The primary objective of this study is to determine the effect of exposure to hypoxia on the reaction time to visual stimuli presented at a FoV of 30 and 60 degrees horizontally and vertically.The secondary objective of this study is it to determine…
ID
Source
Brief title
Condition
- Other condition
Synonym
Health condition
Oxygen shortage in body tissue
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
The primary study parameter in this study is reaction time. Reaction time (in
sec) will be measured from the moment a stimulus is presented till the
participants press a right or left button
Secondary outcome
The following scondary study aparemeters will be measured:
1. The following response parameters will be measured during each of the visual
tasks: 1. hits - correct identification of targets, 2. misses * error or
omissions of target , 3. false alarms * error of commission and 4. anticipation
- responses less than 200 ms following the onset of the stimulus.
2. Dwell time - Total duration of fixations made in the area of interest.
Fixation is defined as the time between the end of one saccade and the
beginning of the next one. Only fixations longer than 90 ms will be used in the
analysis.
3. The participants* self-perceived state of alertness. The state of alertness
will be assessed at the beginning and end of each test using the 7-point scale
Sanford Sleepiness Scale (SSS).
Background summary
A recent study showed that exposure to hypoxia impaired the awareness of
environment in helicopter crews. In flight helicopter pilots relay on helmet
mounted display (HMD) to help them maintain awareness of environment. HMD
projects flight, sensor and weapon information (symbology) in the pilot*s field
of view (FoV) eliminating the need to repeatedly look down at the cockpit
instruments. Any factor effecting the pilots* ability to see and perceive a
displayed symbol might have a detrimental effect on their awareness of
environment. For helicopter pilots, one of such factors is hypoxia. Exposure to
hypoxia has been shown to degrade visual contrast and , cause visual field
narrowing. Both effects can lead to increased reaction time (RT) to visual
stimuli. In addition, reduced alertness as a result of exposure to hypoxia can
negatively effecting vigilance and attention which are essential for visual
scanning.
Study objective
The primary objective of this study is to determine the effect of exposure to
hypoxia on the reaction time to visual stimuli presented at a FoV of 30 and 60
degrees horizontally and vertically.
The secondary objective of this study is it to determine the effect of hypoxia
on visual scanning and alertness during a visual scanning task.
Study design
The study design is single blinded, counterbalanced, repeated measures
Intervention
Participants will be exposed to simulated altitudes of 300 (92 meters) and
15,000 feet (4572 meters) in a hypobaric chamber. At these altitudes RT, visual
scanning will be measured for stimuli presented at 30 and 60 degrees FoV.
Study burden and risks
We expedt the risks for the pilots in the present study to be very small. It is
expected that during exposure to the 15.000 ft. altitude the pilots will
experience hypoxia related symptoms. However, as observed in hypobaric chamber
training performed at this altitude the symptoms vanish after descent is
complete and the pilots start breathing ambient air. In addition, pilots of
RNLAF receive hypoxia training every five years. Therefore, they are familiar
with the symptoms of hypoxia. The pilots will not be exposed to extreme
altitudes or additional risks compared to the normal hypoxia training they
follow during their flight career.
Each pilot will spend a total of 4.5 hours, in one day, participating in this
study. This includes the familiarization and test session. Four times during
the test session the participants will fill in a short questionnaire containing
a question regarding their alertness.
Kampweg 53
Soesterberg 3769DE
NL
Kampweg 53
Soesterberg 3769DE
NL
Listed location countries
Age
Inclusion criteria
Pilots of the Royal Netherlands Air Force
Male
Age 22-55
The pilots need to pass their mandatory medical examination and be declared
"fit to fly".
Exclusion criteria
Pilots exposed to altitudes higher than 8000 feet for a period longer than one
week in the three months prior to the research.
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| CCMO | NL75997.018.20 |