Joint Applied Mathematics/Mechanical Engineering Colloquium

THE DEPARTMENT OF MATHEMATICAL SCIENCES AND
THE CENTER FOR APPLIED MATHEMATICS AND STATISTICS,
AND THE DEPARTMENT OF MECHANICAL ENGINEERING,
NEW JERSEY INSTITUTE OF TECHNOLOGY

11:30 AM
Friday, February 7, 2003

Cullimore Hall Lecture Room II
New Jersey Institute of Technology





David Wootton

Department of Mechanical Engineering and Mechanics
Drexel University

" Mechanochemical Thrombosis Models "

Thrombosis, the formation of a clot inside a blood vessel, causes a host of medical problems, including heart attack, stroke, pulmonary embolism, and bleeding disorders. Thrombosis complicates surgical procedures and any intervention or implant where artificial materials contact blood. Models of thrombosis may be useful for improving cardiovascular device design, improving experimental model interpretation, or diagnosis of thrombosis risk. This presentation will review several computational models of thrombosis that link fluid mechanics, cellular transport, cellular activation, and coagulation kinetics.

Commercial computational fluid dynamics (CFD) software was used to model the aggregation of platelets from flowing blood onto a growing thrombus. Blood was treated as a fluid, and platelets as a pseudochemical species transported by convection and shear-enhanced diffusion. Platelet activation was either assumed or modeled as a first-order reaction due to thrombin generation at the thrombus surface. The model is well correlated with experimental measurements in tubular and converging geometry, but the activation kinetics suggest that activation is either more rapid that previously reported, or not necessary for initial platelet-thrombus interaction. Recently the effect of thrombus growth has been modeled by creating an expanding porous zone.

Under low-shear flow conditions, platelet transport is reduced and surface-driven coagulation kinetics may become important. Continuum models of coagulation kinetics in flowing blood are currently not tractable, and lumped parameter modeling has been used to study the role of mass transport and surface reactivity in coagulation. Such models have potential use for cardiovascular device design and management of thrombosis risk but require experimental validation.