Collecting microlymphatics play a vital role in promoting lymph flow from the initial lymphatics in the interstitial spaces to the large transport lymph ducts. In most tissues, the primary mechanism for producing this flow is the spontaneous contractions of the lymphatic wall. Individual units, known as lymphangion, are separated by valves that help prevent backflow when the vessel contracts, thus promoting flow through the lymphatic network. Lymphatic contractile activity is inhibited by flow in isolated lymphatics, however there are virtually no in situ measurements of lymph flow in these vessels. Initially, a high speed imaging system was set up to image in situ preparations at 500 fps. These images were then manually processed to extract information regarding lymphocyte velocity (-4 to 10 mm/sec), vessel diameter (25 to 165 mum), and particle location. Fluid modeling was performed to obtain reasonable estimates of wall shear stress (-8 to 17 dynes/cm 2). One of the difficulties encountered was the time consuming methods of manual particle tracking. Using previously captured images, an image correlation method was developed to automate lymphatic flow measurements and to track wall movements as the vessel contracts. Using this method the standard error of prediction for velocity measurements was 0.4 mm/sec and for diameter measurements it was 7.0 mum. It was found that the actual physical quantity being measured through this approach is somewhere between the spatially averaged velocity and the maximum velocity of a Poiseuille flow model.
展开▼
机译：收集微淋巴管在促进淋巴液从间隙空间中的初始淋巴管向大运输淋巴管的流动中起着至关重要的作用。在大多数组织中，产生这种流动的主要机制是淋巴壁的自发收缩。单个单元，称为淋巴结蛋白，由阀门隔开，有助于防止血管收缩时回流，从而促进通过淋巴管网的流动。淋巴的收缩活性受孤立淋巴管中血流的抑制，但是实际上在这些血管中没有淋巴液的原位测量。最初，建立了一个高速成像系统，以500 fps的速度对原位制备物进行成像。然后手动处理这些图像以提取有关淋巴细胞速度（-4至10 mm / sec），血管直径（25至165 mum）和颗粒位置的信息。进行流体建模以获得壁剪切应力的合理估计值（-8至17达因/ cm 2）。遇到的困难之一是手动粒子跟踪的耗时方法。使用以前捕获的图像，开发了一种图像相关方法来自动进行淋巴流量测量并跟踪血管收缩时的壁运动。使用这种方法，速度测量的预测标准误差为0.4毫米/秒，直径测量的预测误差为7.0微米。已经发现，通过这种方法测量的实际物理量在泊厄伊流动模型的空间平均速度和最大速度之间。
展开▼
