Basic principles for evaluation of less deformable erythrocyte subpopulations with the Microfiltrometer

Area of Science:

• Biomedical Engineering
• Hematology
• Cellular Biophysics

Background:

• Erythrocyte deformability is crucial for microcirculation.
• Assessing red blood cell health requires precise measurement techniques.
• Existing methods may lack sensitivity or throughput.

Purpose of the Study:

• To introduce and validate the Microfiltrometer for quantifying erythrocyte deformability.
• To establish a Microfiltrometer Deformability Index (MDI) for classifying red blood cells.
• To evaluate the diagnostic performance of the Microfiltrometer in healthy blood samples.

Main Methods:

• Utilized a filtration system with 30 micropores (5 µm diameter) and applied sinusoidal alternating current (40 kHz, 300 µA).
• Measured erythrocyte entry time (τ) and maximal impedance variation (ΔZ) as cells transited through micropores.
• Calculated the slope ΔZ/τ to determine pore blockage velocity and derive the Microfiltrometer Deformability Index (MDI).

Main Results:

• The Microfiltrometer Deformability Index (MDI) effectively distinguishes between deformable (MDI ≥ 1) and undeformable (MDI < 1) erythrocytes.
• In healthy blood samples, the Microfiltrometer identified <2% undeformable erythrocytes.
• Achieved high diagnostic performance with 99% specificity and 97.5% sensitivity.

Conclusions:

• The Microfiltrometer provides a reliable and sensitive method for assessing erythrocyte deformability.
• The Microfiltrometer Deformability Index (MDI) offers a quantitative measure for red blood cell health assessment.
• This technology shows potential for clinical applications in diagnosing conditions affecting erythrocyte mechanics.