HUMORAL RHEOLOGY : I. VISCOSITY STUDIES AND ANOMALOUS FLOW PROPERTIES OF HUMAN BLOOD SYSTEMS WITH HEPARIN AND OTHER...

Area of Science:

• Biophysics
• Rheology
• Biomedical Engineering

Background:

• Blood exhibits anomalous flow properties, deviating from Newtonian fluid behavior.
• Previous studies suggested blood's non-Newtonian characteristics, but precise characterization requires advanced viscometry.
• Understanding blood rheology is crucial for diagnosing and managing various hematological conditions.

Purpose of the Study:

• To present a modified rolling ball viscometer for accurate blood flow property measurements.
• To verify and further characterize the anomalous flow properties of blood using the new viscometer.
• To investigate the effects of heparin on blood viscosity and yield value.

Main Methods:

• Development and application of a modified falling ball viscometer (rolling ball viscometer).
• Measurement of blood flow properties at multiple shearing stresses.
• Analysis of viscosity, pseudoviscosity, and yield value under varying conditions and heparin concentrations.

Main Results:

• The rolling ball viscometer effectively measures anomalous flow properties at several stresses.
• Blood flow conforms to the Bingham concept, necessitating multi-stress measurements for complete characterization.
• Increasing heparin concentrations decreased apparent viscosity, pseudoviscosity, and yield value in blood, serum, and plasma.
• Heparinized blood demonstrated thixotropy, dilatancy, and age-hardening.

Conclusions:

• The modified rolling ball viscometer provides a reliable method for studying blood rheology.
• Blood's non-Newtonian behavior is confirmed, with yield value being a key characteristic.
• Heparin acts as a viscosity-reducing agent in blood and its components.
• Complex rheological phenomena in heparinized blood highlight the need for detailed flow analysis.