Method and system for detection of microbial growth in a specimen container
AssigneeBiomerieux
InventorMichael Ullery
Life of this patent
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Abstract
A method for determining whether microbial growth is occurring within a specimen container includes steps of incubating the specimen container and obtaining a series of measurement data points while the specimen container is incubated and storing the data points in a machine-readable memory. The series of measurement data points represent a growth curve of microbial growth within the specimen container. The methods determine a positive condition of microbial growth within the container from the measurement data points.
Claims30
A method for determining whether microbial growth is occurring within a specimen container comprising the steps of:
- incubating the specimen container;
- obtaining a series of measurement data points from the specimen container while the specimen container is incubated and storing the data points in a machine-readable memory, the series of measurement data points representing a growth curve of microbial growth within the specimen container;
- and
- performing in parallel with a programmed computer analytical methods (a) and (b), namely:
- (a) an analysis of variation in successive data points in the series of measurement data points, and
- (b) an analysis of changes in the area under the growth curve between sets of data points in the series of measurement data points,
- wherein both analytical methods (a) and (b) include a processing step for determining a positive condition of microbial growth within the container from the measurement data points.
A system for determining whether microbial growth is occurring within a specimen container comprising the steps of:
- apparatus for incubating the specimen container;
- a measurement system obtaining a series of measurement data points from the specimen container while the specimen container is incubated and storing the data points in a machine-readable memory, the series of measurement data points representing a growth curve of microbial growth within the specimen container;
- and
- a programmed computer performing in parallel analytical methods (a) and (b), namely:
- (a) an analysis of variation in successive data points in the series of measurement data points, and
- (b) an analysis of changes in the area under the growth curve between sets of data points in the series of measurement data points,
- wherein both analytical methods (a) and (b) include a processing step for determining a positive condition of microbial growth within the container from the measurement data points.
A method for determining whether microbial growth is occurring within a specimen container containing a sample, comprising the steps of:
- incubating the specimen container;
- obtaining a series of measurement data points while the specimen container is incubated and storing the data points in a machine-readable memory, the series of measurement data points representing a growth curve of microbial growth within the specimen container;
- analyzing the variation in successive data points in the series of measurement data points with respect to a decision threshold, and
- if the variation in the successive data points exceeds the decision threshold a predetermined number of times for successive measurement data points reporting the specimen container as positive for microbial growth.
A method for determining whether microbial growth is occurring within a specimen container containing a sample, comprising the steps of:
- (a) incubating the specimen container;
- (b) obtaining a series of measurement data points while the specimen container is incubated and storing the data points in a machine-readable memory, the series of measurement data points representing a growth curve of microbial growth within the specimen container;
- (c) calculating the area under the growth curve for a pair of measurement data points;
- (d) calculating the area under the growth curve for a second pair of measurement data points;
- (e) calculating the percent difference in the area under the growth curve calculated at steps (c) and (d);
- (f) determining whether the percent difference calculated at step (e) is greater than a decision threshold;
- (g) repeating steps (c), (d), (e), and (f) for successive pairs of measurement data points until the number of successive pairs of measurement data points having a percent difference calculated at step (f) above the decision threshold is greater than a predetermined limit;
- and (h) responsively reporting the specimen containers as positive for microbial growth.
Dependencies are inferred from the claim text.