Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “CATHODE RAYS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 55 records · Page 3Linked to original sources
PubMed1990

Performance tests and quality control of cathode ray tube displays.

Spatial resolution, noise, characteristic curve, and absolute luminance are the essential parameters that describe physical image quality of a display. This paper presents simple procedures for assessing the performance of a cathode ray tube (CRT) in terms of these parameters as well as easy set up techniques. The procedures can be used in the environment where the CRT is used. The procedures are based on a digital representation of the Society of Motion Pictures and Television Engineers pattern plus a few simple other digital patterns. Additionally, measurement techniques are discussed for estimating brightness uniformity, veiling glare, and distortion. Apart from the absolute luminance, all performance features can be assessed with an uncalibrated photodetector and the eyes of a human observer. The measurement techniques especially enable the user to perform comparisons of different display systems.

Data Display↗
PubMed2003

Diagnostic performance of liquid crystal and cathode-ray-tube monitors in brain computed tomography.

The aim of this study was to evaluate feasibility of reporting brain CT examinations on liquid crystal display (LCD) flat-screen monitors vs state-of-the-art cathode-ray-tube (CRT) monitors. Ninety-five brain CT examinations of 95 patients were displayed on Picture archiving and communications system (PACS) workstations equipped either with a dedicated medical imaging LCD colour monitor or on a high-resolution CRT which is used for routine reporting of CT, MRI and digital radiography images in our institution. Fifty cases were negative and 45 cases were positive for early brain infarction (EBI), the latter being defined by a combination of one or more signs: dense artery; hypodensity of brain parenchyma; and local brain swelling verified by control scans. Ten radiologists had to rate presence or absence of EBI on a five-point scale. Ratings were evaluated by CORROC2 ROC software and areas under the ROC curve (A(z)) were computed. Significance of differences between the two viewing conditions were evaluated with Wilcoxon test. Mean A(z) of the ten observers was 0.7901 with LCD vs 0.7695 with CRT which did not show statistical significance (p=0.2030). In the setting investigated, reporting of CT studies from high-performance LCD monitors seems feasible without significant detriment to diagnostic performance.

Acute Disease↗
PubMedDate not supplied

Cathode ray tube quality control and acceptance testing program: initial results for clinical PACS displays.

The use of picture archiving and communication systems (PACS) and primary soft-copy interpretation in radiology is growing rapidly. The authors present a cathode ray tube (CRT) acceptance test and quality control (QC) program developed over a 5-year period on the basis of experience with multiple PACS and CRT vendors. The CRT QC procedures address monitor cleanliness and setup, qualitative image quality, and quantitative luminance and color measurements. Required materials include a photometer with luminance and color probes and 100%-video, flat-field window and test images from the Society of Motion Picture Test Engineers (SMPTE). Luminance was found to change over time for all gray-scale CRTs examined, which necessitated quarterly recalibration. The phosphor color of these monitors was also found to change, but changes were consistent and slow enough to warrant only annual measurements. Color measurements were found to be especially useful at initial setup and for CRT replacement. Use of this program allowed standardization of absolute luminance of individual CRTs, matching of phosphor color for multimonitor workstations, and systematic tracking of image artifacts. Implementation of a QC program is strongly recommended owing to the dynamic nature of CRT displays.

Color↗
PubMed1990

Dermatological symptoms among visual display unit operators using plasma display and cathode ray tube screens.

A questionnaire survey was conducted to determine the prevalence of dermatological complaints in 672 full time visual display unit (VDU) operators in Singapore. Two hundred and sixty-nine operators worked with plasma display (PD) screens, while the other 403 used cathode ray tube (CRT) monitors. The overall one year period prevalence rate for dermatological complaints was 12%. Thirty-six (13%) PD operators and 46 (11%) CRT operators had skin complaints. The age and sex distribution of persons in the two groups were similar. Twenty-eight (10.4%) PD workers and 24 (6.0%) CRT workers had symptoms of itch, tingling, or the feeling of being stroked by a feather after working with the VDU for some time. Furthermore, 19 (7.1%) PD and 14 (3.5%) CRT workers stated that their skin problems improved during weekends or when they were off duty. The difference between these rates were not statistically significant. Operators with dermatological complaints in the past year were more likely to have a personal history of atopy, complain about their work environment, and have musculoskeletal symptoms of the shoulder and low back. The results indicate that the prevalence and nature of dermatological symptoms among operators using either type of VDU monitor are similar.

Adult↗
PubMed2000

Temporal variation in the luminance level of stimuli displayed on a cathode-ray tube monitor: effects on performance on a visual vigilance task.

This paper assesses the extent to which the sensitivity decrement frequently observed in vigilance tasks is affected by temporal variations in the luminance level of the stimuli displayed on the screen of a cathode-ray tube (CRT) monitor. First, it was confirmed that the luminance of the stimuli displayed on the screen of the CRT monitor decreases substantially during the first hour after turning the monitor on, and then it remains quite stable. Second, an experiment was carried out in which participants performed a visual vigilance task at three different time periods within which the luminance of the stimuli displayed on the screen of a CRT monitor either decreased or remained stable. The results indicate that the vigilance decrement is modulated by temporal fluctuations of the luminance of the monitor screen, which is used to display the stimuli. However, the relationship between both variables is not simple: the largest sensitivity decrement was not associated with the largest luminance decrement, but to a medium luminance decrement.

Adult↗
PubMed1973

Developing a graphic set for cathode ray tube display using a 7 x 9 dot pattern.

A symbol set for the 96 graphic characters of the USA Standard Code for Information Exchange is presented in a 7 x 9 dot matrix. The symbols are the result of studies to optimize the legibility and readability of cathode ray tube displays. The symbols are initially presented using a pattern of dots in a 7 wide by 12 high matrix. The lower three rows of the matrix accommodate the 12 characters which have descenders. These characters, however, are redrawn so that they, as well as the other ASCII graphics, fit within a 7 x 9 matrix.

Journal Article↗
PubMed2005

Basal cell carcinoma and World War II-era cathode ray oscilloscope exposure.

BACKGROUND: There is a high prevalence of skin cancer in World War II servicemen stationed in the Pacific theater as a result of various risk factors such as exposure to ultraviolet radiation and genetic predisposition. OBJECTIVE: We sought to describe whether a possible association exists between basal cell carcinoma (BCC) development and the use of high-voltage cathode ray tube (CRT) oscilloscopes manufactured around 1940 to 1955, which were a source of X-radiation. METHODS: We present a case series of 9 men aged 65 to 93 years who presented with similar head and neck distributions of BCC and a history of extensive use of early CRT oscilloscopes during and shortly after the World War II era. The patients were interviewed and their medical records reviewed to determine CRT exposure times and BCC location, subtype, and treatment. Representative BCC histologic sections were reviewed. RESULTS: A total of 230 BCCs of the head and neck region were identified and mapped. Questionnaires determined a minimum exposure of 600 (range, 624-9600) hours within a 60-cm distance of early CRT screens in all patients. The average number of aggressive histologic subtypes was 23.5%. The average number of Mohs micrographic surgery layers required to obtain negative margins was 1.99 compared with 1.63 in the control group treated by the same Mohs micrographic surgeon (P < .002). CONCLUSION: This descriptive study is the first to suggest that ionizing radiation from early CRT oscilloscopes may be a factor in the development of multiple BCCs of the head and neck with increased subclinical spread.

Aged↗
PubMed2001

A study of the effect of color photostimulation from a cathode-ray tube (CRT) display on photosensitive patients: the effect of alternating red-cyan flicker stimulation.

PURPOSE: In an attempt to establish evidence for developing better guidelines for the production of animation programs that would not induce photosensitive seizures in Japan, we evaluated the effects of red flicker, alternating red/cyan (complementary color to red) flicker stimuli, and of contrast between the red and cyan frames from a cathode-ray tube (CRT) display in photosensitive patients. METHODS: We studied 35 photosensitive patients. They were exposed to seven types of flicker. The first three types were alternating red/cyan flicker (R/C) with the luminance of cyan set at three different levels, high, equal, and low luminance (65, 20, and 16 cd/m2, respectively) relative to the red (20 cd/m2). The following four types were red, cyan, yellow, and magenta flicker stimuli. EEGs were recorded while the patients watched these stimuli on a CRT display. RESULTS: Rates of photoparoxysmal response (PPR) provocation were 11.4, 13.7, and 14.0% with high-, no- and low-contrast R/C flicker, respectively, and 3.7% with red flicker. The differences between red and each of the other R/C flicker stimuli were all statistically significant (p<0.05, 0.01, 0.01). No significant differences were found between the effects by each of the three levels of contrast in alternating R/C flicker (p > 0.05). CONCLUSIONS: These findings suggest that alternating R/C flicker is more provocative than simple red flicker, and that contrast between frames of different colors may play some role in the effects of alternating flicker stimuli from a CRT display in photosensitive patients. Therefore, caution against the use of the combination of red and cyan, in addition to the red flicker stimulus, should be included in any guidelines drawn up to prevent photosensitive seizures.

Adolescent↗