The effect of straining maneuvers on G-protection during assisted pressure breathing
2003 (English)In: Aviation, Space and Environmental Medicine, ISSN 0095-6562, Vol. 74, no 8, 822-826 p.Article in journal (Refereed) Published
INTRODUCTION: Pilots flying high-performance aircraft increase their acceleration tolerance by using straining maneuvers and anti-G suits. Recently, assisted positive pressure breathing has been added in some aircraft systems. This study assessed the effect of anti-G straining maneuvers on the G-protective properties of one such system, the AGE-39 anti-G ensemble used in the Swedish JAS 39 Gripen aircraft.
METHODS: Ten subjects were studied in a centrifuge using each of the following: 1) the AGE-39 in combination with anti-G straining maneuvers (AGSM) throughout each high-G exposure (full maneuver; FM); 2) the AGE-39 in combination with AGSM only during the initial part of each high-G exposure (reduced maneuver; RM). G-tolerance was established during exposures to rapid onset rate (ROR) G profiles with plateau levels ranging from 6.5 to 9.0 G.
RESULTS: Mean G-tolerance was > or = 8.8 G (range: 8.5 to > or = 9.0 G) in the RM condition and > or = 9.0 G in all subjects in the FM condition. Mean arterial pressure was 30-50 mm Hg higher (p < 0.001) in the FM than in the RM condition at any given ROR G-load.
CONCLUSIONS: AGE-39 in combination with a brief period of straining provide efficient G-protection as illustrated by the finding that all subjects could tolerate 8.5 G while performing AGSM during the initial part of the high-G exposures. However, at 9.0 G, 40% of the subjects had to perform AGSM throughout the duration of the G-exposure. That arterial pressure was only 30-50 mm Hg higher in the FM than RM condition suggests that in the presence of straining maneuvers, pressure breathing makes only a minute contribution to the arterial-pressure response.
Place, publisher, year, edition, pages
2003. Vol. 74, no 8, 822-826 p.
anti-G suit, muscular straining, G-protection, G-tolerance, pressure breathing
IdentifiersURN: urn:nbn:se:kth:diva-44599ISI: 000184478800003PubMedID: 12924755OAI: oai:DiVA.org:kth-44599DiVA: diva2:451604
QC 201111032011-10-262011-10-252011-11-03Bibliographically approved