Document Detail

Head and helmet biodynamics and tracking performance in vibration environments.
MedLine Citation:
PMID:  16676649     Owner:  NLM     Status:  MEDLINE    
INTRODUCTION: There are potential effects of vibration on aircrew performance and safety when using helmet-mounted equipment. The objective of this study was to quantify the effects of head orientation and helmet center-of-gravity (CG) on head and helmet biodynamics and tracking performance during exposures to aircraft buffeting and quasi-random vibration. METHODS: Three head orientations, including two off-axis or off-boresight configurations [Side (40 degree elevation, 70 degree azimuth) and Up (40 degree elevation, 0 degree azimuth)], and three helmet CGs were tested. The overall head, helmet, and helmet slippage displacement rotations, and rms tracking error and percent time-on-target were evaluated. RESULTS: For both exposures, the two off-axis orientations produced significantly higher head, helmet, and slippage displacements; a relationship was observed between the orientation and the rotation that was affected (roll, pitch, or yaw). The highest slippage observed was in pitch in the forward (For) and Up orientations. Significantly higher performance degradation occurred with the Side orientation for two of the three CGs during aircraft buffeting, with minimal degradation observed with the quasi-random exposure. Higher head pitch and lower pitch slippage were associated with the CG estimated to produce loading behind the human head CG. CONCLUSIONS: The high off-boresight head movements may influence visual performance in operational vibration environments. Helmet instability appeared to be the greatest in pitch, which could have a significant effect on the design size of the exit pupil. The weight distribution or moments-of-inertia of the helmet system may also have a significant influence on both head/helmet biodynamics and tracking performance and should be investigated.
Suzanne D Smith; Jeanne A Smith
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Publication Detail:
Type:  Journal Article; Research Support, U.S. Gov't, Non-P.H.S.    
Journal Detail:
Title:  Aviation, space, and environmental medicine     Volume:  77     ISSN:  0095-6562     ISO Abbreviation:  Aviat Space Environ Med     Publication Date:  2006 Apr 
Date Detail:
Created Date:  2006-05-08     Completed Date:  2006-09-28     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  7501714     Medline TA:  Aviat Space Environ Med     Country:  United States    
Other Details:
Languages:  eng     Pagination:  388-97     Citation Subset:  IM; S    
Human Effectiveness Directorate, Air Force Research Laboratory, Wright-Patterson AFB, OH 45433-7947, USA.
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MeSH Terms
Aerospace Medicine*
Head / physiology*
Head Protective Devices*

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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