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Risk Reduction and Measures of Injury for EVA Associated Upper Extremity Medical Issues: Extended Vent Tube StudyDuring Neutral Buoyancy Lab (NBL) training sessions, a large amount of moisture accumulates in the EVA gloves. The glove design restricts the extension of the EVA suit s ventilation/cooling system to the hand. Subungual redness and fingernail pain develops for many astronauts following their NBL training sessions with subsequent oncholysis occurring over succeeding weeks. Various attempts have been made to reduce or avoid this problem. The causal role of moisture has yet to be defined. Methods: To determine the contribution that moisture plays in the injury to the fingers and fingernails during EVA training operations in NBL, the current Extravehicular Mobility Unit (EMU), with a Portable Life Support System (PLSS) was configured with a ventilation tube that extended down a single arm of the crewmember during the test and compared with the unventilated contralateral arm; with the ventilated hand serving as the experimental condition (E) and the opposite arm as the control (C). A cross-over design was used with opposite handedness for the vent tube on a subsequent NBL training run. Moisture content measures were conducted at six points on each hand with three types of moisture meters. A questionnaire was administered to determine subjective thermal hand discomfort, skin moisture perception, and hand and nail discomfort. Photographs and video were recorded. Measures were applied to six astronauts pre- and post-run in the NBL. Results: The consistent trends in relative hydration ratios at the dorsum, from 3.34 for C to 2.11 for E, and first ring finger joint locations, from 2.46 for C to 1.96 for E, indicated the extended vent tube promoted skin drying. The experimental treatment appeared to be more effective on the left hand versus the right hand, implying an interaction with hand anthropometry and glove fit. Video analyses differentiated fine and gross motor training tasks during runs and will be discussed. Conclusions: This potential countermeasure was effective in reducing the risks of hand and nail discomfort symptoms from moderate to low in two of six subjects. Improved design in the ventilation pattern of such a countermeasure is expected to improve the countermeasure s efficiency.
Document ID
20070006845
Acquisition Source
Johnson Space Center
Document Type
Conference Paper
Authors
Jones, Jeffrey A.
(NASA Johnson Space Center Houston, TX, United States)
Hoffman, Ronald B.
(Mei Technology Corp. Houston, TX, United States)
Harvey, C. M.
(Louisiana State Univ. Baton Rouge, LA, United States)
Bowen, C. K.
(Lockheed Martin Corp. Houston, TX, United States)
Hudy, C. E.
(Lockheed Martin Corp. Houston, TX, United States)
Gernhardt, M. L.
(NASA Johnson Space Center Houston, TX, United States)
Date Acquired
August 24, 2013
Publication Date
January 1, 2007
Subject Category
Aerospace Medicine
Meeting Information
Meeting: Humans om Space
Location: Beijing
Country: China
Start Date: May 20, 2007
End Date: May 24, 2007
Sponsors: International Academy of Astronautics
Distribution Limits
Public
Copyright
Other

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