Search

This paper describes a methodology for increasing the scope and precision of diagnostic Knowledge Based (KB) Systems. It has been stated that medical KB systems are either highly specialised, lack accuracy or are just too simple. To resolve this problem of scope we propose the use of a phased approach to diagnosis. The first phase being the querying of a symptoms ontology, to direct diagnostic systems to the most appropriate domain or class reference given input symptoms. Additional symptoms can then be targeted, extracted and analysed with a domain specific set of KB systems. This process allows us to forecast key symptoms, patient characteristics and increase the value of available data in decision making. In addition this approach could allow a system to dynamically correct an inappropriate domain decision. Such an approach also has the potential to be used to build a bridge between existing specialised medical KB systems.

Computer-Assisted Orthopaedic Surgery (CAOS) has made much progress over the last 10 years. Navigation systems have been recognized as important tools that help surgeons, and various such systems have been developed. A disadvantage of these systems is that they use non-standard formalisms and techniques. As a result, there are no standard concepts for implant and tool management or data formats to store information for use in 3D planning and navigation. We addressed these limitations and developed a practical and generic solution that offers benefits for surgeons, implant manufacturers, and CAS application developers. We developed a virtual implant database containing geometrical as well as calibration information for orthopedic implants and instruments, with a focus on trauma. This database has been successfully tested for various applications in the client/server mode. The implant information is not static, however, because manufacturers periodically revise their implants, resulting in the deletion of some implants and the introduction of new ones. Tracking these continuous changes and keeping CAS systems up to date is a tedious task if done manually. This leads to additional costs for system development, and some errors are inevitably generated due to the huge amount of information that has to be processed. To ease management with respect to implant life cycle, we developed a tool to assist end-users (surgeons, hospitals, CAS system providers, and implant manufacturers) in managing their implants. Our system can be used for pre-operative planning and intra-operative navigation, and also for any surgical simulation involving orthopedic implants. Currently, this tool allows addition of new implants, modification of existing ones, deletion of obsolete implants, export of a given implant, and also creation of backups. Our implant management system has been successfully tested in the laboratory with very promising results. It makes it possible to fill the current gap that exists between the CAS system and implant manufacturers, hospitals, and surgeons.

We propose to enhance a schema integration process with a validation phase employing logic-based data models. In our methodology, we validate the source schemas against the data model; the inter-schema mappings are validated against the semantics of the data model and the syntax of the correspondence language. In this paper, we focus on how to employ a reasoning engine to validate spatio-temporal schemas and describe where the reasoning engine is plugged into our integration methodology. The validation phase distinguishes our integration methodology from other approaches. We shift the emphasis on automation from the a priori discovery to the a posteriori checking of the inter-schema mappings. By doing so, we take advantage of the expressive power of the common data model in the source schema description and inter-schema mapping definition.

Are database concepts and techniques suitable for ontology design and management? The question has been on the floor for some time already. It gets a new emphasis today, thanks to the focus on ontologies and ontology services due to the spread of web services as a new paradigm for information management. This paper analyzes some of the arguments that are relevant to the debate, in particular the question whether conceptual data models would adequately support the design and use of ontologies. It concludes suggesting a hybrid approach, combining databases and logic-based services.

While the real world is supposedly unique, the perception we have of it is extremely personal. For instance, a traffic manager is likely to consider roads as segments linking different points in space, while a road maintenance service is likely to be interested in the status and nature of the road pavement. Perception is also time varying, as the same person looks differently at the world at different instants. In order to reconcile diverging requirements from users sharing the same database, research in databases has always looked for ways to support multiple representations of the same data.

One of the requirements which is poorly supported by spatial data models is a consistent management of different representations of the same spatial phenomena from different viewpoints or at different resolutions. This need is well known by users and designers. Modelling of applications, where users share the same database for different contexts and cartographic applications are examples of environments where such a need arises. This paper proposes a conceptual data model providing full support for multiple representations of the same real world data. The model addresses two complementary aspects: the integrated approach, that leads to the definition of customised database items, and the inter-relationship approach, where the representations are linked through inter-representation links. Both approaches use the stamping technique to differentiate among multiple representations of a given phenomenon and to access a particular representation. Finally, we focus on consequences of multiple coexisting representations on data manipulation. This proposal has been tested and validated with users, and implemented as a front-end to existing DBMS1.

Cartography is one of the major application areas using geographical databases. Whether it is for the business of producing paper maps for sale, or whether it is for displaying maps on a screen to visualize the result of a query, we need computer systems that know how to represent the same geographical area at different scales. The concept of multiscale database has become popular in the GIS domain as a way to enforce consistency between representations and reduce the global update load. Scaling, however, is just one of the facets that may lead to keeping several representations for the same real-world object. Viewpoint and classification are two major abstracttractions in the design process that also generate multiple representations. This paper investigates the generic issues and solutions to achieve flexible support of multiple representation in a GIS database.

Later on, Plus tard

International audience; The objective of this paper is to define an ontology language to support multiple representations of ontologies. In our research, we focus on the logic-based ontology languages. As a matter of fact, we will consider only languages that are based on description logics (DLs). At first, we propose a sub-language of DL as an ontology language. Furthermore we achieve multiple representations of ontological concepts by extending such sub-language through the use of stamping mechanism proposed in the context of multiple representation of spatial databases. The proposed language should offer a modest solution to the problem of multirepresentation ontologies.

Nowadays, Computer Assisted Orthopedic planning and navigation systems have been recognized as an important tool that helps surgeons. Various systems have been developed so far, but most of them use non-standard formalisms and techniques. As a result there are no standard concepts for implant and tool management or data formats to store information for use in 3D planning and navigation systems. We addressed these limitations and developed a practical and generic solution which brings benefits for surgeons, implant manufacturers and CAS application developers. We developed a virtual implant database containing geometrical as well as calibration information for orthopedic implants and instruments with a focus on Trauma. This database has been successfully tested with various applications in client/server mode. Nevertheless, the implant information is not static because periodically manufacturers revise implants, resulting in the removal of some implants and addition of new ones. To ease the implant management in respect to implant life cycle, we developed an implant management tool which helps end-users to manage their implants. Currently, this tool allows the addition of new implants, modification of existing ones, deletion of obsolete implants, export of a given implant and also creation of backups. Our implant management system has been successfully tested in the laboratory and gave very promising results. It makes it possible to fill the current existing gap between CAS system, implant manufacturers, hospitals and surgeons.

Analysis of trajectory data is the key to a growing number of applications aiming at global understanding and management of complex phenomena that involve moving objects (e.g. worldwide courier distribution, city traffic management, bird migration monitoring). Current DBMS support for such data is limited to the ability to store and query raw movement (i.e. the spatio-temporal position of an object). This paper explores how conceptual modeling could provide applications with direct support of trajectories (i.e. movement data that is structured into countable semantic units) as a first class concept. A specific concern is to allow enriching trajectories with semantic annotations allowing users to attach semantic data to specific parts of the trajectory. Building on a preliminary requirement analysis and an application example, the paper proposes two modeling approaches, one based on a design pattern, the other based on dedicated data types, and illustrates their differences in terms of implementation in an extended-relational context.