Validación del instrumento "Computer Vision Syndrome Questionnaire (CVS-Q)" para la evaluación del síndrome visual informático en personal de salud de Lima

Objetivos: Determinar la validez y confiabilidad del instrumento "Computer Vision Syndrome Questionnaire (CVS-Q)" en la medición del Síndrome Visual Informático en personal de salud de Lima. Material y métodos: Estudio observacional, descriptivo y de corte transversal, de tipo evaluación de cuestionario, realizado en 82 trabajadores de salud. La validez de contenido se evaluó mediante juicio de expertos con método estadístico de V de Aiken; Validez de constructo, mediante análisis factorial; validez discriminante, a través de la curva operador-receptor (ROC) contrastada con el cuestionario CSSV17; confiabilidad de consistencia interna, con alfa de Cronbach; confiabilidad test - re-test (con 7 días de diferencia); con Rho de Spearman y Coeficiente de Correlación Intraclase (CCI), con intervalos de confianza (IC) del 95%. Se empleó para el procesamiento el software SPSS versión 20.0 para Windows con licencia de prueba. Resultados: El V de Aiken obtuvo un valor de 100%. El análisis factorial extrajo 3 componentes principales que explicaron el 69,455% de la varianza total. El área bajo la curva ROC fue 0,889 [(0,845-0,934); IC=0,95] (p=0,000), sensibilidad 72,22% y especificidad 100%. El alfa de Cronbach fue 0,939, Rho de Spearman 0,884 (p=0,000) y CCI 0,856 [(0,777 - 0,907); IC=0,95] (p=0,000). Conclusiones: El Cuestionario CVS-Q es válido y confiable para ser aplicado sobre el grupo ocupacional de profesionales de la salud con buenas propiedades psicométricas.

SUMMARY Objectives: To determine the validity and reliability of the instrument "Computer Vision Syndrome Questionnaire (CVS-Q)" in the measurement of the Computer Visual Syndrome in health personnel in Lima. Methods: A quantitative, observational, descriptive, cross-sectional and questionnaire study was carried out in 82 health workers. Content validity was evaluated by expert judgment with the Aiken V statistical method; construct validity, through factor analysis; discriminant validity, through the receiver operating characteristic curve (ROC) curve contrasted with the CSSV17 questionnaire; internal consistency reliability, with Cronbach's alpha; reliability test - re-test (7 days apart); with Spearman's Rho and Interclass Correlation Coefficient (ICC) with 95% CI. The SPSS software version 20.0 for Windows with a trial license was used for its processing. Results: The V of Aiken obtained a value of 100%. The factor analysis extracted 3 main components that explain 69.455% of the total variance. The area under the ROC curve was 0.889 [(0.845-0,934); CI=0.95] (p=0.000), sensitivity 72.2% and specificity 100%. Cronbach's alpha was 0.939, Spearman's Rho 0.884 (p=0.000) and ICC 0.856 [(0.777 - 0.907); CI=0.95] (p=0.000). Conclusions: The CVS-Q questionnaire is valid and reliable to be applied in the health professionals' occupational group with good psychometric properties.

Association between screen time and psychology behaviors of preschool children / 中国学校卫生

Objective@#To explore the correlation between screen time, exposure time to different screens and psychology behaviors of preschool children.@*Methods@#A total of 2 582 children from kindergartens in urban Xuzhou areas were recruited to perform the physical examination, a cluster sampling method being explored. Parent questionnaires were performed to understand the time of screens and children’s psychology behaviors. Multi-linear regression and Logistic regression models were also used to analyze the correlation between them in preschool children.@*Results@#The prevalence of abnormal internalization behavior of preschool children in Xuzhou City was 3.8%, the detection rate of abnormal externalization behavior was 22.4%, and the detection rate of prosocial behavior abnormality was 20.9%. The time spent by the preschool boys on TV time, learning day screen time and one-week video time is significantly higher than the girls (P<0.05). After adjusting for age and gender, the results of multiple linear regression analysis showed that the longer the average screen time, the more serious the problem of internalizing and externalizing problems; and the longer the average screen time of the weekend and the week, the worse the prosocial behavior of children (P<0.05). After correcting multiple covariates, it was found that the average screen time was positively correlated with children’s internal and external behavioral problems (P<0.05). Logistic regression analysis showed that after adjusting for age and gender, the average screen time of study day, weekend and week was a risk factor for preschool children’s internal and external behavior problems, and the average weekly screen time was a protective factor for prosocial behavior (P<0.05). After adjusting for multiple covariates, the learning day and the average weekly screen time were risk factors for children’s internal and external behavior (P<0.05). In addition, the results of association analysis between different types of video time exposure and psychological behavior showed that after adjusting for age and gender, all types of video exposures affected the internal and external behaviors of patients (P<0.05); after correcting multiple covariates The association was still statistically significant (P<0.05). Logistic regression analysis showed that after adjusting for age and gender, the exposure time of each type of video screen was a risk factor for children’s internal and external behavior problems (P<0.05). After correcting multiple covariates, all types of video exposure were internalized behavior problems. The risk factors, and the video time of other electronic products were risk factors for externalization behavior problems (P<0.05).@*Conclusion@#Average screen time has a significant positive correlation with psychological behavior, and the exposure time of screens such as TV and mobile phone could increase the incidence of psychological behaviors in preschool children.

Association between screen time and autistic behavior in infants and toddlers / 中国学校卫生

Objective@#To explore the association between screen time and autistic behavior in infants and young children, and to provide clues to the mechanism for further research.@*Methods@#The primary caregivers of 22 586 children in the district of Longhua in Shenzhen were surveyed. Demographic data and screen time were collected using a selfdisigned questionnaire, and children’s autistic behavior was assessed using the child Autism Behavior Checklist(ABC).The chisquare test was used to analyze the correlation between demographic data and screen time, demographic data and autistic behavior, and screen time and autistic behavior. Unconditioned Logistic regression model was used to study the effect of electronic screen exposure on autistic behavior.@*Results@#The amount of screen time spent in infancy increased with age. For children ages 0-,1- and 2-3 years, 60.1%, 35.0% and 20.2% respectively did not watch TV, and 74.0%, 52.6% and 26.8% respectively did not watch the new generation of electronic products. The positive rate of ABC scale screening was 5.3%, including 6.0% male and 4.4% female, OR(95%CI)=1.37 (1.23-1.54).There was correlations between screen time and autistic behavior in infants at all ages (P<0.05).Screen time increased the risk of autistic behavior in younger age groups than in older age groups. For 1 year olds with moderate screen exposure, increased screen exposure at 2 to 3 years of age was associated with an increased risk of autistic behaviors, while reduced screen exposure at 2 to 3 years of age was associated with a lower risk of autistic behaviors(OR=2.14, 2.77, P<0.05). The higher daily screen time at 0-3 years old was, the greater risk of autistic behaviors. Compared with the noncontact electronic screen group, the OR values of the daily TV screens in the ≥1 h/d group and the ＜1 h/d group were 2.01 and 2.45, respectively (P＜0.05).Compared with the non-contact electronic screen group, the OR values of the screens exposed to the new generation of electronic products in the ≥1 h/d group and the ＜1 h/d group were 2.01 and 2.33, respectively(P<0.05).The higher the time of single exposure to electronic screen between 0 and 3 years old, the greater the risk of autistic behaviors. The OR values were 2.50, 1.79 and 1.47 when ≥1 h/time, 0.5-1 h/time and 15-30 min/time compared with <15 min/time（P<0.05）. @*Conclusion@#Early exposure to electronic screens in infants, excessive total daily exposure to electronic screens, and excessive screen time each time are all likely to increase autistic behavior. Therefore, it is suggested that children under 2 years old should not be exposed to electronic screens every day. Children aged 2-3 years old who are exposed to electronic screens＜0.5 h/d and whose screen time <15 min might not significantly increase autistic behaviors.

Pantallas: discordancias entre las recomendaciones y el uso real / Screens: discrepancy between recommendations and actual use

La utilización de dispositivos electrónicos con pantallas y su introducción cada vez más temprana en la vida de los niños presentan un desafío que debe ser reconocido por el pediatra para contribuir a evitar su exceso. Se ha detectado una manifiesta discordancia entre las recomendaciones ideales y el uso real de las pantallas en los niños pequeños. Un correcto asesoramiento dentro de un contexto familiar, junto con una evidencia más sólida sobre los impactos a largo plazo del uso de la tecnología digital, permitirán a los pediatras apoyar adecuadamente a las familias.

The use of electronic devices with screens and the early introduction in small-age children present a challenge that must be recognized by the pediatrician, who must contribute to avoid the excess in their use. We have detected a manifest discrepancy between the ideal recommendations and the actual use of screens in young children. Correct counseling within a family context, with stronger evidence on the long-term impacts of the use of digital technology, will allow pediatricians to adequately provide support to families.

Efecto de una emulsión lubricante en la sintomatología, daño a la superficie ocular e inestabilidad de la película lagrimal de pacientes con ojo seco asociado al síndrome visual informático / Effects of a lubricating emulsion upon symptoms, eye surface damage, and tear film instability in patients with dry eye associated to the computer vision syndrome

Objetivo: Evaluar el efecto de una emulsión lubricante en la sintomatología, inestabilidad de la película lagrimal (PL) y daño a la superficie ocular de pacientes con ojo seco asociado al síndrome visual informático (SVI). Materiales y métodos: Estudio de serie de casos, que analizó el efecto de una emulsión lubricante en pacientes con ojo seco asociado al SVI. Los síntomas se evaluaron a través del cuestionario Ocular Surface Disease Index (OSDI), la inestabilidad de la PL a través del tiempo de ruptura de película lagrimal con fluoresceína (TRPL-F), y el daño a la superficie ocular a través del test de Oxford. Las mediciones fueron realizadas antes y después de 30 días de tratamiento. Resultados: Se evaluaron a 96 pacientes, edad de 25,9 ± 7,2 (18 - 44) años, 62,9% mujeres. El TRPL-F se incrementó en 4,3 + 2,6 s (p<0,001), post-tratamiento. Este incremento fue clínicamente importante en el 70,8% de los casos. El puntaje OSDI se redujo en promedio 15,8 + 7,4 puntos luego del tratamiento (p<0,001), siendo esta reducción clínicamente importante en el 95,8% de los casos. Antes del tratamiento, el 21,9% presentaron daño de la superficie ocular (Oxford 1/5), el cual se resolvió al finalizar el tratamiento (p<0,001). Conclusiones: En pacientes con ojo seco asociado a SVI, la emulsión en estudio produjo una mejoría clínicamente significativa en las tres variables evaluadas, predominando el alivio de los síntomas. El daño a la superficie ocular fue infrecuente y leve en estos pacientes resolviéndose al mes de tratamiento.

Objective: To assess the effect of a lubricant emulsion upon symptoms, tear film instability, and eye surface damage in patients with dry eye associated to the computer vision syndrome (CVS). Materials and Methods: This is a case series study, which analyzed the effect of a lubricant emulsion in patients with CVS-associated dry eye. Symptoms were assessed using the Ocular Surface Disease Index (OSDI) questionnaire, tear film instability was assessed measuring the tear film breakup time (TFBT) using fluorescein, and eye surface damage was assessed using the Oxford Schema. Measurements were performed before and after 30-day therapy. Results: Ninety-six patients were assessed, their age was 25.9 7.2 (18 -44) years, and 62.9% were female. TFBT had a 4.3 2.6 second increase (p<0.001) after therapy. This increase was clinically important in 70.8% of all cases. The OSDI score had an average 15.8 7.4 point reduction after therapy (p<0.001), and this reduction was clinically important in 95.8% of all cases. Before therapy, 21.9% subjects had damage on the eye surface (Oxford 1/5), which was solved at the end of therapy (p<0.001). Conclusions: In patients with CVS-associated dry eye, the studied emulsion led to clinically significant improvement in the three variables that were assessed, particularly in symptom alleviation. Eye surface damage was non-frequent and mild in these patients, and it got solved after one month with therapy.

Effects of watching different screens on students’ visual acuity / 中国学校卫生

Objective@#To explore the association between watching TV and watching computer and visual acuity among children and adolescents, and to provide reference for Chinese students to choose electronic products in life and study.@*Methods@#Subjects were from 2014 Chinese National Surveys on Students’ Constitution and Health(CNSSCH). In this survey, 213 857 Han students participated. The visual acuity results of 5 m visual acuity chart examination were recorded, and the time of completion of homework and the time of different video behaviors were investigated.@*Results@#The incidence of reduced vision acuity among Chinese students increases with the time spent on homework and computer(χ2=3 748.99, 949.39, P<0.01).And it decreased as time spent at the computer increased(χ2=2 725.08, P<0.01). It was found that the incidence of poor vision of students who watched TV for a long time was lower(61.81%), followed by those who watched TV and watched computer for the same time(70.62%), and those who watched computer for a long time(79.03%). The results were statistically significant(χ2=4 862.43, P<0.01). The results of multivariate Logistic regression analysis showed that compared with the students who watched TV for a long time, the students who watched TV for the same time and watched computer for a long time were more likely to have poor vision(OR=1.17, 1.21, P<0.01).@*Conclusion@#When using electronic products, the preference of watching large electronic screens is conducive to reducing the impact of video behavior on students' eyesight.

Association of screen time with emotional and behavioral problems in preschool children / 中国学校卫生

Objective@#To understand the emotional and behavioral problems among preschool children in Ezhou city, and to analyze its association with screen time,to provide a reference for making preventive measures.@*Methods@#1 720 children were selected from 9 kindergartens in Ezhou by cluster sampling method. Questionnaires were completed by the children’s parents or primary caregivers.@*Results@#High total difficulty score accounted for 9.8%(169/1 720) of all participants,the abnormal proportion of peer communication problems is the highest. The average screen time was (1.95±1.88) hours, among them 2.6% spent more than 2 hours. The average screen time on weekends was (2.84±2.58) hours, among them 19.1% spent more than 2 hours. The results of multiple linear regression analysis showed that weekday, weekend and total screen times was associated with children’s total difficulty score, emotional problems, conduct problems, peer interaction and hyperactivity(P<0.05). Furthermore, with the duration of screen time increased, the susceptibility of emotional and behavioral problems in these four dimensions increased.@*Conclusion@#Screen time is associated with emotional and behavioral problems among preschool children. Schools and parents should pay attention to interventions that target family TV viewing practices, and parent-child interaction and communication.

Parental influences on screen time among children and adolescents and associated gender disparity / 中国学校卫生

Objective@#To analyze the effect of parental correlates on screen time among children and adolescents and to explore possible gender disparity,and to provide the reference for taking measures to control and prevent the phenomenon.@*Methods@#By stratified cluster sampling, 4 schools were selected from each of the urban middle school, urban primary school, rural middle school and rural primary school in Fangshan district, Beijing city. Students and parents in the selected school were recruited and investigated on general demographic characteristics and screen time. The effect of parental correlates on screen time and associated gender disparity were analyzed.@*Results@#The prevalence of high screen time among children and adolescents was 10.4%, with boys’(11.9%) higher than girls’(8.9%). Students whose father spent more than 180 min in moderate and vigorous physical activity weekly were at lower risk for high screen time(OR=0.64). Students whose father spent more than 120 min screen time during weekday or on average were at higher risk for high screen time(OR=1.88,1.91). Students whose mother spent more than 120 min screen during weekday, during weekend or on average were at higher risk for high screen time compared with control group(OR=1.87,1.52,1.76). Father’s screen time during weekday or on average showed impact on screen time of their daughters and sons. Mother’s screen time only showed impacts on their daughters.@*Conclusion@#A strong effect of parental daily screen time on children’s screen time has been observed. Parental practice and roles should be considered to tailor interventions for healthy screen time among children and adolescents.

Effects of video work on the ocular vascular hemodynamic and visual of the operators / 中华劳动卫生职业病杂志

Objective@#To investigate the effects of long time video display terminal (VDT) operation on the ocular vascular hemodynamic and visual acuity.@*Methods@#During March and October 2015, 120 cases of video monitoring warriors were selected as study group, another 155 cases of logistics personnel as the control group. The low vision of the two groups was calculated and compared, and the color Doppler flow imaging was used to measure the central retinal artery (CRA) , short posterior ciliary artery (SPCA) , anterior ciliary artery (ACA) , (peak systolic velocity, PSV) , end diastolic velocity (EDV) and (resistance index (RI) . The differences of hemodynamic parameters between these two groups were evaluated, and the relationship between the visual acuity and each hemodynamic parameter was analyzed.@*Results@#The visual acuity of the study group was[0.8 (0.4-1.2) ], much lower than the control group, and the rate of low version in the study group was 40.00%, much higher than that of the control group. Compared with the control group, both of ACA and CRA of SPCA, PSV and EDV in the study group were decreased, while RI of CRA, ACA were increased (P<0.05) ; Compared with the control group, no statistical significance was found in the RI of SPCA in the study group (P>0.05) . The PSV and EDV were negatively correlated with visual acuity (r value of PSV and visual acuity were -0.352, -0.265 and -0.304; r value of EDV and visual acuity were -0.324, -0.348 and -0.365, while RI was positively correlated with visual acuity (r value were 0.363, 0.326 and 0.344) .@*Conclusion@#Our data suggest that long time video operation may be associated with changes of ocular vascular hemodynamic parameters and raise the incidence of low vision.

Visual Display Terminal Syndrome, Sleep Quality and Physical Activity according to Smartphone Addiction in Nursing Students / 재활간호학회지

PURPOSE: The purpose of this study was to investigate visual display terminal (VDT) Syndrome, syndrome, sleep quality and physical activity level according to smartphone addiction level in nursing students. METHODS: The study subjects were 211 nursing students who gave informed consent. The VDT syndrome symptoms, sleep quality, physical activity, smartphone addiction level were measured by structured questionnaires. The data were analyzed using x2 test, Fisher's exact test, one way ANOVA, Pearson's correlation coefficient by IBM SPSS 20.0 program. RESULTS: The average score of smartphone addiction was 35.89 and the high risk group of smartphone addiction was 11.9%, potential risk group was 17.5% and normal group was 70.6%. Smartphone addiction level was significantly associated with gender, grade point, satisfaction with college life, smartphone fare, smartphone using time, smartphone using period, daily using time. In the high risk group, VDT syndrome score was higher, and sleep quality was lower than normal group. Physical activity had no significant difference according to smartphone addiction. Smartphone addiction level was significantly positive correlation with VDT syndrome and sleep quality score, and negative correlation with physical activity. CONCLUSION: Based on the outcomes of this study, it is necessary to develop a smartphone addiction management program with concrete measures to prevent VDT syndrome and poor sleep quality and multidisciplinary approach for controlling smartphone addiction in nursing students.

Prevention of MSDs and psychological stress at computer-equipped workplaces / Prevención de trastornos musculo-esqueléticos y estrés psicológico en los lugares de trabajo equipados con computadores

Introduction: The human body responds to stress-factors through four systems - central nervous, autonomic nervous, endocrine and immune - which are constantly interacting as a complex network. The main stress-factor at the computer-equipped workplaces is a poorly designed workplace, specifically the positioning of equipment on and around the workstation. The number of occupational diseases among office workers is the specific indicator of influencing of existing hazards and risk factors on the worker in the work environment. Objective: To find out the health disturbances and to make the suggestions for health promotion for computer workers. Methods: Over 400 computer workers' working conditions were measured with subsequent measuring equipment; the fatigue of muscles was measured with myometer; the investigation of the workers' opinion on working conditions based on Nordic, Work ability index (WAI) and Kiva questionnaire was carried out. The workers were divided into different groups by the age (A: under 40 years and B: over 40 years). This paper investigates the satisfaction of computer workers with their working conditions. Results: According to the results of Nordic and WAI questionnaires, musculoskeletal disorders (MSDs) were observed by 53.6%; the cardiovascular disturbances by 20.4% and visual disturbances by 16.7% of the respondents in group A (under 40 years). In group B, MSDs were observed by 50.1%; cardiovascular disorders by 45.7% and visual disturbances by 23.2% of the respondents (over 40 years). Muscle and joint complaints were reported only by 19.7% of workers. The majority of the respondents declared the existence of two or more local pain points. Neck, shoulder, wrist and back pain were registered as the main complaints. Conclusions: The results of measurements of physical workplaces revealed that in some offices there are deficiencies in lighting, problems with stuffy air (high CO2 value) and low relative humidity value on cold season. As muscle strain is often coming from the static posture, it may be influenced also by the psycho-emotional stress at workplace. The questionnaires, objective methods and environmental measurements are useful to plan prevention and early rehabilitation before the disability appears.

Introducción: El cuerpo humano responde a los factores estresantes a través de cuatro sistemas - nervioso central, autónomo, endocrino e inmune- los cuales están constantemente interactuando como una red compleja. Los factores estresantes principales en los lugares de trabajo equipados con computadores son lugares de trabajo pobremente diseñados, específicamente el posicionamiento de los equipos en y alrededor de los puestos de trabajo. El número de enfermedades ocupacionales en los trabajadores de oficina es el indicador específico de la influencia de los peligros existentes y factores de riesgo sobre trabajador en el ambiente de trabajo. Objetivo: Encontrar los problemas en salud y realizar sugerencias para la promoción en salud para trabajadores con computadores. Materiales y métodos: Más de 400 condiciones en trabajadores con computadores fueron medidas con el equipo de medición pertinente; la fatiga muscular fue medida con el miometro, la opinión de los trabajadores sobre las condiciones de trabajo fueron registradas por medio de Nordic, el índice de habilidad de trabajo (WAI por sus siglas en ingles) y el cuestionario Kiva. Los trabajadores fueron divididos en diferentes grupos por edad (A: menores de 40 años y B: mayores de 40 años). En este artículo se investiga la satisfacción de los trabajadores de computadores con su condición de trabajo. Resultados: De acuerdo con los resultado de los cuestionarios Nordic y WAI, los trastornos musculo-esqueléticos (TME) fueron observadas en el 53.6%; los problemas cardiovasculares en un 20.4% y los problemas visuales en un 16.7% de los encuestados del grupo A (menores de 40 años). En grupo B, los TME fueron observados en un 50.1%; los problemas cardiovasculares en un 45.7% y los problemas visuales en un 23.2% de los encuestados (mayores de 40 años). Las quejas musculares y articulares fueron reportados solo en el 19.7% de los trabajadores. La mayoría de los encuestados reportaron la existencia de dos o más puntos locales de dolor. Los dolores de cuello, hombros, muñeca y espalda fueron registrados como las principales quejas. Conclusiones: Los resultados de las mediciones de los lugares de trabajo físicos revelaron que en algunas oficinas hay deficiencias en la iluminación, problemas con la contaminación del aire (altos niveles de CO²) y el bajo valor de la humedad relativa en la estación fría. La tensión muscular es a menudo a causa de la postura estática, esta puede estar influenciada también por el estrés psico-emocional en lugar de trabajo. Los cuestionarios, métodos objetivos y mediciones ambientales son útiles para planificar la prevención y la rehabilitación temprana antes de que aparezca la discapacidad.

Monitor Preference for Electronic Medical Record in Outpatient Clinic / 대한의료정보학회지

OBJECTIVES: The objective of this paper is to assess which wide type monitor configurations are preferred when physicians use an Electronic Medical Record (EMR) system in an outpatient clinic setting. METHODS: We selected three kinds of monitor configurations available for adoption at outpatient clinics with reference to monitor market trends. Fifteen attending physicians of the Seoul National University Bundang Hospital used each monitor configuration in their outpatient clinics. After completing the outpatient sessions, they selected the best monitor configuration for criteria described in five questionnaire items. We counted the number of votes and reviewed opinions of participants. RESULTS: The Wide Quad High Definition (WQHD) 27-inch single monitor configuration was most preferred for all questionnaire items. All participants answered that the WQHD 27-inch single monitor configuration was the best for desk space utilization. Eleven out of fifteen participants chose the WQHD 27-inch single monitor configuration as the most suitable monitor for outpatient practice. CONCLUSIONS: This study found that physicians preferred the WQHD 27-inch single monitor configuration in outpatient clinic settings. Healthcare organizations need to consider this finding when they purchase wide type monitors for EMR systems instead of the standard type monitor.

Comparative study of the blinking time between young adult and adult video display terminal users in indoor environment / Estudo comparativo do tempo de piscadas entre adultos jovens e adultos usuários de monitor de microcomputador em ambiente climatizado

OBJECTIVE: Investigate the average blinking time in conversation and in Video Display Terminal use of young adults and adults in the presbyopic age group. METHODS: A transversal analytical study in a readily accessible sample consisting of Volkswagen do Brasil - Curitiba, Paraná employees was performed. The cohort group consisted of 108 subjects divided into two age groups: Group 1, the young adult group (age range 20-39): 77 employees, mean age of 30.09 ± 5.09; Group 2, the presbyopic adult group, (age range 40-53): 31 employees, mean age of 44.17 ± 3. Subjects under 18 years of age, with a history of ocular disorders, contact lens wearers and computer non-users were excluded. The subjects had their faces filmed for 10 minutes in conversation and VDT reading. Student's t-test was used and the statistical significance level was 95 percent. RESULTS: The average time between blinks in Group 1 for conversation and VDT reading was 5.16 ± 1.83 and 10.42 ± 7.78 seconds, respectively; in Group 2. 4,9 ± 1.49 and 10.46 ± 5.54 seconds. In both age groups, the time between blinks in VDT reading situations was higher (p<0.0001). There was no statistically meaningful difference for conversation and VDT reading situations when the two studied age groups were compared (p>0.05). CONCLUSION: There was an increase in the blinking time between young adults and the presbyopic group in VDT use situations when compared with reading situations. The difference in the blinking frequency between young adults and the presbyopic group in VDT use and reading situations was not statistically significant.

OBJETIVOS: Investigar o intervalo entre as piscadas em adultos jovens e em présbitas, durante conversação e leitura no monitor do computador. MÉTODOS: Realizou-se estudo transversal, analítico, em amostra prontamente acessível, composta por funcionários da Volkswagen do Brasil, em Curitiba (Paraná-Brasil). A amostra foi dividida em dois grupos de acordo com a idade: grupo 1 (20-39 anos); grupo 2 (40-53 anos). Foram excluídos menores de 18 anos, portadores de doenças oculares, usuários de lentes de contato e não usuários de computador. Os participantes tiveram suas faces filmadas por 10 minutos durante atividades de conversação e leitura no monitor do computador. Utilizou-se teste t de Student,com nível de significância de 95 por cento. RESULTADOS: A amostra compôs-se de 108 indivíduos, sendo o grupo 1 com 77 indivíduos, com idade média 30,09 ± 5,09 anos e grupo 2 com 31 indivíduos, com idade média 44,17 ± 3 anos. O tempo médio entre as piscadas, no grupo 1, em conversação foi de 5,16 ± 1,83 e leitura no monitor de 10,42 ± 7,78 segundos; no grupo 2, em conversação foi de 4,9 ± 1,49 e leitura no monitor de 10,46 ± 5,54 segundos. Encontrou-se distância maior entre as piscadas, durante a leitura no monitor (p<0,0001) nos dois grupos etários. Conferindo os resultados encontrados nos dois grupos, nas situações de conversação e leitura no monitor, não houve diferença estatisticamente significativa (p>0,05). CONCLUSÃO: Houve um aumento no intervalo entre as piscadas, em adultos jovens e em présbitas, durante a leitura em monitor quando comparada com situação de conversação. Não se evidenciou diferença estatisticamente significativa entre os participantes dos dois grupos, nas situações de conversação e leitura no monitor.

The effect of X-ray radiography exposure intensity on image quality of the monitor / 中华放射学杂志

Objective To explore the relationship between image quality and different exposure intensity of digital radiography(DR).Methods Using a contrast-detail phantom Cdrad 2.0,observers evaluated images on the monitots when exposure parameters were 90 kV and mAs ranged from 0.5 to 16.0 mAs.Then calculate image quality figure(IQF),and ANOVA was used to analyze the difference of IQF under different radiation dose in 8 subjects.Results (1)When exposure parameters were 90 kV and mAs altered from 0.5 to 8.0 mAs.the IQF observed on the monitor was reduced,and the minimal value was 38.54±2.82.When mAs changing from 8.0 to 16.0 mAs.IQF observed on the monitor was increased,and the maximum was 44.33±2.35.(2)Under the different exposure condition,the difference of IQF values were statistically significant(F=60.35,P＜0.01).Conclusions With the increased exposure intensity,the image quality on monitor increased.When mAs was 8.0 mAs,image quality was the optimum When mAs was more than 8.0 mAs,the image quality on monitor reduced.

A Study on the Usefulness of the AAPM TG18 Evaluation Tool for Diagnostic Monitor QC

PURPOSE: We created an 'AAPM TG18 Evaluation Tool' and we determined its usefulness for the quality control of a diagnostic monitor. MATERIALS AND METHODS: We created an evaluation tool (the AAPM TG18) for conducting quality control of a diagnostic monitor, and we evaluated the measurement items of the AAPM TG18 evaluation tool. The measurement items were geometric distortion, fixed quantity assessment and visual assessment of the veiling glare, and we carried out adjustment for the luminance meter 0% calibration, which was used to revise the diagnostic monitor DICOM LUT. RESULTS: With the AAPM TG18 Evaluation Tool, we measured the 2-dimensional length when evaluating the quantitative geometric distortions in the TG18-QC test pattern, and we measured the veiling-glare ring response function, which provided information regarding the spatial extent of the luminance spread, and this measurement of the can be performed using the TG18-GV pattern. Additionally, the AAPM TG18 Evaluation Tool can be used for sensor calibration to standardize the basic rate of 0% luminance when performing periodic calibration. CONCLUSION: The evaluation tool is a very useful for easily evaluating many of the examination items of the AAPM TG18 for performing quality control of a diagnostic monitor.

A study on the influence of CRT brightness for image reading / 中华放射学杂志

Objective To study the influence of CRT brightness on image reading. Methods Both physical testing and compared viewing were used in the study. (1) Setting the CRT brightness at high and low grade (the blank brightness of CRT was 112 cd/m 2 and 82 cd/m 2, respectively). (2) 21 films with the density ranging from 0.27 to 2.71 were digitized by a scanner and displayed on the CRT. The brightness of CRT that varied with film density was measured by a bright meter, then the relation chart between CRT brightness and the film density was drawn. (3) Thirteen films on which there were many small and low contrast signals were viewed on CRT by three doctors. The tested data were calculated by statistics (? 2 test, the difference was significantly marked when P 0.05), but the signals viewed in the lung were 87 and 29, and the difference was significantly marked (? 2=53.73, P

The scheme and implementing of workstation configuration for medical imaging information system / 中华放射学杂志

Objective To discuss the scheme and implementing for workstation configuration of medical imaging information system which would be adapted to the practice situation of China. Methods The workstations were logically divided into PACS workstations and RIS workstations, the former applied to three kinds of diagnostic practice: the small matrix images, large matrix images, and high resolution grayscale display application, and the latter consisted of many different models which depended upon the usage and function process. Results A dual screen configuration for image diagnostic workstation integrated the image viewing and reporting procedure physically, while the small matrix images as CT or MR were operated on 17 in (1 in =2.54 cm) color monitors, the conventional X ray diagnostic procedure was implemented based on 21 in color monitors or portrait format grayscale 2 K by 2.5 K monitors. All other RIS workstations not involved in image process were set up with a common PC configuration. Conclusion The essential principle for designing a workstation scheme of medical imaging information system should satisfy the basic requirements of medical image diagnosis and fit into the available investment situation.