Professor J. Van Campenhout heads the ELIS Department, which hosts ten different research groups, among which is MEDISIP, Medical Image and Signal Processing. This team has 20 researchers, featuring Dr. Rik Van de Walle, Dr. Ignace Lemahieu and MoS. Boris Rogge, who are the authors of a paper on the generic software framework for XML- and Web-based remote multimedia data access. ELIS-student Koen Dreelinck has performed a great deal of the work for the generic software project. The aim of the department is pure development though, and involves neither selling nor any commercial purposes.
Radiology departments in hospitals work with hundreds of patients and tens of radiologists, leading to a very large number of multimedia medical data of images, audio and text. This has to be stored in state-of-the-art databases with a uniform XML-based description to synchronise the streaming data, as Dr. Van de Walle explained. For the synchronous rendering and processing of different medical data, medical staff likes to use a standard Web browser. The basic layer of such a system is the database, which can be relational or object-oriented. In the latter case, the objects themselves are stored in the database.
In order to build a user-friendly database, different aspects have to be taken into account. The researcher has to design specific application programming interfaces (APIs). The database management system (DBMS) should integrate scaleability and portability and have a great ease of use and legacy data. The solution consists in trying to hide the characteristics of the DBMS and make abstraction of it. There are different types of databases, including types with open DB connectivity (ODBC) and object linking and embedding (OLE) types. ODBC constitutes an old application within Universal Data Access, using a standard API and supporting consumers, drivers and servers. The OLE DBs in turn are strongly object-oriented and extensible. They support both data and service providers, according to Dr. Van de Walle.
The markup languages currently in use are "HTML", which is a description language for presenting and rendering information, and XML, which is rather a standard than a language. Dr. Van de Walle offered a quick overview of the different XML-foundations. The Document Type Definitions (DTDs) are not obligatory but they describe grammar. The XML schema as a language grammar is the successor of DTD. XSL forms a style-description language, still under development, whereas XSLT transforms one description into another one. These transformations are necessary since each user has his own way of describing objects.
XML can mean a big help when it comes to synchronising multimedia data in radiology departments. Huge amounts of data have to be post-processed, so you will have to need a system which is fast and easy to use and has been implemented by using open standards. The suitable characteristics of the Internet do not suffice for real synchronisation. The Quality of Service (QoS) heavily relies on the server. To meet these requirements, the ELIS research team has built an XML-driven demonstrator for radiological images, administrative patient data, and radiologist's comments. The database describes the links between the data.
Dr. Van de Walle stressed the importance of a few issues, such as security to guarantee the patient's privacy. There is also an urgent need for encryption in the system, as well as authorisation and authentication facilities. Quality of Service is of crucial meaning with regard to the network characteristics in order to obtain a framework for meta-data driven data intelligent processing. Future work will consist in a content-driven delivery of multimedia streams which involves efficient compression of the data. The ELIS research team will also optimise the system's interactivity. More information on the activities of the MEDISIP group are available on the home page of the ELIS Department at the University of Ghent.