A ventricular assist device (VAD) for use with a heart includes a housing, an upper membrane pump including a pumping chamber coupled to one-way upper inlet and outlet valves, a lower membrane pump including a pumping chamber coupled to one-way lower inlet and outlet valves, and an actuator that causes the upper membrane pump and the lower membrane pump to alternately draw blood into and pump blood out of their respective pumping chambers, and a control module in operative communication with the actuator, wherein the actuator operates with a pumping frequency which is greater than a pulse frequency of the heart.

A ventricular assist device (VAD) for use with a heart includes a housing, an upper membrane pump including a pumping chamber coupled to one-way upper inlet and outlet valves, a lower membrane pump including a pumping chamber coupled to one-way lower inlet and outlet valves, and an actuator that causes the upper membrane pump and the lower membrane pump to alternately draw blood into and pump blood out of their respective pumping chambers, and a control module in operative communication with the actuator, wherein the actuator operates with a pumping frequency which is greater than a pulse frequency of the heart.

A heart pump assembly includes an impeller blade coupled to a rotor or a drive shaft, a cannula, a distal projection coupled to a distal end of the cannula and a blood inlet having a plurality of apertures. The plurality of apertures is radially oriented and disposed about a circumference of the cannula. The plurality of apertures includes at least a first ring of apertures which are proximal to the distal projection and a second ring of apertures which are proximal of the first ring of apertures. The plurality of apertures can allow the heart pump assembly to continue to function if anatomical structures or tissue become suctioned to a portion of the heart pump.

A heart pump assembly includes an impeller blade coupled to a rotor or a drive shaft, a cannula, a distal projection coupled to a distal end of the cannula and a blood inlet having a plurality of apertures. The plurality of apertures is radially oriented and disposed about a circumference of the cannula. The plurality of apertures includes at least a first ring of apertures which are proximal to the distal projection and a second ring of apertures which are proximal of the first ring of apertures. The plurality of apertures can allow the heart pump assembly to continue to function if anatomical structures or tissue become suctioned to a portion of the heart pump.

Fluid pumps and medical treatment devices, in particular dialysis machines, include devices configured such that operating pressures and flow rates of the fluid pumps assume desired characteristics, in particular constant values or controlled profiles. The operating point of a peristaltic hose roller pump is adjusted based on an angle of rotation of a pump rotor, or by adjusting the operating point of a centrifugal pump in accordance with a profile.

A heart pump assembly includes an impeller blade coupled to a rotor or a drive shaft, a cannula, a distal projection coupled to a distal end of the cannula and a blood inlet having a plurality of apertures. The plurality of apertures is radially oriented and disposed about a circumference of the cannula. The plurality of apertures includes at least a first ring of apertures which are proximal to the distal projection and a second ring of apertures which are proximal of the first ring of apertures. The plurality of apertures can allow the heart pump assembly to continue to function if anatomical structures or tissue become suctioned to a portion of the heart pump.

A heart pump assembly includes an impeller blade coupled to a rotor or a drive shaft, a cannula, a distal projection coupled to a distal end of the cannula and a blood inlet having a plurality of apertures. The plurality of apertures is radially oriented and disposed about a circumference of the cannula. The plurality of apertures includes at least a first ring of apertures which are proximal to the distal projection and a second ring of apertures which are proximal of the first ring of apertures. The plurality of apertures can allow the heart pump assembly to continue to function if anatomical structures or tissue become suctioned to a portion of the heart pump.