A Computer-Based Method for Determination of the Cell-Free Layer Width in Microcirculation

  1. SANGHO KIM1,
  2. ROBERT L. KONG1,
  3. ALEKSANDER S. POPEL2,
  4. MARCOS INTAGLIETTA1,
  5. PAUL C. JOHNSON1,*

Article first published online: 26 JAN 2010

DOI: 10.1080/10739680600556878

Issue

Microcirculation

Microcirculation

Volume 13, Issue 3, pages 199–207, April-May 2006

Additional Information

How to Cite

KIM, S., KONG, R. L., POPEL, A. S., INTAGLIETTA, M. and JOHNSON, P. C. (2006), A Computer-Based Method for Determination of the Cell-Free Layer Width in Microcirculation. Microcirculation, 13: 199–207. doi: 10.1080/10739680600556878

Author Information

  1. 1

    Department of Bioengineering, University of California, San Diego, La Jolla, California, USA

  2. 2

    Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland, USA

*Address correspondence to Paul C. Johnson, PhD, Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093-0412, USA. E-mail: pjohnson@bioeng.ucsd.edu

Publication History

  1. Issue published online: 26 JAN 2010
  2. Article first published online: 26 JAN 2010
  3. Received 23 July 2005; accepted 6 October 2005.

SEARCH

SEARCH BY CITATION

ARTICLE TOOLS

View Full Article (HTML) Get PDF (473K)

Keywords:

  • axial migration;
  • hemodynamics;
  • in vivo blood rheology;
  • line intensity scanning method

ABSTRACT

Objectives: The cell-free layer between the erythrocyte column and the vessel wall is an important determinant of hydrodynamic resistance in microcirculatory vessels. The authors report a method for continuous measurement of the width of this layer.

Methods: The light intensity of a linear array of pixels perpendicular to the vessel axis is continuously determined from a video image of a microcirculatory vessel. A threshold level based on Otsu's method is used to establish the interface between the cell-free layer and the erythrocyte column. To test the method, video images at 750–4500 frames/s were obtained from venules and arterioles in rat spinotrapezius muscle at normal and reduced arterial pressures before and after induction of erythrocyte aggregation with Dextran 500. The current measurements were compared to manual measurements of the same images.

Results: Values obtained by the manual and the new methods were in agreement within the 95% confidence limit by the Bland-Altman analysis and within 90–95% range by the correlation coefficient (R2). The more frequent measurements reveal substantial, rapid variations in cell-free layer width and changes in mean values with alteration of arterial pressure and red cell aggregability.

Conclusions: A new, computer-based technique has been developed that provides measurements of rapid, time-dependent variations in the width of the cell-free layer in the microcirculation.

View Full Article (HTML) Get PDF (473K)