Microorganism Counting via Growth Model Extrapolation

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Solution Overview

Problem

Current methods for counting microorganisms in biological samples require lengthy incubation periods, which can lead to significant economic losses due to delayed product marketing and potential withdrawal from the market if results are negative, as they often exceed the shelf life of perishable products.

Innovation Solution

A method and device that use a growth model to extrapolate the number of microorganisms after a standard incubation period by calculating based on a relationship involving decimal logarithms and predetermined parameters, allowing for earlier estimation of microorganism counts, thereby reducing incubation time without compromising reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a long incubation period is used to obtain reliable microorganism counts, then the reliability of the count is improved, but the time required for the process increases significantly

Engineering Contradiction:
Improvereliability of microorganism countVSAvoidincubation time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The method performs preliminary counting of microorganisms at an intermediate stage (after partial incubation) and uses a growth model to predict the final count. This preliminary action allows the system to obtain reliable results without completing the full incubation period, thus reducing time loss while maintaining counting reliability.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

A growth model acts as an intermediary between the intermediate-stage count and the final expected count. The model (log(NSU) = log(NSA) + α + β×T + γ) translates the partial incubation data into a reliable prediction of the final result, eliminating the need to wait for complete incubation while preserving accuracy.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If a long incubation period is used to ensure accurate microorganism enumeration, then the measurement precision is improved, but the productivity of the quality control process decreases

Engineering Contradiction:
Improveprecision of microorganism enumerationVSAvoidproductivity of quality control
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The system performs the counting measurement at an intermediate stage and uses predictive modeling to obtain the final result. This preliminary measurement combined with mathematical prediction maintains measurement precision while dramatically improving productivity by reducing the time required for quality control decisions.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The method replaces the mechanical/biological waiting process (full incubation) with a computational approach (growth model calculation). The formula log(NSU) = log(NSA) + α + β×T + γ substitutes the physical incubation time with mathematical computation, maintaining precision while boosting productivity.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If the incubation time is extended to obtain reliable counts, then the reliability of product quality assessment is improved, but the economic loss increases due to delayed product marketing

Engineering Contradiction:
Improvereliability of product quality assessmentVSAvoidtime to market
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The method enables preliminary quality assessment by predicting final microorganism counts from intermediate measurements. This allows producers to make marketing decisions earlier with reliable predictions, improving the time-to-market while maintaining assessment reliability through the growth model.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The growth model serves as an intermediary that bridges intermediate-stage data and final quality assessment requirements. By using the formula log(NSU) = log(NSA) + α + β×T + γ, the system provides reliable quality predictions earlier in the process, reducing economic losses from delayed marketing while maintaining assessment reliability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP2547783B1Method for estimating the number of microorganisms in a sample and device for implementing said method
Publication Date: 2015.11.11 BIOMERIEUX SA
  • EP2547783B1 patent drawingFigure 1~2
  • EP2547783B1 patent drawing
  • EP2547783B1 patent drawing

AI summary

A method for counting microorganisms present in a biological sample in contact with a culture medium suitable for the growth of said microorganisms, characterized in that it comprises the steps consisting in: determining at a prior stage the number NSA of microorganisms present in the sample, and calculating the number NSU of microorganisms present at a subsequent stage as a function of the number NSA, wherein the calculation is based on a model of growth of the microorganisms in the culture medium according to the relationship: log(Nsu ) = a × log (NSA) - ß × log(CSA )+ ? where log is the decimal logarithm, NSU is the number of microorganisms calculated, NSA is the number of microorganisms at the prior stage, CSA is the number of micro­organisms at the prior stage divided by the volume of the sample, and a, ß and ? are predetermined parameters dependent on the microorganisms, on the culture medium and on the time separating the subsequent stage from the prior stage, a and ß being positive.