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PubMed1994

An expert system for the calculation of sample size.

Calculation of sample size is a useful technique for researchers who are designing a study, and for clinicians who wish to interpret research findings. The elements that must be specified to calculate the sample size include alpha, beta, Type I and Type II errors, 1- and 2-tail tests, confidence intervals, and confidence levels. A computer software program written by one of the authors (MHE), Sample Size Expert, facilitates sample size calculations. The program uses an expert system to help inexperienced users calculate sample sizes for analytic and descriptive studies. The software is available at no cost from the author or electronically via several on-line information services.

Data Interpretation, Statistical↗

PubMed1994

Kinesiological motion expert system.

Kinesiology builds on anatomical information by establishing which muscles contribute to human motion and to what extent. This 'body as machine' approach seeks to identify particular muscles as contractile 'engines'. The learning of muscular contributions to human motions based on long tables of origins, insertions, innervations, and actions is tedious and often incomplete based on author judgments of which muscles and motions to include. The kinesiological motion expert system (KMES) was developed so that students could easily select joints, actions, and tension types and receive computerized output listing the muscles that could contribute to the motion requested. In addition, a student can select a particular muscle and tension type and the program will return all of the motions that the selected muscle might contribute. The KMES was written in PDC Prolog and has a knowledge base of 1583 movements. Implementation of the KMES in kinesiology classes resulted in an increase in average student final scores of approximately 15% (F(3,190) = 12.11, P < 0.0001).

Anatomy↗

PubMed2003

Integration of distributed multi-analyzer monitoring and control in bioprocessing based on a real-time expert system.

A computer system solution for integration of a distributed bioreactor monitoring and control instrumentation on the laboratory scale is described. Bioreactors equipped with on-line analyzers for mass spectrometry, near-infrared spectroscopy, electrochemical probes and multi-array gas sensors and their respective software were networked through a real-time expert systems platform. The system allowed data transmission of more than 1800 different signals from the instrumentation, including signals from gas sensors, electrodes, spectrometer detectors, balances, flowmeters, etc., and were used for processing and carrying out a number of computational tasks such as partial least-square regression, principal component analysis, artificial neural network modelling, heuristic decision-making and adaptive control. The system was demonstrated on different cultivations/fermentations which illustrated sensor fusion control, multivariate statistical process monitoring, adaptive glucose control and adaptive multivariate control. The performance of these examples showed high operational stability and reliable function and meet typical requirements for production safety and quality.

Algorithms↗

PubMed1999

Knowledge-based expert systems for toxicity and metabolism prediction: DEREK, StAR and METEOR.

It has long been recognised that the ability to predict the metabolic fate of a chemical substance and the potential toxicity of either the parent compound or its metabolites are important in novel drug design. The popularity of using computer models as an aid in this area has grown considerably in recent years. LHASA Limited has been developing knowledge-based expert systems for toxicity and metabolism prediction in collaboration with industry and regulatory authorities. These systems, DEREK, StAR and METEOR, use rules to describe the relationship between chemical structure and either toxicity in the case of DEREK and StAR, or metabolic fate in the case of METEOR. The rule refinement process for DEREK often involves assessing the predictions for a novel set of compounds and comparing them to their biological assay results as a measure of the system's performance. For example, 266 non-congeneric chemicals from the National Toxicology Program database have been processed through the DEREK mutagenicity knowledge base and the predictions compared to their Salmonella typhimurium mutagenicity data. Initially, 81 of 114 mutagens (71%) and 117 of 152 non-mutagens (77%) were correctly identified. Following further knowledge base development, the number of correctly identified mutagens has increased to 96 (84%). Further work on improving the predictive capabilities of DEREK, StAR and METEOR is in progress.

Computer Simulation↗

PubMed2002

Application of a new expert system for the structure elucidation of natural products from their 1D and 2D NMR data.

Described herein are applications of the latest version of the StrucEluc expert software system, enhanced to use 2D NMR data, to the structure elucidation of 60 recently isolated natural products. In this study, selected molecules containing between 15 and 65 skeletal atoms and having molecular masses ranging from 200 to 900 amu have been investigated. The correct structure was determined unambiguously for 58 of these molecules. The structures for 75% of the data sets were determined in less than one minute, while 90% of the analyses required no more than 30 minutes. The strategy of structure elucidation by this expert system is described, and several examples are discussed. These illustrate that StrucEluc is a powerful and versatile analytical tool for the structure elucidation of natural products.

Biological Products↗

PubMed1997

An expert systems approach to medical school admissions.

Medical school applicants for 1994 to 1995 broke the record of 42,621 applicants set in 1974 to 1975 with a new record of 45,365 applicants. Applications for the next few years are projected to steadily increase. Currently most medical school admissions committees screen every application. With the rising numbers of applications received each year, this task will soon be unfeasible. Our goal was to develop a computer-based expert system with high sensitivity that could be used as a preliminary screening tool for applications. A screening tool with high sensitivity should allow well-qualified and borderline candidates to go on to be fully evaluated by the admissions committee. This article is a report of the program developed, the attributes used, their assigned values, case scenarios, and suggestions for further uses.

College Admission Test↗

PubMed1987

Expert systems for implanted pacemaker analysis.

A computer-based software system has been proposed that will assist clinicians in the often difficult task of analyzing multi-channel pacemaker modified ECGs. The system contains three integrated modules. First, digital signal processing indentifies cardiac events from two sources provided by the latest pacemaker technology, intracardiac atrial and ventricular signals, activity markers, and a surface ECG. Secondly, the pacemaker's functional status at each event is analyzed by a rule-based monitor model of the pacemaker. Thirdly, Expert System (ES) techniques were used to combine the digital signal processing metrics, the pacemaker's functional status at each event, and the programmed parameters stored in the pacemaker's memory with a clinical knowledge base relating known problems and their causes. The domain specific tasks, briefly described here, that were most useful in the implementation of the ES are: data reduction, knowledge acquisition methods, knowledge representation, inferencing, and presentation of results.

Electrocardiography↗

PubMed2006

IBZM tool: a fully automated expert system for the evaluation of IBZM SPECT studies.

PURPOSE: Visual reading of [(123)I]IBZM SPECT scans depends on the experience of the interpreter. Therefore, semi-quantification of striatal IBZM uptake is commonly considered mandatory. However, semi-quantification is time consuming and prone to error, particularly if the volumes of interest (VOIs) are positioned manually. Therefore, the present paper proposes a new software tool ("IBZM tool") for fully automated and standardised processing, evaluation and documentation of [(123)I]IBZM SPECT scans. METHODS: The IBZM tool is an easy-to-use SPM toolbox. It includes automated procedures for realignment and summation of multiple frames (motion correction), stereotactic normalisation, scaling, VOI analysis of striatum-to-reference ratio R, classification of R and standardised display. In order to evaluate the tool, which was developed at the University of Hamburg, the tool was transferred to the University of Hannover. There it was applied to 27 well-documented subjects: eight patients with multi-system atrophy (MSA), 12 patients with Parkinson's disease (PD) and seven controls. The IBZM tool was compared with manual VOI analysis. RESULTS: The sensitivity and specificity of the IBZM tool for the differentiation of the MSA subjects from the controls were 100% and 86%, respectively. The IBZM tool provided improved statistical power compared with manual VOI analysis. CONCLUSION: The IBZM tool is an expert system for the detection of reduced striatal D(2) availability on [(123)I]IBZM SPECT scans. The standardised documentation supports visual and semi-quantitative evaluation, and it is useful for presenting the findings to the referring physician. The IBZM tool has the potential for widespread use, since it appears to be fairly independent of the performance characteristics of the particular SPECT system used. The tool is available free of charge.

Adult↗

PubMed1987

Studies on rationales for an expert system approach to the interpretation of protein sequence data. Preliminary analysis of the human epidermal growth factor receptor.

The molecular modelling of larger proteins benefits from a preliminary analysis of the sequence to identify regions of potential structural and functional importance. In this study the sequence of the epidermal growth factor receptor has been analysed using a variety of established methods and novel procedures developed for the study of weak internal and external homologies and for the use of homologous sequences in the prediction of secondary and super-secondary structures. The procedures explored here are potentially suitable for incorporation into an expert system for the initial investigation of protein sequence data.

Amino Acid Sequence↗

PubMed1990

Nursing education application of a computerized nursing expert system.

Nurse educators are required to be knowledgeable about a wide variety of complex health care problems in order to provide quality education. At the same time, they are given a multitude of other responsibilities such as participating in scholarly activity, advising students, maintaining an active role in nursing practice, and performing community service. These educators must find innovative ways to present current lectures while at the same time meeting their other obligations. The use of Creighton Online Multiple Modular Expert System (COMMES), a computerized decision support consultant, was evaluated as a technique for faculty use in developing and organizing new lecture content. The study found that COMMES was beneficial as a systematic prompt for lecture content, as a tool for organizing content, and as a means to verify completeness of lecture material.

Curriculum↗

PubMed1991

Design and preliminary evaluation of an expert system for platelet request evaluation.

In spite of growing awareness of the potential risks associated with transfusion, the number of platelet units transfused in the United States continues to increase each year. There is a growing interest in ensuring that all transfusions are administered for appropriate reasons. Prospective review of requests for transfusions has been used to accomplish this goal. Although successful in reducing the number of inappropriate transfusions, this review method requires great time commitments by blood bank personnel and physicians. A knowledge-based system (ESPRE) that aids hospital blood bank personnel in the review of requests for platelet transfusions has been developed. The system automatically obtains most of the required patient data via a direct link to the hospital's main laboratory computers. The system generates a printed report that includes a list of patient-specific data, a list of the conditions for which a transfusion would be appropriate for the particular patient (given the clinical condition), and the conclusions drawn by the system. During a preliminary clinical evaluation of ESPRE, 73 randomly selected platelet transfusion requests were evaluated for approval by laboratory personnel and ESPRE. Overall, ESPRE would have approved 71 of the requests and laboratory staff would have approved 72. Forty-four percent of the requests would have been approved for the same reasons given by the staff. There were only three disagreements on final approval between ESPRE and blood bank personnel. This computerized expert system is a promising approach to the prospective review of all platelet transfusions.

Blood Banks↗

PubMedDate not supplied

[Anamnesis: expert systems and the rediscovery of Cinderella].

Up to today there is universal consensus that the anamnesis is a fundamental and unsubstitutable phase both for the formulation of the diagnosis and for establishing the correct physician-patient relationship. In a high percentage of cases the diagnostic hypothesis formulated during the history taking is successively confirmed. The analysis of the structure of the anamnesis has demonstrated that it realizes a cognitive approach of "phenomenological" type. This kind of approach is fitting with the structure of illness if it is considered during its evolution. The necessity of a reconsideration of the anamnesis also stems from the future likely diffusion of "Expert Systems" to support diagnosis. Their utilization requires, indeed, a correct acquisition of the data from anamnestic and physical examination.

Diagnostic Techniques and Procedures↗

PubMedDate not supplied

Prediction of the rodent carcinogenicity of 60 pesticides by the DEREKfW expert system.

The two-year rodent bioassay represents the golden standard for evaluating the carcinogenicity of chemicals. Because of practical and ethical reasons, alternative approaches have been investigated for many years. Among these approaches, the (quantitative) structure-activity relationships [(Q)SARs] offer promising perspectives for quickly screening a large number of chemicals. To increase the acceptance of (Q)SARs among the regulators, their predictive power needs to be scientifically validated. In this article, we tested the capacity of the DEREKfW expert system to qualitatively predict the rodent carcinogenicity and the genotoxic potential of 60 pesticides recently registered in Switzerland. The percentage of false negatives was found to be 31% for carcinogenicity. The associated sensitivity of 69% indicates that most of the pesticides with positive rodent bioassay results were detected by DEREKfW. On the other hand, the low specificity of 47% indicates that many pesticides may be flagged as carcinogenic while rodent bioassays would not confirm this potential. This may lead to unnecessary testing or the unnecessary restriction of a chemical.

Animals↗

PubMed2005

Health risk appraisal for older people in general practice using an expert system: a pilot study.

The prevention of disability in later life is a major challenge facing industrialised societies. Primary care practitioners are well positioned to maintain and promote health in older people, but the British experience of population-wide preventive interventions has been disappointing. Health risk appraisal (HRA), an emergent information-technology-based approach from the USA, has the potential for fulfilling some of the objectives of the National Service Framework for Older People. Information technology and expert systems allow the perspectives of older people on their health and health risk behaviours to be collated, analysed and converted into tailored health promotion advice without adding to the workload of primary care practitioners. The present paper describes a preliminary study of the portability of HRA to British settings. Cultural adaptation and feasibility testing of a comprehensive health risk assessment questionnaire was carried out in a single group practice with 12,500 patients, in which 58% of the registered population aged 65 years and over participated in the study. Eight out of 10 respondents at all ages found the questionnaire easy or very easy to understand and complete, although more than one-third had or would have liked assistance. More than half felt that the length of the questionnaire was about right, and one respondent in 10 disliked some questions. Of those who completed the questionnaire and received tailored, written health promotion advice, 39% provided feedback on this with comments that can be used for increasing the acceptability of tailored advice. These findings have informed a wider exploratory study in general practice.

Aged↗

PubMed2004

Target-biased scoring approaches and expert systems in structure-based virtual screening.

Structure-based virtual screening followed by selection of a top fraction of the rank-ordered result list suffers from many false positives and false negatives because the general scoring functions are not accurate enough. Many approaches have emerged to address this problem by including knowledge about the specific target in the scoring and selection steps. This target bias can include requirements for critical interactions, use of pharmacophore patterns or interaction patterns found in known co-crystal structures, and similarity to known ligands. Such biases are implemented in methods that vary from filtering tools for pre- or post-processing, to expert systems, quantitative (re)scoring functions, and docking tools that generate target-biased poses.

Algorithms↗

PubMed2001

Implementation of an expert system to determine eligibility and priorities for bone marrow transplants.

The Bone Marrow Transplant Unit (BMTU) (Serviço de Transplante de Medula Ossea) at HC-UFPR, in Curitiba, Brazil, commonly receives a large number of candidates for bone marrow transplants (BMT). Managing information on the BMTU's waiting list is extremely complex and vital to services as eligibility and priorities are established with implications on both pre and post transplant survival. Consequently, physicians working at the BMTU have to regularly evaluate each candidate to determine his or her eligibility and priority for a BMT. This report describes the implementation of an expert system (ES) in aiding the assessment of candidates for BMT. The ES prototype was created as a means to help healthcare providers define eligibility and priority by using production rules and the Bayesian net (BN). Some factors contributed a lot to test and to validate the systems of this project. Real cases were tested, therefore BMTU presents a database (DB) with all the patients that are awaiting transplant. The system was capable of determining all the patients' eligibility with the diagnosis of Chronic Myeloid Leukemia (CML) and to indicate transplant priority.

Bayes Theorem↗

PubMed1992

Expert systems in histopathology. V. DS theory, certainty factors and possibility theory.

Uncertainty management for the evaluation of evidence based on linguistic and conceptual data is taking advantage of developments in the Dempster-Shafer (DS) theory of evidence, possibility theory and fuzzy logic. The DS theory offers the capability to assess the uncertainty of different subsets of assertions in a domain and the way in which uncertainty is affected by accumulating evidence. The DS theory goes beyond probability theory in its ability to represent ignorance about certain aspects of a situation. However, the theory is very sensitive to the numerical assessments provided by users and can lead to intuitively unexpected and even undesirable results. Certainty factors are widely used in various expert systems. Their definition and updating may follow either a probabilistic model or fuzzy set theoretic concept.

Data Interpretation, Statistical↗

PubMed2003

Screening of high production volume chemicals for estrogen receptor binding activity (II) by the MultiCASE expert system.

A structurally and functionally diverse and cross-validated quantitative structure-activity knowledge database generated by the MultiCASE expert system was used to screen 2526 high production volume chemicals (HPVCs) for their estrogen receptor binding activity. 73 HPVCs were found to contain structural features or biophores that have been documented as having the ability to bind to the estrogen receptor. Potential chemicals were ranked according to their quantitatively predicted ER binding potential and the details of the biophores found in them are discussed.

Animals↗