Sterilization Assessment Using Chemical Indicator Color Analysis

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing sterilization methods face challenges in ensuring effective sterilization of medical devices, particularly those with diffusion-restricted spaces, due to packaging that can impede sterilant penetration and the lack of reliable indicators to confirm sterilization efficacy.

Innovation Solution

A method using a chemical indicator placed in a sterilization chamber, where images are captured and analyzed to determine color values, which are then compared to predetermined thresholds to automatically end the sterilization procedure once efficacy is confirmed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If packaging with semi-permeable barrier is used to prevent contamination, then protection against contaminating organisms is improved, but sterilant penetration is worsened

Engineering Contradiction:
Improveprotection against contaminationVSAvoidsterilant penetration rate
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The packaging is designed with different permeability characteristics in different regions: the semi-permeable barrier provides high protection against contamination while allowing controlled sterilant penetration through specific pathways. This local differentiation resolves the contradiction by optimizing each region's function according to local requirements.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The packaging is pre-designed with predetermined sterilant penetration pathways and optimized barrier properties before the sterilization process begins. This preliminary configuration ensures that the packaging maintains its protective function while facilitating adequate sterilant access to the medical device.

Inventive Principle:
Principle #10Preliminary action

2Adaptability or versatility

If diffusion-restricted spaces are present in medical devices, then device functionality is improved, but sterilization efficacy is worsened

Engineering Contradiction:
Improvedevice functionalityVSAvoidsterilization efficacy
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

A chemical indicator acts as an intermediary substance that penetrates into the diffusion-restricted spaces and provides visual confirmation of sterilant presence and efficacy. The indicator mediates between the sterilant and the hard-to-reach areas, allowing verification of sterilization in spaces that would otherwise be difficult to assess.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The chemical indicator undergoes color changes in response to sterilant exposure, providing visual evidence of sterilization efficacy in diffusion-restricted spaces. This color-change mechanism allows direct observation of sterilant penetration and effectiveness in areas that are difficult to access or verify otherwise.

Inventive Principle:
Principle #32Color changes

3Measurement precision

If chemical indicator is used to assess sterilization efficacy, then verification of sterilization is improved, but complexity of assessment system is worsened

Engineering Contradiction:
Improvesterilization verification accuracyVSAvoidassessment system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The chemical indicator is designed as a simple, inexpensive, single-use component that provides reliable sterilization verification without requiring complex systems. The indicator's disposable nature eliminates the need for sophisticated monitoring equipment or complex assessment procedures, resolving the contradiction between verification accuracy and system complexity.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

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 method provides a rapid and reliable assessment of sterilization efficacy, ensuring that medical devices are properly sterilized and reducing the risk of contamination.

Implementation Method 1

a chemical indicator composition (ink) for detecting an oxidizing agent, such as hydrogen peroxide

Methodology Applied
Scientific EffectOxidation: Oxidation

Data Source

PatentEP3948265B1Sterilization assessment methods with chemical indicators
Publication Date: 2025.04.30 ADVANCED STERILIZATION PRODUCTS INC
  • EP3948265B1 patent drawingFigure 1
  • EP3948265B1 patent drawingFigure 2
  • EP3948265B1 patent drawingFigure 3

AI summary

A class 5 chemical indicator color may be imaged such that a color of the indicator may be determined and compared to a color-value threshold indicative of an efficacious sterilization procedure. Color changes of the indicator during a sterilization procedure are typically not uniform. As such, colors on the indicator may be averaged and then compared to the color-value threshold to determine if the procedure has been efficacious or if additional exposure to a sterilant may be desired. Color values and color-value thresholds may be based on, e.g., the L*a*b* color model or a grayscale color model.