An infusion system, comprising: a drive assembly (5, 205) comprising: a drive fluid reservoir (30, 230); and a drive mechanism configured to apply a force to drive fluid from the drive fluid reservoir through a length of tubing (10, 210); and a hydraulic assembly (15, 215) comprising a syringe assembly having a syringe barrel, a first fluid chamber (35, 235) having an inlet port configured to be in fluid communication with the drive fluid reservoir (30, 230) through the length of tubing (10, 210), and a second fluid chamber (45, 245) having an outlet port configured to be in fluid communication with a patient extension set (20, 220); a cap coupled to and sealing off a proximal end of the first fluid chamber (35, 235) and comprising a vent filter; and a flexible, movable divider (40, 240) positioned within the syringe barrel and sealing the first fluid chamber (35, 235) from the second fluid chamber (45, 245), wherein the force applied by the drive mechanism propels the fluid from the drive fluid reservoir (30, 230) through the length of tubing (10, 210) into the first fluid chamber (35, 235) to move the divider (40, 240) causing infusate to exit the second fluid chamber (45, 245) through the outlet port characterized in that the drive assembly (5, 205) is configured as a reusable component and comprises one or more pressure sensors and wherein the hydraulic assembly (15, 215) is configured as a disposable and is reversibly couplable to the drive assembly (5, 205). a drive assembly (5, 205) comprising: a drive fluid reservoir (30, 230); and a drive mechanism configured to apply a force to drive fluid from the drive fluid reservoir through a length of tubing (10, 210); and a hydraulic assembly (15, 215) comprising a syringe assembly having a syringe barrel, a first fluid chamber (35, 235) having an inlet port configured to be in fluid communication with the drive fluid reservoir (30, 230) through the length of tubing (10, 210), and a second fluid chamber (45, 245) having an outlet port configured to be in fluid communication with a patient extension set (20, 220); a drive fluid reservoir (30, 230); and a drive mechanism configured to apply a force to drive fluid from the drive fluid reservoir through a length of tubing (10, 210); and a hydraulic assembly (15, 215) comprising a syringe assembly having a syringe barrel, a first fluid chamber (35, 235) having an inlet port configured to be in fluid communication with the drive fluid reservoir (30, 230) through the length of tubing (10, 210), and a second fluid chamber (45, 245) having an outlet port configured to be in fluid communication with a patient extension set (20, 220); a cap coupled to and sealing off a proximal end of the first fluid chamber (35, 235) and comprising a vent filter; and a flexible, movable divider (40, 240) positioned within the syringe barrel and sealing the first fluid chamber (35, 235) from the second fluid chamber (45, 245), wherein the force applied by the drive mechanism propels the fluid from the drive fluid reservoir (30, 230) through the length of tubing (10, 210) into the first fluid chamber (35, 235) to move the divider (40, 240) causing infusate to exit the second fluid chamber (45, 245) through the outlet port characterized in that the drive assembly (5, 205) is configured as a reusable component and comprises one or more pressure sensors and wherein the hydraulic assembly (15, 215) is configured as a disposable and is reversibly couplable to the drive assembly (5, 205).