Biomedical subjects

M C Jaulent

Publications and source records attributed to M C Jaulent.

32 records · Page 2Linked to original sources

PubMed1998

IDEM: a Web application of case-based reasoning in histopathology.

Different software engineering and artificial intelligence methods can be used to design Internet retrieval of prototypical medical images. We used the case-based reasoning (CBR) approach to provide an 'intelligent' access to a collection of illustrated medical cases through the Internet. This paper presents a Web interface for the CBR system IDEM (image and diagnosis from examples in medicine) in the domain of breast pathology. Thanks to the definition of a similarity measure between the descriptions of cases we propose a flexible querying of the case-base and a quantitative browsing among cases through similarity links. The resemblance rates provided by the system argue for the quality and the relevancy of the retrieved data. The flexibility of the querying process is robust to missing information and could be adapted to a daily practice. The CBR approach is a promising method for a clinical relevant and an efficient retrieval of reference images and diagnosis clues through Internet.

Artificial Intelligence↗

PubMed1998

Implementation of a fuzzy prototype-based machine learning method to predict myocardial infarction from coronary angiography.

Formal knowledge on the predictive value of morphological angiographic factors is lacking to estimate the risk of myocardial infarction. This article presents a computer system for predicting the incidence of myocardial infarction from angiographic morphological descriptions of coronary lesions. The system includes two phases. The learning phase consists in extracting from a large database of described stenoses two classes represented by one or several fuzzy prototypes. One class corresponds to stenoses leading to infarction and the other to stenoses not leading to that event. The evaluation phase consists in classifying a stenosis according to its morphological characteristics in one of these two classes. The learning method is based on a fuzzy supervised Machine Learning algorithm that combines some aspects of the K-nearest neighbours clustering approach with a defined measure of similarity, and a prototype induction function from the most similar stenoses, taking into account their degree of typicality. The current results of the evaluation phase to correctly predicted X% stenoses for their risk of myocardial infarction. This article emphasizes the feasibility of the approach, however, the learning phase relies on some heuristics that should be validated to get a formal evaluation of the system.

Artificial Intelligence↗

PubMed1998

Case based diagnosis in histopathology of breast tumours.

Relevant knowledge and decision making process in histopathology is mostly included in typical pathological cases encountered by the expert. In this article we address the issue of exploiting this knowledge in the diagnosis process. We present the first steps of a Case-Based-Reasoning (CBR) system that uses the previously resolved pathological cases in order to facilitate decision making and diagnosis formulation of a new case. The work has been performed in two phases. Firstly, an object-oriented model of the domain was developed and 35 pathological cases of breast tumours were represented within this model. Secondly, the functional architecture of the CBR system was designed and the main procedure, the selection of similar cases, was achieved. The selection procedure is based on an original similarity measure that takes into account both semantic and structural resemblances and differences between the cases. A first evaluation of the system was performed on several cases of the data base. The interest of the CBR approach in situations where heuristic rules cannot be clearly defined is discussed.

Algorithms↗

PubMed1998

Rationale and design considerations for a semantic mediator in health information systems.

Rapid development of community health information networks raises the issue of semantic interoperability between distributed and heterogeneous systems. Indeed, operational health information systems originate from heterogeneous teams of independent developers and have to cooperate in order to exchange data and services. A good cooperation is based on a good understanding of the messages exchanged between the systems. The main issue of semantic interoperability is to ensure that the exchange is not only possible but also meaningful. The main objective of this paper is to analyze semantic interoperability from a software engineering point of view. It describes the principles for the design of a semantic mediator (SM) in the framework of a distributed object manager (DOM). The mediator is itself a component that should allow the exchange of messages independently of languages and platforms. The functional architecture of such a SM is detailed. These principles have been partly applied in the context of the HELIOS object-oriented software engineering environment. The resulting service components are presented with their current state of achievement.

Computer Communication Networks↗

PubMed1998

A fuzzy classification system to predict renal artery restenosis after angioplasty.

Percutaneous transluminal angioplasty (PTRA) has emerged as a promising treatment for patients with renovascular hypertension. However, the benefit of this procedure is hampered by restenosis that frequently occurs within around 6 months after a successful angioplasty. This paper presents a fuzzy classification system based on a fuzzy pattern matching model that is being developed to evaluate the risk of short-term restenosis. First, identified classes are represented by fuzzy prototypes that take into account the imprecision of the criteria. Second, the system is applied to angiographic features of given stenoses and provides the membership degree of these stenosis to the two classes "short term restenosis" or "no restenosis". The fuzzy classifier's performances have been tested on twenty two patients who underwent balloon angioplasty in the context of a French multicenter randomized trial EMMA. With the fuzzy classifier, restenosis were predicted prospectively with 100% while its sensitivity is about 73%. The fuzzy classification system is expected to become a reliable tool to predict PTRA outcomes.

Angioplasty, Balloon↗

PubMed1998

Unified modeling language and design of a case-based retrieval system in medical imaging.

One goal of artificial intelligence research into case-based reasoning (CBR) systems is to develop approaches for designing useful and practical interactive case-based environments. Explaining each step of the design of the case-base and of the retrieval process is critical for the application of case-based systems to the real world. We describe herein our approach to the design of IDEM--Images and Diagnosis from Examples in Medicine--a medical image case-based retrieval system for pathologists. Our approach is based on the expressiveness of an object-oriented modeling language standard: the Unified Modeling Language (UML). We created a set of diagrams in UML notation illustrating the steps of the CBR methodology we used. The key aspect of this approach was selecting the relevant objects of the system according to user requirements and making visualization of cases and of the components of the case retrieval process. Further evaluation of the expressiveness of the design document is required but UML seems to be a promising formalism, improving the communication between the developers and users.

Artificial Intelligence↗

PubMed1997

Fuzzy classification of renal artery lesions from angiograms in the context of angioplasty.

This paper describes a system that automatically classifies renal artery lesions from arteriograms in the context of Percutaneous Transluminal Renal Angioplasty (PTRA). PTRA outcomes have been categorized into type A (success) or type B (failure) according to morphological features. The morphological features are naturally represented by fuzzy sets. The classification process is based on a fuzzy pattern matching procedure between fuzzy prototypes of lesions in the classes A and B and fuzzy quantified assessments of lesions in angiograms. The system provides a meaningful membership degree to the class rather than an abrupt yes or no answer. The system is expected to be a good framework to study the technical results of PTRA according to the anatomy of the lesion.

Angioplasty, Balloon↗

PubMed1997

Automatic stenosis detection and quantification in renal arteriography.

Visual assessment of the degree of renal artery stenosis on renal arteriography has a large inter- and intraobserver variability. This degree is usually estimated by the ratio between the most narrowed portion of the artery and the reference diameter. The latter is a priori unknown information and thus operator dependent. The objective of the present work was to test the performances of a computer system that was designed to analyze and quantify lesions on 2D renal arteriograms. The main hypothesis was to consider that the most frequent diameter computed along the artery was a good candidate to approximate the reference diameter. Forty nine patient images were collected from the EMMA randomized trial, a multicenter study comparing two treatment strategies in unilateral atheromatous renal artery stenosis of at least 60%. For each image, the degree of stenosis was evaluated by five independent experts and the mean value was used to represent the gold standard for the computer system. The system is based on a fuzzy automaton and performs a syntactic analysis of the arterial segment providing automatic and reproducible quantification of lesions. Both the radiologist caring for the patient and the system were compared to the gold standard. Compared to individual radiologists, the computer system gave a more precise estimation of percent stenosis and did not over or under estimate the severity of the lesion.

Fuzzy Logic↗

PubMed1997

Automatic detection of cardiac contours on MR images using fuzzy logic and dynamic programming.

This paper deals with the use of fuzzy logic and dynamic programming in the detection of cardiac contours in MR Images. The definition of two parameters for each pixel allows the construction of the fuzzy set of the cardiac contour points. The first parameter takes into account the grey level, and the second the presence of an edge. A corresponding fuzzy matrix is derived from the initial image. Finally, a dynamic programming with graph searching is performed on this fuzzy matrix. The method has been tested on several MR images and the results of the contouring were validated by an expert in the domain. This preliminary work clearly demonstrates the interest of this method, although a formal evaluation has to be done.

Fuzzy Logic↗

PubMed1996

[Computer-assisted medical decision].

A physician deals everyday with uncertainty to take decisions and treat patients. The goal of decision making systems is to facilitate and improve the decision. Classical approaches, such as decision trees or statistical tools, provide rates about possible actions and outcomes of physicians' decisions. Such information is essentially numerical. Other computer approaches, like expert systems, provide both numeric and symbolic information. The expert knowledge is embedded in the system and used to elaborate new decisions and to provide reasoning explanations. The use of computer making decision systems will certainly increase the performances in future medical activity as it will provide a reliable additional expert information to take decisions.

Algorithms↗

PubMed1994

ARTEMIS-2: an application development experiment with the HELIOS environment.

A medical application is a highly complex system that embraces many data types and a very large number of data processing functions and methods. The development of integrated software engineering environments has deeply changed the conception of applications and the profile of the application developers. In this paper, we address the problem of the development process of a specific multimedia application, called ARTEMIS, within the distributed HELIOS environment. The application is intended to manage information about hypertensive patients, in particular, retrieval and display of administrative, clinical and biological data and display and analysis of digital angiography images and medical reports. The objective is to show how the developer can use, customize and organize the services HELIOS provides. A particular focus is set on reuse strategies and integration during the development process. A scenario has been realized and illustrates the current state of the application. The discussion focuses on the advantages of such distributed environments in medical application development.

Computer Communication Networks↗

PubMed1993

Description and representation of segmented renal arteries from angiograms.

This paper presents the first prototype of a system that uses syntactic techniques to describe normal and abnormal aspects of segmented renal arteries from angiographic images. The system is one part of a full understanding system devoted to the interpretation of angiograms. Its purpose is to provide symbolic descriptions of lesions that can further contribute to an accurate diagnosis from the image. The prototype consists of a modular system that takes artery outlines as input and provides a structural description of the artery as output in the framework of a precise quantification scheme. Each module yields heuristic parameters that influence the resulting description. The system is intended to be a tool to study independently the role of these different parameters in the inter and intra observer variability.

Humans↗

PubMed1991

Distribution and communication in software engineering environments. Application to the HELIOS Software Bus.

Modularity, distribution and integration are current trends in Software Engineering. To reach these goals HELIOS, a distributive Software Engineering Environment dedicated to the medical field, has been conceived and a prototype implemented. This environment is made by the collaboration of several, well encapsulated Software Components. This paper presents the architecture retained to allow communication between the different components and focus on the implementation details of the Software Bus, the communication and integration vector of the currently running prototype.

Computer Communication Networks↗

PubMedDate not supplied

An approach for the evaluation of software engineering environments in medicine.

This article examines several criteria for the evaluation of software engineering environments (SEE) in medicine. The study is restricted to the evaluation of the SEE itself, not of its by-products which are the medical applications developed with the SEE. Basic principles for an evaluation methodology are presented. They consist in determining the evaluation objectives and judging a SEE according to criteria which are grouped into three broad categories--functional, generic and environmental. Each category reflects a particular domain of evaluation of the SEE. Methods of measurement and questions highlighting these specific areas are mentioned. Criteria are extracted from the list of objectives that follows the HELIOS European AIM project of the Commission of the European Communities. Special emphasis is drawn on the criteria for which the medical specificity and usefulness of a SEE can be approach. For this purpose a method of measurement of such appropriateness is proposed.

Attitude to Computers↗