|
KMID : 1024120110580010025
|
|
Journal of Aerospace Medical Center, ROKAF
2011 Volume.58 No. 1 p.25 ~ p.41
|
|
|
Differences of head tilt during roll manuever by pilot’s characteristics
|
|
Hwang Sang-Ho
Yun Hye-Sik
Lee Kwang-Jin
Oh Ki-Wook
|
|
|
Abstract
|
|
|
Introduction : Since the most optokinetic cervical reflex(OKCR) studies were conducted using fixed-base simulators, it is not clear whether the vestibular system involves in the process of OKCR. It is also doubtful that the name of this phenomenon, OKCR, is adequate enough to describe this phenomenon as a whole. The purpose of this study is to analyze head tilts in various simulated flight settings of roll maneuver between pilots and controls in order to make answers for inquiring above questions.
Methods : 15 pilots and 15 non-pilot volunteers completed 9 different simulated flights in a constant-radius planetary simulator. The experimental simulated flights consisted of the combination of three different roll angles (30, 45, and 60 degrees) and three different flight conditions (visual flight rule(VFR), instrumental flight rule(IFR), and blindfold). The head tilts before, during, and after roll maneuver were recorded by digital camcorder. And then, the movie data turned into individual pictures with 100ms interval for time-sequence analysis. Rotational chair test was also done to obtain vestibular parameters from pilot and control groups.
Results : The significant differences of peak head tilt angles between pilots and controls were noted from all roll angles in VFR, IFR, and blindfold simulated flight settings. In pilot group, head tilts from 60 degrees roll maneuver was smaller than ones from 30 and 45 degrees roll maneuvers in VFR condition. Head tilts from 60 degrees roll maneuver was smaller than ones from 30 degrees roll maneuver in blindfold condition. However, regardless of angles of roll maneuvers, there was no significant difference in head tilts in IFR condition. In control group, when the same flight condition was applied, there was no significant difference in head tilts among 30, 45, and 60 degrees roll maneuvers. Head tilts in blindfold condition was smaller than ones in VFR conditions at 30 and 45 degrees roll maneuvers. Head tilts in blindfold condition was smaller than ones in VFR and IFR conditions at 60 degrees roll maneuver. The gain values at 0.01 and 0.02 Hz of pilots were significantly lower than ones of control group. There was significant negative correlation between total
flying hours and peak head tilt angles in 45 degrees roll of VFR. There also were significant negative correlations between total flying hours and gain values at 0.04, 0.08, 0.16 and 0.64 Hz.
Conclusion : Although the optokinetic stimulus appeared to be the most important factor to induce head tilt during roll maneuver, it can be concluded that vestibular stimulus involved in this response as well. The differences of peak head tilt angles and vestibular parameters between pilots and control suggested that head tilt during roll maneuver can be modulated by vestibular habituation. The level of consciousness and musculoskeletal factors might be also involved in the process of head tilt to roll maneuver in various simulated flights. Considering all results from this study, it is more appropriate to call this phenomenon ’head tilt during roll maneuver’ rather than OKCR.
|
|
|
KEYWORD
|
|
|
Optokinetic cervical reflex, Head tilt during roll maneuvering, Vestibular habituation
|
|
|
FullTexts / Linksout information
|
|
|
|
|
Listed journal information
|
|
|
|
|