视觉显示终端(VDT)周围照明对视觉功能影响的研究

VDT 作业的视觉负荷较重,在连续3小时的作业中,随着作业时间的延续及工作面上照度的降低,操作人员普遍产生视疲劳,并对工效产生影响,主要表现为被试明视近点的延长和错误率的上升。在200Lux、100Lux、50Lux 这三种照度水平下,以50Lux 最为严重,其作业后的变化与作业前对照值有显著差异,作业第三小时与前两小时相比也达显著或非常显著之差异。为减缓减轻视疲劳的发生及其对操作员视功能及工效的不利影响,本文建议VDT 场所的周围照明不应低于200Lux(寻址性作业以100Lux 为宜),同时,每作业一小时后应适当休息。     

通信兵保健要点

预防疲劳 因长时间受耳机内高频声音的刺激，容易引起听觉疲劳；固定的坐姿、注意力高度集中、工作时间过长，也容易引起体力疲劳。因此，在情况许可时，可采用缩短工作时间、工作中穿插小休息或做工间操方法来预防疲劳的发生。收报和发报人员定时互换工作，也可以减轻或推迟疲劳的产生。此外，要注意合理膳食，加强营养；保证必要的体育锻炼时间，提高身体素质。 　　保护视力 工作场所要有足够的照明，光线要均匀，避免闪光和眩光，以防引起视觉疲劳和视力减退。多吃含维生素 A丰富的食物，有利于保护视力。 　　预防不良工作环境的危…     

军用飞机座舱温度控制的生理学要求

根据人-机-环境系统理论，论证了军用飞机座舱温度控制的生理学要求。采用国际上通用的环境生理学指标，将座舱温度划分为舒适区、工效保证区和应激区，分别提出了夏季、冬季着装及使用个体调温装备条件下座舱温度控制的范围和允许飞行时间。     

艇员仪表刻度视觉辨认效率测评系统的研制及应用

目的为开展“人-机-环境”系统中艇员视觉工效、信息处理的研究提供方便、实用的检测手段。方法用数码相机采集艇上实际应用的仪表图像，运用Photoshop图像处理系统，依据仪表的实际尺寸建立图像资料库，利用Delphi可视化软件开发工具，编制系统的操作软件，利用人机对话窗口对被试者进行辨认仪表刻度效率的测定。结果在2种不同强度的照明环境中进行测试。当环境照度由75lx升高到150lx时，被试者辨认仪表刻度的反应时间明显缩短（P〈0．01）；辨认仪表刻度的正确率差异无统计学意义（P〉0．05）。结论该系统对艇员仪表刻度视觉辨认效率的测量敏感、方便、实用，适于普及和应用。     

视屏显示终端综合征研究进展

VDT（ video display terminal）对操作者健康的影响已被公认,主要体现在作业者的眼部、骨骼肌和神经系统等,尤以视觉功能的损害最为突出。 VDT作业引发的视觉功能损害在影响工作效率和质量的同时,也危害着工作者的身心健康。因此简要概述VDT的发病机制、临床表现、测量方法以及治疗方式,让人们更好的了解VDT综合征,并及早地认识和防范。     

视屏显示终端综合征研究进展

VDT(video display terminal)对操作者健康的影响已被公认,主要体现在作业者的眼部、骨骼肌和神经系统等,尤以视觉功能的损害最为突出.VDT作业引发的视觉功能损害在影响工作效率和质量的同时,也危害着工作者的身心健康.因此简要概述VDT的发病机制、临床表现、测量方法以及治疗方式,让人们更好的了解VDT综合征,并及早地认识和防范.     

眩光试验及其在航空医学中的应用

介绍了眩光研究的意义、眩光现象的产生、不适眩光、失能眩光、眩光失能值的表达、眩光试验等概念。对眩光试验在某些眼科疾病诊断中的意义和实用价值以及其在航空医学中的应用前景作了探讨，提出眩光试验作为机功能的一种检查方法，其重要临床意义不可忽视。     

航天员出舱作业人机界面的工效学研究进展

目的综述航天员出舱作业人机界面工效学的研究状况。资料来源与选择结合已有的工作基础，并引用国内外公开发表的相关论文及著作。资料引用论文14篇，著作2部。资料综合论述影响航天员舱外作业效能的主要因素，划分了出舱活动的类型，归纳国外在气闸舱、舱外活动工作台或装配架、舱外工作点的设计与舱外航天服等方面涉及的工效学研究状况，并分析采取的解决措施。结论国外在进行舱外作业人机界面工效学评价时，利用了嵌入人体的计算机模型，有效地解决了相关技术问题，我们府着重加以考虑．     

振动和照明光波长特性对判读仪表所需照明水平的影响

实验在暗室内进行。16名正常男性青年作为被试者，取屈腿半卧位。与仪表视距为70cm，测定了胸背轴人全身振动，仪表振动，人和仪表同时振动以及不同波长下判读仪表所需最低照明水平。结果表明，不同振动频率在等现力振动条件下仪表判读所需的照度无显著性差异，当视力因振动的增强而下降时，仪表判读所需的照度提高。人体与仪表同时振动及人体单独振动时所需的照度显著高于仪表单独振动时。振动条件下照明光的波长特性对仪表判该影响很大。5种照明光接仪表判谈所需照度由高至低排序依次为：起始被长620um的红光，白光，峰值波长640、620和600um的红光。     

对某部视屏操作人员眼健康的调查分析

目的：分析长期从事视频显示终端（VDT）操作人员眼健康的情况。方法：对从事VDT操作1年、2年及2年以上108人分别进行眼科的一般检查、屈光状态分析、调节灵活性测定、隐斜及交叉柱镜（FCC）测定,并同非VDT操作126人的眼科检查情况进行对比。结果：长期从事VDT操作者,其眼调节灵活性明显降低47例（43．59／6）,调节滞后66例（61．1％）,未矫正老视53例（48．1％）,屈光矫正不足或未予矫正87例（81．3％）,内隐斜24例（22．2％）,外隐斜17例（15．79／6）,屈光参差8例（7．4％）。眼肿、眼痛、视物模糊等显著多于非VDT操作者,VDT操作者随工作时间的延长,有明显的视疲劳倾向。结论：长期从事视屏操作对视力有一定影响,应加强对视屏操作者视疲劳的防护。     

多用户系统控制中寻呼员视觉机能的测评

目的 评价多用户系统控制中寻呼员的视觉机能状态,探讨视疲劳产生的原因。方法 对寻呼员上午工作前和工作后的主观感觉进行了测评,并分别在８：１５、９：１５、１０：１５、１１：１５、１２：１５对闪光融合频率、动态视力和屈光度等视觉指标进行现场测试。结果作业过程中工作人员没有出现严重的视觉不舒适症状,对不同阶段测试结果俩俩比较,闪光融合频率、动态视力等指标没有下降;与８：１５所测结果比较,屈光度除右眼在１     

北京某网络公司职员视频终端综合征调查

 目的 了解北京某网络公司视频终端综合征(visual display terminal syndrome, VDT syndrome,简称VDT)的发生情况、临床表现及相关因素。方法 对北京某网络公司141名在岗员工进行问卷调查和眼科检查:调查表内容包括一般资料、屈光状态、工作环境和时间,以及最近3个月内视频使用时间、视疲劳症状调查、眼外症状、久视疲劳时间、日疲劳次数;眼科检查包括视力、眼压、干眼症检查及眼底检查。结果 该网络公司116名为网络技术人员(一线员工组),人力资源、公关、策划、翻译等共25名(非一线员工组)。该公司87.2%有近视,使用视频时间(13.9±2.0)h/d。97.9%的人患有VDT,其中,一线员工组100%,发生率高于非一线员工组(88.0%),差异有统计学意义(χ²=9.04,P=0.0026)。久视疲劳时间为(4.60±2.3)h,日疲劳次数为2.35±1.46。视疲劳症状前四位分别是眼干涩、神疲乏力、眼胀、视物模糊。结论 该网络公司VDT发生率高,不同工种员工VDT发生有差别,视疲劳症状及眼外症状明显,急需进行健康宣教及干预治疗进行防治。     

Using a human visual system model to optimize soft-copy mammography display: influence of veiling glare

RATIONALE AND OBJECTIVES: This project evaluated human observer performance and that of a human visual system model (JNDmetrix) to assess whether the veiling glare of a digital display influences observer performance during soft-copy interpretation of mammographic images for the detection of masses. MATERIALS AND METHODS: A set of 160 mammographic images, half containing a single mass, was processed to simulate four levels of veiling glare: none, comparable to a medical grade monochrome curved-screen cathode ray tube (CRT) display, double that of the CRT and quadruple that of the CRT. The images were shown to six observers in a randomized presentation order on a liquid crystal display (LCD) that had essentially no veiling glare. The images were also analyzed using the JNDmetrix human visual system model. RESULTS: Observer performance as measured using receiver operating characteristic techniques declined with increasing veiling glare (F = 6.884, P = .0035), with quadruple veiling glare yielding significantly lower performance than the lower veiling glare levels. The JNDmetrix model did not show a large reduction in performance as a function of veiling glare, and correlation with the human observer data was modest (0.588). CONCLUSIONS: Soft-copy display veiling glare can influence observer performance, but only at extreme levels. The impact of veiling glare on performance may be more pronounced for less experienced readers.     

模拟失重条件下长时间脑力负荷始末前额区脑电多尺度墒的变化分析

目的 观察头低位卧床模拟失重期间脑电信号复杂度的变化,研究脑电信号多尺度熵与脑疲劳的关系.方法 8名健康男性志愿者以-15°头低位卧床(HDBR)为模拟失重,+15°头高位卧床(HUBR)为对照,志愿者静息30 min后进行2h内容为1-back图片记忆匹配VDT作业.结果 实验初HDBR条件下志愿者前额区脑电多尺度熵...     

Generalization of tolerance to motion environments

The aim of the present investigation was to determine to what extent training tolerance to one motion stimulus would generalize other motion experiences. Twenty subjects prone to motion sickness were selected and assigned to one of four groups after pretesting in a Dichgans and Brandt drum to determine their susceptibility to visually-induced apparent motion. They were also pretested with a VDT display of an expanding surface, and on a revolving/tilting chair. Subjects were assigned to one of the four groups by matching their mean tolerance to visually-induced motion. Subjects in the first group served as controls and received only cognitive counseling regarding their ability to tolerate motion environments. Subjects in the other groups received the same counseling coupled with incremental exposures to the drum, chair, or VDT, respectively. Posttests on each apparatus revealed that the treatments involving the chair and the drum provided specific increases in tolerance to the device used during treatment, and that the treatment involving the chair provided a generalized tolerance to visually-induced motion. These results support the notion that there are both specific and general components in learning to tolerate motion environments.     

Bronchial blood flow measured by video dilution technique in sheep

Bronchial blood flow was studied with the video dilution technique (VDT) in seven sheep. All animals were anesthetized (thiamylal and halothane) and ventilated. A videodensitometer and a videotape replay of the fluoroscopic image of dye moving through the common bronchial artery were used to construct dye mass vs. time curves. The areas under the curves were inversely proportional to flow in the bronchoesophageal artery, the site of dye injection. At thoracotomy, an electromagnetic flow probe (EMFP) was placed on the common bronchial artery (the major branch of the bronchoesophageal artery) to measure blood flow changes simultaneously by EMFP and by VDT. These two methods of measurement of blood flow to the airways were compared to validate the use of VDT in this circulation. Common bronchial artery blood flow was increased by injection of radiocontrast dye into the fluoroscopically positioned bronchoesophageal artery catheter causing hyperosmotically induced hyperemia. In 160 simultaneous measurements in five sheep, the percent change in flow as measured by EMFP and VDT correlated closely (r = 0.96). When flow changed because of spontaneous aortic pressure changes or pharmacologic intervention (28 simultaneous measurements in five sheep), the percent change in flow by EMFP and VDT also correlated well (r = 0.98). Bronchial blood flow changes in sheep can be measured accurately using the video dilution technique.     

易发青光眼合并白内障应用超声乳化联合小梁切除术的临床疗效及并发症发生率影响评价

目的 分析超声乳化联合小梁切除术对易发青光眼合并白内障的治疗效果和安全性.方法 选取2019年1月-12月治疗青光眼合并白内障的30例患者,以随机数字表法为分组方法,将其分别纳入对照组、研究组,各15例.对照组采取的术法为小梁切除术,研究组采取的术法为超声乳化联合小梁切除术.组间对比治疗前后的视力、眼压以及并发症发生率...     

Direct oblique sagittal CT of orbital wall fractures

Direct oblique sagittal CT was used to evaluate trauma to 77 orbits. Sixty-seven orbital wall fractures with intact orbital rims (36 floor, 22 medial wall, nine roof) were identified in 47 orbits. Since persistent diplopia and/or enophthalmos may warrant surgical repair of orbital floor fractures, optimal imaging should include an evaluation of extraocular muscle status, the nature and amount of displaced orbital contents, and an accurate definition of fracture margins. For orbital floor fractures, a combination of the direct oblique sagittal and direct coronal projections optimally displayed all fracture margins, the fracture's relationship to the inferior orbital rim and medial orbital wall, and the amount of displacement into the maxillary sinus. Inferior rectus muscle status with 36 floor fractures was best seen on the direct oblique sagittal projection in 30 fractures (83.3%) and was equally well seen on sagittal and coronal projections in two fractures (5.5%). Floor fractures were missed on 100% of axial, 5.5% of sagittal, and 0% of coronal projections. Since the direct oblique sagittal projection complements the direct coronal projection in evaluating orbital floor fractures, it should not be performed alone. A technical approach to the CT evaluation or orbital wall fractures is presented.