The invention relates to a flexible shaft arrangement having a flexible hollow shaft which has an end at the drive side and an end at the output side, wherein the hollow shaft is reinforced sectionally between these ends by a core extending in its interior. Stiffer and more flexible sections can hereby be selectively positioned within the shaft arrangement.

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. The blood pump also includes an impeller coupled to the axial shaft such that, as the axial shaft rotates, the impeller pumps blood of the subject. Proximal and distal radial bearings surround the axial shaft and are configured to radially stabilize the axial shaft while the axial shaft rotates. Proximal and distal sleeves, which are less flexible than the axial shaft, are disposed around the axial shaft, such that the proximal and distal sleeves contact the proximal and distal radial bearings, respectively, as the axial shaft rotates. A ratio between a length of the axial shaft and a combined length of the proximal sleeve and distal sleeve is between 2:1 and 6:1. Other applications are also described.

Apparatus and methods are described including a solid axial shaft having a shaft diameter that is less than 0.8 mm, an impeller configured for insertion into a left ventricle of a heart of a subject and coupled to the axial shaft, and a hollow drive cable coupled, at a distal end of the drive cable, to the axial shaft, and configured to rotate so as to rotate the axial shaft, thereby causing the impeller to pump blood of the subject from the left ventricle. Other applications are also described.

Fluid pressure or flow in a human body may be adjusted with circulation or perfusion systems and methods. The system may include a first pump implantable in a chamber or vessel of the human body, and a plurality of struts connected to a housing of said first pump, wherein the struts secure the first pump in a desired location of the chamber or vessel. The system may also include one or more flow modification elements disposed on the first pump, where the flow modification elements direct flow to a desired organ or a desired vessel to adjust pressure or flow as desired.

Catheter blood pumps that include an expandable conduit coupled to at least one hub shaped to promote smooth blood flow. In some examples, the at least one hub includes non-metallic configuration and the struts comprise a metallic configuration (e.g., nitinol). The hub can include one or more layers, including a combination of Chronoflex and Pebax.

Catheter blood pumps that include an expandable conduit coupled to at least one hub shaped to promote smooth blood flow. In some examples, the at least one hub includes non-metallic configuration and the struts comprise a metallic configuration (e.g., nitinol). The hub can include one or more layers, including a combination of Chronoflex and Pebax.

Apparatus and methods are described including a delivery catheter and a delivery tube configured to extend from outside a subject's body into the subject's left ventricle via the delivery catheter. A locking unit is configured to couple to a proximal end of the delivery catheter and the delivery tube is configured to pass through the locking unit. The locking unit includes at least one internal seal configured to surround the delivery tube and to inhibit backflow of blood of the subject, from the delivery catheter, through the locking unit. The locking unit also includes a clip, which has only two states, which consist of a closed state, in which the clip grips the delivery tube so as to inhibit movement of the delivery tube relative to the delivery catheter, and an open state, in which the clip does not grip the delivery tube. Other applications are also described.

Apparatus and methods are described including a delivery catheter and a delivery tube configured to extend from outside a subject's body into the subject's left ventricle via the delivery catheter. A locking unit is configured to couple to a proximal end of the delivery catheter and the delivery tube is configured to pass through the locking unit. The locking unit includes at least one internal seal configured to surround the delivery tube and to inhibit backflow of blood of the subject, from the delivery catheter, through the locking unit. The locking unit also includes a clip, which has only two states, which consist of a closed state, in which the clip grips the delivery tube so as to inhibit movement of the delivery tube relative to the delivery catheter, and an open state, in which the clip does not grip the delivery tube. Other applications are also described.

A distal extension for a blood pump may be provided. The distal extension may include a tubular body. The distal end of the tubular body may be coupled to an intermediate point on the tubular body to form a closed loop at a distal end of an atraumatic distal extension. The closed loop may define an aperture extending through the closed loop, the closed loop having a central plane parallel to a central axis of the tubular body at the proximal end. In various aspects, the tubular body may include a bend. The bend may define an angle between a central axis of a first substantially straight section of the tubular body proximal to the bend and a central axis of a second substantially straight section of the tubular body distal to the bend. In various aspects, the closed loop may be a non-circular closed loop.

A distal extension for a blood pump may be provided. The distal extension may include a tubular body. The distal end of the tubular body may be coupled to an intermediate point on the tubular body to form a closed loop at a distal end of an atraumatic distal extension. The closed loop may define an aperture extending through the closed loop, the closed loop having a central plane parallel to a central axis of the tubular body at the proximal end. In various aspects, the tubular body may include a bend. The bend may define an angle between a central axis of a first substantially straight section of the tubular body proximal to the bend and a central axis of a second substantially straight section of the tubular body distal to the bend. In various aspects, the closed loop may be a non-circular closed loop.