Oxygen is essential for brain function, as neurons have very high metabolic demands and even small changes in oxygen availability can affect their activity. The brain relies on a dense microcirculation network to deliver oxygen efficiently to all regions. Despite years of research, the understanding of oxygen transport in the brain remains limited. Computational modeling has become an important tool to explore these mechanisms and provide insights that experiments alone cannot deliver. A key element in oxygen transport is the exchange of oxygen between red blood cells (RBCs) and plasma, quantified by the mass transfer coefficient (MTC). The MTC determines the rate at which oxygen moves from RBCs to plasma, thereby influencing tissue oxygenation.