Operational Evaluation of a Photic Countermeasure to Improve Alertness, Performance, and Mood During Nightshift Work on a 105-day Simulated Human Exploration Mission to Mars (Mars 105)

The recruitment status of this study is unknown because the information has not been verified recently.
Verified June 2011 by Brigham and Women's Hospital.
Recruitment status was  Active, not recruiting
Sponsor:
Collaborators:
The Institute of Biomedical Problems
University of Pennsylvania
National Space Biomedical Research Institute
Information provided by:
Brigham and Women's Hospital
ClinicalTrials.gov Identifier:
NCT01169233
First received: January 12, 2010
Last updated: June 22, 2011
Last verified: June 2011
  Purpose

The success of human expedition missions critically depend on the ability of the crew to be alert and maintain high levels of cognitive function while operating complex, technical equipment. Optimal human health, performance and safety during space flight requires sufficient sleep and synchrony between the circadian pacemaker—which regulates the timing of sleep, endocrine function, alertness and performance—and the timing of the imposed sleep-wake schedule.

Crewmembers of the 105-day simulation study will be required to work one night shift every sixth night. This schedule will likely result in sleep loss and circadian misalignment, especially when lighting conditions are similar to those that crewmembers experience during spaceflight. External mission controllers will work 24-hour shifts, also resulting in both sleep loss and circadian misalignment.

It has been well documented in laboratory and field studies that both working the night shift and working extended duration shifts result in decrement alertness, performance and mood. In addition to the negative effects that night shift work has on alertness, performance and mood, shift work causes significant short and long-term health problems. Shift workers, particularly night shift workers who invert their normal sleep/wake schedule, suffer for several reasons. First, their endogenous circadian rhythms and the imposed sleep/work schedule are typically out of phase. This is similar to the experience of jet lag. However, while environment cues (e.g., sunrise, sunset, the timing of meals and sleep) enable travelers to adapt quickly to a new time zone, crewmembers in the 105-day simulation will be unable to do so because they will only spend one night of every five working. When working the night shift, the timing of meals, work, and sleep will therefore be out of phase with the normal entrained phase of the circadian timing system. Ingestion of meals at an inappropriate circadian phase results in impaired metabolism, likely underlying the gastrointestinal and metabolic problems experienced by shift workers. Second, this circadian misalignment leads to a substantial loss of sleep efficiency during the (daytime) sleep period, independent of, and in addition to, environmental obstacles to sleep (e.g., noise, light, other crewmembers). Third, misalignment of circadian phase coupled with sleep loss will each result in deterioration of alertness and impairment of performance during the night. Since these adverse effects are particularly acute on the first night of work, the plan for crewmembers on the Mars 105 mission to work the midnight shift every sixth night will subject them repeatedly to the performance impairments associated with acute circadian misalignment and acute sleep deprivation.

Lighting Countermeasure. Our group at the Harvard Medical School has successfully developed and tested effective photic countermeasures to alleviate circadian misalignment and improve alertness, performance and mood in night shift workers. The most effective countermeasure to circadian alignment is appropriately-timed and sufficiently intense light. Light also acutely improves alertness, performance and mood. Most recently it has been reported that short wavelength light has been shown to be most effective for both resetting circadian rhythms and acutely improving performance during night work via antecedent suppression of the soporific hormone melatonin.

These photic countermeasures have been tested in individual subjects living in laboratory simulations (Countermeasures readiness level/Technology readiness level 7; Evaluation with human subjects in controlled laboratory simulating operational spaceflight environment). The next critical step is to evaluate our countermeasures in an operational simulation of space flight that includes study of the interaction among crew members in a high fidelity simulation (Countermeasures readiness level/Technology readiness level 8; Validation with human subjects in actual operational spaceflight to demonstrate efficacy and operational feasibility).

Adequate sleep and circadian alignment are critical to maintaining the health and performance of expedition mission crewmembers. Testing of the developed lighting countermeasure in a high fidelity operational environment imitating the conditions of a future expedition mission (e.g., to Mars) is critical to ensure countermeasure readiness and to reduce the risk of human performance errors due to factors related to circadian disruption, sleep loss and fatigue. Development and testing of this photic countermeasure for mission controllers working 24-hour shifts will further ensure the success of the future long duration expedition missions.


Condition Intervention
Sleep
Alertness
Fatigue
Device: Bright Light Box

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Crossover Assignment
Masking: Open Label
Primary Purpose: Treatment
Official Title: Operational Evaluation of a Photic Countermeasure to Improve Alertness, Performance, and Mood During Nightshift Work on a 105-day Simulated Human Exploration Mission to Mars

Resource links provided by NLM:


Further study details as provided by Brigham and Women's Hospital:

Primary Outcome Measures:
  • performance on variety of cognitive tasks (e.g., psychomotor vigilance task, digit symbol substitution task) [ Time Frame: During the 105-day isolation ] [ Designated as safety issue: No ]
  • sleep, measured with actigraphy [ Time Frame: During the 105-day isolation ] [ Designated as safety issue: No ]
  • circadian phase [ Time Frame: During the 105-day isolation ] [ Designated as safety issue: No ]
  • subjective alertness [ Time Frame: During the 105-day isolation ] [ Designated as safety issue: No ]

Estimated Enrollment: 40
Study Start Date: August 2008
Estimated Study Completion Date: January 2012
Estimated Primary Completion Date: January 2012 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Shorter Wavelength (green) Device: Bright Light Box
Increased lighting used during night shifts to prevent sleepiness.
Intermediate Wavelength (white w/ green filter) Device: Bright Light Box
Increased lighting used during night shifts to prevent sleepiness.
Longer Wavelength (red)
Placebo
Device: Bright Light Box
Increased lighting used during night shifts to prevent sleepiness.

  Show Detailed Description

  Eligibility

Ages Eligible for Study:   18 Years to 64 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Criteria

The Institute of Biomedical Problems (IBMP) selected the participants for the 105-day simulated spaceflight mission. All participants that were selected by the IBMP were eligible to participate in this study.

Inclusion

  • Any individual chosen by the Institute of Biomedical Problems to participate in or support the space flight simulation study was eligible to participate in the study.

Exclusion

  • None. Any individual chosen by the Institute of Biomedical Problems to participate in or support the space flight simulation study was eligible to participate in the study.
  Contacts and Locations
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Please refer to this study by its ClinicalTrials.gov identifier: NCT01169233

Locations
Russian Federation
Institute of Biomedical Problems in Moscow
Moscow, Russian Federation
Sponsors and Collaborators
Brigham and Women's Hospital
The Institute of Biomedical Problems
University of Pennsylvania
National Space Biomedical Research Institute
Investigators
Principal Investigator: Charles A Czeisler, Ph.D., M.D. Brigham and Women's Hospital, Harvard Medical School
  More Information

Additional Information:
Publications:
Czeisler CA and Wright Jr. KP. Influence of light on circadian rhythmicity in humans. edited by Turek FW and Zee PC. New York: Marcel Dekker, Inc., 1999, p. 149-180.

Responsible Party: Charles A. Czeisler, Ph.D., M.D., Harvard Medical School & Brigham & Women's Hospital
ClinicalTrials.gov Identifier: NCT01169233     History of Changes
Other Study ID Numbers: 2008-P-001304, HFP00002
Study First Received: January 12, 2010
Last Updated: June 22, 2011
Health Authority: United States: Institutional Review Board

Keywords provided by Brigham and Women's Hospital:
Sleep
Alertness
fatigue
performance
spaceflight
isolation
light
Sleep , alertness and performance during a simulated spaceflight mission

Additional relevant MeSH terms:
Fatigue
Signs and Symptoms

ClinicalTrials.gov processed this record on October 16, 2014