IEEE Trans Biomed Eng. 2020 Sep;67(9):2683-2695. doi: 10.1109/TBME.2020.2968488. Epub 2020 Jan 21.
This paper aims to propose a 3D laparoscopic imaging system that can realize dense 3D reconstruction in real time.
Based on the active stereo technique which yields high-density, accurate and robust 3D reconstruction by combining structured light and stereo vision, we design a laparoscopic system consisting of two image feedback channels and one pattern projection channel. Remote high-speed image acquisition and pattern generation lay the foundation for the real-time dense 3D surface reconstruction and enable the miniaturization of the laparoscopic probe. To enhance the reconstruction efficiency and accuracy, we propose a novel active stereo method by which the dense 3D point cloud is obtained using only five patterns, while most existing multiple-shot structured light techniques require [Formula: see text] patterns. In our method, dual-frequency phase-shifting fringes are utilized to uniquely encode the pixels of the measured targets, and a dual-codeword matching scheme is developed to simplify the matching procedure and achieve high-precision reconstruction.
Compared with the existing structured light techniques, the proposed method shows better real-time efficiency and accuracy in both quantitative and qualitative ways. Ex-vivo experiments demonstrate the robustness of the proposed method to different biological organs and the effectiveness to lesions and deformations of the organs. Feasibility of the proposed system for real-time dense 3D reconstruction is verified in dynamic experiments. According to the experimental results, the system acquires 3D point clouds with a speed of 12 frames per second. Each frame contains more than 40,000 points, and the average errors tested on standard objects are less than 0.2 mm.
This paper provides a new real-time dense 3D reconstruction method for 3D laparoscopic imaging. The established prototype system has shown good performance in reconstructing surface of biological tissues.
本文旨在提出一种能够实时实现密集三维重建的三维腹腔镜成像系统。
基于主动立体技术，该技术通过结合结构光和立体视觉来实现高密度、精确和鲁棒的三维重建，我们设计了一个由两个图像反馈通道和一个模式投影通道组成的腹腔镜系统。远程高速图像采集和模式生成为实时密集三维表面重建奠定了基础，并实现了腹腔镜探头的小型化。为了提高重建效率和精度，我们提出了一种新的主动立体方法，仅使用五个图案即可获得密集的三维点云，而大多数现有的多次结构光技术需要[Formula: see text]个图案。在我们的方法中，双频相移条纹用于唯一地对测量目标的像素进行编码，并且开发了双码字匹配方案来简化匹配过程并实现高精度重建。
与现有的结构光技术相比，该方法在定量和定性方面均表现出更好的实时效率和精度。离体实验证明了该方法对不同生物器官的鲁棒性以及对器官病变和变形的有效性。动态实验验证了所提出系统实时密集三维重建的可行性。根据实验结果，系统以每秒 12 帧的速度获取三维点云。每帧包含超过 40000 个点，在标准物体上测试的平均误差小于 0.2mm。
本文为三维腹腔镜成像提供了一种新的实时密集三维重建方法。所建立的原型系统在重建生物组织表面方面表现出良好的性能。
