战斗机飞行员准分子激光术后飞行14年一例文献复习

目的探讨准分子激光手术后对飞行工作的影响,了解研究现状及发展趋势。方法结合1例曾行准分子激光手术的男性战斗机飞行员飞行14年情况及复习文献,就准分子激光手术后对飞行的影响,以及国外军事飞行人员行准分子激光手术后的医学鉴定进行总结交流。结果该飞行员飞行14年未出现眼红、视力下降、眩光等视觉问题。2006年改新机种体检飞行合格,2011年度体检飞行合格。结论准分子激光手术的安全性逐步提高,根据我国目前的实际情况,可以考虑在满足一定条件下参加招飞体检和军事飞行人员准分子激光手术后无后遗症评定合格。     

Late traumatic flap displacement after laser in situ keratomileuisis

Laser in situ keratomileusis (LASIK) has become the community standard in corneal refractive surgery and is being performed by surgeons in the Army, Navy, and Air Force. LASIK differs from photorefractive keratectomy (PRK) in that a partial-thickness corneal flap is created in the LASIK procedure before removing a microscopic amount of corneal tissue, whereas no flap creation is required in PRK. The benefits of LASIK include minimal discomfort after surgery, as well as a much faster return of visual function. PRK involves a surface ablation and therefore heals differently, involving more discomfort and a slower return of functional vision. LASIK flap integrity is a concern to anyone undergoing the procedure, as well as for those making recommendations on the best form of refractive surgery for military personnel. A case report and a review of the literature are presented on the identification and management of LASIK flap trauma.     

飞行员返回抑制的时程特征及其与飞行绩效相关的研究

目的研究飞行员返回抑制(inhibition of return,IOR)时程特征,并探讨其对飞行绩效的影响,为飞行员的训练和选拔提供参考依据。方法采用线索-靶子范式中的辨别任务形式对32名飞行员进行实验。结果熟练飞行员在SOA为800 ms出现返回抑制(P<0.05),优秀飞行员在SOA为600 ms和800ms出现返回抑制(P<0.05),新手飞行员在SOA为400 ms出现易化效应(P<0.05),在600 ms和800ms均未出现返回抑制;优秀飞行员比新手飞行员拥有更强的返回抑制能力,他们能在较短SOA里出现IOR特征。所有飞行员在400 ms、600 ms和800 ms的返回抑制效应值与飞行绩效相关显著(r=0.601～0.639,P<0.01)。结论优秀飞行员更早出现返回抑制,返回抑制能力和飞行绩效相关,对飞行绩效的评估具有一定的参考价值。     

Simulator-induced spatial disorientation: effects of age, sleep deprivation, and type of conflict

INTRODUCTION: Spatial disorientation mishaps are greater at night and with greater time on task, and sleep deprivation is known to decrease cognitive and overall flight performance. However, the ability to perceive and to be influenced by physiologically appropriate simulated SD conflicts has not previously been studied in an automated simulator flight profile. METHODS: A set of 10 flight profiles were flown by 10 U.S. Air Force (USAF) pilots over a period of 28 h in a specially designed flight simulator for spatial disorientation research and training. Of the 10 flights, 4 had a total of 7 spatial disorientation (SD) conflicts inserted into each of them, 5 simulating motion illusions and 2 involving visual illusions. The percentage of conflict reports was measured along with the effects of four conflicts on flight performance. RESULTS: The results showed that, with one exception, all motion conflicts were reported over 60% of the time, whereas the two visual illusions were reported on average only 25% of the time, although they both significantly affected flight performance. Pilots older than 35 yr of age were more likely to report conflicts than were those under 30 yr of age (63% vs. 38%), whereas fatigue had little effect overall on either recognized or unrecognized SD. DISCUSSION: The overall effects of these conflicts on perception and performance were generally not altered by sleep deprivation, despite clear indications of fatigue in our pilots.     

Heart rate and performance during combat missions in a flight simulator

INTRODUCTION: The psychological workload of flying has been shown to increase heart rate (HR) during flight simulator operation. The association between HR changes and flight performance remains unclear. METHODS: There were 15 pilots who performed a combat flight mission in a Weapons Tactics Trainer simulator of an F-18 Hornet. An electrocardiogram (ECG) was recorded, and individual incremental heart rates (deltaHR) from the HR during rest were calculated for each flight phase and used in statistical analyses. The combat flight period was divided into 13 phases, which were evaluated on a scale of 1 to 5 by the flight instructor. RESULTS: HR increased during interceptions (from a mean resting level of 79.0 to mean value of 96.7 bpm in one of the interception flight phases) and decreased during the return to base and slightly increased during the ILS approach and landing. DeltaHR appeared to be similar among experienced and less experienced pilots. DeltaHR responses during the flight phases did not correlate with simulator flight performance scores. Overall simulator flight performance correlated statistically significantly (r = 0.50) with the F-18 Hornet flight experience. CONCLUSIONS: HR reflected the amount of cognitive load during the simulated flight. Hence, HR analysis can be used in the evaluation of the psychological workload of military simulator flight phases. However, more detailed flight performance evaluation methods are needed for this kind of complex flight simulation to replace the traditional but rough interval scales. Use of a visual analog scale by the flight instructors is suggested for simulator flight performance evaluation.     

Ejection from an aircraft following photorefractive keratectomy: a case report

A 32-yr-old active duty United States Navy Lieutenant Naval Flight Officer (NFO), 6 mo status post photorefractive keratectomy (PRK) in both eyes performed as part of the first protocol to evaluate laser refractive surgery in aviators, ejected from a Navy S-3B Viking aircraft while performing field carrier landing practice. Neither the pilot nor the NFO suffered physical consequences as a result of the ejection. Coincidentally, the NFO had been examined just 1 wk before the mishap and was noted to have uncorrected visual acuity of 20/16 in each eye. Examination 1 wk following the mishap could not detect a change in vision. The NFO's vision status and his post-PRK status was not listed as a causal factor in the mishap. While this case report will not settle the debate regarding the appropriateness of refractive surgery in aviators, it does provide anecdotal evidence to support the safety of PRK in the aviation community.     

The effects of visual scenes on roll and pitch thresholds in pilots versus nonpilots

BACKGROUND: Previous studies have indicated that, compared with nonpilots, pilots rely more on vision than "seat-of-the-pants" sensations when presented with visual-vestibular conflict. The objective of this study was to evaluate whether pilots and nonpilots differ in their thresholds for tilt perception while viewing visual scenes depicting simulated flight. METHODS: This study was conducted in the Advanced Spatial Disorientation Demonstrator (ASDD) at Brooks AFB, TX. There were 14 subjects (7 pilots and 7 nonpilots) who recorded tilt detection thresholds in pitch and roll while exposed to sub-threshold movement in each axis. During each test run, subjects were presented with computer-generated visual scenes depicting accelerating forward flight by day or night, and a blank (control) condition. RESULTS: The only significant effect detected by an analysis of variance (ANOVA) was that all subjects were more sensitive to tilt in roll than in pitch [F (2,24) = 18.96, p < 0.001]. Overall, pilots had marginally higher tilt detection thresholds compared with nonpilots (p = 0.055), but the type of visual scene had no significant effect on thresholds. CONCLUSION: In this study, pilots did not demonstrate greater visual dominance over vestibular and proprioceptive cues than nonpilots, but appeared to have higher pitch and roll thresholds overall. The finding of significantly lower detection thresholds in the roll axis vs. the pitch axis was an incidental finding for both subject groups.     

歼击机飞行员准分子激光角膜屈光手术后放飞一例并文献复习

目的 探讨飞行员角膜屈光手术治疗的飞行适应性及航空医学的鉴定原则.方法 分析1例歼轰-7飞行员双眼近视的临床诊断、治疗过程及医学鉴定情况,复习相关文献.结果 本例飞行员诊断为近视性屈光不正2年,保守治疗无效.本人要求手术治疗.眼科检查未见手术禁忌证,经过准分子激光上皮下角膜磨削术治疗,术后常规局部抗炎、促进角膜伤口愈合等药物治疗约1个半月,3个月后复查视功能（包括视力、立体视觉、对比敏感度）恢复正常;双眼角膜伤口愈合良好,电脑验光屈光度稳定;角膜地形图示切削区居中.经低压舱模拟航空低压缺氧环境检查,视功能稳定,给予特许飞行合格.术后正常参加双座机飞行40 h. 结论 军事飞行员近视角膜屈光手术治疗后,角膜伤口愈合良好,视功能恢复正常者可以考虑放飞.飞行适应性评价除常规定期视功能、屈光度、角膜等检查外,应进行对比敏感度、眩光等与飞行环境相关的特殊视功能检测.准分子激光角膜屈光手术是解决军事飞行员近视的有效方法.     

Simulator induced syndrome: evidence for long-term aftereffects

Pilots have experienced various adverse symptoms hours and even days following flight simulator training. This study surveyed pilots undergoing simulator training in an attempt to provide an initial gauge of the extent, severity, and possible risk factors of long-term (greater than 1 day) simulator aftereffects. A three-part voluntary and anonymous questionnaire was used to gather data. We studied pilots of varying experience undergoing advanced flight training which included the use of flight simulators. Some 238 pilots participated in the study, and 196 completed the follow-up survey concerning long-term effects. Nine (4.6%) pilots experienced adverse symptoms 24 h or more after completion of their last simulator training, which they attributed to their recent simulator experience. Symptoms reported included: recurrent visual flashbacks, continued balance disturbance, and hand-eye discoordination. Three pilots (1.5%) reported difficulties flying aircraft. Pilot flight experience level, total simulator time, length of simulator session, and sex were not predictive of risk. This study suggests that long-term (greater than 1 day) adverse aftereffects may occur following simulator training.     

低度近视眼准分子激光角膜屈光手术后视觉及相关角膜参数与飞行员正视眼的对比分析

目的检测中国歼击机飞行员视觉及相关角膜参数,并与低度近视眼行准分子激光角膜屈光手术后的数据进行对比分析,评估准分子激光角膜屈光手术在我空军应用的前景。方法选取进行准分子激光原位角膜磨镶术(LASIK)或角膜表面切削手术(PRK)的低度近视眼,分别观察裸眼视力、屈光状态、Astramax角膜地形图获得的波阵面像差,即总高/低阶像差、垂直彗差、水平彗差和球差,以及角膜前表面Q值、角膜曲率等角膜参数,与歼击机飞行员正视眼数据进行对比分析。结果PRK和LASIK治疗≤-3.00D轻度近视眼,术后裸眼视力达到飞行员的标准;屈光状态,即球镜度数、柱镜度数、等效球镜三组差异无统计学意义;手术组角膜的Q值没有改变;中央角膜曲率显著下降;术后总高/低阶像差和球差与飞行员组差异有统计学意义。LASIK术后球差的增加显著高于PRK。结论 低度近视眼行PRK或LASIK术后裸眼视力、屈光状态、角膜的Q值可以达到飞行员的标准。但总高阶像差、彗差和球差的增加可能严重影响视觉质量,LASIK较PRK对球差的影响更大。在选拔飞行员时,对做过角膜屈光手术的患者应该慎重。同时在屈光手术中如何减少和避免波阵面像差的改变,如何通过手术保持和提高视觉质量也是我们今后的课题。     

Circadian rhythms in airline pilots submitted to long-haul transmeridian flights

BACKGROUND: Circadian rhythms shift out of phase after transmeridian flights. Desynchronization between body rhythms and the environment is linked to jet lag, which depends on age, flight direction, and number of time zones crossed. METHODS: To investigate this problem in airline pilots, we performed a multivariate analysis of their circadian systems during Madrid-Mexico-Madrid flights (-7 time zones, n = 12) and Madrid-Tokyo-Madrid flights (+8 time zones, n = 21). Telemetry was used to record pilots' activity, skin temperature, and heart rate, obtaining 6 d of continuous data, including 2 d before the flight, the flights themselves, 2 d at the stopover, and 1 d after the return flight. Time series were analyzed by cosinor, and the resulting parameters of the rhythms were compared by ANOVA and Tukey contrasts in every category formed by the age groups (under and over 50 yr old) and flight direction groups. Subjective time estimation of short, intermediate, and long intervals was recorded. Other psychological variables were measured, including anxiety, tiredness, and performance. RESULTS AND CONCLUSIONS: Activity/rest and heart rate rhythms appeared to be linked to a "weak oscillator." Temperature rhythms manifested a rigid response after the phase shifts of the light/dark cycle, closely related to the biological clock. Subjective time appreciation tended to be overestimated without exhibiting a clear circadian component, but attributable to fatigue and stress. Psychometric evaluation showed that desynchronization affected all the pilots. Some results showed an age-related variability with a more marked influence in younger pilots. No consistent effects regarding flight direction were found.     

Radio frequency radiation exposure of the F-15 crewmember

INTRODUCTION: In the United States Air Force, pilots of F-15 fighter aircraft use fire control radars to search for enemy targets and to launch beyond visual range radar missiles. The fire control radars must be of a sufficient power output to enable a target return, but pilots are concerned about deleterious health effects from the levels of radio frequency radiation (RFR) they are exposed to. Measurement of RFR while actually in flight in the F-15 has never been performed. This study was designed to document the RFR levels that pilots are exposed to on normal missions while in flight with the radar on and active. METHODS: A hand-held meter was used to measure electromagnetic fields during three F-15 flights. Instrumentation consisted of a Narda Microwave Model 8718 digital survey meter and Model 8723 broadband isotropic E-field probe with a frequency range between 300 MHz and 50 GHz. The measurements were conducted in the rear cockpit of an F-15D aircraft. Three missions were flown representing the standard missions an F-15 pilot flies on an everyday basis. The missions were: night intercepts, offensive basic fighter maneuvers, and defensive basic fighter maneuvers. RESULT: Based on the data collected during three F-15 missions, all recorded RFR exposure to the crewmember in the F-15 was within the OSHA Permissible Exposure Limit (PEL) of 10 mW x cm(-2). CONCLUSION: Based on a limited sample, RFR exposures in F-15 cockpits appear to be well below the PEL.     

Visual neglect: occurrence and patterns in pilots in a simulated overnight flight

INTRODUCTION: Visual neglect is the unconscious inability to recognize or acknowledge some visual information in the presence of a structurally intact visual system, and was hypothesized to occur with less than 24 h of continuous wakefulness. Visual perception was evaluated in military pilots during a simulated overnight flight to explore for the possible occurrence of visual neglect. METHODS: There were eight military pilots (male, 31-52 yr of age, mean 37 yr) on flight status who were recruited to perform the primary task of flying a simulated 12.5 h overnight mission after a day of continuous wakefulness and the secondary task of responding to repeated 20 min presentations of single- and double-light stimuli displayed in random sequence at 15 degrees intervals across the cockpit instrument panel. In addition to the visual performance task, simulator shutdowns occurring when the tolerances of the simulator were exceeded were measured and simple reaction time on the psychomotor vigilance task was assessed. Total continuous wakefulness was 26.5 h. RESULTS: Combined performance on the visual perception task showed response omissions increasing at 19 h of continuous wakefulness. Patterns included omissions at all stimulus locations, of primarily peripherally located stimuli, and of one of two simultaneously presented stimuli. Simulator shutdowns began at 21.5 h of continuous wakefulness. Correlation of visual task response omissions with simulator shutdowns was r = 0.95, p < 0.0001. CONCLUSIONS: Significant neglect of visual stimuli occurred in pilots beginning at 19 h of continuous wakefulness in a simulated overnight fixed wing aircraft flight, preceded simulator shutdowns, and correlated at 0.95 with simulator shutdowns.     

Surgical correction of disc pathology in fighter pilots: a review of 14 cases

BACKGROUND: Disorders of the spine are common in fighter crewmembers. The high cost of training and experience for pilots makes it important to use all reasonable clinical means to restore grounded pilots to their flying duties, provided that all safety standards are maintained. To date, there has been limited research into specific surgical treatment of spine injury in pilots. This study was designed to examine the efficacy of surgical procedures in Spanish Air Force fighter pilots with injuries to the spine, as well as the aeromedical disposition of such pilots. METHODS: A retrospective study was conducted using the medical records of 14 fighter pilots with symptomatic spinal disorders treated by surgery. RESULTS: The 14 pilots underwent surgery: 12 cases involved fusion of vertebral structures (arthrodesis), while 2 pilots underwent discectomy. All pilots were subsequently given waivers to resume flying duties. DISCUSSION: The successful return to flight status of these pilots indicates the practical application of surgical techniques that safely stabilize the spine. However, due the sample limited size of the sample, further studies are needed.     

高性能战斗机大强度飞行对飞行员生理指标及飞行劳动负荷主观评价的影响

目的观察高性能战斗机大强度飞行对飞行员的生理指标及飞行劳动负荷主观评价的影响。方法5名健康男性高性能战斗机飞行员在1个飞行日内共进行22架次的大强度飞行。记录飞行过程中的心电信号,分析心率及心率变异性（heart rate variability,HRV）;飞行后进行飞行劳动负荷和疲劳程度主观评价。结果飞行员大强度飞行时,随着飞行负荷的降低,心率和HRV频域及时域指标呈现一定的规律性变化。心率在夜问较日问低;夜间校正高频功率（high frequency normalized unit,HFnu）高于日间,校正低频功率（low frequency normalized unit,LFnu）及低频高频比值（LF／HF）则低于日问。飞行员飞行劳动负荷及疲劳程度主观评价分值均较低,没有明显的主观疲劳感。结论高性能战斗机大强度飞行对飞行员生理指标有一定影响,但尚未引起飞行疲劳。合理的飞行安排及有力的航卫保障有利于飞行员身体机能的恢复,预防飞行疲劳,保障飞行安全。     

飞行后血小板聚集功能的变化

为观察飞行后血小板聚集功能的变化，在飞行前后即刻，对92名歼-6男性飞行员采耳血进行血小板（PC）与聚集堆（PAGC）计数，同时对其中18名飞行员进行了动态观察（飞行后即刻、10、20、30、60min采耳血，测定血小板与聚集堆个数）。结果表明，飞行后PC与PAGC分别明显减少（P＜0．01）和增加（P＜0．001），二者呈负相关，这种变化多数人自飞行后20min开始恢复，60min时接近飞行前水平，为可逆过程。飞行后PAGC中的PC明显多于飞行前。上述变化与年龄和飞行时间有关。提示飞行应激是影响血小板聚集功能变化的一个因素。     

High +Gz induced acute inguinal herniation in an F-16 aircrew member: case report and review

This paper describes previously unreported, acute inguinal herniation during high +Gz air combat maneuvers. The flight surgeon aircrew member involved incorrectly analyzed the etiology of the abdominal wall discomfort during and immediately after the mission. Several factors contributed to the delayed diagnosis. Surgical exploration and repair revealed larger than expected defects. An open, anterior "tension-free" repair using polypropylene mesh grafts adequately reinforced the muscular and fascial defects. Return to full flight status occurred 4 wk following surgery. Post-operatively, repeat exposures to both a high +Gz flight environment and exertionally induced increased intra-abdominal pressures were well tolerated. Minimal sequelae from the injury and repair resolved within 1 yr of the surgery and did not affect mission capability or lifestyle activities. This article includes a review of hernia repairs and their aeromedical implications, with a discussion of epidemiology, surgical techniques, risk factors, surgical complications and recovery times for return to full activity.     

Intraocular lenses in aviators: a review of the U.S. Army experience

Intraocular lenses are known to be efficacious in the correction of aphakia, but their suitability and durability in Army aviators has not been previously evaluated. Eight experienced pilots (preoperative flight time average: 7,660 hours), who had intraocular lens implants following removal of cataractus lenses, were studied. All had returned to flight duty, seven as pilots, with a total of 2,700 hours postoperative flight time accumulated. All were very pleased with the surgery and with the effectiveness of their lenses. Minor problems included: halos around lights in low illumination (5/8 pilots), erythropsia (2/8), and difficulties with a fixed focal length (2/8). Two aviators reported significant visual problems: complications associated with a platinum loop iris supported intraocular lens, and discomfort and glare stemming from traumatic corneal scarring. A detailed ophthalmological examination revealed abnormalities (5/8 pilots), but none which would be directly attributed to flying. Modern intraocular lenses appear to be an acceptable means of correcting aphakia in Army aviators.     

Visual acuity, corrective lenses, and accidents in helicopter pilots

The visual acuity of 38 helicopter pilots experiencing serious air accidents was compared to that of a control group of 72 pilots, matched for age, aircraft, and hours of flight. Decrease in visual acuity was divided into two groups: 1) minor decreases in vision up to 20/25 (not requiring corrective lenses); and 2) visual acuity of 20/30 or less with correction to 20/20. Minor decreases in visual acuity were found in 23.7% (9/38) of those in the accident group compared to 25.0% (18/72) in the control group. There were more pilots in the control group who needed corrective lenses (12.5% (18/72) versus 2.8% (1/38), p less than 0.07). We conclude that helicopter pilots with corrective lenses or minor uncorrected decreases in visual acuity are not at increased risk for serious air accidents.