Infusion apparatus

Abstract

Apparatus for infusion of a solution into a catheter or the like, the apparatus including a syringe with an administration set having a cup-shaped member configured for selective interlocking engagement with the syringe. The syringe includes a piston member and a coil spring within the bore having a first end urging against the piston. A separable handle member has a shaft axially positionable within the bore, with a reduced diameter threaded end configured for threadably engaging an aperture in the piston. A spring retaining cup within the bore acts against the other end of the spring, with the cup having a central aperture of a dimension sufficient for passage therethrough of the reduced diameter end of the shaft of the handle. Coupling of the handle to the piston compresses the spring via the cup. After filling the syringe, attaching the administration set, and attaching the dispensing fitting to the catheter for the patient, the handle is removed, enabling expansion of the spring, which thus powers the piston to discharge the solution. A controlled flow rate is obtained by providing a fluid flow path of a given or restricted orifice size at the syringe outlet or within the administration set, preferably the latter.