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:
Oct. 03, 1995
Filed:
Nov. 08, 1993
Behzad Moeenziai, San Diego, CA (US);
Kurt Zublin, Poway, CA (US);
Jack Goldberg, San Diego, CA (US);
IVAC Corporation, San Diego, CA (US);
Abstract
A non-invasive, fluid monitor engages an open resonator with a segment of fluid line. The fluid line is disposed such that it and the fluid within become a part of the dielectric loading on the resonator. The open resonator is a part of an oscillator circuit that changes frequency of oscillation in response to the dielectric loading on the resonator. A frequency discriminator monitors the frequency of the oscillator to detect an air bubble in the fluid line. In the case where the resonator comprises a microstrip line, the microstrip line is disposed in parallel to the segment of the fluid line and the length of the microstrip line is selected to be equal to or greater than the maximum length of air bubble permitted thus providing a volumetric air-in-line sensor. The output of the frequency discriminator is compared to a threshold to determine a frequency shift large enough to indicate the presence of an air bubble.