B.S., Ch. E. (1956); M.S. (1957) University of Texas

Ph.D. (1961) University of Michigan

Fluid mechanics and transport processes with emphasis in biomedical engineering: reactions of blood and vascular cells under the influence of fluid mechanical stresses, oxygen transport in the microcirculation, blood substitutes

Email: jhellums@rice.edu
Phone: (713)348-5116
Office: Keck Hall, 116C

Professor Hellums emphasizes the application of principles of fluid mechanics and transport processes in biology and medicine. The work is carried out in cooperation with biological and medical scientists from both Rice University and the Texas Medical Center.

Human blood platelets, neutrophils, and vascular cells are known to play crucial roles in hemostatic, thrombotic, and inflammatory events in the human vascular system. Hellums and his colleagues have shown that the shear stress field associated with flow in blood vessels plays an important role in determining receptor expression and blood cell reactions. They have developed several reactors for studying these reactions under known, controlled fluid stresses. Rotational viscometers, fiberoptic probes, and flow cytometry are used with fluorophores, specific antibodies, and other inhibitors in studies designed to elucidate the molecular and hydrodynamic factors in blood and vascular cell reactions. Understanding of the kinetics and molecular mechanisms of these cell reactions can aid in development of strategies for prophylaxis and therapy for thrombotic and inflammatory disorders.

Professor Hellums and his colleagues are engaged in studies on flow and transport in the microcirculation with emphasis on oxygen transport. They have developed a unique experimental system that can be used to determine oxygen fluxes to and from hemoglobin solutions and red cell suspensions under carefully controlled conditions simulating the microcirculation. A combination of experimental and mathematical methods are being applied to contribute to the understanding of transport in the microcirculation, and to the mathematical methodology used in simulations of these processes. The methods are used to study the gas transport properties of two important classes of blood substitutes: chemically modified free hemoglobin and artificial red cells. The objective is to obtain experimental and theoretical information that will allow the design of blood surrogates with optimized oxygen transport efficiencies. An additional application of the methods is in improving our understanding of microcirculatory oxygen transport in sickle cell disease and other blood cell disorders.

Selected Publications

Book chapter