Biomechanical Assessment of Red Blood Cells in Pulsatile Blood Flows

Area of Science:

• Biomedical Engineering
• Fluid Mechanics
• Hematology

Background:

• Blood rheology is crucial for disease diagnosis, influenced by red blood cells (RBCs) and plasma.
• Separating individual rheological contributions is essential for accurate health assessments.
• Current methods may lack the precision to detect subtle changes in blood properties.

Purpose of the Study:

• To develop and validate a microfluidic technique for simultaneously measuring three key blood rheological properties.
• To assess the method's capability in detecting alterations in blood composition and RBCs.
• To establish a foundation for improved early disease detection through rheological analysis.

Main Methods:

• Utilized a microfluidic device with pulsatile flow to analyze blood velocity and image intensity.
• Derived an analytical formula for viscoelasticity (time constant, λ) from pulsatile velocity data.
• Employed an air compliance unit (ACU) and image analysis to quantify RBC aggregation (AI) and blood junction pressure (β).

Main Results:

• Successfully measured viscoelasticity, RBC aggregation, and blood junction pressure using the developed microfluidic system.
• Demonstrated the method's ability to detect differences in blood samples with varying dextran concentrations (simulating aggregation) and thermally treated RBCs (simulating hardening).
• Showcased consistent detection of diluent or RBC variations through the three rheological parameters.

Conclusions:

• The developed microfluidic method offers a reliable approach to simultaneously assess critical blood rheological properties.
• This technique shows promise for non-invasive and early detection of diseases by identifying abnormal blood rheology.
• The ability to differentiate blood based on rheological changes provides a valuable tool for diagnostic applications.