Abstract: The present invention is an adjustable re-usable syringe actuator that delivers liquid at a substantially constant rate that is unaffected by a change in the viscosity of the liquid being pumped. The disposable syringe actuator is well suited for the infusion of small to medium volumes of liquid medication at low flow-rates. A preferred embodiment includes a purely mechanical device with no need for electricity, thereby providing a high level of patient mobility. The spring-powered device uses a variable length elongated flow regulation passageway to regulate the rate at which the spring depresses the syringe plunger. Thus, the rate of medication infusion is regulated by varying the length of the flow regulation passageway.

Abstract: The present invention is a flow metering system for accurately metering and regulating the flow rate of fluid in a gravity fed intravenous fluid delivery system. The fluid flow is directed through a flow path guide that is suspended at an angle from one end. As the fluid flows through the flow path guide, the flow path guide bends due to the weight of the fluid. A drop of fluid forms at the end of the flow path guide then falls off, thereby releasing the flow path guide, which springs back it its original position. The sequence of drops and springing back continues throughout the fluid delivery procedure, and is monitored by sensors. The resultant data is used by a processor to determine the flow rate of the fluid. The flow rate may be adjusted as needed by a flow regulator that is responsive to an adjustment actuator that is controlled by the processor.

Abstract: A fluid flow regulator of a type having a variable outlet defined by a spacing between an outlet aperture and a flexible diaphragm, and in which the position of the flexible diaphragm varies as a function of a pressure differential between a sensing chamber on a first side of the diaphragm and an outlet chamber on a second side of the diaphragm. The regulator includes an adjustable flow impedance configuration in the flow path from the sensing chamber to the outlet chamber has a two elements providing opposing cylindrical surfaces in sliding contact. One of the cylindrical surfaces has a groove configured to define a flow-attenuating passageway having a net flow vector substantially parallel to the axis of the cylindrical surfaces. Axial relative movement between the elements causes a variation in an extent of overlap between the cylindrical surfaces, thereby varying an operative length of the flow-attenuating passageway.