A device that regulates, monitors, and provides data on the progress of a large-volume injector during its injection sequence. The device comprises an injector and a monitor assembly. The injector has a syringe having a plunger, and a biasing device that biases the plunger through the syringe. The monitor assembly comprises a resistance unit configured to resist movement of the plunger, a gear connected to the plunger by the resistance unit, and a control unit configured to monitor the position, and regulate the rotation, of the gear. Wherein linear movement of the plunger causes the gear to rotate so that the control unit generates information on the position of the plunger.
