[The multimedia workstation, electronic assistant to the health care professional]. / Le poste de travail multimédia, assistant électronique du professionnel de santé.

The health professional multimedia workstation is the natural entry point to health and knowledge networks. It should allow an easy and transparent management of all the data necessary for patient management. Multimedia nature of processed information reflects evolution of medical techniques that involve more and more complex objects such as video sequences or digitized signals. Workstations can be considered from 3 points of view: the professional end-users, the developers and the decision makers. The long term goal for the end-user is to establish an easy access in a working environment, that gives him/her the feeling of a single comprehensive application running on a single computer when the information system relies on a set of heterogeneous and geographically distributed components. Development of a workstation requires the integration into the same environment of tools to localize, access, manipulate and communicate the required information within a health information network. Analysis of the 445 Medline-indexed publications for the January 1991 to December 1994 period, that included the word workstation either in their title or in their abstract, helps in refining objectives and challenges both for the health professionals and the decision makers.

Multimedia Workstations: Electronic Assistants for Health-Care Professionals.

The increasing costs of health care and the economic reality has produced an interesting paradox for the health professional to perform more clinical work with fewer support personnel. Moreover, an explosion of the knowledge-base that underlies sound clinical care not only makes effective time management critical, but also knowledge management compelling. A multimedia workstation is an electronic assistant for the busy health professional that can help with administrative tasks and give access to clinical information and knowledge networks. The multimedia nature of processed information reflects an evolution of medical technologies that involve more and more complex objects such as video sequences or digitized signals. Analysis of the 445 Medline-indexed publications for the January 1991 to December 1994 period, that included the word "workstation" either in their title or in their abstract, helps in refining objectives and challenges both for health professionals and decision makers. From an engineering perspective, development of a workstation requires the integration into the same environments of tools to localize, access, manipulate and communicate the required information. The long-term goal is to establish an easy access in a collaborative working environment that gives the end-user the feeling of a single virtual health enterprise, driven by an integrated computer system when the information system relies on a set of heterogeneous and geographically distributed components. Consequences in terms of migration from traditional client/server architectures to more client/network architectures are considered.

The health care professional multimedia workstation: development and integration issues.

Workstations for health care professionals provide access to distributed healthcare information systems. They are complex systems that have to manage, in a unified framework, the distributed and multimedia information needed for optimal patient care. The objective is to provide the end-user with a virtual and unified device that conceals the complexity of the underlying information system. Integration and reuse of modular software components are important in the development of such a workstation. A reference set of evaluation criteria is proposed that includes functional, technical, organizational, medical, cultural and ethical, economic and industrial components.

The image related services of the HELIOS software engineering environment.

This paper describes the approach of the European HELIOS project to integrate image processing tools into ward information systems. The image processing tools are the result of the basic research in image analysis in the Department Medical and Biological Informatics at the German Cancer Research Center. These tools for the analysis of two-dimensional images and three-dimensional data volumes with 3D reconstruction and visualization ae part of the Image Related Services of HELIOS. The HELIOS software engineering environment allows to use the image processing functionality in integrated applications.

Legacy systems: managing evolution through integration in a distributed and object-oriented computing environment.

Legacy systems are crucial for organizations since they support key functionalities. But they become obsolete with aging and the apparition of new techniques. Managing their evolution is a key issue in software engineering. This paper presents a strategy that has been developed at Broussais University Hospital in Paris to make a legacy system devoted to the management of health care units evolve towards a new up-to-date software. A two-phase evolution pathway is described. The first phase consists in separating the interface from the data storage and application control and in using a communication channel between the individualized components. The second phase proposes to use an object-oriented DBMS in place of the homegrown system. An application example for the management of hypertensive patients is described.

An object oriented computer-based patient record reference model.

In the context of health care information systems based on client/server architecture, we address the problem of a common Computer-based Patient Record (CPR). We define it as a collection of faithful observations about patients care, with respect to the free expression of physicians. This CPR model supports several views of the medical data, in order to provide applications with a comprehensive and standardized access to distributed patient data. Finally, we validated our CPR approach as a primary data model server for an application for hypertensive patient management.

A development environment to create medical applications.

This paper describes a Development Environment for medical applications developers coupling Reuse and Object-Oriented technologies. It presents the two main phases of the reuse process, the reusable component creation and the reusable component use, and stresses on the very nature of reusable development components. We provide both a classification model for those reusable components that is a support for an efficient and simple retrieval mechanism, and a reusable component model that considers the same way components of large and low-granularity levels (e.g., application frameworks and methods of a given class). The reusable component model is based on the underlying idea that development components are not operational components since they do not have the same purpose. This model first represents each component as an aggregation of other sub-components, together with all information needed for its retrieval (e.g., classification and facets), its understanding (e.g., informal functional description), and its dependencies with other development components, in particular the applications in which it occurs, since applications are considered here as abstract development components.

Integrated image processing in clinical applications: the HELIOS approach.

This paper describes the approach of the European HELIOS project to integrate image processing tools into ward information systems. The image processing tools are the result of the basic research in image analysis in the Department Medical and Biological Informatics at the German Cancer Research Center. Tools for the analysis of 2-dimensional images and 3-dimensional data volumes with 3-dimensional reconstruction and visualization are part of the Image Related Services of HELIOS.

The component-based architecture of the HELIOS medical software engineering environment.

The constitution of highly integrated health information networks and the growth of multimedia technologies raise new challenges for the development of medical applications. We describe in this paper the general architecture of the HELIOS medical software engineering environment devoted to the development and maintenance of multimedia distributed medical applications. HELIOS is made of a set of software components, federated by a communication channel called the HELIOS Unification Bus. The HELIOS kernel includes three main components, the Analysis-Design and Environment, the Object Information System and the Interface Manager. HELIOS services consist in a collection of toolkits providing the necessary facilities to medical application developers. They include Image Related services, a Natural Language Processor, a Decision Support System and Connection services. The project gives special attention to both object-oriented approaches and software re-usability that are considered crucial steps towards the development of more reliable, coherent and integrated applications.

The HELIOS Medical Connection Services.

This paper presents the design and implementation of the HELIOS software component that deals with integration of medical applications in health information networks. The problem of interoperability between health information systems based on different data exchange syntaxes is first discussed. A meta-model, relying on CEN TC251 recommendations, is then presented as a possible solution to this problem and a message description language including these recommendations is proposed. Using this meta-model, the Medical Connection Services that comprises a generic message processing automaton, a resource manager and a mapper is able either to interpret messages expressed in a given syntax (e.g., EDIFACT, ASTM) and map them to the application objects or to automate the translation of the messages in another syntax. Special focus is given on the position of the Medical Connection Services within the HELIOS integration strategy (i.e., through data, presentation and communication). The problem of semantic heterogeneity is then discussed.

The HELIOS Unification Bus: a toolbox to develop client/server applications.

In the medical domain, new developments commonly rely on client/server architectures. But face to distributed environments, the software developers encounter a tremendously increasing complexity when building integrated applications. This paper presents the HELIOS Unification Bus (HUB), a communication integration framework for the HELIOS medical software engineering environment that allows the exchange of data between components that can be hosted on heterogeneous machines linked by a network. The HUB is developed as a C++ toolbox over UNIX and TCP/IP. It includes a message routing entity called router and a generic application programming interface (API), implemented as a C++ library, that allows to build easily software components compliant with the standardised HELIOS language. Messages conveyed by the bus are composite objects that are serialized to be transmitted over the bus using the ASN.1 ISO presentation protocol. The article describes the use of the bus to ease the development and execution of distributed medical applications and its role from the communication integration standpoint.

Analysing and developing object-oriented medical applications with HELIOS.

The HELIOS project promotes systematic reuse of existing software in a valuable methodological context. In order to reach this goal, the Analysis and Design Development Environment (ADDE) has been realized as a HELIOS component. This component includes the Analysis and Design sub-component (ADT), which supports the Rumbaugh's object-oriented methodology and the Insertion Retrieval Tool (IRT), which implements the reuse. The ADT sub-component enhances the quality of software development permitting a correct analysis, and design and a satisfactory documentation. The IRT Tool is dedicated to reuse by retrieving parts of existing applications (retrieve) and by qualifying elements just created or updated (insertion). A faceted system adapted to the medical domain allows an efficient search among the object database. Both tools contribute to reducing the cost of software development. This paper presents the design and the implementation of these tools in the HELIOS framework.

A reuse oriented Development Database: the HELIOS Object Information System.

This paper describes the Development Database of a Software Engineering Environment (SEE), that couples reuse and object-oriented technologies. We propose a classification model for the repository of reusable components that is a support for an efficient retrieval mechanism, and a reusable component model that considers components of large and low-granularity levels (e.g., application frameworks and methods of a given class). The reusable component model is based on the underlying idea that development components are not operational components since they do not have the same purpose. This model first represents each component as an aggregation of other sub-components, together with all information needed for its retrieval (e.g., classification and facets), its under-standing (e.g., informal functional description) and its dependencies with other development components, in particular the applications in which it occurs, since applications are considered also as abstract development components. This approach was tested thanks to an existing application which was loaded into the SEE. From that moment, it was possible to regenerate a new application in a reasonably short time. Moreover, the existence of a retrieval tool permits to validate the development components classification, but also put forward the importance of the qualification step. In particular, the versioning should be carefully processed. Furthermore the fact that all the development objects are built on an homogeneous model allows easier tools management and interapplication reusability.

The HELIOS medical software engineering environment.

The aim of the HELIOS project is to create an integrated Software Engineering Environment (SEE) to facilitate the development and maintenance of medical applications. HELIOS is made of a set of software components, communicating through a software bus called the HELIOS Unification Bus. The object oriented paradigm is used both as the basic structure for building the software components and as the methodology for modelling, storing and retrieving the entities and procedures used in an application. Development standards include UNIX as operating system and X Window/MOTIF as windowing environment. One of the target applications for the HELIOS prototype is the development of a multimedia medical workstation as a front end to a hospital information system.

Integration of data driven decision support into the HELIOS environment.

The development of large-scale, clinically accepted decision support systems (DSS) calls for powerful and commonly available methods and tools for knowledge acquisition, system realisation, and knowledge base maintenance. The paper addresses problems associated with the integration of knowledge-based systems within the clinical setting with special reference to (i) data driven decision support, (ii) the Arden Syntax as a knowledge representation format and, (iii) the HELIOS software engineering environment. Architecture of a DSS based on Arden Syntax and its integration in the HELIOS environment are presented. Realisation of the DSS is discussed in relation to client-server architecture and object-oriented databases, which are essential concepts of the HELIOS environment. Sharability and reusability of the knowledge, together with commonality of used software tools are also discussed.

A software engineering approach for medical workstations development.

Multimedia medical workstations represent the natural tool for accessing the hospital information system environment. They are complex medical systems that have to gather, in a single framework, a large collection of components dealing with multimedia medical objects. To remain current with both medical practice and with advances in the computer science field, they have to allow the iterative addition of new functions to the set of existing ones. In this paper, after a survey of commonly required medical workstation functional components, we shall try to discuss how a software engineering approach can streamline the development of a medical workstation. Different software engineering tools needed to build the functional components of a workstation are described. Their integration in a single dedicated environment is considered through four perspectives: data, presentation, communication and control. Benefits and limitations of an object-oriented approach are discussed.

Using a meta-model to build a connection service in an object oriented medical application development environment.

Interoperability is a key issue in distributed health information systems. This paper presents the design and implementation of the Connection Service (CS) component of the HELIOS medical software engineering environment. An exchange message meta-model based on CEN TC251 recommendations and a message description language are proposed. Using this meta-model, the CS is able either to interpret messages expressed in a given syntax (e.g., EDIFACT, ASTM) and map them to the application objects or to automate the translation of the messages in another syntax. It is concluded that this meta-model approach contributes to the management of semantic heterogeneity.

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.

Object-oriented Information System in the HELIOS Medical Software Engineering Environment.

This paper presents the architecture of the Information System of HELIOS, a medical Software Engineering Environment. It is an object oriented framework for the development of medical applications which puts particular emphasis on tools and techniques favouring reuse of previous work and enhancing collaboration between developers.