Patent ID: 8814541
Filing Date: 2014-08-26
Classification: A61M,F04D

Abstract:
1. A turbo blood pump, comprising: a housing having a pump chamber, an inlet port, and an outlet port; an impeller supported rotatably in the pump chamber; a rotatable rotor provided in an outside lower portion of the housing; and a drive force transmitting element for rotating the impeller, the impeller including: a rotating shaft supported rotatably by an upper bearing and a lower bearing at upper and lower ends; a plurality of vanes connected to the rotating shaft on an inner circumferential edge side; an annular coupling portion coupling an outer circumferential edge side of each of the vanes; and a driven magnet portion placed in a lower portion of the annular coupling portion, in which the inlet port is positioned above the upper bearing and the outlet port is positioned at a lateral outside of a periphery of the pump chamber, the drive force transmitting element being formed of magnetic coupling between the driven magnet portion and a drive magnet portion provided at the rotor, wherein an upper edge of each of the vanes is bent so as to form a peripheral upper vane edge on an outer circumferential edge side with respect to a bend point and a central upper vane edge on a center side with respect to the bend point, when a peripheral upper vane edge angle α is defined as an angle formed by the peripheral upper vane edge relative to a downward direction of the rotating shaft direction, and a central upper vane edge angle β is defined as an angle formed by the central upper vane edge relative to the downward direction of the rotating shaft direction, the peripheral upper vane edge angle α and the central upper vane edge angle β are both acute angles and have a relationship of α<β, a ratio Lo/Li is set in a range of 0.75 to 3.20, where Lo represents a length of a region of the central upper vane edge and Li represents a length of a region of the peripheral upper vane edge in a radial direction of the impeller, and an inner wall surface of the pump chamber of the housing in a region opposed to the upper edge of each of the vanes has a bent portion corresponding to the upper edge of each of the vanes, with the upper bearing that supports the rotating shaft being disposed between the inlet port and bent portion, thereby enhancing an effect of a secondary flow of blood toward the inlet port for suppressing formation of a blood clot in a vicinity of the upper bearing.