My research interests are related to human performance. I have a particular interest in the human component of spaceflight, with strong emphasis on the biomedical, human factors, and mission design aspects of space exploration. Below you will find a list of current and recent research projects in the lab. If you are interested in one of these projects or similar research, please don’t hesitate to contact me at ad877@cornell.edu.

Artificial Gravity as a Countermeasure for Human Spaceflight Deconditioning

Astronauts experience a strong physiological deconditioning during space missions, primarily due to the weightless conditions. Some of these adverse consequences include bone loss, muscle atrophy, sensory-motor/vestibular deconditioning, visual impairment, and overall cardiovascular adaptation, which may lead to orthostatic intolerance when astronauts are exposed again to a gravitational environment. Physiological deconditioning will be even more challenging in future long-duration space missions, for example to Mars, in which astronauts will be exposed to weightlessness for six to eight months before landing without external help to support egress. In order to mitigate these negative effects, several countermeasures are currently in place, particularly very intensive exercise protocols. However, despite these countermeasures, physiological deconditioning still persist to a certain degree, highlighting the need for new approaches to maintain the astronauts’ physiological state within acceptable limits.

Artificial gravity (generated by centrifugation) has long been suggested as a comprehensive countermeasure that is capable of challenging multiple physiological systems at the same time, therefore maintaining overall health during extended weightlessness. However, human centrifuges hasn’t been tested in space, and there are still many questions about its implementation (including centrifuge configuration, exposure time, gravity level, gravity gradient, and use/intensity of exercise, etc). We want to investigate these research questions using a combination of human experiments on ground-based centrifuges and modeling techniques of physiological systems to complement the experimental results.

Artificial Gravity Combined with Exercise

In order to investigate physiological responses of centrifugation combined with exercise, we conducted a human experiment on 12 subjects using the MIT short-radius centrifuge. The centrifuge was constrained to a radius of 1.4 meters (the upper radial limit for a centrifuge to fit within an International Space Station (ISS) module without extensive structural alterations), and a cycle ergometer was added for exercise during centrifugation. We tested different levels of artificial gravity (0g, 1g, and 1.4g at the feet in the centripetal direction) and exercise intensity (25W warm-up, 50W moderate, and 100W vigorous) while collecting a variety of data including cardiovascular parameters, foot forces, and subjective comfort and motion sickness data. Check it out some videos of the MIT centrifuge experiment below!

Subjects successfully completed the exercise protocol and they tolerated the centrifugation well and motion sickness was minimal. Foot forces measurements indicate that there is a significant effect of both artificial gravity (AG) level and workload intensity on peak forces generated during ergometer exercise. The cardiovascular responses were more prominent (measured as larger deviations from their baseline values) at higher levels of artificial gravity and exercise intensity. In particular, cardiac output, stroke volume, and pulse pressure significantly increased with both AG level and workload intensity, suggesting that the combination of artificial gravity and exercise may be beneficial against cardiovascular deconditioning in space. Mathematical models were fit to these variables across the condition tested. These results suggest that centrifugation combined with exercise may be effective in improving musculoskeletal and cardiovascular functions during long-duration spaceflight. This work was partially supported by Fulbright Commission, the NSBRI (PI: Larry Young), and the MIT/Skoltech Seed grant.

Computational Physiology: Cardiovascular Modeling under Centrifugation and Exercise (in construction)

Biomechanics: Human-Spacesuit Interaction (in construction)

Perception and Manual Control in Altered-Gravity Environments (in construction)