Single-Use Biopharma Assembly X-Ray Sterilization Dosimetry

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Solution Overview

Problem

Existing gamma radiation sterilization methods for bioreactor containers are inadequate as they fail to achieve complete sterility (1 in 1 million organisms) due to damage from high doses to sensitive components like sensors, and edge effects from uneven irradiation distribution in heterogeneous assemblies.

Innovation Solution

A method using X-ray sterilization with dosimeters to determine an optimal power-time pair ensuring all dosimeters receive a minimum effective dose without exceeding the maximum dose for sensitive components, addressing heterogeneity and edge effects in assemblies with heights up to 90% of the radiation window size.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If gamma radiation is used at high dose to achieve complete sterility, then sterility is improved, but sensor components are damaged

Engineering Contradiction:

ImprovesterilityVSAvoidsensor damage

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent changes the radiation type parameter from gamma rays to X-rays, and optimizes the power-time pairs to achieve complete sterility while keeping sensor exposure below damage thresholds. This parameter change allows simultaneous achievement of both sterility and sensor protection.

Inventive Principle:

Principle #35Parameter changes

2Object-affected harmful factors

If gamma radiation is used at low dose to protect sensor components, then sensor integrity is improved, but sterility is insufficient

Engineering Contradiction:

Improvesensor integrityVSAvoidsterility

Core Design Contradiction:

Object-affected harmful factorsVSReliability

Solution Approach 1:

The patent changes the radiation type from gamma rays to X-rays and optimizes power-time pairs to achieve complete sterility while maintaining sensor integrity through controlled exposure levels.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent implements a feedback mechanism by mapping irradiation doses received by dosimeters at different positions and orientations, then using this information to determine optimal power-time pairs that ensure complete sterility while protecting sensitive components.

Inventive Principle:

Principle #23Feedback

3Productivity

If assembly height increases to accommodate more products, then productivity is improved, but edge effects increase causing uneven irradiation

Engineering Contradiction:

Improveproduct batch sizeVSAvoidirradiation uniformity

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The patent addresses edge effects in tall assemblies by implementing irradiation from multiple dimensions - passing the assembly through the radiation window multiple times at different orientations (first face, second face, third face, fourth face). This multi-dimensional approach ensures uniform irradiation distribution throughout the entire assembly volume.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent performs preliminary mapping of irradiation doses at different positions and orientations before final sterilization. This preliminary action identifies optimal power-time pairs that ensure uniform irradiation throughout the assembly, preventing edge effects in subsequent processing.

Inventive Principle:

Principle #10Preliminary action

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

Achieves complete sterility (1 in 1 million organisms) while protecting sensitive components by optimizing X-ray irradiation power-time pairs, overcoming uneven irradiation distribution and edge effects in large, heterogeneous assemblies.

Implementation Method 1

The energy of the emitted radiation allows destroying the micro-organisms... sterilization by X-rays... repeating a passage of the assembly in front of the X-ray radiation window

Methodology Applied

Scientific EffectIonization: Ionisation

Implementation Method 2

The density of the assembly being heterogeneous... the energy absorbed during radiation depends on several factors, including the exposure duration, the radiation intensity, the material density

Methodology Applied

Scientific EffectX-Ray absorption: Absorption (EM radiation)

Data Source

PatentUS12383638B2Method for sterilizing an assembly comprising at least one single-use device for biopharmaceutical fluid

Publication Date: 2025.08.12 SARTORIUS STEDIM FMT SAS

AI summary

A method for sterilizing by X-rays an assembly containing a single-use device intended to receive a biopharmaceutical fluid, comprising: placing a plurality of dosimeters, repeatedly passing the assembly in front of the X-ray radiation window, according to a first face then according to a second face of the assembly, at several irradiation power-time pairs (PTi), followed by mapping the radiation dose; and —determining an optimum power-time pair (PTopt) for which the mapping reveals that all dosimeters have recorded a radiation dose above a minimum sterility dose (Dmin), and for which the dosimeter associated with a fragile element of the single-use device records a radiation dose below a maximum dose (Dmax) defined as being the dose from which the X-ray irradiation deteriorates the fragile element.