Unlocking the mysteries of spaceflight impact on the human body

In this interview, Prof. Dr. Ana Diaz Artiles shares insights from her groundbreaking research, highlighting the use of advanced technologies and the implications of her findings for the future of human spaceflight.

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What medical questions is your research group at Texas A&M University seeking to answer?

We are particularly interested in understanding and quantifying how fluid shifts affect the cardiovascular system. Fluid shifts can occur due to various factors, such as changes in posture (e.g., moving from an upright to a supine or head-down position) or variations in gravitational forces, such as those experienced during spaceflight or centrifugation. One of our primary areas of focus is the Internal Jugular Vein (IJV), specifically its cross-sectional area and pressure, since flow stasis and thrombosis have been observed in this vein during space missions.

Can you describe the experiment?

We conducted an experiment with twelve male participants who were exposed to a graded tilt, ranging from 45° head-up tilt (HUT) to 45° head-down tilt (HDT), in 15° increments, using a tilt table. The protocol was repeated in both supine and prone positions. At each tilt angle, we gathered extensive cardiovascular data to generate dose-response curves based on gravitational exposure. Specifically, we measured the cross-sectional areas of the left and right common carotid arteries and internal jugular veins, as well as the pressures within the internal jugular veins.

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„Space has always fascinated me – it represents the ultimate challenge for both engineers and scientists. The opportunity to contribute to humanity's understanding of how to survive and thrive beyond earth is both humbling and exhilarating."

Prof. Dr. Ana Diaz Artiles, associate professor at Texas A&M University

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What were your key findings?

The Internal Jugular Vein (IJV) exhibited a pronounced non-linear response to gravity changes, with both the area and pressure increasing as the body was tilted to a headdown position. Notably, the IJV area was consistently larger on the right side than the left at all angles. Additionally, IJV pressure was higher when participants were in a prone position compared to a supine position. Interestingly, the cross-sectional area of the common carotid artery (CCA) did not show any gravitational dependency.

Why is this important in the context of spaceflight?

During recent spaceflights, astronauts have experienced stagnant or even retrograde blood flow in the Internal Jugular Vein, and in one case, an astronaut developed a potentially life-threatening internal jugular vein thrombus, which required immediate intervention. We believe these issues are related to the fluid shifts that occur in microgravity. By studying these phenomena in terrestrial models, such as the tilt paradigm, we aim to better understand the underlying mechanisms and contribute to the development of countermeasures to protect astronauts during longduration space missions.

What problems did you encounter addressing your medical questions?

Conducting human experiments is always challenging due to individual variability among subjects and the numerous factors that can affect outcomes. Additionally, our study used a terrestrial model – the tilt paradigm – which, while useful, does not fully replicate the conditions of true microgravity. Therefore, it is crucial to consider these limitations when interpreting our results. However, despite these challenges, we have gained valuable insights into cardiovascular responses in altered gravity environments.

In what way did Compremium‘s technology help you advance your research?

Compremium’s technology was instrumental in allowing us to measure the pressures in the left and right Internal Jugular Veins of our subjects non-invasively and with high accuracy. This capability has provided us with critical data on how fluid shifts impact the cardiovascular system in altered gravity environments, helping us to better understand the potential risks astronauts may face.

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„The research of Ana Diaz and her team, supported by cutting-edge technologies like those developed by Compremium, is helping to pave the way for safer, longer missions in space, unlocking the potential for human exploration of the cosmos."

Vincent Baumann, CEO Compremium AG

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How does the future of your research with Compremium’s device look like?

We plan to continue using Compremium technologies in our ongoing studies, not only within tilt paradigms but also in other environments that simulate altered gravity, such as the Lower Body Negative Pressure (LBNP) chamber and short-radius centrifugation. These studies will enable us to further refine our understanding of fluid shifts and cardiovascular health in space.

Compremium‘s unique technology has enabled my research group to gain unparalleled insights into the cardiovascular response to altered-gravity environments. In particular, we have been able to better characterize the internal jugular vein‘s behavior during graded tilt, which contributes to the assessment of cardiovascular changes during spaceflight and the development of countermeasures for future space travel.

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Prof. Dr. Ana Diaz Artiles

Prof. Dr. Ana Diaz Artiles is an associate professor in the Department of Aerospace Engineering at Texas A&M University, where she leads the “Bioastronautics and Human Performance” research lab. With a background in aeronautical engineering and a Ph.D. from the Massachusetts Institute of Technology (MIT), her work is at the forefront of human health in space exploration. Dr. Diaz Artiles focuses on developing countermeasures to combat the physiological effects of spaceflight, including the design of artificial gravity systems and spacesuit innovations.

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