Optical Sensor Protector for Gamma Sterilization

Solution Overview

Problem

Optical sensors based on porous matrices, such as fluorescence-based pH sensors, are damaged during gamma radiation sterilization due to reduced fluorescence intensity and sensitivity, especially when exposed to air or conventional gases, which are ionized or generate free radicals, making them vulnerable and costly to protect.

Innovation Solution

A sensor protector with an upper and lower part, where the optical sensor is positioned offset and covered, minimizing contact with reactive ions, using a projection and variable force to maintain sterility and accessibility, and made from plastic to reduce costs, allowing for reduced sensitivity to radiation sterilization while maintaining functionality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If optical sensors based on porous matrices are sterilized with gamma radiation, then sterilization is achieved, but the sensor sensitivity and fluorescence intensity are reduced

Engineering Contradiction:

Improvesterilization effectivenessVSAvoidsensor sensitivity

Core Design Contradiction:

ReliabilityVSMeasurement precision

Solution Approach 1:

The sensor system is divided into two separate components: the optical sensor patch and the container. The sensor patch can be sterilized separately using gamma radiation without exposing the entire container to high radiation doses, thereby preserving sensor sensitivity while achieving sterilization where needed

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A protective coating or barrier layer is introduced between the optical sensor and the reactive species generated during gamma radiation sterilization. This intermediary protects the sensor chemistry from direct exposure to ionizing radiation and free radicals, maintaining sensor functionality while allowing sterilization to proceed

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If the sensor is exposed to air or conventional protective gases during radiation sterilization, then sterilization is effective, but free radicals are generated that damage the sensor

Engineering Contradiction:

Improvesterilization effectivenessVSAvoidfree radical damage

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The sensor patch is sterilized in an inert or reduced atmosphere (e.g., nitrogen, argon, or vacuum) instead of air or conventional protective gases. This prevents the generation of reactive free radicals during gamma radiation exposure, as the inert atmosphere does not ionize or form radicals under radiation, thereby protecting the sensor chemistry from damage

Inventive Principle:

Principle #39Inert atmosphere (Inert environment)

Solution Approach 2:

A protective coating or barrier layer is introduced between the optical sensor and the reactive species generated during gamma radiation sterilization. This intermediary protects the sensor chemistry from direct exposure to ionizing radiation and free radicals, maintaining sensor functionality while allowing sterilization to proceed

Inventive Principle:

Principle #24Intermediary (Mediator)

3Adaptability or versatility

If the sensor chemistry is immobilized on the surface of a porous matrix for sample contact, then measurement function is enabled, but the sensor becomes vulnerable to radiation damage

Engineering Contradiction:

Improvesample contact capabilityVSAvoidradiation sensitivity

Core Design Contradiction:

Adaptability or versatilityVSObject-affected harmful factors

Solution Approach 1:

The sensor system is divided into two separate components: the optical sensor patch and the container. The sensor patch can be sterilized separately using gamma radiation without exposing the entire container to high radiation doses, thereby preserving sensor sensitivity while achieving sterilization where needed

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A protective coating or barrier layer is introduced between the optical sensor and the reactive species generated during gamma radiation sterilization. This intermediary protects the sensor chemistry from direct exposure to ionizing radiation and free radicals, maintaining sensor functionality while allowing sterilization to proceed

Inventive Principle:

Principle #24Intermediary (Mediator)

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

The sensor protector effectively reduces the sensor's sensitivity to radiation-induced damage, maintaining signal quality and sensitivity by minimizing gas volume and reactive particles, ensuring better signal-to-noise ratios and prolonged sensor functionality.

Implementation Method 1

optical sensors based on porous matrices, for example fluorescence-based pH sensors

Methodology Applied

Scientific EffectFluorescence: Fluorescence

Implementation Method 2

During the radiation sterilization, the gasses are partly ionized, or free radicals are generated

Methodology Applied

Scientific EffectIonization: Ionisation

Data Source

PatentUS8809765B2Sensor protector

Publication Date: 2014.08.19 SARTORIUS STEDIM BIOTECH GMBH

AI summary

A sensor protector is intended to reduce the sensitivity of the optical sensor (4) to radiation products which, for example, are formed during sterilization with gamma radiation and to ensure simple and cost-effective manufacture. The sensor protector includes an upper part (1), a lower part (3) and an optical sensor (4). The optical sensor (4) situated on the lower part is positionable in an offset manner with respect to an opening (2) situated in the upper part and movable by means of displacement toward the opening (2) of the upper part (1). The sensor protector is suitable for use in containers and laboratory products that are sterilized by gamma radiation, for example disposable bioreactors.