation with realistic visual effects.