Apparatus and methods are described including a blood pump that includes an impeller, and a motor configured to drive the impeller to pump blood by rotating the impeller. The impeller is configured to undergo axial motion, in response to changes in a pressure against which the impeller is pumping. A sensor detects the axial motion of the impeller, and generates a sensor signal in response thereto. A computer processor receives the sensor signal and generates an output in response thereto. Other applications are also described.

Apparatus and methods are described including a blood pump that includes an impeller, and a motor configured to drive the impeller to pump blood by rotating the impeller. The impeller is configured to undergo axial motion, in response to changes in a pressure against which the impeller is pumping. A sensor detects the axial motion of the impeller, and generates a sensor signal in response thereto. A computer processor receives the sensor signal and generates an output in response thereto. Other applications are also described.

Apparatus and methods are described including a blood pump that includes an axial shaft, an impeller disposed on the axial shaft, a frame disposed around the impeller, and a motor disposed outside a subject's body, and configured to drive the impeller to pump blood from a distal end of the impeller to a proximal end of the impeller. A drive cable extends from outside the subject's body to the axial shaft, and is configured to impart rotational motion from the motor to the impeller by rotating. The drive cable is held in a preloaded state with respect to the frame, such that initiation of pumping of blood by rotation of the impeller does not cause the drive cable to axially elongate. Other applications are also described.

Apparatus and methods are described including a blood pump that includes an axial shaft, an impeller disposed on the axial shaft, a frame disposed around the impeller, and a motor disposed outside a subject's body, and configured to drive the impeller to pump blood from a distal end of the impeller to a proximal end of the impeller. A drive cable extends from outside the subject's body to the axial shaft, and is configured to impart rotational motion from the motor to the impeller by rotating. The drive cable is held in a preloaded state with respect to the frame, such that initiation of pumping of blood by rotation of the impeller does not cause the drive cable to axially elongate. Other applications are also described.

Devices, system, and methods are provided based on a technique for purging a blood pump. The technique may include providing a blood pump having an impeller and providing a fluid comprising a bicarbonate. The technique may include flowing the fluid through a first gap between a bearing and an outer surface of a rotatable shaft coupled to the impeller, the bearing and gap being disposed within a lumen of a tubular member and depending on the flow rate of the fluid and the speed of the impeller, the fluid may flow through the first gap and into a second gap between the bearing and a surface of the impeller facing the bearing. The bicarbonate reduces denaturation and adsorption of any blood proteins in the gap(s).

Devices, system, and methods are provided based on a technique for purging a blood pump. The technique may include providing a blood pump having an impeller and providing a fluid comprising a bicarbonate. The technique may include flowing the fluid through a first gap between a bearing and an outer surface of a rotatable shaft coupled to the impeller, the bearing and gap being disposed within a lumen of a tubular member and depending on the flow rate of the fluid and the speed of the impeller, the fluid may flow through the first gap and into a second gap between the bearing and a surface of the impeller facing the bearing. The bicarbonate reduces denaturation and adsorption of any blood proteins in the gap(s).

The invention relates to a blood pump. The blood pump comprises a flexible drive shaft guided in a catheter, a conveying element connected to the drive shaft in a distal region of the drive shaft, and a motor, wherein the motor has a stator and a rotor mounted such that it can move in the stator. The stator comprises a winding and the rotor comprises a rotor magnet. In addition, the drive shaft is connected to the rotor at a proximal end of the drive shaft. The stator and the rotor are nondetachably connected to one another, and form a gap with a ring-shaped cross-section, which is delimited by the rotor and the stator.

The invention relates to a blood pump. The blood pump comprises a flexible drive shaft guided in a catheter, a conveying element connected to the drive shaft in a distal region of the drive shaft, and a motor, wherein the motor has a stator and a rotor mounted such that it can move in the stator. The stator comprises a winding and the rotor comprises a rotor magnet. In addition, the drive shaft is connected to the rotor at a proximal end of the drive shaft. The stator and the rotor are nondetachably connected to one another, and form a gap with a ring-shaped cross-section, which is delimited by the rotor and the stator.

A temporary, removable mechanical circulatory support heart-assist device has at least two propellers or impellers. Each propeller or impeller has a number of blades arranged around an axis of rotation. The blades are configured to pump blood. The two propellers or impellers rotate in opposite directions from each other. The device can be configured to be implanted and removed with minimally invasive surgery.

A temporary, removable mechanical circulatory support heart-assist device has at least two propellers or impellers. Each propeller or impeller has a number of blades arranged around an axis of rotation. The blades are configured to pump blood. The two propellers or impellers rotate in opposite directions from each other. The device can be configured to be implanted and removed with minimally invasive surgery.