Adapter Assembly for Microbial Detection via Septum Penetration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for testing samples for microbial contamination face challenges in maintaining a sealed environment to prevent sample contamination and ensuring accurate detection of microbial growth, as existing systems may lead to false positives due to external contamination or leakage.
Innovation Solution
An adapter assembly is designed to penetrate the septum of a collection vessel, allowing gaseous communication with a sensor while maintaining a gas-tight seal, using a gas-permeable membrane to prevent liquid contact and ensure that gases from the headspace are delivered to the sensor without contaminating the environment, utilizing a cannula, adapter ring, sleeve, and o-ring configuration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If the collection vessel is opened to access the sample, then subculturing and aliquotting become possible, but sample contamination and false positives occur
Solution Approach 1:
A needle assembly with a beveled needle penetrates the septum to provide access to the sample interior, while a barrier membrane prevents liquid sample from contacting the exterior environment. This intermediary structure enables sample access without direct opening, maintaining sterility and preventing contamination.
Solution Approach 2:
A barrier membrane (such as a polymeric film) is positioned at the septum interface to prevent liquid sample leakage while allowing needle penetration. This thin film creates a selective barrier that maintains the sealed environment during access operations.
2Stress or pressure
If gases are allowed to escape from the collection vessel, then pressure relief is achieved, but environmental contamination and sample contamination occur
Solution Approach 1:
The barrier membrane provides selective permeability with different properties for different substances: it allows gases to pass through for pressure relief while blocking liquid sample from escaping. This local quality differentiation resolves the contradiction between pressure management and contamination prevention.
3Reliability
If a sealed environment is maintained, then sample contamination is prevented, but access to the sample for subculturing is limited
Solution Approach 1:
The needle assembly acts as an intermediary tool that penetrates the sealed environment through the septum, enabling sample access for subculturing and aliquotting without breaking the seal. The barrier membrane maintains sterility while the needle provides operational access.
4Measurement precision
If the sensor is positioned to detect headspace gases, then microbial growth detection is enabled, but liquid sample contact with the sensor causes false readings
Solution Approach 1:
The barrier membrane is positioned between the liquid sample and the sensor assembly, allowing headspace gases to reach the sensor for microbial detection while preventing liquid sample from contacting the sensor. This intermediary barrier ensures accurate measurements without sensor contamination.
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 configuration ensures accurate detection of microbial growth by preventing external contamination and ensuring that gases from the sample are transmitted to the sensor without leakage, maintaining a sterile environment and reducing the risk of false positives, thus enhancing the reliability of microbial contamination testing.
Implementation Method 1
the adapter assembly includes a gas permeable membrane configured to prevent liquid in the collection vessel from contacting the sensor
Data Source
AI summary
Various embodiments of the present disclosure describe systems and methods for testing samples (e.g., biological samples, environmental samples, food samples etc.) for microbial contamination. For example, some embodiments describe an adapter assembly with a means to penetrate a septum of a collection vessel and permit gaseous communication between a headspace of the collection vessel and a sensor. In some embodiments, the gases in the headspace of the collection vessel can exit the collection vessel without contaminating the environment outside the system or allowing sample contamination. In some embodiments, the adapter assembly includes a membrane configured to prevent liquid in the collection vessel from contacting the sensor. In some embodiments, the adapter assembly can be used to access media inside the collection vessel for subculturing or aliquotting for another diagnostic process such as molecular diagnostics.