交互式基于点的外科手术软组织变形仿真

Interactive Point based Method for Soft Tissue Deformation in Surgical Simulation

近年来,手术仿真领域中交互式生物力学仿真技术取得了显著的进步,但仍存在一些问题亟需解决。例如,大形变情况下的软组织形变模型,碰撞检测以及体积守恒等。因此提出了一种简单有效的计算框架来解决这些问题。为了更好地在计算机上重现人体器官的力学性质,采用基于点的方法来模拟大变形下的弹性固体,并且通过引入基于位置的方法模拟手术场景中复杂交互,摩擦过程和体积守恒,较大程度的提高了虚拟手术场景中复杂交互的实时性及稳定性。该方法经过多种基准问题的验证,实验结果表明该计算框架在视觉效果以及稳定性方面的有效性。此外,该变形计算模型可较好的扩展应用于交互式穿刺和剪切仿真中。

Although recent years have witnessed great improvement in the research of biomechanical simulation with user interactions for surgical simulation, it still suffers from many challenges such as computational model of soft tissue undergoing large deformation, collision detection, volume conservation, etc. A simple and efficient framework was proposed to meet these challenges. To well reproduce the mechanical response of organs, point based method was used to model the elastic solids undergoing large deformations. In addition, position based dynamics was adopted to model the objects collision, friction and volume conservation, which considerably improved the real-time performance and stability of complex interactions in surgical simulation. The method was validated in several benchmark problems. Experiments results demonstrate the effectiveness of the framework in terms of both visual effects and stability. In addition, the computational model for deformation has a great potential to be extended to interactive biopsy and cutting simulation.