Microfluidic-Based Novel Optical Quantification of Red Blood Cell Concentration in Blood Flow

Area of Science:

• Biomedical Engineering
• Microfluidics
• Optical Physics

Background:

• Accurate hematocrit measurement is vital for microfluidic biosensing sensitivity.
• Existing methods are impractical for dynamic microfluidic blood flow.
• A need exists for real-time, in-situ hematocrit quantification in microchannels.

Purpose of the Study:

• To develop and validate a novel optical method for quantifying hematocrit in dynamic microfluidic blood flow.
• To establish a relationship between image grayscale and hematocrit levels.
• To demonstrate the method's utility for microfluidic biosensing applications.

Main Methods:

• Utilized high-speed imaging and an inverted transmission microscope to capture blood flow images.
• Employed image processing to measure the grayscale intensity of blood flow images.
• Correlated average grayscale values with varying hematocrit levels (5-70%) in microchannels.

Main Results:

• Established a reliable relationship between blood flow image grayscale and hematocrit concentration.
• Demonstrated instant and easy quantification of hematocrit at a targeted microchannel location.
• Validated the optical method using porcine blood samples in microfluidic channels (1000 µm width, 100 µm depth).

Conclusions:

• The developed optical method offers a practical solution for real-time hematocrit measurement in microfluidic systems.
• This technique enhances the design and sensitivity of microfluidic biosensing platforms.
• The method shows strong potential for various applications requiring dynamic hematocrit monitoring.