Apparatus are provided for motor control systems and related medical devices. In one embodiment, a control system includes a motor having a rotor, a modulation module coupled to the motor, and a control module coupled to the modulation module. The modulation module generates a modulated voltage that is applied to the motor and rotates the rotor to deliver fluid via a fluid path. The control module adjusts a duty cycle of the modulated voltage to achieve a commanded rotation of the rotor and detects an occlusion condition in the fluid path based on the duty cycle.
