Capillary Plasma Separation and Metering Without Centrifugation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing plasma separation methods for clinical diagnostics are time-consuming, require additional instrumentation, and are impractical for point-of-care applications, often leading to hemolysis and loss of waived status for diagnostic assays.
Innovation Solution
A device and method utilizing a sample device with a capillary channel, membrane, and RBC binding reagent to separate and meter plasma, allowing for efficient plasma extraction and integration with a reaction cartridge for diagnostic assays.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If centrifugation is used to separate plasma from whole blood, then plasma separation accuracy is improved, but time consumption increases and device complexity increases
Solution Approach 1:
The patent extracts the plasma separation function from complex centrifugation instrumentation and implements it through a simple capillary-based device with a membrane barrier. The capillary draws whole blood via capillary action, and the membrane physically separates plasma from cellular components without requiring centrifugal force, thereby eliminating time-consuming centrifugation steps while maintaining separation accuracy.
Solution Approach 2:
The patent replaces the mechanical centrifugation system with a capillary-driven passive separation system. Instead of using external mechanical centrifugal force, the system utilizes capillary action to draw blood through the membrane, where plasma naturally passes through while cellular components are retained, substituting complex mechanical instrumentation with simple passive physical principles.
2Measurement precision
If centrifugation is used to separate plasma from whole blood, then plasma separation accuracy is improved, but device complexity increases
Solution Approach 1:
The patent extracts the essential plasma separation function from complex centrifugation instrumentation and implements it through a simple capillary-based device with a membrane barrier. This eliminates the need for expensive, complex centrifuges while maintaining the ability to accurately separate plasma from whole blood samples.
Solution Approach 2:
The patent employs a disposable capillary device with an integrated membrane that can be discarded after single use. This eliminates the need for complex, reusable centrifugation equipment that requires maintenance, calibration, and sterilization, thereby significantly reducing device complexity and instrumentation requirements while maintaining separation accuracy.
3Quantity of substance
If traditional separation methods are used, then plasma can be separated, but hemolysis occurs and assay accuracy decreases
Solution Approach 1:
The patent replaces mechanical centrifugation with a gentle capillary-based separation method that does not subject blood cells to high g-forces or mechanical stress. The capillary draws blood through a membrane at low flow rates, allowing plasma to pass through while keeping cellular components intact, thereby preventing hemolysis and maintaining sample integrity for accurate assays.
Solution Approach 2:
The patent changes the physical parameters of the separation process by using capillary pressure and membrane filtration instead of high-speed centrifugal forces. This alters the mechanical stress profile from high-intensity centrifugation to low-intensity passive flow, preventing red blood cell rupture while achieving effective plasma separation.
4Quantity of substance
If additional separation steps are added, then plasma can be separated, but waived status under CLIA is lost
Solution Approach 1:
The patent merges the plasma separation function directly into the sample collection capillary itself, rather than requiring a separate centrifugation step followed by plasma transfer. The membrane-integrated capillary performs both sample collection and plasma separation in one integrated component, maintaining simplicity and preserving waived status under CLIA regulations.
Solution Approach 2:
The patent creates a multi-functional capillary device that simultaneously serves as the sample collection vessel, separation membrane support, and plasma delivery mechanism. This universal design consolidates multiple functions into a single component, avoiding additional separate steps that would increase assay complexity and threaten waived status.
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
Enables rapid, efficient plasma separation and metering from small blood samples, maintaining assay accuracy and preserving waived status for point-of-care diagnostics.
Implementation Method 1
at least a portion of the patient's liquid test sample is drawn into the at least one channel of the sample device via capillary action
Implementation Method 2
The sample device includes a membrane with a pore size that substantially prevents agglutinated red blood cells from flowing therethrough
Implementation Method 3
the patient's liquid test sample mixes with the at least one reagent, thereby agglutinating RBCs within the patient's liquid test sample
Data Source
AI summary
Devices, assemblies, and kits are disclosed for separating and/or metering a plasma sample from a patient's liquid test sample. Also disclosed are methods of producing and using same.