Generating artificial pulse

A mechanical circulatory assist system comprising:

• a continuous-flow pump implantable in fluid communication with a left ventricle of a patient's heart and an aorta of the patient to assist blood flow from the left ventricle to the aorta;
• and
• a controller operatively connected to the continuous-flow pump and operable to control the continuous-flow pump to generate a blood flow pattern that produces opening of a native aortic valve of the patient, the controller repeating an operational cycle in which the controller controls a rotation speed of the continuous-flow pump to:
• operate the continuous-flow pump in an artificial pulse mode over a first period of time,
• transition operation of the continuous-flow pump from the artificial pulse mode to a rotation speed that produces a reduced blood flow rate that accomodates generation of a blood flow rate by the patient's heart, which produces opening of a native aortic valve of the patient,
• operate the continuous-flow pump at the rotation speed that produces the reduced blood flow rate over a second period of time, and
• increase the rotation speed of the continuous-flow pump from the rotation speed that produces the reduced blood flow rate.

A method of controlling a rotation speed of a ventricular assist device to produce opening of a native aortic valve of a patient, the method comprising controlling, via a controller, the ventricular assist device over an operational cycle that comprises:

• a first segment over which the ventricular assist device is operated in an artificial pulse mode;
• a second segment over which operation of the ventricular assist device is transitioned from the artificial pulse mode to a rotation speed that produces a reduced blood flow rate that accommodates generation of a blood flow rate by the patient's heart;
• a third segment over which the ventricular assist device is operated at the rotation speed that produces the reduced blood flow rate, wherein a contraction of the left ventricle that opens and closes the native aortic valve occurs during the third segment, and
• a fourth segment over which the rotation speed of the ventricular assist device is increased from the rotation speed that produces the reduced blood flow rate.