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 within the subject's left ventricle. A frame disposed within the distal portion of the tube defines cells, and a width of each of the cells within a generally cylindrical portion of the frame is less than 2 mm. An inner lining lines at least some of the cylindrical portion of the frame. An impeller is disposed inside the frame. Other applications are also described.

Abstract: Apparatus and methods are described including identifying a subject as suffering from a condition that causes the subject to have elevated central venous pressure. In response thereto, a device is placed inside the subject's vena cava, and the device is deployed inside the subject's vena cava, such that, in a passive manner, the device reduces blood pressure within the subject's renal veins relative to the subject's central venous pressure. 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 provided including a mitral valve prosthesis. The prosthesis includes an inner support structure having downstream and upstream sections, the upstream section having a cross-sectional area greater than the downstream section. The inner support structure is configured to be positioned on an atrial side of the native valve complex, and to prevent the prosthesis from being dislodged into the left ventricle. A prosthetic valve having prosthetic valve leaflets is coupled to the inner support structure. An outer support structure has engagement arms, downstream ends of the engagement arms being coupled to the inner support structure. The prosthesis is configured such that, upon implantation thereof: downstream ends of the native valve leaflets, downstream ends of the engagement arms, and downstream ends of the prosthetic leaflets, are disposed at a longitudinal distance from one another of less than 3 mm. Other embodiments are also described.

Abstract: Apparatus and methods are described including manufacturing an impeller by coupling a material to a helical elongate element, such that the helical elongate element with the material coupled thereto defines a blade of the impeller. A portion of a structure that includes the helical elongate element is dipped into the material while the material is in a liquid state. The material is dried, while the material is being supported by the at least one helical elongate element. During the drying of material, the structure is rotated about its longitudinal axis, such as to facilitate the formation of a film of the material having a substantially uniform thickness within the impeller blade. Other applications are also described.

Abstract: Apparatus and methods are described including manufacturing a housing for an impeller of a blood pump by placing an inner lining around a mandrel, placing a cylindrical portion of a frame around the inner lining, and placing a distal portion of an elongate tube around a portion of the frame. While the distal portion of the elongate tube is disposed around the portion of the frame, the inner lining, the frame, and the distal portion of the elongate tube are heated, via the mandrel, and pressure is applied from outside the distal portion of the elongate tube, such as to cause the distal portion of the elongate tube to conform with a structure of the struts of the frame, and to cause the inner lining and the distal portion of the elongate tube to become coupled to the frame. 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 at least one helical elongate element that winds from the proximal end portion to the distal end portion. A film of material is coupled to the at least one helical elongate element, such that the helical elongate element with the film of material coupled thereto defines a blade of the impeller. The film of material is shaped to define a hollow central lumen therethrough. 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 catheter (20) configured to be placed inside a blood vessel of a subject. A first impeller (28) is disposed on the catheter, and a second impeller (28) is disposed on the catheter, proximally to the first impeller. A support structure (160) is disposed upon the catheter such that a longitudinal center of the support structure is disposed between the first and second impellers, the support structure being configured to support an inner wall of the blood vessel in an open configuration in a region between the first and second impellers. Other applications are also described.

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 a plurality of winged projections are coupled to the frame. An impeller is disposed inside the tube, the impeller including at least one helical elongate element, and a film of material supported at least partially by the helical elongate element. The impeller is rotated, such as to pump blood from the subject's left ventricle to the subject's aorta. Blood flow that is generated by the rotation of the impeller is rectified, by using the winged projections to direct blood flow toward a direction of the longitudinal axis of the tube. 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 within the subject's left ventricle. A frame disposed within the distal portion of the tube defines cells, and a width of each of the cells within a cylindrical portion of the frame is less than 2 mm. An inner lining lines at least some of the cylindrical portion of the frame. An impeller is disposed inside the frame such that a gap between an outer edge of the impeller and the inner lining is less than 1 mm. The impeller is stabilized with respect to the frame, such that, during rotation of the impeller, the gap between the outer edge of the impeller and the inner lining is maintained and is substantially constant. Other applications are also described.

Abstract: Apparatus and methods are described including placing, into a subject's body, a blood-pump tube, with an impeller disposed within the blood-pump tube. At least one blood-pressure-measurement element extends to at least an outer surface of the blood-pump tube, such that the distal end of the blood-pressure-measurement element is in direct fluid communication with a bloodstream of the subject outside the blood-pump tube at a location that is proximal to blood-inlet opening(s) defined by the blood-pump tube. Blood is pumped through the blood-pump tube, using the impeller. Pressure of the bloodstream of the subject outside the blood-pump tube is measured by measuring blood pressure at the distal end of the left-ventricular blood-pressure-measurement element. 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 left ventricle of a subject. A driving magnet is coupled to a motor and is rotated by the motor. A driven magnet is magnetically coupled to the driving magnet and is rotated by the driving magnet. A drive cable extends from the driven magnet and imparts rotational motion from the driven magnet to the impeller. A set of sensors is configured to detect a magnetic phase difference between the driven magnet and the driving magnet. A computer processor receives the detected magnetic phase difference and determines a physiological parameter of the subject, at least partially in response thereto. 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 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 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 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 method are described including identifying a subject as suffering from a condition that causes the subject to have elevated central venous pressure. In response thereto, a device is placed inside the subject's vena cava such that an upstream end of the device is placed at a location upstream of junctions of the vena cava with all of the subject's renal veins. The device defines a passage through the device, at least a portion of the passage converging in a direction from an upstream end of the device to downstream end of the device. Other applications are also described.

Abstract: Apparatus and methods are described including a catheter, and first and second impellers configured to be inserted into a subject's body via the catheter, the first and second impellers being disposed in series with each other. A motor is configured to generate rotational motion. A rotation shaft extends from the motor to the first impeller and imparts the rotational motion from the motor to the first impeller. A gear mechanism disposed between the first and second impeller is configured to effect a change in rotational motion that is imparted from the first impeller to the second impeller, such that the second impeller rotates in a different manner from the first impeller. Other applications are also described.