Cerdeira, Tânia Filipa AlvesLima, Rui A.Oliveira, MónicaMonteiro, Fernando C.Ishikawa, TakujiImai, YohsukeYamaguchi, Takami2011-06-092011-06-092010Cerdeira, T.; Lima, R.; Oliveira, M.; Monteiro, Fernando C.; Ishikawa, T.; Imai, Y.; Yamaguchi, T. (2010). Determination of the cell-free layer in circular PDMS microchannels. In COMPUTATIONAL VISION AND MEDICAL IMAGING PROCESSING VIP Image. Porto. ISBN 978-0-415-57041-1.978-0-415-57041-1http://hdl.handle.net/10198/5103In microcirculation the cell-free layer is believed to reduce the friction between red blood cells (RBCs) and endothelial cells and consequently reduce blood flow resistance. However, the complex formation of the cell-free layer has not yet been convincingly described mainly due to multi-physical and hemorheological factors that affect this phenomenon. In this experimental work, we study the effect of hematocrit (Hct) on the thickness of the cell-free layer in straight circular polydimethylsiloxane (PDMS) microchannels. The channels studied are 73 ± 2 mm in diameter, flexible and circular to mimic blood vessels. The images are captured using confocal microscopy and are post-processed using Image J and MATLAB. The formation of a cell-free layer is clearly visible in the images captured and by using a combination of image analysis techniques we are able to detect an increase in the cell-free layer thickness as Hct decreases.engCell-free layerMicrochannelsconference paper