The effect of long-term microgravity exposure on cardiac autonomic function by analyzing 48-hours electrocardiogram (Biological Rhythms 48hrs) - 07.12.17

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Biological Rhythms 48hrs studies the effects of long-term microgravity exposure on heart function by analyzing an astronaut’s electrocardiogram for 48 hours. While the International Space Station keeps Houston time, it remains unknown whether a separate biological rhythm is imposed on long-term flight crews. To study this, astronauts wear an Actiwatch sleep monitor for 96 hours and a Holter electrocardiograph for 48 hours in the middle of that sequence.
Science Results for Everyone
Information Pending

The following content was provided by Chiaki Mukai, M.D., Ph.D., and is maintained in a database by the ISS Program Science Office.
Information provided courtesy of the Japan Aerospace and Exploration Agency (JAXA).
Experiment Details


Principal Investigator(s)
Chiaki Mukai, M.D., Ph.D., Japan Aerospace Exploration Agency, Tsukuba, Japan

Shin Yamada, M.D., Ph.D., Japan Aerospace Exploration Agency, Tsukuba, Japan
Hiroshi Ohshima, M.D., Ph.D., Japan Aerospace and Exploration Agency, Ibaraki, Japan
Ichiro Tayama, Chiyoda Advanced Solutions Corporations , Yokohama, Japan
Satoru Ishida, Tsukuba Space Center, Ibaraki, Japan
Tatsuya Aiba, Tsukuba Space Center, Ibaraki, Japan
Naomune Yamamoto, Tokyo Women's Medical University, Japan
Yasushi Mizuno, JAXA, Japan

Japan Aerospace Exploration Agency (JAXA), Tsukuba, Japan

Sponsoring Space Agency
Japan Aerospace Exploration Agency (JAXA)

Sponsoring Organization
Japan Aerospace Exploration Agency

Research Benefits
Information Pending

ISS Expedition Duration
May 2012 - March 2016; March 2016 - April 2017

Expeditions Assigned

Previous Missions
Continuous 24-hour RR interval measurements was conducted in ten crews for preliminary data of this project. The preliminary data showed various changes on biological rhythms, and some biological rhythm of crews showed prolonged for 24 hours or more than those before and after flight.

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Experiment Description

Research Overview

  • Clarification of the change of an accurate biological clock from space circumstance.
  • Evaluation of continuous 48-hour RR intervals measurement on Holter ECG and sleep/wake rhythm on Actiwatch for 96-hour.
  • The Biological Rhythms 48hrs research is analyzed for improving the health care technology of long-duration astronauts, for checking out the difference of them between before and after the flight on the earth and during long-duration spaceflight.

Information Pending

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Space Applications
Monitoring cardio autonomic functions is important for improving crew health technology during long-duration spaceflight.

Earth Applications
The crew health care technology for the biological rhythm disruption during spaceflight provides general public with useful hint to promote healthy daily lifestyle.

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Operational Requirements and Protocols
Information Pending

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Decadal Survey Recommendations

Information Pending

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Results/More Information

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Related Websites

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image Holter ECG. Image courtesy of JAXA.
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