Abstract: Apparatus and methods are described including a tube configured to traverse a subject's aortic valve. A frame is disposed within a portion of the tube, and an impeller is disposed inside the tube such that, when the impeller and the tube are deployed inside the subject, a gap between an outer edge of the impeller and an inner surface of the tube is less than 1 mm. The impeller rotates such as to pump blood from the left ventricle to the aorta, and is stabilized with respect to the tube, such that, during rotation of the impeller, the gap between the outer edge of the impeller and the inner surface of the tube is maintained. The impeller includes at least one impeller blade defined by a helical elongate element, and a film of material supported by the helical elongate element. Other applications are also described.

Abstract: Apparatus and methods are described including a left-ventricular assist device that includes a tube configured to traverse a subject's aortic valve, with a distal portion of the tube disposed within the subject's left ventricle. A frame is disposed within the distal portion of the tube. A pump disposed within the frame pumps blood through the tube. A distal-tip element 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 before passing through an inflection point and curving in a second direction with respect to the longitudinal axis, such that the curved distal portion defines a bulge on one side of the longitudinal axis. Other applications are also described.

Abstract: Apparatus and methods are described including placing, into a subject's body, a blood-pump tube, with a blood pump disposed within the blood-pump tube. At least one blood-pressure-measurement tube, which defines an opening at a distal end thereof, extends to at least an outer surface of the blood-pump tube, such that the opening at the distal end of the blood-pressure-measurement tube is in direct fluid communication with a bloodstream of the subject outside the blood-pump tube. Blood is pumped through the blood-pump tube, using the blood pump. Pressure of the bloodstream of the subject outside the blood-pump tube is measured by measuring pressure of blood within the blood-pressure-measurement tube. Other applications are also described.

Abstract: Apparatus and methods are described including a blood pump that includes an impeller that has proximal and distal bushings, and is configured to pump blood through a subject's body. A frame, which includes proximal and distal bearings, is disposed around the impeller. An axial shaft passes through the proximal and distal bearings of the frame and the proximal and distal bushings of the impeller. The axial shaft is coupled to at least one of the proximal and distal bushings of the impeller, such that the at least one bushing is held in an axially-fixed position with respect to the axial shaft, and is not held in an axially-fixed position with respect to the proximal and distal bearings. Other applications are also described.

Abstract: Apparatus and methods are described including a tube (20) that defines a flared downstream portion (30) that diverges toward a downstream end (32) of the tube, and a flared upstream portion (26) that diverges toward an upstream end (28) of the tube, such that a central portion (34) of the tube is narrower than at the ends of the tube. The tube defines a plurality of lateral openings (36). A support frame (24) supports the tube within a subject's vena cava, such that the downstream portion is sealed with respect to the wall of the vena cava downstream of junctions of the vena cava with all of the subject's renal veins, and the upstream portion is sealed with respect to the inner wall of the vena cava upstream of junctions of the vena cava with all of the subject's renal veins. 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: A blood pump is described that includes an impeller having proximal and distal bushings, at least one helical elongate element, a spring that is disposed inside of the helical elongate element and along an axis around which the helical elongate element winds, and a film of material supported between the helical elongate element and the spring. A frame is disposed around the impeller. A flexible elongate element extends radially from the spring to the helical elongate element, and maintains the helical elongate element within a given distance from the spring, to thereby maintain a gap between an outer edge of a blade of the impeller and an inner surface of the frame, during rotation of the impeller. Other applications are also described.

Abstract: Apparatus and methods are described including a blood pump that includes an axial shaft, an impeller disposed on the axial shaft, a frame disposed around the impeller, and a motor disposed outside a subject's body, and configured to drive the impeller to pump blood from a distal end of the impeller to a proximal end of the impeller. A drive cable extends from outside the subject's body to the axial shaft, and is configured to impart rotational motion from the motor to the impeller by rotating. The drive cable is held in a preloaded state with respect to the frame, such that initiation of pumping of blood by rotation of the impeller does not cause the drive cable to axially elongate. 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 an elongate tube configured to traverse an aortic valve of a subject, such that a proximal end of the tube is disposed within an aorta of the subject and a distal end of the tube is disposed within a left ventricle of the subject, the elongate tube comprising a blood-impermeable material, and a radially-expandable frame disposed within at least a portion of the tube. An impeller is disposed inside the radially-expandable frame, the impeller being configured to rotate such as to pump blood from the left ventricle to the aorta. A protective structure is disposed around the impeller, in addition to the radially-expandable frame of the elongate tube. Other applications are also described.

Abstract: Apparatus and methods are described including placing an impeller of a ventricular assist device inside a left ventricle of a subject, with a frame disposed around the impeller. The impeller is driven to pump blood from the left ventricle to an aorta of the subject, by rotating the impeller. The impeller is placed inside the left ventricle such that the impeller is allowed to undergo axial motion with respect to the frame, in response to cyclical changes in a pressure difference between the left ventricle and the aorta. 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 a left ventricular assist device. The left ventricular assist device includes an impeller configured to be placed inside a subject's left ventricle, and to pump blood from the subject's 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 subject's aorta and a distal portion of the tube is disposed within the subject's left ventricle. The distal portion of the tube defines one or more blood inlet openings that are configured to allow blood to flow from the subject's left ventricle into the tube. A braided element is configured to prevent inner structures of the left ventricle from passing into the one or more blood inlet openings. Other applications are also described.

Abstract: Apparatus and methods are described including a left ventricular assist device. The left ventricular assist device includes an impeller configured to be placed inside a subject's left ventricle, and to pump blood from the subject's 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 subject's aorta and a distal portion of the tube is disposed within the subject's left ventricle. The distal portion of the tube defines one or more blood inlet openings that are configured to allow blood to flow from the subject's left ventricle into the tube. A mesh is configured to prevent inner structures of the left ventricle from passing into the one or more blood inlet openings. 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 ventricular assist device that includes a tube. A proximal portion of the tube traverses a subject's aortic valve, and a distal portion of the tube is disposed within the subject's left ventricle. A blood pump is disposed within the distal portion of the tube and pumps blood through the tube from the subject's left ventricle to the subject's aorta, by pumping the blood into the tube via one or more blood inlet openings that are defined by the tube and that are configured to be disposed within the subject's left ventricle, and by pumping blood out of the tube via one or more blood outlet openings that are defined by the tube and that are configured to be disposed within the subject's aorta. The one or more blood outlet openings have teardrop shapes. Other applications are also described.

Abstract: Apparatus comprising and methods are described including a blood pump that includes an axial shaft, and an impeller disposed on the axial shaft. The impeller is configured to pump blood of the subject by rotating. The impeller and the axial shaft are configured to undergo axial back-and-forth motion during operation of the impeller. A distal tip element is disposed at a distal end of the blood pump. The distal tip element defines an axial-shaft-receiving tube, configured to receive at least a portion of the axial shaft during forward motion of the axial shaft. The distal tip element additionally defines an atraumatic distal tip portion disposed distally of the axial-shaft-receiving tube. Other applications are also described.

Abstract: Apparatus and methods are described including a blood pump that is placed inside a body of subject. The blood pump includes an impeller that includes proximal and distal bushings, and that defines an axial lumen that extends from the proximal bushing to the distal bushing, a frame disposed around the impeller, and an axial shaft that passes through the proximal and distal bushings of the impeller. A distal end of a delivery catheter, and the frame and the impeller, are configured to be moved with respect to one another, to thereby cause the frame to assume a radially-constrained configuration by the frame becoming axially elongated, and cause the impeller to assume a radially-constrained configuration by the impeller becoming axially elongated. Other applications are also described.

Abstract: Apparatus and methods are described including a ventricular assist device that includes an impeller configured to be placed inside a subject's left ventricle. A frame is disposed around the impeller, the frame defining generally-cylindrical central portion, and a proximal conical portion that widens from a proximal end of the frame to a proximal end of the generally-cylindrical central portion. A motor drives the impeller to pump blood from the left ventricle to the subject's aorta, by rotation of the impeller. The impeller is configured to be disposed at least partially within the proximal conical portion of the frame during at least some of a time during which the impeller rotates. Other applications are also described.

Abstract: Apparatus and methods are described including placing a blood pump into a subject's body, the blood pump including an axial shaft, an impeller disposed on the axial shaft, and a drive cable extending from outside the subject's body to the axial shaft. The impeller is driven to pump blood from a distal end of the impeller to a proximal end of the impeller by imparting rotational motion to the impeller via the drive cable, in a given direction of rotation. At least a portion of the drive cable includes a plurality of wires disposed in a coiled configuration that is such that, in response to the drive cable rotating in the given direction of rotation, the plurality of wires disposed in the coiled configuration at least partially unwind, such that the portion of the drive cable shortens axially. Other applications are also described.