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W E Drew

Publications and source records attributed to W E Drew.

5 recordsLinked to original sources
PubMed2001

Protection to +12 Gz.

BACKGROUND: The U.S. Air Force has developed +Gz-protective equipment that will provide most pilots protection to +9 Gz with minimal-to-no straining. This equipment includes a pressure breathing system called COMBAT EDGE (CE), which is currently operational, and the Advanced Technology Anti-G Suit (ATAGS), which is not yet operational. For future high-performance aircraft design it is important to know the upper limit of various protective equipment and techniques. METHODS: Six subjects were randomly exposed to a 12-cell matrix composed of +Gz and the following combinations of protective equipment at three seat-back angles (13 degrees, 30 degrees and 55 degrees from the vertical): 1) the standard CSU-13B/P anti-G suit (STD); 2) the STD suit with CE; 3) the ATAGS; and 4) the ATAGS with CE. Relaxed, followed by straining +Gz tolerance was determined using 15-s rapid onset runs to a maximum of +12 Gz. A comprehensive battery of baseline and post-exposure medical surveillance studies was performed to evaluate the medical consequences of these high +Gz exposures. RESULTS: All 6 subjects were able to achieve +12 Gz with various combinations of +Gz-protective equipment, seat-back angle, and various amounts of straining, from none to maximum. When the data were collapsed over all protective equipment there was a significant (p < 0.05) seat effect. Relaxed tolerance to ROR increased with seat-back angle from 13 degrees to 30 degrees to 55 degrees. There was also a significant protective equipment effect when the data were collapsed over all seat-back angles. CONCLUSIONS: These data confirm that effortless protection to +9 Gz is available using ATAGS/CE with the 13 degree and 30 degree seat-back angle (F-15, F-16 and F-22) and to +10.5 Gz with a 55 degree seat-back angle. Moreover, with ATAGS/CE, and a moderate degree of straining, +12 Gz is definitely achievable at 55 degrees, even with reduced anti-G suit pressure at 55 degrees. With additional straining +12 GC is also achievable at the 13 degree and 30 degree seat-back angles.

Acceleration↗
PubMed2000

Spinal symptoms in aviators and their relationship to G-exposure and aircraft seating angle.

BACKGROUND: Aviator spinal symptoms related to G-exposure such as neck pain may limit flying performance and result in an increase in acute and chronic spinal disease. METHODS: An anonymous survey was conducted to better establish the nature and degree of G-related spinal symptoms. HP (high-performance) aviators were compared with a control group of non-high-performance (NHP) aviators. RESULTS: Of 161 surveys distributed, 79 were returned for a return rate of 49%. No greater incidence of chronic spinal symptoms or disease in the neck or lower back were reported in the HP group as compared with the NHP group. However, a majority of HP aviators (54%) did report acute spinal symptoms, especially neck pain, temporally associated with pulling Gz, occurring either during or shortly after sorties. Some 20% of the total number of HP aviators responding reported that neck symptoms limited their flying performance, including pulling Gz, checking 6, and air combat maneuvers. Despite the increased seat angle slant in the F-16 as compared with the F-15, no significant difference in neck symptoms or performance limitations were reported as a result. Both HP and NHP aviators were noted in general to have good exercise habits with minimal use of tobacco. However, moderate use of alcohol was noted in both groups. CONCLUSIONS: Spinal symptoms, especially neck pain, are a common problem associated with HP flying and frequently limit flying performance though do not appear to result in any increase in long-term morbidity in this relatively young, predominantly male, group of aviators. (Survey form included as an appendix for reference and future research.) KEYWORDS: aerospace medicine, aircraft, aviation, health surveys, military personnel, questionnaires, risk factors, spinal diseases.

Adult↗
PubMed1995

Convulsive syncope in the aviation environment.

Syncope in the aviation environment can be a very difficult problem to assess. Even more difficult is the differential diagnosis between convulsive syncope and epilepsy after the first event. This paper discusses syncope in general and the differential diagnosis between vasovagal syncope and other forms of syncope. About 50% of all syncopal episodes cannot be identified as to etiology. However, a benign outcome for a single syncopal episode, non-cardiac in origin, is the norm. The diagnosis of syncope is discussed, emphasizing that a meticulous history from an observer or the patient, a good physical examination, and an ECG are the cornerstones of diagnosis. Other diagnostic venues are discussed. Convulsive syncope occurs in only about 12% of syncopal episodes, 65% of these being vasovagal in origin. The other 35% are due to a variety of causes. We found no good algorithm to differentiate convulsive syncope from epilepsy. We reviewed the literature to develop a differential diagnostic table, focusing on: age, awake status, position, emotional/physiologic stressors, onset, aura, appearance, injury on falling, seizure characteristics, automatism, length of unconsciousness and subsequent confusion, pulse characteristics, blood pressure, urinary incontinence, seizure duration, recovery time post-event, post-seizure sequelae, amnesia, posture vs. recovery, EEG characteristics, and the value of sophisticated diagnostic procedures.

Aircraft↗
PubMed1994

Diabetes mellitus, advances and their implications for aerospace medicine.

The authors describe a case of Type 1 diabetes mellitus (insulin dependent) in a 34-year-old fighter pilot, which included a 15-month remission ("honeymoon period"). The pathogenesis, characteristics, diagnosis, evaluation, and the aeromedical implications of Type 1 diabetes are discussed. The use of C-peptide values in accessing beta cell function is also discussed. The risk of poorly controlled diabetes, diabetic ketoacidosis, and visual acuity fluctuations were major reasons to disqualify this individual when in remission. The importance of determining the type of diabetes for prognosis and aeromedical disposition is stressed.

Adult↗