School of Aerospace, Mechanical & Manufacturing Engineering, RMIT University, PO Box 71, Bundoora, VIC 3083, Australia.
Med Eng Phys. 2010 Mar;32(2):174-88. doi: 10.1016/j.medengphy.2009.11.007. Epub 2009 Dec 22.
In a chamber of the heart, large-scale vortices are shown to exist as the result of the dynamic blood flow and unique morphological changes of the chamber wall. As the cardiovascular flow varies over a cardiac cycle, there is a need for a robust quantification method to analyze its vorticity and circulation. We attempt to measure vortex characteristics by means of two-dimensional vorticity maps and vortex circulation. First, we develop vortex component analysis by segmenting the vortices using an data clustering algorithm before histograms of their vorticity distribution are generated. The next stage is to generate the statistics of the vorticity maps for each phase of the cardiac cycle to allow analysis of the flow. This is followed by evaluating the circulation of each segmented vortex. The proposed approach is dedicated to examining vortices within the human heart chamber. The vorticity field can indicate the strength and number of large-scale vortices in the chamber. We provide the results of the flow analysis after vorticity map segmentation and the statistical properties that characterize the vorticity components. The success of the cardiac measurement and analysis is illustrated by a case study of the right atrium. Our investigation shows that it is possible to utilize a data clustering algorithm to segment vortices after vorticity mapping, and that the vorticity and circulation analysis of a chamber vorticity can provide new insights into the blood flow within the cardiovascular structure.
在心腔的一个腔室中，由于血液的动力学流动和腔室壁的独特形态变化，大尺度涡旋被证明存在。由于心血管流动在心动周期中变化，因此需要一种强大的量化方法来分析其涡度和环流。我们尝试通过二维涡度图和涡度环流来测量涡旋特性。首先，我们通过在生成其涡度分布的直方图之前使用数据聚类算法对涡旋进行分段，从而开发涡旋分量分析。下一阶段是为心动周期的每个阶段生成涡度图的统计信息，以便分析流动。接下来是评估每个分段涡旋的环流。所提出的方法专门用于检查人心腔中的涡旋。涡度场可以指示腔室内大尺度涡旋的强度和数量。在对涡度图进行分段和对描述涡度分量的统计特性进行分析之后，我们提供了流动分析的结果。通过右心房的案例研究说明了心脏测量和分析的成功。我们的研究表明，在进行涡度映射后，使用数据聚类算法对涡旋进行分段是可行的，并且腔室涡度的涡度和环流分析可以为心血管结构内的血流提供新的见解。
