Vigilance, Stress and Sleep/Wake Measures and Low-Autonomy Study in NEEMO 13 – A Simulated Space Environment
Principal Investigator:
David F. Dinges, Ph.D.
Organization:
University of Pennsylvania School of Medicine
The NASA Extreme Environment Mission Operations (NEEMO) missions are used as an analog for space missions. During NEEMO 13, the crew members living in the Aquarius underwater habitat had more autonomy, with schedules and tasks that made the mission more like what crews will experience on future long-duration missions beyond low-Earth orbit. High stress and fatigue levels could impact spaceflight operations and crew safety during these long missions.
Dr. David F. Dinges and colleagues used NEEMO 13 to test tools that measure behavioral performance factors such as stress and fatigue. The project’s three major goals were to test the usefulness of the three-minute Psychomotor Vigilance Test (PVT) Self Test of performance and fatigue; to acquire salivary cortisol measures of stress; and to monitor sleep-wake patterns using wrist actigraphs and sleep logs.
The PVT Self Test will have useful applications for a wide-range of occupations on Earth. Some of the occupations that could benefit are the military, firefighters and power plant workers.
NASA Taskbook Entry
NASA Extreme Environment Mission Operations (NEEMO) has astronauts live in the NOAA Aquarius habitat (19 meters underwater off the coast of Florida). Aquarius is an excellent space analog environment for challenges in the area of behavior and performance such as confinement, limited personal space, isolation, workload timeline demands, extravehicular activity (EVA), environmental risk and no quick return to surface in an emergency.
Aquarius is operated by the National Underwater Research Center of the University of North Carolina at Wilmington. NEEMO missions work best for research that is directed toward proof of concept and feasibility studies in isolated and extreme environments. Research that needs testing in an analog mission works well in a NEEMO setting as it gives the researcher an idea of how the product works in a confined, but crowded, environment focused on multiple mission accomplishments.
The eleven-day NEEMO 13 mission, from August 6-15, 2007, was co-sponsored by NASA and the National Space Biomedical Research Institute (NSBRI). The primary operational objectives of NEEMO 13 focused on testing lunar exploration concepts, autonomy, and a suite of long-duration spaceflight medical objectives. The four-person crew conducted a variety of undersea "moon walks" to test concepts for future lunar exploration using advanced navigation and communication equipment. The medical objectives involved behavioral health and performance, immune function changes, oxidative damage and hardware and/or software evaluations of Portable Unit of Metabolic Analysis (PUMA) and GuideView.
The crew worked much more independently from the mission control team than on previous missions. The autonomous mode of operation encouraged the crew to make real-time decisions about daily operations similar to what we think will be necessary for lunar and Mars missions. The approach is to show how procedures and training for future missions can be adapted, considering the reduced direct communication with mission control those crews will encounter. This report covers specifically the behavioral health and performance measures in NEEMO 13 that involved testing the usefulness of the three-minute Psychomotor Vigilance Test (PVT) of performance; acquisition of salivary cortisol measures of stress; and monitoring sleep-wake patterns using ambulatory technology (wrist actigraphs and sleep logs).
Data acquisition in NEEMO 13 was successful. A total of 149 PVT performance tests were acquired, 150 salivary cortisol measures were obtained, and 36 days of wrist actigraphy, sleep-wake diary and subjective fatigue and stress scales were acquired, for a 97 percent adherence rate. The salivary cortisol and subjective ratings revealed no elevated stress during NEEMO 13, and the wrist actigraphy, sleep-wake diary and subjective fatigue data from NEEMO 13 revealed no sleep loss or elevated fatigue. These outcomes made the three-minute PVT performance data from NEEMO 13 useful for adding to the normative PVT performance database for astronauts begun with PVT data from NEEMO 9 and 12 missions. The resulting larger three-minute PVT performance database on ten astronauts and two aquanauts will be used to generate a PVT SelfTest user interface for use by astronauts in spaceflight.
Development of a three-minute Psychomotor Vigilance Test performance test that is a very sensitive, objective measure of fatigue and sleepiness in astronauts during spaceflight will also have extensive utility in a wide range of activities on Earth, including evaluating readiness to perform in military personnel, transportation and security personnel, and people working in high-risk operational environments (e.g., power plants). The test will also have use in identifying excessive sleepiness in patients.
