Plunger-Driven Filtration Assembly for Sensitive Particulate Testing
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Solution Overview
Problem
Existing methods for detecting particulates such as bacteria and viruses in fluids are inefficient and lack sensitivity, particularly in non-centrifuged samples, and do not effectively expose biological targets for accurate testing.
Innovation Solution
A filtration assembly is used to capture particulates in a fluid sample by size-based filtration, followed by creating a cavity to introduce extraction reagents that expose biological targets, allowing for testing of these targets in the extraction liquid.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If size-based filtration is used to capture particulates, then detection sensitivity is improved, but device complexity increases due to the need for filtration assembly with plunger and cavity
Solution Approach 1:
The filtration assembly is integrated within the fluid container structure, with the plunger nested inside the container and the filtration layer formed on the plunger surface. This nesting approach allows the filtration function to be incorporated without adding separate external filtration devices, thereby improving detection sensitivity while minimizing the increase in overall device complexity.
Solution Approach 2:
The plunger serves multiple functions: it acts as a piston to apply pressure for fluid movement, as a support structure for the filtration layer, and as a component that defines the cavity when retracted. This multi-functionality reduces the need for separate components, addressing the complexity concern while enabling effective size-based filtration for improved detection sensitivity.
2Measurement precision
If extraction reagents are introduced to expose biological targets, then testing accuracy is improved, but loss of time increases due to additional extraction steps
Solution Approach 1:
The filtration step is performed in advance to concentrate particulates on the filtration layer before extraction begins. This preliminary concentration action reduces the volume of sample that needs to be processed during extraction, allowing reagents to contact targeted particulates more efficiently and reducing overall extraction time while maintaining or improving testing accuracy.
Solution Approach 2:
Pressure differential is used to drive extraction reagents through the filtration layer and into the cavity, and subsequently to move the extracted liquid to the detection chamber. This pneumatic/hydraulic approach replaces manual or mechanical transfer steps, accelerating the extraction process while ensuring complete reagent contact with captured particulates for accurate target exposure.
3Loss of time
If non-centrifuged samples are tested, then loss of time is reduced by eliminating centrifugation, but measurement precision deteriorates due to sample complexity
Solution Approach 1:
The filtration assembly physically separates and extracts particulates (bacteria, viruses) from the complex non-centrifuged sample matrix by size-based filtration. This extraction action isolates the target particulates from interfering substances in the original sample, maintaining detection accuracy while eliminating the need for time-consuming centrifugation steps to achieve similar separation.
Solution Approach 2:
A porous filtration layer with specific pore sizes is used to selectively capture particulates based on their size. This porous material allows the filtration to occur rapidly without centrifugation while effectively separating target particulates from the complex sample matrix, thereby maintaining measurement precision despite the simplified, faster sample processing approach.
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 method enables rapid and sensitive detection of particulates, such as bacteria and viruses, in non-centrifuged samples by effectively capturing and exposing biological targets for analysis, enhancing the accuracy and speed of diagnostic testing.
Implementation Method 1
The fluid sample is passed through a porous filter of the filtration assembly and into a filtrate receptacle by distally advancing a plunger of the filtration assembly within the fluid container toward a distal end of the fluid container, thereby capturing, on or within the porous filter, by size-based filtration, at least a portion of any particulate present in the fluid sample.
Implementation Method 2
An extraction liquid is prepared by introducing one or more extraction reagents into the cavity and bathing the porous filter in the one or more extraction reagents, the one or more extraction reagents configured to extract and expose a biological target from any particulate captured on or within the porous filter.
Data Source
AI summary
A method is provided that includes introducing a fluid sample (19) into a fluid container (2, 502, 702) of a filtration assembly (20, 500, 720) and passing the fluid sample (19) through a porous filter (5, 705) by distally advancing a plunger (3, 610, 703) within the fluid container (2, 502, 702), thereby capturing, on or within the porous filter (5, 705) at least a portion of any particulate present in the fluid sample (19). Thereafter, a cavity (28, 628, 728) is created within the fluid container (2, 502, 702) between a distal end of the plunger and a distal end (49, 549, 749) of the fluid container (2, 502, 702) by proximally partially withdrawing the plunger (3, 610, 703) within the fluid container (2, 502, 702), while one or more vacuum-prevention openings (11, 711) are open. An extraction liquid (30) is prepared by introducing one or more extraction reagents (29) into the cavity (28, 628, 728) and bathing the porous filter (5, 705). The extraction liquid (30) is tested for the presence of a biological target. Other embodiments are also described.