WorldWideScience

Sample records for diagnostic errors

  1. Cognitive aspect of diagnostic errors.

    Science.gov (United States)

    Phua, Dong Haur; Tan, Nigel C K

    2013-01-01

    Diagnostic errors can result in tangible harm to patients. Despite our advances in medicine, the mental processes required to make a diagnosis exhibits shortcomings, causing diagnostic errors. Cognitive factors are found to be an important cause of diagnostic errors. With new understanding from psychology and social sciences, clinical medicine is now beginning to appreciate that our clinical reasoning can take the form of analytical reasoning or heuristics. Different factors like cognitive biases and affective influences can also impel unwary clinicians to make diagnostic errors. Various strategies have been proposed to reduce the effect of cognitive biases and affective influences when clinicians make diagnoses; however evidence for the efficacy of these methods is still sparse. This paper aims to introduce the reader to the cognitive aspect of diagnostic errors, in the hope that clinicians can use this knowledge to improve diagnostic accuracy and patient outcomes.

  2. Diagnostic errors in pediatric radiology

    International Nuclear Information System (INIS)

    Taylor, George A.; Voss, Stephan D.; Melvin, Patrice R.; Graham, Dionne A.

    2011-01-01

    Little information is known about the frequency, types and causes of diagnostic errors in imaging children. Our goals were to describe the patterns and potential etiologies of diagnostic error in our subspecialty. We reviewed 265 cases with clinically significant diagnostic errors identified during a 10-year period. Errors were defined as a diagnosis that was delayed, wrong or missed; they were classified as perceptual, cognitive, system-related or unavoidable; and they were evaluated by imaging modality and level of training of the physician involved. We identified 484 specific errors in the 265 cases reviewed (mean:1.8 errors/case). Most discrepancies involved staff (45.5%). Two hundred fifty-eight individual cognitive errors were identified in 151 cases (mean = 1.7 errors/case). Of these, 83 cases (55%) had additional perceptual or system-related errors. One hundred sixty-five perceptual errors were identified in 165 cases. Of these, 68 cases (41%) also had cognitive or system-related errors. Fifty-four system-related errors were identified in 46 cases (mean = 1.2 errors/case) of which all were multi-factorial. Seven cases were unavoidable. Our study defines a taxonomy of diagnostic errors in a large academic pediatric radiology practice and suggests that most are multi-factorial in etiology. Further study is needed to define effective strategies for improvement. (orig.)

  3. Dual Processing and Diagnostic Errors

    Science.gov (United States)

    Norman, Geoff

    2009-01-01

    In this paper, I review evidence from two theories in psychology relevant to diagnosis and diagnostic errors. "Dual Process" theories of thinking, frequently mentioned with respect to diagnostic error, propose that categorization decisions can be made with either a fast, unconscious, contextual process called System 1 or a slow, analytical,…

  4. Dual processing and diagnostic errors.

    Science.gov (United States)

    Norman, Geoff

    2009-09-01

    In this paper, I review evidence from two theories in psychology relevant to diagnosis and diagnostic errors. "Dual Process" theories of thinking, frequently mentioned with respect to diagnostic error, propose that categorization decisions can be made with either a fast, unconscious, contextual process called System 1 or a slow, analytical, conscious, and conceptual process, called System 2. Exemplar theories of categorization propose that many category decisions in everyday life are made by unconscious matching to a particular example in memory, and these remain available and retrievable individually. I then review studies of clinical reasoning based on these theories, and show that the two processes are equally effective; System 1, despite its reliance in idiosyncratic, individual experience, is no more prone to cognitive bias or diagnostic error than System 2. Further, I review evidence that instructions directed at encouraging the clinician to explicitly use both strategies can lead to consistent reduction in error rates.

  5. Spectrum of diagnostic errors in radiology

    OpenAIRE

    Pinto, Antonio; Brunese, Luca

    2010-01-01

    Diagnostic errors are important in all branches of medicine because they are an indication of poor patient care. Since the early 1970s, physicians have been subjected to an increasing number of medical malpractice claims. Radiology is one of the specialties most liable to claims of medical negligence. Most often, a plaintiff’s complaint against a radiologist will focus on a failure to diagnose. The etiology of radiological error is multi-factorial. Errors fall into recurrent patterns. Errors ...

  6. Spectrum of diagnostic errors in radiology.

    Science.gov (United States)

    Pinto, Antonio; Brunese, Luca

    2010-10-28

    Diagnostic errors are important in all branches of medicine because they are an indication of poor patient care. Since the early 1970s, physicians have been subjected to an increasing number of medical malpractice claims. Radiology is one of the specialties most liable to claims of medical negligence. Most often, a plaintiff's complaint against a radiologist will focus on a failure to diagnose. The etiology of radiological error is multi-factorial. Errors fall into recurrent patterns. Errors arise from poor technique, failures of perception, lack of knowledge and misjudgments. The work of diagnostic radiology consists of the complete detection of all abnormalities in an imaging examination and their accurate diagnosis. Every radiologist should understand the sources of error in diagnostic radiology as well as the elements of negligence that form the basis of malpractice litigation. Error traps need to be uncovered and highlighted, in order to prevent repetition of the same mistakes. This article focuses on the spectrum of diagnostic errors in radiology, including a classification of the errors, and stresses the malpractice issues in mammography, chest radiology and obstetric sonography. Missed fractures in emergency and communication issues between radiologists and physicians are also discussed.

  7. [Cognitive errors in diagnostic decision making].

    Science.gov (United States)

    Gäbler, Martin

    2017-10-01

    Approximately 10-15% of our diagnostic decisions are faulty and may lead to unfavorable and dangerous outcomes, which could be avoided. These diagnostic errors are mainly caused by cognitive biases in the diagnostic reasoning process.Our medical diagnostic decision-making is based on intuitive "System 1" and analytical "System 2" diagnostic decision-making and can be deviated by unconscious cognitive biases.These deviations can be positively influenced on a systemic and an individual level. For the individual, metacognition (internal withdrawal from the decision-making process) and debiasing strategies, such as verification, falsification and rule out worst-case scenarios, can lead to improved diagnostic decisions making.

  8. Common patterns in 558 diagnostic radiology errors.

    Science.gov (United States)

    Donald, Jennifer J; Barnard, Stuart A

    2012-04-01

    As a Quality Improvement initiative our department has held regular discrepancy meetings since 2003. We performed a retrospective analysis of the cases presented and identified the most common pattern of error. A total of 558 cases were referred for discussion over 92 months, and errors were classified as perceptual or interpretative. The most common patterns of error for each imaging modality were analysed, and the misses were scored by consensus as subtle or non-subtle. Of 558 diagnostic errors, 447 (80%) were perceptual and 111 (20%) were interpretative errors. Plain radiography and computed tomography (CT) scans were the most frequent imaging modalities accounting for 246 (44%) and 241 (43%) of the total number of errors, respectively. In the plain radiography group 120 (49%) of the errors occurred in chest X-ray reports with perceptual miss of a lung nodule occurring in 40% of this subgroup. In the axial and appendicular skeleton missed fractures occurred most frequently, and metastatic bone disease was overlooked in 12 of 50 plain X-rays of the pelvis or spine. The majority of errors within the CT group were in reports of body scans with the commonest perceptual errors identified including 16 missed significant bone lesions, 14 cases of thromboembolic disease and 14 gastrointestinal tumours. Of the 558 errors, 312 (56%) were considered subtle and 246 (44%) non-subtle. Diagnostic errors are not uncommon and are most frequently perceptual in nature. Identification of the most common patterns of error has the potential to improve the quality of reporting by improving the search behaviour of radiologists. © 2012 The Authors. Journal of Medical Imaging and Radiation Oncology © 2012 The Royal Australian and New Zealand College of Radiologists.

  9. Errors and mistakes in breast ultrasound diagnostics

    Directory of Open Access Journals (Sweden)

    Wiesław Jakubowski

    2012-09-01

    Full Text Available Sonomammography is often the first additional examination performed in the diagnostics of breast diseases. The development of ultrasound imaging techniques, particularly the introduction of high frequency transducers, matrix transducers, harmonic imaging and finally, elastography, influenced the improvement of breast disease diagnostics. Neverthe‑ less, as in each imaging method, there are errors and mistakes resulting from the techni‑ cal limitations of the method, breast anatomy (fibrous remodeling, insufficient sensitivity and, in particular, specificity. Errors in breast ultrasound diagnostics can be divided into impossible to be avoided and potentially possible to be reduced. In this article the most frequently made errors in ultrasound have been presented, including the ones caused by the presence of artifacts resulting from volumetric averaging in the near and far field, artifacts in cysts or in dilated lactiferous ducts (reverberations, comet tail artifacts, lateral beam artifacts, improper setting of general enhancement or time gain curve or range. Errors dependent on the examiner, resulting in the wrong BIRADS‑usg classification, are divided into negative and positive errors. The sources of these errors have been listed. The methods of minimization of the number of errors made have been discussed, includ‑ ing the ones related to the appropriate examination technique, taking into account data from case history and the use of the greatest possible number of additional options such as: harmonic imaging, color and power Doppler and elastography. In the article examples of errors resulting from the technical conditions of the method have been presented, and those dependent on the examiner which are related to the great diversity and variation of ultrasound images of pathological breast lesions.

  10. [Diagnostic and organizational error in head injuries].

    Science.gov (United States)

    Zaba, Czesław; Zaba, Zbigniew; Swiderski, Paweł; Lorkiewicz-Muszyíska, Dorota

    2009-01-01

    The study aimed at presenting a case of a diagnostic and organizational error involving lack of detection of foreign body presence in the soft tissues of the head. Head radiograms in two projections clearly demonstrated foreign bodies that resembled in shape flattened bullets, which could not have been missed upon evaluation of the X-rays. On the other hand, description of the radiograms entered by the attending physicians to the patient's medical record indicated an absence of traumatic injuries or foreign bodies. In the opinion of the authors, the case in question involved a diagnostic error: the doctors failed to detect the presence of foreign bodies in the head. The organizational error involved the failure of radiogram evaluation performed by a radiologist.

  11. Meniscal tear. Diagnostic errors in MR imaging

    International Nuclear Information System (INIS)

    Barrera, M. C.; Recondo, J. A.; Gervas, C.; Fernandez, E.; Villanua, J. A.M.; Salvador, E.

    2003-01-01

    To analyze diagnostic discrepancies found between magnetic resonance (MR) and arthroscopy, and the determine the reasons that they occur. Two-hundred and forty-eight MR knee explorations were retrospectively checked. Forty of these showed diagnostic discrepancies between MR and arthroscopy. Two radiologists independently re-analyzed the images from 29 of the 40 studies without knowing which diagnosis had resulted from which of the two techniques. Their interpretations were correlated with the initial MR diagnosis, MR images and arthroscopic results. Initial errors in MR imaging were classified as either unavoidable, interpretive, or secondary to equivocal findings. Eleven MR examinations could not be checked since their corresponding imaging results could not be located. Of 34 errors found in the original diagnoses, 12 (35.5%)were classified as unavoidable, 14 (41.2%) as interpretative and 8 (23.5%) as secondary to equivocal findings. 41.2% of the errors were avoided in the retrospective study probably due to our department having greater experience in interpreting MR images, 25.5% were unavailable even in the retrospective study. A small percentage of diagnostic errors were due to the presence of subtle equivocal findings. (Author) 15 refs

  12. Advancing the research agenda for diagnostic error reduction

    NARCIS (Netherlands)

    Zwaan, L.; Schiff, G.D.; Singh, H.

    2013-01-01

    Diagnostic errors remain an underemphasised and understudied area of patient safety research. We briefly summarise the methods that have been used to conduct research on epidemiology, contributing factors and interventions related to diagnostic error and outline directions for future research.

  13. The next organizational challenge: finding and addressing diagnostic error.

    Science.gov (United States)

    Graber, Mark L; Trowbridge, Robert; Myers, Jennifer S; Umscheid, Craig A; Strull, William; Kanter, Michael H

    2014-03-01

    Although health care organizations (HCOs) are intensely focused on improving the safety of health care, efforts to date have almost exclusively targeted treatment-related issues. The literature confirms that the approaches HCOs use to identify adverse medical events are not effective in finding diagnostic errors, so the initial challenge is to identify cases of diagnostic error. WHY HEALTH CARE ORGANIZATIONS NEED TO GET INVOLVED: HCOs are preoccupied with many quality- and safety-related operational and clinical issues, including performance measures. The case for paying attention to diagnostic errors, however, is based on the following four points: (1) diagnostic errors are common and harmful, (2) high-quality health care requires high-quality diagnosis, (3) diagnostic errors are costly, and (4) HCOs are well positioned to lead the way in reducing diagnostic error. FINDING DIAGNOSTIC ERRORS: Current approaches to identifying diagnostic errors, such as occurrence screens, incident reports, autopsy, and peer review, were not designed to detect diagnostic issues (or problems of omission in general) and/or rely on voluntary reporting. The realization that the existing tools are inadequate has spurred efforts to identify novel tools that could be used to discover diagnostic errors or breakdowns in the diagnostic process that are associated with errors. New approaches--Maine Medical Center's case-finding of diagnostic errors by facilitating direct reports from physicians and Kaiser Permanente's electronic health record--based reports that detect process breakdowns in the followup of abnormal findings--are described in case studies. By raising awareness and implementing targeted programs that address diagnostic error, HCOs may begin to play an important role in addressing the problem of diagnostic error.

  14. A national physician survey of diagnostic error in paediatrics.

    Science.gov (United States)

    Perrem, Lucy M; Fanshawe, Thomas R; Sharif, Farhana; Plüddemann, Annette; O'Neill, Michael B

    2016-10-01

    This cross-sectional survey explored paediatric physician perspectives regarding diagnostic errors. All paediatric consultants and specialist registrars in Ireland were invited to participate in this anonymous online survey. The response rate for the study was 54 % (n = 127). Respondents had a median of 9-year clinical experience (interquartile range (IQR) 4-20 years). A diagnostic error was reported at least monthly by 19 (15.0 %) respondents. Consultants reported significantly less diagnostic errors compared to trainees (p value = 0.01). Cognitive error was the top-ranked contributing factor to diagnostic error, with incomplete history and examination considered to be the principal cognitive error. Seeking a second opinion and close follow-up of patients to ensure that the diagnosis is correct were the highest-ranked, clinician-based solutions to diagnostic error. Inadequate staffing levels and excessive workload were the most highly ranked system-related and situational factors. Increased access to and availability of consultants and experts was the most highly ranked system-based solution to diagnostic error. We found a low level of self-perceived diagnostic error in an experienced group of paediatricians, at variance with the literature and warranting further clarification. The results identify perceptions on the major cognitive, system-related and situational factors contributing to diagnostic error and also key preventative strategies. • Diagnostic errors are an important source of preventable patient harm and have an estimated incidence of 10-15 %. • They are multifactorial in origin and include cognitive, system-related and situational factors. What is New: • We identified a low rate of self-perceived diagnostic error in contrast to the existing literature. • Incomplete history and examination, inadequate staffing levels and excessive workload are cited as the principal contributing factors to diagnostic error in this study.

  15. Advancing the research agenda for diagnostic error reduction.

    Science.gov (United States)

    Zwaan, Laura; Schiff, Gordon D; Singh, Hardeep

    2013-10-01

    Diagnostic errors remain an underemphasised and understudied area of patient safety research. We briefly summarise the methods that have been used to conduct research on epidemiology, contributing factors and interventions related to diagnostic error and outline directions for future research. Research methods that have studied epidemiology of diagnostic error provide some estimate on diagnostic error rates. However, there appears to be a large variability in the reported rates due to the heterogeneity of definitions and study methods used. Thus, future methods should focus on obtaining more precise estimates in different settings of care. This would lay the foundation for measuring error rates over time to evaluate improvements. Research methods have studied contributing factors for diagnostic error in both naturalistic and experimental settings. Both approaches have revealed important and complementary information. Newer conceptual models from outside healthcare are needed to advance the depth and rigour of analysis of systems and cognitive insights of causes of error. While the literature has suggested many potentially fruitful interventions for reducing diagnostic errors, most have not been systematically evaluated and/or widely implemented in practice. Research is needed to study promising intervention areas such as enhanced patient involvement in diagnosis, improving diagnosis through the use of electronic tools and identification and reduction of specific diagnostic process 'pitfalls' (eg, failure to conduct appropriate diagnostic evaluation of a breast lump after a 'normal' mammogram). The last decade of research on diagnostic error has made promising steps and laid a foundation for more rigorous methods to advance the field.

  16. Diagnostic Error in Correctional Mental Health: Prevalence, Causes, and Consequences.

    Science.gov (United States)

    Martin, Michael S; Hynes, Katie; Hatcher, Simon; Colman, Ian

    2016-04-01

    While they have important implications for inmates and resourcing of correctional institutions, diagnostic errors are rarely discussed in correctional mental health research. This review seeks to estimate the prevalence of diagnostic errors in prisons and jails and explores potential causes and consequences. Diagnostic errors are defined as discrepancies in an inmate's diagnostic status depending on who is responsible for conducting the assessment and/or the methods used. It is estimated that at least 10% to 15% of all inmates may be incorrectly classified in terms of the presence or absence of a mental illness. Inmate characteristics, relationships with staff, and cognitive errors stemming from the use of heuristics when faced with time constraints are discussed as possible sources of error. A policy example of screening for mental illness at intake to prison is used to illustrate when the risk of diagnostic error might be increased and to explore strategies to mitigate this risk. © The Author(s) 2016.

  17. Relating faults in diagnostic reasoning with diagnostic errors and patient harm.

    NARCIS (Netherlands)

    Zwaan, L.; Thijs, A.; Wagner, C.; Wal, G. van der; Timmermans, D.R.M.

    2012-01-01

    Purpose: The relationship between faults in diagnostic reasoning, diagnostic errors, and patient harm has hardly been studied. This study examined suboptimal cognitive acts (SCAs; i.e., faults in diagnostic reasoning), related them to the occurrence of diagnostic errors and patient harm, and studied

  18. Diagnostic Error in Medical Education: Where Wrongs Can Make Rights

    Science.gov (United States)

    Eva, Kevin W.

    2009-01-01

    This paper examines diagnostic error from an educational perspective. Rather than addressing the question of how educators in the health professions can help learners avoid error, however, the literature reviewed leads to the conclusion that educators should be working to induce error in learners, leading them to short term pain for long term…

  19. Using Fault Trees to Advance Understanding of Diagnostic Errors.

    Science.gov (United States)

    Rogith, Deevakar; Iyengar, M Sriram; Singh, Hardeep

    2017-11-01

    Diagnostic errors annually affect at least 5% of adults in the outpatient setting in the United States. Formal analytic techniques are only infrequently used to understand them, in part because of the complexity of diagnostic processes and clinical work flows involved. In this article, diagnostic errors were modeled using fault tree analysis (FTA), a form of root cause analysis that has been successfully used in other high-complexity, high-risk contexts. How factors contributing to diagnostic errors can be systematically modeled by FTA to inform error understanding and error prevention is demonstrated. A team of three experts reviewed 10 published cases of diagnostic error and constructed fault trees. The fault trees were modeled according to currently available conceptual frameworks characterizing diagnostic error. The 10 trees were then synthesized into a single fault tree to identify common contributing factors and pathways leading to diagnostic error. FTA is a visual, structured, deductive approach that depicts the temporal sequence of events and their interactions in a formal logical hierarchy. The visual FTA enables easier understanding of causative processes and cognitive and system factors, as well as rapid identification of common pathways and interactions in a unified fashion. In addition, it enables calculation of empirical estimates for causative pathways. Thus, fault trees might provide a useful framework for both quantitative and qualitative analysis of diagnostic errors. Future directions include establishing validity and reliability by modeling a wider range of error cases, conducting quantitative evaluations, and undertaking deeper exploration of other FTA capabilities. Copyright © 2017 The Joint Commission. Published by Elsevier Inc. All rights reserved.

  20. Identification of factors associated with diagnostic error in primary care

    Science.gov (United States)

    2014-01-01

    Background Missed, delayed or incorrect diagnoses are considered to be diagnostic errors. The aim of this paper is to describe the methodology of a study to analyse cognitive aspects of the process by which primary care (PC) physicians diagnose dyspnoea. It examines the possible links between the use of heuristics, suboptimal cognitive acts and diagnostic errors, using Reason’s taxonomy of human error (slips, lapses, mistakes and violations). The influence of situational factors (professional experience, perceived overwork and fatigue) is also analysed. Methods Cohort study of new episodes of dyspnoea in patients receiving care from family physicians and residents at PC centres in Granada (Spain). With an initial expected diagnostic error rate of 20%, and a sampling error of 3%, 384 episodes of dyspnoea are calculated to be required. In addition to filling out the electronic medical record of the patients attended, each physician fills out 2 specially designed questionnaires about the diagnostic process performed in each case of dyspnoea. The first questionnaire includes questions on the physician’s initial diagnostic impression, the 3 most likely diagnoses (in order of likelihood), and the diagnosis reached after the initial medical history and physical examination. It also includes items on the physicians’ perceived overwork and fatigue during patient care. The second questionnaire records the confirmed diagnosis once it is reached. The complete diagnostic process is peer-reviewed to identify and classify the diagnostic errors. The possible use of heuristics of representativeness, availability, and anchoring and adjustment in each diagnostic process is also analysed. Each audit is reviewed with the physician responsible for the diagnostic process. Finally, logistic regression models are used to determine if there are differences in the diagnostic error variables based on the heuristics identified. Discussion This work sets out a new approach to studying the

  1. Identification of factors associated with diagnostic error in primary care.

    Science.gov (United States)

    Minué, Sergio; Bermúdez-Tamayo, Clara; Fernández, Alberto; Martín-Martín, José Jesús; Benítez, Vivian; Melguizo, Miguel; Caro, Araceli; Orgaz, María José; Prados, Miguel Angel; Díaz, José Enrique; Montoro, Rafael

    2014-05-12

    Missed, delayed or incorrect diagnoses are considered to be diagnostic errors. The aim of this paper is to describe the methodology of a study to analyse cognitive aspects of the process by which primary care (PC) physicians diagnose dyspnoea. It examines the possible links between the use of heuristics, suboptimal cognitive acts and diagnostic errors, using Reason's taxonomy of human error (slips, lapses, mistakes and violations). The influence of situational factors (professional experience, perceived overwork and fatigue) is also analysed. Cohort study of new episodes of dyspnoea in patients receiving care from family physicians and residents at PC centres in Granada (Spain). With an initial expected diagnostic error rate of 20%, and a sampling error of 3%, 384 episodes of dyspnoea are calculated to be required. In addition to filling out the electronic medical record of the patients attended, each physician fills out 2 specially designed questionnaires about the diagnostic process performed in each case of dyspnoea. The first questionnaire includes questions on the physician's initial diagnostic impression, the 3 most likely diagnoses (in order of likelihood), and the diagnosis reached after the initial medical history and physical examination. It also includes items on the physicians' perceived overwork and fatigue during patient care. The second questionnaire records the confirmed diagnosis once it is reached. The complete diagnostic process is peer-reviewed to identify and classify the diagnostic errors. The possible use of heuristics of representativeness, availability, and anchoring and adjustment in each diagnostic process is also analysed. Each audit is reviewed with the physician responsible for the diagnostic process. Finally, logistic regression models are used to determine if there are differences in the diagnostic error variables based on the heuristics identified. This work sets out a new approach to studying the diagnostic decision-making process

  2. Cognitive and system factors contributing to diagnostic errors in radiology.

    Science.gov (United States)

    Lee, Cindy S; Nagy, Paul G; Weaver, Sallie J; Newman-Toker, David E

    2013-09-01

    In this article, we describe some of the cognitive and system-based sources of detection and interpretation errors in diagnostic radiology and discuss potential approaches to help reduce misdiagnoses. Every radiologist worries about missing a diagnosis or giving a false-positive reading. The retrospective error rate among radiologic examinations is approximately 30%, with real-time errors in daily radiology practice averaging 3-5%. Nearly 75% of all medical malpractice claims against radiologists are related to diagnostic errors. As medical reimbursement trends downward, radiologists attempt to compensate by undertaking additional responsibilities to increase productivity. The increased workload, rising quality expectations, cognitive biases, and poor system factors all contribute to diagnostic errors in radiology. Diagnostic errors are underrecognized and underappreciated in radiology practice. This is due to the inability to obtain reliable national estimates of the impact, the difficulty in evaluating effectiveness of potential interventions, and the poor response to systemwide solutions. Most of our clinical work is executed through type 1 processes to minimize cost, anxiety, and delay; however, type 1 processes are also vulnerable to errors. Instead of trying to completely eliminate cognitive shortcuts that serve us well most of the time, becoming aware of common biases and using metacognitive strategies to mitigate the effects have the potential to create sustainable improvement in diagnostic errors.

  3. Osseous Metastase of Occult Paraganglioma: A Diagnostic Medical Error

    Directory of Open Access Journals (Sweden)

    Ghasemi TA

    2013-10-01

    Full Text Available Introduction: Diagnostic errors have a natural complexity. Medical diagnoses make up a large proportion of all medical errors and cause much suffering and harm. Compared to other types of error, diagnostic errors receive little attention-a major factor in continuity of unacceptable rates of diagnostic error. Case: A 55-year-old woman presented to the emergency department (ED complaining of bone pain which has been started a month ago and increased gradually in the upper right thigh. Following the emergency evaluation she was sent home with pain medication. On the second visit, a femur neck fracture was seen in the x-ray. She underwent hemiarthroplasty and was discharged. Over several weeks she was reevaluated by many Physicians, because of her worsening pain .In the third visit after the surgery, her x-ray showed bone destruction and following bone biopsy, malignant paraganglioma was diagnosed. Discussion and solution: In all cases in which patient comes to us with skeletal pain, getting a comprehensive history and a full physical examination are prior to lab tests and x-rays. Bone metastasis which can develop severe pain and pathological fractures, is common in patients with malignant paraganglioma. Effective steps for diagnostic error prevention are: Considering the diagnostic error in the normal range of quality assurance surveillance and review, identifying the elements leading to diagnostic errors and getting feedback on the diagnoses Physicians make, in order to improve their skills. Conclusion: It is an every health system priority to identify, analyze, and prevent diagnostic errors in order to improve patient safety

  4. Reducing diagnostic errors in medicine: what's the goal?

    Science.gov (United States)

    Graber, Mark; Gordon, Ruthanna; Franklin, Nancy

    2002-10-01

    This review considers the feasibility of reducing or eliminating the three major categories of diagnostic errors in medicine: "No-fault errors" occur when the disease is silent, presents atypically, or mimics something more common. These errors will inevitably decline as medical science advances, new syndromes are identified, and diseases can be detected more accurately or at earlier stages. These errors can never be eradicated, unfortunately, because new diseases emerge, tests are never perfect, patients are sometimes noncompliant, and physicians will inevitably, at times, choose the most likely diagnosis over the correct one, illustrating the concept of necessary fallibility and the probabilistic nature of choosing a diagnosis. "System errors" play a role when diagnosis is delayed or missed because of latent imperfections in the health care system. These errors can be reduced by system improvements, but can never be eliminated because these improvements lag behind and degrade over time, and each new fix creates the opportunity for novel errors. Tradeoffs also guarantee system errors will persist, when resources are just shifted. "Cognitive errors" reflect misdiagnosis from faulty data collection or interpretation, flawed reasoning, or incomplete knowledge. The limitations of human processing and the inherent biases in using heuristics guarantee that these errors will persist. Opportunities exist, however, for improving the cognitive aspect of diagnosis by adopting system-level changes (e.g., second opinions, decision-support systems, enhanced access to specialists) and by training designed to improve cognition or cognitive awareness. Diagnostic error can be substantially reduced, but never eradicated.

  5. Diagnostic Error in Stroke-Reasons and Proposed Solutions.

    Science.gov (United States)

    Bakradze, Ekaterina; Liberman, Ava L

    2018-02-13

    We discuss the frequency of stroke misdiagnosis and identify subgroups of stroke at high risk for specific diagnostic errors. In addition, we review common reasons for misdiagnosis and propose solutions to decrease error. According to a recent report by the National Academy of Medicine, most people in the USA are likely to experience a diagnostic error during their lifetimes. Nearly half of such errors result in serious disability and death. Stroke misdiagnosis is a major health care concern, with initial misdiagnosis estimated to occur in 9% of all stroke patients in the emergency setting. Under- or missed diagnosis (false negative) of stroke can result in adverse patient outcomes due to the preclusion of acute treatments and failure to initiate secondary prevention strategies. On the other hand, the overdiagnosis of stroke can result in inappropriate treatment, delayed identification of actual underlying disease, and increased health care costs. Young patients, women, minorities, and patients presenting with non-specific, transient, or posterior circulation stroke symptoms are at increased risk of misdiagnosis. Strategies to decrease diagnostic error in stroke have largely focused on early stroke detection via bedside examination strategies and a clinical decision rules. Targeted interventions to improve the diagnostic accuracy of stroke diagnosis among high-risk groups as well as symptom-specific clinical decision supports are needed. There are a number of open questions in the study of stroke misdiagnosis. To improve patient outcomes, existing strategies to improve stroke diagnostic accuracy should be more broadly adopted and novel interventions devised and tested to reduce diagnostic errors.

  6. Irregular analytical errors in diagnostic testing - a novel concept.

    Science.gov (United States)

    Vogeser, Michael; Seger, Christoph

    2018-02-23

    In laboratory medicine, routine periodic analyses for internal and external quality control measurements interpreted by statistical methods are mandatory for batch clearance. Data analysis of these process-oriented measurements allows for insight into random analytical variation and systematic calibration bias over time. However, in such a setting, any individual sample is not under individual quality control. The quality control measurements act only at the batch level. Quantitative or qualitative data derived for many effects and interferences associated with an individual diagnostic sample can compromise any analyte. It is obvious that a process for a quality-control-sample-based approach of quality assurance is not sensitive to such errors. To address the potential causes and nature of such analytical interference in individual samples more systematically, we suggest the introduction of a new term called the irregular (individual) analytical error. Practically, this term can be applied in any analytical assay that is traceable to a reference measurement system. For an individual sample an irregular analytical error is defined as an inaccuracy (which is the deviation from a reference measurement procedure result) of a test result that is so high it cannot be explained by measurement uncertainty of the utilized routine assay operating within the accepted limitations of the associated process quality control measurements. The deviation can be defined as the linear combination of the process measurement uncertainty and the method bias for the reference measurement system. Such errors should be coined irregular analytical errors of the individual sample. The measurement result is compromised either by an irregular effect associated with the individual composition (matrix) of the sample or an individual single sample associated processing error in the analytical process. Currently, the availability of reference measurement procedures is still highly limited, but LC

  7. Awareness of Diagnostic Error among Japanese Residents: a Nationwide Study.

    Science.gov (United States)

    Nishizaki, Yuji; Shinozaki, Tomohiro; Kinoshita, Kensuke; Shimizu, Taro; Tokuda, Yasuharu

    2018-04-01

    Residents' understanding of diagnostic error may differ between countries. We sought to explore the relationship between diagnostic error knowledge and self-study, clinical knowledge, and experience. Our nationwide study involved postgraduate year 1 and 2 (PGY-1 and -2) Japanese residents. The Diagnostic Error Knowledge Assessment Test (D-KAT) and General Medicine In-Training Examination (GM-ITE) were administered at the end of the 2014 academic year. D-KAT scores were compared with the benchmark scores of US residents. Associations between D-KAT score and gender, PGY, emergency department (ED) rotations per month, mean number of inpatients handled at any given time, and mean daily minutes of self-study were also analyzed, both with and without adjusting for GM-ITE scores. Student's t test was used for comparisons with linear mixed models and structural equation models (SEM) to explore associations with D-KAT or GM-ITE scores. The mean D-KAT score among Japanese PGY-2 residents was significantly lower than that of their US PGY-2 counterparts (6.2 vs. 8.3, p ITE scores correlated with ED rotations (≥6 rotations: 2.14; 0.16-4.13; p = 0.03), inpatient caseloads (5-9 patients: 1.79; 0.82-2.76; p ITE scores (ß = 0.37, 95% CI: 0.34-0.41) and indirectly associated with ED rotations (ß = 0.06, 95% CI: 0.02-0.10), inpatient caseload (ß = 0.04, 95% CI: 0.003-0.08), and average daily minutes of study (ß = 0.13, 95% CI: 0.09-0.17). Knowledge regarding diagnostic error among Japanese residents was poor compared with that among US residents. D-KAT scores correlated strongly with GM-ITE scores, and the latter scores were positively associated with a greater number of ED rotations, larger caseload (though only up to 15 patients), and more time spent studying.

  8. Reducing Diagnostic Errors through Effective Communication: Harnessing the Power of Information Technology

    Science.gov (United States)

    Naik, Aanand Dinkar; Rao, Raghuram; Petersen, Laura Ann

    2008-01-01

    Diagnostic errors are poorly understood despite being a frequent cause of medical errors. Recent efforts have aimed to advance the "basic science" of diagnostic error prevention by tracing errors to their most basic origins. Although a refined theory of diagnostic error prevention will take years to formulate, we focus on communication breakdown, a major contributor to diagnostic errors and an increasingly recognized preventable factor in medical mishaps. We describe a comprehensive framework that integrates the potential sources of communication breakdowns within the diagnostic process and identifies vulnerable steps in the diagnostic process where various types of communication breakdowns can precipitate error. We then discuss potential information technology-based interventions that may have efficacy in preventing one or more forms of these breakdowns. These possible intervention strategies include using new technologies to enhance communication between health providers and health systems, improve patient involvement, and facilitate management of information in the medical record. PMID:18373151

  9. Analysis of errors during medical and computerized diagnostics of spherical lung neoplasms

    International Nuclear Information System (INIS)

    Pozmogov, A.I.; Petruk, D.A.

    1985-01-01

    Reasons for errors in medical and computerized diagnostics of spherical lung neoplasms are studied based on material of 212 case records and clinicoroentgenological data; it should promote improvement of their diagnostics

  10. Cognitive strategies: a method to reduce diagnostic errors in ER

    Directory of Open Access Journals (Sweden)

    Carolina Prevaldi

    2009-02-01

    Full Text Available I wonder why sometimes we are able to rapidly recognize patterns of disease presentation, formulate a speedy diagnostic closure, and go on with a treatment plan. On the other hand sometimes we proceed studing in deep our patient in an analytic, slow and rational way of decison making. Why decisions sometimes can be intuitive, while sometimes we have to proceed in a rigorous way? What is the “back ground noise” and the “signal to noise ratio” of presenting sintoms? What is the risk in premature labeling or “closure” of a patient? When is it useful the “cook-book” approach in clinical decision making? The Emergency Department is a natural laboratory for the study of error” stated an author. Many studies have focused on the occurrence of errors in medicine, and in hospital practice, but the ED with his unique operating characteristics seems to be a uniquely errorprone environment. That's why it is useful to understand the underlying pattern of thinking that can lead us to misdiagnosis. The general knowledge of thought processes gives the psysician awareness an the ability to apply different tecniques in clinical decision making and to recognize and avoid pitfalls.

  11. Missed opportunities for diagnosis: lessons learned from diagnostic errors in primary care.

    Science.gov (United States)

    Goyder, Clare R; Jones, Caroline H D; Heneghan, Carl J; Thompson, Matthew J

    2015-12-01

    Because of the difficulties inherent in diagnosis in primary care, it is inevitable that diagnostic errors will occur. However, despite the important consequences associated with diagnostic errors and their estimated high prevalence, teaching and research on diagnostic error is a neglected area. To ascertain the key learning points from GPs' experiences of diagnostic errors and approaches to clinical decision making associated with these. Secondary analysis of 36 qualitative interviews with GPs in Oxfordshire, UK. Two datasets of semi-structured interviews were combined. Questions focused on GPs' experiences of diagnosis and diagnostic errors (or near misses) in routine primary care and out of hours. Interviews were audiorecorded, transcribed verbatim, and analysed thematically. Learning points include GPs' reliance on 'pattern recognition' and the failure of this strategy to identify atypical presentations; the importance of considering all potentially serious conditions using a 'restricted rule out' approach; and identifying and acting on a sense of unease. Strategies to help manage uncertainty in primary care were also discussed. Learning from previous examples of diagnostic errors is essential if these events are to be reduced in the future and this should be incorporated into GP training. At a practice level, learning points from experiences of diagnostic errors should be discussed more frequently; and more should be done to integrate these lessons nationally to understand and characterise diagnostic errors. © British Journal of General Practice 2015.

  12. Normal lymphographic findings and diagnostic errors in the retroperitoneal space

    International Nuclear Information System (INIS)

    Klein, U.; Heinze, H.G.

    1980-01-01

    Diagnostic erros in the lymphograms of 194 normal patients are shown to be due to topographical variations of the lymph system, influx and distribution of contrast media in the lymph ducts and nodes, and degenerative changes caused by old age. (orig.) [de

  13. Automatic diagnostic system for measuring ocular refractive errors

    Science.gov (United States)

    Ventura, Liliane; Chiaradia, Caio; de Sousa, Sidney J. F.; de Castro, Jarbas C.

    1996-05-01

    Ocular refractive errors (myopia, hyperopia and astigmatism) are automatic and objectively determined by projecting a light target onto the retina using an infra-red (850 nm) diode laser. The light vergence which emerges from the eye (light scattered from the retina) is evaluated in order to determine the corresponding ametropia. The system basically consists of projecting a target (ring) onto the retina and analyzing the scattered light with a CCD camera. The light scattered by the eye is divided into six portions (3 meridians) by using a mask and a set of six prisms. The distance between the two images provided by each of the meridians, leads to the refractive error of the referred meridian. Hence, it is possible to determine the refractive error at three different meridians, which gives the exact solution for the eye's refractive error (spherical and cylindrical components and the axis of the astigmatism). The computational basis used for the image analysis is a heuristic search, which provides satisfactory calculation times for our purposes. The peculiar shape of the target, a ring, provides a wider range of measurement and also saves parts of the retina from unnecessary laser irradiation. Measurements were done in artificial and in vivo eyes (using cicloplegics) and the results were in good agreement with the retinoscopic measurements.

  14. Errors and risks of urological X-ray diagnostics

    International Nuclear Information System (INIS)

    Blech, M.; Truss, F.

    1987-01-01

    Classical methods of radiologic diagnosis like excretory urogram, retrograde ureteropyelography or urethrography - only to mention a few - are as much as ever corner pillars of the whole urologic diagnosis. Similar to other diagnostic methods certain risks and complications, which is intented to summarize, also exist in this area. Problems related to intravenous infusion of contrast medium or radioprotection are not discussed in this article. (orig.) [de

  15. Fault-tolerant quantum computing in the Pauli or Clifford frame with slow error diagnostics

    Directory of Open Access Journals (Sweden)

    Christopher Chamberland

    2018-01-01

    Full Text Available We consider the problem of fault-tolerant quantum computation in the presence of slow error diagnostics, either caused by measurement latencies or slow decoding algorithms. Our scheme offers a few improvements over previously existing solutions, for instance it does not require active error correction and results in a reduced error-correction overhead when error diagnostics is much slower than the gate time. In addition, we adapt our protocol to cases where the underlying error correction strategy chooses the optimal correction amongst all Clifford gates instead of the usual Pauli gates. The resulting Clifford frame protocol is of independent interest as it can increase error thresholds and could find applications in other areas of quantum computation.

  16. Diagnostic errors in the interpretation of cerebral infarction

    International Nuclear Information System (INIS)

    Ostertag, C.B.; Mundinger, F.

    1978-01-01

    Acute and subacute infarcts show a changing pattern and inconstant characteristics up to the fourth week of onset. There is a wide spectrum of other lesions presenting identical alterations in the CT scan. These include tumorous lesions, mostly gliomas (glioblastomas, astrocytomas), demarcating inflammatory lesions (abscesses, viral encephalitis), metastatic lesions, resolving intracerebral hematomas, subdural hematomas, subarachnoid hemorrhages and a.v. malformations. False negative results are frequently found in cases of recent infarcts that present isodense lesions without mass effect. Only consecutive CT scans - native as well as with enhancement - and other diagnostic procedures can help to establish a definite diagnosis. (orig.) [de

  17. Inborn errors of metabolism for the diagnostic radiologist

    Energy Technology Data Exchange (ETDEWEB)

    Hendriksz, Chris J. [Birmingham Children' s Hospital NHS Foundation Trust, Department of Clinical Inherited Metabolic Disorders, Birmingham (United Kingdom)

    2009-03-15

    Inherited metabolic disorders are becoming more important with the increasing availability of diagnostic methods and therapies for these conditions. The radiologist has become an important link in making the diagnosis or collaborating with the specialist centre to diagnose these disorders and monitor effects of therapy. The modes of presentation, disease-specific groups, classic radiological features and investigations are explored in this article to try and give the general radiologist some crucial background knowledge. The following presentations are covered: acute intoxication, hypoglycaemia, developmental delay and storage features. Specific groups of disorders covered are the abnormalities of intermediary metabolism, disorders of fatty acid oxidation and ketogenesis, mitochondrial disorders, lysosomal storage disorders, and, briefly, other groups such as peroxisomal disorders, disorders of glycosylation, and creatine synthesis disorders. New advances and the demands for monitoring are also briefly explored. (orig.)

  18. Inborn errors of metabolism for the diagnostic radiologist

    International Nuclear Information System (INIS)

    Hendriksz, Chris J.

    2009-01-01

    Inherited metabolic disorders are becoming more important with the increasing availability of diagnostic methods and therapies for these conditions. The radiologist has become an important link in making the diagnosis or collaborating with the specialist centre to diagnose these disorders and monitor effects of therapy. The modes of presentation, disease-specific groups, classic radiological features and investigations are explored in this article to try and give the general radiologist some crucial background knowledge. The following presentations are covered: acute intoxication, hypoglycaemia, developmental delay and storage features. Specific groups of disorders covered are the abnormalities of intermediary metabolism, disorders of fatty acid oxidation and ketogenesis, mitochondrial disorders, lysosomal storage disorders, and, briefly, other groups such as peroxisomal disorders, disorders of glycosylation, and creatine synthesis disorders. New advances and the demands for monitoring are also briefly explored. (orig.)

  19. Diagnostic errors related to acute abdominal pain in the emergency department.

    Science.gov (United States)

    Medford-Davis, Laura; Park, Elizabeth; Shlamovitz, Gil; Suliburk, James; Meyer, Ashley N D; Singh, Hardeep

    2016-04-01

    Diagnostic errors in the emergency department (ED) are harmful and costly. We reviewed a selected high-risk cohort of patients presenting to the ED with abdominal pain to evaluate for possible diagnostic errors and associated process breakdowns. We conducted a retrospective chart review of ED patients >18 years at an urban academic hospital. A computerised 'trigger' algorithm identified patients possibly at high risk for diagnostic errors to facilitate selective record reviews. The trigger determined patients to be at high risk because they: (1) presented to the ED with abdominal pain, and were discharged home and (2) had a return ED visit within 10 days that led to a hospitalisation. Diagnostic errors were defined as missed opportunities to make a correct or timely diagnosis based on the evidence available during the first ED visit, regardless of patient harm, and included errors that involved both ED and non-ED providers. Errors were determined by two independent record reviewers followed by team consensus in cases of disagreement. Diagnostic errors occurred in 35 of 100 high-risk cases. Over two-thirds had breakdowns involving the patient-provider encounter (most commonly history-taking or ordering additional tests) and/or follow-up and tracking of diagnostic information (most commonly follow-up of abnormal test results). The most frequently missed diagnoses were gallbladder pathology (n=10) and urinary infections (n=5). Diagnostic process breakdowns in ED patients with abdominal pain most commonly involved history-taking, ordering insufficient tests in the patient-provider encounter and problems with follow-up of abnormal test results. 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/

  20. CT for suspected appendicitis in children: an analysis of diagnostic errors

    International Nuclear Information System (INIS)

    Taylor, George A.; Callahan, Michael J.; Rodriguez, Diana; Smink, Douglas S.

    2006-01-01

    Mistakes have been made by the use of CT in diagnosing children with suspected appendicitis. Although others have reported the frequency of diagnostic errors, we were unable to find any studies that addressed the specific situations in which diagnostic errors occurred in children with suspected appendicitis. To investigate the frequency and type of diagnostic errors resulting from CT of children with suspected appendicitis when compared to surgical and pathological diagnosis. We reviewed imaging, clinical and pathological data on 1,207 consecutive pediatric patients who underwent CT examination for suspected appendicitis. Imaging findings were categorized as false-positive, false-negative, or indeterminate. Errors were classified as interpretative, technical or unavoidable. Concordance between surgical and pathological findings was also evaluated. The imaging findings of 34 patients (2.8%) were discrepant with the pathological examination or clinical follow-up. The errors in 23 cases were classified as interpretive (68%) and 11 as unavoidable (32%), and no errors were classified as technical. There were 23 false-positive errors (68%), 6 false-negative errors (18%), and 5 indeterminate imaging studies (15%). Isolated CT findings of an enlarged (greater than 6 mm) appendix, fat stranding, thickened bowel or non-visualization of the distal appendix were the most common false-positive CT findings. Of these 34 patients, 22 underwent appendectomy, with 10 (45%) having discordant surgical and pathological findings. (orig.)

  1. The frequency of diagnostic errors in radiologic reports depends on the patient's age

    International Nuclear Information System (INIS)

    Diaz, Sandra; Ekberg, Olle

    2010-01-01

    Background: Patients who undergo treatment may suffer preventable medical errors. Some of these errors are due to diagnostic imaging procedures. Purpose: To compare the frequency of diagnostic errors in different age groups in an urban European population. Material and Methods: A total of 19 129 reported radiologic examinations were included. During a 6-month period, the analyzed age groups were: children (aged 0-9 years), adults (40-49 years), and elderly (86-95 years). Results: The frequency of radiologic examinations per year was 0.3 in children, 0.6 in adults, and 1.1 in elderly. Significant errors were significantly more frequent in the elderly (1.7%) and children (1.4%) compared with adults (0.8%). There were 60 false-positive reports and 232 false-negative reports. Most errors were made by staff radiologists after hours when they reported on examinations outside their area of expertise. Conclusion: Diagnostic errors are more frequent in children and the elderly compared with middle-aged adults

  2. Evaluation of Analysis by Cross-Validation, Part II: Diagnostic and Optimization of Analysis Error Covariance

    Directory of Open Access Journals (Sweden)

    Richard Ménard

    2018-02-01

    Full Text Available We present a general theory of estimation of analysis error covariances based on cross-validation as well as a geometric interpretation of the method. In particular, we use the variance of passive observation-minus-analysis residuals and show that the true analysis error variance can be estimated, without relying on the optimality assumption. This approach is used to obtain near optimal analyses that are then used to evaluate the air quality analysis error using several different methods at active and passive observation sites. We compare the estimates according to the method of Hollingsworth-Lönnberg, Desroziers et al., a new diagnostic we developed, and the perceived analysis error computed from the analysis scheme, to conclude that, as long as the analysis is near optimal, all estimates agree within a certain error margin.

  3. Learning from diagnostic errors: A good way to improve education in radiology

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, Antonio, E-mail: antopin1968@libero.it [Department of Diagnostic Imaging, A. Cardarelli Hospital, I-80131 Naples (Italy); Acampora, Ciro, E-mail: itrasente@libero.it [Department of Diagnostic Imaging, A. Cardarelli Hospital, I-80131 Naples (Italy); Pinto, Fabio, E-mail: fpinto1966@libero.it [Department of Diagnostic Imaging, A. Cardarelli Hospital, I-80131 Naples (Italy); Kourdioukova, Elena, E-mail: Elena.Kourdioukova@UGent.be [Department of Radiology, Ghent University Hospital (UZG), MR/-1K12, De Pintelaan 185, B-9000 Ghent (Belgium); Romano, Luigia, E-mail: luigia.romano@fastwebnet.it [Department of Diagnostic Imaging, A. Cardarelli Hospital, I-80131 Naples (Italy); Verstraete, Koenraad, E-mail: Koenraad.Verstraete@UGent.be [Department of Radiology, Ghent University Hospital (UZG), MR/-1K12, De Pintelaan 185, B-9000 Ghent (Belgium)

    2011-06-15

    Purpose: To evaluate the causes and the main categories of diagnostic errors in radiology as a method for improving education in radiology. Material and methods: A Medline search was performed using PubMed (National Library of Medicine, Bethesda, MD) for original research publications discussing errors in diagnosis with specific reference to radiology. The search strategy employed different combinations of the following terms: (1) diagnostic radiology, (2) radiological error and (3) medical negligence. This review was limited to human studies and to English-language literature. Two authors reviewed all the titles and subsequently the abstracts of 491 articles that appeared pertinent. Additional articles were identified by reviewing the reference lists of relevant papers. Finally, the full text of 75 selected articles was reviewed. Results: Several studies show that the etiology of radiological error is multi-factorial. The main category of claims against radiologists includes the misdiagnoses. Radiologic 'misses' typically are one of two types: either missed fractures or missed diagnosis of cancer. The most commonly missed fractures include those in the femur, the navicular bone, and the cervical spine. The second type of 'miss' is failure to diagnose cancer. Lack of appreciation of lung nodules on chest radiographs and breast lesions on mammograms are the predominant problems. Conclusion: Diagnostic errors should be considered not as signs of failure, but as learning opportunities.

  4. Learning from diagnostic errors: A good way to improve education in radiology

    International Nuclear Information System (INIS)

    Pinto, Antonio; Acampora, Ciro; Pinto, Fabio; Kourdioukova, Elena; Romano, Luigia; Verstraete, Koenraad

    2011-01-01

    Purpose: To evaluate the causes and the main categories of diagnostic errors in radiology as a method for improving education in radiology. Material and methods: A Medline search was performed using PubMed (National Library of Medicine, Bethesda, MD) for original research publications discussing errors in diagnosis with specific reference to radiology. The search strategy employed different combinations of the following terms: (1) diagnostic radiology, (2) radiological error and (3) medical negligence. This review was limited to human studies and to English-language literature. Two authors reviewed all the titles and subsequently the abstracts of 491 articles that appeared pertinent. Additional articles were identified by reviewing the reference lists of relevant papers. Finally, the full text of 75 selected articles was reviewed. Results: Several studies show that the etiology of radiological error is multi-factorial. The main category of claims against radiologists includes the misdiagnoses. Radiologic 'misses' typically are one of two types: either missed fractures or missed diagnosis of cancer. The most commonly missed fractures include those in the femur, the navicular bone, and the cervical spine. The second type of 'miss' is failure to diagnose cancer. Lack of appreciation of lung nodules on chest radiographs and breast lesions on mammograms are the predominant problems. Conclusion: Diagnostic errors should be considered not as signs of failure, but as learning opportunities.

  5. Diagnostic errors in interpretation of pediatric musculoskeletal radiographs at common injury sites

    International Nuclear Information System (INIS)

    Bisset, George S.; Crowe, James

    2014-01-01

    Extremity pain represents one of the most common reasons for obtaining conventional radiographs in childhood. Despite the frequency of these examinations little is known about the incidence of diagnostic errors by interpreting pediatric radiologists. The purpose of this study was to develop a standard error rate of pediatric radiologists by double-reading of extremity radiographs (elbow, wrists, knees and ankles) in children presenting with a history of trauma or pain. During a 6-month period all major extremity radiographs (excluding digits) obtained at a large pediatric referral hospital for evaluation of pain or trauma were reviewed by two senior pediatric radiologists and compared to the official interpretation. All radiographs were interpreted initially by a board-certified pediatric radiologist with a Certificate of Added Qualification (CAQ). We reviewed 3,865 radiographic series in children and young adults 2-20 years of age. We tabulated misses and overcalls. We did not assess the clinical significance of the errors. There were 61 miss errors and 44 overcalls in 1,235 abnormal cases and 2,630 normal cases, for a 1.6% miss rate and a 1.1% overcall rate. Misses and overcalls were most common in the ankle. Interpretive errors by pediatric radiologists reviewing certain musculoskeletal radiographs are relatively infrequent. Diagnostic errors in the form of a miss or overcall occurred in 2.7% of the radiographs. (orig.)

  6. The Effect of Random Error on Diagnostic Accuracy Illustrated with the Anthropometric Diagnosis of Malnutrition

    Science.gov (United States)

    2016-01-01

    Background It is often thought that random measurement error has a minor effect upon the results of an epidemiological survey. Theoretically, errors of measurement should always increase the spread of a distribution. Defining an illness by having a measurement outside an established healthy range will lead to an inflated prevalence of that condition if there are measurement errors. Methods and results A Monte Carlo simulation was conducted of anthropometric assessment of children with malnutrition. Random errors of increasing magnitude were imposed upon the populations and showed that there was an increase in the standard deviation with each of the errors that became exponentially greater with the magnitude of the error. The potential magnitude of the resulting error of reported prevalence of malnutrition were compared with published international data and found to be of sufficient magnitude to make a number of surveys and the numerous reports and analyses that used these data unreliable. Conclusions The effect of random error in public health surveys and the data upon which diagnostic cut-off points are derived to define “health” has been underestimated. Even quite modest random errors can more than double the reported prevalence of conditions such as malnutrition. Increasing sample size does not address this problem, and may even result in less accurate estimates. More attention needs to be paid to the selection, calibration and maintenance of instruments, measurer selection, training & supervision, routine estimation of the likely magnitude of errors using standardization tests, use of statistical likelihood of error to exclude data from analysis and full reporting of these procedures in order to judge the reliability of survey reports. PMID:28030627

  7. Diagnostic omission errors in acute paediatric practice: impact of a reminder system on decision-making

    Directory of Open Access Journals (Sweden)

    Fisher Helen

    2006-11-01

    Full Text Available Abstract Background Diagnostic error is a significant problem in specialities characterised by diagnostic uncertainty such as primary care, emergency medicine and paediatrics. Despite wide-spread availability, computerised aids have not been shown to significantly improve diagnostic decision-making in a real world environment, mainly due to the need for prolonged system consultation. In this study performed in the clinical environment, we used a Web-based diagnostic reminder system that provided rapid advice with free text data entry to examine its impact on clinicians' decisions in an acute paediatric setting during assessments characterised by diagnostic uncertainty. Methods Junior doctors working over a 5-month period at four paediatric ambulatory units consulted the Web-based diagnostic aid when they felt the need for diagnostic assistance. Subjects recorded their clinical decisions for patients (differential diagnosis, test-ordering and treatment before and after system consultation. An expert panel of four paediatric consultants independently suggested clinically significant decisions indicating an appropriate and 'safe' assessment. The primary outcome measure was change in the proportion of 'unsafe' workups by subjects during patient assessment. A more sensitive evaluation of impact was performed using specific validated quality scores. Adverse effects of consultation on decision-making, as well as the additional time spent on system use were examined. Results Subjects attempted to access the diagnostic aid on 595 occasions during the study period (8.6% of all medical assessments; subjects examined diagnostic advice only in 177 episodes (30%. Senior House Officers at hospitals with greater number of available computer workstations in the clinical area were most likely to consult the system, especially out of working hours. Diagnostic workups construed as 'unsafe' occurred in 47/104 cases (45.2%; this reduced to 32.7% following system

  8. Error tolerance analysis of wave diagnostic based on coherent modulation imaging in high power laser system

    Science.gov (United States)

    Pan, Xingchen; Liu, Cheng; Zhu, Jianqiang

    2018-02-01

    Coherent modulation imaging providing fast convergence speed and high resolution with single diffraction pattern is a promising technique to satisfy the urgent demands for on-line multiple parameter diagnostics with single setup in high power laser facilities (HPLF). However, the influence of noise on the final calculated parameters concerned has not been investigated yet. According to a series of simulations with twenty different sampling beams generated based on the practical parameters and performance of HPLF, the quantitative analysis based on statistical results was first investigated after considering five different error sources. We found the background noise of detector and high quantization error will seriously affect the final accuracy and different parameters have different sensitivity to different noise sources. The simulation results and the corresponding analysis provide the potential directions to further improve the final accuracy of parameter diagnostics which is critically important to its formal applications in the daily routines of HPLF.

  9. Model and Reduction of Inactive Times in a Maintenance Workshop Following a Diagnostic Error

    Directory of Open Access Journals (Sweden)

    T. Beda

    2011-04-01

    Full Text Available The majority of maintenance workshops in manufacturing factories are hierarchical. This arrangement permits quick response in advent of a breakdown. Reaction of the maintenance workshop is done by evaluating the characteristics of the breakdown. In effect, a diagnostic error at a given level of the process of decision making delays the restoration of normal operating state. The consequences are not just financial loses, but loss in customers’ satisfaction as well. The goal of this paper is to model the inactive time of a maintenance workshop in case that an unpredicted catalectic breakdown has occurred and a diagnostic error has also occurred at a certain level of decision-making, during the treatment process of the breakdown. We show that the expression for the inactive times obtained, is depended only on the characteristics of the workshop. Next, we propose a method to reduce the inactive times.

  10. Predicting diagnostic error in Radiology via eye-tracking and image analytics: Application in mammography

    Energy Technology Data Exchange (ETDEWEB)

    Voisin, Sophie [ORNL; Pinto, Frank M [ORNL; Morin-Ducote, Garnetta [University of Tennessee, Knoxville (UTK); Hudson, Kathy [University of Tennessee, Knoxville (UTK); Tourassi, Georgia [ORNL

    2013-01-01

    Purpose: The primary aim of the present study was to test the feasibility of predicting diagnostic errors in mammography by merging radiologists gaze behavior and image characteristics. A secondary aim was to investigate group-based and personalized predictive models for radiologists of variable experience levels. Methods: The study was performed for the clinical task of assessing the likelihood of malignancy of mammographic masses. Eye-tracking data and diagnostic decisions for 40 cases were acquired from 4 Radiology residents and 2 breast imaging experts as part of an IRB-approved pilot study. Gaze behavior features were extracted from the eye-tracking data. Computer-generated and BIRADs images features were extracted from the images. Finally, machine learning algorithms were used to merge gaze and image features for predicting human error. Feature selection was thoroughly explored to determine the relative contribution of the various features. Group-based and personalized user modeling was also investigated. Results: Diagnostic error can be predicted reliably by merging gaze behavior characteristics from the radiologist and textural characteristics from the image under review. Leveraging data collected from multiple readers produced a reasonable group model (AUC=0.79). Personalized user modeling was far more accurate for the more experienced readers (average AUC of 0.837 0.029) than for the less experienced ones (average AUC of 0.667 0.099). The best performing group-based and personalized predictive models involved combinations of both gaze and image features. Conclusions: Diagnostic errors in mammography can be predicted reliably by leveraging the radiologists gaze behavior and image content.

  11. Predicting diagnostic error in radiology via eye-tracking and image analytics: Preliminary investigation in mammography

    Energy Technology Data Exchange (ETDEWEB)

    Voisin, Sophie; Tourassi, Georgia D. [Biomedical Science and Engineering Center, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Pinto, Frank [School of Engineering, Science, and Technology, Virginia State University, Petersburg, Virginia 23806 (United States); Morin-Ducote, Garnetta; Hudson, Kathleen B. [Department of Radiology, University of Tennessee Medical Center at Knoxville, Knoxville, Tennessee 37920 (United States)

    2013-10-15

    Purpose: The primary aim of the present study was to test the feasibility of predicting diagnostic errors in mammography by merging radiologists’ gaze behavior and image characteristics. A secondary aim was to investigate group-based and personalized predictive models for radiologists of variable experience levels.Methods: The study was performed for the clinical task of assessing the likelihood of malignancy of mammographic masses. Eye-tracking data and diagnostic decisions for 40 cases were acquired from four Radiology residents and two breast imaging experts as part of an IRB-approved pilot study. Gaze behavior features were extracted from the eye-tracking data. Computer-generated and BIRADS images features were extracted from the images. Finally, machine learning algorithms were used to merge gaze and image features for predicting human error. Feature selection was thoroughly explored to determine the relative contribution of the various features. Group-based and personalized user modeling was also investigated.Results: Machine learning can be used to predict diagnostic error by merging gaze behavior characteristics from the radiologist and textural characteristics from the image under review. Leveraging data collected from multiple readers produced a reasonable group model [area under the ROC curve (AUC) = 0.792 ± 0.030]. Personalized user modeling was far more accurate for the more experienced readers (AUC = 0.837 ± 0.029) than for the less experienced ones (AUC = 0.667 ± 0.099). The best performing group-based and personalized predictive models involved combinations of both gaze and image features.Conclusions: Diagnostic errors in mammography can be predicted to a good extent by leveraging the radiologists’ gaze behavior and image content.

  12. Predicting diagnostic error in radiology via eye-tracking and image analytics: Preliminary investigation in mammography

    International Nuclear Information System (INIS)

    Voisin, Sophie; Tourassi, Georgia D.; Pinto, Frank; Morin-Ducote, Garnetta; Hudson, Kathleen B.

    2013-01-01

    Purpose: The primary aim of the present study was to test the feasibility of predicting diagnostic errors in mammography by merging radiologists’ gaze behavior and image characteristics. A secondary aim was to investigate group-based and personalized predictive models for radiologists of variable experience levels.Methods: The study was performed for the clinical task of assessing the likelihood of malignancy of mammographic masses. Eye-tracking data and diagnostic decisions for 40 cases were acquired from four Radiology residents and two breast imaging experts as part of an IRB-approved pilot study. Gaze behavior features were extracted from the eye-tracking data. Computer-generated and BIRADS images features were extracted from the images. Finally, machine learning algorithms were used to merge gaze and image features for predicting human error. Feature selection was thoroughly explored to determine the relative contribution of the various features. Group-based and personalized user modeling was also investigated.Results: Machine learning can be used to predict diagnostic error by merging gaze behavior characteristics from the radiologist and textural characteristics from the image under review. Leveraging data collected from multiple readers produced a reasonable group model [area under the ROC curve (AUC) = 0.792 ± 0.030]. Personalized user modeling was far more accurate for the more experienced readers (AUC = 0.837 ± 0.029) than for the less experienced ones (AUC = 0.667 ± 0.099). The best performing group-based and personalized predictive models involved combinations of both gaze and image features.Conclusions: Diagnostic errors in mammography can be predicted to a good extent by leveraging the radiologists’ gaze behavior and image content

  13. Human reliability analysis during PSA at Trillo NPP: main characteristics and analysis of diagnostic errors

    International Nuclear Information System (INIS)

    Barquin, M.A.; Gomez, F.

    1998-01-01

    The design difference between Trillo NPP and other Spanish nuclear power plants (basic Westinghouse and General Electric designs) were made clear in the Human Reliability Analysis of the Probabilistic Safety Analysis (PSA) for Trillo NPP. The object of this paper is to describe the most significant characteristics of the Human Reliability Analysis carried out in the PSA, with special emphasis on the possible diagnostic errors and their consequences, based on the characteristics in the Emergency Operations Manual for Trillo NPP. - In the case of human errors before the initiating event (type 1), the existence of four redundancies in most of the plant safety systems, means that the impact of this type or error on the final results of the PSA is insignificant. However, in the case common cause errors, especially in certain calibration errors, some actions are significant in the final equation for core damage - The number of human actions that the operator has to carry out during the accidents (type 3) modelled, is relatively small in comparison with this value in other PSAs. This is basically due to the high level of automation at Rillo NPP - The Plant Operations Manual cannot be strictly considered to be a symptoms-based procedure. The operation Group must select the chapter from the Operations Manual to be followed, after having diagnosed the perturbing event, using for this purpose and Emergency and Anomaly Decision Tree (M.O.3.0.1) based on the different indications, alarms and symptoms present in the plant after the perturbing event. For this reason, it was decided to analyse the possible diagnosis errors. In the bibliography on diagnosis and commission errors available at the present time, there is no precise methodology for the analysis of this type of error and its incorporation into PSAs. The method used in the PSA for Trillo y NPP to evaluate this type of interaction, is to develop a Diagnosis Error Table, the object of which is to identify the situations in

  14. Diagnostic and therapeutic errors in trigeminal autonomic cephalalgias and hemicrania continua: a systematic review

    Science.gov (United States)

    2013-01-01

    Trigeminal autonomic cephalalgias (TACs) and hemicrania continua (HC) are relatively rare but clinically rather well-defined primary headaches. Despite the existence of clear-cut diagnostic criteria (The International Classification of Headache Disorders, 2nd edition - ICHD-II) and several therapeutic guidelines, errors in workup and treatment of these conditions are frequent in clinical practice. We set out to review all available published data on mismanagement of TACs and HC patients in order to understand and avoid its causes. The search strategy identified 22 published studies. The most frequent errors described in the management of patients with TACs and HC are: referral to wrong type of specialist, diagnostic delay, misdiagnosis, and the use of treatments without overt indication. Migraine with and without aura, trigeminal neuralgia, sinus infection, dental pain and temporomandibular dysfunction are the disorders most frequently overdiagnosed. Even when the clinical picture is clear-cut, TACs and HC are frequently not recognized and/or mistaken for other disorders, not only by general physicians, dentists and ENT surgeons, but also by neurologists and headache specialists. This seems to be due to limited knowledge of the specific characteristics and variants of these disorders, and it results in the unnecessary prescription of ineffective and sometimes invasive treatments which may have negative consequences for patients. Greater knowledge of and education about these disorders, among both primary care physicians and headache specialists, might contribute to improving the quality of life of TACs and HC patients. PMID:23565739

  15. Reducing Cognitive Skill Decay and Diagnostic Error: Theory-Based Practices for Continuing Education in Health Care

    Science.gov (United States)

    Weaver, Sallie J.; Newman-Toker, David E.; Rosen, Michael A.

    2012-01-01

    Missed, delayed, or wrong diagnoses can have a severe impact on patients, providers, and the entire health care system. One mechanism implicated in such diagnostic errors is the deterioration of cognitive diagnostic skills that are used rarely or not at all over a prolonged period of time. Existing evidence regarding maintenance of effective…

  16. The role of radiology in diagnostic error: a medical malpractice claims review.

    Science.gov (United States)

    Siegal, Dana; Stratchko, Lindsay M; DeRoo, Courtney

    2017-09-26

    Just as radiologic studies allow us to see past the surface to the vulnerable and broken parts of the human body, medical malpractice claims help us see past the surface of medical errors to the deeper vulnerabilities and potentially broken aspects of our healthcare delivery system. And just as the insights we gain through radiologic studies provide focus for a treatment plan for healing, so too can the analysis of malpractice claims provide insights to improve the delivery of safe patient care. We review 1325 coded claims where Radiology was the primary service provider to better understand the problems leading to patient harm, and the opportunities most likely to improve diagnostic care in the future.

  17. Reliability assessment of fiber optic communication lines depending on external factors and diagnostic errors

    Science.gov (United States)

    Bogachkov, I. V.; Lutchenko, S. S.

    2018-05-01

    The article deals with the method for the assessment of the fiber optic communication lines (FOCL) reliability taking into account the effect of the optical fiber tension, the temperature influence and the built-in diagnostic equipment errors of the first kind. The reliability is assessed in terms of the availability factor using the theory of Markov chains and probabilistic mathematical modeling. To obtain a mathematical model, the following steps are performed: the FOCL state is defined and validated; the state graph and system transitions are described; the system transition of states that occur at a certain point is specified; the real and the observed time of system presence in the considered states are identified. According to the permissible value of the availability factor, it is possible to determine the limiting frequency of FOCL maintenance.

  18. Pressurized water reactor monitoring. Study of detection, diagnostic and estimation methods (least error squares and filtering)

    International Nuclear Information System (INIS)

    Gillet, M.

    1986-07-01

    This thesis presents a study for the surveillance of the ''primary coolant circuit inventory monitoring'' of a pressurized water reactor. A reference model is developed in view of an automatic system ensuring detection and diagnostic in real time. The methods used for the present application are statistical tests and a method related to pattern recognition. The estimation of failures detected, difficult owing to the non-linearity of the problem, is treated by the least error squares method of the predictor or corrector type, and by filtering. It is in this frame that a new optimized method with superlinear convergence is developed, and that a segmented linearization of the model is introduced, in view of a multiple filtering [fr

  19. Estimation of genetic connectedness diagnostics based on prediction errors without the prediction error variance-covariance matrix.

    Science.gov (United States)

    Holmes, John B; Dodds, Ken G; Lee, Michael A

    2017-03-02

    An important issue in genetic evaluation is the comparability of random effects (breeding values), particularly between pairs of animals in different contemporary groups. This is usually referred to as genetic connectedness. While various measures of connectedness have been proposed in the literature, there is general agreement that the most appropriate measure is some function of the prediction error variance-covariance matrix. However, obtaining the prediction error variance-covariance matrix is computationally demanding for large-scale genetic evaluations. Many alternative statistics have been proposed that avoid the computational cost of obtaining the prediction error variance-covariance matrix, such as counts of genetic links between contemporary groups, gene flow matrices, and functions of the variance-covariance matrix of estimated contemporary group fixed effects. In this paper, we show that a correction to the variance-covariance matrix of estimated contemporary group fixed effects will produce the exact prediction error variance-covariance matrix averaged by contemporary group for univariate models in the presence of single or multiple fixed effects and one random effect. We demonstrate the correction for a series of models and show that approximations to the prediction error matrix based solely on the variance-covariance matrix of estimated contemporary group fixed effects are inappropriate in certain circumstances. Our method allows for the calculation of a connectedness measure based on the prediction error variance-covariance matrix by calculating only the variance-covariance matrix of estimated fixed effects. Since the number of fixed effects in genetic evaluation is usually orders of magnitudes smaller than the number of random effect levels, the computational requirements for our method should be reduced.

  20. Pediatric echocardiograms performed at primary centers: Diagnostic errors and missing links!

    International Nuclear Information System (INIS)

    Saraf, Rahul P; Suresh, PV; Maheshwari, Sunita; Shah, Sejal S

    2015-01-01

    The present study was undertaken to assess the accuracy of pediatric echocardiograms done at non-tertiary centers and to evaluate the relationship of inaccurate interpretations with age, echocardiogram performer and complexity of congenital heart disease (CHD). The echocardiogram reports of 182 consecutive children with CHD (5 days-16 years) who were evaluated at a non-tertiary center and subsequently referred to our center were reviewed. Age of the child at echocardiogram, echocardiogram performer and complexity of CHD were noted. These reports were compared with echocardiogram done at our center. Discrepancies were noted and categorized. To assess our own error rate, we compared our echocardiogram reports with the findings obtained during surgery (n = 172), CT scan (n = 9) or cardiac catheterization reports (n = 1). Most of the children at the non-tertiary center (92%) underwent echocardiogram by personnel other than a pediatric cardiologist. Overall, diagnostic errors were found in 69/182 (38%) children. Moderate and major discrepancies affecting the final management were found in 42/182 (23%) children. Discrepancies were higher when the echocardiogram was done by personnel other than pediatric cardiologist (P < 0.01) and with moderate and high complexity lesions (P = 0.0001). There was no significant difference in proportion of these discrepancies in children ≤ 1 year vs. >1 year of age. A significant number of pediatric echocardiograms done at non-tertiary centers had discrepancies that affected the management of these children. More discrepancies were seen when the echocardiogram performer was not a pediatric cardiologist and with complex CHD

  1. The Scientific Method, Diagnostic Bayes, and How to Detect Epistemic Errors

    Science.gov (United States)

    Vrugt, J. A.

    2015-12-01

    evaluation. This hybrid approach, coined diagnostic Bayes, uses the summary metrics as prior distribution and original data in the likelihood function, or P(x|\\hat {D}) ∝ P(x|S(\\hat {D})) L(x|\\hat {D}). A case study illustrates the ability of the proposed methodology to diagnose epistemic errors and provide guidance on model refinement.

  2. Errors in the determination of the total filtration of diagnostic x-ray tubes by the HVL method

    International Nuclear Information System (INIS)

    Gilmore, B.J.; Cranley, K.

    1990-01-01

    Optimal technique and an analysis of errors are essential for interpreting whether the total filtration of a diagnostic x-ray tube is acceptable. The study discusses this problem from a theoretical viewpoint utilising recent theoretical HVL-total-filtration data relating to 10 0 and 16 0 tungsten target angles and 0-30% kilovoltage ripples. The theory indicates the typical accuracy to which each appropriate parameter must be determined to maintain acceptable errors in total filtration. A quantitative approach is taken to evaluate systematic errors in a technique for interpolation of HVL from raw attenuation curve data. A theoretical derivation is presented to enable random errors in HVL due to x-ray set inconsistency to be estimated for particular experimental techniques and data analysis procedures. Further formulae are presented to enable errors in the total filtration estimate to be readily determined from those in the individual parameters. (author)

  3. Evaluating the Performance Diagnostic Checklist-Human Services to Assess Incorrect Error-Correction Procedures by Preschool Paraprofessionals

    Science.gov (United States)

    Bowe, Melissa; Sellers, Tyra P.

    2018-01-01

    The Performance Diagnostic Checklist-Human Services (PDC-HS) has been used to assess variables contributing to undesirable staff performance. In this study, three preschool teachers completed the PDC-HS to identify the factors contributing to four paraprofessionals' inaccurate implementation of error-correction procedures during discrete trial…

  4. Advanced error diagnostics of the CMAQ and Chimere modelling systems within the AQMEII3 model evaluation framework

    Directory of Open Access Journals (Sweden)

    E. Solazzo

    2017-09-01

    Full Text Available The work here complements the overview analysis of the modelling systems participating in the third phase of the Air Quality Model Evaluation International Initiative (AQMEII3 by focusing on the performance for hourly surface ozone by two modelling systems, Chimere for Europe and CMAQ for North America. The evaluation strategy outlined in the course of the three phases of the AQMEII activity, aimed to build up a diagnostic methodology for model evaluation, is pursued here and novel diagnostic methods are proposed. In addition to evaluating the base case simulation in which all model components are configured in their standard mode, the analysis also makes use of sensitivity simulations in which the models have been applied by altering and/or zeroing lateral boundary conditions, emissions of anthropogenic precursors, and ozone dry deposition. To help understand of the causes of model deficiencies, the error components (bias, variance, and covariance of the base case and of the sensitivity runs are analysed in conjunction with timescale considerations and error modelling using the available error fields of temperature, wind speed, and NOx concentration. The results reveal the effectiveness and diagnostic power of the methods devised (which remains the main scope of this study, allowing the detection of the timescale and the fields that the two models are most sensitive to. The representation of planetary boundary layer (PBL dynamics is pivotal to both models. In particular, (i the fluctuations slower than ∼ 1.5 days account for 70–85 % of the mean square error of the full (undecomposed ozone time series; (ii a recursive, systematic error with daily periodicity is detected, responsible for 10–20 % of the quadratic total error; (iii errors in representing the timing of the daily transition between stability regimes in the PBL are responsible for a covariance error as large as 9 ppb (as much as the standard deviation of the network

  5. Advanced error diagnostics of the CMAQ and Chimere modelling systems within the AQMEII3 model evaluation framework

    Science.gov (United States)

    Solazzo, Efisio; Hogrefe, Christian; Colette, Augustin; Garcia-Vivanco, Marta; Galmarini, Stefano

    2017-09-01

    The work here complements the overview analysis of the modelling systems participating in the third phase of the Air Quality Model Evaluation International Initiative (AQMEII3) by focusing on the performance for hourly surface ozone by two modelling systems, Chimere for Europe and CMAQ for North America. The evaluation strategy outlined in the course of the three phases of the AQMEII activity, aimed to build up a diagnostic methodology for model evaluation, is pursued here and novel diagnostic methods are proposed. In addition to evaluating the base case simulation in which all model components are configured in their standard mode, the analysis also makes use of sensitivity simulations in which the models have been applied by altering and/or zeroing lateral boundary conditions, emissions of anthropogenic precursors, and ozone dry deposition. To help understand of the causes of model deficiencies, the error components (bias, variance, and covariance) of the base case and of the sensitivity runs are analysed in conjunction with timescale considerations and error modelling using the available error fields of temperature, wind speed, and NOx concentration. The results reveal the effectiveness and diagnostic power of the methods devised (which remains the main scope of this study), allowing the detection of the timescale and the fields that the two models are most sensitive to. The representation of planetary boundary layer (PBL) dynamics is pivotal to both models. In particular, (i) the fluctuations slower than ˜ 1.5 days account for 70-85 % of the mean square error of the full (undecomposed) ozone time series; (ii) a recursive, systematic error with daily periodicity is detected, responsible for 10-20 % of the quadratic total error; (iii) errors in representing the timing of the daily transition between stability regimes in the PBL are responsible for a covariance error as large as 9 ppb (as much as the standard deviation of the network-average ozone observations in

  6. Automatic component calibration and error diagnostics for model-based accelerator control. Phase I final report

    International Nuclear Information System (INIS)

    Carl Stern; Martin Lee

    1999-01-01

    Phase I work studied the feasibility of developing software for automatic component calibration and error correction in beamline optics models. A prototype application was developed that corrects quadrupole field strength errors in beamline models

  7. Automatic component calibration and error diagnostics for model-based accelerator control. Phase I final report

    CERN Document Server

    Carl-Stern

    1999-01-01

    Phase I work studied the feasibility of developing software for automatic component calibration and error correction in beamline optics models. A prototype application was developed that corrects quadrupole field strength errors in beamline models.

  8. Prevalence of Pre-Analytical Errors in Clinical Chemistry Diagnostic Labs in Sulaimani City of Iraqi Kurdistan.

    Directory of Open Access Journals (Sweden)

    Dereen Najat

    Full Text Available Laboratory testing is roughly divided into three phases: a pre-analytical phase, an analytical phase and a post-analytical phase. Most analytical errors have been attributed to the analytical phase. However, recent studies have shown that up to 70% of analytical errors reflect the pre-analytical phase. The pre-analytical phase comprises all processes from the time a laboratory request is made by a physician until the specimen is analyzed at the lab. Generally, the pre-analytical phase includes patient preparation, specimen transportation, specimen collection and storage. In the present study, we report the first comprehensive assessment of the frequency and types of pre-analytical errors at the Sulaimani diagnostic labs in Iraqi Kurdistan.Over 2 months, 5500 venous blood samples were observed in 10 public diagnostic labs of Sulaimani City. The percentages of rejected samples and types of sample inappropriateness were evaluated. The percentage of each of the following pre-analytical errors were recorded: delay in sample transportation, clotted samples, expired reagents, hemolyzed samples, samples not on ice, incorrect sample identification, insufficient sample, tube broken in centrifuge, request procedure errors, sample mix-ups, communication conflicts, misinterpreted orders, lipemic samples, contaminated samples and missed physician's request orders. The difference between the relative frequencies of errors observed in the hospitals considered was tested using a proportional Z test. In particular, the survey aimed to discover whether analytical errors were recorded and examine the types of platforms used in the selected diagnostic labs.The analysis showed a high prevalence of improper sample handling during the pre-analytical phase. In appropriate samples, the percentage error was as high as 39%. The major reasons for rejection were hemolyzed samples (9%, incorrect sample identification (8% and clotted samples (6%. Most quality control schemes

  9. Prevalence of Pre-Analytical Errors in Clinical Chemistry Diagnostic Labs in Sulaimani City of Iraqi Kurdistan.

    Science.gov (United States)

    Najat, Dereen

    2017-01-01

    Laboratory testing is roughly divided into three phases: a pre-analytical phase, an analytical phase and a post-analytical phase. Most analytical errors have been attributed to the analytical phase. However, recent studies have shown that up to 70% of analytical errors reflect the pre-analytical phase. The pre-analytical phase comprises all processes from the time a laboratory request is made by a physician until the specimen is analyzed at the lab. Generally, the pre-analytical phase includes patient preparation, specimen transportation, specimen collection and storage. In the present study, we report the first comprehensive assessment of the frequency and types of pre-analytical errors at the Sulaimani diagnostic labs in Iraqi Kurdistan. Over 2 months, 5500 venous blood samples were observed in 10 public diagnostic labs of Sulaimani City. The percentages of rejected samples and types of sample inappropriateness were evaluated. The percentage of each of the following pre-analytical errors were recorded: delay in sample transportation, clotted samples, expired reagents, hemolyzed samples, samples not on ice, incorrect sample identification, insufficient sample, tube broken in centrifuge, request procedure errors, sample mix-ups, communication conflicts, misinterpreted orders, lipemic samples, contaminated samples and missed physician's request orders. The difference between the relative frequencies of errors observed in the hospitals considered was tested using a proportional Z test. In particular, the survey aimed to discover whether analytical errors were recorded and examine the types of platforms used in the selected diagnostic labs. The analysis showed a high prevalence of improper sample handling during the pre-analytical phase. In appropriate samples, the percentage error was as high as 39%. The major reasons for rejection were hemolyzed samples (9%), incorrect sample identification (8%) and clotted samples (6%). Most quality control schemes at Sulaimani

  10. Combining principles of Cognitive Load Theory and diagnostic error analysis for designing job aids: Effects on motivation and diagnostic performance in a process control task.

    Science.gov (United States)

    Kluge, Annette; Grauel, Britta; Burkolter, Dina

    2013-03-01

    Two studies are presented in which the design of a procedural aid and the impact of an additional decision aid for process control were assessed. In Study 1, a procedural aid was developed that avoids imposing unnecessary extraneous cognitive load on novices when controlling a complex technical system. This newly designed procedural aid positively affected germane load, attention, satisfaction, motivation, knowledge acquisition and diagnostic speed for novel faults. In Study 2, the effect of a decision aid for use before the procedural aid was investigated, which was developed based on an analysis of diagnostic errors committed in Study 1. Results showed that novices were able to diagnose both novel faults and practised faults, and were even faster at diagnosing novel faults. This research contributes to the question of how to optimally support novices in dealing with technical faults in process control. Copyright © 2012 Elsevier Ltd and The Ergonomics Society. All rights reserved.

  11. Magnetic resonance imaging of the shoulder: a review of potential sources of diagnostic errors

    International Nuclear Information System (INIS)

    Carroll, K.W.; Helms, C.A.

    2002-01-01

    Shoulder magnetic resonance (MR) imaging and MR arthrography are frequently utilized in the evaluation of shoulder pain and instability. The clinical scenario and imaging findings may be confusing to clinicians and radiologists and may present diagnostic challenges for those involved in evaluating and treating shoulder pathology. Often rotator cuff and labral abnormalities may be coexistent, clinical manifestations of denervation syndromes may be confusing to clinicians, and normal anatomic variations, imaging pitfalls, and various artifacts may cause dilemmas for the radiologist. This article will review the most frequently encountered mimickers and pitfalls of MR imaging of the shoulder. (orig.)

  12. Error diagnóstico en la neuropatía óptica epidémica Diagnostic error in epidemic optic neuropathy

    Directory of Open Access Journals (Sweden)

    Rosaralis Santiesteban Freixas

    2005-12-01

    Full Text Available La forma óptica de la epidemia de neuropatía, aparecida en el decenio pasado en Cuba, ha sido motivo de discusión por el posible hiperdiagnóstico, de los más de 22 000 casos notificados. El propósito principal de este trabajo es profundizar en la caracterización de esta enfermedad y dar a conocer la congruencia que debe de existir entre la agudeza visual y la visión de colores en las neuropatías de este tipo; además, estimar sobre la base de este elemento la posible cifra de errores diagnósticos de dos grupos de pacientes con neuropatía optica epidérmica y en un tercer grupo de pacientes que no mejoraron con tratamiento, donde se reunieron 78 casos remitidos porque no mejoraban con tratamiento vitamínico. Los resultados demostraron congruencia entre el estado de afectación de la agudeza visual y la visión de colores en más del 90 % de los 960 casos de los grupos 1 y 2, con diagnóstico de neuropatía óptica epidémica comprobados por expertos, a diferencia de los casos del tercer grupo, en los que se detectó que el 96,1 % tuvieron de inicio falsos diagnósticos de esta enfermedad p The optic form of the neuropathy epidemic that appeared in the last decade in Cuba has been discussed due to the possible hyperdiagnosis of the more than 22 000 notified cases. The main objective of this paper was to go deep into the characterization of this disease, to make known the congruency that should exist between the visual acuity and the vision of colors in the neuropathies of this type, and to estimate, on the basis of this element, the possible figure of diagnostic errors in 2 groups of patients with EON and of a third group of patients that did not improve with the treatment. In this group, there were 78 cases that were referred because they did not respond to vitamin therapy. The results showed congruency between the state of affection of visual acuity and the vision of colors in more than 90 % of the 960 cases from groups 1 and 2 with

  13. Clinical cognition and diagnostic error: applications of a dual process model of reasoning.

    Science.gov (United States)

    Croskerry, Pat

    2009-09-01

    Both systemic and individual factors contribute to missed or delayed diagnoses. Among the multiple factors that impact clinical performance of the individual, the caliber of cognition is perhaps the most relevant and deserves our attention and understanding. In the last few decades, cognitive psychologists have gained substantial insights into the processes that underlie cognition, and a new, universal model of reasoning and decision making has emerged, Dual Process Theory. The theory has immediate application to medical decision making and provides an overall schema for understanding the variety of theoretical approaches that have been taken in the past. The model has important practical applications for decision making across the multiple domains of healthcare, and may be used as a template for teaching decision theory, as well as a platform for future research. Importantly, specific operating characteristics of the model explain how diagnostic failure occurs.

  14. Diagnostic errors in musculoskeletal ultrasound imaging and how to avoid them

    Directory of Open Access Journals (Sweden)

    Małgorzata Serafin-Król

    2017-09-01

    Full Text Available The article reviews the major challenges related to the principles of the correct technique of musculoskeletal ultrasound (MSK US. All the crucial aspects of correct MSK soft tissue diagnosis have been discussed, including equipment settings, use of recent image software innovations and ultrasound standoff pads, and correct transducer positioning. The importance of the fundamental principles of MSK US, facilitating good quality image and limiting the occurrence of artifacts, has been highlighted. The most common artifacts of the musculoskeletal system have been described, including those that diagnostically helpful, such as the presence of echo enhancement deep to a fluidfilled structure, or an acoustic shadow behind a calcification. The presence of acoustic shadow in the context of lesions of a different type has also been discussed. The common anisotropy-related artifacts, frequently leading to diagnosis of a pathological condition where none is present, have been elaborated on. The frequently encountered mirror reflection artifact has been described. Special attention has been paid to the means of either eliminating, or taking advantage of artifacts for the correct diagnosis of musculoskeletal lesions. The possibilities and technique of correct differentiation of hypoechoic or anechoic foci, commonly found in the pathological conditions of the musculoskeletal system, have been analysed. Non-typical ultrasound findings leading to misdiagnosis of given pathological conditions have been discussed.

  15. Diagnostics

    DEFF Research Database (Denmark)

    Donné, A.J.H.; Costley, A.E.; Barnsley, R.

    2007-01-01

    of the measurements—time and spatial resolutions, etc—will in some cases be more stringent. Many of the measurements will be used in the real time control of the plasma driving a requirement for very high reliability in the systems (diagnostics) that provide the measurements. The implementation of diagnostic systems...... on ITER is a substantial challenge. Because of the harsh environment (high levels of neutron and gamma fluxes, neutron heating, particle bombardment) diagnostic system selection and design has to cope with a range of phenomena not previously encountered in diagnostic design. Extensive design and R......&D is needed to prepare the systems. In some cases the environmental difficulties are so severe that new diagnostic techniques are required. The starting point in the development of diagnostics for ITER is to define the measurement requirements and develop their justification. It is necessary to include all...

  16. Peer Feedback, Learning, and Improvement: Answering the Call of the Institute of Medicine Report on Diagnostic Error.

    Science.gov (United States)

    Larson, David B; Donnelly, Lane F; Podberesky, Daniel J; Merrow, Arnold C; Sharpe, Richard E; Kruskal, Jonathan B

    2017-04-01

    In September 2015, the Institute of Medicine (IOM) published a report titled "Improving Diagnosis in Health Care," in which it was recommended that "health care organizations should adopt policies and practices that promote a nonpunitive culture that values open discussion and feedback on diagnostic performance." It may seem counterintuitive that a report addressing a highly technical skill such as medical diagnosis would be focused on organizational culture. The wisdom becomes clearer, however, when examined in the light of recent advances in the understanding of human error and individual and organizational performance. The current dominant model for radiologist performance improvement is scoring-based peer review, which reflects a traditional quality assurance approach, derived from manufacturing in the mid-1900s. Far from achieving the goals of the IOM, which are celebrating success, recognizing mistakes as an opportunity to learn, and fostering openness and trust, we have found that scoring-based peer review tends to drive radiologists inward, against each other, and against practice leaders. Modern approaches to quality improvement focus on using and enhancing interpersonal professional relationships to achieve and maintain high levels of individual and organizational performance. In this article, the authors review the recommendations set forth by the recent IOM report, discuss the science and theory that underlie several of those recommendations, and assess how well they fit with the current dominant approach to radiology peer review. The authors also offer an alternative approach to peer review: peer feedback, learning, and improvement (or more succinctly, "peer learning"), which they believe is better aligned with the principles promoted by the IOM. © RSNA, 2016.

  17. Worked Examples with Errors: When Self-Explanation Prompts Hinder Learning of Teachers Diagnostic Competences on Problem-Based Learning

    Science.gov (United States)

    Heitzmann, Nicole; Fischer, Frank; Fischer, Martin R.

    2018-01-01

    To diagnose classroom situations is crucial for teachers' everyday practice. The approach of worked examples with errors seems promising to support the diagnosis of classroom situations in student teachers (Stark et al. in "Learn Instr" 21(1):22-33, 2011). To enhance that approach, error-explanation prompts and an adaptable feedback…

  18. Prevalence of Pre-Analytical Errors in Clinical Chemistry Diagnostic Labs in Sulaimani City of Iraqi Kurdistan

    OpenAIRE

    Najat, Dereen

    2017-01-01

    Background Laboratory testing is roughly divided into three phases: a pre-analytical phase, an analytical phase and a post-analytical phase. Most analytical errors have been attributed to the analytical phase. However, recent studies have shown that up to 70% of analytical errors reflect the pre-analytical phase. The pre-analytical phase comprises all processes from the time a laboratory request is made by a physician until the specimen is analyzed at the lab. Generally, the pre-analytical ph...

  19. Data contributed by EPA/ORD/NERL/CED researchers to the manuscript "Advanced Error Diagnostics of the CMAQ and CHIMERE modeling systems within the AQMEII3 Model Evaluation Framework"

    Data.gov (United States)

    U.S. Environmental Protection Agency — This dataset contains the data contributed by EPA/ORD/NERL/CED researchers to the manuscript "Advanced Error Diagnostics of the CMAQ and CHIMERE modeling systems...

  20. Simultaneous analysis of amino acid and organic acid by NMR spectrometry, 2. Diagnostic aids for inborn error of metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Koda, Naoya; Yamaguchi, Shuichi; Mori, Takeshi.

    1987-09-01

    Analysis of urine from patients with inborn error of metabolism were studied by /sup 1/H-nuclear magnetic resonance (NMR) spectrometry. Diseases studied were as follows; phenylketonuria, biotin responsive multiple carboxylase deficiency, non-ketotic hyperglycinemia, 3-ketothiolase deficiency, alkaptonuria, methylmalonic acidemia, isovaleric acidemia, glutaric aciduria, argininosuccinic aciduria and hyperornithinemia. In each disease, specific metabolites in urine were recognized by NMR spectrometry. This method is accomplished within 10 minutes with non-treated small volume of urine and will be successfully available for the screening andor diagnosis of inherited metabolic diseases of amino acid and organic acid.

  1. Giant teratoma of anterior mediastinum in a 14-year-old girl as an example of potential diagnostic problems and errors

    Directory of Open Access Journals (Sweden)

    Przemysław Wolak

    2013-10-01

    Full Text Available Teratomas are tumors originating from the three primary germ layers, most commonly located within gonads or in the sacral region. Chest locations are rare. Mediastinal teratoma showing no tumor-specific symptoms may be treated as exudative pneumonia. The goal of the article was to present a case encountered in our practice as a showcase of possible diagnostic problems and errors. Despite a thorough medical examination with additional exams (ultrasound scans of pleural cavities, chest X-ray and laboratory analyses, the diagnosis of a thoracic tumor was made only after chest computed tomography scan was performed following ineffective attempts at antibiotic therapy and pleural drainage. Following the diagnosis of mediastinal tumor, the patient was subjected to surgery. A giant teratoma (confirmed in histopathological examination was removed upon left-sided thoracotomy. Following the procedure, lung expansion and patient recovery were observed. Computed tomography of the chest should be performed routinely upon encountering difficulties in the treatment of exudative pneumonia in children. In every case of pneumonia with pleural effusion in children, inflammatory mask of mediastinal tumors should be ruled out.

  2. Model supported sensor information platform for the transversal dynamics and longitudinal dynamics of vehicles. Applications to error diagnostics and error tolerance; Modellgestuetzte Sensorinformationsplattform fuer die Quer- und Laengsdynamik von Kraftfahrzeugen. Anwendungen zur Fehlerdiagnose und Fehlertoleranz

    Energy Technology Data Exchange (ETDEWEB)

    Halbe, Iris

    2008-07-01

    The contribution under consideration contacts engineers and scientists within the range of the motor vehicle dynamics. For the monitoring of the signals measured in series vehicle, a sensor information platform is designed. Thus, this supplies correct sensor information to the monitoring systems and offers estimated parameters and conditions for the regulation. The basis is a comprehensive concept of the transverse dynamics, longitudinal dynamics and staggering dynamics with different physical and experimental models. On the basis of these models, several procedures of error recognition are pointed out (observer, parity equations, parameter estimation), and their suitability in the driving dynamics is examined. Based on the results of error recognition, the defective sensor is diagnosed with Fuzzy in order to replace it with a computed signal. This error tolerance becomes possible by a two-trace model with a Kalman filter. Furthermore, conditions and parameters are estimated with different methods.

  3. Correcting AUC for Measurement Error.

    Science.gov (United States)

    Rosner, Bernard; Tworoger, Shelley; Qiu, Weiliang

    2015-12-01

    Diagnostic biomarkers are used frequently in epidemiologic and clinical work. The ability of a diagnostic biomarker to discriminate between subjects who develop disease (cases) and subjects who do not (controls) is often measured by the area under the receiver operating characteristic curve (AUC). The diagnostic biomarkers are usually measured with error. Ignoring measurement error can cause biased estimation of AUC, which results in misleading interpretation of the efficacy of a diagnostic biomarker. Several methods have been proposed to correct AUC for measurement error, most of which required the normality assumption for the distributions of diagnostic biomarkers. In this article, we propose a new method to correct AUC for measurement error and derive approximate confidence limits for the corrected AUC. The proposed method does not require the normality assumption. Both real data analyses and simulation studies show good performance of the proposed measurement error correction method.

  4. Combining wrist age and third molars in forensic age estimation: how to calculate the joint age estimate and its error rate in age diagnostics.

    Science.gov (United States)

    Gelbrich, Bianca; Frerking, Carolin; Weiss, Sandra; Schwerdt, Sebastian; Stellzig-Eisenhauer, Angelika; Tausche, Eve; Gelbrich, Götz

    2015-01-01

    Forensic age estimation in living adolescents is based on several methods, e.g. the assessment of skeletal and dental maturation. Combination of several methods is mandatory, since age estimates from a single method are too imprecise due to biological variability. The correlation of the errors of the methods being combined must be known to calculate the precision of combined age estimates. To examine the correlation of the errors of the hand and the third molar method and to demonstrate how to calculate the combined age estimate. Clinical routine radiographs of the hand and dental panoramic images of 383 patients (aged 7.8-19.1 years, 56% female) were assessed. Lack of correlation (r = -0.024, 95% CI = -0.124 to + 0.076, p = 0.64) allows calculating the combined age estimate as the weighted average of the estimates from hand bones and third molars. Combination improved the standard deviations of errors (hand = 0.97, teeth = 1.35 years) to 0.79 years. Uncorrelated errors of the age estimates obtained from both methods allow straightforward determination of the common estimate and its variance. This is also possible when reference data for the hand and the third molar method are established independently from each other, using different samples.

  5. Diagnostic potential of stored dried blood spots for inborn errors of metabolism: a metabolic autopsy of medium-chain acyl-CoA dehydrogenase deficiency.

    Science.gov (United States)

    Kaku, Noriyuki; Ihara, Kenji; Hirata, Yuichiro; Yamada, Kenji; Lee, Sooyoung; Kanemasa, Hikaru; Motomura, Yoshitomo; Baba, Haruhisa; Tanaka, Tamami; Sakai, Yasunari; Maehara, Yoshihiko; Ohga, Shouichi

    2018-05-02

    It is estimated that 1-5% of sudden infant death syndrome (SIDS) cases might be caused by undiagnosed inborn errors of metabolism (IEMs); however, the postmortem identification of IEMs remains difficult. This study aimed to evaluate the usefulness of dried blood spots (DBSs) stored after newborn screening tests as a metabolic autopsy to determine the causes of death in infants and children who died suddenly and unexpectedly. Infants or toddlers who had suddenly died without a definite diagnosis between July 2008 and December 2012 at Kyushu University Hospital in Japan were enrolled in this study. Their Guthrie cards, which had been stored for several years at 4-8°C, were used for an acylcarnitine analysis by tandem mass spectrometry to identify inborn errors of metabolism. Fifteen infants and children who died at less than 2 years of age and for whom the cause of death was unknown were enrolled for the study. After correcting the C0 and C8 values assuming the hydrolysation of acylcarnitine in the stored DBSs, the corrected C8 value of one case just exceeded the cut-off level for medium-chain acyl-CoA dehydrogenase (MCAD) deficiency screening. Genetic and biochemical analyses confirmed this patient to have MCAD deficiency. DBSs stored after newborn screening tests are a promising tool for metabolic autopsy. The appropriate compensation of acylcarnitine data and subsequent genetic and biochemical analyses are essential for the postmortem diagnosis of inborn errors of metabolism. © 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.

  6. Error Patterns

    NARCIS (Netherlands)

    Hoede, C.; Li, Z.

    2001-01-01

    In coding theory the problem of decoding focuses on error vectors. In the simplest situation code words are $(0,1)$-vectors, as are the received messages and the error vectors. Comparison of a received word with the code words yields a set of error vectors. In deciding on the original code word,

  7. Companion diagnostics

    DEFF Research Database (Denmark)

    Jørgensen, Jan Trøst; Hersom, Maria

    2016-01-01

    of disease mechanisms, things are slowly changing. Within the last few years, we have seen an increasing number of predictive biomarker assays being developed to guide the use of targeted cancer drugs. This type of assay is called companion diagnostics and is developed in parallel to the drug using the drug-diagnostic...... co-development model. The development of companion diagnostics is a relatively new discipline and in this review, different aspects will be discussed including clinical and regulatory issues. Furthermore, examples of drugs, such as the ALK and PD-1/PD-L1 inhibitors, that have been approved recently....... Despite having discussed personalized medicine for more than a decade, we still see that most drug prescriptions for severe chronic diseases are largely based on 'trial and error' and not on solid biomarker data. However, with the advance of molecular diagnostics and a subsequent increased understanding...

  8. Carcinosarcoma of the Ureter with a Small Cell Component: Report of a Rare Pathologic Entity and Potential for Diagnostic Error on Biopsy

    Directory of Open Access Journals (Sweden)

    Kent Newsom

    2014-01-01

    Full Text Available Carcinosarcomas of the ureter are rare biphasic neoplasms, composed of both malignant epithelial (carcinomatous and malignant mesenchymal (sarcomatous components. Carcinosarcomas of the urinary tract are exceedingly rare. We report a unique case of a carcinosarcoma of the ureter with a chondrosarcoma and small cell tumor component arising in a 68-year-old male who presented with microscopic hematuria. CT intravenous pyelogram revealed right-sided hydroureter and hydronephrosis with thickening and narrowing of the right ureter. The patient underwent robot-assisted ureterectomy with bladder cuff excision and subsequent adjuvant chemotherapy. The patient is disease-free at 32 months after treatment. We provide a brief synoptic review of carcinosarcoma of the ureter and bladder with utilization of immunohistochemical (IHC stains and potential diagnostic pitfalls.

  9. Operator errors

    International Nuclear Information System (INIS)

    Knuefer; Lindauer

    1980-01-01

    Besides that at spectacular events a combination of component failure and human error is often found. Especially the Rasmussen-Report and the German Risk Assessment Study show for pressurised water reactors that human error must not be underestimated. Although operator errors as a form of human error can never be eliminated entirely, they can be minimized and their effects kept within acceptable limits if a thorough training of personnel is combined with an adequate design of the plant against accidents. Contrary to the investigation of engineering errors, the investigation of human errors has so far been carried out with relatively small budgets. Intensified investigations in this field appear to be a worthwhile effort. (orig.)

  10. Einstein's error

    International Nuclear Information System (INIS)

    Winterflood, A.H.

    1980-01-01

    In discussing Einstein's Special Relativity theory it is claimed that it violates the principle of relativity itself and that an anomalous sign in the mathematics is found in the factor which transforms one inertial observer's measurements into those of another inertial observer. The apparent source of this error is discussed. Having corrected the error a new theory, called Observational Kinematics, is introduced to replace Einstein's Special Relativity. (U.K.)

  11. Errors in Neonatology

    Directory of Open Access Journals (Sweden)

    Antonio Boldrini

    2013-06-01

    Full Text Available Introduction: Danger and errors are inherent in human activities. In medical practice errors can lean to adverse events for patients. Mass media echo the whole scenario. Methods: We reviewed recent published papers in PubMed database to focus on the evidence and management of errors in medical practice in general and in Neonatology in particular. We compared the results of the literature with our specific experience in Nina Simulation Centre (Pisa, Italy. Results: In Neonatology the main error domains are: medication and total parenteral nutrition, resuscitation and respiratory care, invasive procedures, nosocomial infections, patient identification, diagnostics. Risk factors include patients’ size, prematurity, vulnerability and underlying disease conditions but also multidisciplinary teams, working conditions providing fatigue, a large variety of treatment and investigative modalities needed. Discussion and Conclusions: In our opinion, it is hardly possible to change the human beings but it is likely possible to change the conditions under they work. Voluntary errors report systems can help in preventing adverse events. Education and re-training by means of simulation can be an effective strategy too. In Pisa (Italy Nina (ceNtro di FormazIone e SimulazioNe NeonAtale is a simulation center that offers the possibility of a continuous retraining for technical and non-technical skills to optimize neonatological care strategies. Furthermore, we have been working on a novel skill trainer for mechanical ventilation (MEchatronic REspiratory System SImulator for Neonatal Applications, MERESSINA. Finally, in our opinion national health policy indirectly influences risk for errors. Proceedings of the 9th International Workshop on Neonatology · Cagliari (Italy · October 23rd-26th, 2013 · Learned lessons, changing practice and cutting-edge research

  12. Medication Errors - A Review

    OpenAIRE

    Vinay BC; Nikhitha MK; Patel Sunil B

    2015-01-01

    In this present review article, regarding medication errors its definition, medication error problem, types of medication errors, common causes of medication errors, monitoring medication errors, consequences of medication errors, prevention of medication error and managing medication errors have been explained neatly and legibly with proper tables which is easy to understand.

  13. Heuristics and Cognitive Error in Medical Imaging.

    Science.gov (United States)

    Itri, Jason N; Patel, Sohil H

    2018-05-01

    The field of cognitive science has provided important insights into mental processes underlying the interpretation of imaging examinations. Despite these insights, diagnostic error remains a major obstacle in the goal to improve quality in radiology. In this article, we describe several types of cognitive bias that lead to diagnostic errors in imaging and discuss approaches to mitigate cognitive biases and diagnostic error. Radiologists rely on heuristic principles to reduce complex tasks of assessing probabilities and predicting values into simpler judgmental operations. These mental shortcuts allow rapid problem solving based on assumptions and past experiences. Heuristics used in the interpretation of imaging studies are generally helpful but can sometimes result in cognitive biases that lead to significant errors. An understanding of the causes of cognitive biases can lead to the development of educational content and systematic improvements that mitigate errors and improve the quality of care provided by radiologists.

  14. Error Budgeting

    Energy Technology Data Exchange (ETDEWEB)

    Vinyard, Natalia Sergeevna [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Perry, Theodore Sonne [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Usov, Igor Olegovich [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-10-04

    We calculate opacity from k (hn)=-ln[T(hv)]/pL, where T(hv) is the transmission for photon energy hv, p is sample density, and L is path length through the sample. The density and path length are measured together by Rutherford backscatter. Δk = $\\partial k$\\ $\\partial T$ ΔT + $\\partial k$\\ $\\partial (pL)$. We can re-write this in terms of fractional error as Δk/k = Δ1n(T)/T + Δ(pL)/(pL). Transmission itself is calculated from T=(U-E)/(V-E)=B/B0, where B is transmitted backlighter (BL) signal and B0 is unattenuated backlighter signal. Then ΔT/T=Δln(T)=ΔB/B+ΔB0/B0, and consequently Δk/k = 1/T (ΔB/B + ΔB$_0$/B$_0$ + Δ(pL)/(pL). Transmission is measured in the range of 0.2

  15. Understanding and Confronting Our Mistakes: The Epidemiology of Error in Radiology and Strategies for Error Reduction.

    Science.gov (United States)

    Bruno, Michael A; Walker, Eric A; Abujudeh, Hani H

    2015-10-01

    Arriving at a medical diagnosis is a highly complex process that is extremely error prone. Missed or delayed diagnoses often lead to patient harm and missed opportunities for treatment. Since medical imaging is a major contributor to the overall diagnostic process, it is also a major potential source of diagnostic error. Although some diagnoses may be missed because of the technical or physical limitations of the imaging modality, including image resolution, intrinsic or extrinsic contrast, and signal-to-noise ratio, most missed radiologic diagnoses are attributable to image interpretation errors by radiologists. Radiologic interpretation cannot be mechanized or automated; it is a human enterprise based on complex psychophysiologic and cognitive processes and is itself subject to a wide variety of error types, including perceptual errors (those in which an important abnormality is simply not seen on the images) and cognitive errors (those in which the abnormality is visually detected but the meaning or importance of the finding is not correctly understood or appreciated). The overall prevalence of radiologists' errors in practice does not appear to have changed since it was first estimated in the 1960s. The authors review the epidemiology of errors in diagnostic radiology, including a recently proposed taxonomy of radiologists' errors, as well as research findings, in an attempt to elucidate possible underlying causes of these errors. The authors also propose strategies for error reduction in radiology. On the basis of current understanding, specific suggestions are offered as to how radiologists can improve their performance in practice. © RSNA, 2015.

  16. Impact of Measurement Error on Synchrophasor Applications

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Yilu [Univ. of Tennessee, Knoxville, TN (United States); Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gracia, Jose R. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Ewing, Paul D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Zhao, Jiecheng [Univ. of Tennessee, Knoxville, TN (United States); Tan, Jin [Univ. of Tennessee, Knoxville, TN (United States); Wu, Ling [Univ. of Tennessee, Knoxville, TN (United States); Zhan, Lingwei [Univ. of Tennessee, Knoxville, TN (United States)

    2015-07-01

    Phasor measurement units (PMUs), a type of synchrophasor, are powerful diagnostic tools that can help avert catastrophic failures in the power grid. Because of this, PMU measurement errors are particularly worrisome. This report examines the internal and external factors contributing to PMU phase angle and frequency measurement errors and gives a reasonable explanation for them. It also analyzes the impact of those measurement errors on several synchrophasor applications: event location detection, oscillation detection, islanding detection, and dynamic line rating. The primary finding is that dynamic line rating is more likely to be influenced by measurement error. Other findings include the possibility of reporting nonoscillatory activity as an oscillation as the result of error, failing to detect oscillations submerged by error, and the unlikely impact of error on event location and islanding detection.

  17. [Medical errors: inevitable but preventable].

    Science.gov (United States)

    Giard, R W

    2001-10-27

    Medical errors are increasingly reported in the lay press. Studies have shown dramatic error rates of 10 percent or even higher. From a methodological point of view, studying the frequency and causes of medical errors is far from simple. Clinical decisions on diagnostic or therapeutic interventions are always taken within a clinical context. Reviewing outcomes of interventions without taking into account both the intentions and the arguments for a particular action will limit the conclusions from a study on the rate and preventability of errors. The interpretation of the preventability of medical errors is fraught with difficulties and probably highly subjective. Blaming the doctor personally does not do justice to the actual situation and especially the organisational framework. Attention for and improvement of the organisational aspects of error are far more important then litigating the person. To err is and will remain human and if we want to reduce the incidence of faults we must be able to learn from our mistakes. That requires an open attitude towards medical mistakes, a continuous effort in their detection, a sound analysis and, where feasible, the institution of preventive measures.

  18. Modeling coherent errors in quantum error correction

    Science.gov (United States)

    Greenbaum, Daniel; Dutton, Zachary

    2018-01-01

    Analysis of quantum error correcting codes is typically done using a stochastic, Pauli channel error model for describing the noise on physical qubits. However, it was recently found that coherent errors (systematic rotations) on physical data qubits result in both physical and logical error rates that differ significantly from those predicted by a Pauli model. Here we examine the accuracy of the Pauli approximation for noise containing coherent errors (characterized by a rotation angle ɛ) under the repetition code. We derive an analytic expression for the logical error channel as a function of arbitrary code distance d and concatenation level n, in the small error limit. We find that coherent physical errors result in logical errors that are partially coherent and therefore non-Pauli. However, the coherent part of the logical error is negligible at fewer than {ε }-({dn-1)} error correction cycles when the decoder is optimized for independent Pauli errors, thus providing a regime of validity for the Pauli approximation. Above this number of correction cycles, the persistent coherent logical error will cause logical failure more quickly than the Pauli model would predict, and this may need to be combated with coherent suppression methods at the physical level or larger codes.

  19. Learning from prescribing errors

    OpenAIRE

    Dean, B

    2002-01-01

    

 The importance of learning from medical error has recently received increasing emphasis. This paper focuses on prescribing errors and argues that, while learning from prescribing errors is a laudable goal, there are currently barriers that can prevent this occurring. Learning from errors can take place on an individual level, at a team level, and across an organisation. Barriers to learning from prescribing errors include the non-discovery of many prescribing errors, lack of feedback to th...

  20. Technical errors in MR arthrography

    International Nuclear Information System (INIS)

    Hodler, Juerg

    2008-01-01

    This article discusses potential technical problems of MR arthrography. It starts with contraindications, followed by problems relating to injection technique, contrast material and MR imaging technique. For some of the aspects discussed, there is only little published evidence. Therefore, the article is based on the personal experience of the author and on local standards of procedures. Such standards, as well as medico-legal considerations, may vary from country to country. Contraindications for MR arthrography include pre-existing infection, reflex sympathetic dystrophy and possibly bleeding disorders, avascular necrosis and known allergy to contrast media. Errors in injection technique may lead to extra-articular collection of contrast agent or to contrast agent leaking from the joint space, which may cause diagnostic difficulties. Incorrect concentrations of contrast material influence image quality and may also lead to non-diagnostic examinations. Errors relating to MR imaging include delays between injection and imaging and inadequate choice of sequences. Potential solutions to the various possible errors are presented. (orig.)

  1. Technical errors in MR arthrography

    Energy Technology Data Exchange (ETDEWEB)

    Hodler, Juerg [Orthopaedic University Hospital of Balgrist, Radiology, Zurich (Switzerland)

    2008-01-15

    This article discusses potential technical problems of MR arthrography. It starts with contraindications, followed by problems relating to injection technique, contrast material and MR imaging technique. For some of the aspects discussed, there is only little published evidence. Therefore, the article is based on the personal experience of the author and on local standards of procedures. Such standards, as well as medico-legal considerations, may vary from country to country. Contraindications for MR arthrography include pre-existing infection, reflex sympathetic dystrophy and possibly bleeding disorders, avascular necrosis and known allergy to contrast media. Errors in injection technique may lead to extra-articular collection of contrast agent or to contrast agent leaking from the joint space, which may cause diagnostic difficulties. Incorrect concentrations of contrast material influence image quality and may also lead to non-diagnostic examinations. Errors relating to MR imaging include delays between injection and imaging and inadequate choice of sequences. Potential solutions to the various possible errors are presented. (orig.)

  2. Pitfalls in diagnostic radiology

    Energy Technology Data Exchange (ETDEWEB)

    Peh, Wilfred C.G. (ed.) [Khoo Teck Puat Hospital (Singapore). Dept. of Diagnostic Radiology

    2015-04-01

    Only textbook to focus primarily on the topic of pitfalls in diagnostic radiology. Highlights the pitfalls in a comprehensive and systematic manner. Written by experts in different imaging modalities and subspecialties from reputable centers across the world. The practice of diagnostic radiology has become increasingly complex, with the use of numerous imaging modalities and division into many subspecialty areas. It is becoming ever more difficult for subspecialist radiologists, general radiologists, and residents to keep up with the advances that are occurring year on year, and this is particularly true for less familiar topics. Failure to appreciate imaging pitfalls often leads to diagnostic error and misinterpretation, and potential medicolegal problems. Diagnostic errors may be due to various factors such as inadequate imaging technique, imaging artifacts, failure to recognize normal structures or variants, lack of correlation with clinical and other imaging findings, and poor training or inexperience. Many, if not most, of these factors are potentially recognizable, preventable, or correctable. This textbook, written by experts from reputable centers across the world, systematically and comprehensively highlights the pitfalls that may occur in diagnostic radiology. Both pitfalls specific to different modalities and techniques and those specific to particular organ systems are described with the help of numerous high-quality illustrations. Recognition of these pitfalls is crucial in helping the practicing radiologist to achieve a more accurate diagnosis.

  3. Pitfalls in diagnostic radiology

    International Nuclear Information System (INIS)

    Peh, Wilfred C.G.

    2015-01-01

    Only textbook to focus primarily on the topic of pitfalls in diagnostic radiology. Highlights the pitfalls in a comprehensive and systematic manner. Written by experts in different imaging modalities and subspecialties from reputable centers across the world. The practice of diagnostic radiology has become increasingly complex, with the use of numerous imaging modalities and division into many subspecialty areas. It is becoming ever more difficult for subspecialist radiologists, general radiologists, and residents to keep up with the advances that are occurring year on year, and this is particularly true for less familiar topics. Failure to appreciate imaging pitfalls often leads to diagnostic error and misinterpretation, and potential medicolegal problems. Diagnostic errors may be due to various factors such as inadequate imaging technique, imaging artifacts, failure to recognize normal structures or variants, lack of correlation with clinical and other imaging findings, and poor training or inexperience. Many, if not most, of these factors are potentially recognizable, preventable, or correctable. This textbook, written by experts from reputable centers across the world, systematically and comprehensively highlights the pitfalls that may occur in diagnostic radiology. Both pitfalls specific to different modalities and techniques and those specific to particular organ systems are described with the help of numerous high-quality illustrations. Recognition of these pitfalls is crucial in helping the practicing radiologist to achieve a more accurate diagnosis.

  4. Two-dimensional errors

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    This chapter addresses the extension of previous work in one-dimensional (linear) error theory to two-dimensional error analysis. The topics of the chapter include the definition of two-dimensional error, the probability ellipse, the probability circle, elliptical (circular) error evaluation, the application to position accuracy, and the use of control systems (points) in measurements

  5. Part two: Error propagation

    International Nuclear Information System (INIS)

    Picard, R.R.

    1989-01-01

    Topics covered in this chapter include a discussion of exact results as related to nuclear materials management and accounting in nuclear facilities; propagation of error for a single measured value; propagation of error for several measured values; error propagation for materials balances; and an application of error propagation to an example of uranium hexafluoride conversion process

  6. Learning from Errors

    OpenAIRE

    Martínez-Legaz, Juan Enrique; Soubeyran, Antoine

    2003-01-01

    We present a model of learning in which agents learn from errors. If an action turns out to be an error, the agent rejects not only that action but also neighboring actions. We find that, keeping memory of his errors, under mild assumptions an acceptable solution is asymptotically reached. Moreover, one can take advantage of big errors for a faster learning.

  7. Generalized Gaussian Error Calculus

    CERN Document Server

    Grabe, Michael

    2010-01-01

    For the first time in 200 years Generalized Gaussian Error Calculus addresses a rigorous, complete and self-consistent revision of the Gaussian error calculus. Since experimentalists realized that measurements in general are burdened by unknown systematic errors, the classical, widespread used evaluation procedures scrutinizing the consequences of random errors alone turned out to be obsolete. As a matter of course, the error calculus to-be, treating random and unknown systematic errors side by side, should ensure the consistency and traceability of physical units, physical constants and physical quantities at large. The generalized Gaussian error calculus considers unknown systematic errors to spawn biased estimators. Beyond, random errors are asked to conform to the idea of what the author calls well-defined measuring conditions. The approach features the properties of a building kit: any overall uncertainty turns out to be the sum of a contribution due to random errors, to be taken from a confidence inter...

  8. Medication errors: prescribing faults and prescription errors.

    Science.gov (United States)

    Velo, Giampaolo P; Minuz, Pietro

    2009-06-01

    1. Medication errors are common in general practice and in hospitals. Both errors in the act of writing (prescription errors) and prescribing faults due to erroneous medical decisions can result in harm to patients. 2. Any step in the prescribing process can generate errors. Slips, lapses, or mistakes are sources of errors, as in unintended omissions in the transcription of drugs. Faults in dose selection, omitted transcription, and poor handwriting are common. 3. Inadequate knowledge or competence and incomplete information about clinical characteristics and previous treatment of individual patients can result in prescribing faults, including the use of potentially inappropriate medications. 4. An unsafe working environment, complex or undefined procedures, and inadequate communication among health-care personnel, particularly between doctors and nurses, have been identified as important underlying factors that contribute to prescription errors and prescribing faults. 5. Active interventions aimed at reducing prescription errors and prescribing faults are strongly recommended. These should be focused on the education and training of prescribers and the use of on-line aids. The complexity of the prescribing procedure should be reduced by introducing automated systems or uniform prescribing charts, in order to avoid transcription and omission errors. Feedback control systems and immediate review of prescriptions, which can be performed with the assistance of a hospital pharmacist, are also helpful. Audits should be performed periodically.

  9. Errors in imaging patients in the emergency setting.

    Science.gov (United States)

    Pinto, Antonio; Reginelli, Alfonso; Pinto, Fabio; Lo Re, Giuseppe; Midiri, Federico; Muzj, Carlo; Romano, Luigia; Brunese, Luca

    2016-01-01

    Emergency and trauma care produces a "perfect storm" for radiological errors: uncooperative patients, inadequate histories, time-critical decisions, concurrent tasks and often junior personnel working after hours in busy emergency departments. The main cause of diagnostic errors in the emergency department is the failure to correctly interpret radiographs, and the majority of diagnoses missed on radiographs are fractures. Missed diagnoses potentially have important consequences for patients, clinicians and radiologists. Radiologists play a pivotal role in the diagnostic assessment of polytrauma patients and of patients with non-traumatic craniothoracoabdominal emergencies, and key elements to reduce errors in the emergency setting are knowledge, experience and the correct application of imaging protocols. This article aims to highlight the definition and classification of errors in radiology, the causes of errors in emergency radiology and the spectrum of diagnostic errors in radiography, ultrasonography and CT in the emergency setting.

  10. Clinical errors and medical negligence.

    Science.gov (United States)

    Oyebode, Femi

    2013-01-01

    This paper discusses the definition, nature and origins of clinical errors including their prevention. The relationship between clinical errors and medical negligence is examined as are the characteristics of litigants and events that are the source of litigation. The pattern of malpractice claims in different specialties and settings is examined. Among hospitalized patients worldwide, 3-16% suffer injury as a result of medical intervention, the most common being the adverse effects of drugs. The frequency of adverse drug effects appears superficially to be higher in intensive care units and emergency departments but once rates have been corrected for volume of patients, comorbidity of conditions and number of drugs prescribed, the difference is not significant. It is concluded that probably no more than 1 in 7 adverse events in medicine result in a malpractice claim and the factors that predict that a patient will resort to litigation include a prior poor relationship with the clinician and the feeling that the patient is not being kept informed. Methods for preventing clinical errors are still in their infancy. The most promising include new technologies such as electronic prescribing systems, diagnostic and clinical decision-making aids and error-resistant systems. Copyright © 2013 S. Karger AG, Basel.

  11. Planetary Transmission Diagnostics

    Science.gov (United States)

    Lewicki, David G. (Technical Monitor); Samuel, Paul D.; Conroy, Joseph K.; Pines, Darryll J.

    2004-01-01

    This report presents a methodology for detecting and diagnosing gear faults in the planetary stage of a helicopter transmission. This diagnostic technique is based on the constrained adaptive lifting algorithm. The lifting scheme, developed by Wim Sweldens of Bell Labs, is a time domain, prediction-error realization of the wavelet transform that allows for greater flexibility in the construction of wavelet bases. Classic lifting analyzes a given signal using wavelets derived from a single fundamental basis function. A number of researchers have proposed techniques for adding adaptivity to the lifting scheme, allowing the transform to choose from a set of fundamental bases the basis that best fits the signal. This characteristic is desirable for gear diagnostics as it allows the technique to tailor itself to a specific transmission by selecting a set of wavelets that best represent vibration signals obtained while the gearbox is operating under healthy-state conditions. However, constraints on certain basis characteristics are necessary to enhance the detection of local wave-form changes caused by certain types of gear damage. The proposed methodology analyzes individual tooth-mesh waveforms from a healthy-state gearbox vibration signal that was generated using the vibration separation (synchronous signal-averaging) algorithm. Each waveform is separated into analysis domains using zeros of its slope and curvature. The bases selected in each analysis domain are chosen to minimize the prediction error, and constrained to have the same-sign local slope and curvature as the original signal. The resulting set of bases is used to analyze future-state vibration signals and the lifting prediction error is inspected. The constraints allow the transform to effectively adapt to global amplitude changes, yielding small prediction errors. However, local wave-form changes associated with certain types of gear damage are poorly adapted, causing a significant change in the

  12. Field error lottery

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, C.J.; McVey, B. (Los Alamos National Lab., NM (USA)); Quimby, D.C. (Spectra Technology, Inc., Bellevue, WA (USA))

    1990-01-01

    The level of field errors in an FEL is an important determinant of its performance. We have computed 3D performance of a large laser subsystem subjected to field errors of various types. These calculations have been guided by simple models such as SWOOP. The technique of choice is utilization of the FELEX free electron laser code that now possesses extensive engineering capabilities. Modeling includes the ability to establish tolerances of various types: fast and slow scale field bowing, field error level, beam position monitor error level, gap errors, defocusing errors, energy slew, displacement and pointing errors. Many effects of these errors on relative gain and relative power extraction are displayed and are the essential elements of determining an error budget. The random errors also depend on the particular random number seed used in the calculation. The simultaneous display of the performance versus error level of cases with multiple seeds illustrates the variations attributable to stochasticity of this model. All these errors are evaluated numerically for comprehensive engineering of the system. In particular, gap errors are found to place requirements beyond mechanical tolerances of {plus minus}25{mu}m, and amelioration of these may occur by a procedure utilizing direct measurement of the magnetic fields at assembly time. 4 refs., 12 figs.

  13. Prescription Errors in Psychiatry

    African Journals Online (AJOL)

    Arun Kumar Agnihotri

    clinical pharmacists in detecting errors before they have a (sometimes serious) clinical impact should not be underestimated. Research on medication error in mental health care is limited. .... participation in ward rounds and adverse drug.

  14. Errors in otology.

    Science.gov (United States)

    Kartush, J M

    1996-11-01

    Practicing medicine successfully requires that errors in diagnosis and treatment be minimized. Malpractice laws encourage litigators to ascribe all medical errors to incompetence and negligence. There are, however, many other causes of unintended outcomes. This article describes common causes of errors and suggests ways to minimize mistakes in otologic practice. Widespread dissemination of knowledge about common errors and their precursors can reduce the incidence of their occurrence. Consequently, laws should be passed to allow for a system of non-punitive, confidential reporting of errors and "near misses" that can be shared by physicians nationwide.

  15. Molecular Diagnostics

    OpenAIRE

    Choe, Hyonmin; Deirmengian, Carl A.; Hickok, Noreen J.; Morrison, Tiffany N.; Tuan, Rocky S.

    2015-01-01

    Orthopaedic infections are complex conditions that require immediate diagnosis and accurate identification of the causative organisms to facilitate appropriate management. Conventional methodologies for diagnosis of these infections sometimes lack accuracy or sufficient rapidity. Current molecular diagnostics are an emerging area of bench-to-bedside research in orthopaedic infections. Examples of promising molecular diagnostics include measurement of a specific biomarker in the synovial fluid...

  16. Introduction to precision machine design and error assessment

    CERN Document Server

    Mekid, Samir

    2008-01-01

    While ultra-precision machines are now achieving sub-nanometer accuracy, unique challenges continue to arise due to their tight specifications. Written to meet the growing needs of mechanical engineers and other professionals to understand these specialized design process issues, Introduction to Precision Machine Design and Error Assessment places a particular focus on the errors associated with precision design, machine diagnostics, error modeling, and error compensation. Error Assessment and ControlThe book begins with a brief overview of precision engineering and applications before introdu

  17. The error in total error reduction.

    Science.gov (United States)

    Witnauer, James E; Urcelay, Gonzalo P; Miller, Ralph R

    2014-02-01

    Most models of human and animal learning assume that learning is proportional to the discrepancy between a delivered outcome and the outcome predicted by all cues present during that trial (i.e., total error across a stimulus compound). This total error reduction (TER) view has been implemented in connectionist and artificial neural network models to describe the conditions under which weights between units change. Electrophysiological work has revealed that the activity of dopamine neurons is correlated with the total error signal in models of reward learning. Similar neural mechanisms presumably support fear conditioning, human contingency learning, and other types of learning. Using a computational modeling approach, we compared several TER models of associative learning to an alternative model that rejects the TER assumption in favor of local error reduction (LER), which assumes that learning about each cue is proportional to the discrepancy between the delivered outcome and the outcome predicted by that specific cue on that trial. The LER model provided a better fit to the reviewed data than the TER models. Given the superiority of the LER model with the present data sets, acceptance of TER should be tempered. Copyright © 2013 Elsevier Inc. All rights reserved.

  18. Analysis of Students' Error in Learning of Quadratic Equations

    Science.gov (United States)

    Zakaria, Effandi; Ibrahim; Maat, Siti Mistima

    2010-01-01

    The purpose of the study was to determine the students' error in learning quadratic equation. The samples were 30 form three students from a secondary school in Jambi, Indonesia. Diagnostic test was used as the instrument of this study that included three components: factorization, completing the square and quadratic formula. Diagnostic interview…

  19. Students' errors in solving linear equation word problems: Case ...

    African Journals Online (AJOL)

    The study examined errors students make in solving linear equation word problems with a view to expose the nature of these errors and to make suggestions for classroom teaching. A diagnostic test comprising 10 linear equation word problems, was administered to a sample (n=130) of senior high school first year Home ...

  20. Errors in Neonatology

    OpenAIRE

    Antonio Boldrini; Rosa T. Scaramuzzo; Armando Cuttano

    2013-01-01

    Introduction: Danger and errors are inherent in human activities. In medical practice errors can lean to adverse events for patients. Mass media echo the whole scenario. Methods: We reviewed recent published papers in PubMed database to focus on the evidence and management of errors in medical practice in general and in Neonatology in particular. We compared the results of the literature with our specific experience in Nina Simulation Centre (Pisa, Italy). Results: In Neonatology the main err...

  1. Radiologic errors, past, present and future.

    Science.gov (United States)

    Berlin, Leonard

    2014-01-01

    During the 10-year period beginning in 1949 with publication of five articles in two radiology journals and UKs The Lancet, a California radiologist named L.H. Garland almost single-handedly shocked the entire medical and especially the radiologic community. He focused their attention on the fact now known and accepted by all, but at that time not previously recognized and acknowledged only with great reluctance, that a substantial degree of observer error was prevalent in radiologic interpretation. In the more than half-century that followed, Garland's pioneering work has been affirmed and reaffirmed by numerous researchers. Retrospective studies disclosed then and still disclose today that diagnostic errors in radiologic interpretations of plain radiographic (as well as CT, MR, ultrasound, and radionuclide) images hover in the 30% range, not too dissimilar to the error rates in clinical medicine. Seventy percent of these errors are perceptual in nature, i.e., the radiologist does not "see" the abnormality on the imaging exam, perhaps due to poor conspicuity, satisfaction of search, or simply the "inexplicable psycho-visual phenomena of human perception." The remainder are cognitive errors: the radiologist sees an abnormality but fails to render a correct diagnoses by attaching the wrong significance to what is seen, perhaps due to inadequate knowledge, or an alliterative or judgmental error. Computer-assisted detection (CAD), a technology that for the past two decades has been utilized primarily in mammographic interpretation, increases sensitivity but at the same time decreases specificity; whether it reduces errors is debatable. Efforts to reduce diagnostic radiological errors continue, but the degree to which they will be successful remains to be determined.

  2. Systematic Procedural Error

    National Research Council Canada - National Science Library

    Byrne, Michael D

    2006-01-01

    .... This problem has received surprisingly little attention from cognitive psychologists. The research summarized here examines such errors in some detail both empirically and through computational cognitive modeling...

  3. Human errors and mistakes

    International Nuclear Information System (INIS)

    Wahlstroem, B.

    1993-01-01

    Human errors have a major contribution to the risks for industrial accidents. Accidents have provided important lesson making it possible to build safer systems. In avoiding human errors it is necessary to adapt the systems to their operators. The complexity of modern industrial systems is however increasing the danger of system accidents. Models of the human operator have been proposed, but the models are not able to give accurate predictions of human performance. Human errors can never be eliminated, but their frequency can be decreased by systematic efforts. The paper gives a brief summary of research in human error and it concludes with suggestions for further work. (orig.)

  4. Learning from Errors

    Science.gov (United States)

    Metcalfe, Janet

    2017-01-01

    Although error avoidance during learning appears to be the rule in American classrooms, laboratory studies suggest that it may be a counterproductive strategy, at least for neurologically typical students. Experimental investigations indicate that errorful learning followed by corrective feedback is beneficial to learning. Interestingly, the…

  5. Action errors, error management, and learning in organizations.

    Science.gov (United States)

    Frese, Michael; Keith, Nina

    2015-01-03

    Every organization is confronted with errors. Most errors are corrected easily, but some may lead to negative consequences. Organizations often focus on error prevention as a single strategy for dealing with errors. Our review suggests that error prevention needs to be supplemented by error management--an approach directed at effectively dealing with errors after they have occurred, with the goal of minimizing negative and maximizing positive error consequences (examples of the latter are learning and innovations). After defining errors and related concepts, we review research on error-related processes affected by error management (error detection, damage control). Empirical evidence on positive effects of error management in individuals and organizations is then discussed, along with emotional, motivational, cognitive, and behavioral pathways of these effects. Learning from errors is central, but like other positive consequences, learning occurs under certain circumstances--one being the development of a mind-set of acceptance of human error.

  6. Design of a study on suboptimal cognitive acts in the diagnostic process, the effect on patient outcomes and the influence of workload, fatigue and experience of physician.

    NARCIS (Netherlands)

    Zwaan, L.; Thijs, A.; Wagner, C.; Wal, G. van der; Timmermans, D.R.M.

    2009-01-01

    Background: Diagnostic error is an important error type since diagnostic adverse events are regularly judged as being preventable and the consequences are considered to be severe. Existing research often focuses on either diagnostic adverse events or on the errors in diagnostic reasoning. Whether

  7. Design of a study on suboptimal cognitive acts in the diagnostic process, the effect on patient outcomes and the influence of workload, fatigue and experience of physician

    NARCIS (Netherlands)

    Zwaan, L.; Thijs, A.; Wagner, C.; Wal, van der G.; Timmermans, D.R.M.

    2009-01-01

    BACKGROUND: Diagnostic error is an important error type since diagnostic adverse events are regularly judged as being preventable and the consequences are considered to be severe. Existing research often focuses on either diagnostic adverse events or on the errors in diagnostic reasoning. Whether

  8. Plasma Diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Zaveryaev, V [Kurchatov Institute, Moscow (Russian Federation); others, and

    2012-09-15

    The success in achieving peaceful fusion power depends on the ability to control a high temperature plasma, which is an object with unique properties, possibly the most complicated object created by humans. Over years of fusion research a new branch of science has been created, namely plasma diagnostics, which involves knowledge of almost all fields of physics, from electromagnetism to nuclear physics, and up-to-date progress in engineering and technology (materials, electronics, mathematical methods of data treatment). Historically, work on controlled fusion started with pulsed systems and accordingly the methods of plasma parameter measurement were first developed for short lived and dense plasmas. Magnetically confined hot plasmas require the creation of special experimental techniques for diagnostics. The diagnostic set is the most scientifically intensive part of a plasma device. During many years of research operation some scientific tasks have been solved while new ones arose. New tasks often require significant changes in the diagnostic system, which is thus a very flexible part of plasma machines. Diagnostic systems are designed to solve several tasks. As an example here are the diagnostic tasks for the International Thermonuclear Experimental Reactor - ITER: (1) Measurements for machine protection and basic control; (2) Measurements for advanced control; (3) Additional measurements for performance evaluation and physics. Every new plasma machine is a further step along the path to the main goal - controlled fusion - and nobody knows in advance what new phenomena will be met on the way. So in the planning of diagnostic construction we should keep in mind further system upgrading to meet possible new scientific and technical challenges. (author)

  9. Uncorrected refractive errors.

    Science.gov (United States)

    Naidoo, Kovin S; Jaggernath, Jyoti

    2012-01-01

    Global estimates indicate that more than 2.3 billion people in the world suffer from poor vision due to refractive error; of which 670 million people are considered visually impaired because they do not have access to corrective treatment. Refractive errors, if uncorrected, results in an impaired quality of life for millions of people worldwide, irrespective of their age, sex and ethnicity. Over the past decade, a series of studies using a survey methodology, referred to as Refractive Error Study in Children (RESC), were performed in populations with different ethnic origins and cultural settings. These studies confirmed that the prevalence of uncorrected refractive errors is considerably high for children in low-and-middle-income countries. Furthermore, uncorrected refractive error has been noted to have extensive social and economic impacts, such as limiting educational and employment opportunities of economically active persons, healthy individuals and communities. The key public health challenges presented by uncorrected refractive errors, the leading cause of vision impairment across the world, require urgent attention. To address these issues, it is critical to focus on the development of human resources and sustainable methods of service delivery. This paper discusses three core pillars to addressing the challenges posed by uncorrected refractive errors: Human Resource (HR) Development, Service Development and Social Entrepreneurship.

  10. Uncorrected refractive errors

    Directory of Open Access Journals (Sweden)

    Kovin S Naidoo

    2012-01-01

    Full Text Available Global estimates indicate that more than 2.3 billion people in the world suffer from poor vision due to refractive error; of which 670 million people are considered visually impaired because they do not have access to corrective treatment. Refractive errors, if uncorrected, results in an impaired quality of life for millions of people worldwide, irrespective of their age, sex and ethnicity. Over the past decade, a series of studies using a survey methodology, referred to as Refractive Error Study in Children (RESC, were performed in populations with different ethnic origins and cultural settings. These studies confirmed that the prevalence of uncorrected refractive errors is considerably high for children in low-and-middle-income countries. Furthermore, uncorrected refractive error has been noted to have extensive social and economic impacts, such as limiting educational and employment opportunities of economically active persons, healthy individuals and communities. The key public health challenges presented by uncorrected refractive errors, the leading cause of vision impairment across the world, require urgent attention. To address these issues, it is critical to focus on the development of human resources and sustainable methods of service delivery. This paper discusses three core pillars to addressing the challenges posed by uncorrected refractive errors: Human Resource (HR Development, Service Development and Social Entrepreneurship.

  11. Preventing Errors in Laterality

    OpenAIRE

    Landau, Elliot; Hirschorn, David; Koutras, Iakovos; Malek, Alexander; Demissie, Seleshie

    2014-01-01

    An error in laterality is the reporting of a finding that is present on the right side as on the left or vice versa. While different medical and surgical specialties have implemented protocols to help prevent such errors, very few studies have been published that describe these errors in radiology reports and ways to prevent them. We devised a system that allows the radiologist to view reports in a separate window, displayed in a simple font and with all terms of laterality highlighted in sep...

  12. Errors and violations

    International Nuclear Information System (INIS)

    Reason, J.

    1988-01-01

    This paper is in three parts. The first part summarizes the human failures responsible for the Chernobyl disaster and argues that, in considering the human contribution to power plant emergencies, it is necessary to distinguish between: errors and violations; and active and latent failures. The second part presents empirical evidence, drawn from driver behavior, which suggest that errors and violations have different psychological origins. The concluding part outlines a resident pathogen view of accident causation, and seeks to identify the various system pathways along which errors and violations may be propagated

  13. Help prevent hospital errors

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000618.htm Help prevent hospital errors To use the sharing features ... in the hospital. If You Are Having Surgery, Help Keep Yourself Safe Go to a hospital you ...

  14. Pedal Application Errors

    Science.gov (United States)

    2012-03-01

    This project examined the prevalence of pedal application errors and the driver, vehicle, roadway and/or environmental characteristics associated with pedal misapplication crashes based on a literature review, analysis of news media reports, a panel ...

  15. Rounding errors in weighing

    International Nuclear Information System (INIS)

    Jeach, J.L.

    1976-01-01

    When rounding error is large relative to weighing error, it cannot be ignored when estimating scale precision and bias from calibration data. Further, if the data grouping is coarse, rounding error is correlated with weighing error and may also have a mean quite different from zero. These facts are taken into account in a moment estimation method. A copy of the program listing for the MERDA program that provides moment estimates is available from the author. Experience suggests that if the data fall into four or more cells or groups, it is not necessary to apply the moment estimation method. Rather, the estimate given by equation (3) is valid in this instance. 5 tables

  16. Spotting software errors sooner

    International Nuclear Information System (INIS)

    Munro, D.

    1989-01-01

    Static analysis is helping to identify software errors at an earlier stage and more cheaply than conventional methods of testing. RTP Software's MALPAS system also has the ability to check that a code conforms to its original specification. (author)

  17. Errors in energy bills

    International Nuclear Information System (INIS)

    Kop, L.

    2001-01-01

    On request, the Dutch Association for Energy, Environment and Water (VEMW) checks the energy bills for her customers. It appeared that in the year 2000 many small, but also big errors were discovered in the bills of 42 businesses

  18. Medical Errors Reduction Initiative

    National Research Council Canada - National Science Library

    Mutter, Michael L

    2005-01-01

    The Valley Hospital of Ridgewood, New Jersey, is proposing to extend a limited but highly successful specimen management and medication administration medical errors reduction initiative on a hospital-wide basis...

  19. Diagnostic development

    International Nuclear Information System (INIS)

    Barnett, C.F.; Brisson, D.A.; Greco, S.E.

    1978-01-01

    During the past year the far-infrared or submillimeter diagnostic research program resulted in three major developments: (1) an optically pumped 0.385-μm D 2 O-laser oscillator-amplifier system was operated at a power level of 1 MW with a line width of less than 50 MHz; (2) a conical Pyrex submillimeter laser beam dump with a retention efficiency greater than 10 4 was developed for the ion temperature Thompson scattering experiment; and (3) a new diagnostic technique was developed that makes use of the Faraday rotation of a modulated submillimeter laser beam to determine plasma current profile. Measurements of the asymmetric distortion of the H/sub α/ (6563 A) spectral line profile show that the effective toroidal drift velocity, dv/sub two vertical bars i/dT/sub i/, may be used as an indicator of plasma quality and as a complement to other ion temperature diagnostics

  20. The surveillance error grid.

    Science.gov (United States)

    Klonoff, David C; Lias, Courtney; Vigersky, Robert; Clarke, William; Parkes, Joan Lee; Sacks, David B; Kirkman, M Sue; Kovatchev, Boris

    2014-07-01

    Currently used error grids for assessing clinical accuracy of blood glucose monitors are based on out-of-date medical practices. Error grids have not been widely embraced by regulatory agencies for clearance of monitors, but this type of tool could be useful for surveillance of the performance of cleared products. Diabetes Technology Society together with representatives from the Food and Drug Administration, the American Diabetes Association, the Endocrine Society, and the Association for the Advancement of Medical Instrumentation, and representatives of academia, industry, and government, have developed a new error grid, called the surveillance error grid (SEG) as a tool to assess the degree of clinical risk from inaccurate blood glucose (BG) monitors. A total of 206 diabetes clinicians were surveyed about the clinical risk of errors of measured BG levels by a monitor. The impact of such errors on 4 patient scenarios was surveyed. Each monitor/reference data pair was scored and color-coded on a graph per its average risk rating. Using modeled data representative of the accuracy of contemporary meters, the relationships between clinical risk and monitor error were calculated for the Clarke error grid (CEG), Parkes error grid (PEG), and SEG. SEG action boundaries were consistent across scenarios, regardless of whether the patient was type 1 or type 2 or using insulin or not. No significant differences were noted between responses of adult/pediatric or 4 types of clinicians. Although small specific differences in risk boundaries between US and non-US clinicians were noted, the panel felt they did not justify separate grids for these 2 types of clinicians. The data points of the SEG were classified in 15 zones according to their assigned level of risk, which allowed for comparisons with the classic CEG and PEG. Modeled glucose monitor data with realistic self-monitoring of blood glucose errors derived from meter testing experiments plotted on the SEG when compared to

  1. The concept of error and malpractice in radiology.

    Science.gov (United States)

    Pinto, Antonio; Brunese, Luca; Pinto, Fabio; Reali, Riccardo; Daniele, Stefania; Romano, Luigia

    2012-08-01

    Since the early 1970s, physicians have been subjected to an increasing number of medical malpractice claims. Radiology is one of the specialties most liable to claims of medical negligence. The etiology of radiological error is multifactorial. Errors fall into recurrent patterns. Errors arise from poor technique, failures of perception, lack of knowledge, and misjudgments. Every radiologist should understand the sources of error in diagnostic radiology as well as the elements of negligence that form the basis of malpractice litigation. Errors are an inevitable part of human life, and every health professional has made mistakes. To improve patient safety and reduce the risk from harm, we must accept that some errors are inevitable during the delivery of health care. We must play a cultural change in medicine, wherein errors are actively sought, openly discussed, and aggressively addressed. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. Error Consistency in Acquired Apraxia of Speech with Aphasia: Effects of the Analysis Unit

    Science.gov (United States)

    Haley, Katarina L.; Cunningham, Kevin T.; Eaton, Catherine Torrington; Jacks, Adam

    2018-01-01

    Purpose: Diagnostic recommendations for acquired apraxia of speech (AOS) have been contradictory concerning whether speech sound errors are consistent or variable. Studies have reported divergent findings that, on face value, could argue either for or against error consistency as a diagnostic criterion. The purpose of this study was to explain…

  3. Design for Error Tolerance

    DEFF Research Database (Denmark)

    Rasmussen, Jens

    1983-01-01

    An important aspect of the optimal design of computer-based operator support systems is the sensitivity of such systems to operator errors. The author discusses how a system might allow for human variability with the use of reversibility and observability.......An important aspect of the optimal design of computer-based operator support systems is the sensitivity of such systems to operator errors. The author discusses how a system might allow for human variability with the use of reversibility and observability....

  4. Apologies and Medical Error

    Science.gov (United States)

    2008-01-01

    One way in which physicians can respond to a medical error is to apologize. Apologies—statements that acknowledge an error and its consequences, take responsibility, and communicate regret for having caused harm—can decrease blame, decrease anger, increase trust, and improve relationships. Importantly, apologies also have the potential to decrease the risk of a medical malpractice lawsuit and can help settle claims by patients. Patients indicate they want and expect explanations and apologies after medical errors and physicians indicate they want to apologize. However, in practice, physicians tend to provide minimal information to patients after medical errors and infrequently offer complete apologies. Although fears about potential litigation are the most commonly cited barrier to apologizing after medical error, the link between litigation risk and the practice of disclosure and apology is tenuous. Other barriers might include the culture of medicine and the inherent psychological difficulties in facing one’s mistakes and apologizing for them. Despite these barriers, incorporating apology into conversations between physicians and patients can address the needs of both parties and can play a role in the effective resolution of disputes related to medical error. PMID:18972177

  5. Thermodynamics of Error Correction

    Directory of Open Access Journals (Sweden)

    Pablo Sartori

    2015-12-01

    Full Text Available Information processing at the molecular scale is limited by thermal fluctuations. This can cause undesired consequences in copying information since thermal noise can lead to errors that can compromise the functionality of the copy. For example, a high error rate during DNA duplication can lead to cell death. Given the importance of accurate copying at the molecular scale, it is fundamental to understand its thermodynamic features. In this paper, we derive a universal expression for the copy error as a function of entropy production and work dissipated by the system during wrong incorporations. Its derivation is based on the second law of thermodynamics; hence, its validity is independent of the details of the molecular machinery, be it any polymerase or artificial copying device. Using this expression, we find that information can be copied in three different regimes. In two of them, work is dissipated to either increase or decrease the error. In the third regime, the protocol extracts work while correcting errors, reminiscent of a Maxwell demon. As a case study, we apply our framework to study a copy protocol assisted by kinetic proofreading, and show that it can operate in any of these three regimes. We finally show that, for any effective proofreading scheme, error reduction is limited by the chemical driving of the proofreading reaction.

  6. [Diagnostic errors in symptom-poor hyperthyroidism in the aged].

    Science.gov (United States)

    Szeszák, F; Kiss, E; Szabó, T; Balázs, C

    1995-02-12

    The diagnosis of hyperthyreoidism manifesting in the elderly meets difficulty in many cases. Lack of some characteristic symptoms observable in younger patients can be misleading. The authors summarize the data of ten clinical cases where the hyperthyreoidism appeared in occult form, reminding rather for heart disease or malignant tumours. The assay of thyroid hormones and the level of antithyreoglobulin and anti-thyreoid peroxidase antibodies was unavoidable in order to establish correct diagnosis. Though the early diagnosis and treatment may enhance the life expectancy of the patients and may considerably decrease the cardial and the consecutive cerebral complications. The authors analyse the reasons and possible pathomechanism of the formation of atypical hyperthyreoidism occurring in the elderly.

  7. Diagnostic dilemma

    DEFF Research Database (Denmark)

    Feldt-Rasmussen, Ulla; Dobrovolny, Robert; Nazarenko, Irina

    2011-01-01

    Fabry disease, an X-linked lysosomal storage disorder, results from the deficient activity of a-galactosidase A (a-Gal A). In affected males, the clinical diagnosis is confirmed by the markedly decreased a-Gal A activity. However, in female heterozygotes, the a-Gal A activity can range from low t...... on enzyme replacement therapy. Thus, gene dosage analyses can detect large deletions (>50bp) in suspect heterozygotes for X-linked and autosomal dominant diseases that are "sequencing cryptic," resolving molecular diagnostic dilemmas....... to normal due to random X-chromosomal inactivation, and diagnostic confirmation requires identification of the family's a-Gal A gene mutation. In a young female who had occasional acroparesthesias, corneal opacities, and 15 to 50% of the lower limit of normal leukocyte a-Gal A activity, a-Gal A sequencing...... in two expert laboratories did not identify a confirmatory mutation, presenting a diagnostic dilemma. A renal biopsy proved diagnostic and renewed efforts to detect an a-Gal A mutation. Subsequent gene dosage analyses identified a large a-Gal A deletion confirming her heterozygosity, and she was started...

  8. Learning from Errors

    Directory of Open Access Journals (Sweden)

    MA. Lendita Kryeziu

    2015-06-01

    Full Text Available “Errare humanum est”, a well known and widespread Latin proverb which states that: to err is human, and that people make mistakes all the time. However, what counts is that people must learn from mistakes. On these grounds Steve Jobs stated: “Sometimes when you innovate, you make mistakes. It is best to admit them quickly, and get on with improving your other innovations.” Similarly, in learning new language, learners make mistakes, thus it is important to accept them, learn from them, discover the reason why they make them, improve and move on. The significance of studying errors is described by Corder as: “There have always been two justifications proposed for the study of learners' errors: the pedagogical justification, namely that a good understanding of the nature of error is necessary before a systematic means of eradicating them could be found, and the theoretical justification, which claims that a study of learners' errors is part of the systematic study of the learners' language which is itself necessary to an understanding of the process of second language acquisition” (Corder, 1982; 1. Thus the importance and the aim of this paper is analyzing errors in the process of second language acquisition and the way we teachers can benefit from mistakes to help students improve themselves while giving the proper feedback.

  9. Compact disk error measurements

    Science.gov (United States)

    Howe, D.; Harriman, K.; Tehranchi, B.

    1993-01-01

    The objectives of this project are as follows: provide hardware and software that will perform simple, real-time, high resolution (single-byte) measurement of the error burst and good data gap statistics seen by a photoCD player read channel when recorded CD write-once discs of variable quality (i.e., condition) are being read; extend the above system to enable measurement of the hard decision (i.e., 1-bit error flags) and soft decision (i.e., 2-bit error flags) decoding information that is produced/used by the Cross Interleaved - Reed - Solomon - Code (CIRC) block decoder employed in the photoCD player read channel; construct a model that uses data obtained via the systems described above to produce meaningful estimates of output error rates (due to both uncorrected ECC words and misdecoded ECC words) when a CD disc having specific (measured) error statistics is read (completion date to be determined); and check the hypothesis that current adaptive CIRC block decoders are optimized for pressed (DAD/ROM) CD discs. If warranted, do a conceptual design of an adaptive CIRC decoder that is optimized for write-once CD discs.

  10. LIBERTARISMO & ERROR CATEGORIAL

    Directory of Open Access Journals (Sweden)

    Carlos G. Patarroyo G.

    2009-01-01

    Full Text Available En este artículo se ofrece una defensa del libertarismo frente a dos acusaciones según las cuales éste comete un error categorial. Para ello, se utiliza la filosofía de Gilbert Ryle como herramienta para explicar las razones que fundamentan estas acusaciones y para mostrar por qué, pese a que ciertas versiones del libertarismo que acuden a la causalidad de agentes o al dualismo cartesiano cometen estos errores, un libertarismo que busque en el indeterminismo fisicalista la base de la posibilidad de la libertad humana no necesariamente puede ser acusado de incurrir en ellos.

  11. Libertarismo & Error Categorial

    OpenAIRE

    PATARROYO G, CARLOS G

    2009-01-01

    En este artículo se ofrece una defensa del libertarismo frente a dos acusaciones según las cuales éste comete un error categorial. Para ello, se utiliza la filosofía de Gilbert Ryle como herramienta para explicar las razones que fundamentan estas acusaciones y para mostrar por qué, pese a que ciertas versiones del libertarismo que acuden a la causalidad de agentes o al dualismo cartesiano cometen estos errores, un libertarismo que busque en el indeterminismo fisicalista la base de la posibili...

  12. Error Free Software

    Science.gov (United States)

    1985-01-01

    A mathematical theory for development of "higher order" software to catch computer mistakes resulted from a Johnson Space Center contract for Apollo spacecraft navigation. Two women who were involved in the project formed Higher Order Software, Inc. to develop and market the system of error analysis and correction. They designed software which is logically error-free, which, in one instance, was found to increase productivity by 600%. USE.IT defines its objectives using AXES -- a user can write in English and the system converts to computer languages. It is employed by several large corporations.

  13. Error Correcting Codes

    Indian Academy of Sciences (India)

    Science and Automation at ... the Reed-Solomon code contained 223 bytes of data, (a byte ... then you have a data storage system with error correction, that ..... practical codes, storing such a table is infeasible, as it is generally too large.

  14. Error Correcting Codes

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 3. Error Correcting Codes - Reed Solomon Codes. Priti Shankar. Series Article Volume 2 Issue 3 March ... Author Affiliations. Priti Shankar1. Department of Computer Science and Automation, Indian Institute of Science, Bangalore 560 012, India ...

  15. Challenge and Error: Critical Events and Attention-Related Errors

    Science.gov (United States)

    Cheyne, James Allan; Carriere, Jonathan S. A.; Solman, Grayden J. F.; Smilek, Daniel

    2011-01-01

    Attention lapses resulting from reactivity to task challenges and their consequences constitute a pervasive factor affecting everyday performance errors and accidents. A bidirectional model of attention lapses (error [image omitted] attention-lapse: Cheyne, Solman, Carriere, & Smilek, 2009) argues that errors beget errors by generating attention…

  16. Team errors: definition and taxonomy

    International Nuclear Information System (INIS)

    Sasou, Kunihide; Reason, James

    1999-01-01

    In error analysis or error management, the focus is usually upon individuals who have made errors. In large complex systems, however, most people work in teams or groups. Considering this working environment, insufficient emphasis has been given to 'team errors'. This paper discusses the definition of team errors and its taxonomy. These notions are also applied to events that have occurred in the nuclear power industry, aviation industry and shipping industry. The paper also discusses the relations between team errors and Performance Shaping Factors (PSFs). As a result, the proposed definition and taxonomy are found to be useful in categorizing team errors. The analysis also reveals that deficiencies in communication, resource/task management, excessive authority gradient, excessive professional courtesy will cause team errors. Handling human errors as team errors provides an opportunity to reduce human errors

  17. Imagery of Errors in Typing

    Science.gov (United States)

    Rieger, Martina; Martinez, Fanny; Wenke, Dorit

    2011-01-01

    Using a typing task we investigated whether insufficient imagination of errors and error corrections is related to duration differences between execution and imagination. In Experiment 1 spontaneous error imagination was investigated, whereas in Experiment 2 participants were specifically instructed to imagine errors. Further, in Experiment 2 we…

  18. Correction of refractive errors

    Directory of Open Access Journals (Sweden)

    Vladimir Pfeifer

    2005-10-01

    Full Text Available Background: Spectacles and contact lenses are the most frequently used, the safest and the cheapest way to correct refractive errors. The development of keratorefractive surgery has brought new opportunities for correction of refractive errors in patients who have the need to be less dependent of spectacles or contact lenses. Until recently, RK was the most commonly performed refractive procedure for nearsighted patients.Conclusions: The introduction of excimer laser in refractive surgery has given the new opportunities of remodelling the cornea. The laser energy can be delivered on the stromal surface like in PRK or deeper on the corneal stroma by means of lamellar surgery. In LASIK flap is created with microkeratome in LASEK with ethanol and in epi-LASIK the ultra thin flap is created mechanically.

  19. Error-Free Software

    Science.gov (United States)

    1989-01-01

    001 is an integrated tool suited for automatically developing ultra reliable models, simulations and software systems. Developed and marketed by Hamilton Technologies, Inc. (HTI), it has been applied in engineering, manufacturing, banking and software tools development. The software provides the ability to simplify the complex. A system developed with 001 can be a prototype or fully developed with production quality code. It is free of interface errors, consistent, logically complete and has no data or control flow errors. Systems can be designed, developed and maintained with maximum productivity. Margaret Hamilton, President of Hamilton Technologies, also directed the research and development of USE.IT, an earlier product which was the first computer aided software engineering product in the industry to concentrate on automatically supporting the development of an ultrareliable system throughout its life cycle. Both products originated in NASA technology developed under a Johnson Space Center contract.

  20. Minimum Tracking Error Volatility

    OpenAIRE

    Luca RICCETTI

    2010-01-01

    Investors assign part of their funds to asset managers that are given the task of beating a benchmark. The risk management department usually imposes a maximum value of the tracking error volatility (TEV) in order to keep the risk of the portfolio near to that of the selected benchmark. However, risk management does not establish a rule on TEV which enables us to understand whether the asset manager is really active or not and, in practice, asset managers sometimes follow passively the corres...

  1. Error-correction coding

    Science.gov (United States)

    Hinds, Erold W. (Principal Investigator)

    1996-01-01

    This report describes the progress made towards the completion of a specific task on error-correcting coding. The proposed research consisted of investigating the use of modulation block codes as the inner code of a concatenated coding system in order to improve the overall space link communications performance. The study proposed to identify and analyze candidate codes that will complement the performance of the overall coding system which uses the interleaved RS (255,223) code as the outer code.

  2. Satellite Photometric Error Determination

    Science.gov (United States)

    2015-10-18

    Satellite Photometric Error Determination Tamara E. Payne, Philip J. Castro, Stephen A. Gregory Applied Optimization 714 East Monument Ave, Suite...advocate the adoption of new techniques based on in-frame photometric calibrations enabled by newly available all-sky star catalogs that contain highly...filter systems will likely be supplanted by the Sloan based filter systems. The Johnson photometric system is a set of filters in the optical

  3. Thyroid diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Scriba, P C; Boerner, W; Emrich, S; Gutekunst, R; Herrmann, J; Horn, K; Klett, M; Krueskemper, H L; Pfannenstiel, P; Pickardt, C R

    1985-03-01

    None of the in-vitro and in-vivo methods listed permits on unambiguous diagnosis when applied alone, owing to the fact that similar or even identical findings are obtained for various individual parameters in different thyroid diseases. Further, especially the in-vitro tests are also subject to extrathyroidal effects which may mask the typical findings. The limited and varying specificity and sensitivity of the tests applied, as well as the falsification of results caused by the patients' idiosyncracies and the methodology, make it necessary to interpret and evaluate the in-vivo and in-vitro findings only if the clinical situation (anamnesis and physical examination) is known. For maximum diagnostic quality of the tests, the initial probability of the assumed type of thyroid disease must be increased (formulation of the clinical problem). The concepts of exclusion diagnosis and identification must be distinguished as well as the diagnosis of functional disturbances on the one hand and of thyroid diseases on the other. Both of this requires a qualified, specific and detailed anamnesis and examination procedure, and the clinical examination remains the obligatory basis of clinical diagnostics. In case of inexplicable discrepancies between the clinical manifestations and the findings obtained with specific methods, or between the findings obtained with a specific method, the patient should be referred to an expert institution, or the expert institution should be consulted.

  4. Thyroid diagnostics

    International Nuclear Information System (INIS)

    Scriba, P.C.; Boerner, W.; Emrich, S.; Gutekunst, R.; Herrmann, J.; Horn, K.; Klett, M.; Krueskemper, H.L.; Pfannenstiel, P.; Pickardt, C.R.; Reiners, C.; Reinwein, D.; Schleusener, H.

    1985-01-01

    None of the in-vitro and in-vivo methods listed permits on unambiguous diagnosis when applied alone, owing to the fact that similar or even identical findings are obtained for various individual parameters in different thyroid diseases. Further, especially the in-vitro tests are also subject to extrathyroidal effects which may mask the typical findings. The limited and varying specificity and sensitivity of the tests applied, as well as the falsification of results caused by the patients' idiosyncracies and the methodology, make it necessary to interpret and evaluate the in-vivo and in-vitro findings only if the clinical situation (anamnesis and physical examination) is known. For maximum diagnostic quality of the tests, the initial probability of the assumed type of thyroid disease must be increased (formulation of the clinical problem). The concepts of exclusion diagnosis and identification must be distinguished as well as the diagnosis of functional disturbances on the one hand and of thyroid diseases on the other. Both of this requires a qualified, specific and detailed anamnesis and examination procedure, and the clinical examination remains the obligatory basis of clinical diagnostics. In case of inexplicable discrepancies between the clinical manifestations and the findings obtained with specific methods, or between the findings obtained with a specific method, the patient should be referred to an expert institution, or the expert institution should be consulted. (orig./MG) [de

  5. Ambient diagnostics

    CERN Document Server

    Cai, Yang

    2014-01-01

    Part I. FundamentalsIntroductionWhat is Ambient Diagnostics?Diagnostic ModelsMultimedia IntelligenceCrowd SourcingSoft SensorsScience of SimplicityPersonal DiagnosesBasic AlgorithmsBasic ToolsSummaryProblemsTransformationEarly Discoveries of Heartbeat PatternsTransforms, Features, and AttributesSequential FeaturesSpatiotemporal FeaturesShape FeaturesImagery FeaturesFrequency Domain FeaturesMulti-Resolution FeaturesSummaryProblemsPattern RecognitionSimilarities and DistancesClustering MethodsClassification MethodsClassifier Accuracy MeasuresSummaryProblemsPart II. Multimedia IntelligenceSound RecognitionMicrophone AppsModern Acoustic Transducers (Microphones)Frequency Response CharacteristicsDigital Audio File FormatsHeart Sound SensingLung Sound SensingSnore MeterSpectrogram (STFT)Ambient Sound AnalysisSound RecognitionRecognizing Asthma SoundPeak ShiftFeature CompressionRegroupingNoise IssuesFuture ApplicationsSummaryProblemsColor SensorsColor SensingHuman Color VisionColor SensorsColor Matching ExperimentsC...

  6. Video Error Correction Using Steganography

    Science.gov (United States)

    Robie, David L.; Mersereau, Russell M.

    2002-12-01

    The transmission of any data is always subject to corruption due to errors, but video transmission, because of its real time nature must deal with these errors without retransmission of the corrupted data. The error can be handled using forward error correction in the encoder or error concealment techniques in the decoder. This MPEG-2 compliant codec uses data hiding to transmit error correction information and several error concealment techniques in the decoder. The decoder resynchronizes more quickly with fewer errors than traditional resynchronization techniques. It also allows for perfect recovery of differentially encoded DCT-DC components and motion vectors. This provides for a much higher quality picture in an error-prone environment while creating an almost imperceptible degradation of the picture in an error-free environment.

  7. Video Error Correction Using Steganography

    Directory of Open Access Journals (Sweden)

    Robie David L

    2002-01-01

    Full Text Available The transmission of any data is always subject to corruption due to errors, but video transmission, because of its real time nature must deal with these errors without retransmission of the corrupted data. The error can be handled using forward error correction in the encoder or error concealment techniques in the decoder. This MPEG-2 compliant codec uses data hiding to transmit error correction information and several error concealment techniques in the decoder. The decoder resynchronizes more quickly with fewer errors than traditional resynchronization techniques. It also allows for perfect recovery of differentially encoded DCT-DC components and motion vectors. This provides for a much higher quality picture in an error-prone environment while creating an almost imperceptible degradation of the picture in an error-free environment.

  8. Treatment delay and radiological errors in patients with bone metastases

    International Nuclear Information System (INIS)

    Ichinohe, K.; Takahashi, M.; Tooyama, N.

    2003-01-01

    During routine investigations, we are surprised to find that therapy for bone metastases is sometimes delayed for a considerable period of time. To determine the extent of this delay and its causes, we reviewed the medical records of symptomatic patients seen at our hospital who had been recently diagnosed as having bone metastases for the last four years. The treatment delay was defined as the interval between presentation with symptoms and definitive treatment for bone metastases. The diagnostic delay was defined as the interval between presentation with symptoms and diagnosis of bone metastases. The results of diagnostic radiological examinations were also reviewed for errors. The study population included 76 males and 34 females with a median age of 66 years. Most bone metastases were diagnosed radiologically. Over 75% of patients were treated with radiotherapy. The treatment delay ranged from 2 to 307 days, with a mean of 53.3 days. In 490 radiological studies reviewed, we identified 166 (33.9%) errors concerning 62 (56.4%) patients. The diagnostic delay was significantly longer for patients with radiological errors than for patients without radiological errors (P < 0.001), and much of it was due to radiological errors. In conclusion, the treatment delay in patients with symptomatic bone metastases was much longer than expected, and much of it was caused by radiological errors. Considerable efforts should therefore be made to more carefully examine the radiological studies in order to ensure prompt treatment of bone metastases. (author)

  9. Medical Error Types and Causes Made by Nurses in Turkey

    Directory of Open Access Journals (Sweden)

    Dilek Kucuk Alemdar

    2013-06-01

    Full Text Available AIM: This study was carried out as a descriptive study in order to determine types, causes and prevalence of medical errors made by nurses in Turkey. METHOD: Seventy eight (78 nurses who have worked in a randomly selected hospital from five hospitals in Giresun city centre were enrolled in the study. The data was collected by the researchers using the ‘Information Form for Nurses’ and ‘Medical Error Form’. The Medical Error Form consists of 2 parts and 40 items including types and causes of medical errors. Nurses’ socio-demographic variables, medical error types and causes were evaluated using the percentage distribution and mean. RESULTS: The mean age of the nurses was 25.5 years, with a standard deviation 6.03 years. 50% of the nurses graduated health professional high school in the study. 53.8% of the nurses are single, 63.1% worked between 1-5 years, 71.8% day and night shifts and 42.3% in medical clinics. The common types of medical errors were hospital infection rate of 15.4%, diagnostic errors 12.8%, needle or cutting tool injuries and problems related to drug usage which has side effects 10.3%. In the study 38.5% of the nurses reported that they thought the cause of medical error highly was tiredness, 36.4% increased workload and 34.6% long working hours. CONCLUSION: As a result of the present study, nurses mentioned hospital infection, diagnostic errors, needle or cutting tool injuries as the most common medical errors and fatigue, over work load and long working hours as the most common medical error reasons. [TAF Prev Med Bull 2013; 12(3.000: 307-314

  10. Learning from mistakes: errors in approaches to melanoma and the urgent need for updated national guidelines.

    Science.gov (United States)

    Simionescu, Olga; Blum, Andreas; Grigore, Mariana; Costache, Mariana; Avram, Alina; Testori, Alessandro

    2016-09-01

    The tracking and identification of errors in the detection and follow-up of melanoma are important because there is huge potential to increase awareness about the most vulnerable aspects of diagnosis and treatment, and to improve both from the perspective of healthcare economics. The present study was designed to identify where errors occur and to propose a minimum set of rules for the routine guidance of any specialist in melanoma management. This report describes the evaluation of a unique series of 33 cases in which errors applying to many steps in the diagnosis and treatment of melanoma were detected. Cases were collected at two centers in Romania, one public and one private, as part of a process of obtaining patient-requested second opinions. A total of 166 errors were identified across the 33 patients, most of which were treatment errors. The errors fell into six categories: clinical diagnostic errors (36 errors among 30 patients); primary surgical errors (31 errors among 16 patients); pathology errors (24 errors among 17 patients); sentinel lymph node biopsy errors (13 errors among 13 patients); staging errors (17 errors among 13 patients); and treatment or management errors (45 errors among 33 patients). Based on the present results, we propose that in countries lacking national guidelines, clinicians should adhere to international evidence-based guidelines for the diagnosis and treatment of melanoma. © 2015 The International Society of Dermatology.

  11. Error-related brain activity and error awareness in an error classification paradigm.

    Science.gov (United States)

    Di Gregorio, Francesco; Steinhauser, Marco; Maier, Martin E

    2016-10-01

    Error-related brain activity has been linked to error detection enabling adaptive behavioral adjustments. However, it is still unclear which role error awareness plays in this process. Here, we show that the error-related negativity (Ne/ERN), an event-related potential reflecting early error monitoring, is dissociable from the degree of error awareness. Participants responded to a target while ignoring two different incongruent distractors. After responding, they indicated whether they had committed an error, and if so, whether they had responded to one or to the other distractor. This error classification paradigm allowed distinguishing partially aware errors, (i.e., errors that were noticed but misclassified) and fully aware errors (i.e., errors that were correctly classified). The Ne/ERN was larger for partially aware errors than for fully aware errors. Whereas this speaks against the idea that the Ne/ERN foreshadows the degree of error awareness, it confirms the prediction of a computational model, which relates the Ne/ERN to post-response conflict. This model predicts that stronger distractor processing - a prerequisite of error classification in our paradigm - leads to lower post-response conflict and thus a smaller Ne/ERN. This implies that the relationship between Ne/ERN and error awareness depends on how error awareness is related to response conflict in a specific task. Our results further indicate that the Ne/ERN but not the degree of error awareness determines adaptive performance adjustments. Taken together, we conclude that the Ne/ERN is dissociable from error awareness and foreshadows adaptive performance adjustments. Our results suggest that the relationship between the Ne/ERN and error awareness is correlative and mediated by response conflict. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Diagnostic accuracy of organ electrodermal diagnostics | Szopinski ...

    African Journals Online (AJOL)

    Objective. To estimate the diagnostic accuracy as well as the scope of utilisation of a new bio-electronic method of organ diagnostics. Design. Double-blind comparative study of the diagnostic results obtained by means of organ electrodermal diagnostics (OED) and clinical diagnoses, as a criterion standard. Setting.

  13. Errors in chest x-ray interpretation

    International Nuclear Information System (INIS)

    Woznitza, N.; Piper, K.

    2015-01-01

    Full text: Reporting of adult chest x-rays by appropriately trained radiographers is frequently used in the United Kingdom as one method to maintain a patient focused radiology service in times of increasing workload. With models of advanced practice being developed in Australia, New Zealand and Canada, the spotlight is on the evidence base which underpins radiographer reporting. It is essential that any radiographer who extends their scope of practice to incorporate definitive clinical reporting perform at a level comparable to a consultant radiologist. In any analysis of performance it is important to quantify levels of sensitivity and specificity and to evaluate areas of error and variation. A critical review of the errors made by reporting radiographers in the interpretation of adult chest x-rays will be performed, examining performance in structured clinical examinations, clinical audit and a diagnostic accuracy study from research undertaken by the authors, and including studies which have compared the performance of reporting radiographers and consultant radiologists. overall performance will be examined and common errors discussed using a case based approach. Methods of error reduction, including multidisciplinary team meetings and ongoing learning will be considered

  14. SNS Diagnostics

    International Nuclear Information System (INIS)

    Shea, T.J.; Cameron, P.; Doolittle, L.; Power, J.

    2000-01-01

    The Spallation Neutron Source (SNS) Project is a collaborative effort to build the next generation neutron science facility at Oak Ridge, TN. The facility will deliver a 2 MW proton beam to a liquid mercury target. Neutrons from this target will be moderated and sent to several state-of-the-art instruments. Six national laboratories are involved in SNS construction. Berkeley (LBNL) will build the front end that produces a 2.5 MeV, 52 mA H-beam. Los Alamos (LANL) is responsible for the 1 GeV linac with a superconducting section provided by Thomas Jefferson (JLab). Brookhaven (BNL) is building the transfer lines and accumulator ring. Oak Ridge (ORNL) and Argonne (ANL) have responsibility for the target and instruments. All activities are coordinated by the SNS project office at Oak Ridge. The high beam power, a desired availability of 95%, and an aggressive commissioning schedule lead to some interesting challenges in beam diagnostics

  15. Minimum Error Entropy Classification

    CERN Document Server

    Marques de Sá, Joaquim P; Santos, Jorge M F; Alexandre, Luís A

    2013-01-01

    This book explains the minimum error entropy (MEE) concept applied to data classification machines. Theoretical results on the inner workings of the MEE concept, in its application to solving a variety of classification problems, are presented in the wider realm of risk functionals. Researchers and practitioners also find in the book a detailed presentation of practical data classifiers using MEE. These include multi‐layer perceptrons, recurrent neural networks, complexvalued neural networks, modular neural networks, and decision trees. A clustering algorithm using a MEE‐like concept is also presented. Examples, tests, evaluation experiments and comparison with similar machines using classic approaches, complement the descriptions.

  16. Errors of Logic and Scholarship Concerning Dissociative Identity Disorder

    Science.gov (United States)

    Ross, Colin A.

    2009-01-01

    The author reviewed a two-part critique of dissociative identity disorder published in the "Canadian Journal of Psychiatry". The two papers contain errors of logic and scholarship. Contrary to the conclusions in the critique, dissociative identity disorder has established diagnostic reliability and concurrent validity, the trauma histories of…

  17. Children's mathematics 4-15 learning from errors and misconceptions

    CERN Document Server

    Ryan, Julie

    2007-01-01

    Develops concepts for teachers to use in organizing their understanding and knowledge of children's mathematics. This book offers guidance for classroom teaching and concludes with theoretical accounts of learning and teaching. It transforms research on diagnostic errors into knowledge for teaching, teacher education and research on teaching.

  18. An Instructor's Diagnostic Aid for Feedback in Training.

    Science.gov (United States)

    Andrews, Dee H.; Uliano, Kevin C.

    1988-01-01

    Instructor's Diagnostic Aid for Feedback in Training (IDAFT) is a computer-assisted method based on error analysis, domains of learning, and events of instruction. Its use with Navy team instructors is currently being explored. (JOW)

  19. Diagnostic thoracoscopy

    Directory of Open Access Journals (Sweden)

    Plavec Goran

    2002-01-01

    Full Text Available Diagnostic thoracoscopy in patients with pleural effusion of unclear origin mostly provides the correct diagnosis. Results from published reports of previous researches are not uniform. In 47 male and 20 female patients with pleural effusion of unknown etiology, after receiving negative results obtained from cytological finding of pleural effusion and percutaneous needle biopsy, thoracoscopy with biopsy of one or both pleurae was performed. Procedure was done in local anesthesia using Stortz rigid thoracoscope. In 37 patients with malignant disease (primary or metastatic diagnosis was confirmed histopathologically in 31 patient (81.12%. In 27 patients with inflammatory pleural disease diagnosis was confirmed histopathologically in 22 patients (81.4%. Among 11 patients with specific pleural effusions, tuberculosis was confirmed in 10 (90.91%. Normal finding in cases of spontaneous pneumothorax and pulmonary embolism was taken as a positive result. Total number of positive findings was 55 (82.10%. In one patient, the third spontaneous pneumothorax was the indication for thoracoscopy, and after numerous bullae were seen during the procedure, talcum powder pleurodesis was done. In four patients low intensity subcutaneous emphysema occurred one day after thoracoscopy. It can be concluded that thoracoscopy in local anesthesia out of the operating room is good and practical method for solving the unclear pleural effusions, with neglectable rate of complications.

  20. Mitigation diagnostics

    International Nuclear Information System (INIS)

    Hall, S.T.

    1990-01-01

    This paper reports that experience in the remediation of schools and other large buildings has shown the importance of the effects of both the location of geologic sources and HVAC-induced distribution of indoor radon. In general, elevated radon in areas of schools with evenly distributed HVAC pressures are correlated with maximum soil radon emanations. However, strong or unequal HVAC effects can redistribute indoor radon to areas away from the direct source. Effective remediation required a complete understanding of both contributions. In some schools, highest indoor radon levels were located near large return ducts and were attributed to proximity to negative HVAC pressure. Successful sub-slab depressurization systems were installed, however, in rooms with lower indoor but greatest sub-slab radon levels, closest to the source. This shows the inadequacy of using indoor radon levels alone as a basis for remediation. Wings of two other schools with radon problems have equivalent window fan coil units in rooms of equal size and no central HVAC system. Highest indoor radon levels correlated well with highest sub-slab radon levels due to the equivalent effects of the window units. Diagnostic tests in other schools have revealed: blockwall radon transport to upper floors; high blockwall radon adjacent to sub-slab sources; and elevated indoor radon over crawlspace being drawn upward by HVAC-induced negative pressure, determined from indoor to outdoor micromanometer measurements

  1. Standard Errors for Matrix Correlations.

    Science.gov (United States)

    Ogasawara, Haruhiko

    1999-01-01

    Derives the asymptotic standard errors and intercorrelations for several matrix correlations assuming multivariate normality for manifest variables and derives the asymptotic standard errors of the matrix correlations for two factor-loading matrices. (SLD)

  2. "First, know thyself": cognition and error in medicine.

    Science.gov (United States)

    Elia, Fabrizio; Aprà, Franco; Verhovez, Andrea; Crupi, Vincenzo

    2016-04-01

    Although error is an integral part of the world of medicine, physicians have always been little inclined to take into account their own mistakes and the extraordinary technological progress observed in the last decades does not seem to have resulted in a significant reduction in the percentage of diagnostic errors. The failure in the reduction in diagnostic errors, notwithstanding the considerable investment in human and economic resources, has paved the way to new strategies which were made available by the development of cognitive psychology, the branch of psychology that aims at understanding the mechanisms of human reasoning. This new approach led us to realize that we are not fully rational agents able to take decisions on the basis of logical and probabilistically appropriate evaluations. In us, two different and mostly independent modes of reasoning coexist: a fast or non-analytical reasoning, which tends to be largely automatic and fast-reactive, and a slow or analytical reasoning, which permits to give rationally founded answers. One of the features of the fast mode of reasoning is the employment of standardized rules, termed "heuristics." Heuristics lead physicians to correct choices in a large percentage of cases. Unfortunately, cases exist wherein the heuristic triggered fails to fit the target problem, so that the fast mode of reasoning can lead us to unreflectively perform actions exposing us and others to variable degrees of risk. Cognitive errors arise as a result of these cases. Our review illustrates how cognitive errors can cause diagnostic problems in clinical practice.

  3. Error forecasting schemes of error correction at receiver

    International Nuclear Information System (INIS)

    Bhunia, C.T.

    2007-08-01

    To combat error in computer communication networks, ARQ (Automatic Repeat Request) techniques are used. Recently Chakraborty has proposed a simple technique called the packet combining scheme in which error is corrected at the receiver from the erroneous copies. Packet Combining (PC) scheme fails: (i) when bit error locations in erroneous copies are the same and (ii) when multiple bit errors occur. Both these have been addressed recently by two schemes known as Packet Reversed Packet Combining (PRPC) Scheme, and Modified Packet Combining (MPC) Scheme respectively. In the letter, two error forecasting correction schemes are reported, which in combination with PRPC offer higher throughput. (author)

  4. Perceptual error and the culture of open disclosure in Australian radiology.

    Science.gov (United States)

    Pitman, A G

    2006-06-01

    The work of diagnostic radiology consists of the complete detection of all abnormalities in an imaging examination and their accurate diagnosis. Errors in diagnostic radiology comprise perceptual errors, which are a failure of detection, and interpretation errors, which are errors of diagnosis. Perceptual errors are subject to rules of human perception and can be expected in a proportion of observations by any human observer including a trained professional under ideal conditions. Current legal standards of medical negligence make no allowance for perceptual errors, comparing human performance to an ideal standard. Diagnostic radiology in Australia has a culture of open disclosure, where full unbiased evidence from an examination is provided to the patient together with the report. This practice benefits the public by allowing genuine differences of opinion and also by allowing a second chance of correct diagnosis in cases of perceptual error. The culture of open disclosure, which is unique to diagnostic radiology, places radiologists at distinct medicolegal disadvantage compared with other specialties. (i) Perceptual error should be acknowledged as an integral inevitable part of diagnostic radiology; (ii) culture of open disclosure should be encouraged by the profession; and (iii) a pragmatic definition of medical negligence should reflect the imperfect performance of human observers.

  5. Perceptual error and the culture of open disclosure in Australian radiology

    International Nuclear Information System (INIS)

    Pitman, A.G.

    2006-01-01

    The work of diagnostic radiology consists of the complete detection of all abnormalities in an imaging examination and their accurate diagnosis. Errors in diagnostic radiology comprise perceptual errors, which are a failure of detection, and interpretation errors, which are errors of diagnosis. Perceptual errors are subject to rules of human perception and can be expected in a proportion of observations by any human observer including a trained professional under ideal conditions. Current legal standards of medical negligence make no allowance for perceptual errors, comparing human performance to an ideal standard. Diagnostic radiology in Australia has a culture of open disclosure, where full unbiased evidence from an examination is provided to the patient together with the report. This practice benefits the public by allowing genuine differences of opinion and also by allowing a second chance of correct diagnosis in cases of perceptual error. The culture of open disclosure, which is unique to diagnostic radiology, places radiologists at distinct medicolegal disadvantage compared with other specialties, (i) Perceptual error should be acknowledged as an integral inevitable part of diagnostic radiology; (ii) culture of open disclosure should be encouraged by the profession; and (iii) a pragmatic definition of medical negligence should reflect the imperfect performance of human observers Copyright (2006) Blackwell Publishing Asia Pty Ltd

  6. Evaluating a medical error taxonomy.

    OpenAIRE

    Brixey, Juliana; Johnson, Todd R.; Zhang, Jiajie

    2002-01-01

    Healthcare has been slow in using human factors principles to reduce medical errors. The Center for Devices and Radiological Health (CDRH) recognizes that a lack of attention to human factors during product development may lead to errors that have the potential for patient injury, or even death. In response to the need for reducing medication errors, the National Coordinating Council for Medication Errors Reporting and Prevention (NCC MERP) released the NCC MERP taxonomy that provides a stand...

  7. Uncertainty quantification and error analysis

    Energy Technology Data Exchange (ETDEWEB)

    Higdon, Dave M [Los Alamos National Laboratory; Anderson, Mark C [Los Alamos National Laboratory; Habib, Salman [Los Alamos National Laboratory; Klein, Richard [Los Alamos National Laboratory; Berliner, Mark [OHIO STATE UNIV.; Covey, Curt [LLNL; Ghattas, Omar [UNIV OF TEXAS; Graziani, Carlo [UNIV OF CHICAGO; Seager, Mark [LLNL; Sefcik, Joseph [LLNL; Stark, Philip [UC/BERKELEY; Stewart, James [SNL

    2010-01-01

    UQ studies all sources of error and uncertainty, including: systematic and stochastic measurement error; ignorance; limitations of theoretical models; limitations of numerical representations of those models; limitations on the accuracy and reliability of computations, approximations, and algorithms; and human error. A more precise definition for UQ is suggested below.

  8. Error Patterns in Problem Solving.

    Science.gov (United States)

    Babbitt, Beatrice C.

    Although many common problem-solving errors within the realm of school mathematics have been previously identified, a compilation of such errors is not readily available within learning disabilities textbooks, mathematics education texts, or teacher's manuals for school mathematics texts. Using data on error frequencies drawn from both the Fourth…

  9. Performance, postmodernity and errors

    DEFF Research Database (Denmark)

    Harder, Peter

    2013-01-01

    speaker’s competency (note the –y ending!) reflects adaptation to the community langue, including variations. This reversal of perspective also reverses our understanding of the relationship between structure and deviation. In the heyday of structuralism, it was tempting to confuse the invariant system...... with the prestige variety, and conflate non-standard variation with parole/performance and class both as erroneous. Nowadays the anti-structural sentiment of present-day linguistics makes it tempting to confuse the rejection of ideal abstract structure with a rejection of any distinction between grammatical...... as deviant from the perspective of function-based structure and discuss to what extent the recognition of a community langue as a source of adaptive pressure may throw light on different types of deviation, including language handicaps and learner errors....

  10. Errors in causal inference: an organizational schema for systematic error and random error.

    Science.gov (United States)

    Suzuki, Etsuji; Tsuda, Toshihide; Mitsuhashi, Toshiharu; Mansournia, Mohammad Ali; Yamamoto, Eiji

    2016-11-01

    To provide an organizational schema for systematic error and random error in estimating causal measures, aimed at clarifying the concept of errors from the perspective of causal inference. We propose to divide systematic error into structural error and analytic error. With regard to random error, our schema shows its four major sources: nondeterministic counterfactuals, sampling variability, a mechanism that generates exposure events and measurement variability. Structural error is defined from the perspective of counterfactual reasoning and divided into nonexchangeability bias (which comprises confounding bias and selection bias) and measurement bias. Directed acyclic graphs are useful to illustrate this kind of error. Nonexchangeability bias implies a lack of "exchangeability" between the selected exposed and unexposed groups. A lack of exchangeability is not a primary concern of measurement bias, justifying its separation from confounding bias and selection bias. Many forms of analytic errors result from the small-sample properties of the estimator used and vanish asymptotically. Analytic error also results from wrong (misspecified) statistical models and inappropriate statistical methods. Our organizational schema is helpful for understanding the relationship between systematic error and random error from a previously less investigated aspect, enabling us to better understand the relationship between accuracy, validity, and precision. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Effectiveness of Toyota process redesign in reducing thyroid gland fine-needle aspiration error.

    Science.gov (United States)

    Raab, Stephen S; Grzybicki, Dana Marie; Sudilovsky, Daniel; Balassanian, Ronald; Janosky, Janine E; Vrbin, Colleen M

    2006-10-01

    Our objective was to determine whether the Toyota Production System process redesign resulted in diagnostic error reduction for patients who underwent cytologic evaluation of thyroid nodules. In this longitudinal, nonconcurrent cohort study, we compared the diagnostic error frequency of a thyroid aspiration service before and after implementation of error reduction initiatives consisting of adoption of a standardized diagnostic terminology scheme and an immediate interpretation service. A total of 2,424 patients underwent aspiration. Following terminology standardization, the false-negative rate decreased from 41.8% to 19.1% (P = .006), the specimen nondiagnostic rate increased from 5.8% to 19.8% (P Toyota process change led to significantly fewer diagnostic errors for patients who underwent thyroid fine-needle aspiration.

  12. Diagnostic Hypothesis Generation and Human Judgment

    Science.gov (United States)

    Thomas, Rick P.; Dougherty, Michael R.; Sprenger, Amber M.; Harbison, J. Isaiah

    2008-01-01

    Diagnostic hypothesis-generation processes are ubiquitous in human reasoning. For example, clinicians generate disease hypotheses to explain symptoms and help guide treatment, auditors generate hypotheses for identifying sources of accounting errors, and laypeople generate hypotheses to explain patterns of information (i.e., data) in the…

  13. Controlling errors in unidosis carts

    Directory of Open Access Journals (Sweden)

    Inmaculada Díaz Fernández

    2010-01-01

    Full Text Available Objective: To identify errors in the unidosis system carts. Method: For two months, the Pharmacy Service controlled medication either returned or missing from the unidosis carts both in the pharmacy and in the wards. Results: Uncorrected unidosis carts show a 0.9% of medication errors (264 versus 0.6% (154 which appeared in unidosis carts previously revised. In carts not revised, the error is 70.83% and mainly caused when setting up unidosis carts. The rest are due to a lack of stock or unavailability (21.6%, errors in the transcription of medical orders (6.81% or that the boxes had not been emptied previously (0.76%. The errors found in the units correspond to errors in the transcription of the treatment (3.46%, non-receipt of the unidosis copy (23.14%, the patient did not take the medication (14.36%or was discharged without medication (12.77%, was not provided by nurses (14.09%, was withdrawn from the stocks of the unit (14.62%, and errors of the pharmacy service (17.56% . Conclusions: It is concluded the need to redress unidosis carts and a computerized prescription system to avoid errors in transcription.Discussion: A high percentage of medication errors is caused by human error. If unidosis carts are overlooked before sent to hospitalization units, the error diminishes to 0.3%.

  14. Prioritising interventions against medication errors

    DEFF Research Database (Denmark)

    Lisby, Marianne; Pape-Larsen, Louise; Sørensen, Ann Lykkegaard

    errors are therefore needed. Development of definition: A definition of medication errors including an index of error types for each stage in the medication process was developed from existing terminology and through a modified Delphi-process in 2008. The Delphi panel consisted of 25 interdisciplinary......Abstract Authors: Lisby M, Larsen LP, Soerensen AL, Nielsen LP, Mainz J Title: Prioritising interventions against medication errors – the importance of a definition Objective: To develop and test a restricted definition of medication errors across health care settings in Denmark Methods: Medication...... errors constitute a major quality and safety problem in modern healthcare. However, far from all are clinically important. The prevalence of medication errors ranges from 2-75% indicating a global problem in defining and measuring these [1]. New cut-of levels focusing the clinical impact of medication...

  15. Social aspects of clinical errors.

    Science.gov (United States)

    Richman, Joel; Mason, Tom; Mason-Whitehead, Elizabeth; McIntosh, Annette; Mercer, Dave

    2009-08-01

    Clinical errors, whether committed by doctors, nurses or other professions allied to healthcare, remain a sensitive issue requiring open debate and policy formulation in order to reduce them. The literature suggests that the issues underpinning errors made by healthcare professionals involve concerns about patient safety, professional disclosure, apology, litigation, compensation, processes of recording and policy development to enhance quality service. Anecdotally, we are aware of narratives of minor errors, which may well have been covered up and remain officially undisclosed whilst the major errors resulting in damage and death to patients alarm both professionals and public with resultant litigation and compensation. This paper attempts to unravel some of these issues by highlighting the historical nature of clinical errors and drawing parallels to contemporary times by outlining the 'compensation culture'. We then provide an overview of what constitutes a clinical error and review the healthcare professional strategies for managing such errors.

  16. Philosophy of science and the diagnostic process.

    Science.gov (United States)

    Willis, Brian H; Beebee, Helen; Lasserson, Daniel S

    2013-10-01

    This is an overview of the principles that underpin philosophy of science and how they may provide a framework for the diagnostic process. Although philosophy dates back to antiquity, it is only more recently that philosophers have begun to enunciate the scientific method. Since Aristotle formulated deduction, other modes of reasoning including induction, inference to best explanation, falsificationism, theory-laden observations and Bayesian inference have emerged. Thus, rather than representing a single overriding dogma, the scientific method is a toolkit of ideas and principles of reasoning. Here we demonstrate that the diagnostic process is an example of science in action and is therefore subject to the principles encompassed by the scientific method. Although a number of the different forms of reasoning are used readily by clinicians in practice, without a clear understanding of their pitfalls and the assumptions on which they are based, it leaves doctors open to diagnostic error. We conclude by providing a case example from the medico-legal literature in which diagnostic errors were made, to illustrate how applying the scientific method may mitigate the chance for diagnostic error.

  17. Errors in clinical laboratories or errors in laboratory medicine?

    Science.gov (United States)

    Plebani, Mario

    2006-01-01

    Laboratory testing is a highly complex process and, although laboratory services are relatively safe, they are not as safe as they could or should be. Clinical laboratories have long focused their attention on quality control methods and quality assessment programs dealing with analytical aspects of testing. However, a growing body of evidence accumulated in recent decades demonstrates that quality in clinical laboratories cannot be assured by merely focusing on purely analytical aspects. The more recent surveys on errors in laboratory medicine conclude that in the delivery of laboratory testing, mistakes occur more frequently before (pre-analytical) and after (post-analytical) the test has been performed. Most errors are due to pre-analytical factors (46-68.2% of total errors), while a high error rate (18.5-47% of total errors) has also been found in the post-analytical phase. Errors due to analytical problems have been significantly reduced over time, but there is evidence that, particularly for immunoassays, interference may have a serious impact on patients. A description of the most frequent and risky pre-, intra- and post-analytical errors and advice on practical steps for measuring and reducing the risk of errors is therefore given in the present paper. Many mistakes in the Total Testing Process are called "laboratory errors", although these may be due to poor communication, action taken by others involved in the testing process (e.g., physicians, nurses and phlebotomists), or poorly designed processes, all of which are beyond the laboratory's control. Likewise, there is evidence that laboratory information is only partially utilized. A recent document from the International Organization for Standardization (ISO) recommends a new, broader definition of the term "laboratory error" and a classification of errors according to different criteria. In a modern approach to total quality, centered on patients' needs and satisfaction, the risk of errors and mistakes

  18. Lectures in plasma diagnostics

    International Nuclear Information System (INIS)

    Hutchinson, I.H.

    1990-06-01

    This paper discusses the following topics on plasma diagnostics: Electric probes in flowing and magnetized plasmas; Electron cyclotron emission absorption; Magnetic diagnostics; Spectroscopy; and Thomson Scattering

  19. Errors in abdominal computed tomography

    International Nuclear Information System (INIS)

    Stephens, S.; Marting, I.; Dixon, A.K.

    1989-01-01

    Sixty-nine patients are presented in whom a substantial error was made on the initial abdominal computed tomography report. Certain features of these errors have been analysed. In 30 (43.5%) a lesion was simply not recognised (error of observation); in 39 (56.5%) the wrong conclusions were drawn about the nature of normal or abnormal structures (error of interpretation). The 39 errors of interpretation were more complex; in 7 patients an abnormal structure was noted but interpreted as normal, whereas in four a normal structure was thought to represent a lesion. Other interpretive errors included those where the wrong cause for a lesion had been ascribed (24 patients), and those where the abnormality was substantially under-reported (4 patients). Various features of these errors are presented and discussed. Errors were made just as often in relation to small and large lesions. Consultants made as many errors as senior registrar radiologists. It is like that dual reporting is the best method of avoiding such errors and, indeed, this is widely practised in our unit. (Author). 9 refs.; 5 figs.; 1 tab

  20. Laboratory errors and patient safety.

    Science.gov (United States)

    Miligy, Dawlat A

    2015-01-01

    Laboratory data are extensively used in medical practice; consequently, laboratory errors have a tremendous impact on patient safety. Therefore, programs designed to identify and reduce laboratory errors, as well as, setting specific strategies are required to minimize these errors and improve patient safety. The purpose of this paper is to identify part of the commonly encountered laboratory errors throughout our practice in laboratory work, their hazards on patient health care and some measures and recommendations to minimize or to eliminate these errors. Recording the encountered laboratory errors during May 2008 and their statistical evaluation (using simple percent distribution) have been done in the department of laboratory of one of the private hospitals in Egypt. Errors have been classified according to the laboratory phases and according to their implication on patient health. Data obtained out of 1,600 testing procedure revealed that the total number of encountered errors is 14 tests (0.87 percent of total testing procedures). Most of the encountered errors lay in the pre- and post-analytic phases of testing cycle (representing 35.7 and 50 percent, respectively, of total errors). While the number of test errors encountered in the analytic phase represented only 14.3 percent of total errors. About 85.7 percent of total errors were of non-significant implication on patients health being detected before test reports have been submitted to the patients. On the other hand, the number of test errors that have been already submitted to patients and reach the physician represented 14.3 percent of total errors. Only 7.1 percent of the errors could have an impact on patient diagnosis. The findings of this study were concomitant with those published from the USA and other countries. This proves that laboratory problems are universal and need general standardization and bench marking measures. Original being the first data published from Arabic countries that

  1. Comparing diagnostic tests on benefit-risk.

    Science.gov (United States)

    Pennello, Gene; Pantoja-Galicia, Norberto; Evans, Scott

    2016-01-01

    Comparing diagnostic tests on accuracy alone can be inconclusive. For example, a test may have better sensitivity than another test yet worse specificity. Comparing tests on benefit risk may be more conclusive because clinical consequences of diagnostic error are considered. For benefit-risk evaluation, we propose diagnostic yield, the expected distribution of subjects with true positive, false positive, true negative, and false negative test results in a hypothetical population. We construct a table of diagnostic yield that includes the number of false positive subjects experiencing adverse consequences from unnecessary work-up. We then develop a decision theory for evaluating tests. The theory provides additional interpretation to quantities in the diagnostic yield table. It also indicates that the expected utility of a test relative to a perfect test is a weighted accuracy measure, the average of sensitivity and specificity weighted for prevalence and relative importance of false positive and false negative testing errors, also interpretable as the cost-benefit ratio of treating non-diseased and diseased subjects. We propose plots of diagnostic yield, weighted accuracy, and relative net benefit of tests as functions of prevalence or cost-benefit ratio. Concepts are illustrated with hypothetical screening tests for colorectal cancer with test positive subjects being referred to colonoscopy.

  2. Dopamine reward prediction error coding.

    Science.gov (United States)

    Schultz, Wolfram

    2016-03-01

    Reward prediction errors consist of the differences between received and predicted rewards. They are crucial for basic forms of learning about rewards and make us strive for more rewards-an evolutionary beneficial trait. Most dopamine neurons in the midbrain of humans, monkeys, and rodents signal a reward prediction error; they are activated by more reward than predicted (positive prediction error), remain at baseline activity for fully predicted rewards, and show depressed activity with less reward than predicted (negative prediction error). The dopamine signal increases nonlinearly with reward value and codes formal economic utility. Drugs of addiction generate, hijack, and amplify the dopamine reward signal and induce exaggerated, uncontrolled dopamine effects on neuronal plasticity. The striatum, amygdala, and frontal cortex also show reward prediction error coding, but only in subpopulations of neurons. Thus, the important concept of reward prediction errors is implemented in neuronal hardware.

  3. Statistical errors in Monte Carlo estimates of systematic errors

    Science.gov (United States)

    Roe, Byron P.

    2007-01-01

    For estimating the effects of a number of systematic errors on a data sample, one can generate Monte Carlo (MC) runs with systematic parameters varied and examine the change in the desired observed result. Two methods are often used. In the unisim method, the systematic parameters are varied one at a time by one standard deviation, each parameter corresponding to a MC run. In the multisim method (see ), each MC run has all of the parameters varied; the amount of variation is chosen from the expected distribution of each systematic parameter, usually assumed to be a normal distribution. The variance of the overall systematic error determination is derived for each of the two methods and comparisons are made between them. If one focuses not on the error in the prediction of an individual systematic error, but on the overall error due to all systematic errors in the error matrix element in data bin m, the number of events needed is strongly reduced because of the averaging effect over all of the errors. For simple models presented here the multisim model was far better if the statistical error in the MC samples was larger than an individual systematic error, while for the reverse case, the unisim model was better. Exact formulas and formulas for the simple toy models are presented so that realistic calculations can be made. The calculations in the present note are valid if the errors are in a linear region. If that region extends sufficiently far, one can have the unisims or multisims correspond to k standard deviations instead of one. This reduces the number of events required by a factor of k2. The specific terms unisim and multisim were coined by Peter Meyers and Steve Brice, respectively, for the MiniBooNE experiment. However, the concepts have been developed over time and have been in general use for some time.

  4. Statistical errors in Monte Carlo estimates of systematic errors

    Energy Technology Data Exchange (ETDEWEB)

    Roe, Byron P. [Department of Physics, University of Michigan, Ann Arbor, MI 48109 (United States)]. E-mail: byronroe@umich.edu

    2007-01-01

    For estimating the effects of a number of systematic errors on a data sample, one can generate Monte Carlo (MC) runs with systematic parameters varied and examine the change in the desired observed result. Two methods are often used. In the unisim method, the systematic parameters are varied one at a time by one standard deviation, each parameter corresponding to a MC run. In the multisim method (see ), each MC run has all of the parameters varied; the amount of variation is chosen from the expected distribution of each systematic parameter, usually assumed to be a normal distribution. The variance of the overall systematic error determination is derived for each of the two methods and comparisons are made between them. If one focuses not on the error in the prediction of an individual systematic error, but on the overall error due to all systematic errors in the error matrix element in data bin m, the number of events needed is strongly reduced because of the averaging effect over all of the errors. For simple models presented here the multisim model was far better if the statistical error in the MC samples was larger than an individual systematic error, while for the reverse case, the unisim model was better. Exact formulas and formulas for the simple toy models are presented so that realistic calculations can be made. The calculations in the present note are valid if the errors are in a linear region. If that region extends sufficiently far, one can have the unisims or multisims correspond to k standard deviations instead of one. This reduces the number of events required by a factor of k{sup 2}.

  5. Statistical errors in Monte Carlo estimates of systematic errors

    International Nuclear Information System (INIS)

    Roe, Byron P.

    2007-01-01

    For estimating the effects of a number of systematic errors on a data sample, one can generate Monte Carlo (MC) runs with systematic parameters varied and examine the change in the desired observed result. Two methods are often used. In the unisim method, the systematic parameters are varied one at a time by one standard deviation, each parameter corresponding to a MC run. In the multisim method (see ), each MC run has all of the parameters varied; the amount of variation is chosen from the expected distribution of each systematic parameter, usually assumed to be a normal distribution. The variance of the overall systematic error determination is derived for each of the two methods and comparisons are made between them. If one focuses not on the error in the prediction of an individual systematic error, but on the overall error due to all systematic errors in the error matrix element in data bin m, the number of events needed is strongly reduced because of the averaging effect over all of the errors. For simple models presented here the multisim model was far better if the statistical error in the MC samples was larger than an individual systematic error, while for the reverse case, the unisim model was better. Exact formulas and formulas for the simple toy models are presented so that realistic calculations can be made. The calculations in the present note are valid if the errors are in a linear region. If that region extends sufficiently far, one can have the unisims or multisims correspond to k standard deviations instead of one. This reduces the number of events required by a factor of k 2

  6. Multicenter Assessment of Gram Stain Error Rates.

    Science.gov (United States)

    Samuel, Linoj P; Balada-Llasat, Joan-Miquel; Harrington, Amanda; Cavagnolo, Robert

    2016-06-01

    Gram stains remain the cornerstone of diagnostic testing in the microbiology laboratory for the guidance of empirical treatment prior to availability of culture results. Incorrectly interpreted Gram stains may adversely impact patient care, and yet there are no comprehensive studies that have evaluated the reliability of the technique and there are no established standards for performance. In this study, clinical microbiology laboratories at four major tertiary medical care centers evaluated Gram stain error rates across all nonblood specimen types by using standardized criteria. The study focused on several factors that primarily contribute to errors in the process, including poor specimen quality, smear preparation, and interpretation of the smears. The number of specimens during the evaluation period ranged from 976 to 1,864 specimens per site, and there were a total of 6,115 specimens. Gram stain results were discrepant from culture for 5% of all specimens. Fifty-eight percent of discrepant results were specimens with no organisms reported on Gram stain but significant growth on culture, while 42% of discrepant results had reported organisms on Gram stain that were not recovered in culture. Upon review of available slides, 24% (63/263) of discrepant results were due to reader error, which varied significantly based on site (9% to 45%). The Gram stain error rate also varied between sites, ranging from 0.4% to 2.7%. The data demonstrate a significant variability between laboratories in Gram stain performance and affirm the need for ongoing quality assessment by laboratories. Standardized monitoring of Gram stains is an essential quality control tool for laboratories and is necessary for the establishment of a quality benchmark across laboratories. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  7. Analysis of errors in spectral reconstruction with a Laplace transform pair model

    International Nuclear Information System (INIS)

    Archer, B.R.; Bushong, S.C.

    1985-01-01

    The sensitivity of a Laplace transform pair model for spectral reconstruction to random errors in attenuation measurements of diagnostic x-ray units has been investigated. No spectral deformation or significant alteration resulted from the simulated attenuation errors. It is concluded that the range of spectral uncertainties to be expected from the application of this model is acceptable for most scientific applications. (author)

  8. Architecture design for soft errors

    CERN Document Server

    Mukherjee, Shubu

    2008-01-01

    This book provides a comprehensive description of the architetural techniques to tackle the soft error problem. It covers the new methodologies for quantitative analysis of soft errors as well as novel, cost-effective architectural techniques to mitigate them. To provide readers with a better grasp of the broader problem deffinition and solution space, this book also delves into the physics of soft errors and reviews current circuit and software mitigation techniques.

  9. Dopamine reward prediction error coding

    OpenAIRE

    Schultz, Wolfram

    2016-01-01

    Reward prediction errors consist of the differences between received and predicted rewards. They are crucial for basic forms of learning about rewards and make us strive for more rewards?an evolutionary beneficial trait. Most dopamine neurons in the midbrain of humans, monkeys, and rodents signal a reward prediction error; they are activated by more reward than predicted (positive prediction error), remain at baseline activity for fully predicted rewards, and show depressed activity with less...

  10. Identifying Error in AUV Communication

    National Research Council Canada - National Science Library

    Coleman, Joseph; Merrill, Kaylani; O'Rourke, Michael; Rajala, Andrew G; Edwards, Dean B

    2006-01-01

    Mine Countermeasures (MCM) involving Autonomous Underwater Vehicles (AUVs) are especially susceptible to error, given the constraints on underwater acoustic communication and the inconstancy of the underwater communication channel...

  11. Human Errors in Decision Making

    OpenAIRE

    Mohamad, Shahriari; Aliandrina, Dessy; Feng, Yan

    2005-01-01

    The aim of this paper was to identify human errors in decision making process. The study was focused on a research question such as: what could be the human error as a potential of decision failure in evaluation of the alternatives in the process of decision making. Two case studies were selected from the literature and analyzed to find the human errors contribute to decision fail. Then the analysis of human errors was linked with mental models in evaluation of alternative step. The results o...

  12. Finding beam focus errors automatically

    International Nuclear Information System (INIS)

    Lee, M.J.; Clearwater, S.H.; Kleban, S.D.

    1987-01-01

    An automated method for finding beam focus errors using an optimization program called COMFORT-PLUS. The steps involved in finding the correction factors using COMFORT-PLUS has been used to find the beam focus errors for two damping rings at the SLAC Linear Collider. The program is to be used as an off-line program to analyze actual measured data for any SLC system. A limitation on the application of this procedure is found to be that it depends on the magnitude of the machine errors. Another is that the program is not totally automated since the user must decide a priori where to look for errors

  13. Heuristic errors in clinical reasoning.

    Science.gov (United States)

    Rylander, Melanie; Guerrasio, Jeannette

    2016-08-01

    Errors in clinical reasoning contribute to patient morbidity and mortality. The purpose of this study was to determine the types of heuristic errors made by third-year medical students and first-year residents. This study surveyed approximately 150 clinical educators inquiring about the types of heuristic errors they observed in third-year medical students and first-year residents. Anchoring and premature closure were the two most common errors observed amongst third-year medical students and first-year residents. There was no difference in the types of errors observed in the two groups. Errors in clinical reasoning contribute to patient morbidity and mortality Clinical educators perceived that both third-year medical students and first-year residents committed similar heuristic errors, implying that additional medical knowledge and clinical experience do not affect the types of heuristic errors made. Further work is needed to help identify methods that can be used to reduce heuristic errors early in a clinician's education. © 2015 John Wiley & Sons Ltd.

  14. A Hybrid Unequal Error Protection / Unequal Error Resilience ...

    African Journals Online (AJOL)

    The quality layers are then assigned an Unequal Error Resilience to synchronization loss by unequally allocating the number of headers available for synchronization to them. Following that Unequal Error Protection against channel noise is provided to the layers by the use of Rate Compatible Punctured Convolutional ...

  15. DIAGNOSTIC OF CNC LATHE WITH QC 20 BALLBAR SYSTEM

    Directory of Open Access Journals (Sweden)

    Jerzy Józwik

    2015-11-01

    Full Text Available This paper presents the evaluation of the influence of the feedmotion speed on the value of selected geometric errors of CNC lathe CTX 310 eco by DMG, indentified by QC 20 Ballbar system. Diagnostically evaluated were: the deviation of the axis squareness, reversal spike, and backlash. These errors determine the forming of the dimensional and shape accuracy of a machine tool. The article discusses the process of the CNC diagnostic test, the diagnostic evaluation and formulates guidelines on further CNC operation. The results of measurements were presented in tables and diagrams.

  16. Error studies for SNS Linac. Part 1: Transverse errors

    International Nuclear Information System (INIS)

    Crandall, K.R.

    1998-01-01

    The SNS linac consist of a radio-frequency quadrupole (RFQ), a drift-tube linac (DTL), a coupled-cavity drift-tube linac (CCDTL) and a coupled-cavity linac (CCL). The RFQ and DTL are operated at 402.5 MHz; the CCDTL and CCL are operated at 805 MHz. Between the RFQ and DTL is a medium-energy beam-transport system (MEBT). This error study is concerned with the DTL, CCDTL and CCL, and each will be analyzed separately. In fact, the CCL is divided into two sections, and each of these will be analyzed separately. The types of errors considered here are those that affect the transverse characteristics of the beam. The errors that cause the beam center to be displaced from the linac axis are quad displacements and quad tilts. The errors that cause mismatches are quad gradient errors and quad rotations (roll)

  17. Error begat error: design error analysis and prevention in social infrastructure projects.

    Science.gov (United States)

    Love, Peter E D; Lopez, Robert; Edwards, David J; Goh, Yang M

    2012-09-01

    Design errors contribute significantly to cost and schedule growth in social infrastructure projects and to engineering failures, which can result in accidents and loss of life. Despite considerable research that has addressed their error causation in construction projects they still remain prevalent. This paper identifies the underlying conditions that contribute to design errors in social infrastructure projects (e.g. hospitals, education, law and order type buildings). A systemic model of error causation is propagated and subsequently used to develop a learning framework for design error prevention. The research suggests that a multitude of strategies should be adopted in congruence to prevent design errors from occurring and so ensure that safety and project performance are ameliorated. Copyright © 2011. Published by Elsevier Ltd.

  18. Disclosing harmful medical errors to patients: tackling three tough cases.

    Science.gov (United States)

    Gallagher, Thomas H; Bell, Sigall K; Smith, Kelly M; Mello, Michelle M; McDonald, Timothy B

    2009-09-01

    A gap exists between recommendations to disclose errors to patients and current practice. This gap may reflect important, yet unanswered questions about implementing disclosure principles. We explore some of these unanswered questions by presenting three real cases that pose challenging disclosure dilemmas. The first case involves a pancreas transplant that failed due to the pancreas graft being discarded, an error that was not disclosed partly because the family did not ask clarifying questions. Relying on patient or family questions to determine the content of disclosure is problematic. We propose a standard of materiality that can help clinicians to decide what information to disclose. The second case involves a fatal diagnostic error that the patient's widower was unaware had happened. The error was not disclosed out of concern that disclosure would cause the widower more harm than good. This case highlights how institutions can overlook patients' and families' needs following errors and emphasizes that benevolent deception has little role in disclosure. Institutions should consider whether involving neutral third parties could make disclosures more patient centered. The third case presents an intraoperative cardiac arrest due to a large air embolism where uncertainty around the clinical event was high and complicated the disclosure. Uncertainty is common to many medical errors but should not deter open conversations with patients and families about what is and is not known about the event. Continued discussion within the medical profession about applying disclosure principles to real-world cases can help to better meet patients' and families' needs following medical errors.

  19. Errors of logic and scholarship concerning dissociative identity disorder.

    Science.gov (United States)

    Ross, Colin A

    2009-01-01

    The author reviewed a two-part critique of dissociative identity disorder published in the Canadian Journal of Psychiatry. The two papers contain errors of logic and scholarship. Contrary to the conclusions in the critique, dissociative identity disorder has established diagnostic reliability and concurrent validity, the trauma histories of affected individuals can be corroborated, and the existing prospective treatment outcome literature demonstrates improvement in individuals receiving psychotherapy for the disorder. The available evidence supports the inclusion of dissociative identity disorder in future editions of the Diagnostic and Statistical Manual of Mental Disorders.

  20. Barriers to medical error reporting

    Directory of Open Access Journals (Sweden)

    Jalal Poorolajal

    2015-01-01

    Full Text Available Background: This study was conducted to explore the prevalence of medical error underreporting and associated barriers. Methods: This cross-sectional study was performed from September to December 2012. Five hospitals, affiliated with Hamadan University of Medical Sciences, in Hamedan,Iran were investigated. A self-administered questionnaire was used for data collection. Participants consisted of physicians, nurses, midwives, residents, interns, and staffs of radiology and laboratory departments. Results: Overall, 50.26% of subjects had committed but not reported medical errors. The main reasons mentioned for underreporting were lack of effective medical error reporting system (60.0%, lack of proper reporting form (51.8%, lack of peer supporting a person who has committed an error (56.0%, and lack of personal attention to the importance of medical errors (62.9%. The rate of committing medical errors was higher in men (71.4%, age of 50-40 years (67.6%, less-experienced personnel (58.7%, educational level of MSc (87.5%, and staff of radiology department (88.9%. Conclusions: This study outlined the main barriers to reporting medical errors and associated factors that may be helpful for healthcare organizations in improving medical error reporting as an essential component for patient safety enhancement.

  1. Pharyngitis – fatal infectious disease or medical error?

    Directory of Open Access Journals (Sweden)

    Marta Rorat

    2015-08-01

    Full Text Available Reporting on adverse events is essential to create a culture of safety, which focuses on protecting doctors and patients from medical errors. We present a fatal case of Streptococcus C pharyngitis in a 56-year-old man. The clinical course and the results of additional diagnostics and autopsy showed that sepsis followed by multiple organ failure was the ultimate cause of death. The clinical course appeared fatal due to a chain of adverse events, including errors made by the physicians caring for the patient for 10 days.

  2. Diagnostic reasoning strategies and diagnostic success.

    Science.gov (United States)

    Coderre, S; Mandin, H; Harasym, P H; Fick, G H

    2003-08-01

    Cognitive psychology research supports the notion that experts use mental frameworks or "schemes", both to organize knowledge in memory and to solve clinical problems. The central purpose of this study was to determine the relationship between problem-solving strategies and the likelihood of diagnostic success. Think-aloud protocols were collected to determine the diagnostic reasoning used by experts and non-experts when attempting to diagnose clinical presentations in gastroenterology. Using logistic regression analysis, the study found that there is a relationship between diagnostic reasoning strategy and the likelihood of diagnostic success. Compared to hypothetico-deductive reasoning, the odds of diagnostic success were significantly greater when subjects used the diagnostic strategies of pattern recognition and scheme-inductive reasoning. Two other factors emerged as independent determinants of diagnostic success: expertise and clinical presentation. Not surprisingly, experts outperformed novices, while the content area of the clinical cases in each of the four clinical presentations demonstrated varying degrees of difficulty and thus diagnostic success. These findings have significant implications for medical educators. It supports the introduction of "schemes" as a means of enhancing memory organization and improving diagnostic success.

  3. A theory of human error

    Science.gov (United States)

    Mcruer, D. T.; Clement, W. F.; Allen, R. W.

    1981-01-01

    Human errors tend to be treated in terms of clinical and anecdotal descriptions, from which remedial measures are difficult to derive. Correction of the sources of human error requires an attempt to reconstruct underlying and contributing causes of error from the circumstantial causes cited in official investigative reports. A comprehensive analytical theory of the cause-effect relationships governing propagation of human error is indispensable to a reconstruction of the underlying and contributing causes. A validated analytical theory of the input-output behavior of human operators involving manual control, communication, supervisory, and monitoring tasks which are relevant to aviation, maritime, automotive, and process control operations is highlighted. This theory of behavior, both appropriate and inappropriate, provides an insightful basis for investigating, classifying, and quantifying the needed cause-effect relationships governing propagation of human error.

  4. Technical errors in planar bone scanning.

    Science.gov (United States)

    Naddaf, Sleiman Y; Collier, B David; Elgazzar, Abdelhamid H; Khalil, Magdy M

    2004-09-01

    Optimal technique for planar bone scanning improves image quality, which in turn improves diagnostic efficacy. Because planar bone scanning is one of the most frequently performed nuclear medicine examinations, maintaining high standards for this examination is a daily concern for most nuclear medicine departments. Although some problems such as patient motion are frequently encountered, the degraded images produced by many other deviations from optimal technique are rarely seen in clinical practice and therefore may be difficult to recognize. The objectives of this article are to list optimal techniques for 3-phase and whole-body bone scanning, to describe and illustrate a selection of deviations from these optimal techniques for planar bone scanning, and to explain how to minimize or avoid such technical errors.

  5. Diagnostic Reasoning and Cognitive Biases of Nurse Practitioners.

    Science.gov (United States)

    Lawson, Thomas N

    2018-04-01

    Diagnostic reasoning is often used colloquially to describe the process by which nurse practitioners and physicians come to the correct diagnosis, but a rich definition and description of this process has been lacking in the nursing literature. A literature review was conducted with theoretical sampling seeking conceptual insight into diagnostic reasoning. Four common themes emerged: Cognitive Biases and Debiasing Strategies, the Dual Process Theory, Diagnostic Error, and Patient Harm. Relevant cognitive biases are discussed, followed by debiasing strategies and application of the dual process theory to reduce diagnostic error and harm. The accuracy of diagnostic reasoning of nurse practitioners may be improved by incorporating these items into nurse practitioner education and practice. [J Nurs Educ. 2018;57(4):203-208.]. Copyright 2018, SLACK Incorporated.

  6. Errors, error detection, error correction and hippocampal-region damage: data and theories.

    Science.gov (United States)

    MacKay, Donald G; Johnson, Laura W

    2013-11-01

    This review and perspective article outlines 15 observational constraints on theories of errors, error detection, and error correction, and their relation to hippocampal-region (HR) damage. The core observations come from 10 studies with H.M., an amnesic with cerebellar and HR damage but virtually no neocortical damage. Three studies examined the detection of errors planted in visual scenes (e.g., a bird flying in a fish bowl in a school classroom) and sentences (e.g., I helped themselves to the birthday cake). In all three experiments, H.M. detected reliably fewer errors than carefully matched memory-normal controls. Other studies examined the detection and correction of self-produced errors, with controls for comprehension of the instructions, impaired visual acuity, temporal factors, motoric slowing, forgetting, excessive memory load, lack of motivation, and deficits in visual scanning or attention. In these studies, H.M. corrected reliably fewer errors than memory-normal and cerebellar controls, and his uncorrected errors in speech, object naming, and reading aloud exhibited two consistent features: omission and anomaly. For example, in sentence production tasks, H.M. omitted one or more words in uncorrected encoding errors that rendered his sentences anomalous (incoherent, incomplete, or ungrammatical) reliably more often than controls. Besides explaining these core findings, the theoretical principles discussed here explain H.M.'s retrograde amnesia for once familiar episodic and semantic information; his anterograde amnesia for novel information; his deficits in visual cognition, sentence comprehension, sentence production, sentence reading, and object naming; and effects of aging on his ability to read isolated low frequency words aloud. These theoretical principles also explain a wide range of other data on error detection and correction and generate new predictions for future test. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Human errors in NPP operations

    International Nuclear Information System (INIS)

    Sheng Jufang

    1993-01-01

    Based on the operational experiences of nuclear power plants (NPPs), the importance of studying human performance problems is described. Statistical analysis on the significance or frequency of various root-causes and error-modes from a large number of human-error-related events demonstrate that the defects in operation/maintenance procedures, working place factors, communication and training practices are primary root-causes, while omission, transposition, quantitative mistake are the most frequent among the error-modes. Recommendations about domestic research on human performance problem in NPPs are suggested

  8. Linear network error correction coding

    CERN Document Server

    Guang, Xuan

    2014-01-01

    There are two main approaches in the theory of network error correction coding. In this SpringerBrief, the authors summarize some of the most important contributions following the classic approach, which represents messages by sequences?similar to algebraic coding,?and also briefly discuss the main results following the?other approach,?that uses the theory of rank metric codes for network error correction of representing messages by subspaces. This book starts by establishing the basic linear network error correction (LNEC) model and then characterizes two equivalent descriptions. Distances an

  9. Error field considerations for BPX

    International Nuclear Information System (INIS)

    LaHaye, R.J.

    1992-01-01

    Irregularities in the position of poloidal and/or toroidal field coils in tokamaks produce resonant toroidal asymmetries in the vacuum magnetic fields. Otherwise stable tokamak discharges become non-linearly unstable to disruptive locked modes when subjected to low level error fields. Because of the field errors, magnetic islands are produced which would not otherwise occur in tearing mode table configurations; a concomitant reduction of the total confinement can result. Poloidal and toroidal asymmetries arise in the heat flux to the divertor target. In this paper, the field errors from perturbed BPX coils are used in a field line tracing code of the BPX equilibrium to study these deleterious effects. Limits on coil irregularities for device design and fabrication are computed along with possible correcting coils for reducing such field errors

  10. The uncorrected refractive error challenge

    Directory of Open Access Journals (Sweden)

    Kovin Naidoo

    2016-11-01

    Full Text Available Refractive error affects people of all ages, socio-economic status and ethnic groups. The most recent statistics estimate that, worldwide, 32.4 million people are blind and 191 million people have vision impairment. Vision impairment has been defined based on distance visual acuity only, and uncorrected distance refractive error (mainly myopia is the single biggest cause of worldwide vision impairment. However, when we also consider near visual impairment, it is clear that even more people are affected. From research it was estimated that the number of people with vision impairment due to uncorrected distance refractive error was 107.8 million,1 and the number of people affected by uncorrected near refractive error was 517 million, giving a total of 624.8 million people.

  11. Quantile Regression With Measurement Error

    KAUST Repository

    Wei, Ying

    2009-08-27

    Regression quantiles can be substantially biased when the covariates are measured with error. In this paper we propose a new method that produces consistent linear quantile estimation in the presence of covariate measurement error. The method corrects the measurement error induced bias by constructing joint estimating equations that simultaneously hold for all the quantile levels. An iterative EM-type estimation algorithm to obtain the solutions to such joint estimation equations is provided. The finite sample performance of the proposed method is investigated in a simulation study, and compared to the standard regression calibration approach. Finally, we apply our methodology to part of the National Collaborative Perinatal Project growth data, a longitudinal study with an unusual measurement error structure. © 2009 American Statistical Association.

  12. Comprehensive Error Rate Testing (CERT)

    Data.gov (United States)

    U.S. Department of Health & Human Services — The Centers for Medicare and Medicaid Services (CMS) implemented the Comprehensive Error Rate Testing (CERT) program to measure improper payments in the Medicare...

  13. Numerical optimization with computational errors

    CERN Document Server

    Zaslavski, Alexander J

    2016-01-01

    This book studies the approximate solutions of optimization problems in the presence of computational errors. A number of results are presented on the convergence behavior of algorithms in a Hilbert space; these algorithms are examined taking into account computational errors. The author illustrates that algorithms generate a good approximate solution, if computational errors are bounded from above by a small positive constant. Known computational errors are examined with the aim of determining an approximate solution. Researchers and students interested in the optimization theory and its applications will find this book instructive and informative. This monograph contains 16 chapters; including a chapters devoted to the subgradient projection algorithm, the mirror descent algorithm, gradient projection algorithm, the Weiszfelds method, constrained convex minimization problems, the convergence of a proximal point method in a Hilbert space, the continuous subgradient method, penalty methods and Newton’s meth...

  14. Looking for trouble? Diagnostics expanding disease and producing patients.

    Science.gov (United States)

    Hofmann, Bjørn

    2018-05-23

    Novel tests give great opportunities for earlier and more precise diagnostics. At the same time, new tests expand disease, produce patients, and cause unnecessary harm in overdiagnosis and overtreatment. How can we evaluate diagnostics to obtain the benefits and avoid harm? One way is to pay close attention to the diagnostic process and its core concepts. Doing so reveals 3 errors that expand disease and increase overdiagnosis. The first error is to decouple diagnostics from harm, eg, by diagnosing insignificant conditions. The second error is to bypass proper validation of the relationship between test indicator and disease, eg, by introducing biomarkers for Alzheimer's disease before the tests are properly validated. The third error is to couple the name of disease to insignificant or indecisive indicators, eg, by lending the cancer name to preconditions, such as ductal carcinoma in situ. We need to avoid these errors to promote beneficial testing, bar harmful diagnostics, and evade unwarranted expansion of disease. Accordingly, we must stop identifying and testing for conditions that are only remotely associated with harm. We need more stringent verification of tests, and we must avoid naming indicators and indicative conditions after diseases. If not, we will end like ancient tragic heroes, succumbing because of our very best abilities. © 2018 John Wiley & Sons, Ltd.

  15. Procedures in diagnostic radiology

    International Nuclear Information System (INIS)

    Doyle, T.; Hare, W.S.C.; Thomson, K.; Tess, B.

    1989-01-01

    This book outlines the various procedures necessary for the successful practice of diagnostic radiology. Topics covered are: general principles, imaging of the urinary and gastrointestinal tracts, vascular radiology, arthrography, and miscellaneous diagnostic radiologic procedures

  16. Diagnostic Algorithm Benchmarking

    Science.gov (United States)

    Poll, Scott

    2011-01-01

    A poster for the NASA Aviation Safety Program Annual Technical Meeting. It describes empirical benchmarking on diagnostic algorithms using data from the ADAPT Electrical Power System testbed and a diagnostic software framework.

  17. Error correcting coding for OTN

    DEFF Research Database (Denmark)

    Justesen, Jørn; Larsen, Knud J.; Pedersen, Lars A.

    2010-01-01

    Forward error correction codes for 100 Gb/s optical transmission are currently receiving much attention from transport network operators and technology providers. We discuss the performance of hard decision decoding using product type codes that cover a single OTN frame or a small number...... of such frames. In particular we argue that a three-error correcting BCH is the best choice for the component code in such systems....

  18. Negligence, genuine error, and litigation

    OpenAIRE

    Sohn DH

    2013-01-01

    David H SohnDepartment of Orthopedic Surgery, University of Toledo Medical Center, Toledo, OH, USAAbstract: Not all medical injuries are the result of negligence. In fact, most medical injuries are the result either of the inherent risk in the practice of medicine, or due to system errors, which cannot be prevented simply through fear of disciplinary action. This paper will discuss the differences between adverse events, negligence, and system errors; the current medical malpractice tort syst...

  19. Eliminating US hospital medical errors.

    Science.gov (United States)

    Kumar, Sameer; Steinebach, Marc

    2008-01-01

    Healthcare costs in the USA have continued to rise steadily since the 1980s. Medical errors are one of the major causes of deaths and injuries of thousands of patients every year, contributing to soaring healthcare costs. The purpose of this study is to examine what has been done to deal with the medical-error problem in the last two decades and present a closed-loop mistake-proof operation system for surgery processes that would likely eliminate preventable medical errors. The design method used is a combination of creating a service blueprint, implementing the six sigma DMAIC cycle, developing cause-and-effect diagrams as well as devising poka-yokes in order to develop a robust surgery operation process for a typical US hospital. In the improve phase of the six sigma DMAIC cycle, a number of poka-yoke techniques are introduced to prevent typical medical errors (identified through cause-and-effect diagrams) that may occur in surgery operation processes in US hospitals. It is the authors' assertion that implementing the new service blueprint along with the poka-yokes, will likely result in the current medical error rate to significantly improve to the six-sigma level. Additionally, designing as many redundancies as possible in the delivery of care will help reduce medical errors. Primary healthcare providers should strongly consider investing in adequate doctor and nurse staffing, and improving their education related to the quality of service delivery to minimize clinical errors. This will lead to an increase in higher fixed costs, especially in the shorter time frame. This paper focuses additional attention needed to make a sound technical and business case for implementing six sigma tools to eliminate medical errors that will enable hospital managers to increase their hospital's profitability in the long run and also ensure patient safety.

  20. Approximation errors during variance propagation

    International Nuclear Information System (INIS)

    Dinsmore, Stephen

    1986-01-01

    Risk and reliability analyses are often performed by constructing and quantifying large fault trees. The inputs to these models are component failure events whose probability of occuring are best represented as random variables. This paper examines the errors inherent in two approximation techniques used to calculate the top event's variance from the inputs' variance. Two sample fault trees are evaluated and several three dimensional plots illustrating the magnitude of the error over a wide range of input means and variances are given

  1. Quantum error correction for beginners

    International Nuclear Information System (INIS)

    Devitt, Simon J; Nemoto, Kae; Munro, William J

    2013-01-01

    Quantum error correction (QEC) and fault-tolerant quantum computation represent one of the most vital theoretical aspects of quantum information processing. It was well known from the early developments of this exciting field that the fragility of coherent quantum systems would be a catastrophic obstacle to the development of large-scale quantum computers. The introduction of quantum error correction in 1995 showed that active techniques could be employed to mitigate this fatal problem. However, quantum error correction and fault-tolerant computation is now a much larger field and many new codes, techniques, and methodologies have been developed to implement error correction for large-scale quantum algorithms. In response, we have attempted to summarize the basic aspects of quantum error correction and fault-tolerance, not as a detailed guide, but rather as a basic introduction. The development in this area has been so pronounced that many in the field of quantum information, specifically researchers who are new to quantum information or people focused on the many other important issues in quantum computation, have found it difficult to keep up with the general formalisms and methodologies employed in this area. Rather than introducing these concepts from a rigorous mathematical and computer science framework, we instead examine error correction and fault-tolerance largely through detailed examples, which are more relevant to experimentalists today and in the near future. (review article)

  2. Medical Error and Moral Luck.

    Science.gov (United States)

    Hubbeling, Dieneke

    2016-09-01

    This paper addresses the concept of moral luck. Moral luck is discussed in the context of medical error, especially an error of omission that occurs frequently, but only rarely has adverse consequences. As an example, a failure to compare the label on a syringe with the drug chart results in the wrong medication being administered and the patient dies. However, this error may have previously occurred many times with no tragic consequences. Discussions on moral luck can highlight conflicting intuitions. Should perpetrators receive a harsher punishment because of an adverse outcome, or should they be dealt with in the same way as colleagues who have acted similarly, but with no adverse effects? An additional element to the discussion, specifically with medical errors, is that according to the evidence currently available, punishing individual practitioners does not seem to be effective in preventing future errors. The following discussion, using relevant philosophical and empirical evidence, posits a possible solution for the moral luck conundrum in the context of medical error: namely, making a distinction between the duty to make amends and assigning blame. Blame should be assigned on the basis of actual behavior, while the duty to make amends is dependent on the outcome.

  3. The VTTVIS line imaging spectrometer - principles, error sources, and calibration

    DEFF Research Database (Denmark)

    Jørgensen, R.N.

    2002-01-01

    work describing the basic principles, potential error sources, and/or adjustment and calibration procedures. This report fulfils the need for such documentationwith special focus on the system at KVL. The PGP based system has several severe error sources, which should be removed prior any analysis......Hyperspectral imaging with a spatial resolution of a few mm2 has proved to have a great potential within crop and weed classification and also within nutrient diagnostics. A commonly used hyperspectral imaging system is based on the Prism-Grating-Prism(PGP) principles produced by Specim Ltd...... in off-axis transmission efficiencies, diffractionefficiencies, and image distortion have a significant impact on the instrument performance. Procedures removing or minimising these systematic error sources are developed and described for the system build at KVL but can be generalised to other PGP...

  4. The 95% confidence intervals of error rates and discriminant coefficients

    Directory of Open Access Journals (Sweden)

    Shuichi Shinmura

    2015-02-01

    Full Text Available Fisher proposed a linear discriminant function (Fisher’s LDF. From 1971, we analysed electrocardiogram (ECG data in order to develop the diagnostic logic between normal and abnormal symptoms by Fisher’s LDF and a quadratic discriminant function (QDF. Our four years research was inferior to the decision tree logic developed by the medical doctor. After this experience, we discriminated many data and found four problems of the discriminant analysis. A revised Optimal LDF by Integer Programming (Revised IP-OLDF based on the minimum number of misclassification (minimum NM criterion resolves three problems entirely [13, 18]. In this research, we discuss fourth problem of the discriminant analysis. There are no standard errors (SEs of the error rate and discriminant coefficient. We propose a k-fold crossvalidation method. This method offers a model selection technique and a 95% confidence intervals (C.I. of error rates and discriminant coefficients.

  5. Veterinary Molecular Diagnostics

    NARCIS (Netherlands)

    Roest, H.I.J.; Engelsma, M.Y.; Weesendorp, E.; Bossers, A.; Elbers, A.R.W.

    2017-01-01

    In veterinary molecular diagnostics, samples originating from animals are tested. Developments in the farm animals sector and in our societal attitude towards pet animals have resulted in an increased demand for fast and reliable diagnostic techniques. Molecular diagnostics perfectly matches this

  6. Diagnostics for Linear Models With Functional Responses

    OpenAIRE

    Xu, Hongquan; Shen, Qing

    2005-01-01

    Linear models where the response is a function and the predictors are vectors are useful in analyzing data from designed experiments and other situations with functional observations. Residual analysis and diagnostics are considered for such models. Studentized residuals are defined and their properties are studied. Chi-square quantile-quantile plots are proposed to check the assumption of Gaussian error process and outliers. Jackknife residuals and an associated test are proposed to det...

  7. Dissociable genetic contributions to error processing: a multimodal neuroimaging study.

    Directory of Open Access Journals (Sweden)

    Yigal Agam

    Full Text Available Neuroimaging studies reliably identify two markers of error commission: the error-related negativity (ERN, an event-related potential, and functional MRI activation of the dorsal anterior cingulate cortex (dACC. While theorized to reflect the same neural process, recent evidence suggests that the ERN arises from the posterior cingulate cortex not the dACC. Here, we tested the hypothesis that these two error markers also have different genetic mediation.We measured both error markers in a sample of 92 comprised of healthy individuals and those with diagnoses of schizophrenia, obsessive-compulsive disorder or autism spectrum disorder. Participants performed the same task during functional MRI and simultaneously acquired magnetoencephalography and electroencephalography. We examined the mediation of the error markers by two single nucleotide polymorphisms: dopamine D4 receptor (DRD4 C-521T (rs1800955, which has been associated with the ERN and methylenetetrahydrofolate reductase (MTHFR C677T (rs1801133, which has been associated with error-related dACC activation. We then compared the effects of each polymorphism on the two error markers modeled as a bivariate response.We replicated our previous report of a posterior cingulate source of the ERN in healthy participants in the schizophrenia and obsessive-compulsive disorder groups. The effect of genotype on error markers did not differ significantly by diagnostic group. DRD4 C-521T allele load had a significant linear effect on ERN amplitude, but not on dACC activation, and this difference was significant. MTHFR C677T allele load had a significant linear effect on dACC activation but not ERN amplitude, but the difference in effects on the two error markers was not significant.DRD4 C-521T, but not MTHFR C677T, had a significant differential effect on two canonical error markers. Together with the anatomical dissociation between the ERN and error-related dACC activation, these findings suggest that

  8. Predictors of Errors of Novice Java Programmers

    Science.gov (United States)

    Bringula, Rex P.; Manabat, Geecee Maybelline A.; Tolentino, Miguel Angelo A.; Torres, Edmon L.

    2012-01-01

    This descriptive study determined which of the sources of errors would predict the errors committed by novice Java programmers. Descriptive statistics revealed that the respondents perceived that they committed the identified eighteen errors infrequently. Thought error was perceived to be the main source of error during the laboratory programming…

  9. Learning time-dependent noise to reduce logical errors: real time error rate estimation in quantum error correction

    Science.gov (United States)

    Huo, Ming-Xia; Li, Ying

    2017-12-01

    Quantum error correction is important to quantum information processing, which allows us to reliably process information encoded in quantum error correction codes. Efficient quantum error correction benefits from the knowledge of error rates. We propose a protocol for monitoring error rates in real time without interrupting the quantum error correction. Any adaptation of the quantum error correction code or its implementation circuit is not required. The protocol can be directly applied to the most advanced quantum error correction techniques, e.g. surface code. A Gaussian processes algorithm is used to estimate and predict error rates based on error correction data in the past. We find that using these estimated error rates, the probability of error correction failures can be significantly reduced by a factor increasing with the code distance.

  10. Redundant measurements for controlling errors

    International Nuclear Information System (INIS)

    Ehinger, M.H.; Crawford, J.M.; Madeen, M.L.

    1979-07-01

    Current federal regulations for nuclear materials control require consideration of operating data as part of the quality control program and limits of error propagation. Recent work at the BNFP has revealed that operating data are subject to a number of measurement problems which are very difficult to detect and even more difficult to correct in a timely manner. Thus error estimates based on operational data reflect those problems. During the FY 1978 and FY 1979 R and D demonstration runs at the BNFP, redundant measurement techniques were shown to be effective in detecting these problems to allow corrective action. The net effect is a reduction in measurement errors and a significant increase in measurement sensitivity. Results show that normal operation process control measurements, in conjunction with routine accountability measurements, are sensitive problem indicators when incorporated in a redundant measurement program

  11. Large errors and severe conditions

    CERN Document Server

    Smith, D L; Van Wormer, L A

    2002-01-01

    Physical parameters that can assume real-number values over a continuous range are generally represented by inherently positive random variables. However, if the uncertainties in these parameters are significant (large errors), conventional means of representing and manipulating the associated variables can lead to erroneous results. Instead, all analyses involving them must be conducted in a probabilistic framework. Several issues must be considered: First, non-linear functional relations between primary and derived variables may lead to significant 'error amplification' (severe conditions). Second, the commonly used normal (Gaussian) probability distribution must be replaced by a more appropriate function that avoids the occurrence of negative sampling results. Third, both primary random variables and those derived through well-defined functions must be dealt with entirely in terms of their probability distributions. Parameter 'values' and 'errors' should be interpreted as specific moments of these probabil...

  12. Negligence, genuine error, and litigation

    Directory of Open Access Journals (Sweden)

    Sohn DH

    2013-02-01

    Full Text Available David H SohnDepartment of Orthopedic Surgery, University of Toledo Medical Center, Toledo, OH, USAAbstract: Not all medical injuries are the result of negligence. In fact, most medical injuries are the result either of the inherent risk in the practice of medicine, or due to system errors, which cannot be prevented simply through fear of disciplinary action. This paper will discuss the differences between adverse events, negligence, and system errors; the current medical malpractice tort system in the United States; and review current and future solutions, including medical malpractice reform, alternative dispute resolution, health courts, and no-fault compensation systems. The current political environment favors investigation of non-cap tort reform remedies; investment into more rational oversight systems, such as health courts or no-fault systems may reap both quantitative and qualitative benefits for a less costly and safer health system.Keywords: medical malpractice, tort reform, no fault compensation, alternative dispute resolution, system errors

  13. Spacecraft and propulsion technician error

    Science.gov (United States)

    Schultz, Daniel Clyde

    Commercial aviation and commercial space similarly launch, fly, and land passenger vehicles. Unlike aviation, the U.S. government has not established maintenance policies for commercial space. This study conducted a mixed methods review of 610 U.S. space launches from 1984 through 2011, which included 31 failures. An analysis of the failure causal factors showed that human error accounted for 76% of those failures, which included workmanship error accounting for 29% of the failures. With the imminent future of commercial space travel, the increased potential for the loss of human life demands that changes be made to the standardized procedures, training, and certification to reduce human error and failure rates. Several recommendations were made by this study to the FAA's Office of Commercial Space Transportation, space launch vehicle operators, and maintenance technician schools in an effort to increase the safety of the space transportation passengers.

  14. Sensation seeking and error processing.

    Science.gov (United States)

    Zheng, Ya; Sheng, Wenbin; Xu, Jing; Zhang, Yuanyuan

    2014-09-01

    Sensation seeking is defined by a strong need for varied, novel, complex, and intense stimulation, and a willingness to take risks for such experience. Several theories propose that the insensitivity to negative consequences incurred by risks is one of the hallmarks of sensation-seeking behaviors. In this study, we investigated the time course of error processing in sensation seeking by recording event-related potentials (ERPs) while high and low sensation seekers performed an Eriksen flanker task. Whereas there were no group differences in ERPs to correct trials, sensation seeking was associated with a blunted error-related negativity (ERN), which was female-specific. Further, different subdimensions of sensation seeking were related to ERN amplitude differently. These findings indicate that the relationship between sensation seeking and error processing is sex-specific. Copyright © 2014 Society for Psychophysiological Research.

  15. Errors of Inference Due to Errors of Measurement.

    Science.gov (United States)

    Linn, Robert L.; Werts, Charles E.

    Failure to consider errors of measurement when using partial correlation or analysis of covariance techniques can result in erroneous conclusions. Certain aspects of this problem are discussed and particular attention is given to issues raised in a recent article by Brewar, Campbell, and Crano. (Author)

  16. Measurement error models with uncertainty about the error variance

    NARCIS (Netherlands)

    Oberski, D.L.; Satorra, A.

    2013-01-01

    It is well known that measurement error in observable variables induces bias in estimates in standard regression analysis and that structural equation models are a typical solution to this problem. Often, multiple indicator equations are subsumed as part of the structural equation model, allowing

  17. Reward positivity: Reward prediction error or salience prediction error?

    Science.gov (United States)

    Heydari, Sepideh; Holroyd, Clay B

    2016-08-01

    The reward positivity is a component of the human ERP elicited by feedback stimuli in trial-and-error learning and guessing tasks. A prominent theory holds that the reward positivity reflects a reward prediction error signal that is sensitive to outcome valence, being larger for unexpected positive events relative to unexpected negative events (Holroyd & Coles, 2002). Although the theory has found substantial empirical support, most of these studies have utilized either monetary or performance feedback to test the hypothesis. However, in apparent contradiction to the theory, a recent study found that unexpected physical punishments also elicit the reward positivity (Talmi, Atkinson, & El-Deredy, 2013). The authors of this report argued that the reward positivity reflects a salience prediction error rather than a reward prediction error. To investigate this finding further, in the present study participants navigated a virtual T maze and received feedback on each trial under two conditions. In a reward condition, the feedback indicated that they would either receive a monetary reward or not and in a punishment condition the feedback indicated that they would receive a small shock or not. We found that the feedback stimuli elicited a typical reward positivity in the reward condition and an apparently delayed reward positivity in the punishment condition. Importantly, this signal was more positive to the stimuli that predicted the omission of a possible punishment relative to stimuli that predicted a forthcoming punishment, which is inconsistent with the salience hypothesis. © 2016 Society for Psychophysiological Research.

  18. ERROR HANDLING IN INTEGRATION WORKFLOWS

    Directory of Open Access Journals (Sweden)

    Alexey M. Nazarenko

    2017-01-01

    Full Text Available Simulation experiments performed while solving multidisciplinary engineering and scientific problems require joint usage of multiple software tools. Further, when following a preset plan of experiment or searching for optimum solu- tions, the same sequence of calculations is run multiple times with various simulation parameters, input data, or conditions while overall workflow does not change. Automation of simulations like these requires implementing of a workflow where tool execution and data exchange is usually controlled by a special type of software, an integration environment or plat- form. The result is an integration workflow (a platform-dependent implementation of some computing workflow which, in the context of automation, is a composition of weakly coupled (in terms of communication intensity typical subtasks. These compositions can then be decomposed back into a few workflow patterns (types of subtasks interaction. The pat- terns, in their turn, can be interpreted as higher level subtasks.This paper considers execution control and data exchange rules that should be imposed by the integration envi- ronment in the case of an error encountered by some integrated software tool. An error is defined as any abnormal behavior of a tool that invalidates its result data thus disrupting the data flow within the integration workflow. The main requirementto the error handling mechanism implemented by the integration environment is to prevent abnormal termination of theentire workflow in case of missing intermediate results data. Error handling rules are formulated on the basic pattern level and on the level of a composite task that can combine several basic patterns as next level subtasks. The cases where workflow behavior may be different, depending on user's purposes, when an error takes place, and possible error handling op- tions that can be specified by the user are also noted in the work.

  19. Analysis of Medication Error Reports

    Energy Technology Data Exchange (ETDEWEB)

    Whitney, Paul D.; Young, Jonathan; Santell, John; Hicks, Rodney; Posse, Christian; Fecht, Barbara A.

    2004-11-15

    In medicine, as in many areas of research, technological innovation and the shift from paper based information to electronic records has created a climate of ever increasing availability of raw data. There has been, however, a corresponding lag in our abilities to analyze this overwhelming mass of data, and classic forms of statistical analysis may not allow researchers to interact with data in the most productive way. This is true in the emerging area of patient safety improvement. Traditionally, a majority of the analysis of error and incident reports has been carried out based on an approach of data comparison, and starts with a specific question which needs to be answered. Newer data analysis tools have been developed which allow the researcher to not only ask specific questions but also to “mine” data: approach an area of interest without preconceived questions, and explore the information dynamically, allowing questions to be formulated based on patterns brought up by the data itself. Since 1991, United States Pharmacopeia (USP) has been collecting data on medication errors through voluntary reporting programs. USP’s MEDMARXsm reporting program is the largest national medication error database and currently contains well over 600,000 records. Traditionally, USP has conducted an annual quantitative analysis of data derived from “pick-lists” (i.e., items selected from a list of items) without an in-depth analysis of free-text fields. In this paper, the application of text analysis and data analysis tools used by Battelle to analyze the medication error reports already analyzed in the traditional way by USP is described. New insights and findings were revealed including the value of language normalization and the distribution of error incidents by day of the week. The motivation for this effort is to gain additional insight into the nature of medication errors to support improvements in medication safety.

  20. Medication errors: definitions and classification

    Science.gov (United States)

    Aronson, Jeffrey K

    2009-01-01

    To understand medication errors and to identify preventive strategies, we need to classify them and define the terms that describe them. The four main approaches to defining technical terms consider etymology, usage, previous definitions, and the Ramsey–Lewis method (based on an understanding of theory and practice). A medication error is ‘a failure in the treatment process that leads to, or has the potential to lead to, harm to the patient’. Prescribing faults, a subset of medication errors, should be distinguished from prescription errors. A prescribing fault is ‘a failure in the prescribing [decision-making] process that leads to, or has the potential to lead to, harm to the patient’. The converse of this, ‘balanced prescribing’ is ‘the use of a medicine that is appropriate to the patient's condition and, within the limits created by the uncertainty that attends therapeutic decisions, in a dosage regimen that optimizes the balance of benefit to harm’. This excludes all forms of prescribing faults, such as irrational, inappropriate, and ineffective prescribing, underprescribing and overprescribing. A prescription error is ‘a failure in the prescription writing process that results in a wrong instruction about one or more of the normal features of a prescription’. The ‘normal features’ include the identity of the recipient, the identity of the drug, the formulation, dose, route, timing, frequency, and duration of administration. Medication errors can be classified, invoking psychological theory, as knowledge-based mistakes, rule-based mistakes, action-based slips, and memory-based lapses. This classification informs preventive strategies. PMID:19594526

  1. Correcting quantum errors with entanglement.

    Science.gov (United States)

    Brun, Todd; Devetak, Igor; Hsieh, Min-Hsiu

    2006-10-20

    We show how entanglement shared between encoder and decoder can simplify the theory of quantum error correction. The entanglement-assisted quantum codes we describe do not require the dual-containing constraint necessary for standard quantum error-correcting codes, thus allowing us to "quantize" all of classical linear coding theory. In particular, efficient modern classical codes that attain the Shannon capacity can be made into entanglement-assisted quantum codes attaining the hashing bound (closely related to the quantum capacity). For systems without large amounts of shared entanglement, these codes can also be used as catalytic codes, in which a small amount of initial entanglement enables quantum communication.

  2. Human Error and Organizational Management

    Directory of Open Access Journals (Sweden)

    Alecxandrina DEACONU

    2009-01-01

    Full Text Available The concern for performance is a topic that raises interest in the businessenvironment but also in other areas that – even if they seem distant from thisworld – are aware of, interested in or conditioned by the economy development.As individual performance is very much influenced by the human resource, wechose to analyze in this paper the mechanisms that generate – consciously or not–human error nowadays.Moreover, the extremely tense Romanian context,where failure is rather a rule than an exception, made us investigate thephenomenon of generating a human error and the ways to diminish its effects.

  3. Preventing statistical errors in scientific journals.

    NARCIS (Netherlands)

    Nuijten, M.B.

    2016-01-01

    There is evidence for a high prevalence of statistical reporting errors in psychology and other scientific fields. These errors display a systematic preference for statistically significant results, distorting the scientific literature. There are several possible causes for this systematic error

  4. Measures to Improve Diagnostic Safety in Clinical Practice.

    Science.gov (United States)

    Singh, Hardeep; Graber, Mark L; Hofer, Timothy P

    2016-10-20

    Timely and accurate diagnosis is foundational to good clinical practice and an essential first step to achieving optimal patient outcomes. However, a recent Institute of Medicine report concluded that most of us will experience at least one diagnostic error in our lifetime. The report argues for efforts to improve the reliability of the diagnostic process through better measurement of diagnostic performance. The diagnostic process is a dynamic team-based activity that involves uncertainty, plays out over time, and requires effective communication and collaboration among multiple clinicians, diagnostic services, and the patient. Thus, it poses special challenges for measurement. In this paper, we discuss how the need to develop measures to improve diagnostic performance could move forward at a time when the scientific foundation needed to inform measurement is still evolving. We highlight challenges and opportunities for developing potential measures of "diagnostic safety" related to clinical diagnostic errors and associated preventable diagnostic harm. In doing so, we propose a starter set of measurement concepts for initial consideration that seem reasonably related to diagnostic safety and call for these to be studied and further refined. This would enable safe diagnosis to become an organizational priority and facilitate quality improvement. Health-care systems should consider measurement and evaluation of diagnostic performance as essential to timely and accurate diagnosis and to the reduction of preventable diagnostic harm.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal.

  5. Tracking Progress in Improving Diagnosis: A Framework for Defining Undesirable Diagnostic Events.

    Science.gov (United States)

    Olson, Andrew P J; Graber, Mark L; Singh, Hardeep

    2018-01-29

    Diagnostic error is a prevalent, harmful, and costly phenomenon. Multiple national health care and governmental organizations have recently identified the need to improve diagnostic safety as a high priority. A major barrier, however, is the lack of standardized, reliable methods for measuring diagnostic safety. Given the absence of reliable and valid measures for diagnostic errors, we need methods to help establish some type of baseline diagnostic performance across health systems, as well as to enable researchers and health systems to determine the impact of interventions for improving the diagnostic process. Multiple approaches have been suggested but none widely adopted. We propose a new framework for identifying "undesirable diagnostic events" (UDEs) that health systems, professional organizations, and researchers could further define and develop to enable standardized measurement and reporting related to diagnostic safety. We propose an outline for UDEs that identifies both conditions prone to diagnostic error and the contexts of care in which these errors are likely to occur. Refinement and adoption of this framework across health systems can facilitate standardized measurement and reporting of diagnostic safety.

  6. Medication errors in pediatric inpatients

    DEFF Research Database (Denmark)

    Rishoej, Rikke Mie; Almarsdóttir, Anna Birna; Christesen, Henrik Thybo

    2017-01-01

    The aim was to describe medication errors (MEs) in hospitalized children reported to the national mandatory reporting and learning system, the Danish Patient Safety Database (DPSD). MEs were extracted from DPSD from the 5-year period of 2010–2014. We included reports from public hospitals on pati...... safety in pediatric inpatients.(Table presented.)...

  7. Learner Corpora without Error Tagging

    Directory of Open Access Journals (Sweden)

    Rastelli, Stefano

    2009-01-01

    Full Text Available The article explores the possibility of adopting a form-to-function perspective when annotating learner corpora in order to get deeper insights about systematic features of interlanguage. A split between forms and functions (or categories is desirable in order to avoid the "comparative fallacy" and because – especially in basic varieties – forms may precede functions (e.g., what resembles to a "noun" might have a different function or a function may show up in unexpected forms. In the computer-aided error analysis tradition, all items produced by learners are traced to a grid of error tags which is based on the categories of the target language. Differently, we believe it is possible to record and make retrievable both words and sequence of characters independently from their functional-grammatical label in the target language. For this purpose at the University of Pavia we adapted a probabilistic POS tagger designed for L1 on L2 data. Despite the criticism that this operation can raise, we found that it is better to work with "virtual categories" rather than with errors. The article outlines the theoretical background of the project and shows some examples in which some potential of SLA-oriented (non error-based tagging will be possibly made clearer.

  8. Theory of Test Translation Error

    Science.gov (United States)

    Solano-Flores, Guillermo; Backhoff, Eduardo; Contreras-Nino, Luis Angel

    2009-01-01

    In this article, we present a theory of test translation whose intent is to provide the conceptual foundation for effective, systematic work in the process of test translation and test translation review. According to the theory, translation error is multidimensional; it is not simply the consequence of defective translation but an inevitable fact…

  9. and Correlated Error-Regressor

    African Journals Online (AJOL)

    Nekky Umera

    in queuing theory and econometrics, where the usual assumption of independent error terms may not be plausible in most cases. Also, when using time-series data on a number of micro-economic units, such as households and service oriented channels, where the stochastic disturbance terms in part reflect variables which ...

  10. Rank error-correcting pairs

    DEFF Research Database (Denmark)

    Martinez Peñas, Umberto; Pellikaan, Ruud

    2017-01-01

    Error-correcting pairs were introduced as a general method of decoding linear codes with respect to the Hamming metric using coordinatewise products of vectors, and are used for many well-known families of codes. In this paper, we define new types of vector products, extending the coordinatewise ...

  11. Finding errors in big data

    NARCIS (Netherlands)

    Puts, Marco; Daas, Piet; de Waal, A.G.

    No data source is perfect. Mistakes inevitably creep in. Spotting errors is hard enough when dealing with survey responses from several thousand people, but the difficulty is multiplied hugely when that mysterious beast Big Data comes into play. Statistics Netherlands is about to publish its first

  12. The Errors of Our Ways

    Science.gov (United States)

    Kane, Michael

    2011-01-01

    Errors don't exist in our data, but they serve a vital function. Reality is complicated, but our models need to be simple in order to be manageable. We assume that attributes are invariant over some conditions of observation, and once we do that we need some way of accounting for the variability in observed scores over these conditions of…

  13. Cascade Error Projection Learning Algorithm

    Science.gov (United States)

    Duong, T. A.; Stubberud, A. R.; Daud, T.

    1995-01-01

    A detailed mathematical analysis is presented for a new learning algorithm termed cascade error projection (CEP) and a general learning frame work. This frame work can be used to obtain the cascade correlation learning algorithm by choosing a particular set of parameters.

  14. PC based diagnostic system for nitrogen production unit of HWP

    International Nuclear Information System (INIS)

    Lamba, D.S.; Rao, V.C.; Krishnan, S.; Kamaraj, T.; Krishnaswamy, C.

    1992-01-01

    The plant diagnostic system monitors the input data from local processing unit and tries to diagnose the cause of the failure. The system is a rule based application program that can perform tasks itself using fault tree model which displays the logical relationships between critical events and their possible ways occurrence, i.e. hardware failure, process faults and human error etc. Unit 37 Nitrogen Plant is taken as a prototype model for trying the plant diagnostics system. (author). 3 refs., 2 figs

  15. Diagnostic Development on NSTX

    International Nuclear Information System (INIS)

    A.L. Roquemore; D. Johnson; R. Kaita; et al

    1999-01-01

    Diagnostics are described which are currently installed or under active development for the newly commissioned NSTX device. The low aspect ratio (R/a less than or equal to 1.3) and low toroidal field (0.1-0.3T) used in this device dictate adaptations in many standard diagnostic techniques. Technical summaries of each diagnostic are given, and adaptations, where significant, are highlighted

  16. TFTR diagnostic vacuum controller

    International Nuclear Information System (INIS)

    Olsen, D.; Persons, R.

    1981-01-01

    The TFTR diagnostic vacuum controller (DVC) provides in conjunction with the Central Instrumentation Control and Data Acquisition System (CICADA), control and monitoring for the pumps, valves and gauges associated with each individual diagnostic vacuum system. There will be approximately 50 systems on TFTR. Two standard versions of the controller (A and B) wil be provided in order to meet the requirements of two diagnostic manifold arrangements. All pump and valve sequencing, as well as protection features, will be implemented by the controller

  17. How common are cognitive errors in cases presented at emergency medicine resident morbidity and mortality conferences?

    Science.gov (United States)

    Chu, David; Xiao, Jane; Shah, Payal; Todd, Brett

    2018-06-20

    Cognitive errors are a major contributor to medical error. Traditionally, medical errors at teaching hospitals are analyzed in morbidity and mortality (M&M) conferences. We aimed to describe the frequency of cognitive errors in relation to the occurrence of diagnostic and other error types, in cases presented at an emergency medicine (EM) resident M&M conference. We conducted a retrospective study of all cases presented at a suburban US EM residency monthly M&M conference from September 2011 to August 2016. Each case was reviewed using the electronic medical record (EMR) and notes from the M&M case by two EM physicians. Each case was categorized by type of primary medical error that occurred as described by Okafor et al. When a diagnostic error occurred, the case was reviewed for contributing cognitive and non-cognitive factors. Finally, when a cognitive error occurred, the case was classified into faulty knowledge, faulty data gathering or faulty synthesis, as described by Graber et al. Disagreements in error type were mediated by a third EM physician. A total of 87 M&M cases were reviewed; the two reviewers agreed on 73 cases, and 14 cases required mediation by a third reviewer. Forty-eight cases involved diagnostic errors, 47 of which were cognitive errors. Of these 47 cases, 38 involved faulty synthesis, 22 involved faulty data gathering and only 11 involved faulty knowledge. Twenty cases contained more than one type of cognitive error. Twenty-nine cases involved both a resident and an attending physician, while 17 cases involved only an attending physician. Twenty-one percent of the resident cases involved all three cognitive errors, while none of the attending cases involved all three. Forty-one percent of the resident cases and only 6% of the attending cases involved faulty knowledge. One hundred percent of the resident cases and 94% of the attending cases involved faulty synthesis. Our review of 87 EM M&M cases revealed that cognitive errors are commonly

  18. Error and its meaning in forensic science.

    Science.gov (United States)

    Christensen, Angi M; Crowder, Christian M; Ousley, Stephen D; Houck, Max M

    2014-01-01

    The discussion of "error" has gained momentum in forensic science in the wake of the Daubert guidelines and has intensified with the National Academy of Sciences' Report. Error has many different meanings, and too often, forensic practitioners themselves as well as the courts misunderstand scientific error and statistical error rates, often confusing them with practitioner error (or mistakes). Here, we present an overview of these concepts as they pertain to forensic science applications, discussing the difference between practitioner error (including mistakes), instrument error, statistical error, and method error. We urge forensic practitioners to ensure that potential sources of error and method limitations are understood and clearly communicated and advocate that the legal community be informed regarding the differences between interobserver errors, uncertainty, variation, and mistakes. © 2013 American Academy of Forensic Sciences.

  19. A methodology for translating positional error into measures of attribute error, and combining the two error sources

    Science.gov (United States)

    Yohay Carmel; Curtis Flather; Denis Dean

    2006-01-01

    This paper summarizes our efforts to investigate the nature, behavior, and implications of positional error and attribute error in spatiotemporal datasets. Estimating the combined influence of these errors on map analysis has been hindered by the fact that these two error types are traditionally expressed in different units (distance units, and categorical units,...

  20. Design of Diagnostics: Case Studies for Wendelstein 7-X

    International Nuclear Information System (INIS)

    Dreier, H.; Dinklage, A.; Fischer, R.; Hirsch, M.; Kornejew, P.; Pasch, E.

    2005-01-01

    The set of start-up diagnostics for Wendelstein 7-X is oriented to resolve physical issues of stellarator optimization [1]. The diagnostics philosophy of W7-X aims at extendable set-ups which are to be supplemented along the operation of the device. Planning diagnostics directly lead to the requirement to optimize their respective outcome. In many cases, the optimization is much restricted by technical constraints. But even in those cases, figures of robustness of the chosen design settings are beneficial for the diagnostic strategy. In this paper a framework for diagnostic design is presented employing the Bayesian probability theory. Part of the approach can be regarded as a virtual diagnostic, which describes the future experimental unit including its error statistics and is able to produce artificial data. The virtual diagnostic is fed with mock-up quantities of interest and hence it enables the designer to compare the outcome of the virtual diagnostic with its input. For the design of diagnostics in fusion experiments several figures of merit are possible, depend- ing on the optimization goal. Here physical questions like estimation of the density distribution or the density gradient are possible optimization targets as well as technical issues as the robustness of density measurements, e.g, for controlling purposes. Also the estimation of derived quantities - like gradients needed for modeling of the bootstrap current or of the radial electric field - might be considered to be the goal of a diagnostic design. (Author)

  1. Psychologists' diagnostic processes during a diagnostic interview

    NARCIS (Netherlands)

    Groenier, Marleen; Beerthuis, Vos R.J.; Pieters, Julius Marie; Witteman, C.L.M.; Witteman, Cilia L.M.; Swinkels, Jan A.

    2011-01-01

    In mental health care, psychologists assess clients’ complaints, analyze underlying problems, and identify causes for these problems, to make treatment decisions. We present a study on psychologists’ diagnostic processes, in which a mixed-method approach was employed. We aimed to identify a common

  2. Screening for Inborn Errors of Metabolism

    Directory of Open Access Journals (Sweden)

    F.A. Elshaari

    2013-09-01

    Full Text Available Inborn errors of metabolism (IEM are a heterogeneous group of monogenic diseases that affect the metabolic pathways. The detection of IEM relies on a high index of clinical suspicion and co-ordinated access to specialized laboratory services. Biochemical analysis forms the basis of the final confirmed diagnosis in several of these disorders. The investigations fall into four main categories1.General metabolic screening tests2.Specific metabolite assays3.Enzyme studies4.DNA analysis The first approach to the diagnosis is by a multi-component analysis of body fluids in clinically selected patients, referred to as metabolic screening tests. These include simple chemical tests in the urine, blood glucose, acid-base profile, lactate, ammonia and liver function tests. The results of these tests can help to suggest known groups of metabolic disorders so that specific metabolites such as amino acids, organic acids, etc. can be estimated. However, not all IEM needs the approach of general screening. Lysosomal, peroxisomal, thyroid and adrenal disorders are suspected mainly on clinical grounds and pertinent diagnostic tests can be performed. The final diagnosis relies on the demonstration of the specific enzyme defect, which can be further confirmed by DNA studies.

  3. Discretization vs. Rounding Error in Euler's Method

    Science.gov (United States)

    Borges, Carlos F.

    2011-01-01

    Euler's method for solving initial value problems is an excellent vehicle for observing the relationship between discretization error and rounding error in numerical computation. Reductions in stepsize, in order to decrease discretization error, necessarily increase the number of steps and so introduce additional rounding error. The problem is…

  4. Total Survey Error for Longitudinal Surveys

    NARCIS (Netherlands)

    Lynn, Peter; Lugtig, P.J.

    2016-01-01

    This article describes the application of the total survey error paradigm to longitudinal surveys. Several aspects of survey error, and of the interactions between different types of error, are distinct in the longitudinal survey context. Furthermore, error trade-off decisions in survey design and

  5. Diagnostic nerve ultrasonography

    International Nuclear Information System (INIS)

    Baeumer, T.; Grimm, A.; Schelle, T.

    2017-01-01

    For the diagnostics of nerve lesions an imaging method is necessary to visualize peripheral nerves and their surrounding structures for an etiological classification. Clinical neurological and electrophysiological investigations provide functional information about nerve lesions. The information provided by a standard magnetic resonance imaging (MRI) examination is inadequate for peripheral nerve diagnostics; however, MRI neurography is suitable but on the other hand a resource and time-consuming method. Using ultrasonography for peripheral nerve diagnostics. With ultrasonography reliable diagnostics of entrapment neuropathies and traumatic nerve lesions are possible. The use of ultrasonography for neuropathies shows that a differentiation between different forms is possible. Nerve ultrasonography is an established diagnostic tool. In addition to the clinical examination and clinical electrophysiology, structural information can be obtained, which results in a clear improvement in the diagnostics. Ultrasonography has become an integral part of the diagnostic work-up of peripheral nerve lesions in neurophysiological departments. Nerve ultrasonography is recommended for the diagnostic work-up of peripheral nerve lesions in addition to clinical and electrophysiological investigations. It should be used in the clinical work-up of entrapment neuropathies, traumatic nerve lesions and spacy-occupying lesions of nerves. (orig.) [de

  6. Ongoing experiments: diagnostics requirements

    International Nuclear Information System (INIS)

    Dickerman, C.E.

    1976-01-01

    The paper reviews the fuel motion diagnostics needs for ongoing LMFBR safety experiments over approximately the next five years, with the discussion centered on TREAT. Brief comments on the direction in which clad motion diagnostics requirements are expected to develop are also presented

  7. Clinical diagnostic ultrasound

    International Nuclear Information System (INIS)

    Barnett, E.; Morley, P.

    1986-01-01

    This textbook on diagnostic ultrasound covers the main systems, with emphasis being placed on the clinical application of diagnostic ultrasound in everyday practice. It provides not only a textbook for postgraduates (particularly FRCR candidates), but also a reference work for practitioners of clinical ultrasound and clinicians generally

  8. Gearbox vibration diagnostic analyzer

    Science.gov (United States)

    1992-01-01

    This report describes the Gearbox Vibration Diagnostic Analyzer installed in the NASA Lewis Research Center's 500 HP Helicopter Transmission Test Stand to monitor gearbox testing. The vibration of the gearbox is analyzed using diagnostic algorithms to calculate a parameter indicating damaged components.

  9. Negligence, genuine error, and litigation

    Science.gov (United States)

    Sohn, David H

    2013-01-01

    Not all medical injuries are the result of negligence. In fact, most medical injuries are the result either of the inherent risk in the practice of medicine, or due to system errors, which cannot be prevented simply through fear of disciplinary action. This paper will discuss the differences between adverse events, negligence, and system errors; the current medical malpractice tort system in the United States; and review current and future solutions, including medical malpractice reform, alternative dispute resolution, health courts, and no-fault compensation systems. The current political environment favors investigation of non-cap tort reform remedies; investment into more rational oversight systems, such as health courts or no-fault systems may reap both quantitative and qualitative benefits for a less costly and safer health system. PMID:23426783

  10. Robot learning and error correction

    Science.gov (United States)

    Friedman, L.

    1977-01-01

    A model of robot learning is described that associates previously unknown perceptions with the sensed known consequences of robot actions. For these actions, both the categories of outcomes and the corresponding sensory patterns are incorporated in a knowledge base by the system designer. Thus the robot is able to predict the outcome of an action and compare the expectation with the experience. New knowledge about what to expect in the world may then be incorporated by the robot in a pre-existing structure whether it detects accordance or discrepancy between a predicted consequence and experience. Errors committed during plan execution are detected by the same type of comparison process and learning may be applied to avoiding the errors.

  11. Error studies of Halbach Magnets

    Energy Technology Data Exchange (ETDEWEB)

    Brooks, S. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2017-03-02

    These error studies were done on the Halbach magnets for the CBETA “First Girder” as described in note [CBETA001]. The CBETA magnets have since changed slightly to the lattice in [CBETA009]. However, this is not a large enough change to significantly affect the results here. The QF and BD arc FFAG magnets are considered. For each assumed set of error distributions and each ideal magnet, 100 random magnets with errors are generated. These are then run through an automated version of the iron wire multipole cancellation algorithm. The maximum wire diameter allowed is 0.063” as in the proof-of-principle magnets. Initially, 32 wires (2 per Halbach wedge) are tried, then if this does not achieve 1e-­4 level accuracy in the simulation, 48 and then 64 wires. By “1e-4 accuracy”, it is meant the FOM defined by √(Σn≥sextupole an 2+bn 2) is less than 1 unit, where the multipoles are taken at the maximum nominal beam radius, R=23mm for these magnets. The algorithm initially uses 20 convergence interations. If 64 wires does not achieve 1e-­4 accuracy, this is increased to 50 iterations to check for slow converging cases. There are also classifications for magnets that do not achieve 1e-4 but do achieve 1e-3 (FOM ≤ 10 units). This is technically within the spec discussed in the Jan 30, 2017 review; however, there will be errors in practical shimming not dealt with in the simulation, so it is preferable to do much better than the spec in the simulation.

  12. Frequency of Burnout, Sleepiness and Depression in Emergency Medicine Residents with Medical Errors in the Emergency Department

    Directory of Open Access Journals (Sweden)

    Alireza Aala

    2014-07-01

    Full Text Available Aims: Medical error is a great concern of the patients and physicians. It usually occurs due to physicians’ exhaustion, distress and fatigue. In this study, we aimed to evaluate frequency of distress and fatigue among emergency medicine residents reporting a medical error. Materials and Methods: The study population consisted of emergency medicine residents who completed an emailed questionnaire including self-assessment of medical errors, the Epworth Sleepiness Scale (ESS score, the Maslach Burnout Inventory, and PRIME-MD validated depression screening tool.   Results: In this survey, 100 medical errors were reported including diagnostic errors in 53, therapeutic errors in 24 and following errors in 23 subjects. Most errors were reported by males and third year residents. Residents had no signs of depression, but all had some degrees of sleepiness and burnout. There were significant differences between errors subtypes and age, residency year, depression, sleepiness and burnout scores (p<0.0001.   Conclusion: In conclusion, residents committing a medical error usually experience burnout and have some grades of sleepiness that makes them less motivated increasing the probability of medical errors. However, as none of the residents had depression, it could be concluded that depression has no significant role in medical error occurrence and perhaps it is a possible consequence of medical error.    Keywords: Residents; Medical error; Burnout; Sleepiness; Depression

  13. Real-Time Adaptive Algorithms for Flight Control Diagnostics and Prognostics, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Model-based machinery diagnostic and prognostic techniques depend upon high-quality mathematical models of the plant. Modeling uncertainties and errors decrease...

  14. Ordering of diagnostic information in encoded medical images. Accuracy progression

    Science.gov (United States)

    Przelaskowski, A.; Jóźwiak, R.; Krzyżewski, T.; Wróblewska, A.

    2008-03-01

    A concept of diagnostic accuracy progression for embedded coding of medical images was presented. Implementation of JPEG2000 encoder with a modified PCRD optimization algorithm was realized and initially verified as a tool for accurate medical image streaming. Mean square error as a distortion measure was replaced by other numerical measures to revise quality progression according to diagnostic importance of successively encoded image information. A faster increment of image diagnostic importance during reconstruction of initial packets of code stream was reached. Modified Jasper code was initially tested on a set of mammograms containing clusters of microcalcifications and malignant masses, and other radiograms. Teleradiologic applications were considered as the first area of interests.

  15. [Errors in laboratory daily practice].

    Science.gov (United States)

    Larrose, C; Le Carrer, D

    2007-01-01

    Legislation set by GBEA (Guide de bonne exécution des analyses) requires that, before performing analysis, the laboratory directors have to check both the nature of the samples and the patients identity. The data processing of requisition forms, which identifies key errors, was established in 2000 and in 2002 by the specialized biochemistry laboratory, also with the contribution of the reception centre for biological samples. The laboratories follow a strict criteria of defining acceptability as a starting point for the reception to then check requisition forms and biological samples. All errors are logged into the laboratory database and analysis report are sent to the care unit specifying the problems and the consequences they have on the analysis. The data is then assessed by the laboratory directors to produce monthly or annual statistical reports. This indicates the number of errors, which are then indexed to patient files to reveal the specific problem areas, therefore allowing the laboratory directors to teach the nurses and enable corrective action.

  16. Development of a Diagnostic Complexity Questionnaire

    International Nuclear Information System (INIS)

    Collier, Steve

    1998-02-01

    The HRP human error analysis project has for some time been investigating what makes certain fault scenarios difficult for operators. One line of research has been to develop a questionnaire to measure diagnostic complexity. This report concerns some theoretical and experimental work underpinning the development of the questionnaire. A study of the literature reviewed the factors or components thought to contribute to difficulty in diagnosing and problem-solving. Two experimental studies of complexity were carried out using two versions of a questionnaire based on the review. The studies were simulator based, using scenarios designed to be diagnostically challenging. A factor-analytic approach to the analysis of the study data was suggested in the literature review. This is reported here (together with other analyses) though the factor analysis did not produce so clear results as was hoped. The present analysis found no clear factor structure with the first version of the complexity questionnaire used in experiment I. Partly because of this result, a factor-analytic approach to a second version of the questionnaire used in experiment II was not considered appropriate. A descriptive and qualitative analysis of the two questionnaire studies and a synthesis of the results from them both was promising. There were indications of components of complexity and some indications of what contributes to a personal perception of high or low diagnostic difficulty in fault scenarios. Components adding to diagnostic difficulty were tentatively named 'severity', 'need for co-operation', 'stress' and 'spread of changes'. Components not adding to difficulty were 'directness of indications', 'familiarity' and 'lack of stress'. There was some evidence of different responses to these components in a comparison of rule-based vs. knowledge-based diagnostic scenarios. These findings and experience with analysis techniques will feed into the design of further work on the human error

  17. Clock error models for simulation and estimation

    International Nuclear Information System (INIS)

    Meditch, J.S.

    1981-10-01

    Mathematical models for the simulation and estimation of errors in precision oscillators used as time references in satellite navigation systems are developed. The results, based on all currently known oscillator error sources, are directly implementable on a digital computer. The simulation formulation is sufficiently flexible to allow for the inclusion or exclusion of individual error sources as desired. The estimation algorithms, following from Kalman filter theory, provide directly for the error analysis of clock errors in both filtering and prediction

  18. Reducing image interpretation errors – Do communication strategies undermine this?

    International Nuclear Information System (INIS)

    Snaith, B.; Hardy, M.; Lewis, E.F.

    2014-01-01

    Introduction: Errors in the interpretation of diagnostic images in the emergency department are a persistent problem internationally. To address this issue, a number of risk reduction strategies have been suggested but only radiographer abnormality detection schemes (RADS) have been widely implemented in the UK. This study considers the variation in RADS operation and communication in light of technological advances and changes in service operation. Methods: A postal survey of all NHS hospitals operating either an Emergency Department or Minor Injury Unit and a diagnostic imaging (radiology) department (n = 510) was undertaken between July and August 2011. The questionnaire was designed to elicit information on emergency service provision and details of RADS. Results: 325 questionnaires were returned (n = 325/510; 63.7%). The majority of sites (n = 288/325; 88.6%) operated a RADS with the majority (n = 227/288; 78.8%) employing a visual ‘flagging’ system as the only method of communication although symbols used were inconsistent and contradictory across sites. 61 sites communicated radiographer findings through a written proforma (paper or electronic) but this was run in conjunction with a flagging system at 50 sites. The majority of sites did not have guidance on the scope or operation of the ‘flagging’ or written communication system in use. Conclusions: RADS is an established clinical intervention to reduce errors in diagnostic image interpretation within the emergency setting. The lack of standardisation in communication processes and practices alongside the rapid adoption of technology has increased the potential for error and miscommunication

  19. Difficulties and errors in radiodiagnosis of lung cancer

    International Nuclear Information System (INIS)

    Al'tshuler, Yu.B.; Ajtakov, Z.N.; Drekalova, T.I.

    1987-01-01

    Diagnostic errors in 96 out of 1043 patients operated for peripheral lung cancer had been analyzed. The diagnosis was not confirmed at operation. Other diseases were diagnosed in them: hamartochondroma in 26, tuberculosis, tuberculoma and other forms of pulmonary tuberculosis in 25, pneumonia and abscesses in 17 and rare tumors in 28. Complete difference in roentgenological and morphological diagnosis was noted in 60 (5.7%) cases, and partial difference in 36 (3.5%) cases. The main causes of the errors could be attributed to small sizes of the formations (diameter under 3 cm in 76.4% of the cases) and the presence of shadows of spherical shape (88.5%). In some cases X-ray signs permitting differential diagnosis were absent. Thoracotomy could be employed as the last diagnosis stage for this group of patients

  20. Measurement of the magnetic field errors on TCV

    International Nuclear Information System (INIS)

    Piras, F.; Moret, J.-M.; Rossel, J.X.

    2010-01-01

    A set of 24 saddle loops is used on the Tokamak a Configuration Variable (TCV) to measure the radial magnetic flux at different toroidal and vertical positions. The new system is calibrated together with the standard magnetic diagnostics on TCV. Based on the results of this calibration, the effective current in the poloidal field coils and their position is computed. These corrections are then used to compute the distribution of the error field inside the vacuum vessel for a typical TCV discharge. Since the saddle loops measure the magnetic flux at different toroidal positions, the non-axisymmetric error field is also estimated and correlated to a shift or a tilt of the poloidal field coils.

  1. Common ECG Lead Placement Errors. Part I: Limb Lead Reversals

    Directory of Open Access Journals (Sweden)

    Allison V. Rosen

    2015-10-01

    Full Text Available Background: Electrocardiography (ECG is a very useful diagnostic tool. However, errors in placement of ECG leads can create artifacts, mimic pathologies, and hinder proper ECG interpretation. It is important for members of the health care team to be able to recognize the common patterns resulting from lead placement errors. Methods: 12-lead ECGs were recorded in a single male healthy subject in his mid 20s. Six different limb lead reversals were compared to ECG recordings from correct lead placement. Results: Classic ECG patterns were observed when leads were reversed. Methods of discriminating these ECG patterns from true pathologic findings were described. Conclusion: Correct recording and interpretation of ECGs is key to providing optimal patient care. It is therefore crucial to be able to recognize common ECG patterns that are indicative of lead reversals.

  2. Righting errors in writing errors: the Wing and Baddeley (1980) spelling error corpus revisited.

    Science.gov (United States)

    Wing, Alan M; Baddeley, Alan D

    2009-03-01

    We present a new analysis of our previously published corpus of handwriting errors (slips) using the proportional allocation algorithm of Machtynger and Shallice (2009). As previously, the proportion of slips is greater in the middle of the word than at the ends, however, in contrast to before, the proportion is greater at the end than at the beginning of the word. The findings are consistent with the hypothesis of memory effects in a graphemic output buffer.

  3. Diagnostics on Z (invited)

    International Nuclear Information System (INIS)

    Nash, T. J.; Derzon, M. S.; Chandler, G. A.; Fehl, D. L.; Leeper, R. J.; Porter, J. L.; Spielman, R. B.; Ruiz, C.; Cooper, G.; McGurn, J.

    2001-01-01

    The 100 ns, 20 MA pinch-driver Z is surrounded by an extensive set of diagnostics. There are nine radial lines of sight set at 12 o above horizontal and each of these may be equipped with up to five diagnostic ports. Instruments routinely fielded viewing the pinch from the side with these ports include x-ray diode arrays, photoconducting detector arrays, bolometers, transmission grating spectrometers, time-resolved x-ray pinhole cameras, x-ray crystal spectrometers, calorimeters, silicon photodiodes, and neutron detectors. A diagnostic package fielded on axis for viewing internal pinch radiation consists of nine lines of sight. This package accommodates virtually the same diagnostics as the radial ports. Other diagnostics not fielded on the axial or radial ports include current B-dot monitors, filtered x-ray scintillators coupled by fiber optics to streak cameras, streaked visible spectroscopy, velocity interferometric system for any reflector, bremsstrahlung cameras, and active shock breakout measurement of hohlraum temperature. The data acquisition system is capable of recording up to 500 channels and the data from each shot is available on the Internet. A major new diagnostic presently under construction is the BEAMLET backlighter. We will briefly describe each of these diagnostics and present some of the highest-quality data from them

  4. Error handling for the CDF online silicon vertex tracker

    CERN Document Server

    Bari, M; Cerri, A; Dell'Orso, Mauro; Donati, S; Galeotti, S; Giannetti, P; Morsani, F; Punzi, G; Ristori, L; Spinella, F; Zanetti, A M

    2001-01-01

    The online silicon vertex tracker (SVT) is composed of 104 VME 9U digital boards (of eight different types). Since the data output from the SVT (few MB/s) are a small fraction of the input data (200 MB/s), it is extremely difficult to track possible internal errors by using only the output stream. For this reason, several diagnostic tools have been implemented: local error registers, error bits propagated through the data streams, and the Spy Buffer system. Data flowing through each input and output stream of every board are continuously copied to memory banks named spy buffers, which act as built-in logic state analyzers hooked continuously to internal data streams. The contents of all buffers can be frozen at any time (e.g., on error detection) to take a snapshot of all data flowing through each SVT board. The spy buffers are coordinated at system level by the Spy Control Board. The architecture, design, and implementation of this system are described. (4 refs).

  5. Subclinical naming errors in mild cognitive impairment: A semantic deficit?

    Directory of Open Access Journals (Sweden)

    Indra F. Willers

    Full Text Available Abstract Mild cognitive impairment (MCI is the transitional stage between normal aging and Alzheimer's disease (AD. Impairments in semantic memory have been demonstrated to be a critical factor in early AD. The Boston Naming Test (BNT is a straightforward method of examining semantic or visuo-perceptual processing and therefore represents a potential diagnostic tool. The objective of this study was to examine naming ability and identify error types in patients with amnestic mild cognitive impairment (aMCI. Methods: Twenty aMCI patients, twenty AD patients and twenty-one normal controls, matched by age, sex and education level were evaluated. As part of a further neuropsychological evaluation, all subjects performed the BNT. A comprehensive classification of error types was devised in order to compare performance and ascertain semantic or perceptual origin of errors. Results: AD patients obtained significantly lower total scores on the BNT than aMCI patients and controls. aMCI patients did not obtain significant differences in total scores, but showed significantly higher semantic errors compared to controls. Conclusion: This study reveals that semantic processing is impaired during confrontation naming in aMCI.

  6. Impact of error fields on plasma identification in ITER

    Energy Technology Data Exchange (ETDEWEB)

    Martone, R., E-mail: Raffaele.Martone@unina2.it [Ass. EURATOM/ENEA/CREATE, Seconda Università di Napoli, Via Roma 29, Aversa (CE) (Italy); Appel, L. [EURATOM/CCFE Fusion Association, Culham Science Centre, Abingdon (United Kingdom); Chiariello, A.G.; Formisano, A.; Mattei, M. [Ass. EURATOM/ENEA/CREATE, Seconda Università di Napoli, Via Roma 29, Aversa (CE) (Italy); Pironti, A. [Ass. EURATOM/ENEA/CREATE, Università degli Studi di Napoli “Federico II”, Via Claudio 25, Napoli (Italy)

    2013-10-15

    Highlights: ► The paper deals with the effect on plasma identification of error fields generated by field coils manufacturing and assembly errors. ► EFIT++ is used to identify plasma gaps when poloidal field coils and central solenoid coils are deformed, and the gaps sensitivity with respect to such errors is analyzed. ► Some examples of reconstruction errors in the presence of deformations are reported. -- Abstract: The active control of plasma discharges in present Tokamak devices must be prompt and accurate to guarantee expected performance. As a consequence, the identification step, calculating plasma parameters from diagnostics, should provide in a very short time reliable estimates of the relevant quantities, such as plasma centroid position, plasma-wall distances at given points called gaps, and other geometrical parameters as elongation and triangularity. To achieve the desired response promptness, a number of simplifying assumptions are usually made in the identification algorithms. Among those clearly affecting the quality of the plasma parameters reconstruction, one of the most relevant is the precise knowledge of the magnetic field produced by active coils. Since uncertainties in their manufacturing and assembly process may cause misalignments between the actual and expected geometry and position of magnets, an analysis on the effect of possible wrong information about magnets on the plasma shape identification is documented in this paper.

  7. Radiological error: analysis, standard setting, targeted instruction and teamworking

    International Nuclear Information System (INIS)

    FitzGerald, Richard

    2005-01-01

    Diagnostic radiology does not have objective benchmarks for acceptable levels of missed diagnoses [1]. Until now, data collection of radiological discrepancies has been very time consuming. The culture within the specialty did not encourage it. However, public concern about patient safety is increasing. There have been recent innovations in compiling radiological interpretive discrepancy rates which may facilitate radiological standard setting. However standard setting alone will not optimise radiologists' performance or patient safety. We must use these new techniques in radiological discrepancy detection to stimulate greater knowledge sharing, targeted instruction and teamworking among radiologists. Not all radiological discrepancies are errors. Radiological discrepancy programmes must not be abused as an instrument for discrediting individual radiologists. Discrepancy rates must not be distorted as a weapon in turf battles. Radiological errors may be due to many causes and are often multifactorial. A systems approach to radiological error is required. Meaningful analysis of radiological discrepancies and errors is challenging. Valid standard setting will take time. Meanwhile, we need to develop top-up training, mentoring and rehabilitation programmes. (orig.)

  8. Cable Diagnostic Focused Initiative

    Energy Technology Data Exchange (ETDEWEB)

    Hartlein, R.A.; Hampton, R.N.

    2010-12-30

    This report summarizes an extensive effort made to understand how to effectively use the various diagnostic technologies to establish the condition of medium voltage underground cable circuits. These circuits make up an extensive portion of the electric delivery infrastructure in the United States. Much of this infrastructure is old and experiencing unacceptable failure rates. By deploying efficient diagnostic testing programs, electric utilities can replace or repair circuits that are about to fail, providing an optimal approach to improving electric system reliability. This is an intrinsically complex topic. Underground cable systems are not homogeneous. Cable circuits often contain multiple branches with different cable designs and a range of insulation materials. In addition, each insulation material ages differently as a function of time, temperature and operating environment. To complicate matters further, there are a wide variety of diagnostic technologies available for assessing the condition of cable circuits with a diversity of claims about the effectiveness of each approach. As a result, the benefits of deploying cable diagnostic testing programs have been difficult to establish, leading many utilities to avoid the their use altogether. This project was designed to help address these issues. The information provided is the result of a collaborative effort between Georgia Tech NEETRAC staff, Georgia Tech academic faculty, electric utility industry participants, as well as cable system diagnostic testing service providers and test equipment providers. Report topics include: •How cable systems age and fail, •The various technologies available for detecting potential failure sites, •The advantages and disadvantages of different diagnostic technologies, •Different approaches for utilities to employ cable system diagnostics. The primary deliverables of this project are this report, a Cable Diagnostic Handbook (a subset of this report) and an online

  9. Plasma diagnostic reflectometry

    International Nuclear Information System (INIS)

    Cohen, B.I.; Afeyan, B.B.; Garrison, J.C.; Kaiser, T.B.; Luhmann, N.C. Jr.; Domier, C.W.; Chou, A.E.; Baang, S.

    1996-01-01

    Theoretical and experimental studies of plasma diagnostic reflectometry have been undertaken as a collaborative research project between the Lawrence Livermore National Laboratory (LLNL) and the University of California Department of Applied Science Plasma Diagnostics Group under the auspices of the Laboratory Directed Research and Development Program at LLNL. Theoretical analyses have explored the basic principles of reflectometry to understand its limitations, to address specific gaps in the understanding of reflectometry measurements in laboratory experiments, and to explore extensions of reflectometry such as ultra-short-pulse reflectometry. The theory has supported basic laboratory reflectometry experiments where reflectometry measurements can be corroborated by independent diagnostic measurements

  10. Investigating the Link Between Radiologists Gaze, Diagnostic Decision, and Image Content

    Energy Technology Data Exchange (ETDEWEB)

    Tourassi, Georgia [ORNL; Voisin, Sophie [ORNL; Paquit, Vincent C [ORNL; Krupinski, Elizabeth [University of Arizona

    2013-01-01

    Objective: To investigate machine learning for linking image content, human perception, cognition, and error in the diagnostic interpretation of mammograms. Methods: Gaze data and diagnostic decisions were collected from six radiologists who reviewed 20 screening mammograms while wearing a head-mounted eye-tracker. Texture analysis was performed in mammographic regions that attracted radiologists attention and in all abnormal regions. Machine learning algorithms were investigated to develop predictive models that link: (i) image content with gaze, (ii) image content and gaze with cognition, and (iii) image content, gaze, and cognition with diagnostic error. Both group-based and individualized models were explored. Results: By pooling the data from all radiologists machine learning produced highly accurate predictive models linking image content, gaze, cognition, and error. Merging radiologists gaze metrics and cognitive opinions with computer-extracted image features identified 59% of the radiologists diagnostic errors while confirming 96.2% of their correct diagnoses. The radiologists individual errors could be adequately predicted by modeling the behavior of their peers. However, personalized tuning appears to be beneficial in many cases to capture more accurately individual behavior. Conclusions: Machine learning algorithms combining image features with radiologists gaze data and diagnostic decisions can be effectively developed to recognize cognitive and perceptual errors associated with the diagnostic interpretation of mammograms.

  11. An adaptive orienting theory of error processing.

    Science.gov (United States)

    Wessel, Jan R

    2018-03-01

    The ability to detect and correct action errors is paramount to safe and efficient goal-directed behaviors. Existing work on the neural underpinnings of error processing and post-error behavioral adaptations has led to the development of several mechanistic theories of error processing. These theories can be roughly grouped into adaptive and maladaptive theories. While adaptive theories propose that errors trigger a cascade of processes that will result in improved behavior after error commission, maladaptive theories hold that error commission momentarily impairs behavior. Neither group of theories can account for all available data, as different empirical studies find both impaired and improved post-error behavior. This article attempts a synthesis between the predictions made by prominent adaptive and maladaptive theories. Specifically, it is proposed that errors invoke a nonspecific cascade of processing that will rapidly interrupt and inhibit ongoing behavior and cognition, as well as orient attention toward the source of the error. It is proposed that this cascade follows all unexpected action outcomes, not just errors. In the case of errors, this cascade is followed by error-specific, controlled processing, which is specifically aimed at (re)tuning the existing task set. This theory combines existing predictions from maladaptive orienting and bottleneck theories with specific neural mechanisms from the wider field of cognitive control, including from error-specific theories of adaptive post-error processing. The article aims to describe the proposed framework and its implications for post-error slowing and post-error accuracy, propose mechanistic neural circuitry for post-error processing, and derive specific hypotheses for future empirical investigations. © 2017 Society for Psychophysiological Research.

  12. WACC: Definition, misconceptions and errors

    OpenAIRE

    Fernandez, Pablo

    2011-01-01

    The WACC is just the rate at which the Free Cash Flows must be discounted to obtain the same result as in the valuation using Equity Cash Flows discounted at the required return to equity (Ke) The WACC is neither a cost nor a required return: it is a weighted average of a cost and a required return. To refer to the WACC as the "cost of capital" may be misleading because it is not a cost. The paper includes 7 errors due to not remembering the definition of WACC and shows the relationship betwe...

  13. Wavefront error sensing for LDR

    Science.gov (United States)

    Tubbs, Eldred F.; Glavich, T. A.

    1988-01-01

    Wavefront sensing is a significant aspect of the LDR control problem and requires attention at an early stage of the control system definition and design. A combination of a Hartmann test for wavefront slope measurement and an interference test for piston errors of the segments was examined and is presented as a point of departure for further discussion. The assumption is made that the wavefront sensor will be used for initial alignment and periodic alignment checks but that it will not be used during scientific observations. The Hartmann test and the interferometric test are briefly examined.

  14. Equipment for radiation diagnostics

    International Nuclear Information System (INIS)

    Tschunt, E.; Platz, W.

    1976-01-01

    The invention relates to an improvement of the line type of the plotter in an X-ray diagnostics apparatus enabling the production of distinguishable recordings by means of a single plot type. The construction is described explicitly. (UWI) [de

  15. National Convective Weather Diagnostic

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Current convective hazards identified by the National Convective Weather Detection algorithm. The National Convective Weather Diagnostic (NCWD) is an automatically...

  16. Diagnostic radiology: I

    International Nuclear Information System (INIS)

    Anon.

    1993-01-01

    This chapter describes the historic development of diagnostic equipment for radiology. The problems associated with fluoroscope design are detailed and the current uses of updated technology, particularly digitization, are considered. Numerous historical photographs are included. 13 refs

  17. Prenatal Genetic Diagnostic Tests

    Science.gov (United States)

    ... are available for many inherited disorders. The main disadvantage is that diagnostic testing carries a very small ... chromosomes, arranged in order of size. Microarray: A technology that examines all of a person’s genes to ...

  18. Molecular diagnostics of periodontitis

    OpenAIRE

    Izabela Korona-Głowniak; Radosław Siwiec; Marcin Berger; Anna Malm; Jolanta Szymańska

    2017-01-01

    The microorganisms that form dental plaque are the main cause of periodontitis. Their identification and the understanding of the complex relationships and interactions that involve these microorganisms, environmental factors and the host’s health status enable improvement in diagnostics and targeted therapy in patients with periodontitis. To this end, molecular diagnostics techniques (both techniques based on the polymerase chain reaction and those involving nucleic acid analysis via hybridi...

  19. Human decision error (HUMDEE) trees

    International Nuclear Information System (INIS)

    Ostrom, L.T.

    1993-01-01

    Graphical presentations of human actions in incident and accident sequences have been used for many years. However, for the most part, human decision making has been underrepresented in these trees. This paper presents a method of incorporating the human decision process into graphical presentations of incident/accident sequences. This presentation is in the form of logic trees. These trees are called Human Decision Error Trees or HUMDEE for short. The primary benefit of HUMDEE trees is that they graphically illustrate what else the individuals involved in the event could have done to prevent either the initiation or continuation of the event. HUMDEE trees also present the alternate paths available at the operator decision points in the incident/accident sequence. This is different from the Technique for Human Error Rate Prediction (THERP) event trees. There are many uses of these trees. They can be used for incident/accident investigations to show what other courses of actions were available and for training operators. The trees also have a consequence component so that not only the decision can be explored, also the consequence of that decision

  20. Apology for errors: whose responsibility?

    Science.gov (United States)

    Leape, Lucian L

    2012-01-01

    When things go wrong during a medical procedure, patients' expectations are fairly straightforward: They expect an explanation of what happened, an apology if an error was made, and assurance that something will be done to prevent it from happening to another patient. Patients have a right to full disclosure; it is also therapeutic in relieving their anxiety. But if they have been harmed by our mistake, they also need an apology to maintain trust. Apology conveys respect, mutual suffering, and responsibility. Meaningful apology requires that the patient's physician and the institution both take responsibility, show remorse, and make amends. As the patient's advocate, the physician must play the lead role. However, as custodian of the systems, the hospital has primary responsibility for the mishap, for preventing that error in the future, and for compensation. The responsibility for making all this happen rests with the CEO. The hospital must have policies and practices that ensure that every injured patient is treated the way we would want to be treated ourselves--openly, honestly, with compassion, and, when indicated, with an apology and compensation. To make that happen, hospitals need to greatly expand training of physicians and others, and develop support programs for patients and caregivers.

  1. Error exponents for entanglement concentration

    International Nuclear Information System (INIS)

    Hayashi, Masahito; Koashi, Masato; Matsumoto, Keiji; Morikoshi, Fumiaki; Winter, Andreas

    2003-01-01

    Consider entanglement concentration schemes that convert n identical copies of a pure state into a maximally entangled state of a desired size with success probability being close to one in the asymptotic limit. We give the distillable entanglement, the number of Bell pairs distilled per copy, as a function of an error exponent, which represents the rate of decrease in failure probability as n tends to infinity. The formula fills the gap between the least upper bound of distillable entanglement in probabilistic concentration, which is the well-known entropy of entanglement, and the maximum attained in deterministic concentration. The method of types in information theory enables the detailed analysis of the distillable entanglement in terms of the error rate. In addition to the probabilistic argument, we consider another type of entanglement concentration scheme, where the initial state is deterministically transformed into a (possibly mixed) final state whose fidelity to a maximally entangled state of a desired size converges to one in the asymptotic limit. We show that the same formula as in the probabilistic argument is valid for the argument on fidelity by replacing the success probability with the fidelity. Furthermore, we also discuss entanglement yield when optimal success probability or optimal fidelity converges to zero in the asymptotic limit (strong converse), and give the explicit formulae for those cases

  2. Measurement error models with interactions

    Science.gov (United States)

    Midthune, Douglas; Carroll, Raymond J.; Freedman, Laurence S.; Kipnis, Victor

    2016-01-01

    An important use of measurement error models is to correct regression models for bias due to covariate measurement error. Most measurement error models assume that the observed error-prone covariate (\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$W$\\end{document}) is a linear function of the unobserved true covariate (\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$X$\\end{document}) plus other covariates (\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$Z$\\end{document}) in the regression model. In this paper, we consider models for \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$W$\\end{document} that include interactions between \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$X$\\end{document} and \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{upgreek} \\usepackage{mathrsfs} \\setlength{\\oddsidemargin}{-69pt} \\begin{document} }{}$Z$\\end{document}. We derive the conditional distribution of

  3. Optics/Optical Diagnostics Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Optics/Optical Diagnostics Laboratory supports graduate instruction in optics, optical and laser diagnostics and electro-optics. The optics laboratory provides...

  4. Error Variability and the Differentiation between Apraxia of Speech and Aphasia with Phonemic Paraphasia

    Science.gov (United States)

    Haley, Katarina L.; Jacks, Adam; Cunningham, Kevin T.

    2013-01-01

    Purpose: This study was conducted to evaluate the clinical utility of error variability for differentiating between apraxia of speech (AOS) and aphasia with phonemic paraphasia. Method: Participants were 32 individuals with aphasia after left cerebral injury. Diagnostic groups were formed on the basis of operationalized measures of recognized…

  5. Identifying Engineering Students' English Sentence Reading Comprehension Errors: Applying a Data Mining Technique

    Science.gov (United States)

    Tsai, Yea-Ru; Ouyang, Chen-Sen; Chang, Yukon

    2016-01-01

    The purpose of this study is to propose a diagnostic approach to identify engineering students' English reading comprehension errors. Student data were collected during the process of reading texts of English for science and technology on a web-based cumulative sentence analysis system. For the analysis, the association-rule, data mining technique…

  6. Determining the Numeracy and Algebra Errors of Students in a Two-Year Vocational School

    Science.gov (United States)

    Akyüz, Gözde

    2015-01-01

    The goal of this study was to determine the mathematics achievement level in basic numeracy and algebra concepts of students in a two-year program in a technical vocational school of higher education and determine the errors that they make in these topics. The researcher developed a diagnostic mathematics achievement test related to numeracy and…

  7. Benefit/risk comparisons in diagnostic radiology

    International Nuclear Information System (INIS)

    Oosterkamp, W.J.

    1976-01-01

    Benefit and risks in radiodiagnostic examination, either with X-rays or with radioactive isotopes, can be expressed in restored health and health impaired by radiation or: lives saved and estimated lives lost as a result of genetic or somatic radiation damage. Published data on benefit-risk comparisons for mass stomach and chest surveys show a considerable benefit surplus. It is demonstrated that this is also true in the case of clinical examinations of the sick. Efforts should be concentrated on better ways and means to reduce the number of diagnostic errors. Risk estimates should be made as realistic as possible

  8. Should we confirm our clinical diagnostic certainty by autopsies?

    Science.gov (United States)

    Podbregar, M; Voga, G; Krivec, B; Skale, R; Pareznik, R; Gabrscek, L

    2001-11-01

    To evaluate the frequency of diagnostic errors assessed by autopsies. Retrospective review of medical and pathological records in an 11-bed closed medical intensive care unit (ICU) at a 860-bed general hospital. Patients who died in the ICU between January 1998 and December 1999. Medical diagnoses were rated into three levels of clinical diagnostic certainty: complete certainty (group L1), minor diagnostic uncertainty (group L2), and major diagnostic uncertainty (group L3). The patients were divided into three error groups: group A, the autopsy confirmed the clinical diagnosis; group B, the autopsy demonstrated a new relevant diagnosis which would probably not have influenced the therapy and outcome; group C, the autopsy demonstrated a new relevant diagnosis which would probably have changed the therapy and outcome. The overall mortality was 20.3% (270/1331 patients). Autopsies were performed in 126 patients (46.9% of deaths), more often in younger patients (66.6+/-13.9 years vs 72.7+/-12.0 years, p<0.001), in patients with shorter ICU stay (4.7+/-5.6 days vs 6.7+/-8.7 days, p=0.054), and in patients in group L3 without chronic diseases (15/126 vs 1/144, p<0.001). Fatal but potentially treatable errors [group C, 12 patients (9.5%)] were found in 8.7%, 10.0%, and 10.5% of patients in groups L1, L2, and L3, respectively (NS between groups). An ICU length of stay shorter than 24 h was not related to the frequency of group C errors. Autopsies are performed more often in younger patients without chronic disease and in patients with a low clinical diagnostic certainty. No level of clinical diagnostic certainty could predict the pathological findings.

  9. Game Design Principles based on Human Error

    Directory of Open Access Journals (Sweden)

    Guilherme Zaffari

    2016-03-01

    Full Text Available This paper displays the result of the authors’ research regarding to the incorporation of Human Error, through design principles, to video game design. In a general way, designers must consider Human Error factors throughout video game interface development; however, when related to its core design, adaptations are in need, since challenge is an important factor for fun and under the perspective of Human Error, challenge can be considered as a flaw in the system. The research utilized Human Error classifications, data triangulation via predictive human error analysis, and the expanded flow theory to allow the design of a set of principles in order to match the design of playful challenges with the principles of Human Error. From the results, it was possible to conclude that the application of Human Error in game design has a positive effect on player experience, allowing it to interact only with errors associated with the intended aesthetics of the game.

  10. Understanding human management of automation errors

    Science.gov (United States)

    McBride, Sara E.; Rogers, Wendy A.; Fisk, Arthur D.

    2013-01-01

    Automation has the potential to aid humans with a diverse set of tasks and support overall system performance. Automated systems are not always reliable, and when automation errs, humans must engage in error management, which is the process of detecting, understanding, and correcting errors. However, this process of error management in the context of human-automation interaction is not well understood. Therefore, we conducted a systematic review of the variables that contribute to error management. We examined relevant research in human-automation interaction and human error to identify critical automation, person, task, and emergent variables. We propose a framework for management of automation errors to incorporate and build upon previous models. Further, our analysis highlights variables that may be addressed through design and training to positively influence error management. Additional efforts to understand the error management process will contribute to automation designed and implemented to support safe and effective system performance. PMID:25383042

  11. An Error Analysis on TFL Learners’ Writings

    Directory of Open Access Journals (Sweden)

    Arif ÇERÇİ

    2016-12-01

    Full Text Available The main purpose of the present study is to identify and represent TFL learners’ writing errors through error analysis. All the learners started learning Turkish as foreign language with A1 (beginner level and completed the process by taking C1 (advanced certificate in TÖMER at Gaziantep University. The data of the present study were collected from 14 students’ writings in proficiency exams for each level. The data were grouped as grammatical, syntactic, spelling, punctuation, and word choice errors. The ratio and categorical distributions of identified errors were analyzed through error analysis. The data were analyzed through statistical procedures in an effort to determine whether error types differ according to the levels of the students. The errors in this study are limited to the linguistic and intralingual developmental errors

  12. Field errors in hybrid insertion devices

    International Nuclear Information System (INIS)

    Schlueter, R.D.

    1995-02-01

    Hybrid magnet theory as applied to the error analyses used in the design of Advanced Light Source (ALS) insertion devices is reviewed. Sources of field errors in hybrid insertion devices are discussed

  13. Field errors in hybrid insertion devices

    Energy Technology Data Exchange (ETDEWEB)

    Schlueter, R.D. [Lawrence Berkeley Lab., CA (United States)

    1995-02-01

    Hybrid magnet theory as applied to the error analyses used in the design of Advanced Light Source (ALS) insertion devices is reviewed. Sources of field errors in hybrid insertion devices are discussed.

  14. Error Covariance Estimation of Mesoscale Data Assimilation

    National Research Council Canada - National Science Library

    Xu, Qin

    2005-01-01

    The goal of this project is to explore and develop new methods of error covariance estimation that will provide necessary statistical descriptions of prediction and observation errors for mesoscale data assimilation...

  15. Errors and malpractice lawsuits in radiology: what the radiologist needs to know.

    Science.gov (United States)

    Busardò, Francesco Paolo; Frati, Paola; Santurro, Alessandro; Zaami, Simona; Fineschi, Vittorio

    2015-09-01

    All medical specialties dealing with patients include an intrinsic risk in exposing them to issues resulting from human errors. Radiology is not spared from this risk since it includes "decision-making under conditions of uncertainty." In medical imaging, the line between the word "error" and misdiagnosis or discrepancy is very difficult to demarcate, mainly because the diagnostic process is not a binary relation and it is not always possible to establish if a pathological condition is present or not. The error in radiology is strongly related to the diagnostic process; hence, it can be defined as a "diagnostic error" which represents the most common cause of medical malpractice suits against radiologists. In this paper, the authors described the features of errors occurring in radiology, trying to establish their impact and prevalence. Secondly, some data coming from different countries were compared in order to highlight the most frequent causes leading to malpractice lawsuits in radiology and how the phenomenon of malpractice in this field is represented worldwide.

  16. Improving Type Error Messages in OCaml

    OpenAIRE

    Charguéraud , Arthur

    2015-01-01

    International audience; Cryptic type error messages are a major obstacle to learning OCaml or other ML-based languages. In many cases, error messages cannot be interpreted without a sufficiently-precise model of the type inference algorithm. The problem of improving type error messages in ML has received quite a bit of attention over the past two decades, and many different strategies have been considered. The challenge is not only to produce error messages that are both sufficiently concise ...

  17. Different grades MEMS accelerometers error characteristics

    Science.gov (United States)

    Pachwicewicz, M.; Weremczuk, J.

    2017-08-01

    The paper presents calibration effects of two different MEMS accelerometers of different price and quality grades and discusses different accelerometers errors types. The calibration for error determining is provided by reference centrifugal measurements. The design and measurement errors of the centrifuge are discussed as well. It is shown that error characteristics of the sensors are very different and it is not possible to use simple calibration methods presented in the literature in both cases.

  18. Naming game with learning errors in communications

    OpenAIRE

    Lou, Yang; Chen, Guanrong

    2014-01-01

    Naming game simulates the process of naming an objective by a population of agents organized in a certain communication network topology. By pair-wise iterative interactions, the population reaches a consensus state asymptotically. In this paper, we study naming game with communication errors during pair-wise conversations, where errors are represented by error rates in a uniform probability distribution. First, a model of naming game with learning errors in communications (NGLE) is proposed....

  19. How Do Simulated Error Experiences Impact Attitudes Related to Error Prevention?

    Science.gov (United States)

    Breitkreuz, Karen R; Dougal, Renae L; Wright, Melanie C

    2016-10-01

    The objective of this project was to determine whether simulated exposure to error situations changes attitudes in a way that may have a positive impact on error prevention behaviors. Using a stratified quasi-randomized experiment design, we compared risk perception attitudes of a control group of nursing students who received standard error education (reviewed medication error content and watched movies about error experiences) to an experimental group of students who reviewed medication error content and participated in simulated error experiences. Dependent measures included perceived memorability of the educational experience, perceived frequency of errors, and perceived caution with respect to preventing errors. Experienced nursing students perceived the simulated error experiences to be more memorable than movies. Less experienced students perceived both simulated error experiences and movies to be highly memorable. After the intervention, compared with movie participants, simulation participants believed errors occurred more frequently. Both types of education increased the participants' intentions to be more cautious and reported caution remained higher than baseline for medication errors 6 months after the intervention. This study provides limited evidence of an advantage of simulation over watching movies describing actual errors with respect to manipulating attitudes related to error prevention. Both interventions resulted in long-term impacts on perceived caution in medication administration. Simulated error experiences made participants more aware of how easily errors can occur, and the movie education made participants more aware of the devastating consequences of errors.

  20. Cognitive balanced model: a conceptual scheme of diagnostic decision making.

    Science.gov (United States)

    Lucchiari, Claudio; Pravettoni, Gabriella

    2012-02-01

    Diagnostic reasoning is a critical aspect of clinical performance, having a high impact on quality and safety of care. Although diagnosis is fundamental in medicine, we still have a poor understanding of the factors that determine its course. According to traditional understanding, all information used in diagnostic reasoning is objective and logically driven. However, these conditions are not always met. Although we would be less likely to make an inaccurate diagnosis when following rational decision making, as described by normative models, the real diagnostic process works in a different way. Recent work has described the major cognitive biases in medicine as well as a number of strategies for reducing them, collectively called debiasing techniques. However, advances have encountered obstacles in achieving implementation into clinical practice. While traditional understanding of clinical reasoning has failed to consider contextual factors, most debiasing techniques seem to fail in raising sound and safer medical praxis. Technological solutions, being data driven, are fundamental in increasing care safety, but they need to consider human factors. Thus, balanced models, cognitive driven and technology based, are needed in day-to-day applications to actually improve the diagnostic process. The purpose of this article, then, is to provide insight into cognitive influences that have resulted in wrong, delayed or missed diagnosis. Using a cognitive approach, we describe the basis of medical error, with particular emphasis on diagnostic error. We then propose a conceptual scheme of the diagnostic process by the use of fuzzy cognitive maps. © 2011 Blackwell Publishing Ltd.

  1. Modeling sequential context effects in diagnostic interpretation of screening mammograms.

    Science.gov (United States)

    Alamudun, Folami; Paulus, Paige; Yoon, Hong-Jun; Tourassi, Georgia

    2018-07-01

    Prior research has shown that physicians' medical decisions can be influenced by sequential context, particularly in cases where successive stimuli exhibit similar characteristics when analyzing medical images. This type of systematic error is known to psychophysicists as sequential context effect as it indicates that judgments are influenced by features of and decisions about the preceding case in the sequence of examined cases, rather than being based solely on the peculiarities unique to the present case. We determine if radiologists experience some form of context bias, using screening mammography as the use case. To this end, we explore correlations between previous perceptual behavior and diagnostic decisions and current decisions. We hypothesize that a radiologist's visual search pattern and diagnostic decisions in previous cases are predictive of the radiologist's current diagnostic decisions. To test our hypothesis, we tasked 10 radiologists of varied experience to conduct blind reviews of 100 four-view screening mammograms. Eye-tracking data and diagnostic decisions were collected from each radiologist under conditions mimicking clinical practice. Perceptual behavior was quantified using the fractal dimension of gaze scanpath, which was computed using the Minkowski-Bouligand box-counting method. To test the effect of previous behavior and decisions, we conducted a multifactor fixed-effects ANOVA. Further, to examine the predictive value of previous perceptual behavior and decisions, we trained and evaluated a predictive model for radiologists' current diagnostic decisions. ANOVA tests showed that previous visual behavior, characterized by fractal analysis, previous diagnostic decisions, and image characteristics of previous cases are significant predictors of current diagnostic decisions. Additionally, predictive modeling of diagnostic decisions showed an overall improvement in prediction error when the model is trained on additional information about

  2. Interpreting the change detection error matrix

    NARCIS (Netherlands)

    Oort, van P.A.J.

    2007-01-01

    Two different matrices are commonly reported in assessment of change detection accuracy: (1) single date error matrices and (2) binary change/no change error matrices. The third, less common form of reporting, is the transition error matrix. This paper discuses the relation between these matrices.

  3. Human Errors and Bridge Management Systems

    DEFF Research Database (Denmark)

    Thoft-Christensen, Palle; Nowak, A. S.

    on basis of reliability profiles for bridges without human errors are extended to include bridges with human errors. The first rehabilitation distributions for bridges without and with human errors are combined into a joint first rehabilitation distribution. The methodology presented is illustrated...... for reinforced concrete bridges....

  4. Error Analysis in Mathematics. Technical Report #1012

    Science.gov (United States)

    Lai, Cheng-Fei

    2012-01-01

    Error analysis is a method commonly used to identify the cause of student errors when they make consistent mistakes. It is a process of reviewing a student's work and then looking for patterns of misunderstanding. Errors in mathematics can be factual, procedural, or conceptual, and may occur for a number of reasons. Reasons why students make…

  5. On-Error Training (Book Excerpt).

    Science.gov (United States)

    Fukuda, Ryuji

    1985-01-01

    This excerpt from "Managerial Engineering: Techniques for Improving Quality and Productivity in the Workplace" describes the development, objectives, and use of On-Error Training (OET), a method which trains workers to learn from their errors. Also described is New Joharry's Window, a performance-error data analysis technique used in…

  6. Human Error Mechanisms in Complex Work Environments

    DEFF Research Database (Denmark)

    Rasmussen, Jens

    1988-01-01

    will account for most of the action errors observed. In addition, error mechanisms appear to be intimately related to the development of high skill and know-how in a complex work context. This relationship between errors and human adaptation is discussed in detail for individuals and organisations...

  7. Measurement error in a single regressor

    NARCIS (Netherlands)

    Meijer, H.J.; Wansbeek, T.J.

    2000-01-01

    For the setting of multiple regression with measurement error in a single regressor, we present some very simple formulas to assess the result that one may expect when correcting for measurement error. It is shown where the corrected estimated regression coefficients and the error variance may lie,

  8. Valuing Errors for Learning: Espouse or Enact?

    Science.gov (United States)

    Grohnert, Therese; Meuwissen, Roger H. G.; Gijselaers, Wim H.

    2017-01-01

    Purpose: This study aims to investigate how organisations can discourage covering up and instead encourage learning from errors through a supportive learning from error climate. In explaining professionals' learning from error behaviour, this study distinguishes between espoused (verbally expressed) and enacted (behaviourally expressed) values…

  9. Improved Landau gauge fixing and discretisation errors

    International Nuclear Information System (INIS)

    Bonnet, F.D.R.; Bowman, P.O.; Leinweber, D.B.; Richards, D.G.; Williams, A.G.

    2000-01-01

    Lattice discretisation errors in the Landau gauge condition are examined. An improved gauge fixing algorithm in which O(a 2 ) errors are removed is presented. O(a 2 ) improvement of the gauge fixing condition displays the secondary benefit of reducing the size of higher-order errors. These results emphasise the importance of implementing an improved gauge fixing condition

  10. Acoustic Evidence for Phonologically Mismatched Speech Errors

    Science.gov (United States)

    Gormley, Andrea

    2015-01-01

    Speech errors are generally said to accommodate to their new phonological context. This accommodation has been validated by several transcription studies. The transcription methodology is not the best choice for detecting errors at this level, however, as this type of error can be difficult to perceive. This paper presents an acoustic analysis of…

  11. Average beta-beating from random errors

    CERN Document Server

    Tomas Garcia, Rogelio; Langner, Andy Sven; Malina, Lukas; Franchi, Andrea; CERN. Geneva. ATS Department

    2018-01-01

    The impact of random errors on average β-beating is studied via analytical derivations and simulations. A systematic positive β-beating is expected from random errors quadratic with the sources or, equivalently, with the rms β-beating. However, random errors do not have a systematic effect on the tune.

  12. Jonas Olson's Evidence for Moral Error Theory

    NARCIS (Netherlands)

    Evers, Daan

    2016-01-01

    Jonas Olson defends a moral error theory in (2014). I first argue that Olson is not justified in believing the error theory as opposed to moral nonnaturalism in his own opinion. I then argue that Olson is not justified in believing the error theory as opposed to moral contextualism either (although

  13. Etiology and outcome of inborn errors of metabolism

    International Nuclear Information System (INIS)

    Choudhry, S.; Khan, M.; Khan, E.A.

    2013-01-01

    Objectives: To study the clinical presentation, diagnostic workup and outcome of children presenting with suspected inborn errors of metabolism. Methods: The cross-sectional study was conducted at the Shifa International Hospital, Islamabad, and included all patients diagnosed with the condition between January 2006 and June 2011. Medical records of the patients were reviewed to collect the relevant data. Results: A total of 10 patients underwent diagnostic work-up. Majority 7 (70%) were males and 6 (60%) presented in the neonatal age group. Seizures and coma were the commonest presentations (n=5; 50% each) followed by breathing difficulty (n=4; 40%) and vomiting (n=2; 20%). The commonest diagnoses were methyl malonic acIdaemia (n=2; 20%), non-ketotic hyperglycinaemia (n=7; 10%), fructose 1,6 diphosphatase deficiency (n=1; 10%), and biotinidase deficiency (n=1; 10%). Mortality was high (n=5; 50%) and half of the survivors had severe neurological impairment. Conclusion: The diagnosis of inborn errors of metabolism requires a high index of suspicion. These disorders have a high mortality and risk of long-term neurological disability. (author)

  14. The use of error and uncertainty methods in the medical laboratory.

    Science.gov (United States)

    Oosterhuis, Wytze P; Bayat, Hassan; Armbruster, David; Coskun, Abdurrahman; Freeman, Kathleen P; Kallner, Anders; Koch, David; Mackenzie, Finlay; Migliarino, Gabriel; Orth, Matthias; Sandberg, Sverre; Sylte, Marit S; Westgard, Sten; Theodorsson, Elvar

    2018-01-26

    Error methods - compared with uncertainty methods - offer simpler, more intuitive and practical procedures for calculating measurement uncertainty and conducting quality assurance in laboratory medicine. However, uncertainty methods are preferred in other fields of science as reflected by the guide to the expression of uncertainty in measurement. When laboratory results are used for supporting medical diagnoses, the total uncertainty consists only partially of analytical variation. Biological variation, pre- and postanalytical variation all need to be included. Furthermore, all components of the measuring procedure need to be taken into account. Performance specifications for diagnostic tests should include the diagnostic uncertainty of the entire testing process. Uncertainty methods may be particularly useful for this purpose but have yet to show their strength in laboratory medicine. The purpose of this paper is to elucidate the pros and cons of error and uncertainty methods as groundwork for future consensus on their use in practical performance specifications. Error and uncertainty methods are complementary when evaluating measurement data.

  15. LHD neutron diagnostics

    International Nuclear Information System (INIS)

    Isobe, M.; Ogawa, K.; Kobuchi, T.

    2015-01-01

    The Large Helical Device (LHD) project will step into a next stage, i.e. experiment by using deuterium gases after two years of preparation. A comprehensive set of neutron and γ-ray diagnostics is going to be installed on the LHD towards extension of energetic-particle (EP) physics research in heliotron plasmas. Conceptual design of fusion products diagnostics for the LHD was made in late 1990s. After conclusion of agreements for the LHD deuterium experiment with local government bodies, development of FPs diagnostics has begun lately. Because there are a lot of tasks to do, all Japan fusion neutron and γ-ray diagnostics team has been organized in the collaboration framework of National Institute for Fusion Science. FPs diagnostics system on the LHD will consist of 1) wide dynamic range neutron flux monitor (NFM), 2) neutron activation system (NAS), 3) vertical neutron camera (VNC). In addition to these, we are developing a directional scintillating fiber detector, an artificial diamond detector and a γ-ray scintillation detector for confinement study of MeV ions. A neutron energy spectrometer prototype is also being developed and tested in KSTAR. In this paper, roles of NFM, NAS and VNC and current status of implementation onto the LHD are briefly described. (author)

  16. List of Error-Prone Abbreviations, Symbols, and Dose Designations

    Science.gov (United States)

    ... Analysis and Coaching Report an Error Report a Medication Error Report a Vaccine Error Consumer Error Reporting Search ... which have been reported through the ISMP National Medication Errors Reporting Program (ISMP MERP) as being frequently misinterpreted ...

  17. Analysis of error patterns in clinical radiotherapy

    International Nuclear Information System (INIS)

    Macklis, Roger; Meier, Tim; Barrett, Patricia; Weinhous, Martin

    1996-01-01

    Purpose: Until very recently, prescription errors and adverse treatment events have rarely been studied or reported systematically in oncology. We wished to understand the spectrum and severity of radiotherapy errors that take place on a day-to-day basis in a high-volume academic practice and to understand the resource needs and quality assurance challenges placed on a department by rapid upswings in contract-based clinical volumes requiring additional operating hours, procedures, and personnel. The goal was to define clinical benchmarks for operating safety and to detect error-prone treatment processes that might function as 'early warning' signs. Methods: A multi-tiered prospective and retrospective system for clinical error detection and classification was developed, with formal analysis of the antecedents and consequences of all deviations from prescribed treatment delivery, no matter how trivial. A department-wide record-and-verify system was operational during this period and was used as one method of treatment verification and error detection. Brachytherapy discrepancies were analyzed separately. Results: During the analysis year, over 2000 patients were treated with over 93,000 individual fields. A total of 59 errors affecting a total of 170 individual treated fields were reported or detected during this period. After review, all of these errors were classified as Level 1 (minor discrepancy with essentially no potential for negative clinical implications). This total treatment delivery error rate (170/93, 332 or 0.18%) is significantly better than corresponding error rates reported for other hospital and oncology treatment services, perhaps reflecting the relatively sophisticated error avoidance and detection procedures used in modern clinical radiation oncology. Error rates were independent of linac model and manufacturer, time of day (normal operating hours versus late evening or early morning) or clinical machine volumes. There was some relationship to

  18. Comparison between calorimeter and HLNC errors

    International Nuclear Information System (INIS)

    Goldman, A.S.; De Ridder, P.; Laszlo, G.

    1991-01-01

    This paper summarizes an error analysis that compares systematic and random errors of total plutonium mass estimated for high-level neutron coincidence counter (HLNC) and calorimeter measurements. This task was part of an International Atomic Energy Agency (IAEA) study on the comparison of the two instruments to determine if HLNC measurement errors met IAEA standards and if the calorimeter gave ''significantly'' better precision. Our analysis was based on propagation of error models that contained all known sources of errors including uncertainties associated with plutonium isotopic measurements. 5 refs., 2 tabs

  19. Communication skills in diagnostic pathology.

    Science.gov (United States)

    Lehr, Hans-Anton; Bosman, Fred T

    2016-01-01

    Communication is an essential element of good medical practice also in pathology. In contrast to technical or diagnostic skills, communication skills are not easy to define, teach, or assess. Rules almost do not exist. In this paper, which has a rather personal character and cannot be taken as a set of guidelines, important aspects of communication in pathology are explored. This includes what should be communicated to the pathologist on the pathology request form, communication between pathologists during internal (interpathologist) consultation, communication around frozen section diagnoses, modalities of communication of a final diagnosis, with whom and how critical and unexpected findings should be communicated, (in-)adequate routes of communication for pathology diagnoses, who will (or might) receive pathology reports, and what should be communicated and how in case of an error or a technical problem. An earlier more formal description of what the responsibilities are of a pathologist as communicator and as collaborator in a medical team is added in separate tables. The intention of the paper is to stimulate reflection and discussion rather than to formulate strict rules.

  20. Medication errors: an overview for clinicians.

    Science.gov (United States)

    Wittich, Christopher M; Burkle, Christopher M; Lanier, William L

    2014-08-01

    Medication error is an important cause of patient morbidity and mortality, yet it can be a confusing and underappreciated concept. This article provides a review for practicing physicians that focuses on medication error (1) terminology and definitions, (2) incidence, (3) risk factors, (4) avoidance strategies, and (5) disclosure and legal consequences. A medication error is any error that occurs at any point in the medication use process. It has been estimated by the Institute of Medicine that medication errors cause 1 of 131 outpatient and 1 of 854 inpatient deaths. Medication factors (eg, similar sounding names, low therapeutic index), patient factors (eg, poor renal or hepatic function, impaired cognition, polypharmacy), and health care professional factors (eg, use of abbreviations in prescriptions and other communications, cognitive biases) can precipitate medication errors. Consequences faced by physicians after medication errors can include loss of patient trust, civil actions, criminal charges, and medical board discipline. Methods to prevent medication errors from occurring (eg, use of information technology, better drug labeling, and medication reconciliation) have been used with varying success. When an error is discovered, patients expect disclosure that is timely, given in person, and accompanied with an apology and communication of efforts to prevent future errors. Learning more about medication errors may enhance health care professionals' ability to provide safe care to their patients. Copyright © 2014 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.

  1. Analysis of errors in forensic science

    Directory of Open Access Journals (Sweden)

    Mingxiao Du

    2017-01-01

    Full Text Available Reliability of expert testimony is one of the foundations of judicial justice. Both expert bias and scientific errors affect the reliability of expert opinion, which in turn affects the trustworthiness of the findings of fact in legal proceedings. Expert bias can be eliminated by replacing experts; however, it may be more difficult to eliminate scientific errors. From the perspective of statistics, errors in operation of forensic science include systematic errors, random errors, and gross errors. In general, process repetition and abiding by the standard ISO/IEC:17025: 2005, general requirements for the competence of testing and calibration laboratories, during operation are common measures used to reduce errors that originate from experts and equipment, respectively. For example, to reduce gross errors, the laboratory can ensure that a test is repeated several times by different experts. In applying for forensic principles and methods, the Federal Rules of Evidence 702 mandate that judges consider factors such as peer review, to ensure the reliability of the expert testimony. As the scientific principles and methods may not undergo professional review by specialists in a certain field, peer review serves as an exclusive standard. This study also examines two types of statistical errors. As false-positive errors involve a higher possibility of an unfair decision-making, they should receive more attention than false-negative errors.

  2. Error management process for power stations

    International Nuclear Information System (INIS)

    Hirotsu, Yuko; Takeda, Daisuke; Fujimoto, Junzo; Nagasaka, Akihiko

    2016-01-01

    The purpose of this study is to establish 'error management process for power stations' for systematizing activities for human error prevention and for festering continuous improvement of these activities. The following are proposed by deriving concepts concerning error management process from existing knowledge and realizing them through application and evaluation of their effectiveness at a power station: an entire picture of error management process that facilitate four functions requisite for maraging human error prevention effectively (1. systematizing human error prevention tools, 2. identifying problems based on incident reports and taking corrective actions, 3. identifying good practices and potential problems for taking proactive measures, 4. prioritizeng human error prevention tools based on identified problems); detail steps for each activity (i.e. developing an annual plan for human error prevention, reporting and analyzing incidents and near misses) based on a model of human error causation; procedures and example of items for identifying gaps between current and desired levels of executions and outputs of each activity; stages for introducing and establishing the above proposed error management process into a power station. By giving shape to above proposals at a power station, systematization and continuous improvement of activities for human error prevention in line with the actual situation of the power station can be expected. (author)

  3. Polychromatic holographic plasma diagnostics

    International Nuclear Information System (INIS)

    Zhiglinskij, A.G.; Morozov, A.O.

    1992-01-01

    Review of holographic interferometry properties is performed and advantages of this method by plasma diagnostics are indicated. Main results obtained by the method of holographic interferometry in studies of various-type plasmas are considered. Special attention is paid to multiwave plasma diagnostics, the necessity of which is related as a rule to multicomponent composition of plasma. The eight laser and gas-discharge sources and holographic schemes, which make it possible to realize plasma polychromatic and holographic interferometry, are considered. The advantages of the method are demonstrated by examples of polychromatic holographic diagnostics of arc discharge and discharge in a hollow cathode. Review of theoretical works determining the applicability area of resonance polychromatic interferometry is carried out

  4. Reversed field pinch diagnostics

    International Nuclear Information System (INIS)

    Weber, P.G.

    1986-01-01

    The Reversed Field Pinch (RFP) is a toroidal, axisymmetric magnetic confinement configuration characterized by a magnetic field configuration in which the toroidal magnetic field is of similar strength to the poloidal field, and is reversed at the edge compared to the center. The RFP routinely operates at high beta, and is a strong candidate for a compact fusion device. Relevant attributes of the configuration will be presented, together with an overview of present and planned experiments and their diagnostics. RFP diagnostics are in many ways similar to those of other magnetic confinement devices (such as tokamaks); these lectures will point out pertinent differences, and will present some diagnostics which provide special insights into unique attributes of the RFP

  5. Metabolomics for laboratory diagnostics.

    Science.gov (United States)

    Bujak, Renata; Struck-Lewicka, Wiktoria; Markuszewski, Michał J; Kaliszan, Roman

    2015-09-10

    Metabolomics is an emerging approach in a systems biology field. Due to continuous development in advanced analytical techniques and in bioinformatics, metabolomics has been extensively applied as a novel, holistic diagnostic tool in clinical and biomedical studies. Metabolome's measurement, as a chemical reflection of a current phenotype of a particular biological system, is nowadays frequently implemented to understand pathophysiological processes involved in disease progression as well as to search for new diagnostic or prognostic biomarkers of various organism's disorders. In this review, we discussed the research strategies and analytical platforms commonly applied in the metabolomics studies. The applications of the metabolomics in laboratory diagnostics in the last 5 years were also reviewed according to the type of biological sample used in the metabolome's analysis. We also discussed some limitations and further improvements which should be considered taking in mind potential applications of metabolomic research and practice. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Corpuscular plasma diagnostics

    International Nuclear Information System (INIS)

    Afrosimov, V.; Petrov, M.

    1984-01-01

    An elementary explanation is presented of the physical principles and important methods of corpuscular plasma diagnostics. The invaluable role of corpuscular methods for measuring the hot plasma ion component in thermonuclear facilities, especially hydrogen ions in tokamaks, is emphasized. All corpuscular methods employ analysis of fast neutral atoms and therefore the mechanism of their creation inside a hot plasma is explained first. The ammount of information obtainable from spectra of fast neutrals is discussed. Multichannel analyzers developed at the FTI A.F. Ioffe in Leningrad are described in detail. Classical passive corpuscular diagnostics are examined as are active methods using artifitial beams of hydrogen atoms. The method used for obtaining local values of ion temperature and density is explained. Corpuscular spectroscopic diagnostics and its application for measuring impurities is mentioned. (J.U.)

  7. [Cytology in uropathological diagnostics].

    Science.gov (United States)

    Gaisa, N T; Lindemann-Docter, K

    2015-11-01

    Cytology in uropathological diagnostics is mainly performed for oncological purposes. The assessment of malignancy by urothelial cell morphology is therefore decisive; however, cytology is only sensitive enough to detect high-grade tumor cells and the different low-grade tumors cannot be reliably diagnosed. Thus, the four-tier classification system of cytological findings (i.e. negative, atypical cells but significance uncertain, suspicious and positive) refers to high-grade tumor cells only. Furthermore, for valid cytological diagnostics not only the cytological specimen but also clinical information on cystoscopy findings and, if applicable, a biopsy should be evaluated together. In difficult differential diagnostic settings, e.g. differentiation between reactive versus neoplastic atypia or difficult to access lesions in the upper urinary tract, additional fluorescence in situ hybridization of cytological preparations might be helpful. At the moment there are no indications for further immunocytology or additional biomarker tests.

  8. ORION laser target diagnostics

    International Nuclear Information System (INIS)

    Bentley, C. D.; Edwards, R. D.; Andrew, J. E.; James, S. F.; Gardner, M. D.; Comley, A. J.; Vaughan, K.; Horsfield, C. J.; Rubery, M. S.; Rothman, S. D.; Daykin, S.; Masoero, S. J.; Palmer, J. B.; Meadowcroft, A. L.; Williams, B. M.; Gumbrell, E. T.; Fyrth, J. D.; Brown, C. R. D.; Hill, M. P.; Oades, K.

    2012-01-01

    The ORION laser facility is one of the UK's premier laser facilities which became operational at AWE in 2010. Its primary mission is one of stockpile stewardship, ORION will extend the UK's experimental plasma physics capability to the high temperature, high density regime relevant to Atomic Weapons Establishment's (AWE) program. The ORION laser combines ten laser beams operating in the ns regime with two sub ps short pulse chirped pulse amplification beams. This gives the UK a unique combined long pulse/short pulse laser capability which is not only available to AWE personnel but also gives access to our international partners and visiting UK academia. The ORION laser facility is equipped with a comprehensive suite of some 45 diagnostics covering optical, particle, and x-ray diagnostics all able to image the laser target interaction point. This paper focuses on a small selection of these diagnostics.

  9. ORION laser target diagnostics.

    Science.gov (United States)

    Bentley, C D; Edwards, R D; Andrew, J E; James, S F; Gardner, M D; Comley, A J; Vaughan, K; Horsfield, C J; Rubery, M S; Rothman, S D; Daykin, S; Masoero, S J; Palmer, J B; Meadowcroft, A L; Williams, B M; Gumbrell, E T; Fyrth, J D; Brown, C R D; Hill, M P; Oades, K; Wright, M J; Hood, B A; Kemshall, P

    2012-10-01

    The ORION laser facility is one of the UK's premier laser facilities which became operational at AWE in 2010. Its primary mission is one of stockpile stewardship, ORION will extend the UK's experimental plasma physics capability to the high temperature, high density regime relevant to Atomic Weapons Establishment's (AWE) program. The ORION laser combines ten laser beams operating in the ns regime with two sub ps short pulse chirped pulse amplification beams. This gives the UK a unique combined long pulse/short pulse laser capability which is not only available to AWE personnel but also gives access to our international partners and visiting UK academia. The ORION laser facility is equipped with a comprehensive suite of some 45 diagnostics covering optical, particle, and x-ray diagnostics all able to image the laser target interaction point. This paper focuses on a small selection of these diagnostics.

  10. Nova diagnostics summary

    International Nuclear Information System (INIS)

    Slivinsky, V.W.; Drake, R.P.

    1985-01-01

    The authors intend that Nova be the best diagnosed ICF research facility in operation today. The authors experience in providing advanced diagnostics for previous laser systems will be extended at Nova, and will be challenged by the development of new instrumentation to diagnose the more advanced targets made possible by this powerful laser. Previous experience has shown that to understand target performance, the authors must have as complete a set of diagnostics as possible. The Nova diagnostics are divided into two sets: the basic set required for the initial Nova experiments and the more advanced set for later, generally more complex, experiments. The basic set will be operational for the first Nova shots; it was a Nova line item funded with Nova construction money. This basic set is presented in a table

  11. Angiography - interventional diagnostic applications

    International Nuclear Information System (INIS)

    Schild, H.

    1994-01-01

    The angiography system is very different from the other systems used in diagnostic radiology. The invasivity of angiography requires special, high standards in theoretical and practical training and experience both of beginners and experienced personnel. This textbook fully meets the demand for in-depth and exhaustive information, as it presents: - The fundamentals and techniques of angiography, the vascular anatomy, and many hints and tips of great help in practice. - A comprehensive survey of diagnostic problems and examination approaches, including neuro-angiography, with 221 reproductions of original angiographs, and additional schematic representations. - A special chapter devoted to indication and relevant techniques for the major vascular interventional examinations. - A great number of tables explain at a glance standard examination techniques, indications and diagnostic criteria. (orig./CB) [de

  12. Advanced hardware design for error correcting codes

    CERN Document Server

    Coussy, Philippe

    2015-01-01

    This book provides thorough coverage of error correcting techniques. It includes essential basic concepts and the latest advances on key topics in design, implementation, and optimization of hardware/software systems for error correction. The book’s chapters are written by internationally recognized experts in this field. Topics include evolution of error correction techniques, industrial user needs, architectures, and design approaches for the most advanced error correcting codes (Polar Codes, Non-Binary LDPC, Product Codes, etc). This book provides access to recent results, and is suitable for graduate students and researchers of mathematics, computer science, and engineering. • Examines how to optimize the architecture of hardware design for error correcting codes; • Presents error correction codes from theory to optimized architecture for the current and the next generation standards; • Provides coverage of industrial user needs advanced error correcting techniques.

  13. Approximate error conjugation gradient minimization methods

    Science.gov (United States)

    Kallman, Jeffrey S

    2013-05-21

    In one embodiment, a method includes selecting a subset of rays from a set of all rays to use in an error calculation for a constrained conjugate gradient minimization problem, calculating an approximate error using the subset of rays, and calculating a minimum in a conjugate gradient direction based on the approximate error. In another embodiment, a system includes a processor for executing logic, logic for selecting a subset of rays from a set of all rays to use in an error calculation for a constrained conjugate gradient minimization problem, logic for calculating an approximate error using the subset of rays, and logic for calculating a minimum in a conjugate gradient direction based on the approximate error. In other embodiments, computer program products, methods, and systems are described capable of using approximate error in constrained conjugate gradient minimization problems.

  14. Beam Instrumentation and Diagnostics

    CERN Document Server

    Strehl, Peter

    2006-01-01

    This treatise covers all aspects of the design and the daily operations of a beam diagnostic system for a large particle accelerator. A very interdisciplinary field, it involves contributions from physicists, electrical and mechanical engineers and computer experts alike so as to satisfy the ever-increasing demands for beam parameter variability for a vast range of operation modi and particles. The author draws upon 40 years of research and work, most of them spent as the head of the beam diagnostics group at GSI. He has illustrated the more theoretical aspects with many real-life examples that will provide beam instrumentation designers with ideas and tools for their work.

  15. Diagnostic Imaging Workshop

    International Nuclear Information System (INIS)

    Sociedad Argentina de Fisica Medica

    2012-01-01

    The American Association of Physicist in Medicine (AAPM), the International Organization for Medical Physics (IOMP) and the Argentina Society of Medical Physics (SAFIM) was organized the Diagnostic Imaging Workshop 2012, in the city of Buenos Aires, Argentina. This workshop was an oriented training and scientific exchange between professionals and technicians who work in medical physics, especially in the areas of diagnostic imaging, nuclear medicine and radiotherapy, with special emphasis on the use of multimodal imaging for radiation treatment, planning as well of quality assurance associates.

  16. Error handling for the CDF Silicon Vertex Tracker

    CERN Document Server

    Belforte, S; Dell'Orso, Mauro; Donati, S; Galeotti, S; Giannetti, P; Morsani, F; Punzi, G; Ristori, L; Spinella, F; Zanetti, A M

    2000-01-01

    The SVT online tracker for the CDF upgrade reconstructs two- dimensional tracks using information from the Silicon Vertex detector (SVXII) and the Central Outer Tracker (COT). The SVT has an event rate of 100 kHz and a latency time of 10 mu s. The system is composed of 104 VME 9U digital boards (of 8 different types) and it is implemented as a data driven architecture. Each board runs on its own 30 MHz clock. Since the data output from the SVT (few Mbytes/sec) are a small fraction of the input data (200 Mbytes/sec), it is extremely difficult to track possible internal errors by using only the output stream. For this reason several diagnostic tools have been implemented: local error registers, error bits propagated through the data streams and the Spy Buffer system. Data flowing through each input and output stream of every board are continuously copied to memory banks named Spy Buffers which act as built in logic state analyzers hooked continuously to internal data streams. The contents of all buffers can be ...

  17. Medication errors in anesthesia: unacceptable or unavoidable?

    Directory of Open Access Journals (Sweden)

    Ira Dhawan

    Full Text Available Abstract Medication errors are the common causes of patient morbidity and mortality. It adds financial burden to the institution as well. Though the impact varies from no harm to serious adverse effects including death, it needs attention on priority basis since medication errors' are preventable. In today's world where people are aware and medical claims are on the hike, it is of utmost priority that we curb this issue. Individual effort to decrease medication error alone might not be successful until a change in the existing protocols and system is incorporated. Often drug errors that occur cannot be reversed. The best way to ‘treat' drug errors is to prevent them. Wrong medication (due to syringe swap, overdose (due to misunderstanding or preconception of the dose, pump misuse and dilution error, incorrect administration route, under dosing and omission are common causes of medication error that occur perioperatively. Drug omission and calculation mistakes occur commonly in ICU. Medication errors can occur perioperatively either during preparation, administration or record keeping. Numerous human and system errors can be blamed for occurrence of medication errors. The need of the hour is to stop the blame - game, accept mistakes and develop a safe and ‘just' culture in order to prevent medication errors. The newly devised systems like VEINROM, a fluid delivery system is a novel approach in preventing drug errors due to most commonly used medications in anesthesia. Similar developments along with vigilant doctors, safe workplace culture and organizational support all together can help prevent these errors.

  18. Electron beam diagnostics study

    International Nuclear Information System (INIS)

    Garganne, P.

    1989-08-01

    This paper summarizes the results of a study on beam diagnostics, using carbon wire scanners and optical transition radiation (DTR) monitors. The main consideration consists in the material selection, taking their thermal properties and their effect on the beam into account [fr

  19. Molecular Beacons in Diagnostics

    OpenAIRE

    Tyagi, Sanjay; Kramer, Fred Russell

    2012-01-01

    Recent technical advances have begun to realize the potential of molecular beacons to test for diverse infections in clinical diagnostic laboratories. These include the ability to test for, and quantify, multiple pathogens in the same clinical sample, and to detect antibiotic resistant strains within hours. The design principles of molecular beacons have also spawned a variety of allied technologies.

  20. Diagnostic radiation and pregnancy

    International Nuclear Information System (INIS)

    Collins, L.; Fitzgerald, P.

    1983-01-01

    Accidental irradiation of the embryo or fetus in the first trimester is a problem which will occasionally occur. The value of a proper estimation of the radiation dose is emphasised. Very rarely does a single diagnostic procedure result in a uterine dose as high as 50 mGy. An accidental irradiation should rarely be cause for termination of a pregnancy

  1. Diagnostic imaging of craniopharyngioma

    International Nuclear Information System (INIS)

    Gradzki, J.; Nowak, S.; Paprzycki, W.

    1993-01-01

    40 patients have been examined with operational and histological confirmation of craniopharyngioma. CT image and X-ray plane of skull were performed in case all of these patients. TMR was conformed to examine 4 patients. X-ray planes was compared to CT. CT permits tumor cyst detection. The efficacy of mentioned above diagnostic techniques was compared with surgical findings. (author)

  2. Diagnostics for induction accelerators

    International Nuclear Information System (INIS)

    Fessenden, T.J.

    1996-04-01

    The induction accelerator was conceived by N. C. Christofilos and first realized as the Astron accelerator that operated at LLNL from the early 1960's to the end of 1975. This accelerator generated electron beams at energies near 6 MeV with typical currents of 600 Amperes in 400 ns pulses. The Advanced Test Accelerator (ATA) built at Livermore's Site 300 produced 10,000 Ampere beams with pulse widths of 70 ns at energies approaching 50 MeV. Several other electron and ion induction accelerators have been fabricated at LLNL and LBNL. This paper reviews the principal diagnostics developed through efforts by scientists at both laboratories for measuring the current, position, energy, and emittance of beams generated by these high current, short pulse accelerators. Many of these diagnostics are closely related to those developed for other accelerators. However, the very fast and intense current pulses often require special diagnostic techniques and considerations. The physics and design of the more unique diagnostics developed for electron induction accelerators are presented and discussed in detail

  3. Diagnostic studies in amyloidosis

    NARCIS (Netherlands)

    Hazenberg, Bouke Pier Cornelis

    2007-01-01

    In this thesis two diagnostic techniques are studied in amyloidosis. Systemic amyloidosis is characterized by deposition of amyloid fibrils (tiny fibres) throughout the body resulting in damage of vital organs. Amyloid can be detected in a tissue specimen stained with Congo red: red-stained amyloid

  4. 1968 Prototype Diagnostic Test.

    Science.gov (United States)

    Veterans Administration Hospital, Bedford, MA.

    This true-false diagnostic test was used for pretesting of employees at a Veterans Administration Hospital. The test is comprised of 20 items. An alternate test--Classification Questionnaire--was used for testing after remedial training. (For related document, see TM 002 334.) (DB)

  5. Diagnostics for induction accelerators

    International Nuclear Information System (INIS)

    Fessenden, T.J.

    1997-01-01

    The induction accelerator was conceived by N. C. Christofilos and first realized as the Astron accelerator that operated at Lawrence Livermore National Laboratory (LLNL) from the early 1960s to the end of 1975. This accelerator generated electron beams at energies near 6 MeV with typical currents of 600 Amperes in 400-ns pulses. The Advanced Test Accelerator (ATA) built at Livermore close-quote s Site 300 produced 10,000-Ampere beams with pulse widths of 70 ns at energies approaching 50 MeV. Several other electron and ion induction accelerators have been fabricated at LLNL and Lawrence Berkeley National Laboratory (LBNL). This paper reviews the principal diagnostics developed through efforts by scientists at both laboratories for measuring the current, position, energy, and emittance of beams generated by these high-current, short-pulse accelerators. Many of these diagnostics are closely related to those developed for other accelerators. However, the very fast and intense current pulses often require special diagnostic techniques and considerations. The physics and design of the more unique diagnostics developed for electron induction accelerators are presented and discussed in detail. copyright 1997 American Institute of Physics

  6. It's diagnostics, stupid.

    Science.gov (United States)

    Bernards, René

    2010-04-02

    To stem the spiraling cost of cancer treatment, a concerted effort is urgently needed to develop molecular diagnostics to better identify the patients that respond to expensive targeted therapies. Opportunities and obstacles in the development of such drug response biomarkers are discussed here. Copyright 2010 Elsevier Inc. All rights reserved.

  7. Diagnostics for pellet experiments

    International Nuclear Information System (INIS)

    Johnson, R.R.

    1978-01-01

    The target diagnostics which are being used and planned in current laser driven ICF Experiments are described. Most of these diagnostics can be easily applied to future ion-beam fusion experiments. The status of laser fusion diagnostics has been much improved in the last 5 years and further improvements can be expected and should be available when the first ICF experiments using ion beams are performed. As an example, x-ray temporal and spatial resolutions are now approximately 5 psec and 3 μm, which is approximately a factor of 4 better than the resolution reported in the first implosion experiments. As one plans ahead for ion-beam fusion experiments it should be emphasized that high yield experiments are easier to diagnose provided adequate shielding is employed. However, in the event that the first high yield experiments fail it will be necessary to have diagnostics available to determine where the problems lie. In laser fusion it is interesting to note that higher laser powers are required now for breakeven experiments than first anticipated, mainly because some aspects of the laser-interaction physics were not recognized until the experiments were carefully diagnosed. Thus as has been pointed out, it may be necessary to increase the energy of the ion-beam driver to enable us to do breakeven experiments with high confidence

  8. Flowfield modeling and diagnostics

    International Nuclear Information System (INIS)

    Gupta, A.K.; Lilley, D.G.

    1985-01-01

    This textbook is devoted solely to flowfield modeling and diagnostics; their practical use, recent and current research, and projected developments and trends. It provides an account of the use of a broad range of techniques in industrial and research practice, both with and without combustion. Application ideas are complemented by details about experimental and modeling techniques

  9. Serbia : Systematic Country Diagnostic

    OpenAIRE

    World Bank Group

    2015-01-01

    This Systematic Country Diagnostic (SCD) aims to identify the major constraints on and opportunities for sustaining poverty reduction and shared prosperity in Serbia. The SCD serves as the analytic foundation on which the World Bank Group and the Government of Serbia will define a new Country Partnership Framework for FY2016 to FY2020. It is based on the best possible analysis, drawing on ...

  10. Diagnostic and interventional radiology

    Energy Technology Data Exchange (ETDEWEB)

    Vogl, Thomas J. [Klinikum der Johann Wolfgang Goethe-Universitaet, Frankfurt am Main (Germany). Inst. fuer Diagnostische und Interventionelle Radiologie; Reith, Wolfgang [Universitaetsklinikum des Saarlandes, Homburg/Saar (Germany). Klinik fuer Diagnostische und Interventionelle Neuroradiologie; Rummeny, Ernst J. (ed.) [Technische Univ. Muenchen Klinikum rechts der Isar, Muenchen (Germany). Inst. fuer Radiologie

    2016-08-01

    This exceptional book covers all aspects of diagnostic and interventional radiology within one volume, at a level appropriate for the specialist. From the basics through diagnosis to intervention: the reader will find a complete overview of all areas of radiology. The clear, uniform structure, with chapters organized according to organ system, facilitates the rapid retrieval of information. Features include: Presentation of the normal radiological anatomy Classification of the different imaging procedures according to their diagnostic relevance Imaging diagnosis with many reference images Precise description of the interventional options The inclusion of many instructive aids will be of particular value to novices in decision making: Important take home messages and summaries of key radiological findings smooth the path through the jungle of facts Numerous tables on differential diagnosis and typical findings in the most common diseases offer a rapid overview and orientation Diagnostic flow charts outline the sequence of diagnostic evaluation All standard procedures within the field of interventional radiology are presented in a clinically relevant and readily understandable way, with an abundance of illustrations. This is a textbook, atlas, and reference in one: with more than 2500 images for comparison with the reader's own findings. This comprehensive and totally up-to-date book provides a superb overview of everything that the radiology specialist of today needs to know.

  11. Tune-Based Halo Diagnostics

    International Nuclear Information System (INIS)

    Cameron, Peter

    2003-01-01

    Tune-based halo diagnostics can be divided into two categories -- diagnostics for halo prevention, and diagnostics for halo measurement. Diagnostics for halo prevention are standard fare in accumulators, synchrotrons, and storage rings, and again can be divided into two categories -- diagnostics to measure the tune distribution (primarily to avoid resonances), and diagnostics to identify instabilities (which will not be discussed here). These diagnostic systems include kicked (coherent) tune measurement, phase-locked loop (PLL) tune measurement, Schottky tune measurement, beam transfer function (BTF) measurements, and measurement of transverse quadrupole mode envelope oscillations. We refer briefly to tune diagnostics used at RHIC and intended for the SNS, and then present experimental results. Tune-based diagnostics for halo measurement (as opposed to prevention) are considerably more difficult. We present one brief example of tune-based halo measurement

  12. Human errors related to maintenance and modifications

    International Nuclear Information System (INIS)

    Laakso, K.; Pyy, P.; Reiman, L.

    1998-01-01

    The focus in human reliability analysis (HRA) relating to nuclear power plants has traditionally been on human performance in disturbance conditions. On the other hand, some studies and incidents have shown that also maintenance errors, which have taken place earlier in plant history, may have an impact on the severity of a disturbance, e.g. if they disable safety related equipment. Especially common cause and other dependent failures of safety systems may significantly contribute to the core damage risk. The first aim of the study was to identify and give examples of multiple human errors which have penetrated the various error detection and inspection processes of plant safety barriers. Another objective was to generate numerical safety indicators to describe and forecast the effectiveness of maintenance. A more general objective was to identify needs for further development of maintenance quality and planning. In the first phase of this operational experience feedback analysis, human errors recognisable in connection with maintenance were looked for by reviewing about 4400 failure and repair reports and some special reports which cover two nuclear power plant units on the same site during 1992-94. A special effort was made to study dependent human errors since they are generally the most serious ones. An in-depth root cause analysis was made for 14 dependent errors by interviewing plant maintenance foremen and by thoroughly analysing the errors. A more simple treatment was given to maintenance-related single errors. The results were shown as a distribution of errors among operating states i.a. as regards the following matters: in what operational state the errors were committed and detected; in what operational and working condition the errors were detected, and what component and error type they were related to. These results were presented separately for single and dependent maintenance-related errors. As regards dependent errors, observations were also made

  13. Angular truncation errors in integrating nephelometry

    International Nuclear Information System (INIS)

    Moosmueller, Hans; Arnott, W. Patrick

    2003-01-01

    Ideal integrating nephelometers integrate light scattered by particles over all directions. However, real nephelometers truncate light scattered in near-forward and near-backward directions below a certain truncation angle (typically 7 deg. ). This results in truncation errors, with the forward truncation error becoming important for large particles. Truncation errors are commonly calculated using Mie theory, which offers little physical insight and no generalization to nonspherical particles. We show that large particle forward truncation errors can be calculated and understood using geometric optics and diffraction theory. For small truncation angles (i.e., <10 deg. ) as typical for modern nephelometers, diffraction theory by itself is sufficient. Forward truncation errors are, by nearly a factor of 2, larger for absorbing particles than for nonabsorbing particles because for large absorbing particles most of the scattered light is due to diffraction as transmission is suppressed. Nephelometers calibration procedures are also discussed as they influence the effective truncation error

  14. Collection of offshore human error probability data

    International Nuclear Information System (INIS)

    Basra, Gurpreet; Kirwan, Barry

    1998-01-01

    Accidents such as Piper Alpha have increased concern about the effects of human errors in complex systems. Such accidents can in theory be predicted and prevented by risk assessment, and in particular human reliability assessment (HRA), but HRA ideally requires qualitative and quantitative human error data. A research initiative at the University of Birmingham led to the development of CORE-DATA, a Computerised Human Error Data Base. This system currently contains a reasonably large number of human error data points, collected from a variety of mainly nuclear-power related sources. This article outlines a recent offshore data collection study, concerned with collecting lifeboat evacuation data. Data collection methods are outlined and a selection of human error probabilities generated as a result of the study are provided. These data give insights into the type of errors and human failure rates that could be utilised to support offshore risk analyses

  15. Error-related anterior cingulate cortex activity and the prediction of conscious error awareness

    Directory of Open Access Journals (Sweden)

    Catherine eOrr

    2012-06-01

    Full Text Available Research examining the neural mechanisms associated with error awareness has consistently identified dorsal anterior cingulate activity (ACC as necessary but not predictive of conscious error detection. Two recent studies (Steinhauser and Yeung, 2010; Wessel et al. 2011 have found a contrary pattern of greater dorsal ACC activity (in the form of the error-related negativity during detected errors, but suggested that the greater activity may instead reflect task influences (e.g., response conflict, error probability and or individual variability (e.g., statistical power. We re-analyzed fMRI BOLD data from 56 healthy participants who had previously been administered the Error Awareness Task, a motor Go/No-go response inhibition task in which subjects make errors of commission of which they are aware (Aware errors, or unaware (Unaware errors. Consistent with previous data, the activity in a number of cortical regions was predictive of error awareness, including bilateral inferior parietal and insula cortices, however in contrast to previous studies, including our own smaller sample studies using the same task, error-related dorsal ACC activity was significantly greater during aware errors when compared to unaware errors. While the significantly faster RT for aware errors (compared to unaware was consistent with the hypothesis of higher response conflict increasing ACC activity, we could find no relationship between dorsal ACC activity and the error RT difference. The data suggests that individual variability in error awareness is associated with error-related dorsal ACC activity, and therefore this region may be important to conscious error detection, but it remains unclear what task and individual factors influence error awareness.

  16. Group representations, error bases and quantum codes

    Energy Technology Data Exchange (ETDEWEB)

    Knill, E

    1996-01-01

    This report continues the discussion of unitary error bases and quantum codes. Nice error bases are characterized in terms of the existence of certain characters in a group. A general construction for error bases which are non-abelian over the center is given. The method for obtaining codes due to Calderbank et al. is generalized and expressed purely in representation theoretic terms. The significance of the inertia subgroup both for constructing codes and obtaining the set of transversally implementable operations is demonstrated.

  17. Practical, Reliable Error Bars in Quantum Tomography

    OpenAIRE

    Faist, Philippe; Renner, Renato

    2015-01-01

    Precise characterization of quantum devices is usually achieved with quantum tomography. However, most methods which are currently widely used in experiments, such as maximum likelihood estimation, lack a well-justified error analysis. Promising recent methods based on confidence regions are difficult to apply in practice or yield error bars which are unnecessarily large. Here, we propose a practical yet robust method for obtaining error bars. We do so by introducing a novel representation of...

  18. Soft errors in modern electronic systems

    CERN Document Server

    Nicolaidis, Michael

    2010-01-01

    This book provides a comprehensive presentation of the most advanced research results and technological developments enabling understanding, qualifying and mitigating the soft errors effect in advanced electronics, including the fundamental physical mechanisms of radiation induced soft errors, the various steps that lead to a system failure, the modelling and simulation of soft error at various levels (including physical, electrical, netlist, event driven, RTL, and system level modelling and simulation), hardware fault injection, accelerated radiation testing and natural environment testing, s

  19. Error calculations statistics in radioactive measurements

    International Nuclear Information System (INIS)

    Verdera, Silvia

    1994-01-01

    Basic approach and procedures frequently used in the practice of radioactive measurements.Statistical principles applied are part of Good radiopharmaceutical Practices and quality assurance.Concept of error, classification as systematic and random errors.Statistic fundamentals,probability theories, populations distributions, Bernoulli, Poisson,Gauss, t-test distribution,Ξ2 test, error propagation based on analysis of variance.Bibliography.z table,t-test table, Poisson index ,Ξ2 test

  20. Beyond Diagnostic Accuracy: The Clinical Utility of Diagnostic Tests

    NARCIS (Netherlands)

    Bossuyt, Patrick M. M.; Reitsma, Johannes B.; Linnet, Kristian; Moons, Karel G. M.

    2012-01-01

    Like any other medical technology or intervention, diagnostic tests should be thoroughly evaluated before their introduction into daily practice. Increasingly, decision makers, physicians, and other users of diagnostic tests request more than simple measures of a test's analytical or technical

  1. Error monitoring issues for common channel signaling

    Science.gov (United States)

    Hou, Victor T.; Kant, Krishna; Ramaswami, V.; Wang, Jonathan L.

    1994-04-01

    Motivated by field data which showed a large number of link changeovers and incidences of link oscillations between in-service and out-of-service states in common channel signaling (CCS) networks, a number of analyses of the link error monitoring procedures in the SS7 protocol were performed by the authors. This paper summarizes the results obtained thus far and include the following: (1) results of an exact analysis of the performance of the error monitoring procedures under both random and bursty errors; (2) a demonstration that there exists a range of error rates within which the error monitoring procedures of SS7 may induce frequent changeovers and changebacks; (3) an analysis of the performance ofthe SS7 level-2 transmission protocol to determine the tolerable error rates within which the delay requirements can be met; (4) a demonstration that the tolerable error rate depends strongly on various link and traffic characteristics, thereby implying that a single set of error monitor parameters will not work well in all situations; (5) some recommendations on a customizable/adaptable scheme of error monitoring with a discussion on their implementability. These issues may be particularly relevant in the presence of anticipated increases in SS7 traffic due to widespread deployment of Advanced Intelligent Network (AIN) and Personal Communications Service (PCS) as well as for developing procedures for high-speed SS7 links currently under consideration by standards bodies.

  2. Neurochemical enhancement of conscious error awareness.

    Science.gov (United States)

    Hester, Robert; Nandam, L Sanjay; O'Connell, Redmond G; Wagner, Joe; Strudwick, Mark; Nathan, Pradeep J; Mattingley, Jason B; Bellgrove, Mark A

    2012-02-22

    How the brain monitors ongoing behavior for performance errors is a central question of cognitive neuroscience. Diminished awareness of performance errors limits the extent to which humans engage in corrective behavior and has been linked to loss of insight in a number of psychiatric syndromes (e.g., attention deficit hyperactivity disorder, drug addiction). These conditions share alterations in monoamine signaling that may influence the neural mechanisms underlying error processing, but our understanding of the neurochemical drivers of these processes is limited. We conducted a randomized, double-blind, placebo-controlled, cross-over design of the influence of methylphenidate, atomoxetine, and citalopram on error awareness in 27 healthy participants. The error awareness task, a go/no-go response inhibition paradigm, was administered to assess the influence of monoaminergic agents on performance errors during fMRI data acquisition. A single dose of methylphenidate, but not atomoxetine or citalopram, significantly improved the ability of healthy volunteers to consciously detect performance errors. Furthermore, this behavioral effect was associated with a strengthening of activation differences in the dorsal anterior cingulate cortex and inferior parietal lobe during the methylphenidate condition for errors made with versus without awareness. Our results have implications for the understanding of the neurochemical underpinnings of performance monitoring and for the pharmacological treatment of a range of disparate clinical conditions that are marked by poor awareness of errors.

  3. [Analysis of intrusion errors in free recall].

    Science.gov (United States)

    Diesfeldt, H F A

    2017-06-01

    Extra-list intrusion errors during five trials of the eight-word list-learning task of the Amsterdam Dementia Screening Test (ADST) were investigated in 823 consecutive psychogeriatric patients (87.1% suffering from major neurocognitive disorder). Almost half of the participants (45.9%) produced one or more intrusion errors on the verbal recall test. Correct responses were lower when subjects made intrusion errors, but learning slopes did not differ between subjects who committed intrusion errors and those who did not so. Bivariate regression analyses revealed that participants who committed intrusion errors were more deficient on measures of eight-word recognition memory, delayed visual recognition and tests of executive control (the Behavioral Dyscontrol Scale and the ADST-Graphical Sequences as measures of response inhibition). Using hierarchical multiple regression, only free recall and delayed visual recognition retained an independent effect in the association with intrusion errors, such that deficient scores on tests of episodic memory were sufficient to explain the occurrence of intrusion errors. Measures of inhibitory control did not add significantly to the explanation of intrusion errors in free recall, which makes insufficient strength of memory traces rather than a primary deficit in inhibition the preferred account for intrusion errors in free recall.

  4. Human error mechanisms in complex work environments

    International Nuclear Information System (INIS)

    Rasmussen, J.

    1988-01-01

    Human error taxonomies have been developed from analysis of industrial incident reports as well as from psychological experiments. In this paper the results of the two approaches are reviewed and compared. It is found, in both cases, that a fairly small number of basic psychological mechanisms will account for most of the action errors observed. In addition, error mechanisms appear to be intimately related to the development of high skill and know-how in a complex work context. This relationship between errors and human adaptation is discussed in detail for individuals and organisations. The implications for system safety and briefly mentioned, together with the implications for system design. (author)

  5. Human error mechanisms in complex work environments

    International Nuclear Information System (INIS)

    Rasmussen, Jens; Danmarks Tekniske Hoejskole, Copenhagen)

    1988-01-01

    Human error taxonomies have been developed from analysis of industrial incident reports as well as from psychological experiments. In this paper the results of the two approaches are reviewed and compared. It is found, in both cases, that a fairly small number of basic psychological mechanisms will account for most of the action errors observed. In addition, error mechanisms appear to be intimately related to the development of high skill and know-how in a complex work context. This relationship between errors and human adaptation is discussed in detail for individuals and organisations. The implications for system safety are briefly mentioned, together with the implications for system design. (author)

  6. Study of Errors among Nursing Students

    Directory of Open Access Journals (Sweden)

    Ella Koren

    2007-09-01

    Full Text Available The study of errors in the health system today is a topic of considerable interest aimed at reducing errors through analysis of the phenomenon and the conclusions reached. Errors that occur frequently among health professionals have also been observed among nursing students. True, in most cases they are actually “near errors,” but these could be a future indicator of therapeutic reality and the effect of nurses' work environment on their personal performance. There are two different approaches to such errors: (a The EPP (error prone person approach lays full responsibility at the door of the individual involved in the error, whether a student, nurse, doctor, or pharmacist. According to this approach, handling consists purely in identifying and penalizing the guilty party. (b The EPE (error prone environment approach emphasizes the environment as a primary contributory factor to errors. The environment as an abstract concept includes components and processes of interpersonal communications, work relations, human engineering, workload, pressures, technical apparatus, and new technologies. The objective of the present study was to examine the role played by factors in and components of personal performance as compared to elements and features of the environment. The study was based on both of the aforementioned approaches, which, when combined, enable a comprehensive understanding of the phenomenon of errors among the student population as well as a comparison of factors contributing to human error and to error deriving from the environment. The theoretical basis of the study was a model that combined both approaches: one focusing on the individual and his or her personal performance and the other focusing on the work environment. The findings emphasize the work environment of health professionals as an EPE. However, errors could have been avoided by means of strict adherence to practical procedures. The authors examined error events in the

  7. Learning from errors in super-resolution.

    Science.gov (United States)

    Tang, Yi; Yuan, Yuan

    2014-11-01

    A novel framework of learning-based super-resolution is proposed by employing the process of learning from the estimation errors. The estimation errors generated by different learning-based super-resolution algorithms are statistically shown to be sparse and uncertain. The sparsity of the estimation errors means most of estimation errors are small enough. The uncertainty of the estimation errors means the location of the pixel with larger estimation error is random. Noticing the prior information about the estimation errors, a nonlinear boosting process of learning from these estimation errors is introduced into the general framework of the learning-based super-resolution. Within the novel framework of super-resolution, a low-rank decomposition technique is used to share the information of different super-resolution estimations and to remove the sparse estimation errors from different learning algorithms or training samples. The experimental results show the effectiveness and the efficiency of the proposed framework in enhancing the performance of different learning-based algorithms.

  8. Magnetic diagnostic plasma position in the TCA/BR tokamak

    International Nuclear Information System (INIS)

    Galvao, R.M.O.; Kuznetsov, Yu.K.; Nascimento, I.C.

    1996-01-01

    The cross-section of the plasma column is TCA/BR has a nearly circular plasma shape. This allows implementation of simplified methods of magnetic diagnostics. Although these methods were in may tokamaks and are well described, their accuracies are not clearly defined because the very simplified theoretical model of plasma equilibrium on which they are based differs from the real conditions in tokamaks like TCA/BR. In this paper we present the methods of plasma position diagnostics in TCA/BR from external magnetic measurements with an error analysis. (author). 4 refs., 3 figs

  9. Random and Systematic Errors Share in Total Error of Probes for CNC Machine Tools

    Directory of Open Access Journals (Sweden)

    Adam Wozniak

    2018-03-01

    Full Text Available Probes for CNC machine tools, as every measurement device, have accuracy limited by random errors and by systematic errors. Random errors of these probes are described by a parameter called unidirectional repeatability. Manufacturers of probes for CNC machine tools usually specify only this parameter, while parameters describing systematic errors of the probes, such as pre-travel variation or triggering radius variation, are used rarely. Systematic errors of the probes, linked to the differences in pre-travel values for different measurement directions, can be corrected or compensated, but it is not a widely used procedure. In this paper, the share of systematic errors and random errors in total error of exemplary probes are determined. In the case of simple, kinematic probes, systematic errors are much greater than random errors, so compensation would significantly reduce the probing error. Moreover, it shows that in the case of kinematic probes commonly specified unidirectional repeatability is significantly better than 2D performance. However, in the case of more precise strain-gauge probe systematic errors are of the same order as random errors, which means that errors correction or compensation, in this case, would not yield any significant benefits.

  10. Investigation of influence of errors of cutting machines with CNC on displacement trajectory accuracy of their actuating devices

    Science.gov (United States)

    Fedonin, O. N.; Petreshin, D. I.; Ageenko, A. V.

    2018-03-01

    In the article, the issue of increasing a CNC lathe accuracy by compensating for the static and dynamic errors of the machine is investigated. An algorithm and a diagnostic system for a CNC machine tool are considered, which allows determining the errors of the machine for their compensation. The results of experimental studies on diagnosing and improving the accuracy of a CNC lathe are presented.

  11. Cancer pancreatis, diagnostic procedures

    International Nuclear Information System (INIS)

    Graadal, Oe.; Schlichting, E.; Aasen, A.O.; Stadaas, J.O.

    1990-01-01

    151 patients treated for carcinoma of the pancreas at Ullevaal Hospital (Oslo University) during the period 1980-89 were studied. The most common initial symptom was abdominal pain. Other frequent debut symptoms were loss of weight and jaundice. ERCP and PTC were found to be the best diagnostic procedures. CT or ultrasonography were normal in 10-20% of the patients. Nearly all tumors of the pancreas were found by the ERCP procedure. Also angiography was used to evaluate operability of the pancreas tumor, but was found to be a very uncertain diagnostic method. This method will not be used in the future evaluation of patients with cancer of the pancreas. 13 refs., 1 fig., 2 tabs

  12. Inertial confinement fusion diagnostics

    International Nuclear Information System (INIS)

    Coleman, L.W.

    1986-10-01

    The concept and goals of ICF will be briefly reviewed and the new 100 kJ class Nova laser facility will be described. Experimental results obtained to date with Nova will be summarized, and the discussions of diagnostics will use examples on the present capabilities of Nova and new developments that are underway. The classes of diagnostic systems to be discussed fall into three basic categories: optical, x-ray, and particle. Examples of highly space resolved, time resolved, and spectrally resolved techniques as well as schemes involving combinations of these capabilities will be presented. A brief summary of the sophisticated acquisition and analysis system in use for Nova data will be provided

  13. Nanodevices in diagnostics

    Science.gov (United States)

    Hu, Ye; Fine, Daniel H.; Tasciotti, Ennio; Bouamrani, Ali; Ferrari, Mauro

    2010-01-01

    The real-time, personalized and highly sensitive early-stage diagnosis of disease remains an important challenge in modern medicine. With the ability to interact with matter at the nanoscale, the development of nanotechnology architectures and materials could potentially extend subcellular and molecular detection beyond the limits of conventional diagnostic modalities. At the very least, nanotechnology should be able to dramatically accelerate biomarker discovery, as well as facilitate disease monitoring, especially of maladies presenting a high degree of molecular and compositional heterogeneity. This article gives an overview of several of the most promising nanodevices and nanomaterials along with their applications in clinical practice. Significant work to adapt nanoscale materials and devices to clinical applications involving large interdisciplinary collaborations is already underway with the potential for nanotechnology to become an important enabling diagnostic technology. PMID:20229595

  14. Nanobiosensors in diagnostics

    Directory of Open Access Journals (Sweden)

    Alejandro Chamorro-Garcia

    2016-11-01

    Full Text Available Medical diagnosis has been greatly improved thanks to the development of new techniques capable of performing very sensitive detection and quantifying certain parameters. These parameters can be correlated with the presence of specific molecules and their quantity. Unfortunately, these techniques are demanding, expensive, and often complicated. On the other side, progress in other fields of science and technology has contributed to the rapid growth of nanotechnology. Although being an emerging discipline, nanotechnology has raised huge interest and expectations. Most of the enthusiasm comes from new possibilities and properties of nanomaterials. Biosensors (simple, robust, sensitive, cost-effective combined with nanomaterials, also called nanobiosensors, are serving as bridge between advanced detection/diagnostics and daily/routine tests. Here we review some of the latest applications of nanobiosensors in diagnostics field.

  15. Diagnostic radiation risks

    Energy Technology Data Exchange (ETDEWEB)

    Sherwood, T [Addenbrooke' s Hospital, Cambridge (UK)

    1980-04-01

    A brief discussion on diagnostic radiation risks is given. First some fundamental facts on the concepts and units of radiation measurement are clarified. Medical diagnostic radiation doses are also compared to the radiation doses received annually by man from natural background radiation. The controversy concerning the '10-day rule' in X-raying women of child-bearing age is discussed; it would appear that the risk of malformation in an unborn child due to X-radiation is very much less than the natural level of risk of malformation. The differences in the radiographic techniques and thus the different X-ray doses needed to make adequate X-ray images of different parts of the body are considered. The radiation burden of nuclear medicine investigations compared to X-ray procedures is also discussed. Finally, the problems of using volunteers in radiation research are aired.

  16. Diagnostics and structure

    International Nuclear Information System (INIS)

    Vial, J.C.

    1986-01-01

    The structure of prominences and the diagnostic techniques used to evaluate their physical parameters are discussed. These include electron temperature, various densities (n sub p, n sub e, n sub l), ionization degree, velocities, and magnetic field vector. UV and radio measurements have already evidenced the existence of different temperature regions, corresponding to different geometrical locations, e.g., the so called Prominence-Corona (P-C) interface. Velocity measurements are important for considering formation and mass balance of prominences but there are conflicting velocity measurements which have led to the basic question: what structure is actually observed at a given wavelength; what averaging is performed within the projected slit area during the exposure time? In optically thick lines, the question of the formation region of the radiation along the line of sight is also not a trivial one. The same is true for low resolution measurements of the magnetic field. Coupling diagnostics with structure is now a general preoccupation

  17. FEL components and diagnostics

    International Nuclear Information System (INIS)

    Carr, R.

    1997-01-01

    FEL hardware includes undulators, alignment systems, electron beam diagnostics, and mechanical and vacuum systems. While most FEL close-quote s employ conventional undulators, there is some interest in novel types, particularly where conventional designs cannot be used, as at very short periods and high fields. For these areas, superconducting technology is indicated. The most serious issue facing long FEL undulators is that of alignment; mechanical techniques may not be accurate enough, and beam-based strategies must be considered. To maintain alignment and control the electron trajectory, beam position monitors with micron precision are required. Beam size monitors are also required to assure control of emittance. The talks given in the working group sessions touch on undulators, alignment, and electron beam diagnostics, and they are summarized here. copyright 1997 American Institute of Physics

  18. Litigations in diagnostic radiology

    International Nuclear Information System (INIS)

    Patil, Ranjit

    2014-01-01

    There are various regulatory bodies at the international and national level, which lay down norms for radiation protection. These are the International Commission for Radiation Protection (ICRP) the National Commission for Radiation Protection (NCRP) in America, and the Atomic Energy Regulatory Board (AERB) in India. These bodies recommend norms on various radiation issues. Radiography and radiology are two key tools for diagnosing and treating diseases. Recently there are concerns about the effect of ionizing radiation on man and the frequent use of diagnostic radiographs. The professionals are expected to conduct their actions according to guidelines which reflect new information and changing technology in diagnostic radiography. Failure to do so may have severe legal consequences. Patient protection is a matter of normal course but knowledge and awareness of the legal issues is important to avoid legal hassles. Implications of the radiation protection guidelines are discussed. (author)

  19. STELLA Experiment - Microbunch Diagnostic

    Energy Technology Data Exchange (ETDEWEB)

    He, P.; Liu, Y.; Cline, D. B.; Babzien, M.; Gallardo, J. C.; Kusche, K. P.; Pogorelsky, I. V.; Skaritka, J.; van Steenbergen, A.; Yakimenko, V.; Kimura, W. D.

    1998-07-01

    A microbunch diagnostic system is built at the Accelerator Test Facility (ATF) of Brookhaven National Laboratory for monitoring microbunches (10-fs bunch length) produced by the Inverse Free Electron Laser accelerator in Staged Electron Laser Acceleration experiment. It is similar to one already demonstrated at the ATF. With greatly improved beam optics conditions higher order harmonic coherent transition radiation will be measurable to determine the microbunch length and shape.

  20. Advanced diagnostic graphics

    International Nuclear Information System (INIS)

    Bray, M.A.; Petersen, R.J.; Clark, M.T.; Gertman, D.I.

    1981-01-01

    This paper reports US NRC-sponsored research at the Idaho National Engineering Laboratory (INEL) involving evaluation of computer-based diagnostic graphics. The specific targets of current evaluations are multivariate data display formats which may be used in Safety Parameter Display Systems (SPDS) being developed for nuclear power plant control rooms. The purpose of the work is to provide a basis for NRC action in regulating licensee SPDSs or later computer/cathode ray tube (CRT) applications in nuclear control rooms

  1. Molecular diagnostics in endodontics

    OpenAIRE

    Rechenberg, Dan-Krister; Zehnder, Matthias

    2014-01-01

    Recent systematic reviews have substantiated the fact that current testing methods to assess the inflammatory state of the pulp and the periapical tissues are of limited value. Consequently, it may be time to search for alternative routes in endodontic diagnostics. Molecular assessment methods could be the future. However, in the field of endodontics, the research in that direction is only about to evolve. Because pulpal and periradicular diseases are related to opportunistic infections, diag...

  2. Molecular Diagnostics of ?-Thalassemia

    OpenAIRE

    Atanasovska, B; Bozhinovski, G; Chakalova, L; Kocheva, S; Karanfilski, O; Plaseska-Karanfiska, D

    2012-01-01

    A high-quality hemoglobinopathy diagnosis is based on the results of a number of tests including assays for molecular identification of causative mutations. We describe the current diagnostic strategy for the identification of ?-thalassemias and hemoglobin (Hb) variants at the International Reference Laboratory for Haemoglobinopathies, Research Centre for Genetic Engineering and Biotechnology (RCGEB) ?Georgi D. Efremov,? Skopje, Republic of Macedonia. Our overall approach and most of the meth...

  3. Equipment for isotope diagnostics

    International Nuclear Information System (INIS)

    Platz, W.

    1976-01-01

    The invention concerns an improvement of equipment for isotope diagnostics allowing to mark special intensity ranges of the recorded measurements by means of different colors. For undisturbed operation it is of advantage to avoid electric circuits between movable and unmovable parts of the color recorder. According to the invention, long gear wheels of glass fiber-reinforced polyamide are used for these connections. (ORU) [de

  4. RFQ1 diagnostic devices

    International Nuclear Information System (INIS)

    Chidley, B.G.; Arbique, G.M.; de Jong, M.S.; McMichael, G.E.; Michel, W.L.; Smith, B.H.

    1991-01-01

    The diagnostic devices in use on RFQ1 will be described. They consist of a double-slit emittance-measuring unit, a 45 degree deflection energy-analysis magnet, parametric current transformers, optical beam sensors, beam-stop current monitors, and an x-ray end-point analyzer. All of these devices are able to operate up to the full output current of RFQ1 (75 mA cw at 0.6 MeV)

  5. Idiopathic chondrolysis - diagnostic difficulties

    International Nuclear Information System (INIS)

    Kozlowski, K.; Scougall, J.; Royal Alexandra Hospital for Children, Sydney

    1984-01-01

    Four cases of idiopathic chondrolysis of the hip in three white girls and one Maori girl are reported. The authors stress the causes why a disease with characteristic clinical and radiographic appearances and normal biochemical findings presents diagnostic difficulties. It is suspected that idiopathic chondrolysis is a metabolic disorder of chondrocytes, triggered by environment circumstances in susceptible individuals. Idiopathic chondrolysis is probably one of the most common causes of coxarthrosis in women. (orig.)

  6. Radiological diagnostics in hyperparathyroidism

    International Nuclear Information System (INIS)

    Moedder, U.; Kuhn, F.P.; Gruetzner, G.

    1991-01-01

    The most important radiologically detectable effects of the primary and secondary hyperparathyroidism of the skeletal system and the periarticular soft tissue structures are presented. In the following sensitivity and specificity of radiological imaging - sonography, scintigraphy, computed tomography, magnetic resonance imaging, arteriography and selective venous sampling - in the preoperative diagnostic of the parathyroid adenomas are discussed. Therefore, radiological imaging can be omitted before primary surgery. It was only in secondary surgery that radiological process proved useful and a guide during surgical intervention. (orig.) [de

  7. Thioaptamer Diagnostic System, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — AM Biotechnologies (AM) will develop a diagnostic system in response to SBIR Topic X10.01 Reusable Diagnostic Lab Technology that will simultaneously detect and...

  8. Molecular diagnostics of periodontitis.

    Science.gov (United States)

    Korona-Głowniak, Izabela; Siwiec, Radosław; Berger, Marcin; Malm, Anna; Szymańska, Jolanta

    2017-01-28

    The microorganisms that form dental plaque are the main cause of periodontitis. Their identification and the understanding of the complex relationships and interactions that involve these microorganisms, environmental factors and the host's health status enable improvement in diagnostics and targeted therapy in patients with periodontitis. To this end, molecular diagnostics techniques (both techniques based on the polymerase chain reaction and those involving nucleic acid analysis via hybridization) come increasingly into use. On the basis of a literature review, the following methods are presented: polymerase chain reaction (PCR), real-time polymerase chain reaction (real-time PCR), 16S rRNA-encoding gene sequencing, checkerboard and reverse-capture checkerboard hybridization, microarrays, denaturing gradient gel electrophoresis (DGGE), temperature gradient gel electrophoresis (TGGE), as well as terminal restriction fragment length polymorphism (TRFLP) and next generation sequencing (NGS). The advantages and drawbacks of each method in the examination of periopathogens are indicated. The techniques listed above allow fast detection of even small quantities of pathogen present in diagnostic material and prove particularly useful to detect microorganisms that are difficult or impossible to grow in a laboratory.

  9. Molecular diagnostics of periodontitis

    Directory of Open Access Journals (Sweden)

    Izabela Korona-Głowniak

    2017-01-01

    Full Text Available The microorganisms that form dental plaque are the main cause of periodontitis. Their identification and the understanding of the complex relationships and interactions that involve these microorganisms, environmental factors and the host’s health status enable improvement in diagnostics and targeted therapy in patients with periodontitis. To this end, molecular diagnostics techniques (both techniques based on the polymerase chain reaction and those involving nucleic acid analysis via hybridization come increasingly into use. On the basis of a literature review, the following methods are presented: polymerase chain reaction (PCR, real-time polymerase chain reaction (real-time PCR, 16S rRNA-encoding gene sequencing, checkerboard and reverse-capture checkerboard hybridization, microarrays, denaturing gradient gel electrophoresis (DGGE, temperature gradient gel electrophoresis (TGGE, as well as terminal restriction fragment length polymorphism (TRFLP and next generation sequencing (NGS. The advantages and drawbacks of each method in the examination of periopathogens are indicated. The techniques listed above allow fast detection of even small quantities of pathogen present in diagnostic material and prove particularly useful to detect microorganisms that are difficult or impossible to grow in a laboratory.

  10. XML Diagnostics Description Standard

    International Nuclear Information System (INIS)

    Neto, A.; Fernandes, H.; Varandas, C.; Lister, J.; Yonekawa, I.

    2006-01-01

    A standard for the self-description of fusion plasma diagnostics will be presented, based on the Extensible Markup Language (XML). The motivation is to maintain and organise the information on all the components of a laboratory experiment, from the hardware to the access security, to save time and money when problems arises. Since there is no existing standard to organise this kind of information, every Association stores and organises each experiment in different ways. This can lead to severe problems when the organisation schema is poorly documented or written in national languages. The exchange of scientists, researchers and engineers between laboratories is a common practice nowadays. Sometimes they have to install new diagnostics or to update existing ones and frequently they lose a great deal of time trying to understand the currently installed system. The most common problems are: no documentation available; the person who understands it has left; documentation written in the national language. Standardisation is the key to solving all the problems mentioned. From the commercial information on the diagnostic (component supplier; component price) to the hardware description (component specifications; drawings) to the operation of the equipment (finite state machines) through change control (who changed what and when) and internationalisation (information at least in the native language and in English), a common XML schema will be proposed. This paper will also discuss an extension of these ideas to the self-description of ITER plant systems, since the problems will be identical. (author)

  11. SNS Diagnostics Timing Integration

    CERN Document Server

    Long, Cary D; Murphy, Darryl J; Pogge, James; Purcell, John D; Sundaram, Madhan

    2005-01-01

    The Spallation Neutron Source (SNS) accelerator systems will deliver a 1.0 GeV, 1.4 MW proton beam to a liquid mercury target for neutron scattering research. The accelerator complex consists of a 1 GeV linear accelerator, an accumulator ring and associated transport lines. The SNS diagnostics platform is PC-based running Windows XP Embedded for its OS and LabVIEW as its programming language. Coordinating timing among the various diagnostics instruments with the generation of the beam pulse is a challenging task that we have chosen to divide into three phases. First, timing was derived from VME based systems. In the second phase, described in this paper, timing pulses are generated by an in house designed PCI timing card installed in ten diagnostics PCs. Using fan-out modules, enough triggers were generated for all instruments. This paper describes how the Timing NAD (Network Attached Device) was rapidly developed using our NAD template, LabVIEW's PCI driver wizard, and LabVIEW Channel Access library. The NAD...

  12. Insight into biases and sequencing errors for amplicon sequencing with the Illumina MiSeq platform.

    Science.gov (United States)

    Schirmer, Melanie; Ijaz, Umer Z; D'Amore, Rosalinda; Hall, Neil; Sloan, William T; Quince, Christopher

    2015-03-31

    With read lengths of currently up to 2 × 300 bp, high throughput and low sequencing costs Illumina's MiSeq is becoming one of the most utilized sequencing platforms worldwide. The platform is manageable and affordable even for smaller labs. This enables quick turnaround on a broad range of applications such as targeted gene sequencing, metagenomics, small genome sequencing and clinical molecular diagnostics. However, Illumina error profiles are still poorly understood and programs are therefore not designed for the idiosyncrasies of Illumina data. A better knowledge of the error patterns is essential for sequence analysis and vital if we are to draw valid conclusions. Studying true genetic variation in a population sample is fundamental for understanding diseases, evolution and origin. We conducted a large study on the error patterns for the MiSeq based on 16S rRNA amplicon sequencing data. We tested state-of-the-art library preparation methods for amplicon sequencing and showed that the library preparation method and the choice of primers are the most significant sources of bias and cause distinct error patterns. Furthermore we tested the efficiency of various error correction strategies and identified quality trimming (Sickle) combined with error correction (BayesHammer) followed by read overlapping (PANDAseq) as the most successful approach, reducing substitution error rates on average by 93%. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

  13. A framework to estimate probability of diagnosis error in NPP advanced MCR

    International Nuclear Information System (INIS)

    Kim, Ar Ryum; Kim, Jong Hyun; Jang, Inseok; Seong, Poong Hyun

    2018-01-01

    Highlights: •As new type of MCR has been installed in NPPs, the work environment is considerably changed. •A new framework to estimate operators’ diagnosis error probabilities should be proposed. •Diagnosis error data were extracted from the full-scope simulator of the advanced MCR. •Using Bayesian inference, a TRC model was updated for use in advanced MCR. -- Abstract: Recently, a new type of main control room (MCR) has been adopted in nuclear power plants (NPPs). The new MCR, known as the advanced MCR, consists of digitalized human-system interfaces (HSIs), computer-based procedures (CPS), and soft controls while the conventional MCR includes many alarm tiles, analog indicators, hard-wired control devices, and paper-based procedures. These changes significantly affect the generic activities of the MCR operators, in relation to diagnostic activities. The aim of this paper is to suggest a framework to estimate the probabilities of diagnosis errors in the advanced MCR by updating a time reliability correlation (TRC) model. Using Bayesian inference, the TRC model was updated with the probabilities of diagnosis errors. Here, the diagnosis error data were collected from a full-scope simulator of the advanced MCR. To do this, diagnosis errors were determined based on an information processing model and their probabilities were calculated. However, these calculated probabilities of diagnosis errors were largely affected by context factors such as procedures, HSI, training, and others, known as PSFs (Performance Shaping Factors). In order to obtain the nominal diagnosis error probabilities, the weightings of PSFs were also evaluated. Then, with the nominal diagnosis error probabilities, the TRC model was updated. This led to the proposal of a framework to estimate the nominal probabilities of diagnosis errors in the advanced MCR.

  14. Radiological diagnostics of skeletal tumors

    International Nuclear Information System (INIS)

    Uhl, M.; Herget, G.W.

    2008-01-01

    The book contains contributions concerning the following topics: 1. introduction and fundamentals: WHO classification of bone tumors, imaging diagnostics and their function; localization, typical clinical and radiological criteria, TNM classification and status classification, invasive tumor diagnostics; 2. specific tumor diagnostics: chondrogenic bone tumors, osseous tumors, connective tissue bony tumors, osteoclastoma, osteomyelogenic bone tumors, vascular bone tumors, neurogenic bone tumors, chordoma; adamantinoma of the long tubular bone; tumor-like lesions, bony metastases, bone granulomas, differential diagnostics: tumor-like lesions

  15. Investigating the link between radiologists’ gaze, diagnostic decision, and image content

    Science.gov (United States)

    Tourassi, Georgia; Voisin, Sophie; Paquit, Vincent; Krupinski, Elizabeth

    2013-01-01

    Objective To investigate machine learning for linking image content, human perception, cognition, and error in the diagnostic interpretation of mammograms. Methods Gaze data and diagnostic decisions were collected from three breast imaging radiologists and three radiology residents who reviewed 20 screening mammograms while wearing a head-mounted eye-tracker. Image analysis was performed in mammographic regions that attracted radiologists’ attention and in all abnormal regions. Machine learning algorithms were investigated to develop predictive models that link: (i) image content with gaze, (ii) image content and gaze with cognition, and (iii) image content, gaze, and cognition with diagnostic error. Both group-based and individualized models were explored. Results By pooling the data from all readers, machine learning produced highly accurate predictive models linking image content, gaze, and cognition. Potential linking of those with diagnostic error was also supported to some extent. Merging readers’ gaze metrics and cognitive opinions with computer-extracted image features identified 59% of the readers’ diagnostic errors while confirming 97.3% of their correct diagnoses. The readers’ individual perceptual and cognitive behaviors could be adequately predicted by modeling the behavior of others. However, personalized tuning was in many cases beneficial for capturing more accurately individual behavior. Conclusions There is clearly an interaction between radiologists’ gaze, diagnostic decision, and image content which can be modeled with machine learning algorithms. PMID:23788627

  16. Characteristics of pediatric chemotherapy medication errors in a national error reporting database.

    Science.gov (United States)

    Rinke, Michael L; Shore, Andrew D; Morlock, Laura; Hicks, Rodney W; Miller, Marlene R

    2007-07-01

    Little is known regarding chemotherapy medication errors in pediatrics despite studies suggesting high rates of overall pediatric medication errors. In this study, the authors examined patterns in pediatric chemotherapy errors. The authors queried the United States Pharmacopeia MEDMARX database, a national, voluntary, Internet-accessible error reporting system, for all error reports from 1999 through 2004 that involved chemotherapy medications and patients aged error reports, 85% reached the patient, and 15.6% required additional patient monitoring or therapeutic intervention. Forty-eight percent of errors originated in the administering phase of medication delivery, and 30% originated in the drug-dispensing phase. Of the 387 medications cited, 39.5% were antimetabolites, 14.0% were alkylating agents, 9.3% were anthracyclines, and 9.3% were topoisomerase inhibitors. The most commonly involved chemotherapeutic agents were methotrexate (15.3%), cytarabine (12.1%), and etoposide (8.3%). The most common error types were improper dose/quantity (22.9% of 327 cited error types), wrong time (22.6%), omission error (14.1%), and wrong administration technique/wrong route (12.2%). The most common error causes were performance deficit (41.3% of 547 cited error causes), equipment and medication delivery devices (12.4%), communication (8.8%), knowledge deficit (6.8%), and written order errors (5.5%). Four of the 5 most serious errors occurred at community hospitals. Pediatric chemotherapy errors often reached the patient, potentially were harmful, and differed in quality between outpatient and inpatient areas. This study indicated which chemotherapeutic agents most often were involved in errors and that administering errors were common. Investigation is needed regarding targeted medication administration safeguards for these high-risk medications. Copyright (c) 2007 American Cancer Society.

  17. ERF/ERFC, Calculation of Error Function, Complementary Error Function, Probability Integrals

    International Nuclear Information System (INIS)

    Vogel, J.E.

    1983-01-01

    1 - Description of problem or function: ERF and ERFC are used to compute values of the error function and complementary error function for any real number. They may be used to compute other related functions such as the normal probability integrals. 4. Method of solution: The error function and complementary error function are approximated by rational functions. Three such rational approximations are used depending on whether - x .GE.4.0. In the first region the error function is computed directly and the complementary error function is computed via the identity erfc(x)=1.0-erf(x). In the other two regions the complementary error function is computed directly and the error function is computed from the identity erf(x)=1.0-erfc(x). The error function and complementary error function are real-valued functions of any real argument. The range of the error function is (-1,1). The range of the complementary error function is (0,2). 5. Restrictions on the complexity of the problem: The user is cautioned against using ERF to compute the complementary error function by using the identity erfc(x)=1.0-erf(x). This subtraction may cause partial or total loss of significance for certain values of x

  18. Iterative optimization of quantum error correcting codes

    International Nuclear Information System (INIS)

    Reimpell, M.; Werner, R.F.

    2005-01-01

    We introduce a convergent iterative algorithm for finding the optimal coding and decoding operations for an arbitrary noisy quantum channel. This algorithm does not require any error syndrome to be corrected completely, and hence also finds codes outside the usual Knill-Laflamme definition of error correcting codes. The iteration is shown to improve the figure of merit 'channel fidelity' in every step

  19. Measurement Error in Education and Growth Regressions

    NARCIS (Netherlands)

    Portela, Miguel; Alessie, Rob; Teulings, Coen

    2010-01-01

    The use of the perpetual inventory method for the construction of education data per country leads to systematic measurement error. This paper analyzes its effect on growth regressions. We suggest a methodology for correcting this error. The standard attenuation bias suggests that using these

  20. Random error in cardiovascular meta-analyses

    DEFF Research Database (Denmark)

    Albalawi, Zaina; McAlister, Finlay A; Thorlund, Kristian

    2013-01-01

    BACKGROUND: Cochrane reviews are viewed as the gold standard in meta-analyses given their efforts to identify and limit systematic error which could cause spurious conclusions. The potential for random error to cause spurious conclusions in meta-analyses is less well appreciated. METHODS: We exam...

  1. The Impact of Error-Management Climate, Error Type and Error Originator on Auditors’ Reporting Errors Discovered on Audit Work Papers

    NARCIS (Netherlands)

    A.H. Gold-Nöteberg (Anna); U. Gronewold (Ulfert); S. Salterio (Steve)

    2010-01-01

    textabstractWe examine factors affecting the auditor’s willingness to report their own or their peers’ self-discovered errors in working papers subsequent to detailed working paper review. Prior research has shown that errors in working papers are detected in the review process; however, such

  2. Error tracking in a clinical biochemistry laboratory

    DEFF Research Database (Denmark)

    Szecsi, Pal Bela; Ødum, Lars

    2009-01-01

    BACKGROUND: We report our results for the systematic recording of all errors in a standard clinical laboratory over a 1-year period. METHODS: Recording was performed using a commercial database program. All individuals in the laboratory were allowed to report errors. The testing processes were cl...

  3. Sources of Error in Satellite Navigation Positioning

    Directory of Open Access Journals (Sweden)

    Jacek Januszewski

    2017-09-01

    Full Text Available An uninterrupted information about the user’s position can be obtained generally from satellite navigation system (SNS. At the time of this writing (January 2017 currently two global SNSs, GPS and GLONASS, are fully operational, two next, also global, Galileo and BeiDou are under construction. In each SNS the accuracy of the user’s position is affected by the three main factors: accuracy of each satellite position, accuracy of pseudorange measurement and satellite geometry. The user’s position error is a function of both the pseudorange error called UERE (User Equivalent Range Error and user/satellite geometry expressed by right Dilution Of Precision (DOP coefficient. This error is decomposed into two types of errors: the signal in space ranging error called URE (User Range Error and the user equipment error UEE. The detailed analyses of URE, UEE, UERE and DOP coefficients, and the changes of DOP coefficients in different days are presented in this paper.

  4. Volterra Filtering for ADC Error Correction

    Directory of Open Access Journals (Sweden)

    J. Saliga

    2001-09-01

    Full Text Available Dynamic non-linearity of analog-to-digital converters (ADCcontributes significantly to the distortion of digitized signals. Thispaper introduces a new effective method for compensation such adistortion based on application of Volterra filtering. Considering ana-priori error model of ADC allows finding an efficient inverseVolterra model for error correction. Efficiency of proposed method isdemonstrated on experimental results.

  5. Errors and untimely radiodiagnosis of occupational diseases

    International Nuclear Information System (INIS)

    Sokolik, L.I.; Shkondin, A.N.; Sergienko, N.S.; Doroshenko, A.N.; Shumakov, A.V.

    1987-01-01

    Most errors in the diagnosis of occupational diseases occur due to hyperdiagnosis (37%), because data of dynamic clinico-roentgenological examination were not considered (23%). Defects in the organization of prophylactic fluorography results in untimely diagnosis of dust-induced occupational diseases. Errors also occurred because working conditions were not always considered atypical development and course were not always analyzed

  6. Comparing classifiers for pronunciation error detection

    NARCIS (Netherlands)

    Strik, H.; Truong, K.; Wet, F. de; Cucchiarini, C.

    2007-01-01

    Providing feedback on pronunciation errors in computer assisted language learning systems requires that pronunciation errors be detected automatically. In the present study we compare four types of classifiers that can be used for this purpose: two acoustic-phonetic classifiers (one of which employs

  7. Comparison of Prediction-Error-Modelling Criteria

    DEFF Research Database (Denmark)

    Jørgensen, John Bagterp; Jørgensen, Sten Bay

    2007-01-01

    Single and multi-step prediction-error-methods based on the maximum likelihood and least squares criteria are compared. The prediction-error methods studied are based on predictions using the Kalman filter and Kalman predictors for a linear discrete-time stochastic state space model, which is a r...

  8. Error and uncertainty in scientific practice

    NARCIS (Netherlands)

    Boumans, M.; Hon, G.; Petersen, A.C.

    2014-01-01

    Assessment of error and uncertainty is a vital component of both natural and social science. Empirical research involves dealing with all kinds of errors and uncertainties, yet there is significant variance in how such results are dealt with. Contributors to this volume present case studies of

  9. Measurement Error in Education and Growth Regressions

    NARCIS (Netherlands)

    Portela, M.; Teulings, C.N.; Alessie, R.

    The perpetual inventory method used for the construction of education data per country leads to systematic measurement error. This paper analyses the effect of this measurement error on GDP regressions. There is a systematic difference in the education level between census data and observations

  10. Measurement error in education and growth regressions

    NARCIS (Netherlands)

    Portela, Miguel; Teulings, Coen; Alessie, R.

    2004-01-01

    The perpetual inventory method used for the construction of education data per country leads to systematic measurement error. This paper analyses the effect of this measurement error on GDP regressions. There is a systematic difference in the education level between census data and observations

  11. Position Error Covariance Matrix Validation and Correction

    Science.gov (United States)

    Frisbee, Joe, Jr.

    2016-01-01

    In order to calculate operationally accurate collision probabilities, the position error covariance matrices predicted at times of closest approach must be sufficiently accurate representations of the position uncertainties. This presentation will discuss why the Gaussian distribution is a reasonable expectation for the position uncertainty and how this assumed distribution type is used in the validation and correction of position error covariance matrices.

  12. Opportunistic Error Correction for WLAN Applications

    NARCIS (Netherlands)

    Shao, X.; Schiphorst, Roelof; Slump, Cornelis H.

    2008-01-01

    The current error correction layer of IEEE 802.11a WLAN is designed for worst case scenarios, which often do not apply. In this paper, we propose a new opportunistic error correction layer based on Fountain codes and a resolution adaptive ADC. The key part in the new proposed system is that only

  13. 40 CFR 73.37 - Account error.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 16 2010-07-01 2010-07-01 false Account error. 73.37 Section 73.37 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) SULFUR DIOXIDE ALLOWANCE SYSTEM Allowance Tracking System § 73.37 Account error. The Administrator may, at his or her sole...

  14. Error Discounting in Probabilistic Category Learning

    Science.gov (United States)

    Craig, Stewart; Lewandowsky, Stephan; Little, Daniel R.

    2011-01-01

    The assumption in some current theories of probabilistic categorization is that people gradually attenuate their learning in response to unavoidable error. However, existing evidence for this error discounting is sparse and open to alternative interpretations. We report 2 probabilistic-categorization experiments in which we investigated error…

  15. Learning mechanisms to limit medication administration errors.

    Science.gov (United States)

    Drach-Zahavy, Anat; Pud, Dorit

    2010-04-01

    This paper is a report of a study conducted to identify and test the effectiveness of learning mechanisms applied by the nursing staff of hospital wards as a means of limiting medication administration errors. Since the influential report ;To Err Is Human', research has emphasized the role of team learning in reducing medication administration errors. Nevertheless, little is known about the mechanisms underlying team learning. Thirty-two hospital wards were randomly recruited. Data were collected during 2006 in Israel by a multi-method (observations, interviews and administrative data), multi-source (head nurses, bedside nurses) approach. Medication administration error was defined as any deviation from procedures, policies and/or best practices for medication administration, and was identified using semi-structured observations of nurses administering medication. Organizational learning was measured using semi-structured interviews with head nurses, and the previous year's reported medication administration errors were assessed using administrative data. The interview data revealed four learning mechanism patterns employed in an attempt to learn from medication administration errors: integrated, non-integrated, supervisory and patchy learning. Regression analysis results demonstrated that whereas the integrated pattern of learning mechanisms was associated with decreased errors, the non-integrated pattern was associated with increased errors. Supervisory and patchy learning mechanisms were not associated with errors. Superior learning mechanisms are those that represent the whole cycle of team learning, are enacted by nurses who administer medications to patients, and emphasize a system approach to data analysis instead of analysis of individual cases.

  16. Beam property studies in the PLS diagnostic beamline

    CERN Document Server

    Ko, I S; Seon, D K; Kim, C B; Lee, T Y

    1999-01-01

    A diagnostic beamline has been operated in the Pohang Light Source (PLS) storage ring for the diagnostics of electron and photon beam properties. It consists of two 1:1 imaging systems: a visible-light imaging system and a soft X-ray imaging system. We have measured the transverse and the longitudinal structures of beams by using a streak camera to obtain a visible image. Accurate transverse beam size have been measured to be 186 mu m horizontally and 43.1 mu m vertically by using soft X-ray images with minimum diffraction errors. The corresponding emittances are 11.7 nm-rad horizontally and 0.59 nm-rad vertically. By comparing the measured data with the design values, we confirmed that the PLS storage ring has reached its designed performance within an error of 3.3 % in the transverse direction.

  17. The architecture of diagnostic research

    DEFF Research Database (Denmark)

    Colli, Agostino; Fraquelli, Mirella; Casazza, Giovanni

    2014-01-01

    The diagnostic research process can be divided into five phases, designed to establish the clinical utility of a new diagnostic test - the index test. The aim of the present review is to illustrate the study designs that are appropriate for each diagnostic phase, using clinical examples regarding...

  18. Automatic error compensation in dc amplifiers

    International Nuclear Information System (INIS)

    Longden, L.L.

    1976-01-01

    When operational amplifiers are exposed to high levels of neutron fluence or total ionizing dose, significant changes may be observed in input voltages and currents. These changes may produce large errors at the output of direct-coupled amplifier stages. Therefore, the need exists for automatic compensation techniques. However, previously introduced techniques compensate only for errors in the main amplifier and neglect the errors induced by the compensating circuitry. In this paper, the techniques introduced compensate not only for errors in the main operational amplifier, but also for errors induced by the compensation circuitry. Included in the paper is a theoretical analysis of each compensation technique, along with advantages and disadvantages of each. Important design criteria and information necessary for proper selection of semiconductor switches will also be included. Introduced in this paper will be compensation circuitry for both resistive and capacitive feedback networks

  19. El error en el delito imprudente

    Directory of Open Access Journals (Sweden)

    Miguel Angel Muñoz García

    2011-12-01

    Full Text Available La teoría del error en los delitos culposos constituye un tema álgido de tratar, y controversial en la dogmática penal: existen en realidad muy escasas referencias, y no se ha llegado a un consenso razonable. Partiendo del análisis de la estructura dogmática del delito imprudente, en donde se destaca el deber objetivo de cuidado como elemento del tipo sobre el que recae el error, y de las diferentes posiciones doctrinales que defienden la aplicabilidad del error de tipo y del error de prohibición, se plantea la viabilidad de este último, con fundamento en razones dogmáticas y de política criminal, siendo la infracción del deber objetivo de cuidado en tanto consecuencia del error, un tema por analizar en sede de culpabilidad.

  20. Error Resilient Video Compression Using Behavior Models

    Directory of Open Access Journals (Sweden)

    Jacco R. Taal

    2004-03-01

    Full Text Available Wireless and Internet video applications are inherently subjected to bit errors and packet errors, respectively. This is especially so if constraints on the end-to-end compression and transmission latencies are imposed. Therefore, it is necessary to develop methods to optimize the video compression parameters and the rate allocation of these applications that take into account residual channel bit errors. In this paper, we study the behavior of a predictive (interframe video encoder and model the encoders behavior using only the statistics of the original input data and of the underlying channel prone to bit errors. The resulting data-driven behavior models are then used to carry out group-of-pictures partitioning and to control the rate of the video encoder in such a way that the overall quality of the decoded video with compression and channel errors is optimized.

  1. Telemetry location error in a forested habitat

    Science.gov (United States)

    Chu, D.S.; Hoover, B.A.; Fuller, M.R.; Geissler, P.H.; Amlaner, Charles J.

    1989-01-01

    The error associated with locations estimated by radio-telemetry triangulation can be large and variable in a hardwood forest. We assessed the magnitude and cause of telemetry location errors in a mature hardwood forest by using a 4-element Yagi antenna and compass bearings toward four transmitters, from 21 receiving sites. The distance error from the azimuth intersection to known transmitter locations ranged from 0 to 9251 meters. Ninety-five percent of the estimated locations were within 16 to 1963 meters, and 50% were within 99 to 416 meters of actual locations. Angles with 20o of parallel had larger distance errors than other angles. While angle appeared most important, greater distances and the amount of vegetation between receivers and transmitters also contributed to distance error.

  2. The District Nursing Clinical Error Reduction Programme.

    Science.gov (United States)

    McGraw, Caroline; Topping, Claire

    2011-01-01

    The District Nursing Clinical Error Reduction (DANCER) Programme was initiated in NHS Islington following an increase in the number of reported medication errors. The objectives were to reduce the actual degree of harm and the potential risk of harm associated with medication errors and to maintain the existing positive reporting culture, while robustly addressing performance issues. One hundred medication errors reported in 2007/08 were analysed using a framework that specifies the factors that predispose to adverse medication events in domiciliary care. Various contributory factors were identified and interventions were subsequently developed to address poor drug calculation and medication problem-solving skills and incorrectly transcribed medication administration record charts. Follow up data were obtained at 12 months and two years. The evaluation has shown that although medication errors do still occur, the programme has resulted in a marked shift towards a reduction in the associated actual degree of harm and the potential risk of harm.

  3. A Comparative Study on Error Analysis

    DEFF Research Database (Denmark)

    Wu, Xiaoli; Zhang, Chun

    2015-01-01

    Title: A Comparative Study on Error Analysis Subtitle: - Belgian (L1) and Danish (L1) learners’ use of Chinese (L2) comparative sentences in written production Xiaoli Wu, Chun Zhang Abstract: Making errors is an inevitable and necessary part of learning. The collection, classification and analysis...... the occurrence of errors either in linguistic or pedagogical terms. The purpose of the current study is to demonstrate the theoretical and practical relevance of error analysis approach in CFL by investigating two cases - (1) Belgian (L1) learners’ use of Chinese (L2) comparative sentences in written production...... of errors in the written and spoken production of L2 learners has a long tradition in L2 pedagogy. Yet, in teaching and learning Chinese as a foreign language (CFL), only handful studies have been made either to define the ‘error’ in a pedagogically insightful way or to empirically investigate...

  4. Medication Error, What Is the Reason?

    Directory of Open Access Journals (Sweden)

    Ali Banaozar Mohammadi

    2015-09-01

    Full Text Available Background: Medication errors due to different reasons may alter the outcome of all patients, especially patients with drug poisoning. We introduce one of the most common type of medication error in the present article. Case:A 48 year old woman with suspected organophosphate poisoning was died due to lethal medication error. Unfortunately these types of errors are not rare and had some preventable reasons included lack of suitable and enough training and practicing of medical students and some failures in medical students’ educational curriculum. Conclusion:Hereby some important reasons are discussed because sometimes they are tre-mendous. We found that most of them are easily preventable. If someone be aware about the method of use, complications, dosage and contraindication of drugs, we can minimize most of these fatal errors.

  5. [Errors in Peruvian medical journals references].

    Science.gov (United States)

    Huamaní, Charles; Pacheco-Romero, José

    2009-01-01

    References are fundamental in our studies; an adequate selection is asimportant as an adequate description. To determine the number of errors in a sample of references found in Peruvian medical journals. We reviewed 515 scientific papers references selected by systematic randomized sampling and corroborated reference information with the original document or its citation in Pubmed, LILACS or SciELO-Peru. We found errors in 47,6% (245) of the references, identifying 372 types of errors; the most frequent were errors in presentation style (120), authorship (100) and title (100), mainly due to spelling mistakes (91). References error percentage was high, varied and multiple. We suggest systematic revision of references in the editorial process as well as to extend the discussion on this theme. references, periodicals, research, bibliometrics.

  6. A qualitative description of human error

    International Nuclear Information System (INIS)

    Li Zhaohuan

    1992-11-01

    The human error has an important contribution to risk of reactor operation. The insight and analytical model are main parts in human reliability analysis. It consists of the concept of human error, the nature, the mechanism of generation, the classification and human performance influence factors. On the operating reactor the human error is defined as the task-human-machine mismatch. The human error event is focused on the erroneous action and the unfavored result. From the time limitation of performing a task, the operation is divided into time-limited and time-opened. The HCR (human cognitive reliability) model is suited for only time-limited. The basic cognitive process consists of the information gathering, cognition/thinking, decision making and action. The human erroneous action may be generated in any stage of this process. The more natural ways to classify human errors are presented. The human performance influence factors including personal, organizational and environmental factors are also listed

  7. A qualitative description of human error

    Energy Technology Data Exchange (ETDEWEB)

    Zhaohuan, Li [Academia Sinica, Beijing, BJ (China). Inst. of Atomic Energy

    1992-11-01

    The human error has an important contribution to risk of reactor operation. The insight and analytical model are main parts in human reliability analysis. It consists of the concept of human error, the nature, the mechanism of generation, the classification and human performance influence factors. On the operating reactor the human error is defined as the task-human-machine mismatch. The human error event is focused on the erroneous action and the unfavored result. From the time limitation of performing a task, the operation is divided into time-limited and time-opened. The HCR (human cognitive reliability) model is suited for only time-limited. The basic cognitive process consists of the information gathering, cognition/thinking, decision making and action. The human erroneous action may be generated in any stage of this process. The more natural ways to classify human errors are presented. The human performance influence factors including personal, organizational and environmental factors are also listed.

  8. A memory of errors in sensorimotor learning.

    Science.gov (United States)

    Herzfeld, David J; Vaswani, Pavan A; Marko, Mollie K; Shadmehr, Reza

    2014-09-12

    The current view of motor learning suggests that when we revisit a task, the brain recalls the motor commands it previously learned. In this view, motor memory is a memory of motor commands, acquired through trial-and-error and reinforcement. Here we show that the brain controls how much it is willing to learn from the current error through a principled mechanism that depends on the history of past errors. This suggests that the brain stores a previously unknown form of memory, a memory of errors. A mathematical formulation of this idea provides insights into a host of puzzling experimental data, including savings and meta-learning, demonstrating that when we are better at a motor task, it is partly because the brain recognizes the errors it experienced before. Copyright © 2014, American Association for the Advancement of Science.

  9. 2012 HIV Diagnostics Conference: the molecular diagnostics perspective.

    Science.gov (United States)

    Branson, Bernard M; Pandori, Mark

    2013-04-01

    2012 HIV Diagnostic Conference Atlanta, GA, USA, 12-14 December 2012. This report highlights the presentations and discussions from the 2012 National HIV Diagnostic Conference held in Atlanta (GA, USA), on 12-14 December 2012. Reflecting changes in the evolving field of HIV diagnostics, the conference provided a forum for evaluating developments in molecular diagnostics and their role in HIV diagnosis. In 2010, the HIV Diagnostics Conference concluded with the proposal of a new diagnostic algorithm which included nucleic acid testing to resolve discordant screening and supplemental antibody test results. The 2012 meeting, picking up where the 2010 meeting left off, focused on scientific presentations that assessed this new algorithm and the role played by RNA testing and new developments in molecular diagnostics, including detection of total and integrated HIV-1 DNA, detection and quantification of HIV-2 RNA, and rapid formats for detection of HIV-1 RNA.

  10. Integrated data analysis of fusion diagnostics by means of the Bayesian probability theory

    International Nuclear Information System (INIS)

    Fischer, R.; Dinklage, A.

    2004-01-01

    Integrated data analysis (IDA) of fusion diagnostics is the combination of heterogeneous diagnostics to obtain validated physical results. Benefits from the integrated approach result from a systematic use of interdependencies; in that sense IDA optimizes the extraction of information from sets of different data. For that purpose IDA requires a systematic and formalized error analysis of all (statistical and systematic) uncertainties involved in each diagnostic. Bayesian probability theory allows for a systematic combination of all information entering the diagnostic model by considering all uncertainties of the measured data, the calibration measurements, and the physical model. Prior physics knowledge on model parameters can be included. Handling of systematic errors is provided. A central goal of the integration of redundant or complementary diagnostics is to provide information to resolve inconsistencies by exploiting interdependencies. A comparable analysis of sets of diagnostics (meta-diagnostics) is performed by combining statistical and systematical uncertainties with model parameters and model uncertainties. Diagnostics improvement and experimental optimization and design of meta-diagnostics will be discussed

  11. Common Errors in Ecological Data Sharing

    Directory of Open Access Journals (Sweden)

    Robert B. Cook

    2013-04-01

    Full Text Available Objectives: (1 to identify common errors in data organization and metadata completeness that would preclude a “reader” from being able to interpret and re-use the data for a new purpose; and (2 to develop a set of best practices derived from these common errors that would guide researchers in creating more usable data products that could be readily shared, interpreted, and used.Methods: We used directed qualitative content analysis to assess and categorize data and metadata errors identified by peer reviewers of data papers published in the Ecological Society of America’s (ESA Ecological Archives. Descriptive statistics provided the relative frequency of the errors identified during the peer review process.Results: There were seven overarching error categories: Collection & Organization, Assure, Description, Preserve, Discover, Integrate, and Analyze/Visualize. These categories represent errors researchers regularly make at each stage of the Data Life Cycle. Collection & Organization and Description errors were some of the most common errors, both of which occurred in over 90% of the papers.Conclusions: Publishing data for sharing and reuse is error prone, and each stage of the Data Life Cycle presents opportunities for mistakes. The most common errors occurred when the researcher did not provide adequate metadata to enable others to interpret and potentially re-use the data. Fortunately, there are ways to minimize these mistakes through carefully recording all details about study context, data collection, QA/ QC, and analytical procedures from the beginning of a research project and then including this descriptive information in the metadata.

  12. Analyzing temozolomide medication errors: potentially fatal.

    Science.gov (United States)

    Letarte, Nathalie; Gabay, Michael P; Bressler, Linda R; Long, Katie E; Stachnik, Joan M; Villano, J Lee

    2014-10-01

    The EORTC-NCIC regimen for glioblastoma requires different dosing of temozolomide (TMZ) during radiation and maintenance therapy. This complexity is exacerbated by the availability of multiple TMZ capsule strengths. TMZ is an alkylating agent and the major toxicity of this class is dose-related myelosuppression. Inadvertent overdose can be fatal. The websites of the Institute for Safe Medication Practices (ISMP), and the Food and Drug Administration (FDA) MedWatch database were reviewed. We searched the MedWatch database for adverse events associated with TMZ and obtained all reports including hematologic toxicity submitted from 1st November 1997 to 30th May 2012. The ISMP describes errors with TMZ resulting from the positioning of information on the label of the commercial product. The strength and quantity of capsules on the label were in close proximity to each other, and this has been changed by the manufacturer. MedWatch identified 45 medication errors. Patient errors were the most common, accounting for 21 or 47% of errors, followed by dispensing errors, which accounted for 13 or 29%. Seven reports or 16% were errors in the prescribing of TMZ. Reported outcomes ranged from reversible hematological adverse events (13%), to hospitalization for other adverse events (13%) or death (18%). Four error reports lacked detail and could not be categorized. Although the FDA issued a warning in 2003 regarding fatal medication errors and the product label warns of overdosing, errors in TMZ dosing occur for various reasons and involve both healthcare professionals and patients. Overdosing errors can be fatal.

  13. NLO error propagation exercise: statistical results

    International Nuclear Information System (INIS)

    Pack, D.J.; Downing, D.J.

    1985-09-01

    Error propagation is the extrapolation and cumulation of uncertainty (variance) above total amounts of special nuclear material, for example, uranium or 235 U, that are present in a defined location at a given time. The uncertainty results from the inevitable inexactness of individual measurements of weight, uranium concentration, 235 U enrichment, etc. The extrapolated and cumulated uncertainty leads directly to quantified limits of error on inventory differences (LEIDs) for such material. The NLO error propagation exercise was planned as a field demonstration of the utilization of statistical error propagation methodology at the Feed Materials Production Center in Fernald, Ohio from April 1 to July 1, 1983 in a single material balance area formed specially for the exercise. Major elements of the error propagation methodology were: variance approximation by Taylor Series expansion; variance cumulation by uncorrelated primary error sources as suggested by Jaech; random effects ANOVA model estimation of variance effects (systematic error); provision for inclusion of process variance in addition to measurement variance; and exclusion of static material. The methodology was applied to material balance area transactions from the indicated time period through a FORTRAN computer code developed specifically for this purpose on the NLO HP-3000 computer. This paper contains a complete description of the error propagation methodology and a full summary of the numerical results of applying the methodlogy in the field demonstration. The error propagation LEIDs did encompass the actual uranium and 235 U inventory differences. Further, one can see that error propagation actually provides guidance for reducing inventory differences and LEIDs in future time periods

  14. Repeated speech errors: evidence for learning.

    Science.gov (United States)

    Humphreys, Karin R; Menzies, Heather; Lake, Johanna K

    2010-11-01

    Three experiments elicited phonological speech errors using the SLIP procedure to investigate whether there is a tendency for speech errors on specific words to reoccur, and whether this effect can be attributed to implicit learning of an incorrect mapping from lemma to phonology for that word. In Experiment 1, when speakers made a phonological speech error in the study phase of the experiment (e.g. saying "beg pet" in place of "peg bet") they were over four times as likely to make an error on that same item several minutes later at test. A pseudo-error condition demonstrated that the effect is not simply due to a propensity for speakers to repeat phonological forms, regardless of whether or not they have been made in error. That is, saying "beg pet" correctly at study did not induce speakers to say "beg pet" in error instead of "peg bet" at test. Instead, the effect appeared to be due to learning of the error pathway. Experiment 2 replicated this finding, but also showed that after 48 h, errors made at study were no longer more likely to reoccur. As well as providing constraints on the longevity of the effect, this provides strong evidence that the error reoccurrences observed are not due to item-specific difficulty that leads individual speakers to make habitual mistakes on certain items. Experiment 3 showed that the diminishment of the effect 48 h later is not due to specific extra practice at the task. We discuss how these results fit in with a larger view of language as a dynamic system that is constantly adapting in response to experience. Copyright © 2010 Elsevier B.V. All rights reserved.

  15. Beam-Based Diagnostics of RF-Breakdown in the Two-Beam Test-Stand in CTF3

    CERN Document Server

    Johnson, M

    2007-01-01

    The general outline of a beam-based diagnostic method of RF-breakdown, using BPMs, at the two-beam test-stand in CTF3 is discussed. The basic components of the set-up and their functions in the diagnostic are described. Estimations of the expected error in the measured parameters are performed.

  16. Error budget calculations in laboratory medicine: linking the concepts of biological variation and allowable medical errors

    NARCIS (Netherlands)

    Stroobants, A. K.; Goldschmidt, H. M. J.; Plebani, M.

    2003-01-01

    Background: Random, systematic and sporadic errors, which unfortunately are not uncommon in laboratory medicine, can have a considerable impact on the well being of patients. Although somewhat difficult to attain, our main goal should be to prevent all possible errors. A good insight on error-prone

  17. Error-information in tutorial documentation: Supporting users' errors to facilitate initial skill learning

    NARCIS (Netherlands)

    Lazonder, Adrianus W.; van der Meij, Hans

    1995-01-01

    Novice users make many errors when they first try to learn how to work with a computer program like a spreadsheet or wordprocessor. No matter how user-friendly the software or the training manual, errors can and will occur. The current view on errors is that they can be helpful or disruptive,

  18. MAST magnetic diagnostics

    Science.gov (United States)

    Edlington, T.; Martin, R.; Pinfold, T.

    2001-01-01

    The mega-ampere spherical tokamak (MAST) experiment is a new, large, low aspect ratio device (R=0.7-0.8 m, a=0.5-0.65 m, maximum BT˜0.63 T at R=0.7 m) operating its first experimental physics campaign. Designed to study a wide variety of plasma shapes with up to 2 MA of plasma current with an aspect ratio down to 1.3, the poloidal field (PF) coils used for plasma formation, equilibrium and shaping are inside the main vacuum vessel. For plasma control and to investigate a wide range of plasma phenomena, an extensive set of magnetic diagnostics have been installed inside the vacuum vessel. More than 600 vacuum compatible, bakeable diagnostic coils are configured in a number of discrete arrays close to the plasma edge with about half the coils installed behind the graphite armour tiles covering the center column. The coil arrays measure the toroidal and poloidal variation in the equilibrium field and its high frequency fluctuating components. Internal coils also measure currents in the PF coils, plasma current, stored energy and induced currents in the mechanical support structures of the coils and graphite armour tiles. The latter measurements are particularly important when halo currents are induced following a plasma termination, for example, when the plasma becomes vertically unstable. The article describes the MAST magnetic diagnostic coil set and their calibration. The way in which coil signals are used to control the plasma equilibrium is described and data from the first MAST experimental campaign presented. These coil data are used as input to the code EFIT [L. Lao et al., Nucl. Fusion 25, 1611 (1985)], for measurement of halo currents in the vacuum vessel structure and for measurements of the structure of magnetic field fluctuations near the plasma edge.

  19. Soft x-ray virtual diagnostics for tokamak simulations

    Science.gov (United States)

    Kim, J. S.; Zhao, L.; Bogatu, I. N.; In, Y.; Turnbull, A.; Osborne, T.; Maraschek, M.; Comer, K.

    2009-11-01

    The numerical toolset, FAR-TECH Virtual Diagnostic Utility, for generating virtual experimental data based on theoretical models and comparing it with experimental data, has been developed for soft x-ray diagnostics on DIII-D. The virtual (or synthetic) soft x-ray signals for a sample DIII-D discharge are compared with the experimental data. The plasma density and temperature radial profiles needed in the soft x-ray signal modeling are obtained from experimental data, i.e., from Thomson scattering and electron cyclotron emission. The virtual soft x-ray diagnostics for the equilibriums have a good agreement with the experimental data. The virtual diagnostics based on an ideal linear instability also agree reasonably well with the experimental data. The agreements are good enough to justify the methodology presented here for utilizing virtual diagnostics for routine comparison of experimental data. The agreements also motivate further detailed simulations with improved physical models such as the nonideal magnetohydrodynamics contributions (resistivity, viscosity, nonaxisymmetric error fields, etc.) and other nonlinear effects, which can be tested by virtual diagnostics with various stability modeling.

  20. Soft x-ray virtual diagnostics for tokamak simulations

    International Nuclear Information System (INIS)

    Kim, J. S.; Zhao, L.; Bogatu, I. N.; In, Y.; Turnbull, A.; Osborne, T.; Maraschek, M.; Comer, K.

    2009-01-01

    The numerical toolset, FAR-TECH Virtual Diagnostic Utility, for generating virtual experimental data based on theoretical models and comparing it with experimental data, has been developed for soft x-ray diagnostics on DIII-D. The virtual (or synthetic) soft x-ray signals for a sample DIII-D discharge are compared with the experimental data. The plasma density and temperature radial profiles needed in the soft x-ray signal modeling are obtained from experimental data, i.e., from Thomson scattering and electron cyclotron emission. The virtual soft x-ray diagnostics for the equilibriums have a good agreement with the experimental data. The virtual diagnostics based on an ideal linear instability also agree reasonably well with the experimental data. The agreements are good enough to justify the methodology presented here for utilizing virtual diagnostics for routine comparison of experimental data. The agreements also motivate further detailed simulations with improved physical models such as the nonideal magnetohydrodynamics contributions (resistivity, viscosity, nonaxisymmetric error fields, etc.) and other nonlinear effects, which can be tested by virtual diagnostics with various stability modeling.

  1. Biotechnology in diagnostics

    International Nuclear Information System (INIS)

    Koprowski, H.; Ferrone, S.; Albertini, A.

    1985-01-01

    In recent years much progress has been made in the area of biotechnology. The cellular and molecular cloning methodology to develop monoclonal antibodies and DNA probes have been extensively utilized in basic and clinical research. These investigations have provided the necessary information to apply these reagents to diagnostic problems. The RIA 85 meeting focused on the application of monoclonal antibodies and DNA probes in laboratory medicine. The papers presented at this meeting clearly indicate that biotechnology has already had a significant impact on clinical medicine. (Auth.)

  2. Bouveret's Syndrome: diagnostic considerations

    International Nuclear Information System (INIS)

    Cooper, S.G.; Sherman, S.B.; Steinhardt, J.E.; Wilson, J.M. Jr.; Richman, A.H.

    1987-01-01

    Bouveret's syndrome is a rare disease entity manifested by the formation of a cholecystoduodenal or choledochoduodenal fistula with passage of a gallstone into the duodenal bulb and subsequent obstruction of the gastric outlet. To date, no report of this entity using computed tomographic (CT) imaging is available. This article presents a case of Bouveret's syndrome with the classic findings on upper gastrointestinal (GI) tract series and a description of the CT manifestations. The literature is reviewed with discussion of the diagnostic approach to patients with Bouveret's syndrome

  3. FASTBUS Snoop Diagnostic Module

    International Nuclear Information System (INIS)

    Walz, H.V.; Downing, R.

    1980-11-01

    Development of the FASTBUS Snoop Module, undertaken as part of the prototype program for the new interlaboratory data bus standard, is described. The Snoop Module resides on a FASTBUS crate segment and provides diagnostic monitoring and testing capability. Communication with a remote host computer is handled independent of FASTBUS through a serial link. The module consists of a high-speed ECL front-end to monitor and single-step FASTBUS cycles, a master-slave interface, and a control microprocessor with serial communication ports. Design details and performance specifications of the prototype module are reported. 9 figures, 1 table

  4. Isotope diagnostics apparatus

    International Nuclear Information System (INIS)

    Herrschaft, H.

    1976-01-01

    The invention relates to a measuring probe for an isotope diagnostics apparatus to determine the distribution of radioactive substances in a body by measuring the radiation emanating from this body by means of a multiplicity of measuring probes directed simultaneously towards areas of measuring surfae and carried in guidances of a holding block. The measuring results of the individual probes are recorded separately, thus allowing the possibility of being evaluated separately, too. Measuring probes of this kind are used in multi-channel measuring objects and are useful particularly for determining the regional cerebral blood flow. (orig./ORU) [de

  5. Vibration control, machine diagnostics

    International Nuclear Information System (INIS)

    1990-01-01

    Changing vibrations announce damage in the form of wear or cracks on components of, e.g., engine rotors, pumps, power plant turbo sets, rounding-up tools, or marine diesel engines. Therefore, machine diagnostics use frequency analyses, system tests, trend analyses as well as expert systems to localize or estimate the causes of these damages and malfunctions. Data acquisistion, including not only sensors, but also reliable and redundant data processing systems and analyzing systems, play an important role. The lectures pertaining to the data base are covered in detail. (DG) [de

  6. Diagnostic radiology 1987

    International Nuclear Information System (INIS)

    Margulis, A.R.; Gooding, C.A.

    1987-01-01

    This is the latest version of the continuing education course on diagnostic radiology given yearly by the Department of Radiology at the University of California, San Francisco. The lectures are grouped into sections on gastrointestinal radiology, mammography, uroradiology, magnetic resonance, hepatobiliary radiology, pediatric radiology, ultrasound, interventional radiology, chest radiology, nuclear medicine, cardiovascular radiology, and skeletal radiology. Each section contains four to eight topics. Each of these consists of text that represents highlights in narrative form, selected illustrations, and a short bibliography. The presentation gives a general idea of what points were made in the lecture

  7. Nuclear power plant diagnostics

    International Nuclear Information System (INIS)

    Hollo, E.; Siklossy, P.

    1982-01-01

    The cooling circuit vibration diagnostic system of the Block 1 of the Paks nuclear power station is described. The automatic online vibration monitoring system consisting presently of 42 acceleration sensors and 9 pressure fluctuation sensors, which could be extended, performs both global and local inspection of the primary cooling circuit and its components. The offline data processing system evaluates the data for failure mode analysis. The software under development will be appropriate for partial preliminary identification of failure reasons during their initial phases. The installation experiences and the preliminary results during the hot operational testing of Block 1 are presented. (Sz.J.)

  8. Thermal diagnostics for LTP

    International Nuclear Information System (INIS)

    Lobo, Alberto; Nofrarias, M; Sanjuan, J

    2005-01-01

    This is a short note reporting on the current state of development of the temperature sensors which are part of the LTP Diagnostics Subsystem on board the LISA Pathfinder mission (LPF). A thermal insulator has been designed which ensures sufficient stability of a set of eight NTC sensors (negative temperature coefficient of resistance or thermistors), and the front-end electronics has also been designed and manufactured. Tests have been performed which nearly approach the goal of a global stability of 10 -5 K Hz -1/2

  9. Evaluation of Data with Systematic Errors

    International Nuclear Information System (INIS)

    Froehner, F. H.

    2003-01-01

    Application-oriented evaluated nuclear data libraries such as ENDF and JEFF contain not only recommended values but also uncertainty information in the form of 'covariance' or 'error files'. These can neither be constructed nor utilized properly without a thorough understanding of uncertainties and correlations. It is shown how incomplete information about errors is described by multivariate probability distributions or, more summarily, by covariance matrices, and how correlations are caused by incompletely known common errors. Parameter estimation for the practically most important case of the Gaussian distribution with common errors is developed in close analogy to the more familiar case without. The formalism shows that, contrary to widespread belief, common ('systematic') and uncorrelated ('random' or 'statistical') errors are to be added in quadrature. It also shows explicitly that repetition of a measurement reduces mainly the statistical uncertainties but not the systematic ones. While statistical uncertainties are readily estimated from the scatter of repeatedly measured data, systematic uncertainties can only be inferred from prior information about common errors and their propagation. The optimal way to handle error-affected auxiliary quantities ('nuisance parameters') in data fitting and parameter estimation is to adjust them on the same footing as the parameters of interest and to integrate (marginalize) them out of the joint posterior distribution afterward

  10. Sources of medical error in refractive surgery.

    Science.gov (United States)

    Moshirfar, Majid; Simpson, Rachel G; Dave, Sonal B; Christiansen, Steven M; Edmonds, Jason N; Culbertson, William W; Pascucci, Stephen E; Sher, Neal A; Cano, David B; Trattler, William B

    2013-05-01

    To evaluate the causes of laser programming errors in refractive surgery and outcomes in these cases. In this multicenter, retrospective chart review, 22 eyes of 18 patients who had incorrect data entered into the refractive laser computer system at the time of treatment were evaluated. Cases were analyzed to uncover the etiology of these errors, patient follow-up treatments, and final outcomes. The results were used to identify potential methods to avoid similar errors in the future. Every patient experienced compromised uncorrected visual acuity requiring additional intervention, and 7 of 22 eyes (32%) lost corrected distance visual acuity (CDVA) of at least one line. Sixteen patients were suitable candidates for additional surgical correction to address these residual visual symptoms and six were not. Thirteen of 22 eyes (59%) received surgical follow-up treatment; nine eyes were treated with contact lenses. After follow-up treatment, six patients (27%) still had a loss of one line or more of CDVA. Three significant sources of error were identified: errors of cylinder conversion, data entry, and patient identification error. Twenty-seven percent of eyes with laser programming errors ultimately lost one or more lines of CDVA. Patients who underwent surgical revision had better outcomes than those who did not. Many of the mistakes identified were likely avoidable had preventive measures been taken, such as strict adherence to patient verification protocol or rigorous rechecking of treatment parameters. Copyright 2013, SLACK Incorporated.

  11. Research trend on human error reduction

    International Nuclear Information System (INIS)

    Miyaoka, Sadaoki

    1990-01-01

    Human error has been the problem in all industries. In 1988, the Bureau of Mines, Department of the Interior, USA, carried out the worldwide survey on the human error in all industries in relation to the fatal accidents in mines. There was difference in the results according to the methods of collecting data, but the proportion that human error took in the total accidents distributed in the wide range of 20∼85%, and was 35% on the average. The rate of occurrence of accidents and troubles in Japanese nuclear power stations is shown, and the rate of occurrence of human error is 0∼0.5 cases/reactor-year, which did not much vary. Therefore, the proportion that human error took in the total tended to increase, and it has become important to reduce human error for lowering the rate of occurrence of accidents and troubles hereafter. After the TMI accident in 1979 in USA, the research on man-machine interface became active, and after the Chernobyl accident in 1986 in USSR, the problem of organization and management has been studied. In Japan, 'Safety 21' was drawn up by the Advisory Committee for Energy, and also the annual reports on nuclear safety pointed out the importance of human factors. The state of the research on human factors in Japan and abroad and three targets to reduce human error are reported. (K.I.)

  12. Human error theory: relevance to nurse management.

    Science.gov (United States)

    Armitage, Gerry

    2009-03-01

    Describe, discuss and critically appraise human error theory and consider its relevance for nurse managers. Healthcare errors are a persistent threat to patient safety. Effective risk management and clinical governance depends on understanding the nature of error. This paper draws upon a wide literature from published works, largely from the field of cognitive psychology and human factors. Although the content of this paper is pertinent to any healthcare professional; it is written primarily for nurse managers. Error is inevitable. Causation is often attributed to individuals, yet causation in complex environments such as healthcare is predominantly multi-factorial. Individual performance is affected by the tendency to develop prepacked solutions and attention deficits, which can in turn be related to local conditions and systems or latent failures. Blame is often inappropriate. Defences should be constructed in the light of these considerations and to promote error wisdom and organizational resilience. Managing and learning from error is seen as a priority in the British National Health Service (NHS), this can be better achieved with an understanding of the roots, nature and consequences of error. Such an understanding can provide a helpful framework for a range of risk management activities.

  13. Wind power error estimation in resource assessments.

    Directory of Open Access Journals (Sweden)

    Osvaldo Rodríguez

    Full Text Available Estimating the power output is one of the elements that determine the techno-economic feasibility of a renewable project. At present, there is a need to develop reliable methods that achieve this goal, thereby contributing to wind power penetration. In this study, we propose a method for wind power error estimation based on the wind speed measurement error, probability density function, and wind turbine power curves. This method uses the actual wind speed data without prior statistical treatment based on 28 wind turbine power curves, which were fitted by Lagrange's method, to calculate the estimate wind power output and the corresponding error propagation. We found that wind speed percentage errors of 10% were propagated into the power output estimates, thereby yielding an error of 5%. The proposed error propagation complements the traditional power resource assessments. The wind power estimation error also allows us to estimate intervals for the power production leveled cost or the investment time return. The implementation of this method increases the reliability of techno-economic resource assessment studies.

  14. Wind power error estimation in resource assessments.

    Science.gov (United States)

    Rodríguez, Osvaldo; Del Río, Jesús A; Jaramillo, Oscar A; Martínez, Manuel

    2015-01-01

    Estimating the power output is one of the elements that determine the techno-economic feasibility of a renewable project. At present, there is a need to develop reliable methods that achieve this goal, thereby contributing to wind power penetration. In this study, we propose a method for wind power error estimation based on the wind speed measurement error, probability density function, and wind turbine power curves. This method uses the actual wind speed data without prior statistical treatment based on 28 wind turbine power curves, which were fitted by Lagrange's method, to calculate the estimate wind power output and the corresponding error propagation. We found that wind speed percentage errors of 10% were propagated into the power output estimates, thereby yielding an error of 5%. The proposed error propagation complements the traditional power resource assessments. The wind power estimation error also allows us to estimate intervals for the power production leveled cost or the investment time return. The implementation of this method increases the reliability of techno-economic resource assessment studies.

  15. The benefit of generating errors during learning.

    Science.gov (United States)

    Potts, Rosalind; Shanks, David R

    2014-04-01

    Testing has been found to be a powerful learning tool, but educators might be reluctant to make full use of its benefits for fear that any errors made would be harmful to learning. We asked whether testing could be beneficial to memory even during novel learning, when nearly all responses were errors, and where errors were unlikely to be related to either cues or targets. In 4 experiments, participants learned definitions for unfamiliar English words, or translations for foreign vocabulary, by generating a response and being given corrective feedback, by reading the word and its definition or translation, or by selecting from a choice of definitions or translations followed by feedback. In a final test of all words, generating errors followed by feedback led to significantly better memory for the correct definition or translation than either reading or making incorrect choices, suggesting that the benefits of generation are not restricted to correctly generated items. Even when information to be learned is novel, errorful generation may play a powerful role in potentiating encoding of corrective feedback. Experiments 2A, 2B, and 3 revealed, via metacognitive judgments of learning, that participants are strikingly unaware of this benefit, judging errorful generation to be a less effective encoding method than reading or incorrect choosing, when in fact it was better. Predictions reflected participants' subjective experience during learning. If subjective difficulty leads to more effort at encoding, this could at least partly explain the errorful generation advantage.

  16. Use of digital speech recognition in diagnostics radiology

    International Nuclear Information System (INIS)

    Arndt, H.; Stockheim, D.; Mutze, S.; Petersein, J.; Gregor, P.; Hamm, B.

    1999-01-01

    Purpose: Applicability and benefits of digital speech recognition in diagnostic radiology were tested using the speech recognition system SP 6000. Methods: The speech recognition system SP 6000 was integrated into the network of the institute and connected to the existing Radiological Information System (RIS). Three subjects used this system for writing 2305 findings from dictation. After the recognition process the date, length of dictation, time required for checking/correction, kind of examination and error rate were recorded for every dictation. With the same subjects, a correlation was performed with 625 conventionally written finding. Results: After an 1-hour initial training the average error rates were 8.4 to 13.3%. The first adaptation of the speech recognition system (after nine days) decreased the average error rates to 2.4 to 10.7% due to the ability of the program to learn. The 2 nd and 3 rd adaptations resulted only in small changes of the error rate. An individual comparison of the error rate developments in the same kind of investigation showed the relative independence of the error rate on the individual user. Conclusion: The results show that the speech recognition system SP 6000 can be evaluated as an advantageous alternative for quickly recording radiological findings. A comparison between manually writing and dictating the findings verifies the individual differences of the writing speeds and shows the advantage of the application of voice recognition when faced with normal keyboard performance. (orig.) [de

  17. Medication Errors: New EU Good Practice Guide on Risk Minimisation and Error Prevention.

    Science.gov (United States)

    Goedecke, Thomas; Ord, Kathryn; Newbould, Victoria; Brosch, Sabine; Arlett, Peter

    2016-06-01

    A medication error is an unintended failure in the drug treatment process that leads to, or has the potential to lead to, harm to the patient. Reducing the risk of medication errors is a shared responsibility between patients, healthcare professionals, regulators and the pharmaceutical industry at all levels of healthcare delivery. In 2015, the EU regulatory network released a two-part good practice guide on medication errors to support both the pharmaceutical industry and regulators in the implementation of the changes introduced with the EU pharmacovigilance legislation. These changes included a modification of the 'adverse reaction' definition to include events associated with medication errors, and the requirement for national competent authorities responsible for pharmacovigilance in EU Member States to collaborate and exchange information on medication errors resulting in harm with national patient safety organisations. To facilitate reporting and learning from medication errors, a clear distinction has been made in the guidance between medication errors resulting in adverse reactions, medication errors without harm, intercepted medication errors and potential errors. This distinction is supported by an enhanced MedDRA(®) terminology that allows for coding all stages of the medication use process where the error occurred in addition to any clinical consequences. To better understand the causes and contributing factors, individual case safety reports involving an error should be followed-up with the primary reporter to gather information relevant for the conduct of root cause analysis where this may be appropriate. Such reports should also be summarised in periodic safety update reports and addressed in risk management plans. Any risk minimisation and prevention strategy for medication errors should consider all stages of a medicinal product's life-cycle, particularly the main sources and types of medication errors during product development. This article

  18. MEDICAL ERROR: CIVIL AND LEGAL ASPECT.

    Science.gov (United States)

    Buletsa, S; Drozd, O; Yunin, O; Mohilevskyi, L

    2018-03-01

    The scientific article is focused on the research of the notion of medical error, medical and legal aspects of this notion have been considered. The necessity of the legislative consolidation of the notion of «medical error» and criteria of its legal estimation have been grounded. In the process of writing a scientific article, we used the empirical method, general scientific and comparative legal methods. A comparison of the concept of medical error in civil and legal aspects was made from the point of view of Ukrainian, European and American scientists. It has been marked that the problem of medical errors is known since ancient times and in the whole world, in fact without regard to the level of development of medicine, there is no country, where doctors never make errors. According to the statistics, medical errors in the world are included in the first five reasons of death rate. At the same time the grant of medical services practically concerns all people. As a man and his life, health in Ukraine are acknowledged by a higher social value, medical services must be of high-quality and effective. The grant of not quality medical services causes harm to the health, and sometimes the lives of people; it may result in injury or even death. The right to the health protection is one of the fundamental human rights assured by the Constitution of Ukraine; therefore the issue of medical errors and liability for them is extremely relevant. The authors make conclusions, that the definition of the notion of «medical error» must get the legal consolidation. Besides, the legal estimation of medical errors must be based on the single principles enshrined in the legislation and confirmed by judicial practice.

  19. Imaging of body packing: errors and medico-legal issues.

    Science.gov (United States)

    Reginelli, Alfonso; Russo, Anna; Urraro, Fabrizio; Maresca, Duilia; Martiniello, Ciro; D'Andrea, Alfredo; Brunese, Luca; Pinto, Antonio

    2015-10-01

    Body packing is the ingestion or insertion in the human body of packed illicit substances. Over the last 20 years, drug smuggling has increased global and new means of transport of narcotics have emerged. Among these, the most frequent one is the gastrointestinal tract: from mouth to anus, vagina, and ears. Cocaine is one of the most traded drugs, followed by heroin. Condoms, latex gloves, and balloons are typically used as drug packets for retention in the body. There are different radiologic modalities to detect illicit drugs in body packing: Plain radiography, computed tomography (CT), ultrasound, and magnetic resonance. Current protocols recommend the use of radiography to confirm packet retention and, in case of doubt, the use of abdominal CT scan with reduced mAs. In case of packet rupture, catastrophic effects can occur. Management of patients carrying packets of drugs is a recurrent medico-legal problem. To improve diagnostic accuracy and prevent hazardous complications, radiologists and emergency physicians should be familiar with radiologic features of body packing. The radiologist plays both a social and a medico-legal role in their assessment, and it should not be limited only to the identification of the packages but must also provide accurate information about their number and their exact location. In this review, we focus on diagnostic errors and medico-legal issues related to the radiological assessment of body packers.

  20. Notes on human error analysis and prediction

    International Nuclear Information System (INIS)

    Rasmussen, J.

    1978-11-01

    The notes comprise an introductory discussion of the role of human error analysis and prediction in industrial risk analysis. Following this introduction, different classes of human errors and role in industrial systems are mentioned. Problems related to the prediction of human behaviour in reliability and safety analysis are formulated and ''criteria for analyzability'' which must be met by industrial systems so that a systematic analysis can be performed are suggested. The appendices contain illustrative case stories and a review of human error reports for the task of equipment calibration and testing as found in the US Licensee Event Reports. (author)