A blood pump for supporting the heart may be provided that includes: a rotor with delivery elements; a rotor drive; a pressure sensor; and a regulating device that regulates a pressure or a hemodynamic parameter by means of control of the rotor drive. The pressure and/or the hemodynamic parameter may be determined by means of one or a plurality of hemodynamic sensors and/or from operating parameters of the pump. The regulating device may be suitable for regulating a hemodynamic parameter successively, such as periodically, to different target values. Using such regulation, the blood pump may be operated in an optimized manner, and operation of the blood pump may be varied in a targeted and patient-protective manner in order to attain certain goals.

A circulation assist system measures impeller displacement for use in estimating a blood flow rate related parameter. A circulation assist system includes a blood pump and a controller. The blood pump includes an impeller magnetically supported within a blood flow channel. The blood pump includes one or more sensors configured to generate output indicative of displacement of the impeller along the blood flow channel induced by a blood-flow induced thrust load applied to the impeller. The controller is configured to process the output generated by the one or more sensors to determine the displacement of the impeller along the blood flow channel. The controller is configured to process the determined displacement of the impeller to estimate at least one of the thrust load applied to the impeller, a pressure differential of the blood impelled through the blood flow channel, and a flow rate of blood pumped by the blood pump.

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 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.

Methods and apparatus for determining whether a circulatory support device is correctly positioned in a heart of a patient are provided. The method comprises receiving a motor current signal from a motor of the circulatory support device, receiving a pressure signal from a pressure sensor arranged on the circulatory support device, generating a normalized motor current signal based, at least in part, on the pressure signal, determining a pulsatility of the normalized motor current signal, determining whether the circulatory support device is correctly positioned in the heart of the patient based, at least in part, on the pulsatility of the normalized motor current signal, and outputting an alarm when it is determined that the circulatory support device is not correctly positioned in the heart of the patient.

Methods and apparatus for determining whether a circulatory support device is correctly positioned in a heart of a patient are provided. The method comprises receiving a motor current signal from a motor of the circulatory support device, receiving a pressure signal from a pressure sensor arranged on the circulatory support device, generating a normalized motor current signal based, at least in part, on the pressure signal, determining a pulsatility of the normalized motor current signal, determining whether the circulatory support device is correctly positioned in the heart of the patient based, at least in part, on the pulsatility of the normalized motor current signal, and outputting an alarm when it is determined that the circulatory support device is not correctly positioned in the heart of the patient.

Systems and methods for improving kidney function. A first mechanical circulatory support system (MCS) is introduced in a patient's heart, and a second mechanical circulatory support system is introduced in a patient's inferior vena cava or renal vein. The second mechanical circulatory support system is operated while the first mechanical circulatory support system is operating. A renal parameter is monitored during. Combined operation of the two mechanical circulatory support systems results in a change in renal parameter, e.g. pressure drop in the renal vein, indicating an improvement in kidney function. Once the renal parameter is determined to be below a target threshold, operation of the second mechanical circulatory support device is stopped.

A method of controlling an implantable blood pump including a housing having a proximal portion including an inlet, a distal portion including an outlet, and an impeller therein, the method including detecting when a pressure in the housing exceeds a pressure threshold and executing a first vector control command to displace the impeller axially in a distal direction from a primary position to a secondary position different than the primary position in response to the pressure exceeding the pressure threshold.