One embodiment of the present patent application is a syringe infusion pump that includes a syringe, a syringe barrel holder, and a force sensor. The syringe includes a barrel and a plunger. The plunger has a plunger axis and the barrel has a barrel axis and a barrel diameter. The syringe is one of a plurality of syringes, each having a different barrel diameter. The force sensor is positioned for detecting a force along the barrel axis. The syringe holder provides the barrel axis automatically aligned with the force sensor for each syringe of the plurality of syringes.
