Measurement of the Velocity Relative to the Impeller of the Ultracompact Centrifugal Pump

Abstract

The relative velocity field in the impeller of the ultracompact centrifugal pump developed as an artificial heart has been investigated by high speed videography and particle image velocimetry. The transient motion of the velocity field relative to the rotating impeller blades has been clearly visualized by the use of image rotating system composed of the beam splitter and the right angle prism. The flow field in a passage exhibited strongly unsteady motion. The secondary flows developed in the passage were considered to play an important role in antithrombogenicity of the pump which depended upon the shear stresses acting on the blood contacting surface.