The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 07, 1993
Filed:
Aug. 29, 1990
William J Dirr, Jr, Cincinnati, OH (US);
Random Corporation, Cincinnati, OH (US);
Abstract
A drop detector for intravenous systems in which an infrared emitter is pulsed at 10 kHz. The pulsed radiation passes through a drip chamber and then to a detector. The detector circuit determines the amplitude modulation of the 10 kHz. carrier frequency. This provides an indication of when the drop falling through the drip chamber has interrupted the light beam. An automatic gain control circuit maintains the output of the detector, on a long time constant basis, at a constant level to eliminate the vagaries of drip chambers with different optical characteristics and the like. When the AGC circuit lacks the ability to maintain the output of the detector circuitry at a constant level, a fault detector provides an alarm to indicate that the circuitry has exceeded its operational range.