IEEE J Biomed Health Inform. 2016 Jan;20(1):355-66. doi: 10.1109/JBHI.2014.2381772. Epub 2014 Dec 18.
This study presents a new visuo-haptic virtual reality (VR) training and planning system for percutaneous transhepatic cholangio-drainage (PTCD) based on partially segmented virtual patient models. We only use partially segmented image data instead of a full segmentation and circumvent the necessity of surface or volume mesh models. Haptic interaction with the virtual patient during virtual palpation, ultrasound probing and needle insertion is provided. Furthermore, the VR simulator includes X-ray and ultrasound simulation for image-guided training. The visualization techniques are GPU-accelerated by implementation in Cuda and include real-time volume deformations computed on the grid of the image data. Computation on the image grid enables straightforward integration of the deformed image data into the visualization components. To provide shorter rendering times, the performance of the volume deformation algorithm is improved by a multigrid approach. To evaluate the VR training system, a user evaluation has been performed and deformation algorithms are analyzed in terms of convergence speed with respect to a fully converged solution. The user evaluation shows positive results with increased user confidence after a training session. It is shown that using partially segmented patient data and direct volume rendering is suitable for the simulation of needle insertion procedures such as PTCD.
本研究提出了一种新的基于部分分割虚拟患者模型的经皮经肝胆道引流 (PTCD) 视触一体虚拟现实 (VR) 培训和规划系统。我们仅使用部分分割的图像数据，而不是完整的分割，并避免了表面或体积网格模型的必要性。在虚拟触诊、超声探测和针插入过程中，与虚拟患者进行触觉交互。此外，VR 模拟器还包括 X 射线和超声模拟，用于图像引导培训。可视化技术通过在 Cuda 中的实现得到 GPU 加速，包括在图像数据的网格上计算实时体积变形。在图像网格上进行计算可将变形的图像数据直接集成到可视化组件中。为了提供更短的渲染时间，通过多网格方法来提高体积变形算法的性能。为了评估 VR 培训系统，已经进行了用户评估，并根据完全收敛解的收敛速度分析了变形算法。用户评估显示，在培训后，用户的信心增加，结果为正。结果表明，使用部分分割的患者数据和直接体绘制适合于模拟经皮经肝胆道引流等针插入手术。
