Fuzzy Decision Support System for Coronary Artery Disease Diagnosis Based on Rough Set Theory

The objective of this research is to develop an evidence based fuzzy decision support system for the diagnosis of coronary artery disease. The development of decision support system is implemented based on three processing stages: rule generation, rule selection and rule fuzzification. Rough Set Theory (RST) is used to generate the classification rules from training data set. The training data are obtained from University California Irvine (UCI) data repository. Rule selection is conducted by transforming the rules into a decision table based on unseen data set. Furthermore, RST attributes reduction is proposed and applied to select the most important rules. The selected rules are transformed into fuzzy rules based on discretization cuts of numerical input attributes and simple triangular and trapezoidal membership functions. Fuzzy rules weighing is also proposed and applied based on rules support on the training data. The system is validated using UCI heart disease data sets collected from the U.S., Switzerland and Hungary and data set from Ipoh Specialist Hospital Malaysia. The system is verified by three cardiologists. The results show that the system is able to give the approximate possibility of coronary artery blocking.

Automated classification of patients with coronary artery disease using grayscale features from left ventricle echocardiographic images

Coronary Artery Disease (CAD), caused by the buildup of plaque on the inside of the coronary arteries, has a high mortality rate. To efficiently detect this condition from echocardiography images, with lesser inter-observer variability and visual interpretation errors, computer based data mining techniques may be exploited. We have developed and presented one such technique in this paper for the classification of normal and CAD affected cases. A multitude of grayscale features (fractal dimension, entropies based on the higher order spectra, features based on image texture and local binary patterns, and wavelet based features) were extracted from echocardiography images belonging to a huge database of 400 normal cases and 400 CAD patients. Only the features that had good discriminating capability were selected using t-test. Several combinations of the resultant significant features were used to evaluate many supervised classifiers to find the combination that presents a good accuracy. We observed that the Gaussian Mixture Model (GMM) classifier trained with a feature subset made up of nine significant features presented the highest accuracy, sensitivity, specificity, and positive predictive value of 100%. We have also developed a novel, highly discriminative HeartIndex, which is a single number that is calculated from the combination of the features, in order to objectively classify the images from either of the two classes. Such an index allows for an easier implementation of the technique for automated CAD detection in the computers in hospitals and clinics.

Machine learning techniques for arterial pressure waveform analysis

The Arterial Pressure Waveform (APW) can provide essential information about arterial wall integrity and arterial stiffness. Most of APW analysis frameworks individually process each hemodynamic parameter and do not evaluate inter-dependencies in the overall pulse morphology. The key contribution of this work is the use of machine learning algorithms to deal with vectorized features extracted from APW. With this purpose, we follow a five-step evaluation methodology: (1) a custom-designed, non-invasive, electromechanical device was used in the data collection from 50 subjects; (2) the acquired position and amplitude of onset, Systolic Peak (SP), Point of Inflection (Pi) and Dicrotic Wave (DW) were used for the computation of some morphological attributes; (3) pre-processing work on the datasets was performed in order to reduce the number of input features and increase the model accuracy by selecting the most relevant ones; (4) classification of the dataset was carried out using four different machine learning algorithms: Random Forest, BayesNet (probabilistic), J48 (decision tree) and RIPPER (rule-based induction); and (5) we evaluate the trained models, using the majority-voting system, comparatively to the respective calculated Augmentation Index (AIx). Classification algorithms have been proved to be efficient, in particular Random Forest has shown good accuracy (96.95%) and high area under the curve (AUC) of a Receiver Operating Characteristic (ROC) curve (0.961). Finally, during validation tests, a correlation between high risk labels, retrieved from the multi-parametric approach, and positive AIx values was verified. This approach gives allowance for designing new hemodynamic morphology vectors and techniques for multiple APW analysis, thus improving the arterial pulse understanding, especially when compared to traditional single-parameter analysis, where the failure in one parameter measurement component, such as Pi, can jeopardize the whole evaluation.

An extensible six-step methodology to automatically generate fuzzy DSSs for diagnostic applications

Background

The diagnosis of many diseases can be often formulated as a decision problem; uncertainty affects these problems so that many computerized Diagnostic Decision Support Systems (in the following, DDSSs) have been developed to aid the physician in interpreting clinical data and thus to improve the quality of the whole process. Fuzzy logic, a well established attempt at the formalization and mechanization of human capabilities in reasoning and deciding with noisy information, can be profitably used. Recently, we informally proposed a general methodology to automatically build DDSSs on the top of fuzzy knowledge extracted from data.

Methods

We carefully refine and formalize our methodology that includes six stages, where the first three stages work with crisp rules, whereas the last three ones are employed on fuzzy models. Its strength relies on its generality and modularity since it supports the integration of alternative techniques in each of its stages.

Results

The methodology is designed and implemented in the form of a modular and portable software architecture according to a component-based approach. The architecture is deeply described and a summary inspection of the main components in terms of UML diagrams is outlined as well. A first implementation of the architecture has been then realized in Java following the object-oriented paradigm and used to instantiate a DDSS example aimed at accurately diagnosing breast masses as a proof of concept.

Conclusions

The results prove the feasibility of the whole methodology implemented in terms of the architecture proposed.

Prediction of coronary atherosclerosis progression using dynamic Bayesian networks

In this paper we propose a methodology for predicting the progression of atherosclerosis in coronary arteries using dynamic Bayesian networks. The methodology takes into account patient data collected at the baseline study and the same data collected in the follow-up study. Our aim is to analyze all the different sources of information (Demographic, Clinical, Biochemical profile, Inflammatory markers, Treatment characteristics) in order to predict possible manifestations of the disease; subsequently, our purpose is twofold: i) to identify the key factors that dictate the progression of atherosclerosis and ii) based on these factors to build a model which is able to predict the progression of atherosclerosis for a specific patient, providing at the same time information about the underlying mechanism of the disease.

A novel mathematical approach to diagnose premenstrual syndrome

Diagnosis of Premenstrual syndrome (PMS) is a research challenge due to its subjective presentation. An undiagnosed PMS case is often termed as 'borderline' ('B') that further add to the diagnostic fuzziness. This study proposes a methodology to diagnose PMS cases using a combined knowledge engineering and soft computing techniques. According to the guidelines of American College of Gynecology (ACOG), ten symptoms have been selected and technically processed for 50 cases each having class labels-'B' or 'NB' (not borderline) using domain expertise. Any Attribute that fails normality test has been excluded from the study. Decision tree (DT) has then been induced in obtaining the initial class boundaries and mining the important Attributes to classify PMS cases. Prior doing so, the best split criterion has been set using the maximum information gain measure. Initial information about classification boundaries are finally used to measure fuzzy membership values and the corresponding firing strengths have been measured for final classification of PMS 'B' cases.

Supporting diagnostic decisions using hybrid and complementary data mining applications: a pilot study in the pediatric emergency department

INTRODUCTION

This article demonstrates the capacity of a combination of different data mining (DM) methods to support diagnosis in pediatric emergency patients. By using a novel combination of these DM procedures, a computer-based diagnosis was created.

METHODS

A support vector machine (SVM), artificial neural networks (ANNs), fuzzy logics, and a voting algorithm were simultaneously used to allocate a patient to one of 18 diagnoses (e.g., pneumonia, appendicitis). Anonymized data sets of patients who presented in the emergency department (ED) of a pediatric care clinic were chosen. For each patient, 26 identical clinical and laboratory parameters were used (e.g., blood count, C-reactive protein) to finally develop the program.

RESULTS

The combination of four DM operations arrived at a correct diagnosis in 98% of the cases, retrospectively. A subgroup analysis showed that the highest diagnostic accuracy was for appendicitis (97% correct diagnoses) and idiopathic thrombocytopenic purpura or erythroblastopenia (100% correct diagnoses). During the prospective testing, 81% of the patients were correctly diagnosed by the system.

DISCUSSION

The combination of these DM methods was suitable for proposing a diagnosis using both laboratory and clinical parameters. We conclude that an optimized combination of different but complementary DM methods might serve to assist medical decisions in the ED.

A web-based decision support system for dietary analysis and recommendations

OBJECTIVES

Because of lack of integrated databases for Chinese menus and the need for nutrition information by dietitians in Taiwan, we developed a Web-based platform for dietary analysis and recommendations.

METHODS

The fuzzy decision model was utilized to develop a Web-based support system that searches food composition databases, calculates dietary intake, and provides the guidance for decision making in nutrition counseling.

RESULTS

The online support system generated menu- or food-based recommendations using a fuzzy decision model. The homogeneity of food composition between five selected menus generated by the fuzzy decision model in a randomly selective case was strongly correlated with a correlation coefficient of 0.31-0.99. The correlation coefficients were 0.42-0.45 and 0.13-0.44 between food composition of five most correlated menus or five selected menus generated by the fuzzy decision model and nutrient requirements computed by the fuzzy decision model, respectively. The most correlated menus and the menus generated by the fuzzy decision model were also similar.

CONCLUSIONS

The recommended menus generated by the fuzzy decision model are considerably reliable and valid, and the online support system for dietary analysis and recommendations can provide a Web-based and decision-making tool for dietitians in Taiwan.

Patient specific cardiovascular risk assessment and treatment decision support based on multiscale modelling and medical guidelines

In this work we present an enhanced medical workflow and a decision support system for atherosclerotic risk assessment and treatment, that is based both on existing medical guidelines and on patient specific multiscale data. The medical expert that uses the system is able to apply both existing medical guidelines as well as to take into account additional information for the patient by inspecting the 3D geometry of an arterial segment or the arterial tree, model the blood flow in the patient specific arterial model and predict the progression of the plaque. Moreover, the user is able to apply plaque characterization techniques in Intravascular Ultrasound images (IVUS) and Tomography Images (CT). The combination of the medical guidelines with the patient specific multiscale data provides a detailed view in the patient status for risk assessment and treatment suggestion.

Clinical decision support system: risk level prediction of heart disease using weighted fuzzy rules and decision tree rules

The development of medical domain applications has been one of the most active research areas recently. One example of a medical domain application is a detection system for heart disease based on computer-aided diagnosis methods, where the data is obtained from some other sources and is evaluated by computer based applications. Up to now, computers have usually been used to build knowledge based clinical decision support systems which used the knowledge from medical experts, and transferring this knowledge into computer algorithms was done manually. This process is time consuming and really depends on the medical expert’s opinion, which may be subjective. To handle this problem, machine learning techniques have been developed to gain knowledge automatically from examples or raw data. Here, a weighted fuzzy rule-based clinical decision support system (CDSS) is presented for the diagnosis of heart disease, automatically obtaining the knowledge from the patient’s clinical data. The proposed clinical decision support system for risk prediction of heart patients consists of two phases, (1) automated approach for generation of weighted fuzzy rules and decision tree rules, and, (2) developing a fuzzy rule-based decision support system. In the first phase, we have used the mining technique, attribute selection and attribute weightage method to obtain the weighted fuzzy rules. Then, the fuzzy system is constructed in accordance with the weighted fuzzy rules and chosen attributes. Finally, the experimentation is carried out on the proposed system using the datasets obtained from the UCI repository and the performance of the system is compared with the neural network-based system utilizing accuracy, sensitivity and specificity.