A fluid pump for pumping a subject fluid. The fluid pump including, a pump body, a first cavity within the pump body, a second cavity within the pump body, a flexible member, an incompressible fluid, a subject fluid chamber, and a piston. Piston may include a piston head and an elongated piston shaft. The piston may be configured to amplify a first pressure experienced on a first side of the piston head and exerted by a pressurized drive fluid to a second pressure experienced on an end surface of the elongated piston shaft and exerted on the incompressible fluid within the flexible member. The subject fluid may in turn be pressurized to a third pressure substantially equal to the second pressure.