Blood-material interaction can range from transient hemolysis and minimal protein adsorption to activation of coagulation, complement, and significant destruction of cells. Complicated mechanisms exist in the cardiovascular system which may interact with medical devices. Devices vary enormously in type, function, and duration of blood contact (Cooper et al., 1987; Dewangee, 1987), particularly now that combination and nanotechnology devices are increasingly moving to market. Therefore, a multidisciplinary approach to hemocompatibility testing is important. This includes in vitro static and dynamic tests, acute extracorporeal tests, tests of cardiovascular devices in appropriate animal models, and clinical studies. For most devices only the in vitro static tests are performed. Complex interactions are operative between the surfaces of devices/materials and the blood, based on both chemical and physical parameters (Zaslavsky et al., 1975), such as the rate of release of chemical moieties from a device and the nature of the blood contacting device surface.