HealthGrid 2007 (http://geneva2007.healthgrid.org) is the fifth edition of this open forum for the integration of grid technologies and their applications in the biomedical, medical, and biological domains to pave the path towards an international research area in the HealthGrid field. The main objective of the HealthGrid conference and of the HealthGrid Association is the exchange and discussion of ideas, technologies, solutions and requirements that interest the grid and the life-science communities to foster the integration of grids into health. Participation is encouraged for grid middleware and grid application developers, biomedical and health informatics users, and security and policy makers to participate in a set of multidisciplinary sessions with a common focus on the application in the health domain.

HealthGrid conferences have been organized on an annual basis. The first conference, held in 2003 in Lyon (http://lyon2003.healthgrid.org), reflected the need to involve all actors – physicians, scientists and technologists – who might play a role in the application of grid technology to health, whether healthcare or bio-medical research. The second conference, held in Clermont-Ferrand in January 2004 (http://clermont2004. healthgrid.org) reported research and work in progress from a large number of projects. The third conference in Oxford (http://oxford2005.healthgrid.org) had a major focus on the results and deployment strategies in healthcare. The fourth conference in Valencia (http://valencia2006.healthgrid.org) aimed at consolidating the collaboration among biologists, healthcare professionals and grid technology experts. This fifth conference will focus on the five domains defined by the European Commission as application areas for grids in the biomedical field: molecules, cells, organs, individuals, and populations. For each of these five domains, an invited speaker will give a state of the art address followed by concrete projects. The conference venue in a hospital setting should also help to locate healthgrid research where it undoubtedly belongs, in the biomedical field. Potential users need to be shown that grids have now gone beyond hype and can show concrete applications that demonstrate the success of the technology.

The conference includes a number of high-profile keynote presentations complemented by a set of high quality peer reviewed papers. The number of contributions to this conference has increased from previous occasions, reaching the number of 55 submissions of papers, demonstrations and posters from principal authors coming from 21 countries (ordered by the number of contributions: Italy, Switzerland, United Kingdom, Germany, USA, France, Spain, Poland, Russia, Taiwan, Australia, Belgium, Brazil, Cuba, Cyprus, Czech Republic, Greece, Hungary, Portugal, Romania, and Ukraine). Considering the affiliations of all the authors of the papers, the number of contributing countries is extended to 22 countries with Venezuela. These proceedings have been organized in eight chapters. Five chapters focus on state of the art of the grid research and use at molecule, cell, organ, individual and population levels. Two chapters present security and imaging papers. The last chapter includes the best poster contributions.

From among the themes of the conference, it may be thought that molecules present the most amenable target for a healthgrid approach. Although this may be true, it is far from obvious. Even in applications such as BLAST which treat symbolic ‘words’ in a molecular alphabet, there are a great many problems to be addressed, both when searching for large query strings and in seeking to maintain an appropriate ‘rollback’ distributed database, as Trombetti et al. show. Two papers, by Andreas Quandt et al. and by Zosso et al., apply grids in ‘tandem mass spectrometry’ a highly demanding application for protein identification. It is equally good to see applications to screening in Malaria (Jean Salzemann et al.) and early detection of Alzheimer's (Nabil Abdennadher et al.), while the application to sleep disorders in their full breadth (Sebastian Canisius et al.) demonstrates the considerable breadth of application that is possible on a grid platform. Hernandez et al. provide an overview of the substantial progress that has been made in the field in the wake of large platform projects.

By contrast, applications in the cellular and organ domains appear to present as much difficulty in conceiving possible projects as in devising grid deployment schemes. Sinnott et al. identify and are in part motivated by the intrinsic value of microarray data as a major issue, while Roberta Alfieri et al. consider a mathematical model of the cell cycle – two extremes in the exploration of cell issues. Marienne Hibbert et al. describe a molecular medicine model and Emerson and Rossi discuss a simulation of the human immune system. Among organs, Andrés Gómez et al. demonstrate a radiotherapy tool and Blanquer Espert et al. explore the management of DICOM objects on a grid.

The domain of the individual is highly attractive, since it provides an entry point to the whole HealthGrid project and the possible grid health record. Two papers by the SHARE collaboration provide outline ‘road maps’ for the creation of viable healthgrids. Jenny Ure et al. took schizophrenia as a case study for a series of workshops to understand what it might take to create appropriate ontologies for data integration. Michal Kosiedowski et al. discuss a grid-based Electronic Medical Library and Shu-Hui Hung et al. consider the merits of the treatment of asthma in a grid system. Stefan Rüping et al. seek to extend workflow management for knowledge discovery from combined clinical and genomic data towards a fuller electronic health record. Giovanni Aloisio et al. treat the paradigm of Service-Oriented Architecture in bioinformatics.

Thus we arrive at the population domain, where Fabricio Silva et al. report on a grid-based epidemic surveillance system in Brazil for essentially slow evolving diseases. Tiberiu Stef-Praun et al. present the Swift system of workflow description and execution.

Apart from these five domains, two topical areas are considered in depth: security and imaging. In security, in two separate papers Jean Herveg and Luigi Lo Iacono explore familiar questions of data protection and of pseudonymization respectively, providing a theoretical perspective against which some practical proposals by Petr Holub et al. on the Access Grid model and Harald Gjermundrød et al. on the EGEE model can be compared. In imaging, we have papers on Globus MEDICUS (Stephan G. Erberich et al.) which federates DICOM devices through a grid architecture and KnowARC (Henning Müller et al.) on facilitating grid networks for the biomedical research community. Finally, Adina Riposan et al. report on the successful use of multimodal workflows in diabetic retinopathy research.

ACKNOWLEDGEMENTS

The editors express their gratitude to the program committee and the reviewers; each paper was read by at least two reviewers, including the editors. The editors want to thank for the remarkable work that the staff of the HealthGrid association has invested in these conference proceedings and on the organisation of the conference, particularly Yannick Legré.

Opinions expressed in these proceedings are those of individual authors and editors, and not necessarily those of their institutions.