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PubMedDate not supplied

Medical expert system on fuzzy analog ganglionar lattices: explication and prospection based on sensitivity.

A reasoning method to explicate the conclusions-a posteriori- and to prospect for the next test-a priori-applied to medical expert systems based on fuzzy analog ganglionar lattices is presented. This method is founded on the sensitivity criterion of the consequent respect to the antecedents. It proves to be suited for problems of any complexity, specially when they are formulated on well-established intermediate concepts, such as syndromes, clinical finding, laboratory procedures, etc., as is usually the case in medical procedures. This type of expert system uses the structural properties of the ganglionar lattice to produce explications for its conclusions at different levels of abstraction, and to an arbitrary, but fixed, explicative degree. A measure to evaluate the consequent's achieved preciseness (certainty) is also supplied. A full example of application in the diagnosis of cardiac insufficiency with hypertensive myocardiopathy is shown, and a computational implementation of this analog procedure is described. Finally, the reasoning methods for explicating and prospecting are discussed.

Artificial Intelligence↗

PubMed1989

A simple "expert system" for morphometric evaluation of cells in pleural effusions.

Quantitation in diagnostic pathology serves to improve both diagnostic reliability and the prognosis of various malignant tumors. Unfortunately, flexible, user-friendly, reasonably priced and compatible morphometric systems are hardly available on the market. A modular Apple II PC-based system was therefore developed in-house. It records stereologic, planimetric and digital image analysis data and calculates secondary parameters. Detailed statistical analyses can be performed, after data transfer, on larger computers. A typical application of diagnostic morphometry is to determine whether, and with which probability a patient with an unclear histopathologic finding can be assigned to one or more groups of patients with known diseases and prognoses. To this end morphometric data of the patient under investigation are compared with other patient data stored in an expert system. This paper describes the concept of an expert system carried out on the Apple II PC system mentioned above and outlines the evaluation procedures. Invariant moments were used to describe nucleus textures. Results obtained from the cytological analysis of pleural effusions demonstrate that with this approach it is possible to differentiate between normal mesothelium, mesothelioma and metastases of adenocarcinomas.

Adenocarcinoma↗

PubMed2002

An expert system for fault management assistance on a space sleep experiment.

The expert system, Principal Investigator-in-a-box, or [PI], was designed to assist astronauts or other operators in performing experiments outside their expertise. Currently, the software helps astronauts calibrate instruments for a Sleep and Respiration Experiment without contact with the investigator on the ground. It flew on the Space Shuttle missions STS-90 and STS-95. [PI] displays electrophysiological signals in real time, alerts astronauts via the indicator lights when a poor signal quality is detected, and advises astronauts how to restore good signal quality. Thirty subjects received training on the sleep instrumentation and the [PI] interface. A beneficial effects of [PI] and training reduced troubleshooting time. [PI] benefited subjects on the most difficult scenarios, even though its lights were not 100% accurate. Further, questionnaires showed that most subjects preferred monitoring waveforms with [PI] assistance rather than monitoring waveforms alone. This study addresses problems of complex troubleshooting and the extended time between training and execution that is common to many human operator situations on earth such as in power plant operation, and marine exploration.

Adult↗

PubMedDate not supplied

Knowledge acquisition and evaluation of an expert system for managing disorders of the outer eye.

The aim of the current study was to develop and evaluate an expert system for diagnosing outer eye disorders, intended to support family physicians and nurse practitioners in the management of patients with minor eye complaints. The knowledge in the program was gathered from the scientific literature and from 6 experienced ophthalmologists and 6 ophthalmic nurses. Fourteen diagnoses must be considered, and the differential diagnosis is dependent upon 32 signs and symptoms. The program calculates the most likely diagnosis, presents photographs of the typical ocular findings, and provides information regarding management and treatment. The program's output was compared with the diagnosis made by 8 other ophthalmologists at a Swedish university clinic, based on data from 157 patients with disorders of the outer eye, who visited the emergency ward during a one-week period. The concordance between the diagnosis made by the ophthalmologists and the program was 96%. In conclusion, the expert system for disorders of the outer eye provided essentially the same diagnostic information as an examination by an ophthalmologist. Support from the program would make it possible for family physicians and nurse practitioners to manage most of these patients.

Diagnosis, Computer-Assisted↗

PubMed1998

TACHY: an expert system for the management of supraventricular tachycardia in the elderly.

PURPOSE: Many physicians find the management of supraventricular tachyarrhythmia (SVT) in the elderly complex and challenging. With the use of artificial intelligence theory, we developed an interactive computer expert system, TACHY, to recommend therapies and warn physicians of potential therapeutic side effects. METHODS: We developed a knowledge base that stores guidelines for the management of SVT in the elderly. After the diagnosis of current SVT was input into the computer, TACHY generated a list of therapeutic options as hypotheses. TACHY then prompted the user to provide current patient-specific clinical information, and the optimal therapeutic option was then selected. Potential therapeutic side effects were also displayed. TACHY was tested in a retrospective and a prospective study. The retrospective study, comprising 96 patients with 126 episodes of SVT, was performed to determine the concordance of therapy between TACHY and cardiologists. A prospective study in 18 patients with 26 episodes of SVT was also performed to validate TACHY's recommendations in restoring sinus rhythm. RESULTS: In the retrospective study the concordance between TACHY and the cardiologist's first therapeutic option was 95.9% (121 of 126 episodes). In the prospective study sinus rhythm was restored in 18 (69%) of 26 episodes of SVT by the first therapeutic option recommended by TACHY. In the remaining eight episodes use of the second or third suggestion of TACHY was successful in controlling the ventricular response to SVT. No adverse reaction to the therapeutic options suggested by TACHY occurred. CONCLUSION: TACHY, a knowledge-based computer expert system that simulates human decision making, produced promising results in the management of SVT in the elderly.

Aged↗

PubMed2006

RENEX: an expert system for the interpretation of 99mTc-MAG3 scans to detect renal obstruction.

UNLABELLED: A renal expert system (RENEX) has been developed to assist physicians detect renal obstruction in patients undergoing pre- and postfurosemide 99mTc-mercaptoacetyltriglycine (99mTc-MAG3) scans. RENEX uses quantitative parameters extracted from the dynamic renal scan data and heuristic rules in the form of a knowledge base (KB) obtained from expert interpreters to conclude whether a kidney is obstructed. METHODS: Normal limits were established for 47 quantitative parameters extracted from the 99mTc-MAG3 scans of 100 potential renal donors. From these data the domain expert estimated 5 boundary conditions for each parameter: (i) definitely abnormal, (ii) probably abnormal, (iii) equivocal, (iv) probably normal, and (v) definitely normal. A sigmoid-type curve was then generated from these 5 boundary conditions, creating a parameter knowledge library used for converting the value of a prospective patient's individual quantitative parameters to a certainty factor (CF). Sixty heuristic rules were extracted from the domain expert to generate the KB for detecting obstruction. A forward-chaining inference engine was developed using the MYCIN combinatories (an approximation of Bayes theorem) to determine obstruction. A justification engine was implemented, which recorded the sequence of each rule that was fired and the current CF value of all input and output parameters at the time of instantiation to track and justify the logic of the conclusions. The entire system was fine tuned and tested using a pilot group of 32 patients (11 males, 21 females; mean age, 56.8 +/- 17.2 y; 63 kidneys) deemed by an expert panel to have 41 unobstructed kidneys, 13 obstructed kidneys,and 9 equivocal findings. RESULTS: RENEX agreed with the expert panel in 92% (12/13) of the obstructed kidneys, 93% (38/41) of the unobstructed kidneys, and 78% (7/9) of the kidneys interpreted as equivocal for obstructions. Processing time per patient was practically instantaneous using a 3.0-GHz personal computer programmed using interactive data language. CONCLUSION: We have developed a renal expert system for detecting renal obstruction using pre- and postfurosemide 99mTc-MAG3 renal scans, at a standardized expert level. These encouraging preliminary results warrant a prospective study in a large population of patients with and without renal obstruction to establish the diagnostic performance of this system.

Expert Systems↗

PubMed1989

Monitor: an expert system that validates and interprets time-dependent partial data based on a cystic fibrosis home monitoring program.

The use of health diaries to monitor patients with chronic diseases has often been complicated by difficulties encountered in data quality assurance and interpretation. An expert system, Monitor, has been developed to predict the health status of cystic fibrosis patients based on daily home measurements of pulse, respiratory rate, weight, inspired vital capacity, and a check list of symptoms of acute illness. This system ensures data reliability beyond what can be achieved in most current automatic error detection procedures by validating inputs against patient-specific expectations. Its explicit representation of the time dimension and the hierarchical structure of its knowledge base facilitate the abstraction of trends and relationships among the time-dependent data. Dynamically imposed expectations also lend flexibility to the interpretation process by allowing the processing of partial (incomplete) data. Monitor correctly classified 86 percent (three-category classification) and 94 percent (two-category classification) of 111 cases. This demonstrates that expert systems can be a feasible approach in building more robust diary monitoring systems.

Cystic Fibrosis↗

PubMed1994

Expert systems in the control of animal cell culture processes: potentials, functions, and perspectives.

In recent years, the development of advanced systems for bioprocess monitoring and control has become an area of intensive research. Along with traditional techniques, there are several new approaches which are increasingly being applied to bioprocess operations. Among these, of special note is expert system technology, which provides possibilities for the design of efficient bioprocess control systems with new functional capabilities. This technology has been successfully applied to variety of microbial processes at laboratory and industrial scale. The present paper analyzes the possibility for application of expert systems to animal cell cultures processes whose high complexity is well suited to expert control. The discussion focuses on the organization and the functionality of the intelligent control systems, and covers some practical aspects of their design.

Animals↗

PubMed1988

[Use of an expert system as a tool to carry out urinary cyto-bacteriologic tests].

An expert system for urine examinations was developed. Its validation was performed in a routine work, by comparison of expert decisions with software conclusions. Results of finished examinations or in progress were taken into account. The agreement was satisfactory. In addition to reliability, advantages constituted by availability, flexibility and adaptability were notified. Repeatability and reproducibility were also emphasized.

Algorithms↗

PubMed1990

[Computerized expert system for the diagnosis and treatment of intrauterine fetal distress].

A computerized expert system for the diagnosis and treatment of IFD on the basis of a mathematical model using Fuzzy Set Theory and employing the BASIC Language has been developed to provide a reliable modality for rapid and accurate diagnosis and treatment of IFD. The system has been successfully checked in IBM-PC/XT and its compatible computers. Through its application in 300 cases prospectively, the accuracy rate was 92.7%.

Diagnosis, Computer-Assisted↗

PubMed1994

An expert system for processing sequence homology data.

When confronted with the task of finding homology to large numbers of sequences, database searching tools such as Blast and Fasta generate prohibitively large amounts of information. An automatic way of making most of the decisions a trained sequence analyst would make was developed by means of a rule-based expert system combined with an algorithm to avoid non-informative biased residue composition matches. The results found relevant by the system are presented in a very concise and clear way, so that the homology can be assessed with minimum effort. The expert system, HSPcrunch, was implemented to process the output to the programs in the BLAST suite. HSPcrunch embodies rules on detecting distant similarities when pairs of weak matches are consistent with a larger gapped alignment, i.e. when Blast has broken a longer gapped alignment up into smaller ungapped ones. This way, more distant similarities can be detected with no or little side-effects of more spurious matches. The rules for how small the gaps must be to be considered significant have been derived empirically. Currently a set of rules are used that operate on two different scoring levels, one for very weak matches that have very small gaps and one for medium weak matches that have slightly larger gaps. This set of rules proved to be robust for most cases and gives high fidelity separation between real homologies and spurious matches. One of the most important rules for reducing the amount of output is to limit the number of overlapping matches to the same region of the query sequence.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗

PubMed1995

Induction of expert system rules based on rough sets and resampling methods.

Automated knowledge acquisition is an important research issue in developing medical expert systems. While several methods of symbolic inductive learning have been proposed, most of the approaches focus on inducing some rules to classify cases correctly. On the contrary, medical experts also learn other information important for medical diagnostic procedures from clinical cases. In order to acquire both kinds of knowledge, we developed a program that extracts not only classification rules for differential diagnosis, but also other medical knowledge needed for diagnosis. This system is based on a diagnosing model of a medical expert system RHINOS, which diagnoses causes of headache and facial pain. We apply this program to the same domain and compared the induced results with expert rules. The results show that the combination of a rule induction method with resampling methods is effective to estimate the performance of induced results, especially when only small training samples are available without domain knowledge.

Aged↗

PubMed1990

[A diagnostic expert system].

The introduction of new technologies in the field of electronics has influenced the development of technical equipment over the last few years. The progressive miniaturization of integrated circuits makes possible an expansion of the spectrum of functions offered by this equipment. This also applies to medical technology. These more complex units call for new methods of fault detection and diagnosis. In addition to analytical redundancy, tools developed by the artificial intelligence research community, such as expert systems, are becoming more and more important for fault diagnosis. On the basis of a realized diagnosis expert system the possibilities as well as the limits of such system are discussed. Also, possible future developments of artificial intelligence, like machine learning, are considered.

Artificial Intelligence↗

PubMed1990

Potential users' needs for information about expert systems.

Three questions concerning potential users' knowledge about Expert Systems (ESs) were investigated by means of a questionnaire survey which was distributed to over 1100 members of the Northern Irish business community. The first question concerned the existing level of knowledge about, and use of ESs. The second asked about demand for such knowledge from within the business community; and the third area of concern was the degree of technical knowledge that ES users should be expected or presumed to possess. 22% of the 275 respondents claimed some knowledge of ESs and 3% had used them. Almost 80% asked for further information about ESs. The majority of those few who had used them appeared to have a fairly sketchy notion of the functional principles of ESs. It was concluded that potential users of ESs should not necessarily be expected or required to understand the theory and principles on which such systems work. Rather, the ergonomist needs to devise means whereby the strengths, limitations and probabilistic nature of the advice that ESs give are always readily apparent to users.

Journal Article↗

PubMed1984

Expert systems as aids for interpretive reporting.

Interpretive reporting is an established part of the function of many clinical laboratories. Of the three types of information included in these reports, expert system technology is being demonstrated as useful in producing interpretive comments. The ability of expert systems to explain their reasoning and to be easily updated make them superior to prior attempts to computerize this type of interpretation using traditional computer languages. In the future, the broader application of these systems in realistic clinical environments should be expected given recent commercial success in embedding such programs in laboratory instruments.

Information Systems↗

PubMed1997

An expert system for diagnosis of acute myocardial infarction with ECG analysis.

Coronary heart disease is one of the most prevalent and costly health care problems in the world. The early and accurate diagnosis of coronary heart disease is a major problem in emergency settings. However, many primary and secondary hospitals and primary emergency units lack cardiologists on call which makes the diagnosis difficult. This paper describes an expert system for diagnosis of acute myocardial infarction developed to aid physicians without cardiology specialization. Our main goal was to develop an expert system that assists in the diagnosis and indicates the need of hospitalization in a coronary unit.

Electrocardiography↗

PubMed1994

Expert system support using Bayesian belief networks in the diagnosis of fine needle aspiration biopsy specimens of the breast.

AIM: To develop an expert system model for the diagnosis of fine needle aspiration cytology (FNAC) of the breast. METHODS: Knowledge and uncertainty were represented in the form of a Bayesian belief network which permitted the combination of diagnostic evidence in a cumulative manner and provided a final probability for the possible diagnostic outcomes. The network comprised 10 cytological features (evidence nodes), each independently linked to the diagnosis (decision node) by a conditional probability matrix. The system was designed to be interactive in that the cytopathologist entered evidence into the network in the form of likelihood ratios for the outcomes at each evidence node. RESULTS: The efficiency of the network was tested on a series of 40 breast FNAC specimens. The highest diagnostic probability provided by the network agreed with the cytopathologists' diagnosis in 100% of cases for the assessment of discrete, benign, and malignant aspirates. Atypical probably benign cases were given probabilities in favour of a benign diagnosis. Suspicious cases tended to have similar probabilities for both diagnostic outcomes and so, correctly, could not be assigned as benign or malignant. A closer examination of cumulative belief graphs for the diagnostic sequence of each case provided insight into the diagnostic process, and quantitative data which improved the identification of suspicious cases. CONCLUSION: The further development of such a system will have three important roles in breast cytodiagnosis: (1) to aid the cytologist in making a more consistent and objective diagnosis; (2) to provide a teaching tool on breast cytological diagnosis for the non-expert; and (3) it is the first stage in the development of a system capable of automated diagnosis through the use of expert system machine vision.

Bayes Theorem↗

PubMed1988

Antihypertensive therapy for the elderly: an expert system to assist therapeutic decisions.

The prevalence of hypertension among the elderly is high. Recent multicenter studies have shown hypertension, especially isolated systolic hypertension, to be a risk factor and treatment to be effective, if individualized. In addition, the presence of multiple complicating conditions and the need for multiple medications in the elderly increases the required medical knowledge base necessary to appropriately determine antihypertensive therapy. To assist the primary provider, an expert system has been developed that provides advice on therapeutic decisions for elderly patients (greater than 65 years old and less than 85 years old). It takes into account such factors as age, sex, lifestyle, site of care, nutritional status, physiologic and pathophysiologic changes, co-existing diseases, multiple drug use, and prior antihypertensive drug exposure and response. The system user enters patient characteristics, disease states, risk factors, relevant laboratory values, and prior drug therapy. The system responds with a set of recommendations of appropriate therapy individualized for the specific patient. To further assist the process, relative costs of therapy are also included. The system, consisting of over 200 rules, is currently undergoing validation by a panel of cardiologists. It is implemented in IBM's Expert System Environment (ESE) on the IBM 4341. The authors wish to acknowledge the contribution of the ESE software by the IBM Corporation.

Aged↗