Biological Sterilization Indicator with Segmented Chambers

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Solution Overview

Problem

Current biological sterilization indicators often lack efficient mechanisms to separate sterilants from sources of biological activity during sterilization and to ensure reliable activation post-process, which can lead to incomplete sterilization validation.

Innovation Solution

A biological sterilization indicator with a housing containing multiple chambers and a frangible container that separates a sterilant from sources of biological activity during sterilization, allowing for controlled fluid communication and activation post-process, utilizing internal vents and fluid paths to facilitate sterilant movement and nutrient medium release.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a biological sterilization indicator uses a single chamber design with spores and nutrient medium in direct contact, then the device complexity is reduced, but the reliability of sterilization validation deteriorates due to inability to ensure complete separation during sterilization and controlled activation

Engineering Contradiction:
Improvechamber structureVSAvoidsterilization validation
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The device is divided into multiple chambers: a first chamber for receiving sterilant and a second chamber for containing spores and nutrient medium. This segmentation allows complete separation during sterilization validation while enabling controlled interaction during activation, thereby improving reliability without requiring excessive complexity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The nutrient medium is extracted from the spore chamber and placed in a separate container within the first chamber. This extraction ensures that the spores remain isolated from the nutrient medium during sterilization, preventing false positives, while allowing controlled introduction of the medium after sterilization for accurate validation.

Inventive Principle:
Principle #2Taking out (Extraction)

2Ease of operation

If the container with nutrient medium is made frangible for easy activation, then the ease of operation is improved, but the manufacturing precision requirements worsen due to need for controlled fracture properties

Engineering Contradiction:
Improveactivation processVSAvoidfrangible container fabrication
Core Design Contradiction:
Ease of operationVSManufacturing precision

Solution Approach 1:

The container material parameters are specifically engineered to exhibit frangibility - a controlled ability to fracture under certain conditions. This parameter change allows the container to remain intact during sterilization and transport but break easily during activation, improving ease of operation while maintaining acceptable manufacturing precision through careful material selection.

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

Ensures reliable validation of sterilization efficacy by ensuring complete separation and controlled activation, enhancing the detection of sterilization process effectiveness and minimizing contamination and diffusion of biological activity signals.

Implementation Method 1

a first fluid path positioned to fluidly couple the first chamber and the second chamber. The first fluid path can be positioned to allow a sterilant to move from the first chamber into the second chamber

Methodology Applied
Scientific EffectFluid flow:

Implementation Method 2

At least a portion of the container can be frangible, and the container can have a first state in which the container is intact and the liquid is not in fluid communication with an interior of the housing, and a second state in which the container is fractured and the liquid is in fluid communication with the interior of the housing

Methodology Applied
Scientific EffectPhysical separation through fracture: Fracture Mechanics

Implementation Method 3

a second fluid path positioned to fluidly couple the second chamber and another chamber of the biological sterilization indicator. The second fluid path can be positioned to allow displaced gas to move out of the second chamber as the sterilant or the liquid moves from the first chamber to the second chamber

Methodology Applied
Scientific EffectGas displacement:

Data Source

PatentEP2635699B1Biological sterilization indicator and method of using same
Publication Date: 2018.03.21 3M INNOVATIVE PROPERTIES CO
  • EP2635699B1 patent drawingFigure 1
  • EP2635699B1 patent drawingFigure 2
  • EP2635699B1 patent drawingFigure 3

AI summary

A biological sterilization indicator (BI) and method of using same. The BI can include a housing, and a container positioned in the housing. The container can contain a liquid and at least a portion of the container can be frangible. The BI can further include a first chamber and a second chamber. The second chamber can include at least one source of biological activity. The BI can further include a first fluid path positioned to fluidly couple the first chamber and the second chamber, and a second fluid path positioned to allow displaced gas to move out of the second chamber. The method can include moving displaced gas out of the second chamber via the second fluid path as a sterilant is moved into the second chamber via the first fluid path and/or as the liquid is moved into the second chamber via the first fluid path.