Biosensing of Haemorheological Properties Using Microblood Flow Manipulation and Quantification

Area of Science:

• Biophysics
• Biomedical Engineering
• Hematology

Background:

• Blood's biomechanical properties are crucial for diagnosing hematological disorders.
• Simultaneously measuring multiple haemorheological properties aids in distinguishing red blood cell (RBC) and plasma contributions.
• Existing methods may lack precision in isolating individual RBC and plasma effects.

Purpose of the Study:

• To develop and validate a novel method for analyzing blood's biomechanical properties.
• To simultaneously measure blood viscosity, time constant, and RBC aggregation.
• To assess the method's efficacy in detecting variations in hematocrit and RBC condition.

Main Methods:

• Analyzed blood flow under a square-wave profile (steady and transient flow).
• Derived a simplified differential equation from a discrete circuit model to determine the time constant for viscoelasticity.
• Introduced new parameters, <λ> and dλdβ, to represent the linearly varying time constant.

Main Results:

• The time constant (λ) showed a linear relationship with the coflowing channel interface (β).
• Blood viscosity was found to be more effective than the time constant for detecting hematocrit variations.
• Significant differences in viscosity and time constant were observed for hardened RBCs, demonstrating sensitivity to RBC condition.

Conclusions:

• The developed method accurately measures blood viscosity, time constant, and RBC aggregation.
• The method successfully detected continuous hematocrit variations, as seen in RBC sedimentation.
• This technique offers a consistent approach for monitoring multiple haemorheological properties of blood.