US3736432A
Expired / Lapsed
US
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Bacterial colony counting method and apparatus
Assignee: Varian Medical Systems Inc
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Filing: 1971-03-22
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Granted: 1973-05-29
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Expires: 1991-03-22
Abstract
Abstract Light from a localized source is projected through a transparent bacterial culture medium having a multitude of bacterial colonies formed on the surface thereof. The bacterial colonies serve as lenses for focusing images of the light source into a pattern of images which are projected into an image plane forming a pattern of light images corresponding to the pattern of bacterial colonies. A linear array of photodetectors is disposed in the projected image plane. The optical system is scanned relative to the bacterial colony culture such that adjacent scanning tracks overlap each other by approximately the track width of two photodetectors of the array of photodetectors. An output pulse, which is to be counted, from one detector inhibits counting output pulses from its nearest neighbors and the output pulses from the detectors at opposite ends of the array are not counted to form guard detectors, whereby colonies are accurately counted and colonies which overlap adjacent scanning tracks are counted but only once.
Inventors
- 👤 R Sweet
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:48
CPC Classifications
C; C12; C12M; C12M41/00; C12M41/30; C12M41/36; G; G06; G06M; G06M11/00; G06M11/02; Y; Y10; Y10S; Y10S435/00; Y10S435/808
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
151 words
A counter for counting bacterial colonies comprising the combination: light source means for illuminating the bacterial colonies; a side-by-side array of photodetector means responsive to the illumination for detecting the bacteria colonies and generating an electric signal corresponding to each bacteria colony detected; scanning means for systematically moving the side-by-side array relative to the bacterial colonies causing the photodetector means to scan the bacterial colonies a portion at a time through a plurality of adjacent overlapping scanning tracks; counting means for counting the electrical signals from the photodetector means; and guard photodetector means mounted on the opposite ends of the side-by-side array, the counting means being unresponsive to the guard photodetector means, and the adjacent scanning tracks overlapping each other by about the track width of one of the guard photodetectors plus the track width of the photodetector adjacent thereto whereby bacterial colonies overlapping adjacent scanning tracks are counted only once.
Claim 2
Dependent Claim
151 words
A counter for counting bacterial colonies comprising the combination: light source means for illuminating the bacterial colonies; a side-by-side array of photodetector means responsive to the illumination for detecting the bacteria colonies and generating an electric signal corresponding to each bacteria colony detected; scanning means for systematically moving the side-by-side array relative to the bacterial colonies causing the photodetector means to scan the bacterial colonies a portion at a time through a plurality of adjacent overlapping scanning tracks; counting means for counting the electrical signals from the photodetector means; and guard photodetector means mounted on the opposite ends of the side-by-side array, the counting means being unresponsive to the guard photodetector means, and the adjacent scanning tracks overlapping each other by about the track width of one of the guard photodetectors plus the track width of the photodetector adjacent thereto whereby bacterial colonies overlapping adjacent scanning tracks are counted only once.
Claim 3
Dependent Claim
27 words
The counter of claim 1 wherein the relative motion between the side-by-side array of photodetector and the bacterial colonies is a symetrical spiral of overlapping scanning tracks.
Claim 4
Dependent Claim
40 words
The counter of claim 2 wherein the scanning means rotates the bacterial colonies about an axis of rotation and establishes relative translation motion between the bacterial colonies and the side-by-side array generally along a path which traverses the bacterial colonies.
Claim 5
Dependent Claim
38 words
The counter of claim 3 wherein the side-by-side array of photodetector means are mounted on a support arm pivotable about an axis of rotation generally parallel to and spaced from the axis of rotation of the bacterial colonies.
Claim 6
Dependent Claim
49 words
The counter of claim 2 wherein the counting means include inhibiting means for inhibiting counting of the output pulses of the photodetector means adjacent to the photo-detector means first delivering an output pulse in response to a bacteria colony whereby double counting of the same bacteria colony is prevented.
Claim 7
Dependent Claim
180 words
In a method for counting bacterial colonies on the surface of or in the body of a culture medium, comprising the steps of: illuminating the culture medium with photons derived from a localized source, the photons responsive to the light refracting properties of the colonies to create a pattern of individual images of the light source in a region beyond the culture medium there being one image corresponding to each bacterial colony; scanning the image pattern with a side-by-side array of photon detecting means along a plurality of adjacent scanning tracks which overlap by the width of two detectors at one end of the side-by-side array; generating an electric pulse each time the photon detecting means detect a light source image; counting the pulses; blocking the counting of the pulses of adjacent photon detectors in response to light source images overlapping adjacent photon detectors whereby only one count is obtained per image; and blocking the counting of the photon detectors on the opposite ends of the side-by-side array whereby preventing double counting of images which overlap the adjacent scanning tracks.
Claim 8
Dependent Claim
180 words
In a method for counting bacterial colonies on the surface of or in the body of a culture medium, comprising the steps of: illuminating the culture medium with photons derived from a localized source, the photons responsive to the light refracting properties of the colonies to create a pattern of individual images of the light source in a region beyond the culture medium there being one image corresponding to each bacterial colony; scanning the image pattern with a side-by-side array of photon detecting means along a plurality of adjacent scanning tracks which overlap by the width of two detectors at one end of the side-by-side array; generating an electric pulse each time the photon detecting means detect a light source image; counting the pulses; blocking the counting of the pulses of adjacent photon detectors in response to light source images overlapping adjacent photon detectors whereby only one count is obtained per image; and blocking the counting of the photon detectors on the opposite ends of the side-by-side array whereby preventing double counting of images which overlap the adjacent scanning tracks.
Claim 9
Dependent Claim
20 words
The method of claim 6 wherein the scanning step comprises scanning the image pattern with an overlapping spiral scanning track.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-28 | 1976-11-27 | 1977-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-28 | 1980-11-27 | 1981-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-28 | 1984-11-27 | 1985-05-29 | $7700.00 | Window Closed / Lapsed |