Study of the State of Fluids in the Human Body During Long-term Spaceflight (Sprut-MBI) (Sprut-MBI (Octopus-MBI)) - 05.09.18

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ISS Science for Everyone

Science Objectives for Everyone
The Study of the State of Fluids in the Human Body During Long-term Spaceflight (Sprut-MBI) obtains data on the status of fluid systems of the human body during long-term spaceflight in order to evaluate adaptation mechanisms of human physiology and improve microgravity countermeasures aboard the International Space Station for crew health.
Science Results for Everyone
The incredible shrinking astronaut. This investigation, one of several efforts to understand hydration and blood pressure adaptation in microgravity, highlighted the importance of gravity to the body’s water-electrolyte balance. A non-invasive device developed for the study allowed repeat, real-time measurements of hydration status during space flight. All subjects showed uniform loss of body fluids during long-term flight, with maximum loss immediately after return to Earth. Decrease in body fluids and related changes in body composition cause loss of muscle mass as well.  One week post-flight, data showed signs of recovering pre-flight hydration status and body mass.

The following content was provided by V B. Noskov, and is maintained in a database by the ISS Program Science Office.
Experiment Details


Principal Investigator(s)
V B. Noskov, Institute for Biomedical Problems, Moscow, Russia

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Sponsoring Space Agency
Russian Federal Space Agency (Roscosmos)

Sponsoring Organization
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Research Benefits
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ISS Expedition Duration
June 2002 - December 2002; April 2003 - April 2006

Expeditions Assigned

Previous Missions
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Experiment Description

Research Overview
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Space Applications
Water-electrolyte homeostasis plays an important role in the processes of general adaptation of the human body to new living conditions and to microgravity in particular. Spaceflight causes restructuring of water-electrolyte homeostasis, ie, the lack of gravity and other spaceflight factors have a specific effect on the fluid systems of the body. In turn, these changes have direct and indirect effects on the physiological and metabolic functions of the body. Studying the changes of restructuring water-electrolyte exchange during spaceflight and the early postflight period is of great practical significance, since changes in water-electrolyte balance play an important role in developing postflight orthostatic instability and other detrimental changes in the cardiovascular system. Impedancemetry experiments aboard the space station using the Sprut-K Set demonstrate that it is possible to perform automatic measurement of the main fluid volumes of a crew member’s body in real time in long-term spaceflight conditions and show the possibility for using the bioimpedance method in weightlessness. The results of this experiment make it possible to use bioimpedance analysis for real-time medical monitoring since a crew member’s hydration status can be determined using the onboard impedance meter multiple times and at any moment.

Earth Applications
New results for the changes in the body’s hydration level and composition that are obtained via bioimpedance analysis align well with results previously obtained via invasive methods and do not conflict with long-standing ideas on the nature of the adaptation of water-electrolyte homeostasis to microgravity. This investigation demonstrates the advantages bioimpedance analysis has over other methods in the field of space medicine due to its safety and adaptability. The method of 2-frequency bioimpedancemetry is a non-invasive, quick, and safe method for determining body composition and the volume of bodily fluids, based on the electrical properties of biological tissues. Moreover, it provides the necessary precision, and the information obtained is processed immediately during the examination. The portability and high interference-resistance makes the use of Sprut technology possible in field conditions—for example, in ambulances—and also for performing specific tasks of disaster medicine and other extreme situations causing disruption of water-electrolyte homeostasis.

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Operational Requirements and Protocols
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Decadal Survey Recommendations

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Results/More Information

Results of SPRUT-MBI showed that the gravitation factor played the most important role in reaching another level of water-electrolyte homeostasis. The use of a non-invasive, spaceflight-compatible method of bioimpedancemetry for the first time in the world’s space programs made it possible to evaluate the hydration status of the human body directly during long-term spaceflight. Use of the Sprut-K onboard impedancemeter allowed the first repeat measurements in real time of the main fluid systems in 12 cosmonauts during 6-month orbital flights and the diagnosis of the development of dehydration of the body. Analysis of the obtained results showed that all 12 cosmonauts exhibited hydration decrease, and the range of individual changes during flight was quite narrow: from 5 to 10% for various fluid systems. The results showed the uniform loss of fluid from various fluid systems in the body during long-term spaceflight.

The maximum values for the shortage of fluids were noted immediately after the cosmonauts returned to Earth, which spoke to the particular intensity of the effects that the final phase of flight and landing have on water-electrolyte exchange. The development in weightlessness of hypohydration was discovered, expressed as a uniform decrease in fluid spaces, and characteristic changes in body composition. Moreover, the changes in and tempo of the reduction of fluid volumes, as well as the fat and muscle mass of the body, were closely comparable in character and magnitude. The majority of cosmonauts studied showed, despite individual variations, a clear reduction in the level of hydration during long-term exposure to weightlessness accompanied by a simultaneous loss of muscle mass. One week after flight completion, all parameters being studied showed a clear trend towards restoration of preflight hydration status and body mass.

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Results Publications

    Noskov VB, Nichiporuk IA.  Changes in the volume of the fluid spaces in the body of a cosmonaut during long-term spaceflight. Rossiĭskii fiziologicheskiĭ zhurnal imeni I.M. Sechenova / Rossiĭskaia akademiia nauk. 2004; 90(8): 76.

    Noskov VB, Nichiporuk IA, Grigoriev AI.  Dynamics of the Body Liquids and Composition in Long-duration Space Flight (Bioimpedance Analysis). Human Physiology. 2011 December 22; 37(7): 821-825. DOI: 10.1134/S0362119711070231. PMID: 17902350.

    Noskov VB, Kotov AN, Morukov BV, Nichiporuk IA, Shargin YG.  Bioimpedance Analysis of Fluids and Body Composition Under the Conditions of Short-term Space Flight or Hypokinesia. Human Physiology. 2006 October; 32(5): 622-625. DOI: 10.1134/S0362119706050197. [Also: V.B. Noskov, A.N. Kotov, B.V. Morukov, I.A. Nichiporuk, Yu.G. Shargin, "Bioimpedance Analysis of Fluids and Body Composition During Sort-Term Spaceflights and Hypokinesia," Fiziologiya Cheloveka, 2006, Vol. 32, No. 5, pp. 136–139.]

    Noskov VB, Nichiporuk IA, Grigoriev AI.  Changes in fluid media and body composition during long-term spaceflight (bioimpedance analysis). Aviakosmicheskaia i Ekologicheskaia Meditsina (Aerospace and Environmental Medicine). 2007; 41(3): 3-7.

    Noskov VB, Nikolaev DV, Tuikin SA, Kozharinov VI, Grachev VA.  A Portable Impedance Meter for Monitoring Liquid Compartments of the Human Body Under Space Flight Conditions. Meditsinskaia Tekhnika (Biomedical Engineering). 2007 March; 41(2): 94-96. DOI: 10.1007/s10527-007-0020-7.

    Noskov VB, Kotov AN.  Impedancemetric research of hydration status and body composition during antiorthostatic . Aviakosmicheskaia i Ekologicheskaia Meditsina (Aerospace and Environmental Medicine). 2005; 39(4): 41-45.

    Noskov VB, Nichiporuk IA, Morukov BV, Malenchenko YI.  Study of the state of human bodily fluids during long-term spaceflight. Aviakosmicheskaia i Ekologicheskaia Meditsina (Aerospace and Environmental Medicine). 2005; 39(1): 27-31.

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Ground Based Results Publications

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ISS Patents

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Related Publications

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Related Websites
Energia - Science Research on the ISS Russian Segment

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