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Vassilis G. Koutkias

Lab of Medical Informatics, Aristotle University of Thessaloniki, Greece
bikout@med.auth.gr

Journal articles

2009
Malousi, Chouvarda, Koutkias, Kouidou, Maglaveras (2009)  SpliceIT: A hybrid method for splice signal identification based on probabilistic and biological inference.   J Biomed Inform Sep  
Abstract: Splice sites define the boundaries of exonic regions and dictate protein synthesis and function. The splicing mechanism involves complex interactions among positional and compositional features of different lengths. Computational modeling of the underlying constructive information is especially challenging, in order to decipher splicing-inducing elements and alternative splicing factors. SpliceIT (Splice Identification Technique) introduces a hybrid method for splice site prediction that couples probabilistic modeling with discriminative computational or experimental features inferred from published studies in two subsequent classification steps. The first step is undertaken by a Gaussian support vector machine (SVM) trained on the probabilistic profile that is extracted using two alternative position-dependent feature selection methods. In the second step, the extracted predictions are combined with known species-specific regulatory elements, in order to induce a tree-based modeling. The performance evaluation on human and Arabidopsis thaliana splice site datasets shows that SpliceIT is highly accurate compared to current state-of-the-art predictors in terms of the maximum sensitivity, specificity tradeoff without compromising space complexity and in a time-effective way. The source code and supplementary material are available at: http://www.med.auth.gr/research/spliceit/.
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Régis Beuscart, Peter McNair, Stéfan J Darmoni, Vassilis Koutkias, Nicos Maglaveras, Marie-Catherine Beuscart-Zephir, Christian Nohr (2009)  Patient safety: detection and prevention of adverse drug events.   Stud Health Technol Inform 150: 968-971  
Abstract: Adverse Drug Events (ADE) represent a key problem in Public Health. The detection and prevention of ADE is a real challenge for hospitals and healthcare professionals. Healthcare Information and Communication Technologies can contribute to reduce the incidence of preventable ADE. During this workshop, we will discuss the various aspects of detection of ADE through methods like data and semantic mining in medical databases; the possibility of preventing ADE by using clinical decision support systems; the importance of Human Factors Engineering and the contextualization of knowledge. Examples and demonstrations will come from the European Project PSIP, devoted to the detection and prevention of ADE in Hospitals.
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Theodoros Agorastos, Vassilis Koutkias, Manolis Falelakis, Irini Lekka, Themistoklis Mikos, Anastasios Delopoulos, Pericles A Mitkas, Antonios Tantsis, Steven Weyers, Pascal Coorevits, Andreas M Kaufmann, Roberto Kurzeja, Nicos Maglaveras (2009)  Semantic Integration of Cervical Cancer Data Repositories to Facilitate Multicenter Association Studies: The ASSIST Approach.   Cancer Inform 8: 31-44 02  
Abstract: The current work addresses the unification of Electronic Health Records related to cervical cancer into a single medical knowledge source, in the context of the EU-funded ASSIST research project. The project aims to facilitate the research for cervical precancer and cancer through a system that virtually unifies multiple patient record repositories, physically located in different medical centers/hospitals, thus, increasing flexibility by allowing the formation of study groups "on demand" and by recycling patient records in new studies. To this end, ASSIST uses semantic technologies to translate all medical entities (such as patient examination results, history, habits, genetic profile) and represent them in a common form, encoded in the ASSIST Cervical Cancer Ontology. The current paper presents the knowledge elicitation approach followed, towards the definition and representation of the disease's medical concepts and rules that constitute the basis for the ASSIST Cervical Cancer Ontology. The proposed approach constitutes a paradigm for semantic integration of heterogeneous clinical data that may be applicable to other biomedical application domains.
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Vassilis Koutkias, George Stalidis, Ioanna Chouvarda, Katerina Lazou, Vassilis Kilintzis, Nicos Maglaveras (2009)  A Knowledge Engineering Framework towards Clinical Support for Adverse Drug Event Prevention: The PSIP Approach.   Stud Health Technol Inform 148: 131-141  
Abstract: Adverse Drug Events (ADEs) are currently considered as a major public health issue, endangering patients' safety and causing significant healthcare costs. Several research efforts are currently concentrating on the reduction of preventable ADEs by employing Information Technology (IT) solutions, which aim to provide healthcare professionals and patients with relevant knowledge and decision support tools. In this context, we present a knowledge engineering approach towards the construction of a Knowledge-based System (KBS) regarded as the core part of a CDSS (Clinical Decision Support System) for ADE prevention, all developed in the context of the EU-funded research project PSIP (Patient Safety through Intelligent Procedures in Medication). In the current paper, we present the knowledge sources considered in PSIP and the implications they pose to knowledge engineering, the methodological approach followed, as well as the components defining the knowledge engineering framework based on relevant state-of-the-art technologies and representation formalisms.
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2008
Pericles Mitkas, Vassilis Koutkias, Andreas Symeonidis, Manolis Falelakis, Christos Diou, Irini Lekka, Anastasios Delopoulos, Theodoros Agorastos, Nicos Maglaveras (2008)  Association studies on cervical cancer facilitated by inference and semantic technologies: the assist approach.   Stud Health Technol Inform 136: 241-246  
Abstract: Cervical cancer (CxCa) is currently the second leading cause of cancer-related deaths, for women between 20 and 39 years old. As infection by the human papillomavirus (HPV) is considered as the central risk factor for CxCa, current research focuses on the role of specific genetic and environmental factors in determining HPV persistence and subsequent progression of the disease. ASSIST is an EU-funded research project that aims to facilitate the design and execution of genetic association studies on CxCa in a systematic way by adopting inference and semantic technologies. Toward this goal, ASSIST provides the means for seamless integration and virtual unification of distributed and heterogeneous CxCa data repositories, and the underlying mechanisms to undertake the entire process of expressing and statistically evaluating medical hypotheses based on the collected data in order to generate medically important associations. The ultimate goal for ASSIST is to foster the biomedical research community by providing an open, integrated and collaborative framework to facilitate genetic association studies.
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A Triantafyllidis, V Koutkias, I Chouvarda, N Maglaveras (2008)  An open and reconfigurable wireless sensor network for pervasive health monitoring.   Methods Inf Med 47: 3. 229-234  
Abstract: OBJECTIVES: Sensor networks constitute the backbone for the construction of personalized monitoring systems. Up to now, several sensor networks have been proposed for diverse pervasive healthcare applications, which are however characterized by a significant lack of open architectures, resulting in closed, non-interoperable and difficult to extend solutions. In this context, we propose an open and reconfigurable wireless sensor network (WSN) for pervasive health monitoring, with particular emphasis in its easy extension with additional sensors and functionality by incorporating embedded intelligence mechanisms. METHODS: We consider a generic WSN architecture comprised of diverse sensor nodes (with communication and processing capabilities) and a mobile base unit (MBU) operating as the gateway between the sensors and the medical personnel, formulating this way a body area network (BAN). The primary focus of this work is on the intra-BAN data communication issues, adopting SensorML as the data representation mean, including the encoding of the monitoring patterns and the functionality of the sensor network. RESULTS: In our prototype implementation two sensor nodes are emulated; one for heart rate monitoring and the other for blood glucose observations, while the MBU corresponds to a personal digital assistant (PDA) device. Java 2 Micro Edition (J2ME) is used to implement both the sensor nodes and the MBU components. Intra-BAN wireless communication relies on the Blue-tooth protocol. Via an adaptive user interface in the MBU, health professionals may specify the monitoring parameters of the WSN and define the monitoring patterns of interest in terms of rules. CONCLUSIONS: This work constitutes an essential step towards the construction of open, extensible, inter-operable and intelligent WSNs for pervasive health monitoring.
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Andigoni Malousi, Ioanna Chouvarda, Vassilis Koutkias, Sofia Kouidou, Nicos Maglaveras (2008)  Variable-length Positional Modeling for Biological Sequence Classification.   AMIA Annu Symp Proc 91-95 11  
Abstract: Selecting the most informative features in supervised biological classification problems is a decisive pre-processing step for two main reasons: (1) to deal with the dimensionality reduction problem, and (2) to ascribe biological meaning to the underlying feature interactions. This paper presents a filter-based feature selection method that is suitable for positional modeling of biological sequences. The basic motivation is the problem of using a positional model of fixed length that sub-optimally describes biological sequences in a specific classification problem. The core filtering criterion is the F-score and the source features are the positional probabilities describing variable-length interactions among residues. The proposed method was evaluated on human splice sites classification using a linear SVM classifier. The method yields to superior classification accuracy compared to the individual positional models, while it maintains the space complexity of the individual models, in a time-efficient way and independently of the classifier.
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2007
George D Giannoglou, Yiannis S Chatzizisis, Vassilis Koutkias, Ioannis Kompatsiaris, Maria Papadogiorgaki, Vasileios Mezaris, Eirini Parissi, Panagiotis Diamantopoulos, Michael G Strintzis, Nicos Maglaveras, George E Parcharidis, George E Louridas (2007)  A novel active contour model for fully automated segmentation of intravascular ultrasound images: in vivo validation in human coronary arteries.   Comput Biol Med 37: 9. 1292-1302 Sep  
Abstract: The detection of lumen and media-adventitia borders in intravascular ultrasound (IVUS) images constitutes a necessary step for the quantitative assessment of atherosclerotic lesions. To date, most of the segmentation methods reported are either manual, or semi-automated, requiring user interaction at some extent, which increases the analysis time and detection errors. In this work, a fully automated approach for lumen and media-adventitia border detection is presented based on an active contour model, the initialization of which is performed via an analysis mechanism that takes advantage of the inherent morphologic characteristics of IVUS images. The in vivo validation of the proposed model in human coronary arteries revealed that it is a feasible approach, enabling accurate and rapid segmentation of multiple IVUS images.
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Charalampos Bratsas, Vassilis Koutkias, Evangelos Kaimakamis, Panagiotis Bamidis, Nicos Maglaveras (2007)  Ontology-based vector space model and fuzzy query expansion to retrieve knowledge on medical computational problem solutions.   Conf Proc IEEE Eng Med Biol Soc 2007: 3794-3797  
Abstract: Medical Computational Problem (MCP) solving is related to medical problems and their computerized algorithmic solutions. In this paper, an extension of an ontology-based model to fuzzy logic is presented, as a means to enhance the information retrieval (IR) procedure in semantic management of MCPs. We present herein the methodology followed for the fuzzy expansion of the ontology model, the fuzzy query expansion procedure, as well as an appropriate ontology-based Vector Space Model (VSM) that was constructed for efficient mapping of user-defined MCP search criteria and MCP acquired knowledge. The relevant fuzzy thesaurus is constructed by calculating the simultaneous occurrences of terms and the term-to-term similarities derived from the ontology that utilizes UMLS (Unified Medical Language System) concepts by using Concept Unique Identifiers (CUI), synonyms, semantic types, and broader-narrower relationships for fuzzy query expansion. The current approach constitutes a sophisticated advance for effective, semantics-based MCP-related IR.
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Charalampos Bratsas, Vassilis Koutkias, Evangelos Kaimakamis, Panagiotis D Bamidis, George I Pangalos, Nicos Maglaveras (2007)  KnowBaSICS-M: an ontology-based system for semantic management of medical problems and computerised algorithmic solutions.   Comput Methods Programs Biomed 88: 1. 39-51 Oct  
Abstract: In this paper, an ontology-based system (KnowBaSICS-M) is presented for the semantic management of Medical Computational Problems (MCPs), i.e., medical problems and computerised algorithmic solutions. The system provides an open environment, which: (1) allows clinicians and researchers to retrieve potential algorithmic solutions pertinent to a medical problem and (2) enables incorporation of new MCPs into its underlying Knowledge Base (KB). KnowBaSICS-M is a modular system for MCP acquisition and discovery that relies on an innovative ontology-based model incorporating concepts from the Unified Medical Language System (UMLS). Information retrieval (IR) is based on an ontology-based Vector Space Model (VSM) that estimates the similarity among user-defined MCP search criteria and registered MCP solutions in the KB. The results of a preliminary evaluation and specific examples of use are presented to illustrate the benefits of the system. KnowBaSICS-M constitutes an approach towards the construction of an integrated and manageable MCP repository for the biomedical research community.
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2006
George D Giannoglou, Yiannis S Chatzizisis, George Sianos, Dimitrios Tsikaderis, Antonis Matakos, Vassilios Koutkias, Panagiotis Diamantopoulos, Nicos Maglaveras, George E Parcharidis, George E Louridas (2006)  In-vivo validation of spatially correct three-dimensional reconstruction of human coronary arteries by integrating intravascular ultrasound and biplane angiography.   Coron Artery Dis 17: 6. 533-543 Sep  
Abstract: OBJECTIVES: The in-vivo validation of geometrically correct three-dimensional reconstruction of human coronary arteries by integrating intravascular ultrasound and biplane coronary angiography has not been adequately investigated. The purpose of this study was to describe the reconstruction method and investigate its in-vivo feasibility and accuracy. METHODS: In 17 coronary arteries (mean length, 85.7+/-17.1 mm) from nine patients, an intravascular ultrasound procedure along with a biplane coronary angiography was performed. From each angiographic projection, a single end-diastolic frame was selected in order to reconstruct the intravascular ultrasound catheter trajectory in space. In each end-diastolic intravascular ultrasound image, the lumen and media-adventitia contours were detected semi-automatically by an active contour algorithm. Each pair of contours was located on the catheter trajectory appropriately and interpolated with the adjacent pairs creating a three-dimensional volume of the arterial lumen and wall. The reconstructed lumen was back-projected onto both angiographic planes and the agreement between the back-projected and the angiographic luminal outlines was calculated. RESULTS: The angiogram-derived catheter length showed very high correlation (y=0.97 x + 1.8, P<0.001) and agreement with the corresponding pullback-derived values. Accordingly, the semi-automated segmentation of intravascular ultrasound images was also in significant correlation (r> or =0.96, P<0.001) and agreement with the reference manual tracing. The back-projected luminal borders showed good overall association with the corresponding angiographic ones (r=0.78, P<0.001) as well as remarkable agreement. CONCLUSIONS: Spatially correct three-dimensional reconstruction of human coronary arteries constitutes an imaging method with considerably high in-vivo feasibility and accuracy.
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Vassilis Koutkias, Andigoni Malousi, Ioanna Chouvarda, Nicos Maglaveras (2006)  Constructing a semantically enriched biomedical service space: a paradigm with bioinformatics resources.   Stud Health Technol Inform 120: 236-246  
Abstract: Biomedical applications are becoming increasingly reliant on resource integration and information exchange within global solution frameworks that offer seamless connectivity and data sharing in distributed environments. Resource autonomy and data heterogeneity are the most important impediments towards this potential. Aiming to overcome these limitations, we propose an implementation of the service-oriented model towards the construction of an open, semantically enriched biomedical service space that enables advanced service registration, selection and access capabilities, as well as service interoperability. The proposed system is realised by defining service annotation ontologies and applying software agent technology as the means for service registration, matchmaking and interfacing in a Grid environment. The applicability of the envisioned biomedical service space is illustrated on a set of bioinformatics resources, addressing computational identification of protein-coding genes.
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2005
Vassilis G Koutkias, Ioanna Chouvarda, Nicos Maglaveras (2005)  A multiagent system enhancing home-care health services for chronic disease management.   IEEE Trans Inf Technol Biomed 9: 4. 528-537 Dec  
Abstract: In this paper, a multiagent system (MAS) is presented, aiming to enhance monitoring, surveillance, and educational services of a generic medical contact center (MCC) for chronic disease management. In such a home-care scenario, a persistent need arises for efficiently monitoring the patient contacts and the MCC's functionality, in order to effectively manage and interpret the large volume of medical data collected during the patient sessions with the system, and to assess the use of MCC resources. Software agents were adopted to provide the means to accomplish such real-time information-processing tasks, due to their autonomous, reactive and/or proactive nature, and their effectiveness in dynamic environments by incorporating coordination strategies. Specifically, the objective of the MAS is to monitor the MCC environment, detect important cases, and inform the healthcare and administrative personnel via alert messages, notifications, recommendations, and reports, prompting them for actions. The main aim of this paper is to present the overall design and implementation of a proposed MAS, emphasizing its functional model and architecture, as well as on the agent interactions and the knowledge-sharing mechanism incorporated, in the context of a generic MCC.
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Nicos Maglaveras, Ioanna Chouvarda, Vassilis G Koutkias, George Gogou, Irini Lekka, Dimitrios Goulis, Avram Avramidis, Charalambos Karvounis, George Louridas, E Andrew Balas (2005)  The Citizen Health System (CHS): a modular medical contact center providing quality telemedicine services.   IEEE Trans Inf Technol Biomed 9: 3. 353-362 Sep  
Abstract: In the context of the Citizen Health System (CHS) project, a modular Medical Contact Center (MCC) was developed, which can be used in the monitoring, treatment, and management of chronically ill patients at home, such as diabetic or congestive heart failure patients. The virtue of the CHS contact center is that, using any type of communication and telematics technology, it is able to provide timely and preventive prompting to the patients, thus, achieving better disease management. In this paper, we present the structure of the CHS system, describing the modules that enable its flexible and extensible architecture. It is shown, through specific examples, how quality of healthcare delivery can be increased by using such a system.
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Vincent Breton, Kevin Dean, Tony Solomonides, I Blanquer, V Hernandez, E Medico, N Maglaveras, S Benkner, G Lonsdale, S Lloyd, K Hassan, R McClatchey, S Miguet, J Montagnat, X Pennec, W De Neve, C De Wagter, G Heeren, L Maigne, K Nozaki, M Taillet, H Bilofsky, R Ziegler, M Hoffman, C Jones, M Cannataro, P Veltri, G Aloisio, S Fiore, M Mirto, I Chouvarda, V Koutkias, A Malousi, V Lopez, I Oliveira, J P Sanchez, F Martin-Sanchez, G De Moor, B Claerhout, J A M Herveg (2005)  The Healthgrid White Paper.   Stud Health Technol Inform 112: 249-321  
Abstract: Over the last four years, a community of researchers working on Grid and High Performance Computing technologies started discussing the barriers and opportunities that grid technologies must face and exploit for the development of health-related applications. This interest lead to the first Healthgrid conference, held in Lyon, France, on January 16th-17th, 2003, with the focus of creating increased awareness about the possibilities and advantages linked to the deployment of grid technologies in health, ultimately targeting the creation of a European/international grid infrastructure for health. The topics of this conference converged with the position of the eHealth division of the European Commission, whose mandate from the Lisbon Meeting was "To develop an intelligent environment that enables ubiquitous management of citizens' health status, and to assist health professionals in coping with some major challenges, risk management and the integration into clinical practice of advances in health knowledge." In this context "Health" involves not only clinical procedures but covers the whole range of information from molecular level (genetic and proteomic information) over cells and tissues, to the individual and finally the population level (social healthcare). Grid technology offers the opportunity to create a common working backbone for all different members of this large "health family" and will hopefully lead to an increased awareness and interoperability among disciplines. The first HealthGrid conference led to the creation of the Healthgrid association, a non-profit research association legally incorporated in France but formed from the broad community of European researchers and institutions sharing expertise in health grids. After the second Healthgrid conference, held in Clermont-Ferrand on January 29th-30th, 2004, the need for a "white paper" on the current status and prospective of health grids was raised. Over fifty experts from different areas of grid technologies, eHealth applications and the medical world were invited to contribute to the preparation of this document.
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I Chouvarda, V Koutkias, A Malousi, N Maglaveras (2005)  Grid-enabled biosensor networks for pervasive healthcare.   Stud Health Technol Inform 112: 90-99  
Abstract: Current advances in biosensor technology allow multiple miniaturized or textile sensors to record continuously biosignals, such as blood pressure or heart rate, and transmit the information of interest to clinical sites. New applications are emerging, based on such systems, towards pervasive healthcare. This paper describes an architecture enabling biosensors, forming a Body Area Network (BAN), to be integrated in a Grid infrastructure. The Grid services proposed, such as access to recorded data, are offered via the BAN console, an enhanced wearable computer, where the recordings of multiple biosensors are integrated. Medical Grid-enabled Nodes can have access to biosensor measurements upon demand, or can agree to get notifications and alerts. Thus, in such a distributed environment, data and computational resources are independent, yet cooperating unobtrusively, contributing to the notion of pervasive healthcare.
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2003
N Maglaveras, I Chouvarda, V Koutkias, I Lekka, M Tsakali, S Tsetoglou, S Maglavera, L Leondaridis, B Zeevi, V Danelli, T Kotis, G De Moore, E A Balas (2003)  Citizen centered health and lifestyle management via interactive TV: The PANACEIA-ITV health system.   AMIA Annu Symp Proc 415-419  
Abstract: In the context of an IST European project with acronym PANACEIA-ITV, a home care service provisioning system is described, based on interactive TV technology. The purpose of PANACEIA-ITV is to facilitate essential lifestyle changes and to promote compliance with scientifically sound self-care recommendations, through the application of interactive digital television for family health maintenance. The means to achieve these goals are based on technological, health services and business models. PANACEIA-ITV is looking for communication of monitoring micro-devices with I-TV set-top-boxes using infrared technology, and embodiment of analogous H/W and S/W in the I-TV set-top-boxes. Intelligent agents are used to regulate data flow, user queries as well as service provisions from and to the household through the satellite digital platform, the portal and the back-end decision support mechanisms, using predominantly the Active Service Provision (ASP) model. Moreover, interactive digital TV services are developed for the delivery of health care in the home care environment.
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2002
N Maglaveras, V Koutkias, I Chouvarda, D G Goulis, A Avramides, D Adamidis, G Louridas, E A Balas (2002)  Home care delivery through the mobile telecommunications platform: the Citizen Health System (CHS) perspective.   Int J Med Inform 68: 1-3. 99-111 Dec  
Abstract: Health delivery practices are shifting towards home care. The reasons are the better possibilities for managing chronic care, controlling health delivery costs, increasing quality of life and quality of health services and the distinct possibility of predicting and thus avoiding serious complications. For the above goals to become routine, new telemedicine and information technology (IT) solutions need to be implemented and integrated in the health delivery scene, and these solutions need to be assessed through evidence-based medicine in order to provide solid proof for their usefulness. Thus, the concept of contact or call centers has emerged as a new and viable reality in the field of IT for health and telemedicine. In this paper we describe a generic contact center that was designed in the context of an EU funded IST for health project with acronym Citizen Health System (CHS). Since the generic contact center is composed by a number of modules, we shall concentrate in the modules dealing with the communication between the patient and the contact center using mobile telecommunications solutions, which can act as link between the internet and the classical computer telephony communication means. We further elaborate on the development tools of such solutions, the interface problems we face, and on the means to convey information from and to the patient in an efficient and medically acceptable way. This application proves the usefulness of wireless technology in providing health care services all around the clock and everywhere the citizen is located, it proves the necessity for restructuring the medical knowledge for education delivery to the patient, and it shows the virtue of interactivity by means of using the limited, yet useful browsing capabilities of the wireless application protocol (WAP) technology.
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N Maglaveras, I Chouvarda, V Koutkias, S Meletiadis, K Haris, E A Balas (2002)  Information technology can enhance quality in regional health delivery.   Methods Inf Med 41: 5. 393-400  
Abstract: OBJECTIVES: a) The use of information technology (IT) based solutions for quality health delivery in regional health information networks and the study of the enabling factors for their use in a regional health care network from key classes of users such as the medical personnel and the citizens. b) Identification of potential technologies for usage from all citizens and health providers in a regional environment, in all aspects of everyday life. c) Presentation of a generic user model for reference when developing and assessing IT based health delivery solutions. METHODS: After defining the major questions to be addressed, an overview of tele-health and tele-medicine technologies and solutions currently available shall be presented. Further, a generic user model applied to the use of IT based regional health delivery solutions both for the daily life and home care, and for research and clinical routine purposes are presented. Enabling technologies for integration of different IT modules, medical data processing and management procedures and the wireless application protocol (WAP) technology is discussed. RESULTS: Different levels of user applications are presented such as mobile telephony driven health information monitoring and systems integrating electronic health care records with multimedia medical information management and processing modules. CONCLUSIONS: Although IT solutions are advanced and continue to evolve, still the user acceptance and user friendliness issues are unresolved. Mobile telecommunication solutions however may hold the key for wide scale implementation of IT solutions in regional health information networks and increased quality of health services.
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N Maglaveras, G Gogou, I Chouvarda, V Koutkias, I Lekka, G Giaglis, D Adamidis, C Karvounis, G Louridas, D Goulis, A Avramidis, E A Balas (2002)  Communication infrastructure in a contact center for home care monitoring of chronic disease patients.   Proc AMIA Symp 479-483  
Abstract: The Citizen Health System (CHS) is a European Commission (EC) funded project in the field of IST for Health. Its main goal is to develop a generic contact center which in its pilot stage can be used in the monitoring, treatment and management of chronically ill patients at home in Greece, Spain and Germany. Such contact centers, which can use any type of communication technology, and can provide timely and preventive prompting to the patients are envisaged in the future to evolve into well-being contact centers providing services to all citizens. In this paper, we present the structure of such a generic contact center and in particular the telecommunication infrastructure, the communication protocols and procedures, and finally the educational modules that are integrated into this contact center. We discuss the procedures followed for two target groups of patients where two randomized control clinical trials are under way, namely diabetic patients with obesity problems, and congestive heart failure patients. We present examples of the communication means between the contact center medical personnel and these patients, and elaborate on the educational issues involved.
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Vassilios G Koutkias, Ioanna Chouvarda, Nicos Maglaveras (2002)  Agent-based monitoring and alert generation for a home care telemedicine system.   Proc AMIA Symp 395-399  
Abstract: In the present paper, a multi-agent system is proposed, which can be integrated in the home care telemedicine system that was developed in the context of the Citizen Health System (CHS) European project, functioning as a contact center for diabetic and congestive heart failure patients. The objective of the multi-agent system is to provide a set of alert/notification mechanisms for the clinicians, helping them to classify the clinical condition of each patient. Therefore, despite the huge amount of data managed by the system, due to the daily use of the contact center's services, these alert mechanisms provide the clinician with an overview of the cases that need further examination and save him/her time from the trivial cases. The multi-agent system consists of different types of agents, each one assigned with specific tasks, which communicate with each other, in order to share knowledge.
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2001
N Maglaveras, V Koutkias, S Meletiadis, I Chouvarda, E A Balas (2001)  The role of wireless technology in home care delivery.   Stud Health Technol Inform 84: Pt 1. 835-839  
Abstract: Health care delivery is changing drastically. In its current state it tends to use the home care model in order to increase quality of life, to rationalize costs and to achieve wellness. Pivotal to these purposes are contact centers, which act as mediators between the medical staff and the citizens seeking advice and/or therapy. Main platforms used for the development of such applications are the INTERNET and PCs, and the telecommunication networks, including mobile solutions. In this paper, a generic contact center model shall be presented, which is under development in the context of an IST European project in health telematics entitled â Distance Information Technologies for Home care. The Citizen Health System (CHS)'. After the description of this generic contact center, an application for health care delivery to diabetic patients shall be described. In this application we shall see the possible use of the Wireless Application Protocol (WAP) scheme. This application proves the usefulness of wireless technology in providing health care services all around the clock and everywhere the citizen is located, it shows the necessity for restructuring the medical knowledge for education delivery to the patient, and it shows the virtue of interactivity by means of using the limited, yet useful browsing capabilities of the WAP technology.
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2000
I Kompatsiaris, D Tzovaras, V Koutkias, M G Strintzis (2000)  Deformable boundary detection of stents in angiographic images.   IEEE Trans Med Imaging 19: 6. 652-662 Jun  
Abstract: In this paper, a procedure is described for deformable boundary detection of medical tools, called stents, in angiographic images. A stent is a surgical stainless steel coil that is placed in the artery in order to improve blood circulation in regions where a stenosis has appeared. Assuming initially a set of three-dimensional (3-D) models of stents and using perspective projection of various deformations of the 3-D model of the stent, a large set of synthetic two-dimensional (2-D) images of stents is constructed. These synthetic images are then used as a training set for deriving a multivariate Gaussian density estimate based on eigenspace decomposition and formulating a maximum-likelihood estimation framework in order to reach an initial rough estimate for automatic object recognition. The silhouette of the detected stent is then refined by using a 2-D active contour (snake) algorithm integrated with a novel iterative initialization technique, which takes into consideration the geometry of the stent. The algorithm is experimentally evaluated using real angiographic images containing stents.
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I Kompatsiaris, D Tzovaras, V Koutkias, P Dafas, M G Strintzis (2000)  Deformable boundary detection of stents in angiographic images.   Stud Health Technol Inform 77: 1235-1239  
Abstract: In this paper a procedure is described for deformable boundary detection of medical tools, called stents, in angiographic images. A stent is a surgical stainless steel coil which is placed in the artery in order to improve blood circulation, in regions where a stenosis has appeared. Assuming initially a set of 3-D models of stents and using perspective projection of various deformations of the 3-D model of the stent, a large set of synthetic 2D images of stents is constructed. These synthetic images are then used as a training set for deriving a multivariate Gaussian density estimate based on eigenspace decomposition and formulating a Maximum-Likelihood estimation framework in order to reach an initial rough estimate for automatic object recognition. The silhouette of the detected stent is then refined by using a 2D active contour (snake) algorithm integrated with a novel iterative initialization technique which takes into consideration the geometry of the stent. The algorithm is experimentally evaluated using real angiographic images containing stents.
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Book chapters

2009
K I Vegoudakis, V Koutkias, A Malousi, I Chouvarda, Nicos Maglaveras (2009)  Towards User-friendly Interfacing of Biomedical Applications with the Grid : A Paradigm with SVM Optimization for Gene Prediction    
Abstract: Grid computing is currently considered as the key technology towards realization of the e-Science vision, aiming to enable high throughput research. Among several application domains, Grid computing is envisioned to have a strong impact in biomedical research, which is typically characterized by computationally intensive and complex applications. However, although there are significant advances in the construction and availability of the underlying Grid infrastructure worldwide, there is still lack of user-friendly means to either access the Grid or enable the execution of existing biomedical software into Grid infrastructures. In this paper, we present our effort towards the construction of a generic and user-friendly mechanism for accessing and executing applications on the Grid, which requires minor technical knowledge from the end-users and may be used as a paradigm for diverse biomedical applications. The applicability of the proposed UI mechanism is illustrated through a parameter optimization problem of legacy SVMs applied for gene prediction, requiring complex computations and a large amount of training data.
Notes: 10.1007/978-3-540-89208-3_339
2006
Andigoni Malousi, Vassilis Koutkias, Sofia Kouidou, Nicos Maglaveras (2006)  Intrinsic Splicing Profile of Human Genes Undergoing Simple Cassette Exon Events    
Abstract: Alternative pre-mRNA splicing presides over protein diversity and organism complexity. Alternative splicing isoforms in human have been associated with specific developmental stages, tissue-specific expressions and disease-causing factors. In this study, we identified and analysed intrinsic features that discriminate non-conserved human genes that undergo a single internal cassette exon event from constitutively spliced exons. Context-based analysis revealed a guanine-rich track at the donor of the cassetteâÂÂs upstream intronic region that is absent in the constitutive dataset, as well as significant differences in the distribution of CpG and A3/G3 sequences between the alternative and the constitutive intronic regions. Interestingly, introns flanking cassette exons are larger than the constitutive ones, while exon lengths do not vary significantly. Splice sites flanking cassette exons are less identifiable, while splice sites at the outer ends are âÂÂstrongerâ than constitutive introns. The results indicate that specific intrinsic features are linked with the inclusion/excision of internal exons which are indicative of the underlying selection rules. Keywords: Alternative splicing, cassette exons, splice sites, intrinsic features.
Notes: 10.1007/11946465_6
Eirini Parissi, Yiannis Kompatsiaris, Yiannis Chatzizisis, Vassilis Koutkias, Nicos Maglaveras, M Strintzis, George Giannoglou (2006)  An Automated Model for Rapid and Reliable Segmentation of Intravascular Ultrasound Images    
Abstract: The detection of lumen and media-adventitia borders in intravascular ultrasound (IVUS) images constitutes a necessary step for accurate morphometric analyses of coronary plaques and accordingly assessment of the atherosclerotic lesion length. Aiming to tackle this issue, an automated model for lumen and media-adventitia border detection is presented, which is based on active contour models. The proposed approach enables extraction of the corresponding boundaries in sequential IVUS frames by applying an iterative procedure, in which initialization of the two contours in each frame is performed automatically, based on the segmentation of its previous frame. The above procedure is implemented through a user-friendly interface, permitting the interaction of the user when needed. The in vivo application and evaluation of our model in sequential IVUS images indicated that the proposed approach is capable of accurately and rapidly segmenting hundreds of IVUS images. Keywords: image segmentation, intravascular ultrasound (IVUS), snakes, active contours.
Notes: 10.1007/11946465_33
2005
Andigoni Malousi, Vassilis Koutkias, Ioanna Chouvarda, Nicos Maglaveras (2005)  Vertical Integration of Bioinformatics Tools and Information Processing on Analysis Outcome    
Abstract: Biological sources integration has been addressed in several frameworks, considering both information sources incompatibilities and data representation heterogeneities. Most of these frameworks are mainly focused on coping with interoperability constraints among distributed databases that contain diverse types of biological data. In this paper, we propose an XML-based architecture that extends integration efforts from the distributed data sources domain to heterogeneous Bioinformatics tools of similar functionalities (âÂÂvertical integrationâÂÂ). The proposed architecture is based on the mediator/wrapper integration paradigm and a set of prescribed definitions that associates the capabilities and functional constraints of each analysis tool. The resulting XML-formatted information is further exploited by a visualization module that generates comparative views of the analysis outcome and a query mechanism that handles multiple information sources. The applicability of the proposed integration architecture and the information handling mechanisms was tested and substantiated on widely-known ab-initio gene finders that are publicly accessible through Web interfaces.
Notes: 10.1007/11573067_10
2004
Vassilis Koutkias, Andigoni Malousi, Nicos Maglaveras (2004)  Performing Ontology-Driven Gene Prediction Queries in a Multi-agent Environment    
Abstract: Gene prediction is one of the most challenging problems in Computational Biology. Motivated by the strengths and limitations of the currently available Web-based gene predictors, a Knowledge Base was constructed that conceptualizes the functionalities and requirements of each tool, following an ontology-based approach. According to this classification, a Multi-Agent System was developed that exploits the potential of the underlying semantic representation, in order to provide transparent and efficient query services based on user-implied criteria. Given a query, a broker agent searches for matches in the Knowledge Base, and coordinates correspondingly the submission/retrieval tasks via a set of wrapper agents. This approach is intended to enable efficient query processing in a resource-sharing environment by embodying a meta-search mechanism that maps queries to the appropriate gene prediction tools and obtains the overall prediction outcome.
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Conference papers

2008
Alexander Astaras, Marina Arvanitidou, Ioanna Chouvarda, Vassilis Kilintzis, Vassilis Koutkias, Eduardo Monton Sanchez, George Stalidis, Andreas Triantafyllidis, Nicos Maglaveras (2008)  An integrated biomedical telemetry system for sleep monitoring employing a portable body area network of sensors (SENSATION).   In: Conf Proc IEEE Eng Med Biol Soc 5254-5257  
Abstract: A flexible, scaleable and cost-effective medical telemetry system is described for monitoring sleep-related disorders in the home environment. The system was designed and built for real-time data acquisition and processing, allowing for additional use in intensive care unit scenarios where rapid medical response is required in case of emergency. It comprises a wearable body area network of Zigbee-compatible wireless sensors worn by the subject, a central database repository residing in the medical centre and thin client workstations located at the subject's home and in the clinician's office. The system supports heterogeneous setup configurations, involving a variety of data acquisition sensors to suit several medical applications. All telemetry data is securely transferred and stored in the central database under the clinicians' ownership and control.
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