Bleeding simulation with stepless adaptive particles for surgical simulation systems.

Background And Objectives: In virtual surgery, the resolution of bleeding surface has a significant impact on the realism. The computational complexity of internal particles reduces real-time performance, which has no obvious contribution to the visual effect of simulation. This paper focuses on the study of bleeding simulation in virtual surgery to improve the visual realism while meeting real-time performance and physical properties. An innovative adaptive-particle-based algorithm is proposed, which combines the repulsive force and the biomechanical properties, to achieve both realistic and computational efficiency in bleeding simulation.

Methods: This paper integrates three modules based on Lagrangian particle method to achieve high fidelity real-time bleeding simulation in virtual surgery. Stepless adaptive particle algorithm is proposed to change the mass (radius) based on the proportion of particle positions between the bleeding surface and the soft tissue, which improves the resolution of bleeding surface and reduces the computational complexity of internal particles. The particle repulsion is introduced to avoid volume distortion caused by permeation of adaptive particles during collision, meeting the requirement of mass conservation. The biomechanics of bleeding particles are explored through the improved smoothed particle hydrodynamics (SPH) algorithm solving the Navier-Stokes (N-S) equation to improve the realism of physical properties.

Results And Conclusions: Compared to traditional simulation, the method proposed in this paper performs smoother bleeding surface, especially when topological changes occur during suction operation. Through particle tracking curves, it is possible to visually read the stepless variations of particle radius with position in different regions. Bleeding simulation is suitable for the bleeding effect of various types of wounds, which is well applied in virtual surgical scenes.