飞行人员的对比视力与年龄,机种,职务,飞行总时间的关系

采用透射式双变量对比视力表对３９８名现径健康男性军事飞行人员计７９６只眼，在２００ｌｘ和６ｌｘ照度条件下检测了９２％、５２％、３０％、１１％和６％对比度兰道环视力，分析了对比视力值与年龄、机种、职务及飞行总时间的关系。结果表明，飞行人员的对比视力随年龄增长而逐渐降低，不随飞行训练时间的增加而相应提高，且不同的机种、职务间均无显著性差异。     

飞行人员视力下降调查分析

目的：调查飞行人员视力不良现状及规律,分析其发病特点及原因,为做好保护视力工作提供科学依据。方法：对1673例飞行人员裸眼视力及屈光不正检测,对检测结果进行分析。结果：飞行人员视力下降人数为161人．占9．62％。主要原因为近视,人数为143人,占88．81％。各年龄段间差异无统计学意义（P〉0．05）,飞行员视力下降检出率为12．36％,领航员视力下降检出率为10．82％,空中机械师视力下降检出率为7．71％,通信员视力下降检出率为4．87％。飞行员与空中机械师、通信员相比,与通信员差畀有非常显著意义（P〈0．01）,与空中机械师差异有显著意义（P〈0．05）,与领航员相比,差异无显著意义（P〉0．05）。结论：行人员视力下降的主要原因是用眼习惯不符合卫生学要求,用眼过度。少数人与睡眠不足、神经衰弱有关。应广泛开展用眼卫生教育,纠正不合理用眼习惯,改善阅读照明条件,定期检查,对不符合飞行标准者进行治疗,使其视力逐渐恢复,以保持良好的视觉功能。     

动态视力与飞行成绩关系的调查

应用LDS－Ⅰ型动态视力检测仪，对115名飞行学员在进入飞行训练前检测动态视力与其放单飞后的飞行成绩作双盲对照分析。统计结果，30km／h时的动态视效率在飞行合格组中的不合格率为8．33％，在技术停飞组中为42.11％，两组间有非常显著性差异（P＜0．01）。60km／h动态视效率在两组中分别占9．37％和3684％，亦有非常显著性差异（P＜0．01）。说明动态机功能的好坏与飞行技术密切相关。因此，在选拔飞行学员时，把动态视力作为预测性检查，有实际价值，对提高飞行员成才率将起到积极作用。     

动态视力与飞行成绩关系的调查

应用ＬＤＳ－Ｉ型动态视力检测仪，对１１５名飞行员在进入飞行训练前检测动态视力与其放单飞后的飞行成绩作双盲对照分析。统计结果，３０ｋｍ／ｈ时的动态视效率在飞行合格组中的不合格率为８．３３％，在技术停飞组中为４２．１１％，两组间有非常显著性差异。６０ｋｍ／ｈ动态视效率在两组中分别占９．３７％和３６．８４％，亦有非常显著性差异，说明动态视功能的好坏与飞行技术密切相关。因此，在选拔飞行学员时，把动态视力作     

飞行人员常见疾病发生率与普通人群对比

目的为提高飞行员健康，通过研究飞行人员疾病发生率与普通人群对比，制定相应干预措施。方法收集飞行人员1893人次体检结果与普通人群体检进行统计分析。结果对飞行影响较大常见病为高血压、高血脂、老视、近视和身体超重。结论这些常见多发疾病会影响飞行人员健康，应引起重视、注意预防。     

飞行员视力、对比视力和对比敏感度函数与目标识别的相关性研究

目的为探讨飞行人员的视觉功能指标与小视角目标识别能力的相关性，以便为制订定量标准提供依据。方法对61名视力正常男性飞行员的双眼常规视力、3个对比水平处（0．92、0．30和0．11）的对比视力和7个空间频率处（0．5、1．0、1．8、3．7、9．2、29．1和43．6cpd）的对比敏感度以及他们对5种视角（13．18’、10．31’、8．25’、6．67’和5．56’）、两个对比度（90．61和2．03）的飞机图形的识别正确率进行测量。测量数据输入微机进行多元相关分析。结果①常规视力与上述图形识别无相关性；②对比视力与低对比时的5种视角图形识别均有显著相关，与高对比时的3种视角图形识别存在显著相关；③对比敏感度函数与高、低对比时的3种视角图形识别存在显著相关。结论常规视力作为识别目标能力的评价在视力≥1的人员中是没有什么作用的。对比敏感度函数作为预示识别具有不同对比、不同大小目标的能力，对比视力作为预示识别具有不同对比的小目标能力均是有意义的。     

海军飞行学员中间视觉对比视力观察

目的观察在中间视觉状态下,海军飞行学员分辨不同对比度视标的细节能力。方法使用多功能夜间视觉检查仪,测量110名常规视力大于国际标准对数视力5.0的海军飞行学员中间视觉状态下100%、80%、60%、40%和20%对比度的对比视力。结果本组海军飞行学员中间视觉100%、80%、60%、40%和20%对比度下的对比视力分别为4.78、4.77、4.76、4.71、4.68。对比视力达到4.8的百分率分别为90%、86%、76%、41%和39%。结论本组海军飞行学员中间视觉的对比视力随着对比度的降低而下降,达到4.8的百分率也随着对比度的降低而下降。     

空军招飞学员视力与对比敏感度关系的研究

目的分析招飞学员群体中视力与对比敏感度（contrast sensitivity,CS）的关系,并探讨在招飞选拔体检工作中应用对比敏感度检查的可能性。方法检查招飞学员对比敏感度函数（contrast sensitivity function,CSF）值,将符合纳入标准的98例样本按视力1.0为标准分为两组,比较4种空间频率（3、6、12、18 cpd）、3种状态（明视、暗视、暗视＋眩光）的CSF值。结果两组在不同状态、不同空间频率的CSF值差异均无统计学意义（P〉0.05）;在各空间频率下,明视与暗视状态下的CSF值差异有统计学意义（P〈0.05）,暗视与暗视＋眩光状态下的CSF值差异均无统计学意义（P〉0.05）。结论部分招飞学员视力表检查结果正常,而CSF值出现异常,特别是在高空间频率段的明暗分辨率下降。现行招飞选拔体检标准无法筛选这些学员,可以尝试增加中高空间频率下暗视的CSF值作为招飞体检的指标。     

空军招飞学员视力与对比敏感度关系的研究

目的分析招飞学员群体中视力与对比敏感度(contrast sensitivity,CS)的关系,并探讨在招飞选拔体检工作中应用对比敏感度检查的可能性。方法检查招飞学员对比敏感度函数(contrast sensitivity function,CSF)值,将符合纳入标准的98例样本按视力1.0为标准分为两组,比较4种空间频率(3、6、12、18 cpd)、3种状态(明视、暗视、暗视+眩光)的CSF值。结果两组在不同状态、不同空间频率的CSF值差异均无统计学意义(P>0.05);在各空间频率下,明视与暗视状态下的CSF值差异有统计学意义(P<0.05),暗视与暗视+眩光状态下的CSF值差异均无统计学意义(P>0.05)。结论部分招飞学员视力表检查结果正常,而CSF值出现异常,特别是在高空间频率段的明暗分辨率下降。现行招飞选拔体检标准无法筛选这些学员,可以尝试增加中高空间频率下暗视的CSF值作为招飞体检的指标。     

应招飞行学员共同性斜视检出率与远视力相关性分析

目的 探讨应招飞行学员群体共同性斜视检出特点及与远视力的相关性.方法 回顾分析某部2013-2015年应招飞行学员共同性斜视检出资料,并与其远视力进行相关性分析.结果 应招飞行学员共同性斜视检出率为2.30％;远视力不足者显性斜视检出率略高于远视力正常者,但差异无统计学意义(x2=0.1662,P=0.6836);斜视类型全部为共同性外斜视,其中间歇性外斜视占97.60％,恒定性外斜视占2.40％;斜视＜10°的占94.71％,≥10°的占5.29％.结论 应招飞行学员共同性斜视以间歇性外斜视为主,远视力不足者显性斜视检出率高于远视力正常者,间歇性外斜视斜视角变异较大,是影响眼位检查准确率的重要因素.     

Relationship between the visual evaluation of pathology visibility and the physical measure of low contrast detail detectability in neonatal chest radiography

IntroductionThe detectability of low contrast detail (LCD) is a method used to assess image quality (IQ) in neonatal radiography; however, there is a lack of data on the relationship between LCD detectability and visual IQ. The study aims at investigating the relationship between the LCD detectability and visual IQ and pathology visibility (PV).MethodsSeveral acquisition parameters were employed to obtain a group of images from a neonatal Gammex chest phantom. Three observers applied relative visual grading analysis (VGA) for assessing the IQ and PV. A simulated pneumothorax visibility (PNV) and simulated hyaline membrane disease visibility (HMV) represented PV. Next, a CDRAD 2.0 phantom was radiographed utilising the same acquisition protocols, and several paired images were obtained. With the use of CDRAD analyser software, the detectability of LCD was assessed and expressed by an image quality figure inverse (IQFi_inv) metric. The correlation between the IQF_inv and each of IQ, PNV and HMV was examined.ResultsThe physical measure (IQF_inv) and the visual assessment of IQ were shown to be strongly correlated (r = 0.95; p < 0.001). Using Pearson's correlation, the IQF_inv, PNV, and HMV were found to be strongly correlated (r = 0.94; p < 0.001) and (r = 0.92; p < 0.001), correspondingly.ConclusionResults of the study show that physical measures of LCD detectability utilising the CDRAD 2.0 phantom is strongly corelated with visual IQ and PV (PNV and HMV) and can be used to evaluate IQ when undertaking neonatal chest radiography (CXR).Implications for practiceThis study establishes the feasibility of utilising the physical measure (IQF_inv) and the CDRAD 2.0 phantom in routine quality assurance and neonatal CXR optimisation studies.     

Stepping characteristics and Centre of Mass control during stair descent: Effects of age, fall risk and visual factors

Stair edges provide important visual cues for appropriate foot placement on the stair and balance control during stair descent. Previous studies explored age-related changes in stepping performance and balance control during stair descent and included fit older adults. The present study investigates both age- and frailty-related changes to stepping parameters and Centre of Mass (COM) control during stair descent and how these measures are affected by visual factors. Older adults were split into two groups containing participants with the lowest (LROA, n = 7) and highest (HROA, n = 8) combined scores on tests of balance and confidence to negotiate stairs. Data were also collected from younger adult participants (YA, n = 8). Kinematic data were collected from participants while they descended stairs under combinations of ambient light (bright and dimmed) and stair edge contrast conditions (high and low). A three (group) × two (illumination) × two (contrast) ANCOVA was performed with average stair walking speed as covariate. HROA cleared the stair edge vertically (p = 0.001) and horizontally (p < 0.001) with less distance than LROA. Dimmed ambient light resulted in decreased step length in HROA (p = 0.006) compared to bright lighting. High stair edge contrast led to reduced vertical COM acceleration variability in HROA (p = 0.009) and increased distance between COM and anterior base of support (p = 0.017) in LROA. YA increased horizontal foot clearance (p = 0.011) when stair edge contrast was high. We conclude that the aforementioned differences in stepping behaviour shown by HROA may contribute towards an increased risk of tripping and that high stair edge contrast has a beneficial effect on balance control in older adults.     

飞行人员冠心病危险因素聚集度与胰岛素抵抗的关系

目的研究飞行人员心血管病危险因素聚集情况及其与胰岛素抵抗（IR）的关系。方法对230名健康疗养飞行人员进行心血管病危险因素问卷调查，检查血糖、血脂和血胰岛素水平，计算胰岛素抵抗指数（HOMA—IR）及8细胞的分泌功能，比较心血管病危险因素聚集度与胰岛素抵抗的关系。结果230名飞行人员中完成全部设计项目的155名，体质指数（BMI）、收缩压（SBP）、舒张压（DBP）与HOMA—IR呈正性相关，分别为：r=0．236，P=0．003；r=0．221，P=0．012；r=0．200，P=0．023。年龄≥40岁者HOMA—IR高于年龄〈40岁者（P〈0．05）；BMI≥25kg／m^2者HOMA—IR大于BMI〈25kg／m^2者（P〈0.05）；具有1项、2项代谢危险因素者HOMA-IR大于无危险因素者（P〈0.05）；同时具有≥3项代谢危险因素和心血管病相关生活因子者HOMA—IR大于无危险因素者（P〈0.05）。结论飞行人员胰岛素抵抗与体质指数、收缩压、舒张压相关，与年龄、飞行时间、血脂等因素不相关；具多项危险因素者IR高于不具危险因素者；BMI≥25kg／m^2可作为初步筛查飞行人员IR的界值。     

Histopathologic diversity of gastric cancers: Relationship between enhancement pattern on dynamic contrast-enhanced CT and histological type

PurposeTo evaluate the diagnostic value of contrast-enhanced computed tomography gastrography (CE-CTG) to predict the histological type of gastric cancer.Materials and methodsWe analyzed 47 consecutive patients with resectable advanced gastric cancer preoperatively evaluated by multiphasic dynamic contrast-enhanced CT. Two radiologists independently reviewed the CT images and they determined the peak enhancement phase, and then measured the CT attenuation value of the gastric lesion for each phase. The histological types of gastric cancers were assigned to three groups as differentiated-type, undifferentiated-type, and mixed-type. We compared the peak enhancement phase of the three types and compared the CT attenuation values in each phase.ResultsThe peak enhancement was significantly different between the three types of gastric cancers for both readers (reader 1, p = 0.001; reader 2, p = 0.009); most of the undifferentiated types had peak enhancement in the delayed phase. The CT attenuation values of undifferentiated type were significantly higher than those of differentiated or mixed type in the delayed phase according to both readers (reader 1, p = 0.002; reader 2, p = 0.004).ConclusionCE-CTG could provide helpful information in diagnosing the histological type of gastric cancers preoperatively.     

The association of age, flying time, and aircraft type with hearing loss of aircrew in the Israeli Air Force

Exposure to aircraft (A/C) noise is considered to be one of the factors which causes permanent hearing threshold shifts among military aircrew. Consequently most studies, dealing with this field of evaluation, fail to focus on the contribution of other elements, especially biological (physiological) ones. We, therefore, decided to evaluate the effect of the subject's age on this process. Audiometric records of 777 aircrew members within the Israeli Air Force were examined. The average age was 27.2 +/- 5.2 years. The individual files were composed of all yearly audiograms from time of recruitment to present, personal information, recorded flight time and type of A/C flown (i.e., rotary-wing and fighter, transport and light fixed-wing aircraft). Hearing loss was studied using two criteria (a. USAF criteria; b. acoustic trauma criteria we devised). The significance of each of the factors was analysed by using uni- and multivariate analysis (Pearson correlation and stepwise multiple regression). A progressive linear correlation between age and hearing loss was exhibited (p less than 0.001). The results suggest that the age of the subject is strongly correlated with values of hearing threshold shift, while A/C type and accumulated time played a minor role.