182 research outputs found
Wave propagation in human long bones of arbitrary cross-section
No full textThe dynamic behavior of a dry long bone considered as a piezoelectric cylinder of crystal class 6 with arbitrary cross-section is presented. For the solution of the wave propagation problem we follow the procedure proposed in a previous work (D.I, Fotiadis, G. Foutsitzi, C.V. Massalas, Wave propogation modeling in human long bones, Acta Mechanica 137 (1-2) (1999) 65-82). The boundary conditions on the inner and outer lateral surface of the cylinder, which is of irregular shape, are satisfied by using the Fourier expansion collocation method. The obtained dispersion relation is solved numerically and results are presented for various cross-sections and geometrical parameters of the system. (C) 2000 Elsevier Science Ltd. All rights reserved.International Journal of Engineering Scienc
Support of Future Disaster Response Using Generalized Access Networks (GANs)
No full textEfficient communication and coordination are major challenges experienced by the emergency services (firebrigade, police, ambulance) during the first response to a major incident. A major incident can happen anywhere and at any time, hence support for emergency communications services should be ubiquitous and independent of communication technologies and infrastructure used. We present a vision of how ambient intelligent environments may be used in the future to support the emergency services during first response to a major incident. Support includes enabling emergency communications and biomedical monitoring for front line personnel. In this paper we focus on the possibilities and challenges raised by using the GAN (Generalized Access Network) infrastructure to support ambient intelligent services and emergency services (fire-brigade, police, ambulance) for major incident management
eSEEd: emotional State Estimation based on Eye-tracking dataset
No full text<p>We present eSEEd- emotional State Estimation based on Eye-tracking database. Eye movements of 48 participants were recorded as they watched 10 emotion evoking videos each of them followed by a neutral video. Participants rated five emotions (tenderness, anger, disgust, sadness, neutral) on a scale from 0 to 10, later translated in terms of emotional arousal and valence levels. Furthermore, each participant filled 3 self-assessment questionnaires. An extensive analysis of the participants' answers to the questionnaires self-assessment scores as well as their ratings during the experiments is presented. Moreover, eye and gaze features were extracted from the low level eye recorded metrics and their correlations with the participants' ratings are investigated. Finally, analysis and results are presented for machine learning approaches, for the classification of various arousal and valence levels based solely on eye and gaze features. The dataset is made publicly available and we encourage other researchers to use it for testing new methods and analytic pipelines for the estimation of an individual's affective state.<br><br>TO USE THIS DATASET PLEASE CITE:<br>Skaramagkas, V.; Ktistakis, E.; Manousos, D.; Kazantzaki, E.; Tachos, N.S.; Tripoliti, E.; Fotiadis, D.I.; Tsiknakis, M. eSEE-d: Emotional State Estimation Based on Eye-Tracking Dataset. <em>Brain Sci.</em> 2023, <em>13</em>, 589. https://doi.org/10.3390/brainsci13040589</p><p>This project has received funding from the European Union's Horizon 2020 research and innovation program under grant agreement No 826429 (Project: SeeFar). This paper reflects only the author's view and the Commission is not responsible for any use that may be made of the information it contains. Please cite: Skaramagkas, V.; Ktistakis, E.; Manousos, D.; Kazantzaki, E.; Tachos, N.S.; Tripoliti, E.; Fotiadis, D.I.; Tsiknakis, M. eSEE-d: Emotional State Estimation Based on Eye-Tracking Dataset. <em>Brain Sci.</em> <strong>2023</strong>, <em>13</em>, 589. https://doi.org/10.3390/brainsci13040589</p>
Multivariate prediction of subcutaneous glucose concentration in type 1 diabetes patients based on support vector regression.
No full textAbstract
Data-driven techniques have recently drawn significant interest in the predictive modeling of subcutaneous (s.c.) glucose concentration in type 1 diabetes. In this study, the s.c. glucose prediction is treated as a multivariate regression problem, which is addressed using support vector regression (SVR). The proposed method is based on variables concerning: (i) the s.c. glucose profile, (ii) the plasma insulin concentration, (iii) the appearance of meal-derived glucose in the systemic circulation, and (iv) the energy expenditure during physical activities. Six cases corresponding to different combinations of the aforementioned variables are used to investigate the influence of the input on the daily glucose prediction. The proposed method is evaluated using a dataset of 27 patients in free-living conditions. 10-fold cross validation is applied to each dataset individually to both optimize and test the SVR model. In the case where all the input variables are considered, the average prediction errors are 5.21, 6.03, 7.14 and 7.62 mg/dl for 15, 30, 60 and 120 min prediction horizons, respectively. The results clearly indicate that the availability of multivariable data and their effective combination can significantly increase the accuracy of both short-term and long-term predictions
Derivation of Mindlin’s first and second strain gradient elastic theory via simple lattice and continuum models
No full textAbstractMindlin, in his celebrated papers of Arch. Rat. Mech. Anal. 16, 51–78, 1964 and Int. J. Solids Struct. 1, 417–438, 1965, proposed two enhanced strain gradient elastic theories to describe linear elastic behavior of isotropic materials with micro-structural effects. Since then, many works dealing with strain gradient elastic theories, derived either from lattice models or homogenization approaches, have appeared in the literature. Although elegant, none of them reproduces entirely the equation of motion as well as the classical and non-classical boundary conditions appearing in Mindlin theory, in terms of the considered lattice or continuum unit cell. Furthermore, no lattice or continuum models that confirm the second gradient elastic theory of Mindlin have been reported in the literature. The present work demonstrates two simple one dimensional models that conclude to first and second strain gradient elastic theories being identical to the corresponding ones proposed by Mindlin. The first is based on the standard continualization of the equation of motion taken for a sequence of mass-spring lattices, while the second one exploits average processes valid in continuum mechanics. Furthermore, Mindlin developed his theory by adding new terms in the expressions of potential and kinetic energy and introducing intrinsic micro-structural parameter without however providing explicit expressions that correlate micro-structure with macro-structure. This is accomplished in the present work where in both models the derived internal length scale parameters are correlated to the size of the considered unit cell
Guest Editorial: Introduction to the Special Section on Biomedical Informatics
No full textTHIS Special Issue is based on selected papers presented at the International Special Topic Conference on Infor- mation Technology in Biomedicine, held in October 2006, in Ioannina, Epirus, Greece. The event was technically cospon- soredbytheIEEEEngineeringinMedicineandBiologySociety and sponsored by the University of Ioannina, Greece, the Na- tional Technical University of Athens, Greece, the University of Cyprus, Cyprus, and SPIRIT, Greece. It marked the con- tinuation of the previous five successful conferences held in Prague in 1997, in Washington, DC, in 1998, in Amsterdam in 1999, in Virginia in 2000, and in Birmingham in 2003, whereas two more successful conferences were held after Ioannina, in Tokyo in 2007, and in Shenzhen in 2008. The International Conference on Information Technology and Applications in Biomedicine (ITAB) 2009 will be held in Cyprus, November 2009 (see http://www.cs.ucy.ac.cy/itab2009/).
The works of the ITAB 2006 Conference were dedicated to the memory of two pioneers of information technology in biomedicine, namely, Prof. Swamy Laxminarayan, Idaho State University, USA, and Prof. Stelios Orphanoudakis, University of Crete, Greece. It is very difficult to describe their contribu- tions in the field, but, simply, to say a few words, they have both played a catalytical role in both research and applications in biomedical information technology. Moreover, it should be mentionedthatitwastheideaofProf.Laxminarayantoorganize the first ITAB conference in Prague, together with the late Prof. Ian Krekule of the Academy of Sciences of the Czech Repub- lic. Also, Prof. Laxminrayan was the Founding Editor of this journal.
The overall objective of ITAB 2006 was to cover the state of the art of information technology applications in biomedicine. A total of 138 papers were presented, with 48 on eHealth, 36 on biosignal analysis, and 24 on medical imaging. These papers originated from 27 different countries. Also, 38 papers were presented by students and a student paper competition took place. The first prize was awarded to Anna Karahaliou from the University of Patras, Greece (see paper [1]), the second prize to Ver ́ onica Garc ́ ıa-P ́ erez from the University de Valladolid, Spain (see paper [2]), and the third prize to Vaclav Gerla from the Czech Technical University in Prague, Czech Republic (see paper [3]).
The aim of this Special Issue is to provide a snapshot of emerging technologies in biomedical informatics, based on a selected number of papers and the finalists of the student’s paper competition presented at ITAB 2006. A total of ten papers were accepted organized under the topics Computational Biol- ogy,BiosignalAnalysis,MedicalImaging,andVirtualandAug- mented Reality and Visualization, and with two, three, four, and one papers, respectively. Some of these papers have been pub- lished in previous issues of IEEE Transactions on Information Technology in Biomedicine. These papers are briefly presented in the following section
An efficient system for the detection of arrhythmic segments in ECG recordings based on non-linear features of the RR interval signal
No full textXMedIA communication system: an XML driven medical image processing and archiving environment
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