초록 ▼

A liquid drop rate controller for controlling flow of fluid from an infusion fluid reservoir to an intravenous infusion site which includes a cam means in the form of a wheel mounted eccentrically on a shaft which varies the compression on a flexible tube carrying the liquid; the controller senses t

A liquid drop rate controller for controlling flow of fluid from an infusion fluid reservoir to an intravenous infusion site which includes a cam means in the form of a wheel mounted eccentrically on a shaft which varies the compression on a flexible tube carrying the liquid; the controller senses the actual drip rate optically and compares this to a preselected desired drip rate and varies the compression accordingly. The comparison is accomplished electronically by the generation of a time base whose frequency is controlled by the selected drip rate; this time base is compared to the actual drip rate observed by the optical sensing means, and the cam means is controlled in relation to an error signal obtained through the comparison. The controller includes a separate comparison circuit which comes into operation at low drip rates so as to increase accuracy of control.

대표청구항 ▼

An infusion drop rate controller, comprising: means for sensing the drip rate of liquid from an infusion liquid reservoir: means for selecting and storing a desired drip rate; means for varying the hydraulic impedance formed from a flexible tube in a flow line from said reservoir; and, means for con

An infusion drop rate controller, comprising: means for sensing the drip rate of liquid from an infusion liquid reservoir: means for selecting and storing a desired drip rate; means for varying the hydraulic impedance formed from a flexible tube in a flow line from said reservoir; and, means for controlling said varying means in response to the sensed drip rate to maintain the flow of liquid to the selected and stored drip rate, wherein the varying means comprises a cam means mounted on a shaft for compressing said flexible tube against an anvil member, the anvil member comprising a compression lever capable of movement toward and away from said cam means, whereby rotation of said shaft varies the extent of compression to vary said hydraulic impedance.