Optical Reconstruction of High-Speed Surface Dynamics in an Uncontrollable Environment
Optical Reconstruction of High-Speed Surface Dynamics in an Uncontrollable Environment
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DOI：
10.1109/tmi.2010.2055578
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发表时间：
2010-12-01
影响因子：
10.6
通讯作者：
Doellinger, Michael
中科院分区：
文献类型：
--
作者：
Luegmair, Georg;Kniesburges, Stefan;Doellinger, Michael
我们用声音交流的能力可以被看作是“发声”和“调制”两个过程的串联。“这些分别发生在喉、腭和口腔区域。在发声期间，可听见的主要语音信号是通过声带与肺的呼出气流的相互反应而产生的。物质、流体和声学的潜在相互作用还有待于确定和理解。主要信号的声源之一是涡激振动，如e。例如，在一个实施例中，由空气流中的柯恩达效应产生。这些涡流的发展是由喉部声带的形状和三维运动决定的。目前声带的临床活体研究方法不能为基础研究提供令人满意的质量数据。例如，在一个实施例中，内窥镜限于2-D图像信息。在此基础上，提出了一些改进的方法，但只提供选择性的三维信息，无论是对一个单一的点或一条线。这与整个声带表面的3-D运动形成对比。更复杂的成像方法，如MRI，不能实时提供信息。因此，有必要开发一种易于应用的、更改进的检查方法，该方法允许获得声带表面的3-D数据。我们提出了一种方法来校准的3-D重建设置，包括激光投影系统和高速摄像机。该装置的设计考虑到了小型化和体内应用。激光投影系统通过衍射光栅产生196个激光点的发散网格。它是通过平面单应性与平面校准目标校准。一般来说，该设置允许以高帧速率（高达每秒4000帧）和在不可控的环境中重建表面的拓扑，如e。例如，在一个实施例中，由照明情况（几乎没有环境光）和变化的纹理（例如，例如，在一个实施例中，不同等级的反射）。特别是，该系统测量发声过程中的3-D声带表面动态。应用于合成数据，校准被证明是强大的（误差约0.5 μ m）关于噪声和系统误差。用线性Z-工作台获得的实验数据证明，该系统重建点的3-D坐标，误差约为15 μ m。应用该方法对猪和人工声带发声过程中的表面进行了重建。局部差异，如左右折叠动力学之间的不对称性，以及全局参数，如打开和关闭速度和最大位移，被确定和量化。
The ability to communicate with our voice can be regarded as the concatenation of the two processes "phonation" and "modulation." These take place in the larynx and palatal and oral region, respectively. During phonation the audible primary voice signal is created by mutual reaction of vocal folds with the exhaled air stream of the lungs. The underlying interactions of masses, fluids and acoustics have yet to be identified and understood. One part of the primary signal's acoustical source are vortex induced vibrations, as e. g., created by the Coandaeffect in the air stream. The development of these vorteces is determined by the shape and 3-D movements of the vocal folds in the larynx. Current clinical in vivo research methods for vocal folds do not deliver data of satisfactory quality for fundamental research, e. g., an endoscope is limited to 2-D image information. Based hereupon, a few improved methods have been presented, however delivering only selective 3-D information, either for a single point or a line. This stands in contrast to the 3-D motions of the entire vocal fold surface. More complex imaging methods, such as MRI, do not deliver information in real-time. Thus, it is necessary to develop an easily applicable, more improved examination method, which allows for 3-D data of the vocal folds surfaces to be obtained. We present a method to calibrate a 3-D reconstruction setup including a laser projection system and a high-speed camera. The setup is designed with miniaturization and an in vivo application in mind. The laser projection system generates a divergent grid of 196 laser dots by diffraction gratings. It is calibrated with a planar calibration target through planar homography. In general, the setup allows to reconstruct the topology of a surface at high frame rates (up to 4000 frames per second) and in uncontrollable environments, as e. g., given by the lighting situation (little to no ambient light) and varying texture (e. g., varying grade of reflection) in the human larynx. In particular, this system measures the 3-D vocal fold surface dynamics during phonation. Applied to synthetic data, the calibration is shown to be robust (error approximately 0.5 mu m) regarding noise and systematic errors. Experimental data gained with a linear z-stage proved that the system reconstructs the 3-D coordinates of points with an error at approximately 15 mu m. The method was applied exemplarily to reconstruct porcine and artificial vocal folds' surfaces during phonation. Local differences such as asymmetry between left and right fold dynamics, as well as global parameters, such as opening and closing speed and maximum displacements, were identified and quantified.