Microfluidics and Nanofluidics

, Volume 17, Issue 6, pp 1071–1078 | Cite as

Simplified analysis method of cell-free layers in blood flows as tool for the optimization of gas exchange devices

  • Tina RieperEmail author
  • Paul Čvančara
  • Claas Müller
  • Holger Reinecke
Research Paper


A novel analyzing method is presented, which allows precise characterization of cell-free layers (CFLs) of blood flowing through microchannels. The CFL occurs due to axial migration of the erythrocytes (RBCs). A confocal laser scanning microscope (CLSM) is used to detect the reflected light of channel walls and cells within the blood flow. Since the presented method does not depend on emitted fluorescence signals, there is no necessity for a complex sample preparation as fluorescence marking of cells. Furthermore, it allows the characterization of the thickness of the CFL in whole blood. Due to the high vertical resolution of the used CLSM, the developed characterization method enables measurements along the optical axis of the microscope. It is exemplarily used to analyze the thickness of the CFL in human blood flowing through microchannels as a function of the hematocrit and blood flow velocity. The microchannels are made of silicone rubber with a height of 100 µm. The microchannels are intended for a gas exchange application.


Cell-free layer Blood flow Microchannels Confocal laser scanning microscope 



We thank the Life Imaging Center (LIC) of the University Freiburg, especially Dr. Roland Nitschke and Dr. Angela Naumann, for facilitating the measurements.


  1. Campbell NA, Reece JB (2002) Biology, 6th edn. Benjamin Cummings, San FranciscoGoogle Scholar
  2. Cerdeira T, Lima R, Oliveira M, Monteiro FC, Ishikawa T, Imai Y, Yamaguchi T (2009) Determination of the cell-free layer in circular PDMS microchannels. ECCOMAS Thematic Conference on Computational Vision and Medical Image Processing, Porto, PortugalGoogle Scholar
  3. Fahraeus R, Lindqvist T (1931) The viscosity of the blood in narrow capillary tubes. Am J Physiol Leg Content 96(3):562–568. doi: 10.1161/01.RES.22.1.28 Google Scholar
  4. Feng J, Hu HH, Joseph DD (1994) Direct simulation of initial value problems for the motion of solid bodies in a Newtonian fluid. Part 1. Sedimentation. J Fluid Mech 261(1):95. doi: 10.1017/S0022112094000285 CrossRefzbMATHGoogle Scholar
  5. Garcia V, Dias RP, Lima R (2012) In vitro blood flow behaviour in microchannels with simple and complex geometries. In: Naik GR (ed) Applied biological engineering. Principles and practice. InTech, Rijeka, pp 393–416Google Scholar
  6. Karnis A, Goldsmith HL, Mason SG (1966) The flow of suspensions through tubes: V. Inertial effects. Can J Chem Eng 44(4):181–193. doi: 10.1002/cjce.5450440401 CrossRefGoogle Scholar
  7. Lima R, Wada S, Tanaka S, Takeda M, Ishikawa T, Tsubota K, Imai Y, Yamaguchi T (2008) In vitro blood flow in a rectangular PDMS microchannel: experimental observations using a confocal micro-PIV system. Biomed Microdevices 10(2):153–167. doi: 10.1007/s10544-007-9121-z CrossRefGoogle Scholar
  8. Lima R, Oliveira MS, Ishikawa T, Kaji H, Tanaka S, Nishizawa M, Yamaguchi T (2009) Axisymmetric polydimethysiloxane microchannels for in vitro hemodynamic studies. Biofabrication 1(3):35005. doi: 10.1088/1758-5082/1/3/035005 CrossRefGoogle Scholar
  9. Park CW, Shin SH, Kim GM, Jang JH, Gu YH (2006) A hemodynamic study on a marginal cell depletion layer of blood flow inside a microchannel. KEM 326–328:863–866. doi: 10.4028/ CrossRefGoogle Scholar
  10. Rieper T, Wehrstein B, Maurer AN, Mueller C, Reinecke H (2012a) Evaluation model of an extracorporeal gas exchange device made of silicone rubber. Biomed Tech/Biomed Eng 57:1109–1112. doi: 10.1515/bmt-2012-4191 Google Scholar
  11. Rieper T, Mueller C, Wehrstein B, Maurer AN, Reinecke H (2012a) Virtually monolithic device for diffusive mass transfer enabling high volume flow. In: Proceedings of The Sixteenth International Conference on Miniaturized Systems for Chemistry and Life Sciences (µTAS 2012)Google Scholar
  12. Rieper T, Cvancara P, Gast, Sophie, Wehrstein, Bettina, Maurer, Andreas N., Mueller, Class, Reinecke, Holger (2013) An artificial lung based on gas exchange and blood flow optimization. In: Zengerle R (ed) Proceedings of the 17th International Conference on Miniaturized Systems for Chemistry and Life Sciences, pp 1188–1190Google Scholar
  13. Segré G, Silberberg A (1962) Behaviour of macroscopic rigid spheres in Poiseuille flow. Part 2 Experimental results and interpretation. J Fluid Mech 14(01):136–157CrossRefGoogle Scholar
  14. Tilly de A, Sousa de JM, Willaime H, Pinto JF, Duate Silve OM, Bettencourt Moreira Silva I, Carrapico B, Semiao V (2010) Non-Newtonian micellar microflow visualization in a contraction Geometry. In: Proceedings of the 2nd European Conference on Microfluidics, μFlu’10, Toulouse, France, 08–10 December 2010Google Scholar

Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  • Tina Rieper
    • 1
    Email author
  • Paul Čvančara
    • 1
  • Claas Müller
    • 1
  • Holger Reinecke
    • 1
  1. 1.Laboratory for Process Technology, Department of Microsystems Engineering - IMTEKUniversity of FreiburgFreiburgGermany

Personalised recommendations