A new capillary viscometer for small samples of whole blood

Area of Science:

• Biomedical Engineering
• Fluid Dynamics
• Materials Science

Background:

• Accurate blood viscosity measurement is crucial for diagnosing various health conditions.
• Existing viscometry methods can be complex, require large sample volumes, or lack comprehensive shear stress analysis.

Purpose of the Study:

• To introduce and validate a new capillary viscometer for blood viscosity analysis.
• To assess the performance of the new viscometer against established methods and theoretical models.

Main Methods:

• A novel capillary viscometer was designed to discharge blood under constant pressure, generating variable shear stresses.
• Viscosity of Newtonian sucrose solutions was measured for system calibration.
• Whole blood viscosity was measured using both the new capillary viscometer and a cone-and-plate viscometer.
• Data was analyzed using a power law model to characterize blood rheology.

Main Results:

• The capillary viscometer demonstrated good agreement with expected values for sucrose solutions.
• Excellent correlation was observed between capillary and rotational viscometer results for whole blood at low to medium shear rates.
• The system's capability to achieve high shear rates by increasing driving pressure was confirmed.

Conclusions:

• The new capillary viscometer is a simple, reliable tool for blood viscosity measurement.
• It offers accurate results using a small test volume and provides comprehensive shear stress data.
• This device shows promise for both research and clinical applications in hemorheology.