Artificial intelligence: expert systems.
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Artificial Intelligence↗
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A wake-up call from expert systems.
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Expert Systems↗
Second evaluation of HEPAR, an expert system for the diagnosis of disorders of the liver and biliary tract.
HEPAR is an expert system which can be used as a supportive tool in the diagnosis of disorders of the liver and biliary tract. When consulted for a particular patient, the system assesses the patient's disorder in two stages. In the first stage, data of medical history, physical examination and routine laboratory tests are used to determine whether the disorder is hepatocellular or biliary obstructive, and whether benign or malignant features are present. In the second stage, the system produces a differential diagnosis out of a set of 80 disease categories, using the conclusions of the first stage of the assessment and the results of a restricted number of supplementary investigations, i.e. serological tests and ultrasonography. The conclusions of the two stages are ordered by the amount of evidence computed by HEPAR. The system is not yet suitable for clinical use. The system has been evaluated using data of 181 patients selected from a population of 214 consecutively admitted patients with jaundice. The patients were classified by the system as having a hepatocellular or biliary obstructive, and a benign or malignant disorder in 96% and 100% of the cases, respectively. When comparing the conclusions with strongest evidence with the final clinical diagnoses, the patients were classified correctly in 86% and 83% of the classified cases, respectively. A differential diagnosis was produced in 87% of the patients. A correspondence between the diagnosis with strongest evidence and the final clinical diagnosis was found in 78% of the classified patients.
Adolescent↗
[Development of an expert system for assessment of criminal responsibility capacity of mentally ill offenders].
The objective of this study was to develop an expert system for the assessment of legal capacity (ESALC). Visual Basic for Windows 3.0 was employed in establishing ESALC, and 281 cases were assessed by the system. The results were in substantial agreement with those of expert assessment. Kappa = 0.68 (P < 0.01); accuracy 90.04%, sensitivity, 85.63% and specificity 96.49%. ESALC can be used as a supplementary instrument in forensic psychiatric assessment.
Adolescent↗
Problems in establishing the medical expert systems CADIAG-1 and CADIAG-2 in rheumatology.
CADIAG-1 and CADIAG-2 are medical expert systems with applications in rheumatology, gastroenterology, and hepatology. CADIAG-1 is based on a symbolic logic representation of medical relationships between symptoms, signs, or findings and diseases. Definite relationships (obligatory occurrence, confirming, and excluding) as well as uncertain relationships (facultative occurrence and not confirming) are applied to confirm or exclude diagnoses and to establish diagnostic hypotheses. CADIAG-2 employs fuzzy set theory and fuzzy logic to formalize medical entities and relationships. The medical concept of confirming or excluding diagnoses is identical to that of CADIAG-1, but diagnostic hypotheses are generated differently. Here, a documentation of medical relationships allowing gradual transitions from "always" to "never" for the frequencies of occurrence of symptoms with and from "strong" to "weak" for their strengths of confirmation for diseases leads to strongly or weakly supported diagnostic hypotheses in the actual case. Tests with 322 real patient cases from a rheumatological hospital, each including between 500 and 700 symptoms, signs, and findings, were carried out. The percentage of cases diagnosed correctly is about 80%. Problems and pitfalls that became apparent in the evaluation of the cases are shown and discussed.
Adult↗
A desktop expert system for the differential diagnosis of dementia. An evaluation study.
EVINCE-I is a desktop expert system for the differential diagnosis of dementia, implemented on a personal computer. It is intended to assess the effectiveness of this new technology in modeling a psychiatrist who uses international guidelines for diagnosing dementia. EVINCE-I was tested in diagnosing 19 patients with varying stages of dementia and 10 patients showing other disorders except dementia. EVINCE-I and the human expert were in perfect agreement on the diagnosis of dementia and correlated highly on the diagnosis of dementia of the Alzheimer type and multiple infarct dementia. EVINCE-I thus offers important possibilities as a tool in investigating the data and procedures used by the human expert.
Aged↗
Integrated expert systems and videodisc in surgical pathology: an overview.
We present an overview of our 6-year experience in the design of expert systems for anatomic pathology. Our practical goal is to help practicing pathologists with learning, teaching, and the task of diagnosis by providing them with dynamic expert knowledge by means of a personal computer. This project could only be undertaken by first addressing a scientific goal: to characterize the problem-solving strategies that expert pathologists use in making a diagnosis and to state them in the logical terms of computer science. Our approach has been to build systems first for experimentation and then for use. The result of our work is an integrated computer-based approach that handles expert knowledge as formal relationships and morphologic images and that uses a number of logical strategies to provide multiple perspectives on diagnostic tasks. Configured as a pathologist's workstation, this approach can be expected to enhance the performance of trained general pathologists and pathologists in training. Lymph node pathology has been used as the prototype domain for this research, but care has been taken to seek a generalized authoring and inference structure that can be applied to other areas of pathology by changing the contents but not the structure itself. Excursions into various surgical pathology specialties suggest that the ways the system is constructed and exercised is fundamentally robust. Such computer-based expert systems can be expected to generate a new standard in the practice of pathology--based on the "gold standard" of classical morphology, but including the coordinated use of new methods from immunology and molecular biology in a multidisciplinary approach to diagnosis when these techniques are relevant. The benefits from this technology can be expected to be widespread with the evolution, refinement, and diffusion of these systems.
Artificial Intelligence↗
Expert systems for third-party reimbursement: planting seeds for accuracy.
Predictably, the genesis of most business expert systems development is not related to one particular issue, but to a series of business issues that converge to form the basis for system design as either enhancements or overhauls. Rarely, if ever, is there a conclusion to the system's enhancement process, but rather, an ongoing evolution of the system as dictated by a multitude of both internal and external forces. The focal point of these processes must be to benefit our customers and the markets we serve.
Computer Communication Networks↗
[Clinical use of an expert system for interpreting lung function tests--relation of results to the respective examiner].
We used a new expert system for interpretation of lung function tests to check the differences between four investigators. The data base of the program system consists of vectors which yield statistical informations concerning the decisions of the users.
Airway Resistance↗
The development of a hybrid expert system for the interpretation of fetal acid-base status.
This article presents the development of an expert system for the interpretation of fetal scalp acid-base status. The system consists of logistic transformations, back-propagation neural networks and decision algorithms connected in series. It checks for out-of-range errors and the physiological coherence between measurements. It then determines whether acidosis should be diagnosed, and if so, whether it is more likely to be metabolic, respiratory or mixed. It will also flag those cases where it is difficult to interpret the data in physiological terms. The system was tested on a database of 2174 scalp blood samples collected at the Queens Medical Centre, Nottingham. Of these 88 samples were rejected as erroneous; 13 because of an out-of-range pH alone (> or = 7.48); 73 because more than one measurement was marginally out of range, and two because the relationship between measurements did not make sense. A total of 527 cases (24.2%) were diagnosed as being acidotic; of these, 139 were respiratory, 114 mixed and 274 metabolic. We were unable to fault the system's interpretation when the cases at the margins between diagnostic categories were reviewed clinically.
Acid-Base Equilibrium↗
Scaling an expert system data mart: more facilities in real-time.
Clinical Data Repositories are being rapidly adopted by large healthcare organizations as a method of centralizing and unifying clinical data currently stored in diverse and isolated information systems. Once stored in a clinical data repository, healthcare organizations seek to use this centralized data to store, analyze, interpret, and influence clinical care, quality and outcomes. A recent trend in the repository field has been the adoption of data marts--specialized subsets of enterprise-wide data taken from a larger repository designed specifically to answer highly focused questions. A data mart exploits the data stored in the repository, but can use unique structures or summary statistics generated specifically for an area of study. Thus, data marts benefit from the existence of a repository, are less general than a repository, but provide more effective and efficient support for an enterprise-wide data analysis task. In previous work, we described the use of batch processing for populating data marts directly from legacy systems. In this paper, we describe an architecture that uses both primary data sources and an evolving enterprise-wide clinical data repository to create real-time data sources for a clinical data mart to support highly specialized clinical expert systems.
Computer Systems↗
Artificial intelligence. Expert systems for clinical diagnosis: are they worth the effort?
Modeling the decision-making processes of human experts has been studied by scientists who call themselves psychologists and by scientists who say they are students of artificial intelligence (Al). The psychological research literature suggests that experts' decision-making processes can be adequately captured by simple mathematical models. On the other hand, those in Al who are preoccupied with human expertise maintain that complex computer models, in the form of expert systems, are required to do justice to those same processes. The resultant paradox of simple versus complex decision-making models is investigated here. The relevant literatures in psychology and Al are reviewed and, based on these findings, a resolution of the paradox is offered.
Artificial Intelligence↗
Learning about sex outside the gutter: attitudes toward a computer sex-expert system.
In an ongoing research program investigating the utility of Sexpert, an expert computer system designed to counsel couples about their sexual relationships, we tested whether sexually active couples' attitudes concerning computerized sexual counseling could be affected by interacting with Sexpert. Eighty-one young heterosexual couples drawn from the university and general community were assigned to one of three sources of feedback about couple sexual functioning (Sexpert, a video, a self-help book) or a control condition. Attitudes toward all counseling sources used in the study were assessed through semantic differential and similarity-dissimilarity questionnaires. Subjects in the Sexpert condition showed significant improvements in their attitudes toward computerized sexual counseling and evaluated Sexpert significantly better and more similar to a human therapist as a result of exposure. Subjects in the other three conditions showed no significant changes in attitudes. This study provides strong evidence for the acceptability of a computerized sex-expert system.
Adolescent↗
The performance characteristics of an expert system for the "on-line" assessment of thalassemia trait and iron deficiency--Micro Hema Screen.
An Expert System (ES) approach to the assessment of thalassemia trait and iron deficiency was evaluated by transferring data from a Coulter S-Plus II Analyzer to an Apple II e computer. The discriminant rules of the algorithm were derived retrospectively from multivariate analysis of an existing data base. The parameters used were MCV, RDW, HGB, RBC, MPV, and PLT. Subsequently, the system has been evaluated for its ability to detect thalassemia and hemoglobinophathies in 1671 females and 1490 males in a real laboratory setting. The 845 cases of microcytosis among them were used to estimate the real frequencies of the diagnostic groups as identified by the ES (Micro Hema Screen). "On-Line" assessment of microcytosis may provide a quick method of acquiring and processing the data from an automated analyser. It can be applied in thalassemia and iron deficiency discrimination either as an intralaboratory primary assessment or as a population screening method.
Adolescent↗
High performance for expert systems: I. Escaping from the demonstrator class.
An investigation was performed to elucidate the problems of converting a demonstrator expert system for leukaemia diagnosis into a large high-performance system. Analysis of the logical completeness of the demonstrator system revealed only minor errors and a limited representation of the domain. Most of its test cases were quite simple and correction of the minor errors raised the performance to 94%. However, the remaining cases were very complex and it is doubtful whether the system could handle them without fundamental changes to its representation of the domain. Demonstrator systems can function with an imperfect view of the domain since the small sacrifice of accuracy is of little consequence; but in a high-performance system the imperfections must be corrected before extra detail is added. The use of default mechanisms for making specific conclusions was harmful because they concealed errors, and a numerical method for handling uncertainty contributed nothing of value to the system.
Diagnosis, Computer-Assisted↗
Clinical evaluation of the DIABETES expert system for decision support by multiple regimen insulin dose adjustment.
A performance evaluation of the DIABETES rule-based expert system prototype for clinical decision making is presented. The system facilitates multiple insulin regimen and dose adjustment of insulin dependent Type I or II diabetic patients. The study was performed on 600 subjects from two diabetological centres and three diabetological offices of Greek hospitals. The responses of the attendant medical doctors were compared with those of the DIABETES system, with the aid of a specifically devised valuation range (0-5 degrees, 0 indicating full agreement and 5 full disagreement). The capabilities and the weakness of the system in terms of its practicality for decision support in assisting therapy of diabetes mellitus by blood glucose monitoring and subsequent insulin dose adjustment are discussed. The potential benefits of decision support systems for diabetic patient management are seen to be the cost saving they provide in terms of man-hours of verbal instruction by medical experts, the support in terms of objective and consistent decision making, as well as the recording of medical knowledge in the ill-defined field of insulin administration, thus aiding the education and training of medical personnel.
Aged↗
The TOPOSCOUT expert system for stroke localization.
Clinically, strokes are localized by the findings on neurologic examination. TOPOSCOUT is an expert system designed to diagnose the anatomic location and the corresponding vascular territory of strokes based on the clinical signs and symptoms. The inference engine of TOPOSCOUT uses a backtracking algorithm and a rule-based data base that includes associations of neurologic signs with vascular and anatomic areas. TOPOSCOUT is capable of detecting typical stroke patterns, for example, "top-of-the-basilar" or Wallenberg's syndromes. The accuracy of TOPOSCOUT's diagnoses has been tested for conformity with the final diagnoses of 129 patients in the Hamburg Stroke Data Bank, and a high level of agreement was found for hemispheric lesions. The program runs on microcomputers with MS-DOS and is intended as a practical aid for physicians not fully familiar with topologic stroke diagnosis and as an interactive teaching device.
Cerebral Arteries↗
[Braindex--an expert system for the diagnosis of brain death].
An IBM PC-based system was developed as a decision-supporting system for the diagnosis of brain death. Braindex has been realized with the expert system Tool PC-Plus, and includes a knowledge base containing 300 rules organized in 8 frames. Both forward chaining and backward chaining are used in the inference engine. Braindex also includes a text archive and a lexicon. The data of 42 brain death patients are stored in the data bank (300 parameter per patient). The system is presently in the first stage of clinical application.
Brain Death↗