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At least 289 records · Page 16Linked to original sources
PubMed2003

EEG activity of aviators during imagery flight training.

OBJECTIVE: Imagery flight training (IFT) is widely used in aviation without neurophysiological evaluation. Electroencephalogram (EEG) during IFT was compared between experienced fighter pilots (FP) and novice pilots (NP). METHODS: Six FP and 9 NP performed imagery right bank, left bank, right roll, and left roll maneuvers. Each task was repeated 5 times in a random order. Instantaneous EEG power was calculated by the intertrial variance method. RESULTS: In FP, 3 waves of event-related desynchronization (ERD) were observed. The third ERD (ERD3) was observed at all the electrode positions except Fp1 which began 0.25 s before the beginning of IFT and reached its peak 0.25 s after the beginning of IFT. In NP, ERD was not related to the start of IFT. The difference in event-related EEG at the peak of ERD3 was not significant between FP and NP. However, the negative change to the peak of ERD3 was significantly larger in FP than in NP. CONCLUSIONS: It is speculated that ERD3 in FP may indicate the activation of cortical areas including visual- and motor-related areas involved in IFT. SIGNIFICANCE: It is speculated that the representation of IFT was programmed in visual- and motor-related cortical areas as an aviator's career advances.

Adult↗
PubMed2001

The natural history of Wolff-Parkinson-White syndrome in 228 military aviators: a long-term follow-up of 22 years.

BACKGROUND: Wolff-Parkinson-White (WPW) syndrome poses a risk for tachyarrhythmias and sudden cardiac death. Most WPW studies have relatively limited numbers of subjects and brief follow-up periods. METHODS: We reviewed records of 238 consecutive military aviators with WPW syndrome evaluated from 1955 to 1999. Follow-up was by questionnaires, telephone interviews, or death certificates. Events included sudden cardiac death and supraventricular tachycardia (SVT) (by electrocardiographic [ECG] documentation or suggestive symptoms). RESULTS: The mean age was 34.3 years (range 17-56 years). Forty-two (42/238, 17.6%) had SVT (WPW syndrome) and 196 of 238 (82.4%) had the WPW ECG pattern only. The mean follow-up of 21.8 years (range 2-41 years) was obtained on 228 of 238 (96%) for a total of 4906 patient-years. Sudden cardiac death occurred in 1 of 228, an incidence of 0.0002 per patient-year (95% confidence interval 0.0-0.001). SVT occurred in 47 of 228 (20.6%) or 0.01 per patient-year. One hundred eighty-seven (187/228, 82%) initially had the WPW ECG pattern only; 28 of 187 (15.0%) reported SVT during follow-up. Forty-one (41/228, 18%) initially had WPW syndrome; 19 of 41(46.3%) reported additional SVT during follow-up. CONCLUSION: Sudden cardiac death risk was low (0.02%/patient-year) in this WPW population. The SVT incidence was 1% per patient-year. Referral bias and some characteristics of the unique military aviator population may partly account for these low event rates. However, these results may be more applicable to unselected populations than are tertiary referral-based studies.

Adult↗
PubMed2000

Radiation exposure during air travel: guidance provided by the Federal Aviation Administration for air carrier crews.

Air carrier crews are occupationally exposed to ionizing radiation, principally from galactic cosmic radiation. To promote radiation safety in aviation the Federal Aviation Administration has: issued educational material on the nature of the radiation received during air travel; recommended radiation exposure limits for pregnant and nonpregnant aircrew members; developed computer programs that estimate for a given flight profile the amount of galactic radiation received on a current flight or on one flown at any time back to January 1958; published tables that enable aircrew members to estimate possible health risks associated with their occupational exposure to radiation; and conducted research on effects of radiation during pregnancy. References for this material are given in the article. In addition, graphic and tabular data in the article show how galactic radiation levels and the composition of the galactic radiation has changed between 1958 and 1999. Also given are estimates of effective doses received by air travelers on a wide variety of air carrier flights.

Aircraft↗
PubMed1991

Assessment of cycloplegic effects on the vistech contrast sensitivity test in Army aviator candidates.

This study was designed to provide information regarding two aspects of contrast sensitivity testing of aviator candidates: first to determine whether contrast sensitivity functions (CSF's) obtained with the Vistech Visual Contrast Test System (VCTS) are affected by cycloplegia and second to determine whether the VCTS provides useful CSF's under clinical screening conditions in a timely and simple manner. Contrast sensitivity thresholds were obtained at 5 spatial frequencies from 106 aviator candidates before and after administering a cycloplegic. CSF's obtained under cycloplegia were reduced by about 20%. The VCTS provided useful CSF's under military screening conditions, and added about 6 min to the time required for the standard flight physical.

Adult↗
PubMed2006

A cost-benefit analysis of alternative device configurations for aviation-checked baggage security screening.

The terrorist attacks of September 11, 2001 have resulted in dramatic changes in aviation security. As of early 2003, an estimated 1,100 explosive detection systems (EDS) and 6,000 explosive trace detection machines (ETD) have been deployed to ensure 100% checked baggage screening at all commercial airports throughout the United States. The prohibitive costs associated with deploying and operating such devices is a serious issue for the Transportation Security Administration. This article evaluates the cost effectiveness of the explosive detection technologies currently deployed to screen checked baggage as well as new technologies that could be used in the future. Both single-device and two-device systems are considered. In particular, the expected annual direct cost of using these devices for 100% checked baggage screening under various scenarios is obtained and the tradeoffs between using single- and two-device strategies are studied. The expected number of successful threats under the different checked baggage screening scenarios with 100% checked baggage screening is also obtained. Lastly, a risk-based screening strategy proposed in the literature is analyzed. The results reported suggest that for the existing security setup, with current device costs and probability parameters, single-device systems are less costly and have fewer expected number of successful threats than two-device systems due to the way the second device affects the alarm or clear decision. The risk-based approach is found to have the potential to significantly improve security. The cost model introduced provides an effective tool for the execution of cost-benefit analyses of alternative device configurations for aviation-checked baggage security screening.

Journal Article↗
PubMed1993

Protozoa in subsurface sediments from sites contaminated with aviation gasoline or jet fuel.

Numbers of protozoa in the subsurface of aviation gasoline and jet fuel spill areas at a Coast Guard base at Traverse City, Mich., were determined. Boreholes were drilled in an uncontaminated location, in contaminated but untreated parts of the fuel plumes, and in the aviation gasoline source area undergoing H(2)O(2) biotreatment. Samples were taken from the unsaturated zone to depths slightly below the floating free product in the saturated zone. Protozoa were found to occur in elevated numbers in the unsaturated zone, where fuel vapors mixed with atmospheric oxygen, and below the layer of floating fuel, where uncontaminated groundwater came into contact with fuel. The same trends were noted in the biotreatment area, except that numbers of protozoa were higher. Numbers of protozoa in some contaminated areas equalled or exceeded those found in surface soil. The abundance of protozoa in the biotreatment area was high enough that it would be expected to significantly reduce the bacterial community that was degrading the fuel. Little reduction in hydraulic conductivity was observed, and no bacterial fouling of the aquifer was observed during biotreatment.

Journal Article↗
PubMed1984

Aviation medicine and the Army.

The purpose of this short series of articles is not to present the reader with a vast amount of technical data, soon to be forgotten, but to provide some items of general interest from the past, present, and future of Army aviation. Obviously there will be a concentration on medical matters, but the aim is to give the reader a feel for the rapid progress being made in helicopter design and the likely problems we may face in the future. The first article serves as an introduction to the series and three further articles will cover various aspects of the speciality. The second will be concerned with AAC helicopter accidents and will include accident investigation, crashworthiness and the contribution made by pilot error. The third article will cover major environmental problems of helicopters, particularly noise, vibration and thermal stress. The fourth article will examine ways in which microprocessors and modern technology will affect future helicopter and ancillary equipment development; for instance, a helicopter with no external windows has been suggested, 'The Iron Cockpit'. The fifth article will be concerned with the clinical aspects of Army Aviation medicine.

Aerospace Medicine↗
PubMed2006

Use of conventional and alternative treatment strategies for a case of low back pain in a F/A-18 aviator.

BACKGROUND: Low back pain can diminish jet pilot concentration and function during flight and be severe enough to ground pilots or cause decreased flying time. The objective of this case report is to present an example of the integration of chiropractic care with conventional treatments for the management of low back pain in a F/A-18 aviator. CASE PRESENTATION: The patient had insidious severe low back pain without radiation or neurological deficit, resulting in 24 hours of hospitalization. Spinal degeneration was discovered upon imaging. Four months later, it still took up to 10 minutes for him to get out of bed and several minutes to exit the jet due to stiffness and pain. He had discontinued his regular Marine Corps fitness training due to pain avoidance. Pain severity ranged from 1.5-7.1 cm on a visual analog scale. His Roland Morris Disability Questionnaire score was 5 out of 24. The pilot's pain was managed with the coordinated efforts of the flight surgeon, physiatrist, physical therapist, and doctor of chiropractic. Following this regimen he had no pain and no functional disability; he was able to fly multiple training missions per week and exercise to Marine Corps standards. CONCLUSION: A course of care integrating flight medicine, chiropractic, physical therapy, and physiatry appeared to alleviate pain and restore function to this F/A-18 aviator with low back pain.

Journal Article↗
PubMed1976

Aviation and environmental benzo(a)pyrene pollution.

Spectrofluorescent methods of analysis have shown that soot and exhaust products of aviation engines, both piston and turbine, contain benzo[a]pyrene (BP). A modern aircraft engine releases into the atmosphere from 2-10 mg BP per min. Extracts of aviation engine soot applied to the skin of mice induced malignant tumors in almost all treated animals. The ground within airports is polluted with BP, its level diminishing with distance from the runway. The concentration of carcinogenic hydrocarbons in aircraft exhausts is dependent on the working regime of the engine and on the character of fuel combustion.

Air Pollutants↗
PubMed1999

[Health care safety should be focused on prevention. Lessons to be learned from aviation, nuclear power plants and offshore industries].

In many respects the approach to questions of safety adopted in the aviation, nuclear energy and offshore oil industries is highly relevant to safety in the health care sector, even where legislation is concerned. Characteristic features are the emphasis on risk-factor identification, and such demands as risk analysis, knowledge checks, and the limitation of working hours. In addition, there is a need of disaster inquiries in cases of serious incidents, and of an organisation specifically responsible for safety issues. Regarding the development of an incident report system for use in health care, the importance of which increases with the risks involved, a commendable model is the risk report system adopted by civil aviation authorities in the USA, where those submitting reports are guaranteed immunity.

Aerospace Medicine↗
PubMed2000

Efficacy of Dexedrine for maintaining aviator performance during 64 hours of sustained wakefulness: a simulator study.

INTRODUCTION: The efficacy of Dexedrine for sustaining aviator performance despite 64 h of extended wakefulness was investigated. This study was conducted to extend the findings of earlier research that had proven the efficacy of Dexedrine during shorter periods (i.e., 40 h) of sleep deprivation. METHODS: Dexedrine (10 mg) or placebo was given at midnight, 0400, and 0800 hours on two deprivation days in each of two 64-h cycles of continuous wakefulness. Test sessions consisting of simulator flights, electroencephalographic evaluations, mood questionnaires, and cognitive tasks were conducted at 0100, 0500, 0900, 1300, and 1700 hours on both deprivation days. Two nights of recovery sleep separated the first and second 64-h sleep-deprivation cycles. RESULTS: Simulator flight performance was maintained by Dexedrine throughout sleep deprivation. The most benefit occurred at 0500 and 0900 hours (around the circadian trough) on the first deprivation day, but continued throughout 1700 hours (after 58 h awake) on the second day. Dexedrine suppressed slow-wave EEG activity which occurred under placebo after 23 h awake and continued to exert this effect throughout 55 h (and sometimes 59 h) of deprivation. The drug sustained self-perceptions of vigor while reducing fatigue and confusion. Recovery sleep was slightly less restful under Dexedrine. CONCLUSIONS: Dexedrine sustained aviator performance and alertness during periods of extended wakefulness, but its use should be well controlled. Although effective, Dexedrine is no replacement for adequate crew rest management or restful sleep.

Adult↗
PubMed2000

[Classification of myocardial dystrophies in aviation medical certification].

Myocardial dystrophy is one of the most common noncoronary lesions of the myocardium in pilots. However, the abundance of proposed classifications of myocardial dystrophies poses certain problems to medical experts. The authors attempt to consider the existing classifications from the standpoint of aviation medical certification and advocate the most acceptable, to their thinking, systematics by N.P. Paleev and L.I.Levitina (1991). Examples of establishing diagnoses of myocardial dystrophy are included. The best suited program for the aviation medical certification board to work out the final statement regarding the occupational fitness of pilots with myocardial dystrophy is proposed.

Aerospace Medicine↗
PubMed2000

[The assessment and correction of the body functional state of aviation specialists working with video display terminals].

The investigations have shown that military and aviation specialist working with video-display terminals are exposed to unfavourable effect of professional environment of anthropogenic genesis. It is accompanied with development of energo-informative stress. Manifestations of stress-effect have a cumulative character. One can notice the decrease in physiologic reserve level, homeostatic potential, worsening of the quality of operators' professional health and safety in the "man-machine" system. The proposed and appropriated methods of premorbid state diagnosis and working capacity support have confirmed its adequate efficiency both in experimental conditions and in aviation specialists against the background of their professional activity.

Aerospace Medicine↗
PubMed1975

Motion sickness questionnaire and field independence scores as predictors of success in naval aviation training.

The present report has shown that a motion sickness questionnaire can be used to predict susceptibility to motion sickness or flight training success, depending on the items scored. There is a discussion of the theory that motion sickness results from conflicting perceptual inputs. This theory is related to aircraft operating conditions. Scores on a personality test which appear to be related to similar perceptual phenomena are related to aviation success. One phenotype, field independence, seems to be promising in this regard. In addition to use of this finding in aviator selection, it is felt that studies of this trait, as it relates to an ability to reconcile conflict and to motion sickness insusceptibility, should be conducted.

Aerospace Medicine↗
PubMed2003

Testicular carcinoma in U.S. Air Force aviators: a case-control study.

BACKGROUND: Previous descriptive studies have suggested an increased risk of testicular carcinoma in military aviators. The association between testicular carcinoma and aviation in the U.S. Air Force was measured using a case-control study design. METHODS: A Department of Defense hospitalization database was used to obtain a set of testicular carcinoma cases (seminomas, embryonal cell carcinomas, teratocarcinomas, and choriocarcinomas) and an unmatched set of male appendicitis controls from October 1988 to February 1999. A centralized U.S. Air Force personnel database was used to obtain demographic and flying history data on the subjects. Multiple logistic regression was used to obtain odds ratios (OR) and confidence intervals (CI) for the following exposure factors: total flight time, rank, crew position, and general type of aircraft. Study subjects were restricted to white active duty officers. RESULTS: For one or more total flight hours, the age-adjusted OR was 1.74 (95% CI 1.04-2.92). Age-adjusted OR's for 1-499, 500-1999, and 2000 or more flight hours were, respectively, 1.37, 1.92, and 1.67. These OR's were not statistically significant. Age- and flight hour-adjusted OR's were increased for the navigator crew position and for bomber/tanker/ transport/reconnaissance type aircraft (2.13 and 1.67, respectively), but the ratios were not statistically significant. OR's were not increased for senior rank, fighter/trainer type aircraft, and rotary-wing aircraft. CONCLUSIONS: There is an association between testicular carcinoma and flight time in U.S. Air Force officers. There was a suggestion of a dose-response effect; however, the OR's were not statistically significant.

Adult↗
PubMed1992

Ethical concerns in the practice of military aviation medicine.

Military aviation physicians are frequently placed in conflicting ethical situations regarding the areas of patient loyalty, confidentiality, and reporting of findings or hazards. The American College of Occupational and Environmental Medicine has developed a set of guidelines for ethical conduct to assist physicians providing occupational health services. This paper attempts to show that these guidelines can be applied similarly by physicians providing aeromedical services. These guidelines can be helpful in resolving ethical dilemmas that can occur in the daily practice of aviation medicine.

Aerospace Medicine↗
PubMed2004

Aeromedical regulation of aviators using selective serotonin reuptake inhibitors for depressive disorders.

This report, prepared at the request of the Aerospace Medical Association (AsMA), reviews the present status of aeromedical regulation of depressive disorders and antidepressant medications, emphasizing the role of serotonin specific reuptake inhibitors (SSRIs). Aeromedical certifying authorities (CAs) generally prohibit pilots from flying with a diagnosed depressive disorder, and also prohibit flying while taking antidepressant medications, including SSRIs. Some CAs are reassessing these prohibitions, which are based on long aeromedical practices, in view of changing medical management of depressive disorders. Many pilots choose to fly while depressed, with or without medications, because of the long grounding periods mandated by current policies. Some SSRIs have very few aeromedically significant side effects. Modern psychiatric practice calls for long-term use of medication following clinical recovery from depressive disorders in order to prevent recurrent episodes. Given these and other factors, AsMA proposes that CAs remove the current absolute prohibitions against pilots flying while taking SSRIs, and adopt aeromedical protocols that include carefully controlled follow-up and review. AsMA urges all certificatory and regulatory authorities to consider immediately instituting a policy of using study groups to manage depressed aviators who require SSRI antidepressants. Protocols designed to aggressively manage the full spectrum of adverse possibilities related to SSRI use may enable the safe use of SSRIs in formerly depressed aviators who suffer no aeromedically significant side effects. In these closely managed cases of depressive disorders, special issuances or waivers for SSRI use are justified.

Aerospace Medicine↗
PubMed2005

Color vision tests for aviation: comparison of the anomaloscope and three lantern types.

INTRODUCTION: A comparison of the results obtained with the Nagel anomaloscope and the Holmes-Wright Type A, Spectrolux, and Beyne aviation color vision lanterns was undertaken. The Joint Aviation Requirements (JAR) specify pass/fail limits for these four secondary color vision tests and the Ishihara screening test. The results for individuals on all five tests were studied. METHODS: The color vision of 55 color-vision deficient and 24 color-vision normal subjects, mostly applicant pilots, was assessed using a battery of tests, including the Ishihara plates, the Nagel anomaloscope, and three lanterns. The testing methods and characteristics of the lanterns and anomaloscope were compared. RESULTS: Of the color-deficient applicants, only deuteranomalous trichromats passed more than one of the four secondary JAR tests, but a pass on one test did not reliably predict a pass on another test. Three out of nine protanomalous trichromats passed the Nagel anomaloscope but failed all three lantern tests. Of the normal trichromats, 12 failed the anomaloscope and 12 failed the Beyne lantern. DISCUSSION: Variability in pass/fail results can be attributed to many factors apart from loss of chromatic sensitivity. Some normal trichromats can fail both the Ishihara screening and the secondary tests. The approved secondary test varies between countries and the outcome of regulatory assessment depends on the color vision test used. Since the flight safety consequences of the current situation cannot be ignored, the development of a less variable technique for color vision assessment that is accepted internationally, allied with a better understanding of color vision requirements, is needed.

Aerospace Medicine↗