Abstract
Soft tissue warping is one of the key technologies in dynamic simulation of many surgical procedures, such as image-guided surgery, surgical navigation and structural/lesion localization. Previously, we proposed a force asynchronous diffusion model (FADM) for soft tissue warping simulation. The FADM works well if a lesion or an anatomical object has a convex shape. However, in some cases, this convex assumption is invalid. In order to remove this significant limitation, this paper presents an energy-based free boundary asynchronous diffusion model (EBFBADM) with three unique features. First, we utilize hexahedral voxels to represent the physical model of the surface triangular mesh and a regional proliferation algorithm to remove invalid voxels, simplify computation and improve realness in warping simulation. Second, we adopt the concept of free boundary to simulate soft tissue geometric characteristics more precisely during the warping process. Finally, we optimize the process of asynchronous diffusion by using the mechanical energy of mass point to achieve realistic soft tissue warping effects. Experimental results have shown that the EBFBADM improves performance in both computation and realness in surgical simulation.
Acknowledgements
This work was supported by a grant from the National Basic Research Programme of China (Grant No. 2011CB707904), grants from the National Natural Science Foundation of China (No.61272276 and No.61190125) and a grant from the open funding project of State Key Laboratory of Virtual Technology and Systems, Beihang University (Grant No. BUAA-VR-13KF-15).