CoMed : Cooperation in Medicine

This paper presents the architecture of CoMed, a desktop conferencing application which allows interactive real-time cooperation among several medical experts. The proposed architecture offers short response time and reduced network load, while it is implemented using portable components. As a result, CoMed operates successfully in various operating systems and over heterogeneous networks. CoMed has been developed to support the cooperative delivery of medical care within the integrated regional health care telematics network, currently under development on the island of Crete. INTRODUCTION In recent years, the number and complexity of biological signals, which can be recorded and also presented in the form of reconstructed images, has increased substantially. This has given rise to the need for subspecialization, which in turn has resulted in an increased demand for consultation among different medical experts. Providing a shared workspace among medical experts at remote and distant locations is one of the main functions of the teleconsultation service [1]. This service requires the synchronous viewing and manipulation of the same set of radiological images and other patient data, as well as the real-time exchange of comments among all parties involved in the session. In this paper, we present the architecture of CoMed, a desktop conferencing application which allows interactive real-time cooperation among several medical experts. This application provides a shared workspace for the display, discussion and annotation of multiple radiological images which are multicasted to conference participants prior to the consultation session. An agent based architecture and techniques for cashing, data compression and screening of events allow its successful operation over heterogeneous, relatively slow networks. CoMed has been developed to support the cooperative delivery of medical care within the integrated regional health care telematics network, currently under development on the island of Crete [2]. DESIGN ISSUES AND SYSTEM CHARACTERISTICS Computer supported teleconferencing applications have been developed in the field of computer supported cooperative work and are currently providing more effective support for teleradiology services. Such applications provide a virtual common workspace in which many users can view and manipulate multimedia data and exchange comments during a computer supported conference. Critical to the creation of a virtual conferencing environment is the real time response of the application to the actions of remote participants. This can be achieved by a combination of high performance networks and reduced data transmissions during the conference. However, in order to meet the requirement for scaleable and readily expandable teleradiology services, the underlying applications can not always rely on the availability of a high performance networking infrastructure. Therefore, our focus is on developing mechanisms to reduce data transmission during the conference. CoMed is based on a distributed agent architecture that enhances the performance of the shared window environment, offering short response time and reducing the network load. Additionally, conference material is transmitted to each participant at the beginning of the conference by special pre-conference management mechanisms. The combination of data replication and a distributed agent architecture enables CoMed to make efficient use of the network resources during the conference, by transmitting only the events that are actually needed to maintain consistency among the various instances of the shared workspace. As a result, CoMed operates successfully in heterogeneous networks where lowbandwidth networks may be connected to high-speed networks, e.g. combinations of Ethernet, ISDN, FDDI, ATM, etc. Unlike other systems that require the group of participants to be known at the beginning of the conference, CoMed supports the addition of new members into the conference at any time. A global authentication service supports public and private (at various levels of privacy) teleconsultation sessions, while image data integrity is ensured by the use of standard digital signature technology. Such functional features address specific requirements of the medical domain, such as the sensitive, unpredictable and often urgent nature of medical consultations. In addition to mechanisms that are responsible for the management of the conference, CoMed addresses pre-conference and post-conference management issues. These include conference scheduling and data pre-fetching, maintaining conference proceedings and broadcasting final conclusions to participants and other authorized personnel after the end of the conference. ARCHITECTURE AND IMPLEMENTATION Groupware architectures range from centralized to fully replicated [3,4], but a hybrid solution often proves to be most efficient (considering user requirements, task complexity, distributed computing and integration issues, etc.) [5-7]. CoMed is based on a hybrid architecture, which is mainly distributed, but also incorporates a central module. The main body of the teleconsultation session is supported by distributed replicated applications, while the central module is only used to provide sophisticated management and authentication facilities. The basic architectural components are the conference management agent, the mediator, and the user application, as shown in Figure 1. Figure 1. System Architecture. 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