Digital apparatus for rapidly detecting the growth of and identifying micro-biological organisms
US3984766A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Oct 15, 1974 |
| Grant date | Oct 5, 1976 |
| Priority date | — |
| Expiry date | Oct 15, 1994 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R19/10
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
Digital apparatus is disclosed which provides means for plotting the change with respect to time in the impedance ratio between a pair of cells, both cells of the cell pair containing a selected nutrient media and one (specimen) cell of the cell pair further including a micro-organism contaminant the growth of which is to be detected. Growth of the contaminant within the specimen cell over a selected period of time provides a characteristic change in the impedance of the specimen cell which provides, in turn, a corresponding change in the impedance ratio between the cells of the cell pair. Measurements are digitally made via means which compares the impedance ratio between the cells of the cell pair to successive resistive approximations of the ratio, and then outputs a digital word corresponding to the nearest approximation. Each digital word thus represents the impedance ratio at a given point in time of growth. At least a portion of the digital word or an arbitrary value indicative thereof is recorded with respect to time, for example, by electromagnetic means or as one point on a strip chart. Thus, a characteristic record is produced of the change with respect to time in the im…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.