Abstract: An apparatus and method for effecting transfer of fluid from any one of a plurality of fluid sources to single fluid outlet. The apparatus comprises a valve head having (i) a bore longitudinally extending therethrough, (ii) a plurality of radially extending fluid channels, each channel having an inlet in fluid communication with a corresponding fluid source and an outlet in communication with the bore, and (iii) a valve head fluid outlet in communication with the bore, a valve stem movably disposed within the bore of the valve head, the valve stem having an axially extending fluid channel that has a fluid outlet in communication with the valve head fluid outlet and a fluid inlet, and a valve control system for effecting rotation and axial displacement of the valve stem so as to effect or terminate fluid communication between the valve stem fluid inlet and a fluid outlet of any one of the radially extending fluid channels.

Abstract: A syringe driving unit comprising free pistons in interconnected cylindrical chambers, one of the pistons carrying a syringe plunger driver and being biased, directly or indirectly, in the driving direction, and one piston being movable to force both pistons into primed or loaded position, the connections between the chambers including a pressure regulator, flow regulator and a needle valve to regulate adjustably the return flow or hydraulic fluid corresponding to the movement of the driving piston. The priming piston may be moved mechanically or pneumatically, and fail-safe mechanism may be provided, if needed, to become effective in case of leakage. Bolus delivery, to augment optionally the adjusted flow, is also provided for.