The present disclosure is directed generally to mechanical cardiovascular support systems used in the medical field to assist the movement of blood. In particular the present disclosure is directed to an impeller having features that allow improved performance. An annular flow area around a rotating impeller may be variable along the axial length of the impeller. A first radial gap, between a distal region of the impeller and a surrounding tubular housing, may be greater or smaller than a second radial gap, between a proximal region of the impeller and the surrounding tubular housing.

Catheter blood pumps that include a pump portion with an impeller. The blood pumps include an axially extendable member with a distal end that is disposed further distally than the distal end of the impeller, and a guide member extending through the pump portion and axially moveable relative to the pump portion, the guide member inoperable axial communication with the extendable member such that axial movement of the guide member causes axial movement of the extendable member relative to the pump portion.

A sealed micropump includes an integrated motor and at least one impeller for generating fluid flow inside a housing of the micropump. The impeller includes a radial sliding bearing with a spider bearing for supporting an impeller pin of the impeller inside the housing. The impeller pin includes a sheathing of a material different from a material of the spider bearing.

A sealed micropump includes an integrated motor and at least one impeller for generating fluid flow inside a housing of the micropump. The impeller includes a radial sliding bearing with a spider bearing for supporting an impeller pin of the impeller inside the housing. The impeller pin includes a sheathing of a material different from a material of the spider bearing.

Apparatus and methods are described including an impeller (50) that includes a proximal bushing (64) and a distal bushing (58). Two or more helical elongate elements (52) extend from the proximal bushing (64) to the distal bushing (58), and an axial structure (54) is disposed inside of the two or more helical elongate elements (52), and along an axis around which the helical elongate elements (52) wind. The impeller (50) includes an impeller-overexpansion-prevention element (72). The impeller-overexpansion-prevention element is a single integrated structure that includes a ring (73) disposed around the axial structure (54), and a plurality of elongate elements (67) each of the elongate elements (67) extending from the ring to a respective helical elongate element (52) and being coupled to the respective helical elongate element (52) so as to prevent radial expansion of the impeller (50). Other applications are also described.

Various aspects of the present disclosure are directed towards apparatuses, systems, and methods that may include a blood pump. The blood pump may include a magnetic field source and an impeller assembly. The impeller assembly includes an impeller and a driven magnet. The driven magnet is longitudinally offset and distally disposed relative to the magnetic field source, and the driven magnet is rotatable and longitudinally controlled by the magnetic field source. The driven magnet includes a distal side, the distal side faces the impeller. The blood pump further includes a bearing assembly near the distal side of the driven magnet.

Various aspects of the present disclosure are directed towards apparatuses, systems, and methods that may include a blood pump. The blood pump may include a magnetic field source and an impeller assembly. The impeller assembly includes an impeller and a driven magnet. The driven magnet is longitudinally offset and distally disposed relative to the magnetic field source, and the driven magnet is rotatable and longitudinally controlled by the magnetic field source. The driven magnet includes a distal side, the distal side faces the impeller. The blood pump further includes a bearing assembly near the distal side of the driven magnet.

A flexible drive shaft assembly is provided for an intravascular medical device, for example and without limitation, a blood pump, a rotational atherectomy device, or a rotational thrombectomy device. The blood pump embodiment provides an electric motor and a rotational impeller, with a rotational drive shaft disposed therebetween and configured to rotationally drive the impeller. The drive shaft is moved from an undeformed length to a deformed length when connected between the electric motor and the rotational impeller to provide a biasing force on the rotational impeller in the proximal direction to maintain the impeller in a desired axial or linear location. In other embodiments, drive shaft comprises a proximal section with a length and a spring constant and a distal section of relatively longer length and a relatively higher spring constant. In other embodiments, hypotube(s) and/or support mandrel(s) may be provided.

A flexible drive shaft assembly is provided for an intravascular medical device, for example and without limitation, a blood pump, a rotational atherectomy device, or a rotational thrombectomy device. The blood pump embodiment provides an electric motor and a rotational impeller, with a rotational drive shaft disposed therebetween and configured to rotationally drive the impeller. The drive shaft is moved from an undeformed length to a deformed length when connected between the electric motor and the rotational impeller to provide a biasing force on the rotational impeller in the proximal direction to maintain the impeller in a desired axial or linear location. In other embodiments, drive shaft comprises a proximal section with a length and a spring constant and a distal section of relatively longer length and a relatively higher spring constant. In other embodiments, hypotube(s) and/or support mandrel(s) may be provided.

A percutaneous trans-valvular blood pump system including a pump subsystem, catheter, and sheath is described. The pump subsystem includes a plurality of impeller pump assemblies arranged in tandem within a cannula portion of the catheter. The impeller pump assemblies are configured to operate in parallel so that blood pumped through one pump does not enter another pump.