Performance Of Visual Inspection Research Articles

Adequacy of visual inspection with acetic acid in women of advancing age

Objective The present study assessed the adequacy and predictive performance of visual inspection with acetic acid (VIA) in women over the age of 50 years and compared the specificity and sensitivity of VIA with that of the conventional cytology. Methods In total, 588 Salvadoran women ages 50–79 underwent VIA, Pap smear, and cervical biopsy. VIA was considered adequate if the squamocolumnar junction was completely visible. A positive biopsy was defined as cervical intraepithelial neoplasia (CIN) 2 or worse. Results Age was negatively correlated with VIA adequacy ( P = 0.04). Nevertheless, the majority of women—even in the older age groups—had adequate examinations. The adequacy of VIA was positively correlated with gravida ( P = 0.01) and was higher in women who had been treated by cryotherapy ( P = 0.02). The rate of positive biopsies was unexpectedly low (n = 6 [1%]) making it difficult to assess the predictive performance of VIA. In this small sample, the sensitivities of VIA (17%) and Pap (33%) were low; the high number of false negatives could not be fully explained by inadequacy of the examinations. Conclusions Adequacy of VIA declined with age. However, the squamocolumnar junction was visible to the naked eye in the majority of women, indicating that they are good candidates for VIA.

Effects of learning for linear and differential video magnifiers

This study sought to determine the learning effects of repeated practice with the traditional linear and the novel differential linear and differential non-linear magnification methods on visual inspection performance. Performance feedback of speed and accuracy and process feedback of scan paths and coverage of search area were given to subjects in order to facilitate the learning process. Objective performance in terms of speed and accuracy and subjective evaluation using the NASA Task Load Index paradigm were captured and analysed. The results showed that there were positive learning effects for the three magnification methods and the learning effects for the two differential magnification methods were greater than that for the traditional linear method. Three exponential learning curves were established for the three search tasks, which showed that search performance with the differential linear and differential non-linear magnifications would surpass the traditional linear method after four and 10 sessions of repeated practice, respectively.

Visual inspection as a cervical cancer screening method in a primary health care setting in Africa

We evaluated the feasibility and performance of visual inspection with acetic acid (VIA) and Lugol's iodine (VILI) for cervical cancer screening in a primary health-care setting in Kinshasa, Congo. Women (1,528) aged > or =30 years were screened independently by nurses and physicians by VIA and VILI and Pap cytology. Biopsy samples were obtained from women with abnormal colposcopies and from 290 randomly chosen women with normal colposcopy. Cytological and histological examinations were performed in Lyon and Montreal, respectively. The prevalence of cervical intraepithelial neoplasia (CIN) of grades 1, 2 and 3 was 4.5, 1.3 and 4%, respectively. Using biopsy as the reference, the sensitivity, specificity and negative predictive value (NPV) for > or =CIN 2 for VIA-nurse were 55.5% (95% CI: 34.7-76.2), 64.6% (95% CI: 62.0-67.1) and 96.8% (95% CI: 93.5-98.7), respectively. The corresponding values for VILI-nurse were 44.0% (95% CI: 24.2-63.8), 74.6% (95% CI: 72.3-76.9) and 96.7% (95% CI: 93.7-98.6). The equivalent parameters for physicians were 71.1% (95% CI: 46.7-95.5), 71.3% (95% CI: 68.9-73.6) and 98.6% (95% CI: 96.0-99.7) for VIA and 68.3% (95% CI: 42.5-94.0), 76.2% (95% CI: 74.0-78.4) and 97.2% (95% CI: 95.3-98.5) for VILI. The sensitivity of cytology ranged between 31 and 72%, depending on the abnormality threshold used to define positivity, with a corresponding specificity range of 94-99% and a NPV range of 97-99%. Our results show that VIA and VILI performed by nurses and physicians are slightly more sensitive but less specific than Pap cytology across multiple combinations of test and lesion thresholds. Given their lower cost and easy deployment, visual inspection methods merit further assessment as cervical cancer screening methods for low-resource countries.

Screening for cervical carcinoma using visual inspection with acetic acid

Objective: To assess the performance of visual inspection with acetic acid (VIA) as a screening test for early detection of cervical carcinoma in the Dakahlia Governorate in Egypt. Methods: Diluted acetic acid (5%) was applied to the cervix during routine gynecologic examination. Women with positive results were referred for colposcopy. Those with negative results were referred for colposcopy only when they had clinical indications. Results: Among the 5000 women who were screened using VIA, 409 were referred for colposcopy. Cervical intraepithelial neoplasia (CIN) was diagnosed in 151 (60%) of the 253 women with positive screening results and in 4 of the 156 women with negative screening results. There were 39 women with high-grade and 116 with low-grade CIN. The sensitivity and negative predictive value of the VIA screening test was 97%. Its positive predictive value was 60% for all grades of CIN and 90% for high-grade CIN. Conclusion: Visual inspection with acetic acid, although associated with a relatively high rate of false-positive results, is a valuable test for the screening of cervical carcinoma.

Fully automatic diagnostic system for early- and late-onset mild Alzheimer’s disease using FDG PET and 3D-SSP

The purpose of this study was to design a fully automatic computer-assisted diagnostic system for early- and late-onset mild Alzheimer's disease (AD). Glucose metabolic images were obtained from mild AD patients and normal controls using positron emission tomography (PET) and( 18)F-fluorodeoxyglucose (FDG). Two groups of 20 mild AD patients with different ages of onset were examined. A fully automatic diagnostic system using the statistical brain mapping method was established from the early-onset (EO) and late-onset (LO) groups, with mean ages of 59.1 and 70.9 years and mean MMSE scores of 23.3 and 22.8, respectively. Aged-matched normal subjects were used as controls. We compared the diagnostic performance of visual inspection of conventional axial FDG PET images by experts and beginners with that of our fully automatic diagnostic system in another 15 EO and 15 LO AD patients (mean age 58.4 and 71.7, mean MMSE 23.6 and 23.1, respectively) and 30 age-matched normal controls. A receiver operating characteristic (ROC) analysis was performed to compare data. The diagnostic performance of the automatic diagnostic system was comparable with that of visual inspection by experts. The area under the ROC curve for the automatic diagnostic system was 0.967 for EO AD patients and 0.878 for LO AD patients. The mean area under the ROC curve for visual inspection by experts was 0.863 and 0.881 for the EO and LO AD patients, respectively. The mean area under the ROC curve for visual inspection by beginners was 0.828 and 0.717, respectively. The fully automatic diagnostic system for EO and LO AD was able to perform at a similar diagnostic level to visual inspection of conventional axial images by experts.

Collaborative Virtual Environment to Simulate on-the-Job Aircraft Inspection Training Aided by Hand Pointing

The human inspector performing visual inspection of an aircraft is the backbone of the aircraft inspection process, a vital element in assuring safety and reliability of an air transportation system. Training is an effective strategy for improving their inspection performance. A drawback of present-day on-the-job (OJT) training provided to aircraft inspectors is the limited exposure to different defect types. Previous studies have shown offline feedback training using virtual reality (VR) simulators to be effective in improving visual inspection performance. This research aims at combining the advantages of VR technology that includes exposure to a wide variety of defects and the one-on-one tutoring approach of OJT by implementing a collaborative virtual training environment. In an immersive collaborative virtual environment (CVE), avatars are used to represent the co-participants. In a CVE, information of where the trainer is pointing can be provided to a trainee as visual deictic reference (VDR). This study evaluates the effectiveness of simulating on-the-job training in a CVE for aircraft inspection training, providing VDR slaved to a 3D mouse used by the trainer for pointing. The results of this study show that the training was effective in improving inspection performance.

Performance of methods of occlusal caries detection in permanent teeth under clinical and laboratory conditions

To compare performance of visual inspection and Laser fluorescence methods to detect occlusal caries lesions under clinical and laboratory conditions in permanent teeth. One hundred and ten sites in 57 third molars scheduled for extraction were examined with visual inspection and laser fluorescence (DIAGNOdent) device by two trained examiners. After the extraction, teeth were re-examined. Then, teeth were sectioned to perform histological validation. Best cut-off points were calculated with ROC analysis, and sensitivity, specificity and accuracy were calculated at D2 and D3 thresholds. Comparisons between the methods and conditions of examination were performed using McNemar test. Inter-examiner agreement in the same conditions and agreement between the methods performed in vivo and in vitro conditions were assessed by Kappa test. Laser fluorescence values obtained in two conditions were compared with Wilcoxon test. No difference was observed with visual inspection in both conditions. Laser fluorescence performed in vitro presented higher specificity and accuracy at D3 threshold. Visual inspection showed higher reproducibility. After adjustment of cut-off points for laser fluorescence method, there was no difference between the evaluated parameters. Only slightly differences were observed between the examinations performed under clinical and laboratory conditions in the detection of occlusal caries lesions in permanent teeth.

Xanthrochromia? By What Method? A Comparison of Visual and Spectrophotometric Xanthrochromia

Most US hospitals use visual inspection for the detection of cerebrospinal fluid xanthrochromia. We compared visual inspection with spectrophotometric xanthrochromia and studied the effect of tube diameter on the sensitivity of visual inspection. Blinded, experienced laboratory technicians visually examined unmarked samples to determine the presence or absence of xanthrochromia. Samples were prepared by lysing RBCs in distilled water. Serial dilutions were placed in clear polystyrene tubes obtained from standard lumbar puncture trays. Laboratory technicians were asked to examine each sample for xanthrochromia using visual inspection. Next, they were asked to interpret the same set of samples with the assistance of a threshold standard. Last, they were asked to interpret the same dilutions, but this time presented in a larger-diameter tube. The absorbance of each sample was measured in a double-beam spectrophotometer at wavelengths between 300 and 700 nm. Samples were said to demonstrate spectrophotometric xanthrochromia if they had an absorbance greater than 0.023 at 415 nm. Sixteen laboratory technicians were shown a total of 160 samples, of which 64 (40%) demonstrated spectrophotometric xanthrochromia. Visual inspection of the samples was 26.6% sensitive (95% confidence interval [CI] 16% to 38%) and 97.9% specific (95% CI 95% to 100%) for spectrophotometric xanthrochromia. Using a reference standard did not improve the performance of visual inspection, but increasing collection-tube diameter increased the sensitivity to 55% (95% CI 43% to 68%). Visual inspection is not sensitive for the detection of spectrophotometric xanthrochromia. Increasing the diameter of the collection tubes did improve sensitivity. Emergency physicians should be aware of how xanthrochromia is determined at their institutions and understand the implications of using visual detection to determine the presence or absence of xanthrochromia.

Evaluating the Eye Fatigue Problem in Wafer Inspection

After develop inspection (ADI) and after etching inspection (AEI) are the main inspection tasks in the wafer manufacturing fab. Because of the detailed and tiny circuit patterns, ADI and AEI are carried out with the aid of a microscope. ADI and AEI inspectors frequently complain about visual fatigue problems. In this study, we focused on evaluating the effects of display mode, search pattern, and inspection strategy on visual fatigue and inspection performance. A field study experiment was conducted. The results indicated that the display mode had significant influence on visual fatigue. Using a liquid crystal display (LCD) to inspect wafer defects can reduce the visual strain and body discomfort feelings. The change in inspection strategy had a positive effect on eye fatigue and inspection performance.

Performance of Direct Visual Inspection of the Cervix with Acetic Acid and Magnification in a Previously Screened Population

To assess the screening performance of direct visual inspection with acetic acid and x2 magnification (VIAM) in a previously screened population, as performed by experienced gynecologic nurses with minimal training in VIAM. Performance of VIAM was evaluated in 2,080 women from a population-based cohort in Guanacaste, Costa Rica, 5 years after they had negative enrollment results of conventional and liquid-based cytologic analysis, cervigram, and human papillomavirus DNA by Hybrid Capture Tube Test (Digene Corporation, Gaithersburg, MD). The VIAM results were compared with repeat conventional Pap smears, liquid-based cytologic examinations, and cervicography, with adjudication of differences by reference to MY09/MY11 L1 consensus primer polymerase chain reaction detection of oncogenic human papillomavirus DNA. Less than 5% of women were classified as having positive results using VIAM. The VIAM positivity was also very low among women with high-grade squamous intraepithelial lesion conventional Pap smear results (8.3%), high-grade squamous intraepithelial lesion liquid-based cytologic results (6.3%), or cervigrams suggesting cervical intraepithelial neoplasia 2,3 or cancer (30%). The VIAM positivity was not associated with human papillomavirus DNA positivity. As we practiced it, VIAM was not sensitive for detection of possibly serious incident cervical lesions in this previously screened population where cytologic screening is in place.

Direct Visual Inspection of the Cervix for the Detection of Premalignant Lesions

To assess the feasibility and performance of direct visual inspection (DVI) of the cervix as a primary tool for the detection of premalignant lesions of the cervix (HPV/CIN 1 and CIN 2,3). The early cancer detection unit at the Ain Shams University Maternity Hospital in Cairo, Egypt. The study included 2049 women. Cervical smears were obtained from all women for cytologic evaluation followed by direct visual inspection (DVI) of the cervix after painting with 5% acetic acid. Women whose smear reports showed abnormal cells suggestive of squamous intraepithelial lesion (SIL) or human papillomavirus (HPV) infection or those who showed abnormalities or acetowhite areas on direct visual inspection subsequently were referred for colposcopy and biopsy when appropriate. Colposcopy also was performed for women with negative DVI and negative smears if they had contact bleeding or chronic per vaginal discharge. Mean (SD) age of women included in the study was 39.9 (10.2) years with their mean (SD) parity 2.9 (1.1). Results of DVI were normal in 1916 women (93.4%) and showed abnormal acetowhite appearance in 133 (6.6%) women. There were 458 (22.4%) colposcopic examinations and 130 biopsies (6.34%) were carried out, picking up 83 cases of premalignant lesions (4.0%). Premalignant lesions were 80 HPV/CIN 1 and CIN 2,3. Direct visual inspection detected 71 of the 83 premalignant lesions (sensitivity, 85.5%; specificity, 96.8%; positive predictive value, 52.6%). Direct visual inspection missed one of the three samples showing CIN 2,3. Cervical cytologic analysis showed abnormal cells in 60 (2.9%) and identified only 14 of the premalignant lesions (sensitivity, 16.9%; specificity, 97.8%; positive predictive value, 23.3%). Twelve of the premalignant lesions had positive smear results and a negative DVI, with none of them being of a high grade. Direct visual inspection is feasible and had superior sensitivity compare with cervical cytologic analysis in detecting premalignant lesions of the cervix. Direct visual inspection can be used as a primary screening tool with a satisfactory low biopsy rate in low-resource settings or where cytologic services are suboptimal.

The Impact of Instructions on Aircraft Visual Inspection Performance: A First Look at the Overall Results

The purpose of this study was to investigate the impact of instructions on aircraft visual inspection performance and strategy. Forty-two inspectors from industry were asked to perform inspections of six areas of a Boeing 737. Six different instruction versions were developed for each inspection task, varying in the number and type of directed inspections. The amount of time spent inspecting, the number of calls made, and the number of the feedback calls detected all varied widely across the inspectors. However, inspectors who used instructions with a higher number of directed inspections referred to the instructions more often during and after the task, and found a higher percentage of a selected set of feedback cracks than inspectors using other instruction versions. This suggests that specific instructions can help overall inspection performance, not just performance on the defects specified. Further, instructions were shown to change the way an inspector approaches a task.

An Evaluation of a Job-Aiding Tool for an Inspection Task

Various job aids have been developed to improve visual-inspection performance. Many of the job aids have been developed with the purpose of training inspectors to adopt systematic search strategies. While various research has shown that systematic search strategies are superior to random search strategies, exactly what systematic search strategy constitutes the most efficient search is still unclear. The purpose of this paper is to examine the effectiveness of a job-aiding tool that allows inspectors to inspect a stimulus with a natural search strategy while informing inspectors of areas that have already been searched. In general, the job-aiding tool significantly increased accuracy while decreasing search times and stopping times.

Performance of visual inspection with acetic acid for cervical cancer screening: a qualitative summary of evidence to date.

Developing countries often lack the necessary resources to use the Papanicolaou (Pap) smear as a screening tool for cervical abnormalities. Because the burden of cervical cancer is highest in such low-resource settings, alternative techniques have been sought. Recently, interest in visual inspection with acetic acid (VIA) has increased. Numerous studies have been conducted on its accuracy and its ability to detect cervical lesions when compared with other techniques, both conventional and nonconventional. This review summarizes key findings from the literature to provide researchers and policymakers with an up-to-date summary on VIA. PubMed was used to identify relevant journal articles published between 1982 and 2002. Key words were cervical cancer screening, visual inspection, VIA (visual inspection with acetic acid), DVI (direct visual inspection), AAT (acetic acid test), and cervicoscopy. Studies were eligible for review only if they involved analysis of primary VIA data (ie, not review articles); studies involving magnification devices were excluded. Fifteen studies were reviewed in total; key results were extracted and a summary analysis was performed for sensitivity and specificity parameters. When reported, sensitivity ranged between 66% and 96% and specificity between 64% and 98%. Authors comparing VIA with cytology noted that the overall usefulness of VIA compares favorably with that of the Pap test. The reported findings reviewed here suggest that VIA has the potential to be a cervical cancer screening tool, especially in low resource settings. Obstetricians & Gynecologists, Family Physicians. After completion of this article, the reader will be able to describe how visual inspection of the cervix for cervical cancer screening (VIA) is performed, to summarize the current literature on VIA, and to list potential advantages of VIA.

Impact of Feedback Training in Cbt in Visual Inspection

Training has been a consistently effective intervention in improving inspection performance. For example, existing inspection training in the aircraft maintenance domain is mainly a combination of classroom and on-the-job training (OJT). Computer-based training (CBT) has been promoted ever since it was introduced to this domain. In this study we investigate how effectively feedback training can be combined with CBT to improve visual inspection performance. Specifically, we examine the potential positive impacts of performance and process feedback in CBT, given in an on-line manner, on a trainee's performance and process assessment in a visual inspection task. The CBT system for inspection we used was adopted from the ASSIST program (Chen, Gramopadhye and Melloy, 2000). In our computer simulation of a familiar situation, participants were asked to search certain areas inside of a car in order to detect certain targets (dropped coins) with the aid of computerized tools (e.g., a magnifying glass, a flashlight), and fill out an inspection report based upon detection. A significant test effect was found across performance measures. Type of feedback training was found to be significant for search time. Performance measures were significantly correlated with target difficulty level; on-line performance feedback was significantly more efficient in improving performance measures than conventional delayed performance feedback; feedback training did affect process assessment measures.

Use of job aid to promote systematic search under different levels of task complexity

AbstractJob aids of various kinds have improved visual‐inspection performance. In particular, these job aids include a dynamic pointer that traces a systematic scan path across a search field. The efficacy of this specific job aid, however, has only been verified under a limited set of conditions. Moreover, the effectiveness of this job aid is a function of the speed of the pointer. Thus, it remains to be determined what pointer speeds will yield the best performances under a wide range of conditions. These conditions are defined here by four of the following task‐complexity factors: background density, fault rate, target conspicuity, and fault mix; the performance measure used is search accuracy. In general, increasing either the speed of the cursor or task complexity degraded accuracy, and the optimal pointer speed was specific to the conditions. © 2002 Wiley Periodicals, Inc.

Cognitive Feedback Training using 3D Binocular Eye Tracker

Studies in visual search have shown that feedback training can improve visual inspection performance (speed and accuracy), provided it is given in a timely and appropriate manner. Traditionally, performance feedback, i.e. information about the outcome, serves as the basis of most feedback training schemes. Other forms of feedback, which provide search strategy information, may have a role to play in improving inspection performance. This form of feedback is referred to as ‘cognitive feedback’. This paper describes the setup for collecting and analyzing eye movements using a 3D binocular eye tracker, which serves as a tool for providing cognitive feedback training. It also emphasizes the various technical issues related with eye tracker integration and further discusses the use of a new 3D-fixation recognition algorithm.

Adjunctive testing for cervical cancer in low resource settings with visual inspection, HPV, and the Pap smear

Objective: To test whether the performance of visual inspection using acetic acid (VIA) could be improved through adjunctive testing and to determine whether the combination of visual inspection of the cervix and HPV testing could prove useful for identifying those at highest risk of cervical precancer. Methods: Between October 1995 and August 1997, 2199 women willing to be screened for cervical cancer in peri-urban clinics in Harare, Zimbabwe received VIA, Pap smear and HPV as screening tests. The presence or absence of (pre)cancer was confirmed via colposcopy with biopsy as indicated for >97% of all women. Computerized simulations of sequential testing scenarios provided estimates of the joint (net) test qualities of different paired combinations of the three tests and allowed for comparisons with the individual test qualities. Results: Using HGSIL/CIN II-III as the reference threshold of disease, the net sensitivity and specificity of VIA and HPV when used sequentially were 63.6 and 81.9%, respectively, compared to 43.3 and 91%, respectively, when Pap smears were followed by HPV testing. VIA followed by the Pap smear yielded a net sensitivity of 37.5% and net specificity of 94.3%. Conclusions: For programs with limited resources but with the capacity for HPV testing, sequential testing involving the use of VIA followed by HPV could yield fewer false positives than the use of VIA alone at a cost of relatively few additional false negatives.

The Effects of Individual Differences and Training on Paced and Unpaced Aircraft Visual Inspection Performance

The aircraft maintenance system is a complex one with many interrelated human and machine components. Inspection is the first critical step in locating and identifying non-conformities that are later removed or fixed as part of maintenance. Thus, inspection constitutes a critical step in the overall maintenance process. Significantly, 90% of all inspection, which is visual, is conducted by human inspectors. Moreover aircraft inspection is often performed under varying pacing conditions. If we are to provide the general public with a safe and reliable air transportation system, inspection must be performed effectively, efficiently and consistently over time. However, past studies in human inspection have reported large individual differences in inspection performance. Even though it is difficult to eliminate errors completely, continuing emphasis must be placed on identifying interventions to reduce errors and improve consistency in performance.

Visual Inspection of Circuit Boards: Effect of Gender, Age, Defect type, and Defect Proportion

Visual inspection of printed circuit boards was evaluated through a simulated experiment. Photographs of circuit boards were scanned into a PC and the images were manipulated using a Visual Basic program. The visual inspection performance measured reaction time in seconds and accuracy by measuring the number of incorrect responses given. The independent variables studied in this research were age, gender, defect type, board size, inspection pace, and proportion of defects. Forty subjects participated in this experiment. In summary, the study showed that defect proportion, defect type, age and gender do influence both inspection time and inspection accuracy. Perhaps the most interesting result is that rate of false alarm (decision 2) and misses (decision 1) depend on defect type and proportion. This has interesting ramification for quality professionals.