The present invention refers to a blood pump, preferably to an implantable blood pump for supporting or replacing the cardiac function on the left and/or the right hand side.
From U.S. Pat. No. 4,994,078, an implantable blood pump is known that is shaped like a snail shell, the stator of the motor being integrated in the pump housing, while the rotor is firmly connected to a pump impeller wheel and is flushed by the blood flow. Thus, the blood flows through the inside of the motor, with one wall of the annular channel formed by the motor being stationary, while the other wall rotates. This gives rise to the risk of damage to the blood caused by shear forces occurring there.
EP 0 611 580 A2 describes an artificial cardiac pump, wherein blood also flows around the rotor and the stator of the motor. At the outlet side, a pump impeller wheel is arranged that is designed as a radial pump and pumps blood, drawn axially along the stator, into a surrounding annular channel from which the blood exits tangentially. Here, there are two suction paths, namely the main suction path surrounding the stator and a relatively narrow annular channel between the stator and the rotor. Again, there is a risk of damaging the blood by shear forces.
Finally, a blood pump is known from WO 94/09274 that has a helical rotor surrounding a stator.
It is the object of the present invention to provide a blood pump in which damage to the blood and thrombogenesis are substantially avoided.
According to the invention, the object is solved with the features of claim 1.