Abstract: Apparatus and methods are described including a ventricular assist device that includes a frame having struts that define a plurality of cells. In its non-radially-constrained configuration, the frame includes a generally cylindrical portion. A tube defines blood outlet openings, and a portion of the tube is disposed outside the frame and is coupled to the generally cylindrical portion of the frame, such that the portion of the tube conforms with a structure of struts of the frame. An inner lining is coupled to an inside of the generally cylindrical portion of the frame, such as to provide the generally cylindrical portion of the frame with a smooth inner surface. An impeller is disposed at least partially inside the generally cylindrical portion of the frame and is configured to pump blood through the tube and out of the one of more blood outlet openings. 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 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. 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 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 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 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 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 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 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 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 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.

Abstract: Apparatus and methods are described including a blood pump that includes an axial shaft configured for insertion into, and rotation within, a body of a subject. 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 includes a proximally-facing ceramic surface disposed distally from the axial shaft so as to inhibit distal movement of the axial shaft beyond the thrust bearing, and a distally-facing ceramic cover that covers a distal end of the axial shaft, such that the ceramic cover contacts the ceramic surface as the axial shaft rotates. Other applications are also described.

Abstract: Apparatus and methods are described including manufacturing an impeller by forming a structure having first and second bushings at proximal and distal ends of the structure, the first and second bushings being connected to one another by at least one elongate element. The elongate element is caused to radially expand and form at least one helical elongate element, at least partially by axially compressing the structure. The helical elongate element is coated with a coupling agent configured to enhance bonding between the helical elongate element and an elastomeric layer. The coated helical elongate element is coated with the elastomeric layer. Subsequently, an elastomeric film is coupled to the helical elongate element, such that the helical elongate element with the elastomeric film coupled thereto defines a blade of the impeller. Other applications are also described.

Abstract: Apparatus and methods are described including a left-ventricular assist device that includes a pump-outlet tube shaped to define one or more blood-outlet openings and 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 with the blood-outlet openings being disposed within the aorta. A blood pump is disposed at least partly within a distal portion of the pump-outlet tube and is configured to pump blood of the subject proximally through the pump-outlet tube. A proximal end of the pump-outlet tube is folded inwardly so as to define one or more surfaces configured to direct the blood through the blood-outlet openings by virtue of being oblique with respect to a longitudinal axis of the pump-outlet tube. Other applications are also described.

Abstract: Apparatus and methods are described including an axial shaft and an impeller configured for rotation within a subject's body. A coupling element includes a first portion, which is disposed around the axial shaft, is shaped to define one or more slits that facilitate a radial expansion of the first portion such that the first portion is placeable around the axial shaft, and is shape-set to have an inner diameter that is smaller than a diameter of the axial shaft such that, following placement of the first portion around the axial shaft, the first portion becomes radially contracted around, and thus locked in place with respect to, the axial shaft. A second portion of the coupling element is coupled to a bushing of the impeller. Other applications are also described.

Abstract: Apparatus and methods are described including a ventricular assist device that includes an axial shaft and an impeller disposed on the axial shaft, the impeller being configured to pump blood. A frame is disposed around the impeller. The distal end of the axial shaft is configured to engage with a distal thrust bearing such as to prevent the axial shaft from undergoing axial motion in response to variations in the pressure gradient against which the impeller pumps blood. An impeller-stabilizing spring is disposed around the axial shaft between a distal end of the impeller and the thrust bearing, the impeller-stabilizing spring being configured to stabilize the distal end of the impeller. Other applications are also described.

Abstract: Apparatus and methods are described including a blood pump including an axial shaft configured for insertion into, and rotation within, a body of a subject, 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. One or more steering wires are coupled to the frame and configured to extend from the frame, to outside the body of the subject, while the frame is within the body. Other applications are also described.