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.

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.

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.

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.

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.

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.

Various systems and methods are provided for reducing pressure at an outflow of a duct such as the thoracic duct or the lymphatic duct. A catheter system can include a catheter shaft configured to be at least partially implantable within a patient's vein, a flexible membrane attached to the catheter shaft, the flexible membrane being a collapsible, tube-like member having a lumen extending therethrough, and a single selectively deployable restriction member formed over a portion of the flexible membrane at substantially a midpoint between a proximal end of the flexible membrane and a distal end of the flexible membrane, the restriction member being configured to control a size of the lumen so as to direct a controlled volume of fluid from an upstream side of the restriction member to a downstream side the restriction member.

Various systems and methods are provided for reducing pressure at an outflow of a duct, such as the thoracic duct or the lymphatic duct, for example, the right lymphatic duct. A catheter system can be configured to be at least partially implanted within a vein of a patient in the vicinity of an outflow port of a duct of the lymphatic system. The catheter system includes first and second selectively deployable restriction members each configured to be activated to at least partially occlude the vein within which the catheter is implanted and to thus restrict fluid within a portion of the vein. The catheter system includes an impeller configured to be driven by a motor to induce a low pressure zone between the restriction members by causing blood to be pumped through the catheter when the restriction members occlude the vein.

A cardiac pump having a turbine with internal blades, includes a pump designed to circulate a fluid, including a housing, and a turbine which is arranged in the housing and is designed to move rotationally relative to the housing. The turbine includes a body designed to move rotationally, a hollow central part which extends through the body from one side to the other and is intended to allow the fluid to pass through the turbine, and at least one blade that is positioned on the inner wall of the body, in the hollow central part, and is designed to circulate the fluid.

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.