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PubMed1989

Combining clinical judgement and statistical data in expert systems: over-the-telephone management decisions for critical congenital heart disease in the first month of life.

When a new-born baby with congenital heart disease is referred to a regional specialist centre, the transportation management is crucial but must be decided on the basis of clinical information obtained over the telephone. We consider algorithmic and naive statistical approaches to helping in this decision, and on the basis of preliminary results the relative strengths and weaknesses are discussed. A synthesised logical and probabilistic approach appears to have the best potential and could be implemented on hand-held computers.

Algorithms↗

PubMedDate not supplied

Computerized expert system for the diagnosis of pulp-related pain.

A major problem in the correct diagnosis of pulpal pain is that the associated clinical signs do not predictably correlate with the underlying pathological process. Using conditional probabilities of various pulp conditions from published data, Bayesian Statistical Inference provides the means for deriving a composite probability of the presence of a disease from a multiple set of symptoms. A computer program that can infer a diagnosis for pulpal pain from any combination of 17 clinical symptoms has been developed. From the data, the program provides the computed relative probabilities of a healthy pulp, a saveable pulp, an unsaveable pulp, and a necrotic pulp being present.

Bayes Theorem↗

PubMed1994

The Mental Status Expert (MSE): an expert system for scoring and interpreting the mental status examination.

The mental status examination is the most difficult and time-consuming portion of the neurological examination. A complete mental status examination requires the examiner to assess alertness, memory, language, praxis, gnosis, attention, and visual-spatial functions. Findings of the mental status need to be interpreted in terms of severity of deficits, nature of the deficits, likely etiology, and likely area of corresponding brain injury. The performance of an accurate, complete, and detailed mental status examination is a daunting task for the medical student or resident in training. Traditional mental status examinations show considerable inter-examiner variability for items administered and for interpretation of abnormalities. Even in academic settings, mental status examinations have little educational content.

Expert Systems↗

PubMed1994

MAMCAT: an expert system for distinguishing between mammillary and catenary compartmental models.

MAMCAT is a user-friendly, interactive, graphics-based PC program for addressing a common compartmental model discrimination problem in the framework of model indistinguishability theory: can mammillary and catenary models of the same order be distinguished from each other? The software is designed to teach the theory and solve specific problems. The user is guided step-by-step through definitions, examples, theory and problem solution. Topological properties are used first to screen out some distinguishable models and thereby reduce the number of candidates for indistinguishability. Transfer function analysis is then used to explore the remaining candidates. Analytical results for up to 5-compartment models are given and a more general algorithm is induced from these results.

Algorithms↗

PubMed1999

Development of an expert system for the interpretation of serial peak expiratory flow measurements in the diagnosis of occupational asthma. Midlands Thoracic Society Research Group.

If asthma is due to work exposures there must be a relation between these exposures and the asthma. Asthma causes airway hyperresponsiveness and obstruction; the obstruction can be measured with portable meters, which usually measure peak expiratory flow, or sometimes forced expiratory volume in 1 second (FEV1). These can be measured serially (for instance 2 hourly) over several weeks at and away from work. Once occupational asthma develops, the asthma will be induced by many non-specific triggers common to non-occupational asthma. The challenge is to identify changes in peak expiratory flow due to work among other non-occupational causes. Standard statistical tests have been found to be insensitive or non-specific, principally because of the variable period for deterioration to occur after exposure, and the sometimes prolonged time for recovery to occur, such that days away from work may initially have lower measurements than days at work. A computer assisted diagnostic aid (Oasys) has been developed to separate occupational from non-occupational causes of airflow obstruction. Oasys-2 is based on a discriminant analysis, and achieved a sensitivity of 75% and a specificity of at least 94%; therefore peak expiratory flow monitoring combined with Oasys-2 analysis is better to confirm than to exclude occupational asthma. A neural network version in development has improved on this. Both have been based on expert interpretation of peak flow measurements plotted as daily maximum, mean, and minimum, with the first reading at work taken as the first reading of the day. Oasys has been evaluated with independent criteria against measurements made in a wide range of occupational situations. Oasys is sufficiently developed to be the initial method for the confirmation, although less so for exclusion of occupational asthma.

Asthma↗

PubMed1994

Clinical evaluation of a renal mass diagnostic expert system.

In this paper, we describe our clinical evaluation of the diagnostic accuracy of the renal mass diagnostic system (RMDS) and of seven physicians. To investigate the value of intravenous urography (IVU) and/or retrograde urography (RU) in diagnosing renal parenchymal tumors and tumors of the renal pelvis, RMDS and the seven physicians were tested with and without the information regarding IVU/RU at two different times. From this study we believe that RMDS can help residents in making more accurate presurgical renal mass diagnosis, and may eliminate the need for IVU/RU in the diagnosing process for a specific group of patients.

Adolescent↗

PubMed2006

Introduction of a new orthodontic treatment planning software; a fuzzy logic expert system.

General practitioners can learn the mechanical aspects of orthodontics quickly. But they are not usually sure about the treament plans they propose. In this article, new software is described that proposes treatment plans fornon-surgical orthodontic cases. This computer program can receive patients' data in both graphical and numerical forms. The concepts of fuzzy logic have been used to enable the software to work with nominal parameters. This feature greatly simplifies the use of the software because it does not force the user to measure several numerical variables. Each patients' data is saved by this software and the saved data can be modified or deleted later. The computer program is prepared to deal with special cases such as incomplete dentitions appropriately. The software is supposed to reduce the number of inappropriate extractions and erroneous treatment plans for orthodontic purposes.

Adult↗

PubMed1988

Expert-system-based fuzzy control of arterial pressure by drug infusion.

This paper proposes a new type of fuzzy controller which is based on the general-purpose Fuzzy LOgic Production System shell FLOPS [1, 2, 7, 12, 13]. Human mean arterial pressure was controlled by the proposed fuzzy controller, in digital computer stimulation, by regulating the infusion rate of the drug, sodium nitroprusside. Under nonstationary arterial background pressure noise, mean arterial pressures of different patients with different sensitivities to sodium nitroprusside were controlled satisfactorily. Furthermore, the effects of changing the adjustable parameters of the proposed fuzzy controller on the control results were studied. Finally, the performance of the proposed fuzzy controller was compared to that of a fine-tuned Proportional-Integral (PI) controller by using a first-order linear model.

Blood Pressure↗

PubMed1994

Analysis of ultrasonographic prostate images for the detection of prostatic carcinoma: the automated urologic diagnostic expert system.

This paper describes a study on the automated analysis of ultrasonographic prostate images. With image processing, tissue characterization in the prostate was performed to assess the probability of malignancy. During prostate examinations, images were recorded at the positions where biopsies were taken. The used samples were divided into three groups. Two of them were used for the construction of a classification tree, and the third was used for the evaluation of this classification. A sensitivity of 80.6% and specificity of 77.1% were reached retrospectively. In a prospective way, these results were 80.0% and 88.2%, respectively. The prospective predictive value for cancer detection was 85.7%. The presented prospective value for image analysis was almost twice as high as the values normally found for prostate examination.

Aged↗

PubMed1994

An expert system approach for the objective interpretation of serum tumour marker levels.

The aim of our work was to study specific aspects of statistical Weinstein-Bayes's analysis in order to find the most suitable program for presenting our results and for obtaining information which could be used as a guide in the clinical decision-making process. Our efforts resulted in a computer processing system based on modified Weinstein-Bayes receiver operating characteristics (ROC) analysis. The data analysis provides numeric values of sensitivity, specificity, positive predictive value and negative predictive values as output tumour marker databases, which would serve as graphic input. It becomes possible to plot the ROC curve as a graphical distribution of tumour marker levels. The computer program also allows the estimation of the potential utility of the serum tumour marker measured in patients with various diseases, simultaneous determination of serum tumour markers in diseased patients, and the real value of each serum tumour marker level in diseased patients.

Adenocarcinoma↗

PubMed1999

An expert system for the evaluation of historical asbestos exposure as diagnostic criterion in asbestos-related diseases.

Compensation schemes for asbestos-related diseases have developed different strategies for attributing a specific disease to occupational exposure to asbestos in the past. In the absence of quantitative exposure information that allows a valid estimate of an individual's historical exposure, general guidelines are required to retrospectively evaluate asbestos exposure. A risk matrix has been developed that contains qualitative information on the proportion of workers exposed and the level of exposure in particular industries over time. Based on this risk matrix, stepwise decision trees were formulated for decisions regarding the decisive role of historical asbestos exposure in case ascertainment of asbestosis and mesothelioma. Application of decision schemes will serve to speed up the process of verifying compensation claims and also contribute to a uniform decision-making process in legal procedures.

Asbestosis↗

PubMedDate not supplied

The role of expert system shell induction in the analysis of phase and amplitude images obtained from nuclear cardiology.

In an attempt to explain the results of a perception experiment, estimates of statistical parameters were obtained from phase and amplitude images of nuclear medicine multiple-gated cardiac studies. A commercially available induction system was used to create a rule-based decision tree using these estimates as a training set. In the classification of normal and abnormal studies two useful rules were found; one of these involved the standard deviation of the left ventricular phase histogram and the other concerned the correlation of adjacent pixels in the left ventricular region of the amplitude image. A discriminant analysis performed on five amplitude and five phase parameters produced no better discrimination than the use of the phase standard deviation alone. Although it was hoped that induction would find more than two useful rules, the results of the discriminant analysis confirm that induction has performed creditably on a difficult problem.

Algorithms↗

PubMed1997

Knowledge generating in expert systems as support of immunological investigations.

One of the most important parameters in immunologic investigations linked with the analysis of TIL phenotypic characteristics is the ratio between particular populations and subpopulations of TIL. Values of exact parameter are not obtained with its direct measurement but with indirect measurement of values in its numerator and its denominator that represent mean values of absolute TIL figures. Exactness of estimate of specific parameter is obtained by determining the intervals of values where this parameter should lie. Determination of confidence intervals for relationship between particular populations and subpopulations of TIL was performed using Fieller's theorem which full filled requests from the nature and process of obtaining exact parameter. By analyzing the obtained confidence intervals informations can be obtained regarding TIL phenotypic characteristics of various histologic types of tumors and various types of intervals within, as well as changes in TIL content that are occurring in malignant tumors.

Artificial Intelligence↗

PubMed2005

Hypertext atlas of dermatopathology with expert system for epithelial tumors of the skin.

BACKGROUND: Image resolution required for reference histological images is high. Obtaining high-resolution images requires a system, composing large image from individual smaller components. Such systems must thus be capable of automatically taking individual image parts, performing shading compensation and fusion of the image parts into one large image. Distribution of such images over the Internet requires developing a suitable user's interface with access to the image details. METHODS: The ways of creating high-resolution images (virtual slides) and the interface enabling access to image details using Internet browser are described. RESULTS: A collection of about 3200 dermatopathological, mostly histologic images is available at http://www.muni.cz/atlases: Hypertext atlas of dermatopathology. Methods of high-resolution image acquisition were used in digitizing the collection of skin lymphomas (Dermatology Institute, University Hospital, Zurich), which is a part of the atlas. The atlas is continuously maintained and upgraded; the number of contributors is growing.

Dermatology↗

PubMed2005

Software and expert system for the management of chronic hepatitis B.

Whereas the doubling time of overall biomedical knowledge bases has been estimated at about 19 years, the body of indexed information related to HBV has doubled in the last 8 years; the one related to HBV and antivirals has doubled in the last 5 years and the one related to Interferon and contraindications has doubled in less than 48 months. In Hepatology, as well as in other fast changing areas of medicine, the demand that clinical decision should always be based on the best verified knowledge available, is becoming more and more difficult to comply with. The Italian network of competence for hepatic diseases (Liver Unit Networks Association or LUNA) was established in 2003 with the patronage of the Italian Ministry of Health, with the primary goal of promoting advanced clinical research and real-time information exchange among the participating centres, facilitating knowledge sharing and identification of best practices. The ICT infrastructure designed for this purpose includes four sets of online accessible software tools:

Chronic Disease↗

PubMed1998

Role and use of expert systems within the clinical laboratory.

Artificial intelligence can be used, mainly in the form of knowledge based systems, for different parts of clinical laboratory activity. Most of the iterative tasks for control and validation, or for maintenance or repair of automated instruments can be assisted by specialized software. There are now specific programmes (i) for control and validation of the request, where the goal is to modify the requesting behaviour of the physician, using protocol driven requests and immediate feedback, incorporating simultaneously a check of test request redundancy, (ii) for helping in equipment trouble-shooting, (iii) for technical and biological validation because too many QC data are issued from large equipment to be checked and used properly by the technologist whilst the pathologist can be assisted for the final revision of reports and (iv) for assistance in the interpretation of laboratory reports, one of the most valuable aspects of the pathologist's participation in the patient care process.

Clinical Chemistry Tests↗

PubMed1990

An expert system for synoptic interpretation of lung function tests.

We simulate the interpretation process by the testing of preformed working hypotheses. A clinical syndrome, "bronchial obstruction," is described by a set of suitable parameters (FEV1, MMEF, Raw, etc.). For a given patient, this set forms a normalized vector. It has to be compared with equivalent data derived from patients which fulfilled the criteria for the clinical syndrome in question. If the patient's vector has a similar direction as the vector of the collective, the working hypothesis is accepted. The length of the vector is then used to quantify the severity of the functional disturbances in verbal terms ("slight," "moderate," "severe"). The limits used for severity grading and the typical parameter pattern for the given syndrome are adapted to the user's criteria by a built-in learning capability. On the other hand, the assembled data may be used for the training of newcomers. The use of vector algorithms allows for a high flexibility of our program with respect to all methods used in lung function testing.

Algorithms↗

PubMed2006

A new expert systems (SeDeM diagram) for control batch powder formulation and preformulation drug products.

The new SeDeM Method is proposed for testing the batch-to-batch reproducibility of the same active pharmaceutical ingredient (API) in powder form. The procedure describes the study of the galenic properties of substances in powder form in terms of the applicability of direct compression technology. Through experimental determination of the SeDeM Method parameters, and their subsequent mathematical treatment and graphical expression (SeDeM Diagram), three batches of the same API were analysed to determine whether it was suitable for direct compression. Batch-to-batch reproducibility of the results was verified. It was concluded that the SeDeM Method is suitable for testing batch-to-batch reproducibility of characteristics in powdered APIs substances. The results obtained confirm that the SeDeM Method is a useful, effective tool for drug-preformulation studies providing the pharmacotechnical data required when formulating a drug in tablet form. In addition, the results were effective for defining the most appropriate manufacturing technology.

Chemistry, Pharmaceutical↗