A blood pump controller is configured to be operated according to a pump speed pattern that is selected according to a pump power consumption rate associated with the pump speed pattern, or according to a pump efficiency associated with the pump speed pattern. In a first mode, the controller is operated to produce a pump speed pattern that produces a desired rate of blood pressure change. When a low power condition is detected, the controller can be switched to a power-saving mode to produce a pump speed pattern that has a low power consumption rate, even if the desired rate of pressure change is not produced in the power-saving mode.