Accession Number : ADA202960

Title :   G-Induced Loss of Consciousness and Its Prevention

Descriptive Note : Final rept. Jan 42-Jan 88

Corporate Author : MAYO CLINIC ROCHESTER MN

Personal Author(s) : Wood, Earl H.

PDF Url : ADA202960

Report Date : SEP 1988

Pagination or Media Count : 54

Abstract : The current capabilities of trained individuals to maintain clear vision during sustained exposures to 9 Gz, an increase in protected G tolerance of about 4 G over World War II fighter pilots, is a result of combined use of a G suit and very effective self-protective straining maneuvers such as the M-1, L-1 and pressure breathing, all of which are variants of the Valsalva maneuver developed in the 1940s. However, more than ten fatal crashes attributed to acceleration-induced loss of consciousness have occurred in recent years. The most plausible causes are: (1) increased capability of jet-powered fighters to sustain, with minimal pilot effort, accelerations in the 7-10 Gz range for periods longer than the symptom-free 3-8 second cerebral ischemic anoxic period which precedes GLOC, (2) an improperly performed Valsalva-type straining maneuver, and (3) development of a hypotensive vasovagal type reaction. A foolproof GLOC warning system such as detection of zero arterial pulsations at ear level to activate an automatic plane control takeover system could avoid most GLOC crashes. However, an omni-directional surveillance fighter plane cockpit for a fully horizontal position, preferable prone, is the only physically and physiologically certain and safest way to eliminate GLOC and to achieve the probable tactical advantages of sustained combat maneuvering in the 9-15 Gz range. Keywords: Acceleration, G stress, Anti-G suit, Anti-G straining maneuver, Acceleration tolerance. (aw)

Descriptors :   *WARNING SYSTEMS, *ACCELERATION TOLERANCE, *BIOINSTRUMENTATION, *BLACKOUT(PHYSIOLOGY), CONTROL, MANEUVERABILITY, WARFARE, DETECTION, ACCELERATION, VARIATIONS, G SUITS, VISION, HORIZONTAL ORIENTATION, FLIGHT MANEUVERS, AUTOMATIC PILOTS, EAR, CRASHES, PRESSURE BREATHING.

Subject Categories : Medicine and Medical Research
      Stress Physiology
      Biomedical Instrumentation and Bioengineering
      Life Support Systems

Distribution Statement : APPROVED FOR PUBLIC RELEASE