医学生视觉显示终端阅读与纸版阅读脑力负荷的比较

目的 比较医学生视觉显示终端(VDT)阅读与纸版阅读的脑力负荷.方法 采用主观评分法、主任务评定法、心理生理学评定法评价医学生受试者的脑力负荷.结果 在VDT阅读和纸版阅读两者之间,Cooper-Harper量表评分分值、正确率、阅读速度、阅读效率、瞳孔直径、眨眼率、心率变异性(HRV)各指标的差异均无统计学意义(P＞0.05).与休息时相比,阅读时的眨眼率减少;纸版阅读的总的频域值(TP)值、低频成分(LF)值和高频成分(HF)值均增加,差异有统计学意义(P＜0.05);纸版阅读和VDT阅读的正常RR间期标准差(SDNN)值均增加,差异亦有统计学意义(P＜0.01).结论 VDT阅读与纸版阅读在30 min内,经常进行VDT阅读的医学生受试者的脑力负荷没有明显差异.3种脑力负荷评定方法结论较一致,均可用来评价阅读任务的脑力负荷.     

视觉显示终端心算作业脑力负荷的评价

目的探讨用主观评分法、主任务评定法、心理生理学评定法3种脑力负荷评定方法来评价视觉显示终端（WT）心算作业时脑力负荷的可行性。方法记录分析了受试者完成3种不同难度心算时的Cooper-Harper量表评分、正确率、做题速度、心率变异性、瞳孔直径、眨眼率等脑力负荷评定指标。结果随着心算算式变数位数的增加，3组心算的Cooper-Harper量表评分分值逐渐增加；心算的正确率逐渐下降；做题的速度逐渐减慢；瞳孔直径逐渐增大；眨眼率逐渐减少。与休息时相比，心算时心率变异性（HRV）的总的频域值（TP）、极低频成分（VLF）、低频成分（LF）、低频的归一化值（LFnorm）、低频／高频比率（LF／HF）值降低，高频的归一化值（HFnorm）、HF／TP、相邻RR间期差的均方根（rMSSD）值增大，但3组心算之间的差异无统计学意义（P〉0．05）。结论随着心算算式变数位数的增加，受试者脑力负荷增加。3种脑力负荷评定方法均能在一定程度上反映不同难度心算任务的脑力负荷信息，联合应用多种指标评定脑力负荷更为可行。     

睡眠剥夺疲劳模型生理性电刺激恢复任务绩效方案研究

目的通过睡眠剥夺构建脑力疲劳模型,用生理性电刺激的方法提高被试警觉水平,从而提高任务绩效水平。方法 2019年12月—2020年1月选取40名被试分为测试组与对照组,早晨8:00至次日8:00进行24 h睡眠剥夺,全程测量心率变异性指标,每2 h测量主观疲劳、立位平衡和反应时测试,于上午10点、凌晨3点及4点疲劳对两组进行任务绩效及美国航空航天局任务负荷指数量表(NASA-TLX)测量,其中4点给予测试组电刺激,对照组不给予任何干预措施,测试后评价任务绩效。结果两组疲劳时主观疲劳、立位平衡、反应时测试和多任务成绩与正常情况相比均显著下降(均P0.05),心率变异性指标较正常时上升(均P0.05)。给予电刺激后,测试组任务水平恢复到正常水平(P0.01),2 h后主观疲劳、立位平衡及反应时测试成绩仍保持较高水平(均P0.05);对照组成绩显著下降,且无明显提升。结论疲劳后给予生理性电刺激可以有效提高任务作业水平及警觉水平。     

多感知音乐疗法对心率变异性的影响

目的:探讨音乐疗法对心率变异性的影响。方法:对20名受试者进行音乐疗法实验,用3种方法分析治疗前、中、后心率变异性各种参数的变化。结果:随着治疗时间的增加,受试者主观感觉明显放松。心率变异性的VLF、LF、HF成分在音乐治疗后明显增加,而LF/HF无明显变化规律。音乐治疗后的近似熵也普遍低于音乐治疗前。结论:轻松的音乐可以增加副交感神经系统的活性,对心率变异性的影响显著。     

CHANGES OF HEART RATE VARIABILITY IN PILOT WITH PROTECTIVE APPARATUS DURING SIMULATED LONG HAUL

目的 研究飞行员佩戴不同质量的个体防护装具进行模拟长航飞行时心率变异性的变化,为制订针对性的防护对策提供依据.方法 将10名健康男性高教机停飞学员随机分为有盔显组(受试者佩戴有头盔显示器的保护头盔)和无盔显组(受试者佩戴无头盔显示器的保护头盔).2组受试者佩戴保护头盔及供氧面罩在教八飞行模拟器上进行8 h(飞行与休息各1h交替)的长航模拟飞行.记录模拟飞行过程中的心电信号,分析心率、心率变异性(heart rate variability,HRV)指标的变化.结果 模拟长航飞行中,有盔显组的平均心率为(72.1±7.7)次/min,显著高于无盔显组[(66.6±5.8)次/min](P＜0.01).整个模拟长航飞行期间,有盔显组5 min内正常相邻R-R间期差值的均方根均值(RMSSD)为(13.90±4.50)ms,显著高于无盔显组[(10.29±3.27ms)(P＜0.01)];低频功率(LF)及高频功率(HF)均显著低于无盔显组(P＜0.01),而低频高频比值(LF/HF)则显著高于无盔显组(P＜0.01).结论 模拟长航飞行时,有盔显组飞行员的心率、RMSSD及LF/HF均显著高于无盔显组,表明飞行员佩戴的个体防护装具由于加装头盔显示器使质量增加,对心脏自主神经活动有一定影响.     

心率变异性在脑力负荷评价中的应用

目的探讨用心率变异性(HRV)来评价脑力负荷的可行性。方法受试者在计算机前输入随机数字,模拟脑力劳动。采用Holter8800型动态心电图分析仪连续记录其心电信号,并将心电信号转变为数字信号,应用Holter分析软件分析HRV频域指标:总功率(TP)、低频(LF)、高频(HF)、LFHF。结果输入数字的速度随时间的延长而逐渐增加,输入正确率却逐渐下降。输入速度与HRV的TP和LF呈明显的正相关(r值分别为0.851和0.827,P<0.05),并呈现剂量-反应关系,而HF和LFHF与输入速度之间没有明显相关。休息和脑力劳动开始时HRV各指标的值分别为:TP:(2745.4±1301.6)、(686.2±420.7)ms2Hz;HF:(670.6±393.8)、(202.6±171.7)ms2Hz;LF:(870.5±553.7)、(206.0±187.9)ms2Hz。脑力劳动时HRV各指标与休息时相比,均明显降低,这是一个总的趋势。然后它们在低水平上随着负荷量(强度和时间)的增加而波动且有逐渐升高的趋势。结论心率变异性可以用作脑力劳动负荷的评价指标,但其变化规律有待于进一步的研究。     

不同记忆负荷对事件相关电位—P300的影响

我们研究了不同记忆负荷条件下,ERP-P_(300)变化的规律性和特点及ERP-P_(300)与脑力负荷难度之间的关系。在三种脑力作业时,要求受试者记忆2、4、6位随机数字。结果表明,1、随着记忆数字增加,P_(300)波幅相应增大,三种记忆作业P_(300)波幅之间均有显著性差异。2、记忆错误率和记忆难度主观评价值,亦随着记忆数字增加而增大,且在三种记忆作业之间均有显著性差异。3、P_(300)波幅和记忆难度主观评价值之间相关分析表明呈正相关(P<0.01)。我们建议,P_(300)波幅测量可以作为评价脑力负荷的一项客观指标。     

飞行员佩戴防护装具模拟长航飞行时心率变异性的变化

目的研究飞行员佩戴不同质量的个体防护装具进行模拟长航飞行时心率变异性的变化,为制订针对性的防护对策提供依据。方法将10名健康男性高教机停飞学员随机分为有盔显组(受试者佩戴有头盔显示器的保护头盔)和无盔显组(受试者佩戴无头盔显示器的保护头盔)。2组受试者佩戴保护头盔及供氧面罩在教八飞行模拟器上进行8 h(飞行与休息各1 h交替)的长航模拟飞行。记录模拟飞行过程中的心电信号,分析心率、心率变异性(heart rate var-iability,HRV)指标的变化。结果模拟长航飞行中,有盔显组的平均心率为(72.1±7.7)次/min,显著高于无盔显组〔(66.6±5.8)次/min〕(P<0.01)。整个模拟长航飞行期间,有盔显组5min内正常相邻R-R间期差值的均方根均值(RMSSD)为(13.90±4.50)ms,显著高于无盔显组〔(10.29±3.27 ms)(P<0.01)〕;低频功率(LF)及高频功率(HF)均显著低于无盔显组(P<0.01),而低频高频比值(LF/HF)则显著高于无盔显组(P<0.01)。结论模拟长航飞行时,有盔显组飞行员的心率、RMSSD及LF/HF均显著高于无盔显组,表明飞行员佩戴的个体防护装具由于加装头盔显示器使质量增加,对心脏自主神经活动有一定影响。     

转场部队飞行员心率变异性分析

目的研究分析转场部队飞行员心率变异性状况。方法随机选取转场及驻场部队飞行员各36名,连续记录2 h心电信号,检测分析心率变异性。结果转场部队飞行员心率变异性的异常率(94.4%)明显高于驻场部队飞行员(63.9%),P0.01;转场部队飞行员的R-R间期标准差、相邻R-R间期谱的方根值、总功率、低频、高频较驻场部队飞行员均明显低(P0.01),转场部队飞行员的低频与高频比较驻场部队飞行员明显偏高(P0.05)。结论转场部队飞行员心率变异性明显降低,应进行有效干预。     

视频显示终端作业工间休息制度的探讨

目的探讨不同类型的视频显示终端(VDT)作业工间休息制度。方法14名大学生作为志愿受试者在计算机上阅读短文各自15、30和60min,记录分析了受试者不同阅读时段的Cooper-Harper量表评分、正确率、阅读速度、阅读效率、自感用力度(RPE)评分等指标。另外,让46名大学生在计算机前输入随机数字60min,每10min自动记录1次输入速度和正确率。结果随着阅读时间的延长,Cooper-Harper量表评分、RPE评分有逐渐增加的趋势,正确率、阅读速度有下降的趋势,但差异无显著性;60min阅读与15min相比,阅读效率下降。在60min内,输入数字的速度随时间的延长而逐渐增加;而正确率呈现出一种逐渐降低的趋势,但差异不显著。结论在60min内,阅读效率下降,而输入数字的速度逐渐增加;不同类型的VDT作业,作业者的作业能力有不同的变动规律,需要设置不同的工间休息制度。     

肥胖青少年脑力作业负荷后注意能力变化特点

目的通过观察脑力负荷前后肥胖青少年划消试验及视觉追踪测验完成速度、正确率的变化，探讨肥胖青少年注意能力的特点。方法对选取的2．50名研究对象进行体成分测定，以体脂百分比作为划分肥胖的标准，共选取肥胖及对照82对。以瑞文标准推理测试、韦氏智力量表中部分项目测试60～70min作为脑力作业负荷，负荷前、后分别进行划消试验和视觉追踪测验，统计划消试验的阅读速度、错误率、脑力工作能力指数（IMC），统计视觉追踪试验的完成时间及正确数，分析脑力作业负荷对肥胖组和对照组各指标的影响及2组间的差异，分析肥胖青少年注意能力的特点。结果脑力作业负荷后，肥胖组划消试验阅读速度、脑力工作能力指数明显下降，错误率明显升高（P〈0．05或P〈0．01），视觉追踪测验完成时间显著增加；而对照组划消试验阅读速度、IMC、视觉追踪测验的正确数在脑力负荷后差异无显著性（P〉0．05）。脑力作业负荷后，肥胖组阅读速度、IMC均低于对照组，错误率高于对照组（P〈0．05），视觉追踪测验完成时间显著长于对照组。结论相比于正常青少年，肥胖青少年在同样强度的脑力负荷后，注意能力下降明显。     

沈阳市与绍兴市不同肥胖程度青少年脑力负荷前后Stroop测验研究

目的通过观察脑力负荷前后肥胖青少年Stroop测验中各任务条件下耗时数的变化,初步探讨分析肥胖青少年的部分认知功能。方法采用方便取样,最终254名学生纳入分析,根据体质指数(BMI)进行肥胖程度划分。以韦氏智力量表测试60～70min作为脑力活动负荷,负荷前后分别进行Stroop测验。结果脑力活动负荷前,3组学生Stroop测验各指标的耗时数分别进行比较发现,肥胖组和超重组字色矛盾耗时数明显高于正常组(P<0.05)。脑力活动负荷后,肥胖组和超重组纯颜色和字色无关的耗时数均高于正常组(P<0.05),并且随着BMI Z分的增加,3个指标的耗时数均增加。结论青少年超重和肥胖可明显影响Stroop实验相关认知加工过程,且BMI Z分越高,这种认知加工受累越明显。     

职业紧张对视屏作业人员心理健康的影响

目的　探讨不同性别视屏作业者主要的职业紧张因素及其心理健康状况。方法　采用职业紧张调查表(OSI)对宁夏某银行视屏作业者进行问卷调查。结果　男性视屏作业者认知负荷、心理卫生、心理满足、心情平静与竞争性的得分显著高于女性 (P <0 0 5或P <0 0 1) ,而工作负荷与躯体不适因素的得分明显低于女性 (P <0 0 5或P<0 0 1)。逐步回归分析结果显示 ,男性工作满意感、心理卫生及躯体不适最主要的影响因素分别为对工作的影响力、其它紧张来源与家庭 /工作平衡、工作负荷 ,女性分别为人际关系与对工作的影响力、人际关系与工龄、其它紧张来源与管理角色。结论　不同性别视屏作业者主要的职业紧张因素及其心理健康状况不同 ,影响心理健康的主要因素也不完全相同。     

Association between duration of daily VDT use and subjective symptoms

BACKGROUND: Although visual display terminal (VDT) work has become a common task among office workers, surveys which would help to determine the allowable duration of daily VDT use are limited. METHODS: We investigated more than 25,000 workers three times over a 3-year period using a self-administered questionnaire. Three factors, namely mental, physical and sleep-related symptoms, were extracted by factor analysis. Adjusted means of each factor score were compared with the duration of daily VDT use by general linear model. RESULTS: Physical symptoms score became higher with increasing duration of daily VDT use without a threshold effect. Mental and sleep-related symptom scores of the workers using VDT for more 5 hr/day were significantly higher than that of the groups using VDT for >1, 1-3, and 3-5 hr/day. CONCLUSIONS: Duration of daily VDT use was linearly related to the physical symptom score, and was non-linearly related to mental and sleep-related symptom score with a threshold effect of 5 hr/day.     

An experimental study on the duration of a single spell of work on VDT (visual display terminal) performance

The relation between work load and the duration of a single spell of work on VDT performance studied in an experimental word processing task. Nine healthy male college students performed 2-hour visual tasks under the following three sets of work conditions. In the first set, subjects performed VDT work for two hours without intermission. In the second set, subjects had a 10-minute intermission after a 1-hour task. In the third set, there was a 5-minute intermission after a 30-minute task. Critical flicker fusion, near point distance, subjective fatigue symptoms, heart rate, respiratory rate, blinking counts, electromyogram in upper limb and performance score were measured. Results are as follows. Decrease in critical flicker fusion, increase in near point distance and subjective fatigue symptoms appeared in all three sets of experimental conditions after two hour tasks. Increased slow wave components on electromyogram and increased errors in performance appeared after 60-minute or more tasks without intermission. Effects on the critical flicker fusion, near point distance, subjective fatigue symptoms, electromyogram, blinking counts and errors in performance were least in the third set. The results of this study suggest that in order to reduce operators' fatigue on VDT work of the conversation type, countermeasures such as shortening the duration of a single spell of work to less than 60 minutes and taking frequent short intermission are necessary.     

Fatigue estimation of visual display terminal (VDT) workers by physiological data--preliminary study of a new computer program for VDT work analysis

The methods for assessing VDT workload based on individual capabilities are necessary to evaluate general fatigue by VDT work. We have developed a new computer program for assessing data entry performance of each individual. Four healthy male volunteers conducted a data entry task at their own pace using this program under a controlled environment. They performed the task for 30 minutes twice with 10 minutes rest between them. As a result, the average number of inputs was 133.2 characters/min in the first task and 129.1 characters/min after taking the rest. The error rate was 8.6% and 10.6% in each task. This program was useful to evaluate their data entry performance. We also reported our concern with a drop in nasal skin temperature that was observed during these VDT tasks.     

Influence of work duration or physical symptoms on mental health among Japanese visual display terminal users

The present study examined the relationship of work duration or physical symptoms to the mental health of visual display terminal (VDT) workers in Japan. The mental health status of 2,327 VDT users at an administrative office was investigated using the 12-item General Health Questionnaire (GHQ-12). Subjects were asked about their age, sex, hours of daily VDT use, rest and breaks during VDT work, eyestrain, and musculoskeletal pain. Logistic regression analysis was used to evaluate the associations with mental health status (GHQ-12 scores). The mean age of subjects was 39.5 yr (SD=10.3). Among all subjects, 36.7% could rest during VDT work and 66.9% received breaks during VDT work. The proportion of subjects who reported eyestrain and musculoskeletal pain were 19.6% and 25.7%, respectively. Eighteen percent of subjects were classified into a GHQ-12 high score group. Logistic regression analysis showed that age less than 40 yr, not receiving breaks during VDT work, and the presence of eyestrain and musculoskeletal pain were significantly associated with poor mental health status (high GHQ-12 scores). Using a VDT for more than 5 h/d and being female were also marginally associated with high GHQ scores (p<0.1). In conclusion, the management of physical health as well as work duration is important for good mental health status among VDT users.     

视屏作业人员职业紧张分析

目的　探讨视屏作业者的职业紧张程度、紧张反应及有关的影响因素。方法　采用职业紧张调查表 (OSI)对宁夏某银行 177名视屏作业者进行问卷调查。结果　视屏作业者的紧张因素总分、工作负荷、人际关系以及家庭 /工作平衡因素的得分显著高于对照组 (P <0 0 5或P <0 0 1) ,工作满意感及工作本身满意感与工作组织满意感的得分显著低于对照组 (均P <0 0 1)。逐步回归分析结果显示 ,视屏作业人员的工作满意感与心理卫生的强预测因素均为人际关系 ,躯体不适的强预测因素为工作负荷。视屏作业人员紧张水平的主要影响因素为对工作的影响力。结论　视屏作业者的紧张水平高于对照组 ,主要的职业紧张因素有工作负荷、人际关系与家庭 /工作平衡 ,紧张反应主要为工作满意度的降低 ;其紧张程度与紧张反应除受职业紧张因素与中和缓解因素的影响外 ,也受个人背景特征的影响     

The Dutch version of the Radner Reading Chart for assessing vision function

A chart for measuring visual acuity is a better functional test than the routine distance visual acuity testing with single optotypes. The characteristics of a good reading chart are: logarithmically diminishing print size, simultaneous measurement of reading acuity and reading speed, and the calculation of one score for reading acuity corrected for the number of reading errors. The original German-language Radner Reading Chart meets all these requirements, and above all emphasizes the principle of 'sentence optotypes' i.e. highly standardized sentences, because sentence complexity also influences reading performance. Sentence optotypes were created in the Dutch language and tested according to Radner's strict principles. The most equally matched sentence optotypes in terms of reading speed and number of reading errors were selected for the introduction and printing of the first Dutch version of the Radner Reading Chart. The Dutch Radner Reading Chart is precise and practical and therefore useful for research and daily practice.