Abstract: A syringe pump comprises (a) a casing; (b) within said casing, a motor (c) an externally screw-threaded drive rod connected at one end thereof to said motor so that, in use, the motor can rotate the drive rod about its axis, the other end of said drive rod being free to rotate in a journal bearing; (d) a carriage mounted for sliding movement within said casing and driveably mounted on said drive rod in engagement with the external screw-thread thereof; (e) a strain gauge operatively connected to measure the torque reaction between said motor and said carriage when the carriage acts, in use, against the plunger of a syringe to expel fluid from the syringe; (f) means located externally of the main body of the casing for holding a syringe in position on the syringe pump; (g) means for sensing the position of said carriage with respect to the ends of said drive rod; (h) a microprocessor arranged to receive input signals from said strain gauge and said carriage position sensing means and to derive therefrom (when