Patent ID: 7699586
Filing Date: 2010-04-20
Classification: A61M

Abstract:
1. An axial flow blood pump, comprising: a pump housing; a rotor for effecting axial blood flow through the axial flow pump, said rotor being positioned in said housing and comprising an impeller having a hydrodynamic surface for pumping blood; a motor including a plurality of magnetic poles carried by the impeller, and a rotor stator including an electrically conductive coil located adjacent to or within said housing; and said rotor comprising wide, radially outwardly extending, bladelike projections that define generally longitudinally extending spaces between said projections, said projections being shaped to form curves in said spaces of a shape tending to drive blood in said spaces in an axial direction as the impeller is rotated, said spaces collectively having a total width at the radial periphery of the rotor, that is substantially equal to or less than the collective total width of said projections along most of their lengths at said radial periphery; said projections having radially outer faces carrying hydrodynamic bearings, said hydrodynamic bearings comprising curved surfaces that are recessed into said outer faces of said projections to form recessed surfaces that are tapered in a gradual manner, the most recessed end forming a leading edge of rotation, whereby as the rotor rotates the hydrodynamic bearings scoop blood into a cross-sectional recessed area that decreases going from a leading portion of the projection to a trailing portion thereby pressurizing the blood.