School of Electrical and Information Engineering, The University of Sydney, Sydney, NSW 2006, Australia.
Prog Biophys Mol Biol. 2010 Dec;103(2-3):236-51. doi: 10.1016/j.pbiomolbio.2010.09.011. Epub 2010 Oct 25.
Surgical simulators provide another tool for training and practising surgical procedures, usually restricted to the use of cadavers. Our surgical simulator utilises Finite Element (FE) models based on linear elasticity. It is driven by displacements, as opposed to forces, allowing for realistic simulation of both deformation and haptic response at real-time rates. To achieve demanding computational requirements, the stiffness matrix K, which encompasses the geometrical and physical properties of the object, is precomputed, along with K⁻¹. Common to many surgical procedures is the requirement of cutting tissue. Introducing topology modifications, such as cutting, into these precomputed schemes does however come as a challenge, as the precomputed data needs to be modified, to reflect the new topology. In particular, recomputing K⁻¹ is too costly to be performed during the simulation. Our topology modification method is based upon updating K⁻¹ rather than entirely recomputing the matrix. By integrating condensation, we improve efficiency to allow for interaction with larger models. We can further enhance this by redistributing computational load to improve the system's real-time response. We exemplify our techniques with results from our surgical simulation system.
外科模拟器为训练和练习外科手术提供了另一种工具，通常仅限于使用尸体。我们的外科模拟器使用基于线弹性的有限元 (FE) 模型。它由位移驱动，而不是力，允许以实时速率逼真地模拟变形和触觉响应。为了满足苛刻的计算要求，刚度矩阵 K（包含物体的几何和物理特性）以及 K⁻¹ 被预先计算。许多外科手术都需要切割组织。然而，将拓扑修改（如切割）引入这些预计算方案是一个挑战，因为需要修改预计算数据以反映新的拓扑。特别是，重新计算 K⁻¹ 在模拟过程中太昂贵而无法执行。我们的拓扑修改方法基于更新 K⁻¹ 而不是完全重新计算矩阵。通过集成凝聚，我们提高了效率，允许与更大的模型进行交互。我们可以通过重新分配计算负载来进一步提高系统的实时响应能力。我们用我们的外科模拟系统的结果来说明我们的技术。
