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:
Aug. 03, 1993
Filed:
Apr. 16, 1992
Gideon Eden, Ann Arbor, MI (US);
Nadine M Sullivan, Ann Arbor, MI (US);
Difco Laboratories Incorporated, Ann Arbor, MI (US);
Abstract
In such a method and apparatus for detecting microbiological growth in a sealed sample container, pressure within the headspace of the container is monitored for detecting rate of change of such headspace pressure. Presence of microbiological growth within the container is indicated as a function of rate of change of headspace pressure. The rate of pressure change is compared with a standard rate for a family of microorganisms., and growth is indicated when the absolute value of the rate of pressure change (which may be positive or negative) exceeds the absolute value of the standard rate (which also may be positive or negative). For detecting microbiological growths which may have differing growth rates, absolute value of rate of pressure change is compared to a plurality of standard rates for differing families of microorganisms. At least some of the rates may be positive, corresponding to growth of gas-producing organisms, and at least some of the rates may be negative, corresponding to growth of gas-consuming organisms. In either case, microbiological growth in the test sample is indicated when absolute mathematical value of the rate of headspace pressure change exceeds absolute mathematical value of any of the standard rates.