Apparatus and methods are described including a blood pump that includes an impeller, and a motor configured to drive the impeller to pump blood by rotating the impeller. The impeller is configured to undergo axial motion, in response to changes in a pressure against which the impeller is pumping. A sensor detects the axial motion of the impeller, and generates a sensor signal in response thereto. A computer processor receives the sensor signal and generates an output in response thereto. Other applications are also described.

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.

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.

In a pump housing having an interior for accommodating a pump rotor, which may be transferred from a radially compressed state into a radially expanded state, and comprises a housing skin revolving in circumferential direction, as well as at least one reinforcement element, a stretch-resistant element revolving in circumferential direction is provided, which is stretched less than 5% in the expanded state as opposed to the force-free state in circumferential direction, and which limits any further expansion of the pump housing in radial direction.

In a pump housing having an interior for accommodating a pump rotor, which may be transferred from a radially compressed state into a radially expanded state, and comprises a housing skin revolving in circumferential direction, as well as at least one reinforcement element, a stretch-resistant element revolving in circumferential direction is provided, which is stretched less than 5% in the expanded state as opposed to the force-free state in circumferential direction, and which limits any further expansion of the pump housing in radial direction.

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.

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.

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.

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.

An intravascular device for pumping blood includes a catheter comprising a membrane chamber located between a proximal end and a distal end of the catheter. An inflatable membrane is disposed within the membrane chamber. The intravascular device includes a first one-way valve and optionally a second one-way valve configured to permit blood flow in a first direction. The first one-way valve may be positioned proximal to the membrane chamber, and the second one-way valve may be positioned distal to the membrane chamber. Methods related to intravascular devices and their respective use are provided.