A syringe plunger driver system capable of capturing syringes of widely varying sizes comprises a pair of asymmetric plunger retainer arms pivotally mounted to a plunger driver. The system includes a low profile driver having a length that exceeds its width so that it may be mounted adjacent control modules and other operational modules. The arms are biased toward each other and one arm is longer than the other with a notch on an inside edge to receive the tip of the shorter arm when capturing small syringe flanges. A rotation knob mounted to the front surface of the low profile driver forces the arms apart when rotated to a first rotation position. A force sensor is mounted in the driver to detect occlusions in the fluid line. A processor monitors the force sensed by the force sensor and provides an alarm if the force exceeds a threshold. The driver includes a force concentrator that defines a pushing surface adapted to press against a plunger flange so that the force applied to the plunger flange is concentrated at a defined location for more accurate measurement.