Abstract
A novel modification of conventional video imaging techniques has been developed to determine the velocity of red blood cells (RBCs), which offers compatibility with existing video-based methods for determining blood oxygenation and hemoglobin concentration. Traditional frame-by-frame analysis of video recordings limits the maximum velocity that can be measured for individual cells in vivo to about 2 mm/s. We have extended this range to about 20 mm/s, by electronic shuttering of an intensified charge-coupled device camera to produce multiple images of a single RBC in the same video frame. RBCs were labeled with fluorescein isothiocyanate and the labeled cells (FRBCs) were used as probes to determine RBC velocities in microvessels of the hamster retractor muscle. Velocity was computed as the product of the distance between centroids of two consecutive image positions of a FRBC and the shuttering frequency of the camera intensifier. In vitro calibrations of the system using FRBC and Sephadex beads coated onto a rotating disk yielded an average coefficient of variation of about 6%. Flow conservation studies at bifurcations indicated that the maximum diameter of microvessels below which all the FRBCs in the lumen could be detected was 50 μm. The technique was used to estimate mean-FRBC velocity distributions in vessels with diameters ranging from 8 to 50 μm. The mean-FRBC velocity profiles were found to be blunter than would be expected for Poiseuille flow. Single FRBCs tracked along an unbranched arteriole exhibited significant temporal variations in velocity. © 1999 Biomedical Engineering Society.
PAC99: 8719Tt, 8717Jj, 4279Pw, 8780Tq, 8719Ff, 4230Va, 0705Pj
Similar content being viewed by others
REFERENCES
Baker, M., and H. Wayland. On-line volume flow rate and velocity profile measurement in blood in microvessels. Microvasc. Res. 7:131–143, 1974.
Ellis, C. G., K. Tyml, and A. C. Groom. Computer-assisted analysis of video images: A new tool for microvascular measurement. In: Microcirculatory Technology, edited by C. H. Baker and W. L. Nastuk. New York, NY: Academic, 1986, pp. 229–244.
Gaehtgens, P., H. J. Meiselman, and H. Wayland. Velocity profiles of human blood at normal and reduced hematocrit in glass tubes up to 130 μm diameter. Microvasc. Res. 2:13–23, 1970.
Hudetz, A. G., C. G. M. Weigle, F. J. Fenoy, and R. J. Roman. Use of fluorescently labeled erythrocytes and digital cross-correlation for the measurement of flow velocity in the cerebral microcirculation. Microvasc. Res. 43:334–341, 1992.
Japee, S. A. Determination of Red Blood Cell Velocity Distributions in Microvessels Using a Video Imaging Technique. Virginia Commonwealth University, MS Thesis, 1996.
Johnson, P. C. Flow measurement techniques in the microcirculation. In: Microcirculatory Technology, edited by C. H. Baker and W. L. Nastuk. New York, NY: Academic, 1986, pp. 149–160.
Lih, M. M. Transport Phenomena in Medicine and Biology. New York, NY: Wiley-Interscience, 1974, pp. 378–414.
Lipowsky, H. H., L. E. Cram, W. Justice, and M. J. Eppihimer. Effect of erythrocyte deformability on in vivo red cell transit time and hematocrit and their correlation with in vitro filterability. Microvasc. Res. 46:43–64, 1992.
Nuttal, A. L. Techniques for the observation and measurement of red blood cell velocity in vessels of the guinea pig cochlea. Hearing Res. 27:111–119, 1987.
Parthasarathi, A. A. Determination of Microvascular Red Blood Cell Velocity Distribution Using Video Image Analysis. Virginia Commonwealth University, MS Thesis, 1995.
Parthasarathi, K., and R. N. Pittman. Determination of diffusive oxygen transport from measurements of hemoglobin concentration and oxygen saturation profiles in arterioles of striated muscle using intravital video microscopy and image analysis. In: Oxygen Transport to Tissue XV, edited by P. D. Wagner, M. C. Hogan, O. Mathieu-Costello, and D. C. Poole. New York, NY: Plenum, 1994, pp. 249–260.
Pittman, R. N., and B. R. Duling. Measurement of percent oxyhemoglobin in the microvasculature. J. Appl. Physiol. 38:321–327, 1975.
Pittman, R. N., and M. L. Ellsworth. Estimation of red cell flow in microvessels: Consequences of the Baker-Wayland spatial averaging. Microvasc. Res. 32:371–388, 1986.
Pries, A. R., T. W. Secomb, T. Geßner, M. B. Sperandio, J. F. Gross, and P. Gaethgens. Resistance to blood flow in microvessels in vivo. Circ. Res. 75:904–915, 1994.
Rumsey, W. L., J. M. Vanderkooi, and D. F. Wilson. Imaging of phosphorescence: A novel method for measuring oxygen distribution in perfused tissue. Science 241:1649–1651, 1988.
Sarelius, I. H., and B. R. Duling. Direct measurement of microvessel hematocrit, red cell flux, velocity, and transit time. Am. J. Physiol. 243:H1018-H1026, 1982.
Sullivan, S. M., and R. N. Pittman. Hamster retractor muscle: A new preparation for intravital microscopy. Microvasc. Res. 23:329–335, 1982.
Tangelder, G. J., D. W. Slaaf, H. C. Teirlinck, R. Alewijnse, and R. S. Reneman. Localization within a thin optical section of fluorescent blood platelets flowing in a microvessel. Microvasc. Res. 23:214–230, 1982.
Tangelder, G. J., H. C. Teirlinck, D. W. Slaaf, and R. S. Reneman. Distribution of blood platelets flowing in arterioles. Am. J. Physiol. 248:H318-H323, 1985.
Tangelder, G. J., D. W. Slaaf, M. M. Muijtjens, T. Arts, M. G. A. Egbrink, and R. S. Reneman. Velocity profiles of blood platelets and red blood cells flowing in arterioles of the rabbit mesentery. Circ. Res. 59:505–514, 1986.
Unthank, J. L., L. M. Lash, J. C. Nixon, R. A. Sidner, and H. G. Bohlen. Evaluation of carbocynanine-labeled erythrocytes for microvascular measurements. Microvasc. Res. 45:193–210, 1993.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Parthasarathi, A.A., Japee, S.A. & Pittman, R.N. Determination of Red Blood Cell Velocity by Video Shuttering and Image Analysis. Annals of Biomedical Engineering 27, 313–325 (1999). https://doi.org/10.1114/1.144
Issue Date:
DOI: https://doi.org/10.1114/1.144