Rapid Pupil-Based Assessment of Glaucomatous Damage

PubMed Central

Chen, Yanjun; Wyatt, Harry J.; Swanson, William H.; Dul, Mitchell W.

2010-01-01

Purpose To investigate the ability of a technique employing pupillometry and functionally-shaped stimuli to assess loss of visual function due to glaucomatous optic neuropathy. Methods Pairs of large stimuli, mirror images about the horizontal meridian, were displayed alternately in the upper and lower visual field. Pupil diameter was recorded and analyzed in terms of the “contrast balance” (relative sensitivity to the upper and lower stimuli), and the pupil constriction amplitude to upper and lower stimuli separately. A group of 40 patients with glaucoma was tested twice in a first session, and twice more in a second session, 1 to 3 weeks later. A group of 40 normal subjects was tested with the same protocol. Results Results for the normal subjects indicated functional symmetry in upper/lower retina, on average. Contrast balance results for the patients with glaucoma differed from normal: half the normal subjects had contrast balance within 0.06 log unit of equality and 80% had contrast balance within 0.1 log unit. Half the patients had contrast balances more than 0.1 log unit from equality. Patient contrast balances were moderately correlated with predictions from perimetric data (r = 0.37, p < 0.00001). Contrast balances correctly classified visual field damage in 28 patients (70%), and response amplitudes correctly classified 24 patients (60%). When contrast balance and response amplitude were combined, receiver operating characteristic area for discriminating glaucoma from normal was 0.83. Conclusions Pupillary evaluation of retinal asymmetry provides a rapid method for detecting and classifying visual field defects. In this patient population, classification agreed with perimetry in 70% of eyes. PMID:18521026

THE CHOICE OF OPTIMAL STRUCTURE OF ARTIFICIAL NEURAL NETWORK CLASSIFIER INTENDED FOR CLASSIFICATION OF WELDING FLAWS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sikora, R.; Chady, T.; Baniukiewicz, P.

2010-02-22

Nondestructive testing and evaluation are under continuous development. Currently researches are concentrated on three main topics: advancement of existing methods, introduction of novel methods and development of artificial intelligent systems for automatic defect recognition (ADR). Automatic defect classification algorithm comprises of two main tasks: creating a defect database and preparing a defect classifier. Here, the database was built using defect features that describe all geometrical and texture properties of the defect. Almost twenty carefully selected features calculated for flaws extracted from real radiograms were used. The radiograms were obtained from shipbuilding industry and they were verified by qualified operator. Twomore » weld defect's classifiers based on artificial neural networks were proposed and compared. First model consisted of one neural network model, where each output neuron corresponded to different defect group. The second model contained five neural networks. Each neural network had one neuron on output and was responsible for detection of defects from one group. In order to evaluate the effectiveness of the neural networks classifiers, the mean square errors were calculated for test radiograms and compared.« less

The Choice of Optimal Structure of Artificial Neural Network Classifier Intended for Classification of Welding Flaws

NASA Astrophysics Data System (ADS)

Sikora, R.; Chady, T.; Baniukiewicz, P.; Caryk, M.; Piekarczyk, B.

2010-02-01

Nondestructive testing and evaluation are under continuous development. Currently researches are concentrated on three main topics: advancement of existing methods, introduction of novel methods and development of artificial intelligent systems for automatic defect recognition (ADR). Automatic defect classification algorithm comprises of two main tasks: creating a defect database and preparing a defect classifier. Here, the database was built using defect features that describe all geometrical and texture properties of the defect. Almost twenty carefully selected features calculated for flaws extracted from real radiograms were used. The radiograms were obtained from shipbuilding industry and they were verified by qualified operator. Two weld defect's classifiers based on artificial neural networks were proposed and compared. First model consisted of one neural network model, where each output neuron corresponded to different defect group. The second model contained five neural networks. Each neural network had one neuron on output and was responsible for detection of defects from one group. In order to evaluate the effectiveness of the neural networks classifiers, the mean square errors were calculated for test radiograms and compared.

Visual disability rates in a ten-year cohort of patients with anterior visual pathway meningiomas.

PubMed

Bor-Shavit, Elite; Hammel, Naama; Nahum, Yoav; Rappaport, Zvi Harry; Stiebel-Kalish, Hadas

2015-01-01

To examine the visual outcome of anterior visual pathway meningioma (AVPM) patients followed for at least one year. Data were collected on demographics, clinical course and management. Visual disability was classified at the first and last examination as follows: I--no visual disability; II--mild visual defect in one eye; III--mild visual defect in both eyes; IV--loss of driver's license; V--legally blind. Eight-one AVPM patients had their tumor originate in the clinoid process in 23 (28%), sphenoid-wing area in 18 (22%), cavernous sinus in 15 (19%), tuberculum sellae in 8 (10%), and mixed in 17 (21%). On last examination, 46 patients (57%) had good visual acuity in one or both eyes (Class I or II) and 17 (21%) were mildly affected in both eyes. The rate of Class IV disability was 16%, and Class V disability was 6%. Attention needs to be addressed to the considerable proportion of patients with AVPM (22% in this study) who may lose their driver's license or become legally blind. Occupational therapists should play an important role in the multidisciplinary management of those patients to help them adapt to their new physical and social situation. Anterior visual pathway meningiomas (AVPMs) are commonly not life-threatening but they can lead to profound visual disability, especially when the tumor originates in the tuberculum sellae and cavernous sinus. Particular attention should be paid to visual acuity and visual field deficits, as these can profoundly affect the patient's quality of life including ability to drive and activities of daily living. The interdisciplinary management of patients with AVPM should include the neurosurgeon, neuro-ophthalmologist and occupational therapist. Also, early intervention by the occupational therapist can help patients adapt to their current physical and social situation and return to everyday tasks more rapidly.

Context-based automated defect classification system using multiple morphological masks

DOEpatents

Gleason, Shaun S.; Hunt, Martin A.; Sari-Sarraf, Hamed

2002-01-01

Automatic detection of defects during the fabrication of semiconductor wafers is largely automated, but the classification of those defects is still performed manually by technicians. This invention includes novel digital image analysis techniques that generate unique feature vector descriptions of semiconductor defects as well as classifiers that use these descriptions to automatically categorize the defects into one of a set of pre-defined classes. Feature extraction techniques based on multiple-focus images, multiple-defect mask images, and segmented semiconductor wafer images are used to create unique feature-based descriptions of the semiconductor defects. These feature-based defect descriptions are subsequently classified by a defect classifier into categories that depend on defect characteristics and defect contextual information, that is, the semiconductor process layer(s) with which the defect comes in contact. At the heart of the system is a knowledge database that stores and distributes historical semiconductor wafer and defect data to guide the feature extraction and classification processes. In summary, this invention takes as its input a set of images containing semiconductor defect information, and generates as its output a classification for the defect that describes not only the defect itself, but also the location of that defect with respect to the semiconductor process layers.

The accuracy of confrontation visual field test in comparison with automated perimetry.

PubMed Central

Johnson, L. N.; Baloh, F. G.

1991-01-01

The accuracy of confrontation visual field testing was determined for 512 visual fields using automated static perimetry as the reference standard. The sensitivity of confrontation testing excluding patchy defects was 40% for detecting anterior visual field defects, 68.3% for posterior defects, and 50% for both anterior and posterior visual field defects combined. The sensitivity within each group varied depending on the type of visual field defect encountered. Confrontation testing had a high sensitivity (75% to 100%) for detecting altitudinal visual loss, central/centrocecal scotoma, and homonymous hemianopsia. Confrontation testing was fairly insensitive (20% to 50% sensitivity) for detecting arcuate scotoma and bitemporal hemianopsia. The specificity of confrontation testing was high at 93.4%. The high positive predictive value (72.6%) and negative predictive value (75.7%) would indicate that visual field defects identified during confrontation testing are often true visual field defects. However, the many limitations of confrontation testing should be remembered, particularly its low sensitivity for detecting visual field loss associated with parasellar tumors, glaucoma, and compressive optic neuropathies. PMID:1800764

Research on metallic material defect detection based on bionic sensing of human visual properties

NASA Astrophysics Data System (ADS)

Zhang, Pei Jiang; Cheng, Tao

2018-05-01

Due to the fact that human visual system can quickly lock the areas of interest in complex natural environment and focus on it, this paper proposes an eye-based visual attention mechanism by simulating human visual imaging features based on human visual attention mechanism Bionic Sensing Visual Inspection Model Method to Detect Defects of Metallic Materials in the Mechanical Field. First of all, according to the biologically visually significant low-level features, the mark of defect experience marking is used as the intermediate feature of simulated visual perception. Afterwards, SVM method was used to train the advanced features of visual defects of metal material. According to the weight of each party, the biometrics detection model of metal material defect, which simulates human visual characteristics, is obtained.

Accelerated defect visualization of microelectronic systems using binary search with fixed pitch-catch distance laser ultrasonic scanning

NASA Astrophysics Data System (ADS)

Park, Byeongjin; Sohn, Hoon

2018-04-01

The practicality of laser ultrasonic scanning is limited because scanning at a high spatial resolution demands a prohibitively long scanning time. Inspired by binary search, an accelerated defect visualization technique is developed to visualize defect with a reduced scanning time. The pitch-catch distance between the excitation point and the sensing point is also fixed during scanning to maintain a high signal-to-noise ratio of measured ultrasonic responses. The approximate defect boundary is identified by examining the interactions between ultrasonic waves and defect observed at the scanning points that are sparsely selected by a binary search algorithm. Here, a time-domain laser ultrasonic response is transformed into a spatial ultrasonic domain response using a basis pursuit approach so that the interactions between ultrasonic waves and defect can be better identified in the spatial ultrasonic domain. Then, the area inside the identified defect boundary is visualized as defect. The performance of the proposed defect visualization technique is validated through an experiment on a semiconductor chip. The proposed defect visualization technique accelerates the defect visualization process in three aspects: (1) The number of measurements that is necessary for defect visualization is dramatically reduced by a binary search algorithm; (2) The number of averaging that is necessary to achieve a high signal-to-noise ratio is reduced by maintaining the wave propagation distance short; and (3) With the proposed technique, defect can be identified with a lower spatial resolution than the spatial resolution required by full-field wave propagation imaging.

Anosognosia for obvious visual field defects in stroke patients.

PubMed

Baier, Bernhard; Geber, Christian; Müller-Forell, Wiebke; Müller, Notger; Dieterich, Marianne; Karnath, Hans-Otto

2015-01-01

Patients with anosognosia for visual field defect (AVFD) fail to recognize consciously their visual field defect. There is still unclarity whether specific neural correlates are associated with AVFD. We studied AVFD in 54 patients with acute stroke and a visual field defect. Nineteen percent of this unselected sample showed AVFD. By using modern voxelwise lesion-behaviour mapping techniques we found an association between AVFD and parts of the lingual gyrus, the cuneus as well as the posterior cingulate and corpus callosum. Damage to these regions appears to induce unawareness of visual field defects and thus may play a significant role for conscious visual perception.

Wood texture classification by fuzzy neural networks

NASA Astrophysics Data System (ADS)

Gonzaga, Adilson; de Franca, Celso A.; Frere, Annie F.

1999-03-01

The majority of scientific papers focusing on wood classification for pencil manufacturing take into account defects and visual appearance. Traditional methodologies are base don texture analysis by co-occurrence matrix, by image modeling, or by tonal measures over the plate surface. In this work, we propose to classify plates of wood without biological defects like insect holes, nodes, and cracks, by analyzing their texture. By this methodology we divide the plate image in several rectangular windows or local areas and reduce the number of gray levels. From each local area, we compute the histogram of difference sand extract texture features, given them as input to a Local Neuro-Fuzzy Network. Those features are from the histogram of differences instead of the image pixels due to their better performance and illumination independence. Among several features like media, contrast, second moment, entropy, and IDN, the last three ones have showed better results for network training. Each LNN output is taken as input to a Partial Neuro-Fuzzy Network (PNFN) classifying a pencil region on the plate. At last, the outputs from the PNFN are taken as input to a Global Fuzzy Logic doing the plate classification. Each pencil classification within the plate is done taking into account each quality index.

Automated objective characterization of visual field defects in 3D

NASA Technical Reports Server (NTRS)

Fink, Wolfgang (Inventor)

2006-01-01

A method and apparatus for electronically performing a visual field test for a patient. A visual field test pattern is displayed to the patient on an electronic display device and the patient's responses to the visual field test pattern are recorded. A visual field representation is generated from the patient's responses. The visual field representation is then used as an input into a variety of automated diagnostic processes. In one process, the visual field representation is used to generate a statistical description of the rapidity of change of a patient's visual field at the boundary of a visual field defect. In another process, the area of a visual field defect is calculated using the visual field representation. In another process, the visual field representation is used to generate a statistical description of the volume of a patient's visual field defect.

The SCHEIE Visual Field Grading System

PubMed Central

Sankar, Prithvi S.; O’Keefe, Laura; Choi, Daniel; Salowe, Rebecca; Miller-Ellis, Eydie; Lehman, Amanda; Addis, Victoria; Ramakrishnan, Meera; Natesh, Vikas; Whitehead, Gideon; Khachatryan, Naira; O’Brien, Joan

2017-01-01

Objective No method of grading visual field (VF) defects has been widely accepted throughout the glaucoma community. The SCHEIE (Systematic Classification of Humphrey visual fields-Easy Interpretation and Evaluation) grading system for glaucomatous visual fields was created to convey qualitative and quantitative information regarding visual field defects in an objective, reproducible, and easily applicable manner for research purposes. Methods The SCHEIE grading system is composed of a qualitative and quantitative score. The qualitative score consists of designation in one or more of the following categories: normal, central scotoma, paracentral scotoma, paracentral crescent, temporal quadrant, nasal quadrant, peripheral arcuate defect, expansive arcuate, or altitudinal defect. The quantitative component incorporates the Humphrey visual field index (VFI), location of visual defects for superior and inferior hemifields, and blind spot involvement. Accuracy and speed at grading using the qualitative and quantitative components was calculated for non-physician graders. Results Graders had a median accuracy of 96.67% for their qualitative scores and a median accuracy of 98.75% for their quantitative scores. Graders took a mean of 56 seconds per visual field to assign a qualitative score and 20 seconds per visual field to assign a quantitative score. Conclusion The SCHEIE grading system is a reproducible tool that combines qualitative and quantitative measurements to grade glaucomatous visual field defects. The system aims to standardize clinical staging and to make specific visual field defects more easily identifiable. Specific patterns of visual field loss may also be associated with genetic variants in future genetic analysis. PMID:28932621

Progression of Patterns (POP): A Machine Classifier Algorithm to Identify Glaucoma Progression in Visual Fields

PubMed Central

Goldbaum, Michael H.; Lee, Intae; Jang, Giljin; Balasubramanian, Madhusudhanan; Sample, Pamela A.; Weinreb, Robert N.; Liebmann, Jeffrey M.; Girkin, Christopher A.; Anderson, Douglas R.; Zangwill, Linda M.; Fredette, Marie-Josee; Jung, Tzyy-Ping; Medeiros, Felipe A.; Bowd, Christopher

2012-01-01

Purpose. We evaluated Progression of Patterns (POP) for its ability to identify progression of glaucomatous visual field (VF) defects. Methods. POP uses variational Bayesian independent component mixture model (VIM), a machine learning classifier (MLC) developed previously. VIM separated Swedish Interactive Thresholding Algorithm (SITA) VFs from a set of 2,085 normal and glaucomatous eyes into nine axes (VF patterns): seven glaucomatous. Stable glaucoma was simulated in a second set of 55 patient eyes with five VFs each, collected within four weeks. A third set of 628 eyes with 4,186 VFs (mean ± SD of 6.7 ± 1.7 VFs over 4.0 ± 1.4 years) was tested for progression. Tested eyes were placed into suspect and glaucoma categories at baseline, based on VFs and disk stereoscopic photographs; a subset of eyes had stereophotographic evidence of progressive glaucomatous optic neuropathy (PGON). Each sequence of fields was projected along seven VIM glaucoma axes. Linear regression (LR) slopes generated from projections onto each axis yielded a degree of confidence (DOC) that there was progression. At 95% specificity, progression cutoffs were established for POP, visual field index (VFI), and mean deviation (MD). Guided progression analysis (GPA) was also compared. Results. POP identified a statistically similar number of eyes (P > 0.05) as progressing compared with VFI, MD, and GPA in suspects (3.8%, 2.7%, 5.6%, and 2.9%, respectively), and more eyes than GPA (P = 0.01) in glaucoma (16.0%, 15.3%, 12.0%, and 7.3%, respectively), and more eyes than GPA (P = 0.05) in PGON eyes (26.3%, 23.7%, 27.6%, and 14.5%, respectively). Conclusions. POP, with its display of DOC of progression and its identification of progressing VF defect pattern, adds to the information available to the clinician for detecting VF progression. PMID:22786913

Relationship between progression of visual field defect and intraocular pressure in primary open-angle glaucoma.

PubMed

Naito, Tomoko; Yoshikawa, Keiji; Mizoue, Shiro; Nanno, Mami; Kimura, Tairo; Suzumura, Hirotaka; Shiraga, Fumio

2015-01-01

To analyze the relationship between intraocular pressure (IOP) and the progression of visual field defects in Japanese primary open-angle glaucoma (POAG) and normal-tension glaucoma (NTG) patients. The subjects of the study were patients undergoing treatment for POAG or NTG who had performed visual field tests at least ten times with a Humphrey field analyzer (Swedish interactive thresholding algorithm standard, C30-2 program). The progression of visual field defects was defined by a significantly negative value of the mean deviation slope at the final visual field test during the follow-up period. The relationships between the progression of visual field defects and IOP, as well as other clinical factors, were retrospectively analyzed. A total of 156 eyes of 156 patients were included in the analysis. Significant progression of visual field defects was observed in 70 eyes of 70 patients (44.9%), while no significant progression was evident in 86 eyes of 86 patients (55.1%). The eyes with visual field defect progression had significantly lower baseline IOP (P<0.05), as well as significantly lower IOP reduction rate (P<0.01). The standard deviation of IOP values during follow-up was significantly greater in the eyes with visual field defect progression than in eyes without (P<0.05). Reducing IOP is thought to be useful for Japanese POAG or NTG patients to suppress the progression of visual field defects. In NTG, IOP management should take into account not only achieving the target IOP, but also minimizing the fluctuation of IOP during follow-up period.

7 CFR 42.106 - Classifying and recording defects.

Code of Federal Regulations, 2013 CFR

2013-01-01

... container is scored only once for these two defects since the rust condition can be atributed to the leak... “leaker” (a critical defect) and not as “pitted rust” (a major defect). (2) Unrelated defects are defects...

7 CFR 42.106 - Classifying and recording defects.

Code of Federal Regulations, 2014 CFR

2014-01-01

... container is scored only once for these two defects since the rust condition can be attributed to the leak... “leaker” (a critical defect) and not as “pitted rust” (a major defect). (2) Unrelated defects are defects...

7 CFR 42.106 - Classifying and recording defects.

Code of Federal Regulations, 2011 CFR

2011-01-01

... container is scored only once for these two defects since the rust condition can be atributed to the leak... “leaker” (a critical defect) and not as “pitted rust” (a major defect). (2) Unrelated defects are defects...

7 CFR 42.106 - Classifying and recording defects.

Code of Federal Regulations, 2012 CFR

2012-01-01

... container is scored only once for these two defects since the rust condition can be atributed to the leak... “leaker” (a critical defect) and not as “pitted rust” (a major defect). (2) Unrelated defects are defects...

7 CFR 42.106 - Classifying and recording defects.

Code of Federal Regulations, 2010 CFR

2010-01-01

... container is scored only once for these two defects since the rust condition can be atributed to the leak... “leaker” (a critical defect) and not as “pitted rust” (a major defect). (2) Unrelated defects are defects...

Automated defect spatial signature analysis for semiconductor manufacturing process

DOEpatents

Tobin, Jr., Kenneth W.; Gleason, Shaun S.; Karnowski, Thomas P.; Sari-Sarraf, Hamed

1999-01-01

An apparatus and method for performing automated defect spatial signature alysis on a data set representing defect coordinates and wafer processing information includes categorizing data from the data set into a plurality of high level categories, classifying the categorized data contained in each high level category into user-labeled signature events, and correlating the categorized, classified signature events to a present or incipient anomalous process condition.

Visual field defects may not affect safe driving.

PubMed

Dow, Jamie

2011-10-01

In Quebec a driver whose acquired visual field defect renders them ineligible for a driver's permit renewal may request an exemption from the visual field standard by demonstrating safe driving despite the defect. For safety reasons it was decided to attempt to identify predictors of failure on the road test in order to avoid placing driving evaluators in potentially dangerous situations when evaluating drivers with visual field defects. During a 4-month period in 2009 all requests for exemptions from the visual field standard were collected and analyzed. All available medical and visual field data were collated for 103 individuals, of whom 91 successfully completed the evaluation process and obtained a waiver. The collated data included age, sex, type of visual field defect, visual field characteristics, and concomitant medical problems. No single factor, or combination of factors, could predict failure of the road test. All 5 failures of the road test had cognitive problems but 6 of the successful drivers also had known cognitive problems. Thus, cognitive problems influence the risk of failure but do not predict certain failure. Most of the applicants for an exemption were able to complete the evaluation process successfully, thereby demonstrating safe driving despite their handicap. Consequently, jurisdictions that have visual field standards for their driving permit should implement procedures to evaluate drivers with visual field defects that render them unable to meet the standard but who wish to continue driving.

Visual defects and commercial motorcycle accidents in south eastern Nigeria.

PubMed

Achigbu, E O; Fiebai, B

2013-01-01

Commercial motorcyclists are a regular part of our highways, especially with the decrease in the number and quality of good roads. This study is aimed at determining the role of vision if any in the increasing number of road traffic accidents (RTA's) among commercial motorcyclists in Enugu metropolis, Nigeria. A cross sectional survey with a multi stage random sampling design was used to select the 615 commercial motorcyclists in Enugu metropolis enrolled in the study. Out of the 615 motorcyclists, seven (1.14% +/- 0.70%) motorcyclists had visual impairment (< 6/18-3/60). Visual field defect was noted in 2.3% +/- 0.98% while 2.6% +/- 0.98% had colour vision defect. The prevalence of road traffic accident (RTA) was 57.7%. Visual impairment was not significantly associated with RTA (P = 0.333) while visual field defect (P = 0.000), and colour vision defect (P = 0.003) were positively associated with RTA. Inexperienced riders had significantly more RTAs than their counterparts (P = 0.000). CONCLUSION; Visual field defect, and colour vision defect were significantly associated with RTA but this finding is in the backdrop of poor training, and inexperience which also significantly affected RTA among the predominantly young riders involved in RTA.

The Optic Nerve Head in Primary Open-Angle Glaucoma Eyes With High Myopia: Characteristics and Association With Visual Field Defects.

PubMed

Chen, Li-Wei; Lan, Yu-Wen; Hsieh, Jui-Wen

2016-06-01

To evaluate the morphologic characteristics of optic neuropathy and its association with visual field (VF) defects in primary open-angle glaucoma (POAG) eyes with high myopia. In this cross-sectional study, we reviewed data from 375 Taiwanese patients (375 eyes) of POAG, ages 20 to 60 years. Optic disc photographs were used for planimetric measurements of morphologic variables. The myopic refraction was divided into high myopia (<-6.0 D) and nonhigh myopia (moderate myopia to hyperopia). The optic disc area was classified as moderate (1.59 to 2.85 mm), large, and small. Differences in characteristics between groups, correlations with the disc area, and factors associated with VF defects were determined. Of the 142 highly myopic eyes, 33 (23%) had a large disc, 26 (18%) had a small disc, and 55 (39%) had a tilted disc. Large discs had a higher cup-to-disc (C/D) area ratio and a higher tilt ratio; small discs had a smaller rim area and a lower tilt ratio (all P<0.05). Characteristics associated with high myopia included a smaller rim area, a higher C/D area ratio, and a lower tilt ratio (all P<0.001). In logistic regression, the refraction, the C/D area ratio, the rim area, and the tilt ratio (all P<0.05) were associated with VF defects. In Taiwanese individuals with POAG, our study found that tilted, large, or small discs were prevalent in highly myopic eyes. Of these characteristics, only the disc tilt and high myopia by itself were associated with the severity of glaucomatous optic neuropathy.

Active Learning in Neuroscience: A Manipulative to Simulate Visual Field Defects

ERIC Educational Resources Information Center

Li, Andrew Yue-Lin; Carvalho, Helena

2016-01-01

Prevalent in 20-57% of stroke patients, visual field defects have been shown to impact quality of life. Studies have shown increased risk of falling, ambulatory difficulties, impaired reading ability, and feelings of panic in crowded or unfamiliar places in patients with visual field defects. Rehabilitation, independence, and mental health may…

The efficacy of a novel mobile phone application for goldmann ptosis visual field interpretation.

PubMed

Maamari, Robi N; D'Ambrosio, Michael V; Joseph, Jeffrey M; Tao, Jeremiah P

2014-01-01

To evaluate the efficacy of a novel mobile phone application that calculates superior visual field defects on Goldmann visual field charts. Experimental study in which the mobile phone application and 14 oculoplastic surgeons interpreted the superior visual field defect in 10 Goldmann charts. Percent error of the mobile phone application and the oculoplastic surgeons' estimates were calculated compared with computer software computation of the actual defects. Precision and time efficiency of the application were evaluated by processing the same Goldmann visual field chart 10 repeated times. The mobile phone application was associated with a mean percent error of 1.98% (95% confidence interval[CI], 0.87%-3.10%) in superior visual field defect calculation. The average mean percent error of the oculoplastic surgeons' visual estimates was 19.75% (95% CI, 14.39%-25.11%). Oculoplastic surgeons, on average, underestimated the defect in all 10 Goldmann charts. There was high interobserver variance among oculoplastic surgeons. The percent error of the 10 repeated measurements on a single chart was 0.93% (95% CI, 0.40%-1.46%). The average time to process 1 chart was 12.9 seconds (95% CI, 10.9-15.0 seconds). The mobile phone application was highly accurate, precise, and time-efficient in calculating the percent superior visual field defect using Goldmann charts. Oculoplastic surgeon visual interpretations were highly inaccurate, highly variable, and usually underestimated the field vision loss.

Unsupervised classification of surface defects in wire rod production obtained by eddy current sensors.

PubMed

Saludes-Rodil, Sergio; Baeyens, Enrique; Rodríguez-Juan, Carlos P

2015-04-29

An unsupervised approach to classify surface defects in wire rod manufacturing is developed in this paper. The defects are extracted from an eddy current signal and classified using a clustering technique that uses the dynamic time warping distance as the dissimilarity measure. The new approach has been successfully tested using industrial data. It is shown that it outperforms other classification alternatives, such as the modified Fourier descriptors.

Vision-related fitness to drive mobility scooters: A practical driving test.

PubMed

Cordes, Christina; Heutink, Joost; Tucha, Oliver M; Brookhuis, Karel A; Brouwer, Wiebo H; Melis-Dankers, Bart J M

2017-03-06

To investigate practical fitness to drive mobility scooters, comparing visually impaired participants with healthy controls. Between-subjects design. Forty-six visually impaired (13 with very low visual acuity, 10 with low visual acuity, 11 with peripheral field defects, 12 with multiple visual impairment) and 35 normal-sighted controls. Participants completed a practical mobility scooter test-drive, which was recorded on video. Two independent occupational therapists specialized in orientation and mobility evaluated the videos systematically. Approximately 90% of the visually impaired participants passed the driving test. On average, participants with visual impairments performed worse than normal-sighted controls, but were judged sufficiently safe. In particular, difficulties were observed in participants with peripheral visual field defects and those with a combination of low visual acuity and visual field defects. People with visual impairment are, in practice, fit to drive mobility scooters; thus visual impairment on its own should not be viewed as a determinant of safety to drive mobility scooters. However, special attention should be paid to individuals with visual field defects with or without a combined low visual acuity. The use of an individual practical fitness-to-drive test is advised.

Discriminant Analysis of Defective and Non-Defective Field Pea (Pisum sativum L.) into Broad Market Grades Based on Digital Image Features.

PubMed

McDonald, Linda S; Panozzo, Joseph F; Salisbury, Phillip A; Ford, Rebecca

2016-01-01

Field peas (Pisum sativum L.) are generally traded based on seed appearance, which subjectively defines broad market-grades. In this study, we developed an objective Linear Discriminant Analysis (LDA) model to classify market grades of field peas based on seed colour, shape and size traits extracted from digital images. Seeds were imaged in a high-throughput system consisting of a camera and laser positioned over a conveyor belt. Six colour intensity digital images were captured (under 405, 470, 530, 590, 660 and 850nm light) for each seed, and surface height was measured at each pixel by laser. Colour, shape and size traits were compiled across all seed in each sample to determine the median trait values. Defective and non-defective seed samples were used to calibrate and validate the model. Colour components were sufficient to correctly classify all non-defective seed samples into correct market grades. Defective samples required a combination of colour, shape and size traits to achieve 87% and 77% accuracy in market grade classification of calibration and validation sample-sets respectively. Following these results, we used the same colour, shape and size traits to develop an LDA model which correctly classified over 97% of all validation samples as defective or non-defective.

Discriminant Analysis of Defective and Non-Defective Field Pea (Pisum sativum L.) into Broad Market Grades Based on Digital Image Features

PubMed Central

McDonald, Linda S.; Panozzo, Joseph F.; Salisbury, Phillip A.; Ford, Rebecca

2016-01-01

Field peas (Pisum sativum L.) are generally traded based on seed appearance, which subjectively defines broad market-grades. In this study, we developed an objective Linear Discriminant Analysis (LDA) model to classify market grades of field peas based on seed colour, shape and size traits extracted from digital images. Seeds were imaged in a high-throughput system consisting of a camera and laser positioned over a conveyor belt. Six colour intensity digital images were captured (under 405, 470, 530, 590, 660 and 850nm light) for each seed, and surface height was measured at each pixel by laser. Colour, shape and size traits were compiled across all seed in each sample to determine the median trait values. Defective and non-defective seed samples were used to calibrate and validate the model. Colour components were sufficient to correctly classify all non-defective seed samples into correct market grades. Defective samples required a combination of colour, shape and size traits to achieve 87% and 77% accuracy in market grade classification of calibration and validation sample-sets respectively. Following these results, we used the same colour, shape and size traits to develop an LDA model which correctly classified over 97% of all validation samples as defective or non-defective. PMID:27176469

Reading performance after vision rehabilitation of subjects with homonymous visual field defects.

PubMed

Gall, Carolin; Sabel, Bernhard A

2012-12-01

To examine whether increased visual functioning after vision-restoration training (VRT) coincides with improved reading abilities. Prospective noncontrolled open-label trial. Controlled laboratory setting for all diagnostic procedures that were conducted before and after 6 months of home-based VRT with telemedicine support. Eleven subjects who had experienced a posterior-parietal stroke and have homonymous visual field defects. Six months of VRT (1 hour daily repeated light stimulation in the partially damaged visual field). VRT outcome measures were the number of detected light stimuli in eye-tracker controlled high-resolution perimetry and the spared visual field within the affected hemifield up to the relative and absolute defect visual field border (square degrees). Enlargements of spared visual field within the affected hemifield were correlated with changes of reading speed after VRT. After VRT, the number of detected light stimuli increased by 5.02 ± 4.31% (mean ± SD; P = .03). The spared visual field up to the relative defect visual field border increased from 18.09 ± 32.35 square degrees before to 137.40 ± 53.32 after VRT (P = .006), as well as for the absolute defect visual field border from 36.95 ± 33.77 square degrees before VRT to 152.02 ± 49.70 after VRT (P = .005). Reading speed increased from 108.95 ± 33.95 words per minute before VRT to 122.26 ± 30.35 after VRT (P = .017), which significantly correlated with increased spared visual field up to the relative defect visual field border (r = 0.73, P = .016). Measures of eye movement variability did not correlate with VRT outcome. VRT improved visual fields in parafoveal areas, which are most relevant for reading. This finding cannot be explained by changes in eye movement behavior. Because of a significant association between improvements of parafoveal vision and reading speed, we propose that patients with homonymous visual field defects who have reading deficits may benefit from visual stimulation by training. Copyright © 2012 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.

Visualization of Subsurface Defects in Composites using a Focal Plane Array Infrared Camera

NASA Technical Reports Server (NTRS)

Plotnikov, Yuri A.; Winfree, William P.

1999-01-01

A technique for enhanced defect visualization in composites via transient thermography is presented in this paper. The effort targets automated defect map construction for multiple defects located in the observed area. Experimental data were collected on composite panels of different thickness with square inclusions and flat bottom holes of different depth and orientation. The time evolution of the thermal response and spatial thermal profiles are analyzed. The pattern generated by carbon fibers and the vignetting effect of the focal plane array camera make defect visualization difficult. An improvement of the defect visibility is made by the pulse phase technique and the spatial background treatment. The relationship between a size of a defect and its reconstructed image is analyzed as well. The image processing technique for noise reduction is discussed.

Visualization and automatic detection of defect distribution in GaN atomic structure from sampling Moiré phase.

PubMed

Wang, Qinghua; Ri, Shien; Tsuda, Hiroshi; Kodera, Masako; Suguro, Kyoichi; Miyashita, Naoto

2017-09-19

Quantitative detection of defects in atomic structures is of great significance to evaluating product quality and exploring quality improvement process. In this study, a Fourier transform filtered sampling Moire technique was proposed to visualize and detect defects in atomic arrays in a large field of view. Defect distributions, defect numbers and defect densities could be visually and quantitatively determined from a single atomic structure image at low cost. The effectiveness of the proposed technique was verified from numerical simulations. As an application, the dislocation distributions in a GaN/AlGaN atomic structure in two directions were magnified and displayed in Moire phase maps, and defect locations and densities were detected automatically. The proposed technique is able to provide valuable references to material scientists and engineers by checking the effect of various treatments for defect reduction. © 2017 IOP Publishing Ltd.

WELDSMART: A vision-based expert system for quality control

NASA Technical Reports Server (NTRS)

Andersen, Kristinn; Barnett, Robert Joel; Springfield, James F.; Cook, George E.

1992-01-01

This work was aimed at exploring means for utilizing computer technology in quality inspection and evaluation. Inspection of metallic welds was selected as the main application for this development and primary emphasis was placed on visual inspection, as opposed to other inspection methods, such as radiographic techniques. Emphasis was placed on methodologies with the potential for use in real-time quality control systems. Because quality evaluation is somewhat subjective, despite various efforts to classify discontinuities and standardize inspection methods, the task of using a computer for both inspection and evaluation was not trivial. The work started out with a review of the various inspection techniques that are used for quality control in welding. Among other observations from this review was the finding that most weld defects result in abnormalities that may be seen by visual inspection. This supports the approach of emphasizing visual inspection for this work. Quality control consists of two phases: (1) identification of weld discontinuities (some of which may be severe enough to be classified as defects), and (2) assessment or evaluation of the weld based on the observed discontinuities. Usually the latter phase results in a pass/fail judgement for the inspected piece. It is the conclusion of this work that the first of the above tasks, identification of discontinuities, is the most challenging one. It calls for sophisticated image processing and image analysis techniques, and frequently ad hoc methods have to be developed to identify specific features in the weld image. The difficulty of this task is generally not due to limited computing power. In most cases it was found that a modest personal computer or workstation could carry out most computations in a reasonably short time period. Rather, the algorithms and methods necessary for identifying weld discontinuities were in some cases limited. The fact that specific techniques were finally developed and successfully demosntrated to work illustrates that the general approach taken here appears to be promising for commercial development of computerized quality inspection systems. Inspection based on these techniques may be used to supplement or substitute more elaborate inspection methods, such as x-ray inspections.

The influence of artificial scotomas on eye movements during visual search.

PubMed

Cornelissen, Frans W; Bruin, Klaas J; Kooijman, Aart C

2005-01-01

Fixation durations are normally adapted to the difficulty of the foveal analysis task. We examine to what extent artificial central and peripheral visual field defects interfere with this adaptation process. Subjects performed a visual search task while their eye movements were registered. The latter were used to drive a real-time gaze-dependent display that was used to create artificial central and peripheral visual field defects. Recorded eye movements were used to determine saccadic amplitude, number of fixations, fixation durations, return saccades, and changes in saccade direction. For central defects, although fixation duration increased with the size of the absolute central scotoma, this increase was too small to keep recognition performance optimal, evident from an associated increase in the rate of return saccades. Providing a relatively small amount of visual information in the central scotoma did substantially reduce subjects' search times but not their fixation durations. Surprisingly, reducing the size of the tunnel also prolonged fixation duration for peripheral defects. This manipulation also decreased the rate of return saccades, suggesting that the fixations were prolonged beyond the duration required by the foveal task. Although we find that adaptation of fixation duration to task difficulty clearly occurs in the presence of artificial scotomas, we also find that such field defects may render the adaptation suboptimal for the task at hand. Thus, visual field defects may not only hinder vision by limiting what the subject sees of the environment but also by limiting the visual system's ability to program efficient eye movements. We speculate this is because of how visual field defects bias the balance between saccade generation and fixation stabilization.

Quantitative analysis of external limiting membrane, ellipsoid zone and interdigitation zone defects in patients with macular holes.

PubMed

Houly, Jacques Ramos; Veloso, Carlos Eduardo; Passos, Elke; Nehemy, Márcio Bittar

2017-07-01

To investigate the correlation between the length of external limiting membrane (ELM), ellipsoid zone (EZ) and interdigitation zone (IZ) defects and visual prognosis in patients undergoing macular hole (MH) surgery, using spectral-domain optical coherence tomography (SD-OCT). This is a retrospective, consecutive, observational case series study. Fifty-two eyes of 52 patients with primary MH were evaluated. A quantitative analysis of ELM, EZ and IZ defects was performed preoperatively and at 3 and 6 months postoperatively using SD-OCT. The correlation between pre- and postoperative ELM, EZ and IZ defects and the best-corrected visual acuity (BCVA) was investigated. The lengths of ELM, EZ and IZ defects correlated significantly with BCVA in each study period (P < 0.001). Preoperative measures of these band defects were also associated with visual outcomes 3 and 6 months after surgery (P < 0.05). Considering all preoperative parameters, the length of the ELM defect was the factor most strongly correlated with BCVA at 6 months (β = 0.643, P < 0.012). The integrity of the ELM was the only factor significantly associated with BCVA at 6 months (β = 0.427; P = 0.004). The preoperative length of the ELM defect is the strongest predictor of visual acuity after MH surgery. Postoperative integrity of the ELM is significantly associated with visual restoration after surgical treatment of MH.

Patterned Video Sensors For Low Vision

NASA Technical Reports Server (NTRS)

Juday, Richard D.

1996-01-01

Miniature video cameras containing photoreceptors arranged in prescribed non-Cartesian patterns to compensate partly for some visual defects proposed. Cameras, accompanied by (and possibly integrated with) miniature head-mounted video display units restore some visual function in humans whose visual fields reduced by defects like retinitis pigmentosa.

A support vector machine approach for classification of welding defects from ultrasonic signals

NASA Astrophysics Data System (ADS)

Chen, Yuan; Ma, Hong-Wei; Zhang, Guang-Ming

2014-07-01

Defect classification is an important issue in ultrasonic non-destructive evaluation. A layered multi-class support vector machine (LMSVM) classification system, which combines multiple SVM classifiers through a layered architecture, is proposed in this paper. The proposed LMSVM classification system is applied to the classification of welding defects from ultrasonic test signals. The measured ultrasonic defect echo signals are first decomposed into wavelet coefficients by the wavelet packet transform. The energy of the wavelet coefficients at different frequency channels are used to construct the feature vectors. The bees algorithm (BA) is then used for feature selection and SVM parameter optimisation for the LMSVM classification system. The BA-based feature selection optimises the energy feature vectors. The optimised feature vectors are input to the LMSVM classification system for training and testing. Experimental results of classifying welding defects demonstrate that the proposed technique is highly robust, precise and reliable for ultrasonic defect classification.

Photographic guide to selected external defect indicators and associated internal defects in black cherry

Treesearch

Everette D. Rast; John A. Beaton; John A. Beaton

1985-01-01

To properly classify or grade logs or trees, one must be able to correctly identify defect indicators and assess the effect of the underlying defect on possible end products. This guide aids the individual in identifying the surface defect indicator and also shows the progressive stages of the defect throughout its development for black cherry. It illustrates and...

Photographic guide of selected external defect indicators and associated internal defects in yellow birch

Treesearch

Everette D. Rast; John A. Beaton; David L. Sonderman

1991-01-01

To properly classify or grade logs or trees, one must be able to correctly identify defect indicators and assess the effect of the underlying defect on possible end products. This guide assists the individual in identifying the surface defect indicator and shows the progressive stages of the defect throughout its development for yellow birch. Eleven types of external...

Photographic guide of selected external defect indicators and associated internal defects in sugar maple

Treesearch

Everette D. Rast; John A. Beaton; David L. Sonderman

1991-01-01

To properly classify or grade logs or trees, one must be able to correctly identify defect indicators and assess the effect of the underlying defect on possible end products. This guide assists the individual in identifying the surface defect indicator and shows the progressive stages of the defect throughout its development for sugar maple. Eleven types of external...

Photographic guide to selected external defect indicators and associated internal defects in black walnut

Treesearch

Everette D.Beaton John A. Rast; David L. Sonderman; David L. Sonderman

1988-01-01

To properly classify qr grade logs or trees, one must be able to correctly identify defect indicators and assess the effect of the underlying defect on possible end products. This guide aids the individual in identifying the surface defect indicator and also shows the progressive stages of the defect throughout its develqpment for black walnut. It illustrates and...

Photographic guide of selected external defect indicators and associated internal defects in white oak

Treesearch

Everette D. Rast; John A. Beaton; David L. Sonderman; David L. Sonderman

1989-01-01

To properly classify or grade logs or trees, one must be able to correctly identify defect indicators and assess the effect of the underlying defect on possible end products. This guide assists the individual in identifying the surface defect indicator and also shows the progressive stages of the defect throughout its development for white oak. It illustrates and...

Photographic guide of selected external defect indicators and associated internal defects in yellow-poplar

Treesearch

Everette D. Rast; John A. Beaton; David L. Sonderman

1991-01-01

To properly classify or grade logs or trees, one must be able to correctly identify defect indicators and assess the effect of the underlying defect on possible end products. This guide assists the individual in identifying the surface defect indicator and shows the progressive stages of the defect throughout its development for yellow-poplar. Twelve types of external...

Photographic guide of selected external defect indicators and associated internal defects in northern red oak

Treesearch

Everette D. Rast

1982-01-01

To properly classify or grade logs or trees, one must be able to correctly identify defect indicators and assess the effect of the underlying defect on possible end products. This guide aids the individual in identifying the surface defect indicator and also shows the progressive stages of the defect throughout its development. It illustrates and describes eight types...

Field of dreamers and dreamed-up fields: functional and fake perimetry.

PubMed

Thompson, J C; Kosmorsky, G S; Ellis, B D

1996-01-01

Hysterical and malingering patients can manifest visual field defects on perimetry (visual field testing), including defects suggestive of true visual pathway pathology. It has been shown that control subjects can easily imitate some pathologic defects with automated, computed perimetry. The authors sought to determine whether subjects could imitate the same pathologic defect with manual and automated perimetry. Six subjects posed as patients with neurologic problems. They had manual perimetry with both an experienced and inexperienced technician followed by automated perimetry. They were later interviewed about the methods of the technicians and the difficulty of the exercise. Four of six subjects easily imitated the assigned defects with both technicians on manual perimetry and with automated perimetry. These included quadrantic, altitudinal, hemianopic, and enlarged blind-spot defects. Two subjects who were assigned cecocentral and paracentral scotomas instead produced enlarged blind spots by manual perimetry and defects suggestive of chiasmal pathology by automated perimetry. Paradoxically, some subjects found that experienced technicians were easier to fool than inexperienced technicians because of the systematic way in which experienced technicians defined defects. With minimal coaching, some subjects can imitate visual fields with enlarged blind spots, quadrantic, hemianopic, and altitudinal defects with ease and reproducibility by both automated and manual perimetry. Cecocentral and paracentral scotomas are harder to imitate but may be mistaken as representing chiasmal pathology. Paradoxically, experienced technicians may not be better at detecting hysterical or malingering individuals.

The Role of Visual Form in Lexical Access: Evidence from Chinese Classifier Production

ERIC Educational Resources Information Center

Bi, Yanchao; Yu, Xi; Geng, Jingyi; Alario, F. -Xavier.

2010-01-01

The interface between the conceptual and lexical systems was investigated in a word production setting. We tested the effects of two conceptual dimensions--semantic category and visual shape--on the selection of Chinese nouns and classifiers. Participants named pictures with nouns ("rope") or classifier-noun phrases ("one-"classifier"-rope") in…

Chronic Invasive Fungal Sinusitis Presenting as Inferior Altitudinal Visual Field Defect.

PubMed

Bansal, Reema; Takkar, Aastha; Lal, Vivek; Bal, Amanjit; Bansal, Sandeep

2017-06-01

A young male with acute blurring of vision (6/9) complained of an inferior altitudinal field defect in right eye. Clinical ophthalmological examination was normal. Magnetic resonance imaging (MRI) of the brain revealed the expansion and mucosal thickening of right posterior ethmoid and sphenoid sinuses and opacified right maxillary sinus. Surgical intervention (transethmoidal sphenoidotomy) and histopathological examination revealed chronic invasive granulomatous fungal sinusitis. Anti-fungal therapy led to resolution of visual complaints and restoration of visual field defects.

Do NiTi instruments show defects before separation? Defects caused by torsional fatigue in hand and rotary nickel-titanium (NiTi) instruments which lead to failure during clinical use.

PubMed

Chakka, N V Murali Krishna; Ratnakar, P; Das, Sanjib; Bagchi, Anandamy; Sudhir, Sudhir; Anumula, Lavanya

2012-11-01

Visual and microscopic evaluation of defects caused by torsional fatigue in hand and rotary nickel titanium (NiTi) instruments. Ninety-six NiTi greater taper instruments which were routinely used for root canal treatment only in anterior teeth were selected for the study. The files taken include ProTaper for hand use, ProTaper Rotary files and Endowave rotary files. After every use, the files were observed visually and microscopically (Stereomicroscope at 10×) to evaluate the defects caused by torsional fatigue. Scoring was given according to a new classification formulated which gives an indication of the severity of the defect or damage. Data was statistically analyzed using KruskallWallis and Mann-Whitney U test. Number of files showing defects were more under stereomicroscope than visual examination. But, the difference in the evaluation methods was not statistically significant. The different types of defects observed were bent instrument, straightening/stretching of twist contour and partial reverse twisting. Endowave files showed maximum number of defects followed by ProTaper for hand use and least in ProTaper Rotary. Visible defects due to torsional fatigue do occur in NiTi instruments after clinical use. Both visual and microscopic examinations were efficient in detecting defects caused due to torsional fatigue. This study emphasizes that all files should be observed for any visible defects before and after every instrumentation cycle to minimize the risk of instrument separation and failure of endodontic therapy.

Integrating concept ontology and multitask learning to achieve more effective classifier training for multilevel image annotation.

PubMed

Fan, Jianping; Gao, Yuli; Luo, Hangzai

2008-03-01

In this paper, we have developed a new scheme for achieving multilevel annotations of large-scale images automatically. To achieve more sufficient representation of various visual properties of the images, both the global visual features and the local visual features are extracted for image content representation. To tackle the problem of huge intraconcept visual diversity, multiple types of kernels are integrated to characterize the diverse visual similarity relationships between the images more precisely, and a multiple kernel learning algorithm is developed for SVM image classifier training. To address the problem of huge interconcept visual similarity, a novel multitask learning algorithm is developed to learn the correlated classifiers for the sibling image concepts under the same parent concept and enhance their discrimination and adaptation power significantly. To tackle the problem of huge intraconcept visual diversity for the image concepts at the higher levels of the concept ontology, a novel hierarchical boosting algorithm is developed to learn their ensemble classifiers hierarchically. In order to assist users on selecting more effective hypotheses for image classifier training, we have developed a novel hyperbolic framework for large-scale image visualization and interactive hypotheses assessment. Our experiments on large-scale image collections have also obtained very positive results.

Design of an aid to visual inspection workstation

NASA Astrophysics Data System (ADS)

Tait, Robert; Harding, Kevin

2016-05-01

Visual Inspection is the most common means for inspecting manufactured parts for random defects such as pits, scratches, breaks, corrosion or general wear. The reason for the need for visual inspection is the very random nature of what might be a defect. Some defects may be very rare, being seen once or twice a year, but May still be critical to part performance. Because of this random and rare nature, even the most sophisticated image analysis programs have not been able to recognize all possible defects. Key to any future automation of inspection is obtaining good sample images of what might be a defect. However, most visual check take no images and consequently generate no digital data or historical record beyond a simple count. Any additional tool to captures such images must be able to do so without taking addition time. This paper outlines the design of a potential visual inspection station that would be compatible with current visual inspection methods, but afford the means for reliable digital imaging and in many cases augmented capabilities to assist the inspection. Considerations in this study included: resolution, depth of field, feature highlighting, and ease of digital capture, annotations and inspection augmentation for repeatable registration as well as operator assistance and training.

Towards more reliable automated multi-dose dispensing: retrospective follow-up study on medication dose errors and product defects.

PubMed

Palttala, Iida; Heinämäki, Jyrki; Honkanen, Outi; Suominen, Risto; Antikainen, Osmo; Hirvonen, Jouni; Yliruusi, Jouko

2013-03-01

To date, little is known on applicability of different types of pharmaceutical dosage forms in an automated high-speed multi-dose dispensing process. The purpose of the present study was to identify and further investigate various process-induced and/or product-related limitations associated with multi-dose dispensing process. The rates of product defects and dose dispensing errors in automated multi-dose dispensing were retrospectively investigated during a 6-months follow-up period. The study was based on the analysis of process data of totally nine automated high-speed multi-dose dispensing systems. Special attention was paid to the dependence of multi-dose dispensing errors/product defects and pharmaceutical tablet properties (such as shape, dimensions, weight, scored lines, coatings, etc.) to profile the most suitable forms of tablets for automated dose dispensing systems. The relationship between the risk of errors in dose dispensing and tablet characteristics were visualized by creating a principal component analysis (PCA) model for the outcome of dispensed tablets. The two most common process-induced failures identified in the multi-dose dispensing are predisposal of tablet defects and unexpected product transitions in the medication cassette (dose dispensing error). The tablet defects are product-dependent failures, while the tablet transitions are dependent on automated multi-dose dispensing systems used. The occurrence of tablet defects is approximately twice as common as tablet transitions. Optimal tablet preparation for the high-speed multi-dose dispensing would be a round-shaped, relatively small/middle-sized, film-coated tablet without any scored line. Commercial tablet products can be profiled and classified based on their suitability to a high-speed multi-dose dispensing process.

Interventions for visual field defects in patients with stroke.

PubMed

Pollock, Alex; Hazelton, Christine; Henderson, Clair A; Angilley, Jayne; Dhillon, Baljean; Langhorne, Peter; Livingstone, Katrina; Munro, Frank A; Orr, Heather; Rowe, Fiona J; Shahani, Uma

2011-10-05

Visual field defects are estimated to affect 20% to 57% of people who have had a stroke. Visual field defects can affect functional ability in activities of daily living (commonly affecting mobility, reading and driving), quality of life, ability to participate in rehabilitation, and depression, anxiety and social isolation following stroke. There are many interventions for visual field defects, which are proposed to work by restoring the visual field (restitution); compensating for the visual field defect by changing behaviour or activity (compensation); substituting for the visual field defect by using a device or extraneous modification (substitution); or ensuring appropriate diagnosis, referral and treatment prescription through standardised assessment or screening, or both. To determine the effects of interventions for people with visual field defects after stroke. We searched the Cochrane Stroke Group Trials Register (February 2011), the Cochrane Eyes and Vision Group Trials Register (December 2009) and nine electronic bibliographic databases including CENTRAL (The Cochrane Library 2009, Issue 4), MEDLINE (1950 to December 2009), EMBASE (1980 to December 2009), CINAHL (1982 to December 2009), AMED (1985 to December 2009), and PsycINFO (1967 to December 2009). We also searched reference lists and trials registers, handsearched journals and conference proceedings and contacted experts. Randomised trials in adults after stroke, where the intervention was specifically targeted at improving the visual field defect or improving the ability of the participant to cope with the visual field loss. The primary outcome was functional ability in activities of daily living and secondary outcomes included functional ability in extended activities of daily living, reading ability, visual field measures, balance, falls, depression and anxiety, discharge destination or residence after stroke, quality of life and social isolation, visual scanning, adverse events and death. Two review authors independently screened abstracts, extracted data and appraised trials. We undertook an assessment of methodological quality for allocation concealment, blinding of outcome assessors, method of dealing with missing data, and other potential sources of bias. Thirteen studies (344 randomised participants, 285 of whom were participants with stroke) met the inclusion criteria for this review. However, only six of these studies compared the effect of an intervention with a placebo, control or no treatment group and were included in comparisons within this review. Four studies compared the effect of scanning (compensatory) training with a control or placebo intervention. Meta-analysis demonstrated that scanning training is more effective than control or placebo at improving reading ability (three studies, 129 participants; mean difference (MD) 3.24, 95% confidence interval (CI) 0.84 to 5.59) and visual scanning (three studies, 129 participants; MD 18.84, 95% CI 12.01 to 25.66) but that scanning may not improve visual field outcomes (two studies, 110 participants; MD -0.70, 95% CI -2.28 to 0.88). There were insufficient data to enable generalised conclusions to be made about the effectiveness of scanning training relative to control or placebo for the primary outcome of activities of daily living (one study, 33 participants). Only one study (19 participants) compared the effect of a restitutive intervention with a control or placebo intervention and only one study (39 participants) compared the effect of a substitutive intervention with a control or placebo intervention. There is limited evidence which supports the use of compensatory scanning training for patients with visual field defects (and possibly co-existing visual neglect) to improve scanning and reading outcomes. There is insufficient evidence to reach a conclusion about the impact of compensatory scanning training on functional activities of daily living. There is insufficient evidence to reach generalised conclusions about the benefits of visual restitution training (VRT) (restitutive intervention) or prisms (substitutive intervention) for patients with visual field defects after stroke.

Clinical spectrum of lamellar macular defects including pseudoholes and pseudocysts defined by optical coherence tomography

PubMed Central

Chen, J C; Lee, L R

2008-01-01

Objective: To present the clinical spectrum of lamellar macular defects and describe the different subtypes based on their optical coherence tomography (OCT) configuration and visual prognosis. Methods: The retrospective observational case series reviewed OCT scans of 92 eyes with lamellar macular defects. Lamellar macular defects were categorised into subtypes of macular pseudohole (MPH), lamellar macular hole (LMH) and foveal pseudocyst (FP) according to their OCT morphology. The defects were quantitatively characterised in terms of base diameter, depth and central foveal thickness, and examined for the presence of associated epiretinal membranes (ERM). Results: Visual acuity (VA) was significantly correlated with the central foveal thickness and depth of the lamellar defect. MPH was associated with better VA compared with LMH and FP. MPH was of a smaller base diameter and had a greater central foveal thickness than that of LMH and FP. Fifty-per cent of all lamellar defects had an associated ERM. Conclusions: Different profiles of lamellar macular defects were characterised and quantified by OCT. Deeper and wider lamellar defects were associated with poorer visual outcome. Such objective parameters lamellar macular defects are of value when explaining to patients regarding their decreased acuity. Future prospective investigations are required to study the natural history of lamellar defects of different aetiology and surgical indications. PMID:18684752

Advanced Image Processing for Defect Visualization in Infrared Thermography

NASA Technical Reports Server (NTRS)

Plotnikov, Yuri A.; Winfree, William P.

1997-01-01

Results of a defect visualization process based on pulse infrared thermography are presented. Algorithms have been developed to reduce the amount of operator participation required in the process of interpreting thermographic images. The algorithms determine the defect's depth and size from the temporal and spatial thermal distributions that exist on the surface of the investigated object following thermal excitation. A comparison of the results from thermal contrast, time derivative, and phase analysis methods for defect visualization are presented. These comparisons are based on three dimensional simulations of a test case representing a plate with multiple delaminations. Comparisons are also based on experimental data obtained from a specimen with flat bottom holes and a composite panel with delaminations.

Diagnostic Accuracy of Nonmydriatic Fundus Photography for the Detection of Glaucoma in Diabetic Patients.

PubMed

Muñoz-Negrete, Francisco J; Contreras, Inés; Oblanca, Noelia; Pinazo-Durán, M Dolores; Rebolleda, Gema

2015-01-01

To determine the diagnostic accuracy for glaucoma of a set of criteria with nonmydriatic monoscopic fundus photography (NMFP) in diabetics. Diabetics recruited from a screening program for diabetic retinopathy and diabetic glaucoma patients recruited from our glaucoma unit were included. Any patient with evidence of diabetic retinopathy was excluded. Diabetic patients had to have no visual field defects to be included as controls. Glaucoma patients had to have a glaucomatous field defect in at least one eye to be included. One NMFP was taken per eye for all subjects. These photographs were evaluated by two masked glaucoma specialists for the presence of the following: bilateral cup to disc (C/D) ratio ≥ 0.6, notching or thinning of the neuroretinal rim, disc hemorrhages, and asymmetry in the C/D ratio between both eyes ≥ 0.2. This evaluation led to a dichotomous classification: if any of the above criteria was present, the patient was classified as glaucoma. If none were present, the patient was classified as normal. 72 control subjects and 72 glaucoma patients were included. Evaluation of NMFP had a sensitivity of 79.17% and a specificity of 80.56% for specialist 1 and a sensitivity of 72.22% and a specificity of 88.88% for specialist 2 for the detection of glaucoma. The overall accuracy was 79.83% and 80.55%, respectively. NMFP evaluation by a glaucoma specialist may be useful for the detection of glaucoma in diabetics.

Comparison of Diagnostic Accuracy between Octopus 900 and Goldmann Kinetic Visual Fields

PubMed Central

Rowe, Fiona J.; Rowlands, Alison

2014-01-01

Purpose. To determine diagnostic accuracy of kinetic visual field assessment by Octopus 900 perimetry compared with Goldmann perimetry. Methods. Prospective cross section evaluation of 40 control subjects with full visual fields and 50 patients with known visual field loss. Comparison of test duration and area measurement of isopters for Octopus 3, 5, and 10°/sec stimulus speeds. Comparison of test duration and type of visual field classification for Octopus versus Goldmann perimetry. Results were independently graded for presence/absence of field defect and for type and location of defect. Statistical evaluation comprised of ANOVA and paired t test for evaluation of parametric data with Bonferroni adjustment. Bland Altman and Kappa tests were used for measurement of agreement between data. Results. Octopus 5°/sec perimetry had comparable test duration to Goldmann perimetry. Octopus perimetry reliably detected type and location of visual field loss with visual fields matched to Goldmann results in 88.8% of results (K = 0.775). Conclusions. Kinetic perimetry requires individual tailoring to ensure accuracy. Octopus perimetry was reproducible for presence/absence of visual field defect. Our screening protocol when using Octopus perimetry is 5°/sec for determining boundaries of peripheral isopters and 3°/sec for blind spot mapping with further evaluation of area of field loss for defect depth and size. PMID:24587983

Qualitative properties of roasting defect beans and development of its classification methods by hyperspectral imaging technology.

PubMed

Cho, Jeong-Seok; Bae, Hyung-Jin; Cho, Byoung-Kwan; Moon, Kwang-Deog

2017-04-01

Qualitative properties of roasting defect coffee beans and their classification methods were studied using hyperspectral imaging (HSI). The roasting defect beans were divided into 5 groups: medium roasting (Cont), under developed (RD-1), over roasting (RD-2), interior under developed (RD-3), and interior scorching (RD-4). The following qualitative properties were assayed: browning index (BI), moisture content (MC), chlorogenic acid (CA), trigonelline (TG), and caffeine (CF) content. Their HSI spectra (1000-1700nm) were also analysed to develop the classification methods of roasting defect beans. RD-2 showed the highest BI and the lowest MC, CA, and TG content. The accuracy of classification model of partial least-squares discriminant was 86.2%. The most powerful wavelength to classify the defective beans was approximately 1420nm (related to OH bond). The HSI reflectance values at 1420nm showed similar tendency with MC, enabling the use of this technology to classify the roasting defect beans. Copyright © 2016. Published by Elsevier Ltd.

Textual and visual content-based anti-phishing: a Bayesian approach.

PubMed

Zhang, Haijun; Liu, Gang; Chow, Tommy W S; Liu, Wenyin

2011-10-01

A novel framework using a Bayesian approach for content-based phishing web page detection is presented. Our model takes into account textual and visual contents to measure the similarity between the protected web page and suspicious web pages. A text classifier, an image classifier, and an algorithm fusing the results from classifiers are introduced. An outstanding feature of this paper is the exploration of a Bayesian model to estimate the matching threshold. This is required in the classifier for determining the class of the web page and identifying whether the web page is phishing or not. In the text classifier, the naive Bayes rule is used to calculate the probability that a web page is phishing. In the image classifier, the earth mover's distance is employed to measure the visual similarity, and our Bayesian model is designed to determine the threshold. In the data fusion algorithm, the Bayes theory is used to synthesize the classification results from textual and visual content. The effectiveness of our proposed approach was examined in a large-scale dataset collected from real phishing cases. Experimental results demonstrated that the text classifier and the image classifier we designed deliver promising results, the fusion algorithm outperforms either of the individual classifiers, and our model can be adapted to different phishing cases. © 2011 IEEE

Role of Visual Feedback Treatment for Defective /s/ Sounds in Patients with Cleft Palate.

ERIC Educational Resources Information Center

Michi, Ken-ichi; And Others

1993-01-01

Six patients with cleft palate were provided treatment using either visual feedback for tongue placement and frication or no visual feedback. Results indicated the feedback was especially useful in the treatment of defective /s/ sounds in the patients who exhibited abnormal posterior tongue posturing during dental or alveolar sounds. (Author/DB)

COMPUTERIZED EXPERT SYSTEM FOR EVALUATION OF AUTOMATED VISUAL FIELDS FROM THE ISCHEMIC OPTIC NEUROPATHY DECOMPRESSION TRIAL: METHODS, BASELINE FIELDS, AND SIX-MONTH LONGITUDINAL FOLLOW-UP

PubMed Central

Feldon, Steven E

2004-01-01

ABSTRACT Purpose To validate a computerized expert system evaluating visual fields in a prospective clinical trial, the Ischemic Optic Neuropathy Decompression Trial (IONDT). To identify the pattern and within-pattern severity of field defects for study eyes at baseline and 6-month follow-up. Design Humphrey visual field (HVF) change was used as the outcome measure for a prospective, randomized, multi-center trial to test the null hypothesis that optic nerve sheath decompression was ineffective in treating nonarteritic anterior ischemic optic neuropathy and to ascertain the natural history of the disease. Methods An expert panel established criteria for the type and severity of visual field defects. Using these criteria, a rule-based computerized expert system interpreted HVF from baseline and 6-month visits for patients randomized to surgery or careful follow-up and for patients who were not randomized. Results A computerized expert system was devised and validated. The system was then used to analyze HVFs. The pattern of defects found at baseline for patients randomized to surgery did not differ from that of patients randomized to careful follow-up. The most common pattern of defect was a superior and inferior arcuate with central scotoma for randomized eyes (19.2%) and a superior and inferior arcuate for nonrandomized eyes (30.6%). Field patterns at 6 months and baseline were not different. For randomized study eyes, the superior altitudinal defects improved (P = .03), as did the inferior altitudinal defects (P = .01). For nonrandomized study eyes, only the inferior altitudinal defects improved (P = .02). No treatment effect was noted. Conclusions A novel rule-based expert system successfully interpreted visual field defects at baseline of eyes enrolled in the IONDT. PMID:15747764

Defect classification in sparsity-based structural health monitoring

NASA Astrophysics Data System (ADS)

Golato, Andrew; Ahmad, Fauzia; Santhanam, Sridhar; Amin, Moeness G.

2017-05-01

Guided waves have gained popularity in structural health monitoring (SHM) due to their ability to inspect large areas with little attenuation, while providing rich interactions with defects. For thin-walled structures, the propagating waves are Lamb waves, which are a complex but well understood type of guided waves. Recent works have cast the defect localization problem of Lamb wave based SHM within the sparse reconstruction framework. These methods make use of a linear model relating the measurements with the scene reflectivity under the assumption of point-like defects. However, most structural defects are not perfect points but tend to assume specific forms, such as surface cracks or internal cracks. Knowledge of the "type" of defects is useful in the assessment phase of SHM. In this paper, we present a dual purpose sparsity-based imaging scheme which, in addition to accurately localizing defects, properly classifies the defects present simultaneously. The proposed approach takes advantage of the bias exhibited by certain types of defects toward a specific Lamb wave mode. For example, some defects strongly interact with the anti-symmetric modes, while others strongly interact with the symmetric modes. We build model based dictionaries for the fundamental symmetric and anti-symmetric wave modes, which are then utilized in unison to properly localize and classify the defects present. Simulated data of surface and internal defects in a thin Aluminum plate are used to validate the proposed scheme.

Acquired color vision and visual field defects in patients with ocular hypertension and early glaucoma.

PubMed

Papaconstantinou, Dimitris; Georgalas, Ilias; Kalantzis, George; Karmiris, Efthimios; Koutsandrea, Chrysanthi; Diagourtas, Andreas; Ladas, Ioannis; Georgopoulos, Gerasimos

2009-01-01

To study acquired color vision and visual field defects in patients with ocular hypertension (OH) and early glaucoma. In a prospective study we evaluated 99 eyes of 56 patients with OH without visual field defects and no hereditary color deficiencies, followed up for 4 to 6 years (mean = 4.7 +/- 0.6 years). Color vision defects were studied using a special computer program for Farnsworth-Munsell 100 hue test and visual field tests were performed with Humphrey analyzer using program 30-2. Both tests were repeated every six months. In fifty-six eyes, glaucomatous defects were observed during the follow-up period. There was a statistically significant difference in total error score (TES) between eyes that eventually developed glaucoma (157.89 +/- 31.79) and OH eyes (75.51 +/- 31.57) at the first examination (t value 12.816, p < 0.001). At the same time visual field indices were within normal limits in both groups. In the glaucomatous eyes the earliest statistical significant change in TES was identified at the first year of follow-up and was -20.62 +/- 2.75 (t value 9.08, p < 0.001) while in OH eyes was -2.11 +/- 4.36 (t value 1.1, p = 0.276). Pearson's coefficient was high in all examinations and showed a direct correlation between TES and mean deviation and corrected pattern standard deviation in both groups. Quantitative analysis of color vision defects provides the possibility of follow-up and can prove a useful means for detecting early glaucomatous changes in patients with normal visual fields.

A new computer-based Farnsworth Munsell 100-hue test for evaluation of color vision.

PubMed

Ghose, Supriyo; Parmar, Twinkle; Dada, Tanuj; Vanathi, Murugesan; Sharma, Sourabh

2014-08-01

To evaluate a computer-based Farnsworth-Munsell (FM) 100-hue test and compare it with a manual FM 100-hue test in normal and congenital color-deficient individuals. Fifty color defective subjects and 200 normal subjects with a best-corrected visual acuity ≥ 6/12 were compared using a standard manual FM 100-hue test and a computer-based FM 100-hue test under standard operating conditions as recommended by the manufacturer after initial trial testing. Parameters evaluated were total error scores (TES), type of defect and testing time. Pearson's correlation coefficient was used to determine the relationship between the test scores. Cohen's kappa was used to assess agreement of color defect classification between the two tests. A receiver operating characteristic curve was used to determine the optimal cut-off score for the computer-based FM 100-hue test. The mean time was 16 ± 1.5 (range 6-20) min for the manual FM 100-hue test and 7.4 ± 1.4 (range 5-13) min for the computer-based FM 100-hue test, thus reducing testing time to <50 % (p < 0.05). For grading color discrimination, Pearson's correlation coefficient for TES between the two tests was 0.91 (p < 0.001). For color defect classification, Cohen's agreement coefficient was 0.98 (p < 0.01). The computer-based FM 100-hue is an effective and rapid method for detecting, classifying and grading color vision anomalies.

Ensemble of classifiers for confidence-rated classification of NDE signal

NASA Astrophysics Data System (ADS)

Banerjee, Portia; Safdarnejad, Seyed; Udpa, Lalita; Udpa, Satish

2016-02-01

Ensemble of classifiers in general, aims to improve classification accuracy by combining results from multiple weak hypotheses into a single strong classifier through weighted majority voting. Improved versions of ensemble of classifiers generate self-rated confidence scores which estimate the reliability of each of its prediction and boost the classifier using these confidence-rated predictions. However, such a confidence metric is based only on the rate of correct classification. In existing works, although ensemble of classifiers has been widely used in computational intelligence, the effect of all factors of unreliability on the confidence of classification is highly overlooked. With relevance to NDE, classification results are affected by inherent ambiguity of classifica-tion, non-discriminative features, inadequate training samples and noise due to measurement. In this paper, we extend the existing ensemble classification by maximizing confidence of every classification decision in addition to minimizing the classification error. Initial results of the approach on data from eddy current inspection show improvement in classification performance of defect and non-defect indications.

Driving with Binocular Visual Field Loss? A Study on a Supervised On-Road Parcours with Simultaneous Eye and Head Tracking

PubMed Central

Aehling, Kathrin; Heister, Martin; Rosenstiel, Wolfgang; Schiefer, Ulrich; Papageorgiou, Elena

2014-01-01

Post-chiasmal visual pathway lesions and glaucomatous optic neuropathy cause binocular visual field defects (VFDs) that may critically interfere with quality of life and driving licensure. The aims of this study were (i) to assess the on-road driving performance of patients suffering from binocular visual field loss using a dual-brake vehicle, and (ii) to investigate the related compensatory mechanisms. A driving instructor, blinded to the participants' diagnosis, rated the driving performance (passed/failed) of ten patients with homonymous visual field defects (HP), including four patients with right (HR) and six patients with left homonymous visual field defects (HL), ten glaucoma patients (GP), and twenty age and gender-related ophthalmologically healthy control subjects (C) during a 40-minute driving task on a pre-specified public on-road parcours. In order to investigate the subjects' visual exploration ability, eye movements were recorded by means of a mobile eye tracker. Two additional cameras were used to monitor the driving scene and record head and shoulder movements. Thus this study is novel as a quantitative assessment of eye movements and an additional evaluation of head and shoulder was performed. Six out of ten HP and four out of ten GP were rated as fit to drive by the driving instructor, despite their binocular visual field loss. Three out of 20 control subjects failed the on-road assessment. The extent of the visual field defect was of minor importance with regard to the driving performance. The site of the homonymous visual field defect (HVFD) critically interfered with the driving ability: all failed HP subjects suffered from left homonymous visual field loss (HL) due to right hemispheric lesions. Patients who failed the driving assessment had mainly difficulties with lane keeping and gap judgment ability. Patients who passed the test displayed different exploration patterns than those who failed. Patients who passed focused longer on the central area of the visual field than patients who failed the test. In addition, patients who passed the test performed more glances towards the area of their visual field defect. In conclusion, our findings support the hypothesis that the extent of visual field per se cannot predict driving fitness, because some patients with HVFDs and advanced glaucoma can compensate for their deficit by effective visual scanning. Head movements appeared to be superior to eye and shoulder movements in predicting the outcome of the driving test under the present study scenario. PMID:24523869

Corticosteroid therapy in patients with non-arteritic anterior ischemic optic neuropathy.

PubMed

Vidović, Tomislav; Cerovski, Branimir; Perić, Sanja; Kordić, Rajko; Mrazovac, Danijela

2015-03-01

Non-arteritic anterior ischemic optic neuropathy is one of the most common conditions affecting the optic nerve in the elderly. It may lead to severe visual loss. Typical symptoms are painless impairment of visual function accompanied by relative afferent pupillary defect, edema of the optic disc and visual field defects. Aim is to present 38 patients with nonarteritic anterior ischemic optic neuropathy who were treated with corticosteroid therapy. This prospective study involved 38 patients, 20 men and 18 women aged 60-75 years who were treated with corticosteroid therapy. The study included patients with visual acuity in the affected eye from 0.1 to 0.8 according to Snellen. Every patient underwent clinical examination, the Octopus 900 perimetry in G program, laboratory testing, while the compressive optic neuropathy was rule out with MSCT of the brain and orbits. The most common forms of visual field defect are altitudinal defect and diffuse depression. Corticosteroid therapy led to recovery in 65% of patient, in 30% of patients did not change, while the deterioration occurred in 5% of patients.

Neurorehabilitation of saccadic ocular movement in a patient with a homonymous hemianopia postgeniculate caused by an arteriovenous malformation

PubMed Central

Pineda-Ortíz, Mirna; Pacheco-López, Gustavo; Rubio-Osornio, Moisés; Rubio, Carmen; Valadez-Rodríguez, Juan

2018-01-01

Abstract Rationale: Visual therapy, which includes a restorative and compensatory approach, seems to be a viable treatment option for homonymous defects of the visual field in patients with postgeniculate injury of the visual pathway, due to occipital arteriovenous malformation (AVM). Until now, the Mexican population suffering from homonymous hemianopia did not have health services that provided any type of visual therapy for their condition. Patient concerns: A 31-year-old patient, who underwent a surgical procedure for resection of the AVM, was referred with posterior low vision on the left side. Diagnoses: The patient was diagnosed with left homonymous hemianopia. Interventions: Visual neurorehabilitation therapy (NRT), which integrated restorative and compensatory approaches, was administered for 3 hours each week. NRT included fixation, follow-up, search, peripheral vision, and reading. Outcomes: The NRT did not change visual field defects and, retinotopocally, the same campimetric defects remained. However, after training the tracking ocular movements improved to standard values on the ENG, further, the visual search became more organized. The reading reached a level without mistakes, with rhythm and goog intonation. The Beck test demostrated an improvement in depression symptoms. Regarding the daily life activities, the patient reported significant improvements. Lessons: Visual NRT can significantly improve eye movements, as well as the quality of life and independence of the patient. This integral approach could be an effective therapeutic option for homonymous defects of the visual field. PMID:29538218

Red square test for visual field screening. A sensitive and simple bedside test.

PubMed

Mandahl, A

1994-12-01

A reliable bedside test for screening of visual field defects is a valuable tool in the examination of patients with a putative disease affecting the sensory visual pathways. Conventional methods such as Donders' confrontation method, counting fingers in the visual field periphery, of two-hand confrontation are not sufficiently sensitive to detect minor but nevertheless serious visual field defects. More sensitive methods requiring only simple tools are also described. In this study, a test card with four red squares surrounding a fixation target, a black dot, with a total test area of about 11 x 12.5 degrees at a distance of 30 cm, was designed for testing experience of red colour saturation in four quadrants, red square test. The Goldmann visual field was used as reference. 125 consecutive patients with pituitary adenoma (159 eyes), craniopharyngeoma (9 eyes), meningeoma (21 eyes), vascular hemisphere lesion (40 eyes), hemisphere tumour (10 eyes) and hemisphere abscess (2 eyes) were examined. The Goldmann visual field and red square test were pathological in pituitary adenomas in 35%, in craniopharyngeomas in 44%, in meningeomas in 52% and in hemisphere tumours or abscess in 100% of the eyes. Among these, no false-normal or false-pathological tests were found. However, in vascular hemisphere disease the corresponding figures were Goldmann visual field 90% and red square test 85%. The 5% difference (4 eyes) was due to Goldmann visual field defects strictly peripheral to the central 15 degrees. These defects were easily diagnosed with two-hand confrontation and

Anatomical Variant of Atlas : Arcuate Foramen, Occpitalization of Atlas, and Defect of Posterior Arch of Atlas.

PubMed

Kim, Myoung Soo

2015-12-01

We sought to examine anatomic variations of the atlas and the clinical significance of these variations. We retrospectively reviewed 1029 cervical 3-dimensional (3D) CT images. Cervical 3D CT was performed between November 2011 and August 2014. Arcuate foramina were classified as partial or complete and left and/or right. Occipitalization of the atlas was classified in accordance with criteria specified by Mudaliar et al. Posterior arch defects of the atlas were classified in accordance with criteria specified by Currarino et al. One hundred and eight vertebrae (108/1029, 10.5%) showed an arcuate foramen. Bilateral arcuate foramina were present in 41 of these vertebrae and the remaining 67 arcuate foramina were unilateral (right 31, left 36). Right-side arcuate foramina were partial on 18 sides and complete on 54 sides. Left-side arcuate foramina were partial on 24 sides and complete on 53 sides. One case of atlas assimilation was found. Twelve patients (12/1029, 1.17%) had a defect of the atlantal posterior arch. Nine of these patients (9/1029, 0.87%) had a type A posterior arch defect. We also identified one type B, one type D, and one type E defect. Preoperative diagnosis of occipitalization of the atlas and arcuate foramina using 3D CT is of paramount importance in avoiding neurovascular injury during surgery. It is important to be aware of posterior arch defects of the atlas because they may be misdiagnosed as a fracture.

Modified classification and single-stage microsurgical repair of posttraumatic infected massive bone defects in lower extremities.

PubMed

Yang, Yun-fa; Xu, Zhong-he; Zhang, Guang-ming; Wang, Jian-wei; Hu, Si-wang; Hou, Zhi-qi; Xu, Da-chuan

2013-11-01

Posttraumatic infected massive bone defects in lower extremities are difficult to repair because they frequently exhibit massive bone and/or soft tissue defects, serious bone infection, and excessive scar proliferation. This study aimed to determine whether these defects could be classified and repaired at a single stage. A total of 51 cases of posttraumatic infected massive bone defect in lower extremity were included in this study. They were classified into four types on the basis of the conditions of the bone defects, soft tissue defects, and injured limb length, including Type A (without soft tissue defects), Type B (with soft tissue defects of 10 × 20 cm or less), Type C (with soft tissue defects of 10 × 20 cm or more), and Type D (with the limb shortening of 3 cm or more). Four types of single-stage microsurgical repair protocols were planned accordingly and implemented respectively. These protocols included the following: Protocol A, where vascularized fibular graft was implemented for Type A; Protocol B, where vascularized fibular osteoseptocutaneous graft was implemented for Type B; Protocol C, where vascularized fibular graft and anterior lateral thigh flap were used for Type C; and Protocol D, where limb lengthening and Protocols A, B, or C were used for Type D. There were 12, 33, 4, and 2 cases of Types A, B, C, and D, respectively, according to this classification. During the surgery, three cases of planned Protocol B had to be shifted into Protocol C; however, all microsurgical repairs were completed. With reference to Johner-Wruhs evaluation method, the total percentage of excellent and good results was 82.35% after 6 to 41 months of follow-up. It was concluded that posttraumatic massive bone defects could be accurately classified into four types on the basis of the conditions of bone defects, soft tissue coverage, and injured limb length, and successfully repaired with the single-stage repair protocols after thorough debridement. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Vitreoretinal Interface Characteristics in Eyes with Idiopathic Macular Holes: Qualitative and Quantitative Analysis.

PubMed

Seyhan Karatepe, Arzu; Menteş, Jale; Erakgün, E Tansu; Afrashi, Filiz; Nalçacı, Serhad; Akkın, Cezmi; Ateş, Yeşim

2018-04-01

To determine the qualitative and quantitative vitreoretinal interface characteristics with spectral domain optical coherence tomography (SD-OCT) in eyes with macular hole (MH) and investigate their relation with best corrected visual acuity (BCVA) and MH duration. Sixty-one eyes of 46 consecutive patients diagnosed with idiopathic MH were included in the study. The mean age of the patients was 66.7±7.5 (51-79) years. Complete ophthalmologic examination and SD-OCT examination were performed in all eyes and MH stages were determined according to SD-OCT findings. Qualitative characteristics of the vitreoretinal interface were investigated, including vitreomacular traction, vitreopapillary traction, maculopapillary traction, vitreoschisis, intraretinal cyst, presence of epiretinal membrane, and the integrity of the photoreceptor inner segment-outer segment junction (IS/OS) and external limiting membrane (ELM). In addition, MH diameter, MH base diameter (MHBD), ELM defect diameter, IS/OS defect diameter, and MH height were quantitatively measured and the MH index was calculated. Out of 61 eyes, 9.8% were classified as stage 1a, 19.7% as stage 1b, 18% as stage 2, 23% as stage 3, and 29.5% as stage 4. Mean BCVA was 0.28±0.24 (1 mps-1.0) Snellen and MH duration was 10.08±18.6 (1-108) months. The most common interface characteristics associated with MH were determined as intraretinal cyst (91.8%), IS/OS defect (78.7%) and ELM defect (63.9%). Duration and stage of MH were inversely proportional to BCVA but directly proportional to the presence and diameter of IS/OS and ELM defects. BCVA was significantly lower in eyes with IS/OS and ELM defects (p<0.0001; p<0.0001 Mann-Whitney U test). We determined that the most important factors affecting BCVA in cases with idiopathic MH were MH stage, MH duration, MHBD, and the presence and diameter of IS/OS and ELM defects, which suggests that these parameters should be considered while making decisions about prognosis and treatment.

Integrating visual learning within a model-based ATR system

NASA Astrophysics Data System (ADS)

Carlotto, Mark; Nebrich, Mark

2017-05-01

Automatic target recognition (ATR) systems, like human photo-interpreters, rely on a variety of visual information for detecting, classifying, and identifying manmade objects in aerial imagery. We describe the integration of a visual learning component into the Image Data Conditioner (IDC) for target/clutter and other visual classification tasks. The component is based on an implementation of a model of the visual cortex developed by Serre, Wolf, and Poggio. Visual learning in an ATR context requires the ability to recognize objects independent of location, scale, and rotation. Our method uses IDC to extract, rotate, and scale image chips at candidate target locations. A bootstrap learning method effectively extends the operation of the classifier beyond the training set and provides a measure of confidence. We show how the classifier can be used to learn other features that are difficult to compute from imagery such as target direction, and to assess the performance of the visual learning process itself.

Acquired color vision and visual field defects in patients with ocular hypertension and early glaucoma

PubMed Central

Papaconstantinou, Dimitris; Georgalas, Ilias; Kalantzis, George; Karmiris, Efthimios; Koutsandrea, Chrysanthi; Diagourtas, Andreas; Ladas, Ioannis; Georgopoulos, Gerasimos

2009-01-01

Purpose: To study acquired color vision and visual field defects in patients with ocular hypertension (OH) and early glaucoma. Methods: In a prospective study we evaluated 99 eyes of 56 patients with OH without visual field defects and no hereditary color deficiencies, followed up for 4 to 6 years (mean = 4.7 ± 0.6 years). Color vision defects were studied using a special computer program for Farnsworth–Munsell 100 hue test and visual field tests were performed with Humphrey analyzer using program 30–2. Both tests were repeated every six months. Results: In fifty-six eyes, glaucomatous defects were observed during the follow-up period. There was a statistically significant difference in total error score (TES) between eyes that eventually developed glaucoma (157.89 ± 31.79) and OH eyes (75.51 ± 31.57) at the first examination (t value 12.816, p < 0.001). At the same time visual field indices were within normal limits in both groups. In the glaucomatous eyes the earliest statistical significant change in TES was identified at the first year of follow-up and was −20.62 ± 2.75 (t value 9.08, p < 0.001) while in OH eyes was −2.11 ± 4.36 (t value 1.1, p = 0.276). Pearson’s coefficient was high in all examinations and showed a direct correlation between TES and mean deviation and corrected pattern standard deviation in both groups. Conclusion: Quantitative analysis of color vision defects provides the possibility of follow-up and can prove a useful means for detecting early glaucomatous changes in patients with normal visual fields. PMID:19668575

Visual field defects after missile injuries to the geniculo-striate pathway in man.

NASA Technical Reports Server (NTRS)

Koerner, F.; Teuber, H.-L.

1973-01-01

The main objective of the survey reported was a quantitative comparison of different visual functions at identical retinal points of individual patients. The possibility to develop objective forms of visual-field testing was also explored, taking into account reports by Frydrychowicz and Harms (1940) and Harms (1951). These investigators had insisted that pupillary responses to light are depressed in areas of homonymous scotomata. The shapes of homonymous visual field defects are discussed together with questions regarding the association and dissociation of symptoms.

The effect of simulated altitude on the visual fields of glaucoma patients and the elderly.

DOT National Transportation Integrated Search

1991-01-01

This study tests whether mild hypoxia, that is typically encountered in civilian aircraft, causes temporary visual field defects in elderly persons or temporarily increases pre-existing defects in persons with glaucoma. The central 24-2 program on th...

The 1980 and 1981 accident experience of civil airmen with selected visual pathology.

DOT National Transportation Integrated Search

1983-07-01

In studies of the 1974-76 accident experience of U.S. general aviation pilots with static physical defects, all the significantly increased rates and ratios were for visual defect categories--blindness, or absence of either eye, deficient distant vis...

Adaptive classifier for steel strip surface defects

NASA Astrophysics Data System (ADS)

Jiang, Mingming; Li, Guangyao; Xie, Li; Xiao, Mang; Yi, Li

2017-01-01

Surface defects detection system has been receiving increased attention as its precision, speed and less cost. One of the most challenges is reacting to accuracy deterioration with time as aged equipment and changed processes. These variables will make a tiny change to the real world model but a big impact on the classification result. In this paper, we propose a new adaptive classifier with a Bayes kernel (BYEC) which update the model with small sample to it adaptive for accuracy deterioration. Firstly, abundant features were introduced to cover lots of information about the defects. Secondly, we constructed a series of SVMs with the random subspace of the features. Then, a Bayes classifier was trained as an evolutionary kernel to fuse the results from base SVMs. Finally, we proposed the method to update the Bayes evolutionary kernel. The proposed algorithm is experimentally compared with different algorithms, experimental results demonstrate that the proposed method can be updated with small sample and fit the changed model well. Robustness, low requirement for samples and adaptive is presented in the experiment.

Visual Field Defects and Retinal Ganglion Cell Losses in Human Glaucoma Patients

PubMed Central

Harwerth, Ronald S.; Quigley, Harry A.

2007-01-01

Objective The depth of visual field defects are correlated with retinal ganglion cell densities in experimental glaucoma. This study was to determine whether a similar structure-function relationship holds for human glaucoma. Methods The study was based on retinal ganglion cell densities and visual thresholds of patients with documented glaucoma (Kerrigan-Baumrind, et al.) The data were analyzed by a model that predicted ganglion cell densities from standard clinical perimetry, which were then compared to histologic cell counts. Results The model, without free parameters, produced accurate and relatively precise quantification of ganglion cell densities associated with visual field defects. For 437 sets of data, the unity correlation for predicted vs. measured cell densities had a coefficient of determination of 0.39. The mean absolute deviation of the predicted vs. measured values was 2.59 dB, the mean and SD of the distribution of residual errors of prediction was -0.26 ± 3.22 dB. Conclusions Visual field defects by standard clinical perimetry are proportional to neural losses caused by glaucoma. Clinical Relevance The evidence for quantitative structure-function relationships provides a scientific basis of interpreting glaucomatous neuropathy from visual thresholds and supports the application of standard perimetry to establish the stage of the disease. PMID:16769839

75 FR 54915 - Notice Pursuant to the National Cooperative Research and Production Act of 1993-Sensory System...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-09-09

... DEPARTMENT OF JUSTICE Antitrust Division Notice Pursuant to the National Cooperative Research and Production Act of 1993--Sensory System for Critical Infrastructure Defect Recognition, Visualization and... Critical Infrastructure Defect Recognition, Visualization and Failure Prediction ('Sensory System'') has...

[Are Visual Field Defects Reversible? - Visual Rehabilitation with Brains].

PubMed

Sabel, B A

2017-02-01

Visual field defects are considered irreversible because the retina and optic nerve do not regenerate. Nevertheless, there is some potential for recovery of the visual fields. This can be accomplished by the brain, which analyses and interprets visual information and is able to amplify residual signals through neuroplasticity. Neuroplasticity refers to the ability of the brain to change its own functional architecture by modulating synaptic efficacy. This is actually the neurobiological basis of normal learning. Plasticity is maintained throughout life and can be induced by repetitively stimulating (training) brain circuits. The question now arises as to how plasticity can be utilised to activate residual vision for the treatment of visual field loss. Just as in neurorehabilitation, visual field defects can be modulated by post-lesion plasticity to improve vision in glaucoma, diabetic retinopathy or optic neuropathy. Because almost all patients have some residual vision, the goal is to strengthen residual capacities by enhancing synaptic efficacy. New treatment paradigms have been tested in clinical studies, including vision restoration training and non-invasive alternating current stimulation. While vision training is a behavioural task to selectively stimulate "relative defects" with daily vision exercises for the duration of 6 months, treatment with alternating current stimulation (30 min. daily for 10 days) activates and synchronises the entire retina and brain. Though full restoration of vision is not possible, such treatments improve vision, both subjectively and objectively. This includes visual field enlargements, improved acuity and reaction time, improved orientation and vision related quality of life. About 70 % of the patients respond to the therapies and there are no serious adverse events. Physiological studies of the effect of alternating current stimulation using EEG and fMRI reveal massive local and global changes in the brain. These include local activation of the visual cortex and global reorganisation of neuronal brain networks. Because modulation of neuroplasticity can strengthen residual vision, the brain deserves a better reputation in ophthalmology for its role in visual rehabilitation. For patients, there is now more light at the end of the tunnel, because vision loss in some areas of the visual field defect is indeed reversible. Georg Thieme Verlag KG Stuttgart · New York.

Echocardiographic detection of ventricular septal defects in large animals.

PubMed

Pipers, F S; Reef, V; Wilson, J

1985-10-15

Ventricular septal defects in a foal, a 2-year-old filly, and 2 calves were demonstrated with M-mode and two-dimensional real-time echocardiography. The studies were performed with the animals unsedated, either standing or in lateral recumbency. Cardiac windows were located between the 4th and 7th intercostal spaces, approximately at the level of the olecranon. In each case, the septal defect was visualized high in the membranous portion of the interventricular septum. Defects were visualized by use of sector scanning or linear-array ultrasonic equipment, with transducer frequencies of 2.25 to 3.5 MHz.

Detecting wood surface defects with fusion algorithm of visual saliency and local threshold segmentation

NASA Astrophysics Data System (ADS)

Wang, Xuejuan; Wu, Shuhang; Liu, Yunpeng

2018-04-01

This paper presents a new method for wood defect detection. It can solve the over-segmentation problem existing in local threshold segmentation methods. This method effectively takes advantages of visual saliency and local threshold segmentation. Firstly, defect areas are coarsely located by using spectral residual method to calculate global visual saliency of them. Then, the threshold segmentation of maximum inter-class variance method is adopted for positioning and segmenting the wood surface defects precisely around the coarse located areas. Lastly, we use mathematical morphology to process the binary images after segmentation, which reduces the noise and small false objects. Experiments on test images of insect hole, dead knot and sound knot show that the method we proposed obtains ideal segmentation results and is superior to the existing segmentation methods based on edge detection, OSTU and threshold segmentation.

Laser vibrometry in the quality control of the break of tanned leather

NASA Astrophysics Data System (ADS)

Preciado, J. Sanchez; Lopez, C. Perez; Hernandez-Montes, M. del Socorro; Torre-Ibarra, M. de la; Moreno, J. M. Flores; Ruiz, C. Tavera; Mendoza Santoyo, F.; Galan, M.

2018-05-01

Tanning industry treats hides and the skin of animals for their use in products such as clothes, furniture and car's interiors. The worth of leather is highly affected by defects that may appear prior or during the tanning process. Break, which refers to the wrinkling of the grain surface of leather, is one of the main issues because it affects not only the visual appearance of leather, but also its mechanical properties. The standardized method to classify the break pattern is done by bending the leather with the hand and comparing visually the resulting wrinkles that appear with a reference pattern, which makes the classification subjective and limits the evaluation to small areas. Laser vibrometry is an optical technique that has been applied in vibrational and modal analysis, which are methodologies used to obtain the mechanical properties of materials. This work demonstrates the use of a single-point vibrometer as a noncontact and nondestructive optical method to discriminate among five break levels, which could increase the effectiveness of leather classification for quality control in the tanning industry.

A randomized controlled trial comparing 2 interventions for visual field loss with standard occupational therapy during inpatient stroke rehabilitation.

PubMed

Mödden, Claudia; Behrens, Marion; Damke, Iris; Eilers, Norbert; Kastrup, Andreas; Hildebrandt, Helmut

2012-06-01

Compensatory and restorative treatments have been developed to improve visual field defects after stroke. However, no controlled trials have compared these interventions with standard occupational therapy (OT). A total of 45 stroke participants with visual field defect admitted for inpatient rehabilitation were randomized to restorative computerized training (RT) using computer-based stimulation of border areas of their visual field defects or to a computer-based compensatory therapy (CT) teaching a visual search strategy. OT, in which different compensation strategies were used to train for activities of daily living, served as standard treatment for the active control group. Each treatment group received 15 single sessions of 30 minutes distributed over 3 weeks. The primary outcome measures were visual field expansion for RT, visual search performance for CT, and reading performance for both treatments. Visual conjunction search, alertness, and the Barthel Index were secondary outcomes. Compared with OT, CT resulted in a better visual search performance, and RT did not result in a larger expansion of the visual field. Intragroup pre-post comparisons demonstrated that CT improved all defined outcome parameters and RT several, whereas OT only improved one. CT improved functional deficits after visual field loss compared with standard OT and may be the intervention of choice during inpatient rehabilitation. A larger trial that includes lesion location in the analysis is recommended.

Comparison of Multidetector Computed Tomography and Flat-Panel Computed Tomography Regarding Visualization of Cortical Fractures, Cortical Defects, and Orthopedic Screws: A Phantom Study.

PubMed

Neubauer, Jakob; Benndorf, Matthias; Lang, Hannah; Lampert, Florian; Kemna, Lars; Konstantinidis, Lukas; Neubauer, Claudia; Reising, Kilian; Zajonc, Horst; Kotter, Elmar; Langer, Mathias; Goerke, Sebastian M

2015-08-01

To compare the visualization of cortical fractures, cortical defects, and orthopedic screws in a dedicated extremity flat-panel computed tomography (FPCT) scanner and a multidetector computed tomography (MDCT) scanner.We used feet of European roe deer as phantoms for cortical fractures, cortical defects, and implanted orthopedic screws. FPCT and MDCT scans were performed with equivalent dose settings. Six observers rated the scans according to number of fragments, size of defects, size of defects opposite orthopedic screws, and the length of different screws. The image quality regarding depiction of the cortical bone was assessed. The gold standard (real number of fragments) was evaluated by autopsy.The correlation of reader assessment of fragments, cortical defects, and screws with the gold standard was similar for FPCT and MDCT. Three readers rated the subjective image quality of the MDCT to be higher, whereas the others showed no preferences.Although the image quality was rated higher in the MDCT than in the FPCT by 3 out of 6 observers, both modalities proved to be comparable regarding the visualization of cortical fractures, cortical defects, and orthopedic screws and of use to musculoskeletal radiology regarding fracture detection and postsurgical evaluation in our experimental setting.

Labeling Defects in CT Images of Hardwood Logs with Species-Dependent and Species-Independent Classifiers

Treesearch

Pei Li; Jing He; A. Lynn Abbott; Daniel L. Schmoldt

1996-01-01

This paper analyses computed tomography (CT) images of hardwood logs, with the goal of locating internal defects. The ability to detect and identify defects automatically is a critical component of efficiency improvements for future sawmills and veneer mills. This paper describes an approach in which 1) histogram equalization is used during preprocessing to normalize...

A Comparison of Rule-Based, K-Nearest Neighbor, and Neural Net Classifiers for Automated

Treesearch

Tai-Hoon Cho; Richard W. Conners; Philip A. Araman

1991-01-01

Over the last few years the authors have been involved in research aimed at developing a machine vision system for locating and identifying surface defects on materials. The particular problem being studied involves locating surface defects on hardwood lumber in a species independent manner. Obviously, the accurate location and identification of defects is of paramount...

Automatic casting surface defect recognition and classification

NASA Astrophysics Data System (ADS)

Wong, Boon K.; Elliot, M. P.; Rapley, C. W.

1995-03-01

High integrity castings require surfaces free from defects to reduce, if not eliminate, vulnerability to component failure from such as physical or thermal fatigue or corrosion attack. Previous studies have shown that defects on casting surfaces can be optically enhanced from the surrounding randomly textured surface by liquid penetrants, magnetic particle and other methods. However, very little has been reported on recognition and classification of the defects. The basic problem is one of shape recognition and classification, where the shape can vary in size and orientation as well as in actual shape generally within an envelope that classifies it as a particular defect. The initial work done towards this has focused on recognizing and classifying standard shapes such as the circle, square, rectangle and triangle. Various approaches were tried and this led eventually to a series of fuzzy logic based algorithms from which very good results were obtained. From this work fuzzy logic memberships were generated for the detection of defects found on casting surfaces. Simulated model shapes of such as the quench crack, mechanical crack and hole have been used to test the generated algorithm and the results for recognition and classification are very encouraging.

Classification of Partial Discharge Measured under Different Levels of Noise Contamination.

PubMed

Jee Keen Raymond, Wong; Illias, Hazlee Azil; Abu Bakar, Ab Halim

2017-01-01

Cable joint insulation breakdown may cause a huge loss to power companies. Therefore, it is vital to diagnose the insulation quality to detect early signs of insulation failure. It is well known that there is a correlation between Partial discharge (PD) and the insulation quality. Although many works have been done on PD pattern recognition, it is usually performed in a noise free environment. Also, works on PD pattern recognition in actual cable joint are less likely to be found in literature. Therefore, in this work, classifications of actual cable joint defect types from partial discharge data contaminated by noise were performed. Five cross-linked polyethylene (XLPE) cable joints with artificially created defects were prepared based on the defects commonly encountered on site. Three different types of input feature were extracted from the PD pattern under artificially created noisy environment. These include statistical features, fractal features and principal component analysis (PCA) features. These input features were used to train the classifiers to classify each PD defect types. Classifications were performed using three different artificial intelligence classifiers, which include Artificial Neural Networks (ANN), Adaptive Neuro-Fuzzy Inference System (ANFIS) and Support Vector Machine (SVM). It was found that the classification accuracy decreases with higher noise level but PCA features used in SVM and ANN showed the strongest tolerance against noise contamination.

Defect Categorization: Making Use of a Decade of Widely Varying Historical Data

NASA Technical Reports Server (NTRS)

Shull, Forrest; Seaman, Carolyn; Godfrey, Sara H.; Guo, Yuepu

2008-01-01

This paper describes our experience in aggregating a number of historical datasets containing inspection defect data using different categorizing schemes. Our goal was to make use of the historical data by creating models to guide future development projects. We describe our approach to reconciling the different choices used in the historical datasets to categorize defects, and the challenges we faced. We also present a set of recommendations for others involved in classifying defects.

[Visual field defect in a patient given sodium valporate then carbamazepine: possible effect of aminotransferase inhibition].

PubMed

Jung, Ph; Doussard-Lefaucheux, S

2002-04-01

We report the case of a 25-years old woman with anti-epileptic drugs who presents a visual field defect similar to those described with vigabatrin even though she was successfully treated with valproic acid then carbamazepine without vigabatrin. The association with trichorrhexis nodosa, a hair disease sometimes associated with inherited perturbation of metabolism of urea cycle in which visual loss can occur, could suggest an aspecific inhibition of several aminotransferases which could explain different adverse effects of some anti-epileptic drugs (visual abnormalities, alopecia) perhaps in genetic predisposed patients.

[Analysis of 180 patients with sensory defect nystagmus (SDN) and congenital idiopathic nystagmus (CIN)].

PubMed

Lorenz, B; Gampe, E

2001-01-01

Analysis of the diseases underlying congenital nystagmus in a series of patients registered during 6 years as a prerequisite for adequate counselling of the families. Retrospective study of all patients that presented between 1992 and 1998 with congenital nystagmus not related to visual deprivation or acquired pathologies of the visual pathways. The patients were examined clinically and in dependence on the findings also by electrophysiological (Ganzfeld ERG and VEP, Albino-flash-VEP), psychophysical (colour vision, dark adaptation, spectral sensitivity), and molecular genetic methods. When estimated necessary, family members affected by history and unaffected family members were also examined. In cases of complex neuroophthalmological diseases a neuropaediatric examination including neuroimaging was initiated. In total, 180 patients could be analysed. A sensory defect nystagmus (SDN) was present in 142 patients (79%). The diagnoses were as follows: albinism (any form) in 56 patients (30%), progressive photoreceptor dystrophy in 20 patients (11%), stationary cone dysfunction in 18 patients (10%), bilateral optic nerve hypoplasia in 15 patients (8%), chorioretinal or optic nerve colobomata in 10 patients (6%), aniridia and its variants in 10 patients (6%), familial isolated nystagmus in 8 patients (5%), and congenital stationary night blindness in 5 patients (3%). 38 patients (21%) could not (yet) be classified. The prevalence of SDN as the manifesting symptom of a variety of well defined diseases in the present series of at least 79% is similar to that of 90% reported earlier. The precise diagnosis is a prerequisite for counselling the families as to functional prognosis and recurrence risk. Unnecessary neurological examinations including neuroimaging can be avoided.

Olive oil sensory defects classification with data fusion of instrumental techniques and multivariate analysis (PLS-DA).

PubMed

Borràs, Eva; Ferré, Joan; Boqué, Ricard; Mestres, Montserrat; Aceña, Laura; Calvo, Angels; Busto, Olga

2016-07-15

Three instrumental techniques, headspace-mass spectrometry (HS-MS), mid-infrared spectroscopy (MIR) and UV-visible spectrophotometry (UV-vis), have been combined to classify virgin olive oil samples based on the presence or absence of sensory defects. The reference sensory values were provided by an official taste panel. Different data fusion strategies were studied to improve the discrimination capability compared to using each instrumental technique individually. A general model was applied to discriminate high-quality non-defective olive oils (extra-virgin) and the lowest-quality olive oils considered non-edible (lampante). A specific identification of key off-flavours, such as musty, winey, fusty and rancid, was also studied. The data fusion of the three techniques improved the classification results in most of the cases. Low-level data fusion was the best strategy to discriminate musty, winey and fusty defects, using HS-MS, MIR and UV-vis, and the rancid defect using only HS-MS and MIR. The mid-level data fusion approach using partial least squares-discriminant analysis (PLS-DA) scores was found to be the best strategy for defective vs non-defective and edible vs non-edible oil discrimination. However, the data fusion did not sufficiently improve the results obtained by a single technique (HS-MS) to classify non-defective classes. These results indicate that instrumental data fusion can be useful for the identification of sensory defects in virgin olive oils. Copyright © 2016 Elsevier Ltd. All rights reserved.

Multifocal visual evoked potentials for early glaucoma detection.

PubMed

Weizer, Jennifer S; Musch, David C; Niziol, Leslie M; Khan, Naheed W

2012-07-01

To compare multifocal visual evoked potentials (mfVEP) with other detection methods in early open-angle glaucoma. Ten patients with suspected glaucoma and 5 with early open-angle glaucoma underwent mfVEP, standard automated perimetry (SAP), short-wave automated perimetry, frequency-doubling technology perimetry, and nerve fiber layer optical coherence tomography. Nineteen healthy control subjects underwent mfVEP and SAP for comparison. Comparisons between groups involving continuous variables were made using independent t tests; for categorical variables, Fisher's exact test was used. Monocular mfVEP cluster defects were associated with an increased SAP pattern standard deviation (P = .0195). Visual fields that showed interocular mfVEP cluster defects were more likely to also show superior quadrant nerve fiber layer thinning by OCT (P = .0152). Multifocal visual evoked potential cluster defects are associated with a functional and an anatomic measure that both relate to glaucomatous optic neuropathy. Copyright 2012, SLACK Incorporated.

Defining defect specifications to optimize photomask production and requalification

NASA Astrophysics Data System (ADS)

Fiekowsky, Peter

2006-10-01

Reducing defect repairs and accelerating defect analysis is becoming more important as the total cost of defect repairs on advanced masks increases. Photomask defect specs based on printability, as measured on AIMS microscopes has been used for years, but the fundamental defect spec is still the defect size, as measured on the photomask, requiring the repair of many unprintable defects. ADAS, the Automated Defect Analysis System from AVI is now available in most advanced mask shops. It makes the use of pure printability specs, or "Optimal Defect Specs" practical. This software uses advanced algorithms to eliminate false defects caused by approximations in the inspection algorithm, classify each defect, simulate each defect and disposition each defect based on its printability and location. This paper defines "optimal defect specs", explains why they are now practical and economic, gives a method of determining them and provides accuracy data.

Ultrasonic Signal Processing for Structural Health Monitoring

NASA Astrophysics Data System (ADS)

Michaels, Jennifer E.; Michaels, Thomas E.

2004-02-01

Permanently mounted ultrasonic sensors are a key component of systems under development for structural health monitoring. Signal processing plays a critical role in the viability of such systems due to the difficulty in interpreting signals received from structures of complex geometry. This paper describes a differential feature-based approach to classifying signal changes as either "environmental" or "structural". Data are presented from piezoelectric discs bonded to an aluminum specimen subjected to both environmental changes and introduction of artificial defects. The classifier developed as part of this study was able to correctly identify artificial defects that were not part of the initial training and evaluation data sets. Central to the success of the classifier was the use of the Short Time Cross Correlation to measure coherency between the signal and reference as a function of time.

Non-Mutually Exclusive Deep Neural Network Classifier for Combined Modes of Bearing Fault Diagnosis.

PubMed

Duong, Bach Phi; Kim, Jong-Myon

2018-04-07

The simultaneous occurrence of various types of defects in bearings makes their diagnosis more challenging owing to the resultant complexity of the constituent parts of the acoustic emission (AE) signals. To address this issue, a new approach is proposed in this paper for the detection of multiple combined faults in bearings. The proposed methodology uses a deep neural network (DNN) architecture to effectively diagnose the combined defects. The DNN structure is based on the stacked denoising autoencoder non-mutually exclusive classifier (NMEC) method for combined modes. The NMEC-DNN is trained using data for a single fault and it classifies both single faults and multiple combined faults. The results of experiments conducted on AE data collected through an experimental test-bed demonstrate that the DNN achieves good classification performance with a maximum accuracy of 95%. The proposed method is compared with a multi-class classifier based on support vector machines (SVMs). The NMEC-DNN yields better diagnostic performance in comparison to the multi-class classifier based on SVM. The NMEC-DNN reduces the number of necessary data collections and improves the bearing fault diagnosis performance.

Plant photonics: application of optical coherence tomography to monitor defects and rots in onion

NASA Astrophysics Data System (ADS)

Meglinski, I. V.; Buranachai, C.; Terry, L. A.

2010-04-01

The incidence of physiological and/or pathological defects in many fresh produce types is still unacceptably high and accounts for a large proportion of waste. With increasing interest in food security their remains strong demand in developing reliable and cost effective technologies for non-destructive screening of internal defects and rots, these being deemed unacceptable by consumers. It is well recognized that the internal defects and structure of turbid scattering media can be effectively visualized by using optical coherence tomography (OCT). In the present study, the high spatial resolution and advantages of OCT have been demonstrated for imaging the skins and outer laminae (concentric tissue layers) of intact whole onion bulbs with a view to non-invasively visualizing potential incidence/severity of internal defects.

Perception of olive oils sensory defects using a potentiometric taste device.

PubMed

Veloso, Ana C A; Silva, Lucas M; Rodrigues, Nuno; Rebello, Ligia P G; Dias, Luís G; Pereira, José A; Peres, António M

2018-01-01

The capability of perceiving olive oils sensory defects and intensities plays a key role on olive oils quality grade classification since olive oils can only be classified as extra-virgin if no defect can be perceived by a human trained sensory panel. Otherwise, olive oils may be classified as virgin or lampante depending on the median intensity of the defect predominantly perceived and on the physicochemical levels. However, sensory analysis is time-consuming and requires an official sensory panel, which can only evaluate a low number of samples per day. In this work, the potential use of an electronic tongue as a taste sensor device to identify the defect predominantly perceived in olive oils was evaluated. The potentiometric profiles recorded showed that intra- and inter-day signal drifts could be neglected (i.e., relative standard deviations lower than 25%), being not statistically significant the effect of the analysis day on the overall recorded E-tongue sensor fingerprints (P-value = 0.5715, for multivariate analysis of variance using Pillai's trace test), which significantly differ according to the olive oils' sensory defect (P-value = 0.0084, for multivariate analysis of variance using Pillai's trace test). Thus, a linear discriminant model based on 19 potentiometric signal sensors, selected by the simulated annealing algorithm, could be established to correctly predict the olive oil main sensory defect (fusty, rancid, wet-wood or winey-vinegary) with average sensitivity of 75 ± 3% and specificity of 73 ± 4% (repeated K-fold cross-validation variant: 4 folds×10 repeats). Similarly, a linear discriminant model, based on 24 selected sensors, correctly classified 92 ± 3% of the olive oils as virgin or lampante, being an average specificity of 93 ± 3% achieved. The overall satisfactory predictive performances strengthen the feasibility of the developed taste sensor device as a complementary methodology for olive oils' defects analysis and subsequent quality grade classification. Furthermore, the capability of identifying the type of sensory defect of an olive oil may allow establishing helpful insights regarding bad practices of olives or olive oils production, harvesting, transport and storage. Copyright © 2017 Elsevier B.V. All rights reserved.

A 3D Laser Profiling System for Rail Surface Defect Detection

PubMed Central

Li, Qingquan; Mao, Qingzhou; Zou, Qin

2017-01-01

Rail surface defects such as the abrasion, scratch and peeling often cause damages to the train wheels and rail bearings. An efficient and accurate detection of rail defects is of vital importance for the safety of railway transportation. In the past few decades, automatic rail defect detection has been studied; however, most developed methods use optic-imaging techniques to collect the rail surface data and are still suffering from a high false recognition rate. In this paper, a novel 3D laser profiling system (3D-LPS) is proposed, which integrates a laser scanner, odometer, inertial measurement unit (IMU) and global position system (GPS) to capture the rail surface profile data. For automatic defect detection, first, the deviation between the measured profile and a standard rail model profile is computed for each laser-imaging profile, and the points with large deviations are marked as candidate defect points. Specifically, an adaptive iterative closest point (AICP) algorithm is proposed to register the point sets of the measured profile with the standard rail model profile, and the registration precision is improved to the sub-millimeter level. Second, all of the measured profiles are combined together to form the rail surface through a high-precision positioning process with the IMU, odometer and GPS data. Third, the candidate defect points are merged into candidate defect regions using the K-means clustering. At last, the candidate defect regions are classified by a decision tree classifier. Experimental results demonstrate the effectiveness of the proposed laser-profiling system in rail surface defect detection and classification. PMID:28777323

A Novel Locally Linear KNN Method With Applications to Visual Recognition.

PubMed

Liu, Qingfeng; Liu, Chengjun

2017-09-01

A locally linear K Nearest Neighbor (LLK) method is presented in this paper with applications to robust visual recognition. Specifically, the concept of an ideal representation is first presented, which improves upon the traditional sparse representation in many ways. The objective function based on a host of criteria for sparsity, locality, and reconstruction is then optimized to derive a novel representation, which is an approximation to the ideal representation. The novel representation is further processed by two classifiers, namely, an LLK-based classifier and a locally linear nearest mean-based classifier, for visual recognition. The proposed classifiers are shown to connect to the Bayes decision rule for minimum error. Additional new theoretical analysis is presented, such as the nonnegative constraint, the group regularization, and the computational efficiency of the proposed LLK method. New methods such as a shifted power transformation for improving reliability, a coefficients' truncating method for enhancing generalization, and an improved marginal Fisher analysis method for feature extraction are proposed to further improve visual recognition performance. Extensive experiments are implemented to evaluate the proposed LLK method for robust visual recognition. In particular, eight representative data sets are applied for assessing the performance of the LLK method for various visual recognition applications, such as action recognition, scene recognition, object recognition, and face recognition.

Detection of Visual Field Loss in Pituitary Disease: Peripheral Kinetic Versus Central Static

PubMed Central

Rowe, Fiona J.; Cheyne, Christopher P.; García-Fiñana, Marta; Noonan, Carmel P.; Howard, Claire; Smith, Jayne; Adeoye, Joanne

2015-01-01

Abstract Visual field assessment is an important clinical evaluation for eye disease and neurological injury. We evaluated Octopus semi-automated kinetic peripheral perimetry (SKP) and Humphrey static automated central perimetry for detection of neurological visual field loss in patients with pituitary disease. We carried out a prospective cross-sectional diagnostic accuracy study comparing Humphrey central 30-2 SITA threshold programme with a screening protocol for SKP on Octopus perimetry. Humphrey 24-2 data were extracted from 30-2 results. Results were independently graded for presence/absence of field defect plus severity of defect. Fifty patients (100 eyes) were recruited (25 males and 25 females), with mean age of 52.4 years (SD = 15.7). Order of perimeter assessment (Humphrey/Octopus first) and order of eye tested (right/left first) were randomised. The 30-2 programme detected visual field loss in 85%, the 24-2 programme in 80%, and the Octopus combined kinetic/static strategy in 100% of eyes. Peripheral visual field loss was missed by central threshold assessment. Qualitative comparison of type of visual field defect demonstrated a match between Humphrey and Octopus results in 58%, with a match for severity of defect in 50%. Tests duration was 9.34 minutes (SD = 2.02) for Humphrey 30-2 versus 10.79 minutes (SD = 4.06) for Octopus perimetry. Octopus semi-automated kinetic perimetry was found to be superior to central static testing for detection of pituitary disease-related visual field loss. Where reliant on Humphrey central static perimetry, the 30-2 programme is recommended over the 24-2 programme. Where kinetic perimetry is available, this is preferable to central static programmes for increased detection of peripheral visual field loss. PMID:27928344

Quantitative assessment of specific defects in roasted ground coffee via infrared-photoacoustic spectroscopy.

PubMed

Dias, Rafael Carlos Eloy; Valderrama, Patrícia; Março, Paulo Henrique; Dos Santos Scholz, Maria Brigida; Edelmann, Michael; Yeretzian, Chahan

2018-07-30

Chemical analyses and sensory evaluation are the most applied methods for quality control of roasted and ground coffee (RG). However, faster alternatives would be highly valuable. Here, we applied infrared-photoacoustic spectroscopy (FTIR-PAS) on RG powder. Mixtures of specific defective beans were blended with healthy (defect-free) Coffea arabica and Coffea canephora bases in specific ratios, forming different classes of blends. Principal Component Analysis allowed predicting the amount/fraction and nature of the defects in blends while partial Least Squares Discriminant Analysis revealed similarities between blends (=samples). A successful predictive model was obtained using six classes of blends. The model could classify 100% of the samples into four classes. The specificities were higher than 0.9. Application of FTIR-PAS on RG coffee to characterize and classify blends has shown to be an accurate, easy, quick and "green" alternative to current methods. Copyright © 2018 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Objects Classification by Learning-Based Visual Saliency Model and Convolutional Neural Network.

PubMed

Li, Na; Zhao, Xinbo; Yang, Yongjia; Zou, Xiaochun

2016-01-01

Humans can easily classify different kinds of objects whereas it is quite difficult for computers. As a hot and difficult problem, objects classification has been receiving extensive interests with broad prospects. Inspired by neuroscience, deep learning concept is proposed. Convolutional neural network (CNN) as one of the methods of deep learning can be used to solve classification problem. But most of deep learning methods, including CNN, all ignore the human visual information processing mechanism when a person is classifying objects. Therefore, in this paper, inspiring the completed processing that humans classify different kinds of objects, we bring forth a new classification method which combines visual attention model and CNN. Firstly, we use the visual attention model to simulate the processing of human visual selection mechanism. Secondly, we use CNN to simulate the processing of how humans select features and extract the local features of those selected areas. Finally, not only does our classification method depend on those local features, but also it adds the human semantic features to classify objects. Our classification method has apparently advantages in biology. Experimental results demonstrated that our method made the efficiency of classification improve significantly.

Functional Defects in Color Vision in Patients With Choroideremia.

PubMed

Jolly, Jasleen K; Groppe, Markus; Birks, Jacqueline; Downes, Susan M; MacLaren, Robert E

2015-10-01

To characterize defects in color vision in patients with choroideremia. Prospective cohort study. Thirty patients with choroideremia (41 eyes) and 10 age-matched male controls (19 eyes) with visual acuity of ≥6/36 attending outpatient clinics in Oxford Eye Hospital underwent color vision testing with the Farnsworth-Munsell 100 hue test, visual acuity testing, and autofluorescence imaging. To exclude changes caused by degeneration of the fovea, a subgroup of 14 patients with a visual acuity ≥6/6 was analyzed. Calculated color vision total error scores were compared between the groups and related to a range of factors using a random-effects model. Mean color vision total error scores were 120 (95% confidence interval [CI] 92, 156) in the ≥6/6 choroideremia group, 206 (95% CI 161, 266) in the <6/6 visual acuity choroideremia group, and 47 (95% CI 32, 69) in the control group. Covariate analysis showed a significant difference in color vision total error score between the groups (P < .001 between each group). Patients with choroideremia have a functional defect in color vision compared with age-matched controls. The color vision defect deteriorates as the degeneration encroaches on the fovea. The presence of an early functional defect in color vision provides a useful biomarker against which to assess successful gene transfer in gene therapy trials. Copyright © 2015 Elsevier Inc. All rights reserved.

Decay detection in red oak trees using a combination of visual inspection, acoustic testing, and resistance microdrilling

Treesearch

Xiping Wang; R. Bruce Allison

2008-01-01

Arborists are often challenged to identify internal structural defects hidden from view within tree trunks. This article reports the results of a study using a trunk inspection protocol combining visual observation, single-path stress wave testing, acoustic tomography, and resistance microdrilling to detect internal defects. Two century-old red oak (Quercus rubra)...

Scanning electron microscope automatic defect classification of process induced defects

NASA Astrophysics Data System (ADS)

Wolfe, Scott; McGarvey, Steve

2017-03-01

With the integration of high speed Scanning Electron Microscope (SEM) based Automated Defect Redetection (ADR) in both high volume semiconductor manufacturing and Research and Development (R and D), the need for reliable SEM Automated Defect Classification (ADC) has grown tremendously in the past few years. In many high volume manufacturing facilities and R and D operations, defect inspection is performed on EBeam (EB), Bright Field (BF) or Dark Field (DF) defect inspection equipment. A comma separated value (CSV) file is created by both the patterned and non-patterned defect inspection tools. The defect inspection result file contains a list of the inspection anomalies detected during the inspection tools' examination of each structure, or the examination of an entire wafers surface for non-patterned applications. This file is imported into the Defect Review Scanning Electron Microscope (DRSEM). Following the defect inspection result file import, the DRSEM automatically moves the wafer to each defect coordinate and performs ADR. During ADR the DRSEM operates in a reference mode, capturing a SEM image at the exact position of the anomalies coordinates and capturing a SEM image of a reference location in the center of the wafer. A Defect reference image is created based on the Reference image minus the Defect image. The exact coordinates of the defect is calculated based on the calculated defect position and the anomalies stage coordinate calculated when the high magnification SEM defect image is captured. The captured SEM image is processed through either DRSEM ADC binning, exporting to a Yield Analysis System (YAS), or a combination of both. Process Engineers, Yield Analysis Engineers or Failure Analysis Engineers will manually review the captured images to insure that either the YAS defect binning is accurately classifying the defects or that the DRSEM defect binning is accurately classifying the defects. This paper is an exploration of the feasibility of the utilization of a Hitachi RS4000 Defect Review SEM to perform Automatic Defect Classification with the objective of the total automated classification accuracy being greater than human based defect classification binning when the defects do not require multiple process step knowledge for accurate classification. The implementation of DRSEM ADC has the potential to improve the response time between defect detection and defect classification. Faster defect classification will allow for rapid response to yield anomalies that will ultimately reduce the wafer and/or the die yield.

[Agnosia for streets and defective root finding].

PubMed

Takahashi, Nobuyoshi

2011-08-01

Topographical disorientation is identified as a condition in which patients are unable to find their way in familiar surroundings, such as their home neighborhood or the admitting hospital after the onset of illness. I proposed to classify topographical disorientation into two categories: agnosia for streets (landmark agnosia) and defective root finding (heading disorientation). Patients with agnosia for streets are unable to identify familiar buildings and landscapes. They can, however, morphologically perceive them and remember their way around familiar areas. The lesions are located in the right posterior part of the parahippocampus gyrus, anterior half of the lingual gyrus and adjacent fusiform gyrus. Clinical findings and functional imaging studies suggest that these regions play a crucial role in the interaction between the visual information of streets and memories of them, which are thought to be retained in the right anterior part of the temporal lobe. In particular, the posterior part of the parahippocampus gyrus is critical for the acquisition of novel information. On the other hand, patients with defective root finding can identify familiar streets, but cannot remember their own location or positional relation between two points within a comparatively wide range not surveyable at one time. The lesions are located in the right retrosplenial cortex (Areas 29, 30), posterior cingulate cortex (Areas 23, 31) and precuneus. Clinical findings and functional imaging studies suggest that these regions are involved in the orientation function for navigating in wide spaces. In particular, the retrosplenial cortex is critical for encoding novel information.

Cost-Sensitive Radial Basis Function Neural Network Classifier for Software Defect Prediction

PubMed Central

Venkatesan, R.

2016-01-01

Effective prediction of software modules, those that are prone to defects, will enable software developers to achieve efficient allocation of resources and to concentrate on quality assurance activities. The process of software development life cycle basically includes design, analysis, implementation, testing, and release phases. Generally, software testing is a critical task in the software development process wherein it is to save time and budget by detecting defects at the earliest and deliver a product without defects to the customers. This testing phase should be carefully operated in an effective manner to release a defect-free (bug-free) software product to the customers. In order to improve the software testing process, fault prediction methods identify the software parts that are more noted to be defect-prone. This paper proposes a prediction approach based on conventional radial basis function neural network (RBFNN) and the novel adaptive dimensional biogeography based optimization (ADBBO) model. The developed ADBBO based RBFNN model is tested with five publicly available datasets from the NASA data program repository. The computed results prove the effectiveness of the proposed ADBBO-RBFNN classifier approach with respect to the considered metrics in comparison with that of the early predictors available in the literature for the same datasets. PMID:27738649

Cost-Sensitive Radial Basis Function Neural Network Classifier for Software Defect Prediction.

PubMed

Kumudha, P; Venkatesan, R

Effective prediction of software modules, those that are prone to defects, will enable software developers to achieve efficient allocation of resources and to concentrate on quality assurance activities. The process of software development life cycle basically includes design, analysis, implementation, testing, and release phases. Generally, software testing is a critical task in the software development process wherein it is to save time and budget by detecting defects at the earliest and deliver a product without defects to the customers. This testing phase should be carefully operated in an effective manner to release a defect-free (bug-free) software product to the customers. In order to improve the software testing process, fault prediction methods identify the software parts that are more noted to be defect-prone. This paper proposes a prediction approach based on conventional radial basis function neural network (RBFNN) and the novel adaptive dimensional biogeography based optimization (ADBBO) model. The developed ADBBO based RBFNN model is tested with five publicly available datasets from the NASA data program repository. The computed results prove the effectiveness of the proposed ADBBO-RBFNN classifier approach with respect to the considered metrics in comparison with that of the early predictors available in the literature for the same datasets.

Visual feature extraction and establishment of visual tags in the intelligent visual internet of things

NASA Astrophysics Data System (ADS)

Zhao, Yiqun; Wang, Zhihui

2015-12-01

The Internet of things (IOT) is a kind of intelligent networks which can be used to locate, track, identify and supervise people and objects. One of important core technologies of intelligent visual internet of things ( IVIOT) is the intelligent visual tag system. In this paper, a research is done into visual feature extraction and establishment of visual tags of the human face based on ORL face database. Firstly, we use the principal component analysis (PCA) algorithm for face feature extraction, then adopt the support vector machine (SVM) for classifying and face recognition, finally establish a visual tag for face which is already classified. We conducted a experiment focused on a group of people face images, the result show that the proposed algorithm have good performance, and can show the visual tag of objects conveniently.

Intraoperative Subcortical Electrical Mapping of the Optic Tract in Awake Surgery Using a Virtual Reality Headset.

PubMed

Mazerand, Edouard; Le Renard, Marc; Hue, Sophie; Lemée, Jean-Michel; Klinger, Evelyne; Menei, Philippe

2017-01-01

Brain mapping during awake craniotomy is a well-known technique to preserve neurological functions, especially the language. It is still challenging to map the optic radiations due to the difficulty to test the visual field intraoperatively. To assess the visual field during awake craniotomy, we developed the Functions' Explorer based on a virtual reality headset (FEX-VRH). The impaired visual field of 10 patients was tested with automated perimetry (the gold standard examination) and the FEX-VRH. The proof-of-concept test was done during the surgery performed on a patient who was blind in his right eye and presenting with a left parietotemporal glioblastoma. The FEX-VRH was used intraoperatively, simultaneously with direct subcortical electrostimulation, allowing identification and preservation of the optic radiations. The FEX-VRH detected 9 of the 10 visual field defects found by automated perimetry. The patient who underwent an awake craniotomy with intraoperative mapping of the optic tract using the FEX-VRH had no permanent postoperative visual field defect. Intraoperative visual field assessment with the FEX-VRH during direct subcortical electrostimulation is a promising approach to mapping the optical radiations and preventing a permanent visual field defect during awake surgery for epilepsy or tumor. Copyright © 2016 Elsevier Inc. All rights reserved.

Classification of Partial Discharge Measured under Different Levels of Noise Contamination

PubMed Central

2017-01-01

Cable joint insulation breakdown may cause a huge loss to power companies. Therefore, it is vital to diagnose the insulation quality to detect early signs of insulation failure. It is well known that there is a correlation between Partial discharge (PD) and the insulation quality. Although many works have been done on PD pattern recognition, it is usually performed in a noise free environment. Also, works on PD pattern recognition in actual cable joint are less likely to be found in literature. Therefore, in this work, classifications of actual cable joint defect types from partial discharge data contaminated by noise were performed. Five cross-linked polyethylene (XLPE) cable joints with artificially created defects were prepared based on the defects commonly encountered on site. Three different types of input feature were extracted from the PD pattern under artificially created noisy environment. These include statistical features, fractal features and principal component analysis (PCA) features. These input features were used to train the classifiers to classify each PD defect types. Classifications were performed using three different artificial intelligence classifiers, which include Artificial Neural Networks (ANN), Adaptive Neuro-Fuzzy Inference System (ANFIS) and Support Vector Machine (SVM). It was found that the classification accuracy decreases with higher noise level but PCA features used in SVM and ANN showed the strongest tolerance against noise contamination. PMID:28085953

[Atypical optic neuritis in systemic lupus erythematosus (SLE)].

PubMed

Eckstein, A; Kötter, I; Wilhelm, H

1995-11-01

A 67-year-old woman experienced acute unilateral visual loss accompanied by pain with eye movements. There was a marked relative afferent pupillary defect and a nerve fiber bundle defect in the upper half of the visual field. Optic discs were normal. After 4 days vision worsened to motion detection and only a temporal island was left in the visual field. The optic disc margin was blurred. Since thirty years she had been suffering from renal insufficiency. Immunoserologic examination revealed elevated ANA and DS-DNA antibody titers. An optic neuritis in systemic lupus erythematosus was diagnosed, which is called atopic, because of its association to a systemic disease and the old age of the patient. The patient was treated with 100 mg prednisolone/day, slowly tapered. Within 6 weeks visual acuity improved to 0.6 and visual field normalized except for a small nerve fiber bundle defect. Autoimmune optic neuritis often responds to treatment with corticosteroids. Early onset of treatment is important. Immunopathologic examinations are an important diagnostic tool in atopic optic neuritis. Their results may even have consequences for the treatment of the underlying disease.

7 CFR 52.3761 - Defects.

Code of Federal Regulations, 2011 CFR

2011-01-01

... harmless extraneous vegetable material, stems, and portions thereof, blemishes, wrinkles, mutilated olives... to olives pitted along an axis other than the stem-flower axis. A defect is a unit where the angle of.... (12) Stem means a stem that measures 3 mm or more from the shoulder of the olive. Stems are classified...

7 CFR 52.3761 - Defects.

Code of Federal Regulations, 2012 CFR

2012-01-01

... harmless extraneous vegetable material, stems, and portions thereof, blemishes, wrinkles, mutilated olives... to olives pitted along an axis other than the stem-flower axis. A defect is a unit where the angle of.... (12) Stem means a stem that measures 3 mm or more from the shoulder of the olive. Stems are classified...

Hierarchical Learning of Tree Classifiers for Large-Scale Plant Species Identification.

PubMed

Fan, Jianping; Zhou, Ning; Peng, Jinye; Gao, Ling

2015-11-01

In this paper, a hierarchical multi-task structural learning algorithm is developed to support large-scale plant species identification, where a visual tree is constructed for organizing large numbers of plant species in a coarse-to-fine fashion and determining the inter-related learning tasks automatically. For a given parent node on the visual tree, it contains a set of sibling coarse-grained categories of plant species or sibling fine-grained plant species, and a multi-task structural learning algorithm is developed to train their inter-related classifiers jointly for enhancing their discrimination power. The inter-level relationship constraint, e.g., a plant image must first be assigned to a parent node (high-level non-leaf node) correctly if it can further be assigned to the most relevant child node (low-level non-leaf node or leaf node) on the visual tree, is formally defined and leveraged to learn more discriminative tree classifiers over the visual tree. Our experimental results have demonstrated the effectiveness of our hierarchical multi-task structural learning algorithm on training more discriminative tree classifiers for large-scale plant species identification.

38 CFR 4.75 - General considerations for evaluating visual impairment.

Code of Federal Regulations, 2012 CFR

2012-07-01

... refraction), visual field, and muscle function. (b) Examination for visual impairment. The examination must.... Examinations of visual fields or muscle function will be conducted only when there is a medical indication of disease or injury that may be associated with visual field defect or impaired muscle function. Unless...

38 CFR 4.75 - General considerations for evaluating visual impairment.

Code of Federal Regulations, 2013 CFR

2013-07-01

... refraction), visual field, and muscle function. (b) Examination for visual impairment. The examination must.... Examinations of visual fields or muscle function will be conducted only when there is a medical indication of disease or injury that may be associated with visual field defect or impaired muscle function. Unless...

38 CFR 4.75 - General considerations for evaluating visual impairment.

Code of Federal Regulations, 2014 CFR

2014-07-01

... refraction), visual field, and muscle function. (b) Examination for visual impairment. The examination must.... Examinations of visual fields or muscle function will be conducted only when there is a medical indication of disease or injury that may be associated with visual field defect or impaired muscle function. Unless...

Intensity compensation for on-line detection of defects on fruit

NASA Astrophysics Data System (ADS)

Wen, Zhiqing; Tao, Yang

1997-10-01

A machine-vision sorting system was developed that utilizes the difference in light reflectance of fruit surfaces to distinguish the defective and good apples. To accommodate to the spherical reflectance characteristics of fruit with curved surface like apple, a spherical transform algorithm was developed that converts the original image to a non-radiant image without losing defective segments on the fruit. To prevent high-quality dark-colored fruit form being classified into the defective class and increase the defect detection rate for light-colored fruit, an intensity compensation method using maximum propagation was used. Experimental results demonstrated the effectiveness of the method based on maximum propagation and spherical transform for on-line detection of defects on apples.

Local defect resonance for sensitive non-destructive testing

NASA Astrophysics Data System (ADS)

Adebahr, W.; Solodov, I.; Rahammer, M.; Gulnizkij, N.; Kreutzbruck, M.

2016-02-01

Ultrasonic wave-defect interaction is a background of ultrasound activated techniques for imaging and non-destructive testing (NDT) of materials and industrial components. The interaction, primarily, results in acoustic response of a defect which provides attenuation and scattering of ultrasound used as an indicator of defects in conventional ultrasonic NDT. The derivative ultrasonic-induced effects include e.g. nonlinear, thermal, acousto-optic, etc. responses also applied for NDT and defect imaging. These secondary effects are normally relatively inefficient so that the corresponding NDT techniques require an elevated acoustic power and stand out from conventional ultrasonic NDT counterparts for their specific instrumentation particularly adapted to high-power ultrasonic. In this paper, a consistent way to enhance ultrasonic, optical and thermal defect responses and thus to reduce an ultrasonic power required is suggested by using selective ultrasonic activation of defects based on the concept of local defect resonance (LDR). A strong increase in vibration amplitude at LDR enables to reliably detect and visualize the defect as soon as the driving ultrasonic frequency is matched to the LDR frequency. This also provides a high frequency selectivity of the LDR-based imaging, i.e. an opportunity of detecting a certain defect among a multitude of other defects in material. Some examples are shown how to use LDR in non-destructive testing techniques, like vibrometry, ultrasonic thermography and shearography in order to enhance the sensitivity of defect visualization.

Early detection of glaucoma by means of a novel 3D computer‐automated visual field test

PubMed Central

Nazemi, Paul P; Fink, Wolfgang; Sadun, Alfredo A; Francis, Brian; Minckler, Donald

2007-01-01

Purpose A recently devised 3D computer‐automated threshold Amsler grid test was used to identify early and distinctive defects in people with suspected glaucoma. Further, the location, shape and depth of these field defects were characterised. Finally, the visual fields were compared with those obtained by standard automated perimetry. Patients and methods Glaucoma suspects were defined as those having elevated intraocular pressure (>21 mm Hg) or cup‐to‐disc ratio of >0.5. 33 patients and 66 eyes with risk factors for glaucoma were examined. 15 patients and 23 eyes with no risk factors were tested as controls. The recently developed 3D computer‐automated threshold Amsler grid test was used. The test exhibits a grid on a computer screen at a preselected greyscale and angular resolution, and allows patients to trace those areas on the grid that are missing in their visual field using a touch screen. The 5‐minute test required that the patients repeatedly outline scotomas on a touch screen with varied displays of contrast while maintaining their gaze on a central fixation marker. A 3D depiction of the visual field defects was then obtained that was further characterised by the location, shape and depth of the scotomas. The exam was repeated three times per eye. The results were compared to Humphrey visual field tests (ie, achromatic standard or SITA standard 30‐2 or 24‐2). Results In this pilot study 79% of the eyes tested in the glaucoma‐suspect group repeatedly demonstrated visual field loss with the 3D perimetry. The 3D depictions of visual field loss associated with these risk factors were all characteristic of or compatible with glaucoma. 71% of the eyes demonstrated arcuate defects or a nasal step. Constricted visual fields were shown in 29% of the eyes. No visual field changes were detected in the control group. Conclusions The 3D computer‐automated threshold Amsler grid test may demonstrate visual field abnormalities characteristic of glaucoma in glaucoma suspects with normal achromatic Humphrey visual field testing. This test may be used as a screening tool for the early detection of glaucoma. PMID:17504855

The Advanced Glaucoma Intervention Study (AGIS): 7. The relationship between control of intraocular pressure and visual field deterioration.The AGIS Investigators.

PubMed

2000-10-01

To investigate the association between control of intraocular pressure after surgical intervention for glaucoma and visual field deterioration. In the Advanced Glaucoma Intervention Study, eyes were randomly assigned to one of two sequences of glaucoma surgery, one beginning with argon laser trabeculoplasty and the other trabeculectomy. In the present article we examine the relationship between intraocular pressure and progression of visual field damage over 6 or more years of follow-up. In the first analysis, designated Predictive Analysis, we categorize 738 eyes into three groups based on intraocular pressure determinations over the first three 6-month follow-up visits. In the second analysis, designated Associative Analysis, we categorize 586 eyes into four groups based on the percent of 6-month visits over the first 6 follow-up years in which eyes presented with intraocular pressure less than 18 mm Hg. The outcome measure in both analyses is change from baseline in follow-up visual field defect score (range, 0 to 20 units). In the Predictive Analysis, eyes with early average intraocular pressure greater than 17.5 mm Hg had an estimated worsening during subsequent follow-up that was 1 unit of visual field defect score greater than eyes with average intraocular pressure less than 14 mm Hg (P =.002). This amount of worsening was greater at 7 years (1.89 units; P <.001) than at 2 years (0.64 units; P =.071). In the Associative Analysis, eyes with 100% of visits with intraocular pressure less than 18 mm Hg over 6 years had mean changes from baseline in visual field defect score close to zero during follow-up, whereas eyes with less than 50% of visits with intraocular pressure less than 18 mm Hg had an estimated worsening over follow-up of 0.63 units of visual field defect score (P =.083). This amount of worsening was greater at 7 years (1.93 units; P <.001) than at 2 years (0.25 units; P =.572). In both analyses low intraocular pressure is associated with reduced progression of visual field defect, supporting evidence from earlier studies of a protective role for low intraocular pressure in visual field deterioration.

Photoreceptor change and visual outcome after idiopathic epiretinal membrane removal with or without additional internal limiting membrane peeling.

PubMed

Ahn, Seong Joon; Ahn, Jeeyun; Woo, Se Joon; Park, Kyu Hyung

2014-01-01

To compare the postoperative photoreceptor status and visual outcome after epiretinal membrane removal with or without additional internal limiting membrane (ILM) peeling. Medical records of 40 eyes from 37 patients undergoing epiretinal membrane removal with residual ILM peeling (additional ILM peeling group) and 69 eyes from 65 patients undergoing epiretinal membrane removal without additional ILM peeling (no additional peeling group) were reviewed. The length of defects in cone outer segment tips, inner segment/outer segment junction, and external limiting membrane line were measured using spectral domain optical coherence tomography images of the fovea before and at 1, 3, 6, and 12 months after the surgery. Cone outer segment tips and inner segment/outer segment junction line defects were most severe at postoperative 1 month and gradually restored at 12 months postoperatively. The cone outer segment tips line defect in the additional ILM peeling group was significantly greater than that in the no additional peeling group at postoperative 1 month (P = 0.006), and best-corrected visual acuity was significantly worse in the former group at the same month (P = 0.001). There was no significant difference in the defect size and best-corrected visual acuity at subsequent visits and recurrence rates between the two groups. Patients who received epiretinal membrane surgery without additional ILM peeling showed better visual and anatomical outcome than those with additional ILM peeling at postoperative 1 month. However, surgical outcomes were comparable between the two groups, thereafter. In terms of visual outcome and photoreceptor integrity, additional ILM peeling may not be an essential procedure.

Non-Mutually Exclusive Deep Neural Network Classifier for Combined Modes of Bearing Fault Diagnosis

PubMed Central

Kim, Jong-Myon

2018-01-01

The simultaneous occurrence of various types of defects in bearings makes their diagnosis more challenging owing to the resultant complexity of the constituent parts of the acoustic emission (AE) signals. To address this issue, a new approach is proposed in this paper for the detection of multiple combined faults in bearings. The proposed methodology uses a deep neural network (DNN) architecture to effectively diagnose the combined defects. The DNN structure is based on the stacked denoising autoencoder non-mutually exclusive classifier (NMEC) method for combined modes. The NMEC-DNN is trained using data for a single fault and it classifies both single faults and multiple combined faults. The results of experiments conducted on AE data collected through an experimental test-bed demonstrate that the DNN achieves good classification performance with a maximum accuracy of 95%. The proposed method is compared with a multi-class classifier based on support vector machines (SVMs). The NMEC-DNN yields better diagnostic performance in comparison to the multi-class classifier based on SVM. The NMEC-DNN reduces the number of necessary data collections and improves the bearing fault diagnosis performance. PMID:29642466

Puberty as a risk factor for less favorable visual outcome in idiopathic intracranial hypertension.

PubMed

Stiebel-Kalish, Hadas; Kalish, Yuval; Lusky, Moshe; Gaton, Dan D; Ehrlich, Rita; Shuper, Avinoam

2006-08-01

To test the hypothesis that puberty is a risk factor for poorer visual outcome in idiopathic intracranial hypertension (IIH). Retrospective chart review case series. Tertiary referral center, neuro-ophthalmology unit. Ninety-six patients with IIH followed for a minimum of one year. Age (grouped into prepubertal, pubertal, teenage, or adult), obesity, initial intracranial pressure (ICP), measurements and presence of hypertension, anemia, or renal failure were correlated with final visual outcome using chi(2), stepwise logistic regression, and model-selection log linear analyses. Visual outcome was graded into "excellent" -- no evidence of an optic neuropathy or any permanent visual field defect in either eye, "moderate"-- evidence of an optic neuropathy and/or a mild (nasal constriction) visual field defect, or "poor outcome" (peripheral constriction) -- permanent visual field defect. Outcome data were complete for 96 patients. Moderate to poor visual outcome, as opposed to excellent, was significantly associated with puberty (P = .007 using the gender-specific definition of puberty, .0002 using the broad definition). Moderate-poor visual outcome occurred in none of seven IIH patients of prepubertal age (<9 years), in 15 of 26 patients presenting between nine to 16 years, in two of six patients aged 17 to 22 years, and in seven of 57 adult patients over the age of 23 years. In this series of 96 patients with IIH, visual outcome was less favorable in pubertal patients than in prepubertal, teenage, and adult patients. We recommend that clinicians maintain a high index of awareness when caring for pubescent children with IIH.

CANDELS Visual Classifications: Scheme, Data Release, and First Results

NASA Technical Reports Server (NTRS)

Kartaltepe, Jeyhan S.; Mozena, Mark; Kocevski, Dale; McIntosh, Daniel H.; Lotz, Jennifer; Bell, Eric F.; Faber, Sandy; Ferguson, Henry; Koo, David; Bassett, Robert;

Log Defect Recognition Using CT-images and Neural Net Classifiers

Treesearch

Daniel L. Schmoldt; Pei Li; A. Lynn Abbott

1995-01-01

Although several approaches have been introduced to automatically identify internal log defects using computed tomography (CT) imagery, most of these have been feasibility efforts and consequently have had several limitations: (1) reports of classification accuracy are largely subjective, not statistical, (2) there has been no attempt to achieve real-time operation,...

Cost minimization through optimized raw material quality composition

Treesearch

Urs Buehlmann; R. Edward Thomas; Xiaoqui Zuo

2011-01-01

Lumber, a heterogeneous, anisotropic material produced from sawing logs, contains a varying number of randomly dispersed, unusable areas (defects) distributed over each boards’ surface area. Each board's quality is determined by the frequency and distribution of these defects and the board's dimension. Typically, the industry classifies lumber into five...

A collaborative vendor-buyer production-inventory systems with imperfect quality items, inspection errors, and stochastic demand under budget capacity constraint: a Karush-Kuhn-Tucker conditions approach

NASA Astrophysics Data System (ADS)

Kurdhi, N. A.; Nurhayati, R. A.; Wiyono, S. B.; Handajani, S. S.; Martini, T. S.

2017-01-01

In this paper, we develop an integrated inventory model considering the imperfect quality items, inspection error, controllable lead time, and budget capacity constraint. The imperfect items were uniformly distributed and detected on the screening process. However there are two types of possibilities. The first is type I of inspection error (when a non-defective item classified as defective) and the second is type II of inspection error (when a defective item classified as non-defective). The demand during the lead time is unknown, and it follows the normal distribution. The lead time can be controlled by adding the crashing cost. Furthermore, the existence of the budget capacity constraint is caused by the limited purchasing cost. The purposes of this research are: to modify the integrated vendor and buyer inventory model, to establish the optimal solution using Kuhn-Tucker’s conditions, and to apply the models. Based on the result of application and the sensitivity analysis, it can be obtained minimum integrated inventory total cost rather than separated inventory.

Neural attractor network for application in visual field data classification.

PubMed

Fink, Wolfgang

2004-07-07

The purpose was to introduce a novel method for computer-based classification of visual field data derived from perimetric examination, that may act as a 'counsellor', providing an independent 'second opinion' to the diagnosing physician. The classification system consists of a Hopfield-type neural attractor network that obtains its input data from perimetric examination results. An iterative relaxation process determines the states of the neurons dynamically. Therefore, even 'noisy' perimetric output, e.g., early stages of a disease, may eventually be classified correctly according to the predefined idealized visual field defect (scotoma) patterns, stored as attractors of the network, that are found with diseases of the eye, optic nerve and the central nervous system. Preliminary tests of the classification system on real visual field data derived from perimetric examinations have shown a classification success of over 80%. Some of the main advantages of the Hopfield-attractor-network-based approach over feed-forward type neural networks are: (1) network architecture is defined by the classification problem; (2) no training is required to determine the neural coupling strengths; (3) assignment of an auto-diagnosis confidence level is possible by means of an overlap parameter and the Hamming distance. In conclusion, the novel method for computer-based classification of visual field data, presented here, furnishes a valuable first overview and an independent 'second opinion' in judging perimetric examination results, pointing towards a final diagnosis by a physician. It should not be considered a substitute for the diagnosing physician. Thanks to the worldwide accessibility of the Internet, the classification system offers a promising perspective towards modern computer-assisted diagnosis in both medicine and tele-medicine, for example and in particular, with respect to non-ophthalmic clinics or in communities where perimetric expertise is not readily available.

Relation between lung perfusion defects and intravascular clots in acute pulmonary thromboembolism: assessment with breath-hold SPECT-CT pulmonary angiography fusion images.

PubMed

Suga, Kazuyoshi; Yasuhiko, Kawakami; Iwanaga, Hideyuki; Tokuda, Osamu; Matsunaga, Naofumi

2008-09-01

The relation between lung perfusion defects and intravascular clots in acute pulmonary thromboembolism (PTE) was comprehensively assessed on deep-inspiratory breath-hold (DIBrH) perfusion SPECT-computed tomographic pulmonary angiography (CTPA) fusion images. Subjects were 34 acute PTE patients, who had successfully performed DIBrH perfusion SPECT using a dual-headed SPECT and a respiratory tracking system. Automated DIBrH SPECT-CTPA fusion images were used to assess the relation between lung perfusion defects and intravascular clots detected by CTPA. DIBrH SPECT visualized 175 lobar/segmental or subsegmental defects in 34 patients, and CTPA visualized 61 intravascular clots at variable locations in 30 (88%) patients, but no clots in four (12%) patients. In 30 patients with clots, the fusion images confirmed that 69 (41%) perfusion defects (20 segmental, 45 subsegmental and 4 lobar defects) of total 166 defects were located in lung territories without clots, although the remaining 97 (58%) defects were located in lung territories with clots. Perfusion defect was absent in lung territories with clots (one lobar branch and three segmental branches) in four (12%) of these patients. In four patients without clots, nine perfusion defects including four segmental ones were present. Because of unexpected dissociation between intravascular clots and lung perfusion defects, the present fusion images will be a useful adjunct to CTPA in the diagnosis of acute PTE.

Ocular findings in MELAS syndrome – a case report.

PubMed

Modrzejewska, Monika; Chrzanowska, Martyna; Modrzejewska, Anna; Romanowska, Hanna; Ostrowska, Iwona; Giżewska, Maria

We present a case of a child with MELAS syndrome (mitochondrial encephalo-myopathy with lactic acidosis and stroke-like episodes), discussing clinical manifestation, ocular findings and diagnostic challenges. Predominant ocular symptom was a transient complete visual loss, while the predominant ocular sign was a visual field defect. The diagnosia was based on clinical manifestation, laboratory tests, brain scans and genetic testing which confirmed the pathognomonic mutation in the MTTL1 gene encoding the mitochondrial tRNA for leucine 3243> G. Ocular examination demonstrated decreased visual acuity (with bilateral best corrected visual acuity of .1). Periodical, transient visual loss and visual field defects were clinically predominant. Specialist investigations were carried out, which demonstrated homonymous hemianopia (kinetic perimetry), bilateral partial optic nerve atrophy (RetCam). Funduscopy and electrophysiology mfERG study did not confirm features of retinitis pigmentosa. The brain scans revealed numerous small cortical ischemic lesions within the frontal, parietal and temporal lobes, post-stroke focal areas within the occipital lobes and diffuse calcifications of the basal ganglia. During several years of follow-up, visual field defects showed progressive concentric narrowing. The patient received a long-term treatment with arginine, coenzyme Q and vitamin D, both oral and intravenous, but no beneficial effect for the improvement of ophthalmic condition was observed. As it is the case in severe MELAS syndrome, the course of disease was fatal and the patientdied at the age of 14.

Construction Productivity Advancement Research (CPAR) Program: Improved Materials and Processes for Sealing and Resealing Joints in Portland Cement Concrete Pavements - Field Evaluation

DTIC Science & Technology

1993-10-01

sealant was determined by noting the type and number of defects each sealant incurred. Figure 4 provides a sample evaluation sheet used dur- ing the field...was conducted by visually inspect- ing the mater~al for defects . If any defects were noted, the type of defect was described and the quant~ty of that... defect was measured. The quantity of the defect was dividted by the total quantity of sealant and the result reported as percent defect . Adhesion and

Epigenetic silencing of MLH1 in endometrial cancers is associated with larger tumor volume, increased rate of lymph node positivity and reduced recurrence-free survival.

PubMed

Cosgrove, Casey M; Cohn, David E; Hampel, Heather; Frankel, Wendy L; Jones, Dan; McElroy, Joseph P; Suarez, Adrian A; Zhao, Weiqiang; Chen, Wei; Salani, Ritu; Copeland, Larry J; O'Malley, David M; Fowler, Jeffrey M; Yilmaz, Ahmet; Chassen, Alexis S; Pearlman, Rachel; Goodfellow, Paul J; Backes, Floor J

2017-09-01

To determine the relationship between mismatch repair (MMR) classification and clinicopathologic features including tumor volume, and explore outcomes by MMR class in a contemporary cohort. Single institution cohort evaluating MMR classification for endometrial cancers (EC). MMR immunohistochemistry (IHC)±microsatellite instability (MSI) testing and reflex MLH1 methylation testing was performed. Tumors with MMR abnormalities by IHC or MSI and MLH1 methylation were classified as epigenetic MMR deficiency while those without MLH1 methylation were classified as probable MMR mutations. Clinicopathologic characteristics were analyzed. 466 endometrial cancers were classified; 75% as MMR proficient, 20% epigenetic MMR defects, and 5% as probable MMR mutations. Epigenetic MMR defects were associated with advanced stage, higher grade, presence of lymphovascular space invasion, and older age. MMR class was significantly associated with tumor volume, an association not previously reported. The epigenetic MMR defect tumors median volume was 10,220mm 3 compared to 3321mm 3 and 2,846mm 3 , for MMR proficient and probable MMR mutations respectively (P<0.0001). Higher tumor volume was associated with lymph node involvement. Endometrioid EC cases with epigenetic MMR defects had significantly reduced recurrence-free survival (RFS). Among advanced stage (III/IV) endometrioid EC the epigenetic MMR defect group was more likely to recur compared to the MMR proficient group (47.7% vs 3.4%) despite receiving similar adjuvant therapy. In contrast, there was no difference in the number of early stage recurrences for the different MMR classes. MMR testing that includes MLH1 methylation analysis defines a subset of tumors that have worse prognostic features and reduced RFS. Copyright © 2017 Elsevier Inc. All rights reserved.

A lightning strike to the head causing a visual cortex defect with simple and complex visual hallucinations

PubMed Central

Kleiter, Ingo; Luerding, Ralf; Diendorfer, Gerhard; Rek, Helga; Bogdahn, Ulrich; Schalke, Berthold

2007-01-01

The case of a 23‐year‐old mountaineer who was hit by a lightning strike to the occiput causing a large central visual field defect and bilateral tympanic membrane ruptures is described. Owing to extreme agitation, the patient was set to a drug‐induced coma for 3 days. After extubation, she experienced simple and complex visual hallucinations for several days, but otherwise recovered largely. Neuropsychological tests revealed deficits in fast visual detection tasks and non‐verbal learning, and indicated a right temporal lobe dysfunction, consistent with a right temporal focus on electroencephalography. Four months after the accident, she developed a psychological reaction consisting of nightmares with reappearance of the complex visual hallucinations and a depressive syndrome. Using the European Cooperation for Lightning Detection network, a meteorological system for lightning surveillance, the exact geographical location and nature of the lightning flash were retrospectively retraced. PMID:17369595

A lightning strike to the head causing a visual cortex defect with simple and complex visual hallucinations

PubMed Central

Kleiter, Ingo; Luerding, Ralf; Diendorfer, Gerhard; Rek, Helga; Bogdahn, Ulrich; Schalke, Berthold

2009-01-01

The case of a 23-year-old mountaineer who was hit by a lightning strike to the occiput causing a large central visual field defect and bilateral tympanic membrane ruptures is described. Owing to extreme agitation, the patient was sent into a drug-induced coma for 3 days. After extubation, she experienced simple and complex visual hallucinations for several days, but otherwise largely recovered. Neuropsychological tests revealed deficits in fast visual detection tasks and non-verbal learning and indicated a right temporal lobe dysfunction, consistent with a right temporal focus on electroencephalography. At 4 months after the accident, she developed a psychological reaction consisting of nightmares, with reappearance of the complex visual hallucinations and a depressive syndrome. Using the European Cooperation for Lightning Detection network, a meteorological system for lightning surveillance, the exact geographical location and nature of the lightning strike were retrospectively retraced PMID:21734915

Automated Analysis of CT Images for the Inspection of Hardwood Logs

Treesearch

Harbin Li; A. Lynn Abbott; Daniel L. Schmoldt

1996-01-01

This paper investigates several classifiers for labeling internal features of hardwood logs using computed tomography (CT) images. A primary motivation is to locate and classify internal defects so that an optimal cutting strategy can be chosen. Previous work has relied on combinations of low-level processing, image segmentation, autoregressive texture modeling, and...

Nondestructive rule-based defect detection and identification system in CT images of hardwood logs

Treesearch

Erol Sarigul; A. Lynn Abbott; Daniel L. Schmoldt

2001-01-01

This paper is concerned with the detection of internal defects in hardwood logs. Because the commercial value of hardwood lumber is directly related to the quantity, type, and location of defects in the wood, sawing strategies are typically chosen in an attempt to minimize the defects in the resulting boards. Traditionally, the sawyer makes sawing decisions by visually...

Visual terrain mapping for traversable path planning of mobile robots

NASA Astrophysics Data System (ADS)

Shirkhodaie, Amir; Amrani, Rachida; Tunstel, Edward W.

2004-10-01

In this paper, we have primarily discussed technical challenges and navigational skill requirements of mobile robots for traversability path planning in natural terrain environments similar to Mars surface terrains. We have described different methods for detection of salient terrain features based on imaging texture analysis techniques. We have also presented three competing techniques for terrain traversability assessment of mobile robots navigating in unstructured natural terrain environments. These three techniques include: a rule-based terrain classifier, a neural network-based terrain classifier, and a fuzzy-logic terrain classifier. Each proposed terrain classifier divides a region of natural terrain into finite sub-terrain regions and classifies terrain condition exclusively within each sub-terrain region based on terrain visual clues. The Kalman Filtering technique is applied for aggregative fusion of sub-terrain assessment results. The last two terrain classifiers are shown to have remarkable capability for terrain traversability assessment of natural terrains. We have conducted a comparative performance evaluation of all three terrain classifiers and presented the results in this paper.

Soft computing-based terrain visual sensing and data fusion for unmanned ground robotic systems

NASA Astrophysics Data System (ADS)

Shirkhodaie, Amir

2006-05-01

In this paper, we have primarily discussed technical challenges and navigational skill requirements of mobile robots for traversability path planning in natural terrain environments similar to Mars surface terrains. We have described different methods for detection of salient terrain features based on imaging texture analysis techniques. We have also presented three competing techniques for terrain traversability assessment of mobile robots navigating in unstructured natural terrain environments. These three techniques include: a rule-based terrain classifier, a neural network-based terrain classifier, and a fuzzy-logic terrain classifier. Each proposed terrain classifier divides a region of natural terrain into finite sub-terrain regions and classifies terrain condition exclusively within each sub-terrain region based on terrain visual clues. The Kalman Filtering technique is applied for aggregative fusion of sub-terrain assessment results. The last two terrain classifiers are shown to have remarkable capability for terrain traversability assessment of natural terrains. We have conducted a comparative performance evaluation of all three terrain classifiers and presented the results in this paper.

Topological defects in two-dimensional liquid crystals confined by a box

NASA Astrophysics Data System (ADS)

Yao, Xiaomei; Zhang, Hui; Chen, Jeff Z. Y.

2018-05-01

When a spatially uniform system that displays a liquid-crystal ordering on a two-dimensional surface is confined inside a rectangular box, the liquid crystal direction field develops inhomogeneous textures accompanied by topological defects because of the geometric frustrations. We show that the rich variety of nematic textures and defect patterns found in recent experimental and theoretical studies can be classified by the solutions of the rather fundamental, extended Onsager model. This is critically examined based on the determined free energies of different defect states, as functions of a few relevant, dimensionless geometric parameters.

Exploring Verbal, Visual and Schematic Learners' Static and Dynamic Mental Images of Scientific Species and Processes in Relation to Their Spatial Ability

ERIC Educational Resources Information Center

Al-Balushi, Sulaiman M.; Coll, Richard Kevin

2013-01-01

The current study compared different learners' static and dynamic mental images of unseen scientific species and processes in relation to their spatial ability. Learners were classified into verbal, visual and schematic. Dynamic images were classified into: appearing/disappearing, linear-movement, and rotation. Two types of scientific entities and…

CANDELS Visual Classifications: Scheme, Data Release, and First Results

NASA Astrophysics Data System (ADS)

Kartaltepe, Jeyhan S.; Mozena, Mark; Kocevski, Dale; McIntosh, Daniel H.; Lotz, Jennifer; Bell, Eric F.; Faber, Sandy; Ferguson, Harry; Koo, David; Bassett, Robert; Bernyk, Maksym; Blancato, Kirsten; Bournaud, Frederic; Cassata, Paolo; Castellano, Marco; Cheung, Edmond; Conselice, Christopher J.; Croton, Darren; Dahlen, Tomas; de Mello, Duilia F.; DeGroot, Laura; Donley, Jennifer; Guedes, Javiera; Grogin, Norman; Hathi, Nimish; Hilton, Matt; Hollon, Brett; Koekemoer, Anton; Liu, Nick; Lucas, Ray A.; Martig, Marie; McGrath, Elizabeth; McPartland, Conor; Mobasher, Bahram; Morlock, Alice; O'Leary, Erin; Peth, Mike; Pforr, Janine; Pillepich, Annalisa; Rosario, David; Soto, Emmaris; Straughn, Amber; Telford, Olivia; Sunnquist, Ben; Trump, Jonathan; Weiner, Benjamin; Wuyts, Stijn; Inami, Hanae; Kassin, Susan; Lani, Caterina; Poole, Gregory B.; Rizer, Zachary

2015-11-01

We have undertaken an ambitious program to visually classify all galaxies in the five CANDELS fields down to H < 24.5 involving the dedicated efforts of over 65 individual classifiers. Once completed, we expect to have detailed morphological classifications for over 50,000 galaxies spanning 0 < z < 4 over all the fields, with classifications from 3 to 5 independent classifiers for each galaxy. Here, we present our detailed visual classification scheme, which was designed to cover a wide range of CANDELS science goals. This scheme includes the basic Hubble sequence types, but also includes a detailed look at mergers and interactions, the clumpiness of galaxies, k-corrections, and a variety of other structural properties. In this paper, we focus on the first field to be completed—GOODS-S, which has been classified at various depths. The wide area coverage spanning the full field (wide+deep+ERS) includes 7634 galaxies that have been classified by at least three different people. In the deep area of the field, 2534 galaxies have been classified by at least five different people at three different depths. With this paper, we release to the public all of the visual classifications in GOODS-S along with the Perl/Tk GUI that we developed to classify galaxies. We present our initial results here, including an analysis of our internal consistency and comparisons among multiple classifiers as well as a comparison to the Sérsic index. We find that the level of agreement among classifiers is quite good (>70% across the full magnitude range) and depends on both the galaxy magnitude and the galaxy type, with disks showing the highest level of agreement (>50%) and irregulars the lowest (<10%). A comparison of our classifications with the Sérsic index and rest-frame colors shows a clear separation between disk and spheroid populations. Finally, we explore morphological k-corrections between the V-band and H-band observations and find that a small fraction (84 galaxies in total) are classified as being very different between these two bands. These galaxies typically have very clumpy and extended morphology or are very faint in the V-band.

Are Hemianopic Reading and Visual Exploration Impairments Visually Elicited? New Insights from Eye Movements in Simulated Hemianopia

ERIC Educational Resources Information Center

Schuett, Susanne; Kentridge, Robert W.; Zihl, Josef; Heywood, Charles A.

2009-01-01

Hemianopic reading and visual exploration impairments are well-known clinical phenomena. Yet, it is unclear whether they are primarily caused by the hemianopic visual field defect itself or by additional brain injury preventing efficient spontaneous oculomotor adaptation. To establish the extent to which these impairments are visually elicited we…

Level-2 Milestone 4797: Early Users on Max, Sequoia Visualization Cluster

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cupps, Kim C.

This report documents the fact that an early user has run successfully on Max, the Sequoia visualization cluster, ASC L2 milestone 4797: Early Users on Sequoia Visualization System (Max), due December 31, 2013. The Max visualization and data analysis cluster will provide Sequoia users with compute cycles and an interactive option for data exploration and analysis. The system will be integrated in the first quarter of FY14 and the system is expected to be moved to the classified network by the second quarter of FY14. The goal of this milestone is to have early users running their visualization and datamore » analysis work on the Max cluster on the classified network.« less

An Analysis of the Magneto-Optic Imaging System

NASA Technical Reports Server (NTRS)

Nath, Shridhar

1996-01-01

The Magneto-Optic Imaging system is being used for the detection of defects in airframes and other aircraft structures. The system has been successfully applied to detecting surface cracks, but has difficulty in the detection of sub-surface defects such as corrosion. The intent of the grant was to understand the physics of the MOI better, in order to use it effectively for detecting corrosion and for classifying surface defects. Finite element analysis, image classification, and image processing are addressed.

Reduction of Defects in Jewelry Manufacturing

NASA Astrophysics Data System (ADS)

Ayudhya, Phitchaya Phanomwan na; Tangjitsitcharoen, Somkiat

2017-06-01

The aim of this research was to reduce the defects of gem bracelet found during manufacturing process at a jewelry company. It was found that gem bracelet product has the highest rejects compared to the rejects found in ring, earring, and pendant products. Types of defect were classified by using Pareto Diagram consisting of gem falling, seam, unclean casting, impinge, and deformation. The causes of defect were analyzed by Cause and Effect Diagram and applied Failure Mode and Effects Analysis (FMEA) was applied during manufacturing processes. This research found that the improvement of manufacturing process could reduce the Risk Priority Number (RPN) and total of all defects by 48.70% and 48.89%, respectively.

The ability of healthy volunteers to simulate a neurologic field defect on automated perimetry.

PubMed

Ghate, Deepta; Bodnarchuk, Brian; Sanders, Sheila; Deokule, Sunil; Kedar, Sachin

2014-03-01

To determine if volunteers can simulate and reproduce 3 types of neurologic field defects: hemianopia, quadrantanopia, and central scotoma. Cross-sectional study. Thirty healthy volunteers new to perimetry (including automated perimetry). After informed consent, volunteers were randomized to 1 of the 3 visual field defects listed above. All visual field testing was performed on the right eye using the Humphrey Field Analyzer (HFA; Carl Zeiss Meditec, Dublin, CA) SITA Fast 24-2 protocol. Each volunteer was provided with standard new patient instructions and was shown a diagram of the defect to be simulated. Two sets of visual fields were performed on the right eye with 10 minutes between tests. Three experts used the Ocular Hypertension Treatment Study reading center criteria and determined if the simulation was successful. Proportion of volunteers able to simulate the assigned visual field. All 10 volunteers (100%) successfully simulated a hemianopia on the first and second fields. All 10 volunteers (100%) simulated a quadrantanopia on the first field and 9 (90%) did so on the second field. Eight volunteers (80%) successfully simulated a central scotoma in the first field and all 10 (100%) did so on in the second field. Reliability criteria were excellent. Forty-seven fields (78%) had 0 fixation losses, 48 (80%) had 0 false-positive results, and 44 (73%) had 0 false-negative results. It is easy to simulate reproducible and reliable neurologic field defects on automated perimetry using HFA. Copyright © 2014 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Ocular vascular occlusive disorders: Natural history of visual outcome☆

PubMed Central

Hayreh, Sohan Singh

2014-01-01

Ocular vascular occlusive disorders collectively constitute the most common cause of visual disability. Before a disease can be managed, it is essential to understand its natural history, so as to be able to assess the likely effectiveness of any intervention. I investigated natural history of visual outcome in prospective studies of 386 eyes with non-arteritic anterior ischemic optic neuropathy (NA-AION), 16 eyes with non-arteritic posterior ischemic optic neuropathy, 697 eyes with central retinal vein occlusion (CRVO), 67 eyes with hemi-CRVO (HCRVO), 216 eyes with branch retinal vein occlusion (BRVO), 260 eyes with central retinal artery occlusion (CRAO), 151 eyes with branch retinal artery occlusion (BRAO) and 61 eyes with cilioretinal artery occlusion (CLRAO). My studies have shown that every one of these disorders consists of multiple distinct clinical sub-categories with different visual findings. When an ocular vascular occlusive disorder is caused by giant cell arteritis, which is an ophthalmic emergency, it would be unethical to do a natural history study of visual outcome in them, because in this case early diagnosis and immediate, intensive high-dose steroid therapy is essential to prevent any further visual loss, not only in the involved eye but also in the fellow, normal eye. In NA-AION in eyes seen ≤2 weeks after the onset, visual acuity (VA) improved in 41% of those with VA 20/70 or worse, and visual field (VF) improved in 26% of those with moderate to severe VF defect. In non-ischemic CRVO eyes with VA 20/70 or worse, VA improved in 47% and in ischemic CRVO in 23%; moderate to severe VF defect improved in 79% in non-ischemic CRVO and in 27% in ischemic CRVO. In HCRVO, overall findings demonstrated that initial VA and VF defect and the final visual outcome were different in non-ischemic from ischemic HCRVO – much better in the former than the latter. In major BRVO, in eyes with initial VA of 20/70 or worse, VA improved in 69%, and moderate to severe VF defect improved in 52%. In macular BRVO with 20/70 or worse initial VA, it improved in 53%, and initial minimal-mild VF defect was stable or improved in 85%. In various types of CRAO there are significant differences in both initial and final VA and VF defects. In CRAO eyes seen within 7 days of onset and initial VA of counting fingers or worse, VA improved in 82% with transient non-arteritic CRAO, 67% with non-arteritic CRAO with cilioretinal artery sparing, 22% with non-arteritic CRAO. Central VF improved in 39% of transient non-arteritic CRAO, 25% of non-arteritic CRAO with cilioretinal artery sparing and 21% of non-arteritic CRAO. Peripheral VF improved in non-arteritic CRAO in 39% and in transient non-arteritic CRAO in 39%. In transient CRAO, finally peripheral VFs were normal in 93%. In non-arteritic CRAO eyes initially 22% had normal peripheral VF and in the rest it improved in 39%. Final VA of 20/40 or better was seen in 89% of permanent BRAO, and in 100% of transient BRAO and non-arteritic CLRAO. In permanent BRAO eyes, among those seen within 7 days of onset, central VF defect improved in 47% and peripheral VF in 52%, and in transient BRAO central and peripheral VFs were normal at follow-up. My studies showed that AION, CRVO, BRVO, CRAO and BRAO, each consist of multiple distinct clinical sub-categories with different visual outcome. Contrary to the prevalent impression, these studies on the natural history of visual outcome have shown that there is a statistically significant spontaneous visual improvement in each category. The factors which influence the visual outcome in various ocular vascular occlusive disorders are discussed. PMID:24769221

The application of an optical Fourier spectrum analyzer on detecting defects in mass-produced satellite photographs

NASA Technical Reports Server (NTRS)

Athale, R.; Lee, S. H.

1976-01-01

Various defects in mass-produced pictures transmitted to earth from a satellite are investigated. It is found that the following defects are readily detectable via Fourier spectrum analysis: (1) bit slip, (2) breakup causing loss of image, and (3) disabled track at the top of the imagery. The scratches made on the film during mass production, which are difficult to detect by visual observation, also show themselves readily in Fourier spectrum analysis. A relation is established between the number of scratches, their width and depth and the intensity of their Fourier spectra. Other defects that are found to be equally suitable for Fourier spectrum analysis or visual (image analysis) detection are synchronous loss without blurring of image, and density variation in gray scale. However, the Fourier spectrum analysis is found to be unsuitable for detection of such defects as pin holes, annotation error, synchronous loss with blurring of images, and missing image in the beginning of the work order. The design of an automated, real time system, which will reject defective films, is treated.

Nondestructive optical testing of the materials surface structure based on liquid crystals

NASA Astrophysics Data System (ADS)

Tomilin, M. G.; Stafeev, S. K.

2011-08-01

Thin layers of nematic liquid crystals (NLCs) may be used as recording media for visualizing structural and microrelief defects, distribution of low power physical fields and modifications of the surface. NLCs are more sensitive in comparison with cholesteric and smectic LCs having super molecular structures. The detecting properties of NLCs are based on local layers deformation, induced by surface fields and observed in polarizing microscope. The structural surface defects or physical field's distribution are dramatically change the distribution of surface tension. Surface defects recording becomes possible if NLC deformed structure is illuminated in transparent or reflective modes and observed in optical polarizing microscope and appearing image is compared with background structure. In this case one observes not the real defect but the local deformation in NLCs. The theory was developed to find out the real size of defects. The resolution of NLC layer is more than 2000 lines/mm. The fields of NLC application are solid crystals symmetry, minerals, metals, semiconductors, polymers and glasses structure inhomogeneities and optical coatings defects detecting. The efficiency of NLC method in biophotonics is illustrated by objective detecting cancer tissues character and visualizing the interaction traces of grippe viruses with antibodies. NLCs may detect solvent components structure in tea, wine and perfume giving unique information of their structure. It presents diagnostic information alternative to dyes and fluorescence methods. For the first time the structures of some juices and beverages are visualized to illustrate the unique possibilities of NLCs.

Screening methods for post-stroke visual impairment: a systematic review.

PubMed

Hanna, Kerry Louise; Hepworth, Lauren Rachel; Rowe, Fiona

2017-12-01

To provide a systematic overview of the various tools available to screen for post-stroke visual impairment. A review of the literature was conducted including randomised controlled trials, controlled trials, cohort studies, observational studies, systematic reviews and retrospective medical note reviews. All languages were included and translation was obtained. Participants included adults ≥18 years old diagnosed with a visual impairment as a direct cause of a stroke. We searched a broad range of scholarly online resources and hand-searched articles registers of published, unpublished and on-going trials. Search terms included a variety of MESH terms and alternatives in relation to stroke and visual conditions. Study selection was performed by two authors independently. The quality of the evidence and risk of bias were assessed using the STROBE, GRACE and PRISMA statements. A total of 25 articles (n = 2924) were included in this review. Articles appraised reported on tools screening solely for visual impairments or for general post-stroke disabilities inclusive of vision. The majority of identified tools screen for visual perception including visual neglect (VN), with few screening for visual acuity (VA), visual field (VF) loss or ocular motility (OM) defects. Six articles reported on nine screening tools which combined visual screening assessment alongside screening for general stroke disabilities. Of these, three included screening for VA; three screened for VF loss; three screened for OM defects and all screened for VN. Two tools screened for all visual impairments. A further 19 articles were found which reported on individual vision screening tests in stroke populations; two for VF loss; 11 for VN and six for other visual perceptual defects. Most tools cannot accurately account for those with aphasia or communicative deficits, which are common problems following a stroke. There is currently no standardised visual screening tool which can accurately assess all potential post-stroke visual impairments. The current tools screen for only a number of potential stroke-related impairments, which means many visual defects may be missed. The sensitivity of those which screen for all impairments is significantly lowered when patients are unable to report their visual symptoms. Future research is required to develop a tool capable of assessing stroke patients which encompasses all potential visual deficits and can also be easily performed by both the patients and administered by health care professionals in order to ensure all stroke survivors with visual impairment are accurately identified and managed. Implications for Rehabilitation Over 65% of stroke survivors will suffer from a visual impairment, whereas 45% of stroke units do not assess vision. Visual impairment significantly reduces the quality of life, such as being unable to return to work, driving and depression. This review outlines the available screening methods to accurately identify stroke survivors with visual impairments. Identifying visual impairment after stroke can aid general rehabilitation and thus, improve the quality of life for these patients.

Diagnostic Value of Ganglion Cell-Inner Plexiform Layer Thickness in Glaucoma With Superior or Inferior Visual Hemifield Defects.

PubMed

Kim, Ho Soong; Yang, Heon; Lee, Tae Heon; Lee, Kyung Heon

2016-06-01

To determine the diagnostic value of the ganglion cell-inner plexiform layer (GCIPL) thickness in glaucomatous eyes with superior or inferior visual hemifield defects. Eighty-five patients with glaucoma (42 isolated superior hemifield defects and 43 isolated inferior hemifield defects) and 46 normal subjects were enrolled. All patients underwent Cirrus high-definition optical coherence tomography and standard automated perimetry. The area under the receiver operating characteristic curve (AUC) was calculated to determine the diagnostic ability of the GCIPL and peripapillary retinal nerve fiber layer (pRNFL). In the superior hemifield defect glaucoma group, the best parameters for discriminating normal eyes from glaucomatous eyes were the inferotemporal GCIPL thickness (0.942), inferior quadrant RNFL thickness (0.974), and 7 o'clock sector RNFL thickness (0.999). For diagnosing inferior hemifield defect glaucoma, the AUCs of all GCIPL parameters (0.331 to 0.702) were significantly lower than that of the superior quadrant RNFL thickness (0.866, P<0.05). The diagnostic ability of GCIPL parameters was similar to that of the pRNFL parameters in superior hemifield defect glaucoma. However, the diagnostic performance of the GCIPL parameters was significantly inferior to those of the pRNFL parameters in eyes with inferior hemifield defect glaucoma.

A statistical-textural-features based approach for classification of solid drugs using surface microscopic images.

PubMed

Tahir, Fahima; Fahiem, Muhammad Abuzar

2014-01-01

The quality of pharmaceutical products plays an important role in pharmaceutical industry as well as in our lives. Usage of defective tablets can be harmful for patients. In this research we proposed a nondestructive method to identify defective and nondefective tablets using their surface morphology. Three different environmental factors temperature, humidity and moisture are analyzed to evaluate the performance of the proposed method. Multiple textural features are extracted from the surface of the defective and nondefective tablets. These textural features are gray level cooccurrence matrix, run length matrix, histogram, autoregressive model and HAAR wavelet. Total textural features extracted from images are 281. We performed an analysis on all those 281, top 15, and top 2 features. Top 15 features are extracted using three different feature reduction techniques: chi-square, gain ratio and relief-F. In this research we have used three different classifiers: support vector machine, K-nearest neighbors and naïve Bayes to calculate the accuracies against proposed method using two experiments, that is, leave-one-out cross-validation technique and train test models. We tested each classifier against all selected features and then performed the comparison of their results. The experimental work resulted in that in most of the cases SVM performed better than the other two classifiers.

Comparison of Matrix Frequency-Doubling Technology (FDT) Perimetry with the SWEDISH Interactive Thresholding Algorithm (SITA) Standard Automated Perimetry (SAP) in Mild Glaucoma.

PubMed

Doozandeh, Azadeh; Irandoost, Farnoosh; Mirzajani, Ali; Yazdani, Shahin; Pakravan, Mohammad; Esfandiari, Hamed

2017-01-01

This study aimed to compare second-generation frequency-doubling technology (FDT) perimetry with standard automated perimetry (SAP) in mild glaucoma. Forty-seven eyes of 47 participants who had mild visual field defect by SAP were included in this study. All participants were examined using SITA 24-2 (SITA-SAP) and matrix 24-2 (Matrix-FDT). The correlations of global indices and the number of defects on pattern deviation (PD) plots were determined. Agreement between two sets regarding the stage of visual field damage was assessed. Pearson's correlation, intra-cluster comparison, paired t-test, and 95% limit of agreement were calculated. Although there was no significant difference between global indices, the agreement between the two devices regarding the global indices was weak (the limit of agreement for mean deviation was -6.08 to 6.08 and that for pattern standard deviation was -4.42 to 3.42). The agreement between SITA-SAP and Matrix-FDT regarding the Glaucoma Hemifield Test (GHT) and the number of defective points in each quadrant and staging of the visual field damage was also weak. Because the correlation between SITA-SAP and Matrix-FDT regarding global indices, GHT, number of defective points, and stage of the visual field damage in mild glaucoma is weak, Matrix-FDT cannot be used interchangeably with SITA-SAP in the early stages of glaucoma.

Defect-selective dry etching for quick and easy probing of hexagonal boron nitride domains.

PubMed

Wu, Qinke; Lee, Joohyun; Park, Sangwoo; Woo, Hwi Je; Lee, Sungjoo; Song, Young Jae

2018-03-23

In this study, we demonstrate a new method to selectively etch the point defects or the boundaries of as-grown hexagonal boron nitride (hBN) films and flakes in situ on copper substrates using hydrogen and argon gases. The initial quality of the chemical vapor deposition-grown hBN films and flakes was confirmed by UV-vis absorption spectroscopy, atomic force microscopy, and transmission electron microscopy. Different gas flow ratios of Ar/H 2 were then employed to etch the same quality of samples and it was found that etching with hydrogen starts from the point defects and grows epitaxially, which helps in confirming crystalline orientations. However, etching with argon is sensitive to line defects (boundaries) and helps in visualizing the domain size. Finally, based on this defect-selective dry etching technique, it could be visualized that the domains of a polycrystalline hBN monolayer merged together with many parts, even with those that grew from a single nucleation seed.

Defect-selective dry etching for quick and easy probing of hexagonal boron nitride domains

NASA Astrophysics Data System (ADS)

Wu, Qinke; Lee, Joohyun; Park, Sangwoo; Woo, Hwi Je; Lee, Sungjoo; Song, Young Jae

2018-03-01

In this study, we demonstrate a new method to selectively etch the point defects or the boundaries of as-grown hexagonal boron nitride (hBN) films and flakes in situ on copper substrates using hydrogen and argon gases. The initial quality of the chemical vapor deposition-grown hBN films and flakes was confirmed by UV-vis absorption spectroscopy, atomic force microscopy, and transmission electron microscopy. Different gas flow ratios of Ar/H2 were then employed to etch the same quality of samples and it was found that etching with hydrogen starts from the point defects and grows epitaxially, which helps in confirming crystalline orientations. However, etching with argon is sensitive to line defects (boundaries) and helps in visualizing the domain size. Finally, based on this defect-selective dry etching technique, it could be visualized that the domains of a polycrystalline hBN monolayer merged together with many parts, even with those that grew from a single nucleation seed.

Improved detection following Neuro-Eye Therapy in patients with post-geniculate brain damage.

PubMed

Sahraie, Arash; Macleod, Mary-Joan; Trevethan, Ceri T; Robson, Siân E; Olson, John A; Callaghan, Paula; Yip, Brigitte

2010-09-01

Damage to the optic radiation or the occipital cortex results in loss of vision in the contralateral visual field, termed partial cortical blindness or hemianopia. Previously, we have demonstrated that stimulation in the field defect using visual stimuli with optimal properties for blindsight detection can lead to increases in visual sensitivity within the blind field of a group of patients. The present study was aimed to extend the previous work by investigating the effect of positive feedback on recovery of visual sensitivity. Patients' abilities for detection of a range of spatial frequencies within their field defect were determined using a temporal two-alternative forced-choice technique, before and after a period of visual training (n = 4). Patients underwent Neuro-Eye Therapy which involved detection of temporally modulated spatial grating patches at specific retinal locations within their field defect. Three patients showed improved detection ability following visual training. Based on our previous studies, we had hypothesised that should the occipital brain lesion extend anteriorly to the thalamus, little recovery would be expected. Here, we describe one such case who showed no improvements after extensive training. The present study provides further evidence that recovery (a) can be gradual and may require a large number of training sessions (b) can be accelerated using positive feedback and (c) may be less likely to take place if the occipital damage extends anteriorly to the thalamus.

Vision restoration through extrastriate stimulation in patients with visual field defects: a double-blind and randomized experimental study.

PubMed

Jobke, Sandra; Kasten, Erich; Sabel, Bernhard A

2009-01-01

. Vision restoration therapy (VRT) to treat visual field defects used single-point visual stimulation in areas of residual vision up to now. The question arises if the efficiency of restoration can be increased when the entire region of blindness is trained by a visual stimulus aimed at activating extrastriate pathways (extrastriate VRT). . In this crossover study, 18 patients with visual field defects with prior VRT experience were treated with 2 training paradigms. Group 1 (n = 8) first used extrastriate VRT followed by conventional standard VRT. Group 2 (n = 10) trained in reverse order. Visual field size was assessed with computer-based perimetry and subjective vision with the National Eye Institute Visual Function Questionnaire (NEI-VFQ). . In group 1, stimulus detection in high-resolution perimetry (HRP) improved by 5.9% (P < .01) after extrastriate VRT. After the second training period (standard VRT), detection further improved by 1.8% (P = .093). In group 2, detection performance improved after standard VRT by 2.9% (P < .05) and after extrastriate VRT by 2.9% (P < .05). Detection performance increased twice as much after extrastriate VRT (4.2%) than after standard VRT (2.4%; P < .05). All changes in fixation performance were unrelated to detection improvements. NEI-VFQ did not show any significant changes. . Greater improvement after extrastriate VRT is interpreted as an activation of extrastriate pathways by massive "spiral-like" stimulation. These pathways bypass the damaged visual cortex, stimulating extrastriate cortical regions, and are thought to be involved in blindsight.

Observers' cognitive states modulate how visual inputs relate to gaze control.

PubMed

Kardan, Omid; Henderson, John M; Yourganov, Grigori; Berman, Marc G

2016-09-01

Previous research has shown that eye-movements change depending on both the visual features of our environment, and the viewer's top-down knowledge. One important question that is unclear is the degree to which the visual goals of the viewer modulate how visual features of scenes guide eye-movements. Here, we propose a systematic framework to investigate this question. In our study, participants performed 3 different visual tasks on 135 scenes: search, memorization, and aesthetic judgment, while their eye-movements were tracked. Canonical correlation analyses showed that eye-movements were reliably more related to low-level visual features at fixations during the visual search task compared to the aesthetic judgment and scene memorization tasks. Different visual features also had different relevance to eye-movements between tasks. This modulation of the relationship between visual features and eye-movements by task was also demonstrated with classification analyses, where classifiers were trained to predict the viewing task based on eye movements and visual features at fixations. Feature loadings showed that the visual features at fixations could signal task differences independent of temporal and spatial properties of eye-movements. When classifying across participants, edge density and saliency at fixations were as important as eye-movements in the successful prediction of task, with entropy and hue also being significant, but with smaller effect sizes. When classifying within participants, brightness and saturation were also significant contributors. Canonical correlation and classification results, together with a test of moderation versus mediation, suggest that the cognitive state of the observer moderates the relationship between stimulus-driven visual features and eye-movements. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Anatomical Origin of Tuberculum Sellae Meningioma: Off-Midline Location and Its Clinical Implications.

PubMed

Lee, Seungjoo; Hong, Seok Ho; Cho, Young Hyun; Kim, Jeong Hoon; Kim, Chang Jin

2016-05-01

Tuberculum sellae meningiomas (TSM) arise from the dura mater of tuberculum sellae, limbus sphenoidale, and chiasmatic sulcus and cause asymmetric visual disturbances. In this study, we analyzed the laterality of the origin of TSM and discussed its clinical implications on immediate and long-term visual outcomes. Between 1994 and 2013, TSM was diagnosed in 100 patients after microsurgical resection. The medical records, radiologic features, and operative findings were retrospectively reviewed and analyzed in these patients. Visual disturbances were evident in 95 patients (95%) after neuro-ophthalmologic testing. Among them, 89 patients (89%) showed marked asymmetric visual field defect, and 6 patients (6%) had relatively symmetric visual field defect. On intraoperative inspection, the origin of TSM was at the one lateral end portion of the tuberculum sellae in 85 patients (85%). In 15 patients (15%), the TSM originated from the midline region, including the central portion of the tuberculum sellae (n = 13) and diaphragm sellae (n = 2). Optic canal involvement was observed in 73 patients (73%). Preexisting visual field defects were improved in 70 patients (70%), were stationary in 25 patients (25%), and aggravated in 5 patients (5%) during postoperative follow-up (mean 58 months, 24∼122 months). The preoperative symptom duration, the laterality of the origin of TSM, and optic disc atrophy were associated with long-term poor visual outcomes. Most TSMs that originated from the dura of one lateral end portion of the tuberculum sellae correlated with asymmetric visual symptoms and poor visual outcomes. This microsurgical feature should be considered in the planning of optimal surgical strategy to achieve favorable outcomes. Copyright © 2016 Elsevier Inc. All rights reserved.

Infrared machine vision system for the automatic detection of olive fruit quality.

PubMed

Guzmán, Elena; Baeten, Vincent; Pierna, Juan Antonio Fernández; García-Mesa, José A

2013-11-15

External quality is an important factor in the extraction of olive oil and the marketing of olive fruits. The appearance and presence of external damage are factors that influence the quality of the oil extracted and the perception of consumers, determining the level of acceptance prior to purchase in the case of table olives. The aim of this paper is to report on artificial vision techniques developed for the online estimation of olive quality and to assess the effectiveness of these techniques in evaluating quality based on detecting external defects. This method of classifying olives according to the presence of defects is based on an infrared (IR) vision system. Images of defects were acquired using a digital monochrome camera with band-pass filters on near-infrared (NIR). The original images were processed using segmentation algorithms, edge detection and pixel value intensity to classify the whole fruit. The detection of the defect involved a pixel classification procedure based on nonparametric models of the healthy and defective areas of olives. Classification tests were performed on olives to assess the effectiveness of the proposed method. This research showed that the IR vision system is a useful technology for the automatic assessment of olives that has the potential for use in offline inspection and for online sorting for defects and the presence of surface damage, easily distinguishing those that do not meet minimum quality requirements. Crown Copyright © 2013 Published by Elsevier B.V. All rights reserved.

Neural Network Classifiers to Grade Parts Based on Surface Defects with Spatial Dependencies

Treesearch

Daniel L. Schmoldt

1995-01-01

In many manufacturing situations, production parts must be assigned a qualitative grade, rather than only accepted or rejected. When this is done, spatial relationships between defect areas can be a critical factor in making grade assignments. In the case of grading hardwood lumber, for instance, there exists a highly complex set of grading rules which incorporate...

ANN based Performance Evaluation of BDI for Condition Monitoring of Induction Motor Bearings

NASA Astrophysics Data System (ADS)

Patel, Raj Kumar; Giri, V. K.

2017-06-01

One of the critical parts in rotating machines is bearings and most of the failure arises from the defective bearings. Bearing failure leads to failure of a machine and the unpredicted productivity loss in the performance. Therefore, bearing fault detection and prognosis is an integral part of the preventive maintenance procedures. In this paper vibration signal for four conditions of a deep groove ball bearing; normal (N), inner race defect (IRD), ball defect (BD) and outer race defect (ORD) were acquired from a customized bearing test rig, under four different conditions and three different fault sizes. Two approaches have been opted for statistical feature extraction from the vibration signal. In the first approach, raw signal is used for statistical feature extraction and in the second approach statistical features extracted are based on bearing damage index (BDI). The proposed BDI technique uses wavelet packet node energy coefficients analysis method. Both the features are used as inputs to an ANN classifier to evaluate its performance. A comparison of ANN performance is made based on raw vibration data and data chosen by using BDI. The ANN performance has been found to be fairly higher when BDI based signals were used as inputs to the classifier.

9 CFR 318.301 - Containers and closures.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Section 318.301 Animals and Animal Products FOOD SAFETY AND INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE... examinations for rigid containers (cans)—(1) Visual examinations. A closure technician shall visually examine... container shall be examined for product leakage or obvious defects. A visual examination shall be performed...

Advanced pigment dispersion glaucoma secondary to phakic intraocular collamer lens implant.

PubMed

Ye, Clara; Patel, Cajal K; Momont, Anna C; Liu, Yao

2018-06-01

We report a case of pigment dispersion glaucoma secondary to uncomplicated phakic intraocular collamer lens (ICL) (Visian ICL™, Staar Inc., Monrovia, CA) implant that resulted in advanced visual field loss. A 50-year-old man presented for routine follow-up status post bilateral phakic intraocular collamer lens (ICL) placement 8 years earlier. He was incidentally found to have a decline in visual acuity from an anterior subcapsular cataract and elevated intraocular pressure (IOP) in the left eye. There were signs of pigment dispersion and no evidence of angle closure. Diffuse optic nerve thinning was consistent with advanced glaucomatous visual field defects. Pigment dispersion was also present in the patient's right eye, but without elevated IOP or visual field defects. The patient was treated with topical glaucoma medications and the phakic ICL in the left eye was removed concurrently with cataract surgery to prevent further visual field loss. Pigment dispersion glaucoma is a serious adverse outcome after phakic ICL implantation and regular post-operative monitoring may prevent advanced visual field loss.

Visual modifications on the P300 speller BCI paradigm

NASA Astrophysics Data System (ADS)

Salvaris, M.; Sepulveda, F.

2009-08-01

The best known P300 speller brain-computer interface (BCI) paradigm is the Farwell and Donchin paradigm. In this paper, various changes to the visual aspects of this protocol are explored as well as their effects on classification. Changes to the dimensions of the symbols, the distance between the symbols and the colours used were tested. The purpose of the present work was not to achieve the highest possible accuracy results, but to ascertain whether these simple modifications to the visual protocol will provide classification differences between them and what these differences will be. Eight subjects were used, with each subject carrying out a total of six different experiments. In each experiment, the user spelt a total of 39 characters. Two types of classifiers were trained and tested to determine whether the results were classifier dependant. These were a support vector machine (SVM) with a radial basis function (RBF) kernel and Fisher's linear discriminant (FLD). The single-trial classification results and multiple-trial classification results were recorded and compared. Although no visual protocol was the best for all subjects, the best performances, across both classifiers, were obtained with the white background (WB) visual protocol. The worst performance was obtained with the small symbol size (SSS) visual protocol.

Visual functions of commercial drivers in relation to road accidents in Nigeria

PubMed Central

Oladehinde, M. K.; Adeoye, A. O.; Adegbehingbe, B. O.; Onakoya, A. O.

2007-01-01

Objective: To determine the effects of the visual functions on the occurrence of road traffic accidents (RTA) amongst commercial drivers in Ife central local government area (LGA) of Osun state of Nigeria. Design: A cross-sectional study. Settings: Four major motor parks located at Ife Central LGA. Materials and Methods: Of the estimated 270 commercial drivers in the four major parks of the LGA, 215 consecutive drivers were interviewed and had their eyes examined. Structured questionnaires were administered by an ophthalmologist. Results: The prevalence of visual impairment (visual acuity < 6/18) in the better eye without correction was 3.3% ± 2.4 and there was a significant association between uncorrected visual acuity impairment in the better eye and RTA (P = 0.0152). Refractive error was seen in 8.4% of the drivers, but none of these wear corrective glasses. Visual field defect, abnormal stereopsis and color vision impairment did not have any significant association with RTA. Conclusion: Poor visual acuity is strongly associated with RTA amongst Nigerian commercial drivers as opposed to visual field defect, abnormal color vision and stereopsis. A significant proportion of visual impairment was due to uncorrected refractive errors. PMID:21938219

Mixing apples with oranges: Visual attention deficits in schizophrenia.

PubMed

Caprile, Claudia; Cuevas-Esteban, Jorge; Ochoa, Susana; Usall, Judith; Navarra, Jordi

2015-09-01

Patients with schizophrenia usually present cognitive deficits. We investigated possible anomalies at filtering out irrelevant visual information in this psychiatric disorder. Associations between these anomalies and positive and/or negative symptomatology were also addressed. A group of individuals with schizophrenia and a control group of healthy adults performed a Garner task. In Experiment 1, participants had to rapidly classify visual stimuli according to their colour while ignoring their shape. These two perceptual dimensions are reported to be "separable" by visual selective attention. In Experiment 2, participants classified the width of other visual stimuli while trying to ignore their height. These two visual dimensions are considered as being "integral" and cannot be attended separately. While healthy perceivers were, in Experiment 1, able to exclusively respond to colour, an irrelevant variation in shape increased colour-based reaction times (RTs) in the group of patients. In Experiment 2, RTs when classifying width increased in both groups as a consequence of perceiving a variation in the irrelevant dimension (height). However, this interfering effect was larger in the group of schizophrenic patients than in the control group. Further analyses revealed that these alterations in filtering out irrelevant visual information correlated with positive symptoms in PANSS scale. A possible limitation of the study is the relatively small sample. Our findings suggest the presence of attention deficits in filtering out irrelevant visual information in schizophrenia that could be related to positive symptomatology. Copyright © 2015 Elsevier Ltd. All rights reserved.

Image Statistics and the Representation of Material Properties in the Visual Cortex

PubMed Central

Baumgartner, Elisabeth; Gegenfurtner, Karl R.

2016-01-01

We explored perceived material properties (roughness, texturedness, and hardness) with a novel approach that compares perception, image statistics and brain activation, as measured with fMRI. We initially asked participants to rate 84 material images with respect to the above mentioned properties, and then scanned 15 of the participants with fMRI while they viewed the material images. The images were analyzed with a set of image statistics capturing their spatial frequency and texture properties. Linear classifiers were then applied to the image statistics as well as the voxel patterns of visually responsive voxels and early visual areas to discriminate between images with high and low perceptual ratings. Roughness and texturedness could be classified above chance level based on image statistics. Roughness and texturedness could also be classified based on the brain activation patterns in visual cortex, whereas hardness could not. Importantly, the agreement in classification based on image statistics and brain activation was also above chance level. Our results show that information about visual material properties is to a large degree contained in low-level image statistics, and that these image statistics are also partially reflected in brain activity patterns induced by the perception of material images. PMID:27582714

Image Statistics and the Representation of Material Properties in the Visual Cortex.

PubMed

Baumgartner, Elisabeth; Gegenfurtner, Karl R

2016-01-01

We explored perceived material properties (roughness, texturedness, and hardness) with a novel approach that compares perception, image statistics and brain activation, as measured with fMRI. We initially asked participants to rate 84 material images with respect to the above mentioned properties, and then scanned 15 of the participants with fMRI while they viewed the material images. The images were analyzed with a set of image statistics capturing their spatial frequency and texture properties. Linear classifiers were then applied to the image statistics as well as the voxel patterns of visually responsive voxels and early visual areas to discriminate between images with high and low perceptual ratings. Roughness and texturedness could be classified above chance level based on image statistics. Roughness and texturedness could also be classified based on the brain activation patterns in visual cortex, whereas hardness could not. Importantly, the agreement in classification based on image statistics and brain activation was also above chance level. Our results show that information about visual material properties is to a large degree contained in low-level image statistics, and that these image statistics are also partially reflected in brain activity patterns induced by the perception of material images.

VizioMetrics: Mining the Scientific Visual Literature

ERIC Educational Resources Information Center

Lee, Po-Shen

2017-01-01

Scientific results are communicated visually in the literature through diagrams, visualizations, and photographs. In this thesis, we developed a figure processing pipeline to classify more than 8 million figures from PubMed Central into different figure types and study the resulting patterns of visual information as they relate to scholarly…

A novel visual pipework inspection system

NASA Astrophysics Data System (ADS)

Summan, Rahul; Jackson, William; Dobie, Gordon; MacLeod, Charles; Mineo, Carmelo; West, Graeme; Offin, Douglas; Bolton, Gary; Marshall, Stephen; Lille, Alexandre

2018-04-01

The interior visual inspection of pipelines in the nuclear industry is a safety critical activity conducted during outages to ensure the continued safe and reliable operation of plant. Typically, the video output by a manually deployed probe is viewed by an operator looking to identify and localize surface defects such as corrosion, erosion and pitting. However, it is very challenging to estimate the nature and extent of defects by viewing a large structure through a relatively small field of view. This work describes a new visual inspection system employing photogrammetry using a fisheye camera and a structured light system to map the internal geometry of pipelines by generating a photorealistic, geometrically accurate surface model. The error of the system output was evaluated through comparison to a ground truth laser scan (ATOS GOM Triple Scan) of a nuclear grade split pipe sample (stainless steel 304L, 80mm internal diameter) containing defects representative of the application - the error was found to be submillimeter across the sample.

Treatment of a Focal Articular Cartilage Defect of the Talus with Polymer-Based Autologous Chondrocyte Implantation: A 12-Year Follow-Up Period.

PubMed

Kreuz, Peter Cornelius; Kalkreuth, Richard Horst; Niemeyer, Philipp; Uhl, Markus; Erggelet, Christoph

Autologous chondrocyte implantation (ACI) is a first-line treatment option for large articular cartilage defects. Although well-established for cartilage defects in the knee, studies of the long-term outcomes of matrix-assisted ACI to treat cartilage defects in the ankle are rare. In the present report, we describe for the first time the long-term clinical and radiologic results 12 years after polymer-based matrix-assisted ACI treat a full-thickness talar cartilage defect in a 25-year-old male patient. The clinical outcome was assessed using the visual analog scale and Freiburg ankle score, magnetic resonance imaging evaluation using the Henderson-Kreuz scoring system and T2 mapping. Clinical assessment revealed improved visual analog scale and Freiburg ankle scores. The radiologic analysis and T2 relaxation time values indicated the formation of hyaline-like repair tissue. Polymer-based autologous chondrocytes has been shown to be a safe and clinically effective long-term treatment of articular cartilage defects in the talus. Copyright © 2017 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.

[Comparison of initial and delayed myocardial imaging with beta-methyl-p-[123I]-iodophenylpentadecanoic acid in acute myocardial infarction].

PubMed

Naruse, H; Yoshimura, N; Yamamoto, J; Morita, M; Fukutake, N; Ohyanagi, M; Iwasaki, T; Fukuchi, M

1994-01-01

Myocardial imaging using beta-methyl-p-[123I]-iodophenylpentadecanoic acid (BMIPP) of 15 patients with acute myocardial infarction was performed to assess "fill-in" and "washout" defects in the delayed myocardial image. The initial and delayed images were evaluated by a visual and quantitative washout rate method. Visual judgement found 8/180 (4%) segments showed "fill-in" defects, and 24/180 segments (13%) showed "washout" defects. There was no relationship between days from onset to the study and the frequency of fill-in and washout defects. The mean washout rate in the segments with "fill-in" defects was 9.0 +/- 16.6%, and that of "washout" defects was 24.9 +/- 18.1% which was significantly higher than in controls (8.7 +/- 15.4%, p < 0.05). There was no correlation between mean washout rate and total blood lipids, total cholesterol, triglyceride and HDL-cholesterol. Therefore, neither time from onset nor blood lipids level was related to changes from the initial image to the delayed image. These changes may be due to relative (false) findings due to changes in circumference, and may be based on myocardial characteristics after myocardial infarction and/or reperfusion.

One-Dimensional Quantum Walks with One Defect

NASA Astrophysics Data System (ADS)

Cantero, M. J.; Grünbaum, F. A.; Moral, L.; Velázquez, L.

The CGMV method allows for the general discussion of localization properties for the states of a one-dimensional quantum walk, both in the case of the integers and in the case of the nonnegative integers. Using this method we classify, according to such localization properties, all the quantum walks with one defect at the origin, providing explicit expressions for the asymptotic return probabilities to the origin.

Development of visual field defect after first-detected optic disc hemorrhage in preperimetric open-angle glaucoma.

PubMed

Kim, Hae Jin; Song, Yong Ju; Kim, Young Kook; Jeoung, Jin Wook; Park, Ki Ho

2017-07-01

To evaluate functional progression in preperimetric glaucoma (PPG) with disc hemorrhage (DH) and to determine the time interval between the first-detected DH and development of glaucomatous visual field (VF) defect. A total of 87 patients who had been first diagnosed with PPG were enrolled. The medical records of PPG patients without DH (Group 1) and with DH (Group 2) were reviewed. When glaucomatous VF defect appeared, the time interval from the diagnosis of PPG to the development of VF defect was calculated and compared between the two groups. In group 2, the time intervals from the first-detected DH to VF defect of the single- and recurrent-DH were compared. Of the enrolled patients, 45 had DH in the preperimetric stage. The median time interval from the diagnosis of PPG to the development of VF defect was 73.3 months in Group 1, versus 45.4 months in Group 2 (P = 0.042). The cumulative probability of development of VF defect after diagnosis of PPG was significantly greater in Group 2 than in Group 1. The median time interval from first-detected DH to the development of VF defect was 37.8 months. The median time interval from DH to VF defect and cumulative probability of VF defect after DH did not show a statistical difference between single and recurrent-DH patients. The median time interval between the diagnosis of PPG and the development of VF defect was significantly shorter in PPG with DH. The VF defect appeared 37.8 months after the first-detected DH in PPG.

Cranial Nerve II

PubMed Central

Gillig, Paulette Marie; Sanders, Richard D.

2009-01-01

This article contains a brief review of the anatomy of the visual system, a survey of diseases of the retina, optic nerve and lesions of the optic chiasm, and other visual field defects of special interest to the psychiatrist. It also includes a presentation of the corticothalamic mechanisms, differential diagnosis, and various manifestations of visual illusions, and simple and complex visual hallucinations, as well as the differential diagnoses of these various visual phenomena. PMID:19855858

Etiology and clinical presentation of birth defects: population based study

PubMed Central

Carey, John C; Byrne, Janice L B; Krikov, Sergey; Botto, Lorenzo D

2017-01-01

Objective To assess causation and clinical presentation of major birth defects. Design Population based case cohort. Setting Cases of birth defects in children born 2005-09 to resident women, ascertained through Utah’s population based surveillance system. All records underwent clinical re-review. Participants 5504 cases among 270 878 births (prevalence 2.03%), excluding mild isolated conditions (such as muscular ventricular septal defects, distal hypospadias). Main outcome measures The primary outcomes were the proportion of birth defects with a known etiology (chromosomal, genetic, human teratogen, twinning) or unknown etiology, by morphology (isolated, multiple, minors only), and by pathogenesis (sequence, developmental field defect, or known pattern of birth defects). Results Definite cause was assigned in 20.2% (n=1114) of cases: chromosomal or genetic conditions accounted for 94.4% (n=1052), teratogens for 4.1% (n=46, mostly poorly controlled pregestational diabetes), and twinning for 1.4% (n=16, conjoined or acardiac). The 79.8% (n=4390) remaining were classified as unknown etiology; of these 88.2% (n=3874) were isolated birth defects. Family history (similarly affected first degree relative) was documented in 4.8% (n=266). In this cohort, 92.1% (5067/5504) were live born infants (isolated and non-isolated birth defects): 75.3% (4147/5504) were classified as having an isolated birth defect (unknown or known etiology). Conclusions These findings underscore the gaps in our knowledge regarding the causes of birth defects. For the causes that are known, such as smoking or diabetes, assigning causation in individual cases remains challenging. Nevertheless, the ongoing impact of these exposures on fetal development highlights the urgency and benefits of population based preventive interventions. For the causes that are still unknown, better strategies are needed. These can include greater integration of the key elements of etiology, morphology, and pathogenesis into epidemiologic studies; greater collaboration between researchers (such as developmental biologists), clinicians (such as medical geneticists), and epidemiologists; and better ways to objectively measure fetal exposures (beyond maternal self reports) and closer (prenatally) to the critical period of organogenesis. PMID:28559234

76 FR 28308 - Compliance Policy Guide: Surgeons' Gloves and Patient Examination Gloves; Defects-Criteria for...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-17

... quality levels (AQLs) for leaks and visual defects observed during FDA testing of medical gloves. The CPG... practices regulation (21 CFR 10.115). The CPG represents FDA's current thinking on the criteria for direct...

Echocardiographic imaging techniques with subcostal and right parasternal longitudinal views in detecting sinus venosus atrial septal defects.

PubMed

McDonald, R W; Rice, M J; Reller, M D; Marcella, C P; Sahn, D J

1996-01-01

Sinus venosus atrial septal defects are frequently missed and difficult to visualize with conventional two-dimensional echocardiographic views. Using modified subcostal and right parasternal longitudinal views, nine patients were found to have a sinus venosus atrial septal defect. The modified subcostal view showed a sinus venosus atrial septal defect in all nine patients; three patients had secundum atrial septal defects as well. The right parasternal view detected only six patients with sinus venosus atrial septal defect. Partial anomalous pulmonary venous return was diagnosed in seven patients using these views. The combination of subcostal and right parasternal longitudinal imaging views will improve the detection of sinus venosus atrial septal defects.

Visual, Algebraic and Mixed Strategies in Visually Presented Linear Programming Problems.

ERIC Educational Resources Information Center

Shama, Gilli; Dreyfus, Tommy

1994-01-01

Identified and classified solution strategies of (n=49) 10th-grade students who were presented with linear programming problems in a predominantly visual setting in the form of a computerized game. Visual strategies were developed more frequently than either algebraic or mixed strategies. Appendix includes questionnaires. (Contains 11 references.)…

Combined Microsatellite Instability, MLH1 Methylation Analysis, and Immunohistochemistry for Lynch Syndrome Screening in Endometrial Cancers From GOG210: An NRG Oncology and Gynecologic Oncology Group Study.

PubMed

Goodfellow, Paul J; Billingsley, Caroline C; Lankes, Heather A; Ali, Shamshad; Cohn, David E; Broaddus, Russell J; Ramirez, Nilsa; Pritchard, Colin C; Hampel, Heather; Chassen, Alexis S; Simmons, Luke V; Schmidt, Amy P; Gao, Feng; Brinton, Louise A; Backes, Floor; Landrum, Lisa M; Geller, Melissa A; DiSilvestro, Paul A; Pearl, Michael L; Lele, Shashikant B; Powell, Matthew A; Zaino, Richard J; Mutch, David

2015-12-20

The best screening practice for Lynch syndrome (LS) in endometrial cancer (EC) remains unknown. We sought to determine whether tumor microsatellite instability (MSI) typing along with immunohistochemistry (IHC) and MLH1 methylation analysis can help identify women with LS. ECs from GOG210 patients were assessed for MSI, MLH1 methylation, and mismatch repair (MMR) protein expression. Each tumor was classified as having normal MMR, defective MMR associated with MLH1 methylation, or probable MMR mutation (ie, defective MMR but no methylation). Cancer family history and demographic and clinical features were compared for the three groups. Lynch mutation testing was performed for a subset of women. Analysis of 1,002 ECs suggested possible MMR mutation in 11.8% of tumors. The number of patients with a family history suggestive of LS was highest among women whose tumors were classified as probable MMR mutation (P = .001). Lynch mutations were identified in 41% of patient cases classified as probable mutation (21 of 51 tested). One of the MSH6 Lynch mutations was identified in a patient whose tumor had intact MSH6 expression. Age at diagnosis was younger for mutation carriers than noncarriers (54.3 v 62.3 years; P < .01), with five carriers diagnosed at age > 60 years. Combined MSI, methylation, and IHC analysis may prove useful in Lynch screening in EC. Twenty-four percent of mutation carriers presented with ECs at age > 60 years, and one carrier had an MSI-positive tumor with no IHC defect. Restricting Lynch testing to women diagnosed at age < 60 years or to women with IHC defects could result in missing a substantial fraction of genetic disease. © 2015 by American Society of Clinical Oncology.

Combined Microsatellite Instability, MLH1 Methylation Analysis, and Immunohistochemistry for Lynch Syndrome Screening in Endometrial Cancers From GOG210: An NRG Oncology and Gynecologic Oncology Group Study

PubMed Central

Goodfellow, Paul J.; Billingsley, Caroline C.; Lankes, Heather A.; Ali, Shamshad; Cohn, David E.; Broaddus, Russell J.; Ramirez, Nilsa; Pritchard, Colin C.; Hampel, Heather; Chassen, Alexis S.; Simmons, Luke V.; Schmidt, Amy P.; Gao, Feng; Brinton, Louise A.; Backes, Floor; Landrum, Lisa M.; Geller, Melissa A.; DiSilvestro, Paul A.; Pearl, Michael L.; Lele, Shashikant B.; Powell, Matthew A.; Zaino, Richard J.; Mutch, David

2015-01-01

Purpose The best screening practice for Lynch syndrome (LS) in endometrial cancer (EC) remains unknown. We sought to determine whether tumor microsatellite instability (MSI) typing along with immunohistochemistry (IHC) and MLH1 methylation analysis can help identify women with LS. Patients and Methods ECs from GOG210 patients were assessed for MSI, MLH1 methylation, and mismatch repair (MMR) protein expression. Each tumor was classified as having normal MMR, defective MMR associated with MLH1 methylation, or probable MMR mutation (ie, defective MMR but no methylation). Cancer family history and demographic and clinical features were compared for the three groups. Lynch mutation testing was performed for a subset of women. Results Analysis of 1,002 ECs suggested possible MMR mutation in 11.8% of tumors. The number of patients with a family history suggestive of LS was highest among women whose tumors were classified as probable MMR mutation (P = .001). Lynch mutations were identified in 41% of patient cases classified as probable mutation (21 of 51 tested). One of the MSH6 Lynch mutations was identified in a patient whose tumor had intact MSH6 expression. Age at diagnosis was younger for mutation carriers than noncarriers (54.3 v 62.3 years; P < .01), with five carriers diagnosed at age > 60 years. Conclusion Combined MSI, methylation, and IHC analysis may prove useful in Lynch screening in EC. Twenty-four percent of mutation carriers presented with ECs at age > 60 years, and one carrier had an MSI-positive tumor with no IHC defect. Restricting Lynch testing to women diagnosed at age < 60 years or to women with IHC defects could result in missing a substantial fraction of genetic disease. PMID:26552419

Landmark Image Retrieval by Jointing Feature Refinement and Multimodal Classifier Learning.

PubMed

Zhang, Xiaoming; Wang, Senzhang; Li, Zhoujun; Ma, Shuai; Xiaoming Zhang; Senzhang Wang; Zhoujun Li; Shuai Ma; Ma, Shuai; Zhang, Xiaoming; Wang, Senzhang; Li, Zhoujun

2018-06-01

Landmark retrieval is to return a set of images with their landmarks similar to those of the query images. Existing studies on landmark retrieval focus on exploiting the geometries of landmarks for visual similarity matches. However, the visual content of social images is of large diversity in many landmarks, and also some images share common patterns over different landmarks. On the other side, it has been observed that social images usually contain multimodal contents, i.e., visual content and text tags, and each landmark has the unique characteristic of both visual content and text content. Therefore, the approaches based on similarity matching may not be effective in this environment. In this paper, we investigate whether the geographical correlation among the visual content and the text content could be exploited for landmark retrieval. In particular, we propose an effective multimodal landmark classification paradigm to leverage the multimodal contents of social image for landmark retrieval, which integrates feature refinement and landmark classifier with multimodal contents by a joint model. The geo-tagged images are automatically labeled for classifier learning. Visual features are refined based on low rank matrix recovery, and multimodal classification combined with group sparse is learned from the automatically labeled images. Finally, candidate images are ranked by combining classification result and semantic consistence measuring between the visual content and text content. Experiments on real-world datasets demonstrate the superiority of the proposed approach as compared to existing methods.

HD-MTL: Hierarchical Deep Multi-Task Learning for Large-Scale Visual Recognition.

PubMed

Fan, Jianping; Zhao, Tianyi; Kuang, Zhenzhong; Zheng, Yu; Zhang, Ji; Yu, Jun; Peng, Jinye

2017-02-09

In this paper, a hierarchical deep multi-task learning (HD-MTL) algorithm is developed to support large-scale visual recognition (e.g., recognizing thousands or even tens of thousands of atomic object classes automatically). First, multiple sets of multi-level deep features are extracted from different layers of deep convolutional neural networks (deep CNNs), and they are used to achieve more effective accomplishment of the coarseto- fine tasks for hierarchical visual recognition. A visual tree is then learned by assigning the visually-similar atomic object classes with similar learning complexities into the same group, which can provide a good environment for determining the interrelated learning tasks automatically. By leveraging the inter-task relatedness (inter-class similarities) to learn more discriminative group-specific deep representations, our deep multi-task learning algorithm can train more discriminative node classifiers for distinguishing the visually-similar atomic object classes effectively. Our hierarchical deep multi-task learning (HD-MTL) algorithm can integrate two discriminative regularization terms to control the inter-level error propagation effectively, and it can provide an end-to-end approach for jointly learning more representative deep CNNs (for image representation) and more discriminative tree classifier (for large-scale visual recognition) and updating them simultaneously. Our incremental deep learning algorithms can effectively adapt both the deep CNNs and the tree classifier to the new training images and the new object classes. Our experimental results have demonstrated that our HD-MTL algorithm can achieve very competitive results on improving the accuracy rates for large-scale visual recognition.

Comparison of Octopus Semi-Automated Kinetic Perimetry and Humphrey Peripheral Static Perimetry in Neuro-Ophthalmic Cases

PubMed Central

Rowe, Fiona J.; Noonan, Carmel; Manuel, Melanie

2013-01-01

Aim. To compare semikinetic perimetry (SKP) on Octopus 900 perimetry to a peripheral static programme with Humphrey automated perimetry. Methods. Prospective cross-section study comparing Humphrey full field (FF) 120 two zone programme to a screening protocol for SKP on Octopus perimetry. Results were independently graded for presence/absence of field defect plus type and location of defect. Results. 64 patients (113 eyes) underwent dual perimetry assessment. Mean duration of assessment for SKP was 4.54 minutes ±0.18 and 6.17 ± 0.12 for FF120 (P = 0.0001). 80% of results were correctly matched for normal or abnormal visual fields using the I4e target versus FF120, and 73.5% were correctly matched using the I2e target versus FF120. When comparing Octopus results with combined I4e and I2e isopters to the FF120 result, a match for normal or abnormal fields was recorded in 87%. Conclusions. Humphrey perimetry test duration was generally longer than Octopus SKP. In the absence of kinetic perimetry, peripheral static suprathreshold programme options such as FF120 may be useful for detection of visual field defects. However, statokinetic dissociation may occur. Octopus SKP utilising both I4e and I2e targets provides detailed information of both the defect depth and size and may provide a more representative view of the actual visual field defect. PMID:24558605

46 CFR 108.187 - Ventilation for brush type electric motors in classified spaces.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 46 Shipping 4 2010-10-01 2010-10-01 false Ventilation for brush type electric motors in classified... Ventilation for brush type electric motors in classified spaces. Ventilation for brush type electric motors in... Electrical Equipment in Hazardous Locations”, except audible and visual alarms may be used if shutting down...

Classifying the Perceptual Interpretations of a Bistable Image Using EEG and Artificial Neural Networks

PubMed Central

Hramov, Alexander E.; Maksimenko, Vladimir A.; Pchelintseva, Svetlana V.; Runnova, Anastasiya E.; Grubov, Vadim V.; Musatov, Vyacheslav Yu.; Zhuravlev, Maksim O.; Koronovskii, Alexey A.; Pisarchik, Alexander N.

2017-01-01

In order to classify different human brain states related to visual perception of ambiguous images, we use an artificial neural network (ANN) to analyze multichannel EEG. The classifier built on the basis of a multilayer perceptron achieves up to 95% accuracy in classifying EEG patterns corresponding to two different interpretations of the Necker cube. The important feature of our classifier is that trained on one subject it can be used for the classification of EEG traces of other subjects. This result suggests the existence of common features in the EEG structure associated with distinct interpretations of bistable objects. We firmly believe that the significance of our results is not limited to visual perception of the Necker cube images; the proposed experimental approach and developed computational technique based on ANN can also be applied to study and classify different brain states using neurophysiological data recordings. This may give new directions for future research in the field of cognitive and pathological brain activity, and for the development of brain-computer interfaces. PMID:29255403

Weak scratch detection and defect classification methods for a large-aperture optical element

NASA Astrophysics Data System (ADS)

Tao, Xian; Xu, De; Zhang, Zheng-Tao; Zhang, Feng; Liu, Xi-Long; Zhang, Da-Peng

2017-03-01

Surface defects on optics cause optic failure and heavy loss to the optical system. Therefore, surface defects on optics must be carefully inspected. This paper proposes a coarse-to-fine detection strategy of weak scratches in complicated dark-field images. First, all possible scratches are detected based on bionic vision. Then, each possible scratch is precisely positioned and connected to a complete scratch by the LSD and a priori knowledge. Finally, multiple scratches with various types can be detected in dark-field images. To classify defects and pollutants, a classification method based on GIST features is proposed. This paper uses many real dark-field images as experimental images. The results show that this method can detect multiple types of weak scratches in complex images and that the defects can be correctly distinguished with interference. This method satisfies the real-time and accurate detection requirements of surface defects.

On the relationship between topological and geometric defects.

PubMed

Griffin, Sinéad M; Spaldin, Nicola A

2017-08-31

The study of topology in solids is undergoing a renaissance following renewed interest in the properties of ferroic domain walls as well as recent discoveries regarding skyrmionic lattices. Each of these systems possess a property that is 'protected' in a symmetry sense, and is defined rigorously using a branch of mathematics known as topology. In this article we review the formal definition of topological defects as they are classified in terms of homotopy theory, and discuss the precise symmetry-breaking conditions that lead to their formation. We distinguish topological defects from defects that arise from the details of the stacking or structure of the material but are not protected by symmetry, and we propose the term 'geometric defects' to describe the latter. We provide simple material examples of both topological and geometric defect types, and discuss the implications of the classification on the resulting material properties.

Photothermal coherence tomography for 3-D visualization and structural non-destructive imaging of a wood inlay

NASA Astrophysics Data System (ADS)

Tavakolian, Pantea; Sfarra, Stefano; Gargiulo, Gianfranco; Sivagurunathan, Koneshwaran; Mandelis, Andreas

2018-06-01

The aim of this research is to investigate the suitability of truncated correlation photothermal coherence tomography (TC-PCT) for the non-destructive imaging of a replica of a real inlay to identify subsurface features that often are invisible areas of vulnerability and damage. Defects of inlays involve glue-rich areas, glue-starved areas, termite attack, insect damage, and laminar splitting. These defects have the potential to result in extensive damage to the art design layers of inlays. Therefore, there is a need for an imaging technique to visualize and determine the location of defects within the sample. The recently introduced TC-PCT modality proved capable of providing 3-D images of specimens with high axial resolution, deep subsurface depth profiling capability, and high signal-to-noise ratio (SNR). Therefore, in this study the authors used TC-PCT to image a fabricated inlay sample with various natural and artificial defects in the middle and top layers. The inlay in question reproduces to scale a piece of art preserved in the "Mirror room" of the Castle Laffitte in France. It was built by a professional restorer following the ancient procedure named element by element. Planar TC-PCT images of the inlay were stacked coherently to provide 3-D visualization of areas with known defects in the sample. The experimental results demonstrated the identification of defects such as empty holes, a hole filled with stucco, subsurface delaminations and natural features such as a wood knot and wood grain in different layers of the sample. For this wooden sample that has a very low thermal diffusivity, a depth range of 2 mm was achieved.

Sub-surface defects detection of by using active thermography and advanced image edge detection

NASA Astrophysics Data System (ADS)

Tse, Peter W.; Wang, Gaochao

2017-05-01

Active or pulsed thermography is a popular non-destructive testing (NDT) tool for inspecting the integrity and anomaly of industrial equipment. One of the recent research trends in using active thermography is to automate the process in detecting hidden defects. As of today, human effort has still been using to adjust the temperature intensity of the thermo camera in order to visually observe the difference in cooling rates caused by a normal target as compared to that by a sub-surface crack exists inside the target. To avoid the tedious human-visual inspection and minimize human induced error, this paper reports the design of an automatic method that is capable of detecting subsurface defects. The method used the technique of active thermography, edge detection in machine vision and smart algorithm. An infrared thermo-camera was used to capture a series of temporal pictures after slightly heating up the inspected target by flash lamps. Then the Canny edge detector was employed to automatically extract the defect related images from the captured pictures. The captured temporal pictures were preprocessed by a packet of Canny edge detector and then a smart algorithm was used to reconstruct the whole sequences of image signals. During the processes, noise and irrelevant backgrounds exist in the pictures were removed. Consequently, the contrast of the edges of defective areas had been highlighted. The designed automatic method was verified by real pipe specimens that contains sub-surface cracks. After applying such smart method, the edges of cracks can be revealed visually without the need of using manual adjustment on the setting of thermo-camera. With the help of this automatic method, the tedious process in manually adjusting the colour contract and the pixel intensity in order to reveal defects can be avoided.

Binasal hemianopia.

PubMed

Salinas-Garcia, R F; Smith, J L

1978-09-01

The visual fields of 100 patients referred for neuro-ophthalmologic examination were reviewed; eight cases had binasal visual field defects. Most clinicians have suspected an intracranial cause for such field defects since the classic report of Cushing and Walker in 1912. However, in this study, the cause for the binasal hemianopia was found to be ischemic optic neuropathy in two patients, and one case each of optic nerve drusen, glaucoma, congenital optic nerve pits, and retinitis pigmentosa sine pigmento. Thus 75% of the cases had an intraocular cause for the binasal hemianopia. Two patients had congenital hydrocephalus, and an intracranial basis was thus noted in 25% of these cases. The neurosurgeon should realize that the patient with binasal field defects is much more likely to have an ocular cause than an intracranial one for his problem.

Quality-Related Monitoring and Grading of Granulated Products by Weibull-Distribution Modeling of Visual Images with Semi-Supervised Learning.

PubMed

Liu, Jinping; Tang, Zhaohui; Xu, Pengfei; Liu, Wenzhong; Zhang, Jin; Zhu, Jianyong

2016-06-29

The topic of online product quality inspection (OPQI) with smart visual sensors is attracting increasing interest in both the academic and industrial communities on account of the natural connection between the visual appearance of products with their underlying qualities. Visual images captured from granulated products (GPs), e.g., cereal products, fabric textiles, are comprised of a large number of independent particles or stochastically stacking locally homogeneous fragments, whose analysis and understanding remains challenging. A method of image statistical modeling-based OPQI for GP quality grading and monitoring by a Weibull distribution(WD) model with a semi-supervised learning classifier is presented. WD-model parameters (WD-MPs) of GP images' spatial structures, obtained with omnidirectional Gaussian derivative filtering (OGDF), which were demonstrated theoretically to obey a specific WD model of integral form, were extracted as the visual features. Then, a co-training-style semi-supervised classifier algorithm, named COSC-Boosting, was exploited for semi-supervised GP quality grading, by integrating two independent classifiers with complementary nature in the face of scarce labeled samples. Effectiveness of the proposed OPQI method was verified and compared in the field of automated rice quality grading with commonly-used methods and showed superior performance, which lays a foundation for the quality control of GP on assembly lines.

Mobility scooter driving ability in visually impaired individuals.

PubMed

Cordes, Christina; Heutink, Joost; Brookhuis, Karel A; Brouwer, Wiebo H; Melis-Dankers, Bart J M

2018-06-01

To investigate how well visually impaired individuals can learn to use mobility scooters and which parts of the driving task deserve special attention. A mobility scooter driving skill test was developed to compare driving skills (e.g. reverse driving, turning) between 48 visually impaired (very low visual acuity = 14, low visual acuity = 10, peripheral field defects = 11, multiple visual impairments = 13) and 37 normal-sighted controls without any prior experience with mobility scooters. Performance on this test was rated on a three-point scale. Furthermore, the number of extra repetitions on the different elements were noted. Results showed that visually impaired participants were able to gain sufficient driving skills to be able to use mobility scooters. Participants with visual field defects combined with low visual acuity showed most problems learning different skills and needed more training. Reverse driving and stopping seemed to be most difficult. The present findings suggest that visually impaired individuals are able to learn to drive mobility scooters. Mobility scooter allocators should be aware that these individuals might need more training on certain elements of the driving task. Implications for rehabilitation Visual impairments do not necessarily lead to an inability to acquire mobility scooter driving skills. Individuals with peripheral field defects (especially in combination with reduced visual acuity) need more driving ability training compared to normal-sighted people - especially to accomplish reversing. Individual assessment of visually impaired people is recommended, since participants in this study showed a wide variation in ability to learn driving a mobility scooter.

Evaluating Silent Reading Performance with an Eye Tracking System in Patients with Glaucoma

PubMed Central

Murata, Noriaki; Fukuchi, Takeo

2017-01-01

Objective To investigate the relationship between silent reading performance and visual field defects in patients with glaucoma using an eye tracking system. Methods Fifty glaucoma patients (Group G; mean age, 52.2 years, standard deviation: 11.4 years) and 20 normal controls (Group N; mean age, 46.9 years; standard deviation: 17.2 years) were included in the study. All participants in Group G had early to advanced glaucomatous visual field defects but better than 20/20 visual acuity in both eyes. Participants silently read Japanese articles written horizontally while the eye tracking system monitored and calculated reading duration per 100 characters, number of fixations per 100 characters, and mean fixation duration, which were compared with mean deviation and visual field index values from Humphrey visual field testing (24–2 and 10–2 Swedish interactive threshold algorithm standard) of the right versus left eye and the better versus worse eye. Results There was a statistically significant difference between Groups G and N in mean fixation duration (G, 233.4 msec; N, 215.7 msec; P = 0.010). Within Group G, significant correlations were observed between reading duration and 24–2 right mean deviation (rs = -0.280, P = 0.049), 24–2 right visual field index (rs = -0.306, P = 0.030), 24–2 worse visual field index (rs = -0.304, P = 0.032), and 10–2 worse mean deviation (rs = -0.326, P = 0.025). Significant correlations were observed between mean fixation duration and 10–2 left mean deviation (rs = -0.294, P = 0.045) and 10–2 worse mean deviation (rs = -0.306, P = 0.037), respectively. Conclusions The severity of visual field defects may influence some aspects of reading performance. At least concerning silent reading, the visual field of the worse eye is an essential element of smoothness of reading. PMID:28095478

Defect Detection of Steel Surfaces with Global Adaptive Percentile Thresholding of Gradient Image

NASA Astrophysics Data System (ADS)

Neogi, Nirbhar; Mohanta, Dusmanta K.; Dutta, Pranab K.

2017-12-01

Steel strips are used extensively for white goods, auto bodies and other purposes where surface defects are not acceptable. On-line surface inspection systems can effectively detect and classify defects and help in taking corrective actions. For detection of defects use of gradients is very popular in highlighting and subsequently segmenting areas of interest in a surface inspection system. Most of the time, segmentation by a fixed value threshold leads to unsatisfactory results. As defects can be both very small and large in size, segmentation of a gradient image based on percentile thresholding can lead to inadequate or excessive segmentation of defective regions. A global adaptive percentile thresholding of gradient image has been formulated for blister defect and water-deposit (a pseudo defect) in steel strips. The developed method adaptively changes the percentile value used for thresholding depending on the number of pixels above some specific values of gray level of the gradient image. The method is able to segment defective regions selectively preserving the characteristics of defects irrespective of the size of the defects. The developed method performs better than Otsu method of thresholding and an adaptive thresholding method based on local properties.

Fabric defect detection based on visual saliency using deep feature and low-rank recovery

NASA Astrophysics Data System (ADS)

Liu, Zhoufeng; Wang, Baorui; Li, Chunlei; Li, Bicao; Dong, Yan

2018-04-01

Fabric defect detection plays an important role in improving the quality of fabric product. In this paper, a novel fabric defect detection method based on visual saliency using deep feature and low-rank recovery was proposed. First, unsupervised training is carried out by the initial network parameters based on MNIST large datasets. The supervised fine-tuning of fabric image library based on Convolutional Neural Networks (CNNs) is implemented, and then more accurate deep neural network model is generated. Second, the fabric images are uniformly divided into the image block with the same size, then we extract their multi-layer deep features using the trained deep network. Thereafter, all the extracted features are concentrated into a feature matrix. Third, low-rank matrix recovery is adopted to divide the feature matrix into the low-rank matrix which indicates the background and the sparse matrix which indicates the salient defect. In the end, the iterative optimal threshold segmentation algorithm is utilized to segment the saliency maps generated by the sparse matrix to locate the fabric defect area. Experimental results demonstrate that the feature extracted by CNN is more suitable for characterizing the fabric texture than the traditional LBP, HOG and other hand-crafted features extraction method, and the proposed method can accurately detect the defect regions of various fabric defects, even for the image with complex texture.

A Generic Deep-Learning-Based Approach for Automated Surface Inspection.

PubMed

Ren, Ruoxu; Hung, Terence; Tan, Kay Chen

2018-03-01

Automated surface inspection (ASI) is a challenging task in industry, as collecting training dataset is usually costly and related methods are highly dataset-dependent. In this paper, a generic approach that requires small training data for ASI is proposed. First, this approach builds classifier on the features of image patches, where the features are transferred from a pretrained deep learning network. Next, pixel-wise prediction is obtained by convolving the trained classifier over input image. An experiment on three public and one industrial data set is carried out. The experiment involves two tasks: 1) image classification and 2) defect segmentation. The results of proposed algorithm are compared against several best benchmarks in literature. In the classification tasks, the proposed method improves accuracy by 0.66%-25.50%. In the segmentation tasks, the proposed method reduces error escape rates by 6.00%-19.00% in three defect types and improves accuracies by 2.29%-9.86% in all seven defect types. In addition, the proposed method achieves 0.0% error escape rate in the segmentation task of industrial data.

An intelligent system for real time automatic defect inspection on specular coated surfaces

NASA Astrophysics Data System (ADS)

Li, Jinhua; Parker, Johné M.; Hou, Zhen

2005-07-01

Product visual inspection is still performed manually or semi automatically in most industries from simple ceramic tile grading to complex automotive body panel paint defect and surface quality inspection. Moreover, specular surfaces present additional challenge to conventional vision systems due to specular reflections, which may mask the true location of objects and lead to incorrect measurements. There are some sophisticated visual inspection methods developed in recent years. Unfortunately, most of them are highly computational. Systems built on those methods are either inapplicable or very costly to achieve real time inspection. In this paper, we describe an integrated low-cost intelligent system developed to automatically capture, extract, and segment defects on specular surfaces with uniform color coatings. The system inspects and locates regular surface defects with lateral dimensions as small as a millimeter. The proposed system is implemented on a group of smart cameras using its on-board processing ability to achieve real time inspection. The experimental results on real test panels demonstrate the effectiveness and robustness of proposed system.

Validation of the Preverbal Visual Assessment (PreViAs) questionnaire.

PubMed

García-Ormaechea, Inés; González, Inmaculada; Duplá, María; Andres, Eva; Pueyo, Victoria

2014-10-01

Visual cognitive integrative functions need to be evaluated by a behavioral assessment, which requires an experienced evaluator. The Preverbal Visual Assessment (PreViAs) questionnaire was designed to evaluate these functions, both in general pediatric population or in children with high risk of visual cognitive problems, through primary caregivers' answers. We aimed to validate the PreViAs questionnaire by comparing caregiver reports with results from a comprehensive clinical protocol. A total of 220 infants (<2 years old) were divided into two groups according to visual development, as determined by the clinical protocol. Their primary caregivers completed the PreViAs questionnaire, which consists of 30 questions related to one or more visual domains: visual attention, visual communication, visual-motor coordination, and visual processing. Questionnaire answers were compared with results of behavioral assessments performed by three pediatric ophthalmologists. Results of the clinical protocol classified 128 infants as having normal visual maturation, and 92 as having abnormal visual maturation. The specificity of PreViAs questionnaire was >80%, and sensitivity was 64%-79%. More than 80% of the infants were correctly classified, and test-retest reliability exceeded 0.9 for all domains. The PreViAs questionnaire is useful to detect abnormal visual maturation in infants from birth to 24months of age. It improves the anamnesis process in infants at risk of visual dysfunctions. Copyright © 2014. Published by Elsevier Ireland Ltd.

An improved PSO-SVM model for online recognition defects in eddy current testing

NASA Astrophysics Data System (ADS)

Liu, Baoling; Hou, Dibo; Huang, Pingjie; Liu, Banteng; Tang, Huayi; Zhang, Wubo; Chen, Peihua; Zhang, Guangxin

2013-12-01

Accurate and rapid recognition of defects is essential for structural integrity and health monitoring of in-service device using eddy current (EC) non-destructive testing. This paper introduces a novel model-free method that includes three main modules: a signal pre-processing module, a classifier module and an optimisation module. In the signal pre-processing module, a kind of two-stage differential structure is proposed to suppress the lift-off fluctuation that could contaminate the EC signal. In the classifier module, multi-class support vector machine (SVM) based on one-against-one strategy is utilised for its good accuracy. In the optimisation module, the optimal parameters of classifier are obtained by an improved particle swarm optimisation (IPSO) algorithm. The proposed IPSO technique can improve convergence performance of the primary PSO through the following strategies: nonlinear processing of inertia weight, introductions of the black hole and simulated annealing model with extremum disturbance. The good generalisation ability of the IPSO-SVM model has been validated through adding additional specimen into the testing set. Experiments show that the proposed algorithm can achieve higher recognition accuracy and efficiency than other well-known classifiers and the superiorities are more obvious with less training set, which contributes to online application.

Comparison of Threshold Saccadic Vector Optokinetic Perimetry (SVOP) and Standard Automated Perimetry (SAP) in Glaucoma. Part II: Patterns of Visual Field Loss and Acceptability.

PubMed

McTrusty, Alice D; Cameron, Lorraine A; Perperidis, Antonios; Brash, Harry M; Tatham, Andrew J; Agarwal, Pankaj K; Murray, Ian C; Fleck, Brian W; Minns, Robert A

2017-09-01

We compared patterns of visual field loss detected by standard automated perimetry (SAP) to saccadic vector optokinetic perimetry (SVOP) and examined patient perceptions of each test. A cross-sectional study was done of 58 healthy subjects and 103 with glaucoma who were tested using SAP and two versions of SVOP (v1 and v2). Visual fields from both devices were categorized by masked graders as: 0, normal; 1, paracentral defect; 2, nasal step; 3, arcuate defect; 4, altitudinal; 5, biarcuate; and 6, end-stage field loss. SVOP and SAP classifications were cross-tabulated. Subjects completed a questionnaire on their opinions of each test. We analyzed 142 (v1) and 111 (v2) SVOP and SAP test pairs. SVOP v2 had a sensitivity of 97.7% and specificity of 77.9% for identifying normal versus abnormal visual fields. SAP and SVOP v2 classifications showed complete agreement in 54% of glaucoma patients, with a further 23% disagreeing by one category. On repeat testing, 86% of SVOP v2 classifications agreed with the previous test, compared to 91% of SAP classifications; 71% of subjects preferred SVOP compared to 20% who preferred SAP. Eye-tracking perimetry can be used to obtain threshold visual field sensitivity values in patients with glaucoma and produce maps of visual field defects, with patterns exhibiting close agreement to SAP. Patients preferred eye-tracking perimetry compared to SAP. This first report of threshold eye tracking perimetry shows good agreement with conventional automated perimetry and provides a benchmark for future iterations.

Visual function among commercial vehicle drivers in the central region of Ghana

PubMed Central

Boadi-Kusi, Samuel Bert; Kyei, Samuel; Asare, Frederick Afum; Owusu-Ansah, Andrew; Awuah, Agnes; Darko-Takyi, Charles

2015-01-01

Aim To determine the relationship between some visual functions: colour vision defects, abnormal stereopsis, visual acuity and the occurrence of road traffic accident (RTAs) among commercial vehicle drivers in the central region of Ghana, and to assess their knowledge of these anomalies. Method A descriptive cross-sectional study employing a multi-stage random sampling approach was conducted in the major commercial towns within the central region of Ghana. Participants were taken through a comprehensive eye examination after the administration of a structured questionnaire. Results 520 male commercial vehicle drivers were enrolled for this study with a mean age of 39.23 years ±10.96 years and mean visual acuity of 0.02 ± 0.08 logMAR. Protans were more likely to be involved in RTAs (χ2 = 6.194, p = 0.034). However, there was no statistically significant association between abnormal stereopsis (OR = 0.89 95% CI: 0.44–1.80, p = 0.56), poor vision due to refractive error (χ2 = 3.090, p = 0.388) and the occurrence of RTAs. While 86.9% were aware of abnormal stereopsis, only 45% were aware of colour vision defects. There was a statistically significant association between stereopsis anomaly and colour vision defect (r = 0.371, p < 0.005). Conclusion The study found an association between protanopia and RTAs but none between stereopsis anomalies, refractive errors and the occurrence of RTAs. Drivers were less knowledgeable on colour vision defects as compared to stereopsis anomalies. PMID:26364760

Visual function among commercial vehicle drivers in the central region of Ghana.

PubMed

Boadi-Kusi, Samuel Bert; Kyei, Samuel; Asare, Frederick Afum; Owusu-Ansah, Andrew; Awuah, Agnes; Darko-Takyi, Charles

2016-01-01

To determine the relationship between some visual functions: colour vision defects, abnormal stereopsis, visual acuity and the occurrence of road traffic accident (RTAs) among commercial vehicle drivers in the central region of Ghana, and to assess their knowledge of these anomalies. A descriptive cross-sectional study employing a multi-stage random sampling approach was conducted in the major commercial towns within the central region of Ghana. Participants were taken through a comprehensive eye examination after the administration of a structured questionnaire. 520 male commercial vehicle drivers were enrolled for this study with a mean age of 39.23 years ±10.96 years and mean visual acuity of 0.02±0.08 logMAR. Protans were more likely to be involved in RTAs (χ(2)=6.194, p=0.034). However, there was no statistically significant association between abnormal stereopsis (OR=0.89 95% CI: 0.44-1.80, p=0.56), poor vision due to refractive error (χ(2)=3.090, p=0.388) and the occurrence of RTAs. While 86.9% were aware of abnormal stereopsis, only 45% were aware of colour vision defects. There was a statistically significant association between stereopsis anomaly and colour vision defect (r=0.371, p<0.005). The study found an association between protanopia and RTAs but none between stereopsis anomalies, refractive errors and the occurrence of RTAs. Drivers were less knowledgeable on colour vision defects as compared to stereopsis anomalies. Copyright © 2015 Spanish General Council of Optometry. Published by Elsevier Espana. All rights reserved.

A novel inspection system for cosmetic defects

NASA Astrophysics Data System (ADS)

Hazra, S.; Roy, R.; Williams, D.; Aylmore, R.; Hollingdale, D.

2013-12-01

The appearance of automotive skin panels creates desirability for a product and differentiates it from the competition. Because of the importance of skin panels, considerable care is taken in minimizing defects such as the 'hollow' defect that occur around door-handle depressions. However, the inspection process is manual, subjective and time-consuming. This paper describes the development of an objective and inspection scheme for the 'hollow' defect. In this inspection process, the geometry of a panel is captured using a structured lighting system. The geometry data is subsequently analyzed by a purpose-built wavelet-based algorithm to identify the location of any defects that may be present and to estimate the perceived severity of the defects without user intervention. This paper describes and critically evaluates the behavior of this physically-based algorithm on an ideal and real geometry and compares its result to an actual audit. The results show that the algorithm is capable of objectively locating and classifying 'hollow' defects in actual panels.

Characterization technique for detection of atom-size crystalline defects and strains using two-dimensional fast-Fourier-transform sampling Moiré method

NASA Astrophysics Data System (ADS)

Kodera, Masako; Wang, Qinghua; Ri, Shien; Tsuda, Hiroshi; Yoshioka, Akira; Sugiyama, Toru; Hamamoto, Takeshi; Miyashita, Naoto

2018-04-01

Recently, we have developed a two-dimensional (2D) fast-Fourier-transform (FFT) sampling Moiré technique to visually and quantitatively determine the locations of minute defects in a transmission electron microscopy (TEM) image. We applied this technique for defect detection with GaN high electron mobility transistor (HEMT) devices, and successfully and clearly visualized atom-size defects in AlGaN/GaN crystalline structures. The defect density obtained in the AlGaN/GaN structures is ∼1013 counts/cm2. In addition, we have successfully confirmed that the distribution and number of defects closely depend on the process conditions. Thus, this technique is quite useful for a device development. Moreover, the strain fields in an AlGaN/GaN crystal were effectively calculated with nm-scale resolution using this method. We also demonstrated that this sampling Moiré technique is applicable to silicon devices, which have principal directions different from those of AlGaN/GaN crystals. As a result, we believe that the 2D FFT sampling Moiré method has great potential applications to the discovery of new as yet unknown phenomena occurring between the characteristics of a crystalline material and device performance.

[Visual rehabilitation of patients with large post-traumatic defects of the anterior eye segment through iris-lens diaphragm implantation].

PubMed

Khodzhaev, N S; Sobolev, N P; Mushkova, I A; Izmaylova, S B; Karimova, A N

The diversity of methodological approaches and lack of pathogenetically reasonable tactics for patients with combined ocular injuries became the basis for the development and systematization of surgical rehabilitation stages of patients, in whom post-traumatic cataract is combined with post-traumatic aniridia and corneal scarring. to construct a visual rehabilitation approach to patients with post-traumatic defects of the anterior eye segment following optical-reconstructive surgery that involved implantation of an iris-lens diaphragm (ILD). We have analyzed 80 reconstructive cases with ILD implantation in patients with post-traumatic aniridia and corneal damage. These patients constituted the first study group (Group 1). We have also investigated 58 eyes with residual ametropy and stable visual function 1 year after ILD implantation before and after conducting a laser keratorefractive surgery. These patients were assigned to the second study group (Group 2). Rehabilitation approach to patients after anterior segment injuries that has been proposed allows to achieve high clinical and functional results and reduce the risk of intra- and postoperative complications. The proposed approach to patients after optical-reconstructive surgery with iris-lens diaphragm implantation followed by keratorefractive surgery is an effective method of visual rehabilitation of anterior eye segment post-traumatic defects.

14 CFR 15.101 - Applicability.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PROCEDURAL RULES... (b) Aeronautical data that— (1) Is visually displayed in the cockpit of an aircraft; and (2) When visually displayed, accurately depicts a defective or deficient flight procedure or airway promulgated by...

Evaluation of hemifield sector analysis protocol in multifocal visual evoked potential objective perimetry for the diagnosis and early detection of glaucomatous field defects.

PubMed

Mousa, Mohammad F; Cubbidge, Robert P; Al-Mansouri, Fatima; Bener, Abdulbari

2014-02-01

Multifocal visual evoked potential (mfVEP) is a newly introduced method used for objective visual field assessment. Several analysis protocols have been tested to identify early visual field losses in glaucoma patients using the mfVEP technique, some were successful in detection of field defects, which were comparable to the standard automated perimetry (SAP) visual field assessment, and others were not very informative and needed more adjustment and research work. In this study we implemented a novel analysis approach and evaluated its validity and whether it could be used effectively for early detection of visual field defects in glaucoma. Three groups were tested in this study; normal controls (38 eyes), glaucoma patients (36 eyes) and glaucoma suspect patients (38 eyes). All subjects had a two standard Humphrey field analyzer (HFA) test 24-2 and a single mfVEP test undertaken in one session. Analysis of the mfVEP results was done using the new analysis protocol; the hemifield sector analysis (HSA) protocol. Analysis of the HFA was done using the standard grading system. Analysis of mfVEP results showed that there was a statistically significant difference between the three groups in the mean signal to noise ratio (ANOVA test, p < 0.001 with a 95% confidence interval). The difference between superior and inferior hemispheres in all subjects were statistically significant in the glaucoma patient group in all 11 sectors (t-test, p < 0.001), partially significant in 5 / 11 (t-test, p < 0.01), and no statistical difference in most sectors of the normal group (1 / 11 sectors was significant, t-test, p < 0.9). Sensitivity and specificity of the HSA protocol in detecting glaucoma was 97% and 86%, respectively, and for glaucoma suspect patients the values were 89% and 79%, respectively. The new HSA protocol used in the mfVEP testing can be applied to detect glaucomatous visual field defects in both glaucoma and glaucoma suspect patients. Using this protocol can provide information about focal visual field differences across the horizontal midline, which can be utilized to differentiate between glaucoma and normal subjects. Sensitivity and specificity of the mfVEP test showed very promising results and correlated with other anatomical changes in glaucoma field loss.

Evaluation of Hemifield Sector Analysis Protocol in Multifocal Visual Evoked Potential Objective Perimetry for the Diagnosis and Early Detection of Glaucomatous Field Defects

PubMed Central

Mousa, Mohammad F.; Cubbidge, Robert P.; Al-Mansouri, Fatima

2014-01-01

Purpose Multifocal visual evoked potential (mfVEP) is a newly introduced method used for objective visual field assessment. Several analysis protocols have been tested to identify early visual field losses in glaucoma patients using the mfVEP technique, some were successful in detection of field defects, which were comparable to the standard automated perimetry (SAP) visual field assessment, and others were not very informative and needed more adjustment and research work. In this study we implemented a novel analysis approach and evaluated its validity and whether it could be used effectively for early detection of visual field defects in glaucoma. Methods Three groups were tested in this study; normal controls (38 eyes), glaucoma patients (36 eyes) and glaucoma suspect patients (38 eyes). All subjects had a two standard Humphrey field analyzer (HFA) test 24-2 and a single mfVEP test undertaken in one session. Analysis of the mfVEP results was done using the new analysis protocol; the hemifield sector analysis (HSA) protocol. Analysis of the HFA was done using the standard grading system. Results Analysis of mfVEP results showed that there was a statistically significant difference between the three groups in the mean signal to noise ratio (ANOVA test, p < 0.001 with a 95% confidence interval). The difference between superior and inferior hemispheres in all subjects were statistically significant in the glaucoma patient group in all 11 sectors (t-test, p < 0.001), partially significant in 5 / 11 (t-test, p < 0.01), and no statistical difference in most sectors of the normal group (1 / 11 sectors was significant, t-test, p < 0.9). Sensitivity and specificity of the HSA protocol in detecting glaucoma was 97% and 86%, respectively, and for glaucoma suspect patients the values were 89% and 79%, respectively. Conclusions The new HSA protocol used in the mfVEP testing can be applied to detect glaucomatous visual field defects in both glaucoma and glaucoma suspect patients. Using this protocol can provide information about focal visual field differences across the horizontal midline, which can be utilized to differentiate between glaucoma and normal subjects. Sensitivity and specificity of the mfVEP test showed very promising results and correlated with other anatomical changes in glaucoma field loss. PMID:24511212

Study on the intrinsic defects in tin oxide with first-principles method

NASA Astrophysics Data System (ADS)

Sun, Yu; Liu, Tingyu; Chang, Qiuxiang; Ma, Changmin

2018-04-01

First-principles and thermodynamic methods are used to study the contribution of vibrational entropy to defect formation energy and the stability of the intrinsic point defects in SnO2 crystal. According to thermodynamic calculation results, the contribution of vibrational entropy to defect formation energy is significant and should not be neglected, especially at high temperatures. The calculated results indicate that the oxygen vacancy is the major point defect in undoped SnO2 crystal, which has a higher concentration than that of the other point defect. The property of negative-U is put forward in SnO2 crystal. In order to determine the most stable defects much clearer under different conditions, the most stable intrinsic defect as a function of Fermi level, oxygen partial pressure and temperature are described in the three-dimensional defect formation enthalpy diagrams. The diagram visually provides the most stable point defects under different conditions.

The ophthalmic natural history of paediatric craniopharyngioma: a long-term review.

PubMed

Drimtzias, Evangelos; Falzon, Kevin; Picton, Susan; Jeeva, Irfan; Guy, Danielle; Nelson, Olwyn; Simmons, Ian

2014-12-01

We present our experience over the long-term of monitoring of visual function in children with craniopharyngioma. Our study involves an analysis of all paediatric patients with craniopharyngioma younger than 16 at the time of diagnosis and represents a series of predominantly sub-totally resected tumours. Visual data, of multiple modality, of the paediatric patients was collected. Twenty patients were surveyed. Poor prognostic indicators of the visual outcome and rate of recurrence were assessed. Severe visual loss and papilledema at the time of diagnosis were more common in children under the age of 6. In our study visual signs, tumour calcification and optic disc atrophy at presentation are predictors of poor visual outcome with the first two applying only in children younger than 6. In contrast with previous reports, preoperative visual field (VF) defects and type of surgery were not documented as prognostic indicators of poor postoperative visual acuity (VA) and VF. Contrary to previous reports calcification at diagnosis, type of surgery and preoperative VF defects were not found to be associated with tumour recurrence. Local recurrence is common. Younger age at presentation is associated with a tendency to recur. Magnetic resonance imaging (MRI) remains the recommended means of follow-up in patients with craniopharyngioma.

A Visual Galaxy Classification Interface and its Classroom Application

NASA Astrophysics Data System (ADS)

Kautsch, Stefan J.; Phung, Chau; VanHilst, Michael; Castro, Victor H

2014-06-01

Galaxy morphology is an important topic in modern astronomy to understand questions concerning the evolution and formation of galaxies and their dark matter content. In order to engage students in exploring galaxy morphology, we developed a web-based, graphical interface that allows students to visually classify galaxy images according to various morphological types. The website is designed with HTML5, JavaScript, PHP, and a MySQL database. The classification interface provides hands-on research experience and training for students and interested clients, and allows them to contribute to studies of galaxy morphology. We present the first results of a pilot study and compare the visually classified types using our interface with that from automated classification routines.

New data clustering for RBF classifier of agriculture products from x-ray images

NASA Astrophysics Data System (ADS)

Casasent, David P.; Chen, Xuewen

1999-08-01

Classification of real-time x-ray images of randomly oriented touching pistachio nuts is discussed. The ultimate objective is the development of a subsystem for automated non-invasive detection of defective product items on a conveyor belt. We discuss the use of clustering and how it is vital to achieve useful classification. New clustering methods using class identify and new cluster classes are advanced and shown to be of use for this application. Radial basis function neural net classifiers are emphasized. We expect our results to be of use for other classifiers and applications.

Visual pathway impairment by pituitary adenomas: quantitative diagnostics by diffusion tensor imaging.

PubMed

Lilja, Ylva; Gustafsson, Oscar; Ljungberg, Maria; Starck, Göran; Lindblom, Bertil; Skoglund, Thomas; Bergquist, Henrik; Jakobsson, Karl-Erik; Nilsson, Daniel

2017-09-01

OBJECTIVE Despite ample experience in surgical treatment of pituitary adenomas, little is known about objective indices that may reveal risk of visual impairment caused by tumor growth that leads to compression of the anterior visual pathways. This study aimed to explore diffusion tensor imaging (DTI) as a means for objective assessment of injury to the anterior visual pathways caused by pituitary adenomas. METHODS Twenty-three patients with pituitary adenomas, scheduled for transsphenoidal tumor resection, and 20 healthy control subjects were included in the study. A minimum suprasellar tumor extension of Grade 2-4, according to the SIPAP (suprasellar, infrasellar, parasellar, anterior, and posterior) scale, was required for inclusion. Neuroophthalmological examinations, conventional MRI, and DTI were completed in all subjects and were repeated 6 months after surgery. Quantitative assessment of chiasmal lift, visual field defect (VFD), and DTI parameters from the optic tracts was performed. Linear correlations, group comparisons, and prediction models were done in controls and patients. RESULTS Both the degree of VFD and chiasmal lift were significantly correlated with the radial diffusivity (r = 0.55, p < 0.05 and r = 0.48, p < 0.05, respectively) and the fractional anisotropy (r = -0.58, p < 0.05 and r = -0.47, p < 0.05, respectively) but not with the axial diffusivity. The axial diffusivity differed significantly between controls and patients with VFD, both before and after surgery (p < 0.05); however, no difference was found between patients with and without VFD. Based on the axial diffusivity and fractional anisotropy, a prediction model classified all patients with VFD correctly (sensitivity 1.0), 9 of 12 patients without VFD correctly (sensitivity 0.75), and 17 of 20 controls as controls (specificity 0.85). CONCLUSIONS DTI could detect pathology and degree of injury in the anterior visual pathways that were compressed by pituitary adenomas. The correlation between radial diffusivity and visual impairment may reflect a gradual demyelination in the visual pathways caused by an increased tumor effect. The low level of axial diffusivity found in the patient group may represent early atrophy in the visual pathways, detectable on DTI but not by conventional methods. DTI may provide objective data, detect early signs of injury, and be an additional diagnostic tool for determining indication for surgery in cases of pituitary adenomas.

Comparison of standard automated perimetry with matrix frequency-doubling technology in patients with resolved optic neuritis.

PubMed

Sakai, Tsutomu; Matsushima, Masato; Shikishima, Keigo; Kitahara, Kenji

2007-05-01

To examine performance characteristics of frequency-doubling perimetry (FDP) in comparison with standard automated perimetry (SAP) in patients with resolved optic neuritis in a short-term follow-up study. Comparative consecutive case series. Twenty patients with resolved optic neuritis and 20 healthy volunteers participated in this study. The subjects were patients who recovered normal vision (1.0 or better) after optic neuritis. The Swedish interactive thresholding algorithm 30-2 program was used for SAP and a full-threshold 30-2 program was used for FDP. Using both forms of perimetry, the mean deviation (MD), pattern standard deviation (PSD), and the percentage of abnormal points significantly depressed <0.5% in the total deviation probability plot were compared. The visual fields were divided into 5 zones, and the mean sensitivity in each zone in affected eyes was compared with that in healthy eyes of the volunteers within 2 weeks of vision recovery and in follow-up after 2 weeks and 2 and 5 months. Standard automated perimetry and FDP showed general depression in the fovea and extrafoveal areas. Correlations between SAP and FDP were statistically significant for MD (Pearson r>0.75; P<0.001) and PSD (r>0.6; P<0.005). Defects detected with FDP were larger than with SAP in 14 eyes (70 %). In follow-up after 2 weeks and again after 2 and 5 months, FDP indicated slower improvement in visual field defects in the fovea and extrafoveal areas, whereas SAP indicated rapid improvement in these defects. Frequency-doubling perimetry is at least comparable with and potentially more sensitive than SAP in detecting visual field defects in resolved optic neuritis. This short-term follow-up study in patients with resolved optic neuritis suggests that FDP detects characteristics of slower recovery more effectively than SAP in the fovea and extrafoveal areas. These properties may allow more accurate detection of visual field defects and may prove advantageous for monitoring of patients with resolved optic neuritis.

Visual Problems and Reading. Number 4.

ERIC Educational Resources Information Center

Griffin, Margaret; Eberly, Donald W.

As one of a series commissioned by the National Reading Center to help inform all citizens about reading issues and to promote national functional literacy, this brochure is designed to acquaint readers with different forms of visual impairment, and describes their symptoms for easy recognition. Visual difficulties are classified into two major…

Visual Communication for Medicines: Malignant Assumptions and Benign Design?

ERIC Educational Resources Information Center

van der Waarde, Karel

2010-01-01

An area of visual communication that might be classified as a "design failure" is the visual presentation of information about "prescription-only medicines" for patients. This information is provided on packaging, leaflets, brochures, labels and websites. The practical issue is that there are problems in convincing patients to…

CRF: detection of CRISPR arrays using random forest.

PubMed

Wang, Kai; Liang, Chun

2017-01-01

CRISPRs (clustered regularly interspaced short palindromic repeats) are particular repeat sequences found in wide range of bacteria and archaea genomes. Several tools are available for detecting CRISPR arrays in the genomes of both domains. Here we developed a new web-based CRISPR detection tool named CRF (CRISPR Finder by Random Forest). Different from other CRISPR detection tools, a random forest classifier was used in CRF to filter out invalid CRISPR arrays from all putative candidates and accordingly enhanced detection accuracy. In CRF, particularly, triplet elements that combine both sequence content and structure information were extracted from CRISPR repeats for classifier training. The classifier achieved high accuracy and sensitivity. Moreover, CRF offers a highly interactive web interface for robust data visualization that is not available among other CRISPR detection tools. After detection, the query sequence, CRISPR array architecture, and the sequences and secondary structures of CRISPR repeats and spacers can be visualized for visual examination and validation. CRF is freely available at http://bioinfolab.miamioh.edu/crf/home.php.

Genetics Home Reference: critical congenital heart disease

MedlinePlus

... into and out of the heart (including the aorta and pulmonary artery). Still others involve a combination ... defects classified as CCHD include coarctation of the aorta , double-outlet right ventricle, D-transposition of the ...

Sensor Spatial Distortion, Visual Latency, and Update Rate Effects on 3D Tracking in Virtual Environments

NASA Technical Reports Server (NTRS)

Ellis, S. R.; Adelstein, B. D.; Baumeler, S.; Jense, G. J.; Jacoby, R. H.; Trejo, Leonard (Technical Monitor)

1998-01-01

Several common defects that we have sought to minimize in immersing virtual environments are: static sensor spatial distortion, visual latency, and low update rates. Human performance within our environments during large amplitude 3D tracking was assessed by objective and subjective methods in the presence and absence of these defects. Results show that 1) removal of our relatively small spatial sensor distortion had minor effects on the tracking activity, 2) an Adapted Cooper-Harper controllability scale proved the most sensitive subjective indicator of the degradation of dynamic fidelity caused by increasing latency and decreasing frame rates, and 3) performance, as measured by normalized RMS tracking error or subjective impressions, was more markedly influenced by changing visual latency than by update rate.

Predictive value of spectral-domain optical coherence tomography features in assessment of visual prognosis in eyes with acute welding arc maculopathy.

PubMed

Zhang, Chunxia; Dang, Guangfu; Zhao, Tianmei; Wang, DongLin; Su, Yan; Qu, Yi

2018-04-12

To observe spectral-domain optical coherence tomography (SD-OCT) features and to determine whether baseline OCT features can be used as predictors of visual acuity outcome in eyes with acute welding arc maculopathy. This retrospective study enrolled twenty-two eyes of eleven subjects with acute welding arc maculopathy. All subjects were evaluated by SD-OCT at baseline and final visit. The involved parameters included best-corrected visual acuity (BCVA), central macular thickness (CMT), the length of ellipsoid zone (EZ) defects, the greatest linear dimension (GLD) of outer retinal lesions, EZ reflectivity and relative EZ reflectivity (defined as the ratio of EZ reflectivity to retinal pigment epithelium reflectivity on OCT). Acute welding arc maculopathy was presented as abnormal hyperreflectivity, hyporeflectivity and defects of outer retinal layer in fovea on OCT. Compared with baseline, BCVA improved significantly accompanied by decreased GLD of outer retinal lesions and the length of EZ defects at final visit (P = 0.0004, P < 0.0001 and P < 0.0001, respectively). No significant changes were shown on CMT (P = 0.248). In multivariate regression analysis, final BCVA was associated with baseline BCVA and the length of EZ defects (P = 0.012 and P = 0.045, respectively). However, EZ reflectivity and relative EZ reflectivity were not associated with final BCVA (P > 0.05). In conclusion, SD-OCT images clearly reveal morphological changes in outer retinal layer in acute welding arc maculopathy. The baseline BCVA and length of EZ defects are the strongest predictors of final BCVA.

New Method of Screening Young Children for Defects in Visual Acuity*

PubMed Central

Withnell, Allan; Wilson, H. E.

1968-01-01

The methods used at present for screening young children's vision have disadvantages, such as that the child's intelligence can affect the result. In a new method three white cards are used; these are printed with one, two, or three black blocks arranged so that if a child can correctly state the number of blocks at 6 metres the visual acuity is at least 6/9. When tested on 186 children the new method gave better results than conventional tests; eight children with defective vision were picked up only by the new method and none were missed. PMID:5681052

New method of screening young children for defects in visual acuity.

PubMed

Withnell, A; Wilson, H E

1968-10-19

The methods used at present for screening young children's vision have disadvantages, such as that the child's intelligence can affect the result. In a new method three white cards are used; these are printed with one, two, or three black blocks arranged so that if a child can correctly state the number of blocks at 6 metres the visual acuity is at least 6/9. When tested on 186 children the new method gave better results than conventional tests; eight children with defective vision were picked up only by the new method and none were missed.

A collaborative inventory model for vendor-buyer system with inspection errors, unequal sized shipment, and repairable item

NASA Astrophysics Data System (ADS)

Hamdani, Irfan Hilmi; Jauhari, Wakhid Ahmad; Rosyidi, Cucuk Nur

2017-11-01

This paper develops an integrated inventory model consisting of single-vendor and single-buyer system. The demand in buyer side is deterministic and the production process is imperfect and produces a certain number of defective items. The delivery within a single production batch from vendor to buyer is increasing by a fixed factor. After the delivery arrives at the buyer, an inspection process is conducted. The inspection process in not perfect. Errors may occur when the inspector is misclassifies a non-defective item as defective ne, or incorrectly classifies a defective item as non-defective. All the product which defective will be repair by repair-shop. After the defective arrives at repair shop, will perfect inspection. The defective item will repair and back to buyer. This model provides an optimal solution for the expected integrated total annual cost of the vendor and the buyer. The result from numerical examples shows that the integrated model will result in lower joint total cost in comparison with the equal-sized policy.

Please Don't Move-Evaluating Motion Artifact From Peripheral Quantitative Computed Tomography Scans Using Textural Features.

PubMed

Rantalainen, Timo; Chivers, Paola; Beck, Belinda R; Robertson, Sam; Hart, Nicolas H; Nimphius, Sophia; Weeks, Benjamin K; McIntyre, Fleur; Hands, Beth; Siafarikas, Aris

Most imaging methods, including peripheral quantitative computed tomography (pQCT), are susceptible to motion artifacts particularly in fidgety pediatric populations. Methods currently used to address motion artifact include manual screening (visual inspection) and objective assessments of the scans. However, previously reported objective methods either cannot be applied on the reconstructed image or have not been tested for distal bone sites. Therefore, the purpose of the present study was to develop and validate motion artifact classifiers to quantify motion artifact in pQCT scans. Whether textural features could provide adequate motion artifact classification performance in 2 adolescent datasets with pQCT scans from tibial and radial diaphyses and epiphyses was tested. The first dataset was split into training (66% of sample) and validation (33% of sample) datasets. Visual classification was used as the ground truth. Moderate to substantial classification performance (J48 classifier, kappa coefficients from 0.57 to 0.80) was observed in the validation dataset with the novel texture-based classifier. In applying the same classifier to the second cross-sectional dataset, a slight-to-fair (κ = 0.01-0.39) classification performance was observed. Overall, this novel textural analysis-based classifier provided a moderate-to-substantial classification of motion artifact when the classifier was specifically trained for the measurement device and population. Classification based on textural features may be used to prescreen obviously acceptable and unacceptable scans, with a subsequent human-operated visual classification of any remaining scans. Copyright © 2017 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

Comparison of Classifiers for Decoding Sensory and Cognitive Information from Prefrontal Neuronal Populations

PubMed Central

Astrand, Elaine; Enel, Pierre; Ibos, Guilhem; Dominey, Peter Ford; Baraduc, Pierre; Ben Hamed, Suliann

2014-01-01

Decoding neuronal information is important in neuroscience, both as a basic means to understand how neuronal activity is related to cerebral function and as a processing stage in driving neuroprosthetic effectors. Here, we compare the readout performance of six commonly used classifiers at decoding two different variables encoded by the spiking activity of the non-human primate frontal eye fields (FEF): the spatial position of a visual cue, and the instructed orientation of the animal's attention. While the first variable is exogenously driven by the environment, the second variable corresponds to the interpretation of the instruction conveyed by the cue; it is endogenously driven and corresponds to the output of internal cognitive operations performed on the visual attributes of the cue. These two variables were decoded using either a regularized optimal linear estimator in its explicit formulation, an optimal linear artificial neural network estimator, a non-linear artificial neural network estimator, a non-linear naïve Bayesian estimator, a non-linear Reservoir recurrent network classifier or a non-linear Support Vector Machine classifier. Our results suggest that endogenous information such as the orientation of attention can be decoded from the FEF with the same accuracy as exogenous visual information. All classifiers did not behave equally in the face of population size and heterogeneity, the available training and testing trials, the subject's behavior and the temporal structure of the variable of interest. In most situations, the regularized optimal linear estimator and the non-linear Support Vector Machine classifiers outperformed the other tested decoders. PMID:24466019

Noninvasive 3D Visualization of Defects and Crack Propagation in Layered Foam Structures by Phase Contrast Microimaging

NASA Technical Reports Server (NTRS)

Hu, Z. W.; DeCarlo, F.

2006-01-01

Applications of polymeric foams in our modern society continue to grow because of their light weight, high strength, excellent thermal and mechanical insulation, and the ease of engineering. Among others, closed-cell foam has been structurally used for thermally insulating the shuttle external tank. However, internal defects of the foams were difficult to observe non-invasively due to limited sensitivity to the low-density structures possessed by traditional imaging tools such as computed X-ray tomography By combining phase contrast X-ray imaging with pressure loading, we succeeded in precisely mapping intact cellular structure and defects inside the bulk of layered foam and visualizing its subsequent response to the pressure in three-dimensional space. The work demonstrated a powerfir1 approach for yielding insight into underlying problems in lightweight cellular materials otherwise unobtainable.

Real-time decoding of the direction of covert visuospatial attention

NASA Astrophysics Data System (ADS)

Andersson, Patrik; Ramsey, Nick F.; Raemaekers, Mathijs; Viergever, Max A.; Pluim, Josien P. W.

2012-08-01

Brain-computer interfaces (BCIs) make it possible to translate a person’s intentions into actions without depending on the muscular system. Brain activity is measured and classified into commands, thereby creating a direct link between the mind and the environment, enabling, e.g., cursor control or navigation of a wheelchair or robot. Most BCI research is conducted with scalp EEG but recent developments move toward intracranial electrodes for paralyzed people. The vast majority of BCI studies focus on the motor system as the appropriate target for recording and decoding movement intentions. However, properties of the visual system may make the visual system an attractive and intuitive alternative. We report on a study investigating feasibility of decoding covert visuospatial attention in real time, exploiting the full potential of a 7 T MRI scanner to obtain the necessary signal quality, capitalizing on earlier fMRI studies indicating that covert visuospatial attention changes activity in the visual areas that respond to stimuli presented in the attended area of the visual field. Healthy volunteers were instructed to shift their attention from the center of the screen to one of four static targets in the periphery, without moving their eyes from the center. During the first part of the fMRI-run, the relevant brain regions were located using incremental statistical analysis. During the second part, the activity in these regions was extracted and classified, and the subject was given visual feedback of the result. Performance was assessed as the number of trials where the real-time classifier correctly identified the direction of attention. On average, 80% of trials were correctly classified (chance level <25%) based on a single image volume, indicating very high decoding performance. While we restricted the experiment to five attention target regions (four peripheral and one central), the number of directions can be higher provided the brain activity patterns can be distinguished. In summary, the visual system promises to be an effective target for BCI control.

Special tinted contact lens on colour-defects.

PubMed

Mutilab, H A; Sharanjeet-Kaur; Keu, L K; Choo, P F

2012-01-01

The objective of this study was to determine the visual function of colour-deficient subjects when wearing special red tint contact lenses. A total of 17 subjects with congenital colour vision deficiency (14 deutans and 3 protans), voluntarily participated in this study. The average age for the subjects was 23.00 ± 4.06 years old. Visual functions tested were visual acuity (LogMAR), contrast sensitivity (FACT Chart) and stereopsis (TNO and Howard Dolman tests). Two types of special red tint lenses were used in this study; Type I (light red) and Type II (dark red). The protans and deutans showed no significant changes in visual acuity and contrast sensitivity when wearing either type of contact lens. Stereopsis testing using the Horward-Dolman test gave no significant changes but significant differences were seen using the TNO test. Stereopsis using the TNO test was significantly poorer with the red tinted contact lenses compared to without for both protons and deutans. Testing binocularly with Ishihara plates showed that 88% (n=15) of patients passed the test with Type I and Type II contact lenses. When D15 test was done, 3 patients (17.6%) were 'normal' when using the Type I contact lenses and 2 patients (11.8%) were 'normal' when using the Type II contact lenses. However, with FM100Hue test, most patients showed deutan responses. Total error scores (TES) were found to be higher with Type I and Type II contact lenses compared to without. The Type I and II special tinted contact lens used in this study did not cause a reduction of visual acuity and contrast sensitivity for the colour defects. Stereopsis was also not reduced with the Type I and Type II contact lenses for the colour defects except when tested with the TNO test. Colour vision defects became difficult to detect using the Ishihara plates but FM100Hue test did not show any improvement with the Type I and Type II contact lenses.

Quality-Related Monitoring and Grading of Granulated Products by Weibull-Distribution Modeling of Visual Images with Semi-Supervised Learning

PubMed Central

Liu, Jinping; Tang, Zhaohui; Xu, Pengfei; Liu, Wenzhong; Zhang, Jin; Zhu, Jianyong

2016-01-01

The topic of online product quality inspection (OPQI) with smart visual sensors is attracting increasing interest in both the academic and industrial communities on account of the natural connection between the visual appearance of products with their underlying qualities. Visual images captured from granulated products (GPs), e.g., cereal products, fabric textiles, are comprised of a large number of independent particles or stochastically stacking locally homogeneous fragments, whose analysis and understanding remains challenging. A method of image statistical modeling-based OPQI for GP quality grading and monitoring by a Weibull distribution(WD) model with a semi-supervised learning classifier is presented. WD-model parameters (WD-MPs) of GP images’ spatial structures, obtained with omnidirectional Gaussian derivative filtering (OGDF), which were demonstrated theoretically to obey a specific WD model of integral form, were extracted as the visual features. Then, a co-training-style semi-supervised classifier algorithm, named COSC-Boosting, was exploited for semi-supervised GP quality grading, by integrating two independent classifiers with complementary nature in the face of scarce labeled samples. Effectiveness of the proposed OPQI method was verified and compared in the field of automated rice quality grading with commonly-used methods and showed superior performance, which lays a foundation for the quality control of GP on assembly lines. PMID:27367703

Control of a visual keyboard using an electrocorticographic brain-computer interface.

PubMed

Krusienski, Dean J; Shih, Jerry J

2011-05-01

Brain-computer interfaces (BCIs) are devices that enable severely disabled people to communicate and interact with their environments using their brain waves. Most studies investigating BCI in humans have used scalp EEG as the source of electrical signals and focused on motor control of prostheses or computer cursors on a screen. The authors hypothesize that the use of brain signals obtained directly from the cortical surface will more effectively control a communication/spelling task compared to scalp EEG. A total of 6 patients with medically intractable epilepsy were tested for the ability to control a visual keyboard using electrocorticographic (ECOG) signals. ECOG data collected during a P300 visual task paradigm were preprocessed and used to train a linear classifier to subsequently predict the intended target letters. The classifier was able to predict the intended target character at or near 100% accuracy using fewer than 15 stimulation sequences in 5 of the 6 people tested. ECOG data from electrodes outside the language cortex contributed to the classifier and enabled participants to write words on a visual keyboard. This is a novel finding because previous invasive BCI research in humans used signals exclusively from the motor cortex to control a computer cursor or prosthetic device. These results demonstrate that ECOG signals from electrodes both overlying and outside the language cortex can reliably control a visual keyboard to generate language output without voice or limb movements.

Collision avoidance in persons with homonymous visual field defects under virtual reality conditions.

PubMed

Papageorgiou, Eleni; Hardiess, Gregor; Ackermann, Hermann; Wiethoelter, Horst; Dietz, Klaus; Mallot, Hanspeter A; Schiefer, Ulrich

2012-01-01

The aim of the present study was to examine the effect of homonymous visual field defects (HVFDs) on collision avoidance of dynamic obstacles at an intersection under virtual reality (VR) conditions. Overall performance was quantitatively assessed as the number of collisions at a virtual intersection at two difficulty levels. HVFDs were assessed by binocular semi-automated kinetic perimetry within the 90° visual field, stimulus III4e and the area of sparing within the affected hemifield (A-SPAR in deg(2)) was calculated. The effect of A-SPAR, age, gender, side of brain lesion, time since brain lesion and presence of macular sparing on the number of collisions, as well as performance over time were investigated. Thirty patients (10 female, 20 male, age range: 19-71 years) with HVFDs due to unilateral vascular brain lesions and 30 group-age-matched subjects with normal visual fields were examined. The mean number of collisions was higher for patients and in the more difficult level they experienced more collisions with vehicles approaching from the blind side than the seeing side. Lower A-SPAR and increasing age were associated with decreasing performance. However, in agreement with previous studies, wide variability in performance among patients with identical visual field defects was observed and performance of some patients was similar to that of normal subjects. Both patients and healthy subjects displayed equal improvement of performance over time in the more difficult level. In conclusion, our results suggest that visual-field related parameters per se are inadequate in predicting successful collision avoidance. Individualized approaches which also consider compensatory strategies by means of eye and head movements should be introduced. Copyright © 2011 Elsevier Ltd. All rights reserved.

Usefulness of myocardial parametric imaging to evaluate myocardial viability in experimental and in clinical studies.

PubMed

Korosoglou, G; Hansen, A; Bekeredjian, R; Filusch, A; Hardt, S; Wolf, D; Schellberg, D; Katus, H A; Kuecherer, H

2006-03-01

To evaluate whether myocardial parametric imaging (MPI) is superior to visual assessment for the evaluation of myocardial viability. Myocardial contrast echocardiography (MCE) was assessed in 11 pigs before, during, and after left anterior descending coronary artery occlusion and in 32 patients with ischaemic heart disease by using intravenous SonoVue administration. In experimental studies perfusion defect area assessment by MPI was compared with visually guided perfusion defect planimetry. Histological assessment of necrotic tissue was the standard reference. In clinical studies viability was assessed on a segmental level by (1) visual analysis of myocardial opacification; (2) quantitative estimation of myocardial blood flow in regions of interest; and (3) MPI. Functional recovery between three and six months after revascularisation was the standard reference. In experimental studies, compared with visually guided perfusion defect planimetry, planimetric assessment of infarct size by MPI correlated more significantly with histology (r2 = 0.92 versus r2 = 0.56) and had a lower intraobserver variability (4% v 15%, p < 0.05). In clinical studies, MPI had higher specificity (66% v 43%, p < 0.05) than visual MCE and good accuracy (81%) for viability detection. It was less time consuming (3.4 (1.6) v 9.2 (2.4) minutes per image, p < 0.05) than quantitative blood flow estimation by regions of interest and increased the agreement between observers interpreting myocardial perfusion (kappa = 0.87 v kappa = 0.75, p < 0.05). MPI is useful for the evaluation of myocardial viability both in animals and in patients. It is less time consuming than quantification analysis by regions of interest and less observer dependent than visual analysis. Thus, strategies incorporating this technique may be valuable for the evaluation of myocardial viability in clinical routine.

Organization of area hV5/MT+ in subjects with homonymous visual field defects.

PubMed

Papanikolaou, Amalia; Keliris, Georgios A; Papageorgiou, T Dorina; Schiefer, Ulrich; Logothetis, Nikos K; Smirnakis, Stelios M

2018-04-06

Damage to the primary visual cortex (V1) leads to a visual field loss (scotoma) in the retinotopically corresponding part of the visual field. Nonetheless, a small amount of residual visual sensitivity persists within the blind field. This residual capacity has been linked to activity observed in the middle temporal area complex (V5/MT+). However, it remains unknown whether the organization of hV5/MT+ changes following early visual cortical lesions. We studied the organization of area hV5/MT+ of five patients with dense homonymous defects in a quadrant of the visual field as a result of partial V1+ or optic radiation lesions. To do so, we developed a new method, which models the boundaries of population receptive fields directly from the BOLD signal of each voxel in the visual cortex. We found responses in hV5/MT+ arising inside the scotoma for all patients and identified two possible sources of activation: 1) responses might originate from partially lesioned parts of area V1 corresponding to the scotoma, and 2) responses can also originate independent of area V1 input suggesting the existence of functional V1-bypassing pathways. Apparently, visually driven activity observed in hV5/MT+ is not sufficient to mediate conscious vision. More surprisingly, visually driven activity in corresponding regions of V1 and early extrastriate areas including hV5/MT+ did not guarantee visual perception in the group of patients with post-geniculate lesions that we examined. This suggests that the fine coordination of visual activity patterns across visual areas may be an important determinant of whether visual perception persists following visual cortical lesions. Copyright © 2018 Elsevier Inc. All rights reserved.

CLASSIFICATION AND QUANTITATIVE ANALYSIS OF GEOGRAPHIC ATROPHY JUNCTIONAL ZONE USING SPECTRAL DOMAIN OPTICAL COHERENCE TOMOGRAPHY.

PubMed

Qu, Jinfeng; Velaga, Swetha Bindu; Hariri, Amir H; Nittala, Muneeswar Gupta; Sadda, Srinivas

2017-08-22

The junctional zone at the border of areas of geographic atrophy (GA) in eyes with nonneovascular age-related macular degeneration is an important target region for future therapeutic strategies. The goal of this study was to perform a detailed classification and quantitative characterization of the junctional zone using spectral domain optical coherence tomography. Spectral domain optical coherence tomography volume cube scans (Spectralis OCT, 1024 × 37, Automatic Real Time > 9) were obtained from 15 eyes of 11 patients with GA because of nonneovascular age-related macular degeneration. Volume optical coherence tomography data were imported into previously described validated grading software (3D-OCTOR), and manual segmentation of the retinal pigment epithelium (RPE) and photoreceptor layers was performed on all B-scans (total of 555). Retinal pigment epithelium and photoreceptor defect maps were produced for each case. The borders of the photoreceptor defect area and RPE defect area were delineated individually on separate annotation layers. The two outlines were then superimposed to compare the areas of overlap and nonoverlap. The perimeter of the RPE defect area was calculated by the software in pixels. The superimposed outline of the photoreceptor defect area and the RPE defect area was scrutinized to classify the overlap configuration of the junctional zone into one of three categories: Type 0, exact correspondence between the edge of the RPE defect and photoreceptor defect; Type 1, loss of photoreceptors outside and beyond the edge of the RPE defect; Type 2, preservation of photoreceptors beyond the edge of the RPE defect. The relative proportion of the various border configurations was expressed as a percentage of the perimeter of the RPE defect. Each configuration was then classified into four subgroups according to irregularity of the RPE band and the presence of debris. Fifteen eyes of 11 patients (mean age: 79.3 ± 4.3 years; range: 79-94 years) were included in this study. Seventeen GA lesions were analyzed. Two hundred and thirty-two B-scans were found to pass through the GA lesions, yielding 612 individual GA borders which were separately analyzed and classified. The mean area of the RPE defect was 4.0 ± 4.4 mm, which was significantly smaller than that of the photoreceptor defect which measured 4.4 ± 4.1 mm (paired t test, P = 0.037). On average, 18.0 ± 9.6% (range, 2.3-36.6%) of the junctional zone was of the Type 0 configuration, 57.3 ± 19.0% (range, 21.3-96.8%) was Type 1, and 24.7 ± 18.0% (range, 0.9-64.4%) was Type 2. Type 1 was more prevalent than Type 0 and 2 (analysis of variance, P = 0.000). Debris was present at the margin of the defect in 24.3% (149 of 612) of all assessed junctional zones; 20.0% (14 of 70) of Type 0 junctions, 28.7% (120 of 418) of Type 1, and 12.1% (15 of 124) of Type 2. Debris was more common in Type 1 than Type 2 junctions (P < 0.001). Retinal pigment epithelial irregularity was present at the margin of the defect in 34.8% (213 of 612) of all assessed junctional zones; 52.9% (37 of 70) of Type 0 junctions, 38.0% (159 of 418) of Type 1, and 13.7% (17 of 124) of Type 2. Retinal pigment epithelial irregularity was present more often at Type 0 and Type 1 than at Type 2 junctions (P < 0.001 for both). The size of the optical coherence tomography-visible RPE and photoreceptor defect in GA lesions differ significantly. There were significant areas where the photoreceptor outer segments were preserved despite the absence of visible RPE cells, and also areas of photoreceptor outer segment loss despite apparent RPE preservation. These findings have implications for development of therapeutic strategies, particularly cell-replacement approaches.

Correlation between postoperative area of high autofluorescence in macula and visual acuity after macular hole closure.

PubMed

Zhang, Peng; Shang, Qingli; Ma, Jingxue; Hao, Yuhua; Ye, Cunxi

2017-03-20

To determine the correlation between the preoperative basal diameter of macular hole, the postoperative area of high autofluorescence (AF) in macula, and visual acuity in full-thickness macular hole. Forty-nine patients with full-thickness macular hole who underwent vitrectomy and C3F8 filling were reviewed. The preoperative diameter of macular hole, the 6 months postoperative area of high AF in macula if it existed, the length of inner segment/outer segment (IS/OS) defect, and visual acuity were obtained. The correlation between them was determined. At postoperative 6 months, the rate of high AF in macula was 63.3%. There were statistical differences between with and without high AF groups in postoperative best-corrected visual acuity (BCVA) (t = -2.751, p = 0.008), preoperative basal diameter of macular hole (t = -4.946, p = 0.00001), and postoperative length of IS/OS defect (t = -8.351, p<0.00001). Simple linear regression analysis showed high positive correlations between preoperative basal diameter of macular hole and area of high AF (p<0.00001, r = 0.893), postoperative length of IS/OS defect and area of high fundus AF (FAF) (p<0.00001, r = 0.779), and negative correlations between area of high AF and postoperative BCVA (p = 0.037, r = 0.375). There was low correlation between diameter of macular hole and postoperative BCVA (p = 0.112). The preoperative basal diameter of macular hole and postoperative length of IS/OS defect decides the postoperative area of high AF in macula to some degree, and the postoperative area of high AF in macula can be an evaluating indicator for poor macular function recovery.

Correlation between local glaucomatous visual field defects and loss of nerve fiber layer thickness measured with polarimetry and spectral domain OCT.

PubMed

Horn, Folkert K; Mardin, Christian Y; Laemmer, Robert; Baleanu, Delia; Juenemann, Anselm M; Kruse, Friedrich E; Tornow, Ralf P

2009-05-01

To study the correlation between local perimetric field defects and glaucoma-induced thickness reduction of the nerve layer measured in the peripapillary area with scanning laser polarimetry (SLP) and spectral domain optical coherence tomography (SOCT) and to compare the results with those of a theoretical model. The thickness of the retinal nerve fiber layer was determined in 32 sectors (11.25 degrees each) by using SLP with variable cornea compensation (GDxVCC; Laser Diagnostics, San Diego, CA) and the newly introduced high-resolution SOCT (Spectralis; Heidelberg Engineering, Heidelberg, Germany). Eighty-eight healthy subjects served as control subjects, to determine the thickness deviation in patients with glaucoma. The relationship between glaucomatous nerve fiber reduction and visual field losses was calculated in six nerve fiber bundle-related areas. Sixty-four patients at different stages of open-angle glaucoma and 26 patients with ocular hypertension underwent perimetry (Octopus G1; Haag-Streit, Köniz, Switzerland) and measurements with the two morphometric techniques. Sector-shaped analyses between local perimetric losses and reduction of the retinal nerve fiber layer thickness showed a significant association for corresponding areas except for the central visual field in SLP. Correlation coefficients were highest in the area of the nasal inferior visual field (SOCT, -0.81; SLP, -0.57). A linear model describes the association between structural and functional damage. Localized perimetric defects can be explained by reduced nerve fiber layer thickness. The data indicate that the present SOCT is useful for determining the functional-structural relationship in peripapillary areas and that association between perimetric defects and corresponding nerve fiber losses is stronger for SOCT than for the present SLP. (ClinicalTrials.gov number, NCT00494923.).

Rate of progression of total, upper, and lower visual field defects in patients with open-angle glaucoma and high myopia.

PubMed

Yoshino, Takaiko; Fukuchi, Takeo; Togano, Tetsuya; Sakaue, Yuta; Seki, Masaaki; Tanaka, Takayuki; Ueda, Jun

2016-03-01

We evaluated the rate of progression of total, upper, and lower visual field defects in patients with treated primary open-angle glaucoma (POAG) with high myopia (HM). Seventy eyes of 70 POAG patients with HM [≤-8 diopters (D)] were examined. The mean deviation (MD) slope and the upper and lower total deviation (upper TD, lower TD) slopes of the Humphrey Field Analyzer were calculated in patients with high-tension glaucoma (HTG) (>21 mmHg) versus normal-tension glaucoma (NTG) (≤21 mmHg). The mean age of all the patients (29 eyes with HTG and 41 eyes with NTG) was 48.5 ± 9.6 years. The MD slope, and upper and lower TD slopes of the HM group were compared to those of the non-HM group (NHM) (>-8 D) selected from 544 eyes in 325 age-matched POAG patients. In all, 70 eyes with HM and NHM were examined. The mean MD slope was -0.33 ± 0.33 dB/year in the HM, and -0.38 ± 0.49 dB/year in the NHM. There were no statistical differences between the HM and NHM (p = 0.9565). In the comparison of HTG versus NTG patients in both groups, the MD slope, and upper and lower TD slopes were similar. The rate of progression of total, upper, and lower visual field defects was similar among patients with HM and NHM. Although HM is a risk factor for the onset of glaucoma, HM may not be a risk factor for progression of visual field defects as assessed by the progression rate under treatment.

Cognitive Visual Dysfunctions in Preterm Children with Periventricular Leukomalacia

ERIC Educational Resources Information Center

Fazzi, Elisa; Bova, Stefania; Giovenzana, Alessia; Signorini, Sabrina; Uggetti, Carla; Bianchi, Paolo

2009-01-01

Aim: Cognitive visual dysfunctions (CVDs) reflect an impairment of the capacity to process visual information. The question of whether CVDs might be classifiable according to the nature and distribution of the underlying brain damage is an intriguing one in child neuropsychology. Method: We studied 22 children born preterm (12 males, 10 females;…

Visual Imagery for Letters and Words. Final Report.

ERIC Educational Resources Information Center

Weber, Robert J.

In a series of six experiments, undergraduate college students visually imagined letters or words and then classified as rapidly as possible the imagined letters for some physical property such as vertical height. This procedure allowed for a preliminary assessment of the temporal parameters of visual imagination. The results delineate a number of…

Prediction of texture and colour of dry-cured ham by visible and near infrared spectroscopy using a fiber optic probe.

PubMed

García-Rey, R M; García-Olmo, J; De Pedro, E; Quiles-Zafra, R; Luque de Castro, M D

2005-06-01

The potential of visible and near infrared spectroscopy to predict texture and colour of dry-cured ham samples was investigated. Sensory evaluation was performed on 117 boned and cross-sectioned dry-cured ham samples. Slices of approximate thickness 4cm were cut, vacuum-packaged and kept under frozen storage until spectral analysis. Then, Biceps femoris muscle from the thawed slices was taken and scanned (400-2200nm) using a fiber optic probe. The exploratory analysis using principal component analysis shows that there are two ham groups according to the appearance or not of defects. Then, a K nearest neighbours was used to classify dry-cured hams into defective or no defective classes. The overall accuracy of the classification as a function of pastiness was 88.5%; meanwhile, according to colour was 79.7%. Partial least squares regression was used to formulate prediction equations for pastiness and colour. The correlation coefficients of calibration and cross-validation were 0.97 and 0.86 for optimal equation predicting pastiness, and 0.82 and 0.69 for optimal equation predicting colour. The standard error of cross-validation for predicting pastiness and colour is between 1 and 2 times the standard deviation of the reference method (the error involved in the sensory evaluation by the experts). The magnitude of this error demonstrates the good precision of the methods for predicting pastiness and colour. Furthermore, the samples were classified into defective or no defective classes, with a correct classification of 94.2% according to pasty texture evaluation and 75.7% as regard to colour evaluation.

Origins and consequences of congenital heart defects affecting the right ventricle.

PubMed

Woudstra, Odilia I; Ahuja, Suchit; Bokma, Jouke P; Bouma, Berto J; Mulder, Barbara J M; Christoffels, Vincent M

2017-10-01

Congenital heart disease is a major health issue, accounting for a third of all congenital defects. Improved early surgical management has led to a growing population of adults with congenital heart disease, including patients with defects affecting the right ventricle, which are often classified as severe. Defects affecting the right ventricle often cause right ventricular volume or pressure overload and affected patients are at high risk for complications such as heart failure and sudden death. Recent insights into the developmental mechanisms and distinct developmental origins of the left ventricle, right ventricle, and the outflow tract have shed light on the common features and distinct problems arising in specific defects. Here, we provide a comprehensive overview of the current knowledge on the development into the normal and congenitally malformed right heart and the clinical consequences of several congenital heart defects affecting the right ventricle. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2017. For permissions, please email: journals.permissions@oup.com.

Automated real-time detection of defects during machining of ceramics

DOEpatents

Ellingson, W.A.; Sun, J.

1997-11-18

Apparatus for the automated real-time detection and classification of defects during the machining of ceramic components employs an elastic optical scattering technique using polarized laser light. A ceramic specimen is continuously moved while being machined. Polarized laser light is directed onto the ceramic specimen surface at a fixed position just aft of the machining tool for examination of the newly machined surface. Any foreign material near the location of the laser light on the ceramic specimen is cleared by an air blast. As the specimen is moved, its surface is continuously scanned by the polarized laser light beam to provide a two-dimensional image presented in real-time on a video display unit, with the motion of the ceramic specimen synchronized with the data acquisition speed. By storing known ``feature masks`` representing various surface and sub-surface defects and comparing measured defects with the stored feature masks, detected defects may be automatically characterized. Using multiple detectors, various types of defects may be detected and classified. 14 figs.

Automated real-time detection of defects during machining of ceramics

DOEpatents

Ellingson, William A.; Sun, Jiangang

1997-01-01

Apparatus for the automated real-time detection and classification of defects during the machining of ceramic components employs an elastic optical scattering technique using polarized laser light. A ceramic specimen is continuously moved while being machined. Polarized laser light is directed onto the ceramic specimen surface at a fixed position just aft of the machining tool for examination of the newly machined surface. Any foreign material near the location of the laser light on the ceramic specimen is cleared by an air blast. As the specimen is moved, its surface is continuously scanned by the polarized laser light beam to provide a two-dimensional image presented in real-time on a video display unit, with the motion of the ceramic specimen synchronized with the data acquisition speed. By storing known "feature masks" representing various surface and sub-surface defects and comparing measured defects with the stored feature masks, detected defects may be automatically characterized. Using multiple detectors, various types of defects may be detected and classified.

A Novel Machine Vision System for the Inspection of Micro-Spray Nozzle

PubMed Central

Huang, Kuo-Yi; Ye, Yu-Ting

2015-01-01

In this study, we present an application of neural network and image processing techniques for detecting the defects of an internal micro-spray nozzle. The defect regions were segmented by Canny edge detection, a randomized algorithm for detecting circles and a circle inspection (CI) algorithm. The gray level co-occurrence matrix (GLCM) was further used to evaluate the texture features of the segmented region. These texture features (contrast, entropy, energy), color features (mean and variance of gray level) and geometric features (distance variance, mean diameter and diameter ratio) were used in the classification procedures. A back-propagation neural network classifier was employed to detect the defects of micro-spray nozzles. The methodology presented herein effectively works for detecting micro-spray nozzle defects to an accuracy of 90.71%. PMID:26131678

A Novel Machine Vision System for the Inspection of Micro-Spray Nozzle.

PubMed

Huang, Kuo-Yi; Ye, Yu-Ting

2015-06-29

In this study, we present an application of neural network and image processing techniques for detecting the defects of an internal micro-spray nozzle. The defect regions were segmented by Canny edge detection, a randomized algorithm for detecting circles and a circle inspection (CI) algorithm. The gray level co-occurrence matrix (GLCM) was further used to evaluate the texture features of the segmented region. These texture features (contrast, entropy, energy), color features (mean and variance of gray level) and geometric features (distance variance, mean diameter and diameter ratio) were used in the classification procedures. A back-propagation neural network classifier was employed to detect the defects of micro-spray nozzles. The methodology presented herein effectively works for detecting micro-spray nozzle defects to an accuracy of 90.71%.

Airborne ultrasonic inspection of hides and leather

USDA-ARS?s Scientific Manuscript database

Currently, hides and leather are visually inspected and ranked for quality, sale price and usable area. Visual inspection is not reliable for detecting defects, which are usually hidden inside the material. This manual assessment is non-uniform among operators, and often leads to disputes over fai...

Evaluation of hides and leather using ultrasonic technology

USDA-ARS?s Scientific Manuscript database

Hides are visually inspected and ranked for quality and sale price. Because visual inspection is not reliable for detecting defects when hair is present, hides cannot be effectively sorted at the earliest stage of processing. Furthermore, this subjective assessment is non-uniform among operators, ...

Computer vision-based method for classification of wheat grains using artificial neural network.

PubMed

Sabanci, Kadir; Kayabasi, Ahmet; Toktas, Abdurrahim

2017-06-01

A simplified computer vision-based application using artificial neural network (ANN) depending on multilayer perceptron (MLP) for accurately classifying wheat grains into bread or durum is presented. The images of 100 bread and 100 durum wheat grains are taken via a high-resolution camera and subjected to pre-processing. The main visual features of four dimensions, three colors and five textures are acquired using image-processing techniques (IPTs). A total of 21 visual features are reproduced from the 12 main features to diversify the input population for training and testing the ANN model. The data sets of visual features are considered as input parameters of the ANN model. The ANN with four different input data subsets is modelled to classify the wheat grains into bread or durum. The ANN model is trained with 180 grains and its accuracy tested with 20 grains from a total of 200 wheat grains. Seven input parameters that are most effective on the classifying results are determined using the correlation-based CfsSubsetEval algorithm to simplify the ANN model. The results of the ANN model are compared in terms of accuracy rate. The best result is achieved with a mean absolute error (MAE) of 9.8 × 10 -6 by the simplified ANN model. This shows that the proposed classifier based on computer vision can be successfully exploited to automatically classify a variety of grains. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Noninvasive multi–photon fluorescence microscopy resolves retinol and retinal–condensation products in mouse eyes

PubMed Central

Palczewska, Grazyna; Maeda, Tadao; Imanishi, Yoshikazu; Sun, Wenyu; Chen, Yu; Williams, David R.; Piston, David; Maeda, Akiko; Palczewski, Krzysztof

2010-01-01

Multi–photon excitation fluorescence microscopy (MPM) can image certain molecular processes in vivo. In the eye, fluorescent retinyl esters in sub–cellular structures called retinosomes mediate regeneration of the visual chromophore, 11–cis–retinal, by the visual cycle. But harmful fluorescent condensation products were also identified previously. We report that in wild type mice, excitation with λ ~730 nm identified retinosomes in the retinal pigment epithelium, whereas excitation with λ ~910 nm revealed at least one additional retinal fluorophore. The latter fluorescence was absent in eyes of genetically modified mice lacking a functional visual cycle, but accentuated in eyes of older WT mice and mice with defective clearance of all–trans–retinal, an intermediate in the visual cycle. MPM, a noninvasive imaging modality that facilitates concurrent monitoring of retinosomes along with potentially harmful products in aging eyes, has the potential to detect early molecular changes due to age–related macular degeneration and other defects in retinoid metabolism. PMID:21076393

Image gathering and digital restoration for fidelity and visual quality

NASA Technical Reports Server (NTRS)

Huck, Friedrich O.; Alter-Gartenberg, Rachel; Rahman, Zia-Ur

1991-01-01

The fidelity and resolution of the traditional Wiener restorations given in the prevalent digital processing literature can be significantly improved when the transformations between the continuous and discrete representations in image gathering and display are accounted for. However, the visual quality of these improved restorations also is more sensitive to the defects caused by aliasing artifacts, colored noise, and ringing near sharp edges. In this paper, these visual defects are characterized, and methods for suppressing them are presented. It is demonstrated how the visual quality of fidelity-maximized images can be improved when (1) the image-gathering system is specifically designed to enhance the performance of the image-restoration algorithm, and (2) the Wiener filter is combined with interactive Gaussian smoothing, synthetic high edge enhancement, and nonlinear tone-scale transformation. The nonlinear transformation is used primarily to enhance the spatial details that are often obscurred when the normally wide dynamic range of natural radiance fields is compressed into the relatively narrow dynamic range of film and other displays.

[Surgical treatment with an artificial iris].

PubMed

Mayer, C S; Hoffmann, A E

2015-10-01

Iris defects with their disturbed pupillary function, visual impairment and glare constitute a therapeutic challenge in surgical reconstruction. A new therapeutic option for distinctive defects consists in the implantation of a custom-made silicone iris. This new and challenging therapy provides the opportunity to achieve an individual, aesthetically appealing and good functional result for the patient.

Mental Images and the Modification of Learning Defects.

ERIC Educational Resources Information Center

Patten, Bernard M.

Because human memory and thought involve extremely complex processes, it is possible to employ unusual modalities and specific visual strategies for remembering and problem-solving to assist patients with memory defects. This three-part paper discusses some of the research in the field of human memory and describes practical applications of these…

Three-dimensional textures and defects of soft material layering revealed by thermal sublimation.

PubMed

Yoon, Dong Ki; Kim, Yun Ho; Kim, Dae Seok; Oh, Seong Dae; Smalyukh, Ivan I; Clark, Noel A; Jung, Hee-Tae

2013-11-26

Layering is found and exploited in a variety of soft material systems, ranging from complex macromolecular self-assemblies to block copolymer and small-molecule liquid crystals. Because the control of layer structure is required for applications and characterization, and because defects reveal key features of the symmetries of layered phases, a variety of techniques have been developed for the study of soft-layer structure and defects, including X-ray diffraction and visualization using optical transmission and fluorescence confocal polarizing microscopy, atomic force microscopy, and SEM and transmission electron microscopy, including freeze-fracture transmission electron microscopy. Here, it is shown that thermal sublimation can be usefully combined with such techniques to enable visualization of the 3D structure of soft materials. Sequential sublimation removes material in a stepwise fashion, leaving a remnant layer structure largely unchanged and viewable using SEM, as demonstrated here using a lamellar smectic liquid crystal.

Evolutionary fuzzy ARTMAP neural networks for classification of semiconductor defects.

PubMed

Tan, Shing Chiang; Watada, Junzo; Ibrahim, Zuwairie; Khalid, Marzuki

2015-05-01

Wafer defect detection using an intelligent system is an approach of quality improvement in semiconductor manufacturing that aims to enhance its process stability, increase production capacity, and improve yields. Occasionally, only few records that indicate defective units are available and they are classified as a minority group in a large database. Such a situation leads to an imbalanced data set problem, wherein it engenders a great challenge to deal with by applying machine-learning techniques for obtaining effective solution. In addition, the database may comprise overlapping samples of different classes. This paper introduces two models of evolutionary fuzzy ARTMAP (FAM) neural networks to deal with the imbalanced data set problems in a semiconductor manufacturing operations. In particular, both the FAM models and hybrid genetic algorithms are integrated in the proposed evolutionary artificial neural networks (EANNs) to classify an imbalanced data set. In addition, one of the proposed EANNs incorporates a facility to learn overlapping samples of different classes from the imbalanced data environment. The classification results of the proposed evolutionary FAM neural networks are presented, compared, and analyzed using several classification metrics. The outcomes positively indicate the effectiveness of the proposed networks in handling classification problems with imbalanced data sets.

Differences between Non-arteritic Anterior Ischemic Optic Neuropathy and Open Angle Glaucoma with Altitudinal Visual Field Defect.

PubMed

Han, Sangyoun; Jung, Jong Jin; Kim, Ungsoo Samuel

2015-12-01

To investigate the differences in retinal nerve fiber layer (RNFL) change and optic nerve head parameters between non-arteritic anterior ischemic optic neuropathy (NAION) and open angle glaucoma (OAG) with altitudinal visual field defect. Seventeen NAION patients and 26 OAG patients were enrolled prospectively. The standard visual field indices (mean deviation, pattern standard deviation) were obtained from the Humphrey visual field test and differences between the two groups were analyzed. Cirrus HD-OCT parameters were used, including optic disc head analysis, average RNFL thickness, and RNFL thickness of each quadrant. The mean deviation and pattern standard deviation were not significantly different between the groups. In the affected eye, although the disc area was similar between the two groups (2.00 ± 0.32 and 1.99 ± 0.33 mm(2), p = 0.586), the rim area of the OAG group was smaller than that of the NAION group (1.26 ± 0.56 and 0.61 ± 0.15 mm(2), respectively, p < 0.001). RNFL asymmetry was not different between the two groups (p = 0.265), but the inferior RNFL thickness of both the affected and unaffected eyes were less in the OAG group than in the NAION group. In the analysis of optic disc morphology, both affected and unaffected eyes showed significant differences between two groups. To differentiate NAION from OAG in eyes with altitudinal visual field defects, optic disc head analysis of not only the affected eye, but also the unaffected eye, by using spectral domain optical coherence tomography may be helpful.

Progression of lamellar hole-associated epiretinal proliferation and retinal changes during long-term follow-up.

PubMed

Compera, Denise; Schumann, Ricarda G; Cereda, Matteo G; Acquistapace, Alessandra; Lita, Viviane; Priglinger, Siegfried G; Staurenghi, Giovanni; Bottoni, Ferdinando

2018-01-01

To report on progression of lamellar hole-associated epiretinal proliferation (LHEP) in eyes with lamellar macular holes (LMH) using spectral-domain optical coherence tomography (SD-OCT), and to correlate with intraretinal changes and visual function. From a retrospectively reviewed series of 167 eyes with non-full-thickness macular holes, we exclusively included a subgroup of 34 eyes with LMH and LHEP by SD-OCT evaluation. In these eyes, area of LHEP, intraretinal changes of defect diameter, central retinal thickness, defects of the ellipsoid zone and occurrence of a contractive epiretinal membrane were analysed. Additionally, clinical data were documented. Area of LHEP significantly increased during a mean follow-up period of 40.5 months (median 52 months). Analysing intraretinal changes, a significant enlargement of minimum and maximum horizontal lamellar hole diameter was found that correlated with the area of LHEP. Defects of the ellipsoid zone were seen in 65% of the eyes at baseline and in 85% at the end of follow-up. Increase of maximum horizontal hole diameter and ellipsoid zone defects correlated with a decline of visual acuity. Fifty per cent of patients with LMH and LHEP also demonstrated extrafoveal typical contractive epiretinal membranes with retinal folds. Long-term follow-up revealed an increase of the area of LHEP in eyes with LMH that correlated with the enlargement of lamellar hole diameter and ellipsoid zone defects. Our data delineate the progression of intraretinal changes in association with a decline of visual function in this subgroup of LMH eyes. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Correlation between spectral-domain OCT findings and visual acuity in X-linked retinoschisis.

PubMed

Yang, Hyun Seung; Lee, Jung Bok; Yoon, Young Hee; Lee, Joo Yong

2014-05-08

To investigate the tomographic characteristics of the outer retina and choroid and their relationship with visual acuity in X-linked juvenile retinoschisis (XLRS) patients using spectral-domain optical coherence tomography (SD-OCT). In this retrospective, observational, case-control study, we analyzed 20 eyes of 10 patients with XLRS using SD-OCT. The clinical and tomographic features of the outer retina, including the external limiting membrane (ELM), inner segment/outer segment (IS/OS) junction, cone cell outer segment tips (COST) line, photoreceptor outer segment (PROS) length, and choroid, were evaluated. As controls, 40 age-, sex-, and refraction-matched healthy eyes (1:2 matched) were randomly selected and imaged in parallel. The most prevalent area of abnormality in the outer retina layer of our patients was the outer plexiform layer (OPL; 60% of all affected eyes) and COST line (75% of all affected eyes). On average, the subfoveal choroid and PROS lengths were 35 μm thicker and 19 μm thinner, respectively, in XLRS patients (P = 0.084 and P < 0.001, respectively). A dominant IS/OS junction, COST line defects, and PROS length were related to patient best-corrected visual acuity (BCVA; P = 0.029, P = 0.001, and P < 0.001, respectively) by univariate analysis. Cone cell outer segment tips line defect and PROS length were the only factors related to BCVA in multivariate analysis (P = 0.028 and 0.003, respectively). Outer plexiform layer and photoreceptor microstructure defects are frequent in XLRS patients. Cone cell outer segment tips line defects and shortened PROS lengths as well as other photoreceptor microstructure defects may be closely related to poor vision in XLRS.

Delayed Single Stage Perineal Posterior Urethroplasty.

PubMed

Ali, Shahzad; Shahnawaz; Shahzad, Iqbal; Baloch, Muhammad Umar

2015-06-01

To determine the delayed single stage perineal posterior urethroplasty for treatment of posterior urethral stricture/distraction defect. Descriptive case series. Department of Urology, Jinnah Postgraduate Medical Centre, Karachi, from January 2009 to December 2011. Patients were selected for delayed single stage perineal posterior urethroplasty for treatment of posterior urethral stricture / distraction defect. All were initially suprapubically catheterized followed by definitive surgery after at least 3 months. Thirty male patients were analyzed with a mean follow-up of 10 months, 2 patients were excluded as they developed failure in first 3 months postoperatively. Mean patient's age was 26.25 ± 7.9 years. On follow-up, 7 patients (23.3%) experienced recurrent stricture during first 10 months. Five (16.6%) patients were treated successfully with single direct visual internal urethrotomy. Two patients (6.6%) had more than one direct visual internal urethrotomy and considered failed. Re-do perineal urethroplasty was eventually performed. The overall success rate was 93.3% with permissive criteria allowing single direct visual internal urethrotomy and 76.6% with strict criteria allowing no more procedures postoperatively. Posterior anastomotic urethroplasty offers excellent long-term results to patients with posterior urethral trauma and distraction defect even after multiple prior procedures.

In-TFT-array-process micro defect inspection using nonlinear principal component analysis.

PubMed

Liu, Yi-Hung; Wang, Chi-Kai; Ting, Yung; Lin, Wei-Zhi; Kang, Zhi-Hao; Chen, Ching-Shun; Hwang, Jih-Shang

2009-11-20

Defect inspection plays a critical role in thin film transistor liquid crystal display (TFT-LCD) manufacture, and has received much attention in the field of automatic optical inspection (AOI). Previously, most focus was put on the problems of macro-scale Mura-defect detection in cell process, but it has recently been found that the defects which substantially influence the yield rate of LCD panels are actually those in the TFT array process, which is the first process in TFT-LCD manufacturing. Defect inspection in TFT array process is therefore considered a difficult task. This paper presents a novel inspection scheme based on kernel principal component analysis (KPCA) algorithm, which is a nonlinear version of the well-known PCA algorithm. The inspection scheme can not only detect the defects from the images captured from the surface of LCD panels, but also recognize the types of the detected defects automatically. Results, based on real images provided by a LCD manufacturer in Taiwan, indicate that the KPCA-based defect inspection scheme is able to achieve a defect detection rate of over 99% and a high defect classification rate of over 96% when the imbalanced support vector machine (ISVM) with 2-norm soft margin is employed as the classifier. More importantly, the inspection time is less than 1 s per input image.

Effects of thickness and gain on the amplitude of airborne ultrasonics

USDA-ARS?s Scientific Manuscript database

Currently, hides and leather are visually inspected and ranked for quality, usable area, and sale price. However, visual inspection is not reliable for detecting defects, which are usually hidden inside the material. Development of a non-contact nondestructive method to accurately evaluate the qua...

Reconstruction of maxillectomy and midfacial defects with free tissue transfer.

PubMed

Santamaria, Eric; Cordeiro, Peter G

2006-11-01

The maxillary bones are part of the midfacial skeleton and are closely related to the eyeglobe, nasal airway, and oral cavity. Together with the overlying soft tissues, the two maxillae are responsible to a large extent for facial contour. Maxillectomy defects become more complex when critical structures such as the orbit, globe, and cranial base are resected, and reconstruction with distant tissues become essential. In this article, we describe a classification system and algorithm for reconstruction of these complex defects using various pedicled and free flaps. Most defects that involve resection of the maxilla and adjacent soft tissues may be classified into one of the following four types: Type I defects, Limited maxillectomy; Type II defects, Subtotal maxillectomy; Type III defects, Total maxillectomy; and Type IV defects, Orbitomaxillectomy. Using this classification, reconstruction of maxillectomy and midfacial defects may be approached considering the relationship between volume and surface area requirements, that is, addressing the bony defect first, followed by assessment of the associated soft tissue, skin, palate, and cheek-lining deficits. In our experience, most complex maxillectomy defects are best reconstructed using free tissue transfer. The rectus abdominis and radial forearm free flap in combination with immediate bone grafting or as an osteocutaneous flap reliably provide the best aesthetic and functional results. A temporalis muscle pedicled flap is used for reconstruction of maxillectomy defects only in those patients who are not candidates for a microsurgical procedure.

Mechanisms of oxygen permeation through plastic films and barrier coatings

NASA Astrophysics Data System (ADS)

Wilski, Stefan; Wipperfürth, Jens; Jaritz, Montgomery; Kirchheim, Dennis; Mitschker, Felix; Awakowicz, Peter; Dahlmann, Rainer; Hopmann, Christian

2017-10-01

Oxygen and water vapour permeation through plastic films in food packaging or other applications with high demands on permeation are prevented by inorganic barrier films. Most of the permeation occurs through small defects (<3 µm) in the barrier coating. The defects were visualized by etching with reactive oxygen in a capacitively coupled plasma and subsequent SEM imaging. In this work, defects in SiO x -coatings deposited by plasma-enhanced chemical vapour deposition on polyethylene terephthalate (PET) are investigated and the mass transport through the polymer is simulated in a 3D approach. Calculations of single defects showed that there is no linear correlation between the defect area and the resulting permeability. The influence of adjacent defects in different distances was observed and led to flow reduction functions depending on the defect spacing and defect area. A critical defect spacing where no interaction between defects occurs was found and compared to other findings. According to the superposition principle, the permeability of single defects was added up and compared to experimentally determined oxygen permeation. The results showed the same trend of decreasing permeability with decreasing defect densities.

Cross-Modal Decoding of Neural Patterns Associated with Working Memory: Evidence for Attention-Based Accounts of Working Memory

PubMed Central

Majerus, Steve; Cowan, Nelson; Péters, Frédéric; Van Calster, Laurens; Phillips, Christophe; Schrouff, Jessica

2016-01-01

Recent studies suggest common neural substrates involved in verbal and visual working memory (WM), interpreted as reflecting shared attention-based, short-term retention mechanisms. We used a machine-learning approach to determine more directly the extent to which common neural patterns characterize retention in verbal WM and visual WM. Verbal WM was assessed via a standard delayed probe recognition task for letter sequences of variable length. Visual WM was assessed via a visual array WM task involving the maintenance of variable amounts of visual information in the focus of attention. We trained a classifier to distinguish neural activation patterns associated with high- and low-visual WM load and tested the ability of this classifier to predict verbal WM load (high–low) from their associated neural activation patterns, and vice versa. We observed significant between-task prediction of load effects during WM maintenance, in posterior parietal and superior frontal regions of the dorsal attention network; in contrast, between-task prediction in sensory processing cortices was restricted to the encoding stage. Furthermore, between-task prediction of load effects was strongest in those participants presenting the highest capacity for the visual WM task. This study provides novel evidence for common, attention-based neural patterns supporting verbal and visual WM. PMID:25146374

Decoding brain responses to pixelized images in the primary visual cortex: implications for visual cortical prostheses

PubMed Central

Guo, Bing-bing; Zheng, Xiao-lin; Lu, Zhen-gang; Wang, Xing; Yin, Zheng-qin; Hou, Wen-sheng; Meng, Ming

2015-01-01

Visual cortical prostheses have the potential to restore partial vision. Still limited by the low-resolution visual percepts provided by visual cortical prostheses, implant wearers can currently only “see” pixelized images, and how to obtain the specific brain responses to different pixelized images in the primary visual cortex (the implant area) is still unknown. We conducted a functional magnetic resonance imaging experiment on normal human participants to investigate the brain activation patterns in response to 18 different pixelized images. There were 100 voxels in the brain activation pattern that were selected from the primary visual cortex, and voxel size was 4 mm × 4 mm × 4 mm. Multi-voxel pattern analysis was used to test if these 18 different brain activation patterns were specific. We chose a Linear Support Vector Machine (LSVM) as the classifier in this study. The results showed that the classification accuracies of different brain activation patterns were significantly above chance level, which suggests that the classifier can successfully distinguish the brain activation patterns. Our results suggest that the specific brain activation patterns to different pixelized images can be obtained in the primary visual cortex using a 4 mm × 4 mm × 4 mm voxel size and a 100-voxel pattern. PMID:26692860

Visual brain activity patterns classification with simultaneous EEG-fMRI: A multimodal approach.

PubMed

Ahmad, Rana Fayyaz; Malik, Aamir Saeed; Kamel, Nidal; Reza, Faruque; Amin, Hafeez Ullah; Hussain, Muhammad

2017-01-01

Classification of the visual information from the brain activity data is a challenging task. Many studies reported in the literature are based on the brain activity patterns using either fMRI or EEG/MEG only. EEG and fMRI considered as two complementary neuroimaging modalities in terms of their temporal and spatial resolution to map the brain activity. For getting a high spatial and temporal resolution of the brain at the same time, simultaneous EEG-fMRI seems to be fruitful. In this article, we propose a new method based on simultaneous EEG-fMRI data and machine learning approach to classify the visual brain activity patterns. We acquired EEG-fMRI data simultaneously on the ten healthy human participants by showing them visual stimuli. Data fusion approach is used to merge EEG and fMRI data. Machine learning classifier is used for the classification purposes. Results showed that superior classification performance has been achieved with simultaneous EEG-fMRI data as compared to the EEG and fMRI data standalone. This shows that multimodal approach improved the classification accuracy results as compared with other approaches reported in the literature. The proposed simultaneous EEG-fMRI approach for classifying the brain activity patterns can be helpful to predict or fully decode the brain activity patterns.

Classification of CT examinations for COPD visual severity analysis

NASA Astrophysics Data System (ADS)

Tan, Jun; Zheng, Bin; Wang, Xingwei; Pu, Jiantao; Gur, David; Sciurba, Frank C.; Leader, J. Ken

2012-03-01

In this study we present a computational method of CT examination classification into visual assessed emphysema severity. The visual severity categories ranged from 0 to 5 and were rated by an experienced radiologist. The six categories were none, trace, mild, moderate, severe and very severe. Lung segmentation was performed for every input image and all image features are extracted from the segmented lung only. We adopted a two-level feature representation method for the classification. Five gray level distribution statistics, six gray level co-occurrence matrix (GLCM), and eleven gray level run-length (GLRL) features were computed for each CT image depicted segment lung. Then we used wavelets decomposition to obtain the low- and high-frequency components of the input image, and again extract from the lung region six GLCM features and eleven GLRL features. Therefore our feature vector length is 56. The CT examinations were classified using the support vector machine (SVM) and k-nearest neighbors (KNN) and the traditional threshold (density mask) approach. The SVM classifier had the highest classification performance of all the methods with an overall sensitivity of 54.4% and a 69.6% sensitivity to discriminate "no" and "trace visually assessed emphysema. We believe this work may lead to an automated, objective method to categorically classify emphysema severity on CT exam.

Evaluation of a New Scoring System for Retinal Nerve Fiber Layer Photography Using HRA1 in 964 Eyes

PubMed Central

Hong, Samin; Moon, Jong Wook; Ha, Seung Joo; Kim, Chan Yun; Seong, Gong Je

2007-01-01

Purpose To evaluate retinal nerve fiber layer (RNFL) defect by a new scoring system for RNFL photography using the Heidelberg Retina Angiograph 1 (HRA1). Methods This retrospective study included 128 healthy eyes and 836 primary open-angle glaucoma eyes. The RNFL photography using HRA1 was interpreted using a new scoring system, and correlated with visual field indices of standard automated perimetry (SAP). Using the presence of RNFL defect, darkness, width, and location, we established the new scoring system of RNFL photos. Results The mean RNFL defect score I in the early, moderate, severe, and control groups were 7.3, 9.2, 10.4, and 3.6, respectively. The mean RNFL defect score II in the early, moderate, severe, and control groups were 14.5, 28.5, 43.4, and 3.4, respectively. Correlations between the RNFL defect score II and the mean deviation of SAP was the strongest of the various combinations (r=-0.675, P<.001). Conclusions Using a new scoring system, we propose a method for semi-quantitative interpretation of RNFL photographs. This scoring system may be helpful to distinguish between normal and glaucomatous eyes, and the score is associated with the severity of visual field loss. PMID:18063886

A visual tracking method based on improved online multiple instance learning

NASA Astrophysics Data System (ADS)

He, Xianhui; Wei, Yuxing

2016-09-01

Visual tracking is an active research topic in the field of computer vision and has been well studied in the last decades. The method based on multiple instance learning (MIL) was recently introduced into the tracking task, which can solve the problem that template drift well. However, MIL method has relatively poor performance in running efficiency and accuracy, due to its strong classifiers updating strategy is complicated, and the speed of the classifiers update is not always same with the change of the targets' appearance. In this paper, we present a novel online effective MIL (EMIL) tracker. A new update strategy for strong classifier was proposed to improve the running efficiency of MIL method. In addition, to improve the t racking accuracy and stability of the MIL method, a new dynamic mechanism for learning rate renewal of the classifier and variable search window were proposed. Experimental results show that our method performs good performance under the complex scenes, with strong stability and high efficiency.

Diagnosing cerebral visual impairment in children with good visual acuity.

PubMed

van Genderen, Maria; Dekker, Marjoke; Pilon, Florine; Bals, Irmgard

2012-06-01

To identify elements that could facilitate the diagnosis of cerebral visual impairment (CVI) in children with good visual acuity in the general ophthalmic clinic. We retrospectively investigated the clinical characteristics of 30 children with good visual acuity and CVI and compared them with those of 23 children who were referred with a suspicion of CVI, but proved to have a different diagnosis. Clinical characteristics included medical history, MRI findings, visual acuity, crowding ratio (CR), visual field assessment, and the results of ophthalmologic and orthoptic examination. We also evaluated the additional value of a short CVI questionnaire. Eighty-three percent of the children with an abnormal medical history (mainly prematurity and perinatal hypoxia) had CVI, in contrast with none of the children with a normal medical history. Cerebral palsy, visual field defects, and partial optic atrophy only occurred in the CVI group. 41% of the children with CVI had a CR ≥2.0, which may be related to dorsal stream dysfunction. All children with CVI, but also 91% of the children without CVI gave ≥3 affirmative answers on the CVI questionnaire. An abnormal pre- or perinatal medical history is the most important risk factor for CVI in children, and therefore in deciding which children should be referred for further multidisciplinary assessment. Additional symptoms of cerebral damage, i.e., cerebral palsy, visual field defects, partial optic atrophy, and a CR ≥2 may support the diagnosis. CVI questionnaires should not be used for screening purposes as they yield too many false positives.

Lack of Multisensory Integration in Hemianopia: No Influence of Visual Stimuli on Aurally Guided Saccades to the Blind Hemifield

PubMed Central

Ten Brink, Antonia F.; Nijboer, Tanja C. W.; Bergsma, Douwe P.; Barton, Jason J. S.; Van der Stigchel, Stefan

2015-01-01

In patients with visual hemifield defects residual visual functions may be present, a phenomenon called blindsight. The superior colliculus (SC) is part of the spared pathway that is considered to be responsible for this phenomenon. Given that the SC processes input from different modalities and is involved in the programming of saccadic eye movements, the aim of the present study was to examine whether multimodal integration can modulate oculomotor competition in the damaged hemifield. We conducted two experiments with eight patients who had visual field defects due to lesions that affected the retinogeniculate pathway but spared the retinotectal direct SC pathway. They had to make saccades to an auditory target that was presented alone or in combination with a visual stimulus. The visual stimulus could either be spatially coincident with the auditory target (possibly enhancing the auditory target signal), or spatially disparate to the auditory target (possibly competing with the auditory tar-get signal). For each patient we compared the saccade endpoint deviation in these two bi-modal conditions with the endpoint deviation in the unimodal condition (auditory target alone). In all seven hemianopic patients, saccade accuracy was affected only by visual stimuli in the intact, but not in the blind visual field. In one patient with a more limited quadrantano-pia, a facilitation effect of the spatially coincident visual stimulus was observed. We conclude that our results show that multisensory integration is infrequent in the blind field of patients with hemianopia. PMID:25835952

Activity-Dependent Dysfunction in Visual and Olfactory Sensory Systems in Mouse Models of Down Syndrome

PubMed Central

Saqran, Lubna; Herrick, Scott P.; Frosch, Matthew P.; Hyman, Bradley T.

2017-01-01

Activity-dependent synaptic plasticity plays a critical role in the refinement of circuitry during postnatal development and may be disrupted in conditions that cause intellectual disability, such as Down syndrome (DS). To test this hypothesis, visual cortical plasticity was assessed in Ts65Dn mice that harbor a chromosomal duplication syntenic to human chromosome 21q. We find that Ts65Dn mice demonstrate a defect in ocular dominance plasticity (ODP) following monocular deprivation. This phenotype is similar to that of transgenic mice that express amyloid precursor protein (APP), which is duplicated in DS and in Ts65DN mice; however, normalizing APP gene copy number in Ts65Dn mice fails to rescue plasticity. Ts1Rhr mice harbor a duplication of the telomeric third of the Ts65Dn-duplicated sequence and demonstrate the same ODP defect, suggesting a gene or genes sufficient to drive the phenotype are located in that smaller duplication. In addition, we find that Ts65Dn mice demonstrate an abnormality in olfactory system connectivity, a defect in the refinement of connections to second-order neurons in the olfactory bulb. Ts1Rhr mice do not demonstrate a defect in glomerular refinement, suggesting that distinct genes or sets of genes underlie visual and olfactory system phenotypes. Importantly, these data suggest that developmental plasticity and connectivity are impaired in sensory systems in DS model mice, that such defects may contribute to functional impairment in DS, and that these phenotypes, present in male and female mice, provide novel means for examining the genetic and molecular bases for neurodevelopmental impairment in model mice in vivo. SIGNIFICANCE STATEMENT Our understanding of the basis for intellectual impairment in Down syndrome is hindered by the large number of genes duplicated in Trisomy 21 and a lack of understanding of the effect of disease pathology on the function of neural circuits in vivo. This work describes early postnatal developmental abnormalities in visual and olfactory sensory systems in Down syndrome model mice, which provide insight into defects in the function of neural circuits in vivo and provide an approach for exploring the genetic and molecular basis for impairment in the disease. In addition, these findings raise the possibility that basic dysfunction in primary sensory circuitry may illustrate mechanisms important for global learning and cognitive impairment in Down syndrome patients. PMID:28899917

BDA: A novel method for identifying defects in body-centered cubic crystals.

PubMed

Möller, Johannes J; Bitzek, Erik

2016-01-01

The accurate and fast identification of crystallographic defects plays a key role for the analysis of atomistic simulation output data. For face-centered cubic (fcc) metals, most existing structure analysis tools allow for the direct distinction of common defects, such as stacking faults or certain low-index surfaces. For body-centered cubic (bcc) metals, on the other hand, a robust way to identify such defects is currently not easily available. We therefore introduce a new method for analyzing atomistic configurations of bcc metals, the BCC Defect Analysis (BDA). It uses existing structure analysis algorithms and combines their results to uniquely distinguish between typical defects in bcc metals. In essence, the BDA method offers the following features:•Identification of typical defect structures in bcc metals.•Reduction of erroneously identified defects by iterative comparison to the defects in the atom's neighborhood.•Availability as ready-to-use Python script for the widespread visualization tool OVITO [http://ovito.org].

Pictorial Review of Digital Radiography Artifacts.

PubMed

Walz-Flannigan, Alisa I; Brossoit, Kimberly J; Magnuson, Dayne J; Schueler, Beth A

2018-01-01

Visual familiarity with the variety of digital radiographic artifacts is needed to identify, resolve, or prevent image artifacts from creating issues with patient imaging. Because the mechanism for image creation is different between flat-panel detectors and computed radiography, the causes and appearances of some artifacts can be unique to these different modalities. Examples are provided of artifacts that were found on clinical images or during quality control testing with flat-panel detectors. The examples are meant to serve as learning tools for future identification and troubleshooting of artifacts and as a reminder for steps that can be taken for prevention. The examples of artifacts provided are classified according to their causal connection in the imaging chain, including an equipment defect as a result of an accident or mishandling, debris or gain calibration flaws, a problematic acquisition technique, signal transmission failures, and image processing issues. Specific artifacts include those that are due to flat-panel detector drops, backscatter, debris in the x-ray field during calibration, detector saturation or underexposure, or collimation detection errors, as well as a variety of artifacts that are processing induced. © RSNA, 2018.

Panoramic Night Vision Goggle Testing For Diagnosis and Repair

DTIC Science & Technology

2000-01-01

Visual Acuity Visual Acuity [ Marasco & Task, 1999] measures how well a human observer can see high contrast targets at specified light levels through...grid through the PNVG in-board and out-board channels simultaneously and comparing the defects to the size of grid features ( Marasco & Task, 1999). The

Can Blindsight Be Superior to "Sighted-Sight"?

ERIC Educational Resources Information Center

Trevethan, Ceri T.; Sahraie, Arash; Weiskrantz, Larry

2007-01-01

DB, the first blindsight case to be tested extensively (Weiskrantz, 1986) has demonstrated the ability to detect and discriminate a range of visual stimuli presented within his perimetrically blind visual field defect. In a temporal two alternative forced choice (2AFC) detection experiment we have investigated the limits of DB's detection ability…

Techniques of Final Preseal Visual Inspection

NASA Technical Reports Server (NTRS)

Anstead, R. J.

1975-01-01

A dissertation is given on the final preseal visual inspection of microcircuit devices to detect manufacturing defects and reduce failure rates in service. The processes employed in fabricating monolithic integrated circuits and hybrid microcircuits, various failure mechanisms resulting from deficiencies in those processes, and the rudiments of performing final inspection are outlined.

Multi-voxel patterns of visual category representation during episodic encoding are predictive of subsequent memory

PubMed Central

Kuhl, Brice A.; Rissman, Jesse; Wagner, Anthony D.

2012-01-01

Successful encoding of episodic memories is thought to depend on contributions from prefrontal and temporal lobe structures. Neural processes that contribute to successful encoding have been extensively explored through univariate analyses of neuroimaging data that compare mean activity levels elicited during the encoding of events that are subsequently remembered vs. those subsequently forgotten. Here, we applied pattern classification to fMRI data to assess the degree to which distributed patterns of activity within prefrontal and temporal lobe structures elicited during the encoding of word-image pairs were diagnostic of the visual category (Face or Scene) of the encoded image. We then assessed whether representation of category information was predictive of subsequent memory. Classification analyses indicated that temporal lobe structures contained information robustly diagnostic of visual category. Information in prefrontal cortex was less diagnostic of visual category, but was nonetheless associated with highly reliable classifier-based evidence for category representation. Critically, trials associated with greater classifier-based estimates of category representation in temporal and prefrontal regions were associated with a higher probability of subsequent remembering. Finally, consideration of trial-by-trial variance in classifier-based measures of category representation revealed positive correlations between prefrontal and temporal lobe representations, with the strength of these correlations varying as a function of the category of image being encoded. Together, these results indicate that multi-voxel representations of encoded information can provide unique insights into how visual experiences are transformed into episodic memories. PMID:21925190

[Male pseudohermaphroditism].

PubMed

Fukutani, K

1997-11-01

Male pseudohermaphroditism is a condition of sex differentiation disorders in which the gonads are tests, but the genital ducts and/or external genitalia are incompletely masculinized. This syndrome is caused by a failure of the sequential process in embryonal development of the testis. In the presence of functioning testis the Müllerian ducts regress, while the mesonephric ducts and urogenital sinus differentiate into the internal and external male genitalia. Male pseudohermaphroditism is classified to subtypes according to etiological factors: (1) testicular unresponsiveness to hCG and LH; (2) defect in testosterone biosynthesis; (3) end-organ resistance to androgen; (4) defects in the intracellular metabolism of testosterone; (5) aberrations in testicular organogenesis; (6) defects in anti-Müllerian hormone.

Linking log quality with product performance

Treesearch

D. W. Green; Robert Ross

1997-01-01

In the United States, log grading procedures use visual assessment of defects, in relation to the log scaling diameter, to estimate the yield of lumber that maybe expected from the log. This procedure was satisfactory when structural grades were based only on defect size and location. In recent years, however, structural products have increasingly been graded using a...

Defect Proliferation in Active Nematic Suspensions

NASA Astrophysics Data System (ADS)

Mishra, Prashant; Bowick, Mark J.; Giomi, Luca; Marchetti, M. Cristina

2014-03-01

The rich structure of equilibrium nematic suspensions, with their characteristic disclination defects, is modified when active forces come into play. The uniform nematic state is known to be unstable to splay (extensile) or bend (contractile) deformations above a critical activity. At even higher activity the flow becomes oscillatory and eventually turbulent. Using hydrodynamics, we classify the active flow regimes as functions of activity and order parameter friction for both contractile and extensile systems. The turbulent regime is marked by a non-zero steady state density of mobile defect pairs. The defect density itself scales with an ``active Ericksen number,'' defined as the ratio of the rate at which activity is injected into the system to the relaxation rate of orientational deformations. The work at Syracuse University was supported by the NSF on grant DMR-1004789 and by the Syracuse Soft Matter Program.

Classification of visual and linguistic tasks using eye-movement features.

PubMed

Coco, Moreno I; Keller, Frank

2014-03-07

The role of the task has received special attention in visual-cognition research because it can provide causal explanations of goal-directed eye-movement responses. The dependency between visual attention and task suggests that eye movements can be used to classify the task being performed. A recent study by Greene, Liu, and Wolfe (2012), however, fails to achieve accurate classification of visual tasks based on eye-movement features. In the present study, we hypothesize that tasks can be successfully classified when they differ with respect to the involvement of other cognitive domains, such as language processing. We extract the eye-movement features used by Greene et al. as well as additional features from the data of three different tasks: visual search, object naming, and scene description. First, we demonstrated that eye-movement responses make it possible to characterize the goals of these tasks. Then, we trained three different types of classifiers and predicted the task participants performed with an accuracy well above chance (a maximum of 88% for visual search). An analysis of the relative importance of features for classification accuracy reveals that just one feature, i.e., initiation time, is sufficient for above-chance performance (a maximum of 79% accuracy in object naming). Crucially, this feature is independent of task duration, which differs systematically across the three tasks we investigated. Overall, the best task classification performance was obtained with a set of seven features that included both spatial information (e.g., entropy of attention allocation) and temporal components (e.g., total fixation on objects) of the eye-movement record. This result confirms the task-dependent allocation of visual attention and extends previous work by showing that task classification is possible when tasks differ in the cognitive processes involved (purely visual tasks such as search vs. communicative tasks such as scene description).

Personal factors influencing the visual reaction time of pedestrians to detect turn indicators in the presence of Daytime Running Lamps.

PubMed

Peña-García, Antonio; de Oña, Rocío; García, Pedro Antonio; de Oña, Juan

2016-12-01

Daytime running lamps (DRL) on vehicles have proven to be an effective measure to prevent accidents during the daytime, particularly when pedestrians and cyclists are involved. However, there are negative interactions of DRL with other functions in automotive lighting, such as delays in pedestrians' visual reaction time (VRT) when turn indicators are activated in the presence of DRL. These negative interactions need to be reduced. This work analyses the influence of variables inherent to pedestrians, such as height, gender and visual defects, on the VRT using a classification and regression tree as an exploratory analysis and a generalized linear model to validate the results. Some pedestrian characteristics, such as gender, alone or combined with the DRL colour, and visual defects, were found to have a statistically significant influence on VRT and, hence, on traffic safety. These results and conclusions concerning the interaction between pedestrians and vehicles are presented and discussed. Practitioner Summary: Visual interactions of vehicle daytime running lamps (DRL) with other functions in automotive lighting, such as turn indicators, have an important impact on a vehicle's conspicuity for pedestrians. Depending on several factors inherent to pedestrians, the visual reaction time (VRT) can be remarkably delayed, which has implications in traffic safety.

The identification of credit card encoders by hierarchical cluster analysis of the jitters of magnetic stripes.

PubMed

Leung, S C; Fung, W K; Wong, K H

1999-01-01

The relative bit density variation graphs of 207 specimen credit cards processed by 12 encoding machines were examined first visually, and then classified by means of hierarchical cluster analysis. Twenty-nine credit cards being treated as 'questioned' samples were tested by way of cluster analysis against 'controls' derived from known encoders. It was found that hierarchical cluster analysis provided a high accuracy of identification with all 29 'questioned' samples classified correctly. On the other hand, although visual comparison of jitter graphs was less discriminating, it was nevertheless capable of giving a reasonably accurate result.

Correcting intermittent central suppression improves binocular marksmanship.

PubMed

Hussey, Eric S

2007-04-01

Intermittent central suppression (ICS) is a defect in normal binocular (two-eyed) vision that causes confusion in visual detail. ICS is a repetitive intermittent loss of visual sensation in the central area of vision. As the central vision of either eye "turns on and off", aiming errors in sight can occur that must be corrected when both eyes are seeing again. Any aiming errors in sight might be expected to interfere with marksmanship during two-eyed seeing. We compared monocular (one-eyed, patched) and binocular (two-eyed) marksmanship with pistol shooting with an Army ROTC cadet before and after successful therapy for diagnosed ICS. Pretreatment, monocular marksmanship was significantly better than binocular marksmanship, suggesting defective binocularity reduced accuracy. After treatment for ICS, binocular and monocular marksmanship were essentially the same. Results confirmed predictions that with increased visual stability from correcting the suppression, binocular and monocular marksmanship accuracies should merge.

Selective attention to imagined facial ugliness is specific to body dysmorphic disorder.

PubMed

Grocholewski, Anja; Kliem, Sören; Heinrichs, Nina

2012-03-01

Cognitive-behavioral models postulate that biases in selective attention are key factors contributing to susceptibility to and maintenance of body dysmorphic disorder (BDD). Visual attention in particular toward the imagined defect in appearance may be a crucial element. The present study therefore examined whether individuals with BDD showed increased visual attention to flaws in their own and in unfamiliar faces. Twenty individuals with BDD, 20 individuals with social phobia, and 20 mentally healthy individuals participated in an eye-tracking experiment. Participants were instructed to gaze at the photographs of 15 pictures of themselves and several unfamiliar faces. Only patients with BDD showed heightened selective visual attention to the imagined defect in their own face, as well to corresponding regions in other, unfamiliar faces. The results support the assumption that there is a specific attentional bias in BDD. Copyright © 2012 Elsevier Ltd. All rights reserved.

Falcon: Visual analysis of large, irregularly sampled, and multivariate time series data in additive manufacturing

DOE PAGES

Steed, Chad A.; Halsey, William; Dehoff, Ryan; ...

2017-02-16

Flexible visual analysis of long, high-resolution, and irregularly sampled time series data from multiple sensor streams is a challenge in several domains. In the field of additive manufacturing, this capability is critical for realizing the full potential of large-scale 3D printers. Here, we propose a visual analytics approach that helps additive manufacturing researchers acquire a deep understanding of patterns in log and imagery data collected by 3D printers. Our specific goals include discovering patterns related to defects and system performance issues, optimizing build configurations to avoid defects, and increasing production efficiency. We introduce Falcon, a new visual analytics system thatmore » allows users to interactively explore large, time-oriented data sets from multiple linked perspectives. Falcon provides overviews, detailed views, and unique segmented time series visualizations, all with adjustable scale options. To illustrate the effectiveness of Falcon at providing thorough and efficient knowledge discovery, we present a practical case study involving experts in additive manufacturing and data from a large-scale 3D printer. The techniques described are applicable to the analysis of any quantitative time series, though the focus of this paper is on additive manufacturing.« less

Falcon: Visual analysis of large, irregularly sampled, and multivariate time series data in additive manufacturing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steed, Chad A.; Halsey, William; Dehoff, Ryan

Flexible visual analysis of long, high-resolution, and irregularly sampled time series data from multiple sensor streams is a challenge in several domains. In the field of additive manufacturing, this capability is critical for realizing the full potential of large-scale 3D printers. Here, we propose a visual analytics approach that helps additive manufacturing researchers acquire a deep understanding of patterns in log and imagery data collected by 3D printers. Our specific goals include discovering patterns related to defects and system performance issues, optimizing build configurations to avoid defects, and increasing production efficiency. We introduce Falcon, a new visual analytics system thatmore » allows users to interactively explore large, time-oriented data sets from multiple linked perspectives. Falcon provides overviews, detailed views, and unique segmented time series visualizations, all with adjustable scale options. To illustrate the effectiveness of Falcon at providing thorough and efficient knowledge discovery, we present a practical case study involving experts in additive manufacturing and data from a large-scale 3D printer. The techniques described are applicable to the analysis of any quantitative time series, though the focus of this paper is on additive manufacturing.« less

Branch retinal arterial occlusion.

PubMed

Subedi, S; Shrestha, C

2010-01-01

Retinal arterial occlusion is an ocular emergency in which visual prognosis is poor mostly due to late presentation of the patient and macular involvement. The casee described, in this report is ane incidence of Branch Retinal Arterial Occlusion in a 22 year old female with grade II Mitral Regurgitation. The patiente presented witha complaint of painless, diminution of vision in the right eyn. She also presented with perception of black shadow in the superior visual fiel n of the same eye5 for five days. There was no significant systemic ord personal history. Her visual acuity at presentation was 6/60 and 6/6 in the right and left eyes,y which did not improve with glasses or pin-hole. Anterior segment including papillary reaction was normal in both eyes while Fundus examination of the right eye revealed retinal whitening inside the inferotemporal vascular arcade that was encroaching foveolar avascular zone. Visual field defect was detected at superonasally inside arhade but Fundus Fluorescence Angiography was normal. An echoycardiograph revealed grade II Mitral Regurgitation. The patient was kept on observation and after two2 days of follow-up, vision in the right eye was improved to 6/6 unaided but visual field defect was remained same.

Development of PZT-excited stroboscopic shearography for full-field nondestructive evaluation.

PubMed

Asemani, Hamidreza; Park, Jinwoo; Lee, Jung-Ryul; Soltani, Nasser

2017-05-01

Nondestructive evaluation using shearography requires a way to stress the inspection target. This technique is able to directly measure the displacement gradient distribution on the object surface. Shearography visualizes the internal structural damages as the anomalous pattern in the shearograpic fringe pattern. A piezoelectric (PZT) excitation system is able to generate loadings in the vibrational, acoustic, and ultrasonic regimes. In this paper, we propose a PZT-excited stroboscopic shearography. The PZT excitation could generate vibrational loading, a stationary wavefield, and a nonstationary propagation wave to fulfill the external loading requirement of shearography. The sweeping of the PZT excitation frequency, the formation of a standing wave, and a small shearing to suppress the incident wave were powerful controllable tools to detect the defects. The sweeping of the PZT excitation frequency enabled us to determine one of the defect-sensitive frequencies almost in real time. In addition, because the defect sensitive frequencies always existed in wide and plural ranges, the risk of the defect being overlooked by the inspector could be alleviated. The results of evaluation using stroboscopic shearography showed that an artificial 20 mm-diameter defect could be visualized at the excitation frequencies of 5-8 kHz range and 12.5-15.5 kHz range. This technique provided full field reliable and repeatable inspection results. Additionally, the proposed method overcame the important drawback of the time-averaged shearography, being required to identify the resonance vibration frequency sensitive to the defect.

The classification of phocomelia.

PubMed

Tytherleigh-Strong, G; Hooper, G

2003-06-01

We studied 24 patients with 44 phocomelic upper limbs. Only 11 limbs could be grouped in the classification system of Frantz and O' Rahilly. The non-classifiable limbs were further studied and their characteristics identified. It is confirmed that phocomelia is not an intercalary defect.

A Novel Active Imaging Model to Design Visual Systems: A Case of Inspection System for Specular Surfaces

PubMed Central

Azorin-Lopez, Jorge; Fuster-Guillo, Andres; Saval-Calvo, Marcelo; Mora-Mora, Higinio; Garcia-Chamizo, Juan Manuel

2017-01-01

The use of visual information is a very well known input from different kinds of sensors. However, most of the perception problems are individually modeled and tackled. It is necessary to provide a general imaging model that allows us to parametrize different input systems as well as their problems and possible solutions. In this paper, we present an active vision model considering the imaging system as a whole (including camera, lighting system, object to be perceived) in order to propose solutions to automated visual systems that present problems that we perceive. As a concrete case study, we instantiate the model in a real application and still challenging problem: automated visual inspection. It is one of the most used quality control systems to detect defects on manufactured objects. However, it presents problems for specular products. We model these perception problems taking into account environmental conditions and camera parameters that allow a system to properly perceive the specific object characteristics to determine defects on surfaces. The validation of the model has been carried out using simulations providing an efficient way to perform a large set of tests (different environment conditions and camera parameters) as a previous step of experimentation in real manufacturing environments, which more complex in terms of instrumentation and more expensive. Results prove the success of the model application adjusting scale, viewpoint and lighting conditions to detect structural and color defects on specular surfaces. PMID:28640211

Multifocal blue-on-yellow visual evoked potentials in early glaucoma.

PubMed

Klistorner, Alexander; Graham, Stuart L; Martins, Alessandra; Grigg, John R; Arvind, Hemamalini; Kumar, Rajesh S; James, Andrew C; Billson, Francis A

2007-09-01

To determine the sensitivity and specificity of blue-on-yellow multifocal visual evoked potentials (mfVEPs) in early glaucoma. Cross-sectional study. Fifty patients with a confirmed diagnosis of early glaucoma and 60 normal participants. Black-and-white mfVEPs and blue-on-yellow mfVEPs were recorded using the Accumap version 2.0 (ObjectiVision Pty. Ltd., Sydney, Australia). All patients also underwent achromatic standard automated perimetry (SAP). Multifocal VEP amplitude and latency values in glaucoma patients were analyzed and compared with those of the normal controls. Based on the definition of visual field defect, in the group of glaucomatous eyes with SAP defects, amplitude of blue-on-yellow mfVEP was abnormal in all 64 cases (100% sensitivity), whereas black-and-white mfVEP missed 5 cases (92.2% sensitivity). Generally, larger scotomata were noted on blue-on-yellow mfVEP compared with black-and-white mfVEP for the same eyes. There was high topographic correspondence between SAP and amplitude of blue-on-yellow mfVEP and significant (P<0.0001) correlation between them (correlation coefficient, 0.73). Abnormal amplitude was detected in 3 of 60 eyes of control subjects (95% specificity). There was, however, no correlation between visual field defect and latency delay in glaucoma patients. Although there was a significant difference between averaged latency of control and glaucoma eyes, values considerably overlapped. The blue-on-yellow mfVEP is a sensitive and specific tool for detecting early glaucoma based on amplitude analysis.

Normal versus High Tension Glaucoma: A Comparison of Functional and Structural Defects

PubMed Central

Thonginnetra, Oraorn; Greenstein, Vivienne C.; Chu, David; Liebmann, Jeffrey M.; Ritch, Robert; Hood, Donald C.

2009-01-01

Purpose To compare visual field defects obtained with both multifocal visual evoked potential (mfVEP) and Humphrey visual field (HVF) techniques to topographic optic disc measurements in patients with normal tension glaucoma (NTG) and high tension glaucoma (HTG). Methods We studied 32 patients with NTG and 32 with HTG. All patients had reliable 24-2 HVFs with a mean deviation (MD) of −10 dB or better, a glaucomatous optic disc and an abnormal HVF in at least one eye. Multifocal VEPs were obtained from each eye and probability plots created. The mfVEP and HVF probability plots were divided into a central 10-degree (radius) and an outer arcuate subfield in both superior and inferior hemifields. Cluster analyses and counts of abnormal points were performed in each subfield. Optic disc images were obtained with the Heidelberg Retina Tomograph III (HRT III). Eleven stereometric parameters were calculated. Moorfields regression analysis (MRA) and the glaucoma probability score (GPS) were performed. Results There were no significant differences in MD and PSD values between NTG and HTG eyes. However, NTG eyes had a higher percentage of abnormal test points and clusters of abnormal points in the central subfields on both mfVEP and HVF than HTG eyes. For HRT III, there were no significant differences in the 11 stereometric parameters or in the MRA and GPS analyses of the optic disc images. Conclusions The visual field data suggest more localized and central defects for NTG than HTG. PMID:19223786

Comparison of clinical features and 3-month treatment response among three different choroidal thickness groups in polypoidal choroidal vasculopathy.

PubMed

Kong, Mingui; Kim, Sung Min; Ham, Don-Il

2017-01-01

Eyes with polypoidal choroidal vasculopathy (PCV) were recently reported to have various choroidal thickness, and choroidal thickness might be associated with visual outcome in the treatment of many retinal disorders. The range of subfoveal choroidal thickness (SFCT), clinical features, and 3-month treatment response among three groups having different range of SFCT were investigated in PCV eyes. In 78 treatment-naïve eyes with PCV, SFCT was measured using optical coherence tomography. Eyes were classified into thin, medium, and thick groups, using mean and one standard deviation of SFCT. Clinical features and imaging findings were compared among the three groups. Some eyes were treated with three consecutive monthly injection of anti-vascular endothelial growth factor (VEGF) as an initial treatment. They were also classified into three thickness groups, and the short-term post-treatment improvement in visual acuity and central retinal thickness were compared among groups. The mean SFCT was 271.9 ± 135.6 μm. Twelve, 53, and 13 eyes were classified into thin (<136.3 μm), medium (136.3-407.5 μm), and thick (>407.5 μm) groups, respectively. The thin group showed older age, lower visual acuity, and a higher prevalence of fundus tessellation than the other two groups (P <0.05). In multiple linear regression analyses, baseline BCVA was correlated with baseline SFCT. Forty-six eyes completed three consecutive anti-VEGF treatments. The thin group showed no visual improvement after treatment (P = 0.141), unlike the other two groups showing visual improvement (P<0.05). Eyes with PCV have a broad range of SFCT, and PCV eyes with a thin choroid manifest worse visual function than eyes with a medium or thick choroid.

Bag-of-features based medical image retrieval via multiple assignment and visual words weighting.

PubMed

Wang, Jingyan; Li, Yongping; Zhang, Ying; Wang, Chao; Xie, Honglan; Chen, Guoling; Gao, Xin

2011-11-01

Bag-of-features based approaches have become prominent for image retrieval and image classification tasks in the past decade. Such methods represent an image as a collection of local features, such as image patches and key points with scale invariant feature transform (SIFT) descriptors. To improve the bag-of-features methods, we first model the assignments of local descriptors as contribution functions, and then propose a novel multiple assignment strategy. Assuming the local features can be reconstructed by their neighboring visual words in a vocabulary, reconstruction weights can be solved by quadratic programming. The weights are then used to build contribution functions, resulting in a novel assignment method, called quadratic programming (QP) assignment. We further propose a novel visual word weighting method. The discriminative power of each visual word is analyzed by the sub-similarity function in the bin that corresponds to the visual word. Each sub-similarity function is then treated as a weak classifier. A strong classifier is learned by boosting methods that combine those weak classifiers. The weighting factors of the visual words are learned accordingly. We evaluate the proposed methods on medical image retrieval tasks. The methods are tested on three well-known data sets, i.e., the ImageCLEFmed data set, the 304 CT Set, and the basal-cell carcinoma image set. Experimental results demonstrate that the proposed QP assignment outperforms the traditional nearest neighbor assignment, the multiple assignment, and the soft assignment, whereas the proposed boosting based weighting strategy outperforms the state-of-the-art weighting methods, such as the term frequency weights and the term frequency-inverse document frequency weights.

Effect of Ginkgo biloba on visual field and contrast sensitivity in Chinese patients with normal tension glaucoma: a randomized, crossover clinical trial.

PubMed

Guo, Xinxing; Kong, Xiangbin; Huang, Rui; Jin, Ling; Ding, Xiaohu; He, Mingguang; Liu, Xing; Patel, Mehul Chimanlal; Congdon, Nathan G

2014-01-07

We evaluated the effect of ginkgo biloba extract on visual field defect and contrast sensitivity in a Chinese cohort with normal tension glaucoma. In this prospective, randomized, placebo-controlled crossover study, patients newly diagnosed with normal tension glaucoma, either in a tertiary glaucoma clinic (n = 5) or in a cohort undergoing routine general physical examinations in a primary care clinic (n = 30), underwent two 4-week phases of treatment, separated by a washout period of 8 weeks. Randomization determined whether ginkgo biloba extract (40 mg, 3 times per day) or placebo (identical-appearing tablets) was received first. Primary outcomes were change in contrast sensitivity and mean deviation on 24-2 SITA standard visual field testing, while secondary outcomes included IOP and self-reported adverse events. A total of 35 patients with mean age 63.7 (6.5) years were randomized to the ginkgo biloba extract-placebo (n = 18) or the placebo-ginkgo biloba extract (n = 17) sequence. A total of 28 patients (80.0%, 14 in each group) who completed testing did not differ at baseline in age, sex, visual field mean deviation, contrast sensitivity, IOP, or blood pressure. Changes in visual field and contrast sensitivity did not differ by treatment received or sequence (P > 0.2 for all). Power to have detected a difference in mean defect as large as previously reported was 80%. In contrast to some previous reports, ginkgo biloba extract treatment had no effect on mean defect or contrast sensitivity in this group of normal tension glaucoma patients. (http://www.chictr.org number, ChiCTR-TRC-08000724).

Transcriptome Profiling Identifies Multiplexin as a Target of SAGA Deubiquitinase Activity in Glia Required for Precise Axon Guidance During Drosophila Visual Development.

PubMed

Ma, Jingqun; Brennan, Kaelan J; D'Aloia, Mitch R; Pascuzzi, Pete E; Weake, Vikki M

2016-08-09

The Spt-Ada-Gcn5 Acetyltransferase (SAGA) complex is a transcriptional coactivator with histone acetylase and deubiquitinase activities that plays an important role in visual development and function. In Drosophila melanogaster, four SAGA subunits are required for the deubiquitination of monoubiquitinated histone H2B (ubH2B): Nonstop, Sgf11, E(y)2, and Ataxin 7. Mutations that disrupt SAGA deubiquitinase activity cause defects in neuronal connectivity in the developing Drosophila visual system. In addition, mutations in SAGA result in the human progressive visual disorder spinocerebellar ataxia type 7 (SCA7). Glial cells play a crucial role in both the neuronal connectivity defect in nonstop and sgf11 flies, and in the retinal degeneration observed in SCA7 patients. Thus, we sought to identify the gene targets of SAGA deubiquitinase activity in glia in the Drosophila larval central nervous system. To do this, we enriched glia from wild-type, nonstop, and sgf11 larval optic lobes using affinity-purification of KASH-GFP tagged nuclei, and then examined each transcriptome using RNA-seq. Our analysis showed that SAGA deubiquitinase activity is required for proper expression of 16% of actively transcribed genes in glia, especially genes involved in proteasome function, protein folding and axon guidance. We further show that the SAGA deubiquitinase-activated gene Multiplexin (Mp) is required in glia for proper photoreceptor axon targeting. Mutations in the human ortholog of Mp, COL18A1, have been identified in a family with a SCA7-like progressive visual disorder, suggesting that defects in the expression of this gene in SCA7 patients could play a role in the retinal degeneration that is unique to this ataxia. Copyright © 2016 Ma et al.

In Situ Strength Model for Continuous Fibers and Multi-Scale Modeling the Fracture of C/SiC Composites

NASA Astrophysics Data System (ADS)

Zhang, Sheng; Gao, Xiguang; Song, Yingdong

2018-04-01

A new in situ strength model of carbon fibers was developed based on the distribution of defects to predict the stress-strain response and the strength of C/SiC composites. Different levels of defects in the fibers were considered in this model. The defects in the fibers were classified by their effects on the strength of the fiber. The strength of each defect and the probability that the defect appears were obtained from the tensile test of single fibers. The strength model of carbon fibers was combined with the shear-lag model to predict the stress-strain responses and the strengths of fiber bundles and C/SiC minicomposites. To verify the strength model, tensile tests were performed on fiber bundles and C/SiC minicomposites. The predicted and experimental results were in good agreement. Effects of the fiber length, the fiber number and the heat treatment on the final strengths of fiber bundles and C/SiC minicomposites were also discussed.

Comparison of matrix frequency-doubling technology perimetry and standard automated perimetry in monitoring the development of visual field defects for glaucoma suspect eyes.

PubMed

Hu, Rongrong; Wang, Chenkun; Racette, Lyne

2017-01-01

Perimetry is indispensable for the clinical management of glaucoma suspects. Our goal is to compare the performance of standard automated perimetry (SAP) and Matrix frequency-doubling technology (FDT) perimetry in monitoring the development of visual field (VF) defects in glaucoma suspect eyes. Longitudinal data of paired SAP and FDT from 221 eyes of 155 glaucoma suspects enrolled in the Diagnostic Innovations in Glaucoma Study or the African Descent and Glaucoma Evaluation Study were included. All eyes had glaucomatous optic neuropathy or ocular hypertension, but normal SAP and FDT results at baseline. The development of glaucomatous VF defects was defined as the presence of a cluster of ≥ 3 (less conservative) or ≥ 4 (more conservative) locations confirmed on ≥ 2 additional consecutive tests. Risk factors for the development of VF defects were analyzed by COX proportional hazard models. After conversion into common logarithmic units, the rates of change of global VF indices were fitted with linear mixed models. FDT detected more eyes that developed VF defects than SAP using the less conservative criterion, and no significant difference was observed using the more conservative criterion. For those eyes detected by both SAP and FDT, FDT detected the development of VF defects either earlier than SAP or simultaneously in most cases. Baseline structural measurements were not significantly associated with an increased risk for the development of glaucomatous VF defects on either SAP or FDT. Older age was significantly associated with the development of VF defects on FDT but not on SAP. Both SAP and FDT detected a progressing worsening trend of pattern standard deviation over time with a similar rate of change between these test types. Matrix FDT would be useful to monitor the onset of VF defects in glaucoma suspects and may outperform SAP in the early stage of glaucomatous VF damage.

In-TFT-Array-Process Micro Defect Inspection Using Nonlinear Principal Component Analysis

PubMed Central

Liu, Yi-Hung; Wang, Chi-Kai; Ting, Yung; Lin, Wei-Zhi; Kang, Zhi-Hao; Chen, Ching-Shun; Hwang, Jih-Shang

2009-01-01

Defect inspection plays a critical role in thin film transistor liquid crystal display (TFT-LCD) manufacture, and has received much attention in the field of automatic optical inspection (AOI). Previously, most focus was put on the problems of macro-scale Mura-defect detection in cell process, but it has recently been found that the defects which substantially influence the yield rate of LCD panels are actually those in the TFT array process, which is the first process in TFT-LCD manufacturing. Defect inspection in TFT array process is therefore considered a difficult task. This paper presents a novel inspection scheme based on kernel principal component analysis (KPCA) algorithm, which is a nonlinear version of the well-known PCA algorithm. The inspection scheme can not only detect the defects from the images captured from the surface of LCD panels, but also recognize the types of the detected defects automatically. Results, based on real images provided by a LCD manufacturer in Taiwan, indicate that the KPCA-based defect inspection scheme is able to achieve a defect detection rate of over 99% and a high defect classification rate of over 96% when the imbalanced support vector machine (ISVM) with 2-norm soft margin is employed as the classifier. More importantly, the inspection time is less than 1 s per input image. PMID:20057957

Educational Attainment of 10-Year-Old Children with Treated and Untreated Visual Defects.

ERIC Educational Resources Information Center

Stewart-Brown, Sarah; And Others

1985-01-01

Children with visual impairments who participated in a 10-year survey were compared with peers on measures of intelligence, reading, mathematics, and sporting ability. Results are consistent with earlier findings of increased intelligence among Ss with myopia and slightly reduced intelligence among Ss with amblyopia. It was concluded that the…

[New developments in 2005 for the management of visual deficit in the infant].

PubMed

Bursztyn, J

2005-03-01

The main progress in ophthalmopediatrics is the knowledge of the importance and efficacy of visual refraction defects screening. This screening has to be the earliest possible, allowing a glass equipment preventing complications: amblyopia, strabismus. This screening allows the same time screening of organic anomalies and early treatment.

Long-term abstinent alcoholics have normal memory.

PubMed

Reed, R J; Grant, I; Rourke, S B

1992-08-01

It is generally believed that many non-Korsakoff alcoholics have subtle defects in memory. To determine whether such defects vary as a function of length of abstinence (LOA), we performed extensive memory testing with: (1) recently detoxified (n = 31; LOA-29 days); (2) intermediate-term abstinent (n = 28; LOA = 1.9 years); (3) long-term abstinent (n = 32; LOA-7.0 years) alcoholics; and (4) nonalcoholic controls (n = 37). All subjects were matched on age and education. Alcoholics were matched on years of alcoholic drinking. Memory measures were divided into the following domains: verbal learning, verbal recall, visual learning, visual recall, and paired associate learning. A series of MANOVAs were conducted that revealed a significant relationship between visual learning and length of abstinence, and a significant interaction between age and length of abstinence on visual recall. Long-term abstinent subjects were not significantly different from controls on any test. We conclude that memory disturbance demonstrable among recently detoxified alcoholics in the early weeks of their abstinence is not evident in demographically matched long-term abstinent alcoholics with similar drinking histories.

Current concepts in the diagnosis, pathogenesis and management of nonarteritic anterior ischaemic optic neuropathy.

PubMed

Miller, N R; Arnold, A C

2015-01-01

Nonarteritic anterior ischaemic optic neuropathy (NAION) is the most common acute optic neuropathy in patients over the age of 50 and is the second most common cause of permanent optic nerve-related visual loss in adults after glaucoma. Patients typically present with acute, painless, unilateral loss of vision associated with a variable visual field defect, a relative afferent pupillary defect, a swollen, hyperaemic optic disc, and one or more flame-shaped peripapillary retinal haemorrhages. The pathogenesis of this condition is unknown, but it occurs primarily in patients with structurally small optic discs that have little or no cup and a variety of underlying vascular disorders that may or may not be known at the time of visual loss. There is no consistently beneficial medical or surgical treatment for the condition, but there are now animal models that allow testing of various potential therapies. About 40% of patients experience spontaneous improvement in visual acuity. Patients in whom NAION occurs in one eye have a 15-19% risk of developing a similar event in the opposite eye over the subsequent 5 years.

Current concepts in the diagnosis, pathogenesis and management of nonarteritic anterior ischaemic optic neuropathy

PubMed Central

Miller, N R; Arnold, A C

2015-01-01

Nonarteritic anterior ischaemic optic neuropathy (NAION) is the most common acute optic neuropathy in patients over the age of 50 and is the second most common cause of permanent optic nerve-related visual loss in adults after glaucoma. Patients typically present with acute, painless, unilateral loss of vision associated with a variable visual field defect, a relative afferent pupillary defect, a swollen, hyperaemic optic disc, and one or more flame-shaped peripapillary retinal haemorrhages. The pathogenesis of this condition is unknown, but it occurs primarily in patients with structurally small optic discs that have little or no cup and a variety of underlying vascular disorders that may or may not be known at the time of visual loss. There is no consistently beneficial medical or surgical treatment for the condition, but there are now animal models that allow testing of various potential therapies. About 40% of patients experience spontaneous improvement in visual acuity. Patients in whom NAION occurs in one eye have a 15–19% risk of developing a similar event in the opposite eye over the subsequent 5 years. PMID:24993324

Charles Bonnet syndrome in hemianopia, following antero-mesial temporal lobectomy for drug-resistant epilepsy.

PubMed

Contardi, Sara; Rubboli, Guido; Giulioni, Marco; Michelucci, Roberto; Pizza, Fabio; Gardella, Elena; Pinardi, Federica; Bartolomei, Ilaria; Tassinari, Carlo Alberto

2007-09-01

Charles Bonnet syndrome (CBS) is a disorder characterized by the occurrence of complex visual hallucinations in patients with acquired impairment of vision and without psychiatric disorders. In spite of the high incidence of visual field defects following antero-mesial temporal lobectomy for refractory temporal lobe epilepsy, reports of CBS in patients who underwent this surgical procedure are surprisingly rare. We describe a patient operated on for drug-resistant epilepsy. As a result of left antero-mesial temporal resection, she presented right homonymous hemianopia. A few days after surgery, she started complaining of visual hallucinations, such as static or moving "Lilliputian" human figures, or countryside scenes, restricted to the hemianopic field. The patient was fully aware of their fictitious nature. These disturbances disappeared progressively over a few weeks. The incidence of CBS associated with visual field defects following epilepsy surgery might be underestimated. Patients with post-surgical CBS should be reassured that it is not an epileptic phenomenon, and that it has a benign, self-limiting, course which does not usually require treatment.

Making Choices in Functional Vision Evaluations: "Noodles, Needles, and Haystacks."

ERIC Educational Resources Information Center

Bishop, V. E.

1988-01-01

An approach to functional vision evaluations clarifies the types of data collection and suggests protocols for three broad categories of visually handicapped children: "normal" school-age students, "normal" preschoolers, and multiply handicapped pupils. Visually impaired infants are classified with multiply handicapped pupils…

Cross-Modal Decoding of Neural Patterns Associated with Working Memory: Evidence for Attention-Based Accounts of Working Memory.

PubMed

Majerus, Steve; Cowan, Nelson; Péters, Frédéric; Van Calster, Laurens; Phillips, Christophe; Schrouff, Jessica

2016-01-01

Recent studies suggest common neural substrates involved in verbal and visual working memory (WM), interpreted as reflecting shared attention-based, short-term retention mechanisms. We used a machine-learning approach to determine more directly the extent to which common neural patterns characterize retention in verbal WM and visual WM. Verbal WM was assessed via a standard delayed probe recognition task for letter sequences of variable length. Visual WM was assessed via a visual array WM task involving the maintenance of variable amounts of visual information in the focus of attention. We trained a classifier to distinguish neural activation patterns associated with high- and low-visual WM load and tested the ability of this classifier to predict verbal WM load (high-low) from their associated neural activation patterns, and vice versa. We observed significant between-task prediction of load effects during WM maintenance, in posterior parietal and superior frontal regions of the dorsal attention network; in contrast, between-task prediction in sensory processing cortices was restricted to the encoding stage. Furthermore, between-task prediction of load effects was strongest in those participants presenting the highest capacity for the visual WM task. This study provides novel evidence for common, attention-based neural patterns supporting verbal and visual WM. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Paternal occupation and birth defects: findings from the National Birth Defects Prevention Study.

PubMed

Desrosiers, Tania A; Herring, Amy H; Shapira, Stuart K; Hooiveld, Mariëtte; Luben, Tom J; Herdt-Losavio, Michele L; Lin, Shao; Olshan, Andrew F

2012-08-01

Several epidemiological studies have suggested that certain paternal occupations may be associated with an increased prevalence of birth defects in offspring. Using data from the National Birth Defects Prevention Study, the authors investigated the association between paternal occupation and birth defects in a case-control study of cases comprising over 60 different types of birth defects (n=9998) and non-malformed controls (n=4066) with dates of delivery between 1997 and 2004. Using paternal occupational histories reported by mothers via telephone interview, jobs were systematically classified into 63 groups based on shared exposure profiles within occupation and industry. Data were analysed using bayesian logistic regression with a hierarchical prior for dependent shrinkage to stabilise estimation with sparse data. Several occupations were associated with an increased prevalence of various birth defect categories, including mathematical, physical and computer scientists; artists; photographers and photo processors; food service workers; landscapers and groundskeepers; hairdressers and cosmetologists; office and administrative support workers; sawmill workers; petroleum and gas workers; chemical workers; printers; material moving equipment operators; and motor vehicle operators. Findings from this study might be used to identify specific occupations worthy of further investigation and to generate hypotheses about chemical or physical exposures common to such occupations.

Optical Coherence Tomography Machine Learning Classifiers for Glaucoma Detection: A Preliminary Study

PubMed Central

Burgansky-Eliash, Zvia; Wollstein, Gadi; Chu, Tianjiao; Ramsey, Joseph D.; Glymour, Clark; Noecker, Robert J.; Ishikawa, Hiroshi; Schuman, Joel S.

2007-01-01

Purpose Machine-learning classifiers are trained computerized systems with the ability to detect the relationship between multiple input parameters and a diagnosis. The present study investigated whether the use of machine-learning classifiers improves optical coherence tomography (OCT) glaucoma detection. Methods Forty-seven patients with glaucoma (47 eyes) and 42 healthy subjects (42 eyes) were included in this cross-sectional study. Of the glaucoma patients, 27 had early disease (visual field mean deviation [MD] ≥ −6 dB) and 20 had advanced glaucoma (MD < −6 dB). Machine-learning classifiers were trained to discriminate between glaucomatous and healthy eyes using parameters derived from OCT output. The classifiers were trained with all 38 parameters as well as with only 8 parameters that correlated best with the visual field MD. Five classifiers were tested: linear discriminant analysis, support vector machine, recursive partitioning and regression tree, generalized linear model, and generalized additive model. For the last two classifiers, a backward feature selection was used to find the minimal number of parameters that resulted in the best and most simple prediction. The cross-validated receiver operating characteristic (ROC) curve and accuracies were calculated. Results The largest area under the ROC curve (AROC) for glaucoma detection was achieved with the support vector machine using eight parameters (0.981). The sensitivity at 80% and 95% specificity was 97.9% and 92.5%, respectively. This classifier also performed best when judged by cross-validated accuracy (0.966). The best classification between early glaucoma and advanced glaucoma was obtained with the generalized additive model using only three parameters (AROC = 0.854). Conclusions Automated machine classifiers of OCT data might be useful for enhancing the utility of this technology for detecting glaucomatous abnormality. PMID:16249492

Visual Field Function in School-Aged Children with Spastic Unilateral Cerebral Palsy Related to Different Patterns of Brain Damage

ERIC Educational Resources Information Center

Jacobson, Lena; Rydberg, Agneta; Eliasson, Ann-Christin; Kits, Annika; Flodmark, Olof

2010-01-01

Aim: To relate visual field function to brain morphology in children with unilateral cerebral palsy (CP). Method: Visual field function was assessed using the confrontation technique and Goldmann perimetry in 29 children (15 males, 14 females; age range 7-17y, median age 11y) with unilateral CP classified at Gross Motor Function Classification…

The Relationship between Walk Distance and Muscle Strength, Muscle Pain in Visually Disabled People

ERIC Educational Resources Information Center

Akyol, Betül

2018-01-01

The purpose of this study is to examine the relationship between six-minute walk test and muscle pain, muscle strength in visually disabled people. The study includes 50 visually disabled people, aged between 17, 21 ± 5,3. Participants were classified into three categories according to their degree of vision (B1, B2, B3). All participants were…

Topologically Allowed Nonsixfold Vortices in a Sixfold Multiferroic Material: Observation and Classification

DOE PAGES

Cheng, Shaobo; Li, Jun; Han, Myung-Geun; ...

2017-04-05

Here, we report structural transformation of sixfold vortex domains into two-, four-, and eightfold vortices via a different type of topological defect in hexagonal manganites. Combining high-resolution electron microscopy and Landau-theory-based numerical simulations, we also investigate the remarkable atomic arrangement and the intertwined relationship between the vortex structures and the topological defects. The roles of their displacement field, formation temperature, and nucleation sites are revealed. All conceivable vortices in the system are topologically classified using homotopy group theory, and their origins are identified.

Usefulness of myocardial parametric imaging to evaluate myocardial viability in experimental and in clinical studies

PubMed Central

Korosoglou, G; Hansen, A; Bekeredjian, R; Filusch, A; Hardt, S; Wolf, D; Schellberg, D; Katus, H A; Kuecherer, H

2006-01-01

Objective To evaluate whether myocardial parametric imaging (MPI) is superior to visual assessment for the evaluation of myocardial viability. Methods and results Myocardial contrast echocardiography (MCE) was assessed in 11 pigs before, during, and after left anterior descending coronary artery occlusion and in 32 patients with ischaemic heart disease by using intravenous SonoVue administration. In experimental studies perfusion defect area assessment by MPI was compared with visually guided perfusion defect planimetry. Histological assessment of necrotic tissue was the standard reference. In clinical studies viability was assessed on a segmental level by (1) visual analysis of myocardial opacification; (2) quantitative estimation of myocardial blood flow in regions of interest; and (3) MPI. Functional recovery between three and six months after revascularisation was the standard reference. In experimental studies, compared with visually guided perfusion defect planimetry, planimetric assessment of infarct size by MPI correlated more significantly with histology (r2  =  0.92 versus r2  =  0.56) and had a lower intraobserver variability (4% v 15%, p < 0.05). In clinical studies, MPI had higher specificity (66% v 43%, p < 0.05) than visual MCE and good accuracy (81%) for viability detection. It was less time consuming (3.4 (1.6) v 9.2 (2.4) minutes per image, p < 0.05) than quantitative blood flow estimation by regions of interest and increased the agreement between observers interpreting myocardial perfusion (κ  =  0.87 v κ  =  0.75, p < 0.05). Conclusion MPI is useful for the evaluation of myocardial viability both in animals and in patients. It is less time consuming than quantification analysis by regions of interest and less observer dependent than visual analysis. Thus, strategies incorporating this technique may be valuable for the evaluation of myocardial viability in clinical routine. PMID:15939722

Deep Defects Seen on Visual Fields Spatially Correspond Well to Loss of Retinal Nerve Fiber Layer Seen on Circumpapillary OCT Scans.

PubMed

Mavrommatis, Maria A; Wu, Zhichao; Naegele, Saskia I; Nunez, Jason; De Moraes, Carlos; Ritch, Robert; Hood, Donald C

2018-02-01

To examine the structure-function relationship in glaucoma between deep defects on visual fields (VF) and deep losses in the circumpapillary retinal nerve fiber layer (cpRNFL) on optical coherence tomography (OCT) circle scans. Thirty two glaucomatous eyes with deep VF defects, as defined by at least one test location worse than ≤ -15 dB on the 10-2 and/or 24-2 VF pattern deviation (PD) plots, were included from 87 eyes with "early" glaucoma (i.e., 24-2 mean deviation better than -6 dB). Using the location of the deep VF points and a schematic model, the location of local damage on an OCT circle scan was predicted. The thinnest location of cpRNFL (i.e., deepest loss) was also determined. In 19 of 32 eyes, a region of complete or near complete cpRNFL loss was observed. All 19 of these had deep VF defects on the 24-2 and/or 10-2. All of the 32 eyes with deep VF defects had abnormal cpRNFL regions (red, 1%) and all but 2 had a region of cpRNFL thickness <21 μm. The midpoint of the VF defect and the location of deepest cpRNFL had a 95% limit of agreement within approximately two-thirds of a clock-hour (or 30°) sector (between -22.1° to 25.2°). Individual fovea-to-disc angle (FtoDa) adjustment improved agreement in one eye with an extreme FtoDa. Although studies relating local structural (OCT) and functional (VF) measures typically show poor to moderate correlations, there is good qualitative agreement between the location of deep cpRNFL loss and deep defects on VFs.

Decoding grating orientation from microelectrode array recordings in monkey cortical area V4.

PubMed

Manyakov, Nikolay V; Van Hulle, Marc M

2010-04-01

We propose an invasive brain-machine interface (BMI) that decodes the orientation of a visual grating from spike train recordings made with a 96 microelectrodes array chronically implanted into the prelunate gyrus (area V4) of a rhesus monkey. The orientation is decoded irrespective of the grating's spatial frequency. Since pyramidal cells are less prominent in visual areas, compared to (pre)motor areas, the recordings contain spikes with smaller amplitudes, compared to the noise level. Hence, rather than performing spike decoding, feature selection algorithms are applied to extract the required information for the decoder. Two types of feature selection procedures are compared, filter and wrapper. The wrapper is combined with a linear discriminant analysis classifier, and the filter is followed by a radial-basis function support vector machine classifier. In addition, since we have a multiclass classification problen, different methods for combining pairwise classifiers are compared.

Detecting Strengths and Weaknesses in Learning Mathematics through a Model Classifying Mathematical Skills

ERIC Educational Resources Information Center

Karagiannakis, Giannis N.; Baccaglini-Frank, Anna E.; Roussos, Petros

2016-01-01

Through a review of the literature on mathematical learning disabilities (MLD) and low achievement in mathematics (LA) we have proposed a model classifying mathematical skills involved in learning mathematics into four domains (Core number, Memory, Reasoning, and Visual-spatial). In this paper we present a new experimental computer-based battery…

Identification and prioritization of rail squat defects in the field using rail magnetisation technology

NASA Astrophysics Data System (ADS)

Kaewunruen, Sakdirat

2015-04-01

Inevitably, rail squats and studs are continuing to be a serious problem for railway organisations around the world in the 21st century. They are typically classified as the growth of any cracks that have grown longitudinally through the subsurface and some of the cracks propagating to the bottom of rails transversely, and have branched from initial longitudinal cracks with a depression of rail surface. The horizontal crack, which results in a depression of rail surface, induces increased maintenance level, more frequent monitoring, compromised rail testing (as the crack shields the signal echoes), and possible broken rails. This paper presents field investigations using a magnetised-rail testing device developed by MRX Technologies to identify and prioritise the rail squats. Most of the in situ squats were found on the high rail of the transition (variable-radius curved track), which is associated with rolling contact fatigue (RCF). This investigation highlights the field performance of the MRX's surface crack detection technology in comparison with the traditional ultrasonic method and detailed walking inspection. Visually, it was found in the field that the size of the RCF squats varies from very small to moderate. The predicted crack data were obtained by scanning the magnitised rails. The comparison of the actual crack depths (ultrasonic) and the predicted crack depths (MRX device) shows: • A possible correlation for small RCF/ squat cracks. • Poor interpretation of larger defects and welds. The field assessment also suggests some practical issues required for further development, including the detection of rail spalling, deep transverse crack, welding, and so on.

An open-architecture approach to defect analysis software for mask inspection systems

NASA Astrophysics Data System (ADS)

Pereira, Mark; Pai, Ravi R.; Reddy, Murali Mohan; Krishna, Ravi M.

2009-04-01

Industry data suggests that Mask Inspection represents the second biggest component of Mask Cost and Mask Turn Around Time (TAT). Ever decreasing defect size targets lead to more sensitive mask inspection across the chip, thus generating too many defects. Hence, more operator time is being spent in analyzing and disposition of defects. Also, the fact that multiple Mask Inspection Systems and Defect Analysis strategies would typically be in use in a Mask Shop or a Wafer Foundry further complicates the situation. In this scenario, there is a need for a versatile, user friendly and extensible Defect Analysis software that reduces operator analysis time and enables correct classification and disposition of mask defects by providing intuitive visual and analysis aids. We propose a new vendor-neutral defect analysis software, NxDAT, based on an open architecture. The open architecture of NxDAT makes it easily extensible to support defect analysis for mask inspection systems from different vendors. The capability to load results from mask inspection systems from different vendors either directly or through a common interface enables the functionality of establishing correlation between inspections carried out by mask inspection systems from different vendors. This capability of NxDAT enhances the effectiveness of defect analysis as it directly addresses the real-life scenario where multiple types of mask inspection systems from different vendors co-exist in mask shops or wafer foundries. The open architecture also potentially enables loading wafer inspection results as well as loading data from other related tools such as Review Tools, Repair Tools, CD-SEM tools etc, and correlating them with the corresponding mask inspection results. A unique concept of Plug-In interface to NxDAT further enhances the openness of the architecture of NxDAT by enabling end-users to add their own proprietary defect analysis and image processing algorithms. The plug-in interface makes it possible for the end-users to make use of their collected knowledge through the years of experience in mask inspection process by encapsulating the knowledge into software utilities and plugging them into NxDAT. The plug-in interface is designed with the intent of enabling the pro-active mask defect analysis teams to build competitive differentiation into their defect analysis process while protecting their knowledge internally within their company. By providing interface with all major standard layout and mask data formats, NxDAT enables correlation of defect data on reticles with design and mask databases, further extending the effectiveness of defect analysis for D2DB inspection. NxDAT also includes many other advanced features for easy and fast navigation, visual display of defects, defect selection, multi-tier classification, defect clustering and gridding, sophisticated CD and contact measurement analysis, repeatability analysis such as adder analysis, defect trend, capture rate etc.

Characterization and manipulation of individual defects in insulating hexagonal boron nitride using scanning tunnelling microscopy.

PubMed

Wong, Dillon; Velasco, Jairo; Ju, Long; Lee, Juwon; Kahn, Salman; Tsai, Hsin-Zon; Germany, Chad; Taniguchi, Takashi; Watanabe, Kenji; Zettl, Alex; Wang, Feng; Crommie, Michael F

2015-11-01

Defects play a key role in determining the properties and technological applications of nanoscale materials and, because they tend to be highly localized, characterizing them at the single-defect level is of particular importance. Scanning tunnelling microscopy has long been used to image the electronic structure of individual point defects in conductors, semiconductors and ultrathin films, but such single-defect electronic characterization remains an elusive goal for intrinsic bulk insulators. Here, we show that individual native defects in an intrinsic bulk hexagonal boron nitride insulator can be characterized and manipulated using a scanning tunnelling microscope. This would typically be impossible due to the lack of a conducting drain path for electrical current. We overcome this problem by using a graphene/boron nitride heterostructure, which exploits the atomically thin nature of graphene to allow the visualization of defect phenomena in the underlying bulk boron nitride. We observe three different defect structures that we attribute to defects within the bulk insulating boron nitride. Using scanning tunnelling spectroscopy we obtain charge and energy-level information for these boron nitride defect structures. We also show that it is possible to manipulate the defects through voltage pulses applied to the scanning tunnelling microscope tip.

The identification of van Hiele level students on the topic of space analytic geometry

NASA Astrophysics Data System (ADS)

Yudianto, E.; Sunardi; Sugiarti, T.; Susanto; Suharto; Trapsilasiwi, D.

2018-03-01

Geometry topics are still considered difficult by most students. Therefore, this study focused on the identification of students related to van Hiele levels. The task used from result of the development of questions related to analytical geometry of space. The results of the work involving 78 students who worked on these questions covered 11.54% (nine students) classified on a visual level; 5.13% (four students) on analysis level; 1.28% (one student) on informal deduction level; 2.56% (two students) on deduction and 2.56% (two students) on rigor level, and 76.93% (sixty students) classified on the pre-visualization level.

Multiple-object tracking as a tool for parametrically modulating memory reactivation

PubMed Central

Poppenk, J.; Norman, K.A.

2017-01-01

Converging evidence supports the “non-monotonic plasticity” hypothesis that although complete retrieval may strengthen memories, partial retrieval weakens them. Yet, the classic experimental paradigms used to study effects of partial retrieval are not ideally suited to doing so, because they lack the parametric control needed to ensure that the memory is activated to the appropriate degree (i.e., that there is some retrieval, but not enough to cause memory strengthening). Here we present a novel procedure designed to accommodate this need. After participants learned a list of word-scene associates, they completed a cued mental visualization task that was combined with a multiple-object tracking (MOT) procedure, which we selected for its ability to interfere with mental visualization in a parametrically adjustable way (by varying the number of MOT targets). We also used fMRI data to successfully train an “associative recall” classifier for use in this task: this classifier revealed greater memory reactivation during trials in which associative memories were cued while participants tracked one, rather than five MOT targets. However, the classifier was insensitive to task difficulty when recall was not taking place, suggesting it had indeed tracked memory reactivation rather than task difficulty per se. Consistent with the classifier findings, participants’ introspective ratings of visualization vividness were modulated by MOT task difficulty. In addition, we observed reduced classifier output and slowing of responses in a post-reactivation memory test, consistent with the hypothesis that partial reactivation, induced by MOT, weakened memory. These results serve as a “proof of concept” that MOT can be used to parametrically modulate memory retrieval – a property that may prove useful in future investigation of partial retrieval effects, e.g., in closed-loop experiments. PMID:28387587

Zebrafish embryo developmental toxicology assay.

PubMed

Panzica-Kelly, Julieta M; Zhang, Cindy X; Augustine-Rauch, Karen

2012-01-01

A promising in vitro zebrafish developmental toxicology assay was generated to test compounds for their teratogenic potential. The assay's predictivity is approximately 87% in AB strain fish (Brannen KC et al., Birth Defects Res B Dev Reprod Toxicol 89:66-77, 2010). The procedure entails exposing dechorionated gastrulation-stage embryos to a range of compound concentrations for 5 days throughout embryonic and larva development. The larvae are evaluated for viability in order to identify an LC25 (the compound concentration in which 25% lethality is observed) and morphological anomalies using a numerical score system to identify the NOAEL (no observed adverse effect level). These values are used to calculate the teratogenic index (LC25/NOAEL ratio) of each compound. If the teratogenic index is equal to or greater than 10 then the compound is classified as a teratogen, and if the ratio is less than 10 then the compound is classified as a nonteratogen (Brannen KC et al., Birth Defects Res B Dev Reprod Toxicol 89:66-77, 2010).

Surface inspection system for industrial components based on shape from shading minimization approach

NASA Astrophysics Data System (ADS)

Kotan, Muhammed; Öz, Cemil

2017-12-01

An inspection system using estimated three-dimensional (3-D) surface characteristics information to detect and classify the faults to increase the quality control on the frequently used industrial components is proposed. Shape from shading (SFS) is one of the basic and classic 3-D shape recovery problems in computer vision. In our application, we developed a system using Frankot and Chellappa SFS method based on the minimization of the selected basis function. First, the specialized image acquisition system captured the images of the component. To eliminate noise, wavelet transform is applied to the taken images. Then, estimated gradients were used to obtain depth and surface profiles. Depth information was used to determine and classify the surface defects. Also, a comparison made with some linearization-based SFS algorithms was discussed. The developed system was applied to real products and the results indicated that using SFS approaches is useful and various types of defects can easily be detected in a short period of time.

A comparison of semiautomated versus manual Goldmann kinetic perimetry in patients with visually significant glaucoma.

PubMed

Ramirez, Adriana M; Chaya, Craig J; Gordon, Lynn K; Giaconi, Joann A

2008-03-01

To determine if semiautomated kinetic perimetry (SKP) is reproducible and comparable to Goldmann manual kinetic perimetry (GVF). Glaucoma patients were recruited to perform visual field testing using GVF and SKP. Specific isopters were tested, quantified, and compared. Visual field patterns were analyzed for shape and defect. Ten patients (16 eyes) underwent visual field studies using SKP and GVF, and 8 patients completed a second SKP on a different day. Individual isopter areas were similar between GVF and SKP, although 60% of isopters were larger on SKP by an average of 15%. This was statistically significant for the smaller isopters, I4e (P=0.02) and I2e (P=0.05). Retesting with SKP on a separate day, showed similar isopter areas (P values=0.3 to 1.0), however, the exact location of isopters in degrees from central fixation tended to vary with the smaller test object sizes. Isopter position in degrees from the central axis agreed in at least 3 quadrants in approximately 65% of fields compared. SKP visual field defects and patterns were similar between test strategies. SKP and GVF testing produce similar visual field results in glaucoma patients, and SKP testing seems to be reliable and reproducible in this population. However, overlapping isopters, typically associated with nonorganic vision loss, and jagged isopters were sometimes observed in SKP visual fields. Further study of SKP is needed to explore these findings.

[Case of brain infarction in the anterior choroidal artery territory with homonymous scotomas].

PubMed

Nakae, Yoshiharu; Higashiyama, Yuichi; Kuroiwa, Yoshiyuki

2009-08-01

We report a case of brain infarction in the anterior choroidal artery territory accompanied homonymous scotomas. A 59-year-old man with diabetes mellitus felt weakness in his left upper and lower extremities. He was admitted to our hospital with mild hemiparesis on his left side. He noticed a small black spot in the left inferior portion of his visual field; however, this disappeared within one minute. He had no visual defects as assessed by a confrontation test, but a Goldmann visual field test revealed that there were homonymous scotomas in the left inferior portion of the visual field. Brain MRI showed hyperintense signals on diffusion-weighted images in the territory of the right anterior choroidal artery. He was diagnosed as having a brain infarction. The anterior choroidal artery penetrates the lateral geniculate nucleus from the front, and branches of the artery usually supply the medial and lateral parts of the lateral geniculate nucleus. Occlusion of these branches causes the loss of the upper and lower homonymous sectors in the visual field. The present case exhibited homonymous scotomas. We assumed that our patient's homonymous scotomas were a variant form of wedge-shaped visual field deficits often seen in anterior choroidal artery syndrome. On the basis the experience gained in this case, we consider that patients with brain infarction in the anterior choroidal artery territory should undergo ophthalmological examination, even when no visual defects are detected by a confrontation test.

Visual Inspection Reliability for Precision Manufactured Parts.

PubMed

See, Judi E

2015-12-01

Sandia National Laboratories conducted an experiment for the National Nuclear Security Administration to determine the reliability of visual inspection of precision manufactured parts used in nuclear weapons. Visual inspection has been extensively researched since the early 20th century; however, the reliability of visual inspection for nuclear weapons parts has not been addressed. In addition, the efficacy of using inspector confidence ratings to guide multiple inspections in an effort to improve overall performance accuracy is unknown. Further, the workload associated with inspection has not been documented, and newer measures of stress have not been applied. Eighty-two inspectors in the U.S. Nuclear Security Enterprise inspected 140 parts for eight different defects. Inspectors correctly rejected 85% of defective items and incorrectly rejected 35% of acceptable parts. Use of a phased inspection approach based on inspector confidence ratings was not an effective or efficient technique to improve the overall accuracy of the process. Results did verify that inspection is a workload-intensive task, dominated by mental demand and effort. Hits for Nuclear Security Enterprise inspection were not vastly superior to the industry average of 80%, and they were achieved at the expense of a high scrap rate not typically observed during visual inspection tasks. This study provides the first empirical data to address the reliability of visual inspection for precision manufactured parts used in nuclear weapons. Results enhance current understanding of the process of visual inspection and can be applied to improve reliability for precision manufactured parts. © 2015, Human Factors and Ergonomics Society.

Optic nerve dysfunction during gravity inversion. Visual field abnormalities.

PubMed

Sanborn, G E; Friberg, T R; Allen, R

1987-06-01

Inversion in a head-down position (gravity inversion) results in an intraocular pressure of 35 to 40 mm Hg in normal subjects. We used computerized static perimetry to measure the visual fields of normal subjects during gravity inversion. There were no visual field changes in the central 6 degrees of the visual field compared with the baseline (preinversion) values. However, when the central 30 degrees of the visual field was tested, reversible visual field defects were found in 11 of 19 eyes. We believe that the substantial elevation of intraocular pressure during gravity inversion may pose potential risks to the eyes, and we recommend that inversion for extended periods of time be avoided.

22 CFR 125.5 - Exemptions for plant visits.

Code of Federal Regulations, 2010 CFR

2010-04-01

... license is not required for the oral and visual disclosure of unclassified technical data during the..., production or manufacture of any other defense articles. In the case of visits involving classified... of the Directorate of Defense Trade Controls is not required for the disclosure of oral and visual...

Visuoperceptual impairment in dementia with Lewy bodies.

PubMed

Mori, E; Shimomura, T; Fujimori, M; Hirono, N; Imamura, T; Hashimoto, M; Tanimukai, S; Kazui, H; Hanihara, T

2000-04-01

In dementia with Lewy bodies (DLB), vision-related cognitive and behavioral symptoms are common, and involvement of the occipital visual cortices has been demonstrated in functional neuroimaging studies. To delineate visuoperceptual disturbance in patients with DLB in comparison with that in patients with Alzheimer disease and to explore the relationship between visuoperceptual disturbance and the vision-related cognitive and behavioral symptoms. Case-control study. Research-oriented hospital. Twenty-four patients with probable DLB (based on criteria of the Consortium on DLB International Workshop) and 48 patients with probable Alzheimer disease (based on criteria of the National Institute of Neurological and Communicative Disorders and Stroke-Alzheimer's Disease and Related Disorders Association) who were matched to those with DLB 2:1 by age, sex, education, and Mini-Mental State Examination score. Four test items to examine visuoperceptual functions, including the object size discrimination, form discrimination, overlapping figure identification, and visual counting tasks. Compared with patients with probable Alzheimer disease, patients with probable DLB scored significantly lower on all the visuoperceptive tasks (P<.04 to P<.001). In the DLB group, patients with visual hallucinations (n = 18) scored significantly lower on the overlapping figure identification (P = .01) than those without them (n = 6), and patients with television misidentifications (n = 5) scored significantly lower on the size discrimination (P<.001), form discrimination (P = .01), and visual counting (P = .007) than those without them (n = 19). Visual perception is defective in probable DLB. The defective visual perception plays a role in development of visual hallucinations, delusional misidentifications, visual agnosias, and visuoconstructive disability charcteristic of DLB.

Pigmentary glaucoma accompanied by Usher syndrome.

PubMed

Koucheki, Behrooz; Jalali, Kamran Hodjat

2012-08-01

To report a case of pigmentary glaucoma (PG) accompanied by Usher syndrome. Case report. The results were presented after standard ocular examination, visual field test, anterior segment and fundus photography, electroretinography, and otolaryngology consultation were conducted. Typical retinitis pigmentosa, flat electroretinography, congenital sensorineural hearing loss, high intraocular pressure, Krukenberg spindle, iris concavity, radial iris transillumination defect, severe pigment deposition on the trabecular meshwork, and glaucomatous optic nerve damage were indicative of PG accompanied by Usher syndrome. In some rare cases, PG may coexist with Usher syndrome. Common findings of Usher syndrome, including night blindness, impaired vision, visual field defects, and retinal changes may distract the clinician from considering the diagnosis of glaucoma. Such association should be borne in mind to make a timely diagnosis and treatment possible.

Optic nerve lesion following neuroborreliosis: a case report.

PubMed

Burkhard, C; Gleichmann, M; Wilhelm, H

2001-01-01

Neuroborreliosis may cause various neuro-ophthalmological complications. We describe a case with a bilateral optic neuropathy. A 58-year-old female developed facial paresis six weeks after an insect bite. One week later she developed bilateral optic disc swelling with haemorrhages and nerve fibre bundle defects in the lower visual field of the left eye. In CSF and serum, raised IgM and IgG titres to Borrelia burgdorferi were found. Systemic antibiotic treatment led to improvement of the vision and facial paresis, but not all visual field defects resolved, probably due to ischemic lesions of the optic disc. In optic nerve lesions due to neuroborreliosis it is difficult to distinguish between inflammatory and ischemic lesions. This patient demonstrated features of an ischemic optic nerve lesion.

Polarization imaging of imperfect m-plane GaN surfaces

NASA Astrophysics Data System (ADS)

Sakai, Yuji; Kawayama, Iwao; Nakanishi, Hidetoshi; Tonouchi, Masayoshi

2017-04-01

Surface polar states in m-plane GaN wafers were studied using a laser terahertz (THz) emission microscope (LTEM). Femtosecond laser illumination excites THz waves from the surface due to photocarrier acceleration by local spontaneous polarization and/or the surface built-in electric field. The m-plane, in general, has a large number of unfavorable defects and unintentional polarization inversion created during the regrowth process. The LTEM images can visualize surface domains with different polarizations, some of which are hard to visualize with photoluminescence mapping, i.e., non-radiative defect areas. The present study demonstrates that the LTEM provides rich information about the surface polar states of GaN, which is crucial to improve the performance of GaN-based optoelectronic and power devices.

Color vision defects in adrenomyeloneuropathy.

PubMed Central

Sack, G H; Raven, M B; Moser, H W

1989-01-01

The relationship between abnormal color vision and adrenomyeloneuropathy (AMN) was investigated in 27 AMN patients and 31 age-matched controls by using the Farnsworth-Munsell 100 Hue test. Twelve (44%) of 27 patients showed test scores significantly above normal. The axes of bipolarity determined by the testing differed widely between the patients with abnormal scores, compatible with the notion that different alterations in visual pigment genes occur in different AMN kindreds. These observations confirm our earlier impression that the frequency of abnormal color vision is increased in these kindreds, and it supports our contentions that (1) AMN (and its companion, adrenoleukodystrophy) are very closely linked to the visual pigment loci at Xq28 and (2) this proximity might provide the opportunity to observe contiguous gene defects. PMID:2729274

Detection of Cardiac Abnormalities from Multilead ECG using Multiscale Phase Alternation Features.

PubMed

Tripathy, R K; Dandapat, S

2016-06-01

The cardiac activities such as the depolarization and the relaxation of atria and ventricles are observed in electrocardiogram (ECG). The changes in the morphological features of ECG are the symptoms of particular heart pathology. It is a cumbersome task for medical experts to visually identify any subtle changes in the morphological features during 24 hours of ECG recording. Therefore, the automated analysis of ECG signal is a need for accurate detection of cardiac abnormalities. In this paper, a novel method for automated detection of cardiac abnormalities from multilead ECG is proposed. The method uses multiscale phase alternation (PA) features of multilead ECG and two classifiers, k-nearest neighbor (KNN) and fuzzy KNN for classification of bundle branch block (BBB), myocardial infarction (MI), heart muscle defect (HMD) and healthy control (HC). The dual tree complex wavelet transform (DTCWT) is used to decompose the ECG signal of each lead into complex wavelet coefficients at different scales. The phase of the complex wavelet coefficients is computed and the PA values at each wavelet scale are used as features for detection and classification of cardiac abnormalities. A publicly available multilead ECG database (PTB database) is used for testing of the proposed method. The experimental results show that, the proposed multiscale PA features and the fuzzy KNN classifier have better performance for detection of cardiac abnormalities with sensitivity values of 78.12 %, 80.90 % and 94.31 % for BBB, HMD and MI classes. The sensitivity value of proposed method for MI class is compared with the state-of-art techniques from multilead ECG.

Computer-aided Classification of Mammographic Masses Using Visually Sensitive Image Features

PubMed Central

Wang, Yunzhi; Aghaei, Faranak; Zarafshani, Ali; Qiu, Yuchen; Qian, Wei; Zheng, Bin

2017-01-01

Purpose To develop a new computer-aided diagnosis (CAD) scheme that computes visually sensitive image features routinely used by radiologists to develop a machine learning classifier and distinguish between the malignant and benign breast masses detected from digital mammograms. Methods An image dataset including 301 breast masses was retrospectively selected. From each segmented mass region, we computed image features that mimic five categories of visually sensitive features routinely used by radiologists in reading mammograms. We then selected five optimal features in the five feature categories and applied logistic regression models for classification. A new CAD interface was also designed to show lesion segmentation, computed feature values and classification score. Results Areas under ROC curves (AUC) were 0.786±0.026 and 0.758±0.027 when to classify mass regions depicting on two view images, respectively. By fusing classification scores computed from two regions, AUC increased to 0.806±0.025. Conclusion This study demonstrated a new approach to develop CAD scheme based on 5 visually sensitive image features. Combining with a “visual aid” interface, CAD results may be much more easily explainable to the observers and increase their confidence to consider CAD generated classification results than using other conventional CAD approaches, which involve many complicated and visually insensitive texture features. PMID:27911353

Military Research ColorDx and Printed Color Vision Tests.

PubMed

Almustanyir, Ali; Hovis, Jeffery K

2015-10-01

To determine the equivalence of the ColorDx Military Research version (mColorDx) test and three printed pseudoisochromatic tests (HRR, Ishihara, and PIPIC) for color vision testing. Participating in the study were 75 color-normals and 47 subjects with red-green color vision defects. Color vision was classified by an anomaloscope. The HRR (4(th) edition), Ishihara 38-plate edition, and PIPIC tests are printed color vision tests, whereas mColorDx test figures were displayed on a calibrated computer desktop monitor. All tests were repeated in about 1 wk. The kappa level of agreement (κ) values with the anomaloscope for screening for each test was 0.96 or greater. The values were statistically identical. Specificity for each test was at least 0.99 and sensitivity was at least 0.95. The repeatability of the screening sections for all tests was very good with κ values greater than 0.95. Deutans tended to miss the tritan screening plates on the HRR and mColorDx tests. The Spearman rank correlation coefficients between the severity of the defect and anomaloscope range was moderate with r = 0.45 for the mColorDx and r = 0.6 for the HRR. Both the mColorDx and HRR had perfect agreement with the anomaloscope in classifying the defects as either protan or deutan. The validity of the four tests for color vision screening was statistically identical; however, the HRR may be preferred because it had the highest sensitivity of 0.99, a specificity of 1.0, and a reasonable correlation between the severity rating of the defect and the anomaloscope range.

Ocular characteristics associated with the location of focal lamina cribrosa defects in open-angle glaucoma patients.

PubMed

Park, H-Yl; Hwang, Y S; Park, C K

2017-04-01

PurposeTo investigate the clinical characteristics according to the location of focal lamina cribrosa (LC) defects and its associated ocular features.Patients and methodsA total of 139 open-angle glaucoma patients underwent Spectralis optical coherence tomography (OCT) with enhanced depth imaging. Alterations in the contour of the LC were investigated to find focal LC defects. The location of the visible LC defect from the neural canal wall (far-peripheral and mid-peripheral) and clock-hour position (superotemporal, temporal and inferotemporal) were classified. Disc ovality ratio and disc-foveal angle were measured from disc and retinal nerve fiber layer (RNFL) photographs. The disc tilt degree was measured using a Heidelberg Retina Tomograph (HRT) III system. The en face OCT image of the disc scans was registered to the disc and RNFL photographs, to determine whether the focal LC defects corresponded spatially to the glaucomatous damage location.ResultsEyes with far-peripheral LC defects were significantly myopic and had a higher disc ovality ratio. The disc tilt degree obtained by HRT revealed significant temporal disc tilt in eyes with temporal LC defects (P<0.001). Eyes with inferotemporal LC defects had a significantly larger disc-foveal angle (P=0.027). The inferotemporal LC defects corresponded to the location of glaucomatous damage in 81.6%; however, only 46.2% of eyes with a superotemporal LC defect and 3.2% of eyes with a temporal LC defect corresponded spatially with the glaucomatous damage location.ConclusionsThe clinical characteristics and association with glaucomatous damage location were different according to the location of focal LC defect.

Detection of defects in laser powder deposition (LPD) components by pulsed laser transient thermography

NASA Astrophysics Data System (ADS)

Santospirito, S. P.; Słyk, Kamil; Luo, Bin; Łopatka, Rafał; Gilmour, Oliver; Rudlin, John

2013-05-01

Detection of defects in Laser Powder Deposition (LPD) produced components has been achieved by laser thermography. An automatic in-process NDT defect detection software system has been developed for the analysis of laser thermography to automatically detect, reliably measure and then sentence defects in individual beads of LPD components. A deposition path profile definition has been introduced so all laser powder deposition beads can be modeled, and the inspection system has been developed to automatically generate an optimized inspection plan in which sampling images follow the deposition track, and automatically control and communicate with robot-arms, the source laser and cameras to implement image acquisition. Algorithms were developed so that the defect sizes can be correctly evaluated and these have been confirmed using test samples. Individual inspection images can also be stitched together for a single bead, a layer of beads or multiple layers of beads so that defects can be mapped through the additive process. A mathematical model was built up to analyze and evaluate the movement of heat throughout the inspection bead. Inspection processes were developed and positional and temporal gradient algorithms have been used to measure the flaw sizes. Defect analysis is then performed to determine if the defect(s) can be further classified (crack, lack of fusion, porosity) and the sentencing engine then compares the most significant defect or group of defects against the acceptance criteria - independent of human decisions. Testing on manufactured defects from the EC funded INTRAPID project has successful detected and correctly sentenced all samples.

How do patients with neglect see a horizontal line? Analysis of performances in coloured line bisection task.

PubMed

Misonou, Kaori; Ishiai, Sumio; Seki, Keiko; Koyama, Yasumasa; Nakano, Naomi

2004-06-01

Twelve patients with left unilateral spatial neglect were examined with a newly devised "coloured line bisection task". They were presented with a horizontal line printed in blue on one side and in red on the other side; the proportions of the blue and red segments were varied. Immediately after placement of the subjective midpoint, the line was concealed and the patients were asked to name the colours of the right and left ends. Five patients who identified the left-end colour almost correctly had no visual field defect, while the other seven whose colour naming was impaired on the left side had left visual field defect. The rightward bisection errors were similarly distributed in the fair and poor colour-naming patients except for two patients from the latter group. The lesions of the fair colour-naming patients spared the lingual and fusiform gyri, which are known to be engaged in colour processing. Patients with neglect whose visual field is preserved may neglect the leftward extension of a line but not the colour in the neglected space. The poor colour-naming patients frequently failed to name the left-end colour that appeared to the left of their subjective midpoint, which indicates that they hardly searched leftward beyond that point. In such trials, they reported that the left end had the same colour as the right end. The results suggest that in patients with neglect and left visual field defect, both the leftward extent and the colour of a line may be represented on the basis of the information from the attended right segment.

[Eclipse retinopathy : A case series after the partial solar eclipse on 20 March 2015].

PubMed

Bachmeier, I; Helbig, H; Greslechner, R

2017-01-01

Solar retinopathy refers to damage to the central macula caused by exposure to intense solar radiation, most frequently observed after a solar eclipse. Description of the morphological changes in spectral domain optical coherence tomography (SD-OCT) and the clinical course in patients with acute solar retinopathy. The study included a retrospective analysis of 12 eyes from 7 patients with solar retinopathy after the partial solar eclipse on 20 March 2015. Best corrected visual acuity, fundus changes and SD-OCT findings were analyzed. Out of the 7 patients 5 underwent treatment with 1 mg prednisolone per kg body weight. The average age of the patients was 30.1±13.1 years. Best corrected visual acuity was 0.65 at initial presentation. In the acute stage all affected eyes showed a small yellowish lesion in the centre of the fovea in the fundoscopic examination. In SD-OCT the continuity of all layers in the foveola appeared disrupted. In the follow-up examination these changes were partially resolved. After 2 months SD-OCT revealed a small defect of the ellipsoid zone. In one patient the defect could not be shown due to slightly excentric imaging sections. Best corrected visual acuity increased to 0.97. The SD-OCT is an appropriate tool to determine the exact localization of the site of damage and for follow-up examination in solar retinopathy. In the acute phase it shows a disruption of the continuity of all layers in the foveola. Despite good recovery of visual acuity a small central defect of the ellipsoid zone remains in the long term.

An Exemplar-Based Multi-View Domain Generalization Framework for Visual Recognition.

PubMed

Niu, Li; Li, Wen; Xu, Dong; Cai, Jianfei

2018-02-01

In this paper, we propose a new exemplar-based multi-view domain generalization (EMVDG) framework for visual recognition by learning robust classifier that are able to generalize well to arbitrary target domain based on the training samples with multiple types of features (i.e., multi-view features). In this framework, we aim to address two issues simultaneously. First, the distribution of training samples (i.e., the source domain) is often considerably different from that of testing samples (i.e., the target domain), so the performance of the classifiers learnt on the source domain may drop significantly on the target domain. Moreover, the testing data are often unseen during the training procedure. Second, when the training data are associated with multi-view features, the recognition performance can be further improved by exploiting the relation among multiple types of features. To address the first issue, considering that it has been shown that fusing multiple SVM classifiers can enhance the domain generalization ability, we build our EMVDG framework upon exemplar SVMs (ESVMs), in which a set of ESVM classifiers are learnt with each one trained based on one positive training sample and all the negative training samples. When the source domain contains multiple latent domains, the learnt ESVM classifiers are expected to be grouped into multiple clusters. To address the second issue, we propose two approaches under the EMVDG framework based on the consensus principle and the complementary principle, respectively. Specifically, we propose an EMVDG_CO method by adding a co-regularizer to enforce the cluster structures of ESVM classifiers on different views to be consistent based on the consensus principle. Inspired by multiple kernel learning, we also propose another EMVDG_MK method by fusing the ESVM classifiers from different views based on the complementary principle. In addition, we further extend our EMVDG framework to exemplar-based multi-view domain adaptation (EMVDA) framework when the unlabeled target domain data are available during the training procedure. The effectiveness of our EMVDG and EMVDA frameworks for visual recognition is clearly demonstrated by comprehensive experiments on three benchmark data sets.

Influence of cognitive style and interstimulus interval on the hemispheric processing of tactile stimuli.

PubMed

Minagawa, N; Kashu, K

1989-06-01

16 adult subjects performed a tactile recognition task. According to our 1984 study, half of the subjects were classified as having a left hemispheric preference for the processing of visual stimuli, while the other half were classified as having a right hemispheric preference for the processing of visual stimuli. The present task was conducted according to the S1-S2 matching paradigm. The standard stimulus was a readily recognizable object and was presented tactually to either the left or right hand of each subject. The comparison stimulus was an object-picture and was presented visually by slide in a tachistoscope. The interstimulus interval was .05 sec. or 2.5 sec. Analysis indicated that the left-preference group showed right-hand superiority, and the right-preference group showed left-hand superiority. The notion of individual hemisphericity was supported in tactile processing.

Purtscher's retinopathy associated with acute pancreatitis.

PubMed

Hamp, Ania M; Chu, Edward; Slagle, William S; Hamp, Robert C; Joy, Jeffrey T; Morris, Robert W

2014-02-01

Purtscher's retinopathy is a rare condition that is associated with complement-activating systemic diseases such as acute pancreatitis. After pancreatic injury or inflammation, proteases such as trypsin activate the complement system and can potentially cause coagulation and leukoembolization of retinal precapillary arterioles. Specifically, intermediate-sized emboli are sufficiently small enough to pass through larger arteries yet large enough to remain lodged in precapillary arterioles and cause the clinical appearance of Purtscher's retinopathy. This pathology may present with optic nerve edema, impaired visual acuity, visual field loss, as well as retinal findings such as cotton-wool spots, retinal hemorrhage, artery attenuation, venous dilation, and Purtscher flecken. A 57-year-old white man presented with an acute onset of visual field scotomas and decreased visual acuity 1 week after being hospitalized for acute pancreatitis. The retinal examination revealed multiple regions of discrete retinal whitening surrounding the disk, extending through the macula bilaterally, as well as bilateral optic nerve hemorrhages. The patient identified paracentral bilateral visual field defects on Amsler Grid testing, which was confirmed with subsequent Humphrey visual field analysis. Although the patient presented with an atypical underlying etiology, he exhibited classic retinal findings for Purtscher's retinopathy. After 2 months, best corrected visual acuity improved and the retinal whitening was nearly resolved; however, bilateral paracentral visual field defects remained. Purtscher's retinopathy has a distinctive clinical presentation and is typically associated with thoracic trauma but may be a sequela of nontraumatic systemic disease such as acute pancreatitis. Patients diagnosed with acute pancreatitis should have an eye examination to rule out Purtscher's retinopathy. Although visual improvement is possible, patients should be educated that there may be permanent ocular sequelae.

Association of Visual Acuity and Cognitive Impairment in Older Individuals: Fujiwara-kyo Eye Study.

PubMed

Mine, Masashi; Miyata, Kimie; Morikawa, Masayuki; Nishi, Tomo; Okamoto, Nozomi; Kawasaki, Ryo; Yamashita, Hidetoshi; Kurumatani, Norio; Ogata, Nahoko

2016-01-01

Both visual impairment and cognitive impairment are essential factors that determine the quality of life in the aged population. The aim of this study was to determine if a correlation existed between visual acuity and cognitive impairment in an elderly Japanese population. The Fujiwara-kyo Eye Study was a cross-sectional study of individuals aged ≥68 years who lived in Nara Prefecture of Japan. Participants underwent ophthalmological examinations and cognitive function test. A mild visual impairment was defined as having a best corrected visual acuity (BCVA) >0.2 logarithm of the minimum angle of resolution (logMAR) units in the better eye. Cognitive impairment was defined as having a Mini-Mental State Examination (MMSE) score of ≤23 points. A total to 2818 individuals completed the examinations. The mean age of the participants was 76.3 ± 4.8 years (mean ± standard deviation). The mean BCVA of the better eye was -0.02 ± 0.13 logMAR units and 6.6% subjects were classified as being mildly visually impaired. The mean MMSE score was 27.3 ± 2.3 and 5.7% subjects were classified as being cognitively impaired. The proportion of subjects with cognitive or moderate visual impairment increased with age, and there was a significant correlation between the visual acuity and MMSE score (r = -0.10, p < 0.0001). Subjects with mild visual impairments had 2.4 times higher odds of having cognitive impairment than those without visual impairment (odds ratio 2.4, 95% confidence interval, 1.5-3.8, p < 0.001) after adjusting for age, sex, and length of education. We conclude that it may be important to maintain good visual acuity to reduce the risk of having cognitive impairment.

Evaluation of nondestructive testing techniques for the space shuttle nonmetallic thermal protection system

NASA Technical Reports Server (NTRS)

Tiede, D. A.

1972-01-01

A program was conducted to evaluate nondestructive analysis techniques for the detection of defects in rigidized surface insulation (a candidate material for the Space Shuttle thermal protection system). Uncoated, coated, and coated and bonded samples with internal defects (voids, cracks, delaminations, density variations, and moisture content), coating defects (holes, cracks, thickness variations, and loss of adhesion), and bondline defects (voids and unbonds) were inspected by X-ray radiography, acoustic, microwave, high-frequency ultrasonic, beta backscatter, thermal, holographic, and visual techniques. The detectability of each type of defect was determined for each technique (when applicable). A possible relationship between microwave reflection measurements (or X-ray-radiography density measurements) and the tensile strength was established. A possible approach for in-process inspection using a combination of X-ray radiography, acoustic, microwave, and holographic techniques was recommended.

Quasi-conformal remapping for compensation of human visual field defects - Advances in image remapping for human field defects

NASA Technical Reports Server (NTRS)

Juday, Richard D.; Loshin, David S.

1989-01-01

Image coordinate transformations are investigated for possible use in a low vision aid for human patients. These patients typically have field defects with localized retinal dysfunction predominately central (age related maculopathy) or peripheral (retinitis pigmentosa). Previously simple eccentricity-only remappings which do not maintain conformality were shown. Initial attempts on developing images which hold quasi-conformality after remapping are presented. Although the quasi-conformal images may have less local distortion, there are discontinuities in the image which may counterindicate this type of transformation for the low vision application.

Human vision-based algorithm to hide defective pixels in LCDs

NASA Astrophysics Data System (ADS)

Kimpe, Tom; Coulier, Stefaan; Van Hoey, Gert

2006-02-01

Producing displays without pixel defects or repairing defective pixels is technically not possible at this moment. This paper presents a new approach to solve this problem: defects are made invisible for the user by using image processing algorithms based on characteristics of the human eye. The performance of this new algorithm has been evaluated using two different methods. First of all the theoretical response of the human eye was analyzed on a series of images and this before and after applying the defective pixel compensation algorithm. These results show that indeed it is possible to mask a defective pixel. A second method was to perform a psycho-visual test where users were asked whether or not a defective pixel could be perceived. The results of these user tests also confirm the value of the new algorithm. Our "defective pixel correction" algorithm can be implemented very efficiently and cost-effectively as pixel-dataprocessing algorithms inside the display in for instance an FPGA, a DSP or a microprocessor. The described techniques are also valid for both monochrome and color displays ranging from high-quality medical displays to consumer LCDTV applications.

Analysis, Simulation and Prediction of Cosmetic Defects on Automotive External Panel

NASA Astrophysics Data System (ADS)

Le Port, A.; Thuillier, S.; Borot, C.; Charbonneaux, J.

2011-08-01

The first feeling of quality for a vehicle is linked to its perfect appearance. This has a major impact on the reputation of a car manufacturer. Cosmetic defects are thus more and more taken into account in the process design. Qualifying a part as good or bad from the cosmetic point of view is mainly subjective: the part aspect is considered acceptable if no defect is visible on the vehicle by the final customer. Cosmetic defects that appear during sheet metal forming are checked by visual inspection in light inspection rooms, stoning, or with optical or mechanical sensors or feelers. A lack of cosmetic defect prediction before part production leads to the need for corrective actions, production delays and generates additional costs. This paper first explores the objective description of what cosmetic defects are on a stamped part and where they come from. It then investigates the capability of software to predict these defects, and suggests the use of a cosmetic defects analysis tool developed within PAM-STAMP 2G for its qualitative and quantitative prediction.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Springmeyer, R R; Brugger, E; Cook, R

The Data group provides data analysis and visualization support to its customers. This consists primarily of the development and support of VisIt, a data analysis and visualization tool. Support ranges from answering questions about the tool, providing classes on how to use the tool, and performing data analysis and visualization for customers. The Information Management and Graphics Group supports and develops tools that enhance our ability to access, display, and understand large, complex data sets. Activities include applying visualization software for large scale data exploration; running video production labs on two networks; supporting graphics libraries and tools for end users;more » maintaining PowerWalls and assorted other displays; and developing software for searching and managing scientific data. Researchers in the Center for Applied Scientific Computing (CASC) work on various projects including the development of visualization techniques for large scale data exploration that are funded by the ASC program, among others. The researchers also have LDRD projects and collaborations with other lab researchers, academia, and industry. The IMG group is located in the Terascale Simulation Facility, home to Dawn, Atlas, BGL, and others, which includes both classified and unclassified visualization theaters, a visualization computer floor and deployment workshop, and video production labs. We continued to provide the traditional graphics group consulting and video production support. We maintained five PowerWalls and many other displays. We deployed a 576-node Opteron/IB cluster with 72 TB of memory providing a visualization production server on our classified network. We continue to support a 128-node Opteron/IB cluster providing a visualization production server for our unclassified systems and an older 256-node Opteron/IB cluster for the classified systems, as well as several smaller clusters to drive the PowerWalls. The visualization production systems includes NFS servers to provide dedicated storage for data analysis and visualization. The ASC projects have delivered new versions of visualization and scientific data management tools to end users and continue to refine them. VisIt had 4 releases during the past year, ending with VisIt 2.0. We released version 2.4 of Hopper, a Java application for managing and transferring files. This release included a graphical disk usage view which works on all types of connections and an aggregated copy feature for quickly transferring massive datasets quickly and efficiently to HPSS. We continue to use and develop Blockbuster and Telepath. Both the VisIt and IMG teams were engaged in a variety of movie production efforts during the past year in addition to the development tasks.« less

Enhanced Mass Defect Filtering To Simplify and Classify Complex Mixtures of Lignin Degradation Products.

PubMed

Dier, Tobias K F; Egele, Kerstin; Fossog, Verlaine; Hempelmann, Rolf; Volmer, Dietrich A

2016-01-19

High resolution mass spectrometry was utilized to study the highly complex product mixtures resulting from electrochemical breakdown of lignin. As most of the chemical structures of the degradation products were unknown, enhanced mass defect filtering techniques were implemented to simplify the characterization of the mixtures. It was shown that the implemented ionization techniques had a major impact on the range of detectable breakdown products, with atmospheric pressure photoionization in negative ionization mode providing the widest coverage in our experiments. Different modified Kendrick mass plots were used as a basis for mass defect filtering, where Kendrick mass defect and the mass defect of the lignin-specific guaiacol (C7H7O2) monomeric unit were utilized, readily allowing class assignments independent of the oligomeric state of the product. The enhanced mass defect filtering strategy therefore provided rapid characterization of the sample composition. In addition, the structural similarities between the compounds within a degradation sequence were determined by comparison to a tentatively identified product of this compound series. In general, our analyses revealed that primarily breakdown products with low oxygen content were formed under electrochemical conditions using protic ionic liquids as solvent for lignin.

Structure Defect Property Relationships in Binary Intermetallics

NASA Astrophysics Data System (ADS)

Medasani, Bharat; Ding, Hong; Chen, Wei; Persson, Kristin; Canning, Andrew; Haranczyk, Maciej; Asta, Mark

2015-03-01

Ordered intermetallics are light weight materials with technologically useful high temperature properties such as creep resistance. Knowledge of constitutional and thermal defects is required to understand these properties. Vacancies and antisites are the dominant defects in the intermetallics and their concentrations and formation enthalpies could be computed by using first principles density functional theory and thermodynamic formalisms such as dilute solution method. Previously many properties of the intermetallics such as melting temperatures and formation enthalpies were statistically analyzed for large number of intermetallics using structure maps and data mining approaches. We undertook a similar exercise to establish the dependence of the defect properties in binary intermetallics on the underlying structural and chemical composition. For more than 200 binary intermetallics comprising of AB, AB2 and AB3 structures, we computed the concentrations and formation enthalpies of vacancies and antisites in a small range of stoichiometries deviating from ideal stoichiometry. The calculated defect properties were datamined to gain predictive capabilities of defect properties as well as to classify the intermetallics for their suitability in high-T applications. Supported by the US DOE under Contract No. DEAC02-05CH11231 under the Materials Project Center grant (Award No. EDCBEE).

Development of a Moldable, Biodegradable Polymeric Bone Repair Material

DTIC Science & Technology

1994-03-30

minimally encapsulated by fibrous tissue. Histomorphometric analysis of day 14 specimens showed a very mild foreign body response in terms of area. This...significant visual evidence of foreign body response seen for any Atrix test article. A mass of dense fibrotic tissue was found near the defect site...article in the defect and medullary cavity. The test article was minimally encapsulated by fibrotic tissue. Histomorphometric analysis showed this

Defective pigment granule biogenesis and aberrant behavior caused by mutations in the Drosophila AP-3beta adaptin gene ruby.

PubMed Central

Kretzschmar, D; Poeck, B; Roth, H; Ernst, R; Keller, A; Porsch, M; Strauss, R; Pflugfelder, G O

2000-01-01

Lysosomal protein trafficking is a fundamental process conserved from yeast to humans. This conservation extends to lysosome-like organelles such as mammalian melanosomes and insect eye pigment granules. Recently, eye and coat color mutations in mouse (mocha and pearl) and Drosophila (garnet and carmine) were shown to affect subunits of the heterotetrameric adaptor protein complex AP-3 involved in vesicle trafficking. Here we demonstrate that the Drosophila eye color mutant ruby is defective in the AP-3beta subunit gene. ruby expression was found in retinal pigment and photoreceptor cells and in the developing central nervous system. ruby mutations lead to a decreased number and altered size of pigment granules in various cell types in and adjacent to the retina. Humans with lesions in the related AP-3betaA gene suffer from Hermansky-Pudlak syndrome, which is caused by defects in a number of lysosome-related organelles. Hermansky-Pudlak patients have a reduced skin pigmentation and suffer from internal bleeding, pulmonary fibrosis, and visual system malfunction. The Drosophila AP-3beta adaptin also appears to be involved in processes other than eye pigment granule biogenesis because all ruby allele combinations tested exhibited defective behavior in a visual fixation paradigm. PMID:10790396

Surgical Management of Large Periorbital Cutaneous Defects: Aesthetic Considerations and Technique Refinements.

PubMed

Zou, Yun; Hu, Li; Tremp, Mathias; Jin, Yunbo; Chen, Hui; Ma, Gang; Lin, Xiaoxi

2018-02-23

The aim of this study was to repair large periorbital cutaneous defects by an innovative technique called PEPSI (periorbital elevation and positioning with secret incisions) technique with functional and aesthetic outcomes. In this retrospective study, unilateral periorbital cutaneous defects in 15 patients were repaired by the PEPSI technique. The ages of patients ranged from 3 to 46 years (average, 19 years). The outcome evaluations included scars (Vancouver Scar Scale and visual analog scale score), function and aesthetic appearance of eyelids, and patient satisfaction. The repair size was measured by the maximum advancement distance of skin flap during operation. All patients achieved an effective repair with a mean follow-up of 18.3 months. Except one with a small (approximately 0.3 cm) necrosis, all patients healed with no complication. The mean Vancouver Scar Scale and visual analog scale scores were 2.1 ± 1.7 and 8.5 ± 1.2, respectively. Ideal cosmetic and functional outcomes were achieved in 14 patients (93.3%). All patients achieved complete satisfaction except 1 patient with partial satisfaction. The mean maximum advancement distance of skin flap was 20.2 mm (range, 8-50 mm). This study demonstrated that the PEPSI technique is an effective method to repair large periorbital cutaneous defects with acceptable functional and aesthetic outcomes.

Paternal occupation and birth defects: findings from the National Birth Defects Prevention Study

PubMed Central

Desrosiers, Tania A.; Herring, Amy H.; Shapira, Stuart K.; Hooiveld, Mariette; Luben, Tom J.; Herdt-Losavio, Michele L.; Lin, Shao; Olshan, Andrew F.

2013-01-01

Objectives Several epidemiologic studies have suggested that certain paternal occupations may be associated with an increased prevalence of birth defects in offspring. Using data from the National Birth Defects Prevention Study, we investigated the association between paternal occupation and birth defects in a case-control study of cases comprising over 60 different types of birth defects (n = 9998) and non-malformed controls (n = 4066) with dates of delivery between 1997 and 2004. Methods Using paternal occupational histories reported by mothers via telephone interview, jobs were systematically classified into 63 groups based on shared exposure profiles within occupation and industry. Data were analyzed using Bayesian logistic regression with a hierarchical prior for dependent shrinkage to stabilize estimation with sparse data. Results Several occupations were associated with an increased prevalence of various birth defect categories, including: mathematical, physical and computer scientists; artists; photographers and photo processors; food service workers; landscapers and groundskeepers; hairdressers and cosmetologists; office and administrative support workers; sawmill workers; petroleum and gas workers; chemical workers; printers; material moving equipment operators; and motor vehicle operators. Conclusions Findings from this study might be used to identify specific occupations worthy of further investigation, and to generate hypotheses about chemical or physical exposures common to such occupations. PMID:22782864

[Inconformity between soft tissue defect and bony defect in incomplete cleft palate].

PubMed

Zhou, Xia; Ma, Lian

2014-12-01

To evaluate the inconformity between soft tissue defect and bony defect by observing the cleft extent of palate with complete secondary palate bony cleft in incomplete cleft palate patient. The patients with incomplete cleft palate treated in Hospital of Stomatology Peking University from July 2012 to June 2013 were reviewed, of which 75 cases with complete secondary palate bony cleft were selected in this study. The CT scan and intraoral photograph were taken before operation. The patients were classified as four types according to the extent of soft tissue defect. Type 1: soft tissue defect reached incisive foremen region, Type 2 was hard and soft cleft palate, Type 3 soft cleft palate and Type 4 submucous cleft palate. Type 1 was defined as conformity group (CG). The other three types were defined as inconformity group (ICG) and divided into three subgroups (ICG-I), (ICG-II) and (ICG-III). Fifty-seven patients were in ICG group, and the rate of inconformity was 76% (57/75). The percentage of ICG-I, ICG-II and ICG-III was 47% (27/57), 23% (13/57) and 30% (17/57), respevtively. There are different types of soft tissue deformity with complete secondary palate bony cleft. The inconformity between soft tissue and hard tissue defect exits in 3/4 of isolated cleft palate patients.

Prevalence and Risk of Birth Defects Observed in a Prospective Cohort Study: The Hokkaido Study on Environment and Children's Health.

PubMed

Hanaoka, Tomoyuki; Tamura, Naomi; Ito, Kumiko; Sasaki, Seiko; Araki, Atsuko; Ikeno, Tamiko; Miyashita, Chihiro; Ito, Sachiko; Minakami, Hisanori; Cho, Kazutoshi; Endo, Toshiaki; Baba, Tsuyoshi; Miyamoto, Toshinobu; Sengoku, Kazuo; Kishi, Reiko

2018-03-05

Prevalence rates of all anomalies classified as birth defects, including those identified before the 22nd gestational week, are limited in published reports, including those from the International Clearinghouse for Birth Defects Surveillance and Research (ICBDSR). In our birth cohort study, we collected the data for all birth defects after 12 weeks of gestation. Subjects in this study comprised 19,244 pregnant women who visited one of 37 associated hospitals in the Hokkaido Prefecture from 2003 through 2012, and completed follow-up. All birth defects after 12 weeks of gestation, including 55 marker anomalies associated with environmental chemical exposures, were recorded. We examined parental risk factors for birth defects and the association between birth defects and risk of growth retardation. Prevalence of all birth defects was 18.9/1,000 births. The proportion of patients with birth defects delivered between 12 and 21 weeks of gestation was approximately one-tenth of all patients with birth defects. Among those with congenital malformation of the nerve system, 39% were delivered before 22 weeks of gestation. All patients with anencephaly and encephalocele were delivered before 22 weeks of gestation. We observed different patterns of parental risk factors between birth defect cases included in ISBDSR and cases not included. Cases included in ISBDSR were associated with an increased risk of preterm birth. Cases not included in ISBDSR were associated with an increased risk of being small for gestational age at term. Data from our study complemented the data from ICBDSR. We recommend that birth defects not included in ICBDSR also be analyzed to elucidate the etiology of birth defects.

Automated reticle inspection data analysis for wafer fabs

NASA Astrophysics Data System (ADS)

Summers, Derek; Chen, Gong; Reese, Bryan; Hutchinson, Trent; Liesching, Marcus; Ying, Hai; Dover, Russell

2009-04-01

To minimize potential wafer yield loss due to mask defects, most wafer fabs implement some form of reticle inspection system to monitor photomask quality in high-volume wafer manufacturing environments. Traditionally, experienced operators review reticle defects found by an inspection tool and then manually classify each defect as 'pass, warn, or fail' based on its size and location. However, in the event reticle defects are suspected of causing repeating wafer defects on a completed wafer, potential defects on all associated reticles must be manually searched on a layer-by-layer basis in an effort to identify the reticle responsible for the wafer yield loss. This 'problem reticle' search process is a very tedious and time-consuming task and may cause extended manufacturing line-down situations. Often times, Process Engineers and other team members need to manually investigate several reticle inspection reports to determine if yield loss can be tied to a specific layer. Because of the very nature of this detailed work, calculation errors may occur resulting in an incorrect root cause analysis effort. These delays waste valuable resources that could be spent working on other more productive activities. This paper examines an automated software solution for converting KLA-Tencor reticle inspection defect maps into a format compatible with KLA-Tencor's Klarity Defect(R) data analysis database. The objective is to use the graphical charting capabilities of Klarity Defect to reveal a clearer understanding of defect trends for individual reticle layers or entire mask sets. Automated analysis features include reticle defect count trend analysis and potentially stacking reticle defect maps for signature analysis against wafer inspection defect data. Other possible benefits include optimizing reticle inspection sample plans in an effort to support "lean manufacturing" initiatives for wafer fabs.

Automated reticle inspection data analysis for wafer fabs

NASA Astrophysics Data System (ADS)

Summers, Derek; Chen, Gong; Reese, Bryan; Hutchinson, Trent; Liesching, Marcus; Ying, Hai; Dover, Russell

2009-03-01

To minimize potential wafer yield loss due to mask defects, most wafer fabs implement some form of reticle inspection system to monitor photomask quality in high-volume wafer manufacturing environments. Traditionally, experienced operators review reticle defects found by an inspection tool and then manually classify each defect as 'pass, warn, or fail' based on its size and location. However, in the event reticle defects are suspected of causing repeating wafer defects on a completed wafer, potential defects on all associated reticles must be manually searched on a layer-by-layer basis in an effort to identify the reticle responsible for the wafer yield loss. This 'problem reticle' search process is a very tedious and time-consuming task and may cause extended manufacturing line-down situations. Often times, Process Engineers and other team members need to manually investigate several reticle inspection reports to determine if yield loss can be tied to a specific layer. Because of the very nature of this detailed work, calculation errors may occur resulting in an incorrect root cause analysis effort. These delays waste valuable resources that could be spent working on other more productive activities. This paper examines an automated software solution for converting KLA-Tencor reticle inspection defect maps into a format compatible with KLA-Tencor's Klarity DefectTM data analysis database. The objective is to use the graphical charting capabilities of Klarity Defect to reveal a clearer understanding of defect trends for individual reticle layers or entire mask sets. Automated analysis features include reticle defect count trend analysis and potentially stacking reticle defect maps for signature analysis against wafer inspection defect data. Other possible benefits include optimizing reticle inspection sample plans in an effort to support "lean manufacturing" initiatives for wafer fabs.

Supporting High School Student Accomplishment of Biology Content Using Interactive Computer-Based Curricular Case Studies

NASA Astrophysics Data System (ADS)

Oliver, Joseph Steve; Hodges, Georgia W.; Moore, James N.; Cohen, Allan; Jang, Yoonsun; Brown, Scott A.; Kwon, Kyung A.; Jeong, Sophia; Raven, Sara P.; Jurkiewicz, Melissa; Robertson, Tom P.

2017-11-01

Research into the efficacy of modules featuring dynamic visualizations, case studies, and interactive learning environments is reported here. This quasi-experimental 2-year study examined the implementation of three interactive computer-based instructional modules within a curricular unit covering cellular biology concepts in an introductory high school biology course. The modules featured dynamic visualizations and focused on three processes that underlie much of cellular biology: diffusion, osmosis, and filtration. Pre-tests and post-tests were used to assess knowledge growth across the unit. A mixture Rasch model analysis of the post-test data revealed two groups of students. In both years of the study, a large proportion of the students were classified as low-achieving based on their pre-test scores. The use of the modules in the Cell Unit in year 2 was associated with a much larger proportion of the students having transitioned to the high-achieving group than in year 1. In year 2, the same teachers taught the same concepts as year 1 but incorporated the interactive computer-based modules into the cell biology unit of the curriculum. In year 2, 67% of students initially classified as low-achieving were classified as high-achieving at the end of the unit. Examination of responses to assessments embedded within the modules as well as post-test items linked transition to the high-achieving group with correct responses to items that both referenced the visualization and the contextualization of that visualization within the module. This study points to the importance of dynamic visualization within contextualized case studies as a means to support student knowledge acquisition in biology.

Remote defect imaging for plate-like structures based on the scanning laser source technique

NASA Astrophysics Data System (ADS)

Hayashi, Takahiro; Maeda, Atsuya; Nakao, Shogo

2018-04-01

In defect imaging with a scanning laser source technique, the use of a fixed receiver realizes stable measurements of flexural waves generated by laser at multiple rastering points. This study discussed the defect imaging by remote measurements using a laser Doppler vibrometer as a receiver. Narrow-band burst waves were generated by modulating laser pulse trains of a fiber laser to enhance signal to noise ratio in frequency domain. Averaging three images obtained at three different frequencies suppressed spurious distributions due to resonance. The experimental system equipped with these newly-devised means enabled us to visualize defects and adhesive objects in plate-like structures such as a plate with complex geometries and a branch pipe.

Chapter 3:Sorting red maple logs for structural quality

Treesearch

Xiping Wang

2005-01-01

Nondestructive evaluation (NDE) of wood materials has a long history of application in the wood products industry. Visual grading of lumber is perhaps one of the earliest NDE forms. Visual assessment of a piece of lumber requires the grader to estimate a strength ratio on the basis of observed external defects (USDA 1999). The ratio is used to estimate the strength of...

Visual and x-ray inspection characteristics of eutectic and lead free assemblies

NASA Technical Reports Server (NTRS)

Ghaffarian, R.

2003-01-01

For high reliability applications, visual inspection has been the key technique for most conventional electronic package assemblies. Now, the use of x-ray technique has become an additional inspection requirement for quality control and detection of unique defects due to manufacturing of advanced electronic array packages such as ball grid array (BGAs) and chip scale packages (CSPs).

GMR-based eddy current probe for weld seam inspection and its non-scanning detection study

NASA Astrophysics Data System (ADS)

Gao, Peng; Wang, Chao; Li, Yang; Wang, Libin; Cong, Zheng; Zhi, Ya

2017-04-01

Eddy current testing is one of the most important non-destructive testing methods for welding defects detection. This paper presents the use of a probe consisting of 4 giant magneto-resistive (GMR) sensors to detect weld defects. Information from four measuring points above and on both sides of the weld seam is collected at the same time. By setting the GMR sensors' sensing axes perpendicular to the direction of the excitation magnetic field, the information collected mainly reflects the change in the eddy current which is caused by defects. Digital demodulation technology is applied to extract the real part and imaginary part of the GMR sensors' output signals. The variables containing directional information of the magnetic field are introduced. Based on the data from the four GMR (4-GMR) sensors' output signals, four values, Ran, Mean, Var and k are selected as the feature quantities for defect recognition. Experiments are carried out on weld seams with and without defects, and the detection outputs are given in this paper. The 4-GMR probe is also employed to investigate non-scanning weld defect detection and the four feature quantities (Ran, Mean, Var and k) are studied to evaluate weld quality. The non-scanning weld defect detection is presented. A support vector machine is used to classify and discriminate welds with and without defects. Experiments carried out show that through the method in this paper, the recognition rate is 92% for welds without defects and 90% for welds with defects, with an overall recognition rate of 90.9%, indicating that this method could effectively detect weld defects.

Correlation between morphological defects, electron beam-induced current imaging, and the electrical properties of 4H-SiC Schottky diodes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Y.; Ali, G.N.; Mikhov, M.K.

2005-01-01

Defects in SiC degrade the electrical properties and yield of devices made from this material. This article examines morphological defects in 4H-SiC and defects visible in electron beam-induced current (EBIC) images and their effects on the electrical characteristics of Schottky diodes. Optical Nomarski microscopy and atomic force microscopy were used to observe the morphological defects, which are classified into 26 types based on appearance alone. Forward and reverse current-voltage characteristics were used to extract barrier heights, ideality factors, and breakdown voltages. Barrier heights decrease about linearly with increasing ideality factor, which is explained by discrete patches of low barrier heightmore » within the main contact. Barrier height, ideality, and breakdown voltage all degrade with increasing device diameter, suggesting that discrete defects are responsible. Electroluminescence was observed under reverse bias from microplasmas associated with defects containing micropipes. EBIC measurements reveal several types of features corresponding to recombination centers. The density of dark spots observed by EBIC correlates strongly with ideality factor and barrier height. Most morphological defects do not affect the reverse characteristics when no micropipes are present, but lower the barrier height and worsen the ideality factor. However, certain multiple-tailed defects, irregularly shaped defects and triangular defects with 3C inclusions substantially degrade both breakdown voltage and barrier height, and account for most of the bad devices that do not contain micropipes. Micropipes in these wafers are also frequently found to be of Type II, which do not run parallel to the c axis.« less

Correlation Between Morphological Defects, Electron Beam Induced Current Imaging, and the Electrical Properties of 4H-SiC Schottky Diodes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang,Y.; Ali, G.; Mikhov, M.

2005-01-01

Defects in SiC degrade the electrical properties and yield of devices made from this material. This article examines morphological defects in 4H-SiC and defects visible in electron beam-induced current (EBIC) images and their effects on the electrical characteristics of Schottky diodes. Optical Nomarski microscopy and atomic force microscopy were used to observe the morphological defects, which are classified into 26 types based on appearance alone. Forward and reverse current-voltage characteristics were used to extract barrier heights, ideality factors, and breakdown voltages. Barrier heights decrease about linearly with increasing ideality factor, which is explained by discrete patches of low barrier heightmore » within the main contact. Barrier height, ideality, and breakdown voltage all degrade with increasing device diameter, suggesting that discrete defects are responsible. Electroluminescence was observed under reverse bias from microplasmas associated with defects containing micropipes. EBIC measurements reveal several types of features corresponding to recombination centers. The density of dark spots observed by EBIC correlates strongly with ideality factor and barrier height. Most morphological defects do not affect the reverse characteristics when no micropipes are present, but lower the barrier height and worsen the ideality factor. However, certain multiple-tailed defects, irregularly shaped defects and triangular defects with 3C inclusions substantially degrade both breakdown voltage and barrier height, and account for most of the bad devices that do not contain micropipes. Micropipes in these wafers are also frequently found to be of Type II, which do not run parallel to the c axis.« less

Accurate defect die placement and nuisance defect reduction for reticle die-to-die inspections

NASA Astrophysics Data System (ADS)

Wen, Vincent; Huang, L. R.; Lin, C. J.; Tseng, Y. N.; Huang, W. H.; Tuo, Laurent C.; Wylie, Mark; Chen, Ellison; Wang, Elvik; Glasser, Joshua; Kelkar, Amrish; Wu, David

2015-10-01

Die-to-die reticle inspections are among the simplest and most sensitive reticle inspections because of the use of an identical-design neighboring-die for the reference image. However, this inspection mode can have two key disadvantages: (1) The location of the defect is indeterminate because it is unclear to the inspector whether the test or reference image is defective; and (2) nuisance and false defects from mask manufacturing noise and tool optical variation can limit the usable sensitivity. The use of a new sequencing approach for a die-to-die inspection can resolve these issues without any additional scan time, without sacrifice in sensitivity requirement, and with a manageable increase in computation load. In this paper we explore another approach for die-to-die inspections using a new method of defect processing and sequencing. Utilizing die-to-die double arbitration during defect detection has been proven through extensive testing to generate accurate placement of the defect in the correct die to ensure efficient defect disposition at the AIMS step. The use of this method maintained the required inspection sensitivity for mask quality as verified with programmed-defectmask qualification and then further validated with production masks comparing the current inspection approach to the new method. Furthermore, this approach can significantly reduce the total number of defects that need to be reviewed by essentially eliminating the nuisance and false defects that can result from a die-to-die inspection. This "double-win" will significantly reduce the effort in classifying a die-to-die inspection result and will lead to improved cycle times.

Vehicle response-based track geometry assessment using multi-body simulation

NASA Astrophysics Data System (ADS)

Kraft, Sönke; Causse, Julien; Coudert, Frédéric

2018-02-01

The assessment of the geometry of railway tracks is an indispensable requirement for safe rail traffic. Defects which represent a risk for the safety of the train have to be identified and the necessary measures taken. According to current standards, amplitude thresholds are applied to the track geometry parameters measured by recording cars. This geometry-based assessment has proved its value but suffers from the low correlation between the geometry parameters and the vehicle reactions. Experience shows that some defects leading to critical vehicle reactions are underestimated by this approach. The use of vehicle responses in the track geometry assessment process allows identifying critical defects and improving the maintenance operations. This work presents a vehicle response-based assessment method using multi-body simulation. The choice of the relevant operation conditions and the estimation of the simulation uncertainty are outlined. The defects are identified from exceedances of track geometry and vehicle response parameters. They are then classified using clustering methods and the correlation with vehicle response is analysed. The use of vehicle responses allows the detection of critical defects which are not identified from geometry parameters.

Branching points in the low-temperature dipolar hard sphere fluid

NASA Astrophysics Data System (ADS)

Rovigatti, Lorenzo; Kantorovich, Sofia; Ivanov, Alexey O.; Tavares, José Maria; Sciortino, Francesco

2013-10-01

In this contribution, we investigate the low-temperature, low-density behaviour of dipolar hard-sphere (DHS) particles, i.e., hard spheres with dipoles embedded in their centre. We aim at describing the DHS fluid in terms of a network of chains and rings (the fundamental clusters) held together by branching points (defects) of different nature. We first introduce a systematic way of classifying inter-cluster connections according to their topology, and then employ this classification to analyse the geometric and thermodynamic properties of each class of defects, as extracted from state-of-the-art equilibrium Monte Carlo simulations. By computing the average density and energetic cost of each defect class, we find that the relevant contribution to inter-cluster interactions is indeed provided by (rare) three-way junctions and by four-way junctions arising from parallel or anti-parallel locally linear aggregates. All other (numerous) defects are either intra-cluster or associated to low cluster-cluster interaction energies, suggesting that these defects do not play a significant part in the thermodynamic description of the self-assembly processes of dipolar hard spheres.

Believing is Seeing: Visual Conventions in Barr's Classification of the "Feeble-Minded"

ERIC Educational Resources Information Center

Elks, Martin A.

2004-01-01

The eugenics era (c. 1900?1930) produced a strong desire among mental retardation professionals to recognize and control "the feeble-minded." Some eugenicists believed it was possible to classify individuals visually by learning to recognize what they believed to be observable characteristics of idiocy and imbecility. In this paper I used…

Visual or Auditory Processing Style and Strategy Effectiveness.

ERIC Educational Resources Information Center

Weed, Keri; Ryan, Ellen Bouchard

In a study that investigated differences in the processing styles of beginning readers, a Pictograph Sentence Memory Test (PSMT) was administered to first and second grade students to determine their processing style as well as to assess instructional effects. Based on their responses to the PSMT, the children were classified as either visual or…

Inventory of Electronic Mobility Aids for Persons with Visual Impairments: A Literature Review

ERIC Educational Resources Information Center

Roentgen, Uta R.; Gelderblom, Gert Jan; Soede, Mathijs; de Witte, Luc P.

2008-01-01

This literature review of existing electronic mobility aids for persons who are visually impaired and recent developments in this field identified and classified 146 products, systems, and devices. The 21 that are currently available that can be used without environmental adaptation are described in functional terms. (Contains 2 tables.)

Visualization of dietary patterns and their associations with age-related macular degeneration

USDA-ARS?s Scientific Manuscript database

PURPOSE: We aimed to visualize the relationship of predominant dietary patterns and their associations with AMD. METHODS: A total of 8103 eyes from 4088 participants in the baseline Age-Related Eye Disease Study (AREDS) were classified into three groups: control (n=2739), early AMD (n=4599), and adv...

Implementation of a General Real-Time Visual Anomaly Detection System Via Soft Computing

NASA Technical Reports Server (NTRS)

Dominguez, Jesus A.; Klinko, Steve; Ferrell, Bob; Steinrock, Todd (Technical Monitor)

2001-01-01

The intelligent visual system detects anomalies or defects in real time under normal lighting operating conditions. The application is basically a learning machine that integrates fuzzy logic (FL), artificial neural network (ANN), and generic algorithm (GA) schemes to process the image, run the learning process, and finally detect the anomalies or defects. The system acquires the image, performs segmentation to separate the object being tested from the background, preprocesses the image using fuzzy reasoning, performs the final segmentation using fuzzy reasoning techniques to retrieve regions with potential anomalies or defects, and finally retrieves them using a learning model built via ANN and GA techniques. FL provides a powerful framework for knowledge representation and overcomes uncertainty and vagueness typically found in image analysis. ANN provides learning capabilities, and GA leads to robust learning results. An application prototype currently runs on a regular PC under Windows NT, and preliminary work has been performed to build an embedded version with multiple image processors. The application prototype is being tested at the Kennedy Space Center (KSC), Florida, to visually detect anomalies along slide basket cables utilized by the astronauts to evacuate the NASA Shuttle launch pad in an emergency. The potential applications of this anomaly detection system in an open environment are quite wide. Another current, potentially viable application at NASA is in detecting anomalies of the NASA Space Shuttle Orbiter's radiator panels.

Mutational Analysis of Drosophila Basigin Function in the Visual System

PubMed Central

Munro, Michelle; Akkam, Yazan; Curtin, Kathryn D.

2009-01-01

Drosophila basigin is a cell-surface glycoprotein of the Ig superfamily and a member of a protein family that includes mammalian EMMPRIN/CD147/basigin, neuroplastin, and embigin. Our previous work on Drosophila basigin has shown that it is required for normal photoreceptor cell structure and normal neuron-glia interaction in the fly visual system. Specifically, the photoreceptor neurons of mosaic animals that are mutant in the eye for basigin show altered cell structure with nuclei, mitochondria and rER misplaced and variable axon diameter compared to wild-type. In addition, glia cells in the optic lamina that contact photoreceptor axons are misplaced and show altered structure. All these defects are rescued by expression of either transgenic fly basigin or transgenic mouse basigin in the photoreceptors demonstrating that mouse basigin can functionally replace fly basigin. To determine what regions of the basigin protein are required for each of these functions, we have created mutant basigin transgenes coding for proteins that are altered in conserved residues, introduced these into the fly genome, and tested them for their ability to rescue both photoreceptor cell structure defects and neuron-glia interaction defects of basigin. The results suggest that the highly conserved transmembrane domain and the extracellular domains are crucial for basigin function in the visual system while the short intracellular tail may not play a role in these functions. PMID:19782733

Lung texture classification using bag of visual words

NASA Astrophysics Data System (ADS)

Asherov, Marina; Diamant, Idit; Greenspan, Hayit

2014-03-01

Interstitial lung diseases (ILD) refer to a group of more than 150 parenchymal lung disorders. High-Resolution Computed Tomography (HRCT) is the most essential imaging modality of ILD diagnosis. Nonetheless, classification of various lung tissue patterns caused by ILD is still regarded as a challenging task. The current study focuses on the classification of five most common categories of lung tissues of ILD in HRCT images: normal, emphysema, ground glass, fibrosis and micronodules. The objective of the research is to classify an expert-given annotated region of interest (AROI) using a bag of visual words (BoVW) framework. The images are divided into small patches and a collection of representative patches are defined as visual words. This procedure, termed dictionary construction, is performed for each individual lung texture category. The assumption is that different lung textures are represented by a different visual word distribution. The classification is performed using an SVM classifier with histogram intersection kernel. In the experiments, we use a dataset of 1018 AROIs from 95 patients. Classification using a leave-one-patient-out cross validation (LOPO CV) is used. Current classification accuracy obtained is close to 80%.

Principal component analysis study of visual and verbal metaphoric comprehension in children with autism and learning disabilities.

PubMed

Mashal, Nira; Kasirer, Anat

2012-01-01

This research extends previous studies regarding the metaphoric competence of autistic and learning disable children on different measures of visual and verbal non-literal language comprehension, as well as cognitive abilities that include semantic knowledge, executive functions, similarities, and reading fluency. Thirty seven children with autism (ASD), 20 children with learning disabilities (LD), and 21 typically developed (TD) children participated in the study. Principal components analysis was used to examine the interrelationship among the various tests in each group. Results showed different patterns in the data according to group. In particular, the results revealed that there is no dichotomy between visual and verbal metaphors in TD children but rather metaphor are classified according to their familiarity level. In the LD group visual metaphors were classified independently of the verbal metaphors. Verbal metaphoric understanding in the ASD group resembled the LD group. In addition, our results revealed the relative weakness of the ASD and LD children in suppressing irrelevant information. Copyright © 2011 Elsevier Ltd. All rights reserved.

LCC: Light Curves Classifier

NASA Astrophysics Data System (ADS)

Vo, Martin

2017-08-01

Light Curves Classifier uses data mining and machine learning to obtain and classify desired objects. This task can be accomplished by attributes of light curves or any time series, including shapes, histograms, or variograms, or by other available information about the inspected objects, such as color indices, temperatures, and abundances. After specifying features which describe the objects to be searched, the software trains on a given training sample, and can then be used for unsupervised clustering for visualizing the natural separation of the sample. The package can be also used for automatic tuning parameters of used methods (for example, number of hidden neurons or binning ratio). Trained classifiers can be used for filtering outputs from astronomical databases or data stored locally. The Light Curve Classifier can also be used for simple downloading of light curves and all available information of queried stars. It natively can connect to OgleII, OgleIII, ASAS, CoRoT, Kepler, Catalina and MACHO, and new connectors or descriptors can be implemented. In addition to direct usage of the package and command line UI, the program can be used through a web interface. Users can create jobs for ”training” methods on given objects, querying databases and filtering outputs by trained filters. Preimplemented descriptors, classifier and connectors can be picked by simple clicks and their parameters can be tuned by giving ranges of these values. All combinations are then calculated and the best one is used for creating the filter. Natural separation of the data can be visualized by unsupervised clustering.

The Constitution and Its Critics

ERIC Educational Resources Information Center

Main, Thomas J.

2011-01-01

In planning a freshman undergraduate curriculum with colleagues recently, the question arose as to what type of understanding educators wanted to impart to their students about the Constitution. The alleged defects of the Constitution that these books point to are wide-ranging and can be classified into various categories. Some problems--such as…

Dynamic three-dimensional display of common congenital cardiac defects from reconstruction of two-dimensional echocardiographic images.

PubMed

Hsieh, K S; Lin, C C; Liu, W S; Chen, F L

1996-01-01

Two-dimensional echocardiography had long been a standard diagnostic modality for congenital heart disease. Further attempts of three-dimensional reconstruction using two-dimensional echocardiographic images to visualize stereotypic structure of cardiac lesions have been successful only recently. So far only very few studies have been done to display three-dimensional anatomy of the heart through two-dimensional image acquisition because such complex procedures were involved. This study introduced a recently developed image acquisition and processing system for dynamic three-dimensional visualization of various congenital cardiac lesions. From December 1994 to April 1995, 35 cases were selected in the Echo Laboratory here from about 3000 Echo examinations completed. Each image was acquired on-line with specially designed high resolution image grazmber with EKG and respiratory gating technique. Off-line image processing using a window-architectured interactive software package includes construction of 2-D ehcocardiographic pixel to 3-D "voxel" with conversion of orthogonal to rotatory axial system, interpolation, extraction of region of interest, segmentation, shading and, finally, 3D rendering. Three-dimensional anatomy of various congenital cardiac defects was shown, including four cases with ventricular septal defects, two cases with atrial septal defects, and two cases with aortic stenosis. Dynamic reconstruction of a "beating heart" is recorded as vedio tape with video interface. The potential application of 3D display of the reconstruction from 2D echocardiographic images for the diagnosis of various congenital heart defects has been shown. The 3D display was able to improve the diagnostic ability of echocardiography, and clear-cut display of the various congenital cardiac defects and vavular stenosis could be demonstrated. Reinforcement of current techniques will expand future application of 3D display of conventional 2D images.

Genetic parameters of egg defects and egg quality in layer chickens.

PubMed

Wolc, A; Arango, J; Settar, P; O'Sullivan, N P; Olori, V E; White, I M S; Hill, W G; Dekkers, J C M

2012-06-01

Genetic parameters were estimated for egg defects, egg production, and egg quality traits. Eggs from 11,738 purebred brown-egg laying hens were classified as salable or as having one of the following defects: bloody, broken, calcium deposit, dirty, double yolk, misshapen, pee-wee, shell-less, and soft shelled. Egg quality included albumen height, egg weight, yolk weight, and puncture score. Body weight, age at sexual maturity, and egg production were also recorded. Heritability estimates of liability to defects using a threshold animal model were less than 0.1 for bloody and dirty; between 0.1 and 0.2 for pee-wee, broken, misshapen, soft shelled, and shell-less; and above 0.2 for calcium deposit and double yolk. Quality and production traits were more heritable, with estimates ranging from 0.29 (puncture score) to 0.74 (egg weight). High-producing hens had a lower frequency of egg defects. High egg weight and BW were associated with an increased frequency of double yolks, and to a lesser extent, with more shell quality defects. Estimates of genetic correlations among defect traits that were related to shell quality were positive and moderate to strong (0.24-0.73), suggesting that these could be grouped into one category or selection could be based on the trait with the highest heritability or that is easiest to measure. Selection against defective eggs would be more efficient by including egg defect traits in the selection criterion, along with egg production rate of salable eggs and egg quality traits.

Locating and classifying defects using an hybrid data base

NASA Astrophysics Data System (ADS)

Luna-Avilés, A.; Hernández-Gómez, L. H.; Durodola, J. F.; Urriolagoitia-Calderón, G.; Urriolagoitia-Sosa, G.; Beltrán Fernández, J. A.; Díaz Pineda, A.

2011-07-01

A computational inverse technique was used in the localization and classification of defects. Postulated voids of two different sizes (2 mm and 4 mm diameter) were introduced in PMMA bars with and without a notch. The bar dimensions are 200×20×5 mm. One half of them were plain and the other half has a notch (3 mm × 4 mm) which is close to the defect area (19 mm × 16 mm).This analysis was done with an Artificial Neural Network (ANN) and its optimization was done with an Adaptive Neuro Fuzzy Procedure (ANFIS). A hybrid data base was developed with numerical and experimental results. Synthetic data was generated with the finite element method using SOLID95 element of ANSYS code. A parametric analysis was carried out. Only one defect in such bars was taken into account and the first five natural frequencies were calculated. 460 cases were evaluated. Half of them were plain and the other half has a notch. All the input data was classified in two groups. Each one has 230 cases and corresponds to one of the two sort of voids mentioned above. On the other hand, experimental analysis was carried on with PMMA specimens of the same size. The first two natural frequencies of 40 cases were obtained with one void. The other three frequencies were obtained numerically. 20 of these bars were plain and the others have a notch. These experimental results were introduced in the synthetic data base. 400 cases were taken randomly and, with this information, the ANN was trained with the backpropagation algorithm. The accuracy of the results was tested with the 100 cases that were left. In the next stage of this work, the ANN output was optimized with ANFIS. Previous papers showed that localization and classification of defects was reduced as notches were introduced in such bars. In the case of this paper, improved results were obtained when a hybrid data base was used.

Ethambutol/Linezolid Toxic Optic Neuropathy.

PubMed

Libershteyn, Yevgeniya

2016-02-01

To report a rare toxic optic neuropathy after long-term use of two medications: ethambutol and linezolid. A 65-year-old man presented to the Miami Veterans Affairs Medical Center in December 2014 for evaluation of progressive vision decrease in both eyes. The patient presented with best-corrected visual acuities of 20/400 in the right eye and counting fingers at 5 feet in the left eye. Color vision was significantly reduced in both eyes. Visual fields revealed a cecocentral defect in both eyes. His fundus and optic nerve examination was unremarkable. Because vision continued to decline after discontinuation of ethambutol, linezolid was also discontinued, after which vision, color vision, and visual fields improved. Because of these findings, the final diagnosis was toxic optic neuropathy. Final visual outcome was 20/30 in the right eye and 20/40 in the left eye. Drug-associated toxic optic neuropathy is a rare but vision-threatening condition. Diagnosis is made based on an extensive case history and careful clinical examination. The examination findings include varying decrease in vision, normal pupils and extraocular muscles, and unremarkable fundoscopy, with the possibility of swollen optic discs in the acute stage of the optic neuropathy. Other important findings descriptive of toxic optic neuropathy include decreased color vision and cecocentral visual field defects. This case illustrates the importance of knowledge of all medications and/or substances a patient consumes that may cause a toxic reaction and discontinuing them immediately if the visual functions are worsening or not improving.

AutoBD: Automated Bi-Level Description for Scalable Fine-Grained Visual Categorization.

PubMed

Yao, Hantao; Zhang, Shiliang; Yan, Chenggang; Zhang, Yongdong; Li, Jintao; Tian, Qi

Compared with traditional image classification, fine-grained visual categorization is a more challenging task, because it targets to classify objects belonging to the same species, e.g. , classify hundreds of birds or cars. In the past several years, researchers have made many achievements on this topic. However, most of them are heavily dependent on the artificial annotations, e.g., bounding boxes, part annotations, and so on . The requirement of artificial annotations largely hinders the scalability and application. Motivated to release such dependence, this paper proposes a robust and discriminative visual description named Automated Bi-level Description (AutoBD). "Bi-level" denotes two complementary part-level and object-level visual descriptions, respectively. AutoBD is "automated," because it only requires the image-level labels of training images and does not need any annotations for testing images. Compared with the part annotations labeled by the human, the image-level labels can be easily acquired, which thus makes AutoBD suitable for large-scale visual categorization. Specifically, the part-level description is extracted by identifying the local region saliently representing the visual distinctiveness. The object-level description is extracted from object bounding boxes generated with a co-localization algorithm. Although only using the image-level labels, AutoBD outperforms the recent studies on two public benchmark, i.e. , classification accuracy achieves 81.6% on CUB-200-2011 and 88.9% on Car-196, respectively. On the large-scale Birdsnap data set, AutoBD achieves the accuracy of 68%, which is currently the best performance to the best of our knowledge.Compared with traditional image classification, fine-grained visual categorization is a more challenging task, because it targets to classify objects belonging to the same species, e.g. , classify hundreds of birds or cars. In the past several years, researchers have made many achievements on this topic. However, most of them are heavily dependent on the artificial annotations, e.g., bounding boxes, part annotations, and so on . The requirement of artificial annotations largely hinders the scalability and application. Motivated to release such dependence, this paper proposes a robust and discriminative visual description named Automated Bi-level Description (AutoBD). "Bi-level" denotes two complementary part-level and object-level visual descriptions, respectively. AutoBD is "automated," because it only requires the image-level labels of training images and does not need any annotations for testing images. Compared with the part annotations labeled by the human, the image-level labels can be easily acquired, which thus makes AutoBD suitable for large-scale visual categorization. Specifically, the part-level description is extracted by identifying the local region saliently representing the visual distinctiveness. The object-level description is extracted from object bounding boxes generated with a co-localization algorithm. Although only using the image-level labels, AutoBD outperforms the recent studies on two public benchmark, i.e. , classification accuracy achieves 81.6% on CUB-200-2011 and 88.9% on Car-196, respectively. On the large-scale Birdsnap data set, AutoBD achieves the accuracy of 68%, which is currently the best performance to the best of our knowledge.

A pediatric case of pituitary macroadenoma presenting with pituitary apoplexy and cranial nerve involvement: case report

PubMed Central

Özçetin, Mustafa; Karacı, Mehmet; Toroslu, Ertuğ; Edebali, Nurullah

2016-01-01

Pituitary adenomas usually arise from the anterior lobe of the pituitary gland and are manifested with hormonal disorders or mass effect. Mass effect usually occurs in nonfunctional tumors. Pituitary adenomas may be manifested with visual field defects or rarely in the form of total oculomotor palsy. Visual field defect is most frequently in the form of bitemporal hemianopsia and superior temporal defect. Sudden loss of vision, papilledema and ophthalmoplegia may be observed. Pituitary apoplexy is defined as an acute clinical syndrome characterized with headache, vomiting, loss of vision, ophthalmoplegia and clouding of consciousness. The problem leading to pituitary apoplexy may be decreased blood supply in the adenoma and hemorrhage following this decrease or hemorrhage alone. In this article, we present a patient who presented with fever, vomiting and sudden loss of vision and limited outward gaze in the left eye following trauma and who was found to have pituitary macroadenoma causing compression of the optic chiasma and optic nerve on the left side on cranial and pituitary magnetic resonance imaging. PMID:27738402

[Implantation of an Artificial Iris in 11 Patients].

PubMed

Kniestedt, C; Eberhard, R; Fleischhauer, J

2016-04-01

Background. Iris defects are mostly acquired after injury, or may be iatrogenic after surgical excision of iris tumours or the result of collateral trauma after anterior segment surgery. They cause severe visual disability, e.g. glare, loss of contrast sensitivity, and loss of best corrected visual acuity. The foldable Koch iris prosthesis has a customised iris design and may be used to reconstruct the anterior segment in patients with partial or complete aniridia. History and Signs. We present the surgical management and clinical course of 6 patients with traumatic iris defects, together with 3 patients with partial aniridia after cataract surgery. Cataract surgery and implantation of an artificial iris were performed in 2 female patients (3 eyes) with congenital aniridia syndrome. Therapy and Outcome. No patient exhibited complications in the postoperative course, with the exception of various intraocular pressure peaks due to secondary glaucoma, that were all corrected by medication to lower topical pressure. Conclusions. In patients with major iris defects, the artificial iris allows functionally and aesthetically satisfactory reconstruction of the anterior segment. Georg Thieme Verlag KG Stuttgart · New York.

Predictors of visual outcome in patients operated for craniopharyngioma - a Danish national study.

PubMed

Jacobsen, Mads Forslund; Thomsen, Ann Sofia Skou; Bach-Holm, Daniella; Doroudian, Ghazaleh; Nissen, Kamilla Rothe; Fugleholm, Kåre; Poulsgaard, Lars; Siersma, Volkert; Heegaard, Steffen

2018-02-01

Craniopharyngioma often causes visual loss due to the close relation to the anterior visual pathways. This study investigates the incidence and predictors of visual outcomes in patients with craniopharyngioma. Data from sixty-six patients who underwent surgery for craniopharyngioma from 2009 to 2013 in Denmark were reviewed. Primary outcomes were visual acuity (VA) and visual field (VF) defects from pre-and postoperative visits. Secondary outcomes were optic nerve atrophy (OA) and papilledema. Fifty-eight patients were included. The VA of the patients 1-year after surgery improved by -0.16 log(MAR) (95%CI: -0.30 to -0.02; p = 0.0266). Visual field (VF) defects worsened in 17 eyes (30%), remained stable in 21 eyes (37%) and improved in 19 eyes (33%). The presence of papilledema and the absence of OA were significantly correlated with an improvement in VA postoperatively (p = 0.011 and p = 0.011, respectively). Patients undergoing surgery within a week or less after their first ophthalmological examination had a significant improvement in VA (-0.36; 95%CI: -0.62 to -0.09; p = 0.0099). Patients undergoing surgery using a subfrontal approach also showed improvement in VA (p = 0.048). Tumour recurrence had a significantly worse VA outcome (p = 0.0074). Patients show a slight improvement in VA 1-year after operation for craniopharyngioma. The presence of papilledema and early surgical intervention is associated with a significant improvement in VA. Early involvement of a dedicated ophthalmologist is recommended to secure an early detection of a visual decline and potential tumour recurrence. © 2017 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

Predictive factors of visual function recovery after pituitary adenoma resection: a literature review and Meta-analysis.

PubMed

Sun, Min; Zhang, Zhi-Qiang; Ma, Chi-Yuan; Chen, Sui-Hua; Chen, Xin-Jian

2017-01-01

To determine the dominant predictive factors of postoperative visual recovery for patients with pituitary adenoma. PubMed, Google Scholar, Web of Science and Cochrane Library were searched for relevant human studies, which investigated the prediction of the postoperative visual recovery of patients with pituitary adenoma, from January 2000 to May 2017. Meta-analyses were performed on the primary outcomes. After the related data were extracted by two independent investigators, pooled weighted mean difference (WMD) and odds ratio (OR) with 95% confidence interval (CI) were estimated using a random-effects or a fixed-effects model. Nineteen studies were included in the literature review, and nine trials were included in the Meta-analysis, which comprised 530 patients (975 eyes) with pituitary adenoma. For the primary outcomes, there was a significant difference between preoperative and postoperative mean deviation (MD) values of the visual field (WMD -5.85; 95%CI: -8.19 to -3.51; P <0.00001). Predictive characteristics of four factors were revealed in this Meta-analysis by assigning the patients to sufficient and insufficient groups according to postoperative visual field improvements, including preoperative visual field defect (WMD 10.09; 95%CI: 6.17 to 14.02; P <0.00001), patient age (WMD -12.32; 95%CI: -18.42 to -6.22; P <0.0001), symptom duration (WMD -5.04; 95%CI: -9.71 to -0.37; P =0.03), and preoperative peripapillary retinal nerve fiber layer (pRNFL) thickness (OR 0.1; 95% CI: 0.04 to 0.23; P <0.00001). Preoperative visual field defect, symptom duration, patient age, and preoperative pRNFL thickness are the dominant predictive factors of the postoperative recovery of the visual field for patients with pituitary adenoma.

Saccadic vector optokinetic perimetry in children with neurodisability or isolated visual pathway lesions: observational cohort study.

PubMed

Tailor, Vijay; Glaze, Selina; Unwin, Hilary; Bowman, Richard; Thompson, Graham; Dahlmann-Noor, Annegret

2016-10-01

Children and adults with neurological impairments are often not able to access conventional perimetry; however, information about the visual field is valuable. A new technology, saccadic vector optokinetic perimetry (SVOP), may have improved accessibility, but its accuracy has not been evaluated. We aimed to explore accessibility, testability and accuracy of SVOP in children with neurodisability or isolated visual pathway deficits. Cohort study; recruitment October 2013-May 2014, at children's eye clinics at a tertiary referral centre and a regional Child Development Centre; full orthoptic assessment, SVOP (central 30° of the visual field) and confrontation visual fields (CVF). Group 1: age 1-16 years, neurodisability (n=16), group 2: age 10-16 years, confirmed or suspected visual field defect (n=21); group 2 also completed Goldmann visual field testing (GVFT). Group 1: testability with a full 40-point test protocol is 12.5%; with reduced test protocols, testability is 100%, but plots may be clinically meaningless. Children (44%) and parents/carers (62.5%) find the test easy. SVOP and CVF agree in 50%. Group 2: testability is 62% for the 40-point protocol, and 90.5% for reduced protocols. Corneal changes in childhood glaucoma interfere with SVOP testing. All children and parents/carers find SVOP easy. Overall agreement with GVFT is 64.7%. While SVOP is highly accessible to children, many cannot complete a full 40-point test. Agreement with current standard tests is moderate to poor. Abnormal saccades cause an apparent non-specific visual field defect. In children with glaucoma or nystagmus SVOP calibration often fails. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

The Effects of Compensatory Scanning Training on Mobility in Patients with Homonymous Visual Field Defects: Further Support, Predictive Variables and Follow-Up

PubMed Central

Melis-Dankers, Bart J. M.; Brouwer, Wiebo H.; Tucha, Oliver; Heutink, Joost

2016-01-01

Introduction People with homonymous visual field defects (HVFD) often report difficulty detecting obstacles in the periphery on their blind side in time when moving around. Recently, a randomized controlled trial showed that the InSight-Hemianopia Compensatory Scanning Training (IH-CST) specifically improved detection of peripheral stimuli and avoiding obstacles when moving around, especially in dual task situations. Method The within-group training effects of the previously reported IH-CST are examined in an extended patient group. Performance of patients with HVFD on a pre-assessment, post-assessment and follow-up assessment and performance of a healthy control group are compared. Furthermore, it is examined whether training effects can be predicted by demographic characteristics, variables related to the visual disorder, and neuropsychological test results. Results Performance on both subjective and objective measures of mobility-related scanning was improved after training, while no evidence was found for improvement in visual functions (including visual fields), reading, visual search and dot counting. Self-reported improvement did not correlate with improvement in objective mobility performance. According to the participants, the positive effects were still present six to ten months after training. No demographic characteristics, variables related to the visual disorder, and neuropsychological test results were found to predict the size of training effect, although some inconclusive evidence was found for more improvement in patients with left-sided HVFD than in patients with right-sided HFVD. Conclusion Further support was found for a positive effect of IH-CST on detection of visual stimuli during mobility-related activities specifically. Based on the reports given by patients, these effects appear to be long-term effects. However, no conclusions can be drawn on the objective long-term training effects. PMID:27935973

Automated reticle inspection data analysis for wafer fabs

NASA Astrophysics Data System (ADS)

Summers, Derek; Chen, Gong; Reese, Bryan; Hutchinson, Trent; Liesching, Marcus; Ying, Hai; Dover, Russell

2008-10-01

To minimize potential wafer yield loss due to mask defects, most wafer fabs implement some form of reticle inspection system to monitor photomask quality in high-volume wafer manufacturing environments. Traditionally, experienced operators review reticle defects found by an inspection tool and then manually classify each defect as 'pass, warn, or fail' based on its size and location. However, in the event reticle defects are suspected of causing repeating wafer defects on a completed wafer, potential defects on all associated reticles must be manually searched on a layer-by-layer basis in an effort to identify the reticle responsible for the wafer yield loss. This 'problem reticle' search process is a very tedious and time-consuming task and may cause extended manufacturing line-down situations. Often times, Process Engineers and other team members need to manually investigate several reticle inspection reports to determine if yield loss can be tied to a specific layer. Because of the very nature of this detailed work, calculation errors may occur resulting in an incorrect root cause analysis effort. These delays waste valuable resources that could be spent working on other more productive activities. This paper examines an automated software solution for converting KLA-Tencor reticle inspection defect maps into a format compatible with KLA-Tencor's Klarity DefecTM data analysis database. The objective is to use the graphical charting capabilities of Klarity Defect to reveal a clearer understanding of defect trends for individual reticle layers or entire mask sets. Automated analysis features include reticle defect count trend analysis and potentially stacking reticle defect maps for signature analysis against wafer inspection defect data. Other possible benefits include optimizing reticle inspection sample plans in an effort to support "lean manufacturing" initiatives for wafer fabs.

Soft Computing Application in Fault Detection of Induction Motor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Konar, P.; Puhan, P. S.; Chattopadhyay, P. Dr.

2010-10-26

The paper investigates the effectiveness of different patter classifier like Feed Forward Back Propagation (FFBPN), Radial Basis Function (RBF) and Support Vector Machine (SVM) for detection of bearing faults in Induction Motor. The steady state motor current with Park's Transformation has been used for discrimination of inner race and outer race bearing defects. The RBF neural network shows very encouraging results for multi-class classification problems and is hoped to set up a base for incipient fault detection of induction motor. SVM is also found to be a very good fault classifier which is highly competitive with RBF.

The Advanced Glaucoma Intervention Study (AGIS): 12. Baseline risk factors for sustained loss of visual field and visual acuity in patients with advanced glaucoma.

PubMed

2002-10-01

To examine the relationships between baseline risk factors and sustained decrease of visual field (SDVF) and sustained decrease of visual acuity (SDVA). Cohort study of participants in the Advanced Glaucoma Intervention Study (AGIS). This multicenter study enrolled patients between 1988 and 1992 and followed them until 2001; 789 eyes of 591 patients with advanced glaucoma were randomly assigned to one of two surgical sequences, argon laser trabeculoplasty (ALT)-trabeculectomy-trabeculectomy (ATT) or trabeculectomy-ALT-trabeculectomy (TAT). This report is based on data from 747 eyes. Eyes were offered the next intervention in the sequence upon failure of the previous intervention. Failure was based on recurrent intraocular pressure elevation, visual field defect, and disk rim criteria. Study visits occurred every 6 months; potential follow-up ranged from 8 to 13 years. For each intervention sequence, Cox multiple regression analyses were used to examine the baseline characteristics for association with two vision outcomes: SDVF and SDVA. The magnitude of the association is measured by the hazard ratio (HR), where HR for binary variables is the relative change in the hazard (or risk) of the outcome in eyes with the factor divided by the hazard in eyes without the factor, and HR for continuous variables is the relative change in the hazard (or risk) of the outcome in eyes with a unit increase in the factor. Characteristics associated with increased SDVF risk in the ATT sequence are: less baseline visual field defect (hazard ratio [HR] = 0.86, P <.001, 95% CI = 0.82-0.90), male gender (HR = 2.23, P <.001, 1.54-3.23), and worse baseline visual acuity (HR = 0.96, P =.001, 0.94-0.98); in the TAT sequence: less baseline visual field defect (HR = 0.93, P =.001, 0.89-0.97) and diabetes (HR = 1.87, P =.007, 1.18-2.97). Characteristics associated with increased SDVA risk in both treatment sequences are better baseline acuity (ATT: HR = 1.05, P <.001, 1.02-1.09; TAT: HR = 1.06, P <.001, 1.03-1.08), older age (ATT: HR = 1.05, P =.001, 1.02-1.08; TAT: HR = 1.04, P =.002, 1.01-1.06), and less formal education (ATT: HR = 1.92, P =.001, 1.29-2.88; TAT: HR = 1.77, P =.002, 1.22-2.54). For SDVF, risk factors were better baseline visual field in both treatment sequences, male gender, and worse baseline visual acuity in the ATT sequence, and diabetes in the TAT sequence. For SDVA, risk factors in both treatment sequences were better baseline visual acuity, older age, and less formal education.

Multi-frequency Defect Selective Imaging via Nonlinear Ultrasound

NASA Astrophysics Data System (ADS)

Solodov, Igor; Busse, Gerd

The concept of defect-selective ultrasonic nonlinear imaging is based on visualization of strongly nonlinear inclusions in the form of localized cracked defects. For intense excitation, the ultrasonic response of defects is affected by mechanical constraint between their fragments that makes their vibrations extremely nonlinear. The cracked flaws, therefore, efficiently generate multiple new frequencies, which can be used as a nonlinear "tag" to detect and image them. In this paper, the methodologies of nonlinear scanning laser vibrometry (NSLV) and nonlinear air-coupled emission (NACE) are applied for nonlinear imaging of various defects in hi-tech and constructional materials. A broad database obtained demonstrates evident advantages of the nonlinear approach over its linear counterpart. The higher-order nonlinear frequencies provide increase in signal-to-noise ratio and enhance the contrast of imaging. Unlike conventional ultrasonic instruments, the nonlinear approach yields abundant multi-frequency information on defect location. The application of image recognition and processing algorithms is described and shown to improve reliability and quality of ultrasonic imaging.

Laser Imaging of Airborne Acoustic Emission by Nonlinear Defects

NASA Astrophysics Data System (ADS)

Solodov, Igor; Döring, Daniel; Busse, Gerd

2008-06-01

Strongly nonlinear vibrations of near-surface fractured defects driven by an elastic wave radiate acoustic energy into adjacent air in a wide frequency range. The variations of pressure in the emitted airborne waves change the refractive index of air thus providing an acoustooptic interaction with a collimated laser beam. Such an air-coupled vibrometry (ACV) is proposed for detecting and imaging of acoustic radiation of nonlinear spectral components by cracked defects. The photoelastic relation in air is used to derive induced phase modulation of laser light in the heterodyne interferometer setup. The sensitivity of the scanning ACV to different spatial components of the acoustic radiation is analyzed. The animated airborne emission patterns are visualized for the higher harmonic and frequency mixing fields radiated by planar defects. The results confirm a high localization of the nonlinear acoustic emission around the defects and complicated directivity patterns appreciably different from those observed for fundamental frequencies.

Autophagy as a melanocytic self-defense mechanism.

PubMed

Setaluri, Vijayasaradhi

2015-05-01

Defects in autophagy have implications for melanocyte survival and manifestations of skin pigmentary disorders. Zhang et al. (2015) show that mouse melanocytes lacking the autophagy protein Atg7 undergo premature senescence in vitro and accumulate products of oxidative damage, despite activation of the redox response. Interestingly, contrary to previous findings, the melanocyte-specific deficiency in autophagy did not cause major defects in melanosome biogenesis, nor did it produce visually striking changes in mouse coat color.

A Fuzzy Integral Ensemble Method in Visual P300 Brain-Computer Interface.

PubMed

Cavrini, Francesco; Bianchi, Luigi; Quitadamo, Lucia Rita; Saggio, Giovanni

2016-01-01

We evaluate the possibility of application of combination of classifiers using fuzzy measures and integrals to Brain-Computer Interface (BCI) based on electroencephalography. In particular, we present an ensemble method that can be applied to a variety of systems and evaluate it in the context of a visual P300-based BCI. Offline analysis of data relative to 5 subjects lets us argue that the proposed classification strategy is suitable for BCI. Indeed, the achieved performance is significantly greater than the average of the base classifiers and, broadly speaking, similar to that of the best one. Thus the proposed methodology allows realizing systems that can be used by different subjects without the need for a preliminary configuration phase in which the best classifier for each user has to be identified. Moreover, the ensemble is often capable of detecting uncertain situations and turning them from misclassifications into abstentions, thereby improving the level of safety in BCI for environmental or device control.

The audiovisual structure of onomatopoeias: An intrusion of real-world physics in lexical creation.

PubMed

Taitz, Alan; Assaneo, M Florencia; Elisei, Natalia; Trípodi, Mónica; Cohen, Laurent; Sitt, Jacobo D; Trevisan, Marcos A

2018-01-01

Sound-symbolic word classes are found in different cultures and languages worldwide. These words are continuously produced to code complex information about events. Here we explore the capacity of creative language to transport complex multisensory information in a controlled experiment, where our participants improvised onomatopoeias from noisy moving objects in audio, visual and audiovisual formats. We found that consonants communicate movement types (slide, hit or ring) mainly through the manner of articulation in the vocal tract. Vowels communicate shapes in visual stimuli (spiky or rounded) and sound frequencies in auditory stimuli through the configuration of the lips and tongue. A machine learning model was trained to classify movement types and used to validate generalizations of our results across formats. We implemented the classifier with a list of cross-linguistic onomatopoeias simple actions were correctly classified, while different aspects were selected to build onomatopoeias of complex actions. These results show how the different aspects of complex sensory information are coded and how they interact in the creation of novel onomatopoeias.

Quantification and Visualization of Variation in Anatomical Trees

DOE Office of Scientific and Technical Information (OSTI.GOV)

Amenta, Nina; Datar, Manasi; Dirksen, Asger

This paper presents two approaches to quantifying and visualizing variation in datasets of trees. The first approach localizes subtrees in which significant population differences are found through hypothesis testing and sparse classifiers on subtree features. The second approach visualizes the global metric structure of datasets through low-distortion embedding into hyperbolic planes in the style of multidimensional scaling. A case study is made on a dataset of airway trees in relation to Chronic Obstructive Pulmonary Disease.

High-resolution imaging of retinal nerve fiber bundles in glaucoma using adaptive optics scanning laser ophthalmoscopy.

PubMed

Takayama, Kohei; Ooto, Sotaro; Hangai, Masanori; Ueda-Arakawa, Naoko; Yoshida, Sachiko; Akagi, Tadamichi; Ikeda, Hanako Ohashi; Nonaka, Atsushi; Hanebuchi, Masaaki; Inoue, Takashi; Yoshimura, Nagahisa

2013-05-01

To detect pathologic changes in retinal nerve fiber bundles in glaucomatous eyes seen on images obtained by adaptive optics (AO) scanning laser ophthalmoscopy (AO SLO). Prospective cross-sectional study. Twenty-eight eyes of 28 patients with open-angle glaucoma and 21 normal eyes of 21 volunteer subjects underwent a full ophthalmologic examination, visual field testing using a Humphrey Field Analyzer, fundus photography, red-free SLO imaging, spectral-domain optical coherence tomography, and imaging with an original prototype AO SLO system. The AO SLO images showed many hyperreflective bundles suggesting nerve fiber bundles. In glaucomatous eyes, the nerve fiber bundles were narrower than in normal eyes, and the nerve fiber layer thickness was correlated with the nerve fiber bundle widths on AO SLO (P < .001). In the nerve fiber layer defect area on fundus photography, the nerve fiber bundles on AO SLO were narrower compared with those in normal eyes (P < .001). At 60 degrees on the inferior temporal side of the optic disc, the nerve fiber bundle width was significantly lower, even in areas without nerve fiber layer defect, in eyes with glaucomatous eyes compared with normal eyes (P = .026). The mean deviations of each cluster in visual field testing were correlated with the corresponding nerve fiber bundle widths (P = .017). AO SLO images showed reduced nerve fiber bundle widths both in clinically normal and abnormal areas of glaucomatous eyes, and these abnormalities were associated with visual field defects, suggesting that AO SLO may be useful for detecting early nerve fiber bundle abnormalities associated with loss of visual function. Copyright © 2013 Elsevier Inc. All rights reserved.

Evidence for the Detection of Subclinical Retinal Involvement in Systemic Lupus Erythematosus and Sjögren Syndrome: A Potential Association with Therapies.

PubMed

Conigliaro, Paola; Triggianese, Paola; Draghessi, Gianluca; Canofari, Claudia; Aloe, Gianluca; Chimenti, Maria Sole; Valeri, Claudia; Nucci, Carlo; Perricone, Roberto; Cesareo, Massimo

2018-06-14

Retinal involvement in systemic lupus erythematosus (SLE) and Sjögren syndrome (SS) may be subclinical and thus underdiagnosed. We aimed at evaluating morphological and functional visual abnormalities in a cohort of SLE and SS patients in the absence of an overt clinical visual impairment. We also investigated potential associations between retinal disorders and disease activity, organ involvement, and treatment with steroid and/or hydroxychloroquine. The study comprised 42 SLE and 36 primary SS patients and 76 healthy controls (HC). Ophthalmological examination, standard automated perimetry, spectral-domain optical coherence tomography, and fundus perimetry were performed. Retinal thickness of the posterior pole was not different between SLE and HC groups, but it was reduced in the SS group compared with both the HC and the SLE group. In SLE and SS patients, mean defect and pattern standard deviation by standard automated perimetry were higher than in HC. Visual field index values were lower in both SLE and SS patients than in HC. SLE patients with nephritis displayed increased mean defect and pattern standard deviation and reduced visual field index values compared to patients without nephritis. In SLE and SS patients, fundus perimetry differential sensitivity was reduced, and mean defect values were higher than in HC. Disturbances in fundus perimetry in the SLE group were more prevalent in steroid-naïve patients and in SS patients who received a cumulative hydroxychloroquine dose > 1,000 g. Functional eye impairment was demonstrated in SLE patients, possibly associated with kidney involvement. In SLE, corticosteroids might exert a protective role. Morphological alterations and functional impairment were detected in SS patients, which may be linked to hydroxychloroquine toxicity. © 2018 S. Karger AG, Basel.

A prototype system based on visual interactive SDM called VGC

NASA Astrophysics Data System (ADS)

Jia, Zelu; Liu, Yaolin; Liu, Yanfang

2009-10-01

In many application domains, data is collected and referenced by its geo-spatial location. Spatial data mining, or the discovery of interesting patterns in such databases, is an important capability in the development of database systems. Spatial data mining recently emerges from a number of real applications, such as real-estate marketing, urban planning, weather forecasting, medical image analysis, road traffic accident analysis, etc. It demands for efficient solutions for many new, expensive, and complicated problems. For spatial data mining of large data sets to be effective, it is also important to include humans in the data exploration process and combine their flexibility, creativity, and general knowledge with the enormous storage capacity and computational power of today's computers. Visual spatial data mining applies human visual perception to the exploration of large data sets. Presenting data in an interactive, graphical form often fosters new insights, encouraging the information and validation of new hypotheses to the end of better problem-solving and gaining deeper domain knowledge. In this paper a visual interactive spatial data mining prototype system (visual geo-classify) based on VC++6.0 and MapObject2.0 are designed and developed, the basic algorithms of the spatial data mining is used decision tree and Bayesian networks, and data classify are used training and learning and the integration of the two to realize. The result indicates it's a practical and extensible visual interactive spatial data mining tool.

Intrasellar cysticercosis: a systematic review.

PubMed

Del Brutto, Oscar H; Del Brutto, Victor J

2013-09-01

The objective of this study was to review patients with intrasellar cysticercosis to outline the features of this form of neurocysticercosis. A MEDLINE and manual search of patients with intrasellar cysticercosis were done. Abstracted data included clinical manifestations, neuroimaging findings, therapy, and outcome. Twenty-three patients were reviewed. Ophthalmological disturbances, including diminution of visual acuity and visual field defects following a chiasmatic pattern, were recorded in 67 % of cases. Endocrine abnormalities were found in 56 % of patients (panhypopituitarism, hyperprolactinemia, diabetes insipidus, and isolated hypothyroidism). In addition, some patients complained of seizures or chronic headaches. Neuroimaging studies showed lesions confined to the sellar region in 47 % of cases. The remaining patients also had subarachnoid cysts associated or not with hydrocephalus, parenchymal brain cysts, or parenchymal brain calcifications. Thirteen patients underwent surgical resection of the sellar cyst through a craniotomy in nine cases and by the transsphenoidal approach in four. Visual acuity or visual field defects improved in only two of these patients. Five patients were treated with cysticidal drugs without improvement. Intrasellar cysticercosis is rare and probably under-recognized. Clinical manifestations resemble those caused by pituitary tumors, cysts, or other granulomatous lesions. Neuroimaging findings are of more value when intrasellar cysts are associated with other forms of neurocysticercosis, such as basal subarachnoid cysts or hydrocephalus. Prompt surgical resection is mandatory to reduce the risk of permanent loss of visual function. There seems to be no role for cysticidal drug therapy in these cases.

Adjuvant or radical fractionated stereotactic radiotherapy for patients with pituitary functional and nonfunctional macroadenoma

PubMed Central

2011-01-01

Purpose To evaluate the efficacy and toxicity of stereotactic fractionated radiotherapy (SFRT) for patients with pituitary macroadenoma (PMA). Methods and Materials Between March 2000 and March 2009, 27 patients (male to female ratio, 1.25) with PMA underwent SFRT (median dose, 50.4 Gy). Mean age of the patients was 56.5 years (range, 20.3 - 77.4). In all but one patient, SFRT was administered for salvage treatment after surgical resection (transphenoidal resection in 23, transphenoidal resection followed by craniotomy in 2 and multiple transphenoidal resections in another patient). In 10 (37%) patients, the PMAs were functional (3 ACTH-secreting, 3 prolactinomas, 2 growth hormone-secreting and 2 multiple hormone-secretion). Three (11.1%) and 9 (33.3%) patients had PMA abutting and compressing the optic chiasm, respectively. Mean tumor volume was 2.9 ± 4.6 cm3. Eighteen (66.7%) patients had hypopituitarism prior to SFRT. The mean follow-up period after SFRT was 72.4 ± 37.2 months. Results Tumor size decreased for 6 (22.2%) patients and remained unchanged for 19 (70.4%) other patients. Two (7.4%) patients had tumor growth inside the prescribed treatment volume. The estimated 5-year tumor growth control was 95.5% after SFRT. Biochemical remission occurred in 3 (30%) patients with functional PMA. Two patients with normal anterior pituitary function before SFRT developed new deficits 25 and 65 months after treatment. The 5-year survival without new anterior pituitary deficit was thus 95.8%. Five patients with visual field defect had improved visual function and 1 patient with no visual defect prior to SFRT, but an optic chiasm abutting tumor, had a decline in visual function. The estimated 5-year vision and pituitary function preservation rates were 93.2% and 95.8%, respectively. Conclusions SFRT is a safe and effective treatment for patients with PMA, although longer follow-up is needed to evaluate long-term outcomes. In this study, approximately 1 patient with visual field defect out of two had an improved visual function. PMID:22152397

Congenital Anorectal Malformation Severity Does Not Predict Severity of Congenital Heart Defects.

PubMed

Jonker, Jara E; Liem, Eryn T; Elzenga, Nynke J; Molenbuur, Bouwe; Trzpis, Monika; Broens, Paul M A

2016-12-01

To determine the prevalence of congenital heart defects (CHDs) in patients with mild or severe congenital anorectal malformations (CARMs), and whether all patients with CARM need pediatric cardiology screening. We included 129 patients with CARM born between 2004 and 2013, and referred to University Medical Center Groningen. Recto-perineal and recto-vestibular fistulas were classified as mild CARMs, all others as severe. Significant patent foramen ovale, secundum atrial septal defect, and small ventricular septum defect were classified as minor CHDs, all others as major. Of 129 patients with CARM, 67% had mild CARM, 33% severe CARM, and 17% were additionally diagnosed with CHD. CHDs were distributed equally in patients with mild or severe CARMs. Patients with multiple congenital abnormalities were more frequently diagnosed with CHD (n = 16, 36%) than patients without multiple congenital malformations (n = 5, 9%, P = .001). Patients with CARM diagnosed with CHD using pediatric cardiac echo screening were younger than 3 months of age at diagnosis. Earlier general pediatric examinations missed 7 (50%) children with mild and 4 (50%) with severe CHDs. The severity of CARM could predict neither prevalence nor severity of CHD. More than one-half of CHDs were missed during the first physical examination. No new CHDs were found in patients older than 3 months of age at the time CARMs were diagnosed. We recommend screening all patients with CARM younger than 3 months of age for CHD at the time CARM is diagnosed. Preoperative echocardiography should be the rule in children younger than 3 months of age and with multiple congenital anomalies. Copyright © 2016 Elsevier Inc. All rights reserved.

[Clinical epidemiological study of neural tube defects classified according to the five sites of closure].

PubMed

Sanchis Calvo, A; Martínez- Frías, M

2001-02-01

To identify the frequency at birth of neural tube defects (NTD) in the Spanish population. NTDs were considered as a whole as well as according to the different sites of closure failure, following the theory of multisite closure of the neural tube. To analyze the epidemiological characteristics of the different sites. Data derived from the Spanish Collaborative Study of Congenital Malformations (ECEMC), from April 1976 to March 1995. Among the 1,222,698 live births during this period, 784 infants had NTD were controlled. Among these, 784 infants had NTD. The prevalence of NTD in our population was 1.01 per 1,000 births, a frequency which is considered medium-to low. Only 5.74% of the NTD were of known etiology: 2.17% were genic, 1.27% were chromosomic and 2.29% were environmental. Excluding NTD of genetic etiology, whether genic or chromosomic, most of the remaining were isolated defects (multifactorial) and 16.78% multiple malformations. Site 1, where the closure of the neural tube starts, represented 24% of all the affected sites. However, more than 50% of the NTDs corresponded to closure failure at the junction of two sites. As in other populations with a low prevalence of NTD at birth, the prevalence of these defects in our population showed a trend to decrease with time, due to the possibility of interrupting gestation after prenatal diagnosis. All the NTD could be classified according to the theory of multisite closure of the neural tube, including 13 cases with several noncontiguous affected sites. Two types of NTD were observed: in the first, closure failed to occur and in the second, two closures failed to meet.

Detection of early osteoarthritis in the centrodistal joints of Icelandic horses: Evaluation of radiography and low-field magnetic resonance imaging.

PubMed

Ley, C J; Björnsdóttir, S; Ekman, S; Boyde, A; Hansson, K

2016-01-01

Validated noninvasive detection methods for early osteoarthritis (OA) are required for OA prevention and early intervention treatment strategies. To evaluate radiography and low-field magnetic resonance imaging (MRI) for the detection of early stage OA osteochondral lesions in equine centrodistal joints using microscopy as the reference standard. Prospective imaging of live horses and imaging and microscopy of cadaver tarsal joints. Centrodistal (distal intertarsal) joints of 38 Icelandic research horses aged 27-29 months were radiographed. Horses were subjected to euthanasia approximately 2 months later and cadaver joints examined with low-field MRI. Osteochondral joint specimens were classified as negative or positive for OA using light microscopy histology or scanning electron microscopy. Radiographs and MRIs were evaluated for osteochondral lesions and results compared with microscopy. Forty-two joints were classified OA positive with microscopy. Associations were detected between microscopic OA and the radiography lesion categories; mineralisation front defect (P<0.0001), joint margin lesion (P<0.0001), central osteophyte (P = 0.03) and the low-field MRI lesion categories; mineralisation front defect (P = 0.01), joint margin lesion (P = 0.02) and articular cartilage lesion (P = 0.0003). The most frequent lesion category detected in microscopic OA positive joints was the mineralisation front defect in radiographs (28/42 OA positive joints, specificity 97%, sensitivity 67%). No significant differences were detected between the sensitivity and specificity of radiography and low-field MRI pooled lesion categories, but radiography was often superior when individual lesion categories were compared. Early stage centrodistal joint OA changes may be detected with radiography and low-field MRI. Detection of mineralisation front defects in radiographs may be a useful screening method for detection of early OA in centrodistal joints of young Icelandic horses. © 2015 EVJ Ltd.

Evolutionary Design of a Robotic Material Defect Detection System

NASA Technical Reports Server (NTRS)

Ballard, Gary; Howsman, Tom; Craft, Mike; ONeil, Daniel; Steincamp, Jim; Howell, Joe T. (Technical Monitor)

2002-01-01

During the post-flight inspection of SSME engines, several inaccessible regions must be disassembled to inspect for defects such as cracks, scratches, gouges, etc. An improvement to the inspection process would be the design and development of very small robots capable of penetrating these inaccessible regions and detecting the defects. The goal of this research was to utilize an evolutionary design approach for the robotic detection of these types of defects. A simulation and visualization tool was developed prior to receiving the hardware as a development test bed. A small, commercial off-the-shelf (COTS) robot was selected from several candidates as the proof of concept robot. The basic approach to detect the defects was to utilize Cadmium Sulfide (CdS) sensors to detect changes in contrast of an illuminated surface. A neural network, optimally designed utilizing a genetic algorithm, was employed to detect the presence of the defects (cracks). By utilization of the COTS robot and US sensors, the research successfully demonstrated that an evolutionarily designed neural network can detect the presence of surface defects.

Profiling defect depth in composite materials using thermal imaging NDE

NASA Astrophysics Data System (ADS)

Obeidat, Omar; Yu, Qiuye; Han, Xiaoyan

2018-04-01

Sonic Infrared (IR) NDE, is a relatively new NDE technology; it has been demonstrated as a reliable and sensitive method to detect defects. SIR uses ultrasonic excitation with IR imaging to detect defects and flaws in the structures being inspected. An IR camera captures infrared radiation from the target for a period of time covering the ultrasound pulse. This period of time may be much longer than the pulse depending on the defect depth and the thermal properties of the materials. With the increasing deployment of composites in modern aerospace and automobile structures, fast, wide-area and reliable NDE methods are necessary. Impact damage is one of the major concerns in modern composites. Damage can occur at a certain depth without any visual indication on the surface. Defect depth information can influence maintenance decisions. Depth profiling relies on the time delays in the captured image sequence. We'll present our work on the defect depth profiling by using the temporal information of IR images. An analytical model is introduced to describe heat diffusion from subsurface defects in composite materials. Depth profiling using peak time is introduced as well.

Clinical Correlates of Computationally Derived Visual Field Defect Archetypes in Patients from a Glaucoma Clinic.

PubMed

Cai, Sophie; Elze, Tobias; Bex, Peter J; Wiggs, Janey L; Pasquale, Louis R; Shen, Lucy Q

2017-04-01

To assess the clinical validity of visual field (VF) archetypal analysis, a previously developed machine learning method for decomposing any Humphrey VF (24-2) into a weighted sum of clinically recognizable VF loss patterns. For each of 16 previously identified VF loss patterns ("archetypes," denoted AT1 through AT16), we screened 30,995 reliable VFs to select 10-20 representative patients whose VFs had the highest decomposition coefficients for each archetype. VF global indices and patient ocular and demographic features were extracted retrospectively. Based on resemblances between VF archetypes and clinically observed VF patterns, hypotheses were generated for associations between certain VF archetypes and clinical features, such as an association between AT6 (central island, representing severe VF loss) and large cup-to-disk ratio (CDR). Distributions of the selected clinical features were compared between representative eyes of certain archetypes and all other eyes using the two-tailed t-test or Fisher exact test. 243 eyes from 243 patients were included, representative of AT1 through AT16. CDR was more often ≥ 0.7 among eyes representative of AT6 (central island; p = 0.002), AT10 (inferior arcuate defect; p = 0.048), AT14 (superior paracentral defect; p = 0.016), and AT16 (inferior paracentral defect; p = 0.016) than other eyes. CDR was more often < 0.7 among eyes representative of AT1 (no focal defect; p < 0.001) and AT2 (superior defect; p = 0.027), which was also associated with ptosis (p < 0.001). AT12 (temporal hemianopia) was associated with history of stroke (p = 0.022). AT11 (concentric peripheral defect) trended toward association with trial lens correction > 6D (p = 0.069). Shared clinical features between computationally derived VF archetypes and clinically observed VF patterns support the clinical validity of VF archetypal analysis.

Quasi-Conformal Remapping For Compensation Of Human Visual Field Defects: Advances In Image Remapping For Human Field Defects

NASA Astrophysics Data System (ADS)

Juday, Richard D.; Loshin, David S.

1989-06-01

We are investigating image coordinate transformations possibly to be used in a low vision aid for human patients. These patients typically have field defects with localized retinal dysfunction predominately central (age related maculopathy) or peripheral (retinitis pigmentosa). Previously we have shown simple eccentricity-only remappings which do not maintain conformality. In this report we present our initial attempts on developing images which hold quasi-conformality after remapping. Although the quasi-conformal images may have less local distortion, there are discontinuities in the image which may counterindicate this type of transformation for the low vision application.

Pulse Phase Dynamic Thermal Tomography Investigation on the Defects of the Solid-Propellant Missile Engine Cladding Layer

NASA Astrophysics Data System (ADS)

Peng, Wei; Wang, Fei; Liu, Jun-yan; Xiao, Peng; Wang, Yang; Dai, Jing-min

2018-04-01

Pulse phase dynamic thermal tomography (PP-DTT) was introduced as a nondestructive inspection technique to detect the defects of the solid-propellant missile engine cladding layer. One-dimensional thermal wave mathematical model stimulated by pulse signal was developed and employed to investigate the thermal wave transmission characteristics. The pulse phase algorithm was used to extract the thermal wave characteristic of thermal radiation. Depth calibration curve was obtained by fuzzy c-means algorithm. Moreover, PP-DTT, a depth-resolved photothermal imaging modality, was employed to enable three-dimensional (3D) visualization of cladding layer defects. The comparison experiment between PP-DTT and classical dynamic thermal tomography was investigated. The results showed that PP-DTT can reconstruct the 3D topography of defects in a high quality.

Ensembles of novelty detection classifiers for structural health monitoring using guided waves

NASA Astrophysics Data System (ADS)

Dib, Gerges; Karpenko, Oleksii; Koricho, Ermias; Khomenko, Anton; Haq, Mahmoodul; Udpa, Lalita

2018-01-01

Guided wave structural health monitoring uses sparse sensor networks embedded in sophisticated structures for defect detection and characterization. The biggest challenge of those sensor networks is developing robust techniques for reliable damage detection under changing environmental and operating conditions (EOC). To address this challenge, we develop a novelty classifier for damage detection based on one class support vector machines. We identify appropriate features for damage detection and introduce a feature aggregation method which quadratically increases the number of available training observations. We adopt a two-level voting scheme by using an ensemble of classifiers and predictions. Each classifier is trained on a different segment of the guided wave signal, and each classifier makes an ensemble of predictions based on a single observation. Using this approach, the classifier can be trained using a small number of baseline signals. We study the performance using Monte-Carlo simulations of an analytical model and data from impact damage experiments on a glass fiber composite plate. We also demonstrate the classifier performance using two types of baseline signals: fixed and rolling baseline training set. The former requires prior knowledge of baseline signals from all EOC, while the latter does not and leverages the fact that EOC vary slowly over time and can be modeled as a Gaussian process.

Pituitary gene mutations and the growth hormone pathway.

PubMed

Moseley, C T; Phillips, J A

2000-01-01

Hereditary forms of pituitary insufficiency not associated with anatomic defects of the central nervous system, hypothalamus, or pituitary are a heterogeneous group of disorders that result from interruptions at different points in the hypothalamic-pituitary-somatomedin-peripheral tissue axis. These different types of pituitary dwarfism can be classified on the level of the defect; mode of inheritance; whether the phenotype is isolated growth hormone deficiency (IGHD) or combined pituitary hormone deficiency (CPHD); whether the hormone is absent, deficient, or abnormal; and, in patients with GH resistance, whether insulin-like growth factor 1 (IGF1) is deficient due to GH receptor or IGF1 defects. Information on each disorder is summarized. More detailed information can be obtained through the electronic database Online Mendelian Inheritance in Man which is available at http://www3.ncbi.nlm.nih.gov/Omim/.

Prognostic evaluation in obese patients using a dedicated multipinhole cadmium-zinc telluride SPECT camera.

PubMed

De Lorenzo, Andrea; Peclat, Thais; Amaral, Ana Carolina; Lima, Ronaldo S L

2016-02-01

The purpose of this study is to evaluate the prognostic value of myocardial perfusion SPECT obtained in CZT cameras (CZT-SPECT) with multipinhole collimation in obese patients. CZT-SPECT may be technically challenging in the obese, and its prognostic value remains largely unknown. Patients underwent single-day, rest/stress (supine and prone) imaging. Images were visually inspected and graded as poor, fair or good/excellent. Summed stress and difference scores (SSS and SDS, respectively) were converted into percentages of total perfusion defect and of ischemic defect by division by the maximum possible score. Obesity was defined as a body mass index (BMI) ≥ 30 kg/m(2) and classified as class I (BMI 30-34.9 kg/m(2)), II (BMI 35-39.9 kg/m(2)), or III (BMI ≥ 40 kg/m(2)). Patients were followed-up by telephone interview for the occurrence of all-cause death, myocardial infarction or revascularization. A Cox proportional hazards analysis was used to assess the independent predictors of death. Among 1396 patients, 365 (26.1 %) were obese (mean BMI 33.9 ± 3.6; 17.5 % class I, 3.4 % class II, and 3.4 % class III). Image quality was good/excellent in 94.5 % of the obese patients. The annualized mortality rates were not significantly different among obese and non-obese patients, being <1 % with normal CZT-SPECT, and increased with the degree of scan abnormality in both obese and non-obese patients. Age, the use of pharmacologic stress and an abnormal CZT-SPECT, but not obesity, were independent predictors of death. In obese patients, single-day rest/stress CZT-SPECT with a multipinhole camera provides prognostic discrimination with high image quality.

Separability of Abstract-Category and Specific-Exemplar Visual Object Subsystems: Evidence from fMRI Pattern Analysis

PubMed Central

McMenamin, Brenton W.; Deason, Rebecca G.; Steele, Vaughn R.; Koutstaal, Wilma; Marsolek, Chad J.

2014-01-01

Previous research indicates that dissociable neural subsystems underlie abstract-category (AC) recognition and priming of objects (e.g., cat, piano) and specific-exemplar (SE) recognition and priming of objects (e.g., a calico cat, a different calico cat, a grand piano, etc.). However, the degree of separability between these subsystems is not known, despite the importance of this issue for assessing relevant theories. Visual object representations are widely distributed in visual cortex, thus a multivariate pattern analysis (MVPA) approach to analyzing functional magnetic resonance imaging (fMRI) data may be critical for assessing the separability of different kinds of visual object processing. Here we examined the neural representations of visual object categories and visual object exemplars using multi-voxel pattern analyses of brain activity elicited in visual object processing areas during a repetition-priming task. In the encoding phase, participants viewed visual objects and the printed names of other objects. In the subsequent test phase, participants identified objects that were either same-exemplar primed, different-exemplar primed, word-primed, or unprimed. In visual object processing areas, classifiers were trained to distinguish same-exemplar primed objects from word-primed objects. Then, the abilities of these classifiers to discriminate different-exemplar primed objects and word-primed objects (reflecting AC priming) and to discriminate same-exemplar primed objects and different-exemplar primed objects (reflecting SE priming) was assessed. Results indicated that (a) repetition priming in occipital-temporal regions is organized asymmetrically, such that AC priming is more prevalent in the left hemisphere and SE priming is more prevalent in the right hemisphere, and (b) AC and SE subsystems are weakly modular, not strongly modular or unified. PMID:25528436

Separability of abstract-category and specific-exemplar visual object subsystems: evidence from fMRI pattern analysis.

PubMed

McMenamin, Brenton W; Deason, Rebecca G; Steele, Vaughn R; Koutstaal, Wilma; Marsolek, Chad J

2015-02-01

Previous research indicates that dissociable neural subsystems underlie abstract-category (AC) recognition and priming of objects (e.g., cat, piano) and specific-exemplar (SE) recognition and priming of objects (e.g., a calico cat, a different calico cat, a grand piano, etc.). However, the degree of separability between these subsystems is not known, despite the importance of this issue for assessing relevant theories. Visual object representations are widely distributed in visual cortex, thus a multivariate pattern analysis (MVPA) approach to analyzing functional magnetic resonance imaging (fMRI) data may be critical for assessing the separability of different kinds of visual object processing. Here we examined the neural representations of visual object categories and visual object exemplars using multi-voxel pattern analyses of brain activity elicited in visual object processing areas during a repetition-priming task. In the encoding phase, participants viewed visual objects and the printed names of other objects. In the subsequent test phase, participants identified objects that were either same-exemplar primed, different-exemplar primed, word-primed, or unprimed. In visual object processing areas, classifiers were trained to distinguish same-exemplar primed objects from word-primed objects. Then, the abilities of these classifiers to discriminate different-exemplar primed objects and word-primed objects (reflecting AC priming) and to discriminate same-exemplar primed objects and different-exemplar primed objects (reflecting SE priming) was assessed. Results indicated that (a) repetition priming in occipital-temporal regions is organized asymmetrically, such that AC priming is more prevalent in the left hemisphere and SE priming is more prevalent in the right hemisphere, and (b) AC and SE subsystems are weakly modular, not strongly modular or unified. Copyright © 2014 Elsevier Inc. All rights reserved.

Objective automated quantification of fluorescence signal in histological sections of rat lens.

PubMed

Talebizadeh, Nooshin; Hagström, Nanna Zhou; Yu, Zhaohua; Kronschläger, Martin; Söderberg, Per; Wählby, Carolina

2017-08-01

Visual quantification and classification of fluorescent signals is the gold standard in microscopy. The purpose of this study was to develop an automated method to delineate cells and to quantify expression of fluorescent signal of biomarkers in each nucleus and cytoplasm of lens epithelial cells in a histological section. A region of interest representing the lens epithelium was manually demarcated in each input image. Thereafter, individual cell nuclei within the region of interest were automatically delineated based on watershed segmentation and thresholding with an algorithm developed in Matlab™. Fluorescence signal was quantified within nuclei, cytoplasms and juxtaposed backgrounds. The classification of cells as labelled or not labelled was based on comparison of the fluorescence signal within cells with local background. The classification rule was thereafter optimized as compared with visual classification of a limited dataset. The performance of the automated classification was evaluated by asking 11 independent blinded observers to classify all cells (n = 395) in one lens image. Time consumed by the automatic algorithm and visual classification of cells was recorded. On an average, 77% of the cells were correctly classified as compared with the majority vote of the visual observers. The average agreement among visual observers was 83%. However, variation among visual observers was high, and agreement between two visual observers was as low as 71% in the worst case. Automated classification was on average 10 times faster than visual scoring. The presented method enables objective and fast detection of lens epithelial cells and quantification of expression of fluorescent signal with an accuracy comparable with the variability among visual observers. © 2017 International Society for Advancement of Cytometry. © 2017 International Society for Advancement of Cytometry.

Visual Sensitivities and Discriminations and Their Role in Aviation

DTIC Science & Technology

1987-10-30

both x and y, Aimn can be found by using one quarter of the plane. Hence 2P0r far.eco(-keosy) Ahm = i coa nv (coa x + kcoa y)cos mx dx dy since f(z,y...198-201. 142. Neima D, LeBlanc R & Regan D (1984) Visual field defects in ocular hypertension and glaucoma . Arch Ophthalmol 102, 1042-5. 143. Regan D...Neima D (1984) Visual fatigue and VEPs in multiple sclerosis, glaucoma , ocular hypertension and Parkinson’s disease. J Neurol Neurosurg Psychiat 47

The reliability and clinical correlates of figure-ground perception in schizophrenia.

PubMed

Malaspina, Dolores; Simon, Naomi; Goetz, Raymond R; Corcoran, Cheryl; Coleman, Eliza; Printz, David; Mujica-Parodi, Lilianne; Wolitzky, Rachel

2004-01-01

Schizophrenia subjects are impaired in a number of visual attention paradigms. However, their performance on tests of figure-ground visual perception (FGP), which requires subjects to visually discriminate figures embedded in a rival background, is relatively unstudied. We examined FGP in 63 schizophrenia patients and 27 control subjects and found that the patients performed the FGP test reliably and had significantly lower FGP scores than the control subjects. Figure-ground visual perception was significantly correlated with other neuropsychological test scores and was inversely related to negative symptoms. It was unrelated to antipsychotic medication treatment. Figure-ground visual perception depends on "top down" processing of visual stimuli, and thus this data suggests that dysfunction in the higher-level pathways that modulate visual perceptual processes may also be related to a core defect in schizophrenia.

Integrating image processing and classification technology into automated polarizing film defect inspection

NASA Astrophysics Data System (ADS)

Kuo, Chung-Feng Jeffrey; Lai, Chun-Yu; Kao, Chih-Hsiang; Chiu, Chin-Hsun

2018-05-01

In order to improve the current manual inspection and classification process for polarizing film on production lines, this study proposes a high precision automated inspection and classification system for polarizing film, which is used for recognition and classification of four common defects: dent, foreign material, bright spot, and scratch. First, the median filter is used to remove the impulse noise in the defect image of polarizing film. The random noise in the background is smoothed by the improved anisotropic diffusion, while the edge detail of the defect region is sharpened. Next, the defect image is transformed by Fourier transform to the frequency domain, combined with a Butterworth high pass filter to sharpen the edge detail of the defect region, and brought back by inverse Fourier transform to the spatial domain to complete the image enhancement process. For image segmentation, the edge of the defect region is found by Canny edge detector, and then the complete defect region is obtained by two-stage morphology processing. For defect classification, the feature values, including maximum gray level, eccentricity, the contrast, and homogeneity of gray level co-occurrence matrix (GLCM) extracted from the images, are used as the input of the radial basis function neural network (RBFNN) and back-propagation neural network (BPNN) classifier, 96 defect images are then used as training samples, and 84 defect images are used as testing samples to validate the classification effect. The result shows that the classification accuracy by using RBFNN is 98.9%. Thus, our proposed system can be used by manufacturing companies for a higher yield rate and lower cost. The processing time of one single image is 2.57 seconds, thus meeting the practical application requirement of an industrial production line.

Laterality Defects Other Than Situs Inversus Totalis in Primary Ciliary Dyskinesia

PubMed Central

Davis, Stephanie D.; Ferkol, Thomas; Dell, Sharon D.; Rosenfeld, Margaret; Olivier, Kenneth N.; Sagel, Scott D.; Milla, Carlos; Zariwala, Maimoona A.; Wolf, Whitney; Carson, Johnny L.; Hazucha, Milan J.; Burns, Kimberlie; Robinson, Blair; Knowles, Michael R.; Leigh, Margaret W.

2014-01-01

BACKGROUND: Motile cilia dysfunction causes primary ciliary dyskinesia (PCD), situs inversus totalis (SI), and a spectrum of laterality defects, yet the prevalence of laterality defects other than SI in PCD has not been prospectively studied. METHODS: In this prospective study, participants with suspected PCD were referred to our multisite consortium. We measured nasal nitric oxide (nNO) level, examined cilia with electron microscopy, and analyzed PCD-causing gene mutations. Situs was classified as (1) situs solitus (SS), (2) SI, or (3) situs ambiguus (SA), including heterotaxy. Participants with hallmark electron microscopic defects, biallelic gene mutations, or both were considered to have classic PCD. RESULTS: Of 767 participants (median age, 8.1 years, range, 0.1-58 years), classic PCD was defined in 305, including 143 (46.9%), 125 (41.0%), and 37 (12.1%) with SS, SI, and SA, respectively. A spectrum of laterality defects was identified with classic PCD, including 2.6% and 2.3% with SA plus complex or simple cardiac defects, respectively; 4.6% with SA but no cardiac defect; and 2.6% with an isolated possible laterality defect. Participants with SA and classic PCD had a higher prevalence of PCD-associated respiratory symptoms vs SA control participants (year-round wet cough, P < .001; year-round nasal congestion, P = .015; neonatal respiratory distress, P = .009; digital clubbing, P = .021) and lower nNO levels (median, 12 nL/min vs 252 nL/min; P < .001). CONCLUSIONS: At least 12.1% of patients with classic PCD have SA and laterality defects ranging from classic heterotaxy to subtle laterality defects. Specific clinical features of PCD and low nNO levels help to identify PCD in patients with laterality defects. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT00323167; URL: www.clinicaltrials.gov PMID:24577564

A fast button surface defects detection method based on convolutional neural network

NASA Astrophysics Data System (ADS)

Liu, Lizhe; Cao, Danhua; Wu, Songlin; Wu, Yubin; Wei, Taoran

2018-01-01

Considering the complexity of the button surface texture and the variety of buttons and defects, we propose a fast visual method for button surface defect detection, based on convolutional neural network (CNN). CNN has the ability to extract the essential features by training, avoiding designing complex feature operators adapted to different kinds of buttons, textures and defects. Firstly, we obtain the normalized button region and then use HOG-SVM method to identify the front and back side of the button. Finally, a convolutional neural network is developed to recognize the defects. Aiming at detecting the subtle defects, we propose a network structure with multiple feature channels input. To deal with the defects of different scales, we take a strategy of multi-scale image block detection. The experimental results show that our method is valid for a variety of buttons and able to recognize all kinds of defects that have occurred, including dent, crack, stain, hole, wrong paint and uneven. The detection rate exceeds 96%, which is much better than traditional methods based on SVM and methods based on template match. Our method can reach the speed of 5 fps on DSP based smart camera with 600 MHz frequency.

Natural course of visual field loss in patients with Type 2 Usher syndrome.

PubMed

Fishman, Gerald A; Bozbeyoglu, Simge; Massof, Robert W; Kimberling, William

2007-06-01

To evaluate the natural course of visual field loss in patients with Type 2 Usher syndrome and different patterns of visual field loss. Fifty-eight patients with Type 2 Usher syndrome who had at least three visual field measurements during a period of at least 3 years were studied. Kinetic visual fields measured on a standard calibrated Goldmann perimeter with II4e and V4e targets were analyzed. The visual field areas in both eyes were determined by planimetry with the use of a digitalizing tablet and computer software and expressed in square inches. The data for each visual field area measurement were transformed to a natural log unit. Using a mixed model regression analysis, values for the half-life of field loss (time during which half of the remaining field area is lost) were estimated. Three different patterns of visual field loss were identified, and the half-life time for each pattern of loss was calculated. Of the 58 patients, 11 were classified as having pattern type I, 12 with pattern type II, and 14 with pattern type III. Of 21 patients whose visual field loss was so advanced that they could not be classified, 15 showed only a small residual central field (Group A) and 6 showed a residual central field with a peripheral island (Group B). The average half-life times varied between 3.85 and 7.37 for the II4e test target and 4.59 to 6.42 for the V4e target. There was no statistically significant difference in the half-life times between the various patterns of field loss or for the test targets. The average half-life times for visual field loss in patients with Usher syndrome Type 2 were statistically similar among those patients with different patterns of visual field loss. These findings will be useful for counseling patients with Type 2 Usher syndrome as to their prognosis for anticipated visual field loss.

41 CFR 51-1.3 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... whose visual acuity, if better than 20/200, is accompanied by a limit to the field of vision in the... congenital defect) which so limits the person's functional capabilities (mobility, communication, self-care...

Visual Field Abnormalities among Adolescent Boys with Hearing Impairments

PubMed Central

KHORRAMI-NEJAD, Masoud; HERAVIAN, Javad; SEDAGHAT, Mohamad-Reza; MOMENI-MOGHADAM, Hamed; SOBHANI-RAD, Davood; ASKARIZADEH, Farshad

2016-01-01

The aim of this study was to compare the visual field (VF) categorizations (based on the severity of VF defects) between adolescent boys with hearing impairments and those with normal hearing. This cross-sectional study involved the evaluation of the VF of 64 adolescent boys with hearing impairments and 68 age-matched boys with normal hearing at high schools in Tehran, Iran, in 2013. All subjects had an intelligence quotient (IQ) > 70. The hearing impairments were classified based on severity and time of onset. Participants underwent a complete eye examination, and the VFs were investigated using automated perimetry with a Humphrey Visual Field Analyzer. This device was used to determine their foveal threshold (FT), mean deviation (MD), and Glaucoma Hemifield Test (GHT) results. Most (50%) of the boys with hearing impairments had profound hearing impairments. There was no significant between-group difference in age (P = 0.49) or IQ (P = 0.13). There was no between-group difference in the corrected distance visual acuity (P = 0.183). According to the FT, MD, and GHT results, the percentage of boys with abnormal VFs in the hearing impairment group was significantly greater than that in the normal hearing group: 40.6% vs. 22.1%, 59.4% vs. 19.1%, and 31.2% vs. 8.8%, respectively (P < 0.0001). The mean MD in the hearing impairment group was significantly worse than that in the normal hearing group (-0.79 ± 2.04 and -4.61 ± 6.52 dB, respectively, P < 0.0001), and the mean FT was also significantly worse (38.97 ± 1.66 vs. 35.30 ± 1.43 dB, respectively, P <0.0001). Moreover, there was a significant between-group difference in the GHT results (P < 0.0001). Thus, there were higher percentages of boys with VF abnormalities and higher mean MD, FT, and GHT results among those with hearing impairments compared to those with normal hearing. These findings emphasize the need for detailed VF assessments for patients with hearing impairments. PMID:28293650

An improved method for characterizing photoresist lithographic and defectivity performance for sub-20nm node lithography

NASA Astrophysics Data System (ADS)

Amblard, Gilles; Purdy, Sara; Cooper, Ryan; Hockaday, Marjory

2016-03-01

The overall quality and processing capability of lithographic materials are critical for ensuring high device yield and performance at sub-20nm technology nodes in a high volume manufacturing environment. Insufficient process margin and high line width roughness (LWR) cause poor manufacturing control, while high defectivity causes product failures. In this paper, we focus on the most critical layer of a sub-20nm technology node LSI device, and present an improved method for characterizing both lithographic and post-patterning defectivity performance of state-of-the-art immersion photoresists. Multiple formulations from different suppliers were used and compared. Photoresists were tested under various process conditions, and multiple lithographic metrics were investigated (depth of focus, exposure dose latitude, line width roughness, etc.). Results were analyzed and combined using an innovative approach based on advanced software, providing clearer results than previously available. This increased detail enables more accurate performance comparisons among the different photoresists. Post-patterning defectivity was also quantified, with defects reviewed and classified using state-of-the-art inspection tools. Correlations were established between the lithographic and post-patterning defectivity performances for each material, and overall ranking was established among the photoresists, enabling the selection of the best performer for implementation in a high volume manufacturing environment.

Machine vision based quality inspection of flat glass products

NASA Astrophysics Data System (ADS)

Zauner, G.; Schagerl, M.

2014-03-01

This application paper presents a machine vision solution for the quality inspection of flat glass products. A contact image sensor (CIS) is used to generate digital images of the glass surfaces. The presented machine vision based quality inspection at the end of the production line aims to classify five different glass defect types. The defect images are usually characterized by very little `image structure', i.e. homogeneous regions without distinct image texture. Additionally, these defect images usually consist of only a few pixels. At the same time the appearance of certain defect classes can be very diverse (e.g. water drops). We used simple state-of-the-art image features like histogram-based features (std. deviation, curtosis, skewness), geometric features (form factor/elongation, eccentricity, Hu-moments) and texture features (grey level run length matrix, co-occurrence matrix) to extract defect information. The main contribution of this work now lies in the systematic evaluation of various machine learning algorithms to identify appropriate classification approaches for this specific class of images. In this way, the following machine learning algorithms were compared: decision tree (J48), random forest, JRip rules, naive Bayes, Support Vector Machine (multi class), neural network (multilayer perceptron) and k-Nearest Neighbour. We used a representative image database of 2300 defect images and applied cross validation for evaluation purposes.

Visual field recovery after vision restoration therapy (VRT) is independent of eye movements: an eye tracker study.

PubMed

Kasten, Erich; Bunzenthal, Ulrike; Sabel, Bernhard A

2006-11-25

It has been argued that patients with visual field defects compensate for their deficit by making more frequent eye movements toward the hemianopic field and that visual field enlargements found after vision restoration therapy (VRT) may be an artefact of such eye movements. In order to determine if this was correct, we recorded eye movements in hemianopic subjects before and after VRT. Visual fields were measured in subjects with homonymous visual field defects (n=15) caused by trauma, cerebral ischemia or haemorrhage (lesion age >6 months). Visual field charts were plotted using both high-resolution perimetry (HRP) and conventional perimetry before and after a 3-month period of VRT, with eye movements being recorded with a 2D-eye tracker. This permitted quantification of eye positions and measurements of deviation from fixation. VRT lead to significant visual field enlargements as indicated by an increase of stimulus detection of 3.8% when tested using HRP and about 2.2% (OD) and 3.5% (OS) fewer misses with conventional perimetry. Eye movements were expressed as the standard deviations (S.D.) of the eye position recordings from fixation. Before VRT, the S.D. was +/-0.82 degrees horizontally and +/-1.16 degrees vertically; after VRT, it was +/-0.68 degrees and +/-1.39 degrees , respectively. A cluster analysis of the horizontal eye movements before VRT showed three types of subjects with (i) small (n=7), (ii) medium (n=7) or (iii) large fixation instability (n=1). Saccades were directed equally to the right or the left side; i.e., with no preference toward the blind hemifield. After VRT, many subjects showed a smaller variability of horizontal eye movements. Before VRT, 81.6% of the recorded eye positions were found within a range of 1 degrees horizontally from fixation, whereas after VRT, 88.3% were within that range. In the 2 degrees range, we found 94.8% before and 98.9% after VRT. Subjects moved their eyes 5 degrees or more 0.3% of the time before VRT versus 0.1% after VRT. Thus, in this study, subjects with homonymous visual field defects who were attempting to fixate a central target while their fields were being plotted, typically showed brief horizontal shifts with no preference toward or away from the blind hemifield. These eye movements were usually less than 1 degrees from fixation. Large saccades toward the blind field after VRT were very rare. VRT has no effect on either the direction or the amplitude of horizontal eye movements during visual field testing. These results argue against the theory that the visual field enlargements are artefacts induced by eye movements.

Optic Disc Drusen in Children

PubMed Central

Chang, Melinda Y.; Pineles, Stacy L.

2016-01-01

Optic disc drusen occur in 0.4% of children and consist of acellular intracellular and extracellular deposits that often become calcified over time. They are typically buried early in life and generally become superficial, and therefore visible, later in childhood, at the average age of 12 years. Their main clinical significance lies in the ability of optic disc drusen, particularly when buried, to simulate true optic disc edema. Misdiagnosing drusen as true disc edema may lead to an invasive and unnecessary workup for elevated intracranial pressure. Ancillary testing, including ultrasonography, fluorescein angiography, fundus autofluorescence, and optical coherence tomography, may aid in the correct diagnosis of optic disc drusen. Complications of optic disc drusen in children include visual field defects, hemorrhages, choroidal neovascular membrane, non-arteritic anterior ischemic optic neuropathy, and retinal vascular occlusions. Treatment options for these complications include ocular hypotensive agents for visual field defects and intravitreal anti-vascular endothelial growth factor (anti-VEGF) agents for choroidal neovascular membranes. In most cases, however, children with optic disc drusen can be managed by observation with serial examinations and visual field testing, once true optic disc edema has been excluded. PMID:27033945

Could Buerger's disease cause nonarteritic anterior ischemic optic neuropathy?: a rare case report.

PubMed

Korkmaz, Anil; Karti, Omer; Top Karti, Dilek; Yüksel, Bora; Zengin, Mehmet Ozgur; Kusbeci, Tuncay

2018-04-05

We present an interesting case with nonarteritic anterior ischemic optic neuropathy (NAION) accompanied by Buerger's disease. A 43-year-old man was referred to our neuro-ophthalmology clinic with a complaint of visual deterioration in the left eye that started 5 days ago. He suffered from Buerger's disease, and he had acute pain in the right lower limb below the knee. His best corrected visual acuity was 10/10 in the right eye and 2/10 in the left eye by Snellen chart. There was a relative afferent pupil defect in the left eye. The right optic disc was normal on fundus examination, and blurring, hemorrhagic swelling was found at the left optic disc. Inferior altitudinal visual field defect was observed in the left eye. Neurological examination was normal. Computed tomography angiography scan revealed occlusion in the right posterior tibial artery. Brain imaging and laboratory tests such as blood analyses, genetic screening, coagulation, and lipid panels were unremarkable. NAION may occur in patients with Buerger's disease, but it is extremely rare. Therefore, clinicians should be aware of this rare association.

Extent of resection in temporal lobectomy for epilepsy. II. Memory changes and neurologic complications.

PubMed

Katz, A; Awad, I A; Kong, A K; Chelune, G J; Naugle, R I; Wyllie, E; Beauchamp, G; Lüders, H

1989-01-01

We present correlations of extent of temporal lobectomy for intractable epilepsy with postoperative memory changes (20 cases) and abnormalities of visual field and neurologic examination (45 cases). Postoperative magnetic resonance imaging (MRI) in the coronal plane was used to quantify anteroposterior extent of resection of various quadrants of the temporal lobe, using a 20-compartment model of that structure. The Wechsler Memory Scale-Revised (WMS-R) was administered preoperatively and postoperatively. Postoperative decrease in percentage of retention of verbal material correlated with extent of medial resection of left temporal lobe, whereas decrease in percentage of retention of visual material correlated with extent of medial resection of right temporal lobe. These correlations approached but did not reach statistical significance. Extent of resection correlated significantly with the presence of visual field defect on perimetry testing but not with severity, denseness, or congruity of the defect. There was no correlation between postoperative dysphasia and extent of resection in any quadrant. Assessment of extent of resection after temporal lobectomy allows a rational interpretation of postoperative neurologic deficits in light of functional anatomy of the temporal lobe.

Four-dimensional ultrasonography of the fetal heart using color Doppler spatiotemporal image correlation.

PubMed

Gonçalves, Luís F; Romero, Roberto; Espinoza, Jimmy; Lee, Wesley; Treadwell, Marjorie; Chintala, Kavitha; Brandl, Helmut; Chaiworapongsa, Tinnakorn

2004-04-01

To describe clinical and research applications of 4-dimensional imaging of the fetal heart using color Doppler spatiotemporal image correlation. Forty-four volume data sets were acquired by color Doppler spatiotemporal image correlation. Seven subjects were examined: 4 fetuses without abnormalities, 1 fetus with ventriculomegaly and a hypoplastic cerebellum but normal cardiac anatomy, and 2 fetuses with cardiac anomalies detected by fetal echocardiography (1 case of a ventricular septal defect associated with trisomy 21 and 1 case of a double-inlet right ventricle with a 46,XX karyotype). The median gestational age at the time of examination was 21 3/7 weeks (range, 19 5/7-34 0/7 weeks). Volume data sets were reviewed offline by multiplanar display and volume-rendering methods. Representative images and online video clips illustrating the diagnostic potential of this technology are presented. Color Doppler spatiotemporal image correlation allowed multiplanar visualization of ventricular septal defects, multiplanar display and volume rendering of tricuspid regurgitation, volume rendering of the outflow tracts by color and power Doppler ultrasonography (both in a normal case and in a case of a double-inlet right ventricle with a double-outlet right ventricle), and visualization of venous streams at the level of the foramen ovale. Color Doppler spatiotemporal image correlation has the potential to simplify visualization of the outflow tracts and improve the evaluation of the location and extent of ventricular septal defects. Other applications include 3-dimensional evaluation of regurgitation jets and venous streams at the level of the foramen ovale.

Display Parameters and Requirements

NASA Astrophysics Data System (ADS)

Bahadur, Birendra

The following sections are included: * INTRODUCTION * HUMAN FACTORS * Anthropometry * Sensory * Cognitive * Discussions * THE HUMAN VISUAL SYSTEM - CAPABILITIES AND LIMITATIONS * Cornea * Pupil and Iris * Lens * Vitreous Humor * Retina * RODS - NIGHT VISION * CONES - DAY VISION * RODS AND CONES - TWILIGHT VISION * VISUAL PIGMENTS * MACULA * BLOOD * CHOROID COAT * Visual Signal Processing * Pathways to the Brain * Spatial Vision * Temporal Vision * Colour Vision * Colour Blindness * DICHROMATISM * Protanopia * Deuteranopia * Tritanopia * ANOMALOUS TRICHROMATISM * Protanomaly * Deuteranomaly * Tritanomaly * CONE MONOCHROMATISM * ROD MONOCHROMATISM * Using Colour Effectively * COLOUR MIXTURES AND THE CHROMATICITY DIAGRAM * Colour Matching Functions and Chromaticity Co-ordinates * CIE 1931 Colour Space * CIE PRIMARIES * CIE COLOUR MATCHING FUNCTIONS AND CHROMATICITY CO-ORDINATES * METHODS FOR DETERMINING TRISTIMULUS VALUES AND COLOUR CO-ORDINATES * Spectral Power Distribution Method * Filter Method * CIE 1931 CHROMATICITY DIAGRAM * ADDITIVE COLOUR MIXTURE * CIE 1976 Chromaticity Diagram * CIE Uniform Colour Spaces and Colour Difference Formulae * CIELUV OR L*u*v* * CIELAB OR L*a*b* * CIE COLOUR DIFFERENCE FORMULAE * Colour Temperature and CIE Standard Illuminants and source * RADIOMETRIC AND PHOTOMETRIC QUANTITIES * Photopic (Vλ and Scotopic (Vλ') Luminous Efficiency Function * Photometric and Radiometric Flux * Luminous and Radiant Intensities * Incidence: Illuminance and Irradiance * Exitance or Emittance (M) * Luminance and Radiance * ERGONOMIC REQUIREMENTS OF DISPLAYS * ELECTRO-OPTICAL PARAMETERS AND REQUIREMENTS * Contrast and Contrast Ratio * Luminance and Brightness * Colour Contrast and Chromaticity * Glare * Other Aspects of Legibility * SHAPE AND SIZE OF CHARACTERS * DEFECTS AND BLEMISHES * FLICKER AND DISTORTION * ANGLE OF VIEW * Switching Speed * Threshold and Threshold Characteristic * Measurement Techniques For Electro-optical Parameters * RADIOMETRIC MEASUREMENTS * Broadband Radiometry or Filtered Photodetector Radiometric Method * Spectroradiometric Method * PHOTOMETRIC MEASUREMENTS * COLOUR MEASUREMENTS * LUMINANCE, CONTRAST RATIO, THRESHOLD CHARACTERISTIC AND POLAR PLOT * SWITCHING SPEED * ELECTRICAL AND LIFE PARAMETERS AND REQUIREMENTS * Operating Voltage, Current Drainage and Power Consumption * Operating Frequency * Life Expectancy * LCD FAILURE MODES * Liquid Crystal Materials * Substrate Glass * Electrode Patterns * Alignment and Aligning Material * Peripheral and End Plug Seal * Spacers * Crossover Material * Polarizers and Reflectors * Connectors * Heater * Colour Filters * Backlighting System * Explanation For Some of the Observed Defects * BLOOMING PIXELS * POLARIZER RELATED DEFECTS * DIFFERENTIAL THERMAL EXPANSION RELATED DEFECTS * ELECTROCHEMICAL AND ELECTROHYDRODYNAMIC RELATED DEFECTS * REVERSE TWIST AND REVERSE TILT * MEMORY OR REMINISCENT CONTRAST * LCD RELIABILRY AND ACCELERATED LIFE TESTING * ACKNOWLEDGEMENTS * REFERENCES * APPENDIX

Retinitis Pigmentosa Sine Pigmento Mimicking a Chiasm Disease.

PubMed

Pellegrini, Francesco; Prosdocimo, Giovanni; Romano, Francesco; Interlandi, Emanuela

2017-08-01

A 75-year-old woman presented to her ophthalmologist complaining of visual loss for several years. The ophthalmic examination was remarkable for a bitemporal visual field defect. Magnetic resonance imaging (MRI) scan of the brain was normal without evidence of chiasm compression. Neuro-ophthalmic examination was consistent with a retinal rather than a chiasmal disease. Retinal multimodal imaging helped in the correct diagnosis of retinitis pigmentosa, later confirmed by genetic testing.

Visual brain plasticity induced by central and peripheral visual field loss.

PubMed

Sanda, Nicolae; Cerliani, Leonardo; Authié, Colas N; Sabbah, Norman; Sahel, José-Alain; Habas, Christophe; Safran, Avinoam B; Thiebaut de Schotten, Michel

2018-06-23

Disorders that specifically affect central and peripheral vision constitute invaluable models to study how the human brain adapts to visual deafferentation. We explored cortical changes after the loss of central or peripheral vision. Cortical thickness (CoTks) and resting-state cortical entropy (rs-CoEn), as a surrogate for neural and synaptic complexity, were extracted in 12 Stargardt macular dystrophy, 12 retinitis pigmentosa (tunnel vision stage), and 14 normally sighted subjects. When compared to controls, both groups with visual loss exhibited decreased CoTks in dorsal area V3d. Peripheral visual field loss also showed a specific CoTks decrease in early visual cortex and ventral area V4, while central visual field loss in dorsal area V3A. Only central visual field loss exhibited increased CoEn in LO-2 area and FG1. Current results revealed biomarkers of brain plasticity within the dorsal and the ventral visual streams following central and peripheral visual field defects.

Interocular asymmetry of the visual field defects in newly diagnosed normal-tension glaucoma, primary open-angle glaucoma, and chronic angle-closure glaucoma.

PubMed

Huang, Ping; Shi, Yan; Wang, Xin; Liu, Mugen; Zhang, Chun

2014-09-01

To compare the interocular asymmetry of visual field loss in newly diagnosed normal-tension glaucoma (NTG), primary open-angle glaucoma (POAG), and chronic angle-closure glaucoma (CACG) patients. Visual field results of 117 newly diagnosed, treatment-naive glaucoma patients (42 NTG, 38 POAG, and 37 CACG) were studied retrospectively. The following 3 visual field defect parameters were used to evaluate the interocular asymmetry: (1) global indices; (2) local mean deviations (MDs) of 6 predefined visual field areas; and (3) stage designated by glaucoma staging system 2. The differences of the above parameters between the trial eye (the eye with greater MDs) and the fellow eye in each subject were defined as interocular asymmetry scores. Interocular asymmetry of visual field loss was presented in all the 3 groups (all P<0.05). CACG group had greater total MD interocular asymmetry score compared with the NTG and POAG groups (among groups, P=0.008; NTG vs. CACG, P=0.005; POAG vs. CACG, P=0.009). CACG also presented with significantly higher local MD interocular asymmetry scores at central, inferior, and temporal areas compared with those of the POAG group and at inferior area compared with that of NTG group. No significant difference in either total or local MDs was detected between NTG and POAG (all P>0.05). Interocular asymmetry scores of glaucoma staging system 2 had no significant difference among the 3 groups (P=0.068). All CACG, POAG, and NTG groups presented with interocular asymmetric visual field loss at the time of diagnosis. CACG had greater interocular asymmetry compared with NTG and POAG. No significant interocular asymmetry difference was observed between NTG and POAG.

Dental enamel defects in adult coeliac disease: prevalence and correlation with symptoms and age at diagnosis.

PubMed

Trotta, Lucia; Biagi, Federico; Bianchi, Paola I; Marchese, Alessandra; Vattiato, Claudia; Balduzzi, Davide; Collesano, Vittorio; Corazza, Gino R

2013-12-01

Coeliac disease is a condition characterized by a wide spectrum of clinical manifestations. Any organ can be affected and, among others, dental enamel defects have been described. Our aims were to study the prevalence of dental enamel defects in adults with coeliac disease and to investigate a correlation between the grade of teeth lesion and clinical parameters present at the time of diagnosis of coeliac disease. A dental examination was performed in 54 coeliac disease patients (41 F, mean age 37 ± 13 years, mean age at diagnosis 31 ± 14 years). Symptoms leading to diagnosis were diarrhoea/weight loss (32 pts.), anaemia (19 pts.), familiarity (3 pts.); none of the patients was diagnosed because of enamel defects. At the time of evaluation, they were all on a gluten-free diet. Enamel defects were classified from grade 0 to 4 according to its severity. Enamel defects were observed in 46/54 patients (85.2%): grade 1 defects were seen in 18 patients (33.3%) grade 2 in 16 (29.6%), grade 3 in 8 (14.8%), and grade 4 in 4 (7.4%). We also observed that grades 3 and 4 were more frequent in patients diagnosed with classical rather than non-classical coeliac disease (10/32 vs. 2/20). However, this was not statistically significant. This study confirms that enamel defects are common in adult coeliac disease. Observation of enamel defects is an opportunity to diagnose coeliac disease. Copyright © 2013 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.

Automatic lip reading by using multimodal visual features

NASA Astrophysics Data System (ADS)

Takahashi, Shohei; Ohya, Jun

2013-12-01

Since long time ago, speech recognition has been researched, though it does not work well in noisy places such as in the car or in the train. In addition, people with hearing-impaired or difficulties in hearing cannot receive benefits from speech recognition. To recognize the speech automatically, visual information is also important. People understand speeches from not only audio information, but also visual information such as temporal changes in the lip shape. A vision based speech recognition method could work well in noisy places, and could be useful also for people with hearing disabilities. In this paper, we propose an automatic lip-reading method for recognizing the speech by using multimodal visual information without using any audio information such as speech recognition. First, the ASM (Active Shape Model) is used to track and detect the face and lip in a video sequence. Second, the shape, optical flow and spatial frequencies of the lip features are extracted from the lip detected by ASM. Next, the extracted multimodal features are ordered chronologically so that Support Vector Machine is performed in order to learn and classify the spoken words. Experiments for classifying several words show promising results of this proposed method.

[The Biometric Cabinet of the Escola de Educação Física do Exército: measuring and classifying to produce ideal bodies, 1930-1940].

PubMed

Gomes, Ana Carolina Vimieiro; Silva, André Luiz Dos Santos; Vaz, Alexandre Fernandez

2013-10-01

This paper analyzes biometrical and biotypological practices of the Biometric Cabinet of the Escola de Educação Física do Exército (Physical Education School of the Army) in Rio de Janeiro in the 1930s and 1940s, published in Revista de Educação Física do Exército. It was necessary to classify, monitor the results of the exercises periodically and measure morphological aspects of the bodies. The classifications were made in accordance with foreign parameters and an attempt was made to classify by type, quality and defects. The analysis of the practices of the Cabinet shows that biometrics and biotypology were complementary aspects of physical education, aiming at the standardization of bodies.

Association of Visual Acuity and Cognitive Impairment in Older Individuals: Fujiwara-kyo Eye Study

PubMed Central

Mine, Masashi; Miyata, Kimie; Morikawa, Masayuki; Nishi, Tomo; Okamoto, Nozomi; Kawasaki, Ryo; Yamashita, Hidetoshi; Kurumatani, Norio; Ogata, Nahoko

2016-01-01

Abstract Both visual impairment and cognitive impairment are essential factors that determine the quality of life in the aged population. The aim of this study was to determine if a correlation existed between visual acuity and cognitive impairment in an elderly Japanese population. The Fujiwara-kyo Eye Study was a cross-sectional study of individuals aged ≥68 years who lived in Nara Prefecture of Japan. Participants underwent ophthalmological examinations and cognitive function test. A mild visual impairment was defined as having a best corrected visual acuity (BCVA) >0.2 logarithm of the minimum angle of resolution (logMAR) units in the better eye. Cognitive impairment was defined as having a Mini-Mental State Examination (MMSE) score of ≤23 points. A total to 2818 individuals completed the examinations. The mean age of the participants was 76.3 ± 4.8 years (mean ± standard deviation). The mean BCVA of the better eye was −0.02 ± 0.13 logMAR units and 6.6% subjects were classified as being mildly visually impaired. The mean MMSE score was 27.3 ± 2.3 and 5.7% subjects were classified as being cognitively impaired. The proportion of subjects with cognitive or moderate visual impairment increased with age, and there was a significant correlation between the visual acuity and MMSE score (r = −0.10, p < 0.0001). Subjects with mild visual impairments had 2.4 times higher odds of having cognitive impairment than those without visual impairment (odds ratio 2.4, 95% confidence interval, 1.5–3.8, p < 0.001) after adjusting for age, sex, and length of education. We conclude that it may be important to maintain good visual acuity to reduce the risk of having cognitive impairment. PMID:27610269

Recognition and defect detection of dot-matrix text via variation-model based learning

NASA Astrophysics Data System (ADS)

Ohyama, Wataru; Suzuki, Koushi; Wakabayashi, Tetsushi

2017-03-01

An algorithm for recognition and defect detection of dot-matrix text printed on products is proposed. Extraction and recognition of dot-matrix text contains several difficulties, which are not involved in standard camera-based OCR, that the appearance of dot-matrix characters is corrupted and broken by illumination, complex texture in the background and other standard characters printed on product packages. We propose a dot-matrix text extraction and recognition method which does not require any user interaction. The method employs detected location of corner points and classification score. The result of evaluation experiment using 250 images shows that recall and precision of extraction are 78.60% and 76.03%, respectively. Recognition accuracy of correctly extracted characters is 94.43%. Detecting printing defect of dot-matrix text is also important in the production scene to avoid illegal productions. We also propose a detection method for printing defect of dot-matrix characters. The method constructs a feature vector of which elements are classification scores of each character class and employs support vector machine to classify four types of printing defect. The detection accuracy of the proposed method is 96.68 %.

Inline inspection of textured plastics surfaces

NASA Astrophysics Data System (ADS)

Michaeli, Walter; Berdel, Klaus

2011-02-01

This article focuses on the inspection of plastics web materials exhibiting irregular textures such as imitation wood or leather. They are produced in a continuous process at high speed. In this process, various defects occur sporadically. However, current inspection systems for plastics surfaces are able to inspect unstructured products or products with regular, i.e., highly periodic, textures, only. The proposed inspection algorithm uses the local binary pattern operator for texture feature extraction. For classification, semisupervised as well as supervised approaches are used. A simple concept for semisupervised classification is presented and applied for defect detection. The resulting defect-maps are presented to the operator. He assigns class labels that are used to train the supervised classifier in order to distinguish between different defect types. A concept for parallelization is presented allowing the efficient use of standard multicore processor PC hardware. Experiments with images of a typical product acquired in an industrial setting show a detection rate of 97% while achieving a false alarm rate below 1%. Real-time tests show that defects can be reliably detected even at haul-off speeds of 30 m/min. Further applications of the presented concept can be found in the inspection of other materials.

Precise design-based defect characterization and root cause analysis

NASA Astrophysics Data System (ADS)

Xie, Qian; Venkatachalam, Panneerselvam; Lee, Julie; Chen, Zhijin; Zafar, Khurram

2017-03-01

As semiconductor manufacturing continues its march towards more advanced technology nodes, it becomes increasingly important to identify and characterize design weak points, which is typically done using a combination of inline inspection data and the physical layout (or design). However, the employed methodologies have been somewhat imprecise, relying greatly on statistical techniques to signal excursions. For example, defect location error that is inherent to inspection tools prevents them from reporting the true locations of defects. Therefore, common operations such as background-based binning that are designed to identify frequently failing patterns cannot reliably identify specific weak patterns. They can only identify an approximate set of possible weak patterns, but within these sets there are many perfectly good patterns. Additionally, characterizing the failure rate of a known weak pattern based on inline inspection data also has a lot of fuzziness due to coordinate uncertainty. SEM (Scanning Electron Microscope) Review attempts to come to the rescue by capturing high resolution images of the regions surrounding the reported defect locations, but SEM images are reviewed by human operators and the weak patterns revealed in those images must be manually identified and classified. Compounding the problem is the fact that a single Review SEM image may contain multiple defective patterns and several of those patterns might not appear defective to the human eye. In this paper we describe a significantly improved methodology that brings advanced computer image processing and design-overlay techniques to better address the challenges posed by today's leading technology nodes. Specifically, new software techniques allow the computer to analyze Review SEM images in detail, to overlay those images with reference design to detect every defect that might be present in all regions of interest within the overlaid reference design (including several classes of defects that human operators will typically miss), to obtain the exact defect location on design, to compare all defective patterns thus detected against a library of known patterns, and to classify all defective patterns as either new or known. By applying the computer to these tasks, we automate the entire process from defective pattern identification to pattern classification with high precision, and we perform this operation en masse during R & D, ramp, and volume production. By adopting the methodology, whenever a specific weak pattern is identified, we are able to run a series of characterization operations to ultimately arrive at the root cause. These characterization operations can include (a) searching all pre-existing Review SEM images for the presence of the specific weak pattern to determine whether there is any spatial (within die or within wafer) or temporal (within any particular date range, before or after a mask revision, etc.) correlation and (b) understanding the failure rate of the specific weak pattern to prioritize the urgency of the problem, (c) comparing the weak pattern against an OPC (Optical Procimity Correction) Verification report or a PWQ (Process Window Qualification)/FEM (Focus Exposure Matrix) result to assess the likelihood of it being a litho-sensitive pattern, etc. After resolving the specific weak pattern, we will categorize it as known pattern, and the engineer will move forward with discovering new weak patterns.

Variation of expression defects in cell surface 190-kDa protein antigen of Streptococcus mutans.

PubMed

Lapirattanakul, Jinthana; Nomura, Ryota; Matsumoto-Nakano, Michiyo; Srisatjaluk, Ratchapin; Ooshima, Takashi; Nakano, Kazuhiko

2015-05-01

Streptococcus mutans, which consists of four serotypes, c, e, f, and k, possesses a 190-kDa cell surface protein antigen (PA) for initial tooth adhesion. We used Western blot analysis to determine PA expression in 750 S. mutans isolates from 150 subjects and found a significantly higher prevalence of the isolates with PA expression defects in serotypes f and k compared to serotypes c and e. Moreover, the defect patterns could be classified into three types; no PA expression on whole bacterial cells and in their supernatant samples (Type N1), PA expression mainly seen in supernatant samples (Type N2), and only low expression of PA in the samples of whole bacterial cells (Type W). The underlying reasons for the defects were mutations in the gene encoding PA as well as in the transcriptional processing of this gene for Type N1, defects in the sortase gene for Type N2, and low mRNA expression of PA for Type W. Since cellular hydrophobicity and phagocytosis susceptibility of the PA-defective isolates were significantly lower than those of the normal expression isolates, the potential implication of such defective isolates in systemic diseases involving bacteremia other than dental caries was suggested. Additionally, multilocus sequence typing was utilized to characterize S. mutans clones that represented a proportion of isolates with PA defects of 65-100%. Therefore, we described the molecular basis for variation defects in PA expression of S. mutans. Furthermore, we also emphasized the strong association between PA expression defects and serotypes f and k as well as the clonal relationships among these isolates. Copyright © 2015 Elsevier GmbH. All rights reserved.

Birth defects among children born to HIV-infected women: Pediatric AIDS Clinical Trials Protocols 219 and 219C

PubMed Central

Brogly, Susan B.; Abzug, Mark J.; Watts, D. Heather; Cunningham, Coleen K.; Williams, Paige L.; Oleske, James; Conway, Daniel; Sperling, Rhoda S.; Spiegel, Hans; Van Dyke, Russell B.

2010-01-01

Background Some studies have detected associations between in utero antiretroviral therapy (ARV) exposure and birth defects but evidence is inconclusive. Methods 2,202 HIV-exposed children enrolled in the Pediatric AIDS Clinical Trials Group 219 and 219C protocols before one year of age were included. Birth defects were classified using the Metropolitan Atlanta Congenital Defects Program (MACDP) coding. Logistic regression models were used to evaluate associations between first trimester in utero ARV exposure and birth defects. Results 117 live-born children had birth defects for a prevalence of 5.3% (95% CI: 4.4, 6.3). Prevalence did not differ by HIV infection status or overall ARV exposure; rates were 4.8% (95% CI: 3.7, 6.1) and 5.8% (95% CI: 4.2, 7.8) in children without and with first trimester ARV exposure, respectively. The defect rate was higher among children with first trimester efavirenz exposure (5/32, 15.6%) versus children without first trimester efavirenz exposure [adjusted odds ratio (aOR)=4.31 (95% CI: 1.56, 11.86)]. Protective effects of first trimester zidovudine exposure on musculoskeletal defects were detected [aOR=0.24 (95% CI: 0.08, 0.69)], while a higher risk of heart defects was found [aOR=2.04 (95% CI: 1.03, 4.05)]. Conclusion The prevalence of birth defects was higher in this cohort of HIV-exposed children than in other pediatric cohorts. There was no association with overall ARV exposure, but there were some associations with specific agents including efavirenz. Additional studies are needed to rule out confounding and to evaluate newer ARV agents. PMID:20539252

Human Actions Analysis: Templates Generation, Matching and Visualization Applied to Motion Capture of Highly-Skilled Karate Athletes

PubMed Central

Piekarczyk, Marcin; Ogiela, Marek R.

2017-01-01

The aim of this paper is to propose and evaluate the novel method of template generation, matching, comparing and visualization applied to motion capture (kinematic) analysis. To evaluate our approach, we have used motion capture recordings (MoCap) of two highly-skilled black belt karate athletes consisting of 560 recordings of various karate techniques acquired with wearable sensors. We have evaluated the quality of generated templates; we have validated the matching algorithm that calculates similarities and differences between various MoCap data; and we have examined visualizations of important differences and similarities between MoCap data. We have concluded that our algorithms works the best when we are dealing with relatively short (2–4 s) actions that might be averaged and aligned with the dynamic time warping framework. In practice, the methodology is designed to optimize the performance of some full body techniques performed in various sport disciplines, for example combat sports and martial arts. We can also use this approach to generate templates or to compare the correct performance of techniques between various top sportsmen in order to generate a knowledge base of reference MoCap videos. The motion template generated by our method can be used for action recognition purposes. We have used the DTW classifier with angle-based features to classify various karate kicks. We have performed leave-one-out action recognition for the Shorin-ryu and Oyama karate master separately. In this case, 100% actions were correctly classified. In another experiment, we used templates generated from Oyama master recordings to classify Shorin-ryu master recordings and vice versa. In this experiment, the overall recognition rate was 94.2%, which is a very good result for this type of complex action. PMID:29125560

A comprehensive statistical classifier of foci in the cell transformation assay for carcinogenicity testing.

PubMed

Callegaro, Giulia; Malkoc, Kasja; Corvi, Raffaella; Urani, Chiara; Stefanini, Federico M

2017-12-01

The identification of the carcinogenic risk of chemicals is currently mainly based on animal studies. The in vitro Cell Transformation Assays (CTAs) are a promising alternative to be considered in an integrated approach. CTAs measure the induction of foci of transformed cells. CTAs model key stages of the in vivo neoplastic process and are able to detect both genotoxic and some non-genotoxic compounds, being the only in vitro method able to deal with the latter. Despite their favorable features, CTAs can be further improved, especially reducing the possible subjectivity arising from the last phase of the protocol, namely visual scoring of foci using coded morphological features. By taking advantage of digital image analysis, the aim of our work is to translate morphological features into statistical descriptors of foci images, and to use them to mimic the classification performances of the visual scorer to discriminate between transformed and non-transformed foci. Here we present a classifier based on five descriptors trained on a dataset of 1364 foci, obtained with different compounds and concentrations. Our classifier showed accuracy, sensitivity and specificity equal to 0.77 and an area under the curve (AUC) of 0.84. The presented classifier outperforms a previously published model. Copyright © 2017 Elsevier Ltd. All rights reserved.

The precision-recall plot is more informative than the ROC plot when evaluating binary classifiers on imbalanced datasets.

PubMed

Saito, Takaya; Rehmsmeier, Marc

2015-01-01

Binary classifiers are routinely evaluated with performance measures such as sensitivity and specificity, and performance is frequently illustrated with Receiver Operating Characteristics (ROC) plots. Alternative measures such as positive predictive value (PPV) and the associated Precision/Recall (PRC) plots are used less frequently. Many bioinformatics studies develop and evaluate classifiers that are to be applied to strongly imbalanced datasets in which the number of negatives outweighs the number of positives significantly. While ROC plots are visually appealing and provide an overview of a classifier's performance across a wide range of specificities, one can ask whether ROC plots could be misleading when applied in imbalanced classification scenarios. We show here that the visual interpretability of ROC plots in the context of imbalanced datasets can be deceptive with respect to conclusions about the reliability of classification performance, owing to an intuitive but wrong interpretation of specificity. PRC plots, on the other hand, can provide the viewer with an accurate prediction of future classification performance due to the fact that they evaluate the fraction of true positives among positive predictions. Our findings have potential implications for the interpretation of a large number of studies that use ROC plots on imbalanced datasets.

Detection of paint polishing defects

NASA Astrophysics Data System (ADS)

Rebeggiani, S.; Wagner, M.; Mazal, J.; Rosén, B.-G.; Dahlén, M.

2018-06-01

Surface finish plays a major role on perceived product quality, and is the first thing a potential buyer sees. Today end-of-line repairs of the body of cars and trucks are inevitably to secure required surface quality. Defects that occur in the paint shop, like dust particles, are eliminated by manual sanding/polishing which lead to other types of defects when the last polishing step is not performed correctly or not fully completed. One of those defects is known as ‘polishing roses’ or holograms, which are incredibly hard to detect in artificial light but are clearly visible in sunlight. This paper will present the first tests with a measurement set-up newly developed to measure and analyse polishing roses. The results showed good correlations to human visual evaluations where repaired panels were estimated based on the defects’ intensity, severity and viewing angle.

Disorders of Platelet Function

PubMed Central

Huebsch, Lothar B.; Harker, Laurence A.

1981-01-01

Platelets play an important role in hemostasis, and alterations in platelet function may be the cause of abnormal bleeding in a wide variety of congenital and acquired clinical disorders. Platelet dysfunction may be classified as disorders of (1) substrate connective tissue, (2) adhesion, (3) aggregation and (4) platelet-release reaction. The congenital defects of platelet function, although uncommon, have provided important insights into platelet physiology and pathophysiology and, as a group, are less common, better characterized and more readily classified than the acquired defects. The severity of bleeding resulting from platelet dysfunction varies greatly and is substantially increased when another defect of hemostasis coexists. A disorder of platelet function is suspected on the basis of the history and physical examination and is confirmed by the finding of a prolonged bleeding time in the presence of an adequate number of platelets. A specific diagnosis often requires measurements of the factor VIII and von Willebrand factor complex and other tests of platelet function. Some of these tests may be available only in specialized laboratories. Therapy for bleeding episodes resulting from platelet dysfunction is directed at (1) removing or treating the underlying cause of the platelet disorder; (2) replacing the missing plasma cofactors needed to support normal platelet function (such as by the transfusion of cryoprecipitate in patients with von Willebrand disease, and (3) transfusing functional platelets in the form of platelet concentrates in patients with disorders of intrinsic platelet dysfunction. ImagesFigure 1.Figure 2.Figure 3. PMID:7013276

Handicapping Conditions Associated with the Congenital Rubella Syndrome.

ERIC Educational Resources Information Center

Vernon, McCay; And Others

1980-01-01

The authors discuss the incidence of impairments diagnosed among children with congenital rubella syndrome. Approximately 73 percent are hearing impaired, at least 35 percent have congenital heart disorders, and 33 percent have visual defects. (Author)

47 CFR 73.688 - Indicating instruments.

Code of Federal Regulations, 2010 CFR

2010-10-01

... measuring the operating parameters of the last radio stage of the visual transmitter, and with such other... period not in excess of 60 days without further authority of the FCC, provided that: (1) If the defective...

Homotopy-Theoretic Study & Atomic-Scale Observation of Vortex Domains in Hexagonal Manganites

PubMed Central

Li, Jun; Chiang, Fu-Kuo; Chen, Zhen; Ma, Chao; Chu, Ming-Wen; Chen, Cheng-Hsuan; Tian, Huanfang; Yang, Huaixin; Li, Jianqi

2016-01-01

Essential structural properties of the non-trivial “string-wall-bounded” topological defects in hexagonal manganites are studied through homotopy group theory and spherical aberration-corrected scanning transmission electron microscopy. The appearance of a “string-wall-bounded” configuration in RMnO3 is shown to be strongly linked with the transformation of the degeneracy space. The defect core regions (~50 Å) mainly adopt the continuous U(1) symmetry of the high-temperature phase, which is essential for the formation and proliferation of vortices. Direct visualization of vortex strings at atomic scale provides insight into the mechanisms and macro-behavior of topological defects in crystalline materials. PMID:27324701

Detecting defects in marine structures by using eddy current infrared thermography.

PubMed

Swiderski, W

2016-12-01

Eddy current infrared (IR) thermography is a new nondestructive testing (NDT) technique used for the detection of cracks in electroconductive materials. By combining the well-established inspection methods of eddy current NDT and IR thermography, this technique uses induced eddy currents to heat test samples. In this way, IR thermography allows the visualization of eddy current distribution that is distorted in defect sites. This paper discusses the results of numerical modeling of eddy current IR thermography procedures in application to marine structures.

A Comparison of Several Artificial Neural Network Classifiers for CT Images of Hardwood Logs

Treesearch

Daniel L. Schmoldt; Jing He; A. Lynn Abbott

1998-01-01

Knowledge of internal log defects, obtained by scanning, is critical to efficiency improvements for future hardwood sawmills. Nevertheless, before computed tomography (CT) scanning can be applied in industrial operations, we need to automatically interpret scan information so that it can provide the saw operator with the information necessary to make proper sawing...

Maternal occupation and the risk of neural tube defects in offspring.

PubMed

Kim, Jihye; Langlois, Peter H; Mitchell, Laura E; Agopian, A J

2017-07-19

We evaluated the association between maternal occupation and the risk of neural tube defects (NTDs) in offspring. Data for 491 nonsyndromic cases were obtained from the Texas Birth Defects Registry for deliveries between 1999 and 2009. We randomly selected 2,291 controls among all live births in Texas during this time. Maternal occupations were classified using automated software and manual assignment. Multivariable logistic regression analyses were used to examine the relationship between maternal occupation and risk for any NTD, adjusting for maternal race/ethnicity, any diabetes, and maternal body mass index. These analyses were repeated for spina bifida specifically. Some maternal occupations, particularly those related to business/finance, health care practice, and cleaning/maintenance, were significantly associated with increased risk of spina bifida and/or any NTD. Further research is needed to identify the specific occupational exposures related to NTD risk.

Short stature caused by isolated SHOX gene haploinsufficiency: update on the diagnosis and treatment.

PubMed

Jorge, Alexander A L; Funari, Mariana Fa; Nishi, Mirian Y; Mendonca, Berenice B

2010-12-01

Heterozygous SHOX defects are observed in about 50 to 90% of patients with Leri-Weill dyschondrosteosis (LWD), a common dominant inherited skeletal dysplasia; and in 2 to 15% of children with idiopathic short stature (ISS), indicating that SHOX defects are the most important monogenetic cause of short stature. In addition, children selected by disproportionate idiopathic short stature had a higher frequency of SHOX mutations (22%). A careful clinical evaluation of family members with short stature is recommended since it usually revealed LWD patients in families first classified as having ISS or familial short stature. SHOX-molecular analysis is indicated in families with LWD and ISS children with disproportionate short stature. Treatment with recombinant human growth hormone is considered an accepted approach to treat short stature associated with isolated SHOX defect. Here we review clinical, molecular and therapeutic aspects of SHOX haploinsufficiency.

Self-motion perception in autism is compromised by visual noise but integrated optimally across multiple senses

PubMed Central

Zaidel, Adam; Goin-Kochel, Robin P.; Angelaki, Dora E.

2015-01-01

Perceptual processing in autism spectrum disorder (ASD) is marked by superior low-level task performance and inferior complex-task performance. This observation has led to theories of defective integration in ASD of local parts into a global percept. Despite mixed experimental results, this notion maintains widespread influence and has also motivated recent theories of defective multisensory integration in ASD. Impaired ASD performance in tasks involving classic random dot visual motion stimuli, corrupted by noise as a means to manipulate task difficulty, is frequently interpreted to support this notion of global integration deficits. By manipulating task difficulty independently of visual stimulus noise, here we test the hypothesis that heightened sensitivity to noise, rather than integration deficits, may characterize ASD. We found that although perception of visual motion through a cloud of dots was unimpaired without noise, the addition of stimulus noise significantly affected adolescents with ASD, more than controls. Strikingly, individuals with ASD demonstrated intact multisensory (visual–vestibular) integration, even in the presence of noise. Additionally, when vestibular motion was paired with pure visual noise, individuals with ASD demonstrated a different strategy than controls, marked by reduced flexibility. This result could be simulated by using attenuated (less reliable) and inflexible (not experience-dependent) Bayesian priors in ASD. These findings question widespread theories of impaired global and multisensory integration in ASD. Rather, they implicate increased sensitivity to sensory noise and less use of prior knowledge in ASD, suggesting increased reliance on incoming sensory information. PMID:25941373

The repeatability of mean defect with size III and size V standard automated perimetry.

PubMed

Wall, Michael; Doyle, Carrie K; Zamba, K D; Artes, Paul; Johnson, Chris A

2013-02-15

The mean defect (MD) of the visual field is a global statistical index used to monitor overall visual field change over time. Our goal was to investigate the relationship of MD and its variability for two clinically used strategies (Swedish Interactive Threshold Algorithm [SITA] standard size III and full threshold size V) in glaucoma patients and controls. We tested one eye, at random, for 46 glaucoma patients and 28 ocularly healthy subjects with Humphrey program 24-2 SITA standard for size III and full threshold for size V each five times over a 5-week period. The standard deviation of MD was regressed against the MD for the five repeated tests, and quantile regression was used to show the relationship of variability and MD. A Wilcoxon test was used to compare the standard deviations of the two testing methods following quantile regression. Both types of regression analysis showed increasing variability with increasing visual field damage. Quantile regression showed modestly smaller MD confidence limits. There was a 15% decrease in SD with size V in glaucoma patients (P = 0.10) and a 12% decrease in ocularly healthy subjects (P = 0.08). The repeatability of size V MD appears to be slightly better than size III SITA testing. When using MD to determine visual field progression, a change of 1.5 to 4 decibels (dB) is needed to be outside the normal 95% confidence limits, depending on the size of the stimulus and the amount of visual field damage.

Vision-Based Corrosion Detection Assisted by a Micro-Aerial Vehicle in a Vessel Inspection Application

PubMed Central

Ortiz, Alberto; Bonnin-Pascual, Francisco; Garcia-Fidalgo, Emilio; Company-Corcoles, Joan P.

2016-01-01

Vessel maintenance requires periodic visual inspection of the hull in order to detect typical defective situations of steel structures such as, among others, coating breakdown and corrosion. These inspections are typically performed by well-trained surveyors at great cost because of the need for providing access means (e.g., scaffolding and/or cherry pickers) that allow the inspector to be at arm’s reach from the structure under inspection. This paper describes a defect detection approach comprising a micro-aerial vehicle which is used to collect images from the surfaces under inspection, particularly focusing on remote areas where the surveyor has no visual access, and a coating breakdown/corrosion detector based on a three-layer feed-forward artificial neural network. As it is discussed in the paper, the success of the inspection process depends not only on the defect detection software but also on a number of assistance functions provided by the control architecture of the aerial platform, whose aim is to improve picture quality. Both aspects of the work are described along the different sections of the paper, as well as the classification performance attained. PMID:27983627

Vision-Based Corrosion Detection Assisted by a Micro-Aerial Vehicle in a Vessel Inspection Application.

PubMed

Ortiz, Alberto; Bonnin-Pascual, Francisco; Garcia-Fidalgo, Emilio; Company-Corcoles, Joan P

2016-12-14

Vessel maintenance requires periodic visual inspection of the hull in order to detect typical defective situations of steel structures such as, among others, coating breakdown and corrosion. These inspections are typically performed by well-trained surveyors at great cost because of the need for providing access means (e.g., scaffolding and/or cherry pickers) that allow the inspector to be at arm's reach from the structure under inspection. This paper describes a defect detection approach comprising a micro-aerial vehicle which is used to collect images from the surfaces under inspection, particularly focusing on remote areas where the surveyor has no visual access, and a coating breakdown/corrosion detector based on a three-layer feed-forward artificial neural network. As it is discussed in the paper, the success of the inspection process depends not only on the defect detection software but also on a number of assistance functions provided by the control architecture of the aerial platform, whose aim is to improve picture quality. Both aspects of the work are described along the different sections of the paper, as well as the classification performance attained.

Near-infrared imaging of developmental defects in dental enamel.

PubMed

Hirasuna, Krista; Fried, Daniel; Darling, Cynthia L

2008-01-01

Polarization-sensitive optical coherence tomography (PS-OCT) and near-infrared (NIR) imaging are promising new technologies under development for monitoring early carious lesions. Fluorosis is a growing problem in the United States, and the more prevalent mild fluorosis can be visually mistaken for early enamel demineralization. Unfortunately, there is little quantitative information available regarding the differences in optical properties of sound enamel, enamel developmental defects, and caries. Thirty extracted human teeth with various degrees of suspected fluorosis were imaged using PS-OCT and NIR. An InGaAs camera and a NIR diode laser were used to measure the optical attenuation through transverse tooth sections (approximately 200 microm). A digital microradiography system was used to quantify the enamel defect severity by measurement of the relative mineral loss for comparison with optical scattering measurements. Developmental defects were clearly visible in the polarization-resolved OCT images, demonstrating that PS-OCT can be used to nondestructively measure the depth and possible severity of the defects. Enamel defects on whole teeth that could be imaged with high contrast with visible light were transparent in the NIR. This study suggests that PS-OCT and NIR methods may potentially be used as tools to assess the severity and extent of enamel defects.

Identifying Patients with Atrioventricular Septal Defect in Down Syndrome Populations by Using Self-Normalizing Neural Networks and Feature Selection.

PubMed

Pan, Xiaoyong; Hu, Xiaohua; Zhang, Yu Hang; Feng, Kaiyan; Wang, Shao Peng; Chen, Lei; Huang, Tao; Cai, Yu Dong

2018-04-12

Atrioventricular septal defect (AVSD) is a clinically significant subtype of congenital heart disease (CHD) that severely influences the health of babies during birth and is associated with Down syndrome (DS). Thus, exploring the differences in functional genes in DS samples with and without AVSD is a critical way to investigate the complex association between AVSD and DS. In this study, we present a computational method to distinguish DS patients with AVSD from those without AVSD using the newly proposed self-normalizing neural network (SNN). First, each patient was encoded by using the copy number of probes on chromosome 21. The encoded features were ranked by the reliable Monte Carlo feature selection (MCFS) method to obtain a ranked feature list. Based on this feature list, we used a two-stage incremental feature selection to construct two series of feature subsets and applied SNNs to build classifiers to identify optimal features. Results show that 2737 optimal features were obtained, and the corresponding optimal SNN classifier constructed on optimal features yielded a Matthew's correlation coefficient (MCC) value of 0.748. For comparison, random forest was also used to build classifiers and uncover optimal features. This method received an optimal MCC value of 0.582 when top 132 features were utilized. Finally, we analyzed some key features derived from the optimal features in SNNs found in literature support to further reveal their essential roles.

Automated analysis and reannotation of subcellular locations in confocal images from the Human Protein Atlas.

PubMed

Li, Jieyue; Newberg, Justin Y; Uhlén, Mathias; Lundberg, Emma; Murphy, Robert F

2012-01-01

The Human Protein Atlas contains immunofluorescence images showing subcellular locations for thousands of proteins. These are currently annotated by visual inspection. In this paper, we describe automated approaches to analyze the images and their use to improve annotation. We began by training classifiers to recognize the annotated patterns. By ranking proteins according to the confidence of the classifier, we generated a list of proteins that were strong candidates for reexamination. In parallel, we applied hierarchical clustering to group proteins and identified proteins whose annotations were inconsistent with the remainder of the proteins in their cluster. These proteins were reexamined by the original annotators, and a significant fraction had their annotations changed. The results demonstrate that automated approaches can provide an important complement to visual annotation.

Classification deficits in Alzheimer's disease with special reference to living and nonliving things.

PubMed

Montanes, P; Goldblum, M C; Boller, F

1996-08-01

The present study was conducted to assess the hypothesis that visual similarity between exemplars within a semantic category may affect differentially the recognition process of living and nonliving things, according to task demands, in patients with semantic memory disorders. Thirty-nine Alzheimer's patients and 39 normal elderly subjects were presented with a task in which they had to classify pictures and words, depicting either living or nonliving things, at two levels of classification: subordinate (e.g., mammals versus birds or tools versus vehicles) and attribute (e.g., wild versus domestic animals or fast versus slow vehicles). Contrary to previous results (Montañes, Goldblum, & Boller, 1995) in a naming task, but as expected, living things were better classified than nonliving ones by both controls and patients. As expected, classifications at the subordinate level also gave rise to better performance than classifications at the attribute level. Although (and somewhat unexpectedly) no advantage of picture over word classification emerged, some effects consistent with the hypothesis that visual similarity affects picture classification emerged, in particular within a subgroup of patients with predominant verbal deficits and the most severe semantic memory disorders. This subgroup obtained a better score on classification of pictures than of words depicting living items (that share many visual features) when classification is at the subordinate level (for which visual similarity is a reliable clue to classification), but met with major difficulties when classifying those pictures at the attribute level (for which shared visual features are not reliable clues to classification). These results emphasize the fact that some "normal" effects specific to items in living and nonliving categories have to be considered among the factors causing selective category-specific deficits in patients, as well as their relevance in achieving tasks which require either differentiation between competing exemplars in the same semantic category (naming) or detection of resemblance between those exemplars (categorization).

Kinetic Defects Induced by Melittin in Model Lipid Membranes: A Solution Atomic Force Microscopy Study.

PubMed

Pan, Jianjun; Khadka, Nawal K

2016-05-26

Quantitative characterization of membrane defects (pores) is important for elucidating the molecular basis of many membrane-active peptides. We study kinetic defects induced by melittin in vesicular and planar lipid bilayers. Fluorescence spectroscopy measurements indicate that melittin induces time-dependent calcein leakage. Solution atomic force microscopy (AFM) is used to visualize melittin-induced membrane defects. After initial equilibration, the most probable defect radius is ∼3.8 nm in 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC) bilayers. Unexpectedly, defects become larger with longer incubation, accompanied by substantial shape transformation. The initial defect radius is ∼4.7 nm in 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) bilayers. Addition of 30 mol % cholesterol to DOPC bilayers suppresses defect kinetics, although the inhibitory impact is negated by longer incubation. Overall, the kinetic rate of defect development follows DLPC > DOPC > DOPC/cholesterol. Kinetic defects are also observed when anionic lipids are present. Based on the observation that defects can occupy as large as 40% of the bilayer surface, we propose a kinetic defect growth model. We also study the effect of melittin on the phase behavior of DOPC/egg-sphingomyelin/cholesterol bilayers. We find that melittin initially suppresses or eliminates liquid-ordered (Lo) domains; Lo domains gradually emerge and become the dominant species with longer incubation; and defects in phase-coexisting bilayers have a most probable radius of ∼5 nm and are exclusively localized in the liquid-disordered (Ld) phase. Our experimental data highlight that melittin-induced membrane defects are not static; conversely, spontaneous defect growth is intrinsically associated with membrane permeabilization exerted by melittin.

The effect of defect cluster size and interpolation on radiographic image quality

NASA Astrophysics Data System (ADS)

Töpfer, Karin; Yip, Kwok L.

2011-03-01

For digital X-ray detectors, the need to control factory yield and cost invariably leads to the presence of some defective pixels. Recently, a standard procedure was developed to identify such pixels for industrial applications. However, no quality standards exist in medical or industrial imaging regarding the maximum allowable number and size of detector defects. While the answer may be application specific, the minimum requirement for any defect specification is that the diagnostic quality of the images be maintained. A more stringent criterion is to keep any changes in the images due to defects below the visual threshold. Two highly sensitive image simulation and evaluation methods were employed to specify the fraction of allowable defects as a function of defect cluster size in general radiography. First, the most critical situation of the defect being located in the center of the disease feature was explored using image simulation tools and a previously verified human observer model, incorporating a channelized Hotelling observer. Detectability index d' was obtained as a function of defect cluster size for three different disease features on clinical lung and extremity backgrounds. Second, four concentrations of defects of four different sizes were added to clinical images with subtle disease features and then interpolated. Twenty observers evaluated the images against the original on a single display using a 2-AFC method, which was highly sensitive to small changes in image detail. Based on a 50% just-noticeable difference, the fraction of allowed defects was specified vs. cluster size.

Retinitis Pigmentosa Sine Pigmento Mimicking a Chiasm Disease

PubMed Central

Pellegrini, Francesco; Prosdocimo, Giovanni; Romano, Francesco; Interlandi, Emanuela

2017-01-01

ABSTRACT A 75-year-old woman presented to her ophthalmologist complaining of visual loss for several years. The ophthalmic examination was remarkable for a bitemporal visual field defect. Magnetic resonance imaging (MRI) scan of the brain was normal without evidence of chiasm compression. Neuro-ophthalmic examination was consistent with a retinal rather than a chiasmal disease. Retinal multimodal imaging helped in the correct diagnosis of retinitis pigmentosa, later confirmed by genetic testing. PMID:29344059

Classification of defects in honeycomb composite structure of helicopter rotor blades

NASA Astrophysics Data System (ADS)

Balaskó, M.; Sváb, E.; Molnár, Gy.; Veres, I.

2005-04-01

The use of non-destructive testing methods to qualify the state of rotor blades with respect to their expected flight hours, with the aim to extend their lifetime without any risk of breakdown, is an important financial demand. In order to detect the possible defects in the composite structure of Mi-8 and Mi-24 type helicopter rotor blades used by the Hungarian Army, we have performed combined neutron- and X-ray radiography measurements at the Budapest Research Reactor. Several types of defects were detected, analysed and typified. Among the most frequent and important defects observed were cavities, holes and/or cracks in the sealing elements on the interface of the honeycomb structure and the section boarders. Inhomogeneities of the resin materials (resin-rich or starved areas) at the core-honeycomb surfaces proved to be an other important point. Defects were detected at the adhesive filling, and water percolation was visualized at the sealing interfaces of the honeycomb sections. Corrosion effects, and metal inclusions have also been detected.

Selecting islands and shoals for conservation based on biological and aesthetic criteria

USGS Publications Warehouse

Knutson, M.G.; Leopold, D.J.; Smardon, R.C.

1993-01-01

Consideration of biological quality has long been an important component of rating areas for conservation. Often these same areas are highly valued by people for aesthetic reasons, creating demands for housing and recreation that may conflict with protection plans for these habitats. Most methods of selecting land for conservation purposes use biological factors alone. For some land areas, analysis of aesthetic qualities is also important in describing the scenic value of undisturbed land. A method for prioritizing small islands and shoals based on both biological and visual quality factors is presented here. The study included 169 undeveloped islands and shoals a??0.8 ha in the Thousand Islands Region of the St. Lawrence River, New York. Criteria such as critical habitat for uncommon plant and animal species were considered together with visual quality and incorporated into a rating system that ranked the islands and shoals according to their priority for conservation management and protection from development. Biological factors were determined based on previous research and a field survey. Visual quality was determined by visual diagnostic criteria developed from public responses to photographs of a sample of islands. Variables such as elevation, soil depth, and type of plant community can be used to classify islands into different categories of visual quality but are unsuccessful in classifying islands into categories of overall biological quality.

Sweep visually evoked potentials and visual findings in children with West syndrome.

PubMed

de Freitas Dotto, Patrícia; Cavascan, Nívea Nunes; Berezovsky, Adriana; Sacai, Paula Yuri; Rocha, Daniel Martins; Pereira, Josenilson Martins; Salomão, Solange Rios

2014-03-01

West syndrome (WS) is a type of early childhood epilepsy characterized by progressive neurological development deterioration that includes vision. To demonstrate the clinical importance of grating visual acuity thresholds (GVA) measurement by sweep visually evoked potentials technique (sweep-VEP) as a reliable tool for evaluation of the visual cortex status in WS children. This is a retrospective study of the best-corrected binocular GVA and ophthalmological features of WS children referred for the Laboratory of Clinical Electrophysiology of Vision of UNIFESP from 1998 to 2012 (Committee on Ethics in Research of UNIFESP n° 0349/08). The GVA deficit was calculated by subtracting binocular GVA score (logMAR units) of each patient from the median values of age norms from our own lab and classified as mild (0.1-0.39 logMAR), moderate (0.40-0.80 logMAR) or severe (>0.81 logMAR). Associated ophthalmological features were also described. Data from 30 WS children (age from 6 to 108 months, median = 14.5 months, mean ± SD = 22.0 ± 22.1 months; 19 male) were analyzed. The majority presented severe GVA deficit (0.15-1.44 logMAR; mean ± SD = 0.82 ± 0.32 logMAR; median = 0.82 logMAR), poor visual behavior, high prevalence of strabismus and great variability in ocular positioning. The GVA deficit did not vary according to gender (P = .8022), WS type (P = .908), birth age (P = .2881), perinatal oxygenation (P = .7692), visual behavior (P = .8789), ocular motility (P = .1821), nystagmus (P = .2868), risk of drug-induced retinopathy (P = .4632) and participation in early visual stimulation therapy (P = .9010). The sweep-VEP technique is a reliable tool to classify visual system impairment in WS children, in agreement with the poor visual behavior exhibited by them. Copyright © 2013 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.

Analyzing tree-shape anatomical structures using topological descriptors of branching and ensemble of classifiers.

PubMed

Skoura, Angeliki; Bakic, Predrag R; Megalooikonomou, Vasilis

2013-01-01

The analysis of anatomical tree-shape structures visualized in medical images provides insight into the relationship between tree topology and pathology of the corresponding organs. In this paper, we propose three methods to extract descriptive features of the branching topology; the asymmetry index, the encoding of branching patterns using a node labeling scheme and an extension of the Sholl analysis. Based on these descriptors, we present classification schemes for tree topologies with respect to the underlying pathology. Moreover, we present a classifier ensemble approach which combines the predictions of the individual classifiers to optimize the classification accuracy. We applied the proposed methodology to a dataset of x-ray galactograms, medical images which visualize the breast ductal tree, in order to recognize images with radiological findings regarding breast cancer. The experimental results demonstrate the effectiveness of the proposed framework compared to state-of-the-art techniques suggesting that the proposed descriptors provide more valuable information regarding the topological patterns of ductal trees and indicating the potential of facilitating early breast cancer diagnosis.