Relation between hematocrit partitioning and red blood cell lingering in a microfluidic network

Area of Science:

• Physiology
• Biophysics
• Microcirculation dynamics

Background:

• Quantitative data on lingering red blood cells (LRBCs) and their impact on hematocrit distribution in microcirculation are limited.
• Understanding red blood cell behavior is crucial for comprehending microvascular flow dynamics.

Purpose of the Study:

• To investigate the relationship between red blood cell (RBC) lingering and hematocrit partitioning in a microfluidic model.
• To analyze LRBC behavior at low hematocrit conditions (<10%) in a microvascular bifurcation.

Main Methods:

• Classification of LRBCs based on timing, position, and velocity.
• Statistical analysis of RBC velocity, shape, orientation, and lateral distribution.
• Utilized a microfluidic bifurcation model simulating microvascular conditions.

Main Results:

• LRBCs primarily travel along the parent vessel centerline but marginate towards the distal wall in daughter vessels.
• No direct influence of lingering events on local hematocrit partitioning was observed.
• LRBCs in daughter vessels can influence downstream hematocrit distribution via the network history effect.

Conclusions:

• While LRBCs do not directly alter local hematocrit, their behavior post-lingering can affect downstream hematocrit partitioning.
• The network history effect, influenced by LRBCs, plays a role in the heterogeneous hematocrit distribution in microvascular networks.