Abstract: Apparatus and methods are described including an impeller defining a proximal end and a distal end. The impeller includes an axial element extending from the proximal end to the distal end of the impeller, the axial element defining a lumen therethrough. An impeller blade includes a curved elongate element and material supported between the curved elongate element and the axial element. An axial shaft extends from the proximal end of the impeller to the distal end of the impeller via the lumen defined by the axial element. Other applications are also described.

Abstract: Apparatus and methods are described including a left-ventricular assist device that includes a self-expandable impeller and a pump-outlet tube. The impeller is configured to be deployed in a left ventricle of a subject and to pump blood from the subject's left ventricle to an aorta of the subject via the pump-outlet tube, for a period of more than two days. The impeller is configured to provide blood flow of more than 4.5 L/min, when pumping against a pressure gradient of 50 mmHg. Other applications are also described.

Abstract: Apparatus and methods are described including a left-ventricular assist device configured to assist left-ventricular functioning of a subject. The left-ventricular assist device includes a frame, a rigid axial shaft extending from a proximal end of the frame to a distal end of the frame, and an impeller disposed on the rigid axial shaft. A motor is disposed outside the subject's body, and a flexible drive cable extends from outside the subject's body to the axial shaft. The drive cable imparts rotational motion from the motor to the rigid axial shaft, to thereby rotate the impeller. Other applications are also described.

Abstract: Apparatus and methods are described including a blood pump configured to be placed inside a subject's body. The blood pump includes an impeller, a frame disposed around the impeller, a distal-tip portion disposed distally with respect to the frame, and a valve disposed within the distal-tip portion. Other applications are also described.

Abstract: Apparatus and methods are described including a left-ventricular assist device. A pump pumps blood from the subject's left ventricle to the subject's aorta, via a tube. A distal-tip element is disposed distally to the pump and defines a straight proximal portion that defines a longitudinal axis, and a curved distal portion that is shaped such as to curve in a first direction with respect to the longitudinal axis of the straight proximal portion before passing through an inflection point and curving in a second direction with respect to the longitudinal axis of the straight proximal portion, such that the curved distal portion defines a bulge on one side of the longitudinal axis of the straight proximal portion. Other applications are also described.

Abstract: Apparatus and methods are described including a delivery catheter and a delivery tube configured to extend from outside a subject's body into the subject's left ventricle via the delivery catheter. A locking unit is configured to couple to a proximal end of the delivery catheter and the delivery tube is configured to pass through the locking unit. The locking unit includes at least one internal seal configured to surround the delivery tube and to inhibit backflow of blood of the subject, from the delivery catheter, through the locking unit. The locking unit also includes a clip, which has only two states, which consist of a closed state, in which the clip grips the delivery tube so as to inhibit movement of the delivery tube relative to the delivery catheter, and an open state, in which the clip does not grip the delivery tube. Other applications are also described.

Abstract: Apparatus and methods are described including advancing a guide wire into a left ventricle of a subject and guiding a pump head of a left-ventricular assist device to the subject's left ventricle over the guidewire. The pump head is disposed in a radially-constrained configuration within a delivery catheter during the guiding. When the pump head is disposed within the subject's left ventricle, the pump-head is released from within the delivery catheter, thereby causing an impeller of the pump head to automatically assume a non-radially-constrained configuration by the impeller self-expanding. Other applications are also described.

Abstract: Apparatus and methods are described including deploying a pump head of a left-ventricular assist device in a subject's left ventricle. The pump head includes an axial shaft, and a radially-expandable impeller coupled to the axial shaft. A proximal radial bearing is disposed around the axial shaft proximally to the impeller, and a distal radial bearing is disposed around the axial shaft distally to the impeller. The interface between the axial shaft and the distal radial bearing is purged, by pumping purging fluid into a purging-fluid lumen defined by the left-ventricular assist device. Other applications are also described.

Abstract: Apparatus and methods are described including a blood pump configured to be placed inside a body of subject. The blood pump includes an impeller that defines a lumen therethrough, and an axial shaft that passes through the lumen. The impeller is configured to assume a radially-constrained configuration by becoming axially elongated. Other applications are also described.

Abstract: Apparatus and methods are described including a blood pump configured to be placed inside a subject's body. An impeller includes proximal and distal bushings and an axial shaft configured to pass through the proximal and distal bushings. A first one of the proximal and distal bushings is axially-fixed to the axial shaft, and a second one of the proximal and distal bushings is not axially-fixed to the axial shaft. The impeller defines a radially-constrained configuration in which the impeller is introduced into the subject's body and a non-radially-constrained configuration in which the impeller is configured to pump blood within the subject's body. The impeller changes from its radially-constrained configuration to its non-radially constrained configuration by the second bushing sliding over the axial shaft. Other applications are also described.

Abstract: Apparatus and methods are described including a blood pump that includes an impeller configured to pump blood through a subject's body, and a frame disposed around the impeller. In a radially-non-constrained configuration of the frame, the frame defines a proximal conical portion and a cylindrical portion disposed distally to the proximal conical portion. The blood pump is configured such that such that, during at least some of the operation of the blood pump, at least a portion of the impeller is disposed within the proximal conical portion of the frame. Other applications are also described.

Abstract: 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. The blood pump also includes an impeller coupled to the axial shaft such that, as the axial shaft rotates, the impeller pumps blood of the subject. Proximal and distal radial bearings surround the axial shaft and are configured to radially stabilize the axial shaft while the axial shaft rotates. Proximal and distal sleeves, which are less flexible than the axial shaft, are disposed around the axial shaft, such that the proximal and distal sleeves contact the proximal and distal radial bearings, respectively, as the axial shaft rotates. A ratio between a length of the axial shaft and a combined length of the proximal sleeve and distal sleeve is between 2:1 and 6:1. Other applications are also described.

Abstract: Apparatus and methods are described including a blood pump that includes an impeller, and a frame disposed around the impeller. An axial shaft extends from a proximal end of the frame to a distal end of the frame. The impeller is coupled to the axial shaft. A radial bearing is configured to radially stabilize the axial shaft and aa bearing housing houses the radial bearing. A layer of elastomeric material is disposed between the radial bearing and the bearing housing. Other applications are also described.

Abstract: Apparatus and methods are described including an impeller that includes an impeller frame that comprises proximal and distal end portions and a plurality of blades. Each of the impeller blades includes a curved elongate element and at least one radial element extending radially from the curved elongate element toward a longitudinal axis of the impeller frame. Other applications are also described.

Abstract: Apparatus and methods are described including a solid axial shaft having a shaft diameter that is less than 0.8 mm, an impeller configured for insertion into a left ventricle of a heart of a subject and coupled to the axial shaft, and a hollow drive cable coupled, at a distal end of the drive cable, to the axial shaft, and configured to rotate so as to rotate the axial shaft, thereby causing the impeller to pump blood of the subject from the left ventricle. Other applications are also described.

Abstract: 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. The blood pump also includes an impeller, which includes a proximal bushing disposed over the axial shaft, a distal bushing disposed over the axial shaft distally from the proximal bushing, and one or more blades. Each of the blades includes a single inner helical elongate element, a single outer helical elongate element, and a film of material extending between the inner helical elongate element and the outer helical elongate element. The blades are proximally coupled to the proximal bushing and distally coupled to the distal bushing such that, as the axial shaft rotates, the blades rotate, thereby pumping blood of the subject. Other applications are also described.

Abstract: Apparatus and methods are described including a left-ventricular assist device that includes a frame that includes proximal and distal frame portions that include struts that define cells, and a central frame portion that includes helical struts. An impeller is disposed inside the frame, the impeller being configured to rotate such as to pump blood from a left ventricle of a subject to an aorta of the subject. Other applications are also described.

Abstract: Apparatus and methods are described including a ventricular assist device that includes a tube configured to traverse a subject's aortic valve. The tube defines a generally-cylindrical central portion, and a proximal conical portion that narrows from a proximal end of the central portion to a proximal end of the tube. The tube defines one or more blood inlet openings in a vicinity of a distal end of the tube, and one or more blood outlet openings that extend axially from the central portion of the tube at least partially into the proximal conical portion of the tube. A blood pump pumps blood into the tube from the subject's left ventricle through the one or more blood inlet openings, and from the tube into the aorta through the one or more blood outlet openings. Other applications are also described.

Abstract: Apparatus and methods are described including a blood pump that includes a pump-outlet tube shaped to define one or more blood-outlet openings and configured for insertion into a heart of a subject. An impeller is disposed within a distal portion of the pump-outlet tube and is configured to pump blood of the subject proximally through the pump-outlet tube, such that the blood exits the pump-outlet tube through the blood-outlet openings. A delivery tube extends, from outside a body of the subject, through the pump-outlet tube to the distal portion. A drive cable passes through the delivery tube and is configured to rotate the impeller. A proximal portion of the pump-outlet tube includes multiple strips adhered to the delivery tube. Other embodiments are also described.

Abstract: Apparatus and methods are described including a blood pump that includes an impeller configured to pump blood through a subject's body, and a frame disposed around the impeller. In a radially-non-constrained configuration of the frame, the frame defines a proximal conical portion and a cylindrical portion disposed distally to the proximal conical portion. During operation of the blood pump, the impeller moves with respect to the frame, and a range of movement of the impeller is such that at least a first portion of the impeller is disposed within the proximal conical portion of the frame during at least some of the operation of the blood pump, and at least a second portion of the impeller is disposed within the cylindrical portion of the frame during at least some of the operation of the blood pump. Other applications are also described.