Reichard Daniel, Bodenstedt Sebastian, Suwelack Stefan, Mayer Benjamin, Preukschas Anas, Wagner Martin, Kenngott Hannes, Müller-Stich Beat, Dillmann Rüdiger, Speidel Stefanie
Karlsruhe Institute of Technology , Institute for Anthropomatics and Robotics, Adenauerring 2, D-76131 Karlsruhe, Germany.
University of Heidelberg , Department of General, Abdominal and Transplantation Surgery, Im Neuenheimer Feld 110, D-69120 Heidelberg, Germany.
J Med Imaging (Bellingham). 2015 Oct;2(4):045001. doi: 10.1117/1.JMI.2.4.045001. Epub 2015 Dec 10.
The goal of computer-assisted surgery is to provide the surgeon with guidance during an intervention, e.g., using augmented reality. To display preoperative data, soft tissue deformations that occur during surgery have to be taken into consideration. Laparoscopic sensors, such as stereo endoscopes, can be used to create a three-dimensional reconstruction of stereo frames for registration. Due to the small field of view and the homogeneous structure of tissue, reconstructing just one frame, in general, will not provide enough detail to register preoperative data, since every frame only contains a part of an organ surface. A correct assignment to the preoperative model is possible only if the patch geometry can be unambiguously matched to a part of the preoperative surface. We propose and evaluate a system that combines multiple smaller reconstructions from different viewpoints to segment and reconstruct a large model of an organ. Using graphics processing unit-based methods, we achieved four frames per second. We evaluated the system with in silico, phantom, ex vivo, and in vivo (porcine) data, using different methods for estimating the camera pose (optical tracking, iterative closest point, and a combination). The results indicate that the proposed method is promising for on-the-fly organ reconstruction and registration.
计算机辅助手术的目标是在手术干预过程中为外科医生提供指导，例如使用增强现实技术。为了显示术前数据，必须考虑手术过程中发生的软组织变形。腹腔镜传感器，如立体内窥镜，可用于创建立体框架的三维重建以进行配准。由于视野小且组织结构均匀，通常仅重建一帧无法提供足够的细节来配准术前数据，因为每一帧仅包含器官表面的一部分。只有当补丁几何形状能够明确地与术前表面的一部分匹配时，才能正确地与术前模型进行匹配。我们提出并评估了一种系统，该系统结合了来自不同视角的多个较小的重建结果，以分割和重建器官的大型模型。使用基于图形处理单元的方法，我们实现了每秒四帧。我们使用不同的估计相机姿态的方法（光学跟踪、迭代最近点以及两者结合），对该系统进行了计算机模拟、体模、离体和体内（猪）数据的评估。结果表明，所提出的方法对于实时器官重建和配准具有前景。
