CompBio: Reality-based Data-driven Computer Models for Surgical Simulation

目前在交互式外科训练应用中可变形组织模拟的计算模型在物理精度上做出了巨大的牺牲，以实现实时性能。这对于具有挑战性的工具-组织相互作用的实时触觉力反馈渲染尤其如此，在这种情况下，模拟必须在接近千赫兹的速率下进行。此外，即使实时需求得到满足，比如未来几十年更快的处理器，我们仍然必须解决我们缺乏准确的计算模型的根本问题：(a)现实的、可变的、非线性的软组织的力响应，以及(b)与现实的工具-组织相互作用相关的许多重要物理过程，这些过程是手术干预的核心，例如针头插入。因此，科学界可以通过提供准确和实时的软组织相互作用的计算机模型来帮助外科模拟从业者提高患者的安全性。智力优势：在非常基本的层面上，该项目试图弥合有效的计算机模拟算法与他们试图模仿的现实外科组织和相互作用之间的明显差距。具体而言，我们提出了一个基于现实的测量和计算机模拟的多学科研究计划，利用我们的独特优势来解决三个关键领域：1。基于现实的建模：精确，现实的数学模型，描述非线性软组织反应和校准的相互作用模型，用于执行针头插入。我们将开发一系列实验仪器来测量针头插入时软组织的反应。所有测量都将伴随着严格的经验建模过程，以获得准确的参数组织和相互作用模型。数据驱动的实时仿真算法：给定针与组织相互作用的精确数学模型，将为实时触觉和图形显示设计非常有效的仿真算法。基于数据驱动、预计算、减少坐标、变形算法的新型计算机模型将用于加速精确的非线性变形和针与组织的接触相互作用。为了支持自适应，并允许运行时修改，我们将使用快速简化的领域模型，与直接和数据驱动的仿真模型结合使用分层领域分解。闭环：实验和计算机模拟模型的定量评估将有助于完善和验证我们在整个项目中基于现实的建模过程。在我们的最后一年，我们还将开发一个基于模拟器的培训系统，用于样本针插入任务。更广泛的影响：拟议的研究将在我们准确模拟和推理软组织相互作用的能力方面取得根本性的进步，并将导致一些令人兴奋的科学和临床可能性。在科学上，我们将能够根据实际的实验试验开发出准确的、基于现实的软组织模型，在医学上有广泛的应用。优化后的数值算法可以建立在这些精确的非线性材料和接触相互作用模型之上，用于软组织的实时图形和触觉力反馈显示。在临床上，这将允许更广泛地使用手术模拟器进行住院医师培训（包括微创和直接手术），从而住院医师将能够在手术任务中体验更真实的软组织相互作用反应。在这一领域的进步也将开辟道路，建模任何其他器官或软组织的训练是需要的，在核心的基于现实的仿真问题得到解决后。

Current computational models for deformable tissue simulation in interactive surgical training applications make enormous sacrifices in physical accuracy to achieve real-time performance. This is particularly true of challenging real-time, haptic force-feedback rendering of tool-tissue interactions, where simulations must be ideally performed at near kilohertz rates. Furthermore, even if real-time demands are met, such as by faster processors in coming decades, we must still address our fundamental lack of accurate computational models for (a) force response of realistic, variable, nonlinear, soft tissues, and (b) many nontrivial physical processes associated with realistic tool-tissue interaction that are central to surgical intervention, such as, needle insertion, for example. Consequently, the scientific community can help surgical simulation practitioners improve patient safety by providing both accurate and real-time computer models of soft tissues interactions.INTELLECTUAL MERITS: At the very fundamental level, this project seeks to bridge the apparent gap between efficient computer simulation algorithms, and the realistic surgical tissues and interactions they seek to mimic. Specifically, we propose a multi-disciplinary research program on reality-based measurement and computer simulation that leverages our unique strengths to address three key areas:1. Reality-based modeling: Accurate, realistic mathematical models that describe nonlinear soft-tissue response and calibrated interaction models for performing needle insertion. We will develop a range of experimental apparatuses for measuring soft-tissue responses during needle insertion. All measurements will be accompanied by a rigorous empirical modeling process to arrive at accurate parametric tissue and interaction models.2. Data-driven, real-time, simulation algorithms: Given accurate mathematical models of needle-tissue interaction, very efficient simulation algorithms will be devised for real-time haptics and graphics display. Novel computer models based on data-driven, pre-computed, reduced-coordinate, deformation algorithms will be used to accelerate accurate nonlinear deformation, and needle-tissue contact interactions. To support adaptation, and allow runtime modification, we will combine hierarchical domain decomposition using fast reduced domain models, with direct and data-driven simulation models.3. Closing the loop: Quantitative evaluation of experimental and computer simulation models will help refine and validate our reality-based modeling processes throughout the project. In our final year, we will also develop a simulator-based training system for sample needle insertion tasks.BROADER IMPACTS: The proposed research will make fundamental advances in our ability to simulate and reason about soft-tissue interactions accurately, and will lead to several exciting scientific and clinical possibilities. Scientifically, we will be able to develop accurate and reality-based soft-tissue models based on actual experimental trials, which have wide application in medicine. Optimized numerical algorithms can then build on these accurate nonlinear material and contact interaction models for real-time graphical and haptic force-feedback display of soft tissues. Clinically, this will allow a more widespread use of surgical simulators for resident training (for both minimally invasive and direct procedures), whereby residents will be able to experience more realistic soft-tissue interaction response in surgical tasks. Advancement in this area will also open avenues for modeling any other organ or soft-tissue for which training is desired, after the core reality-based simulation issues are resolved.