title: Confocal imaging of flows in artificial venular bifurcations.
abstract: We describe a new experimental methodology for visualizing three-dimensional structures in microscopic tubes under flow conditions. Through the use of microfabrication techniques, artificial venular bifurcations are constructed from glass tubes with semicircular cross sections (radius = 50 mu). Aqueous fluorescent solutions are infused into the tubes at flow rates of about 1 microliter/min, a value comparable to blood flow in the microcirculation. The flow is imaged using a combination of confocal microscopy and three-dimensional image reconstruction software techniques. The quantitative accuracy of the experimental method is evaluated by measuring the "separation surface," a formation resulting from converging flows at a bifurcation. Details of the fabrication process, fluidics, confocal microscopy, image reconstructions, optical effects, and computations are described. We show the first three-dimensional visualization of a microscopic flow structure using confocal microscopy, and within certain limitations, quantitative agreement between the measured and computed positions of the separation surface.
authors.affiliation: Department of Physics, Loyola College, Baltimore, MD 21210, USA.
authors.forename: D L
authors.initials: DL
authors.lastname: Hitt
authors.forename: M L
authors.initials: ML
authors.lastname: Lowe
mesh_terms: D003287:Contrast Media; D019793:Fluorescein; D018056:Hemorheology; D007091:Image Processing, Computer-Assisted; D008833:Microcirculation / Q000502:physiology*; D018613:Microscopy, Confocal; D008855:Microscopy, Electron, Scanning; D008955:Models, Cardiovascular; D009716:Numerical Analysis, Computer-Assisted; D015203:Reproducibility of Results; D014172:Transillumination; D014699:Venules / Q000033:anatomy & histology* / Q000502:physiology*
chemical_list: D003287:Contrast Media; D019793:Fluorescein