Design of a low-cost electronically controlled gravity-feed infusion set

An electronically regulated, gravity-feed, intravenous infusion set in which a length of intravenous tubing is attached to a drip chamber to deliver a fluid to be administered intravenously. A contraption for monitoring drop flow in the chamber of the intravenous set incorporates a sensor housing containing a reference light source located a fixed distance from a photocell to define a fixed optical sensing gap there between, with a reference light beam normally impinging upon the photocell. The casing can be selectively fastened upon the drip chamber with the drip chamber set within the sensing gap to intercept the reference light beam. The rate of fluid flow is controlled by a non-invasive actuator attached to the intravenous tubing. A round spherical tip attached to a linear actuator stepper motor (constituents of the actuator) is adjusted with reference to a calibrated scale in accordance to feedback from the drop flow sensor. The system regulates fluid flow with an agreeable degree of accuracy (±1 count).