Apparatus and methods are described including a blood pump that includes an axial shaft configured for insertion into, and rotation within, a left ventricle of a subject, and an impeller coupled to the axial shaft such that, as the axial shaft rotates, the impeller pumps blood from the left ventricle. A frame surrounds the impeller and a tip portion is coupled to a distal end of the frame. The tip portion includes a distal curved portion, which, when deployed within the left ventricle, lies in a plane, and a proximal curved portion, which, when deployed within the left ventricle, does not lie in the plane and is curved such that, following the insertion of the axial shaft into the left ventricle via an aorta of the subject, a distal end of the proximal curved portion points toward an apex of the left ventricle. Other applications are also described.

Apparatus and methods are described including a left-ventricular assist device, that includes a collapsible pump-outlet tube configured for insertion, through an aorta of a subject, into a left ventricle of a heart of the subject such that the pump-outlet tube traverses an aortic valve of the subject. The device includes one or more bands, each of which is bonded to an outer wall of the proximal portion of the pump-outlet tube, without extending around a full circumference of the pump-outlet tube, such that, while the proximal portion of the pump-outlet tube is maintained in the open state, the proximal portion of the pump-outlet tube curves at respective locations of the bands. Other applications are also described.

Apparatus and methods are described including an axial shaft configured for insertion into, and rotation within, a ventricle of a heart of a subject. An impeller is coupled to the axial shaft and a frame surrounds the impeller. A pump-outlet tube surrounds the frame such that, as the axial shaft rotates, the impeller pumps blood proximally, from the ventricle, through the pump-outlet tube. A flat inlet guard, which is shaped to define one or more holes, is disposed around, and perpendicular to, the axial shaft and within the frame distally to the impeller, such that the blood flows to the impeller via the holes. Other applications are also described.

Apparatus and methods are described including a blood pump that includes an axial shaft configured for insertion, over a guidewire, into a subject's body, and for rotation within the subject's body. The axial shaft is shaped to define a shaft lumen for passage of the guidewire therethrough. An impeller is coupled to the axial shaft such that, as the axial shaft rotates, the impeller pumps blood of the subject. A thrust bearing is disposed distally from the axial shaft so as to inhibit distal movement of the axial shaft beyond the thrust bearing. The thrust bearing is shaped to define a bearing lumen that is configured to be continuous with the shaft lumen. At least a portion of the bearing lumen is frustoconically-shaped, a wider end of the frustoconically-shaped portion of the bearing lumen facing distally. Other applications are also described.

Apparatus and methods are described including a blood pump that includes an axial shaft configured for insertion into, and rotation within, a subject's body, and an impeller coupled to the axial shaft such that, as the axial shaft rotates, the impeller pumps blood of the subject. A frame surrounds the impeller and includes a distal conical portion. A bearing adjacent to the axial shaft is configured to stabilize the axial shaft while the axial shaft rotates. A bearing housing houses the bearing. The bearing housing is disposed at least partly within the distal conical portion of the frame such that at least 50% of the length of the bearing housing is disposed within the frame. Other applications are also described.

Apparatus and methods are described including inserting a drive-cable end of a drive cable, which includes a plurality of coiled wires, and a hollow-shaft end of a hollow shaft, which hollow-shaft end is shaped to define multiple shaft pores, into opposing ends of a coupling tube, which is shaped to define multiple coupling-tube pores. While the drive-cable end and hollow-shaft end are inside the coupling tube, a molten material is flowed between the coiled wires at the drive-cable end via the coupling-tube pores, and into the hollow-shaft end via the coupling-tube pores and shaft pores, such that, upon solidifying, the material bonds the drive cable to the shaft. Other applications are also described.

Apparatus and methods are described including inserting a drive-cable end of a drive cable, which includes a plurality of coiled wires, and a hollow-shaft end of a hollow shaft, which hollow-shaft end is shaped to define multiple shaft pores, into opposing ends of a coupling tube, which is shaped to define multiple coupling-tube pores. While the drive-cable end and hollow-shaft end are inside the coupling tube, a molten material is flowed between the coiled wires at the drive-cable end via the coupling-tube pores, and into the hollow-shaft end via the coupling-tube pores and shaft pores, such that, upon solidifying, the material bonds the drive cable to the shaft. Other applications are also described.

A cardiac assist system for pumping blood which can be introduced into a blood vessel through a catheter. The system comprises the pump, a pump housing and a tube connected to the pump housing. An inlet guide nozzle in fluid communication with the tube may have a minimum-width constriction, e.g. located at about 50%, or more or less, of the length of the nozzle in the flow direction. The nozzle may have a curved contour protruding into the flow channel with a single concavity or convexity along an entire length thereof. A distal lip of the nozzle may be curved.

A cardiac assist system for pumping blood which can be introduced into a blood vessel through a catheter. The system comprises the pump, a pump housing and a tube connected to the pump housing. An inlet guide nozzle in fluid communication with the tube may have a minimum-width constriction, e.g. located at about 50%, or more or less, of the length of the nozzle in the flow direction. The nozzle may have a curved contour protruding into the flow channel with a single concavity or convexity along an entire length thereof. A distal lip of the nozzle may be curved.

The present disclosure provides a pump for supporting heart function, that includes a housing with a rotor disposed within the housing and spaced from an internal surface of the housing to define a clearance therebetween. An impeller is coupled to the rotor for propelling blood from a first inlet to an outlet of the housing along a primary blood flow path. The housing includes a second inlet fluidly coupled to the clearance between the rotor and the housing to define a secondary flow path through the clearance. The blood flowing through the secondary flow path continuously flushes the space between the rotor and the housing to minimize the formation and/or growth of blood clots and/or to remove heat generated by the pump. The secondary flow path may also provide a fluid bearing for the rotor and/or the impeller to reduce or eliminate contact surfaces and/or mechanical bearings between the rotating components of the pump and its housing, thereby reducing wear on these components and increasing the longevity of the pump.