WorldWideScience
 
 
1

ATSU Point Design (gasdynamics)  

Energy Technology Data Exchange (ETDEWEB)

In this presentation the basic principles outlined in the first talk ''Gas Cell Neutralizers'' will be applied to a problem of particular interest viz., the design of a ''gasdynamic free-jet'' neutralizer for the Los Alamos ATSU project. What will be presented here does not in any way represent the final gas neutralizer design for ATSU. Rather, the material presented herein should be viewed as simply a preliminary design intended to identify and gain insight into the more subtle issues that must be considered in designing this type of gas neutralizer.

Fuehrer, B.

1985-06-01

2

34-meter VAWT point design.  

Science.gov (United States)

The Wind Energy Division at Sandia National Laboratories recently completed a point design based on the 34-m Vertical Axis Wind Turbine (VAWT) Test Bed. The 34-m Test Bed research machine incorporates several innovations that improve Darrieus technology, ...

D. E. Berg H. J. Sutherland H. M. Dodd M. A. Rumsey T. D. Ashwill

1991-01-01

3

EBTR Design-Point Selection.  

Science.gov (United States)

The procedure used to select the design point for the ELMO Bumpy Torus Reactor (EBTR) study is described. The models used in each phase of the selection process are described, with an emphasis placed on the parametric design curves produced by each model....

R. A. Krakowski C. G. Bathke

1981-01-01

4

Turning points in reactor design  

Energy Technology Data Exchange (ETDEWEB)

This article provides some historical aspects on nuclear reactor design, beginning with PWR development for Naval Propulsion and the first commercial application at Yankee Rowe. Five turning points in reactor design and some safety problems associated with them are reviewed: (1) stability of Dresden-1, (2) ECCS, (3) PRA, (4) TMI-2, and (5) advanced passive LWR designs. While the emphasis is on the thermal-hydraulic aspects, the discussion is also about reactor systems.

Beckjord, E.S.

1995-09-01

5

EBTR design-point selection  

Energy Technology Data Exchange (ETDEWEB)

The procedure used to select the design point for the ELMO Bumpy Torus Reactor (EBTR) study is described. The models used in each phase of the selection process are described, with an emphasis placed on the parametric design curves produced by each model. The tradeoffs related to burn physics, stability/equilibrium, electron-ring physics, and magnetics design are discussed. The resulting design point indicates a plasma with a 35-m major radius and a 1-m minor radium operating at an average core-plasma beta of 0.17, which at approx. 30 keV produces an average neutron wall loading of 1.4 MW/m/sup 2/ while maintaining key magnet (< 10 T) and total power (less than or equal to 4000 MWt) constraints.

Krakowski, R.A.; Bathke, C.G.

1981-01-01

6

EBTR design-point selection  

International Nuclear Information System (INIS)

The procedure used to select the design point for the ELMO Bumpy Torus Reactor (EBTR) study is described. The models used in each phase of the selection process are described, with an emphasis placed on the parametric design curves produced by each model. The tradeoffs related to burn physics, stability/equilibrium, electron-ring physics, and magnetics design are discussed. The resulting design point indicates a plasma with a 35-m major radius and a 1-m minor radium operating at an average core-plasma beta of 0.17, which at approx. 30 keV produces an average neutron wall loading of 1.4 MW/m2 while maintaining key magnet (

1981-10-29

7

Design of Eye Movement Interactive Interface and Example Development  

Directory of Open Access Journals (Sweden)

Full Text Available With the unceasing development of HCI (Human Computer Interaction) technology, natural interactive products are valued by more and more people. The next generation of man-machine interface may use touch, hearing or vision, etc. Among them, the visual sense is the most important channel to get information, but researches are mostly focused on the measurement of eye movement or data processing. In the future, the interaction of eyes with machines will have a very wide prospect. After concluding the pluses and minuses of available eye control systems, we puts forth the design principle, system concept and the state transition model of eyes interaction from the consideration of user-centered design principle. The system simplifies the measurement process, focuses on the fast tracking, calibration and accurate eye movement identification. At the same time, we use context information to reduce interaction time and combines with keys to eliminate eye movements’ ambiguity. Based on the design scheme, we develop a system-EyeHUD(Eye Head Up Diaplay) which can be applied in driving. It includes an eye preset interface, an eye control interface and a virtual vehicle scene. Before starting cars, a driver uses the eye tracker to track and calibrate eyes, then chooses an interactive function, like one blink zoom in or two blink chick. When the eye control interface is opened, the driver can use auto eye control to operate it, or choose eyes+keys way to simulate a click. The evaluation results shows: EyeHUD can successfully achieve all the default function and participants don’t need long time to understand the information provided by the interface. Compared with the eyes+keys way, the auto eye control has no obvious difference in recognition success rate.

Fang Zhi-Gang; Kong Xiang-Zong; Xu Jie

2013-01-01

8

Eye tracking, point of gaze, and performance degradation during disorientation.  

UK PubMed Central (United Kingdom)

BACKGROUND: The cognitive cockpit concept has been proposed as a potential disorientation countermeasure. It involves monitoring the pilot's physiological, behavioral and subjective responses during disorientation. This data is combined to provide a real time model of pilot state, which is used as a basis for optimizing pilot performance. This study attempts to investigate whether there are consistent behavioral or physiological "markers" that can be monitored during a specific disorientation scenario. METHODS: An Integrated Physiological Trainer with interactive aircraft controls and an eye-tracking device was employed. Fourteen subjects proficient in maintaining straight-and-level flight and who have acquired the skills in changing attitude participated in the study. They were exposed to a flight profile consisting of straight-and-level flying and change in attitude without exposure to a head roll (control condition) and a profile with exposure to a head roll (experimental conditions) during constant yaw rotation. Flight performance parameters and subjects' eye movements and point of gaze behavior were monitored continuously. RESULTS: Immediately on the return to upright head position, all subjects reported a strong apparent pitch displacement that lasted < or = 20 s and a lesser sensation of lateral movement. Significant differences (p < 0.01) were noted on a number of scanning behaviors between the control and the experimental conditions. The appearance of nystagmus was apparent as indicated by the number of involuntary saccades during disorientation. Flight performance decrement in the experimental conditions was reflected by a significant deviation in maintaining airspeed (p < 0.01). CONCLUSION: It appears that the pitch illusion consistently affects visual scanning behavior and is responsible for the decrement in flight performance observed in the simulator.

Cheung B; Hofer K

2003-01-01

9

Two Eyes, 3D: Stereoscopic Design Principles  

Science.gov (United States)

Two Eyes, 3D is a NSF-funded research project about how people perceive highly spatial objects when shown with 2D or stereoscopic ("3D") representations. As part of the project, we produced a short film about SN 2011fe. The high definition film has been rendered in both 2D and stereoscopic formats. It was developed according to a set of stereoscopic design principles we derived from the literature and past experience producing and studying stereoscopic films. Study participants take a pre- and post-test that involves a spatial cognition assessment and scientific knowledge questions about Type-1a supernovae. For the evaluation, participants use iPads in order to record spatial manipulation of the device and look for elements of embodied cognition. We will present early results and also describe the stereoscopic design principles and the rationale behind them. All of our content and software is available under open source licenses. More information is at www.twoeyes3d.org.

Price, Aaron; Subbarao, M.; Wyatt, R.

2013-01-01

10

Eye-GUIDE (Eye-Gaze User Interface Design) Messaging for Physically-Impaired People  

Directory of Open Access Journals (Sweden)

Full Text Available Eye-GUIDE is an assistive communication tool designed for the paralyzed or physically impaired people who were unable to move parts of their bodies especially people whose communications are limited only to eye movements. The prototype consists of a camera and a computer. Camera captures images then it will be send to the computer, where the computer will be the one to interpret the data. Thus, Eye-GUIDE focuses on camera-based gaze tracking. The proponent designed the prototype to perform simple tasks and provides graphical user interface in order the paralyzed or physically impaired person can easily use it.

Rommel Anacan; James Greggory Alcayde; Retchel Antegra; Leah Luna

2013-01-01

11

Heavy ion fusion (HIF) driver point designs  

International Nuclear Information System (INIS)

[en] In this paper we report on two Heavy Ion Fusion (HIF) driver point design studies. The Robust Point Design (Rd) was completed over a year ago, and the Modular Point Design (MPD) is still in progress. The goal of any point design study is to construct a detailed design that is self-consistent and integrated from injector to target. This has been the primary theme of both studies

2005-05-21

12

Heavy ion fusion (HIF) driver point designs  

Science.gov (United States)

In this paper we report on two Heavy Ion Fusion (HIF) driver point design studies. The Robust Point Design (RPD) was completed over a year ago, and the Modular Point Design (MPD) is still in progress. The goal of any point design study is to construct a detailed design that is self-consistent and integrated from injector to target. This has been the primary theme of both studies.

Yu, S. S.; Abbott, R. P.; Bangerter, R. O.; Barnard, J. J.; Briggs, R. J.; Callahan, D.; Celata, C. M.; Davidson, R.; Debonnel, C. S.; Eylon, S.; Faltens, A.; Friedman, A.; Grote, D. P.; Heitzenroeder, P.; Henestroza, E.; Kaganovich, I.; Kwan, J. W.; Latkowski, J. F.; Lee, E. P.; Logan, B. G.; Peterson, P. F.; Rose, D.; Roy, P. K.; Sabbi, G.-L.; Seidl, P. A.; Sharp, W. M.; Welch, D. R.

2005-05-01

13

Beginning SharePoint Designer 2010  

CERN Multimedia

Teaching Web designers, developers, and IT professionals how to use the new version of SharePoint Designer. Covering both the design and business applications of SharePoint Designer, this complete Wrox guide brings readers thoroughly up to speed on how to use SharePoint Designer in an enterprise. You'll learn to create and modify web pages, use CSS editing tools to modify themes, use Data View to create interactivity with SharePoint and other data, and much more. Coverage includes integration points with Visual Studio, Visio, and InfoPath.: Shows web designers, developers, and IT professionals

Windischman, Woodrow W; Rehmani, Asif

2010-01-01

14

Dynamical Systems in Circuit Designer's Eyes  

Energy Technology Data Exchange (ETDEWEB)

Examples of nonlinear circuit design are given. Focus of the design process is on theory and engineering methods (as opposed to numerical analysis). Modeling is related to measurements It is seen that the phase plane is still very useful with proper models Harmonic balance/describing function offers powerful insight (via the combination of simulation with circuit and ODE theory). Measurement and simulation capabilities increased, especially harmonics measurements (since sinusoids are easy to generate)

Odyniec, M.

2011-05-09

15

Digital cameras with designs inspired by the arthropod eye.  

UK PubMed Central (United Kingdom)

In arthropods, evolution has created a remarkably sophisticated class of imaging systems, with a wide-angle field of view, low aberrations, high acuity to motion and an infinite depth of field. A challenge in building digital cameras with the hemispherical, compound apposition layouts of arthropod eyes is that essential design requirements cannot be met with existing planar sensor technologies or conventional optics. Here we present materials, mechanics and integration schemes that afford scalable pathways to working, arthropod-inspired cameras with nearly full hemispherical shapes (about 160 degrees). Their surfaces are densely populated by imaging elements (artificial ommatidia), which are comparable in number (180) to those of the eyes of fire ants (Solenopsis fugax) and bark beetles (Hylastes nigrinus). The devices combine elastomeric compound optical elements with deformable arrays of thin silicon photodetectors into integrated sheets that can be elastically transformed from the planar geometries in which they are fabricated to hemispherical shapes for integration into apposition cameras. Our imaging results and quantitative ray-tracing-based simulations illustrate key features of operation. These general strategies seem to be applicable to other compound eye devices, such as those inspired by moths and lacewings (refracting superposition eyes), lobster and shrimp (reflecting superposition eyes), and houseflies (neural superposition eyes).

Song YM; Xie Y; Malyarchuk V; Xiao J; Jung I; Choi KJ; Liu Z; Park H; Lu C; Kim RH; Li R; Crozier KB; Huang Y; Rogers JA

2013-05-01

16

Pursuit Eye-Movements in Curve Driving Differentiate between Future Path and Tangent Point Models.  

UK PubMed Central (United Kingdom)

For nearly 20 years, looking at the tangent point on the road edge has been prominent in models of visual orientation in curve driving. It is the most common interpretation of the commonly observed pattern of car drivers looking through a bend, or at the apex of the curve. Indeed, in the visual science literature, visual orientation towards the inside of a bend has become known as "tangent point orientation". Yet, it remains to be empirically established whether it is the tangent point the drivers are looking at, or whether some other reference point on the road surface, or several reference points, are being targeted in addition to, or instead of, the tangent point. Recently discovered optokinetic pursuit eye-movements during curve driving can provide complementary evidence over and above traditional gaze-position measures. This paper presents the first detailed quantitative analysis of pursuit eye movements elicited by curvilinear optic flow in real driving. The data implicates the far zone beyond the tangent point as an important gaze target area during steady-state cornering. This is in line with the future path steering models, but difficult to reconcile with any pure tangent point steering model. We conclude that the tangent point steering models do not provide a general explanation of eye movement and steering during a curve driving sequence and cannot be considered uncritically as the default interpretation when the gaze position distribution is observed to be situated in the region of the curve apex.

Lappi O; Pekkanen J; Itkonen TH

2013-01-01

17

Innovativeness in design investigated by eye movements and pupillometry  

Directory of Open Access Journals (Sweden)

Full Text Available Innovative designs often break common visual habits by integrating more or less familiar parts into a new concept (Leder & Carbon, 2005). When design innovation is realized in an overly advanced way, the resulting designs tend to be rejected by perceivers at first glance, but seem to be favored when perceivers become more familiar with them (Carbon & Leder, 2005b). In the present study, we investigated the properties of innovative car interior designs by analyzing eye movements and the dilatation of the pupil when evaluating these designs. The analysis of eye movements indicates that innovative designs may be interpreted as more balanced in their conceptual structure. This was shown by an increased number of eye movements directed at the focus areas in car designs. Moreover, pupillometry data demonstrated that innovative designs are cognitively more demanding, thus evoking more interest. Such effects of innovativeness were particularly strong after participants had been exposed to and had elaborately dealt with the material during a phase of familiarization realized by the repeated evaluation technique.

CLAUS-CHRISTIAN CARBON; FLORIAN HUTZLER; MICHAEL MINGE

2006-01-01

18

Design and manufacturing of complex optics: the dragonfly eye optic.  

Energy Technology Data Exchange (ETDEWEB)

The ''Design and Manufacturing of Complex Optics'' LDRD sought to develop new advanced methods for the design and manufacturing of very complex optical systems. The project team developed methods for including manufacturability into optical designs and also researched extensions of manufacturing techniques to meet the challenging needs of aspherical, 3D, multi-level lenslet arrays on non-planar surfaces. In order to confirm the applicability of the developed techniques, the team chose the Dragonfly Eye optic as a testbed. This optic has arrays of aspherical micro-lenslets on both the exterior and the interior of a 4mm diameter hemispherical shell. Manufacturing of the dragonfly eye required new methods of plunge milling aspherical optics and the development of a method to create the milling tools using focused ion beam milling. The team showed the ability to create aspherical concave milling tools which will have great significance to the optical industry. A prototype dragonfly eye exterior was created during the research, and the methods of including manufacturability in the optical design process were shown to be successful as well.

Claudet, Andre A.; Sweatt, William C.; Hodges, V. Carter; Adams, David Price; Gill, David Dennis; Vasile, Michael J.

2006-01-01

19

Asymptotically Optimal Design Points for Rejection Algorithms  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Very fast automatic rejection algorithms were developed recently which allow to generate random variates from large classes of unimodal distributions. They require the choice of several design points which decompose the domain of the distribution into small sub-intervals. The optimal choice of these...

Derflinger, Gerhard; Hörmann, Wolfgang

20

Point prevalence of pseudoexfoliation syndrome in patients scheduled for cataract surgery in eye camps in Yemen  

Directory of Open Access Journals (Sweden)

Full Text Available Purpose: To study the point prevalence of pseudoexfoliation syndrome (PXS) among Yemeni patients in different governorates with age-related cataract scheduled for surgery. Settings: Eye camps organized by the Nibras Health Society to perform cataract surgeries during the years 2002-2006. All patients aged 40 years and above were included in the study. Materials and Methods: A total of 2535 eyes of 2535 patients from 13 governorates, scheduled for cataract surgery in eye camps, were included. All eyes underwent complete eye examination before the surgery and were evaluated for the signs of pseudoexfoliation material in the pupil, iris and lens capsule on dilated slit lamp examination. Results: The study found 495 of the 2535 eyes (19.53%) with PXS with males more commonly affected than females (55.2 and 44.8%, respectively). The mean age of patients with PXS was 66.2 years while it was 64.6 years in non-PXS patients. The prevalence of pseudoexfoliation syndrome increased with age (10.1% in the age group of 41-50 years that increased to 28.8% in the age group of more than 81 years old). The rate of PXS detection in camps in 13 governorates ranged from 13.33 to 24.22% with an overall rate of 19.53%. The lowest rate was noticed in Sana?a and the highest in Al-Dhale governorate. Conclusion: This pilot study confirms that PXS was common in patients undergoing cataract surgery in Yemen with an increased detection rate with age. This study also highlights the prevalence of an ocular disease that is associated with systemic and ocular complications; however, further studies based on population studies are needed.

Al-Shaer Mutahar; Bamashmus Mahfouth; Al-Barrag Abdulmoghni

2010-01-01

 
 
 
 
21

A critical evaluation of current views regarding eye movement desensitization and reprocessing (EMDR): clarifying points of confusion.  

UK PubMed Central (United Kingdom)

EMDR is an active psychological treatment for PTSD that has received widely divergent reactions from the scientific and professional community. This article examines points of confusion in the published literature on EMDR, including the theoretical, empirical, and historical issues around EMDR and placebo effects, exposure procedures, the eye movement component, treatment fidelity issues, and outcome studies. It also examines historical information relevant to the scientific process and charges of "pseudoscience" regarding EMDR. We conclude that the confusion in the literature is due to (a) the lack of an empirically validated model capable of convincingly explaining the effects of the EMDR method, (b) inaccurate and selective reporting of research, (c) some poorly designed empirical studies, (d) inadequate treatment fidelity in some outcome research, and (e) multiple biased or inaccurate reviews by a relatively small group of authors. Reading the original research articles frequently helps to reduce the confusion arising from the research review literature.

Perkins BR; Rouanzoin CC

2002-01-01

22

Quiet eye and choking: online control breaks down at the point of performance failure.  

UK PubMed Central (United Kingdom)

PURPOSE: The quiet eye (QE) is a characteristic of highly skilled perceptual and motor performance that has been shown to be sensitive to increases in anxiety. The present study is the first to examine changes in the QE at the precise point of performance failure under heightened anxiety. QE durations were compared for the first, penultimate, and final (missed) putts taken in a pressurized shootout task. To probe the effects of anxiety more specifically, differences in the component of the QE that occurred before (QE-pre), during (QE-online), and after (QE-dwell) putter movement were examined. METHODS: Fifty expert golfers (average handicap of 3.6) performed putts under pressure until they missed ("shootout"). Gaze was recorded throughout with an ASL Mobile Eye Tracker. Total QE, preprogramming QE (the proportion of QE that occurred before backswing; QE-pre), online control QE (the proportion of QE that occurred during the putting stroke; QE-online), and QE-dwell (the proportion of QE that occurred after putter-ball contact; QE-dwell) were calculated for the first, penultimate, and final putts. RESULTS: Total QE duration was significantly shorter for the final (missed) putt compared with the first and penultimate (successful) putts. Although QE-pre duration was similar across the three putts, the components of the QE occurring during (QE-online) and after (QE-dwell) putter movement were significantly shorter on the missed putt. CONCLUSIONS: Performance failure under pressure appears to be due to disruptions in attentional control once movement has been initiated. These findings support the predictions of attentional control theory and suggest that the QE may have an online control function, providing visual sensory information as the movement unfolds.

Vine SJ; Lee D; Moore LJ; Wilson MR

2013-10-01

23

Sensitivity and specificity of a point-of-care matrix metalloproteinase 9 immunoassay for diagnosing inflammation related to dry eye.  

UK PubMed Central (United Kingdom)

OBJECTIVES: To determine the clinical sensitivity, specificity, negative predictive value, and positive predictive value of a rapid point-of-care diagnostic test to detect elevated matrix metalloproteinase 9 levels (InflammaDry). METHODS: In a prospective, sequential, masked, multicenter clinical trial, InflammaDry was performed on 206 patients: 143 patients with clinical signs and symptoms of dysfunctional tear syndrome (dry eyes) and 63 healthy individuals serving as controls. Participants were assessed as healthy controls or for a clinical diagnosis of dry eye using the Ocular Surface Disease Index, Schirmer tear test, tear breakup time, and keratoconjunctival staining. MAIN OUTCOME MEASURES: The sensitivity and specificity of InflammaDry were compared with clinical assessment. RESULTS: InflammaDry showed sensitivity of 85% (in 121 of 143 patients), specificity of 94% (59 of 63), negative predictive value of 73% (59 of 81), and positive predictive value of 97% (121 of 125). CONCLUSION: Compared with clinical assessment, InflammaDry is sensitive and specific in diagnosing dry eye. APPLICATION TO CLINICAL PRACTICE: Dry eye is often underdiagnosed resulting from poor communication between the clinical assessment of dry eye severity between clinicians and patients. This often leads to a lack of effective treatment. Matrix metalloproteinase 9 is an inflammatory biomarker that has been shown to be elevated in the tears of patients with dry eyes. The ability to accurately detect elevated matrix metalloproteinase 9 levels may lead to earlier diagnosis, more appropriate treatment, and better management of ocular surface disease. Preoperative and perioperative management of inflammation related to dry eyes may reduce dry eyes that develop after laser in situ keratomileusis, improve wound healing, and reduce flap complications. Recognition of inflammation may allow for targeted perioperative therapeutic management of care for patients who undergo cataract and refractive surgery and improve outcomes. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01313351.

Sambursky R; Davitt WF 3rd; Latkany R; Tauber S; Starr C; Friedberg M; Dirks MS; McDonald M

2013-01-01

24

Designing theory of point-focusing solar cookers  

Energy Technology Data Exchange (ETDEWEB)

Based upon studies on the process of radiation concentration in point-focusing solar cookers, this paper establishes the fundamental energy transmission equations, forwards a few essential concepts that are needed in design and determines the design concept of the off-set axis. From this basis, radiation intercepting section equations are calculated. Some intrinsic relationships between design parameters are pointed out and practical design methods and formulas necessary for design are advanced. (author).

Gao Yuanchao; Liu Zude; Chen Xiaofu (Chinese Academy of Agricultural Engineering Research and Planning, Beijing (CN))

1989-01-01

25

NIF Ignition Target 3D Point Design  

Energy Technology Data Exchange (ETDEWEB)

We have developed an input file for running 3D NIF hohlraums that is optimized such that it can be run in 1-2 days on parallel computers. We have incorporated increasing levels of automation into the 3D input file: (1) Configuration controlled input files; (2) Common file for 2D and 3D, different types of capsules (symcap, etc.); and (3) Can obtain target dimensions, laser pulse, and diagnostics settings automatically from NIF Campaign Management Tool. Using 3D Hydra calculations to investigate different problems: (1) Intrinsic 3D asymmetry; (2) Tolerance to nonideal 3D effects (e.g. laser power balance, pointing errors); and (3) Synthetic diagnostics.

Jones, O; Marinak, M; Milovich, J; Callahan, D

2008-11-05

26

Study on chromatic aberration in a population of Chinese myopic eyes by means of optical design.  

UK PubMed Central (United Kingdom)

Two kinds of individual eye models, involving and without involving the angle between visual axis and optical axis, are established by means of optical design. We use them to study the properties of the transverse chromatic aberration (TCA) and longitudinal chromatic aberration (LCA) over the visible spectrum. Then the effects of the LCA and TCA on the visual quality of human eyes are evaluated. The statistical averages of TCA and LCA over the visible spectrum for Chinese myopic eyes are obtained. Results show that both TCA and LCA restrict the visual performance, and LCA is more detrimental than TCA.

He Y; Wang Y; Wang Z; Fang C; Liu Y; Zhang L; Zheng S; Wang L; Chang S

2013-05-01

27

An Updated Point Design for Heavy Ion Fusion  

Energy Technology Data Exchange (ETDEWEB)

An updated, self-consistent point design for a heavy ion fusion (HIF) power plant based on an induction linac driver, indirect-drive targets, and a thick liquid wall chamber has been completed. Conservative parameters were selected to allow each design area to meet its functional requirements in a robust manner, and thus this design is referred to as the Robust Point Design (RPD-2002). This paper provides a top-level summary of the major characteristics and design parameters for the target, driver, final focus magnet layout and shielding, chamber, beam propagation to the target, and overall power plant.

Yu, S S; Meier, W R; Abbott, R B; Barnard, J J; Brown, t; Callahan, D A; Heitzenroeder, P; Latkowski, J F; Logan, B G; Pemberton, S J; Peterson, P F; Rose, D V; Sabbi, G -L; Sharp, W M; Welch, D R

2002-12-16

28

An updated point design for heavy ion fusion  

Energy Technology Data Exchange (ETDEWEB)

An updated, self-consistent point design for a heavy ion fusion (HIF) power plant based on an induction linac driver, indirect-drive targets, and a thick liquid wall chamber has been completed. Conservative parameters were selected to allow each design area to meet its functional requirements in a robust manner, and thus this design is referred to as the Robust Point Design (RPD-2002). This paper provides a top-level summary of the major characteristics and design parameters for the target, driver, final focus magnet layout and shielding, chamber, beam propagation to the target, and overall power plant.

Yu, S.S.; Meier, W.R.; Abbott, R.P.; Barnard, J.J.; Brown, T.; Callahan, D.A.; Heitzenroeder, P.; Latkowski, J.F.; Logan, B.G.; Pemberton, S.J.; Peterson, P.F.; Rose, D.V.; Sabbi, G-L.; Sharp, W.M.; Welch, D.R.

2002-11-01

29

An updated point design for heavy ion fusion  

International Nuclear Information System (INIS)

An updated, self-consistent point design for a heavy ion fusion (HIF) power plant based on an induction linac driver, indirect-drive targets, and a thick liquid wall chamber has been completed. Conservative parameters were selected to allow each design area to meet its functional requirements in a robust manner, and thus this design is referred to as the Robust Point Design (RPD-2002). This paper provides a top-level summary of the major characteristics and design parameters for the target, driver, final focus magnet layout and shielding, chamber, beam propagation to the target, and overall power plant

2002-01-01

30

An Updated Point Design for Heavy Ion Fusion  

Energy Technology Data Exchange (ETDEWEB)

An updated, self-consistent point design for a heavy ion fusion (HIF) power plant based on an induction linac driver, indirect-drive targets, and a thick liquid wall chamber has been completed. Conservative parameters were selected to allow each design area to meet its functional requirements in a robust manner, and thus this design is referred to as the Robust Point Design (RPD-2002). This paper provides a top-level summary of the major characteristics and design parameters for the target, driver, final focus magnet layout and shielding, chamber, beam propagation to the target, and overall power plant.

Meier, W R; Yu, S S; Abbott, R P; Barnard, J J; Brown, T; Callahan, D A; Heitzenroeder, P; Latkowski, J F; Logan B G; Pemberton, S J; Peterson, P F; Rose, D V; Sabbi, G-L; Sharp, W M; Welch, D R

2002-11-12

31

The optic chiasm: a turning point in the evolution of eye/hand coordination.  

UK PubMed Central (United Kingdom)

The primate visual system has a uniquely high proportion of ipsilateral retinal projections, retinal ganglial cells that do not cross the midline in the optic chiasm. The general assumption is that this developed due to the selective advantage of accurate depth perception through stereopsis. Here, the hypothesis that the need for accurate eye-forelimb coordination substantially influenced the evolution of the primate visual system is presented. Evolutionary processes may change the direction of retinal ganglial cells. Crossing, or non-crossing, in the optic chiasm determines which hemisphere receives visual feedback in reaching tasks. Each hemisphere receives little tactile and proprioceptive information about the ipsilateral hand. The eye-forelimb hypothesis proposes that abundant ipsilateral retinal projections developed in the primate brain to synthesize, in a single hemisphere, visual, tactile, proprioceptive, and motor information about a given hand, and that this improved eye-hand coordination and optimized the size of the brain. If accurate eye-hand coordination was a major factor in the evolution of stereopsis, stereopsis is likely to be highly developed for activity in the area where the hands most often operate.The primate visual system is ideally suited for tasks within arm's length and in the inferior visual field, where most manual activity takes place. Altering of ocular dominance in reaching tasks, reduced cross-modal cuing effects when arms are crossed, response of neurons in the primary motor cortex to viewed actions of a hand, multimodal neuron response to tactile as well as visual events, and extensive use of multimodal sensory information in reaching maneuvers support the premise that benefits of accurate limb control influenced the evolution of the primate visual system. The eye-forelimb hypothesis implies that evolutionary change toward hemidecussation in the optic chiasm provided parsimonious neural pathways in animals developing frontal vision and visually guided forelimbs, and also suggests a new perspective on vision convergence in prey and predatory animals.

Larsson M

2013-01-01

32

A 34-meter VAWT (Vertical Axis Wind Turbine) point design  

Science.gov (United States)

The Wind Energy Division at Sandia National Laboratories recently completed a point design based on the 34-m Vertical Axis Wind Turbine (VAWT) Test Bed. The 34-m Test Bed research machine incorporates several innovations that improve Darrieus technology, including increased energy production, over previous machines. The point design differs minimally from the Test Bed; but by removing research-related items, its estimated cost is substantially reduced. The point design is a first step towards a Test-Bed-based commercial machine that would be competitive with conventional sources of power in the mid-1990s.

Ashwill, T. D.; Berg, D. E.; Dodd, H. M.; Rumsey, M. A.; Sutherland, H. J.; Veers, P. S.

33

Direct comparison of a tablet computer and a personal digital assistant for point-of-care documentation in eye care.  

Science.gov (United States)

New mobile computing devices including personal digital assistants (PDAs) and tablet computers have emerged to facilitate data collection at the point of care. Unfortunately, little research has been reported regarding which device is optimal for a given care setting. In this study we created and compared functionally identical applications on a Palm operating system-based PDA and a Windows-based tablet computer for point-of-care documentation of clinical observations by eye care professionals when caring for patients with diabetes. Eye-care professionals compared the devices through focus group sessions and through validated usability surveys. We found that the application on the tablet computer was preferred over the PDA for documenting the complex data related to eye care. Our findings suggest that the selection of a mobile computing platform depends on the amount and complexity of the data to be entered; the tablet computer functions better for high volume, complex data entry, and the PDA, for low volume, simple data entry. PMID:16779128

Silvey, Garry M; Macri, Jennifer M; Lee, Paul P; Lobach, David F

2005-01-01

34

Direct comparison of a tablet computer and a personal digital assistant for point-of-care documentation in eye care.  

UK PubMed Central (United Kingdom)

New mobile computing devices including personal digital assistants (PDAs) and tablet computers have emerged to facilitate data collection at the point of care. Unfortunately, little research has been reported regarding which device is optimal for a given care setting. In this study we created and compared functionally identical applications on a Palm operating system-based PDA and a Windows-based tablet computer for point-of-care documentation of clinical observations by eye care professionals when caring for patients with diabetes. Eye-care professionals compared the devices through focus group sessions and through validated usability surveys. We found that the application on the tablet computer was preferred over the PDA for documenting the complex data related to eye care. Our findings suggest that the selection of a mobile computing platform depends on the amount and complexity of the data to be entered; the tablet computer functions better for high volume, complex data entry, and the PDA, for low volume, simple data entry.

Silvey GM; Macri JM; Lee PP; Lobach DF

2005-01-01

35

Pointing control design for autonomous space vehicle applications  

Energy Technology Data Exchange (ETDEWEB)

This paper addresses the design of pointing control systems for autonomous space vehicles. The function of the pointing control system is to keep distant orbiting objects within the field-of-view of an on-board optical sensor. We outline the development of novel nonlinear control algorithms which exploit the availability of on- board sensors. Simulation results comparing the performance of the different pointing control implementations are presented.

Young, K.D.

1993-03-01

36

COMS eye plaque brachytherapy dosimetric sensitivity to source photon energy and seed design.  

UK PubMed Central (United Kingdom)

This study explores the influence of source photon energy on eye plaque brachytherapy dose distributions for a 16 mm COMS plaque filled with (103)Pd, (125)I, or (131)Cs sources or monoenergetic photon emissions ranging from 12 keV to 100 keV. Dose distributions were similarly created for all permutations of three common brachytherapy seed designs. Within this range, sources with average energy ?22 keV may reduce dose to the opposite eye wall by more than a factor of 2 while maintaining tolerable proximal sclera doses when prescribing to depths of 9 mm or less. Current commercially-available brachytherapy sources can exhibit up to 15% relative dosimetric sensitivity to seed design at regions within the eye.

Gagne NL; Rivard MJ

2013-09-01

37

Progress and prospects for an FI relevant point design  

Energy Technology Data Exchange (ETDEWEB)

The physics issues involved in scaling from sub ignition to high gain fast ignition are discussed. Successful point designs must collimate the electrons and minimize the stand off distance to avoid multi mega-joule ignition energies. Collimating B field configurations are identified and some initial designs are explored.

Key, M; Amendt, P; Bellei, C; Clark, D; Cohen, B; Divol, L; Ho, D; Kemp, A; Larson, D; Marinak, M; Patel, P; Shay, H; Strozzi, D; Tabak, M

2011-11-02

38

Design point studies for future spherical torus devices  

Energy Technology Data Exchange (ETDEWEB)

A Systems Code analysis has been developed which provides a tool for the assessment of design points for future spherical torus (ST) devices. The code includes algorithms for plasma physics as well as engineering aspects, which are necessarily simplified but sufficient to capture the essential design-driving considerations. This paper describes the methodology and presents some example cases from ongoing studies.

Neumeyer, C. L. [Princeton Plasma Physics Laboratory (PPPL); Peng, Yueng Kay Martin [ORNL; Rutherford, P. H. [Princeton Plasma Physics Laboratory (PPPL)

2003-01-01

39

Distribution of the points of a design on the sphere  

International Nuclear Information System (INIS)

We determine the size of spherical caps with centres at the points of a design that cover the whole sphere in Euclidean space with a given multiplicity. By projecting q-designs on one-dimensional subspaces, we obtain the nodes of a Chebyshev-type quadrature formula of the same precision q. For large values of q we establish that the points of a minimal q-design are uniformly distributed on the sphere. We construct a weighted cubature formula on the sphere with the minimum number of nodes

2005-10-31

40

Distribution of the points of a design on the sphere  

Energy Technology Data Exchange (ETDEWEB)

We determine the size of spherical caps with centres at the points of a design that cover the whole sphere in Euclidean space with a given multiplicity. By projecting q-designs on one-dimensional subspaces, we obtain the nodes of a Chebyshev-type quadrature formula of the same precision q. For large values of q we establish that the points of a minimal q-design are uniformly distributed on the sphere. We construct a weighted cubature formula on the sphere with the minimum number of nodes.

Yudin, V A [Moscow Power Engineering Institute, Moscow (Russian Federation)

2005-10-31

 
 
 
 
41

A Fusion Chamber for the 2002 Robust Point Design  

Energy Technology Data Exchange (ETDEWEB)

A top-level overview of the mechanical design for the 2002 Robust Point Design (RPD-2002) fusion chamber is introduced. It is based on the HYLIFE-II design and includes modifications to the liquid pocket configuration and first structural wall (FSW), facilitates periodic maintenance or replacement of internal components, and is compliant with all other RPD-2002 parameters. This work has been carried out by constructing a parametric computer model capable of being updated as future changes become necessary.

Abbott, R P

2003-10-01

42

Design of artificial apposition compound eye with cylindrical micro-doublets  

Science.gov (United States)

We present the design of a non-conventional optical system that uses cylindrical micro-doublets (CMD), integrated in an artificial apposition compound eye configuration (AACE). We show some designs of an ultra-thin objective inspired in fly eyes. These designs can give options to create new technologies that will process information in a different and effective way as usual. This process will be carried out by means of sampling the object with an array of multiple micro lenses using a certain value of the acceptance angle, and processing the optical signal to obtain partial images that will be part of a global one. The objective has the advantage of having a smaller size, a wider field of view, and an acceptable image quality compared with some conventional systems. Design parameters of the AACE and optical performance of the CMD are reported.

Garza-Rivera, Anel; Renero-Carrillo, Francisco-J.

2011-01-01

43

Professional SharePoint 2010 Branding and User Interface Design  

CERN Multimedia

A must have guide for creating engaging and usable SharePoint 2010 brandingWith SharePoint 2010, Microsoft has provided a more robust environment for creating collaboration and content management sites that rival any of the popular websites on the internet. Creating a branded SharePoint site involves understanding both traditional web design techniques as well as topics that are typically reserved for developers. This book bridges that gap by not only providing expert guidance for creating beautiful public facing and internal intranet sites but it also addresses the needs of those readers that

Drisgill, Randy; Sanford, Jacob J; Stubbs, Paul; Riemann, Larry

2010-01-01

44

The Tromsø Eye Study : study design, methodology and results on visual acuity and refractive errors  

DEFF Research Database (Denmark)

Purpose:? To describe the study design and methodology of the Tromsø Eye Study (TES), and to describe visual acuity and refractive error in the study population. Methods:? The Tromsø Eye Study is a sub-study of the Tromsø Study, a population-based multipurpose longitudinal study in the municipality of Tromsø, Norway. The Tromsø Eye Study was a part of the sixth survey of the Tromsø Study, conducted from October 2007 through December 2008. The eye examination included information on self-reported eye diseases, assessment of visual acuity and refractive errors, retinal photography and optical coherence tomography. Retinal images were graded for diabetic retinopathy and age-related macular degeneration, and with computer-assisted measurements of arteriolar and venular diameters. In addition, TES researchers have access to the large comprehensive Tromsø Study database including physical examination results, carotid artery ultrasound, electrocardiogram, bone densitometry, cognitive tests, questionnaires, DNA, blood and urine samples and more from the present and the five previous surveys. Results:? Visual acuity was assessed in 6459 subjects and refraction in 6566 subjects aged 38-87?years. Snellen visual acuity

Bertelsen, Geir; Erke, Maja G

2013-01-01

45

Experimental determination of the chromatic difference of magnification of the human eye and the location of the anterior nodal point.  

UK PubMed Central (United Kingdom)

Theory predicts that retinal image size will vary with wavelength. However, this chromatic difference of magnification (CDM) is likely to be very small (< 1% between 400 and 700 nm) under natural viewing conditions. There has been only one attempt to measure CDM experimentally, and the results were inconsistent with optical theory. Using a technique described by Ogle [Research in Binocular Vision, Hafner, New York (1964)], which is sensitive to even small interocular differences in retinal image size, we measured the apparent tilts in the frontoparallel plane induced by interocular differences in wavelength. We obtained the ocular CDM by determining the afocal lens magnification necessary to cancel the apparent frontoparallel plane tilt caused by interocular differences in wavelength. We show that (1) the ocular CDM can be considerably less than theoretical model predictions, (2) the relationship among delta Rx (wavelength-dependent refractive error), CDM, and pupil position is consistent with our theoretical model, (3) CDM increases considerably when an artificial pupil in front of the eye is used, (4) the location of the anterior nodal point of the eye may be inferred from the data, and (5) unlike in the case for delta Rx, large intersubjective differences may exist for CDM. The results suggest caution in the use of artificial pupils experimentally with polychromatic stimuli because of amplification of CDM and concomitant losses of image contrast.

Zhang X; Bradley A; Thibos LN

1993-02-01

46

The Fly's Eye Camera System -- an instrument design for large \\'etendue time-domain survey  

CERN Multimedia

In this paper we briefly summarize the design concepts of the Fly's Eye Camera System, a proposed high resolution all-sky monitoring device which intends to perform high cadence time domain astronomy in multiple optical passbands while still accomplish a high \\'etendue. Fundings have already been accepted by the Hungarian Academy of Sciences in order to design and build a Fly's Eye device unit. Beyond the technical details and the actual scientific goals, this paper also discusses the possibilities and yields of a network operation involving ~10 sites distributed geographically in a nearly homogeneous manner. Currently, we expect to finalize the mount assembly -- that performs the sidereal tracking during the exposures -- until the end of 2012 and to have a working prototype with a reduced number of individual cameras sometimes in the spring or summer of 2013.

Pál, András; Csépány, Gergely; Jaskó, Attila; Schlaffer, Ferenc; Vida, Krisztián; Mez?, György; Döbrentei, László; Farkas, Ern?; Kiss, Csaba; Oláh, Katalin; Regály, Zsolt

2013-01-01

47

The Fly's Eye Camera System: An Instrument Design for Large Étendue Time Domain Surveys  

Science.gov (United States)

In this paper we briefly summarize the design concepts of the Fly's Eye Camera System, a proposed high resolution all-sky monitoring device which intends to perform high cadence time domain astronomy in multiple optical passbands while still accomplish a high étendue. Funding has already been accepted by the Hungarian Academy of Sciences in order to design and build a Fly's Eye device unit. Beyond the technical details and the actual scientific goals, this paper also discusses the possibilities and yields of a network operation involving ˜10 sites distributed geographically in a nearly homogeneous manner. Currently, we expect to finalize the mount assembly – that performs the sidereal tracking during the exposures – until the end of 2012 and to have a working prototype with a reduced number of individual cameras sometime in the spring or summer of 2013.

Csépány, G.; Pál, A.; Vida, K.; Regály, Z.; Mészáros, L.; Oláh, K.; Kiss, C.; Döbrentei, L.; Jaskó, A.; Mezõ, G.; Farkas, E.

2013-10-01

48

Customized schematic eye model for refraction correction design based on ocular wavefront and corneal topography measurements  

Science.gov (United States)

The subject of this paper relates to the ocular optical design and vision analysis of refractive correction of the eye. After the purpose statement and the assumption list, the concept of the schematic eye matching a particular (measured) wavefront is introduced. This concept is based on the fact that the ocular wavefront, together with the corneal topography, can be seen as the mathematical global representation of the eye working in monochromatic light and having a foveal vision. The discussed design technique, including an iterative optimization method, could be applied in any ocular correction that utilizes cornea topography and/or ocular wavefront, e.g. contact lens or intra-corneal implant. However, the application this paper refers to is the ocular refractive correction by a procedure using the LADARVISION. It consists of surgical removal and subsequent replacement of a corneal flap on a stromal surface whose shape has been changed by laser ablation of the tissue. Subsequent sections of this paper are dedicated to establishing the limits of possible refractive correction, the influences of the flap and corneal topography into the refractive correction calculation. Finally a realistic evaluation of the results and a list of possible developments of this new optical design method are discussed.

Curatu, Eugene O.; Pettit, George H.; Campin, John A.

2002-06-01

49

Designed porous media: Optimally nonuniform flow structures connecting one point with more points  

Energy Technology Data Exchange (ETDEWEB)

This paper shows analytically and numerically how an originally uniform flow structure transforms itself into a nonuniform one when the objective is to minimize global flow losses. The flow connects one point (source, sink) to a number of points (sinks, sources) distributed uniformly over a two-dimensional domain. In the first part of the paper, the flow between neighboring points is modeled as fully developed through round tubes. It is shown that flow 'mal-distribution' and the abandonment of symmetry are necessary for the development of flow structures with minimal resistance. The search for better flow structures can be accelerated: tubes that show a tendency of shrinking during the search can be assumed absent in future steps of structure optimization. In the second part of the paper, the flow medium is continuous and permeated by Darcy flow. The development of flow structures (channels) is modeled as a mechanism of erosion, where elements of the original medium are removed one by one, and are replaced with a more permeable medium. The elements selected for removal are identified based on two criteria: maximum pressure integrated over the element boundary, and maximum pressure gradient. The flow structures generated based on the pressure gradient criterion have consistently smaller flow resistances. As flow systems become smaller and more compact, the flow systems themselves become ''designed porous media''. These design optimization trends revealed are generally applicable in constructal design, i.e., where miniaturization, global performance, compactness and complexity rule the design. (authors)

Ordonez, J.C.; Bejan, A. [Department of Mechanical Engineering and Materials Science, Duke University, Box 90300, 27708-0300, Durham, NC (United States); Cherry, R.S. [Idaho National Engineering and Environmental Laboratory, P.O. Box 1625, 83415-2203, Idaho Falls, ID (United States)

2003-09-01

50

The Los Angeles Latino Eye Study: design, methods, and baseline data.  

UK PubMed Central (United Kingdom)

OBJECTIVE: To describe the study design, operational strategies, procedures, and baseline characteristics of the Los Angeles Latino Eye Study (LALES), a population-based assessment of the prevalence of visual impairment, ocular disease, and visual functioning in Latinos. DESIGN: Population-based, cross-sectional study. PARTICIPANTS: Six thousand three hundred fifty-seven Latinos 40 years and older from 6 census tracts in Los Angeles, California. METHODS: A detailed interview and eye examination were performed on each eligible participant. The interview included an assessment of demographic, behavioral, and ocular risk factors and health-related and vision-related quality of life. The eye examination included a measurement of visual acuity, intraocular pressure, and visual fields; fundus and optic disc photography; a detailed anterior and posterior segment examination; and measurement of blood pressure, glycosylated hemoglobin levels, and blood glucose levels. MAIN OUTCOME MEASURES: Prevalence of visual impairment, blindness, cataract, glaucoma, diabetic retinopathy, and age-related macular degeneration constitute the study's primary outcome variables. Secondary outcomes include odds ratios for risk factors associated with eye disease, health-related quality of life, and vision-related quality of life. Response rates and baseline characteristics are presented. RESULTS: Of the 7789 individuals eligible for LALES, 6357 (82%) had a clinical examination; an additional 524 completed only an in-home interview. The majority of participants were female (58%), the average (+/- standard deviation) age was 54.9 (+/-10.8) years, and 80.0% were of Mexican origin and 0.4% self-identified as American Indian or Alaskan Native. The age distribution of LALES participants was similar to that of Latinos of Mexican origin in the rest of the United States. CONCLUSION: The LALES has recruited Latinos 40 and older for an ophthalmic epidemiologic study. The LALES cohort will provide information about the prevalence and risk factors of ocular disease in the largest and fastest growing minority in the United States.

Varma R; Paz SH; Azen SP; Klein R; Globe D; Torres M; Shufelt C; Preston-Martin S

2004-06-01

51

The relative timing between eye and hand in rapid sequential pointing is affected by time pressure, but not by advance knowledge.  

UK PubMed Central (United Kingdom)

The present study examined the effect of timing constraints and advance knowledge on eye-hand coordination strategy in a sequential pointing task. Participants were required to point at two successively appearing targets on a screen while the inter-stimulus interval (ISI) and the trial order were manipulated, such that timing constraints were high (ISI = 300 ms) or low (ISI = 450 ms) and advance knowledge of the target location was present (fixed order) or absent (random order). Analysis of eye and finger onset and completion times per segment of the sequence indicated that oculo-manual behaviour was in general characterized by eye movements preceding the finger, as well as 'gaze anchoring' (i.e. eye fixation of the first target until completion of the finger movement towards that target). Advance knowledge of future target locations lead to shorter latency times of eye and hand, and smaller eye-hand lead times, which in combination resulted in shorter total movement times. There was, however, no effect of advance knowledge on the duration of gaze anchoring. In contrast, gaze anchoring did change as a function of the interval between successive stimuli and was shorter with a 300 ms ISI versus 450 ms ISI. Further correlation analysis provided some indication that shorter residual latency is associated with shorter pointing duration, without affecting accuracy. These results are consistent with a neural mechanism governing the coupling of eye and arm movements, which has been suggested to reside in the superior colliculus. The temporal coordination resulting from this coupling is a function of the time pressure on the visuo-manual system resulting from the appearance of external stimuli.

Deconinck FJ; van Polanen V; Savelsbergh GJ; Bennett SJ

2011-08-01

52

Change-point in stochastic design regression and the bootstrap  

CERN Document Server

In this paper we study the consistency of different bootstrap procedures for constructing confidence intervals (CIs) for the unique jump discontinuity (change-point) in an otherwise smooth regression function in a stochastic design setting. This problem exhibits nonstandard asymptotics and we argue that the standard bootstrap procedures in regression fail to provide valid confidence intervals for the change-point. We propose a version of smoothed bootstrap, illustrate its remarkable finite sample performance in our simulation study, and prove the consistency of the procedure. The $m$ out of $n$ bootstrap procedure is also considered and shown to be consistent. We also provide sufficient conditions for any bootstrap procedure to be consistent in this scenario.

Seijo, Emilio

2011-01-01

53

Change point analysis and assessment : An integrated methodological design  

DEFF Research Database (Denmark)

The aim of this article is to develop an analytical framework for studying processes such as continuous innovation and business development in high-tech SME clusters that transcends the traditional qualitative-quantitative divide. The article's key contribution is the conceptual integration of four existing and well-recognised but separate approaches to studying events, processes, and change, namely change-point analysis (CPA), event-history analysis (EHA), critical-incident technique (CIT), and sequence analysis (SA) into a single design framework which is especially useful for studying complex and long-term or ongoing processes.

Müller, Sabine; Neergaard, Helle

2011-01-01

54

Dry Eye  

Science.gov (United States)

... Eye » Facts About Dry Eye Facts About Dry Eye This information was developed by the National Eye ... information View Eye Health Organizations and more. Dry Eye Defined What is dry eye? Dry eye occurs ...

55

Adaptive Pointing Design and Evaluation of a Precision Enhancing Technique for Absolute Pointing Devices  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We present Adaptive Pointing, a novel approach to addressing the common problem of accuracy when using absolute pointing devices for distant interaction. First, we discuss extensively some related work concerning the problem-domain of pointing accuracy when using absolute or relative pointing device...

König, Werner A.; Gerken, Jens; Dierdorf, Stefan; Reiterer, Harald

56

Oogknipbeheerde rekenaarmuis: ontwerp en evaluering Eye-blink controlled computer mouse: design and evaluation  

Directory of Open Access Journals (Sweden)

Full Text Available Motories gestremde persone vind dit moeilik om ’n rekenaar te gebruik vanweë die feit dat hulle nie ’n muis kan beheer nie. In hierdie artikel word die ontwerp, implementering en evaluering van ’n oogknipbeheerde rekenaarmuis vir gebruik deur gestremde persone beskryf. Die deteksie van willekeurige oogknippe word deur middel van die weerkaatsing van infrarooi- (IR-) lig vanaf die vel langs die oog bewerkstellig, terwyl onwillekeurige knippe verwerp word. Dit stel motories gestremde persone, wat nie meer die gebruik van hul arms het nie, in staat om ’n rekenaar te bedryf. Al die funksies van ’n PS2-muis word geëmuleer.Physically disabled people who do not have the use of their limbs have difficulty operating a computer, since they cannot use a mouse. In this article the design, implementation and evaluation of an eye-blink controlled computer mouse to be used by handicapped people are described. Detection of voluntary blinks is established by the reflection of infrared light from the skin on the side of the eye, while involuntary blinks are ignored. This enables people who do not have the use of their limbs to operate a computer. All the functions of a PS2 mouse are emulated.

S. Viljoen; T. Hanekom; P. J. Cilliers

2004-01-01

57

Using eye movement to control a computer: a design for a lightweight electro-oculogram electrode array and computer interface.  

UK PubMed Central (United Kingdom)

This paper describes a human-computer interface based on electro-oculography (EOG) that allows interaction with a computer using eye movement. The EOG registers the movement of the eye by measuring, through electrodes, the difference of potential between the cornea and the retina. A new pair of EOG glasses have been designed to improve the user's comfort and to remove the manual procedure of placing the EOG electrodes around the user's eye. The interface, which includes the EOG electrodes, uses a new processing algorithm that is able to detect the gaze direction and the blink of the eyes from the EOG signals. The system reliably enabled subjects to control the movement of a dot on a video screen.

Iáñez E; Azorin JM; Perez-Vidal C

2013-01-01

58

Towards a Modular Point Design for Heavy Ion Fusion  

International Nuclear Information System (INIS)

We report on an ongoing study on modular Heavy Ion Fusion (HIF) drivers. The modular driver is characterized by ?20 nearly identical induction linacs, each carrying a single high current beam. In this scheme, one of the full size induction linacs can be tested as an 'integrated Research Experiment' (IRE). Hence this approach offers significant advantages in terms of driver development path. For beam transport, these modules use solenoids, which are capable of carrying high line charge densities, even at low energies. A new injector concept allows compression of the beam to high line densities right after the source. The final drift compression is performed in a plasma in which the large repulsive space charge effects are neutralized. Finally, the beam is transversely compressed onto the target, using either external solenoids or current-carrying channels (in the assisted pinch mode of beam propagation). We report on progress towards a self-consistent point design from injector to target. Considerations of driver architecture, chamber environment as well as the methodology for meeting target requirements of spot size, pulse shape and symmetry are also described. Finally, some near-term experiments to address the key scientific issues are discussed.

2005-01-01

59

The Modular Point Design for Heavy Ion Fusion  

International Nuclear Information System (INIS)

We report on an ongoing study on modular Heavy Ion Fusion drivers. The modular driver is characterized by tens (? 20) nearly identical induction linacs, each carrying a single high current beam. In this scheme, the Integrated Research Experiment (IRE) can be one of the full size induction linacs. Hence, this approach offers significant advantages in terms of driver development path. For beam transport, these modules use solenoids which are capable of carrying high line charge densities, even at low energies. A new injector concept allows compression of the beam to high line densities right at the source. The final drift compression is performed in a plasma, in which the large repulsive space charge effects are neutralized. Finally, the beam is transversely compressed onto the target, using either external solenoids or current-carrying channels (in the Assisted Pinch Mode of beam propagation). We will report on progress towards a self-consistent point design from injector to target. Considerations of driver architecture, chamber environment as well as the methodology for meeting target requirements of spot size, pulse shape and symmetry will also be described. Finally, some near-term experiments to address the key scientific issues will be discussed.

2005-01-01

60

An iodine-125 applicator designed for irradiating blood vessels growing into the cornea of the eye  

International Nuclear Information System (INIS)

The invasion of the traumatized cornea by blood vessels is a well known complication is often associated with graft rejection. Graft acceptance may be improved by the induction of endarteritis with ? radiation but the corneal stroma may be so changed by the necessary dose of radiation (commonly 4500-5000 cGy in three or four fractions) as to significantly increase the risk of sloughing (Macfaul and Bedford, 1970). To overcome this problem, the authors have designed and made an 125I eye applicator to produce an extremely narrow radiation field for treating the vascularization at the base of the cornea only. The anterior part of the cornea receives a very small dose of about 11% of that given to the base and is sufficiently large to receive a 6mm corneal transplant. (author).

1989-01-01

 
 
 
 
61

Iodine-125 applicator designed for irradiating blood vessels growing into the cornea of the eye  

Energy Technology Data Exchange (ETDEWEB)

The invasion of the traumatized cornea by blood vessels is a well known complication is often associated with graft rejection. Graft acceptance may be improved by the induction of endarteritis with ..beta.. radiation but the corneal stroma may be so changed by the necessary dose of radiation (commonly 4500-5000 cGy in three or four fractions) as to significantly increase the risk of sloughing (Macfaul and Bedford, 1970). To overcome this problem, the authors have designed and made an /sup 125/I eye applicator to produce an extremely narrow radiation field for treating the vascularization at the base of the cornea only. The anterior part of the cornea receives a very small dose of about 11% of that given to the base and is sufficiently large to receive a 6mm corneal transplant.

Hering, E.R.; Korrubel, J.B.; Sealy, R.; Hill, J.

1989-03-01

62

Eye movement  

International Nuclear Information System (INIS)

This is a special lecture at the 96th Annual Congress of the Japanese Ophthalmological Society in 1992, presenting studies on eye movement using magnetic resonance imaging (MRI). Using cine mode MRI technology, two methods for producing a series of photographs have been invented: (1) the moving eye method or dynamic method in which the subjects were asked to perform 256 or 512 vertical and horizontal eye movements in synchronization with a sound trigger; and (2) the fixed eye method or static method in which the subjects were asked to gaze at individual points in a 5 to 7 point sequence as indicated by the investigator. MRI data was generated and the resulting series of photographs were observed in cine mode on a televisin monitor. Displaying the MRI-generated photographs in cine mode enables direct observation of eye movement, optic nerve and extraocular muscles within the orbit. Although the moving eye method is more accurate in its portrayal of the actual eye movement, at least 256 eye movements are required for about 5 minutes, causing physical and mental load for the subjects. The fixed eye method was thus used to examine ophthalmoplegia, including abducens palsy, oculomotor palsy, fracture of the orbital wall, foreign bodies in the orbit, Duane's syndrome, endocrine myopathy, esotropia and exotropia. This allowed the investigation of anatomical changes, such as atrophy or hypertrophy, and the functional state caused by contraction and relaxation of the extraocular muscles. Transposition of the extraocular muscles for paralytic squint was reexamined and a new surgical procedure was developed for abducens palsy. The measurement of the length, thickness and weight of the extraocular muscles from the MRI-generated photographs allowed more accurate analysis. Three dimensional reconstructive method of MRI provided a valuable tool for evaluating the orbit. (N.K.) 67 refs.

1992-01-01

63

Design and Simulation of Floating Point Multiplier Based on VHDL  

Science.gov (United States)

Multiplying floating point numbers is a critical requirement for DSP applications involving large dynamic range. This paper focuses only on single precision normalized binary interchange format targeted for Xilinx Spartan-3 FPGA based on VHDL. The multiplier was verified against Xilinx floating point multiplier core. It handles the overflow and underflow cases. Rounding is not implemented to give more precision when using the multiplier in a Multiply and Accumulate (MAC) unit.

Remadevi, R.

2013-03-01

64

Single service point: it's all in the design.  

UK PubMed Central (United Kingdom)

"Design thinking" principles from a leading design firm, IDEO, were key elements in the planning process for a one-desk service model, the ASK Desk, at the John A. Prior Health Sciences Library. The library administration and staff employed the methodology to enhance customer experiences, meet technology challenges, and compete in a changing education environment. The most recent renovations demonstrate how the principles were applied. The concept of "continuous design thinking" is important in the library's daily operations to serve customers most effectively.

Bradigan PS; Rodman RL

2008-01-01

65

Single service point: it's all in the design.  

Science.gov (United States)

"Design thinking" principles from a leading design firm, IDEO, were key elements in the planning process for a one-desk service model, the ASK Desk, at the John A. Prior Health Sciences Library. The library administration and staff employed the methodology to enhance customer experiences, meet technology challenges, and compete in a changing education environment. The most recent renovations demonstrate how the principles were applied. The concept of "continuous design thinking" is important in the library's daily operations to serve customers most effectively. PMID:19042717

Bradigan, Pamela S; Rodman, Ruey L

2008-01-01

66

Design and fabrication of a freeform microlens array for a compact large-field-of-view compound-eye camera.  

Science.gov (United States)

In this research, a unique freeform microlens array was designed and fabricated for a compact compound-eye camera to achieve a large field of view. This microlens array has a field of view of 48°×48°, with a thickness of only 1.6 mm. The freeform microlens array resides on a flat substrate, and thus can be directly mounted to a commercial 2D image sensor. Freeform surfaces were used to design the microlens profiles, thus allowing the microlenses to steer and focus incident rays simultaneously. The profiles of the freeform microlenses were represented using extended polynomials, the coefficients of which were optimized using ZEMAX. To reduce crosstalk among neighboring channels, a micro aperture array was machined using high-speed micromilling. The molded microlens array was assembled with the micro aperture array, an adjustable fixture, and a board-level image sensor to form a compact compound-eye camera system. The imaging tests using the compound-eye camera showed that the unique freeform microlens array was capable of forming proper images, as suggested by design. The measured field of view of ±23.5° also matches the initial design and is considerably larger compared with most similar camera designs using conventional microlens arrays. To achieve low manufacturing cost without sacrificing image quality, the freeform microlens array was fabricated using a combination of ultraprecision diamond broaching and a microinjection molding process. PMID:22534888

Li, Lei; Yi, Allen Y

2012-04-20

67

Design and fabrication of a freeform microlens array for a compact large-field-of-view compound-eye camera.  

UK PubMed Central (United Kingdom)

In this research, a unique freeform microlens array was designed and fabricated for a compact compound-eye camera to achieve a large field of view. This microlens array has a field of view of 48°×48°, with a thickness of only 1.6 mm. The freeform microlens array resides on a flat substrate, and thus can be directly mounted to a commercial 2D image sensor. Freeform surfaces were used to design the microlens profiles, thus allowing the microlenses to steer and focus incident rays simultaneously. The profiles of the freeform microlenses were represented using extended polynomials, the coefficients of which were optimized using ZEMAX. To reduce crosstalk among neighboring channels, a micro aperture array was machined using high-speed micromilling. The molded microlens array was assembled with the micro aperture array, an adjustable fixture, and a board-level image sensor to form a compact compound-eye camera system. The imaging tests using the compound-eye camera showed that the unique freeform microlens array was capable of forming proper images, as suggested by design. The measured field of view of ±23.5° also matches the initial design and is considerably larger compared with most similar camera designs using conventional microlens arrays. To achieve low manufacturing cost without sacrificing image quality, the freeform microlens array was fabricated using a combination of ultraprecision diamond broaching and a microinjection molding process.

Li L; Yi AY

2012-04-01

68

Phase-shifting point diffraction interferometer grating designs  

Energy Technology Data Exchange (ETDEWEB)

In a phase-shifting point diffraction interferometer, by sending the zeroth-order diffraction to the reference pinhole of the mask and the first-order diffraction to the test beam window of the mask, the test and reference beam intensities can be balanced and the fringe contrast improved. Additionally, using a duty cycle of the diffraction grating other than 50%, the fringe contrast can also be improved.

Naulleau, Patrick (Oakland, CA); Goldberg, Kenneth Alan (Berkeley, CA); Tejnil, Edita (San Carlos, CA)

2001-01-01

69

Calcification of different designs of silicone intraocular lenses in eyes with asteroid hyalosis.  

UK PubMed Central (United Kingdom)

PURPOSE: To describe the association between calcification of older and newer designs of silicone intraocular lenses (IOLs) and asteroid hyalosis. DESIGN: Case series with clinicopathologic correlation. PARTICIPANTS: Sixteen silicone IOLs explanted because of decreased visual acuity associated with opacifying deposits on the posterior optic surface. METHODS: All 16 lenses underwent gross and light microscopic analyses. Selected lenses underwent alizarin red staining or scanning electron microscopy coupled with energy dispersive x-ray spectroscopy for elemental composition. Clinical data in each case were obtained by a questionnaire sent to the explanting surgeons. Clinical data in relation to 111 hydrophilic acrylic lenses explanted because of calcification also were assessed for comparison. MAIN OUTCOME MEASURES: Deposit morphologic features and location were evaluated under gross and light microscopy. The calcified nature of the deposits was assessed by histochemical staining and surface analyses. Clinical data obtained included age at IOL implantation, gender, implantation and explantation dates, as well as history of neodymium:yttrium-aluminum-garnet laser treatment. The presence of asteroid hyalosis in the affected eye was investigated for the explanted silicone and hydrophilic acrylic lenses. RESULTS: The 16 lenses were of 8 designs manufactured from different silicone materials, which were explanted 9.21+/-3.66 years after implantation. Neodymium:yttrium-aluminum-garnet laser applications performed in 12 cases partially removed deposits from the lens, followed by a gradual increase in their density after the procedures. The presence of asteroid hyalosis was confirmed in 13 cases; no notes regarding this condition were found in patient charts in the other 3 cases. The deposits were only on the posterior optic surface of the silicone lenses and were composed of calcium and phosphate. A history of asteroid hyalosis was not found in relation to any of the 111 cases of postoperative calcification of hydrophilic acrylic lenses. CONCLUSIONS: Including this current series, there are 22 cases of calcification of silicone lenses involving 8 designs manufactured from different silicone materials described in the literature. The presence of asteroid hyalosis was confirmed in 86.4% of cases. These findings may be added to the list of pros and cons surgeons consider when selecting or recommending an IOL.

Stringham J; Werner L; Monson B; Theodosis R; Mamalis N

2010-08-01

70

Design and Implementation of IEEE-754 Addition and Subtraction for Floating Point Arithmetic Logic Unit  

Directory of Open Access Journals (Sweden)

Full Text Available This paper describes the FPGA implementation of a Decimal Floating Point (DFP) adder/subtractor using IEEE 754-2008 format. In this paper we describe an efficient implementation of an IEEE 754 single precision Standard for Binary Floating-Point Arithmetic to include specifications for decimal floating-point arithmetic. As processor support for decimal floating-point arithmetic emerges, it is important to investigate efficient algorithms and hardware designs for common decimal floating-point arithmetic algorithms. This paper presents novel designs for a decimal floating-point addition and subtraction. They are fully synthesizable hardware descriptions in VERILOG. Each one is presented for high speed computing.

V.VINAY CHAMKUR , Chetana.R

2012-01-01

71

Fiber design and realization of point-by-point written fiber Bragg gratings in polymer optical fibers  

DEFF Research Database (Denmark)

An increasing interest in making sensors based on fiber Bragg gratings (FBGs) written in polymer optical fibers (POFs) has been seen recently. Mostly microstructured POFs (mPOFs) have been chosen for this purpose because they are easier to fabricate compared, for example, to step index fibers and because they allow to tune the guiding parameters by modifying the microstructure. Now a days the only technique used to write gratings in such fibers is the phase mask technique with UV light illumination. Despite the good results that have been obtained, a limited flexibility on the grating design and the very long times required for the writing of FBGs raise some questions about the possibility of exporting POF FBGs and the sensors based on them from the laboratory bench to the mass production market. The possibility of arbitrary design of fiber Bragg gratings and the very short time required to write the gratings make the point-by-point grating writing technique very interesting and would appear to be able to fill this technological gap. On the other end this technique is hardly applicable for microstructured fibers because of the writing beam being scattered by the air-holes. We report on the design and realization of a microstructured polymer optical fiber made of PMMA for direct writing of FBGs. The fiber was designed specifically to avoid obstruction of the writing beam by air-holes. The realized fiber has been used to point-by-point write a 5 mm long fourth order FBG with a Bragg wavelength of 1518 nm. The grating was inspected under Differential Interferometric Contrast microscope and the reflection spectrum was measured. This is, to the best of our knowledge, the first FBGs written into a mPOF with the point-by-point technique and also the fastest ever written into a polymer optical fiber, with less than 2.5 seconds needed.

Stefani, Alessio; Stecher, Matthias

2012-01-01

72

A design process from a collaborative point of view : Exploring the importance of collaboration between designers and clients  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This essay studies the design process from a collaborative point of view. A literature study has been carried out with focus on design processes and collaborative design, where important concepts and notions are presented. A practical design process was carried out where the project was to create a ...

Anttila, Lars; Ögren, Martin

73

New Generation Nuclear Plant (NGNP) Project, Preliminary Point Design  

International Nuclear Information System (INIS)

This paper provides a preliminary assessment of two possible versions of the Next Generation Nuclear Plant (NGNP), a prismatic fuel type helium gas-cooled reactor and a pebble-bed fuel helium gas reactor. Both designs will meet the three basic requirements that have been set for the NGNP: a coolant outlet temperature of 1000 C, passive safety, and a total power output consistent with that expected for commercial high-temperature gas-cooled reactors

2004-01-01

74

New Generation Nuclear Plant (NGNP) Project, Preliminary Point Design  

Energy Technology Data Exchange (ETDEWEB)

This paper provides a preliminary assessment of two possible versions of the Next Generation Nuclear Plant (NGNP), a prismatic fuel type helium gas-cooled reactor and a pebblebed fuel helium gas reactor. Both designs will meet the three basic requirements that have been set for the NGNP: a coolant outlet temperature of 1000 C, passive safety, and a total power output consistent with that expected for commercial high-temperature gas-cooled reactors.

F. H. Southworth; P. E. MacDonald; A. M. Baxter; P. D. Bayless; J. M. Bolin; H. D. Gougar; R. L. Moore; A. M. Ougouag; M. B. Richards; R. L. Sant; J. W. Sterbentz; W. K. Terry

2004-03-01

75

Eye Exam  

Science.gov (United States)

... diagnosing and treating complex eye diseases, and performing eye surgery. Optometrists. Optometrists provide many of the same services ... food or other substances? Have you ever had eye surgery? Does anyone in your family have eye problems, ...

76

Eye Complications  

Science.gov (United States)

... today. Home > Living with Diabetes > Complications > Eye Complications Eye Complications Listen You may have heard that diabetes ... work well if you begin them right away. Eye Insight To understand what happens in eye disorders, ...

77

Studying nanostructured nipple arrays of moth eye facets helps to design better thin film solar cells  

International Nuclear Information System (INIS)

Nipples on the surface of moth eye facets exhibit almost perfect broadband anti-reflection properties. We have studied the facet surface micro-protuberances, known as corneal nipples, of the chestnut leafminer moth Cameraria ohridella by atomic force microscopy, and simulated the optics of the nipple arrays by three-dimensional electromagnetic simulation. The influence of the dimensions and shapes of the nipples on the optics was studied. In particular, the shape of the nipples has a major influence on the anti-reflection properties. Furthermore, we transferred the structure of the almost perfect broadband anti-reflection coatings to amorphous silicon thin film solar cells. The coating that imitates the moth-eye array allows for an increase of the short circuit current and conversion efficiency of more than 40%.

2012-01-01

78

The Age-Related Eye Disease Study 2 (AREDS2): study design and baseline characteristics (AREDS2 report number 1).  

UK PubMed Central (United Kingdom)

PURPOSE: The Age-Related Eye Disease Study (AREDS) demonstrated beneficial effects of oral supplementation with antioxidant vitamins and minerals on the development of advanced age-related macular degeneration (AMD) in persons with at least intermediate AMD (bilateral large drusen with or without pigment changes). Observational data suggest that other oral nutrient supplements might further reduce the risk of progression to advanced AMD. The primary purpose of the Age-Related Eye Disease Study 2 (AREDS2) is to evaluate the efficacy and safety of lutein plus zeaxanthin (L+Z) and/or ?-3 long-chain polyunsaturated fatty acid (LCPUFA) supplementation in reducing the risk of developing advanced AMD. The study also assesses the reduction in zinc and the omission of ?-carotene from original AREDS formulation. DESIGN: Multicenter, phase III, randomized, controlled clinical trial. PARTICIPANTS: Persons aged 50 to 85 with bilateral intermediate AMD or advanced AMD in 1 eye. METHODS: All participants were randomly assigned to placebo (n = 1012), L+Z (10 mg/2 mg; n = 1044), ?-3 LCPUFAs (eicosapentaenoic acid + docosahexaenoic acid [650 mg/350 mg]; n = 1069), or the combination of L+Z and ?-3 LCPUFAs (n = 1078). All participants were offered a secondary randomization to 1 of 4 variations of the original AREDS formulation keeping vitamins C (500 mg) and E (400 IU) and copper (2 mg) unchanged while varying zinc and ?-carotene as follows: Zinc remains at the original level (80 mg), lower only zinc to 25 mg, omit ?-carotene only, or lower zinc to 25 mg and omit ?-carotene. MAIN OUTCOME MEASURES: Progression to advanced AMD determined by centralized grading of annual fundus photographs. RESULTS: We enrolled 4203 participants at 82 clinical centers located in the United States. Population characteristics at baseline were as follows: Mean age, 74 years; 57% female; 97% white; 7% current smokers; 19% with prior cardiovascular disease; and 44% and 50% taking statin-class cholesterol-lowering drugs and aspirin, respectively. Ocular characteristics include 59% with bilateral large drusen, 32% with advanced AMD in 1 eye and mean visual acuity of 20/32 in eyes without advanced AMD. CONCLUSIONS: This report presents the AREDS2 study design and the participants' baseline demographic and ocular characteristics.

Chew EY; Clemons T; SanGiovanni JP; Danis R; Domalpally A; McBee W; Sperduto R; Ferris FL

2012-11-01

79

Stauts of the Laser Inertial Fusion Energy (LIFE) Hohlraum Point Design  

Energy Technology Data Exchange (ETDEWEB)

Progress on the hohlraum point design for the LIFE engine is described. New features in the original design [Amendt et al., Fus. Sci. Technol. 60, 49 (2011)] are incorporated that address the imperatives of low target cost, high manufacturing throughput, efficient and prompt material recycling, an ability for near-term testing of key target design uncertainties on the National Ignition Facility, and robustness to target chamber environment and injection insults. To this end, the novel use of Pb hohlraums and aerogel-supported liquid DT fuel loading within a high-density-carbon (HDC) ablator is implemented in the hohlraum point design.

Amendt, P; Dunne, M; Ho, D; Lasinski, B; Meeker, D; Ross, J S

2012-04-10

80

Low-cost, high-performance, point-focus concentrator array design  

Energy Technology Data Exchange (ETDEWEB)

The design and fabrication of optimized photovoltaic concentrator arrays has been initiated which are meant to demonstrate the technology readiness of actual hardware for the 1980 goal of $2.80/Wp. Two basic approaches are being pursued in parallel. These are a point-focus Fresnel lens concept, and a linear-focus parabolic trough. The point-focus design is presented. The basic approach has been to meld together the best features of a number of designs done previously. These have been combined with extensive analysis, and some innovations to produce a design which will permit demonstration of the 1980 goal in terms of price, hardware performance, durability, and reliability.

Shafer, B.D.; Edenburn, M.W.; Garner, M.; Togami, H.

1980-01-01

 
 
 
 
81

Black Eye  

Science.gov (United States)

... Health News Consumer Alerts What Is a Black Eye? Tweet Black eye is a phrase used to ... an Eye M.D. 1:22 Find An Eye M.D. Enter zip code here Search by Name, City, State or Subspecialty > Subscribe for Eye Health Info Sign up for our monthly e- ...

82

On the design of a radix-10 online floating-point multiplier  

Science.gov (United States)

This paper describes an approach to design and implement a radix-10 online floating-point multiplier. An online approach is considered because it offers computational flexibility not available with conventional arithmetic. The design was coded in VHDL and compiled, synthesized, and mapped onto a Virtex 5 FPGA to measure cost in terms of LUTs (look-up-tables) as well as the cycle time and total latency. The routing delay which was not optimized is the major component in the cycle time. For a rough estimate of the cost/latency characteristics, our design was compared to a standard radix-2 floating-point multiplier of equivalent precision. The results demonstrate that even an unoptimized radix-10 online design is an attractive implementation alternative for FPGA floating-point multiplication.

McIlhenny, Robert D.; Ercegovac, Milos D.

2009-08-01

83

Design and development of a ferroelectric micro photo detector for the bionic eye  

Science.gov (United States)

Driven by no effective therapy for Retinitis Pigmentosa and Age Related Macular Degeneration, artificial vision through the development of an artificial retina that can be implanted into the human eye, is being addressed by the Bionic Eye. This dissertation focuses on the study of a photoferroelectric micro photo detector as an implantable retinal prosthesis for vision restoration in patients with above disorders. This implant uses an electrical signal to trigger the appropriate ocular cells of the vision system without resorting to wiring or electrode implantation. The research work includes fabrication of photoferroelectric thin film micro detectors, characterization of these photoferroelectric micro devices as photovoltaic cells, and Finite Element Method (FEM) modeling of the photoferroelectrics and their device-neuron interface. A ferroelectric micro detector exhibiting the photovoltaic effect (PVE) directly adds electrical potential to the neuron membrane outer wall at the focal adhesion regions. The electrical potential then generates a retinal cell membrane potential deflection through a newly developed Direct-Electric-Field-Coupling (DEFC) model. This model is quite different from the traditional electric current model because instead of current directly working on the cell membrane, the PVE current is used to generate a localized high electric potential in the focal adhesion region by working together with the anisotropic high internal impedance of ferroelectric thin films. General electrodes and silicon photodetectors do not have such anisotropy and high impedance, and thus they cannot generate DEFC. This mechanism investigation is very valuable, because it clearly shows that our artificial retina works in a way that is totally different from the traditional current stimulation methods.

Song, Yang

84

Eye Wear  

Science.gov (United States)

Eye wear protects or corrects your vision. Examples are Sunglasses Safety goggles Glasses (also called eyeglasses) Contact ... jobs and some sports carry a risk of eye injury. Thousands of children and adults get eye ...

85

Eye Injuries  

Science.gov (United States)

The structure of your face helps protect your eyes from injury. Still, injuries can damage your eye, sometimes severely enough that you could lose your vision. Most eye injuries are preventable. If you play sports or ...

86

Eye Cancer  

Science.gov (United States)

Cancer of the eye is uncommon. It can affect the outer parts of the eye, such as the eyelid, which are made up ... adults are melanoma and lymphoma. The most common eye cancer in children is retinoblastoma, which starts in ...

87

DRY EYE SYNDROME  

Directory of Open Access Journals (Sweden)

Full Text Available Objective: To determine the frequency of dry eye syndrome in adult patients. Study Design: A descriptive study. Setting: Eye Department Military Hospital Rawalpindi. Period: From June 2004 to December 2004. Patients and methods: A total of hundred patients were randomly selected from the daily OPD at eye department, MH Rawalpindi. They were tested for the presence of dry eye syndrome by Rose Bengal staining, Schirmer tear strip measurements and Tear film break up time. Results: A total of 67 males and 33 females were recruited. Out of these 10 males and 6 females were found to be having dry eye syndrome. Mean patient age was 34.3±1.3years (range 20–60 years). Conclusion: The frequency of dry eye syndrome in adult patients attending the eye clinic of Military Hospital Rawalpindi is 16%.

TAHIR MUMTAZ MALIK

2009-01-01

88

X-Ray Ablation and Debris Venting for the HIF Point Design  

International Nuclear Information System (INIS)

This paper presents detailed design and analysis for x-ray ablation and venting in the 120-beam, 7-MJ heavy-ion fusion (HIF) 'robust' point design. The HI Robust Point Design ('RPD-2002') is a self-consistent, non-optimized system design that has been generated as a point of reference for ongoing research in the HIF program. The point design uses a thick-liquid protected chamber, derived from HYLIFE-II - no structural surfaces face the target. A ternary salt mixture called flinabe (LiNaBeF4) has been selected for the liquid structures. Detailed two-dimensional, axially symmetric TSUNAMI calculations have been performed to determine the mass of ablation debris generated by the target x-rays following ignition and to predict the venting of the debris from the inside of the pocket into the main chamber and beam lines. These calculations provide predictions of the impulse loading to the surfaces of the liquid pocket - The closest liquid structures will experience a somewhat strong impulse, but further optimization of the design will easily decrease this impulse. The integrated mass and energy fluxes of ablation and target debris reaching the beam-line magnetic shutters are given as well: A small and acceptable magnetic dipole will prevent any debris ingression up in the final focus magnet region

2003-01-01

89

Design of 16-point Radix-4 Fast Fourier Transform in 0.18µm CMOS Technology  

Directory of Open Access Journals (Sweden)

Full Text Available This paper introduces detail design of semi-custom CMOS Fast Fourier Transform (FFT) architecture for computing 16-point radix-4 FFT. FFT is one of the most widely used algorithms in digital signal processing. It is used in many signal processing and communication application as an important block for various multi-carrier systems such as for WLAN (Wireless local area network). This paper describes the design of an ASIC (Application Specific Integrated Circuit) CMOS FFT processor for 16-point radix-4 complex FFT computation, realized utilizing 0.18µm standard CMOS technology. Fixed point data format is preferred in comparison of floating point data format for a shorter dynamic range and reduced hardware utilization; thus, catering to the needs of portability. Furthermore, computations results at particular stage are rounded to avoid overflow issue and to be stored in register. The computation speed of the design is observed to be 50MHz after the synthesis process. Compared to traditional radix-4 algorithm the architecture proposed for 16-point FFT results in 1.73% of power saving and 5.5% of area reduction.

Siva K. Palaniappan; Tun Z.A. Zulkifli

2007-01-01

90

High Performance Hardware Design Of IEEE Floating Point Adder In FPGA With VHDL  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper, we present the design and implementation of a floating-point adder that is compliant with the current draft revision of this standard. We provide synthesis results indicating the estimated area and delay for our design when it is pipelined to various depths.Our work is an important design resource for development of floating-point adder hardware on FPGAs. All sub components within the floating-point adder and known algorithms are researched and implemented to provide versatility and flexibility to designers as an alternative to intellectual property where they have no control over the design. The VHDL code is open source and can be used by designers with proper reference. Each of the sub-operation is researched for different implementations and then synthesized onto a Spartan FPGA device to be chosen for best performance. Our implementation of the standard algorithm occupied 370 slices and had an overall delay of 31 ns. The standard algorithm was pipelined into five stages to run at 100 MHz which took an area of 324 slices and power is 30mw.

2013-01-01

91

Improvements on removing non-optimal support points in D-optimum design algorithms  

CERN Document Server

We improve the inequality used in Pronzato [2003. Removing non-optimal support points in D-optimum design algorithms. Statist. Probab. Lett. 63, 223-228] to remove points from the design space during the search for a $D$-optimum design. Let $\\xi$ be any design on a compact space $\\mathcal{X} \\subset \\mathbb{R}^m$ with a nonsingular information matrix, and let $m+\\epsilon$ be the maximum of the variance function $d(\\xi,\\mathbf{x})$ over all $\\mathbf{x} \\in \\mathcal{X}$. We prove that any support point $\\mathbf{x}_{*}$ of a $D$-optimum design on $\\mathcal{X}$ must satisfy the inequality $d(\\xi,\\mathbf{x}_{*}) \\geq m(1+\\epsilon/2-\\sqrt{\\epsilon(4+\\epsilon-4/m)}/2)$. We show that this new lower bound on $d(\\xi,\\mathbf{x}_{*})$ is, in a sense, the best possible, and how it can be used to accelerate algorithms for $D$-optimum design.

Harman, Radoslav

2007-01-01

92

Hinkley Point 'C' power station public inquiry: proof of evidence on design and safety  

International Nuclear Information System (INIS)

A public inquiry has been set up to examine the planning application made by the Central Electricity Generating Board (CEGB) for the construction of a 1200 MW Pressurized Water Reactor power station at Hinkley Point (Hinkley Point ''C'') in the United Kingdom. The policy is to replicate the Sizewell ''B'' PWR design. The Hinkley Point ''C'' design is described indicating where changes in the Sizewell ''B'' design have been made to accommodate site differences. These are associated with the civil engineering construction and some of the electrical systems and do not affect the safety case. External hazards differ from site to site and the effect on the safety case of those specific to Hinkley Point are examined. The Chernobyl accident and the assessment of the United Kingdom PWR which was carried out subsequently are reviewed. The assessment indicated that no changes in the Sizewell ''B'' design and safety case were called for as a result of this accident; accident management developments are also reviewed, however. The CEGB's approach to minimizing occupational radiation doses is described. (UK)

1988-01-01

93

Implementation of an Expert System for Design of Single-Point Subsurface Oceanographic Moorings.  

Science.gov (United States)

Design of single-point subsurface moorings is done manually at present with the help of some computer programs. These programs are used for analyzing the mooring, but setting up of the initial mooring configuration and the subsequent modifications on the ...

R. A. Skop S. Kumaran

1988-01-01

94

Macular sensitivity and fixation patterns in normal eyes and eyes with uveitis with and without macular edema.  

UK PubMed Central (United Kingdom)

PURPOSE: This study aims to investigate the relationship between macular sensitivity and thickness in eyes with uveitic macular edema (UME). DESIGN: This study is a prospective observational case series. METHODS: The setting for this study was clinical practice. The study included 59 (28 with UME, 31 without UME) eyes of 26 patients with uveitis and 19 eyes of 10 normal subjects. The procedure followed was fundus-related perimetry and retinal thickness map with an automated fundus perimetry/tomography system. Main outcome measures included quantification of macular sensitivity, fixation pattern, and relationship between macular sensitivity and thickness. RESULTS: Fixation stability revealed that 56 eyes (93.44%) had stable fixation (>75% within the central 2° of point of fixation); three eyes (6.56%) were relatively unstable (<75% of fixation points located within 2°, >75% located within 4°); and no eye had unstable fixation (<75% of fixation points located within 4°). Evaluation of fixation location revealed that 45 eyes (76.27%) had central fixation location (>50% of fixation point within 0.5 mm of foveal center); seven eyes (11.86%) had peri-central fixation location (25%?<eyes (11.86%) had eccentric (<25% of fixation point within 0.5 mm) fixation location. We measured macular sensitivity and corresponding thickness in 1,708 loci of 61 study eyes. Macular sensitivity increased by 0.02 dB (95% confidence interval, 0.00, 0.06) per 1 ?m increase in the thickness for the thickness values ?280 ?m. Macular sensitivity decreased by 0.04 dB (95% CI, -0.08, -0.01) per 1 ?m increase in the thickness for the thickness values >280 ?m. CONCLUSIONS: Perimetry quantification of macular sensitivity and retinal thickness, in association with other factors, may offer novel information regarding the impact of UME on retinal function.

Sepah YJ; Hatef E; Colantuoni E; Wang J; Shulman M; Adhi FI; Akhtar A; Ibrahim M; Khwaja A; Channa R; Sophie R; Bittencourt M; Heo J; Do DV; Nguyen QD

2012-06-01

95

Clinical consequences of acrylic intraocular lens material and design: Nd:YAG-laser capsulotomy rates in 3 x 300 eyes 5 years after phacoemulsification.  

UK PubMed Central (United Kingdom)

BACKGROUND/AIMS: To investigate the incidence of Nd:YAG-laser treatment for posterior capsular opacification (PCO) over a period of 5 years from phacoemulsification in an unselected population, comparing outcomes for three acrylic intraocular lenses (IOLs). METHODS: Retrospective longitudinal cohort study comprising 900 eyes. Three subgroups of 300 eyes, receiving the AR40, AR40e (Abbott Medical Optics, Santa Ana, California), or BL27 (Bausch & Lomb, Rochester, New York) IOL respectively, were compared. Data on patient age, gender, IOL type, dates of cataract surgery, Nd:YAG-laser treatment and/or death, and visual acuities before/after cataract surgery/Nd:YAG-laser treatment were collected from five sources: cataract operation register, patient administration system, quality control system for cataract operations, Nd:YAG-laser treatment register and clinical patient records. RESULTS: 216 eyes (24%) received Nd:YAG-laser treatment over a 5-year period. Statistically significant differences (p<0.001, chi(2) test) were found between treatment rates for the three IOLs: AR40 73 eyes (24%), BL27 91 eyes (30%) and AR40e 52 eyes (17%). Eyes of patients who died during the follow-up period had fewer treatments (23/266, 8.6%) than eyes of patients living (193/634, 30%) at the end of the follow-up period. CONCLUSION: In comparison with a hydrophobic acrylic IOL with sharp posterior optic edge, a hydrophilic acrylic IOL was associated with almost twice the number of Nd:YAG-laser treatments over the 5-year period. The results are useful for discussing the economic long-term consequences of choosing an IOL with a design that makes PCO development more or less likely. Caution is advised when applying data from post-mortem PCO studies on living populations.

Johansson B

2010-04-01

96

Eye Injuries at Home  

Science.gov (United States)

... Eyes & the Sun Eye Health News Consumer Alerts Eye Injuries at Home Tweet Eye Health Lifestyle Topics Preventing Eye Injuries Healthy Eyes ... damage to your eyes. Cozy Home Causing Dry Eye? In winter, when indoor heating is in use, ...

97

Compact reversed-field pinch reactors (CRFPR): sensitivity study and design-point determination  

International Nuclear Information System (INIS)

If the costing assumptions upon which the positive assessment of conventional large superconducting fusion reactors are based proves overly optimistic, approaches that promise considerably increased system power density and reduced mass utilization will be required. These more compact reactor embodiments generally must operate with reduced shield thickness and resistive magnets. Because of the unique, magnetic topology associated with the Reversed-Field Pinch (RFP), the compact reactor embodiment for this approach is particularly attractive from the viewpoint of low-field resistive coils operating with Ohmic losses that can be made small relative to the fusion power. A comprehensive system model is developed and described for a steady-state, compact RFP reactor (CRFPR). This model is used to select a unique cost-optimized design point that will be used for a conceptual engineering design. The cost-optimized CRFPR design presented herein would operate with system power densities and mass utilizations that are comparable to fission power plants and are an order of magnitude more favorable than the conventional approaches to magnetic fusion power. The sensitivity of the base-case design point to changes in plasma transport, profiles, beta, blanket thickness, normal vs superconducting coils, and fuel cycle (DT vs DD) is examined. The RFP approach is found to yield a point design for a high-power-density reactor that is surprisingly resilient to changes in key, but relatively unknown, physics and systems parameters

1982-01-01

98

Design status of ITER visible/IR outer strike point view  

International Nuclear Information System (INIS)

For ITER visible/IR imaging of the outer strike point from the six upper ports currently assigned, we show an optical design that provides a 4 mm Airy disk at 5 ?m wavelength at the farthest point in the field of view (much smaller in the visible), with as complete toroidal coverage of the vertical target as possible. Plasma and optical effects provide fundamental limits on the performance and design of the system. Some effects involve interactions of the surfaces with the plasma, such as plasma transport and deposition of material on the surfaces to be viewed, plasma damage to those surfaces, and molecular emission by the plasma at IR wavelengths. We discuss a detailed optical design including the endoscope concept, entrance aperture and collection head, relay optics, and camera specifications and performance. We assess integration times for capture of IR emission from surfaces and visible line emission predicted by boundary modeling.

2009-06-15

99

The ARIES-I high-field-tokamak reactor: Design-point determination and parametric studies  

Energy Technology Data Exchange (ETDEWEB)

The multi-institutional ARIES study has examined the physics, technology, safety, and economic issues associated with the conceptual design of a tokamak magnetic-fusion reactor. The ARIES-I variant envisions a DT-fueled device based on advanced superconducting coil, blanket, and power-conversion technologies and a modest extrapolation of existing tokamak physics. A comprehensive systems and trade study has been conducted as an integral and ongoing part of the reactor assessment in order to identify an acceptable design point to be subjected to detailed analysis and integration as well as to characterize the ARIES-I operating space. Results of parametric studies leading to the identification of such a design point are presented. 15 refs., 6 figs., 2 tabs.

Miller, R.L.

1989-01-01

100

Linear-quadratic-regulator pointing control system design for a high-altitude balloon payload  

Energy Technology Data Exchange (ETDEWEB)

A pointing control system design for the science package of a NASA high-altitude research balloon is described. The balloon assembly consists of a single helium balloon connected to a payload recovery parachute, payload gondola, and ballast hopper. Pointing of the scientific payload is accomplished via an arrangement of drive motors and a flywheel. Linear quadratic regulator (LQR) synthesis techniques are employed to produce the azimuth and elevation controller designs. The use of LQR synthesis is motivated by the azimuthal dynamic coupling encountered between the balloon and gondola. Two control devices are employed in azimuth, one of which is a decoupler motor and the other a flywheel. The decoupler motor is intended to isolate the gondola from the balloon such that the flywheel can be accelerated or decelerated about a steady-state angular velocity to provide precise azimuthal pointing. The multiple-input/multiple-output nature of the azimuth pointing problem is best handled in a matrix synthesis procedure such as LQR. The controller design methodology is explained, and a combination of time responses and singular value analyses are used to analytically evaluate the performance of the control system. 11 refs., 17 figs.

White, J.E.; Etter, J.R.

1987-11-01

 
 
 
 
101

SIM Lite Guide-2 telescope system identification, control design and pointing performance evaluation  

Science.gov (United States)

The Guide-2 telescope (G2T) is an important subsystem of the new SIM Lite Astrometric Observatory. In this paper we present system identification experiments, design and implementation of the G2T stellar pointing loop that achieves milliarcsecond resolution of spacecraft attitude. Special emphasis was placed on characterization and modeling of PZT hysteresis since this nonlinearity plays an important part in the control loop performance. Power spectral densities of the star image centroids were use to evaluate the pointing loop performance with and with out the presence of simulated ACS disturbances injected via a fast steering mirror (FSM).

Shields, Joel F.; Boussalis, Dhemetrio; Fathpour, Nanaz; Weilert, Mark; Hahn, Inseob; Ahmed, Asif

2010-07-01

102

Design and validation of a scanning Shack Hartmann aberrometer for measurements of the eye over a wide field of view  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Peripheral vision and off-axis aberrations not only play an important role in daily visual tasks but may also influence eye growth and refractive development. Thus it is important to measure off-axis wavefront aberrations of human eyes objectively. To achieve efficient measurement, we incorporated a...

Wei, Xin; Thibos, Larry

103

The Design Of Speech-Control Power Point Presentation Tool Using Arm7  

Directory of Open Access Journals (Sweden)

Full Text Available This paper was mainly exploring the important tool for many people who were exchanging knowledge especially proceeding power-point presentation as one auxiliary tool. The lecturer’s most proper position should be between the audience and screen of power-point and this location is far away the mouse or keyboard and also if he want go for particular slide using mouse or keyboard is long process, so if we have designed one facility with wireless control and could be controlled with speech-recognition function so that users need not rush between the screen and computer and also he can easily go for particular slide. Today some identical products with RF [1] and push function on the power-point pen that needs users to pre-learn the functions and those usage often caused errors especially in the dark environment, so in this paper we combined WSN ZigBee modules [2] with speech-recognition function and ARM7 based LPC2148 microcontroller to design the creative product, so to called “Hi-TEC ZigBee remotecontroller of Power-Point presentation”.

P.Vishnu Kumar, Dr.T.JayaChandra Prasad

2012-01-01

104

Eye Melanoma  

Science.gov (United States)

... be reprinted for personal, noncommercial use only. Eye melanoma By Mayo Clinic staff Original Article: http://www.mayoclinic.com/health/eye-melanoma/DS00707 Definition Symptoms Causes Risk factors Complications Preparing ...

105

Stereo and eye movement.  

UK PubMed Central (United Kingdom)

We describe a method to solve stereo correspondence using controlled eye (or camera) movements. Eye movements supply additional image frames and monocular depth estimate, which can be used to constrain stereo matching. Because the eye movements are small, traditional stereo techniques of stereo with multiple frame will not work. We develop an alternative approach using a systematic analysis to define a probability distribution for the errors. Our matching strategy then matches the most probable points first, thereby reducing the ambiguity for the remaining matches. We demonstrate this algorithms with several examples.

Geiger D; Yuille A

1989-01-01

106

How do design features influence consumer attention when looking for nutritional information on food labels? Results from an eye-tracking study on pan bread labels.  

UK PubMed Central (United Kingdom)

The aim of this work was to evaluate consumer visual processing of food labels when evaluating the salt content of pan bread labels and to study the influence of label design and nutritional labelling format on consumer attention. A total of 16 pan bread labels, designed according to a full factorial design, were presented to 52 participants, who were asked to decide whether the sodium content of each label was medium or low, while their eye movements were recorded using an eye tracker. Results showed that most participants looked at nutrition labels and the traffic light system to conclude on the salt content of the labels. However, the average percentage of participants who looked at the actual sodium content was much lower. Nutrition information format affected participants' processing of nutrition information. Among other effects, the inclusion of the traffic light system increased participants' attention towards some kind of nutrition information and facilitated its processing, but not its understanding.

Antúnez L; Vidal L; Sapolinski A; Giménez A; Maiche A; Ares G

2013-08-01

107

Measuring Software Functionality Using Function Point Method Based On Design Documentation  

Directory of Open Access Journals (Sweden)

Full Text Available Estimated value of software as agreed by the end user and the developer team should be expressed in a certain magnitude, one of which is the measure of functionality. Function Point (FP) Method is one of the methods used to obtain the size of the functionality and can be used to estimate cost, duration, and amount of resources required by a software project. However, Function Point measurement is not simple and requires expertise in software analysis. Furthermore, the results of the calculation are considered valid if it is verified by someone with International Function Point User Group (IFPUG) certification. This research aims at designing and implementing a system that makes users convenient in analyzing software functionality size based on FP method referring to IFPUG CPM 4.3.1 standards. The system helps users to perform FP analysis in a faster and easier way without sacrificing accuracy. The input for the system is XMI document resulting from software design documentation derived from UML documents. The study also reveals that the more complete UML documents of the software in the project, the more accurate the FP calculation results obtained.

Anie Rose Irawati; Khabib Mustofa

2012-01-01

108

Critical Points of Contact : Exploring networked relations in urban mobility and service design  

DEFF Research Database (Denmark)

In contemporary urban societies multiple networks and systems interact, overlap, exist in parallel, converge, conflict etc. creating unforeseen complexity and less transparency. By exploring how layered networks of physical movement, service information, goods delivery, commercial communication etc. are connected (and disconnected) we get a much better understanding of how to design and intervene regardless if we are thinking about public spaces in the city or new systems of service design. The many networks orchestrating and facilitating contemporary everyday life are dependent on the strategic sites where the networks meet and establish contact. Thus we argue for the usefulness of the notion of Critical Point of Contact (CPC) to deepen our understanding of the actual life within networks. En route to this notion we draw upon theories within as diverse realms such as interaction design, service design, geography, and mobility studies. After the introduction in section we develop and define the notion of CPC based upon a broad set of disciplines and theories. We illustrate the usefulness of the notion within the field of mobility in the network city and within the field of service design. The paper ends with concluding remarks and perspectives for further theoretical as well as empirical work in prolongation of this beginning research effort.

Jensen, Ole B.; Morelli, Nicola

2011-01-01

109

Raine Eye Health Study: Design, Methodology and Baseline Prevalence of Ophthalmic Disease in a Birth-cohort Study of Young Adults.  

UK PubMed Central (United Kingdom)

ABSTRACT Purpose: The Raine Eye Health Study (REHS) was conceived to determine the prevalence of and risk factors for eye disease in young adults, and to characterize ocular biometric parameters in a young adult cohort. This article summarizes the rationale and study design of REHS and outlines the baseline prevalence of ophthalmic disease in this population. Methods: The Western Australian Pregnancy Cohort (Raine) Study originated as a randomized-controlled trial of 2900 women recruited from the state's largest maternity hospital. Their offspring (N?=?2868) have been followed at birth, ages 1, 2, 3, 5, 8, 10, 14, 17 and 20 years of age in a prospective cohort study. DNA has been collected from participants for genome-wide association studies. At the 20-year follow-up participants completed a comprehensive eye assessment that included visual acuity, orthoptic assessment and cycloplegic autorefraction, as well as several ocular biometric variables and multiple ophthalmic photographs of the anterior and posterior segments. Results: A total of 1344 participants (51.3% male) were assessed over a 24-month period. For the majority of examined participants (85.5%) both parents were Caucasian, 63.3% had completed school year 12 or equivalent, 5.5% had myopia (spherical equivalent ?-3 diopters) and 15 participants (1.2%) had unilateral or bilateral pterygia. Keratoconus, cataract, keratitis and uveitis were rare. Conclusion: The REHS design and methodology allow comparison with other population-based studies of eye disease. The study established the prevalence of eye disorders in a large sample of predominantly Caucasian young Australian adults.

Yazar S; Forward H; McKnight CM; Tan A; Soloshenko A; Oates SK; Ang W; Sherwin JC; Wood D; Mountain JA; Pennell CE; Hewitt AW; Mackey DA

2013-01-01

110

Fixed-Point Design of Generalized Comb Filters: A Statistical Approach  

CERN Multimedia

This paper is concerned with the problem of designing computationally efficient Generalized Comb Filters (GCF). Basically, GCF filters are anti-aliasing filters that guarantee superior performance in terms of selectivity and quantization noise rejection compared to classical comb filters, when used as decimation filters in multistage architectures. Upon employing a partial polyphase (PP) architecture proposed in a companion paper, we develop a sensitivity analysis in order to investigate the effects of the coefficients' quantization on the frequency response of the designed filters. We show that the sensitivity of the filter response to errors in the coefficients is dependent on the particular split of the decimation factor between the two sub-filters constituting the PP architecture. The sensitivity analysis is then used for developing a fixed-point implementation of a sample filter from the class of GCF filters, used as reference filter throughout the paper. Finally, we present computer simulations in order...

Laddomada, Massimiliano

2008-01-01

111

Design Heuristics for Mapping Floating-Point Scientific Computational Kernels onto High Performance Reconfigurable Computers  

Directory of Open Access Journals (Sweden)

Full Text Available Because of the increasing need to develop efficient high-speed computational kernels, researchers have been looking at various acceleration technologies. One approach is to use field programmable gate arrays (FPGAs) in conjunction with general purpose processors to form what are known as high performance reconfigurable computers (HPRCs). HPRCs have already been shown to work well for both fixed-point and integer calculations. Floating-point calculations are a different matter; obtaining speedups has been somewhat elusive. This article, after introducing the three primary HPRC development flows, takes a detailed look at “the three p’s,” which addresses the crucial relationship among performance, pipelining, and parallelism. It also examines “the FPGA design boundary,” which addresses some of the heuristics that allow developers to determine which application modules can be mapped onto the FPGAs. These ideas are illustrated by way of a simple floating-point application that is mapped onto a contemporary HPRC. This article expands upon earlier work by including details on how to map customized intellectual property cores into an HPRC environment via a hybrid development flow.

Justin L. Rice; Khalid H. Abed; Gerald R. Morris

2009-01-01

112

Alternative design of inductive pointing device for oral interface for computers and wheelchairs.  

UK PubMed Central (United Kingdom)

An inductive pointing device was designed and implemented successfully in a tongue controlled oral interface. Sensors were manufactured as an assembly of multilayer coils in the printed circuit board technology on two pads. The sensor pads were encapsulated together with electronics and battery in a mouthpiece, placed in the upper palate of the oral cavity. The PCB technology allowed surface activation of one or more sensors by gliding over the surface of the coils assembly of a small cylindrical unit attached to the tongue. The model consisted of 8 sensors and allowed real time proportional control of both speed and direction similar to a joystick. However, the size of the oral cavity, the number and geometry of the coil loops and characteristics of the activation unit impose limits in designing the sensors and call for an alternative layout design. Two alternative sensor designs are proposed in this paper, aiming to reduce the size of the sensor pad by one third, extending the target group, including children, and increasing the easiness of wear of the oral interface.

Lontis ER; Andreasen Struijk LN

2012-01-01

113

Alternative design of inductive pointing device for oral interface for computers and wheelchairs.  

Science.gov (United States)

An inductive pointing device was designed and implemented successfully in a tongue controlled oral interface. Sensors were manufactured as an assembly of multilayer coils in the printed circuit board technology on two pads. The sensor pads were encapsulated together with electronics and battery in a mouthpiece, placed in the upper palate of the oral cavity. The PCB technology allowed surface activation of one or more sensors by gliding over the surface of the coils assembly of a small cylindrical unit attached to the tongue. The model consisted of 8 sensors and allowed real time proportional control of both speed and direction similar to a joystick. However, the size of the oral cavity, the number and geometry of the coil loops and characteristics of the activation unit impose limits in designing the sensors and call for an alternative layout design. Two alternative sensor designs are proposed in this paper, aiming to reduce the size of the sensor pad by one third, extending the target group, including children, and increasing the easiness of wear of the oral interface. PMID:23366638

Lontis, Eugen R; Andreasen Struijk, Lotte N S

2012-01-01

114

[The theory of floating eye model].  

Science.gov (United States)

Analytical construction of the eye floating was carried out. Buoyancy equations were deduced including the equation for dynamic equilibrium at various eye (head) orientations in space. Design formulae were derived for evaluating buoyancy force on the eye, negative pressure, stability and compensational (heeling) forces of the eye muscles. PMID:2346754

Galoian, V R

115

[The theory of floating eye model  

UK PubMed Central (United Kingdom)

Analytical construction of the eye floating was carried out. Buoyancy equations were deduced including the equation for dynamic equilibrium at various eye (head) orientations in space. Design formulae were derived for evaluating buoyancy force on the eye, negative pressure, stability and compensational (heeling) forces of the eye muscles.

Galoian VR

1990-01-01

116

Clinical decision support system for point of care use--ontology-driven design and software implementation.  

UK PubMed Central (United Kingdom)

OBJECTIVES: The objective of this research was to design a clinical decision support system (CDSS) that supports heterogeneous clinical decision problems and runs on multiple computing platforms. Meeting this objective required a novel design to create an extendable and easy to maintain clinical CDSS for point of care support. The proposed solution was evaluated in a proof of concept implementation. METHODS: Based on our earlier research with the design of a mobile CDSS for emergency triage we used ontology-driven design to represent essential components of a CDSS. Models of clinical decision problems were derived from the ontology and they were processed into executable applications during runtime. This allowed scaling applications' functionality to the capabilities of computing platforms. A prototype of the system was implemented using the extended client-server architecture and Web services to distribute the functions of the system and to make it operational in limited connectivity conditions. RESULTS: The proposed design provided a common framework that facilitated development of diversified clinical applications running seamlessly on a variety of computing platforms. It was prototyped for two clinical decision problems and settings (triage of acute pain in the emergency department and postoperative management of radical prostatectomy on the hospital ward) and implemented on two computing platforms--desktop and handheld computers. CONCLUSIONS: The requirement of the CDSS heterogeneity was satisfied with ontology-driven design. Processing of application models described with the help of ontological models allowed having a complex system running on multiple computing platforms with different capabilities. Finally, separation of models and runtime components contributed to improved extensibility and maintainability of the system.

Farion K; Michalowski W; Wilk S; O'Sullivan D; Rubin S; Weiss D

2009-01-01

117

Design and validation of a scanning Shack Hartmann aberrometer for measurements of the eye over a wide field of view.  

Science.gov (United States)

Peripheral vision and off-axis aberrations not only play an important role in daily visual tasks but may also influence eye growth and refractive development. Thus it is important to measure off-axis wavefront aberrations of human eyes objectively. To achieve efficient measurement, we incorporated a double-pass scanning system with a Shack Hartmann wavefront sensor (SHWS) to develop a scanning Shack Hartmann aberrometer (SSHA). The prototype SSHA successfully measured the off-axis wavefront aberrations over +/- 15 degree visual field within 7 seconds. In two validation experiments with a wide angle model eye, it measured change in defocus aberration accurately (<0.02microm, 4mm pupil) and precisely (<0.03microm, 4mm pupil). A preliminary experiment with a human subject suggests its feasibility in clinical applications. PMID:20173936

Wei, Xin; Thibos, Larry

2010-01-18

118

Design and validation of a scanning Shack Hartmann aberrometer for measurements of the eye over a wide field of view.  

UK PubMed Central (United Kingdom)

Peripheral vision and off-axis aberrations not only play an important role in daily visual tasks but may also influence eye growth and refractive development. Thus it is important to measure off-axis wavefront aberrations of human eyes objectively. To achieve efficient measurement, we incorporated a double-pass scanning system with a Shack Hartmann wavefront sensor (SHWS) to develop a scanning Shack Hartmann aberrometer (SSHA). The prototype SSHA successfully measured the off-axis wavefront aberrations over +/- 15 degree visual field within 7 seconds. In two validation experiments with a wide angle model eye, it measured change in defocus aberration accurately (<0.02microm, 4mm pupil) and precisely (<0.03microm, 4mm pupil). A preliminary experiment with a human subject suggests its feasibility in clinical applications.

Wei X; Thibos L

2010-01-01

119

Principles for the design and calibration of radiation protection dosemeters for operational and protection quantities for eye lens dosimetry  

International Nuclear Information System (INIS)

[en] The work package two of the ORAMED project-Collaborative Project (2008-2011) supported by the European Commission within its seventh Framework Programme-is devoted to the study of the eye lens dosimetry. A first approach is to implement the use of Hp(3) by providing new sets of conversion coefficients and well suited calibration and type test procedures. This approach is presented in other papers in the proceedings of this conference. Taking into account that the eye lens is an organ close to the surface of the body, another approach would be to directly estimate the absorbed dose to the eye lens, Dlens,est through a special calibration procedure although this quantity is not directly measurable. This paper is a methodological paper that tries to identify the critical aspects of a dosimetry in terms of Dlens. (authors)

2011-01-01

120

Designing DOKK1 from a child’s point of view  

DEFF Research Database (Denmark)

Designing DOKK1 from a child’s point of view By Aviaja Borup Lynggaard & Birgitte Geert Jensen This poster presents a design case of collaborative innovation between design students from Aarhus School of Architecture and pupils from the public school, Samsøgades School in Aarhus, facilitated by the research project Kids n’Tweens Lifestyle. The scope of collaborating was to design the content for DOKK1, the new Mediaspace center in Aarhus, where design students took offset from the children’s world in a creative workshop as inspiration for the final design proposals. The task was carried out in collaboration with the working group on the new Dokk1 and the goal was to create a library that makes sense for the whole family. Some of the questions that the students wanted to answer was: • How can you create a library where there are joint activities that makes sense for the whole family? • How to create fun for families in the library? • How can play help to promote interaction and communication? The students worked with the space in Dokk1 as the “third place”, which is identified by Oldenburg (1999) as “great good places”, being public places on neutral ground where people can gather and interact. The cooperative design workshop led to a range of insights and inspiration for the students to implement in their design solutions. An issue that the workshop revealed concerned a variety of interests and requirements when designing across ages. The age difference between users calls for variations in the use of space and design. The workshop also showed that the “third place” is achieved today in existing places around the city, such as in shops and banks. Therefore, several of the solutions showed that there is need to create a residence that can accommodate the versatility and give space for user participation. The workshop was facilitated by Kids n’Tweens Lifestyle, as part of method development when engaging children in the design process. 8 groups were formed and a range of creative methods was tested. The methods varied from: Model making, lego prototyping, mood boards/blocks, inspirational pictures, future scenarios (library in 500 years), thinking out loud, body storming and sketching. The outcome led to new insights about the end users and an ideacatalogue for the students to elaborate from. The poster will present two design results – “Bookscape” and “Tumble”. Bookscape took offset from the children’s aspiration to create small and private spaces, as the shelves can be moved and thus act as space makers. The storage of the books provides a platform where new activities can take place. Tumble took offset from the pupils’ request towards being able to perform multiple activities in DOKK1. This led to the design of transformative furniture that can be rolled around on 4 different edges that each enables different activities. We presented an innovative collaboration between design students and pupils from a public school. A creative workshop led to manifold projects, where two are presented in this poster to exemplify how the inputs from children can feed a creative design process.

Geert Jensen, Birgitte; Borup Lynggaard, Aviaja

 
 
 
 
121

Focal choroidal excavation in eyes with central serous chorioretinopathy.  

UK PubMed Central (United Kingdom)

PURPOSE: To study the prevalence and 3-dimensional (3-D) tomographic features of focal choroidal excavations in eyes with central serous chorioretinopathy (CSC) using swept-source optical coherence tomography (OCT). DESIGN: Prospective, cross-sectional study. METHODS: We examined 116 consecutive eyes with CSC with a prototype 3-D swept-source OCT. 3-D images of the shape of the macular area, covering 6 × 6 mm(2), were reconstructed by segmentation of the outer surface of the retinal pigment epithelium (RPE). RESULTS: The 3-D swept-source OCT detected focal choroidal excavations in 9 eyes (7.8%). The 3-D scanning protocol, coupled with en face scans, allowed for clear visualization of the excavation morphology. In 5 eyes with focal excavations, unusual choroidal tissue was found beneath the excavation, bridging the bottom of the excavation and the outer choroidal boundary. Additionally, 3 of those 5 eyes showed a suprachoroidal space below the excavation, as if the outer choroidal boundary is pulled inward by this bridging tissue. The focal choroidal excavations were located within fluorescein leakage points and areas of choroidal hyperpermeability. Eyes with focal choroidal excavations were more myopic (-4.42 ± 2.92 diopters) than eyes without excavations (-0.27 ± 1.80 diopters, P = .001). Subfoveal choroidal thickness was significantly thinner (301.3 ± 60.1 ?m) in eyes with focal excavations than in eyes without the excavations (376.6 ± 104.8 ?m, P = .036). CONCLUSIONS: Focal choroidal excavations were present in 7.8% of eyes with CSC. In these eyes, focal choroidal excavations may have formed from RPE retraction caused by focal scarring of choroidal connective tissue.

Ellabban AA; Tsujikawa A; Ooto S; Yamashiro K; Oishi A; Nakata I; Miyake M; Akagi-Kurashige Y; Ueda-Arakawa N; Arichika S; Yoshitake S; Takahashi A; Yoshimura N

2013-10-01

122

Using eye-tracking methodology in consumer science  

DEFF Research Database (Denmark)

Eye-tracking methodology will soon be mature enough to become a standard tool in consumer science. The workshop will begin with a short overview of the perceptual and attention processes that can be measured by eye-tracking. The available hardware and software will be compared, and typical experimental designs will be discussed that can be recommended for eye-tracking studies in consumer science. The application potential will then be demonstrated in four case presentations, focusing on different product categories (from dairy products to alcoholic beverages), measurement contexts (laboratory versus point of purchase) and study goals (appearance studies, package design, identification of food choice motives). Furthermore, the presentations will discuss how different components of attention can be distinguished based on eye-tracking data (stimulus-driven versus task-driven processes) and how the explanatory power of eye-tracking studies can be boosted by combining eye-tracking with other methodologies (shelf simulations, choice experiments, neuroimaging techniques). The workshop will conclude with an open discussion in which participants can consult the presenters on the applicability of eye-tracking methods in their own research.

Bialkova, S.; Mueller Loose, Simone

123

Patient-perceived pain during laser in situ keratomileusis: comparison of fellow eyes.  

UK PubMed Central (United Kingdom)

PURPOSE: To compare pain scores during laser in situ keratomileusis (LASIK) between first-eye surgery and second-eye surgery. SETTING: Private practice, Beirut, Lebanon. DESIGN: Cohort study. METHODS: Sequential bilateral LASIK was performed between January 2010 and January 2011 by the same surgeon using a Schwind Amaris excimer laser. Hemodynamics and intraocular pressure (IOP) were monitored intraoperatively. Patients graded their pain perception on a 4-point scale after the completion of each eye's surgery. RESULTS: The study enrolled 154 patients. The first surgery was performed in the right eye in 106 patients and in the left eye in 48 patients. Patients reported discomfort during suction (mean pain score 0.80 ± 0.56 [SD]). More pain was reported during second-eye surgery by 74% of patients; 2% reported more pain in the first eye, and 24% reported equal pain in both eyes. The mean pain score was 0.63 ± 0.35 in the first eye and 0.93 ± 0.51 in the second eye (P=.01). Pain was higher during second-eye surgery whether the procedure was started in the right eye or in the left eye. Systolic blood pressure was also higher during second-eye surgery (P=.001). There was no statistically significant difference in diastolic blood pressure, heart rate, IOP, or suction-ring pressure. CONCLUSIONS: Patients had more pain during second-eye LASIK for reasons that are not clear. A psychological explanation or regional sensitization processes are potential factors and should be studied. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

El Rami H; Fadlallah A; Fahd D; Fahed S

2012-03-01

124

Interaction point feedback design and integrated simulations to stabilize the CLIC final focus  

CERN Document Server

The Compact Linear Collider (CLIC) accelerator has strong precision requirements on the offset position between the beams. Sensitive to ground motion (GM), the beam needs to be stabilized to unprecedented requirements. Different Beam Based Feedback (BBF) algorithms such as Orbit Feedback (OFB) and Interaction Point Feedback (IPFB) have been designed. This paper focuses on the IPFB control which could be added to the CLIC baseline. IPFB control has been tested for different GM models in presence of noises or disturbances and it uses digital linear control with an adaptive loop. The simulations demonstrate that it is possible to achieve the required performances and quantify the maximum allowed noise level. This amount of admitted noises and disturbances is given in terms of an equivalent disturbance on the position of the magnet that controls the beam offset. Due to the limited sampling frequency of the process, the control loop is in a very small bandwidth. The study shows that these disturbances have to be l...

Balik, G; Deleglise, G; Jeremie, A; Pacquet, L; Badel, A; Caron, B; Le Breton, R; Latina, A; Pfingstner, J; Schulte, D; Snuverink, J

2011-01-01

125

From Takeoff to Landing: Looking at the Design Process for the Development of NASA Blast at Thanksgiving Point  

Directory of Open Access Journals (Sweden)

Full Text Available In this article we discuss the process of design used to develop and design the NASA Blast exhibition at Thanksgiving Point, a museum complex in Lehi, Utah. This was a class project for the Advanced Instructional Design Class at Brigham Young University. In an attempt to create a new discourse (Krippendorff, 2006) for Thanksgiving Point visitors and staff members, the design class used a very fluid design approach by utilizing brainstorming, researching, class member personas, and prototyping to create ideas for the new exhibition. Because of the nature of the experience, the design class developed their own techniques to enhance the process of their design. The result of the design was a compelling narrative that brought all the elements of the exhibition together in a cohesive piece.

Stephen Ashton; Anne M. Foisy; Richard Marwedel; J. Aaron Popham; Keith R. Proctor; Daniel L. Randall; Isaku Tateishi; Carrie A. Thompson; Andrew S. Gibbons

2011-01-01

126

Point Frequency Analysis for Determining the Design Flood at Indogyo Site  

Energy Technology Data Exchange (ETDEWEB)

A point frequency analysis is carried out for the Indogyo site at the Han River using 68 annual maximum flood data for the period of 1918{approx}1992. Computed frequency discharges using the three parameter log-normal, type-I extreme value, type-III extreme value, and Person type-III distributions show the appropriate results, and the 100 and 200 year return period flood are computed as 35500 m{sup 3}/sec and 39000 m{sup 3}/sec, respectively, 33500 m{sup 3}/sec and 37500 m{sup 3}/sec of corresponding return periods are computed when the flood control effect of the dams are taken into account. The resulting flood discharge of 37500 m{sup 3}/sec is similar to the current design flood of 37000 m{sup 3}/sec in downstream reach of Han river, so, it could be desirable to keep the current design flood, considering the increasing tendency of the flood due to the climate change. (author). 14 refs., 9 tabs., 4 figs.

Yoon, Yong Nam [Korea University, Seoul (Korea); Wone, Seog Yeon [Daewoo Engineering Co., Seoul (Korea)

1998-08-31

127

An eye on eye development.  

UK PubMed Central (United Kingdom)

The vertebrate eye is composed of both surface ectodermal and neuroectodermal derivatives that evaginate laterally from an epithelial anlage of the forming diencephalon. The retina is composed of a limited number of neuronal and non-neuronal cell types and is seen as a model for the brain with reduced complexity. The eye develops in a stereotypic manner building on evolutionarily conserved molecular networks. Eye formation is initiated at the onset of gastrulation by the determination of the eye field in the anterior neuroectoderm. Homeobox transcription factors, in particular Six3 are crucially involved in the establishment and maintenance of retinal identity. The eye field expands by proliferation as gastrulation proceeds and is initially confined to a single retinal primordium by the differential activity of specifying transcription factors. This central field is subsequently split in response to secreted factors emanating from the ventral midline. Concomitant with medio-lateral patterning at the onset of neurulation, morphogenesis sets in and laterally evaginates the optic vesicle. Strikingly during this process the neuroectoderm in the eye field transiently loses epithelial features and cells migrate individually. In a second morphogenetic event, the vesicle is transformed into the optic cup, concomitant with onset and progression of retinal differentiation. Accompanying optic cup morphogenesis, neural differentiation is initiated from a retinal signalling centre in a stereotypic and species specific manner by secreted signalling factors. Here we will give an overview of key events during vertebrate eye formation and highlight key players in the respective processes.

Sinn R; Wittbrodt J

2013-06-01

128

Platelet-Oriented Inhibition in New TIA and Minor Ischemic Stroke (POINT) Trial: Rationale and design.  

UK PubMed Central (United Kingdom)

BACKGROUND: Ischemic stroke and other vascular outcomes occur in 10-20% of patients in the three-months following a transient ischemic attack or minor ischemic stroke, and many are disabling. The highest risk period for these outcomes is the early hours and days immediately following the ischemic event. Aspirin is the most common antithrombotic treatment used for these patients. AIM: The aim of POINT is to determine whether clopidogrel plus aspirin taken <12?h after transient ischemic attack or minor ischemic stroke symptom onset is more effective in preventing major ischemic vascular events at 90 days in the high-risk, and acceptably safe, compared with aspirin alone. DESIGN: POINT is a prospective, randomized, double-blind, multicenter trial in patients with transient ischemic attack or minor ischemic stroke. Subjects are randomized to clopidogrel (600?mg loading dose followed by 75?mg/day) or matching placebo, and all will receive open-label aspirin 50-325?mg/day, with a dose of 162?mg daily for five-days followed by 81?mg daily strongly recommended. STUDY OUTCOMES: The primary efficacy outcome is the composite of new ischemic vascular events - ischemic stroke, myocardial infarction, or ischemic vascular death - by 90 days. The primary safety outcome is major hemorrhage, which includes symptomatic intracranial hemorrhage. DISCUSSION: Aspirin is the most common antithrombotic given to patients with a stroke or transient ischemic attack, as it reduces the risk of subsequent stroke. This trial expects to determine whether more aggressive antithrombotic therapy with clopidogrel plus aspirin, initiated acutely, is more effective than aspirin alone.

Johnston SC; Easton JD; Farrant M; Barsan W; Battenhouse H; Conwit R; Dillon C; Elm J; Lindblad A; Morgenstern L; Poisson SN; Palesch Y

2013-08-01

129

LASIK - Laser Eye Surgery  

Medline Plus

Full Text Available Eye Health Lifestyle Topics Preventing Eye Injuries Healthy Eyes During Pregnancy Computer Usage & Eye Strain Maintaining Your Sight with ... feet away for 20 seconds. Know Your Eye Care Team Make sure you are seeing the right ...

130

LASIK - Laser Eye Surgery  

Medline Plus

Full Text Available Eye Health Lifestyle Topics Preventing Eye Injuries Healthy Eyes During Pregnancy Computer Usage & Eye Strain Maintaining Your ... ophthalmologist—your sight depends on it. Give your Eyes a Break To prevent computer eyestrain, follow the ...

131

A stochastic point rainfall model of design storms based on 2-copula and dimensionless hyetograph  

Science.gov (United States)

In this study a stochastic model to derive synthetic design storms at a point is presented. Generated rainfall events are totally stochastic but with characteristics in terms of shape, duration and average intensity have to satisfy the parameters derived by statistical analyses of the available historic records. The main advantage of this kind of approach is its applicability when few years of sub-hourly rainfall records, not necessary continuous, are available. The events are derived on the basis of a fixed inter-event time, and selected if their average intensity is bigger than a critical fixed one. In order to characterize the shape, dimensionless events are considered. The probability function to describe the hyetograph shape chosen in this study is the Beta cumulative distribution. Storm duration and average intensity of the observed events are modelled separately by fitting several probability distribution and selecting the best one using several statistical criteria. Finally, their correlation is modelled using the Frank Copula. In order to test the methodology, two sites placed in Sicily, Italy, were sub-hourly rainfall data were available, have been analyzed. The considered raingauges stations are: Monreale, placed in North-West part of Sicily, and Palazzolo Acreide, placed in South-East part of Sicily, where 10 minutes recorded rainfall data were available. The good performance of the model has been tested by comparing the statistics of the simulated events with those of the measured data, and the obtained results confirm the effectiveness of the methodology.

Brigandì, Giuseppina; Tito Aronica, Giuseppe

2013-04-01

132

Design and Implementation of Numerical Linear Algebra Algorithms on Fixed Point DSPs  

Directory of Open Access Journals (Sweden)

Full Text Available Numerical linear algebra algorithms use the inherent elegance of matrix formulations and are usually implemented using C/C++ floating point representation. The system implementation is faced with practical constraints because these algorithms usually need to run in real time on fixed point digital signal processors (DSPs) to reduce total hardware costs. Converting the simulation model to fixed point arithmetic and then porting it to a target DSP device is a difficult and time-consuming process. In this paper, we analyze the conversion process. We transformed selected linear algebra algorithms from floating point to fixed point arithmetic, and compared real-time requirements and performance between the fixed point DSP and floating point DSP algorithm implementations. We also introduce an advanced code optimization and an implementation by DSP-specific, fixed point C code generation. By using the techniques described in the paper, speed can be increased by a factor of up to 10 compared to floating point emulation on fixed point hardware.

Nikoli? Zoran; Nguyen Ha Thai; Frantz Gene

2007-01-01

133

Eye-rubbing optic neuropathy.  

UK PubMed Central (United Kingdom)

PURPOSE: To describe a patient whose "normal tension glaucoma" appears to have been produced by a long-standing habit of repetitive, bilateral eye rubbing. DESIGN: Observational case report. METHODS: A 46-year-old man presented with a "haze" over the left eye and had progressive bilateral optic neuropathy associated with bilateral normal intraocular pressure, pathological cupping of the optic disks, and nerve fiber bundle visual field defects. RESULTS: Over a 4-year period, vision in the left eye deteriorated to no light perception. Progressive deterioration in the right eye stopped only after the patient ceased a 20-year habit of forceful rubbing of his eyes. After that, the decline in vision was terminated and both visual acuity and visual field were stabilized over an 8-year follow-up. CONCLUSION: It may be appropriate to include "eye rubbing" in the differential diagnosis of unexplained progressive optic neuropathy in presumed normal tension glaucoma.

Pecora L; Sibony P; Fourman S

2002-09-01

134

NGNP Point Design - Results of the Initial Neutronics and Thermal-Hydraulic Assessments During FY-03, Rev. 1  

International Nuclear Information System (INIS)

This report presents the preliminary preconceptual designs for two possible versions of the Next Generation Nuclear Plant (NGNP), one for a prismatic fuel type helium gas-cooled reactor and one for a pebble bed fuel helium gas reactor. Both designs are to meet three basic requirements: a coolant outlet temperature of 1000 C, passive safety, and a total power output consistent with that expected for commercial high-temperature gas-cooled reactors. The two efforts are discussed separately below. The analytical results presented in this report are very promising, however, we wish to caution the reader that future, more detailed, design work will be needed to provide final answers to a number of key questions including the allowable power level, the inlet temperature, the power density, the optimum fuel form, and others. The point design work presented in this report provides a starting point for other evaluations, and directions for the detailed design, but not final answers

2003-01-01

135

NGNP Point Design - Results of the Initial Neutronics and Thermal-Hydraulic Assessments During FY-03, Rev. 1  

Energy Technology Data Exchange (ETDEWEB)

This report presents the preliminary preconceptual designs for two possible versions of the Next Generation Nuclear Plant (NGNP), one for a prismatic fuel type helium gas-cooled reactor and one for a pebble bed fuel helium gas reactor. Both designs are to meet three basic requirements: a coolant outlet temperature of 1000 °C, passive safety, and a total power output consistent with that expected for commercial high-temperature gas-cooled reactors. The two efforts are discussed separately below. The analytical results presented in this report are very promising, however, we wish to caution the reader that future, more detailed, design work will be needed to provide final answers to a number of key questions including the allowable power level, the inlet temperature, the power density, the optimum fuel form, and others. The point design work presented in this report provides a starting point for other evaluations, and directions for the detailed design, but not final answers.

Philip E. MacDonald; James W. Sterbentz; Robert L. Sant; P. Bayless; H. D. Gougar; R. L. Moore; A. M. Ougouag; W. K. Terry

2003-09-01

136

CHEMICAL INJURIES TO EYES  

Directory of Open Access Journals (Sweden)

Full Text Available Objective: To find out the chemical agents responsible for eye injuries,assess magnitude of the problem and resultant visual outcomes in our dependent population. Design: Observationalstudy. Place and Duration of Study: Eye department, CMH, Hyderabad from Jan 2004 to Dec 2005. Patients andMethods: Thirty five patients of all ages who presented with history of chemical injury to eyes during a period of twoyears were included in this study. Patients with co-morbidity of eyes were not included. Cases were studied to find outcausative chemical agents and their nature, sex distribution, cause and place of the incident, duration of exposure (timeelapsed between chemical injury and copious irrigation at the time of presentation) and effect on visual function.Results: Chemical injuries sustained by 47 eyes of 35 patients were analyzed. All of them were accidental and mostlymales were affected at their workplace. Nearly one third of the times 12(34.29%) both eyes were affected and23(65.71%) cases were unilaterally affected. 30(85.72%) patients presented within first two hours of the injury.3(8.57%) presented within 12 hours and 2(5.72%) presented within 24 hours. Severity of injury was grade I in mosteyes i.e. 37(78.73%) and grade II in 10(21.27%). None was found to have grade III or IV injury. Immediate irrigationwas reported in 29(82.86%) cases. The visual prognosis for eyes that received immediate irrigation was significantlyimproved. 27(77.14%) cases were caused by alkalis and 8(22.86%) were due to acids. 26(74.28%) of the cases weredue to lime. A visual acuity of 6/6 was achieved in 40(85.10%) eyes at follow up after 01 week. 7(14.89%) eyesdeveloped corneal haze of varying degree resulting in BCVA of 6/9 to 6/18. Eye protection was not used in any of the35(100%) cases. 1(2.13%) eye developed cataract during follow up period and needed to be operated upon for visualrehabilitation. Conclusion: All ocular chemical injuries resulted from accidents; at work or at home and none resultedfrom assault. Most of the injured persons needed to be hospitalized on an average for 03 days. Lime was found to bethe major culprit and was found to be used extensively for painting purposes. Visual outcome correlated with severityof injury at initial presentation.

NOMAN NAZIR AHMED

2006-01-01

137

Miniature curved artificial compound eyes.  

UK PubMed Central (United Kingdom)

In most animal species, vision is mediated by compound eyes, which offer lower resolution than vertebrate single-lens eyes, but significantly larger fields of view with negligible distortion and spherical aberration, as well as high temporal resolution in a tiny package. Compound eyes are ideally suited for fast panoramic motion perception. Engineering a miniature artificial compound eye is challenging because it requires accurate alignment of photoreceptive and optical components on a curved surface. Here, we describe a unique design method for biomimetic compound eyes featuring a panoramic, undistorted field of view in a very thin package. The design consists of three planar layers of separately produced arrays, namely, a microlens array, a neuromorphic photodetector array, and a flexible printed circuit board that are stacked, cut, and curved to produce a mechanically flexible imager. Following this method, we have prototyped and characterized an artificial compound eye bearing a hemispherical field of view with embedded and programmable low-power signal processing, high temporal resolution, and local adaptation to illumination. The prototyped artificial compound eye possesses several characteristics similar to the eye of the fruit fly Drosophila and other arthropod species. This design method opens up additional vistas for a broad range of applications in which wide field motion detection is at a premium, such as collision-free navigation of terrestrial and aerospace vehicles, and for the experimental testing of insect vision theories.

Floreano D; Pericet-Camara R; Viollet S; Ruffier F; Brückner A; Leitel R; Buss W; Menouni M; Expert F; Juston R; Dobrzynski MK; L'Eplattenier G; Recktenwald F; Mallot HA; Franceschini N

2013-06-01

138

Miniature curved artificial compound eyes.  

Science.gov (United States)

In most animal species, vision is mediated by compound eyes, which offer lower resolution than vertebrate single-lens eyes, but significantly larger fields of view with negligible distortion and spherical aberration, as well as high temporal resolution in a tiny package. Compound eyes are ideally suited for fast panoramic motion perception. Engineering a miniature artificial compound eye is challenging because it requires accurate alignment of photoreceptive and optical components on a curved surface. Here, we describe a unique design method for biomimetic compound eyes featuring a panoramic, undistorted field of view in a very thin package. The design consists of three planar layers of separately produced arrays, namely, a microlens array, a neuromorphic photodetector array, and a flexible printed circuit board that are stacked, cut, and curved to produce a mechanically flexible imager. Following this method, we have prototyped and characterized an artificial compound eye bearing a hemispherical field of view with embedded and programmable low-power signal processing, high temporal resolution, and local adaptation to illumination. The prototyped artificial compound eye possesses several characteristics similar to the eye of the fruit fly Drosophila and other arthropod species. This design method opens up additional vistas for a broad range of applications in which wide field motion detection is at a premium, such as collision-free navigation of terrestrial and aerospace vehicles, and for the experimental testing of insect vision theories. PMID:23690574

Floreano, Dario; Pericet-Camara, Ramon; Viollet, Stéphane; Ruffier, Franck; Brückner, Andreas; Leitel, Robert; Buss, Wolfgang; Menouni, Mohsine; Expert, Fabien; Juston, Raphaël; Dobrzynski, Michal Karol; L'Eplattenier, Geraud; Recktenwald, Fabian; Mallot, Hanspeter A; Franceschini, Nicolas

2013-05-20

139

An experimental study on a training support system utilizing trainee's eye gaze point and think aloud protocol for diagnosing nuclear power plant anomalies  

International Nuclear Information System (INIS)

An experimental system has been developed for aiming at supporting the simulator training of diagnosis nuclear power plant anomaly, where an expert provides the instructions to a trainee by his/her own educational and experienced point of view. This system has several characteristics as follows: (1) the expert can provide the instruction through the local area network or the Internet, (2) the training task is the detection of the primary cause of plant anomaly, which is not including the plant operation but requires only thinking, and (3) the system can automatically detects the trainee's view-point and think aloud protocols and provide these two types of information to the expert in real time for supporting his/her instruction. A laboratory experiment using this system was conducted, where an expert, who had really engaged in plant operation as a chief operator, was employed as the instructor for novice students. As the result of analyzing the experimental data, it was found that the two types of information, trainee's viewpoints and his verbal protocols, have some potential of effectiveness for supporting the instructor to estimate the trainees diagnostic thinking process and provide the instruction. (author)

2003-01-01

140

Eye and orbit ultrasound  

Science.gov (United States)

Echography - eye orbit; Ultrasound - eye orbit; Ocular ultrasonography; Orbital ultrasonography ... ophthalmology department of a hospital or clinic. Your eye is numbed with medicine (anesthetic drops). The ultrasound ...

 
 
 
 
141

A CAREM reactor's design evaluation from the nuclear security point of view  

International Nuclear Information System (INIS)

The main objective of this work is to define the adequate rules for CAREM reactor security systems design and processes which aim to assure verification of the CALIN regulations 'Radiological Criteria' in relation to accidents concerning CAREM reactor design. (Author)

1990-01-01

142

Minimal plus one point designs for testing lack of fit for some sigmoid curve models.  

UK PubMed Central (United Kingdom)

D-optimal designs for nonlinear models are often minimally supported. They have been frequently criticized for their inability to test for lack of fit. We construct alternative designs to address this issue for some commonly used sigmoid curves, including logistic, probit, and Gompertz models with two, three, or four parameters. For each model, we compare five nonminimally supported designs in terms of their efficiency, and propose designs that are both statistically efficient and practically convenient for practitioners.

Su Y; Raghavarao D

2013-03-01

143

Design and development of a low-cost eye tracking system for the rehabilitation of the completely locked-in patient.  

UK PubMed Central (United Kingdom)

This article describes the design and development process of an eye tracking-based computer system that benefits from the intact ocular motor control of the completely locked-in patient to provide him or her with an alternative means of communication. A completely locked-in patient is an individual who has lost all types of motor control and communication ability with people in his or her environment. This developed system uses a head-mounted web camera to capture real-time images of the patient's eye. These images are then passed to a program, developed using Matlab, which processes them and computes the coordinates of the pupil position. The program then sends commands to an interactive JAVA-based interface, which provides the patient with a matrix of pictograms representing the most essential daily communication activities. When a pictogram is activated (clicked), the system plays back an audible statement, recorded in any language, reflecting the desired activity. Ten healthy adult volunteers, free from any musculoskeletal or neurological disorders, participated in the validation of the system. Validation results revealed a system accuracy of 96.11+/-5.58 % and repeatability of 94.44+/-2.51 %. The rehabilitative system developed in this project offers the locked-in patient, of any social class, the ability of simple yet effective communication. The advantages of this system over existing systems are low cost, low processing power, ease of operation, little training requirements, minimal disturbance to the patient, and ease of customization to any mother tongue.

Abu-Faraj ZO; Mashaalany MJ; Sleiman HC; Heneine JL; Al Katergi WM

2006-01-01

144

Demands on Shape Memory Alloys from the Application Designer's Point of View  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In order to improve the conditions for utilization of Shape Memory Alloys (SMAs) in engineering design, the engineering design process and the shape memory effect have been studied from the viewpoint of the engineering designer. Further, the maturity of the SMA technology has been evaluated accordin...

Abrahamsson, P.; Møster, E.

145

Point- To- Point Protocol  

Directory of Open Access Journals (Sweden)

Full Text Available The telephone line provides a physical link, but to control and manage the transfer of data, there is a need for point-to-point connection. The first protocol devised for this purpose was serial line internet protocol (SLIP). However, SLIP has some deficiencies: it does not support protocols other than internet protocol (IP). It does not allow the IP addresses to be assigned dynamically, and it does not support authentication of the user. The POINT-TO-POINT (PPP) is a protocol designed to respond to respond to the deficiencies. Today the PPP protocol standard finds wide use in asynchronous and synchronous connections between computers, bridges, routers and other intermediate devices.PPP is gaining acceptance as a standard for Integrated Services Digital Network(ISDN), and many implementations of X.25 also support PPP connection.

Immadisetty L V Chandrika,; Venkata Videhi Balusupati,; A.Rama Krishna,

2012-01-01

146

What Is Dry Eye?  

Medline Plus

Full Text Available Español Media Inquiries find an eye M.D. ask an eye M.D. Search GetEyeSmart.org Diseases & Conditions A to Z Age-related Macular Degeneration (AMD) Allergies Amblyopia (Lazy Eye) Astigmatism ...

147

Smoking and Eye Health  

Science.gov (United States)

... Eyes & the Sun Eye Health News Consumer Alerts Smoking and Eye Health Tweet Eye Health Lifestyle Topics ... vision may start to occur. Follow Us Avoiding smoking, or quitting, is one of the best investments ...

148

LASIK - Laser Eye Surgery  

Medline Plus

Full Text Available ... Topics Preventing Eye Injuries Healthy Eyes During Pregnancy Computer Usage & Eye Strain Maintaining Your Sight with Diabetes ... it. Give your Eyes a Break To prevent computer eyestrain, follow the 20-20-20 rule: Every ...

149

Diabetes - Eye Complications  

Medline Plus

Full Text Available Diabetes - Eye Complications Introduction Patients with diabetes are more likely to have eye problems that can lead to blindness. ... prevent these eye problems from happening. How The Eye Works? Light first hits the cornea of the ...

150

Eye Complications in IBD  

Science.gov (United States)

... Home > Resources > Eye Complications in IBD Go Back Eye Complications in IBD Email Print + Share Approximately 10% ... doctor’s attention sooner rather than later. TYPES OF EYE DISORDERS UVEITIS One of the most common eye ...

151

MCNP-REN - A Monte Carlo Tool for Neutron Detector Design Without Using the Point Model  

Energy Technology Data Exchange (ETDEWEB)

The development of neutron detectors makes extensive use of the predictions of detector response through the use of Monte Carlo techniques in conjunction with the point reactor model. Unfortunately, the point reactor model fails to accurately predict detector response in common applications. For this reason, the general Monte Carlo N-Particle code (MCNP) was modified to simulate the pulse streams that would be generated by a neutron detector and normally analyzed by a shift register. This modified code, MCNP - Random Exponentially Distributed Neutron Source (MCNP-REN), along with the Time Analysis Program (TAP) predict neutron detector response without using the point reactor model, making it unnecessary for the user to decide whether or not the assumptions of the point model are met for their application. MCNP-REN is capable of simulating standard neutron coincidence counting as well as neutron multiplicity counting. Measurements of MOX fresh fuel made using the Underwater Coincidence Counter (UWCC) as well as measurements of HEU reactor fuel using the active neutron Research Reactor Fuel Counter (RRFC) are compared with calculations. The method used in MCNP-REN is demonstrated to be fundamentally sound and shown to eliminate the need to use the point model for detector performance predictions.

Abhold, M.E.; Baker, M.C.

1999-07-25

152

Eye shield device  

UK PubMed Central (United Kingdom)

An eye covering member of opaque material has an inner surface adjacent the eyes of a wearer when in use. A fastening device on the eye covering member removably affixes said member over the eyes of a wearer. A pair of eye pads are removably accommodated in a pair of spaced recesses formed in the inner surface of the eye covering member over the eyes of a wearer for applying medication to the eyes.

D AURIA ROSEMARIE

153

Eye Level  

Science.gov (United States)

Eye level is an art blog written by a collaborative team at the Smithsonian American Art Museum (SAAM). According to the site, "... the conversation at Eye Level will be dedicated to American art and the ways in which the nation's art reflects its history and culture." The SAAM collection is meant as a foundation for the conversation on Eye Level. A recent post begins by talking about a road trip through the American West to see site-specific artwork, but at least one of the artists mentioned, Andrea Zittel, has a prior affiliation with SAAM. She was the 2005 Smithsonian Lucelia Artist Award winner, and the post links to prior entries on artwork at SAAM, both in and inspired by the American Southwest. These links were to works such as Robert Smithson's Spiral Jetty (an installation in the Great Salt Lake) and Albert Bierstadt's Among the Sierra Nevada, California, 1868. The February 1 post considers the future of art blogs, and the impact they may have on art criticism, museums, and the art world on the whole.

154

LASIK - Laser Eye Surgery  

Medline Plus

Full Text Available Eye Health Lifestyle Topics Preventing Eye Injuries Healthy Eyes During Pregnancy Computer Usage & Eye Strain Maintaining Your Sight with Diabetes Sports ... Eyesight Risks for Smokers Veterans & Eye Health More Lifestyle Topics > EyeSmart Tips No Smoking Smoking increases the ...

155

An Experimental Design for Examining Thermoregulatory Set Points in Ectothermic Animals.  

Science.gov (United States)

|Provides a protocol for examining the mechanisms of animal thermoregulation in a straightforward but more sophisticated manner than using a thermal gradient. Describes a methodology for conducting operant conditioning to examine thermal set points for ectothermic animals. Contains 20 references. (WRM)|

Kingsbury, Bruce A.

1999-01-01

156

Design and evaluation of pointing devices; Gestaltung und Evaluation von koordinatengebenden Interaktionsgeraeten  

Energy Technology Data Exchange (ETDEWEB)

Pointing devices e.g. the computer mouse are gaining considerable importance in modern human-machine-systems as a major part of the interaction interface between human beings and machines. During the dialogues with window-based operating systems the human being - the user - moves the cursor to a certain position on the screen by means of pointing devices. Microsoft products like WINDOWS have asserted themselves in the meantime in office applications and are currently conquering the market of industrial control systems as well. In office applications the mouse has become established as the most important pointing device for interaction. However, an 'office mouse' is not really suitable in a manufacturing environment. Only a few investigations exist evaluating alternatives to the mouse, which are suitable for industrial applications. At the Center of Human-Machine-Interaction (ZMMI) of the Institute of Production Automation (pak) at the University of Kaiserslautern a comparative investigation was carried out for alternative pointing devices like mouse, mousepad, mousebutton, mousestick, trackball, joystick, touchscreen, digitizing tablet and keyboard to determine their industrial suitability. This paper presents the methods of investigation and the most important results. The known Fitts' law model is mainly used in the field of HCl for office applications in order to evaluate interaction devices. This paper presents the new method DEVICE and is applied in the field of HMI for the evaluation of pointing devices. Tests with DEVICE and Fitts' method were conducted with machine operators under industrial environments to determine the suitability of thirty different pointing devices. The comparison between DEVICE and Fitts' law model shows that the results of certain partial tests correlate with each other. DEVICE can be used as substitute for Fitts' law model and offers additional parameters such as e.g. error rates and pointing deviation. The advantages of DEVICE are shorter test times (only one tenth of the test times required with the Fitts' method), more diverse tests for the test persons, a parameter that can be exactly evaluated by the person who is in charge of the test and the comparability between different studies. (orig.)

Krauss, L.; Zuehlke, D. [Kaiserslautern Univ. (Germany)

2002-07-01

157

Numerical investigation of the cavitational behaviour into a storage pump at off design operating points  

Energy Technology Data Exchange (ETDEWEB)

The paper presents a new method for the analysis of the cavitational behaviour of hydraulic turbomachines. This new method allows determining the coefficient of the cavitation inception and the cavitation sensitivity of the turbomachines. We apply this method to study the cavitational behaviour of a large storage pump. By plotting in semi-logarithmic coordinates the vapour volume versus the cavitation coefficient, we show that all numerical data collapse in an exponential manner. This storage pump is located in a power plant and operating without the presence of the developed cavitation is vital. We investigate the behaviour of the pump from the cavitational point of view while the pump is operating for variable discharge. A distribution of the vapour volume upon the blade of the impeller is presented for all the four operating points. It can be seen how the volume of vapour evolves from one operating point to another. In order to study the influence of the cavitation phenomena upon the pump, the evolution of the pumping head against the cavitation coefficient is presented. That will show how the pumping head drops while the cavitation coefficient decreases. From analysing the data obtained from the numerical simulation it results that the cavitation phenomena is present for all the investigated operating points. By analysis of the slope of the curve describing the evolution of the vapour volume against the cavitation coefficient we determine the cavitation sensitivity of the pump for each operating point. It is showed that the cavitation sensitivity of the investigated storage pump increases while the flow rate decreases.

Stuparu, A; Susan-Resiga, R; Anton, L E [Department of Hydraulic Machinery, Politehnica University of Timisoara, Bd. Mihai Viteazu 1, Timisoara, 300222 (Romania); Muntean, S, E-mail: astuparu@mh.mec.upt.r [Centre of Advanced Research in Engineering Science, Romanian Academy-Timisoara Branch, Bd. Mihai Viteazu 24, Timisoara, 300223 (Romania)

2010-08-15

158

Numerical investigation of the cavitational behaviour into a storage pump at off design operating points  

International Nuclear Information System (INIS)

The paper presents a new method for the analysis of the cavitational behaviour of hydraulic turbomachines. This new method allows determining the coefficient of the cavitation inception and the cavitation sensitivity of the turbomachines. We apply this method to study the cavitational behaviour of a large storage pump. By plotting in semi-logarithmic coordinates the vapour volume versus the cavitation coefficient, we show that all numerical data collapse in an exponential manner. This storage pump is located in a power plant and operating without the presence of the developed cavitation is vital. We investigate the behaviour of the pump from the cavitational point of view while the pump is operating for variable discharge. A distribution of the vapour volume upon the blade of the impeller is presented for all the four operating points. It can be seen how the volume of vapour evolves from one operating point to another. In order to study the influence of the cavitation phenomena upon the pump, the evolution of the pumping head against the cavitation coefficient is presented. That will show how the pumping head drops while the cavitation coefficient decreases. From analysing the data obtained from the numerical simulation it results that the cavitation phenomena is present for all the investigated operating points. By analysis of the slope of the curve describing the evolution of the vapour volume against the cavitation coefficient we determine the cavitation sensitivity of the pump for each operating point. It is showed that the cavitation sensitivity of the investigated storage pump increases while the flow rate decreases.

2010-01-01

159

The influence of wind conditions on wind turbine design. Experiences and suggestions from the designer point of view  

Energy Technology Data Exchange (ETDEWEB)

This paper describes some aspects of currently used wind field models and touches briefly on some solution techniques to improve these models. Some user experience is given with certification calculations for extreme wind conditions and also ideas are presented for new developments of pitch control algorithms to reduce the influence of wind conditions on the design of the wind turbines. (au)

Luijendijk, R.P. [Stentec BV, Heeg (Netherlands)

1999-04-01

160

Designing group sequential randomized clinical trials with time to event end points using a R function.  

UK PubMed Central (United Kingdom)

A major and difficult task is the design of clinical trials with a time to event endpoint. In fact, it is necessary to compute the number of events and in a second step the required number of patients. Several commercial software packages are available for computing sample size in clinical trials with sequential designs and time to event endpoints, but there are a few R functions implemented. The purpose of this paper is to describe features and use of the R function. plansurvct.func, which is an add-on function to the package gsDesign which permits in one run of the program to calculate the number of events, and required sample size but also boundaries and corresponding p-values for a group sequential design. The use of the function plansurvct.func is illustrated by several examples and validated using East software.

Filleron T; Gal J; Kramar A

2012-10-01

 
 
 
 
161

On climatic reference points for some aspects of engineering design in Nairobi, Kenya  

Energy Technology Data Exchange (ETDEWEB)

This paper draws the attention of engineers to the urban climatological issues which should be noted when designing in Nairobi. The general features of Nairobi with special reference to the atmospheric conditions are described. Using the records provided by Kenya Meteorological Department and some references to previous case studies, on the urban climate of the city, detailed comments are made on the magnitude and relevance of different climatic parameters to urban design in Nairobi. (orig.).

Adebayo, Y.R. (Kenyatta Univ., Nairobi (Kenya). Dept. of Geography)

1991-01-01

162

The Next Generation Nuclear Plant - Insights Gained from the INEEL Point Design Studies  

Energy Technology Data Exchange (ETDEWEB)

This paper provides the results of an assessment of two possible versions of the Next Generation Nuclear Plant (NGNP), a prismatic fuel type helium gas-cooled reactor and a pebble-bed fuel helium gas reactor. Insights gained regarding the strengths and weaknesses of the two designs are also discussed. Both designs will meet the three basic requirements that have been set for the NGNP: a coolant outlet temperature of 1000 C, passive safety, and a total power output consistent with that expected for commercial high-temperature gas-cooled reactors. Two major modifications of the current Gas Turbine- Modular Helium Reactor (GT-MHR) design were needed to obtain a prismatic block design with a 1000 C outlet temperature: reducing the bypass flow and better controlling the inlet coolant flow distribution to the core. The total power that could be obtained for different core heights without exceeding a peak transient fuel temperature of 1600 °C during a high or low-pressure conduction cooldown event was calculated. With a coolant inlet temperature of 490 °C and 10% nominal core bypass flow, it is estimated that the peak power for a 10-block high core is 686 MWt, for a 12-block high core is 786 MWt, and for a 14-block core is about 889 MWt. The core neutronics calculations showed that the NGNP will exhibit strongly negative Doppler and isothermal temperature coefficients of reactivity over the burnup cycle. In the event of rapid loss of the helium gas, there is negligible core reactivity change. However, water or steam ingress into the core coolant channels can produce a relatively large reactivity effect. Two versions of an annular pebble-bed NGNP have also been developed, a 300 and a 600 MWt module. From this work we learned how to design passively safe pebble bed reactors that produce more than 600 MWt. We also found a way to improve both the fuel utilization and safety by modifying the pebble design (by adjusting the fuel zone radius in the pebble to optimize the fuel-to-moderator ratio). We also learned how to perform design optimization calculations by using a genetic algorithm that automatically selects a sequence of design parameter sets to meet specified fitness criteria increasingly well. In the pebble-bed NGNP design work, we use the genetic algorithm to direct the INEEL’s PEBBED code to perform hundreds of code runs in less than a day to find optimized design configurations. And finally, we learned how to calculate cross sections more accurately for pebble bed reactors, and we identified research needs for the further refinement of the cross section calculations.

Philip E. MacDonald; A. M. Baxter; P. D. Bayless; J. M. Bolin; H. D. Gougar; R. L. Moore; A. M. Ougouag; M. B. Richards; R. L. Sant; J. W. Sterbentz; W. K. Terry

2004-08-01

163

Preliminary Fly's Eye results  

International Nuclear Information System (INIS)

The authors describe a unique experiment, the Fly's Eye, designed to measure extensive air showers (EAS) in the energy range 1017 - 1021eV via atmospheric fluorescence. Preliminary results are presented for the following measurements: (1) limits on the extragalactic neutrino flux at 1020eV, (2) the high energy cosmic ray spectrum, (3) sources of high energy cosmic rays, (4) the total proton cross section sigma/sub pp.

1982-01-01

164

Experience Feedback of Current LWR on the Design and Operation of Advanced LWR, under the Safety Analysis Point of View  

International Nuclear Information System (INIS)

[en] Current LWR are operating with an excellent safety record. It is foreseen that they will be progressively replaced by more advanced designs (Generation III, III+, and IV). This paper reviews the role of the safety analysis, both in steady and transient state, in the flexible yet safe operation of the nuclear power plants. Several aspects such as licensing, technological progress, efficiency, public opinion and environmental consideration, and generation replacement, are considered form a broad perspective. Besides, deficiencies, learned lessons and design and operation aspects that could be improved in the new reactor fleet, under the perspective of safety analysis, are also considered from the engineering point of view and experience. (author)

2011-01-01

165

Design and development of a low-cost eye tracking system for the rehabilitation of the completely locked-in patient.  

Science.gov (United States)

This article describes the design and development process of an eye tracking-based computer system that benefits from the intact ocular motor control of the completely locked-in patient to provide him or her with an alternative means of communication. A completely locked-in patient is an individual who has lost all types of motor control and communication ability with people in his or her environment. This developed system uses a head-mounted web camera to capture real-time images of the patient's eye. These images are then passed to a program, developed using Matlab, which processes them and computes the coordinates of the pupil position. The program then sends commands to an interactive JAVA-based interface, which provides the patient with a matrix of pictograms representing the most essential daily communication activities. When a pictogram is activated (clicked), the system plays back an audible statement, recorded in any language, reflecting the desired activity. Ten healthy adult volunteers, free from any musculoskeletal or neurological disorders, participated in the validation of the system. Validation results revealed a system accuracy of 96.11+/-5.58 % and repeatability of 94.44+/-2.51 %. The rehabilitative system developed in this project offers the locked-in patient, of any social class, the ability of simple yet effective communication. The advantages of this system over existing systems are low cost, low processing power, ease of operation, little training requirements, minimal disturbance to the patient, and ease of customization to any mother tongue. PMID:17946657

Abu-Faraj, Ziad O; Mashaalany, Maya J; Sleiman, Habib C Bou; Heneine, Jean-Louis D; Al Katergi, Waleed M

2006-01-01

166

A conceptual design study of point focusing thin-film solar concentrators  

Science.gov (United States)

Candidates for reflector panel design concepts, including materials and configurations, were identified. The large list of candidates was screened and reduced to the five most promising ones. Cost and technical factors were used in making the final choices for the panel conceptual design, which was a stiffened steel skin substrate with a bonded, acrylic overcoated, aluminized polyester film reflective surface. Computer simulations were run for the concentrator optics using the selected panel design, and experimentally determined specularity and reflectivity values. Intercept factor curves and energy to the aperture curves were produced. These curves indicate that surface errors of 2 mrad (milliradians) or less would be required to capture the desired energy for a Brayton cycle 816 C case. Two test panels were fabricated to demonstrate manufacturability and optically tested for surface error. Surface errors in the range of 1.75 mrad and 2.2 mrad were measured.

1981-11-01

167

Deployment Design of Wireless Sensor Network for Simple Multi-Point Surveillance of a Moving Target  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper, we focus on the problem of tracking a moving target in a wireless sensor network (WSN), in which the capability of each sensor is relatively limited, to construct large-scale WSNs at a reasonable cost. We first propose two simple multi-point surveillance schemes for a moving target in a WSN and demonstrate that one of the schemes can achieve high tracking probability with low power consumption. In addition, we examine the relationship between tracking probability and sensor density through simulations, and then derive an approximate expression representing the relationship. As the results, we present guidelines for sensor density, tracking probability, and the number of monitoring sensors that satisfy a variety of application demands.

Kazuya Tsukamoto; Hirofumi Ueda; Hitomi Tamura; Kenji Kawahara; Yuji Oie

2009-01-01

168

Design and Evaluation of Cell Phone Pointing Interface for Robot Control  

Directory of Open Access Journals (Sweden)

Full Text Available In this work a pointing interface based on human gestures using a mobile phone accelerometer for interaction with robots is proposed. Through this interface the user can sketch stroke gestures on a computer screen using the cell phone accelerometer to make a selection and instruct a robot to perform a task. Selection, cancelation and movement, as well as some additional commands such as stop, pause and resume are supported. All the projected gestures are processed using known image analysis algorithms providing instantaneous position and path information. The proposed interface is experimentally evaluated and the results show that it is efficient, natural, robust and easy to use. It also provides asynchronous robot control with minimum operator effort and engagement.

Saso Koceski; Natasa Koceska; Ivica Kocev

2012-01-01

169

Robot design from a neuro-ethological point of view. Shinkei kodogaku kara mita robot  

Energy Technology Data Exchange (ETDEWEB)

The science concerning the method of obtaining the desirable information by adjusting the controllable quantity based on the measurement of the uncontrollable quantity is called cybernetics. The cybernetics is the most ideal image of the robot. The instinct of animals is supported by the nervous system. The science which deals with the nervous system of animals as a function of its instinct is called the neuro-ethology. In this sense, the neuro-ethology is identical to the cybernetics. The fundamental basis of robot design the design of the robot is therefore the neuro-ethology. The treatment of the dependent information about space and time in the auditory nervous system of animals was reviewed. The petuliarity of the auditory system, auditory as an interferometry, and the evolution of the auditory system was explained by taking the sonner system in bats as a prototype of the auditory system of animal. For further explanation of auditory system, the correspondence to the phonetic recognition of Homo-sapiens was also reviewed. It is important for design of the robot to investigate the mechanism to extract informations of the auditory nervous system in animals including Homo-sapiens. 19 refs., 10 figs.

Shimozawa, T. (Hokkaido Univ., Sapporo (Japan). Research Inst. of Applied Electricity)

1991-11-01

170

A study on safety and integrity of the unidentified welding point omitted on as-built design drawing  

Energy Technology Data Exchange (ETDEWEB)

Issued was one welding point omitted on as-built design drawing of pressurizer spray line(Ulchin 1) in the process of parliamentary inspection of the government offices in 1999. Thereafter, the question of whether there are additional unidentified welding points in domestic nuclear power plants has by now been controversial. In the view of material, this report focuses on the integrity of the welding area which the question was posed on the pressurizer spray line for Ulchin Unit 1. Also, we explore the effect of overall safety likely to result from the hypothetical existence of additional unidentified welding points in nuclear station, using probabilistic safety assessment (PSA) method. As a result, there is no significant risk increase due to unidentified welding points. However, this problem was originated from the violation of pre-descriptive welding procedure in the process of construction and a loose supervision, so must the mechanisms to improve it be strengthen and streamlined. 5 refs., 5 figs., 5 tabs. (Author)

Jang, S. C.; Ha, J. J.; Han, S. H. [Korea Atomic Energy Research Institute, Taejon (Korea)

1999-01-01

171

Using Eye Makeup  

Science.gov (United States)

... Download the K Card Be prepared for future eye surgery. Have your LASIK surgeon record your pre- and ... rinse remover off your eyelids. If you have eye surgery, do not wear makeup around the eye until ...

172

Diabetes - Eye Complications  

Medline Plus

Full Text Available Diabetes - Eye Complications Introduction Patients with diabetes are more likely to have eye problems that can lead to blindness. Many of these eye diseases can be prevented or delayed ...

173

LASIK - Laser Eye Surgery  

Medline Plus

Full Text Available ... Eye Health More Lifestyle Topics > EyeSmart Tips No Smoking Smoking increases the risk of developing cataracts – quit or avoid smoking to help keep your eyes healthy. Know Your ...

174

Dark Circles under Eyes  

Science.gov (United States)

Dark circles under eyes Basics Resources Dark circles under eyes By Mayo Clinic staff Original Article: http://www.mayoclinic.com/health/dark-circles-under-eyes/MY00346 Definition Causes When to see a ...

175

What Is Dry Eye?  

Medline Plus

Full Text Available ... Eye Health News Consumer Alerts What Is Dry Eye? Tweet When you blink, a film of tears ... by Dr. Robert Melendez 0:30 Subscribe for Eye Health Info Sign up for our monthly e- ...

176

What Is Dry Eye?  

Medline Plus

Full Text Available ... Dry Eye Floaters & Flashes Glaucoma Hyperopia (Farsightedness) Low Vision Myopia (Nearsightedness) Presbyopia (Aging Eye) Stye Uveitis/Iritis ... Symptoms Blurriness Dark Curtain Dark Spots Discharge Double Vision Drooping Eyelid Eye Pain Eyelash Crusting Eyelid Lump ...

177

What Is Dry Eye?  

Medline Plus

Full Text Available ... Babies & Children Computer Usage Diabetes Diet & Nutrition Eye Screening Guidelines Home Remedies for Simple Eye Problems Know ... blindness? Featured Video Get a Baseline Eye Disease Screening at 40, presented by Dr. Robert Melendez 0: ...

178

Diabetes - Eye Complications  

Medline Plus

Full Text Available ... diabetes are more likely to develop eye problems. Insulin dependent patients are more likely to have eye problems than patients who are not insulin dependent. Doctors cannot predict who will have eye ...

179

What Is Dry Eye?  

Medline Plus

Full Text Available ... Torn Retina Diabetic Retinopathy Dry Eye Floaters & Flashes Glaucoma Hyperopia (Farsightedness) Low Vision Myopia (Nearsightedness) Presbyopia (Aging ... Know Your Eye Care Team Medical Marijuana for Glaucoma Pregnancy Preventing Eye Injuries Smokers Sports Teenagers Using ...

180

Point of View: Intelligent Design: Jonathan Wells and the Tree of Life  

Science.gov (United States)

In recent years, the intelligent design (ID) movement has been very successful in attracting the attention of the general public. The ID movement is centered predominantly at the Center for Science and Culture in the very conservative think tank, the Discovery Institute, of Seattle, Washington. It has gained this attention by completely bypassing scientific channels and going directly to the general public, primarily in the form of op-ed articles, talk-show and TV appearances, and by making their anti-evolution books and video documentaries widely available, especially to school administrators, school boards, teachers, and legislators. The defeat of ID in the highly publicized Dover, Pennsylvania trial will not slow the movement down.

Gregg, Thomas

2007-07-01

 
 
 
 
181

Initial Scaling Studies and Conceptual Thermal Fluids Experiments for the Prismatic NGNP Point Design  

International Nuclear Information System (INIS)

The objective of this report is to document the initial high temperature gas reactor scaling studies and conceptual experiment design for gas flow and heat transfer. The general approach of the project is to develop new benchmark experiments for assessment in parallel with CFD and coupled CFD/ATHENA/RELAP5-3D calculations for the same geometry. Two aspects of the complex flow in an NGNP are being addressed: (1) flow and thermal mixing in the lower plenum (''hot streaking'' issue) and (2) turbulence and resulting temperature distributions in reactor cooling channels (''hot channel'' issue). Current prismatic NGNP concepts are being examined to identify their proposed flow conditions and geometries over the range from normal operation to decay heat removal in a pressurized cooldown. Approximate analyses are being applied to determine key non-dimensional parameters and their magnitudes over this operating range. For normal operation, the flow in the coolant channels can be considered to be dominant forced convection with slight transverse property variation. The flow in the lower plenum can locally be considered to be a situation of multiple buoyant jets into a confined density-stratified crossflow--with obstructions. Experiments are needed for the combined features of the lower plenum flows. Missing from the typical jet experiments are interactions with nearby circular posts and with vertical posts in the vicinity of vertical walls--with near stagnant surroundings at one extreme and significant crossflow at the other. Two heat transfer experiments are being considered. One addresses the ''hot channel'' problem, if necessary. The second experiment will treat heated jets entering a model plenum. Unheated MIR (Matched-Index-of-Refraction) experiments are first steps when the geometry is complicated. One does not want to use a computational technique which will not even handle constant properties properly. The MIR experiment will simulate flow features of the paths of jets as they mix in flowing through the array of posts in a lower plenum en route to the single exit duct. Initial conceptual designs for such experiments are described

2004-01-01

182

Initial Scaling Studies and Conceptual Thermal Fluids Experiments for the Prismatic NGNP Point Design  

Energy Technology Data Exchange (ETDEWEB)

The objective of this report is to document the initial high temperature gas reactor scaling studies and conceptual experiment design for gas flow and heat transfer. The general approach of the project is to develop new benchmark experiments for assessment in parallel with CFD and coupled CFD/ATHENA/RELAP5-3D calculations for the same geometry. Two aspects of the complex flow in an NGNP are being addressed: (1) flow and thermal mixing in the lower plenum ("hot streaking" issue) and (2) turbulence and resulting temperature distributions in reactor cooling channels ("hot channel" issue). Current prismatic NGNP concepts are being examined to identify their proposed flow conditions and geometries over the range from normal operation to decay heat removal in a pressurized cooldown. Approximate analyses are being applied to determine key non-dimensional parameters and their magnitudes over this operating range. For normal operation, the flow in the coolant channels can be considered to be dominant forced convection with slight transverse property variation. The flow in the lower plenum can locally be considered to be a situation of multiple buoyant jets into a confined density-stratified crossflow -- with obstructions. Experiments are needed for the combined features of the lower plenum flows. Missing from the typical jet experiments are interactions with nearby circular posts and with vertical posts in the vicinity of vertical walls - with near stagnant surroundings at one extreme and significant crossflow at the other. Two heat transfer experiments are being considered. One addresses the "hot channel" problem, if necessary. The second experiment will treat heated jets entering a model plenum. Unheated MIR (Matched-Index-of-Refraction) experiments are first steps when the geometry is complicated. One does not want to use a computational technique which will not even handle constant properties properly. The MIR experiment will simulate flow features of the paths of jets as they mix in flowing through the array of posts in a lower plenum en route to the single exit duct. Initial conceptual designs for such experiments are described.

D. M. McEligot; G. E. McCreery

2004-09-01

183

Eye care in ICU  

Directory of Open Access Journals (Sweden)

Full Text Available Context: Patients in intensive care units have impaired ocular protective mechanisms, resulting in a high risk of developing eye complications. Various eye care protocols are being used, but none is proven to be absolutely effective. Aims: To compare the efficacy of using a combination of ocular lubricants and securing tape over the eyelids (Open chamber method), with use of swimming goggles and regular moistening of eyelids with gauze soaked in sterile water (Closed chamber method), to prevent corneal epithelial breakdown in the sedated and semiconscious intensive care adult patient. Settings and Design: A randomized clinical study was performed. Patients with Glasgow coma scale score of £ 10/15, admitted into the Medical ICU of a large teaching hospital, over a four month duration, were studied. Materials and Methods: Patients were examined daily by an Ophthalmologist, using a portable slit lamp and the patient?s corneas were tested daily using 1% Fluorescein drops. Standard grading scales were used to record eyelid position and corneal and conjunctival changes. Statistical analysis used: Quantitative variables were described in terms of their relative frequencies in proportions. Null hypothesis was applied to derive the statistical significance of the observed variations in both the treatment groups. Chi-square test for relationships was used to assess the effect of specific variables on the development of keratopathy. Results: Sixty one patients (122 eyes) in the open chamber group and 63 (126 eyes) in the closed chamber group, were analyzed. Incomplete lid closure was seen in 74 eyes (30%). Exposure keratopathy was noticed in 39 eyes (32%) in open chamber group and ten (8%) in closed chamber group and was more severe in the former group. There was no difference in the incidence of conjunctival oedema in both groups. Incomplete lid closure and use of muscle relaxants, were significant risk factors for developing keratopathy. Conclusions: Use of swimming goggles and regular moistening of eyelids with gauze soaked in sterile water providing a moisture chamber, is more effective than using a combination of ocular lubricants and securing tape over the eyelids, in preventing corneal epithelial breakdown in sedated and semiconscious intensive care unit patients.

Sivasankar S; Jasper S; Simon S; Jacob P; John George; Raju R

2006-01-01

184

Liquid crystal display microperimetry in eyes with reduced visual acuity from macular pathology.  

Directory of Open Access Journals (Sweden)

Full Text Available PURPOSE: To correlate fixation stability and retinal sensitivity measured by liquid crystal display (LCD) microperimetry to visual acuity in eyes with macular pathology. DESIGN: Retrospective chart review METHODS: The cohort included 26 eyes of 26 patients, divided into two groups according to visual acuity (Group 1 eyes 6/15 - 6/48, Group 2: < or = 6/60). Macular sensitivity and fixation stability were measured using the LCD microperimeter. Mean retinal sensitivity (at central 12 degrees) and fixation stability (at 2 degrees and 4 degrees) were correlated with best-corrected visual acuity. RESULTS: Mean retinal sensitivity correlated with the visual acuity in both groups [Group 1 eyes: 28 point central 12 degrees (9.0 dB); Group 2: central 12 degrees (4.183 dB)] (P < 0.05). The fixation stability correlated similarly with the visual acuity for the groups [Group 1 eyes: 2 degrees (81.2%) and 4 degrees (94.6%); Group 2 eyes: 2 degrees (44.1%) and 4 degrees (80.7%] (P < 0.05). CONCLUSION: In the present study, the mean retinal sensitivity and fixation stability measured with LCD microperimeter correlated with visual acuity. LCD microperimetry reliably measures fixation stability and retinal sensitivity in eyes with various macular pathologies.

Chalam Kakarla; Shah Vinay

2004-01-01

185

Eye safe laser range finders  

International Nuclear Information System (INIS)

During the 1970's, Ruby (Q switched) laser based range finders with a wavelength of 694nm were first used. These lasers operated in a pulse mode within the visible light range and produced a risk for the eye retina. The laser beam striking the macula could damage the eye and might cause blindness. Over the years, Nd:YAG (Q switched) lasers were developed (operating at 1064nm) for range finding and designation uses. The wavelength of these lasers, operating in the near Infra-Red range (invisible), is also focused tightly on the retina. The human eye does not respond to the invisible light so there is no natural protection (eye blink reflex) as in the visible light. The operation of these lasers worldwide, especially when the laser beam is exposed, causes occasional eye accidents. Another risk is stemming from the use of observation systems with a high optical gain, in the laser operation areas, which enlarge the range of risk quite significantly. Therefore, research and development efforts were invested in order to introduce eye safe lasers. One of the solutions for this problem is presented in following document.

2004-02-17

186

Hardware description ADSP-21020 40-bit floating point DSP as designed in a remotely controlled digital CW Doppler radar  

Energy Technology Data Exchange (ETDEWEB)

A continuous wave Doppler radar system has been designed which is portable, easily deployed, and remotely controlled. The heart of this system is a DSP/control board using Analog Devices ADSP-21020 40-bit floating point digital signal processor (DSP) microprocessor. Two 18-bit audio A/D converters provide digital input to the DSP/controller board for near real time target detection. Program memory for the DSP is dual ported with an Intel 87C51 microcontroller allowing DSP code to be up-loaded or down-loaded from a central controlling computer. The 87C51 provides overall system control for the remote radar and includes a time-of-day/day-of-year real time clock, system identification (ID) switches, and input/output (I/O) expansion by an Intel 82C55 I/O expander. 5 refs., 8 figs., 2 tabs.

Morrison, R.E.; Robinson, S.H.

1991-01-01

187

Top-gated graphene field-effect transistors with high normalized transconductance and designable dirac point voltage.  

Science.gov (United States)

High-performance graphene field-effect transistors (G-FETs) are fabricated with carrier mobility of up to 5400 cm(2)/V·s and top-gate efficiency of up to 120 (relative to that of back gate with 285 nm SiO(2)) simultaneously through growing high-quality Y(2)O(3) gate oxide at high oxidizing temperature. The transconductance normalized by dimension and drain voltage is found to reach 7900 ?F/V·s, which is among the largest of the published graphene FETs. In an as-fabricated graphene FET with a gate length of 310 nm, a peak transconductance of 0.69 mS/?m is realized, but further improvement is seriously hindered by large series resistance. Benefiting from highly efficient gate control over the graphene channel, the Dirac point voltage of the graphene FETs is shown to be designable via simply selecting a gate metal with an appropriate work function. It is demonstrated that the Dirac point voltage of the graphene FETs can be adjusted from negative to positive, respectively, via changing the gate material from Ti to Pd. PMID:21528892

Xu, Huilong; Zhang, Zhiyong; Xu, Haitao; Wang, Zhenxing; Wang, Sheng; Peng, Lian-Mao

2011-05-06

188

Top-gated graphene field-effect transistors with high normalized transconductance and designable dirac point voltage.  

UK PubMed Central (United Kingdom)

High-performance graphene field-effect transistors (G-FETs) are fabricated with carrier mobility of up to 5400 cm(2)/V·s and top-gate efficiency of up to 120 (relative to that of back gate with 285 nm SiO(2)) simultaneously through growing high-quality Y(2)O(3) gate oxide at high oxidizing temperature. The transconductance normalized by dimension and drain voltage is found to reach 7900 ?F/V·s, which is among the largest of the published graphene FETs. In an as-fabricated graphene FET with a gate length of 310 nm, a peak transconductance of 0.69 mS/?m is realized, but further improvement is seriously hindered by large series resistance. Benefiting from highly efficient gate control over the graphene channel, the Dirac point voltage of the graphene FETs is shown to be designable via simply selecting a gate metal with an appropriate work function. It is demonstrated that the Dirac point voltage of the graphene FETs can be adjusted from negative to positive, respectively, via changing the gate material from Ti to Pd.

Xu H; Zhang Z; Xu H; Wang Z; Wang S; Peng LM

2011-06-01

189

Chapter 2. Eyes  

International Nuclear Information System (INIS)

Ocular scintigraphy can now be carried out with several tracers: 131I diiodofluorescein and sup(99m)Tc, hypervascularisation indicators; 131I iodinated chloroquine, melanoma selective. The detector used is an Anger scintillation camera coupled to a multiparameter analysis chain or a computer. The ''pin-hole'' type collimator, which has a stenopaeic opening in front of each eye, is adaptable to any inter-pupil distance. The very simple scintigraphic procedure is described. The results, taken from two statistical studies on 198 and 80 patients respectively, concern the main types of eye disease encountered: malignant melanic tumours, other tumours, metastases, choroiditis, idiopathic detachments of the retina etc... The interpretation of the scintigrams and the problems involved are considered. Finally the main indications of the method are defined with emphasis on the possibilities of double scintigraphy, diiodofluorescein only showing up the hypervascularisation often associated with the tumour whereas iodinated chloroquine, when the result is positive, points to the presence of a malignant melanoma

1975-01-01

190

CURVACE - CURVed Artificial Compound Eyes  

Digital Repository Infrastructure Vision for European Research (DRIVER)

CURVACE aims at designing, developing, and assessing CURVed Artificial Compound Eyes, a radically novel family of vision systems. This innovative approach will provide more efficient visual abilities for embedded applications that require motion analysis in low-power and small packages. Compared to ...

Giacobino, Elizabeth; Pfeifer, Rolf; Pericet Camara, Ramon; Dobrzynski, Michal; L'Eplattenier, Géraud; Zufferey, Jean-Christophe

191

[Eye and lymph drainage  

UK PubMed Central (United Kingdom)

Up to now lymphatics in the eye could not be pointed out. An ocular lymph drainage is denied. Földi succeeded in producing experimentally the syndrome of "lymphostatic encephalopathy and ophthalmopathy" by operative blockade of the cervical lymphatics in animals. In the first part of the present paper a historical view considering the subject "Eye and lymphatic system" is given. In the second part it is entered into the particulars of own experimental studies. As to our own investigations, rabbits have been injected 99mTc-sulfur-colloid, 99mTc-microcolloid, 99mTc-Albumin and 198Au-colloid into the retrobulbar space, anterior chamber, vitreous body and subconjuctival space of one eye. Measurements of the activity's distribution have been made in vivo with an Anger type camera (pho-Gamma-IV Hp, Searle Nuclear Chicago) and in vitro after section with a sodium iodine crystal well counter (Clinimat-200, Picker). In some animals the investigation has been combined with a bilateral dissection of the cervical lymph nodes. After injection in the retrobulbar space a significant concentration of the activity could be observed for the most part in the equilateral Lymphonodulus cervicalis profundus. By the cervical lymph blockade the removal of lymphoctopic substances from the retrobulbar space was largely inhibited. After injection in the anterior chamber a significant concentration could be observed for the most part in the equilateral Lymphonodulus cervicalis superficialis. After intravitreal injection a drainage to the bilateral deep cervical lymph nodes could be observed. After injection into the subconjunctival space a significant accumulation of activity could be registered in the equilateral Lymphonoduli mandibulares and cervicales superficiales. The data substantiate a segmental lymph drainage from the eye: vitreous body and retrobulbar space for the most part into the Lymphonoduli cervicales profundi, anterior chamber and subconjunctival space for the most part into the Lymphonoduli cervicales superficiales been studied. In albino-rabbits indiaink has been injected into the vitreous body and afterwards its drainage has been controlled histologically (frozen sections). In some animals the investigation has been combined with a bilateral dissection of the cervical lymph nodes. The lymph node dissection causes a massive deceleration of the India-ink's outflow; the perivascular connective tissue shows a clear edematous relaxation. The histological evidence suggests that 1. the vitreous body 2. the interstice between the glia cells of the papilla 3. the pial tissue between the neurone bundles of the optic nerve 4. the perivascular space around the central vessels of the retina 5. the subarachnoid sheath of the optic nerve may be interpreted as prelymphatic pathway.

Grüntzig J; Schicha H; Huth F

1979-06-01

192

Design, simulation and fabrication of a novel contact-enhanced MEMS inertial switch with a movable contact point  

International Nuclear Information System (INIS)

[en] A novel inertial switch based on a micro-electro-mechanical system (MEMS) was designed, which consists of three main parts: a proof mass as the movable electrode, a cross beam as the stationary electrode and a movable contact point to prolong the contact time. A MATLAB/Simulink model, which had been verified by comparison with ANSYS transient simulation, was built to simulate the dynamic response, based on which the contact-enhancing mechanism was confirmed and the dependence of threshold acceleration on the proof mass thickness was studied. The simulated dynamic responses under various accelerations exhibit satisfactory device behaviors: the switch-on time is prolonged under transient acceleration; the switch-on state is more continuous than the conventional design under long lasting acceleration. The inertial micro-switch was fabricated by multilayer electroplating technology and then tested by a drop hammer experiment. The test results indicate that the contact effect was improved significantly and a steady switch-on time of over 50 µs was observed under half-sine wave acceleration with 1 ms duration, in agreement with the dynamic simulation

2008-01-01

193

Effects of dominant and nondominant eyes in binocular rivalry.  

UK PubMed Central (United Kingdom)

PURPOSE: To investigate the relation between sighting and sensory eye dominance and attempt to quantitatively examine eye dominance using a balance technique based on binocular rivalry. METHODS: The durations of exclusive visibility of the dominant and nondominant eye target in binocular rivalry were measured in 14 subjects. The dominant eye was determined by using the hole-in-card test (sighting dominance). In study 1, contrast of the target in one eye was fixed at 100% and contrast of the target in the other eye was varied from 100% to 80% to 60% to 40% to 20%, when using rectangular gratings of 1, 2, and 4 cycles per degree (cpd) at 2 degrees, 4 degrees , and 8 degrees in size. In study 2, contrast of the target in the nondominant eye was fixed at 100% and contrast of the target in the dominant eye was varied from 100% to 80% to 60% to 40% to 20%, when using a rectangular grating of 2 cpd at 4 degrees in size. RESULTS: In study 1, the total duration of exclusive visibilities of the dominant eye target; that is, the target seen by the eye that had sighting dominance was longer compared with that of the nondominant eye target. When using rectangular gratings of 4 cpd, mean total duration of exclusive visibility of the dominant eye target was statistically longer than that of the nondominant eye target (p < 0.05). In study 2, reversals (in which duration of exclusive visibility of the nondominant eye becomes longer than the dominant eye when the contrast of the dominant eye target is decreased) were observed for all contrasts except for 100%. CONCLUSIONS: The dominant sighting eye identified by the hole-in-card test coincided with the dominant eye as determined by binocular rivalry. The contrast at which reversal occurs indicates the balance point of dominance and seems to be a useful quantitative indicator of eye dominance to clinical applications.

Handa T; Mukuno K; Uozato H; Niida T; Shoji N; Shimizu K

2004-05-01

194

Information access at the point of care: what can we learn for designing a mobile CPR system?  

UK PubMed Central (United Kingdom)

OBJECTIVES: Hospitals have started to migrate their paper-based records to computerized patient records (CPR). The majority of today's CPR systems are stationary, which means that physicians use a clinical workstation to access CPR information. But health care professionals need to request and enter information at different locations, for example, on their daily ward round. This suggests the use of mobile computers, enabling an ubiquitous access to needed data. Different studies show that health care professionals are reluctant to use poorly designed mobile CPR systems, as the work at the point of care is very time-pressured and hectic. To design a system with high acceptance, it is essential to obtain empirical insight into the work practices and context in which the mobile CPR system will be used. METHOD: We investigated the physicians' work with the patient record during their daily round. With the help of a compact notation method, the physicians' interaction with the information system was recorded in real time. Fourteen physicians from three different departments (internal medicine, surgery, and geriatrics) of a middle-sized Swiss hospital participated in our study. RESULTS: Physicians have clear access preferences when they interact with the patient record during their daily round. There exists a clear profile of access frequencies and patterns, respectively. As an example, approximately 50% of all patient record accesses concern information about medications, vital signs and lab test results. DISCUSSION/CONCLUSION: A CPR system which is designed to reflect the access frequencies and patterns should improve the efficiency of data entry and retrieval and thus result in a system with high acceptance among physicians in the demanding environment during hospital rounds.

Reuss E; Menozzi M; Büchi M; Koller J; Krueger H

2004-05-01

195

Feature-based eye corner detection from static images  

Science.gov (United States)

Eye corner detection is important for eye extraction, face normalization, other facial landmark extraction and so on. We present a feature-based method for eye corner detection from static images in this paper. This method is capable of locating eye corners automatically. The process of eye corner detection is divided into two stages: classifier training and classifier application. For training, two classifiers trained by AdaBoost with Haar-like features, are skillfully designed to detect inner eye corners and outer eye corners. Then, two classifiers are applied to input images to search targets. Eye corners are finally located according to two eye models from targets. Experimental results tested on BioID face database and our own database demonstrate that our method obtains a high accuracy under clutter conditions.

Xia, Haiying; Yan, Guoping; You, Chao

2009-10-01

196

Functional improvement after one- and two-eye cataract surgery in the Salisbury Eye Evaluation.  

UK PubMed Central (United Kingdom)

PURPOSE: To determine the impact that cataract and cataract surgery have on clinical measurements of vision, reading speed, objective mobility performance, and subjective visual functioning. DESIGN: Prospective, population-based study. PARTICIPANTS: A total of 1739 Salisbury Eye Evaluation (SEE) participants without previous cataract surgery with bilateral baseline best-corrected visual acuity (BCVA) of logarithm of the minimum angle of resolution (logMAR) ? 0.3 (? 20/40) or cataract surgery between rounds 1 and 2. METHODS: Participants were categorized on the basis of cataract surgery by round 2 into no surgery, unilateral surgery, or bilateral surgery. Visual performance, mobility-based tasks, and the Activities of Daily Vision Scale (ADVS) were measured at baseline and 2 years. Mobility score was converted into a z score by subtracting the participant's time from the population baseline average and then dividing by the standard deviation. Comparisons were made between the no surgery and surgery groups using multivariate linear regression. MAIN OUTCOME MEASURES: Change in bilateral BCVA in logMAR, contrast sensitivity, reading speed in words per minute (wpm), mobility score, and ADVS. RESULTS: During the study period, 29 participants had cataract surgery on both eyes, 90 participants had unilateral surgery, and 1620 participants had no surgery. After adjusting for baseline value, demographics, depression, and mental status, the unilateral surgery group's BCVA improved 0.04 logMAR (P = 0.001) and the bilateral group's BCVA improved 0.13 compared with no surgery (P<0.001). Overall mobility declined in all groups. The unilateral group's z score decreased 0.18 more than that of the no surgery group (P = 0.02), whereas the bilateral group showed a 0.18 z score improvement compared with no surgery (P = 0.19). Change in reading speed significantly improved in the unilateral and bilateral groups compared with no surgery (12 and 31 wpm, respectively). The bilateral surgery group showed significant positive change in ADVS compared with no surgery (5 points of relative improvement; P = 0.01), whereas the unilateral group showed a 5-point relative decline (P<0.001). CONCLUSIONS: Cataract negatively affects both subjective quality of life and objective performance measures. Unilateral cataract surgery improves visual functioning, but the largest gains are found in patients who undergo second-eye cataract surgery. This finding supports second-eye cataract surgery for patients with visual or functional symptoms even after successful first-eye surgery. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Lee BS; Munoz BE; West SK; Gower EW

2013-05-01

197

LASIK Eye Surgery  

Science.gov (United States)

LASIK eye surgery Basics In-Depth Multimedia Resources Reprints A single copy of this article may be reprinted for personal, noncommercial use only. LASIK eye surgery By Mayo Clinic staff Original Article: http://www. ...

198

Diabetes - Eye Complications  

Medline Plus

Full Text Available ... to have eye problems that can lead to blindness. Many of these eye diseases can be prevented ... the retina, causing severe vision loss and possibly blindness. If you have diabetic retinopathy, your doctor may ...

199

What Is Dry Eye?  

Medline Plus

Full Text Available ... Tweet When you blink, a film of tears spreads over the eye, making the surface of the ... the conjunctiva. Mucus allows the watery layer to spread evenly over the surface of the eye and ...

200

LASIK - Laser Eye Surgery  

Medline Plus

Full Text Available ... Alternative Refractive Surgery Procedures Find An Eye M.D. Enter zip code here Search by Name, City, State or Subspecialty > Ask An Eye M.D. Enter your question here... Browse Top Answers > Privacy ...

 
 
 
 
201

Bags Under Eyes  

Science.gov (United States)

Bags under eyes Basics In-Depth Multimedia Resources Reprints A single copy of this article may be reprinted for personal, noncommercial use only. Bags under eyes By Mayo Clinic staff Original Article: http:// ...

202

Diabetes - Eye Complications  

Medline Plus

Full Text Available ... that can lead to blindness. Many of these eye diseases can be prevented or delayed through good diabetes ... management of diabetes helps prevent and delay these eye diseases. Management of diabetes consists of the following: • Controlling ...

203

LASIK - Laser Eye Surgery  

Medline Plus

Full Text Available ... a hot tub. It's Not OK to Skip a Day To control glaucoma, take eye drops exactly ... your sight depends on it. Give your Eyes a Break To prevent computer eyestrain, follow the 20- ...

204

LASIK - Laser Eye Surgery  

Medline Plus

Full Text Available ... Page: Alternative Refractive Surgery Procedures Find An Eye M.D. Enter zip code here Search by Name, City, State or Subspecialty > Ask An Eye M.D. Enter your question here... Browse Top Answers > ...

205

Eye Target Apparatus  

UK PubMed Central (United Kingdom)

An eye target apparatus and method helping to control an operative eye focus line of sight position during medical procedures on the operative eye of a cooperative awake patient. The apparatus includes a housing for occluding substantially all visual perception from an exterior environment for a non operative eye, the housing including a cover, with an internal surface that forms a plane approximately perpendicular to the non operative eye line of sight axis.Also included is a visually perceptible element adjacent to the internal surface being in visual communication with the non operative eye and structure for moving the visually perceptible element within the plane to any selected position, the apparatus is operational to help the non operative eye focus on a selected line of sight position upon the visually perceptible element with the result in assisting in the operative eye achieving a stable selected line of sight position.

BISCARDI HENRY M

206

Diabetes - Eye Complications  

Medline Plus

Full Text Available ... more likely to have eye problems that can lead to blindness. Many of these eye diseases can ... the retina can also get completely clogged and lead to the death of parts of the retina. ...

207

Diabetes - Eye Complications  

Medline Plus

Full Text Available ... eye problems such as blurred vision, cataract, and glaucoma. People with diabetes may have blurry vision when ... vision. Cataract can be fixed by minor surgery. Glaucoma is another disease of the eye that is ...

208

The Yazd Eye Study-a population-based survey of adults aged 40-80 years: rationale, study design and baseline population data.  

UK PubMed Central (United Kingdom)

PURPOSE: To describe the rationale, methodology and baseline data of the Yazd Eye Study, a study in the urban and rural areas of Yazd, a district in the center of Iran. METHODS: This population-based cross-sectional study included adults aged 40-80 years from the non-institutionalized population of the Yazd district, in 2010-2011. Using multi-stage, systematic cluster random sampling and a probability proportional to size strategy, 58 clusters of 40 subjects were selected from 251 clusters in different enumeration areas. A detailed interview and eye examination were performed for each eligible participant. The eye examination included refraction testing, uncorrected and best corrected visual acuity testing, slit lamp biomicroscopy, Goldmann applanation tonometry, gonioscopy, dilated fundus examination, visual field, determination of central corneal thickness, and stereoscopic fundus photography. General health assessments and laboratory tests including hemoglobin, hematocrit, glycosylated hemoglobin, fasting blood sugar, serum lipids, and urine albumin to creatinine ratio were also performed to assess anthropometric and systemic risk factors. RESULTS: Of 2320 eligible individuals, 2098 (response rate 90.4%) participated in the study. The mean?±?standard deviation age of participants was 54.1?±?10.0 years, and included 994 men (47.4%) and 1104 women (52.6%). Most participants lived in urban regions (89.2%) and were younger than 60 years old (72.0%). Among the participants, 20.1% were illiterate, and 40.9%, 28.0%, and 11.0% had primary, secondary and college or university level education, respectively. CONCLUSION: This study is expected to provide an estimate of the prevalence and risk factors of major eye diseases and normal eye indices in the Yazd district.

Katibeh M; Ziaei H; Pakravan M; Dehghan MH; Ramezani A; Amini H; Yazdani S; Solaimanizad R; Yaseri M; Javadi MA

2013-01-01

209

Morrow Point dam and powerplant, Colorado River Storage Project, Gunninson Division, Curecanti Unit, Colorado. Technical record of design and construction. A water resources technical publication. Final report  

Energy Technology Data Exchange (ETDEWEB)

This technical record of design and construction for Morrow Point Dam and Powerplant is divided into three parts. Part I is devoted to the general planning, historical information, description of features, summary of costs, and geology. Part II covers the design of the various features and their components. Part III covers contract administration, construction operations, and equipment installations.

1983-09-01

210

Optical properties of the mouse eye.  

UK PubMed Central (United Kingdom)

The Shack-Hartmann wavefront sensor (SHWS) spots upon which ocular aberration measurements depend have poor quality in mice due to light reflected from multiple retinal layers. We have designed and implemented a SHWS that can favor light from a specific retinal layer and measured monochromatic aberrations in 20 eyes from 10 anesthetized C57BL/6J mice. Using this instrument, we show that mice are myopic, not hyperopic as is frequently reported. We have also measured longitudinal chromatic aberration (LCA) of the mouse eye and found that it follows predictions of the water-filled schematic mouse eye. Results indicate that the optical quality of the mouse eye assessed by measurement of its aberrations is remarkably good, better for retinal imaging than the human eye. The dilated mouse eye has a much larger numerical aperture (NA) than that of the dilated human eye (0.5 NA vs. 0.2 NA), but it has a similar amount of root mean square (RMS) higher order aberrations compared to the dilated human eye. These measurements predict that adaptive optics based on this method of wavefront sensing will provide improvements in retinal image quality and potentially two times higher lateral resolution than that in the human eye.

Geng Y; Schery LA; Sharma R; Dubra A; Ahmad K; Libby RT; Williams DR

2011-01-01

211

Perfect drain for the Maxwell Fish Eye lens.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Perfect imaging of electromagnetic waves using the Maxwell ?sh eye (MFE) requires a new concept: a point called the perfect drain that we shall call the perfect point drain. From the mathematical point of view, a perfect point drain is just like an ideal point source, except that it drains power fro...

Gonzalez Lopez, Juan Carlos; Benitez Gimenez, Pablo; Miñano Dominguez, Juan Carlos

212

Eye injuries in children.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We report a retrospective study of children's eye injuries treated during 1977 at Helsinki University Eye Hospital. There were 110 cases representing 34.5% of all eye injuries and 3% of all patients treated in 1977; 81.8% were boys and 18.2% girls. Half of the injuries were caused by another child, ...

Niiranen, M; Raivio, I

213

Occupational laser eye injuries  

Energy Technology Data Exchange (ETDEWEB)

In contrast to a high number of supposed occupational Laser eye injuries, quite few actual accidents of Laser workers are known. After reviewing the incidence of Laser eye injuries, a summary of the clinical picture of these eye injuries is given. It is emphasised that the safe use of the Laser technology is due to very effective safety procedures.

Felixberger, F.; Szadkowski, D.

1982-01-01

214

Optimization of point sources on thin films using a statistical design approach. Application to 60Co sources  

International Nuclear Information System (INIS)

Radioactive point sources prepared by depositing weighed drops on thin membranes are commonly used in ionizing radiation metrology for 47??-? coincidence counting or for low energy electrons spectrometry. The present study deals with the preparation of good quality sources having high detection yields. Some influential parameters on the source quality are studied using 60Co as radioactive tracer. An approach based on experimental statistical designs has been chosen. This approach allows us to obtain reliable results with a number of experiences lower than in the case of a systematic approach. Homogeneous 60Co sources with high metrological qualifies (R?> 96 %) can be prepared using a direct deposit of ? 5 mg drops of 60Co solution ([Co] = 12 ?g/g), [HCl] = 0,5 mol/I) and dried at 60 deg C. The support of the radioactive spot is constituted with a gold coated (130 ?g/cm2 of Au) Vyns films (thickness 45 ?g/cm2) on which a pad (diameter = 7 - 8 mm) of polystyrene microspheres (Estapor K-007) is prepared by an electro-spraying technique under 7,5 kV during 10 minutes. The alcoholic solution used for the electro-spraying step has the following chemical composition [Estapor K-007] 2.5 10-2 wt % and [Tween 20] = 2.7 10-2 wt %. (authors)

2001-01-01

215

Analysis of EEG Related Saccadic Eye Movement  

Science.gov (United States)

Our final goal is to establish the model for saccadic eye movement that connects the saccade and the electroencephalogram(EEG). As the first step toward this goal, we recorded and analyzed the saccade-related EEG. In the study recorded in this paper, we tried detecting a certain EEG that is peculiar to the eye movement. In these experiments, each subject was instructed to point their eyes toward visual targets (LEDs) or the direction of the sound sources (buzzers). In the control cases, the EEG was recorded in the case of no eye movemens. As results, in the visual experiments, we found that the potential of EEG changed sharply on the occipital lobe just before eye movement. Furthermore, in the case of the auditory experiments, similar results were observed. In the case of the visual experiments and auditory experiments without eye movement, we could not observed the EEG changed sharply. Moreover, when the subject moved his/her eyes toward a right-side target, a change in EEG potential was found on the right occipital lobe. On the contrary, when the subject moved his/her eyes toward a left-side target, a sharp change in EEG potential was found on the left occipital lobe.

Funase, Arao; Kuno, Yoshiaki; Okuma, Shigeru; Yagi, Tohru

216

School eye health appraisal.  

UK PubMed Central (United Kingdom)

School children form an important large target group which must be screened adequately for early detection of eye diseases and prevention of blindness. A total approach in a school eye health programme must include teacher orientation and health education of children in addition to screening for eye diseases. The ocular morbidity pattern in 5135 school children of Jodhpur is discussed in this paper and it is hoped that it will be an indicator to all eye care agencies to help plan their priorities in the delivery of school based eye care.

Desai S; Desai R; Desai NC; Lohiya S; Bhargava G; Kumar K

1989-10-01

217

School eye health appraisal  

Directory of Open Access Journals (Sweden)

Full Text Available School children form an important large target group which must be screened adequately for early detection of eye diseases and prevention of blindness. A total approach in a school eye health programme must include teacher orientation and health education of children in addition to screening for eye diseases. The ocular morbidity pattern in 5135 school children of Jodhpur is discussed in this paper and it is hoped that it will be an indicator to all eye care agencies to help plan their priorities in the delivery of school based eye care.

Desai Sanjiv; Desai Rajiv; Desai N; Lohiya Shobha; Bhargava G; Kumar K

1989-01-01

218

The analysis of visual variables for use in the cartographic design of point symbols for mobile Augmented Reality applications  

Science.gov (United States)

The objective of the present deliberations was to systematise our knowledge of static visual variables used to create cartographic symbols, and also to analyse the possibility of their utilisation in the Augmented Reality (AR) applications on smartphone-type mobile devices. This was accomplished by combining the visual variables listed over the years by different researchers. Research approach was to determine the level of usefulness of particular characteristics of visual variables such as selective, associative, quantitative and order. An attempt was made to provide an overview of static visual variables and to describe the AR system which is a new paradigm of the user interface. Changing the approach to the presentation of point objects is caused by applying different perspective in the observation of objects (egocentric view) than it is done on traditional analogue maps (geocentric view). Presented topics will refer to the fast-developing field of cartography, namely mobile cartography. Particular emphasis will be put on smartphone-type mobile devices and their applicability in the process of designing cartographic symbols. Celem artyku?u by?o usystematyzowanie wiedzy na temat statycznych zmiennych wizualnych, które sa kluczowymi sk?adnikami budujacymi sygnatury kartograficzne. Podjeto próbe zestawienia zmiennych wizualnych wyodrebnionych przez kartografów na przestrzeni ostatnich piecdziesieciu lat, zaczynajac od klasyfikacji przedstawionej przez J. Bertin’a. Dokonano analizy stopnia uzytecznosci poszczególnych zmiennych graficznych w aspekcie ich wykorzystania w projektowaniu znaków punktowych dla mobilnych aplikacji tworzonych w technologii Rzeczywistosci Rozszerzonej (Augmented Reality). Zmienne poddano analizie pod wzgledem czterech charakterystyk: selektywnosci, skojarzeniowosci, odzwierciedlenia ilosci oraz porzadku. W artykule zwrócono uwage na odmienne zastosowanie perspektywy pomiedzy tradycyjnymi analogowymi mapami (geocentrycznosc) a aplikacjami tworzonymi w technologii Rozszerzonej Rzeczywistosci (egocentrycznosc). Tresci prezentowane w pracy dotycza szybko rozwijajacej sie ga?ezi kartografii - kartografii mobilnej. Dodatkowy nacisk po?ozony zosta? na próbe implementacji za?ozen projektowania punktowych znaków kartograficznych na urzadzenia mobilne typu smartphone.

Halik, ?ukasz

2012-11-01

219

Problems associated with the use of beryllium in a fusion ceramic blanket. A designer point of view  

International Nuclear Information System (INIS)

[en] Compatibility problems of beryllium with various structural and ceramic breeder materials are being investigated in Europe, both in-pile and out-of-pile. There are, however, three other problems which needs more work: 1. Beryllium swells under neutron irradiation. Extrapolation of experimental data indicates that at a fluence of 3 MWa/m2, foreseen for ITER, and a temperature of 500deg C the swelling is about 4.5%, while for the Demo-reactor (5 MWa/m2 and 600deg C) the swelling could be in excess of 12%. 2. Beryllium becomes very brittle under irradiation. Experimental data show that elongation is reduced practically to zero for temperatures up to 600deg C after a relatively low neutron fluence (1.5 x 1021 cm-2, E > 1 MeV). 3. Recent tritium release experiments from beryllium irradiated at 5 x 1022 n/cm2 (E > 1 MeV) and 75deg C (Baldwin et al.) show that, below 600deg C, a small amount of tritium (? 2%) is released by a process controlled by temperature dependent trapping and diffusivity. The rest (98%) is release for temperatures slightly above 600deg C, whereby this release seems to be connected with the formation of helium bubbles. This phenomenon is probably connected with beryllium swelling as well. The first two points make a design with beryllium very difficult, the third may have not so good safety implications. The data mentioned above refer to beryllium fabricated 25-35 years ago. Futhermore, most irradiations at high fluences have been performed a low temperatures (

1991-01-01

220

Separate effects of the microkeratome incision and laser ablation on the eye's wave aberration.  

UK PubMed Central (United Kingdom)

PURPOSE: To study the optical changes induced by the microkeratome cut, the subsequent laser ablation, and the biomechanical healing response of the cornea in normal laser in situ keratomileusis (LASIK) eyes. DESIGN: Prospective randomized clinical trial. METHODS: A Hansatome microkeratome was used to cut a corneal flap in one eye (study eye) of 17 normal myopic patients and a subsequent laser ablation was performed 2 months after this initial microkeratome incision. Control eyes received conventional LASIK treatments at the latter time point. The wave aberration of both the study and contralateral control eyes were measured over a 6-mm pupil with a Shack-Hartmann wavefront sensor for all preoperative, postflap cut, and postablation visits. RESULTS: The eye's higher order aberrations had a small, but significant increase (P =.03) of approximately 30% 2 months after cutting a flap. No systematic changes were observed in nearly all Zernike coefficients from their preoperative levels at 2 months postflap cut. A significant difference between the study and control eyes was observed for one trefoil mode, Z(3)(3) (P =.04). CONCLUSIONS: There was a wide variation in the response of individual Zernike modes across patients after cutting a flap. The majority of spherical aberration induced by the LASIK procedure seems to be due to the laser ablation and not the microkeratome cut. In addition, the total and higher order root mean square of wavefront errors were nearly identical for both the study and control eyes 3-months after the laser ablation, indicating that a procedure in which the incision and the ablation are separated in time to better control aberrations does not compromise the outcome of a conventional LASIK treatment.

Porter J; MacRae S; Yoon G; Roberts C; Cox IG; Williams DR

2003-08-01

 
 
 
 
221

Effect of artificial tears on automated visual field testing in patients with glaucoma and dry eye.  

UK PubMed Central (United Kingdom)

OBJECTIVE: To evaluate the effects of artificial tears on automated visual field (VF) testing in patients with glaucoma with dry eye syndrome. DESIGN: Prospective study. PARTICIPANTS: Fifty eyes of 50 patients with medically treated primary open-angle glaucoma (POAG) were recruited for this study. The patients were subdivided into 2 subgroups: those with dry eye syndrome (group I) and those without dry eye syndrome (group II). METHODS: Tear break-up time, Lissamine green staining, and Schirmer I test with topical anesthesia were performed in the same order in all patients. Ocular Surface Disease Index questionnaire was completed by the patients. All participants underwent automated perimetry using the 24-2 SITA (Swedish interactive threshold algorithm) standard strategy before and after 1-week treatment with a lubricating eye drop 4 times daily. VF results were compared before and after the treatment using Wilcoxon signed rank test, and Mann-Whitney test was performed to compare the results of patients in groups I and II. RESULTS: Of the 50 patients, 25 (50%) were diagnosed with dry eye syndrome. No significant differences between both groups were found with respect to age (P = 0.779) and glaucoma duration (P = 0.722). In patients with glaucoma with dry eye syndrome, there was a significant improvement in test duration, mean deviation, and the number of depressed points at probability level less than 0.5% and less than 1% in pattern deviation plots after the treatment (P< 0.05). CONCLUSIONS: The use of artificial tears in patients with glaucoma with dry eye syndrome decreased VF testing time and improved test results.

Kocabeyoglu S; Cem Mocan M; Bozkurt B; Irkec M

2013-04-01

222

Eye trauma during the 2011 Egyptian revolution.  

UK PubMed Central (United Kingdom)

BACKGROUND: Cairo university hospitals are at the heart of Cairo with close proximity to Tahrir (Liberation) square and had received the vast majority of casualties during the Egyptian revolution. The aim of this study was to analyze the eye injuries during the uprising. DESIGN: Retrospective cohort study. METHODS: Data were obtained from patients' paper records, interview with treating ophthalmologists, and whenever possible patients were interviewed and examined. An electronic medical template had been specially developed for recording these data. Main outcome measures were the flow of patients and their demographics, diagnoses, visual acuities pre and post interventions, investigations and management. Whenever required results were compared at 95 % confidence interval. RESULTS: There were 184 patients (mean age 27.3 ± 9.6 years) with 195 injured eyes of whom 96.7 % were males and 11 patients had both eyes injured. Seventy seven percent of patients had been admitted within 24 h of injury. Open globe injuries comprised 87 % of the eyes of which 147 eyes received 259 imaging investigations. The presenting visual acuities were worse than 3/60 in 72.5 % of eyes which were even worse post interventions and that was significantly dependent on the presenting vision. Wound repair was the primary intervention in 85 % of eyes while 50 % of the secondary interventions were vitrectomies. CONCLUSIONS: Presenting visual acuity is a valid prognostic factor in the setting of mass eye casualty. Management of open globe injuries continues to pose difficult challenges especially bilateral ones.

Eldaly MA; Abdelhakim MA; Zaki RS; El-Shiaty AF

2013-03-01

223

Impaired exploratory eye movements in children with Asperger's syndrome.  

UK PubMed Central (United Kingdom)

Objective: Previous eye-tracking studies using an eye mark recorder have reported that disturbances in exploratory eye movements in adult schizophrenic patients are associated with social functioning. The current study sought to determine whether exploratory eye-movement disturbances are present in children with Asperger's syndrome (AS) compared with typically developing (TD) children. Materials/Participants: The participants were 23 children with AS and 23 age-matched TD children. We measured exploratory eye movements using an EMR-8B eye mark recorder and an exploratory eye movement-measuring device. Method: Eye movements were recorded while participants freely observed a geometric figure (free viewing task), and while they complied with the instructions of an experimenter (repeat-comparison task). We assessed eye fixation points (EFPs) and total eye scanning length (TESL) in all tasks, and measured the responsive search score (RSS) in the repeat-comparison task. Results: In the free viewing task, children with AS exhibited significantly shorter TESL compared with TD children. In the repeat-comparison task, children with AS exhibited significantly lower RSS. Autism Spectrum Screening Questionnaire scores were negatively correlated with both EFP and TESL, but not RSS. Conclusion: The current results revealed that children with AS exhibited dysfunction in exploratory eye movements. Thus, assessing exploratory eye movements in a repeat-comparison task may be useful for detecting social impairment among children with AS.

Ohya T; Morita K; Yamashita Y; Egami C; Ishii Y; Nagamitsu S; Matsuishi T

2013-05-01

224

New England eye care survey.  

UK PubMed Central (United Kingdom)

BACKGROUND: Descriptive statistics on patient or consumer use of eye care are important for health care policy and professional development. Most survey research has been through doctors or doctors' offices. Some consumer surveys have been completed by direct mail, but information from direct mail surveys suffers from respondent self selection. This study joins a growing number of surveys designs that use random-digit telephone survey methods, which have less self-selection bias. METHODS: This study describes patient use and perceptions of eye care services in three New England areas using random-digit telephone survey. Nine hundred eighteen calls were attempted. A standardized interview and survey questionnaire was used for each phone contact. RESULTS: Of 163 respondents (18% response rate), it was found that most patients were satisfied with the care, time, discussion, and fees provided by their eye care practitioner. Most (78%) planned on returning to the same practitioner in the future. Sixty percent of participants saw an optometrist, 29% saw an ophthalmologist, and 11% were unsure. In a subsample, differences in perception between optometric and ophthalmologic care was investigated, and no statistically significant differences (p < 0.05) were found. CONCLUSIONS: The study findings are similar to others in terms of market share between optometric and ophthalmologic settings for primary eye care. Several new findings were measured and discussed, and the data may be helpful for policy decisions.

Kaminski J; Andrews K; Hatch SW

1997-10-01

225

Improving eye care in the primary health care setting  

Directory of Open Access Journals (Sweden)

Full Text Available One of the challenges facing primary health care in South Africa is the delivery of quality eye care to all South Africans. In this regard the role of the primary health care worker, as the first point of contact, is crucial. This paper reports on the problems primary health care workers experience in providing quality eye care in Region B of the Free State. Problems identified by those involved in the study include the cumbersome referral system, the unavailability of appropriate medicine at clinics, the insufficient knowledge of primary health care workers regarding eye conditions and the lack of communication between the various eye care service providers. Suggestions to address the problems identified included more in-service training of primary health care workers regarding eye conditions, liaison with NGO’s providing eye care, decentralisation of services and the establishment of an eye care committee in the region.

M de Wet; L Ackermann

2000-01-01

226

Mathematical model of geometry of the eye.  

UK PubMed Central (United Kingdom)

A computer program was written in order to construct a geometric model of the human eye, having as a base some subroutines from the SAP IV program designed by the University of California. It was written in Fortran. In order to generate the proposed geometry, it was necessary to divide the eye into three zones, each one corresponding to a plane geometric figure, since the human eye does not correspond to any one shape. When the three zones are joined together, they form an eyeball.

Arciniegas A; Amaya LE; Puccini M

1985-08-01

227

Mathematical model of geometry of the eye.  

Science.gov (United States)

A computer program was written in order to construct a geometric model of the human eye, having as a base some subroutines from the SAP IV program designed by the University of California. It was written in Fortran. In order to generate the proposed geometry, it was necessary to divide the eye into three zones, each one corresponding to a plane geometric figure, since the human eye does not correspond to any one shape. When the three zones are joined together, they form an eyeball. PMID:3840342

Arciniegas, A; Amaya, L E; Puccini, M

1985-08-01

228

Evaluation of Human Emotion from Eye Motions  

Directory of Open Access Journals (Sweden)

Full Text Available The object of this paper is to develop an emotion recognition system that analysis the motion trajectory of the eye and gives the response on appraisal emotion. The emotion recognition solution is based on the data gathering using head mounted eye tracking device. The participants of experimental investigation were provided with a visual stimulus (PowerPoint slides) and the emotional feedback was determined by the combination of eye tracking device and emotion recognition software. The stimulus was divided in four groups by the emotion that should be triggered in the human, i.e., neutral, disgust, exhilaration and excited. Some initial experiments and the data on the recognition accuracy of the emotion from eye motion trajectory are provided along with the description of implemented algorithms.

Vidas Raudonis; Gintaras Dervinis; Andrius Vilkauskas; Agne Paulauskaite - Taraseviciene; Gintare Kersulyte - Raudone

2013-01-01

229

Eye moxibustion equipment  

UK PubMed Central (United Kingdom)

The utility model discloses an eye-moxibustion device, comprising a spectacle frame, an eye shade and a moxa-stick fixing column, wherein the eye shade is arranged in the lens frame of spectacle frame, the moxa-stick fixing column is fixed in front of the eye shade on the spectacle frame. The utility model can take place of hand operation with easy operation, save labor and time with high safety factor and no pain, no pollution (without medicine), can be repeatedly used with low cost and is applicable to medical treatment organizations.

ZHAOQIN MA

230

Sensory eye dominance.  

UK PubMed Central (United Kingdom)

BACKGROUND: Sensory eye dominance is revealed in tasks like the Red Lens test and binocular rivalry. To understand its neural basis, we used a new protocol based on binocular rivalry to quantify its consequent interocular imbalance. Then we investigated whether the extent or sign of interocular imbalance is correlated with the difference in monocular contrast responses at threshold and suprathreshold and with the observer's motor eye dominance. METHODS: To evaluate sensory eye dominance, the stimulus intensity in each eye during rivalry was adjusted to achieve equal predominance. The difference in stimulus intensity constitutes the interocular imbalance. Standard procedures were used to measure monocular spatial contrast sensitivity, suprathreshold brightness judgment, and motor eye dominance. RESULTS: There was no positive correlation between interocular imbalance (sensory eye dominance) and motor eye dominance. No systematic correlation was found between interocular imbalance and monocular contrast sensitivities at 1 and 3 cycles/degree. Correlation coefficient between interocular imbalance and monocular suprathreshold brightness judgment was close to significant, suggesting that a difference in monocular brightness percept might (in part) account for interocular imbalance. But this explanation is only partial, since the difference in the monocular brightness percept was too small to account for the interocular imbalance. CONCLUSIONS: Interocular imbalance is a sensory eye dominance that cannot be equated with motor eye dominance. It manifests largely as a binocular phenomenon, which bears little relationship with the monocular neural mechanisms of contrast detection and brightness perception.

Ooi TL; He ZJ

2001-03-01

231

Inflammation in dry eye.  

UK PubMed Central (United Kingdom)

Dry eye is a condition of altered tear composition that results from a diseased or dysfunctional lacrimal functional unit. Evidence suggests that inflammation causes structural alterations and/or functional paralysis of the tear-secreting glands. Changes in tear composition resulting from lacrimal dysfunction, increased evaporation and/or poor clearance have pro-inflammatory effects on the ocular surface. This inflammation is responsible in part for the irritation symptoms, ocular surface epithelial disease, and altered corneal epithelial barrier function in dry eye. Anti-inflammatory therapies for dry eye target one or more of the inflammatory mediators/pathways that have been identified in dry eye.

Stern ME; Pflugfelder SC

2004-04-01

232

Different schematic eyes and their accuracy to the in vivo eye: a quantitative comparison study  

Scientific Electronic Library Online (English)

Full Text Available Abstract in english Current ophthalmic technology allows the manipulation of eye components, such as anterior cornea and lens, of the human eye with a considerable precision and customization. This technology opens up the possibility of exploiting some characteristics of the eye in order to improve the methods of correcting optical aberrations. Moreover, product development and research for the eye-care professional has reached very high standards, since there is nowadays software available (more) to design and simulate practically any mechanical or optical characteristic of the product, even before it is thrown into production line. Although quite similar in the general form, different human eye models simulate the image formation by considering different property combinations in the constitutive elements of the eye structure (such as refraction index and surface curvatures), producing retinal images that resemble very closely those of the biological eye. Using optical design software, we have implemented a simulation of 5 well-known schematic eyes available in the literature. These models were the Helmholtz-Laurance, Gullstrand, Emsley, Greivenkamp and Liou & Brennan. The optical performance of these different models was compared using different quantitative optical quality parameters. The model of Liou and Brennan, contains features of the biological eye that were not considered in previous models, as the distribution of a gradient refraction index and a decentered pupil. Furthermore, it has great reliability since it takes into account the mean value of empirical measurements of the in vivo eye in order to define size and parameters such as anterior and posterior curvature of cornea, lens, axial length, etc. Comparisons between the MTF (Modulation Transfer Function), spot diagrams and ray fan showed the difference in image quality between eye models, and the Strehl Ratio was also used as a parameter of comparison. A careful comparison between the different models showed that the first four schematic eyes have better optical quality than what is expected for the general and healthy emmetropic in vivo eye. Liou and Brennan schematic eye is the one that most closely resembles the in vivo biological eye. Therefore, in applications, such as research or product development for customized vision correction, which must consider optical properties intrinsic to the biological eye, we recommend this latter model; for applications that do not require refraction-limited performance, most of the other models should be a good approximation.

Almeida, Marina Storani de; Carvalho, Luis Alberto

2007-06-01

233

Efficacy of cyclosporine 0.05% eye drops in stevens johnson syndrome with chronic dry eye.  

UK PubMed Central (United Kingdom)

OBJECTIVE: To evaluate the efficacy of cyclosporine 0.05% (CsA) eye drops in patients with Stevens Johnson syndrome (SJS) who had chronic dry eye. DESIGN: Prospective noncomparative interventional case series. METHODS: Thirty cases of SJS patients who developed dry eye defined by symptoms and signs, including the Schirmer I test, the fluorescein clearance test (FCT), and corneal staining (fluorescein and Rose Bengal staining) were treated with CsA 0.05% eye drops twice daily for 6 months. Dry eye symptoms, eye injection, tear break up time (TBUT), and corneal staining were evaluated before and after the treatment at 0, 2, 4, and 6 months. The Shirmer I test and FCT were evaluated at 0 and 6 months. RESULTS: Seventeen patients (56.67%) completed the study. Eight patients (26.67%) withdrew from the study as a result of intolerable side effects of CsA, which included pain, redness, and eyelid swelling. Five cases were lost in follow up. All 17 cases demonstrated significant improvement in dry eye symptoms, conjunctival injection, corneal staining, Schirmer I test, and FCT (P<0.05). CONCLUSIONS: CsA 0.05% eye drops might be beneficial in the treatment of chronic dry eye associated with SJS.

Prabhasawat P; Tesavibul N; Karnchanachetanee C; Kasemson S

2013-04-01

234

Autologous serum eye drops for dry eye.  

UK PubMed Central (United Kingdom)

BACKGROUND: Theoretically, autologous serum tears (AST) have a potential advantage over traditional therapies based on the assumption that AST serve not only as a lacrimal substitute to provide lubrication, but also contain other biochemical components mimicking natural tears more closely. The application of AST in dry eye treatment has gained popularity as an adjunctive treatment for dry eye. However, thus far there has been no systematic review assessing the effectiveness of AST in the treatment for dry eye. OBJECTIVES: To assess the safety and effectiveness of AST eye drops compared to artificial tears for treating dry eye. SEARCH METHODS: We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2013, Issue 3), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE, (January 1950 to April 2013), EMBASE (January 1980 to April 2013), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to April 2013), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov) and the WHO International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We also searched the Science Citation Index Expanded database and reference lists of included studies. We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 15 April 2013. SELECTION CRITERIA: We included randomized controlled trials (RCTs) in which AST was compared to artificial tears in the treatment of dry eye. DATA COLLECTION AND ANALYSIS: Two review authors independently screened all retrieved articles. Methodological quality and study characteristics of the included trials were assessed by two review authors. We contacted investigators for missing data. For both primary and secondary outcomes, we reported mean differences with corresponding 95% confidence intervals (CIs) for continuous outcomes. MAIN RESULTS: Four eligible trials randomized individuals (n = 72 participants) with dry eye of various etiologies (Sjögren's syndrome-related dry eye, non-Sjögren's syndrome dry eye and postoperative dry eye induced by laser-assisted in situ keratomileusis (LASIK)) to either AST or artificial tear treatment. The quality of the evidence provided by these trials was variable. Incomplete outcome reporting and heterogeneity in the participant populations prevented the inclusion of these trials in a summary meta-analysis. Based on the results of two trials in 32 participants, 20% AST may provide some improvement in participant-reported symptoms compared to traditional artificial tears after two weeks of treatment. One trial also showed promising results with a mean difference in tear break-up time (TBUT) of 2.00 seconds (95% CI 0.99 to 3.01 seconds) between 20% AST and artificial tears after two weeks. These findings in participant-reported symptom improvement and tear film stability were not consistent in the other trials. Based on additional objective clinical assessments, AST was not associated with improvements in aqueous tear production measured by Schirmer's test (two trials, 33 participants), ocular surface condition with fluorescein (four trials, 72 participants) or Rose Bengal staining (three trials, 60 participants), and epithelial metaplasia by impression cytology compared to artificial tears (one trial, 13 participants). Data on adverse effects were not reported consistently in the included studies; however, there were no reported serious adverse events associated with the collection of and treatment with AST. AUTHORS' CONCLUSIONS: Although 20% AST may provide some benefit in improving participant-reported symptoms in the short-term (two weeks), there is still a lack of sufficient and strong evidence to determine whether the application of AST offers a significant advantage over artificial tears on dry eye. Well-planned, large, high-quality RCTs are warranted, comparing different concentrations

Pan Q; Angelina A; Zambrano A; Marrone M; Stark WJ; Heflin T; Tang L; Akpek EK

2013-01-01

235

Eye proprioception may provide real time eye position information.  

UK PubMed Central (United Kingdom)

Because of the frequency of eye movements, online knowledge of eye position is crucial for the accurate spatial perception and behavioral navigation. Both the internal monitoring signal (corollary discharge) of eye movements and the eye proprioception signal are thought to contribute to the localization of the eye position in the orbit. However, the functional role of these two eye position signals in spatial cognition has been disputed for more than a century. The predominant view proposes that the online analysis of eye position is exclusively provided by the corollary discharge signal, while the eye proprioception signal only plays a role in the long-term calibration of the oculomotor system. However, increasing evidence from recent behavioral and physiological studies suggests that the eye proprioception signal may play a role in the online monitoring of eye position. The purpose of this review is to discuss the feasibility and possible function of the eye proprioceptive signal for online monitoring of eye position.

Wang J; Pan Y

2013-03-01

236

Eye-Tracking  

Directory of Open Access Journals (Sweden)

Full Text Available Eye-tracking: one of the newest and most efficient methods of improving on-line marketing communication is called eye-tracking. Marketers have borrowed this technique, usually used in psychological and medical research, in order to study web users with the help of a video camera incorporated in the monitor.

Gabriela GROSSECK

2006-01-01

237

Eye-Tracking  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Eye-tracking: one of the newest and most efficient methods of improving on-line marketing communication is called eye-tracking. Marketers have borrowed this technique, usually used in psychological and medical research, in order to study web users with the help of a video camera incorporated in the ...

Gabriela GROSSECK

238

LASIK - Laser Eye Surgery  

Medline Plus

Full Text Available ... or in a hot tub. It's Not OK to Skip a Day To control glaucoma, take eye drops exactly as prescribed ... depends on it. Give your Eyes a Break To prevent computer eyestrain, follow the 20-20-20 ...

239

The eyes of the olms.  

Science.gov (United States)

The experiments of the Austrian biologist Paul Kammerer to breed eyes in blind olms is probably one of the most notable manifesations of Lamarckian thinking and research at the beginning of the 20th century. If living in the environment of the dark caves in the Slovenian Kraijna for thousands of years has reduced the eyes of the olms until they nearly disappeared, then is it possible to influence the development in the other direction and speed it up? Will a transformed milieux or media (in a Lamarckian sense) conduct olms to vision, to the mysteries of light? Kammerer's legendary skill in taking care of animals (especially amphibians), the highly modern research environment of an institution unique in whole Europe and America at that time (the Biologische Versuchsanstalt Wien), years of experimental crossings, and, finally, the convergence of biological media and technical media (for example media of development in photography), provided the opportunity for Kammerer to succeed. The olm experiments are part of an elaborate research program of the Viennese Versuchsanstalt and its facilities that assume the environment of animals to be the critical point in developmental, hereditary, and evolutionary research. Theoretically Kammerer's olms ask questions about vision in general and its organ, the eye. PMID:20210110

Berz, Peter

2009-01-01

240

The eyes of the olms.  

UK PubMed Central (United Kingdom)

The experiments of the Austrian biologist Paul Kammerer to breed eyes in blind olms is probably one of the most notable manifesations of Lamarckian thinking and research at the beginning of the 20th century. If living in the environment of the dark caves in the Slovenian Kraijna for thousands of years has reduced the eyes of the olms until they nearly disappeared, then is it possible to influence the development in the other direction and speed it up? Will a transformed milieux or media (in a Lamarckian sense) conduct olms to vision, to the mysteries of light? Kammerer's legendary skill in taking care of animals (especially amphibians), the highly modern research environment of an institution unique in whole Europe and America at that time (the Biologische Versuchsanstalt Wien), years of experimental crossings, and, finally, the convergence of biological media and technical media (for example media of development in photography), provided the opportunity for Kammerer to succeed. The olm experiments are part of an elaborate research program of the Viennese Versuchsanstalt and its facilities that assume the environment of animals to be the critical point in developmental, hereditary, and evolutionary research. Theoretically Kammerer's olms ask questions about vision in general and its organ, the eye.

Berz P

2009-01-01

 
 
 
 
241

The Dkk1 dose is critical for eye development  

DEFF Research Database (Denmark)

During mammalian ocular development, several signaling pathways control the spatiotemporal highly defined realization of the three-dimensional eye architecture. Given the complexity of these inductive signals, the developing eye is a sensitive organ for several diseases. In this study, we investigated a Dkk1+/- haploinsufficiency during eye development, resulting in coloboma and anterior eye defects, two common developmental eye disorders. Dkk1 impacts eye development from a defined developmental time point on, and is critical for lens separation from the surface ectoderm via ?-catenin mediated Pdgfr? and E-cadherin expression. Dkk1 does not impact the dorso ventral retina patterning in general but is critical for Shh dependent Pax2 extension into the midline region. The described results also indicate that the retinal Dkk1 dose is critical for important steps during eye development, such as optic fissure closure and cornea formation. Further analysis of the relationship between Dkk1 and Shh signaling revealed that Dkk1 and Shh coordinatively control anterior head formation and eye induction. During eye development itself, retinal Dkk1 activation is depending on cilia mediated Gli3 regulation. Therefore, our data essentially improve the knowledge of coloboma and anterior eye defects, which are common human eye developmental defects.

Lieven, Oliver; Rüther, Ulrich

2011-01-01

242

Measuring effectiveness of eye movement desensitization and reprocessing (EMDR) in non-clinical anxiety: a multi-subject, yoked-control design.  

UK PubMed Central (United Kingdom)

Twenty-eight subjects from a university's subject pool were paired on sex, age, severity, and type of stressful or traumatic incident. One subject in each pair was selected to receive EMDR; the experimental partner spent the same amount of time receiving a visual (non-movement) placebo. Subjective units of discomfort (SUD) scores and physiological measurements were taken prior to and following treatment. Analysis of physiological measurements and self-reported levels of stress were performed within and between each group. While the EMDR group showed significant reductions of stress, EMDR was no better than a placebo. This suggests EMDR's specific intervention involving eye movement may not be a necessary component of the treatment protocol.

Dunn TM; Schwartz M; Hatfield RW; Wiegele M

1996-09-01

243

EYE BASED CONTROL SYSTEM  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper, an individual human computer interface system using eye motion tracking is introduced. Traditionally human computer interface uses mouse, keyboard as an input device. However, the proposed vision-based virtual interface controls system work on various eye movements such as eye blinking. The planned virtual multimodal interface system provides vision-based mechanism, to convey between human and computer system, instead of conventional human computer interaction through mouse and keyboard. For motion tracking, recognition of eye is explored through an optical flow technique. To minimize the error caused by light variation, histogram equalization and max-min normalization is used to improve every frame. An innovative system for user-computer interaction based on the user’s eye-gaze behavior.

Shrunkhala Satish Wankhede, Ms. S. A. Chhabria

2012-01-01

244

Point Lepreau. (Point Lepreau).  

Science.gov (United States)

This brief pamphlet gives general information about the station. The Point Lepreau Nuclear Generating Station consists of a single CANDU 600 unit with a total net capacity of 630,000 kilowatts. This single reactor, the first nuclear installation in Atlant...

1991-01-01

245

Effect of an eye health education program on older African Americans' eye care utilization and attitudes about eye care.  

UK PubMed Central (United Kingdom)

We examined the impact of an eye health education program for older African Americans on attitudes about eye care and utilization, using a randomized trial design in a community setting. Participants were older African Americans attending activities at senior centers: Ten centers were randomized to an eye health education (InCHARGE) or social-contact control presentation. InCHARGE addressed the importance of annual dilated comprehensive examination and strategies reducing barriers to care. The control presentation was on the importance of physical activity. Outcomes were attitudes about eye care 6 months post event through questionnaire and eye care utilization during 12 months post event through medical record abstraction. At baseline, more than 80% participants in both arms said transportation and finding, communicating, and trusting a doctor were not problematic and agreed that yearly care was important. One-fourth said eye examination cost was problematic; one-half said spectacle cost was problematic. There were no group differences 6 months post event. During the 12 months pre event, the dilated exam rate was similar in the groups (38.3% InCHARGE, 40.8% control) and unchanged during the 12 moiths post event. Results suggest fewer than half of older African Americans received annual dilated eye care. Group-administered eye health education did not increase this rate. Even before the program, they had positive attitudes about care, yet many cited examination and spectacle cost as problematic, which was not mitigated by health education. Evidence-based strategies in a community setting for increasing eye care utilization rate in older African Americans have yet to be identified. Policy changes may be more appropriate avenues for addressing cost. Trial Registration: NCT00591110, www.ClinicalTrials.gov

Owsley C; McGwin G Jr; Searcey K; Weston J; Johnson A; Stalvey BT; Liu B; Girkin CA

2013-01-01

246

Home Eye Tests For Children  

Science.gov (United States)

... of Your Sight / Home eye tests for children Home eye tests for children It is possible for ... vision loss. Prevent Blindness America offers the following home eye tests: Distance Vision Test for Younger Children ...

247

Eye burning - itching and discharge  

Science.gov (United States)

Itching - burning eyes; Burning eyes ... Sometimes burning and itching eyes are due to environmental pollutants. If secondhand cigarette smoke is annoying, say so. If an industrial plant in the area ...

248

Preoperative topographic characteristics of eyes that developed postoperative LASIK keratectasia.  

UK PubMed Central (United Kingdom)

PURPOSE: To assess the suitability of corneal anterior and posterior surface aberrations and pachymetry profile data to discriminate between eyes that later developed postoperative LASIK iatrogenic keratectasia and eyes that remained stable. METHODS: Ten eyes of five patients that later developed iatrogenic keratectasia and 245 control eyes of 245 patients with a stable postoperative LASIK follow-up of 12 months or more were included. Zernike coefficients from anterior and posterior cornea, data from corneal pachymetry profiles, and output values of discriminant functions (input from Zernike coefficients, pachymetry data, and age) were assessed for their usefulness to discriminate between preoperative eyes with iatrogenic keratectasia eyes and controls using receiver operator characteristic (ROC) curve analysis. Furthermore, Randleman Ectasia Risk Scores were calculated for each eye. RESULTS: Anterior horizontal coma (C3(1)) was the coefficient with highest discriminative ability (area under the ROC curve [AZROC] = 0.819). For posterior coefficients and pachymetry data, AZROC values were lower. Constructing discriminant functions increased AZROC values. The function containing anterior and posterior Zernike coefficients, pachymetry data, and age reached an AZROC of 0.991. The other functions ranged from 0.858 (pachymetry) to 0.981 (anterior and posterior Zernike coefficients and age). With the Randleman Ectasia Risk Scores, 80.4% were classified correctly if eyes with 4 points or more were excluded from treatment (87.1% for 3 points or more). CONCLUSIONS: Preoperative corneal topographic characteristics of eyes that developed iatrogenic keratectasia were different than those of eyes that remained stable. However, topography patterns were not identical with those found in eyes with subclinical keratoconus in previous studies. Discriminant functions from Zernike coefficients and pachymetry data were useful to discriminate between normal eyes and eyes with preoperative iatrogenic keratectasia.

Bühren J; Schäffeler T; Kohnen T

2013-08-01

249

Factors affecting eye care-seeking behavior of parents for their children.  

UK PubMed Central (United Kingdom)

PURPOSE: Most of the causes of childhood blindness are either treatable or preventable. Eye care-seeking behavior (ESB) of parents for their children plays a pivotal role in reducing this problem. This study was done because there was a sparsity of literature in this context and with a view to help eye care professionals plan better programs and to identify factors facilitating and/or hindering ESB of parents for their school-going children in an urban area. METHODS: This study adopted a qualitative snapshot narrative study design. In-depth interviews and focus group discussions were conducted in areas of Chennai with parents and eye care professionals selected through stratified purposive sampling. Parents were based on those who sought care and did not seek care after a school eye screening program and on their socioeconomic status. Data were transcribed to English, familiarized, and inductive coded, and themes were formed. Redundancy was considered as end point of data collection. RESULTS: Two focus group discussions and 11 in-depth interviews were conducted. Squint, redness or watering of eyes, eye irritation, headache, family history of ocular diseases, severity, and repetitiveness of symptoms facilitate parents seeking eye care for their wards/children. Economic status was an important barrier reported to affect the ESB. Logistic factors like taking appointment with doctor, taking leave from work, transport, and traveling distance were noted. CONCLUSIONS: This study shows the facilitating factors and barriers for ESB of the Chennai urban parents for their wards. The results suggest that efforts needed to be put to overcome the barriers through planned awareness programs.

Balasubramaniam SM; Kumar DS; Kumaran SE; Ramani KK

2013-10-01

250

Identifying cognitive state from eye metrics.  

UK PubMed Central (United Kingdom)

INTRODUCTION: This paper describes a new approach for identifying cognitive state by using information obtained only from the eye. Data are collected from cameras mounted on a lightweight headband. A set of eye metrics captures essential eye information from the raw data of pupil size and point-of-gaze. The metrics are easily calculated every second, so that the entire set of metrics can be computed in real time. METHODS: Three studies provide empirical evidence to test whether the eye metrics are sufficient to discriminate between two different cognitive states. The first study examines the states of relaxed and engaged in the context of problem solving. The second study looks at the states of focused and distracted attention in the context of driving. The third study inspects the states of alert and fatigued in the context of visual search. Two statistical models are used to classify cognitive state for all three studies: linear discriminant function analysis and non-linear neural network analysis. Data for the models are eye metrics computed at 1-, 4-, and 10-s intervals. RESULTS: All discriminant function analyses are statistically significant, and classification rates are high. Neural network models have equal or better performance than discriminant function models across all three studies. DISCUSSION: The seven eye metrics successfully discriminate between the states in all studies. Models from individual participants as well as the aggregate model over all participants are successful in identifying cognitive states based on task condition. Classification rates compare favorably with similar studies.

Marshall SP

2007-05-01

251

Data eye monitor method and apparatus  

Energy Technology Data Exchange (ETDEWEB)

An apparatus and method for providing a data eye monitor. The data eye monitor apparatus utilizes an inverter/latch string circuit and a set of latches to save the data eye for providing an infinite persistent data eye. In operation, incoming read data signals are adjusted in the first stage individually and latched to provide the read data to the requesting unit. The data is also simultaneously fed into a balanced XOR tree to combine the transitions of all incoming read data signals into a single signal. This signal is passed along a delay chain and tapped at constant intervals. The tap points are fed into latches, capturing the transitions at a delay element interval resolution. Using XORs, differences between adjacent taps and therefore transitions are detected. The eye is defined by segments that show no transitions over a series of samples. The eye size and position can be used to readjust the delay of incoming signals and/or to control environment parameters like voltage, clock speed and temperature.

Gara, Alan G. (Mount Kisco, NY); Marcella, James A. (Rochester, MN); Ohmacht, Martin (Yorktown Heights, NY)

2012-01-31

252

Keeping an eye on retinoic acid signaling during eye development.  

UK PubMed Central (United Kingdom)

Retinoic acid is a metabolic derivative of vitamin A that plays an essential function in cell-cell signaling by serving as a ligand for nuclear receptors that directly regulate gene expression. The final step in the conversion of retinol to retinoic acid is carried out by three retinaldehyde dehydrogenases encoded by Raldh1 (Aldh1a1), Raldh2 (Aldh1a2), and Raldh3 (Aldh1a3). Mouse Raldh gene knockout studies have been instrumental in understanding the mechanism of retinoic acid action during eye development. Retinoic acid signaling in the developing eye is particularly complex as all three Raldh genes contribute to retinoic acid synthesis in non-overlapping locations. During optic cup formation Raldh2 is first expressed transiently in perioptic mesenchyme, then later Raldh1 and Raldh3 expression begins in the dorsal and ventral retina, respectively, and these sources of retinoic acid are maintained in the fetus. Retinoic acid is not required for dorsoventral patterning of the retina as originally thought, but it is required for morphogenetic movements that form the optic cup, ventral retina, cornea, and eyelids. These findings will help guide future studies designed to identify retinoic acid target genes during eye organogenesis.

Duester G

2009-03-01

253

Keeping an eye on retinoic acid signaling during eye development.  

Science.gov (United States)

Retinoic acid is a metabolic derivative of vitamin A that plays an essential function in cell-cell signaling by serving as a ligand for nuclear receptors that directly regulate gene expression. The final step in the conversion of retinol to retinoic acid is carried out by three retinaldehyde dehydrogenases encoded by Raldh1 (Aldh1a1), Raldh2 (Aldh1a2), and Raldh3 (Aldh1a3). Mouse Raldh gene knockout studies have been instrumental in understanding the mechanism of retinoic acid action during eye development. Retinoic acid signaling in the developing eye is particularly complex as all three Raldh genes contribute to retinoic acid synthesis in non-overlapping locations. During optic cup formation Raldh2 is first expressed transiently in perioptic mesenchyme, then later Raldh1 and Raldh3 expression begins in the dorsal and ventral retina, respectively, and these sources of retinoic acid are maintained in the fetus. Retinoic acid is not required for dorsoventral patterning of the retina as originally thought, but it is required for morphogenetic movements that form the optic cup, ventral retina, cornea, and eyelids. These findings will help guide future studies designed to identify retinoic acid target genes during eye organogenesis. PMID:18831967

Duester, Gregg

2008-09-11

254

Eye motion increases temporal visual field extent.  

Science.gov (United States)

Purpose:? To study the impact of eye motion on visual field extent. Methods:? Visual fields were tested in 15 healthy volunteers with the Goldmann perimeter using a V4 test object, from seen to unseen, first in primary position of gaze, then allowing eye motion. Temporal points falling out of the cupola were tested again after a controlled nasal head rotation using a headband prototype fitted with a line-laser level having two orthogonal vial levels. Visual field surface areas (cm(2) ) were calculated as projections on a 30-cm virtual Goldmann cupola, whose extent would have been large enough to include all points. Reproducibility error of the method assessed by calculation of the relative difference between surface areas of 12 visual field tests and 12 visual field retests was estimated at 14%. Hertel exophthalmometry was recorded to study the influence of globe position on visual field extent. Results:? Binocular visual field surface area increased by 37% with eye motion (p-value?=?1.20·10(-9) ). This increase was highest (46%; p-value?=?1.2·10(-24) ) in the temporal quadrant. Median maximal visual field temporal eccentricity with eye motion was 128.3° (minimum: 109.5°; maximum: 137.7°) and more than 135° in four eyes of three subjects. Hertel exophthalmometry was positively linked to visual field temporal surface area with eye motion (p-value?=?0.013). Conclusions:? Eye motion greatly expands the temporal visual field. This peculiarity is likely an adaptation to terrestrial life with upright bipedal locomotion and may save head movements through horizontal eyeball scanning. PMID:23586899

Denion, Eric; Dugué, Audrey-E; Coffin-Pichonnet, Sophie; Augy, Sylvain; Mouriaux, Frédéric

2013-04-16

255

Eye motion increases temporal visual field extent.  

UK PubMed Central (United Kingdom)

Purpose:? To study the impact of eye motion on visual field extent. Methods:? Visual fields were tested in 15 healthy volunteers with the Goldmann perimeter using a V4 test object, from seen to unseen, first in primary position of gaze, then allowing eye motion. Temporal points falling out of the cupola were tested again after a controlled nasal head rotation using a headband prototype fitted with a line-laser level having two orthogonal vial levels. Visual field surface areas (cm(2) ) were calculated as projections on a 30-cm virtual Goldmann cupola, whose extent would have been large enough to include all points. Reproducibility error of the method assessed by calculation of the relative difference between surface areas of 12 visual field tests and 12 visual field retests was estimated at 14%. Hertel exophthalmometry was recorded to study the influence of globe position on visual field extent. Results:? Binocular visual field surface area increased by 37% with eye motion (p-value?=?1.20·10(-9) ). This increase was highest (46%; p-value?=?1.2·10(-24) ) in the temporal quadrant. Median maximal visual field temporal eccentricity with eye motion was 128.3° (minimum: 109.5°; maximum: 137.7°) and more than 135° in four eyes of three subjects. Hertel exophthalmometry was positively linked to visual field temporal surface area with eye motion (p-value?=?0.013). Conclusions:? Eye motion greatly expands the temporal visual field. This peculiarity is likely an adaptation to terrestrial life with upright bipedal locomotion and may save head movements through horizontal eyeball scanning.

Denion E; Dugué AE; Coffin-Pichonnet S; Augy S; Mouriaux F

2013-04-01

256

An optomechanical model eye for ophthalmological refractive studies.  

UK PubMed Central (United Kingdom)

PURPOSE: To create an accurate, low-cost optomechanical model eye for investigation of refractive errors in clinical and basic research studies. METHODS: An optomechanical fluid-filled eye model with dimensions consistent with the human eye was designed and fabricated. Optical simulations were performed on the optomechanical eye model, and the quantified resolution and refractive errors were compared with the widely used Navarro eye model using the ray-tracing software ZEMAX (Radiant Zemax, Redmond, WA). The resolution of the physical optomechanical eye model was then quantified with a complementary metal-oxide semiconductor imager using the image resolution software SFR Plus (Imatest, Boulder, CO). Refractive, manufacturing, and assembling errors were also assessed. A refractive intraocular lens (IOL) and a diffractive IOL were added to the optomechanical eye model for tests and analyses of a 1951 U.S. Air Force target chart. RESULTS: Resolution and aberrations of the optomechanical eye model and the Navarro eye model were qualitatively similar in ZEMAX simulations. Experimental testing found that the optomechanical eye model reproduced properties pertinent to human eyes, including resolution better than 20/20 visual acuity and a decrease in resolution as the field of view increased in size. The IOLs were also integrated into the optomechanical eye model to image objects at distances of 15, 10, and 3 feet, and they indicated a resolution of 22.8 cycles per degree at 15 feet. CONCLUSIONS: A life-sized optomechanical eye model with the flexibility to be patient-specific was designed and constructed. The model had the resolution of a healthy human eye and recreated normal refractive errors. This model may be useful in the evaluation of IOLs for cataract surgery.

Arianpour A; Tremblay EJ; Stamenov I; Ford JE; Schanzlin DJ; Lo Y

2013-02-01

257

Is second eye phacoemulsification really more painful?  

UK PubMed Central (United Kingdom)

AIM: To demonstrate a numerical data set for intraoperative pain during phacoemulsification and compare the pain scores for first and second procedures. METHODS: From 200 consecutive cases requiring bilateral cataract removals 187 were enrolled into this prospective, observational, single-surgeon, single-centre study. To evaluate the pain a 10-point visual analogue scale was used. The pain scores for both eyes of each patient were collected perioperatively (T) as well as 2-4 weeks (mean: 2.43 weeks) later, at the follow-up visit (C). Data were pooled and the four groups were compared by ANOVA All Pairweise Multiple Comparison Procedures. RESULTS: Median C-score was 1 for both eyes, T-score was 1 and 0 for the first and second eye, respectively. There wasn't any difference between the first and second eyes either in T- (1.50?±?1.43 vs 1.51?±?1.36) or in C-scores (0.71 vs 1.10). C-values were lower than T-values for either eye (0.71 vs 1.50 and 1.10 vs 1.51), indicating that patients recalled less pain 2-3 weeks after the surgery than that they indicated on the day of the procedure CONCLUSIONS: Consecutive phacoemulsifications do not differ in the perceived pain nevertheless, patients may believe the second eye surgery more painful because they practically compare it with the lower remembered pain for the first eye procedure. In order to avoid any disappointment we suggest warning patients before their second eye operations that they are likely to experience more pain or discomfort.

Hari-Kovacs A; Lovas P; Facsko A; Crate ID

2012-08-01

258

Eye and orbital cancer  

International Nuclear Information System (INIS)

Diseases of the eye and orbital contents which can be treated by radiation therapy are relatively uncommon. They include benign diseases such as pterygium, orbital pseudo-tumor, and Graves' exophthalmos. Malignant diseases in adults include orbital and choroidal metastases, lacrimal gland tumors, carcinoma of the bulbar conjunctiva, orbital lymphomas and melanomas. Pediatric malignancies include retinoblastomas, optic nerve gliomas, and orbital rhabdomyosarcomas. Orbital irradiation may result in a variety of normal eye and orbital tissues responses. Those responses may occur when irradiating the eye or orbital diseases listed above or non-orbital primary tumors, such as nasal cavity and paranasal sinus tumors.

1991-01-01

259

[Treatment of eye allergies].  

UK PubMed Central (United Kingdom)

Seasonal atopic conjunctivitis is treated with antihistamines, cromoglycate and short courses of corticosteroids, in severe cases with subcutaneous or sublingual immunotherapy. Chronic conjunctivitis requires year-round treatment with mast cell stabilizers, antihistamines or topical corticosteroids. Long-term treatment of atopic blepharoconjunctivitis consists of tacrolimus or pimecrolimus cream. For atopic keratoconjunctivitis corticosteroid and, if necessary, cyclosporine eye drops are needed. First-line therapy of vernal conjunctivitis involves mast cell stabilizers and, if necessary, corticosteroid eye drops. Treatment of non-allergic eosinophilic conjunctivitis involves mast cell stabilizers, corticosteroid and, if necessary, cyclosporine eye drops.

Kari O; Saari KM

2012-01-01

260

Vitrectomy outcomes in eyes with diabetic macular edema and vitreomacular traction.  

UK PubMed Central (United Kingdom)

PURPOSE: To evaluate vitrectomy for diabetic macular edema (DME) in eyes with at least moderate vision loss and vitreomacular traction. DESIGN: Prospective cohort study. PARTICIPANTS: The primary cohort included 87 eyes with DME and vitreomacular traction based on investigator's evaluation, visual acuity 20/63-20/400, optical coherence tomography (OCT) central subfield >300 microns and no concomitant cataract extraction at the time of vitrectomy. METHODS: Surgery was performed according to the investigator's usual routine. Follow-up visits were performed after 3 months, 6 months (primary end point), and 1 year. MAIN OUTCOME MEASURES: Visual acuity, OCT retinal thickening, and operative complications. RESULTS: At baseline, median visual acuity in the 87 eyes was 20/100 and median OCT thickness was 491 microns. During vitrectomy, additional procedures included epiretinal membrane peeling in 61%, internal limiting membrane peeling in 54%, panretinal photocoagulation in 40%, and injection of corticosteroids at the close of the procedure in 64%. At 6 months, median OCT central subfield thickness decreased by 160 microns, with 43% having central subfield thickness <250 microns and 68% having at least a 50% reduction in thickening. Visual acuity improved by > or =10 letters in 38% (95% confidence interval, 28%-49%) and deteriorated by > or =10 letters in 22% (95% confidence interval, 13%-31%). Postoperative complications through 6 months included vitreous hemorrhage (5 eyes), elevated intraocular pressure requiring treatment (7 eyes), retinal detachment (3 eyes), and endophthalmitis (1 eye). Few changes in results were noted between 6 months and 1 year. CONCLUSIONS: After vitrectomy performed for DME and vitreomacular traction, retinal thickening was reduced in most eyes. Between 28% and 49% of eyes with characteristics similar to those included in this study are likely to have improvement of visual acuity, whereas between 13% and 31% are likely to have worsening. The operative complication rate is low and similar to what has been reported for this procedure. These data provide estimates of surgical outcomes and serve as a reference for future studies that might consider vitrectomy for DME in eyes with at least moderate vision loss and vitreomacular traction.

Haller JA; Qin H; Apte RS; Beck RR; Bressler NM; Browning DJ; Danis RP; Glassman AR; Googe JM; Kollman C; Lauer AK; Peters MA; Stockman ME

2010-06-01

 
 
 
 
261

Technical evaluation of the electrical, instrumentation, and control design aspects of the low temperature overpressure protection system for the Point Beach Nuclear Power Plant, Units 1 and 2  

International Nuclear Information System (INIS)

The technical evaluation is presented for the electrical, instrumentation, and control design aspects of the low temperature overpressure protection system for the Point Beach nuclear power plant, Units 1 and 2. Design basis criteria used to evaluate the acceptability of the system included operator action, system testability, single failure criterion, and seismic Category I and IEEE Std-279-1971 criteria. This report is supplied as part of the Selected Electrical, Instrumentation, and Control Systems Issues Support Program being conducted for the U.S. Nuclear Regulatory Commission by Lawrence Livermore Laboratory

1979-01-01

262

The Design Process of Physical Security as Applied to a U.S. Border Point of Entry  

Energy Technology Data Exchange (ETDEWEB)

This paper describes the design process of physical security as applied to a U.S. Border Port of Entry (PoE). Included in this paper are descriptions of the elements that compose U.S. border security. The physical security design will describe the various elements that make up the process as well as the considerations that must be taken into account when dealing with system integration of those elements. The distinctions between preventing unlawful entry and exit of illegal contraband will be emphasized.

Wagner, G.G.

1998-10-26

263

Diabetes - Eye Complications  

Medline Plus

Full Text Available ... the pupil. As light passes through the pupil, it enters a clear lens, like the lens of ... passes through a clear gel called “vitreous” until it reaches the back of the eye. The back ...

264

LASIK - Laser Eye Surgery  

Medline Plus

Full Text Available ... before going swimming or in a hot tub. It's Not OK to Skip a Day To control ... prescribed by your ophthalmologist—your sight depends on it. Give your Eyes a Break To prevent computer ...

265

Diabetes - Eye Complications  

Medline Plus

Full Text Available ... can be prevented or delayed through good diabetes management. When they occur, these diseases can be treated ... as retinopathy, cataract, and glaucoma. Prevention through successful management of diabetes helps prevent and delay these eye ...

266

LASIK - Laser Eye Surgery  

Medline Plus

Full Text Available ... LASIK Surgery: Why All Patients Need the K Card (PDF 650K) If you have decide to have ... later, such as cataract surgery. Bring this "K Card" with you to your Eye M.D. appointment ...

267

Eye Safety at Home  

Science.gov (United States)

Eye Safety at Home Believe it or not, the average home is full of dangers that often go unnoticed. In fact, accidents involving ... this simple checklist for different areas of your home: Indoor Safety ? Indoor Safety ? Indoor Safety Provide lights ...

268

Diabetes - Eye Complications  

Medline Plus

Full Text Available ... light passes through the pupil, it enters a clear lens, like the lens of a camera, which ... the eye. The focused light passes through a clear gel called “vitreous” until it reaches the back ...

269

LASIK - Laser Eye Surgery  

Medline Plus

Full Text Available ... of corneal tissue under the flap using an excimer laser. The flap is then laid back into its ... patient reclines under a surgical device called an excimer laser in an outpatient surgical suite. First, the eye ...

270

Diabetes - Eye Complications  

Medline Plus

Full Text Available ... Many of these eye diseases can be prevented or delayed through good diabetes management. When they occur, ... a substitute for the advice of a doctor or healthcare professional or a recommendation for any particular ...

271

LASIK - Laser Eye Surgery  

Medline Plus

Full Text Available ... it is removed, vision appears dim or goes black. Once the cornea is flattened, a hinged flap ... or small pink or red patches on the white of the eye. In a small minority of ...

272

What Is Dry Eye?  

Medline Plus

Full Text Available ... lead to blindness? Featured Video Get a Baseline Eye Disease Screening at 40, presented by Dr. Robert Melendez ... Privacy Policy Email address © 2013 American Academy of Ophthalmology medical disclaimer privacy policy sponsorship & advertising policies about ...

273

Diabetes - Eye Complications  

Medline Plus

Full Text Available ... eyes are small. When they become weak, they leak, burst, or become blocked. Diabetic Retinopathy The weakening ... by diabetes. Blood vessels of the retina may leak if they are weak. This can cause swelling ...

274

Diabetes - Eye Complications  

Science.gov (United States)

... retina, known as the periphery, is important for peripheral vision. Like other parts of the body, the retina ... the eye is increased. Its symptom is reduced peripheral vision, or side vision. Glaucoma can be treated with ...

275

Diabetes - Eye Complications  

Medline Plus

Full Text Available ... retina, known as the periphery, is important for peripheral vision. Like other parts of the body, the retina ... the eye is increased. Its symptom is reduced peripheral vision, or side vision. Glaucoma can be treated with ...

276

Therapy of Eye Cancer  

International Science & Technology Center (ISTC)

Development and Creation of New Forms of Ophthalmology b - Applicators for Radiation Therapy of Eye Cancer and Study of Psycho-Physiological Effects on Man of Low Frequency Electromagnetic Radiation Emitted by Radio Nuclides.

277

Aging and Your Eyes  

Science.gov (United States)

... day. Floaters can be a normal part of aging. But sometimes they are a sign of a ... in the United States. Retinal disorders that affect aging eyes include: Age-related macular degeneration , or AMD . ...

278

AN INNER STRUGGLE: UNDER WESTERN EYES  

Directory of Open Access Journals (Sweden)

Full Text Available This study aims to shed light on the most significant aspect of the modern man’s inner struggle in Joseph Conrad’s Under Western Eyes. Joseph Conrad is one of the authors of the twentieth century who was influenced by the psychological philosophy and he makes use of this influence in his works deeply. He who synthesizes the inner nature of the modern man, having conflicts himself with the deeper analysis field of the psychology aims to point out the incomprehensible and unsettled inner nature of the modern man in Under Western Eyes.

Hale Ya?l?dere

2013-01-01

279

Posterior corneal elevation and back difference corneal elevation in diagnosing forme fruste keratoconus in the fellow eyes of unilateral keratoconus patients.  

UK PubMed Central (United Kingdom)

PURPOSE: To evaluate posterior corneal elevation and back difference corneal elevation in patients with keratoconus in 1 eye and forme fruste keratoconus in the fellow eye. SETTING: Kudret Eye Hospital, Ankara, Turkey. DESIGN: Case-control study. METHODS: This study retrospectively reviewed patients with keratoconus in 1 eye and forme fruste keratoconus in the fellow eye and eyes of normal subjects. All subjects were evaluated with a rotating Scheimpflug imaging system (Pentacam), including sagittal and tangential anterior curve analysis, keratometry, and posterior elevation. The back difference elevation values were extrapolated from the difference maps of the Belin-Ambrosió enhanced ectasia display of the Scheimpflug system. The receiver operating characteristic (ROC) curves were analyzed to evaluate the sensitivity and specificity of the parameters. RESULTS: The corneal power, pachymetric progression index, and posterior corneal elevation (posterior elevation and back difference elevation) measurements were statistically significantly higher in eyes with keratoconus or forme fruste keratoconus than in eyes of normal control subjects (P<.05). Using ROC analysis, the area under the curve values of mean keratometry, steepest point on the tangential curve, minimum corneal thickness, pachymetric progression index, Ambrósio's relational thickness, posterior elevation, and back difference elevation to distinguish forme fruste keratoconus from control subjects were 0.51, 0.84, 0.65, 0.81, 0.72, 0.68, and 0.76, respectively. CONCLUSIONS: Back difference elevation was better than posterior elevation in diagnosing forme fruste keratoconus. However, as sole parameters, both had limited sensitivity and specificity to differentiate between forme fruste keratoconus eyes and normal control eyes. FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.

Muftuoglu O; Ayar O; Ozulken K; Ozyol E; Ak?nc? A

2013-09-01

280

Photodamage to the eye  

International Nuclear Information System (INIS)

A review is given of the important developments from June 1986 to June 1987 in the field of photodamage to the eye. Topics covered include ocular ultraviolet radiation dose, photodamage to the lens including changes in structural proteins and enzymes, photodamage to the retina including damage in continuous light and the role of photodamage in retinal diseases, photodamage in other ocular structures, synergistic and additive effects in photodamage, clinical photodamage and finally protective eye wear. (U.K.).

1987-01-01

 
 
 
 
281

Methodology and concepts for the design of surface storage fills at the Anvil Points Oil Shale Retort Facility  

Energy Technology Data Exchange (ETDEWEB)

Primary obtectives in design of surface disposal fills for processed and raw oil shales are: (a) to insure long-term physical stability, and (b) to prevent surface runoff, surface erosion, and possible subsurface seepage from degrading the water quality of streams and ground water, it was concluded that the analysis and design of spent shale disposal fills should be based on sound geotechnical engineeering principles, considerable experience, and good judgment. An understanding of the source of variability of spent shale materials and its effect on engineering properties is a first step in developing fill design. A second important step is the assessment of long-term changes in the properties of spent shale within a disposal fill. This assessment requires consideration of possible thermal, hydrochemical, and physical interactions within the fill and between the fill and site environment. The site environment is site-specific and depends on the geological, surface and subsurface hydrological, and geotechnical characteristics of the site. The variability of spent shale materials is a direct function of variations in mineral and chemical composition of the raw shale and of the processes applied. Current technology for the design and construction of spent shale disposal fills has not been proven by experience. A major problem is the large quantities of spent shale generated for surface disposal and the lack of available sites other than large gulches in the oil shale country of the western United States. Conceptual research fill designs developed in this study should be refined and constructed to provide needed information on in situ properties and long-term performance. Research fills planned by others should be augmented to obtain needed information, especially for codisposal of spent shales with treated waste water, raw shale fines, and process dust.

Strohm, W.E. Jr.; Krinitzsky, E.L.

1983-12-01

282

Unusual eye injuries  

Directory of Open Access Journals (Sweden)

Full Text Available Purpose: The analysis of ten unusual eye injuries, and the discussion of appropriate preventive measures. Case outline: Ten patients hospitalized at the Clinic of Eye Diseases, Clinical Center of Serbia, Belgrade, in the period from January 2000. to December 2009. were presented. Following data were taken in account: sex and age of the patient, injured eye, the mechanism of injury, type of the injury, applied treatment and final visual acuity. The circumstances of the eye injuring of ten patients were described. The eye injuries in all cases occurred in a bizarre way and they were severe enough to require hospital admission. The surgery was necessary in seven patients. Three injured eyes resulted in blindness, and two additional had subnormal vision. Conclusion: In three quarters of discussed cases injuries can be avoided. It is necessary to implement protective measures constantly and consistently and to think about the possible consequences of certain activities. Particular attention should be paid on safety of children. The iatrogenic injuries require special consideration.

Jovanovi? Miloš; Bobi?-Radovanovi? Anica; Vukovi? Dragan; Markovi? Vujica

2012-01-01

283

Optoelectronic eye examination system  

UK PubMed Central (United Kingdom)

Optoelectronic eye examination apparatus is shown that can test the eyes for refraction errors and color blindness with the additional capability to perform eye strain relief and eye muscle exercises. This invention with its various embodiments exploits the electronic programmability features of Spatial Light Modulators (SLMs) combined with fixed refractive power lenses in a unique thin-lens cascaded arrangement to form an eye examination instrument that provides (a) an assessment of the present state of the refractive powers of the eye; i.e., an update in Diopters of the change in eye wear prescription required for improved vision, (b) an assessment of the color vision capability of the eyes, and (c) a visual platform to subject the eye to image-based muscular and neural processing leading to eye strain relief and other neural/human benefits. The instrument is divided into several sub-modules that include the light source optics, image generation optics via programmable amplitude mode SLM, fixed refractive power optics and optional beam delay optics, SLM-based electronically programmable lens (serves as the adjustable weak lens), and a controller to provide feedback to the programmable optics with input from the human under test and/or a objective image quality and refractive power test system. The preferred no-moving parts embodiment of the invention is based on liquid crystal (LC) optics with a transmissive LC programmable lens for refractive power control and LC SLM for vision image generation required for various eye tests and measurements. For instance, the SLM image generator can produce rapid near zero dark phase test image rotation via software control, implementing astigmatism measurements. An alternate embodiment of this invention uses a reflective lens arrangement via a LC SLM or a mirror-based SLM that function as the weak lens. Both these embodiments have a shutter arrangement that in one shutter state allows external light from an infinity image to impinge on the eye so as to prevent the eye from near field accommodation during far field (e.g., greater than 10 feet standard vision chart distance) testing. In addition, in the other shutter state, only light from the image generation LC display strikes the eye. Another embodiment of the invention introduces the use of a fixed bias lens in close cascade with the SLM-based lens. The purpose of the bias lens is via the thin-lens formula approximation, add to the Dioptric power of the combined eye refractive power test system to cover a wider power range than possible with a single SLM-based lens. Here, bias lenses of various powers can be attached in a wheel where rotating the wheel brings the desired bias lens in line with the SLM-based lens optical axis. Both a transmissive LC lens or a reflective lens such as via an actuated mirror device or an LC device can be used to form this embodiment of the invention. Additional embodiments of the invention use multiple cascaded SLMs to increase the Dioptric power and measurement capability of the vision testing instrument.

RIZA NABEEL AGHA

284

Can the Hazard Assessment and Critical Control Points (HACCP) system be used to design process-based hygiene concepts?  

UK PubMed Central (United Kingdom)

Recently, the HACCP (Hazard Analysis and Critical Control Points) concept was proposed as possible way to implement process-based hygiene concepts in clinical practice, but the extent to which this food safety concept can be transferred into the health care setting is unclear. We therefore discuss possible ways for a translation of the principles of the HACCP for health care settings. While a direct implementation of food processing concepts into health care is not very likely to be feasible and will probably not readily yield the intended results, the underlying principles of process-orientation, in-process safety control and hazard analysis based counter measures are transferable to clinical settings. In model projects the proposed concepts should be implemented, monitored, and evaluated under real world conditions.

Hübner NO; Fleßa S; Haak J; Wilke F; Hübner C; Dahms C; Hoffmann W; Kramer A

2011-01-01

285

Can the Hazard Assessment and Critical Control Points (HACCP) system be used to design process-based hygiene concepts?  

Directory of Open Access Journals (Sweden)

Full Text Available Recently, the HACCP (Hazard Analysis and Critical Control Points) concept was proposed as possible way to implement process-based hygiene concepts in clinical practice, but the extent to which this food safety concept can be transferred into the health care setting is unclear. We therefore discuss possible ways for a translation of the principles of the HACCP for health care settings. While a direct implementation of food processing concepts into health care is not very likely to be feasible and will probably not readily yield the intended results, the underlying principles of process-orientation, in-process safety control and hazard analysis based counter measures are transferable to clinical settings. In model projects the proposed concepts should be implemented, monitored, and evaluated under real world conditions.

Hübner, N.-O.; Fleßa, S.; Haak, J.; Wilke, F.; Hübner, C.; Dahms, C.; Hoffmann, W.; Kramer, A.

2011-01-01

286

Identification system by eye retinal pattern  

Energy Technology Data Exchange (ETDEWEB)

Identification system by eye retinal pattern is introduced from the view-point of history of R and D, measurement, apparatus, evaluation tests, safety and application. According to our evaluation tests, enrolling time is approximately less than 1 min, verification time is a few seconds and false accept rate is 0%. Evaluation tests at Sandia National Laboratories in USA show the comparison data of false accept rates such as 0% for eye retinal pattern, 10.5% for finger-print, 5.8% for signature dynamics and 17.7% for speaker voice. The identification system by eye retinal pattern has only three applications in Japan, but there has been a number of experience in USA. This fact suggests that the system will become an important means for physical protections not only in nuclear field but also in other industrial fields in Japan.

Sunagawa, Takahisa; Shibata, Susumu

1987-06-01

287

Engineering insights for multiplexed real-time nucleic acid sequence-based amplification (NASBA): implications for design of point-of-care diagnostics.  

UK PubMed Central (United Kingdom)

BACKGROUND: Nucleic acid sequence-based amplification (NASBA) offers huge potential for low-cost, point-of-care (POC) diagnostic devices, but has been limited by high false-positive rates and the challenges of primer design. OBJECTIVE: We offer a systematic analysis of NASBA design with a view toward expanding its applicability. METHODS: We examine the parameters that effect dimer formations, and we provide a framework for designing NASBA primers that will reduce false-positive results and make NASBA suitable for more POC diagnostic applications. Then we compare three different oligonucleotide sets to examine (1) the inhibitory effect of dimer formations, (2) false positives with poorly designed primers, and (3) the effect of beacon target location during real-time NASBA. The required T7 promoter sequence adversely affects the reaction kinetics, although the common abridged sequence can improve kinetics without sacrificing accuracy. RESULTS: We demonstrate that poorly designed primers undergo real-time exponential amplification in the absence of target RNA, resulting in false positives with a time to half of the peak value (t(1/2)) of 50 min compared to 45 min for true positives. Redesigning the oligonucleotides to avoid inhibitory dimers eliminated false positives and reduced the true positive t(1/2) by 10 min. Finally, we confirm the efficacy of two molecular beacon design schemes and discuss their multiplexing utility in two clinical scenarios. CONCLUSION: This study provides a pathway for using NASBA in developing POC diagnostic assays.

Morabito K; Wiske C; Tripathi A

2013-06-01

288

Wheelchair Motion Control Guide Using Eye Movement Based on EEG Signals.  

Directory of Open Access Journals (Sweden)

Full Text Available The design and implementation of an Autonomous Movement Robot based on a Wheelchair based on EOG signal is to help a disable or handicapped person. These EOG electrodes are placed at right and left of eye and other pair of electrodes are at top and right of the eye. These electrodes used to response after gazing of one target point for a particular time period. After gazing of point, the wheelchair used to move to a target position. So, it produce delay during eye gaze. To overcome this delay, EEG amplifier are used. These EEG signals are placed to capture brain waves. These brain waves are controlled by microcontroller and it produce analog waves. To convert analog waves to digital output Analog to digital converter is used. Object Sensor is used to avoid obstacles in its path respectively. The main contribution of the work is the combination of several technologies and techniques that came from different areas such as mechanical, electronic engineering. Driver circuit with relay are used to move wheelchair automatically. ZigBee is used for long transmission of wheelchair. Accelerometer and interfacing circuit are done by using head movement. DLOA algorithm used to avoid obstacles while reaching destination point. The target coordinates of the destination place using EEG, to reduce delay for auto navigation process.

D.Uma Mageswar; G.Selvavinayagam

2013-01-01

289

Powered wheelchair controlled by eye-tracking system  

Directory of Open Access Journals (Sweden)

Full Text Available In this paper, we use the optical-type eye tracking system to control powered wheelchair. The userís eye movements are translated to screen position using the optical-type eye tracking system. The pupil-tracking goggles with a video CCD camera and a frame grabber analyzes a series of human pupil images when the user is gazing at the screen. A new calibration algorithm is then used to determine the direction of the eye gaze in real time. We design an interface with nine command zones to control powered wheelchair. The command at the calculated position of the gazed screen is then sent to move the powered wheelchair.

Chern-Sheng Lin; Chien-Wa Ho; Wen-Chen Chen; Chuang-Chien Chiu; Mau-Shiun Yeh

2006-01-01

290

Process of Designing Robust, Dependable, Safe and Secure Software for Medical Devices: Point of Care Testing Device as a Case Study  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents a holistic methodology for the design of medical device software, which encompasses of a new way of eliciting requirements, system design process, security design guideline, cloud architecture design, combinatorial testing process and agile project management. The paper uses point of care diagnostics as a case study where the software and hardware must be robust, reliable to provide accurate diagnosis of diseases. As software and software intensive systems are becoming increasingly complex, the impact of failures can lead to significant property damage, or damage to the environment. Within the medical diagnostic device software domain such failures can result in misdiagnosis leading to clinical complications and in some cases death. Software faults can arise due to the interaction among the software, the hardware, third party software and the operating environment. Unanticipated environmental changes and latent coding errors lead to operation faults despite of the fact that usually a significant effort has been expended in the design, verification and validation of the software system. It is becoming increasingly more apparent that one needs to adopt different approaches, which will guarantee that a complex software system meets all safety, security, and reliability requirements, in addition to complying with standards such as IEC 62304. There are many initiatives taken to develop safety and security critical systems, at different development phases and in different contexts, ranging from infrastructure design to device design. Different approaches are implemented to design error free software for safety critical systems. By adopting the strategies and processes presented in this paper one can overcome the challenges in developing error free software for medical devices (or safety critical systems).

Sivanesan Tulasidas; Ruth Mackay; Pascal Craw; Chris Hudson; Voula Gkatzidou; Wamadeva Balachandran

2013-01-01

291

Fireworks and the eye.  

UK PubMed Central (United Kingdom)

A prospective study involving all casualty departments in Trent Region and 81% of the major eye units in UK was performed to determine ocular morbidity from the use of fireworks during 1986. A serious injury was defined as involving admission to hospital and/or intraocular damage. Of all the injuries from fireworks, 16.7% seen at major eye units were serious and were caused by rockets or exploding fireworks (P less than 0.001). Only 53% of all injuries and 12.5% of serious injuries involved children, and in contrast to the 1950s and early 1960s, young adults appear at greatest risk in the 1980s. Legislation to reduce ocular morbidity should concentrate on restricting the use of rockets and exploding fireworks and encouraging the use of suitable eye protection.

Vernon SA

1988-10-01

292

Real Time Squint Eye Detection  

Directory of Open Access Journals (Sweden)

Full Text Available This paper provides a survey on Real Time Squint Eye Detection. This is due to defective binocular vision which causes Vision loss in the turned eye. The eyes need to be straight for the brain to combine the images seen by the two eyes into a single picture. This gives us 3-D vision, which allows us to judge depth. Any turn of the eye can interrupt 3-D vision, if an eye turns in, it can reduce the total field of vision. Over the years, many methodologies have been developed to detect squint eye. In this paper, we have proposed an overview on squint eye detection system and their classification with some drawback and basic assumption for squint eye detection[1][2].

R. M. Potdar; Anil Mishra; Somesh Yadav

2011-01-01

293

Designing a minimum data set for breast cancer: a starting point for breast cancer registration in iran.  

UK PubMed Central (United Kingdom)

BACKGROUND: Due to the high incidence of deaths from breast cancer, high cost of treatment and limited resources, the need to formulate and implement effective programs in reducing the burden of disease is obvious. Care, control and creation of cancer information system having an infrastructure from collection of minimum data sets (MDS) are the top priorities of research in Iran's Ministry of Health. METHODS: This is an applied descriptive research with comparative approach implemented in 2010. MDS for breast cancer on selected countries were searched and reviewed and proposed model based on the country's need was designed. Research data were implemented in 2 stages; assessment of MDS on selected countries and the validation of the proposed model through several meetings that has been carried out by the Undersecretary for Research and Technology and several oncologists and pathologists. RESULTS: The MDS is composed of 11 parameters in the form of fields in closed structured arrangements with consideration to coding responses. These parameters include: hospital data, demography, referral, physical examination and investigation, diagnostic information, pathology, treatment, palliative care, completion of primary treatment, clinical trials and follow-up. This form is available for use in the cancer registry database. CONCLUSION: MDS provides an opportunity to strengthen communication between performed researches and research results for the improvement of programs, policies and strategies and provides positive effect on equality in the health system. Although the stages of creating the MDS for breast cancer has been successful, but many challenges has been met until its completion.

Ghaneie M; Rezaie A; Ghorbani NR; Heidari R; Arjomandi M; Zare M

2013-01-01

294

Designing a Minimum Data Set for Breast Cancer: a Starting Point for Breast Cancer Registration in Iran  

Science.gov (United States)

Background: Due to the high incidence of deaths from breast cancer, high cost of treatment and limited resources, the need to formulate and implement effective programs in reducing the burden of disease is obvious. Care, control and creation of cancer information system having an infrastructure from collection of minimum data sets (MDS) are the top priorities of research in Iran’s Ministry of Health. Methods: This is an applied descriptive research with comparative approach implemented in 2010. MDS for breast cancer on selected countries were searched and reviewed and proposed model based on the country’s need was designed. Research data were implemented in 2 stages; assessment of MDS on selected countries and the validation of the proposed model through several meetings that has been carried out by the Undersecretary for Research and Technology and several oncologists and pathologists. Results: The MDS is composed of 11 parameters in the form of fields in closed structured arrangements with consideration to coding responses. These parameters include: hospital data, demography, referral, physical examination and investigation, diagnostic information, pathology, treatment, palliative care, completion of primary treatment, clinical trials and follow-up. This form is available for use in the cancer registry database. Conclusion: MDS provides an opportunity to strengthen communication between performed researches and research results for the improvement of programs, policies and strategies and provides positive effect on equality in the health system. Although the stages of creating the MDS for breast cancer has been successful, but many challenges has been met until its completion.

Ghaneie, M; Rezaie, A; Ghorbani, N R; Heidari, RN; Arjomandi, M; Zare, M

2013-01-01

295

[Randomly sampling survey of dry eye awareness in general eye clinic].  

UK PubMed Central (United Kingdom)

OBJECTIVE: To determine the dry eye awareness in the populations visiting general eye clinic. METHODS: This was a cross-sectional study. A questionnaire about dry eye was designed and administrated to Peking University Third Hospital General Eye Clinic patients (n = 804) from June 2010 to June 2011. The questionnaire contents included general demographic characteristics, experience of health-related work, past medical history, medication history and ocular surface symptoms associated with dry eye, contact lens wearing, ocular operation history, etc. Chi-square and Binary logistic regression analysis was used to determine the influence of demographic and clinical features on awareness of dry eye. RESULTS: Awareness of "dry eye" in the general eye clinical patients was relatively low (26.9%, 216/804). Participants whose age were between 40 and 60 years had better dry eye awareness (41.7%, 73/175) (?(2) = 27.365, P = 0.000). Dry eye awareness of female was better than that of male [female: 33.8% (151/447), male: 18.2% (65/357), ?(2) = 24.500, P = 0.000]. Those who had been in health-related work (71.4%, 30/42), and whose friends or relatives were ophthalmologists (54.7%, 52/95) had better dry eye awareness (?(2) = 31.582, 36.400; both P < 0.01). Participants with a history of rheumatoid arthritis (7/10) or diabetes mellitus (63.0%, 17/27) had better dry eye awareness (?(2) = 32.301, 29.887;both P < 0.01). Those who had been using artificial tears (77.5%, 31/40), oral contraceptives (9/14), diuretics (10/18), sedatives (70.4%, 19/27) and anti-depression drugs (4/4) had better dry eye awareness (?(2) = 54.928, 10.154, 7.713, 26.912, 10.943; all P < 0.01). Except frequently blinking (29.5%), participants who had ocular irrigating symptoms (all > 33.0%) had better awareness than those who had not (?(2) = 7.831 - 32.522, all P < 0.01). Those who were allergic to environment irritating factors (all > 30.0%) had better awareness (?(2) = 5.033 - 24.564, all P < 0.01). Participants who had medical history of ocular surgery (47.2%, 34/72), experience of wearing contact lens (33.2%, 94/283), who were diagnosed as dry eye (100.0%, 45/45) and who had regular ocular examinations (31.0%, 96/310) had better awareness (?(2) = 4.321 - 129.763, all P < 0.01). Those who had visited general practitioners (14.8%, 16/108) had lower awareness than those who went to hospital of higher level (28.7%, 200/696) (?(2) = 9.324, P = 0.002). The result of binary logistic regression analysis showed that gender, health-related working experience, relatives or friends working as Ophthalmologists, using artificial tears, oral contraceptives and sedatives, ocular irritations or environment sensitivity, eye surgeries and wearing contact lens were factors that affected dry eye awareness (OR > 1.000, P < 0.10). CONCLUSIONS: Dry eye awareness in the population who visit general eye clinic is low. The knowledge of dry eye should be added to the patient education and public popularization.

Qiu WQ; Liu ZY; Ji J; Zeng L; Li XM; Wang W

2013-03-01

296

Eye banking in America.  

UK PubMed Central (United Kingdom)

In 1961, the Eye Bank Association of America (EBAA) was developed to promote universal standards for the procurement of eye tissue. Over the last 30 years, the EBAA has had to change its original guidelines to include medical standards, technical personnel, updates in serology testing, and public relations. Certified technicians are required to perform procurement after careful donor chart review, where they must also review the lab results and check the postmortem blood sample to see if it tested positive for the human immunodeficiency virus.

Franko-Gazzarari MD

1991-03-01

297

Eye banking in America.  

Science.gov (United States)

In 1961, the Eye Bank Association of America (EBAA) was developed to promote universal standards for the procurement of eye tissue. Over the last 30 years, the EBAA has had to change its original guidelines to include medical standards, technical personnel, updates in serology testing, and public relations. Certified technicians are required to perform procurement after careful donor chart review, where they must also review the lab results and check the postmortem blood sample to see if it tested positive for the human immunodeficiency virus. PMID:2020025

Franko-Gazzarari, M D

298

Gaze Estimation for Off-Angle Iris Recognition Based on the Biometric Eye Model  

Energy Technology Data Exchange (ETDEWEB)

Iris recognition is among the highest accuracy biometrics. However, its accuracy relies on controlled high quality capture data and is negatively affected by several factors such as angle, occlusion, and dilation. Non-ideal iris recognition is a new research focus in biometrics. In this paper, we present a gaze estimation method designed for use in an off-angle iris recognition framework based on the ANONYMIZED biometric eye model. Gaze estimation is an important prerequisite step to correct an off-angle iris images. To achieve the accurate frontal reconstruction of an off-angle iris image, we first need to estimate the eye gaze direction from elliptical features of an iris image. Typically additional information such as well-controlled light sources, head mounted equipment, and multiple cameras are not available. Our approach utilizes only the iris and pupil boundary segmentation allowing it to be applicable to all iris capture hardware. We compare the boundaries with a look-up-table generated by using our biologically inspired biometric eye model and find the closest feature point in the look-up-table to estimate the gaze. Based on the results from real images, the proposed method shows effectiveness in gaze estimation accuracy for our biometric eye model with an average error of approximately 3.5 degrees over a 50 degree range.

Karakaya, Mahmut [ORNL; Barstow, Del R [ORNL; Santos-Villalobos, Hector J [ORNL; Thompson, Joseph W [ORNL; Bolme, David S [ORNL; Boehnen, Chris Bensing [ORNL

2013-01-01

299

Gaze estimation for off-angle iris recognition based on the biometric eye model  

Science.gov (United States)

Iris recognition is among the highest accuracy biometrics. However, its accuracy relies on controlled high quality capture data and is negatively affected by several factors such as angle, occlusion, and dilation. Non-ideal iris recognition is a new research focus in biometrics. In this paper, we present a gaze estimation method designed for use in an off-angle iris recognition framework based on the ORNL biometric eye model. Gaze estimation is an important prerequisite step to correct an off-angle iris images. To achieve the accurate frontal reconstruction of an off-angle iris image, we first need to estimate the eye gaze direction from elliptical features of an iris image. Typically additional information such as well-controlled light sources, head mounted equipment, and multiple cameras are not available. Our approach utilizes only the iris and pupil boundary segmentation allowing it to be applicable to all iris capture hardware. We compare the boundaries with a look-up-table generated by using our biologically inspired biometric eye model and find the closest feature point in the look-up-table to estimate the gaze. Based on the results from real images, the proposed method shows effectiveness in gaze estimation accuracy for our biometric eye model with an average error of approximately 3.5 degrees over a 50 degree range.

Karakaya, Mahmut; Barstow, Del; Santos-Villalobos, Hector; Thompson, Joseph; Bolme, David; Boehnen, Christopher

2013-05-01

300

Gold-nanoparticle-based colorimetric discrimination of cancer-related point mutations with picomolar sensitivity.  

Science.gov (United States)

Point mutations in the Kirsten rat sarcoma viral oncogene homologue (KRAS) gene are being increasingly recognized as important diagnostic and prognostic markers in cancer. In this work, we describe a rapid and low-cost method for the naked-eye detection of cancer-related point mutations in KRAS based on gold nanoparticles. This simple colorimetric assay is sensitive (limit of detection in the low picomolar range), instrument-free, and employs nonstringent room temperature conditions due to a combination of DNA-conjugated gold nanoparticles, a probe design which exploits cooperative hybridization for increased binding affinity, and signal enhancement on the surface of magnetic beads. Additionally, the scheme is suitable for point-of-care applications, as it combines naked-eye detection, small sample volumes, and isothermal (PCR-free) amplification. PMID:23697628

Valentini, Paola; Fiammengo, Roberto; Sabella, Stefania; Gariboldi, Manuela; Maiorano, Gabriele; Cingolani, Roberto; Pompa, Pier Paolo

2013-05-29

 
 
 
 
301

Gold-nanoparticle-based colorimetric discrimination of cancer-related point mutations with picomolar sensitivity.  

UK PubMed Central (United Kingdom)

Point mutations in the Kirsten rat sarcoma viral oncogene homologue (KRAS) gene are being increasingly recognized as important diagnostic and prognostic markers in cancer. In this work, we describe a rapid and low-cost method for the naked-eye detection of cancer-related point mutations in KRAS based on gold nanoparticles. This simple colorimetric assay is sensitive (limit of detection in the low picomolar range), instrument-free, and employs nonstringent room temperature conditions due to a combination of DNA-conjugated gold nanoparticles, a probe design which exploits cooperative hybridization for increased binding affinity, and signal enhancement on the surface of magnetic beads. Additionally, the scheme is suitable for point-of-care applications, as it combines naked-eye detection, small sample volumes, and isothermal (PCR-free) amplification.

Valentini P; Fiammengo R; Sabella S; Gariboldi M; Maiorano G; Cingolani R; Pompa PP

2013-06-01

302

[Cases of congenital eye malformations in children].  

UK PubMed Central (United Kingdom)

PURPOSE: The aim of this work was to present a clinical picture of congenital defects in the anterior and posterior segment of the eye and coexisting systemic developmental anomalies in a group of children during the infantile period. MATERIAL AND METHODS: We performed a retrospective analysis in a group of 1507 infants seen at our outpatient ophthalmology clinic in 2006-2010. Attention was focused on case histories of nine children (0.6%) with congenital defects of the eye. A routine ophthalmologic examination was done and photographs of the anterior and posterior segment of the eye were archived with the Ret - Cam II apparatus. Maternal risk factors during pregnancy and the perinatal period were analyzed, as well as genetic, familial, infectious, traumatic, metabolic, and toxic factors, and drugs which could have contributed to the pathology of the organ of vision. Additionally, congenital polydysplasia was confirmed using ultrasonography, radiography, and imaging techniques (USG, X-ray, MRI). RESULTS: Congenital anomalies of the anterior and posterior segment of the eye were identified in the study group. Abnomalities of the anterior segment of the eye in four infants were in the form of congenital corneal anomalies (keratopathy, microcornea, sclerocornea, congenital mesenchymal dysgenesis), coloboma of the iris, and aniridia. Additionally, ectopic pupil, congenital cataract, aplasia of the lacrimal point, and palpebral coloboma were observed. Developmental anomalies of the posterior segment of the eye in the form of persistent hyperplastic primary vitreous body or primary fetal vasculature syndrome (PHVB or PFVS), choroid coloboma, coloboma of the optic nerve, and optic disc fovea were recognized in eight children. Anomalies of the anterior and posterior segment of the eye were observed in three children and were associated with microphthalmia, nystagmus, and strabismus. Moreover, systemic anomalies coexisting with ophthalmologic defects were confirmed in 6 children. They were seen in the heart (patent ductus arteriosus (PDA), patent foramen ovale (Pfo), atrial septal defect (ASD), nervous system (aplasia of the corpus callosum, hydrocephalus), osteoarticular system (talipes equinovarus, bifurcate rib, butterfly vertebra, dysmorphic splanchnocranium, contracture of the fingers), genitourinary system (cryptorchism, Wilms' tumor, vesicoureteral reflux grade IV), auditory organ (microtia, aplasia of the external auditory meatus, tympanic cavity, and internal ear), and skin (telangiectasia, syndactyly, appendages, and vegetations). Genetic tests revealed one case of an abnormal karyotype (49, XXXXX). Infections, metabolic disorders, and intoxications were excluded as the background for the anomalies. CONCLUSIONS: The finding of a congenital eye anomaly should be followed by a search for other systemic anomalies. Developmental anomalies of the eye and other organs will require a multidisciplinary approach to treatment and care.

Modrzejewska M; Lachowicz E; Karczewicz D

2011-01-01

303

Ophthalmological apparatus for the refractive correction of an eye  

UK PubMed Central (United Kingdom)

An opthalmological apparatus for the refractive correction of an eye comprises a light projector for projecting laser pulses on to a focal point in the interior of the eye in order to break down eye tissue. The apparatus further comprises a positioning module for positioning the focal point (F) at different starting points, and a scanning module for moving the focal point (F) starting from, in each case, one of the starting points in accordance with a scanning pattern for a treatment subarea (a), the scanning pattern and the starting points being defined such that in a number of treatment subareas (a) separated from one another by tissue bridges, the eye tissue is broken down.Through the formation of a multiplicity of separate, disconnected treatment subareas (a) with broken down eye tissue, it is possible not simply to flatten off the curvature of the cornea ( 21 ) in order to correct a myopia but to change the curvature of the cornea ( 21 ) at virtually any desired locations and, in particular, also to change it asymmetrically for a refractive correction.

RATHJEN CHRISTIAN

304

Eye protector for welder  

UK PubMed Central (United Kingdom)

The utility model relates to an electric welding protection glasses to prevent the electric welder from harms of intense lights or sparks to human body, in particular to face and eye, comprising a frame, a pair of glasses lens, a rotary gavelock, a screw, and a base frame through which the protection glasses can be fixed onto various electric simulation soldering pliers.

WANG SHANBAO

305

Eye Disease and Development  

DEFF Research Database (Denmark)

This research advances the hypothesis that cross-country variation in the historical incidence of eye disease has influenced the current global distribution of per capita income. The theory is that pervasive eye disease diminished the incentive to accumulate skills, thereby delaying the fertility transition and the take-off to sustained economic growth. In order to estimate the influence from eye disease incidence empirically, we draw on an important fact from the field of epidemiology: Exposure to solar ultraviolet B radiation (UVB-R) is an underlying determinant of several forms of eye disease; the most important being cataract, which is currently the leading cause of blindness worldwide. Using a satellite-based measure of UVB-R, we document that societies more exposed to UVB-R are poorer and underwent the fertility transition with a significant delay compared to the forerunners. These findings are robust to the inclusion of an extensive set of climate and geography controls. Moreover, using a global data set on economic activity for all terrestrial grid cells we show that the link between UVB-R and economic development survives the inclusion of country fixed effect.

Andersen, Thomas Barnebeck; Dalgaard, Carl-Johan Lars

2011-01-01

306

Eye casualty department.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A retrospective analysis of all new patients attending our eye casualty department was carried out during the 1 year period, from January to December 1987. During this time the casualty unit saw and treated 4905 new patients. Of these 40.61% were traumatic in origin, 30.52% comprised various ocular ...

Verma, L; Arora, R; Tewari, H K; Khosla, P K

307

Oral antioxidant therapy for marginal dry eye.  

UK PubMed Central (United Kingdom)

OBJECTIVE: To assess the efficacy of an orally administered antioxidant dietary supplement for managing marginal dry eye. DESIGN: A prospective, randomised, placebo controlled trial with cross-over. SETTING: Eye Clinic, Department of Vision Sciences, Glasgow Caledonian University. SUBJECTS: Forty marginal dry eye sufferers composed of 30 females and 10 males (median age 53 y; range 38-69 y). INTERVENTIONS: Baseline assessments were made of tear volume sufficiency (thread test), tear quality (stability), ocular surface status (conjunctival impression cytology) and dry eye symptoms (questionnaire). Each subject was administered courses of active treatment, placebo and no treatment, in random order for 1 month each and results compared to baseline. RESULTS: Tear stability and ocular surface status were significantly improved following active treatment (P<0.05). No changes from baseline were detected following administration of placebo and no treatment (P>0.05). Absolute increase in tear stability correlated with absolute change in goblet cell population density. Tear volume was not improved following any treatment period and dry eye symptom responses were subject to placebo effect. CONCLUSIONS: Oral antioxidants improved both tear stability and conjunctival health, although it is not yet understood whether increased ocular surface health mediates increased tear stability or vice versa. SPONSORS: This study was supported by a PhD scholarship funded by the Department of Vision Sciences, Glasgow Caledonian University, Scotland. Antioxidant supplements and placebos were kindly donated by Vitabiotics.

Blades KJ; Patel S; Aidoo KE

2001-07-01

308

If I Had - Dry Eyes  

Medline Plus

Full Text Available ... Dry Eyes - Dr. Penny Asbell, MD, FACS, MBA, Professor of Ophthalmology, Mount Sinai School of Medicine, New ... Dry Eyes - Dr. Penny Asbell, MD, FACS, MBA, Professor of Ophthalmology, Mount Sinai School of Medicine, New ...

309

Eye Bank Association of America  

Science.gov (United States)

... to content Skip to Navigation Find an Eye Bank Near You MEMBER LOGIN The vision of the ... is the nationally-recognized accrediting body for eye banks. Since 1961, EBAA member banks have restored sight ...

310

Disability: recommendations for eye programmes  

Directory of Open Access Journals (Sweden)

Full Text Available In 2012, CBM’s Medical Eye Care Advisory Working Group met in Hyderabad, India to discuss the inclusion of people with disabilities in eye care.As a result of these discussions, recommendations were made.

2013-01-01

311

If I Had - Dry Eyes  

Medline Plus

Full Text Available ... with Severe COPD VIDEO: If I Had - Dry Eyes - Dr. Penny Asbell, MD, FACS, MBA, Professor of ... to Home Page VIDEO: If I Had - Dry Eyes - Dr. Penny Asbell, MD, FACS, MBA, Professor of ...

312

What is Diabetic Eye Disease?  

Medline Plus

Full Text Available ... least half will show signs of a diabetic eye disease and the most common of these by far ... vision. Announcer: Diabetic retinopathy is not the only eye disease that may affect people with diabetes. Others include ...

313

If I Had - Dry Eyes  

Science.gov (United States)

... I Had - Dry Eyes - Dr. Penny Asbell, MD, FACS, MBA, Professor of Ophthalmology, Mount Sinai School of ... I Had - Dry Eyes - Dr. Penny Asbell, MD, FACS, MBA, Professor of Ophthalmology, Mount Sinai School of ...

314

If I Had - Dry Eyes  

Medline Plus

Full Text Available ... I Had - Dry Eyes - Dr. Penny Asbell, MD, FACS, MBA, Professor of Ophthalmology, Mount Sinai School of ... I Had - Dry Eyes - Dr. Penny Asbell, MD, FACS, MBA, Professor of Ophthalmology, Mount Sinai School of ...

315

The effect of eye movement on the control of arm movement to a target.  

UK PubMed Central (United Kingdom)

Abstract The purpose of this study was to investigate the effect of eye movement on the control of arm movement to a target. Healthy humans flexed the elbow to a stationary target in response to a start tone. Simultaneously, the subject moved the eyes to the target (saccade eye movement), visually tracked a laser point moving with the arm (smooth pursuit eye movement), or gazed at a stationary start point at the midline of the horizontal visual angle (non-eye movement-NEM). Arm movement onset was delayed when saccade eye movement accompanied it. The onset of an electromyographic burst in the biceps muscle and the onset of saccade eye movement were almost simultaneous when both the arm and the eyes moved to the target. Arm movement duration during smooth pursuit eye movement was significantly longer than that during saccade eye movement or NEM. In spite of these findings, amplitudes of motor-evoked potential in the biceps and triceps brachii muscles were not significantly different among the eye movement conditions. These findings indicate that eye movement certainly affects the temporal control of arm movement, but may not affect corticospinal excitability in the arm muscles during arm movement.

Horino H; Mori N; Matsugi A; Kamata N; Hiraoka K

2013-09-01

316

Early studies of eye dominances.  

UK PubMed Central (United Kingdom)

Early accounts of eye dominances are considered. An index of sighting dominance (eye closure) was described by Aristotle, and Porta (1593) introduced an alignment test for it. Porta also described rivalry dominance, and asserted that it favoured the right eye. Acuity dominance, on the other hand, was assigned to the left eye by Borelli (1673). These views are placed in the context of prevailing theories of binocular vision.

Wade NJ

1998-04-01

317

Eye Pupil Location Using Webcam  

CERN Multimedia

Three different algorithms used for eye pupil location were described and tested. Algorithm efficiency comparison was based on human faces images taken from the BioID database. Moreover all the eye localisation methods were implemented in a dedicated application supporting eye movement based computer control. In this case human face images were acquired by a webcam and processed in a real-time.

Ciesla, Michal

2012-01-01

318

Variable stars magnitudes estimations exploiting the eye physiology  

CERN Multimedia

The physiology of the dark adaption process of the eye is revisited from an astronomical point of view. A new method for the magnitude estimation of a star is presented. It is based upon the timing of the physiological cycle of the rhodopsin during the eye dark adaption process. The limits of the application of the method are discussed. This method is suitable for bright stars as Betelgeuse, Antares or Delta Scorpii or stars at the limiting magnitude observed with a telescope.

Sigismondi, Costantino

2011-01-01

319

Incorporation of intraocular scattering in schematic eye models  

Energy Technology Data Exchange (ETDEWEB)

Beckmann's theory of scattering from rough surfaces is applied to obtain, from the experimental veiling glare functions, a diffuser that when placed at the pupil plane would produce the same scattering halo as the ocular media. This equivalent diffuser is introduced in a schematic eye model, and its influence on the point-spread function and the modulation-transfer function of the eye is analyzed.

Navarro, R.

1985-11-01

320

A Maxwell's fish eye lens for the terahertz region  

Science.gov (United States)

We implement a two-dimensional Maxwell's fish eye lens using a waveguide-based artificial dielectric. The Maxwell's fish eye lens consists of two metallic cylindrical plates sandwiching a free-space region, with the inner surface of one plate shaped into a hollow conical form. This lens has the capability to image terahertz beams from a source located at the edge (between the plates) to the diametrically opposite point on the edge, independent of the incident angle.

Liu, Jingbo; Mendis, Rajind; Mittleman, Daniel M.

2013-07-01

 
 
 
 
321

Role of the iridescent eye in stickleback female mate choice.  

Science.gov (United States)

Many vertebrates exhibit prominent body colours that are used in courtship and territorial communication. Some fishes also have an eye whose iris becomes iridescent during the mating season, as in the threespine stickleback. Behavioural studies in this species have focused on the redness of the throat/jaw as the primary determinant of female mate choice. Unlike the iridescent eye, however, the red throat/jaw is not present in all stickleback populations, suggesting that the colour of the eye may be equally important for female mate choice. Here, we used data on photoreceptors and environmental light to assess body conspicuousness and the colour contrast of courtship signals for stickleback populations living in a range of waters, from clear (mesotrophic) to red light shifted (dystrophic). This analysis indicated that the redness of the throat/jaw is expressed to enhance the contrast of the eye. To test the importance of eye colour as a courtship signal, we carried out mate choice experiments in which females were presented with identical videos of a courting male but for the colour of the eye and/or the throat/jaw. Females did not choose based on differences in throat/jaw redness between videos, but preferred males with the highest contrast between the eye and the throat/jaw. This result points to the blue iridescent eye as a primary courtship signal in stickleback female mate choice. PMID:23580716

Flamarique, Iñigo Novales; Bergstrom, Carolyn; Cheng, Christiana L; Reimchen, Thomas E

2013-04-11

322

Role of the iridescent eye in stickleback female mate choice.  

UK PubMed Central (United Kingdom)

Many vertebrates exhibit prominent body colours that are used in courtship and territorial communication. Some fishes also have an eye whose iris becomes iridescent during the mating season, as in the threespine stickleback. Behavioural studies in this species have focused on the redness of the throat/jaw as the primary determinant of female mate choice. Unlike the iridescent eye, however, the red throat/jaw is not present in all stickleback populations, suggesting that the colour of the eye may be equally important for female mate choice. Here, we used data on photoreceptors and environmental light to assess body conspicuousness and the colour contrast of courtship signals for stickleback populations living in a range of waters, from clear (mesotrophic) to red light shifted (dystrophic). This analysis indicated that the redness of the throat/jaw is expressed to enhance the contrast of the eye. To test the importance of eye colour as a courtship signal, we carried out mate choice experiments in which females were presented with identical videos of a courting male but for the colour of the eye and/or the throat/jaw. Females did not choose based on differences in throat/jaw redness between videos, but preferred males with the highest contrast between the eye and the throat/jaw. This result points to the blue iridescent eye as a primary courtship signal in stickleback female mate choice.

Flamarique IN; Bergstrom C; Cheng CL; Reimchen TE

2013-08-01

323

Eye movement inhibits the facilitation of perceptual filling-in.  

UK PubMed Central (United Kingdom)

When a small figure is presented in human peripheral vision, it becomes invisible and invaded by surrounding texture, within a few seconds. This visual illusion is called perceptual filling-in. Time to filling-in (filling-in time) is varied by the properties of small figure, surround texture and some experimental conditions. In our preliminary study (Yokota, IEEE/IC-EMBS 2005), we found that incomplete fixation distributes filling-in time. Furthermore, that we can see nothing by restraining eye movement artificially is well known. Therefore, we can consider that filling-in time is influenced by eye movement. Although it has been recently reported that eye movement influences the filling-in occurrence (Martinez-Conde, Neuron 2006), the relation between eye movement and the filling-in time has rarely been reported. For this study, we measured the filling-in time for three subjects, for four surrounding textures, with simultaneous recording of eye movement. The results show that the filling-in time correlates to the standard deviation of the power of the eye distance from the fixation point. Furthermore, we found relatively strong correlation between the filling-in time and the power of high frequency component 50-200 (Hz) in the eye movement, though the correlation of the power of low frequency component 10-50 (Hz) is not so high. Thus we suppose that filling-in is inhibited by small involuntary eye movement.

Yokota M; Yokota Y

2010-01-01

324

Comparison of eye shields in radiotherapeutic beams  

International Nuclear Information System (INIS)

Full text: Both MeV electrons and kV photons are used in the treatment of superficial cancers. The advantages and disadvantages for each of these modalities have been widely reported in the literature (See for example [1-2]). Of particular note in the literature is the use of lead and tungsten eye shields to protect ocular structures during radiotherapy. An investigation addressing issues raised in the literature that are relevant to the Wellington Cancer Centre method of treatment of lesions near the eye shall be summarised. Various small sized fields were irradiated to determine depth dose and profile curves in a water phantom shielded by various commercially available eye shields. Transmission factors relevant to critical ocular structures and particle distribution theories are used to further elucidate the comparison between the use of MeV electrons and kV photons in the treatment of superficial cancers. Superficial X-rays from a Pantak Therapax unit SXT 150 model of HVL 4.90mm Al were used for the lead eye shield measurements and electrons from a Varian Clinac 2100C nominal energies 6MeV and 9MeV (Rp 3.00cm and 4.34cm respectively) were used for the tungsten eye shield measurements. For the photon measurements circular applicators of 3cm, 4cm and 5cm diameter were used and for the electrons standard 6x6cm and 10x 10cm applicators were used, with no custom inserts. A Scanditronix RFA-300 water phantom and Scanditronix RFAplus version 5.3 software application were used to collect and collate all data. The eye shields were the Radiation Products Design Inc. medium lead eye shield (item 934-014) and the MED-TEC tungsten eye shields MT-T-45 M and MT-T-45 S. It is demonstrated that electron fields have appreciably greater scatter into the area directly under the eye shields than the photon fields. Similarly at the region of dmax for the electron fields the relative dose is appreciably greater than the photon fields at similar depth. The relative merits for electron and photon treatments are discussed with respect to the investigations findings and reference to the literature. When comparing electrons and photons it is usually the definite range of electrons within tissue that recommends electron treatments. However, one should weigh this consideration against some of the salient features of a well-constructed superficial photon treatment, for example the effective blocking of kilovoltage photons by lead and the sharp edges of the kilovoltage photon fields. Copyright (2004) Australasian College of Physical Scientists and Engineers in Medicine

2004-01-01

325

Diretrizes para seleção de projetistas e avaliação da prestação do serviço de projeto de edificações na visão do contratante/ Guidelines for designers selection and evaluation of the design service from the building developer point of view  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese A avaliação da prestação do serviço de projeto de edificações pode fomentar a relação entre os contratados (projetistas) e os contratantes (incorporador-construtor). Os resultados advindos da avaliação possibilitam a observação das dificuldades porventura ocorridas durante a prestação do serviço, a análise do desempenho dos contratados, a retroalimentação de informações aos envolvidos, o planejamento de ações de melhorias e a seleção de projetista (more) s em empreendimentos futuros. O objetivo deste trabalho é propor diretrizes para a seleção de projetistas e para a avaliação da PSP, sob a ótica do cliente contratante. Para esse fim, foram realizados estudos de caso em quatro empresas incorporadoras e construtoras e duas empresas de projeto da cidade de São Paulo. Os resultados mostram que as empresas incorporadoras e construtoras possuem suas práticas de seleção e avaliação de projetistas e que as empresas de projeto detêm práticas para avaliação da satisfação do cliente contratante. Ambos os tipos de avaliação mencionados - avaliação dos profissionais de projeto e da satisfação do cliente contratante - apresentam o mesmo objetivo: avaliar a prestação do serviço de projeto. A observação dessas práticas, somada à revisão bibliográfica realizada, contribuíram para a elaboração das diretrizes para a seleção de projetistas e para a avaliação da prestação do serviço de projeto. Abstract in english The evaluation of the building design service can improve the relationship between professionals (designers) and clients (real estate developers or construction companies). The evaluation results allow the observation of the difficulties that may have occurred during service provision, the assessment of designers performance, provide feedback for the stakeholders, planning improvement actions, and the selection of designers for future projects. The aim of this study is to (more) propose a set of guidelines for designer selection and design service evaluation from the building developer point of view. Case studies were carried out in four real estate developing companies and two design firms from the city of São Paulo. The results show that the builders and property developers have practices for designer selection and evaluation and that the design companies have practices for evaluating the satisfaction of their clients. Both types of evaluation - designer evaluation and evaluation of the contractor client satisfaction - have similar goals: to evaluate the design service. The observation of those practices and the literature review contributed to the elaboration of guidelines for designer selection and for the evaluation of the design service.

Paula, Nathália de; Novaes, Celso Carlos

2010-12-01

326

Evaluation of ciliary sulcus diameter using ultrasound biomicroscopy in emmetropic eyes and myopic eyes.  

UK PubMed Central (United Kingdom)

PURPOSE: To measure the ciliary sulcus-to-sulcus (STS) diameter in 4 axes in emmetropic and myopic eyes using ultrasound biomicroscopy (UBM) and compare the measurements with automated horizontal white-to-white (WTW) diameter measurements. SETTING: University Eye Hospital Freiburg, Freiburg im Breisgau, Germany. DESIGN: Evaluation of diagnostic technology. METHODS: The STS diameter was measured at 0, 45, 90, and 135 degrees using 35 MHz UBM. The 0-degree WTW diameters were obtained using scanning-slit topography (Orbscan) and partial coherence interferometry (PCI) biometry (IOLMaster). The 0-degree STS and 90-degree STS were compared using the paired t test; the Pearson correlation was used to assess whether the 0-degree STS diameter could be predicted from the 0-degree WTW diameter. RESULTS: The mean SE refraction was -0.48 diopter (D) ± 0.35 (SD) in emmetropic eyes and -9.55 ± 3.70 D in myopic eyes. In 35 of 37 eyes, 90-degree STS was greater than 0-degree STS. The mean 90-degree STS was 12.51 ± 0.43 mm. The mean 0-degree STS was 12.19 ± 0.47 mm (P<.01). The mean 0-degree WTW diameters were 11.73 ± 0.37 mm (scanning-slit topography) and 12.20 ± 0.42 mm (PCI biometry). The correlations were good between 0-degree STS and 0-degree WTW with PCI biometry (r(2) = 0.82) and scanning-slit topography (r(2) = 0.86) in emmetropic eyes but weak between 0-degree STS and 0-degree WTW in myopic eyes (r(2) = 0.36 and r(2) = 0.40, respectively). CONCLUSIONS: Sulcus diameter measurements were most precise using UBM. The ciliary sulcus is vertically oval. The WTW diameter is not suitable for calculating a PC pIOL diameter, particularly in myopic eyes.

Biermann J; Bredow L; Boehringer D; Reinhard T

2011-09-01

327

Impact of symptomatic dry eye on vision-related daily activities: the Singapore Malay Eye Study.  

UK PubMed Central (United Kingdom)

PURPOSE: To examine the impact of symptomatic dry eye on vision-related daily activities. METHODS: A population-based survey of eye diseases was conducted on 3280 (78.7% response rate) Malay persons aged >or=40 years, who were randomly selected from designated areas in southwestern Singapore. Participants were administered a standardized dry eye questionnaire consisting of six questions on symptoms, a questionnaire on vision-related daily activities, and underwent a comprehensive systemic and ocular examination. Symptomatic dry eye was defined as one or more self-reported symptoms that were frequently present (ranked as often or all the time). Logistic regression method was used to examine the relationship of symptomatic dry eye with difficulty in performing daily activities. RESULTS: In adults without visual impairment, symptomatic dry eye after adjusting for age, gender, and presenting visual acuity was significantly associated with difficulty in vision-related activities such as navigating stairs (odds ratio (OR)=1.96, 95% confidence interval (CI): 1.28-3.00), recognizing friends (OR=1.99, 95% CI: 1.45-2.73), reading road signs (OR=1.87, 95% CI: 1.36-2.57), reading newspaper (OR=1.50, 95% CI: 1.11-2.04), watching television (OR=1.90, 95% CI: 1.26-2.87), cooking (OR=1.94, 95% CI: 1.02-3.71), and driving at night (OR=2.06, 95% CI: 1.32-3.21). CONCLUSION: Symptomatic dry eye was associated with difficulty in performing vision-dependent tasks, independent of visual acuity and other factors. These findings have public health significance and suggest that the visual dysfunction in dry eye should be further characterized.

Tong L; Waduthantri S; Wong TY; Saw SM; Wang JJ; Rosman M; Lamoureux E

2010-09-01

328

Eye testing apparatus  

UK PubMed Central (United Kingdom)

Eye testing apparatus 10 comprises a control unit 12 to be viewed by the operator and a scanner unit 14 to be viewed by the patient, and may be used to detect blind spots in the visual field of an eye looking into the scanner unit through a lens 70. A display panel 24 on the control unit is provided with an array of light bulbs so that the operator can select a number of them to flash on and off, a corresponding number of light bulbs being flashed on and off on the scanner unit 14. The control unit 12 includes a memory which may be operated by the operator to store a record of the lights which the patient cannot see. These can then be recalled for double checking. A light pen can be used to flash on the light bulbs on the display panel individually or to change a selected pattern of illuminated light bulbs.

329

[AIDS and the eye  

UK PubMed Central (United Kingdom)

We are observing a patient who is HIV positive since 1987 and in 1992 he got sick of AIDS. The first ophthalmologist symptom of the illness was a blurred disc margin of the optic nervehead with minor peripapillary hemorrhages and reduction of his visual acuity. After two months the condition of the fundus has improved but on the eyelash in the nasal half a Kaposi sarcoma is emerging. After six month of being sick of AIDS we are observing a reduction of visual acuity on the left eye and we diagnosed a Cytomegalic viral retinitis which is also confirmed serologically. Inspite of the treatment by Gancyclovir his condition is not improving and minor hemorrhages as well as microaneurysms are emerging also in macular area of the right eye.

Cernák A; Filová I; Pont'uchová E; Durcová T; Mokrás M

1993-11-01

330

Night luminous eye drop bottle  

UK PubMed Central (United Kingdom)

The utility model discloses a night luminous eye drop bottle, which belongs to the field of medicament packaging technology. Due to the adoption of the night luminous eye drop bottle, eye drops can be well added without illumination at night. The night luminous eye drop bottle comprises a bottle body and a bottle cap. The bottle body is equipped with a night luminous powder coating and the night luminous powder coating is equipped with sealed paint. The night luminous eye drop bottle has the advantages of simple structure, easy fabrication, good practicability and convenient usage.

SAI CHEN; CHUNHUI LU

331

Use of fellow eye data in the calculation of intraocular lens power for the second eye.  

UK PubMed Central (United Kingdom)

PURPOSE: To test the hypothesis that the refractive outcome of the first eye can be used to improve the intraocular lens (IOL) power calculation for the second eye. DESIGN: Retrospective, consecutive case series in a university clinic setting. PARTICIPANTS: One thousand two hundred thirty-five patients who underwent sequential bilateral IOL implantation using the same type of IOL for both eyes. METHODS: The refractive outcome was analyzed in retrospect and the IOL power calculation was reviewed using 3 different methods: (1) the old Sanders-Retzlaff-Kraff (SRK) II formula, (2) the newer SRK/T formula, and (3) the more recent Olsen formula. In a subgroup of 232 eyes, the actual postoperative anterior chamber depth (ACD) was measured using the Lenstar LS900 laser biometer (Haag-Streit AG, Koeniz, Switzerland). MAIN OUTCOME MEASURES: The error in diopters (D) of the predicted refraction in the spectacle plane. RESULTS: The correlation coefficients between the prediction errors for the right and left eyes were 0.56, 0.38, and 0.27 for the SRK II, SRK/T, and Olsen formula, respectively (P<0.001). Based on the observed correlation, the prediction of the second eye could be corrected according to the regression formula: Rx(cor) = Rx(exp)+?×Px(err), where Rx(cor) and Rx(exp) are the corrected and the uncorrected refractive prediction, respectively, Px(err) is the observed error of the first eye, and ? is a formula-specific regression coefficient. Using this formula, the mean absolute error (MAE) was found to decrease from 0.56 D to 0.46 D, from 0.47 D to 0.41 D, and from 0.42 D to 0.40 D with the SRK II (P<0.001), the SRK/T (P<0.001), and the Olsen formula (P<0.05), respectively. Substituting the measured postoperative ACD of the first eye for the estimated ACD for the second eye in the Olsen formula was found to have a similar accuracy as the empirical regression formula. CONCLUSIONS: Depending on the IOL power calculation formula, the prediction error of the first eye may be used to improve the prediction for the second eye. The reason for this effect seems to be the formula-dependent inaccuracy in the prediction of the IOL position (ACD) after surgery.

Olsen T

2011-09-01

332

Genetic analyses of the human eye colours using a novel objective method for eye colour classification  

DEFF Research Database (Denmark)

In this study, we present a new objective method for measuring the eye colour on a continuous scale that allows researchers to associate genetic markers with different shades of eye colour. With the use of the custom designed software Digital Iris Analysis Tool (DIAT), the iris was automatically identified and extracted from high resolution digital images. DIAT was made user friendly with a graphical user interface. The software counted the number of blue and brown pixels in the iris image and calculated a Pixel Index of the Eye (PIE-score) that described the eye colour quantitatively. The PIE-score ranged from ?1 to 1 (brown to blue). The software eliminated the need for user based interpretation and qualitative eye colour categories. In 94% (570) of 605 analyzed eye images, the iris region was successfully extracted and a PIE-score was calculated. A very high correlation between the PIE-score and the human perception of eye colour was observed. The correlations between the PIE-scores and the six IrisPlexSNPs (HERC2 rs12913832, OCA2 rs1800407, SLC24A4 rs12896399, TYR rs1393350, SLC45A2 rs16891982 and IRF4 rs12203592) were analyzed in 570 individuals. Significant differences (p < 10?6) in the PIE-scores of the individuals typed as HERC2 rs12913832 G (PIE = 0.99) and rs12913832 GA (PIE = ?0.71) or A (PIE = ?0.87) were observed. We adjusted for the effect of HERC2 rs12913832 and showed that the quantitative PIE-scores were significantly associated with SNPs with minor effects (OCA2 rs1800407, SLC24A4 rs12896399 and TYR rs1393350) on the eye colour. We evaluated the two published prediction models for eye colour (IrisPlex [1] and Snipper[2]) and compared the predictions with the PIE-scores. We found good concordance with the prediction from individuals typed as HERC2 rs12913832 G. However, both methods had difficulties in categorizing individuals typed as HERC2 rs12913832 GA because of the large variation in eye colour in HERC2 rs12913832 GA individuals. With the use of the DIAT software and the PIE-score, it will be possible to automatically compare the iris colour of large numbers of iris images obtained by different studies and to perform large meta-studies that may reveal loci with small effects on the eye colour.

Andersen, Jeppe D.; Johansen, Peter

2013-01-01

333

Hyphema Following Eye Trauma  

Directory of Open Access Journals (Sweden)

Full Text Available Background and Objectives: Hyphema, the blood in the anterior eye chamber, can be caused by penetrating or blunt trauma or other causes. This study aimed at investigating the clinical features of 15 cases of traumatic Hyphema, having referred to ophthalmology ward of Shahid Beheshti hospital of Babol university of medical sciences. Methods: In this study the clinical characteristics of 15 patients with eye trauma-who had referred to Shahid Beheshti Hospital of Babol University of medical sciences during 2008-2009- were examined. In addition to eye trauma the selected patients had microscopic or macroscopic anterior eye chamber hemorrhages. Results: The mean age of patients was 25. 1 years. Eleven patients were male and four were female. Increased IOP was seen in 4 cases, three patients improved with drug therapy, but one patient needed surgery due to an increase in IOP and the re-bleeding. Regarding the degree of Hyphema, 4 cases were microscopic Hyphema , 2 cases were grade 1 of Hyphema, 3 cases were grade 2 of Hyphema, 3 cases were grade 3 of Hyphema , 2 cases grade 4 of Hyphema and one case was not assessable due to flattened anterior chamber, Visual Acuity was mostly poor at the beginning of admission which was significantly improved after treatment. On the whole, six patients underwent surgery. Conclusion: The results of this study show that patients with traumatic Hyphema usually have poor Visual Acuity at the beginning of admission, but the vision was relatively improved with early treatment in many cases. Therefore, proper and timely treatment is necessary in these patients.

E Mikaniki

2012-01-01

334

Hyphema Following Eye Trauma  

Directory of Open Access Journals (Sweden)

Full Text Available Background and Objectives: Hyphema, the blood in the anterior eye chamber, can be caused by penetrating or blunt trauma or other causes. This study aimed at investigating the clinical features of 15 cases of traumatic Hyphema, having referred to ophthalmology ward of Shahid Beheshti hospital of Babol university of medical sciences.Methods: In this study the clinical characteristics of 15 patients with eye trauma-who had referred to Shahid Beheshti Hospital of Babol University of medical sciences during 2008-2009- were examined. In addition to eye trauma the selected patients had microscopic or macroscopic anterior eye chamber hemorrhages.Results: The mean age of patients was 25. 1 years. Eleven patients were male and four were female. Increased IOP was seen in 4 cases, three patients improved with drug therapy, but one patient needed surgery due to an increase in IOP and the re-bleeding. Regarding the degree of Hyphema, 4 cases were microscopic Hyphema , 2 cases were grade 1 of Hyphema, 3 cases were grade 2 of Hyphema, 3 cases were grade 3 of Hyphema , 2 cases grade 4 of Hyphema and one case was not assessable due to flattened anterior chamber, Visual Acuity was mostly poor at the beginning of admission which was significantly improved after treatment. On the whole, six patients underwent surgery.Conclusion: The results of this study show that patients with traumatic Hyphema usually have poor Visual Acuity at the beginning of admission, but the vision was relatively improved with early treatment in many cases. Therefore, proper and timely treatment is necessary in these patients.

Mikaniki E; Rasoulinejad A; Mikaniki M; Shirzadian A.H

2011-01-01

335

Eye in the Sky  

Science.gov (United States)

This National Geographic website highlights the history and use of satellites and remote-sensing technology to determine the state of the planet. A timeline covers the history of satellites from 1858 to 2000, including both accomplishments and failures. The Eye contains slide shows and images from satellites covering the topics of volcanoes, tornadoes, hurricanes, wildfires, earthquakes, floods, dams, ozone, deforestation, desertification, overpopulation, exploration of space, and human conflict. A section on classroom ideas provides activities for K-12 classrooms.

336

ANSWER: A painful eye.  

Directory of Open Access Journals (Sweden)

Full Text Available (Refer to page 207)Answer: HypopyonIn this case, hypopyon is seen in the anterior chamber and posterior synaechiae can also be seen at the pupil margin. Hypopyon can be defined as layering of white blood cells in the anterior chamber of the eye following acute, subacute and chronic inflammatory reactions involving the aqueous humor and anatomical structures adjacent to it. It appears as a white milky layer at the bottom of the anterior chamber.

Nadir Ali MOHAMED ALI; Ruben MATHEW, Nayan JOSHI

2011-01-01

337

Phacolysin eye medicinal formulation  

UK PubMed Central (United Kingdom)

The present invention relates to a Fakelin eye medicine preparation. Said preparation includes medicinal active component Fakelin and solvent. Said active component Fakelin can be made into independent solid preparation, and is separated from the solvent. Said active component Fakelin and solvent are packaged separately, when it is used, the solid preparation Fakelin can be dissolved in the solvent, so that it can produce the action of stabilizing preparation.

FAN XIANJIA FAN

338

Nanoparticles biodistribution in the eye.  

UK PubMed Central (United Kingdom)

Nowadays the management of ocular diseases is limited by the inability for controlled drug delivery. In the present study micro and nanoparticles based on Chitosan labeled with fluorescein, prepared by double crosslinking method in water/oil emulsion, were investigated as a new vehicle for intraocular drug delivery. The main objective was to study the biodistribution of the prepared particles after beind administered into the anterior chamber of pig eyes. Nanoparticles were characterized by Scanning Electron Microscopy Laser Difractometry and analysis was performed by Confocal Laser Microscopy. The designed micro and nanoparticles have average size from 500 nm to 2 microm and present round shape, smooth surface, relative high dimensional poly-dispersity and relative high porosity. The particles also present good biodistribution at corneal, scleral, retinal and optic nerve level after being administered. After this eliminary phase we intend to use Chitosan based nanoparticles as a controlled drug delivery system for therapies concerning endophthalmitis, age related macular degeneration etc.

Gardikiotis F; Peptu C; Popa M; Costin D

2011-01-01

339

Michelangelo's eye disease.  

Science.gov (United States)

Charged by the Pope Julius II for painting the Cappella Sistina in Rome (between 1508 and 1512), Michelangelo worked in an elevated scaffolding, in an anomalous position with dyes (including poisoning lead salts) and solvents (such as toxic turpentine) dripping on his face and continuously inhaling, in a dim environment illuminated only with oil lamps and candles, as he described himself and sketched in a sonet addressed to Giovanni da Pistoia. In 1510 he began suffering from eye disease: the main symptom was the necessity to elevate the document he was reading up to the level of his eyes. This defect disappeared few months after he finished painting his masterpiece. We hypothesize that the Michelangelo's eyes disease was a form of acquired and transitory nystagmus induced by the many hours he spent in up gaze, with a skew deviation, a form of ocular tilt reaction resulting from the impairment of spatial sensitivity (inversion illusion) due to the persistence of the artist's head in a horizontal position, looking upward. PMID:22425178

Gallenga, P E; Neri, Giampiero; D'Anastasio, Ruggero; Pettorrossi, Vito Enrico; Alfieri, Emilio; Capasso, Luigi

2012-03-14

340

Michelangelo's eye disease.  

UK PubMed Central (United Kingdom)

Charged by the Pope Julius II for painting the Cappella Sistina in Rome (between 1508 and 1512), Michelangelo worked in an elevated scaffolding, in an anomalous position with dyes (including poisoning lead salts) and solvents (such as toxic turpentine) dripping on his face and continuously inhaling, in a dim environment illuminated only with oil lamps and candles, as he described himself and sketched in a sonet addressed to Giovanni da Pistoia. In 1510 he began suffering from eye disease: the main symptom was the necessity to elevate the document he was reading up to the level of his eyes. This defect disappeared few months after he finished painting his masterpiece. We hypothesize that the Michelangelo's eyes disease was a form of acquired and transitory nystagmus induced by the many hours he spent in up gaze, with a skew deviation, a form of ocular tilt reaction resulting from the impairment of spatial sensitivity (inversion illusion) due to the persistence of the artist's head in a horizontal position, looking upward.

Gallenga PE; Neri G; D'Anastasio R; Pettorrossi VE; Alfieri E; Capasso L

2012-06-01

 
 
 
 
341

Eye movement; Experimental and clinical study using cine mode MRI  

Energy Technology Data Exchange (ETDEWEB)

This is a special lecture at the 96th Annual Congress of the Japanese Ophthalmological Society in 1992, presenting studies on eye movement using magnetic resonance imaging (MRI). Using cine mode MRI technology, two methods for producing a series of photographs have been invented: (1) the moving eye method or dynamic method in which the subjects were asked to perform 256 or 512 vertical and horizontal eye movements in synchronization with a sound trigger; and (2) the fixed eye method or static method in which the subjects were asked to gaze at individual points in a 5 to 7 point sequence as indicated by the investigator. MRI data was generated and the resulting series of photographs were observed in cine mode on a televisin monitor. Displaying the MRI-generated photographs in cine mode enables direct observation of eye movement, optic nerve and extraocular muscles within the orbit. Although the moving eye method is more accurate in its portrayal of the actual eye movement, at least 256 eye movements are required for about 5 minutes, causing physical and mental load for the subjects. The fixed eye method was thus used to examine ophthalmoplegia, including abducens palsy, oculomotor palsy, fracture of the orbital wall, foreign bodies in the orbit, Duane's syndrome, endocrine myopathy, esotropia and exotropia. This allowed the investigation of anatomical changes, such as atrophy or hypertrophy, and the functional state caused by contraction and relaxation of the extraocular muscles. Transposition of the extraocular muscles for paralytic squint was reexamined and a new surgical procedure was developed for abducens palsy. The measurement of the length, thickness and weight of the extraocular muscles from the MRI-generated photographs allowed more accurate analysis. Three dimensional reconstructive method of MRI provided a valuable tool for evaluating the orbit. (N.K.) 67 refs.

Inatomi, Akihiro (Shiga University of Medical Science, Otsu (Japan)); Kaji, Kazutaka; Sasaki, Kenji (and others)

1992-12-01

342

A two-step experimental design for a sediment bioassay using growth of the amphipod Hyalella azteca for the test end point  

Energy Technology Data Exchange (ETDEWEB)

The authors designed a sediment bioassay using 25% growth inhibition of Hyalella azteca as the end point. Hyalella azteca exhibits size-specific fecundity, so growth is a surrogate of reproductive production. They investigated density effects on growth to address whether crowding could affect test interpretation; amphipods in 14,000/m{sup 2} exposures were 16 to 20% smaller than those at 7,000/m{sup 2}. Using power analysis, the authors found that 20 to 25 samples are required to determine significance when {alpha} = 0.10 and 1 {minus} {beta} = 0.90. To minimize the need for laboratory resources, they designed a two-step bioassay, which they tested with field-collected sediments. The screening bioassay compared 11 sediments to a reference. Three sediments were toxic, five sediments were nontoxic, and three sediments were possibly toxic. In the confirmatory bioassay, three possibly toxic and two nontoxic samples were reevaluated. Two were toxic, and the remaining four samples were nontoxic. In summary, five sediments were toxic and six sediments were nontoxic. The two-step analysis used minimal laboratory resources but maximized statistical power, where needed, to discriminate growth effects.

Kubitz, J.A.; Giesy, J.P. [Michigan State Univ., East Lansing, MI (United States); Besser, J.M. [Michigan State Univ., East Lansing, MI (United States)]|[National Biological Service, Columbia, MO (United States). Midwest Science Center

1996-10-01

343

ECEM (Eye Closure, Eye Movements): application to depersonalization disorder.  

UK PubMed Central (United Kingdom)

Eye Closure, Eye Movements (ECEM) is a hypnotically-based approach to treatment that incorporates eye movements adapted from the Eye Movement Desensitization and Reprocessing (EMDR) protocol in conjunction with hypnosis for the treatment of depersonalization disorder. Depersonalization Disorder has been differentiated from post-traumatic stress disorders and has recently been conceptualized as a subtype of panic disorder (Baker et al., 2003; David, Phillips, Medford, & Sierra, 2004; Segui et. al., 2000). During ECEM, while remaining in a hypnotic state, clients self-generated six to seven trials of eye movements to reduce anticipatory anxiety associated with depersonalization disorder. Eye movements were also used to process triggers that elicited breath holding, often followed by episodes of depersonalization. Hypnotic suggestions were used to reverse core symptoms of depersonalization, subjectively described as "feeling unreal" (Simeon et al., 1997).

Harriet EH

2009-10-01

344

ECEM (Eye Closure, Eye Movements): application to depersonalization disorder.  

Science.gov (United States)

Eye Closure, Eye Movements (ECEM) is a hypnotically-based approach to treatment that incorporates eye movements adapted from the Eye Movement Desensitization and Reprocessing (EMDR) protocol in conjunction with hypnosis for the treatment of depersonalization disorder. Depersonalization Disorder has been differentiated from post-traumatic stress disorders and has recently been conceptualized as a subtype of panic disorder (Baker et al., 2003; David, Phillips, Medford, & Sierra, 2004; Segui et. al., 2000). During ECEM, while remaining in a hypnotic state, clients self-generated six to seven trials of eye movements to reduce anticipatory anxiety associated with depersonalization disorder. Eye movements were also used to process triggers that elicited breath holding, often followed by episodes of depersonalization. Hypnotic suggestions were used to reverse core symptoms of depersonalization, subjectively described as "feeling unreal" (Simeon et al., 1997). PMID:19862896

Harriet, E Hollander

2009-10-01

345

Incidence of eye injuries and eye diseases in miners  

Energy Technology Data Exchange (ETDEWEB)

Analyzes types and causes of eye injuries and eye diseases among Donbass coal miners, who have a higher incidence (29.8% of the total) of these than employees in other industries. The mines from which the data were drawn were categorized in terms of seam thickness, dip angle, depth, water content and type of coal. Dust related eye injuries were 6 times more common in thin steep seams and 8 times more common in wet seams than mechanical injuries to the eye. Mathematical models and multiple regression analysis were used to assess the data. Styes tended to be caused by harder coal, where physical exertion led to overheating. Conjunctivitis was related to the frequency with which the eye was exposed to dirt as well as to coal hardness. Both these diseases were also related to the length of employment. Types of eye protection for various jobs performed in underground mines are recommended.

Matyashina, O.M.; Sukhina, L.A.; Malova, L.M.; Zorina, M.B.; Sukhina, I.V.; Krekhova, E.F.; Itkin, M.Z.; Kuida, L.V.; Tsykin, S.I.

1989-01-01

346

A free geometry model-independent neural eye-gaze tracking system  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Eye Gaze Tracking Systems (EGTSs) estimate the Point Of Gaze (POG) of a user. In diagnostic applications EGTSs are used to study oculomotor characteristics and abnormalities, whereas in interactive applications EGTSs are proposed as input devices for human computer interfaces (HCI), e.g. to move a cursor on the screen when mouse control is not possible, such as in the case of assistive devices for people suffering from locked-in syndrome. If the user’s head remains still and the cornea rotates around its fixed centre, the pupil follows the eye in the images captured from one or more cameras, whereas the outer corneal reflection generated by an IR light source, i.e. glint, can be assumed as a fixed reference point. According to the so-called pupil centre corneal reflection method (PCCR), the POG can be thus estimated from the pupil-glint vector. Methods A new model-independent EGTS based on the PCCR is proposed. The mapping function based on artificial neural networks allows to avoid any specific model assumption and approximation either for the user’s eye physiology or for the system initial setup admitting a free geometry positioning for the user and the system components. The robustness of the proposed EGTS is proven by assessing its accuracy when tested on real data coming from: i) different healthy users; ii) different geometric settings of the camera and the light sources; iii) different protocols based on the observation of points on a calibration grid and halfway points of a test grid. Results The achieved accuracy is approximately 0.49°, 0.41°, and 0.62° for respectively the horizontal, vertical and radial error of the POG. Conclusions The results prove the validity of the proposed approach as the proposed system performs better than EGTSs designed for HCI which, even if equipped with superior hardware, show accuracy values in the range 0.6°-1°.

Gneo Massimo; Schmid Maurizio; Conforto Silvia; D’Alessio Tommaso

2012-01-01

347

Influence of corneal cross-linking for keratoconus on several objective parameters of dry eye.  

UK PubMed Central (United Kingdom)

PURPOSE: To evaluate the potential influence of corneal cross-linking (CXL) with ultraviolet-A light and riboflavin in keratoconic eyes on several objective parameters of dry eye syndrome. METHODS: This prospective single center study included 30 consecutive eyes of 16 patients that underwent CXL with riboflavin and ultraviolet-A treatment (epithelial removal, 30 minutes soaking with riboflavin, 30 minutes of illumination with 365 nm, 3 mW/cm(2), 5 cm distance). Several dry eye syndrome parameters were evaluated preoperatively and 3 and 6 months after the procedure: intra-individual comparison of fluorescein and Rose bengal staining, height of tear film meniscus, and tear film break-up time. RESULTS: Pathologic staining (more than 10 point-shaped areas or diffuse staining) with fluorescein was evident before CXL in 1 eye, 3 months after CXL in 1 eye, and 6 months after CXL in 1 eye. Rose bengal staining 3 and 6 months postoperatively was comparable to preoperative staining. Tear film height was reduced in 2 eyes before CXL and in 4 eyes 3 months postoperatively, and was normal in all eyes after 6 months. The number of eyes with reduced tear film break-up time was not significantly changed. CONCLUSIONS: CXL had no significant impact on several parameters of dry eye syndrome 3 and 6 months postoperatively.

Taneri S; Oehler S; Asimellis G; Kanellopoulos AJ

2013-09-01

348

Effective corneal patch of an astigmatic heterocentric eye.  

UK PubMed Central (United Kingdom)

BACKGROUND: The pupil admits to the back of the eye only some of the light arriving from a point in space. As a result only a portion of the cornea is involved when an eye views the point; it is the effective corneal patch for that point. The location, size and shape of the patch are of interest for corneal refractive surgery inter alia. Previous studies have used geometrical optics and a simple model eye (a naked eye with a spherical, single-surface, centred cornea and a concentric circular pupil). Even for the simplest situations geometrical optics provides only implicit formulae which give little insight into relationships and require numerical solution. PURPOSE: To show how linear optics leads to explicit formulae that estimate the geometry of the effective corneal patch in a very wide range of situations. The eye is not restricted to a single refracting surface; the surfaces may be astigmatic and decentred or tilted and the pupil may be decentred and elliptical. The eye may contain implants and it may be looking through a spectacle lens or other optical instrument which may also contain astigmatic and decentred surfaces. METHODS: Linear optics is used to provide general formulae for the geometry of the corneal patch. An appendix illustrates application to some particular cases. RESULTS: General formulae are obtained for the location and geometry of the effective corneal patch for object points that may be near or distant. Formulae are presented in particular for the special case of the naked eye and the case in which all surfaces are spherical and centred on a common axis. Numerical examples in the appendix allow comparison of results obtained via geometrical and linear optics. CONCLUSIONS: In using linear optics one sacrifices some accuracy at increasing angles away from the longitudinal axis but there is considerable gain in the complexity and range of problems that can be tackled, and the explicit formula one obtains clearly exhibit relationships among parameters of clinical relevance.

Harris WF

2011-01-01

349

A push-pull treatment for strengthening the 'lazy eye' in amblyopia.  

Science.gov (United States)

Almost all individuals exhibit sensory eye dominance, one neural basis of which is unequal interocular inhibition. Sensory eye dominance can impair binocular functions that depend on both excitatory and inhibitory mechanisms. We developed a 'push-pull' perceptual learning protocol that simultaneously affects the excitatory and inhibitory networks to reduce sensory eye dominance and improve stereopsis in adults with otherwise normal vision. The push-pull protocol provides a promising clinical paradigm for treating the extreme sensory eye dominance in amblyopia ('lazy eye'). The prevailing standard of care does not directly treat sensory eye dominance; instead, selected excitatory functions in the amblyopic eye are stimulated while the strong eye is patched, on the assumption that recovery of the weak eye's excitatory functions rebalances the eyes. Patching the strong eye does not directly address interocular inhibition; in contrast, the push-pull protocol by design excites the weak eye, while completely inhibiting the strong eye's perception to recalibrate the interocular balance of excitatory and inhibitory interactions. Here, we show that three adult amblyopes who trained on the push-pull protocol gained longstanding improvements in interocular balance and stereopsis. Our findings provide a proof-of-concept and evidence that push-pull learning leads to long-term plasticity. PMID:23618663

Ooi, Teng Leng; Su, Yong R; Natale, Danielle M; He, Zijiang J

2013-04-22

350

A push-pull treatment for strengthening the 'lazy eye' in amblyopia.  

UK PubMed Central (United Kingdom)

Almost all individuals exhibit sensory eye dominance, one neural basis of which is unequal interocular inhibition. Sensory eye dominance can impair binocular functions that depend on both excitatory and inhibitory mechanisms. We developed a 'push-pull' perceptual learning protocol that simultaneously affects the excitatory and inhibitory networks to reduce sensory eye dominance and improve stereopsis in adults with otherwise normal vision. The push-pull protocol provides a promising clinical paradigm for treating the extreme sensory eye dominance in amblyopia ('lazy eye'). The prevailing standard of care does not directly treat sensory eye dominance; instead, selected excitatory functions in the amblyopic eye are stimulated while the strong eye is patched, on the assumption that recovery of the weak eye's excitatory functions rebalances the eyes. Patching the strong eye does not directly address interocular inhibition; in contrast, the push-pull protocol by design excites the weak eye, while completely inhibiting the strong eye's perception to recalibrate the interocular balance of excitatory and inhibitory interactions. Here, we show that three adult amblyopes who trained on the push-pull protocol gained longstanding improvements in interocular balance and stereopsis. Our findings provide a proof-of-concept and evidence that push-pull learning leads to long-term plasticity.

Ooi TL; Su YR; Natale DM; He ZJ

2013-04-01

351

Hypertension and the eye.  

UK PubMed Central (United Kingdom)

In addition to being the chief cause of death in developed countries, systemic hypertension is also a leading cause of visual impairment. The eye is an end arteriolar system and is therefore susceptible to changes in blood pressure. It is also the only place where blood vessels can be clearly viewed by noninvasive techniques. This paper reviews current research into premalignant and malignant retinal signs of systemic hypertension. Previous methods of classifying retinal hypertensive signs are identified, along with more recent image analysis techniques. The need for observing the retinal vasculature as well as measuring blood pressure for monitoring systemic hypertensive patients is discussed in relation to current research.

Wolffsohn JS; Hurcomb PG

2002-12-01

352

Through Einstein's Eyes  

CERN Multimedia

We have developed a relativistically-accurate computer graphics code and have used it to produce photo-realistic images and videos of scenes where special relativistic effects dominate, either in astrophysical contexts or in imaginary worlds where the speed of light is only a few metres per second. The videos have been integrated into our under-graduate teaching programme for several years. Recently we took the next step, encouraging undergraduate students to use the code to explore relativity, develop their own videos, and eventually package them together into Through Einstein's Eyes, a multimedia CD.

Searle, A C; Altin, P A; Bennet, F H; Hush, M R; Searle, Antony C.; Savage, Craig M.; Altin, Paul A.; Bennet, Francis H.; Hush, Michael R.

2005-01-01

353

BIONIC EYE LENS  

UK PubMed Central (United Kingdom)

The present invention relates generally to the restoration or improvement of the quality of human vision and, more particularly to a self-adapting system and method for achieving automatic sharp vision by the human eye of objects for instance at distances between 25 cm and more than 10 meters away. The invention can be situated in at least four technological domains: 1. ophthalmology, in particular the implantation of intraocular lenses. 2. Non- contact biometric signal recording and processing. 3. Electro-optic control of refractive lens power. 4. Wireless energy transfer.

BLANCKAERT JOHAN; GLORIEUX CHRIST; PUERS ROBERT

354

[Formation, development and changes of the eye acupunture region-dividing acupoint location program].  

Science.gov (United States)

Eye acupuncture, a micro-needling therapy, has been widely applied in clinical treatment for over 30 years. Its theoretic system, especially, the eye acupuncture region-dividing point location program has been revised for 2 times, and the third program with reasonability of acupoint distribution, strictness of angle of acupoint region is easily accepted by clinical workers. In the paper, the theoretical basis of professor Peng Jingshan's inspection of the eye for recognition of diseases, diagnosis of diseases and eye acupuncture therapy were explained, and the information, development and change of the eye acupuncture region-dividing acupoint location program were analyzed and the history of development of eye acupuncture were introduced so as to direct clinical application of eye acupuncture. PMID:16309109

Che, Jian; Tian, Wei-zhu

2005-04-01

355

[Formation, development and changes of the eye acupunture region-dividing acupoint location program].  

UK PubMed Central (United Kingdom)

Eye acupuncture, a micro-needling therapy, has been widely applied in clinical treatment for over 30 years. Its theoretic system, especially, the eye acupuncture region-dividing point location program has been revised for 2 times, and the third program with reasonability of acupoint distribution, strictness of angle of acupoint region is easily accepted by clinical workers. In the paper, the theoretical basis of professor Peng Jingshan's inspection of the eye for recognition of diseases, diagnosis of diseases and eye acupuncture therapy were explained, and the information, development and change of the eye acupuncture region-dividing acupoint location program were analyzed and the history of development of eye acupuncture were introduced so as to direct clinical application of eye acupuncture.

Che J; Tian WZ

2005-04-01

356

Assessing and managing eye injuries  

Directory of Open Access Journals (Sweden)

Full Text Available njuries to the eye are common. Many are minor but, if not treated quickly and appropriately, can lead to sight-threatening complications. Other injuries are severe, and even with expert management sight can be lost. Prevention of blindness from eye injuries requires: * injury prevention (health promotion including advocacy) * early presentation by the patient (health promotion and health worker training) * accurate assessment (good primary eye care and first aid) * prompt referral of serious injuries requiring specialist management.

Karin Lecuona

2005-01-01

357

Ultraviolet radiation: the eye  

International Nuclear Information System (INIS)

Under most conditions, the eye is well adapted to protect itself against ultraviolet radiation encountered in the outdoor environment as a result of the exposure geometry of the sun. Only when snow is on the ground does one experience acute effects of UV sunlight exposure (i.e. snow blindness, or photokeratitis). With regard to artificial sources, there are many occasions where one views bright light sources such as tungsten-halogen lamps, arc lamps and welding arcs. Such viewing is normally only momentary because of the aversion response to bright light and due to discomfort glare. However, such an aversion does not take place for germicidal lamps and other UV lamps which do not contain a strong visible component in their spectrum. The adverse effects from viewing such sources has been studied for decades and during the last two decades guidelines for limiting exposure to protect the eye have been developed. The guidelines were fostered to a large extent by the growing use of lasers and the quickly recognized hazard posed by viewing laser sources. (author).

1996-01-01

358

Silicone versus collagen plugs for treating dry eye: results of a prospective randomized trial including lacrimal scintigraphy.  

UK PubMed Central (United Kingdom)

PURPOSE: To compare the short-term efficacy of collagen and silicone plugs for treating dry eye using quantitative lacrimal scintigraphy. DESIGN: Prospective randomized clinical trial. METHODS: In this institutional study, 24 dry eye patients were evaluated in two groups: group I (n = 22 eyes) received collagen plugs and group II (n = 26 eyes) received silicone plugs. Comparisons were made with normal control subjects (n = 22 eyes). Data for the Schirmer I test, tear break-up time, and ocular surface staining with rose bengal dye were recorded before and after punctal occlusion. Lacrimal scintigraphy was performed at each time point, and the time to half maximum activity on the ocular surface (T(1/2)), and the percentage retention of activity on the ocular surface at the end of the dynamic study (RI) were recorded. RESULTS: In both patient groups, Schirmer I results, tear break-up times, and rose bengal staining scores improved significantly after plug insertion. Mean T(1/2) values and RI values increased significantly in both groups (P < .0001 for both). The differences for these values between groups I and II was statistically insignificant (P > .05). CONCLUSIONS: Collagen and silicone plugs both resulted in significant increases in aqueous tear volume, half-life of nuclear material on the ocular surface, and percentage of nuclear material retention. The groups' post-insertion values for all parameters were similar. These results suggest that these two plug types have similar efficacy as treatments for dry eye in the short term. Further studies evaluating long-term results are required.

Altan-Yaycioglu R; Gencoglu EA; Akova YA; Dursun D; Cengiz F; Akman A

2005-07-01

359

Are 3-D Movies Bad for Your Eyes?  

Medline Plus

Full Text Available ... Movies Bad for Your Eyes? Tweet Eye Health Lifestyle Topics Preventing Eye Injuries Healthy Eyes During Pregnancy ... Eyesight Risks for Smokers Veterans & Eye Health More Lifestyle Topics > EyeSmart Tips No Smoking Smoking increases the ...

360

A bionic eye actuated by ionic polymer-metal composite (IPMC) artificial muscle  

Science.gov (United States)

This research was conducted with the aim of developing an energy-efficient, noiseless, movable bionic eye for use in bionic toys. This novel bionic eye is actuated by an ionic polymer-metal composite actuator. The overall size of the eye was 39 mm in length, 45 mm in width, and 45 mm in thickness. The experimental results revealed such a bionic eye design is feasible. This type of bionic eye is appropriate for use in toys and robots to increase their visual impact.

Yu, Min; Li, Yuxiu; He, Qingsong; Song, Linlin; Dai, Zhendong

2011-03-01

 
 
 
 
361

[Fusional vergence hysteresis and sensorimotor connection of the two eyes  

UK PubMed Central (United Kingdom)

Three experiments were conducted to replicate and extend Helmholtz's observation indicating vergence hysteresis. The two stimuli were presented dichoptically to the eyes in the mirror stereoscope and moved temporalward or nasalward. Helmholtz's finding was confirmed in Experiment 1, in which the critical separations were measured for the stimuli divergently moving temporalward when fusion of their images was abruptly broken (breakaway point) and when fusion was re-established (refusion point) for the stimuli moving nasalward. In Experiment 2, in which only the stimulus for one eye moved temporalward while the stimulus for the other eye was stationary, the breakaway point of the moving stimulus was found to be linearly dependent on the position of the stationary stimulus. Experiment 3 showed that, in the asymmetric divergent tracking as in Experiment 2, the change of the perceived visual direction of the fused image was smaller than the angular magnitude of the movement of the tracking eye. These results were discussed as evidence indicating the sensory and motor connection of the two eyes.

Nakamizo S; Kondo M

1986-10-01

362

Trilobite eyes and the optics of Des Cartes and Huygens.  

UK PubMed Central (United Kingdom)

The thick lenses in the aggregate eyes of a group of trilobites were double structures designed to eliminate spherical aberration. The shape of the optically correcting interface is in accord with constructions by Des Cartes and Huygens and is dictated by a fundamental law of physics. Trilobites may have evolved such sophisticated eye-lenses to maximise optic neurone response in a dimly lit environment.

Clarkson EN; Levi-Setti R

1975-04-01

363

Trilobite eyes and the optics of Des Cartes and Huygens.  

Science.gov (United States)

The thick lenses in the aggregate eyes of a group of trilobites were double structures designed to eliminate spherical aberration. The shape of the optically correcting interface is in accord with constructions by Des Cartes and Huygens and is dictated by a fundamental law of physics. Trilobites may have evolved such sophisticated eye-lenses to maximise optic neurone response in a dimly lit environment. PMID:1091864

Clarkson, E N; Levi-Setti, R

1975-04-24

364

Design of the control system for fixed-point keeping in FPSO (Floating Production Storage and Offloading); FPSO no teiten hoji no tame no seigyokei no sekkei ni tsuite  

Energy Technology Data Exchange (ETDEWEB)

The control system for keeping the fixed-point of ships against disturbance was designed by applying an ILQ (Inverse Linear Quadratic) control (possible to specify the response of controlled systems with time constant) theory, to study the effect of different time constants as design parameter on a fixed-point keeping performance. It was assumed that the controlled ship is equipped with two bow thrusters and one stern thruster of 30ton in output to generate a control force. For fixed-point keeping control, the state equation was derived to slave the controlled system to a target input. The ILQ design method uses the result of the inverse problem of optimum regulators. For designing control systems by using the ILQ control theory, the smallest time constant should be selected according to the most severe disturbance condition considering the response performance of controllers, to achieve fixed-point keeping of ships. In fixed-point keeping, it is also essential to put the initial position as close as possible to the target point. 2 refs., 6 figs., 2 tabs.

Kijima, K.; Murata, W.; Furukawa, Y. [Kyushu University, Fukuoka (Japan). Faculty of Engineering

1997-10-01

365

Collaborative eye tracking: a potential training tool in laparoscopic surgery.  

UK PubMed Central (United Kingdom)

BACKGROUND: Eye-tracking technology has been shown to improve trainee performance in the aircraft industry, radiology, and surgery. The ability to track the point-of-regard of a supervisor and reflect this onto a subjects' laparoscopic screen to aid instruction of a simulated task is attractive, in particular when considering the multilingual make up of modern surgical teams and the development of collaborative surgical techniques. We tried to develop a bespoke interface to project a supervisors' point-of-regard onto a subjects' laparoscopic screen and to investigate whether using the supervisor's eye-gaze could be used as a tool to aid the identification of a target during a surgical-simulated task. METHODS: We developed software to project a supervisors' point-of-regard onto a subjects' screen whilst undertaking surgically related laparoscopic tasks. Twenty-eight subjects with varying levels of operative experience and proficiency in English undertook a series of surgically minded laparoscopic tasks. Subjects were instructed with verbal queues (V), a cursor reflecting supervisor's eye-gaze (E), or both (VE). Performance metrics included time to complete tasks, eye-gaze latency, and number of errors. RESULTS: Completion times and number of errors were significantly reduced when eye-gaze instruction was employed (VE, E). In addition, the time taken for the subject to correctly focus on the target (latency) was significantly reduced. CONCLUSIONS: We have successfully demonstrated the effectiveness of a novel framework to enable a supervisor eye-gaze to be projected onto a trainee's laparoscopic screen. Furthermore, we have shown that utilizing eye-tracking technology to provide visual instruction improves completion times and reduces errors in a simulated environment. Although this technology requires significant development, the potential applications are wide-ranging.

Chetwood AS; Kwok KW; Sun LW; Mylonas GP; Clark J; Darzi A; Yang GZ

2012-07-01

366

Perfect drain for the Maxwell fish eye lens  

Energy Technology Data Exchange (ETDEWEB)

Perfect imaging of electromagnetic waves using the Maxwell fish eye (MFE) requires a new concept: a point called the perfect drain that we shall call the perfect point drain. From the mathematical point of view, a perfect point drain is just like an ideal point source, except that it drains power from the electromagnetic field instead of generating it. We introduce here the perfect drain for the MFE as a dissipative region of non-zero size that completely drains the power from the point source. To accomplish this goal, the region must have a precise complex permittivity that depends on its size as well as on the frequency. The perfect point drain is obtained when the diameter of the perfect drain tends to zero. This interpretation of the perfect point drain is connected well with common concepts of electromagnetic theory, opening up both modeling in computer simulations and experimental verification of setups containing a perfect point drain.

Gonzalez, Juan C; BenItez, Pablo; Minano, Juan C, E-mail: jcgonzalez@cedint.upm.es [Universidad Politecnca de Madrid, Cedint Campus de Montegancedo, 28223 Madrid (Spain)

2011-02-15

367

Perfect drain for the Maxwell fish eye lens  

International Nuclear Information System (INIS)

Perfect imaging of electromagnetic waves using the Maxwell fish eye (MFE) requires a new concept: a point called the perfect drain that we shall call the perfect point drain. From the mathematical point of view, a perfect point drain is just like an ideal point source, except that it drains power from the electromagnetic field instead of generating it. We introduce here the perfect drain for the MFE as a dissipative region of non-zero size that completely drains the power from the point source. To accomplish this goal, the region must have a precise complex permittivity that depends on its size as well as on the frequency. The perfect point drain is obtained when the diameter of the perfect drain tends to zero. This interpretation of the perfect point drain is connected well with common concepts of electromagnetic theory, opening up both modeling in computer simulations and experimental verification of setups containing a perfect point drain.

2011-01-01

368

Eye movement and online bisection task in unilateral patients with neglect: a new look to the 'gradient effect'.  

UK PubMed Central (United Kingdom)

PRIMARY OBJECTIVE: The present study explored the behavioural and eye-movement measures in spatial unilateral neglect in response to a bisection task. RESEARCH DESIGN: Four right neglect patients were considered and compared with 11 control subjects during an online task (segment bisection). METHODS AND PROCEDURES: Eye-movements (fixation count and duration) and behavioural responses were monitored during an online bisection task, consisting of unfilled segments (two ending points) to be bisected by subjects. Segment length (six levels) and spatial dislocation (five levels) were modulated to explore a possible 'gradient effect'" (left-to-right) in neglect bias. Main outcomes and results: Consistent spatial biases were found for both bisection position and eye fixations as a function of segment length (from shorter to longer) and segment spatial dislocation (from right to left). However, only the more eccentric left-positions induced a greater rightward bias in patients, with increasing more right-side bisection and visual right-directed fixations. Also segment length produced significant differences between-groups for behavioural responses, with more right-side bisection for longer segment in patients, and eye movement behaviour, with increased fixation count and duration rightward oriented in response to longer segments. CONCLUSIONS: Although a left-to-right and longer-to-shorter 'continuous-gradient effect' was not supported by the results, an 'extreme left-gradient effect' was suggested and discussed.

Balconi M; Amenta S; Sozzi M; Cannatà AP; Pisani L

2013-01-01

369

Semi-automatic evaluation of intraocular lenses (IOL) using a mechanical eye model  

Science.gov (United States)

As cataracts are the most common reason for loss of vision with an age over 55, the implantation of intraocular intraocular lenses is one of the most common surgical interventions. The quality measurement and test instructions for the patients. Therefore more efforts are put into the individualization of IOL in order to achieve better imaging properties. Two examples of typical quality standards for IOL are the modulated transfer function (MTF) and the Strehl ratio which can be measured in vivo or also in mechanical eye models. A mechanical eye model in the scale 1:1 is presented. It has been designed to allow the measurement of the MTF and Strehl ratio and simultaneous evaluation of physiological imaging quality. The eye model allows the automatic analysis of the IOL especially focused on the tolerance for tilting and decentering. Cornea, iris aperture and IOL type are interchangeable, because all these parts are implemented by the use of separated holders. The IOL is mounted on a shift plate. Both are mounted on a tilt plate. This set-up guarantees an independent decentration and tilt of the IOL, both moved by electrical drives. This set-up allows a two-dimensional tolerance analysis of decentration and tilt effects. Different 100×100 point (decentration×tilt) analyzes for various iris apertures, needing only approximately 15 minutes, are presented.

Drauschke, A.; Rank, E.; Forjan, M.; Traxler, L.

2013-03-01

370

Gray Eye Traffic Surveillance  

Directory of Open Access Journals (Sweden)

Full Text Available Gray Eye Traffic Surveillance (GETS) is a system based on image processing technology and database processing for the purpose of Traffic Surveillance. This system is built specifically for India, where standard fonts and scripts for the number plates are rarely followed and corruption is a menace.This paper attempts to present a system to automate the entire process of traffic surveillance and curb corruption at the same time. A two way approach of developing a desktop and a web based mobile application is proposed. The desktop based application uses image processing technology to recognize the license number from image of vehicles captured by surveillance cameras and maintain a track log. The web based mobile application can be used by authorized traffic police to file complaints. The general public can log into this application to view their log and file complaints in case of any discrepancies. Different database schemas are used for various purpose like authentication, crime details, tracking system.

Ayesha Butalia #1, Durgesh Maru*2, Kuldeep Baheti*3, Avais Mohammad*4, Ankit Bagdiya*5

2011-01-01

371

Equipment for eye care  

Directory of Open Access Journals (Sweden)

Full Text Available In many low- and middle-income countries, it is often the people who are poor or with a disability - or both - who find it most challenging to access and pay for health care. When people do come to us for eye care, it is therefore vital that we provide quality services efficiently and effectively.To achieve this goal, we must ensure that our equipment is well maintained and that we have enough spare parts and consumables for it to function with minimum interruptions. To cope with the sometimes inevitable breakdowns, we also need systems that will respond quickly to carry out repairs and replace broken or worn-out parts.

Mason I.; Mathenge W.

2010-01-01

372

[Findings in retinal surgery of pseudophakic eyes  

UK PubMed Central (United Kingdom)

The author reports on experience gathered in retinal detachment surgery in 7 of his own cases with intraocular lens implants. The paper deals with pre-operative diagnosis, intraoperative management and xenon or argon laser coagulation. It is pointed out that the image quality of the intraocular lens implants needs to be improved for successful diagnosis at the periphery of the fundus. After 7 episcleral buckling procedures (Custodi's technique) and 2 encircling procedures (Schepens) reattachment was accomplished in all 7 cases. The detachment surgery in these cases was more difficult than in eyes without intraocular lens implants, not least as a result of the poor image quality of the artificial lenses.

Damaske E

1984-01-01

373

Improving eye care for Indigenous Australians in primary health care settings.  

UK PubMed Central (United Kingdom)

BACKGROUND: This paper aims to assess the barriers and solutions to the delivery of eye care in primary care settings and solutions to improve the use of comprehensive eye care among Indigenous Australians. DESIGN, SETTING, PARTICIPANTS: Qualitative, mixed method study participants include Aboriginal community members, and health and eye care providers in urban, rural and remote settings. MAIN OUTCOME MEASURES: Present evidence for health care providers to better understand and address some of the barriers that limit access to eye care in primary care settings. RESULTS: Patient perspectives on barriers to accessing eye care and reasons they choose to seek care or not are presented. Health system barriers identified by health and eye care providers are also presented. Additionally, key enablers for improving access to eye care through primary care services are identified. CONCLUSION: Primary health care services have an important role in Indigenous eye health. There is a critical role for primary care in the coordination of the patient journey and cooperating with other services to improve access to comprehensive eye care. Through improved provision of primary eye care, monitoring of Indigenous eye health indicators and supporting patients to access eye care, it is possible to close the gap for vision.

Boudville AI; Anjou MD; Taylor HR

2013-04-01

374

Eye protection during mastoid surgery.  

UK PubMed Central (United Kingdom)

A questionnaire was sent to all Full Members of the British Association of Otolaryngologists to ascertain whether and what type of eye protection surgeons and theatre nurses wear during mastoid surgery. Despite Department of Health recommendations only 58 per cent of surgeons and 19 per cent of theatre nurses routinely wear any form of eye protection.

Mitchell TE; Courteney-Harris RG; Innes AJ

1995-08-01

375

Eye trauma in the workplace  

Energy Technology Data Exchange (ETDEWEB)

A baseline visual acuity should be on record for medical and legal purposes. Identifying an eye injury and referring the person for appropriate treatment can save vision. Immediate eye irrigation in the case of chemical burns can substantially decrease the possibility of permanent vision damage.

Boyd-Monk, H.

1990-10-01

376

Community Eye Health MSc dissertations  

Directory of Open Access Journals (Sweden)

Full Text Available All MSc students at the International Centre for Eye Health (ICEH) carry out a dissertation project as part of the Community Eye Health MSc course. Most of the dissertations are excellent pieces of original and valuable research work, sometimes the first of their kind in their authors’ country or region.

Daksha Patel

2007-01-01

377

Pax genes and eye organogenesis.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Pax6 is a highly conserved gene that controls eye development in all species where it has been tested. In spite of this common 'master control regulator', the eyes of different animals are morphologically very different and it is believed that they have evolved independently multiple times through e...

Pichaud, F; Desplan, C

378

Characterizing dual wavelength polarimetry through the eye for monitoring glucose.  

UK PubMed Central (United Kingdom)

Diabetes is an insidious disease that afflicts millions of people worldwide and typically requires the person with the disease to monitor their blood sugar level via finger or forearm sticks multiple times daily. Therefore, the ability to noninvasively measure glucose would be a significant advancement for the diabetic community. The use of optically polarized light passed through the anterior chamber of the eye is one proposed noninvasive approach for glucose monitoring. However, the birefringence of the cornea and the difficulty in coupling the light across the eye have been major drawbacks toward realizing this approach. A dual wavelength optical polarimetric approach has been proposed as a means to potentially overcome the birefringence noise but has never been fully characterized. Therefore, in this paper an optical model has been developed along with experiments performed on New Zealand White rabbit eyes for characterizing the light path and corneal birefringence at two different wavelengths as they are passed through the anterior chamber of the eye. The results show that, without index matching, it is possible to couple the light in and out of the eye but only across a very limited range otherwise the light does not come back out of the eye. It was also shown that there is potential to use a dual wavelength approach to accommodate the birefringence noise of the cornea in the presence of eye motion. These results will be used to help guide the final design of the polarimetric system for use in noninvasive monitoring of glucose in vivo.

Malik BH; Coté GL

2010-01-01

379

Designing and evaluation of the teaching quality assessment form from the point of view of the Lorestan University of Medical Sciences students - 2010.  

UK PubMed Central (United Kingdom)

INTRODUCTION: Education is basically one of the Universities' and faculties' leading missions and duties; its promoted quality will also lead to an elevated educational quality in the University. Teacher assessment can be mentioned as essential for the success of the quality promotion process. This article deals with the designing and evaluation of a teaching quality evaluation form for teachers, from the Lorestan University of Medical Science students' point of view. METHODS: A two-stage, cross-sectional study was conducted on 290 Lorestan University of Medical Science students. First, evaluation priorities were extracted using the Delphi technique in the fifth section, including teaching skills, communication skills, principles of training, and skills assessment. In the second stage, as the priority and importance of each item was evaluated in the fourth Lickert option, sampling was done in few stages. The study instrument was a questionnaire, which included six areas. The first part of the questionnaire was made up of the demographic characteristics and the second part included five evaluation areas that were obtained from the student. The collected data were analyzed using statistical software SPSS-16 and chi-square test, Kruskal-Wallis test. RESULTS: In the areas of teaching skills, mastery of the course, individual characteristics, self-confidence, communication skills, intimate relationship with students, educational principles, rules respecting the beginning and end time of class, skill assessment, and an accurate comprehensive examination at the end of the semester by the students, were chosen as the most important factors. There were significant differences in the majority of expressed comments between the genders and academic status (P < 0.05). CONCLUSION: Students can properly diagnose the essential factors in teachers' evaluation, but in item prioritizing they may be partly affected by some factors such as gender, academic status, semester, and academic course.

Kamran A; Zibaei M; Mirkaimi K; Shahnazi H

2012-01-01

380

Flood-Related Eye Care Precautions  

Science.gov (United States)

... for Your Vision > Flood-Related Eye Care Precautions Flood-Related Eye Care Precautions As flooding continues to ... for contact lens wearers to avoid exposure to flood-related eye infections and complications Avoid contact with ...

 
 
 
 
381

An Appearance based Method for Eye Gaze Tracking  

Directory of Open Access Journals (Sweden)

Full Text Available Problem statement: Gaze estimation systems compute the direction of eye gaze based on observed eye movements. The need for gaze-contingent applications is the basis of the current research work. The gaze pointing systems is a substitute for the existing input devices. Approach: The gaze tracking methods are either feature based or appearance based. In this study, an appearance based approach for gaze tracking is proposed based on Run Length Coding (RLC). The experiment was conducted considering transitional changes and the class-intervals in iris pixels. The image acquisition begins from the center of the screen in anticlockwise direction. The center of the screen was the pivot point. Results: Using RLC, the recognition rate of 95% was achieved. The image analysis in different directions determines the gaze point. The directions was determined with respect to the pivot point. Conclusion: The proposed system provides a robust, less computational gaze tracking method using web camera.

S. V. Sheela; P. A. Vijaya

2011-01-01

382

Tipping Point  

Medline Plus

Full Text Available ... 10) February 2010 (4) January 2010 (8) December 2009 (4) November 2009 (4) October 2009 (8) September 2009 (2) « Hello and Welcome! Home The Tipping Point By CPSC Blogger on September 22, 2009 Watch the video in Adobe Flash format. (Read ...

383

Eye health and safety among Latino farmworkers.  

Science.gov (United States)

Farmworkers face a variety of risk factors for eye injuries. Measures of eye protection use and of eye safety knowledge and beliefs are based on a survey of 300 Latino farmworkers in North Carolina. Few farmworkers report using eye protection (8.3%); most (92.3%) report that employers do not provide eye protection. Approximately 70% report that they are not trained in preventing eye injuries; 81% believe that their chances of getting an eye injury are low. Many farmworkers choose to take risks in order to save time. Interventions are needed that target farmworker knowledge and beliefs about eye safety. PMID:21462026

Verma, Amit; Schulz, Mark R; Quandt, Sara A; Robinson, Erin N; Grzywacz, Joseph G; Chen, Haiying; Arcury, Thomas A

2011-04-01

384

Case study: improving the management of eye care programmes  

Directory of Open Access Journals (Sweden)

Full Text Available Nigeria is a federation of 36 administrative States, which each have a mandate to deliver health care to their population. Sightsavers International has been supporting four State ministries of health (Cross River, Kaduna, Kwara, and Sokoto) in implementing programmes designed to provide comprehensive eye care services.Previously, eye care had been limited to services in big hospitals in the largest cities, which were inaccessible to the general population.These new eye care programmes have been very successful. The Kwara eye care programme (KWECP), for example, has increased the cataract surgical rate from 196 cataract operations per million per year in 2003 to 932 in 2007.This article describes what we have learnt from our experience in managing these programmes and hopefully will provide you with suggestions to improve management.

Kolawole Olumide Ogundimu

2008-01-01

385

Managing your eye unit's supplies  

Directory of Open Access Journals (Sweden)

Full Text Available In order to deliver eye care, many resources have to be in place at the right time: your patients, your staff, your facilities, your equipment, and your supplies. In this article, we focus on how you can manage your supplies to ensure that your eye service runs smoothly. These supplies, or consumables, include every little thing needed in the course of your daily work: IOLs, medicines, gloves, forms used for patient care, housekeeping supplies, and equipment spares. If any of these items become unavailable, your eye centre will be unable to provide the same high quality of services, and you may even have to turn patients away.

RD Thulsiraj

2011-01-01

386

The human eye proteome project.  

UK PubMed Central (United Kingdom)

The human eye proteome is the latest addition to the HUPO Human Proteome Project (HPP). Semba et al. (The Human Eye Proteome Project: Perspectives on an emerging proteome. Proteomics 2013, 13, 2500-2511) establish a provisional baseline for the proteomes of the many anatomical compartments of the eye, based on literature review. As part of the Biology and Disease-driven HPP, they and their colleagues will generate fresh data and meet the stringent guidelines for protein identification and characterization as established by the HPP.

Omenn GS

2013-08-01

387

Eye hazards of environmental lighting  

International Nuclear Information System (INIS)

In the 1950s and 1960s it became clear that the nuclear fireball and lasers could cause thermal retinal injury; at that time, the reference of Verhoeff, Bell, and Walker was often cited to argue that solar eclipse blindness (solar retinitis) was also a thermal retinal injury. It was not until 1975 that it became clear that a photochemical mechanism for retinal injury was possible for lengthy exposures in the primate or human eye. The potential for photochemical injury of the retina suggests the possibilities of delayed effects, and a considerable research effort has been underway over the last decade to study the implications for retinal degradation by intense light. The lens can undergo changes leading to cataract following exposure to ultraviolet radiation (UVR). Although acute UVR injury of the cornea (photokeratitis) has been recognized since the early part of this century, the link between UVR and cataract has long been a point of controversy. Today, most scientists studying optical radiation hazards conclude that UVR is a causative factor in some forms of cataract. Differences of opinion arise as to the exact wavelength range that is effective (i.e., UVA: 315-400 nm and/or UVB: 280-315 nm). Pitts and colleagues have shown that only a very narrow band of UVR wavelengths between 295 and 320 nm appear to be effective in causing acute cataract in experimental animals. Epidemiological studies of cataract incidence appear to show that UVR is a causative factor, despite the fact that at least one investigator had concluded that high ambient temperature was a more likely causative factor than UVR. This author has recently completed a study of UVR exposures in the outdoor environment that would support the epidemiologic studies of UVR induction of cataract.

1984-11-02

388

Symptoms, visual function, and mucin expression of eyes with tear film instability.  

UK PubMed Central (United Kingdom)

PURPOSE: We examined symptoms, tear stability, visual function, and conjunctival cytology in eyes with an unstable tear film (UTF), expressed as a short tear film breakup time without epithelial damage or low tear secretion, and compared the results with those from eyes with aqueous deficiency (AD) associated with epithelial damage, and healthy eyes. METHODS: We divided the patients with ocular discomfort into 2 groups according to the breakup time, Schirmer value, and epithelial staining score: UTF group (?5 seconds, >5 mm, and <3 points; 21 eyes of 21 patients) and AD group (?5 seconds, ?5 mm, and ?3 points; 21 eyes of 21 patients). We examined all patients and 17 healthy subjects for symptoms, tear functions, tear film stability by tear film lipid layer interferometry and tear film analysis system, and functional visual acuity. Conjunctival impression cytology was performed to investigate changes in goblet cell density, squamous metaplasia, and messenger RNA expression of MUC5AC and MUC16. RESULTS: The symptom scores, tear film analysis system index, and functional visual acuity testing were significantly worse in the UTF and AD groups compared with those in the control group (P < 0.05). The messenger RNA expression levels of MUC5AC and MUC16 were significantly lower in UTF and AD eyes compared with those in the control eyes (P < 0.0001). CONCLUSIONS: An UTF itself can cause dry eye symptoms and visual disturbance comparable with those of AD dry eyes.

Shimazaki-Den S; Dogru M; Higa K; Shimazaki J

2013-09-01

389

Point Lepreau  

International Nuclear Information System (INIS)

This brief pamphlet gives general information about the station. The Point Lepreau Nuclear Generating Station consists of a single CANDU 600 unit with a total net capacity of 630,000 kilowatts. This single reactor, the first nuclear installation in Atlantic Canada, is expected to supply about 20% of New Brunswick's electrical energy during the 1980's. The station is located on the Lepreau peninsula, overlooking the Bay of Fundy, 40 km southwest of Saint John on Route 790, off Highway 1. Construction of Point Lepreau began in May 1975 and was completed late in 1981. At the peak of construction activity in 1979, 3,300 workers were employed on the project. First power was produced in September 1982 and Lepreau began commercial operation early in 1983. Point Lepreau was built with provision for an additional 600 MW unit on the site and is essentially a duplicate of CANDU 600 reactors in Quebec, Argentina and Korea. Although started third, Lepreau was the first of these CANDU's in Canada and abroad to be licensed for operation, the first to achieve criticality (start-up), and the first to begin commercial operation. Lepreau is owned and operated by New Brunswick Power

390

B-EYE: The World Through the Eyes of a Honey Bee  

Science.gov (United States)

One of the great treats awaiting Scouts (or any others who learn to search the Web efficiently) is the large number of high quality science Websites put forth by Australian research institutions. B-EYE is yet another such wonderful site. Dr. Andrew Giger, a neuroscientist studying insect vision at the Centre for Visual Science (CVS) at Australian National University, put together this site so visitors could see the world "through the eyes of a honey bee." Although simplified to grayscale images (bees view colors differently than humans), the visual distortions (from human to bee) are fascinating and highly educational. The well-designed site takes the viewer through the specific elements of each visual distortion, offering descriptions, a gallery of pre-processed images, and several options for viewing. The most sophisticated option allows users to set parameters (distance to pattern, horizontal and vertical position, background intensity, etc.) to view a series of images through a human eye, a simulated projection, and eventually, a bee's eye.

Giger, Andrew.

1995-01-01

391

Evaluation of different projectiles in matched experimental eye impact simulations.  

UK PubMed Central (United Kingdom)

Eye trauma results in 30,000 cases of blindness each year in the United States and is the second leading cause of monocular visual impairment. Eye injury is caused by a wide variety of projectile impacts and loading scenarios with common sources of trauma being motor vehicle crashes, military operations, and sporting impacts. For the current study, 79 experimental eye impact tests in literature were computationally modeled to analyze global and localized responses of the eye to a variety of blunt projectile impacts. Simulations were run with eight different projectiles (airsoft pellets, baseball, air gun pellets commonly known as BBs, blunt impactor, paintball, aluminum, foam, and plastic rods) to characterize effects of the projectile size, mass, geometry, material properties, and velocity on eye response. This study presents a matched comparison of experimental test results and computational model outputs including stress, energy, and pressure used to evaluate risk of eye injury. In general, the computational results agreed with the experimental results. A receiver operating characteristic curve analysis was used to establish the stress and pressure thresholds that best discriminated for globe rupture in the matched experimental tests. Globe rupture is predicted by the computational simulations when the corneoscleral stress exceeds 17.21 MPa or the vitreous pressure exceeds 1.01 MPa. Peak stresses were located at the apex of the cornea, the limbus, or the equator depending on the type of projectile impacting the eye. A multivariate correlation analysis revealed that area-normalized kinetic energy was the best single predictor of peak stress and pressure. Additional incorporation of a relative size parameter that relates the projectile area to the area of the eye reduced stress response variability and may be of importance in eye injury prediction. The modeling efforts shed light on the injury response of the eye when subjected to a variety of blunt projectile impacts and further validate the eye model's ability to predict globe rupture. Results of this study are relevant to the design and regulation of safety systems and equipment to protect against eye injury.

Weaver AA; Kennedy EA; Duma SM; Stitzel JD

2011-03-01

392

INTRAVITREAL PHARMACOKINETICS AFTER POSTERIOR SUBTENON TRIAMCINOLONE ACETONIDE INJECTION IN VITRECTOMIZED RABBIT EYES.  

UK PubMed Central (United Kingdom)

PURPOSE:: To investigate the intraocular pharmacokinetics of triamcinolone acetonide (TA) injected into the posterior subtenon of vitrectomized rabbit eyes. METHODS:: Vitrectomy was performed on the right eyes of 35 rabbits. Triamcinolone acetonide (40 mg/mL) was injected into the posterior subtenon space of both eyes. Five rabbits each were killed at days 1, 3, 7, 14, 28, 56, and 84. Both eyes were enucleated. The vitreous was isolated, and TA concentration was measured. RESULTS:: In vitrectomized eyes, the intravitreal concentrations of TA were 1763, 822.9, 321.5, 113.3, 35.5, 14.4, and 6.7 ng/mL, respectively, at the time points indicated above; the concentrations in nonvitrectomized eyes were 397.8, 360.4, 154.4, 48.5, 30.7, 15.2, and 8.0 ng/mL, respectively. Triamcinolone acetonide concentrations were significantly higher in the vitrectomized eyes at days 1, 3, 7, and 14. The terminal half-life of intravitreal TA was 23.3 days in the vitrectomized eyes and 28.9 days in the nonvitrectomized eyes. CONCLUSION:: Intravitreal absorption and excretion of TA in the posterior subtenon space are increased after vitrectomy. Although the terminal half-life of TA was shorter, higher early concentration and similar effective duration were achieved in the vitrectomized eyes.

Park HJ; Lee JE; Kim SI; Pak KY; Oum BS; Lee JS; Jung JH; Lee JE

2013-09-01

393

Protocol for the combined immunosuppression & radiotherapy in thyroid eye disease (CIRTED) trial: A multi-centre, double-masked, factorial randomised controlled trial  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Medical management of thyroid eye disease remains controversial due to a paucity of high quality evidence on long-term treatment outcomes. Glucocorticoids are known to be effective initially but have significant side-effects with long-term use and recrudescence can occur on cessation. Current evidence is conflicting on the efficacy of radiotherapy and non-steroid systemic immunosuppression, and the majority of previous studies have been retrospective, uncontrolled, small or poorly designed. The Combined Immunosuppression and Radiotherapy in Thyroid Eye Disease (CIRTED) trial was designed to investigate the efficacy of radiotherapy and azathioprine in combination with a standard course of oral prednisolone in patients with active thyroid eye disease. Methods/design Patients with active thyroid eye disease will be randomised to receive (i) azathioprine or oral placebo and (ii) radiotherapy or sham-radiotherapy in this multi-centre, factorial randomised control trial. The primary outcome is improvement in disease severity (assessed using a composite binary measure) at 12 months and secondary end-points include quality of life scores and health economic measures. Discussion The CIRTED trial is the first study to evaluate the role of radiotherapy and azathioprine as part of a long-term, combination immunosuppressive treatment regime for Thyroid Eye Disease. It will provide evidence for the role of radiotherapy and prolonged immunosuppression in the management of this condition, as well as pilot data on their use in combination. We have paid particular attention in the trial design to establishing (a) robust placebo controls and masking protocols which are effective and safe for both radiotherapy and the systemic administration of an antiproliferative drug; (b) constructing effective inclusion and exclusion criteria to select for active disease; and (c) selecting pragmatic outcome measures. Trial registration Current controlled trials ISRCTN22471573

Rajendram Rathie; Lee Richard WJ; Potts Mike J; Rose Geoff E; Jain Rajni; Olver Jane M; Bremner Fion; Hurel Steven; Cook Anne; Gattamaneni Rao; Tomlinson Marjorie; Plowman Nicholas; Bunce Catey; Hollinghurst Sandra P; Kingston Laura; Jackson Sue; Dick Andrew D; Rumsey Nichola; Morris Olivia C; Dayan Colin M; Uddin Jimmy M

2008-01-01

394

Community Eye Health MSc dissertations  

Directory of Open Access Journals (Sweden)

Full Text Available The seven Exchange articles that follow are based on the dissertations of students at the International Centre for Eye Health, London School of Hygiene and Tropical Medicine, who graduated in 2008.

Osman L; Cockburn N; Fawad M; Razavi H; Abdull M; Mutombo TK; Leite C

2008-01-01

395

What is Diabetic Eye Disease?  

Medline Plus

Full Text Available ... diabetes and while most will not lose their vision if they receive treatment, their risk is 25 ... detach, resulting in partial or total loss of vision. Announcer: Diabetic retinopathy is not the only eye ...

396

Improved treatment planning for COMS eye plaques  

International Nuclear Information System (INIS)

Purpose: A recent reanalysis of the Collaborative Ocular Melanoma Study (COMS) medium tumor trial concluded that incorporating factors to account for anisotropy, line source approximation, the gold plaque, and attenuation in the Silastic seed carrier into the dose calculations resulted in a significant and consistent reduction of calculated doses to structures of interest within the eye. The authors concluded that future eye plaque dosimetry should be 'performed using the most up-to-date parameters available.' The reason these factors are important is attributable to the low energy 125I radiation (approximately 28 keV) that is primarily absorbed by the photoelectric process. Photoelectric absorption is quite dependent on the atomic composition of the absorbing material. Being 40% silicon by weight, the effective atomic number of Silastic is significantly greater than that of water. Although the AAPM TG43 brachytherapy formalism inherently addresses the issues of source anisotropy and geometry, its parameter that accounts for scatter and attenuation, the radial dose function g(r), assumes that the source is immersed in infinite homogeneous water. In this work, factors are proposed for 125I that correct for attenuation in the Silastic carrier and scatter deficits resulting from the gold plaque and nearby air. The implications of using 103Pd seeds in COMS plaques are also discussed. Methods and materials: An existing TG43-based ophthalmic plaque planning system was modified to incorporate additional scatter and attenuation correction factors that better account for the path length of primary radiation in the Silastic seed carrier and the distance between the dose calculation point and the eye-air interface. Results: Compared with homogeneous water, the dose-modifying effects of the Silastic and gold are greatest near the plaque surface and immediately adjacent to the plaque, while being least near the center of the eye. The calculated dose distribution surrounding a single 125I seed centered in a COMS 20 mm plaque was found to be consistent with previously published examples that used thermoluminescent dosimetry measurements and Monte Carlo methods. For fully loaded 12 and 20 mm plaques, calculated dose to critical ocular structures ranged from 16%-50% less than would have been reported using the standard COMS dose calculation protocol. Conclusions: Treatment planning for COMS eye plaques that accurately accounts for the presence of the gold, Silastic and extraocular air is both possible and practical.

2005-03-15

397

Perspectives on primary eye care  

Directory of Open Access Journals (Sweden)

Full Text Available We think of primary eye care (PEC), and any kind of primary health care (PHC), as a ‘frontline’ activity, providing care and identifying disease before it becomes a serious medical issue. However, as this course showed, even a cursory review of systems across the world reveals that there is no common understanding of what primary eye care means and there exists a wide variation both in its content and in the way in which it is delivered.

GVS Murthy; Usha Raman

2009-01-01

398

Fluorophotometry as a diagnostic tool for the evaluation of dry eye disease  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background Dry eye disease is a common debilitating ocular disease. Current diagnostic tests used in dry eye disease are often neither sensitive nor reproducible, making it difficult to accurately diagnose and determine end points for clinical trials, or evaluate the usefulness of different medications in the treatment of dry eye disease. The recently developed fluorophotometer can objectively detect changes in the corneal epithelium by quantitatively measuring its barrier function or permeability. The purpose of the study is to investigate the use of corneal fluorescein penetration measured by the fluorophotometer as a diagnostic tool in the evaluation of dry eye patients. Methods Dry eye patients (16 eyes), who presented with a chief complaint of ocular irritation corresponding with dry eye, low Schirmer's one test ( Results Ten minutes after fluorescein installition, patients with dry eye disease averaged a five-fold increase in corneal tissue fluorescein concentration (mean = 375.26 ± 202.67 ng/ml) compared with that of normal subjects (mean = 128.19 ± 85.84 ng/ml). Sixty minutes after dye installation, patients with dry eye disease still revealed higher corneal tissue fluorescein concentration (mean = 112.87 ± 52.83 ng/ml) compared with that of controls (mean = 40.64 ± 7.96 ng/ml), averaging a three-fold increase. Conclusion Patients with dry eye disease demonstrated an increased corneal permeability and a slower rate of elimination to topically administered fluorescein when measured by the fluorophotometer. This suggests that fluorophotometry may serve as a valuable quantitative and objective tool for the diagnosis of dry eye disease, and in following patients' response to new treatment modalities. Fluorophotometry may serve as an objective non-invasive tool for end-point analysis in clinical trials of new treatments for dry eye disease.

Fahim Magid M; Haji Shamim; Koonapareddy Chakravarthy V; Fan Vincent C; Asbell Penny A

2006-01-01

399

Can Maxwell's fish eye lens really give perfect imaging?  

CERN Multimedia

Both explicit analysis and FEM numerical simulation are used to analyze the field distribution of a line current in the so-called Maxwell's fish eye lens [bounded with a perfectly electrical conductor (PEC) boundary]. We show that such a 2D Maxwell's fish eye lens cannot give perfect imaging due to the fact that high order modes of the object field can hardly reach the image point in Maxwell's fish eye lens. If only zeroth order mode is excited, a good image of a sharp object may be achieved in some cases, however, its spot-size is larger than the spot size of the initial object field. The image resolution is determined by the field spot size of the image corresponding to the zeroth order component of the object field. Our explicit analysis consists very well with the FEM results for a fish eye lens. Time-domain simulation is also given to verify our conclusion. Multi-point images for a single object point are also demonstrated.

Sun, Fei

2010-01-01

400

On subwavelength imaging with Maxwell's fish eye lens  

CERN Multimedia

Both explicit analysis and FEM numerical simulation are used to analyze the field distribution of a line current in the so-called Maxwell's fish eye lens [bounded with a perfectly electrical conductor (PEC) boundary]. We show that such a 2D Maxwell's fish eye lens cannot give perfect imaging due to the fact that high order modes of the object field can hardly reach the image point in Maxwell's fish eye lens. If only zeroth order mode is excited, a subwavelength image of a sharp object may be achieved in some cases, however, its spot-size is larger than the spot size of the initial object field. The image resolution is determined by the field spot size of the image corresponding to the zeroth order component of the object field. Our explicit analysis consists very well with the FEM results for a fish eye lens. Time-domain simulation is also given to verify our conclusion. Multi-point imaging for a single object point is also demonstrated.

Sun, Fei

2010-01-01

 
 
 
 
401

The eye and the heart.  

UK PubMed Central (United Kingdom)

The vasculature of the eye and the heart share several common characteristics. The easily accessible vessels of the eye are therefore-to some extent-a window to the heart. There is interplay between cardiovascular functions and risk factors and the occurrence and progression of many eye diseases. In particular, arteriovenous nipping, narrowing of retinal arteries, and the dilatation of retinal veins are important signs of increased cardiovascular risk. The pressure in the dilated veins is often markedly increased due to a dysregulation of venous outflow from the eye. Besides such morphological criteria, functional alterations might be even more relevant and may play an important role in future diagnostics. Via neurovascular coupling, flickering light dilates capillaries and small arterioles, thus inducing endothelium-dependent, flow-mediated dilation of larger retinal vessels. Risk factors for arteriosclerosis, such as dyslipidaemia, diabetes, or systemic hypertension, are also risk factors for eye diseases such as retinal arterial or retinal vein occlusions, cataracts, age-related macular degeneration, and increases in intraocular pressure (IOP). Functional alterations of blood flow are particularly relevant to the eye. The primary vascular dysregulation syndrome (PVD), which often includes systemic hypotension, is associated with disturbed autoregulation of ocular blood flow (OBF). Fluctuation of IOP on a high level or blood pressure on a low level leads to instable OBF and oxygen supply and therefore to oxidative stress, which is particularly involved in the pathogenesis of glaucomatous neuropathy. Vascular dysregulation also leads to a barrier dysfunction and thereby to small retinal haemorrhages.

Flammer J; Konieczka K; Bruno RM; Virdis A; Flammer AJ; Taddei S

2013-05-01

402

Eye casualty services in London.  

UK PubMed Central (United Kingdom)

The combined pressures of the European Working Time Directive, 4?h waiting time target, and growing rates of unplanned hospital attendances have forced a major consolidation of eye casualty departments across the country, with the remaining units seeing a rapid increase in demand. We examine the effect of these changes on the provision of emergency eye care in Central London, and see what wider lessons can be learned. We surveyed the managers responsible for each of London's 8 out-of-hours eye casualty services, analysed data on attendance numbers, and conducted detailed interviews with lead clinicians. At London's two largest units, Moorfields Eye Hospital and the Western Eye Hospital, annual attendance numbers have been rising at 7.9% per year (to 76?034 patients in 2010/11) and 9.6% per year (to 31?128 patients in 2010/11), respectively. Using Moorfields as a case study, we discuss methods to increase capacity and efficiency in response to this demand, and also examine some of the unintended consequences of service consolidation including patients travelling long distances to geographically inappropriate units, and confusion over responsibility for out-of-hours inpatient cover. We describe a novel 'referral pathway' developed to minimise unnecessary travelling and delay for patients, and propose a forum for the strategic planning of London's eye casualty services in the future.

Smith HB; Daniel CS; Verma S

2013-03-01

403

Causes of eye removal--analysis of 586 eyes.  

UK PubMed Central (United Kingdom)

BACKGROUND/AIM: Eye enucleation is one of the oldest surgical procedures. The aim of the study was to determine the causes of enucleation as seen in a major reference eye center in Serbia. METHODS: Retrospective case series involving a review of all enucleation procedures performed in the period between January 2000 and December 2008 at the Institute for Eye Diseases, Clinical Center of Serbia, Belgrade. The collected information included the basic demographic data and, diagnosis of the affected eye. The diagnosis was made based on history, clinical and histological examinations. Clinical indications for enucleation were categorized as tumors, glaucoma, trauma, infections and other diseases. A statistical analysis was made using the Student's t-test. RESULTS: There were 586 patients, 315 male and 271 female in our series. The mean age was 57.81, ranging from 3 months to 96 years. The most common cause of enucleations was tumor (76.11%), (p < 0.05). Choroid melanoma was the most common etiology leading to enucleation (81.18%), followed by retinoblastoma (12.34%). A total of 8.02% of enucleations were performed due to glaucoma that was primarily neovascular in 42.55% of cases or caused by trauma in 38.8% of cases. Trauma was the third common etiology of enucleation, and it was acute in 56.26% of cases or resulted in phthisis bulbi in 31.25% of cases. Enucleation caused by inflammation was performed in 2.90% of cases, out of which 52.94% of enucleations occurred after perforation of the cornea. In the group of other diseases the most common cause of enucleation was atrophy of the eye ball. CONCLUSION: Neoplasm, neovascular glaucoma, acute eye injury and atrophy of the eye ball are the most common causes of enucleation.

Knezevi? M; Paovi? J; Paovi? P; Sredojevi? V

2013-01-01

404

Are 3-D Movies Bad for Your Eyes?  

Medline Plus

Full Text Available ... D Movies Bad for Your Eyes? Tweet Eye Health Lifestyle Topics Preventing Eye Injuries Healthy Eyes During ... feet away for 20 seconds. Know Your Eye Care Team Make sure you are seeing the right ...

405

Are 3-D Movies Bad for Your Eyes?  

Medline Plus

Full Text Available ... Alerts Are 3-D Movies Bad for Your Eyes? Tweet Eye Health Lifestyle Topics Preventing Eye Injuries Healthy Eyes ... ophthalmologist—your sight depends on it. Give your Eyes a Break To prevent computer eyestrain, follow the ...

406

Are 3-D Movies Bad for Your Eyes?  

Medline Plus

Full Text Available ... Marijuana for Glaucoma Pregnancy Preventing Eye Injuries Smokers Sports Teenagers Using Eye Makeup Veterans Your Eyes & the ... Usage & Eye Strain Maintaining Your Sight with Diabetes Sports and Eye Protection Eyesight Risks for Smokers Veterans & ...

407

Red eye: the role of primary care  

Directory of Open Access Journals (Sweden)

Full Text Available One of the most common eye problems to present to health workers is acute red eye(s). Approximately 40% of all outpatients seen in Bawku, Ghana, and in ten district hospitals in Pakistan, present with red eyes (Figure 1).

Allen Foster

2005-01-01

408

Dexamethasone eye drops containing ?-cyclodextrin-based nanogels.  

UK PubMed Central (United Kingdom)

Sustained release aqueous eye drops of dexamethasone, based on cyclodextrin (CD) nanogels, were designed and tested in vivo. ?CD units were cross-linked in the form of nanogels by means of an emulsification/solvent evaporation process. The composition of the nanogels was optimized with regard to drug loading and release rate. The eye drops consisted of an aqueous solution of dexamethasone in 2-hydroxypropyl-?-cyclodextrin (HP?CD) medium containing ?CD nanogels. The nanogel eye drops (containing 25 mg dexamethasone per ml) were tested in rabbits and compared to the commercially available product Maxidex(®) (suspension with 1 mg dexamethasone per ml). One drop administration of the nanogel eye drops resulted in nearly constant dexamethasone concentration for at least 6h in the tear fluid (mean concentration±SD=295±59 ?g/ml) whereas the concentration after administration of Maxidex(®) fell rapidly from 9.72±3.45 ?g/ml 1 h after application to 3.76±3.26 ?g/ml 3 h after application. The maximum dexamethasone concentration in the aqueous humor (2 h after application) was 136±24 mg/ml after application of the nanogel eye drops, and only 44.4±7.8 ?g/ml after application of Maxidex(®). The dexamethasone nanogel eye drops were well tolerated with no macroscopic signs of irritation, redness or other toxic effects.

Moya-Ortega MD; Alves TF; Alvarez-Lorenzo C; Concheiro A; Stefánsson E; Thorsteinsdóttir M; Loftsson T

2013-01-01