Study On The Simulation For Cauterization Smoke Based On Hybrid Vortex Model In Virtual Surgery

Virtual surgery simulation system is an important application of virtual reality technology used in medicine,virtual surgery system provides doctors with three-dimensional display of virtual environment,as well as the interactive operation platform,these can vivid simulate the whole process of clinical surgery.Minimally invasive surgery due to the advantages of little injury and pain,rapid recovery,developing rapidly in recent years,the matching electric surgical equipment(ESU),laser and other electric tools in the application of the surgery is becoming more common.These surgeries equipment achieved cut tissue,blood coagulation,wound healing,and other functions by burn tissue and destroy these structure.In the process of these by-products-smoke will greatly affect the operation of doctors,influence the accuracy of the operation.So realize the simulation of surgery cauterization smoke in virtual surgery simulation system is self-evident to guide the teaching of clinical surgery.This paper revolves around smoke in virtual surgery simulation and in order to improve the cauterization smoke simulation authenticity and real-time performance and the mainly work as follows:Firstly,study surgery physical and chemical properties of cauterization smoke,through to the specific method of simulate cauterization smoke of comprehensive analysis in computer graphics,combination of cauterization smoke fluid dynamics characteristics,in order to improve reality of cauterization smoke simulation we determine to use vortex particle method.Starting with the vortex field,discrete the vortex filed as vortex particles,and then based on Biot-Savart Law to process vortex filed and get the velocity filed,thus the cauterization smoke simulation is come true.Compared with the traditional particle system model the smoke reality is greatly improved,compared with Euler view method the numerical dissipation of this method is tiny and the stability is very well.Secondly,in order to improve the real-time performance of the simulation,join in the vortex particle model of nested grid to speed up the calculation,treated a particle cluster as a single particle,reduce the overall number of the vortex particles in the numerical calculation,improved the computation speed of cauterization smoke simulation numerical calculation.Adding ordinary particles as tracer in the particle model,through the velocity grid interpolation initialize ordinary particles properties,under the condition of little sacrifice of calculation increases the cauterization smoke rendering authenticity.Furthermore,to improve the shortcomings of vortex particle model method in respects of vortex surface and turbulence effect,using vortex filament model discrete vortex field,based on uniform grid build a hybrid model of vortex filament and vortex particle.This model using vortex filament model at the early stage of the simulation to sirmulate the cauterization smoke,via Biot-Savart Law we can get self-induced velocity of vortex filament and the velocity field induced by vortex filament,at the same time,through the vortex filament self-induced velocity and other vortex filament induction control the movement of vortex filament.Based on kelvin law,vortex filament stretching and the vortex increase,when the vortex filament stretch after reaching the threshold,using the particle model of vortex continues to the cauterization smoke simulation,thus avoiding the instability caused by the vortex filament stretch without limit.Through this model the simulation of cauterization smoke vortex surface and turbulence effects are well kept,the stability of the whole simulation model is improved.Finally,based on the MFC build the simulation system of cauterization smoke in virtual surgery,through the experimental analysis shows that cauterization smoke simulation method based on hybrid vortex model better in the realistic field,smoke simulation model is stable,meet the real-time requirements,the reality and immersive of virtual surgery system is improved,realistic simulation of cauterization smoke enhanced the accuracy of the operation training and improved the training effect of virtual surgery system.