PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Knowledge base”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,045 records · Page 58Linked to original sources
PubMed1999

[RHEUMexpert: a documentation and expert system for rheumatic diseases].

A computer assisted documentation of signs and findings in rheumatic diseases is described. This documentation was developed by the Austrian Society for Rheumatology and thought to be a minimal standard for the use by general practitioners. In addition, a knowledge-based basic differential diagnosis support was developed, which differentiates between major groups of rheumatic diseases as inflammatory spine diseases, mechanical or metabolic reasons for spine disorders, inflammatory joint diseases, degenerative or metabolic joint diseases, soft tissue diseases. This presentation describes the results of an evaluation of 75 typical case histories and a second study where 252 case histories were documented retrospectively in this new system. The results of the first showed a pretty good discrimination between the described groups of different diagnoses (sensitivity between 71 and 100 percent for all groups with the exception of metabolic joint diseases, specificity between 75 and 94 percent). The second--retrospective--documentation and diagnostic support showed much weaker results (sensitivity for major groups 74-76 percent). The reasons for the different outcomes are discussed: On the one hand, signs and symptoms from case reports could not be transferred completely in the new documentation, as some findings retrospectively could not be defined sharp enough. On the other hand the study showed, that the sensitivity of well defined disorders as inflammatory joint diseases (exp. rheumatoid arthritis) reaches almost 100 percent, whereas it is as low as 50 percent in some other diseases (e.g. gout) whose characteristic findings and symptoms are suppressed by treatment (drug medication) in many cases. The results show that computer based documentation of rheumatic diseases facilitates the systematized and standardised documentation of patient data. However, a few modifications of the knowledge base as well as the knowledge representation formalisms are necessary to achieve a better performance in differential diagnostic support.

Arthritis, Rheumatoid↗
PubMedDate not supplied

Disturbances of impulse formation: an expert system for ECG interpretation.

This paper describes an expert system (ES) that aids in interpretation of some disturbances of impulse formation from electrocardiographic records. The system consists of a user interface, a knowledge base, an inference engine and an explanation facility. It is implemented using Turbo PROLOG and uses the built-in interpreter for goal proving or disproving. The user interface gets information about the case by interrogation through multiple choice or Yes/No questions. The response is processed and stored in a dynamic database. After the interview the processed data are stored in a permanent file for subsequent calls. The knowledge base contains domain rules of the If-Then variety. The inference engine supports the logic-based method of knowledge organization, which is controlled by backward-chaining. The explanation facility is able to give reasons for any fact in the dynamic database. The main diagnosis, the diagnostic criteria and the algorithm used are explained and illustrated with examples. Sample outputs of the system are also given.

Algorithms↗
PubMed1994

Refinement of the HEPAR expert system: tools and techniques.

Methods and tools for the static and dynamic verification and validation of software systems are commonplace in the field of software engineering. In the field of expert systems, where it is more difficult to ensure that a system meets the specifications and expectations than in traditional software engineering, such tools are generally not available. In this paper, the need for more support of the development process by methods and tools is illustrated by the approach taken in building the HEPAR system, a rule-based expert system that can be used as a supportive tool in the diagnosis of disorders of the liver and biliary tract. At a certain stage in the development of this system an incremental development methodology has been adopted, in which implementation of parts of the expert system was followed by dynamic validation. For this purpose, a collection of software tools were implemented as extensions to a rule-based expert-system shell. These tools provide valuable information about the effects of modification of the HEPAR knowledge base, and indicate places in the knowledge base for refinement. It is believed that similar software tools may prove helpful in the development of other expert systems as well.

Artificial Intelligence↗
PubMed2006

A method for classification of transient events in EEG recordings: application to epilepsy diagnosis.

OBJECTIVES: The aim of the paper is to analyze transient events in inter-ictal EEG recordings, and classify epileptic activity into focal or generalized epilepsy using an automated method. METHODS: A two-stage approach is proposed. In the first stage the observed transient events of a single channel are classified into four categories: epileptic spike (ES), muscle activity (EMG), eye blinking activity (EOG), and sharp alpha activity (SAA). The process is based on an artificial neural network. Different artificial neural network architectures have been tried and the network having the lowest error has been selected using the hold out approach. In the second stage a knowledge-based system is used to produce diagnosis for focal or generalized epileptic activity. RESULTS: The classification of transient events reported high overall accuracy (84.48%), while the knowledge-based system for epilepsy diagnosis correctly classified nine out of ten cases. CONCLUSIONS: The proposed method is advantageous since it effectively detects and classifies the undesirable activity into appropriate categories and produces a final outcome related to the existence of epilepsy.

Action Potentials↗
PubMed2003

Logic-based remodeling of the Digital Anatomist Foundational Model.

This paper describes a development cycle for the engineering of large knowledge bases: A graphical tool is used for editing and the content is transformed into a logic-based representation language. This representation is used to check the consistency of the knowledge base as well as to facilitate the reviewing process. Showing the usefulness of this approach, aspects of the Digital Anatomist Foundational Model will be transformed into a Description Logics representation. We introduce a special modeling technique to account for the representation of the complex part/whole relationships in the biomedical domain.

Anatomy↗
PubMed1997

[Toxoplasmosis diagnosis in pregnancy: computer assisted follow-up interpretation of serologic tests].

Primary infection with Toxoplasma gondii during pregnancy can result in fetal infection with serious sequelae for the unborn if not treated properly. Early diagnosis enables drug therapy and significantly reduces the risk of fetal disease. A systematic serological screening procedure was established in Austria in 1975 to detect primary toxoplasma infection as early as possible during pregnancy. Since the screening program is based solely on observation and interpretation of serological data, the question arises whether a knowledge-based system for automatic interpretation can achieve a sufficient interpretative accuracy for introduction to routine work. For this reason the system Toxopert-I was developed. The system is aimed at facilitating routine laboratory work, as well as assuring quality by setting standards for therapy. The required knowledge base was designed as a knowledge graph, each state representing a certain interpretation. One or more available serological test results cause the knowledge graph to change its current state. If all available test results are processed, the final state reached corresponds to the respective current interpretation for the patient. A retrospective analysis of 1000 pregnant women yielded a total diagnostic sensitivity and specificity of over 99% in comparison with the clinician's diagnosis which was used as the Gold Standard.

Animals↗
PubMed1998

Influence of medical school on medical students' opinions about primary care practice.

PURPOSE: To compare first- and fourth-year medical students' opinions about primary care practice. METHOD: A cross-sectional survey was made of medical students at New York Medical College (NYMC) and East Carolina University School of Medicine (ECUSOM) over three years (1993-94, 1994-95, and 1995-96). Three consecutive classes of first-year students from both schools (n = 807), two consecutive classes of fourth-year NYMC students (n = 373), and three consecutive classes of fourth-year ECUSOM students (n = 221) were given a self-administered questionnaire about professional aspects of primary care practice. Responses to ten items about primary care practice were the independent variables in a logistic regression analysis. Career choice, categorized as primary care or non-primary care, was the dependent variable. Independent, two-tailed t-tests were employed to compare the responses of the first-year students interested in primary care careers with those of the fourth-year students interested in primary care careers. RESULTS: In all, 639 (79%) of the first-year students and 396 (67%) of the fourth-year students returned completed questionnaires. The first-year students interested in primary care careers were significantly more likely to believe that primary care practice has more prestige, has more intellectual stimulation, needs a large knowledge base, and involves work that is more important than that of non-primary care physicians, and were significantly more likely to disagree with the assertion that in primary care practice, physicians have more control over their working hours. With one exception (prestige of primary care practice), all these independent variables were significant for the fourth-year students as well. The comparison of the first- and fourth-year students indicated that the fourth-year students were significantly more likely to believe that primary care practice has more intellectual stimulation, needs a large knowledge base, and requires knowledge that non-primary care practice may not; they were also significantly more likely to disagree with the assertions that primary care practice is adequately compensated, has more prestige, and allows more control over working hours. CONCLUSION: It appears that students' positive perceptions about primary care practice may change as realistic perceptions about the professional demands on primary care physicians develop during medical school.

Adult↗
PubMed1991

The application of SSADM to modelling the logical structure of proteins.

A logical design that describes the overall structure of proteins, together with a more detailed design describing secondary and some supersecondary structures, has been constructed using the computer-aided software engineering (CASE) tool, Auto-mate. Auto-mate embodies the philosophy of the Structured Systems Analysis and Design Method (SSADM) which enables the logical design of computer systems. Our design will facilitate the building of large information systems, such as databases and knowledgebases in the field of protein structure, by the derivation of system requirements from our logical model prior to producing the final physical system. In addition, the study has highlighted the ease of employing SSADM as a formalism in which to conduct the transferral of concepts from an expert into a design for a knowledge-based system that can be implemented on a computer (the knowledge-engineering exercise). It has been demonstrated how SSADM techniques may be extended for the purpose of modelling the constituent Prolog rules. This facilitates the integration of the logical system design model with the derived knowledge-based system.

Amino Acid Sequence↗
PubMed2003

A level set approach for shape-driven segmentation and tracking of the left ventricle.

Knowledge-based segmentation has been explored significantly in medical imaging. Prior anatomical knowledge can be used to define constraints that can improve performance of segmentation algorithms to physically corrupted and incomplete data. In this paper, the objective is to introduce such knowledge-based constraints while preserving the ability of dealing with local deformations. Toward this end, we propose a variational level set framework that can account for global shape consistency as well as for local deformations. In order to improve performance, the problems of segmentation and tracking of the structure of interest are dealt with simultaneously by introducing the notion of time in the process and looking for a solution that satisfies that prior constraints while being consistent along consecutive frames. Promising experimental results in magnetic resonance and ultrasonic cardiac images demonstrate the potentials of our approach.

Algorithms↗
PubMed2002

Evidence-based medicine knowledge, attitudes, and skills of community faculty.

CONTEXT: As medical schools turn to community physicians for ambulatory care teaching, assessing the preparation of these faculty in principles of evidence-based medicine (EBM) becomes important. OBJECTIVE: To determine the knowledge and attitudes of community faculty concerning EBM and their use of EBM in patient care and teaching. DESIGN: Cross-sectional survey conducted from January to March of 2000. SETTING: A clinical campus of a state medical school; a midwestern city of a half-million people with demographics close to national means. MAIN OUTCOME MEASURES: Comparisons of community faculty with full-time faculty in perceived importance and understanding of EBM (5-point scale), knowledge of EBM, and use of EBM in patient care and teaching. MAIN RESULTS: Responses were obtained from 63% (177) of eligible community faculty and 71% (22) of full-time faculty. Community faculty considered EBM skills to be less important for daily practice than did full-time faculty (3.1 vs 4.0; P < .01). Primary care community faculty were less confident of their EBM knowledge than were subspecialty community or full-time faculty (2.9 vs 3.3 vs 3.6; P < .01). Objective measures of EBM knowledge showed primary care and subspecialty community faculty about equal and significantly below full-time faculty (P < .01). Thirty-three percent of community faculty versus 5% of full-time faculty do not incorporate EBM principles into their teaching (P < .01). CONCLUSIONS: Community faculty are not as equipped or motivated to incorporate EBM into their clinical teaching as are full-time faculty. Faculty development programs for community faculty should feature how to use and teach basic EBM concepts.

Adult↗
PubMed2001

Services and prevention: pharmacoepidemiology of antidepressant use.

Between 1988 and 1994, data from 3 large sites revealed a 3-5 fold increase in the prevalence of antidepressant (ATD) treatment for U.S. youths aged 2-19 years. In 1994, the ATD prevalence for youths of this age ranged from 13 per 1000 (in the HMO) to 18 per 1000 (in 2 state Medicaid systems). Males predominated in the 10-14-year-olds treated with ATDs, whereas females predominated among 15-19-year-olds. Caucasians were more than twice as likely to receive ATD therapy than their African-American counterparts. Primary care providers were the major source of ATD prescriptions for youths. The leading diagnoses in primary care were ADHD followed by depression, whereas the diagnostic order was reversed for youths who received psychiatric services. This review provides details concerning these patterns and trends in ATD treatment of youths from community-based clinical data sources. In addition, the role of these data in an expanded, comprehensive psychotropic knowledge base is discussed. Finally, the implications of an expanded knowledge base for ATD treatments are discussed in regard to generating research questions on effectiveness and safety and to improve treatment consensus within a public-health perspective.

Adolescent↗
PubMed2004

The KEGG resource for deciphering the genome.

A grand challenge in the post-genomic era is a complete computer representation of the cell and the organism, which will enable computational prediction of higher-level complexity of cellular processes and organism behavior from genomic information. Toward this end we have been developing a knowledge-based approach for network prediction, which is to predict, given a complete set of genes in the genome, the protein interaction networks that are responsible for various cellular processes. KEGG at http://www.genome.ad.jp/kegg/ is the reference knowledge base that integrates current knowledge on molecular interaction networks such as pathways and complexes (PATHWAY database), information about genes and proteins generated by genome projects (GENES/SSDB/KO databases) and information about biochemical compounds and reactions (COMPOUND/GLYCAN/REACTION databases). These three types of database actually represent three graph objects, called the protein network, the gene universe and the chemical universe. New efforts are being made to abstract knowledge, both computationally and manually, about ortholog clusters in the KO (KEGG Orthology) database, and to collect and analyze carbohydrate structures in the GLYCAN database.

Animals↗
PubMed2006

[Narrative-based medicine and clinical knowledge].

Narrative Based Medicine (NBM) can be defined as follows; a) It views the patient's illness as an unfolding story within the wider story of the patient's life and life-world; b) It acknowledges the patient as the narrator of the story and the subject of the tale; c) It recognizes that all medical theories, hypothesis and pathophysiologies as socially constructed narratives and accepts the coexistence of multiple different narratives; d) It regards the emergence of new stories from dialogue and discourse between patients and healthcare professionals as part of the treatment. Because psychiatry is the only area of specialist medicine where talking and listening are explicitly understood to be therapeutic, NBM can be adopted an effective perspective and method in psychiatry.

Narration↗
PubMed2000

From a urinalysis strategy to an evaluated urine protein expert system.

Urine single protein analysis has developed into a routine method for the screening and monitoring of kidney diseases. In order to support clinical decision making by an interpretative report, a urine protein expert system (UPES) has been developed. Based on a database containing more than 500 excretion patterns, a modular knowledge base was extracted in production rules and implemented in a modern expert system shell. The resulting interpretation system has been thoroughly verified and validated. After the need of interpretation of the complex findings had been documented in a survey, its usability in routine and its knowledge representation was evaluated in 11 hospitals. A user conference confirmed a high quality level of the reports proposed by UPES. It revealed that the problem of automatic data transfer as well as the common definition of diagnostic terms by laboratorians and clinicians play a crucial role for the use of knowledge-based systems in laboratory medicine.

Artificial Intelligence↗
PubMed2003

PROTEOME-3D: an interactive bioinformatics tool for large-scale data exploration and knowledge discovery.

Comprehensive understanding of biological systems requires efficient and systematic assimilation of high-throughput datasets in the context of the existing knowledge base. A major limitation in the field of proteomics is the lack of an appropriate software platform that can synthesize a large number of experimental datasets in the context of the existing knowledge base. Here, we describe a software platform, termed PROTEOME-3D, that utilizes three essential features for systematic analysis of proteomics data: creation of a scalable, queryable, customized database for identified proteins from published literature; graphical tools for displaying proteome landscapes and trends from multiple large-scale experiments; and interactive data analysis that facilitates identification of crucial networks and pathways. Thus, PROTEOME-3D offers a standardized platform to analyze high-throughput experimental datasets for the identification of crucial players in co-regulated pathways and cellular processes.

Computational Biology↗
PubMed2006

Second-year baccalaureate nursing Students' decision making in the clinical setting.

This qualitative, intrinsic case study explored the decision-making activities of baccalaureate nursing students in the second year of a 4-year program. It sought to discover how second-year students determine the need to make a clinical decision, how they respond to a pending clinical decision, the types of decisions made in the clinical setting, and the factors that enhance or impede decision making. The study involved 12 students, all of whom were enrolled in their first clinical rotation on an inpatient unit and completed journals and interviews. Inductive analysis revealed three key encounters that demonstrated students' decision making: encounters with the patient, nursing staff, and clinical tutor. Each encounter revealed an emotion-based and knowledge-based response to various clinical situations. Decisions were evident within each of the three encounters. Implications for curriculum development and clinical tutors are described.

Attitude of Health Personnel↗
PubMed1998

Therapy planning as constraint satisfaction: a computer-based antiretroviral therapy advisor for the management of HIV.

We applied the Protégé methodology for building knowledge-based systems to the domain of antiretroviral therapy. We modeled the task of prescribing drug therapy for HIV, abstracting the essential characteristics of the problem solving. We mapped our model of the antiretroviral-therapy domain to the class of constraint-satisfaction problems, and reused the propose-and-revise problem-solving method, from the Protégé library of methods, to build an antiretroviral therapy advisor, ART Critic. Careful modeling and using Protégé allowed us to build a useful and extensible knowledge-based application rapidly.

Anti-HIV Agents↗