Microfluidic Cell Counting With Laser-Free Optical Interruption
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing cell counting devices are bulky, expensive, and require trained professionals, making them unsuitable for point-of-care and at-home use, and they often damage cells or require fluorescent dyes and lasers, limiting their accessibility and accuracy.
Innovation Solution
A microfluidic device with a photodetector system that measures cell passage by optical interruption and deformation, using autofluorescence to distinguish cell types without lasers, allowing for accurate and rapid cell counting without the need for specialist equipment or training.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If sophisticated machinery with lasers and fluorescence markers is used for cell counting, then measurement precision is improved, but device complexity increases and portability is reduced
Solution Approach 1:
The patent extracts and eliminates the laser component from the flow cytometry system, replacing it with a simple LED light source. This removal of the complex laser subsystem while retaining the core flow cytometry functionality resolves the contradiction by maintaining measurement precision through the photodetector-based detection system while dramatically reducing device complexity and enabling portability
Solution Approach 2:
The patent replaces expensive, complex laser systems with inexpensive LED light sources that have simpler alignment requirements and lower cost. This substitution maintains sufficient measurement precision for cell counting while reducing device complexity and making the system portable for point-of-care use
2Measurement precision
If lasers and fluorescence markers are used for cell detection, then measurement precision is improved, but ease of operation deteriorates due to alignment problems and specialized training requirements
Solution Approach 1:
The patent substitutes the mechanically complex laser alignment system with a simpler LED-based illumination system that has inherent tolerance to misalignment. This replacement maintains measurement precision through the microfluidic channel's controlled cell flow and photodetector detection while dramatically improving ease of operation by eliminating the need for precise optical alignment and specialized training
Solution Approach 2:
The microfluidic channel design allows cells to flow through the detection zone automatically based on pressure differential or capillary action, eliminating the need for complex mechanical pumping systems and alignment adjustments. The system self-regulates cell flow and detection, improving ease of operation while maintaining measurement precision
3Measurement precision
If conventional cell counting methods are used, then measurement precision is improved, but object-affected harmful factors increase due to cell damage from lasers and centrifugal separation
Solution Approach 1:
The patent converts the potential harm of high-intensity laser illumination into a beneficial low-intensity LED illumination that is sufficient for detection but harmless to cells. The LED light source provides adequate illumination for photodetector-based cell detection without the thermal and phototoxic effects of lasers, maintaining measurement precision while eliminating cell damage
Solution Approach 2:
The patent extracts and removes the centrifugal separation component from the cell counting system, replacing it with a microfluidic approach that uses passive flow through narrow channels to achieve cell separation and counting. This elimination of high-speed rotating machinery removes the mechanical stress and potential cell damage associated with centrifugal forces while maintaining measurement precision through controlled cell flow and detection
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 device provides reliable, rapid, and cost-effective cell counting suitable for point-of-care and at-home use, minimizing cell interference and eliminating the need for fluorescent dyes or complex machinery.
Implementation Method 1
a first photodetector arranged to receive light that has passed through the microfluidic channel at a first measurement point, such that signal from the photodetector varies due to the received light being restricted by the passage of cells across the first measurement point
Implementation Method 2
the microfluidic channel sized such that target cells within the cell-containing fluid flow consecutively through the microfluidic channel... distinguish the size of a cell passing the first measurement point based on an interruption time
Implementation Method 3
a processing unit configured to receive a signal from the photodetector and distinguish the size of a cell passing the first measurement point based on an interruption time during which the signal intensity received from the photodetector is reduced
Data Source
AI summary
The described invention is a cell counting device for counting target cells within a fluid, the device comprising: a microfluidic channel configured to receive a flow of a cell-containing fluid through an inlet and conduct the flow of the cell-containing fluid along the channel, the microfluidic channel sized such that target cells within the cell-containing fluid flow consecutively through the microfluidic channel; a first photodetector arranged to receive light that has passed through the microfluidic channel at a first measurement point, such that signal from the photodetector varies due to the received light being restricted by the passage of cells across the first measurement point in the microfluidic channel; a processing unit configured to receive a signal from the photodetector and distinguish the size of a cell passing the first measurement point based on an interruption time during which the signal intensity received from the photodetector is reduced, thereby determining the presence of a target cell type. Using an optical interruption signal in this way, provides a low cost device that does not require fluorescent dyes to label the cells nor does it require lasers, microscopes or other specialist equipment such that the device is suitable for point-of-care and at-home use and does not require the direction of a trained specialist operator.