Methods and apparatuses for determining operational parameters of a blood pump comprising a rotor which transports the blood are provided. The change in the behaviour of at least one first and one second operational parameter, independently from each other, of the pump, is determined. A determination of the flow through the pump and/or the difference in pressure across the pump and/or the viscosity of the blood takes into account the determined change in behaviour of the at least two operational parameters. A modelling for a dynamic model of the known quantities may be carried out and an estimation method using a Kalman filter may be used.

Methods and apparatuses for determining operational parameters of a blood pump comprising a rotor which transports the blood are provided. The change in the behaviour of at least one first and one second operational parameter, independently from each other, of the pump, is determined. A determination of the flow through the pump and/or the difference in pressure across the pump and/or the viscosity of the blood takes into account the determined change in behaviour of the at least two operational parameters. A modelling for a dynamic model of the known quantities may be carried out and an estimation method using a Kalman filter may be used.

A method of operating an implantable blood pump having a first stator, a second stator, and an impeller movably disposed there between. The method includes applying a first voltage waveform at first phase to the first stator to generate a magnetic field to rotate the impeller. A second voltage waveform is applied at a second phase shifted from the first phase to the second stator to rotate the impeller, the second voltage waveform is asymmetric to the first voltage waveform.

A method of operating an implantable blood pump having a first stator, a second stator, and an impeller movably disposed there between. The method includes applying a first voltage waveform at first phase to the first stator to generate a magnetic field to rotate the impeller. A second voltage waveform is applied at a second phase shifted from the first phase to the second stator to rotate the impeller, the second voltage waveform is asymmetric to the first voltage waveform.

A mechanical circulatory support device is provided. The device has a housing containing separate first and second pumps. Each pump having an inlet, an outlet, and an impeller. The device also having a switching mechanism located within the housing and movable from a first position to a second position to divert blood flow within the housing to an inlet of one of the pumps and/or to bypass blood flow relative to one of the pumps within the housing.

Blood pumps discussed herein may be suitable for use as a ventricular assist device (VAD) or the like. The blood pumps cause minimal blood damage, are energy efficient, and can be powered by implanted batteries for extended periods of time. Further, these pumps are also beneficial because they may improve the quality of life of a patient with a VAD by reducing restrictions on the patient's lifestyle. The blood pumps can provide radial and axial stability to a rotating impeller that is driven by a separate rotor. Both radial and axial stability can be provided, at least in part, by one or more permanent magnetic couplings between the rotor and the impeller and/or one or more permanent magnetic bearings between the pump housing and the impeller.

Blood pumps discussed herein may be suitable for use as a ventricular assist device (VAD) or the like. The blood pumps cause minimal blood damage, are energy efficient, and can be powered by implanted batteries for extended periods of time. Further, these pumps are also beneficial because they may improve the quality of life of a patient with a VAD by reducing restrictions on the patient's lifestyle. The blood pumps can provide radial and axial stability to a rotating impeller that is driven by a separate rotor. Both radial and axial stability can be provided, at least in part, by one or more permanent magnetic couplings between the rotor and the impeller and/or one or more permanent magnetic bearings between the pump housing and the impeller.

A method and a device for the measurement of one or more fluid-mechanically effective parameters of a fluid, with a fluid pump which comprises a delivery element which is mounted in a magnet bearing, and the delivery element of the fluid pump is excited into an oscillation by way of an excitation device, wherein the oscillation parameters as well as, as the case may be, the oscillation behaviour is measured, and parameters of the fluid are determined from this.

A rotary machine is provided which may include a rotor and a stator within a housing. The stator may be for generating a rotating magnetic field for applying a torque to the rotor. A commutator circuit may provide a plurality of phase voltages to the stator, and a controller may adjust the plurality of phase voltages provided by the commutator circuit to modify an attractive force of the stator on the rotor to move the rotor in an axial direction.

A biomedical apparatus for pumping blood of a human or an animal patient through a secondary blood circuit is provided, including a blood pump, an inlet duct and an outlet duct for guiding blood of the patient to the blood pump and back to the patient. The apparatus further includes a measuring device with at least one pressure sensor for measuring pressure values in the patient's circulatory system. A controller is provided that includes at least two different preset control algorithms for regulating the operating point of the blood pump based on the measured pressure values. The controller is configured to select one of these preset control algorithms for being applied in dependence on the position of the at least one pressure sensor in the patient's circulatory system.