Germicidal Medium Evaporation for Complex Chamber Sterilization
Solution Overview
Problem
Existing methods for reducing microbiological contamination in complexly shaped, closed chambers of container systems, such as double-chamber syringes or infusion bottles, are inadequate due to temperature sensitivity of filling products and material limitations, making traditional sterilization techniques like autoclaving or radiation impractical.
Innovation Solution
A chemical sterilization method using a germicidal medium, such as an aqueous hydrogen peroxide solution, is introduced into the chamber, where it is heated by radiation pulses to evaporate and distribute within the chamber, achieving sterilization without significantly heating the container walls, and allowing for repeated evaporation and condensation cycles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If autoclaving or radiation sterilization is used to sterilize the empty chamber, then the chamber is sterilized, but the temperature-sensitive filling product is damaged or the container materials require complex stabilization
Solution Approach 1:
The sterilization process is segmented into two distinct phases: first, the chamber is sealed while empty; second, a germicidal medium is introduced and activated only within the chamber using microwave radiation. This segmentation allows sterilization to occur without exposing the filling product to damaging temperatures or radiation, as the energy is selectively applied only to the chamber space.
Solution Approach 2:
A germicidal medium (such as hydrogen peroxide solution) is introduced as an intermediary substance to transfer the sterilization function. The medium absorbs microwave energy and converts it to thermal energy locally within the chamber, enabling sterilization without directly heating the container walls or the filling product. This intermediary facilitates selective energy transfer to achieve sterilization while protecting sensitive components.
2Reliability
If heat treatment is applied to the empty chamber to reduce germ count, then sterilization is improved, but the container materials with low temperature stability are damaged
Solution Approach 1:
The heating action is localized specifically to the germicidal medium within the chamber through selective microwave absorption. The container walls and filling product are not directly heated, as they have different dielectric properties and do not absorb microwave energy to the same extent. This local quality approach allows thermal sterilization to occur in the chamber space while preserving the integrity of temperature-sensitive materials.
Solution Approach 2:
The physical state of the germicidal medium is dynamically changed during the process: introduced as liquid, heated to vapor phase for distribution, then condensed back to liquid for degradation. These parameter changes enable the medium to effectively penetrate and sterilize all surfaces of the complex chamber geometry without requiring sustained high temperatures that would damage container materials.
3Reliability
If direct irradiation is used to reach all surfaces in the complex chamber, then sterilization coverage is improved, but dead spot effects prevent complete sterilization
Solution Approach 1:
The microwave radiation is applied in periodic pulses rather than continuous irradiation. This periodic action allows the germicidal medium to cycle through evaporation, distribution, condensation, and degradation phases, ensuring thorough penetration into complex chamber geometries and elimination of dead spots. The cyclic process enhances sterilization effectiveness without requiring complex multi-directional irradiation systems.
4Reliability
If radiation sterilization is used on the empty chamber, then sterilization is achieved, but complex and expensive shielding measures are required to protect the filling product
Solution Approach 1:
The mechanical shielding system is replaced by a selective energy absorption mechanism. Instead of using physical barriers to block radiation, the germicidal medium is used to selectively absorb microwave energy and convert it to localized thermal energy within the chamber. This substitution eliminates the need for complex shielding structures while achieving the same protective effect for the filling product.
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 effectively reduces microbiological contaminants in small, complexly shaped chambers without damaging temperature-sensitive products, using microwave or radio frequency radiation to evaporate and degrade the germicidal fluid, ensuring thorough sterilization of hard-to-reach areas without requiring carrier gases or complex shielding.
Implementation Method 1
the medium inside the chamber is exposed to the effect of an energy source... the energy source is used to heat the fluid to at least partially transition from the liquid phase to the gaseous phase
Implementation Method 2
A particularly rapid evaporation and uniform distribution of fluid and fluid vapors can be achieved if the energy for heating is introduced in the form of radiation pulses... microwave or radio frequency radiation to evaporate and degrade the germicidal fluid
Implementation Method 3
the fluid is selected such that the fluid is at least partially chemically modified or degraded during its residence time in the chamber... degrade the germicidal fluid
Implementation Method 4
the concentration of the fluid or its degradation products can be at least partially reduced by permeation out of the chamber
Data Source
AI summary
A method reduces microbiological contamination in a closed chamber (6), formed by at least two interconnected components (1, 4), by introducing a germicidal medium in liquid form into the chamber (6). The chamber (6) is formed by and between a cap (4) and a head (2) of a filled container.