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 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 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 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. A distal thrust bearing is disposed within the frame, the distal end of the axial shaft being configured to engage with the 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. A plurality of connecting struts extend radially inwardly from the frame to the distal thrust bearing and couple the thrust bearing to the frame. The frame and the connecting struts are formed as a single integral body. Other applications are also described.

Abstract: Apparatus and methods are described including packaging for a ventricular assist device. The packaging defines a pump-head chamber in which the pump head is packaged in a non-radially constrained configuration. A catheter-securement piece is shaped to define a hole and is configured to secure a distal end of the delivery catheter to the packaging by securing the delivery catheter within the hole. The packaging is configured such that the pump head is configured to be radially constrained by being retracted into the distal end of the delivery catheter, while the delivery catheter is secured within the hole. Other applications are also described.

Abstract: Apparatus and methods are described including a pump-outlet tube configured to traverse an aortic valve of a subject, such that the proximal end of the pump-outlet tube is disposed within the subject's aorta and the distal end of the pump-outlet tube is disposed within the subject's left ventricle. An impeller is configured to be disposed within the left ventricle within the pump-outlet tube, and to pump blood through the pump-outlet tube. A frame, disposed around the impeller, includes a cylindrical portion and a proximal conical portion. A proximal end of an optical fiber is disposed outside the subject's body and the distal end of the optical fiber is coupled to the proximal conical portion of the frame such that the distal end of the optical fiber extends to outside the pump-outlet tube in direct fluid communication with left-ventricular bloodstream of the subject. Other applications are also described.

Abstract: Apparatus and methods are described including a ventricular assist device. An impeller is placed inside a left ventricle of a subject, the impeller defining a lumen therethrough. A frame is disposed around the impeller, with a proximal bearing disposed at a proximal end of the frame and a distal bearing disposed at a distal end of the frame. An axial shaft passes through the proximal bearing, the lumen defined by the impeller, and the distal bearing. A motion-cushioning spring is disposed around the axial shaft between a distal end of the impeller and the distal bearing, the motion-cushioning spring being configured to cushion axial motion that the impeller undergoes. 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, a frame disposed around the impeller, and a distal-tip portion disposed distally with respect to the frame. A duckbill valve is disposed entirely within a distal most 10 mm of the distal-tip portion. The duckbill valve defines a wide inlet and a narrow tip that defines a slit therethrough. The duckbill valve is proximally facing, such that the wide inlet faces a distal end of the distal-tip portion and such that the narrow tip faces away from the distal end of distal-tip portion. Other applications are also described.

Abstract: Apparatus and methods are described including a blood pump that includes an impeller configured to be delivered through vasculature of a subject while the impeller is in a radially-constrained configuration. The impeller is configured to self-expand to a non-radially-constrained configuration, and to pump blood while in the non-radially-constrained configuration. A ratio between (a) a diameter of the impeller when the impeller is in its non-radially-constrained configuration at a location at which the diameter of the impeller is at its maximum and (b) a diameter of the impeller when the impeller is in its radially-constrained configuration is greater than 7:2. Other applications are also described.

Abstract: Apparatus and methods are described, including a left-ventricular assist device that includes an impeller, and a frame disposed around the impeller, the frame having a length of more than 25 mm when disposed in a non-radially constrained configuration. A rigid axial shaft extends from a proximal end of the frame to a distal end of the frame. A motor is disposed outside a body of a subject, and drives the impeller to pump blood within the subject's body, by rotating. A drive cable extends from outside the subject's body to the axial shaft. The drive cable imparts rotational motion from the motor to the impeller by rotating. The drive cable is a flexible cable comprising a plurality of coiled wires. 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 including an impeller configured to pump the subject's blood by rotating, and an axial shaft upon which the impeller is disposed. Proximal and distal radial bearings are configured to stabilize the axial shaft radially during rotation of the impeller. An atraumatic distal-tip portion is disposed distally with respect to the impeller, the atraumatic distal-tip portion including an inflatable portion. A purging fluid is pumped toward the distal-tip portion, such as to (a) purge the distal bearing, and (b) inflate the inflatable portion of the distal-tip portion. 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 that are connected to one another by at least one elongate element. The elongate element is made to radially expand and form a helical elongate element. An elastomeric material is coupled to the helical elongate element, such that the helical elongate element with the elastomeric material coupled thereto defines a blade of the impeller. The coupling is performed such that a layer of the material disposed around a radially outer edge of the helical elongate element forms the effective edge of the impeller blade. A step is performed to enhance bonding of the elastomeric material to the helical elongate element in a manner that does not cause a protrusion from the effective edge of the impeller blade. 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. 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 coupling a rigid tube to a drive cable that comprises a plurality of coiled wires, by placing ends of the drive cable and the rigid tube at a given location within a butt-welding overtube. The ends of the drive cable and the rigid tube are visible when they are disposed at the given location within the butt-welding overtube, via a window defined by the butt-welding overtube. The placement of the drive cable within the butt-welding overtube is such that a helical groove within a portion of the butt-welding overtube is disposed over the drive cable. Welding rings are formed around the butt-welding overtube. 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. The frame defines struts having a structure that is such that, as the frame transitions from a proximal end of the frame toward a center of the frame, the struts pass through junctions, at which the two struts branch from a single strut, in a Y-shape. The structure of the struts of the frame is configured such that, in response to a distal end of a delivery catheter and the frame being moved into overlapping positions with respect to each other, the frame assumes a radially-constrained configuration by becoming axially elongated, and the frame causes the impeller to assume a radially-constrained configuration by becoming axially elongated. Other applications are also described.

Abstract: Apparatus and methods are described including delivering a left-ventricular assist device to a subject's aorta. The device including a distal-tip element that defines a straight proximal portion, and a curved distal portion, the curved distal portion defining first and second curves with an elongated straight portion between the first and second curves. The distal-tip element is centered with respect to the aortic valve using the curved distal portion of the distal-tip element, to thereby guide the device through the subject's aortic valve atraumatically. A pump pumps blood through from the subject's left ventricle to the subject's aorta. Other applications are also described.

Abstract: Apparatus and methods are described including delivering a left-ventricular assist device to a subject's left ventricle. A tube is positioned such that a proximal portion of the tube traverses an aortic valve of the subject, and a distal portion of the tube is disposed within a left ventricle of the subject. A pump pumps blood through the tube from the subject's left ventricle to the subject's aorta such as to cause the proximal portion of the tube to be maintained in an open state, and to cause at least a portion of the tube to become curved. Other applications are also described.

Abstract: Apparatus and methods are described including delivering a left-ventricular assist device to a subject's left ventricle. A tube is positioned such that a proximal portion of the tube traverses an aortic valve of the subject, and a distal portion of the tube is disposed within a left ventricle of the subject. A pump pumps blood through the tube from the subject's left ventricle to the subject's aorta. A curved element is disposed within the tube and is configured to cause at least a portion of the tube to become curved. Other applications are also described.

Abstract: Apparatus and methods are described including an impeller (50) that includes a proximal bushing (64) and a distal bushing (58). Two or more helical elongate elements (52) extend from the proximal bushing (64) to the distal bushing (58), and an axial structure (54) is disposed inside of the two or more helical elongate elements (52), and along an axis around which the helical elongate elements (52) wind. The impeller (50) includes an impeller-overexpansion-prevention element (72). The impeller-overexpansion-prevention element is a single integrated structure that includes a ring (73) disposed around the axial structure (54), and a plurality of elongate elements (67) each of the elongate elements (67) extending from the ring to a respective helical elongate element (52) and being coupled to the respective helical elongate element (52) so as to prevent radial expansion of the impeller (50). 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 subject's left ventricle and to pump blood from the left ventricle to the subject's aorta, by rotating. A frame is disposed around the impeller. A tube traverses the subject's aortic valve, such that a proximal portion of the tube is disposed within the aorta and a distal portion of the tube is disposed within the left ventricle. The distal portion of the tube extends to the distal end of the frame and defines more than 10 blood-inlet openings that are sized such as (a) to allow blood to flow from the subject's left ventricle into the tube and (b) to block structures from the subject's left ventricle from entering into the frame. Other applications are also described.