Modeling Cardiovascular Physiology in Space
The cardiovascular system is one of the body systems affected by spaceflight. Altered gravity environments cause a change in the hydrostatic pressure distribution on the body leading to a cephalad fluid shift where blood volume in the lower extremities reduces by up to a liter and increases in the trunk and head (sometimes known as puffy face/chicken leg syndrome). This leads to hypovolemia, changes in hematocrit concentration, aerobic deconditioning, and could be a cause of spaceflight associated neuro-ocular syndrome (SANS).
We use mathematical models of the cardiovascular system to reach beyond the limitations of existing data and study the effects of changing gravity levels and introducing artificial gravity gradients. These models have been validated over a number of experimental studies and are continuously being extended to include the ability to model new conditions and physiological phenomenon including exercise, pulmonary function, long duration hemodynamic changes, and metabolic cost.
Simultaneously, we are considering the impact of individual physiological variation on cardiovascular performance in space, and beginning to look at the total existing dataset of physiology studies from spaceflight and analogs to determine whether we can generate predictive algorithms for long duration performance deconditioning.
Combined with the experimental work, this research will lead to a greater understanding of the temporal effects of space flight on the cardiovascular system, enabling us to better design and implement countermeasures and protocols for long duration exploration missions.