CAREER: Accelerated simulation of nonlinear solids with applications to human anatomy modeling in interactive virtual environments

人体解剖学的数字模型，已经是电影和电脑游戏的常见元素，现在正越来越多地被纳入各种“严肃”的应用，如医疗诊断，手术规划和车辆设计。 当前和新兴的应用都需要改进的照片真实感、增强的生物力学准确性、更好的对象特异性和更快的模拟算法。 由于这些需求往往超过计算机硬件的发展，因此需要新的生物力学建模和仿真算法，以确保即将到来的计算平台能够最大限度地利用它们的能力。在交互式应用中的虚拟材料的基于物理的模拟已经证明，与大的，在HPC设置中对类似现象进行规模模拟。 这部分归因于与大型模型相关的规则性和规模经济，而在较低分辨率下则存在明显的不规则性和异质性。 但这也是由于交互式虚拟材料的常用算法和数据结构反映了在功能，准确性和并行化潜力方面的设计妥协。 在这个项目中，PI将奋进证明，即使在交互式仿真的约束下，也可以重新设计算法和数据结构，以实现非线性虚拟材料的最佳计算效率，并在运行时间，分辨率和准确性方面实现数量级的改进。 这项工作将利用计算机系统、科学计算、连续介质力学和数值分析的专业知识。生物力学模拟为利用人体虚拟模型进行疾病预防和治疗的医疗实践的变革性进步提供了一个很好的机会。 这些新兴的应用程序的任务增加的关注水平的交互性，分辨率和解剖精度的生物力学建模和仿真的临床用途的独特需求。 产生两个或三个数量级的化学改进有可能将临床培训或操作规划任务从离线过程转变为实际的交互式体验。 除了是改善患者护理的宝贵机会之外，使用解剖建模作为有效和可扩展的模拟算法的试验场将具有远远超出临床领域的持久遗产。 人体组织中固有的形状和功能的高度不规则性为材料模型的有效性、离散化技术的准确性和数值求解器的效率提供了一个优秀且具有挑战性的基准。 考虑到诸如拓扑变化的适应性和并行处理的便利性，使得模拟虚拟非线性组织模型成为改进核心计算物理和数值分析技术的极好机会。驾驶和飞行培训），帮助改善操作员的安全记录，而不会有人身伤害的风险。 他们提出了一个很好的机会，影响病人护理的质量，考虑到事实上，大多数外科住院医生目前提高他们的技能，而实际的病人。 解剖模拟器还可以减少对动物试验的需求，并有助于在国际临床界，特别是在发展中国家进行知识转移。 作为该项目的一部分，PI将开发新的学术课程，以连接计算机工程师，应用数学家和临床医生。

Digital models of human anatomy, already common elements of motion pictures and computer games, are now increasingly being incorporated into diverse "serious" applications such as medical diagnostics, surgical planning and vehicle design. Both current and emerging applications demand improved photorealism, enhanced biomechanical accuracy, better subject specificity and faster simulation algorithms. As these demands often outpace the evolution of computer hardware, new algorithms for biomechanical modeling and simulation are necessary to ensure that upcoming computational platforms are utilized to the best of their capacity.With respect to computational performance, physics-based simulations of virtual materials in interactive applications have demonstrated inferior performance in terms of cost per degree of freedom when compared to large-scale simulations of similar phenomena in HPC settings. This is partly attributable to the regularity and economy of scale associated with large models, compared to the pronounced irregularity and heterogeneity at lower resolutions. But it is also due to the fact that the commonly-used algorithms and data structures for interactive virtual materials reflect design compromises with respect to features, accuracy and parallelization potential. In this project the PI will endeavor to show that it is possible to reinvent both algorithms and data structures so as to achieve optimal computational efficiency for nonlinear virtual materials even under the constraints of interactive simulation, and also to achieve improvements of orders of magnitude in runtime, resolution and accuracy. The work will leverage expertise from computer systems, scientific computing, continuum mechanics and numerical analysis.Biomechanical simulation has provided a great opportunity for transformative advances in medical practice using virtual models of the human body for disease prevention and treatment. These emerging applications mandate an increased level of attention to the unique demands of interactivity, resolution and anatomical accuracy for clinical uses of biomechanical modeling and simulation. Algorithmic improvements that yield two or three orders of magnitude have the potential to transform clinical training or operation planning tasks from off-line processes to practical interactive experiences. In addition to being a valuable opportunity to improve patient care, the use of anatomical modeling as a testing ground for effective and scalable simulation algorithms will have a lasting legacy that extends well beyond the clinical field. The high degree of irregularity in shape and function that is inherent in human tissues yields an excellent and challenging benchmark for the validity of material models, the accuracy of discretization techniques and the efficiency of numerical solvers. Considerations such as the accommodation of topology change and facilitation of parallel processing make simulating virtual nonlinear tissue models an excellent opportunity to refine core computational physics and numerical analysis techniques.Broader Impacts: Computer simulations have been established as an educational tool in many fields (e.g., driving and flight training), helping to improve the safety record of operators without risk of physical harm. They present a great opportunity to affect the quality of patient care, considering the fact that most surgical residents currently sharpen their skills while operating on actual patients. Anatomical simulators could also reduce the need for animal testing, and help with knowledge transfer across the international clinical community, especially in developing countries. As part of this project, the PI will develop new academic course offerings that will serve to connect computer engineers, applied mathematicians, and clinical practitioners.