Pierceable Cap With Controlled Venting for Sample Transfer
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Solution Overview
Problem
Existing caps for biological and chemical specimens are prone to leakage and contamination during transport and analysis, leading to cross-contamination and false positive results, especially in nucleic acid detection, due to the formation of aerosols and direct contact with specimen residue.
Innovation Solution
A pierceable cap with a frangible layer and extensions that allow controlled venting to prevent aerosol formation and contamination, featuring a lower and upper frangible layer with extensions that breach upon pressure application, providing a secure seal and controlled air passage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a substantially leak-proof seal is formed between the cap and the vessel, then specimen leakage is prevented during transport, but aerosol formation and contamination occur when the cap is physically removed from the vessel
Solution Approach 1:
The cap is segmented into multiple functional layers: a frangible seal layer that maintains the leak-proof seal during transport, and a vent layer with airflow pathways that enables controlled venting when accessed. This segmentation allows the cap to provide both reliable sealing and controlled access without aerosol generation.
Solution Approach 2:
The vent layer acts as an intermediary between the sealed specimen environment and the external atmosphere. It provides a controlled interface that allows air exchange while preventing uncontrolled aerosol release, mediating between the need for sealing and the need for access.
2Ease of operation
If a frangible layer is used to allow piercing access, then cap removal labor is reduced, but specimen aerosols are released into the surrounding environment
Solution Approach 1:
The cap separates the frangible seal function from the venting function into distinct layers. The frangible layer provides easy piercing access, while the vent layer with its engineered airflow pathways controls the egress of air and prevents aerosol release, allowing easy access without harmful aerosol generation.
Solution Approach 2:
The vent layer incorporates flexible membrane structures that can deform to accommodate the piercing action while maintaining controlled airflow pathways. These thin film structures allow the cap to transition from a sealed state to an accessed state without creating aerosols.
3Productivity
If sealed vessel is penetrated by transfer device, then sample can be transferred, but air displacement releases portions of the sample into surrounding air via aerosol or bubbles
Solution Approach 1:
The vent layer serves as an intermediary airflow pathway that mediates the pressure equalization process during sample transfer. It provides a controlled route for air displacement that prevents sample aerosolization, enabling productive sample transfer without harmful aerosol release.
Solution Approach 2:
The flexible membrane structures in the vent layer adapt to the insertion of the transfer device while maintaining controlled airflow pathways. This allows the system to accommodate the volume displacement caused by the transfer device without creating aerosols or bubbles.
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 pierceable cap minimizes contamination risks by preventing specimen leakage and aerosol formation, ensuring accurate sample transfer and reducing cross-contamination, suitable for both manual and automated applications.
Implementation Method 1
a lower frangible layer disposed across the access port for preventing transfer of the sample specimen through the access port prior to insertion of the at least part of the transfer device
Implementation Method 2
wherein the one or more extensions move and pierce the lower frangible layer upon application of pressure from the transfer device
Implementation Method 3
When a sealed vessel is penetrated by a transfer device, the volume of space occupied by a fluid transfer device will displace an equivalent volume of air from within the collection device. In addition, temperature changes can lead to a sealed collection vessel with a pressure greater than the surrounding air, which is released when the cap is punctured. Such air displacements may release portions of the sample into the surrounding air via an aerosol or bubbles.
Data Source
AI summary
A method for penetrating a pierceable cap (11) on a vessel (21). The pierceable cap (11) prevents escape of sample specimens from the vessel (21) before transfer with a transfer device (43). The pierceable cap (11) may fit over a vessel (21). An access port in the shell of the pierceable cap (11) may allow passage of a transfer device (43) through the pierceable cap (11). At least one frangible layer (215, 216) may be configured with cross slits (506) in a particular cross slit geometry. The cross slits (506) may contain an openable portion (644) or be covered by a thin membrane (645). The shell (610) and frangible layer(s) (215, 216) may be integrated into a one piece cap (601), or be separate components (634). The membrane on which the cross slits 506 are placed can be flat or contoured to guide the transfer device (43) to the cross slits (506). The flat surfaces are supported by rib structures (620, 621) that extend radially inward and downward into the vessel (21).