Progress is being made to obtain sophisticated cardiac rhythm information prior to, during, and after spaceflight. One NSBRI program is developing CV system identification technology for measuring changes in autonomic nervous function. This work addresses the Strategy report recommendations to provide accurate measurements of heart rate and blood pressure. Two NRA projects involve exercise devices, and an in-suit bubble detection system is being used for intravascular bubble detection. Both of these efforts respond to recommendations in the Strategy report. Other Strategy report equipment recommendations (automatic physiological recording devices, cardiac output devices, gas analyzers for pulmonary measurements, scintigraphic imaging systems, aerosol-monitoring equipment) are not being addressed.
Important questions, such as whether cardiac arrhythmias (or a propensity to develop arrhythmias) are stimulated by exposure to spaceflight and whether cardiac atrophy is significant and reversible, have not yet been answered. Mechanisms responsible for orthostatic intolerance, arrhythmias, and cardiac atrophy remain to be elucidated. Countermeasure development has thus far been focused on the well-documented problem of orthostatic intolerance, but no new validated countermeasures exist as yet to prevent this important operational problem. If arrhythmias and/or atrophy are determined to be important barriers to the health and well-being of crew members, then countermeasures will have to be developed to counteract them.
Most pulmonary studies are focused on the important issue of decompression sickness. Two key projects in this area (the clinical trial of reduced prebreathe protocols and in-suit Doppler monitoring) are not supported through either the NRA or the NSBRI programs, but are supported through operational funds. Other efforts recommended in the Strategy report (aerosol deposition, Martian dust effects, respiratory muscle function) are not currently in progress.
The development of the countermeasure evaluation plan and integrated testing regimens addresses important areas outlined in the Strategy report.
Blomqvist, C.G., L.D. Lane, S.J. Wright, G.M. Meny, B.D. Levine, J.C. Buckey, R.M. Peashock, P. Weatherall, J. Stray-Gundersen, F.A. Gaffney, D.E. Watenpaugh, Ph.R.M. Arbeille, and F. Baisch. 1995. Cardiovascular regulation at microgravity. Pp. 688-690 in Proceedings of the Nordeney Symposium on Scientific Results of the German D-2 Spacelab Mission. P.R. Sahm, M.H. Keller, and B. Schieve, eds. Bonn and Köln, Germany: WPF and Deutsche Agentur für Raumfahrtangelegenheiten (DARA) and Deutsche Forschungsanstalt für Luft- und Raumfahrt.
National Aeronautics and Space Administration (NASA). 1997. Task Force Report on Countermeasures: Final Report. Washington, D.C.: NASA.
NASA. 1998a. Astronaut Medical Evaluation Requirements Document (AMERD), JSC 24834, Rev. A. Houston, Tex.: NASA.
NASA. 1998b. Life Sciences Program Tasks and Bibliography for FY 1998. Washington, D.C.: NASA.
NASA. 1999a. Critical Path Research Plan Presentation (including EDOMP results presented at that time). Committee on Space Biology and Medicine meeting, March 3-5, 1999. Houston, Tex.: NASA.
NASA. 1999b. Countermeasure Evaluation and Validation Project Plan. June 16, 1999. Houston, Tex.: NASA.
NASA and Universities Space Research Association (USRA). 1999. Proceedings of the First Biennial Biomedical Investigators’ Workshop, January 11-13, 1999, League City, Texas. Houston, Tex.: NASA and USRA.
National Research Council (NRC), Space Studies Board. 1998. A Strategy for Research in Space Biology and Medicine in the New Century. Washington, D.C.: National Academy Press.
National Space Biomedical Research Institute (NSBRI). 1999. Proceedings of the Artificial Gravity Workshop, January 14–15, 1999, League City, Texas. Houston, Tex.: NSBRI.