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Frederick University, Cyprus

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4 Papers

A Non-linear Finite Element Model for Assessment of Lumbar Spinal Injury Due to Dynamic Loading

Topics: Simulation; Structural Bioinformatics; Model Design and Evaluation

Authors: Alexander Tsouknidas ¹ , Savvas Savvakis ² , Nikolaos Tsirelis ² , Antonios Lontos ³ and Nikolaos Michailidis ⁴

Affiliations: ¹ Fredereick University and Aristoteles University of Thessaloniki, Cyprus , ² BETA CAE Systems S.A, Greece , ³ Fredereick University, Cyprus , ⁴ Aristoteles University of Thessaloniki, Greece

Digital Object Identifier: 10.5220/0004236902920295

Proceedings of BIOINFORMATICS 2013/BIOSTEC, ISBN: 978-989-8565-35-8

Quick Abstract

In this paper a highly detailed model of an adult lumbar spine (L1-L5) was recreated based on Computed Tomography. Next to the viscoelastic deformation of the intervertebral discs, cortical and cancellous bone anisotropy was considered, while seven types of ligaments were simulated either by solid or cable elements. The dynamic behaviour of the spine segment was assessed through stress-strain curves, provoking a non-linear response of all implicated tissues’ material properties. The model was subjected to dynamic loading to determine abnormalities in the anatomy’s stress equilibrium that could provoke gait disturbances. Results indicated the introduced methodology as an effective alternative to in vitro investigations, capable of providing valuable insight on critical movements and loads of potential patients, as the model can be employed to optimize therapeutic training or threshold kinematics of any given lumbar spine pathology.

Related Ontology Subjects/Areas/Topics (11)

Agents	Enterprise Information Systems	Operational Research
Artificial Intelligence	Information Systems Analysis and Specification	Simulation
Bioinformatics	Methodologies and Technologies	Structural Bioinformatics
Biomedical Engineering	Model Design and Evaluation

Directional Variation of Trabecular Bone in the Femoral Head, a μ-CT based Approach

Topics: Structural Bioinformatics; Image Analysis; Structural Variations

Authors: Varitis Emmanouil ¹ , Sagris Dimitrios ² , David Constantine ² and Lontos Antonios ³

Affiliations: ¹ Aristoteles University of Thessaloniki, Greece , ² Technological Education Institute of Serres, Greece , ³ Frederick University, Cyprus

Digital Object Identifier: 10.5220/0004327702370241

Proceedings of BIOINFORMATICS 2013/BIOSTEC, ISBN: 978-989-8565-35-8

Quick Abstract

The structural characteristics of bone are described by features of high complexity, defining the directional anisotropy of its mechanical properties. This phenomenon originates in the orientation of collagen fibers and osteons within the cortical tissue and the trabecular morphology of cancellous bone. the purpose of this study was the examination of the geometrical anisotropy of cancellous bone in the femoral head. 28 femoral heads, harvested during hip replacement of 17 women and 11 men, were studied in total. Cylindrical specimens of 11mm in diameter were extracted perpendicular to the fovea capitis femoris and subjected to micro Computed Tomography (μ-CT). a 11mm sphere was isolated from all samples and the cross-sectional area of the sphere was studied for 8 predefined regions, corresponding to planes perpendicular to principal loading directions of the hip joint. Significant topographical variations of trabecular bone structure in different subchondral regions were determined. in the superior region, the trabecular bone strength was the highest, while the inferior region exhibited the lowest bone strength and medial and lateral regions had intermittent magnitudes. No significant difference in anisotropy was found between male and female samples, although the absolute values were greater in males. The obtained results cohere with recent literature data of osteopenetration experiments in these directions.

Related Ontology Subjects/Areas/Topics (5)

Bioinformatics		Image Analysis		Structural Variations
Biomedical Engineering		Structural Bioinformatics

DUAL-ENERGY X-RAY ABSORPTIOMETRY AS AN INDICATOR FOR FRAGILITY FRACTURE RISKS OF THE FEMORAL NECK

Topics: Simulation; Model Design and Evaluation

Authors: Alexander Tsouknidas ¹ , Nikolaos Michailidis ¹ , Kleovoulos Anagnostidis ¹ and Antonios Lontos ²

Affiliations: ¹ Aristoteles University of Thessaloniki, Greece , ² Frederick University, Cyprus

Digital Object Identifier: 10.5220/0003770000960101

Proceedings of BIOINFORMATICS 2012/BIOSTEC, ISBN: 978-989-8425-90-4

Quick Abstract

Osteoporosis is a clinically silent bone pathology usually manifesting in the form of fragility bone fractures. Due to the high morbidity of the disease, the association of noninvasive imaging techniques to the implicated risk factors, could serve as a valuable indicator for surgeons. In the present investigations, the evaluation of 30 patients femurs' bone mineral density was performed in vivo by Dual-energy X-ray absorptiometry (DXA), while the strength characteristics of the examined specimens were determined ex-vivo using uniaxial compression experiments. The obtained stress strain curves, reflect the mechanical properties of the femur while facilitating their correlation to the obtained DXA measurements. FEM simulations revealed critical stress values within the femoral neck, indicating which DXA values represent abnormal high fragility fracture risks and thus should be considered for surgical intervention.

Related Ontology Subjects/Areas/Topics (10)

Agents	Enterprise Information Systems	Model Design and Evaluation
Artificial Intelligence	Information Systems Analysis and Specification	Operational Research
Bioinformatics	Methodologies and Technologies	Simulation
Biomedical Engineering

TOWARDS USER-CENTRIC SOCIAL NETWORKS

Topics: Context-Awareness; Mobile Social Network Interaction; Mobile Social Network Interaction; Social Network Awareness; Mobile Media Sharing Systems

Authors: Panayiotis Andreou ¹ , Panagiotis Germanakos ² , Andreas Konstantinidis ³ , Dimosthenis Georgiadis ⁴ , Marios Belk ¹ and George Samaras ¹

Affiliations: ¹ University of Cyprus, Cyprus , ² Institute of Informatics and Telematics - CNR, Italy , ³ Frederick University, Cyprus , ⁴ University of Nicosia, Cyprus

Digital Object Identifier: 10.5220/0003932007950798

Proceedings of WEBIST 2012, ISBN: 978-989-8565-08-2

Quick Abstract

Social network portals, such as Facebook and Twitter, often discover and deliver relevant social data to a user’s query, considering only system-oriented conflicting objectives (e.g., time, energy, recall) and frequently ignoring the satisfaction of the individual “needs” of the query user w.r.t. its perceptual preference characteristics (e.g., data comprehensibility, working memory). In this paper, we introduce User-centric Social Network (USN), a novel framework that deals with the conflicting system-oriented objectives of the social network in the context of Multi-Objective Optimization and utilizes user-oriented objectives in the query dissemination/ acquisition process to facilitate decision making. We present the initial design of the USN framework and its major components. Our preliminary evaluation with real datasets shows that USN enhances the usability and satisfaction of the user while in parallel provides optimal system-choices for network performance.

Related Ontology Subjects/Areas/Topics (6)

Context-Awareness		Mobile Media Sharing Systems		Social Network Awareness
Mobile Information Systems		Mobile Social Network Interaction		Web Information Systems and Technologies

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