Patent ID: 8088105

Claim:
A syringe pump comprising: a syringe comprising a plunger that slides in a body which has a discharge port; a driving mechanism coupled to said syringe, comprising a cylinder in which a piston slides, and a plurality of biasing devices arranged about said piston operative to apply urging forces on said piston to drive said piston distally in said cylinder and thereby cause said plunger to slide in said body and discharge a substance found in said body through said discharge port, wherein if one of said biasing devices fails another of said biasing devices continues to apply a force on said piston to drive said piston distally in said cylinder; and a safety catch that initially prevents said biasing device from moving said piston, said safety catch being removable to permit said biasing device to move said piston, wherein said cylinder is at least partially filled with a hydraulic fluid, and as said piston slides in said cylinder, said hydraulic fluid flows from in front of said piston to behind said piston, whereupon said hydraulic fluid continues to flow through a tube out a needle.