Biological Sterilization Indicator with Frangible Nutrient Chamber

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current sterilization indicator systems, particularly in healthcare settings, face challenges in reliably determining the effectiveness of sterilization processes, as they often rely on chemical indicators that provide limited insights into the sterilization conditions and may not accurately reflect the lethality of the process, whereas biological indicators offer a more direct test but require complex handling to ensure proper activation and interpretation.

Innovation Solution

A biological sterilization indicator system comprising a housing with a frangible container and separate chambers, where a nutrient medium is initially separate from the spores but becomes accessible after sterilization, allowing for the detection of spore growth or metabolic activity, thereby confirming the efficacy of the sterilization process through visual or enzymatic reactions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of time

If chemical sterility indicators are used, then immediate reading is possible, but the results only indicate presence of conditions not actual sterilization effectiveness

Engineering Contradiction:
Improvetime to read resultsVSAvoidaccuracy of sterilization effectiveness
Core Design Contradiction:
Loss of timeVSMeasurement precision

Solution Approach 1:

The biological indicator is divided into separate compartments: a spore-containing chamber and a nutrient medium chamber. This segmentation allows the indicator to remain stable during sterilization while enabling post-sterilization activation when the nutrient medium contacts the spores, thus resolving the contradiction between immediate reading and accurate effectiveness measurement.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The spores are pre-prepared and sealed in a protective chamber before sterilization. The nutrient medium is also prepared separately and stored in a frangible container. This preliminary preparation ensures that when activation occurs after sterilization, the biological reaction can proceed immediately without requiring additional setup time, thus achieving both speed and accuracy.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If biological sterility indicators are used, then direct test of sterilization effectiveness is achieved, but complex handling is required for activation

Engineering Contradiction:
Improveaccuracy of sterilization effectivenessVSAvoidsimplicity of activation process
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The spore chamber and nutrient medium chamber are merged into a single integrated biological indicator unit with a frangible separator. This design combines the advantages of biological accuracy with simplified operation, as the entire activation process requires only breaking the frangible container, which is inherently easier than complex multi-step activation procedures.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The frangible container acts as an intermediary mechanism between the spore chamber and nutrient medium. It provides a simple, reliable activation method where breaking the container automatically initiates the biological reaction, eliminating the need for complex handling procedures while maintaining sterilization effectiveness accuracy.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Stability of the object's composition

If spores and nutrient medium are kept separate, then stability during sterilization is maintained, but activation mechanism becomes complex

Engineering Contradiction:
Improvestability during sterilizationVSAvoidcomplexity of activation mechanism
Core Design Contradiction:
Stability of the object's compositionVSDevice complexity

Solution Approach 1:

A frangible container with a brittle wall structure is used to separate the spore chamber from the nutrient medium. This thin, fragile barrier maintains separation during sterilization (ensuring stability) but breaks easily upon contact or pressure change (enabling simple activation), thus resolving the contradiction between stability and activation complexity.

Inventive Principle:
Principle #30Flexible shells and thin films

Solution Approach 2:

The physical state or position of the frangible container changes from intact to broken, triggering the activation process. This parameter change (from sealed to open) automatically initiates nutrient medium contact with spores, providing a simple activation mechanism that doesn't require complex controls while maintaining stability during the sterilization process.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This system provides a reliable and direct method to assess the effectiveness of sterilization processes by ensuring that spores and nutrient medium are in fluid communication post-sterilization, facilitating the growth of surviving spores and enabling visual or enzymatic detection of sterilization efficacy, thus ensuring the lethality of the process is accurately determined.

Implementation Method 1

source metabolism and/or growth indicating that the sterilization process was insufficient to destroy all of the sources of biological activity

Methodology Applied
Scientific EffectMetabolism: Fermentation

Implementation Method 2

a first state in which the container is intact when the second portion of the housing is in the first position, and a second state in which the container is fractured when the second portion of the housing is in the second position

Methodology Applied
Scientific EffectFracture: Fracture Mechanics

Data Source

PatentEP2635701B1Biological sterilization indicator system and method
Publication Date: 2018.01.03 3M INNOVATIVE PROPERTIES CO
  • EP2635701B1 patent drawingFigure 1
  • EP2635701B1 patent drawingFigure 2
  • EP2635701B1 patent drawingFigure 3

AI summary

A biological sterilization indicator (BI) system and method. The system can include a BI and a reading apparatus comprising a well. The BI can include a housing, which can include a first portion, and a second portion movable between a first "unactivated" position and a second "activated" position. The BI can further include a frangible container containing a liquid and dimensioned to be positioned in the housing. The reading apparatus can be configured to detect activation of the biological sterilization indicator, for example, by detecting that the second portion is in the second position, and/or by detecting that the liquid from the frangible container is present in a specific chamber of the biological sterilization indicator. The method can include positioning the BI in the well of the reading apparatus and detecting activation, for example, by detecting one or more of the above conditions.