Image correlation algorithm for measuring lymphocyte velocity and diameterchanges in contracting microlymphatics
Dixon,JB; Gashev,AA; Zawieja,DC; Moore-JE,Jr; Cote,GL
Abstract Efforts have recently been made to estimate wall shear stress throughout thecontractile cycle of mesenteric rat lymphatics with a high speed video microscopy system. This wasprompted by reports in the literature that lymphatic pumping is related to wall shear stress. Whileone can estimate wall shear stress by tracking lymphocyte velocity, it is prohibitively tedious tomanually track particles over a reasonable time frame for a good number of experiments. To overcomethis, an image correlation method similar to digital particle imaging velocimetry was developed andtested on contracting lymphatics to measure both vessel diameter and fluid velocity. The programtracked temporal fluctuations in spatially averaged velocity with a standard error of prediction of0.4 mm/s. From these studies we have measured velocities ranging from -2 to 4 mm/s. Diameter changeswere also measured with a standard error of 7 microm. These algorithms and techniques could bebeneficial for investigating various changes in contractile behavior as a function of changes invelocity and wall shear stress.
Keywords Algorithms; Lymphatic Vessels; Lymphocytes
Annals of Biomedical Engineering
0090-6964, Volume 35, Issue 3, 2007, Pages 3-396
