Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Cathode Ray Tube”

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 307 records · Page 17Linked to original sources
PubMed2006

[Comparison of LCD and CRT monitors for detection of pulmonary nodules and interstitial lung diseases on digital chest radiographs by using receiver operating characteristic analysis].

Soft copy reading of digital images has been practiced commonly in the PACS environment. In this study, we compared liquid-crystal display (LCD) and cathode-ray tube (CRT) monitors for detection of pulmonary nodules and interstitial lung diseases on digital chest radiographs by using receiver operating characteristic (ROC) analysis. Digital chest images with a 1000x1000 matrix size and a 8 bit grayscale were displayed on LCD/CRT monitor with 2M pixels in each observer test. Eight and ten radiologists participated in the observer tests for detection of nodules and interstitial diseases, respectively. In each observer test, radiologists marked their confidence levels for diagnosis of pulmonary nodules or interstitial diseases. The detection performance of radiologists was evaluated by ROC analyses. The average Az values (area under the ROC curve) in detecting pulmonary nodules with LCD and CRT monitors were 0.792 and 0.814, respectively. In addition, the average Az values in detecting interstitial diseases with LCD and CRT monitors were 0.951 and 0.953, respectively. There was no statistically significant difference between LCD and CRT for both detection of pulmonary nodules (P=0.522) and interstitial lung diseases (P=0.869). Therefore, we believe that the LCD monitor instead of the CRT monitor can be used for the diagnosis of pulmonary nodules and interstitial lung diseases in digital chest images.

Data Display↗
PubMed2002

[Influence of electromagnetic waves on portable electronic instruments in medicine].

In this work, we considered the effect of electromagnetic compatibility (EMC) on electronic instruments used in medical facilities. We simulated and measured the intensity distribution of the electromagnetic field around portable phones and examined the influence of electromagnetic field on telemeter-type electrocardiograms (ECG) and computer display cathode ray tubes (CRT) when portable phones were brought close to them. Results showed that the waves observed on ECG are affected up to a distance of 55cm (3.55E+03V/m) from the portable phone, and the grid of the computer display is affected up to a distance of 9cm (7.16E+04V/m) in the front and 14cm (2.97E+04V/m) in the back. Therefore, to reduce electromagnetic intensity (EMI) maintaining a distance far enough from the source is effective.

Cell Phone↗
PubMed2005

Comparison of gradation characteristics between three typical medical imaging display devices using psychophysical analysis.

Although there are remarkable differences in maximum luminance in cathode ray tube (CRT) and liquid crystal display (LCD) monitors and film/viewer systems, these differences cannot be recognized in our perception of them. To clarify the reason for this conflict, we analyzed the psychophysical gradient (delta), which is based on the minimum perceptible luminance difference (DeltaL(min)) and can express contrast visually recognized by observers. In this study, we first confirmed the compatibility of the psychophysical analysis to the CRT and the LCD monitors by using their threshold contrasts (C(t)s). Second, we calculated and compared the delta's of the above output devices. The C(t)s values of each device were in good agreement. Moreover, the Moon & Spencer model, which expressed the perceptibility of luminance change, was well suited to the measured C(t)s over the whole luminance range. The psychophysical analysis is therefore available not only for the film/viewer system, but also for the CRT and LCD systems. The difference of physical gradient G of the luminance characteristics curve among the output devices was larger than 20 times, whereas that of d was within 3 times. The display devices listed in the order of decreasing delta were film/viewer>LCD>CRT. These results corresponded to the visual contrast sensation and our clinical experience, which cannot recognize remarkable differences in perception. By using the psychophysical analysis, we clarified the reason for the conflict between the results of physical evaluation and the contrast visually recognized by observers.

Contrast Sensitivity↗
PubMed2005

Measurement of modulation transfer functions for liquid crystal displays by rectangular waveform analysis.

We measured modulation transfer functions (MTFs) of liquid crystal displays (LCDs) by rectangular waveform analysis. This method consists of taking a picture of the bar pattern on the display surface with a digital camera, and analyzing the picture with a personal computer. The displays used are LCDs of 1M (about 1 million pixels), 2M, 3M, and 5M, and a cathode ray tube (CRT) display with a pixel number of 5M. Two kinds of 2M displays were used, an in-plane switching (IPS) system and vertical alignment (VA) system, from which liquid crystal operation mode differs. MTFs increased as pixels increased. For the LCDs, MTFs in the horizontal direction were higher than those in the vertical direction except for the 2M VA system. For the LCD of the 2M VA system, MTF in a horizontal direction was equal to MTF in a vertical direction. For the displays with the same number of pixels (5M), MTF of a LCD was higher than that of a CRT display. MTFs of LCDs are influenced by the pixel form, pixel composition, and the liquid crystal operation mode.

Data Display↗
PubMed1989

Completely computer-focused ultrasound imaging. First clinical imaging results.

Completely computer-focused ultrasound imaging has been achieved using the UHB (ultrasound holographic B) method. This is a synthetic aperture method that combines ultrasonic holography and the conventional B-scan method. A wide-angle ultrasound burst (4 MHz) is transmitted into the object and the reflected echoes are measured as a function of the propagation time, but both the amplitude and phase angle are recorded, giving multiple one-dimensional holograms in a cross-sectional plane. This UHB data is rearranged to obtain one-dimensional wave fields, which represent the wave fronts reflected from each depth. The image is then reconstructed by propagating these wave fields backward to their original positions on the image using Fourier transform, a spectrum shift theorem, and inverse Fourier transform. The whole UHB image is obtained by calculating the intensity lines from these wave fields and by scanning these lines one by on the cathode ray tube (CRT) monitor. Following extensive laboratory testing with single and multielement transducers, special 32- and 64-element linear array transducers were fabricated, as was computer software capable of producing a UHB image in 40 seconds. Tissue imaging tests followed by clinical imaging of 30 patients showed that images obtained with this prototype compared favorably with those obtained by state-of-the-art conventional ultrasound scanners. The potential advantages of the new method are enhanced lateral resolution and the incorporation of phase information in tissue characterization. This would be important in diagnostic and intraoperative, especially neurosurgical, imaging.

Brain↗
PubMed2000

Concentrations and consequent radiation doses of uranium-238, thorium-232 and potassium-40 contained in the front glass of CRTs.

Concentrations of 238U, 232Th, and 40K contained in the front glass of CRTs (cathode ray tube) of three television sets are measured by gamma-ray spectrometry on the assumption of radioactive equilibrium in uranium and thorium series. The concentrations of 238U and 232Th are also measured by neutron activation analysis. The obtained results by the two different methods agree well within experimental uncertainty, showing that the radioactive equilibrium is found to be established in the present samples, and that the concentrations of 238U and 232Th in the glass can be measured by the gamma-ray spectrometry as well as by the neutron activation analysis. We also found that although the obtained concentrations of 238U (6.5-13.5 ppm in weight) and 232Th (8.4-15.1 ppm) vary considerably between these three kinds of CRTs, those of 40K (average: 7.45 +/- 0.05 ppm) are almost equal for all samples. Moreover, the radiation dose rates are estimated for gamma-rays from the CRT. At distances larger than 30 cm from the surface of the front glass, even the dose rate (5.65 x 10(-3) microSv/h) for the CRT containing the highest concentration of 238U and 232Th is smaller than one-tenth of that (7 x 10(-2) microSv/h) for background radiation, and that is practically negligible.

Background Radiation↗
PubMed2005

A very low level of magnetic field exposure does not affect a participant's mental fatigue and stress as much as VDT work.

Exposure to Magnetic Fields (MF) may affect the health of workers in an occupational environment. However, there is no clear evidence that the emission of MF from the visual display terminals (VDT) affects workers'mental status or induces stress in office environments. The purpose of our study was to investigate whether exposure to the MF during VDT work affects mental fatigue or induces stress related to psycho-physiological changes in workers. Thirty-seven students were voluntarily recruited to participate in this study. We created experimental conditions that a pair of the liquid crystal display (LCD) terminals separated by screens was closely placed in front of the visual suface of the cathode ray tube (CRT) units. All participants were not able to recognize whether the power of the CRT Units was ON or OFF while they worked with the LCD terminals. When the CRT unit was ON, participants who worked with the LCD terminal were called CRT-ON group. On the other hand, when the CRT unit was OFF, participants who worked with the CLD terminal were called CRT-OFF group. Incredibly short profiles of mood states (ISP)and subjective symptom questionnaires were used as indices of the mental fatigue as well as psychological stress before and after VDT work. Furthermore, salivary chromogranin A and urinary 8-hydroxydeoxyguanosine (8-OH-dG) were collected to measure physiological changes before and after VDT work. The results of the questionnaires and salivary and urinary stress markers showed that the exposure to the MF during VDT work did not significantly induce mental fatigue or psychological stress in comparison with the CRT-OFF group. Contrary to the results from the exposure, mood states of vigor decreased greatly (P < 0.05) whereas the states of fatigue and confusion increased significantly (P < 0.001) after VDT work. In the questionnaires for subjective symptoms, participants complained remarkably regarding 14 out of 25 conditions after VDT work. Moreover, urinary 8-OH-dG excretion increased significantly after VDT work. Taken together, the results of this study did not detect any bad health effects of MF exposure on the VDT participants but suggested that VDT work itself affects their mental fatigue and psycho-physiological status.

8-Hydroxy-2'-Deoxyguanosine↗
PubMed1992

The management of medical records.

An optical disk filing system is an efficient approach to storing medical records; however, this system has not yet been put to practical use because it is usually a "stand-alone" type indirectly connected to a hospital information system. We have developed a medical record management system with an optical disk filing system connected to the host computer in the hospital information system. We can retrieve and display the medical records through the CRT (Cathode Ray Tube) terminals of the hospital information system at every ward and outpatient clinic. The patient's clinical information can be sent to several areas in the hospital using the hospital information system.

Computer Communication Networks↗
PubMed2000

[A study of the difficulty of identifying normal intrathoracic structures on CRT images: a search for the optimal luminescence ratio].

This study was concerned with 2 issues: whether there are any normal intrathoracic anatomical structures that are relatively more difficult to identify on CRT (cathode-ray tube) monitor images, and if so, what their features are. Four physicians examined 7 intrathoracic anatomical structures on 50 chest roentgenograms that were displayed on CRT monitors and as conventional X-ray films on a light box. They categorized the visibility of each structure into 5 grades. The 7 structures were the spinal process behind the trachea, right margin of trachea, right main bronchus, left main bronchus, vascular shadow behind right diaphragm, vascular shadow behind cardiac shadow, and right margin of descending aorta. Luminescence ratios were calculated as the ratio of the density of a given viewpoint relative to adjacent areas on the images. We also examined the correlations between luminescence ratio and degree of difficulty in interpreting CRT images at a variety of selected luminescence ratios. Although the spinal process and trachea were easy to identify on CRT images as well as conventional films, other structures were difficult to recognize on CRT images. The luminescence ratio of each structure was higher on conventional film, and relatively low for those structures that were difficult to identify on CRT images. Each structure became gradually easier to identify with increasing luminescence ratios, up to a value of 1.07 maximum. However, this improvement in visibility leveled off beyond 1.07. We concluded that the luminescence ratio should be maintained at more than 1.07 to facilitate optimal identification of overlapping anatomical structures on CRT images.

Aorta, Thoracic↗
PubMed1975

Dynamic study of exocrine function of the pancreas in diabetes mellitus with scintigraphy using 75Se-selenomethionine.

A dynamic study of scintigraphy of the pancreas using 75Se-selenomethionine in diabetic patients was performed. Patients were selected who complained of abdominal pain or diarrhea or both and whose pancreatic exocrine functions were thought to be disturbed. Selenium-75-selenomethionine (3 muCi/kg body weight) was injected intravenously and radioactivity (cpm) was recorded by a scinticamera for 10 min successively up to 120 min. After 20-30 min the increase of radioactivity in the selected area of the displayed pancreas usually reached a plateau. Pancreozymin (1 Harper unit/kg) and secretin (1 harper unit/kg) were administered intravenously and decrease of radioactivity in the same area was followed for 60 min to examine pancreatic exocrine function. After 75Se-selenomethionine injection, the angle of the initial increase of radioactivity, the height of the plateau, and the reactive decrease of radioactivity after pancreozymin and secretin were analyzed in each case. Radioactivity recorded on data tape was reproduced for each 10-min period on a cathode-ray tube display. Areas of interest were selected for dynamic analyses. To supplement the diagnosis by visual image of a scintigram of the pancreas, the scintigram was quantified in the present study and the dynamic curves of radioactivity in the selected area of the displayed pancreas were studied for a total of 3 hr. Application of the dynamic study of the pancreas scintigraphy and the additional data analyses seemed useful for the early detection of pancreatic exocrine dysfunction in diabetic patients in whom the ordinary laboratory pancreatic exocrine function tests gave uncertain results.

Adult↗
PubMedDate not supplied

Automated system for measurement of mechanics of breathing.

We describe a complete automated system for measurement of total respiratory resistance and compliance, and of pulmonary resistance and compliance in humans and anesthetized animals. The device for testing the chest-lung system consists of a sinusoidal pump with a stroke adjustable from 20 ml to 600 ml over a cycling frequency of 0.3 to 30 Hz. Pressure and flow or volume are inputted into an analog network for wave shaping, then to an arithmetic unit composed of sample-and-hold amplifiers, peak, minimum and zero detecting circuits, an analog division circuit, and a digital logic processor. The computer takes the peak-to-peak amplitude of one of two sinusoidal inputs at 0.3 to 10 Hz and the corresponding amplitude of the other input in the presence of a.c. noise and d.c. shifts, divides one into the other, and displays an answer on a digital voltmeter. In addition, the analog output is displayed on the cathode-ray tube of a storage oscilloscope. Plots of total resistance and pulmonary resistance are recorded as a function of lung volume in both humans inspiring voluntarily as well as anesthetized dogs inflated by positive pressure from the test apparatus. Total and pulmonary dynamic compliance, as a function of breathing frequency, can only be measured by the computer if a symmetrical waveform is presented to it. This cannot be achieved in spontaneously breathing subjects but is accomplished in apneic animals by producing sinusoidal oscillations from the test apparatus. Our on-line method for measurement of total respiratory resistance is now used in the Clinical Pulmonary Laboratory for experimental work, and we are in the process of obtaining values in normal subjects.

Adult↗
PubMed2001

Detection of interproximal caries using methods applicable to a field environment: digital radiography, manually processed film, and self-developing film.

The purpose of this study was to determine if the alternatives to conventional dental radiography are diagnostically equivalent to conventional film in a field setting. These alternatives, digital radiography and self-developing film, could significantly decrease the weight and cubic size of a field X-ray set. Five radiographic methods were evaluated: self-developing film, manually processed film, film developed in an automatic processor, digital images on a liquid crystal diode, and digital images on a cathode ray tube screen. The results indicate that the liquid crystal diode system adversely affected the ability of the dentist to detect small interproximal lesions. The other methods were statistically equivalent. A recommendation for an "image acquisition" system to be included in a field dental treatment facility should be based on clinical factors as well as nonclinical factors such as cost, reliability, and logistical support requirements.

Analysis of Variance↗
PubMed2001

[Evaluation of diagnostic accuracy of CRT monitor display for personal computer in the detection of small lung nodules: with particular emphasis on comparison between JPEG and wavelet compression].

PURPOSE: To compare observer performance on cathode-ray-tube(CRT) monitors for personal computers with that on conventional radiographs in the detection of small lung nodules. MATERIALS AND METHODS: Fifty-eight normal chest radiographs and 58 chest radiographs with a small lung nodule were selected. Ten radiologists examined the original conventional films on a viewbox and digitized (8 bit) uncompressed and compressed images of the same patient on a color CRT monitor with a matrix of 1,600 x 1,200, and rated the presence of lung nodules with a five-level scale of confidence. The methods of compression used in this study were the JPEG and wavelet methods, with compression ratios of 6:1 and 15:1. Results were analyzed by receiver operating characteristic methods. RESULTS: There was no significant difference between film and digitized uncompressed and compressed images obtained by the JPEG and wavelet methods with a compression ratio of 6:1. No statistically significant difference was detected between film and digitized image with wavelet compression at 15:1. However, detection was less accurate on digitized images with JPEG compression at 15:1. CONCLUSION: Digitized (8 bit) uncompressed and compressed images with a compression ratio of 6:1 are acceptable for the detection of small lung nodules. Digitized compressed images at a compression ratio of 15:1 are also acceptable when the wavelet method is used.

Data Display↗
PubMed1975

Computer-assisted cataloging: experiences at the UCLA Biomedical Library.

The computer-assisted procedures developed in the UCLA Biomedical Library Cataloging Division have been in effect for approximately three years. The system utilizes a Delta Data System cathode ray tube terminal and cassette attachment for on or off-line input of data. Products of the system include catalog card sets arranged in filing order, a monthly Recent Acquisitions List, and computer-generated book catalogs. Planning, personnel, and equipment requirements are discussed, and preliminary cost figures for various parts of the system are given. Potential applications of the automated system on a regional level and in terms of the library's future automation plans are considered.

California↗
PubMed1975

Choice reaction time to visual motion during prolonged rotary motion in airline pilots.

Thirteen airline pilots were studied to determine the effect of preceding rotary accelerations on the choice reaction time to the horizontal acceleration of a vertical line on a cathode-ray tube. On each trial, one of three levels of ratary and visual acceleration was presented with the ratary stimulus preceding the visual by one of seven periods. The two accelerations were always equal and were presented in the same or opposite directions. The reaction time was found to increase with increases in the time the rotary acceleration preceded the visual acceleration, and to decrease with increased levels of visual and rotary acceleration. The reaction time was found to be shorter when the accelerations were in the same direction than when they were in opposite directions. These results suggest that these findings are a special case of general effect that the authors have termed "gyrovisual modulation."

Acceleration↗
PubMedDate not supplied

The virtual retinal display as a low-vision computer interface: a pilot study.

This pilot study examined the performance of an alternative computer visual interface, the Virtual Retinal Display (VRD), for low-vision use. The VRD scans laser light directly onto the retina, creating a virtual image. Since visually impaired individuals can have difficulty using computer displays, a matched comparison study was done between the VRD and the standard cathode ray tube (CRT) monitor. Reading speed and acuity tests were collected from 13 low-vision volunteers selected to represent the broad range of partially sighted individuals actively involved in the work force. Forty-six percent of subjects had highest visual acuity while viewing the VRD; 30% of subjects had highest acuity viewing the CRT; and 24% of subjects had equal acuity across the two displays. Although mean reading speed across all 13 subjects indicated no significant difference between displays, individual subjects with predominantly optical causes of low vision exhibited clinically important increases in reading speed versus the CRT. However, most subjects with predominantly retinal damage showed a slight disadvantage using the VRD. We give theoretical explanation to the bifurcated results and conclude that for a subset of low-vision users, the VRD technology is very promising as a basis for future low-vision aids.

Adult↗
PubMed2001

[Characteristics of hyperacuity sensitivity in normal and cyclovertical deviated subjects].

PURPOSE: To compare the sensitivity of hyperacuity of cyclovertical deviated patients with that of normal subjects. SUBJECTS AND METHODS: The sensitivity of hyperacuity was measured in 42 normal and 12 cyclovertical deviated patients, using a newly developed computerized device which randomly presents two targets opposed vertically or horizontally on a cathode ray tube(CRT) display. RESULTS: In normal subjects, lower thresholds were obtained when the targets were aligned either vertically or horizontally. These highly sensitive ranges were defined as "the neutral zone of hyperacuity". An anisotropy of the sensitivity of hyperacuity was observed. i.e., better thresholds were obtained when the offset was set away from the neutral zone, whereas worse thresholds were obtained when the offset as close to the neutral zones. In cyclovertical deviated patients, the thresholds of hyperacuity were high around the neutral zones, which may indicate dysfunction of the central nervous system. CONCLUSION: This analytical method may be useful to investigate the pathophysiology of the patients with cyclovertical deviations.

Adolescent↗
PubMed2001

Economic analysis of a filmless system based on the hospital information system.

A filmless system (FLS) based on a picture archiving and communication system (PACS) equipped with UNIX work- stations and a local area network (LAN) specialized for viewing radiographs has not been deemed acceptable, for reasons of economics. However, personal computers (PCs) have recently become more powerful, to the point where PCs approach UNIX workstations in terms of capabilities. As a result, a PC-based image viewing workstation (IVW) has sufficient functions for practical use. Diagnostic resolution is not equal to that of film, but is comparable. Since the hospital information system (HIS) includes many PC terminals connected by a LAN, the cost problem can be resolved by using these PC terminals as the IVWs. In order to investigate the practicability of this idea, two types of FLSs using HIS facilities were designed: one is a system based on the use of high-resolution cathode ray tubes (H-CRTs), and the other is based on the use of conventional CRTs and radiologist reports, minimizing the number of H-CRTs. The total costs of the two systems were analyzed. As a result, the former FLS was found to be about 15% more expensive than the latter, which was less expensive than a film-based system (FBS). However, whether the FLS is more profitable than the FBS from the viewpoint of hospital management strongly depends on the medical insurance system.

Costs and Cost Analysis↗