An infusion device for dispensing fluid at a predetermined flow rate includes an elastic bladder, a pressure regulator, and a flow restrictor. The elastic bladder includes a bladder volume portion and a bladder outlet, and the elastic bladder stores fluid in the bladder volume portion and dispenses fluid through the outlet at a bladder pressure. The pressure regulator is in fluid communication with the outlet of the elastic bladder. The pressure regulator includes a fluid inlet and a fluid outlet. The fluid inlet is coupled to the bladder outlet to receive fluid from the bladder. The flow restrictor is in fluid communication with the fluid outlet. The flow restrictor and the pressure regulator cooperate to discharge fluid from the flow restrictor at a predetermined flow rate.