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 left ventricular assist device that includes an axial flow impeller configured to be disposed within a subject's left ventricle and to pump blood axially from the subject's left ventricle to the subject's aorta. A frame is disposed around the impeller, the frame being shaped such that, in a non-radially-constrained configuration of the frame, the frame defines a central cylindrical portion, and a distal conical portion. The frame is at least partially covered with one or more tube portions, the tube portions defining one or more blood-inlet openings that are configured to allow blood to flow from the subject's left ventricle into the tube portions, wherein at least some of the one or more blood-inlet openings are at least partially disposed over the distal conical portion of the frame. Other applications are also described.

Abstract: Apparatus and methods are described including reducing cardiac preload of a subject by partially occluding a vena cava of the subject at an infra-renal location. One or more physiological parameters of the subject are monitored, the one or more physiological parameters including lower body venous pressure, central venous pressure, central venous blood flow, renal venous pressure, cardiac diameter, cardiac volume, arterial pressure, and/or arterial blood flow. An extent to which the vena cava is occluded at the infra-renal location is modulated, responsively to the one or more physiological parameters. 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 a tube configured to traverse an aortic valve of a subject. A frame is disposed within at least a portion of the tube. An impeller rotates such as to pump blood from the subject's left ventricle to the subject's aorta. The impeller is disposed inside the tube such that, when the impeller and the tube are deployed inside the subject, and prior to rotation of the impeller, a radial gap between an outer edge of the impeller and an inner surface of the tube is less than 1 mm. The impeller is radially stabilized such that, during rotation of the impeller, a radial gap between the outer edge of the impeller and the inner surface of the tube is maintained. Other applications are also described.

Abstract: Apparatus and methods are described including a left ventricular assist device that includes an impeller configured to be placed inside a left ventricle of a subject and to pump blood from the left ventricle to an aorta of the subject, by rotating. A frame is disposed around the impeller. A tube is configured to traverse an aortic valve of the subject, such that a proximal portion of the tube is disposed within the subject's aorta and a distal portion of the tube is disposed within the subject's left ventricle. The distal portion of the tube extends to a distal end of the frame and defines one or more lateral blood inlet openings that are configured to allow blood to flow from the subject's left ventricle into the tube. 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 a tube configured to traverse an aortic valve of a subject. A frame is disposed within at least a portion of the tube. An impeller rotates such as to pump blood from the subject's left ventricle to the subject's aorta. The impeller is disposed inside the tube such that, when the impeller and the tube are deployed inside the subject, and prior to rotation of the impeller, a gap between an outer edge of the impeller and an inner surface of the tube is less than 1 mm. A rigid stabilizing element stabilizes the impeller with respect to the tube, such that during rotation of the impeller, a gap between the outer edge of the impeller and the inner surface of the tube is maintained. 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 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.

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 provided, including inserting an impeller and a delivery tube into a subject's body, the delivery tube including a braid having a pick density that varies along the delivery tube's length such that a flexural rigidity of the delivery tube at a first portion of the delivery tube is less than the flexural rigidity at a second portion of the delivery tube, and the flexural rigidity at the second portion is less than the flexural rigidity at a third portion of the delivery tube. The impeller and delivery tube are positioned such that the impeller is disposed within the subject's left ventricle and the delivery tube passes the subject's aorta into the left ventricle. Using a drive cable, which passes through the delivery tube, the impeller is rotated so as to pump blood from the left ventricle into the aorta. Other applications are also described.

Abstract: 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.

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, 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Apparatus and methods are provided, including a left-ventricular assist device that includes an impeller configured for insertion into a subject's left ventricle. A delivery tube passes through the subject's aorta, from outside the subject into the left ventricle. The delivery tube includes an outer layer that varies along a length of the delivery tube such that a flexural rigidity of the delivery tube at a first portion of the delivery tube, which is configured to traverse the aortic valve, is less than the flexural rigidity at a second portion, which is configured to traverse at least a portion of the aortic arch, and the flexural rigidity at the second portion is less than the flexural rigidity at a third portion, which is configured to traverse the descending aorta. Other applications are also described.