Дисертації з теми "Tissu conjonctif – Modèles mathématiques"
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Chassonnery, Pauline. "Modélisation mathématique en 3D de l'émergence de l'architecture des tissus conjonctifs." Electronic Thesis or Diss., Toulouse 3, 2023. http://www.theses.fr/2023TOU30354.
In this thesis, we investigate whether simple local mechanical interactions between a reduced set of components could govern the emergence of the 3D architecture of biological tissues. To explore this hypothesis, we develop two mathematical models. The first one, ECMmorpho-3D, aims at reproducing a non-specialised connective tissue and is reduced to the Extra-Cellular Matrix (ECM) component, that is a 3D dynamically connected fibre network. The second, ATmorpho-3D, is built by adding to this network spherical cells which spontaneously appear and grow in order to mimic the morphogenesis of Adipose Tissue (AT), a specialised connective tissue with major biomedical importance. We then construct a unified analysis framework to visualise, segment and quantitatively characterise the fibrous and cellular structures produced by our two models. It constitutes a generic tool for the 3D visualisation of systems composed of a mixture of spherical (cells) and rod-like (fibres) elements and for the automatic detection of in such systems of clusters of spherical objects separated by rod-like elements. This tool is also applicable to biological 3D microscopy images, enabling a comparison between in vivo and in silico structures. We study the structures produced by the model ECMmorpho-3D by performing numerical simula- tions. We show that this model is able to spontaneously generate different types of architectures, which we identify and characterise using our analysis framework. An in-depth parametric analysis lead us to identify an intermediate emerging variable, the number of crosslinks per fibre, which explains and partly predicts the fate of the modelled system. A temporal analysis reveals that the characteristic time-scale of the organisation process is a function of the network remodelling speed, and that all systems follow the same, unique evolutionary pathway. Finally, we use the model ATmorpho-3D to explore the influence of round cells over the organisation of a fibre network, taking as reference the model ECMmorpho-3D. We show that the number of cells can influence the local alignment of the fibres but not the global organisation of the network. On the other hand, the cells inside the network spontaneously organise into clusters with realistic morphological features very close to those of in vivo structures, surrounded by sheet-like fibre bundles. Moreover, the distribution of the different morphological types of clusters is similar in in silico and in vivo systems, suggesting that the model is able to produce realistic morphologies not only on the scale of one cluster but also on the scale of the whole system, reproducing the structural variability observed in biological samples. A parametric analysis reveals that the proportion in which each morphology is present in an in silico system is governed mainly by the remodelling characteristic of the fibres, pointing to the essential role of the ECM properties in AT architecture and function (in agreement with several biological results and previous 2D findings). The fact that these very simple mathematical models can produce realistic structures supports our hypothesis that biological tissues architecture could emerge spontaneously from local mechanical inter- actions between the tissue components, independently of the complex biological phenomena taking place around them. This opens many perspectives regarding our understanding of the fundamental principles governing how biological tissue architecture emerges during organogenesis, is maintained throughout life and can be affected by various pathological conditions. Potential applications range from tissue engineering to therapeutic treatment inducing regeneration in adult mammals
Taibi, El Hassane. "Caractérisation, modélisation et simulation du comportement d'un tissu textile." Bordeaux 1, 2001. http://www.theses.fr/2001BOR12441.
Ni, Annaidh Aisling. "Mécanique du coup de couteau : étude numérique et expérimentale de l'attaque à l'arme blanche." Paris 6, 2012. http://www.theses.fr/2012PA066261.
Brasnu, Emmanuelle. "Mise au point de modèles cellulaires pour l'étude des effets toxicologiques infracliniques de thérapeutiques utilisées en ophtalmologie." Paris 5, 2011. http://www.theses.fr/2011PA05P615.
During the past ten years, several toxicological studies on ocular surface focused on the effects of ophthalmologic medications that contain preservatives, particularly benzalkonium chloride. Although, the REACH program, with the limitation of the use of laboratory animals, supports the replacement of classic toxicological tools, i. E. The Draize test, and the development of new strategies. In addition, the widely used Wong-Kilbourne derivative of Chang conjunctiva-derived cell line has been criticized owing to a possible contamination with HeLa tumoral cells. In the present work, we validated the new IOBA-NHC cell line for toxicological studies, showing similar toxicological profiles of BAC on both cell lines. To illustrate our findings, we further studied the effects of the preservative-free formulation of tafluprost, a new prostaglandin analog, on IOBA-NHC cells. However, these monolayer cell models do not take into account the structural properties of cornea in vivo. In addition, unlike on any epithelial cell model, other cell types like goblet and inflammatory cells that interact with epithelial cells play also a major role in the ocular surface protection in vivo. Thus, we hereby reported a new application of a 3D-reconstituted corneal epithelial model, i. E. The analysis of BAC-preserved and unpreserved antiallergic eye drops on this model, and the development of a coculture model between epithelial cells and lymphocytes. Indeed, these new approaches seem to be extremely relevant for the understanding of ocular surface physiopathology, particularly in relation with preservative toxicity
Gaudreault, Mathieu. "Modèles d’identification de tissu basés sur des images acquises avec un tomodensitomètre à double énergie pour des photons à faible énergie en curiethérapie." Master's thesis, Université Laval, 2014. http://hdl.handle.net/20.500.11794/25366.
Clinical Dual-Energy Computed Tomography (DECT) images provide the determination of the effective atomic number and the electronic density. The purpose of this study is to develop a new assessment model of tissues, named the reduced three elements tissue model, for dose calculations from DECT images in brachytherapy and compare it to a known identification method, assignment through the Mahalanobis distance. Both models are applied to DECT scans of the Gammex RMI 467 phantom and for a subset of 10 human tissues. Dose distributions are calculated from Monte Carlo simulations with a point source having the energy spectrum of 125I. The reduced three elements tissue model provides dose equivalence to reference tissues and is equivalent to the calculation of the Mahalanobis distance. The model constructed can be used as a scheme to assess tissues from DECT images for dose calculation.
Seigneuric, Renaud. "Étude d'hétérogénéités simulées et in vitro du tissu cardiaque et de leurs rôles dans les tachycardies ventriculaires par réentrée." Grenoble 1, 2000. http://www.theses.fr/2000GRE19003.
Adam, Sylvie. "La trame urbaine : Hexagone et analyse théorique des semis urbains." Rouen, 1992. http://www.theses.fr/1992ROUEL153.
The main aim of this research is to look into the heuristic value of the regular hexagonal patterns as these appear in central place theories. The link between regular hexagonal patterns, principles of organization, and concepts of central place theories is first examined. Particular attention is given to the theory of centrality and other works by Walter Christaller, and to the theory of economic regions proposed by August Losch. An overview of more recent theories of central places and applications of hexagonal patterns on urban webs in regional settings is provided. The regular hexagonal pattern can be conceived either as a mesh (only nodes and edges are significant), or as a grid which actually contains people and functions. The second part deals with the regular hexagonal tesselation. Using the example of France, the regular geometric pattern is shown not to fit the structure and organization of the urban web. The third part, based upon Georges Nicolas research on Western Switzerland, confirms the same lack of fit for the regular hexagonal grid. For this reason, an adaptable polygonal grid is proposed as a substitute for the traditional and regular hexagonal tesselations. (abstract by Peter R. Gould and Sylvie Adam)
Oudry, Jennifer. "L' élasticité: nouveau biomarqueur du foie : analyse biomécanique et validation par élastographie impulsionnelle." Université Louis Pasteur (Strasbourg) (1971-2008), 2008. http://www.theses.fr/2008STR13236.
Elastography is to quantitatively measure the elasticity of tissue to replace the tactile control often exercised by physicians. This tactile control known as palpation, aims at qualitatively estimate the elasticity of tissues. Elastography is motivated by the large difference of elasticity observed between normal tissues and tumors in which elasticity can be up to 30 times greater. Elasticity becomes an important parameter in the characterization of soft tissues. In soft tissues, elasticity is driven by the shear elasticity, which is involved in the propagation of shear waves. Their study can thus help quantify the tactile information. We propose to develop computational tools for the theoretical study of shear wave propagation in elastic medium. An evolution of the transient elastography technique, based on the use of a new type of ultrasonic transducer combined with an ultrasonic multichannel acquisition system, is also proposed. The validation of this system and corresponding algorithms are then performed on phantoms. We develop a new kind of material models, a mixture of copolymer-in-oil, mimicking the mechanical and acoustic properties of soft tissues for elastography. Finally, we conduct a comparison of the measurement of elasticity obtained by transient elastography with that obtained by magnetic resonance elastography to study possible differences between these techniques increasingly used for the diagnosis of liver fibrosis
Dichamp, Jules. "De l'imagerie tissu entier à la modélisation in silico du réseau vasculaire du tissu adipeux." Phd thesis, Toulouse, INPT, 2018. http://oatao.univ-toulouse.fr/23606/1/Dichamp.pdf.
Chan, Yone Claudia. "Modèle numérique de vieillissement de l'os trabéculaire considérant l'hyperminéralisation du tissu et le chargement mécanique." Thesis, Aix-Marseille, 2012. http://www.theses.fr/2012AIXM4731/document.
Osteoporosis is characterized by a low bone mass density but also an alteration of mechanical properties. The clinical diagnostic is made from the measure of the bone mineral density (BMD) but this examen seems insufficient to quantify bone resistance. In this work, a numerical model of cancellous bone degradation, aging and mechanical adaptation is proposed. Based on hypermineralization, this model simulates the cancellous bone remodeling process over many years. This model allows to predict the behavior of cancellous adaptation in a mechanical low loading case for instance. Results are similar to clinicial tendancy
Thurieau, Nicolas. "Sur la modélisation du tissu cardiaque comme un milieu à microdilatation : une investigation numérique." Thesis, Université de Lorraine, 2014. http://www.theses.fr/2014LORR0018/document.
Background: A soft biological tissue is subjected to numerous exchange phenomena and has an extremely complex structural organization. The knowledge of its mechanical behavior is required in many applications ranging from clinical diagnostic to tissue engineering. To achieve this goal, more or less satisfactory approaches are developed. They all seek to take into account in a more or less systematic manner the microstructure of the medium. Assuming that the biological tissue is a particular micromorphic medium (micropolar medium) leads to good results in the case bone tissue. It is therefore likely that the results of this kind will be obtained for other tissues. Our interest is on the heart tissue and the problem of ischemic heart attack. In this context, it seemed that the most appropriate behavior particularization is that of a microdilatation medium. Work done: The work presented in this thesis is essentially numerical. It aims to highlight the features of the response of microdilatation medium to an external mechanical load. This step is essential for the analysis of the experimental results to be conducted in the future. The work also aims to investigate the potentialities of the model with respect to the heart tissue regarding heart attack and the associated loss of the ability to eject sufficient blood volume. The numerical tools for the analysis of such media are in increasing development. We had to develop our own tool based on the LPI-BEM (Local Point Interpolation - Boundary Element Method). Because of the similarity of the associated field equations, the validity of the numerical strategy is assessed in the case of a piezoelectric material. This choice is not innocent because the piezoelectric medium with microdilatation will allow analyzing the case of an electrical solicitation of the tissue. The details of this original numerical approach are given in Chapter 2 of the thesis. Chapter 3 is devoted to the analysis of the robustness of the method and to the peculiarities of the response of a microdilatation medium. The fourth chapter is devoted to the application to the cardiac tissue. By limiting the study to the case of small strains, it is shown that the model is well suited to the representation of the behavior of cardiac tissue. Indeed, considering the left ventricle as a tubular structure, the left ventricle ejection fraction (clinical criterion of the heart failure) is greatly reduced in the presence of an infarcted area. The latter is modeled as a zone with diffuse boundary where the material points have lost their ability to "breath". These results are promising and encourage further investigations in this direction by taking into account the anisotropic nature of the tissue in a geometrically nonlinear context
Assar, Cuevas Rodrigo. "Modeling and simulation of hybrid systems and cell factory applications." Thesis, Bordeaux 1, 2011. http://www.theses.fr/2011BOR14335/document.
The main aim of this thesis is to develop an approach that allows us to describe biological systems with theoretical sustenance and good results in practice. Biological functions are the result of the interaction of many processes, that connect different hierarchy levels going from macroscopic to microscopic level. Each process works in different way, with its own goal, complexity and hierarchy level. In addition, it is common to observe that changes in the conditions, such as nutrients or environment, modify the behavior of the systems. So, to describe the behavior of a biological system over time, it is convenient to combine different types of models: continuous models for gradual changes, discrete models for instantaneous changes, deterministic models for completely predictable behaviors, and stochastic or non- deterministic models to describe behaviors with imprecise or incomplete information. In this thesis we use the theory of Composition and Hybrid Systems as basis, and the BioRica framework as tool to model biological systems and analyze their emergent properties in silico.With respect to Hybrid Systems, we considered continuous models given by sets of differential equations or more general dynamics. We used Stochastic Transition Systems to describe the dynamics of model changes, allowing cofficient switches that control the parameters of the continuous model, and strong switches that choose different models. Composition, reconciliation and reusing of models allow us to build complete and consistent descriptions of complex biological systems by combining them. Compositions of hybrid systems are hybrid systems, and the refinement of a model forming part of a composed system results in a refinement of the composed system. To implement our approach ideas we complemented the theory of our approach with the improving of the BioRica framework. We contributed to do that giving a BioRica specification of Hybrid Systems that assures integrity of models, allowing composition, reconciliation, and reuse of models with SBML specification.We applied our approach to describe two systems: wine fermentation kinetics, and cell fate decisions leading to bone and fat formation. In the case of wine fermentation, we reused known models that describe the responses of yeasts cells to different temperatures, quantities of resources and toxins, and we reconciled these models choosing the model with best adjustment to experimental data depending on the initial conditions and fermentation variable. The resulting model can be applied to avoid process problems as stuck and sluggish fermentations. With respect to cell fate decisions the idea is very ambitious. By using accurate models to predict the bone and fat formation in response to activation of pathways such as the Wnt pathway, and changes of conditions affecting these functions such as increments in Homocysteine, one can analyze the responses to treatments for osteoporosis and other bone mass disorders. We think that here we are giving a first step to obtain in silico evaluations of medical treatments before testing them in vitro or in vivo
Adam, Jérémy. "Développement, modélisation et caractérisation d'une maille innovante réalisée en fabrication additive pour les grands défauts osseux." Thesis, Paris, ENSAM, 2017. http://www.theses.fr/2017ENAM0068/document.
The work detailed in this thesis is about a titanium 3D printed mesh for large bone defects. Large bone defects are often due to surgical resections, performed after a cancer or an infection. When the defect reach a critical size, bone regeneration is impossible and it often leads to the loss of function. When it happened, the wound need to be cured using reconstructive surgery. The mandibular reconstruction is one of the most performed reconstructive surgery. Nowadays, we reconstruct the mandible with the fibula free flap technique, which require huge amount of time and resources for mixed results (around 10% failure rate). Based on the international literature, we developed a titanium 3D printed mesh to replace the fibula autograft and limit its side effect while offering to mesenchymal cells optimal growing environment. On the mechanical point of view, this environment requires to decrease the titanium initial rigidity from 110GPa to a range between 0.1 and 1GPa. In order to achieve that goal, we have developed a design methodology that lead us to innovation. We developed a load restauration system that allow us to combine low rigidity and high resistance. In order to find the final design, we used finite element modeling. Then, the final design have been tested mechanically in compression, traction and flexion. Because most of the requirements were reached, we designed an animal study which should take place in the next years. Eventually, we discovered some limitation for metallic 3D printing, essentially due to unsupported areas required for the load restauration. This innovative mesh is today optimized in order to be rapidly given to patients in the need
Kandil, Karim. "Modélisation multi-physique et multi-échelle des tissus mous stratifiés : application à la réponse multi-axiale du disque intervertébral humain." Thesis, Lille 1, 2020. http://www.theses.fr/2020LIL1I040.
The intervertebral disc is probably the most extraordinary tissue that the nature produces, mainly for its unusual time-dependent properties strongly influenced by the biochemical environment and the applied mechanical loading. Establishing accurate structure-property relationships for intervertebral disc annulus fibrosus tissue is a fundamental task for a reliable computer simulation of the human spine. The difficulty emanates from the multi-axiality and the anisotropy of the tissue response along with regional dependency of a complex hierarchic structure interacting with the biochemical environment. In addition, the annulus fibrosus exhibits an unusual time-dependent transversal behavior for which a complete constitutive representation is not yet developed. A physically-based chemo-viscoelastic constitutive model that takes into account an accurate disc annulus structure in relation with the biochemical environment is proposed. Numerical models of annulus specimens and lumbar functional spinal units (one disc and the adjacent vertebrae) are designed while taking into consideration the interlamellar matrix connecting the fibers-reinforced lamellae. At the specimen scale, the model capabilities are verified by experimental comparisons under various conditions in terms of osmolarity, strain-rate and multi-axiality while considering the regional dependency. Our results highlight the determinant role of the interlamellar matrix in the disc multi-axial response. The different scenarios applied to lumbar units show encouraging multi-axial predictive capabilities of our approach making it a promising tool for human spine behavior long-term prediction including age-dependency
Douania, Inès. "Multi-scales, multi-physics personalized HD-sEMG model for the evaluation of skeletal muscle aging." Electronic Thesis or Diss., Compiègne, 2022. http://www.theses.fr/2022COMP2679.
The muscle aging, as a disease entity, is known as Sarcopenia. It is defined as a reduction of muscle strength/force accompanied by a loss of muscle mass and a decline in physical functions. The current methodologies used in clinical practice to assess this aging disease, are rather limited to capture the features of this decline at the macroscopic scale. Factors such as the loss of Motor Units (motor unit (MU) is made up of a motoneuron and all the skeletal muscle fibers innervated by the neuron's axon terminals), the atrophy of fibers and the disorder of the neural recruitment pattern are shown to have a clear influence on muscular function. However, diagnosing sarcopenia by only measuring the muscle strength and/or muscle mass is not enough accurate and cannot alert an early loss of muscular function. The inner scales (MU and fiber scale age-related changes) reflecting that loss of muscle mass and strength during aging are more interesting to exploit. Thus, recent studies, based on the surface electromyography (sEMG) technique, have demonstrated the great potential of this technique to be used as a biomarker to detect early signs of sarcopenic muscles. In fact, the sEMG signal is the electrical response of the muscle activation managed by the Central Nervous System (CNS). It is measured with a noninvasive manner at the skin surface using surface electrodes and can be correlated efficiently to the mechanical response of muscle activation. Moreover, mathematical models of sEMG signal can form a useful alliance with sEMG experimental measures and processing to identify and/or quantify bio-indicators (i.e., anatomical, and neural muscle parameters) of a healthy, early, accelerated or sarcopenic muscle aging. In this thesis work, we have used a fast and optimized electrical model describing the electrical activity of the muscle at the skin surface using High Density sEMG technique (HD-sEMG), developed in our laboratory team. The reduced computational time of this model is the major key feature to perform the identification of aging indicators using inverse methods and HD-sEMG technique. However, this identification needs pre-aided-methods such as the sensitivity and the identifiability analysis. Moreover, when dealing with this model, we have observed important limitations such as lack of physiological realism (e.g., MUS territories and the number of fibers per muscle), personalization (e.g., same recruitment pattern for young and elder subject), and simplicity (e.g., adjustment of 50 model parameters according to age and gender). These limitations restrain the use of this model in muscle aging diagnosis. Therefore, we aimed in this thesis to address the limitations of this model and deliver more realistic and user-friendly model to evaluate muscle aging. Therefore, in this work, we first propose an Improved Morris Sensitivity Analysis (IMSA) applied on the developed model. This analysis was performed on young and elder simulated subjects (at low and high force level). Using this IMSA, we success to spotlight with accuracy the influential neuromuscular parameters/factors for each age category, at each force level, and for each statistic feature computed over the HD-sEMG signals. Furthermore, using IMSA, we have outlined the model inaccuracies and limitations mentioned above. To address these limitations, we have modified the model schema implementation to be easier to manipulate (user-friendly model), with less error and inconsistency risks. Only the age and the gender of subject became needed as model entries to initiate a simulation of HD-sEMG signals. All other parameters necessary in simulations are then estimated through "statistical" models. The statistical models employ regression analysis to estimate the relation Parameter versus Age. A bibliographic research reporting these morphological and structural changes according to age, gender, and Biceps Brachii muscle was done
Jguirim, Ines. "Modélisation et génération d'itinéraires contextuels d'activités urbaines dans la ville." Thesis, Brest, 2016. http://www.theses.fr/2016BRES0074/document.
The city is an urban aggregation allowing to offer diverse services to his city-dwellers. She establishes a complex system which depends on several social and economic factors. The configuration of the space influences in a important way the accessibility to the various features of the city. The spatial analysis of the urban structure is realized on cities to study the characteristics of the space and be able to estimate its functional potential. The aim of the thesis is to propose an approach to spatial analysis which takes into account the various structural and semantic aspects of the city. A model based on the graphs was proposed to represent the multimodal transport network of the city which guarantees the accessibility to the various points of interest. Super-networks were used to integrate the possibility of an intermodal transfer into the model of transport by links of interdependence between the sub-graphs associated to the various means of transportation. The temporal aspect was represented in the model by attributes specifying the temporal constraints characterizing the itinerary of every node and every edge such as the time of exploration, the waiting time and the time required for the road penalties. The functional aspect is introduced by the concept of activity. We proposed a conceptual model which aims to model the various contextual elements which can affect the planning and the execution of the urban activities such as the spatiotemporal frame and the profile of the user. This model was enriched by knowledge management which aims to represent information about individual behaviors. The extracted knowledge are represented by a management system of rules allowing the contextual planning of the activity
Ballit, Abbass. "Design and manufacturing process optimization for prosthesis of the lower limb." Thesis, Compiègne, 2020. http://www.theses.fr/2020COMP2589.
The prosthetic socket, an essential interface element between the patient's stump and prosthetic device, is most often the place where the degree of prosthetic success is defined. It is the most critical part of the prosthesis, customized to fit with the unique residual limb of the amputee. Without a proper socket shape and fit, the prosthesis becomes uncomfortable, or even unusable, and causes pain and skin issues. The state-of-the-art prosthetic production is still missing universal numerical standards to design a socket. The current practice is expensive and relies on the manual refinements of the orthopedic technician, and the fit quality strictly correlates with his skills as well as the subjective feedback of the patient. The thesis aims to conduct a deep analysis of an optimal design of the prosthetic socket by studying and developing an alternative computer-aided design process. This process is fully based on the virtual model of the patient’s residual limb and relies on the calculation of the socket-stump interaction. A fast calculation is favorable in this case, that’s why we propose to use the Mass-Spring System (MSS) instead of the widely used FE method to model the soft tissues of the residual limb. A new configuration of the MSS model is proposed to respect the non-compressibility property of the soft tissues by adding non-linear “Corrective Springs”. The numeric model is to be generated from the scanned model of the stump. For this purpose, we propose a fusion scheme of four RGB-Depth sensors for a rapid and low-cost scan with error reduction techniques. Finally, the virtual residual limb is used in the socket designing phase. A parametric design method is proposed and investigated. The design problem is transformed into a constraint-satisfaction-problem whose constraints are derived from the inverse calculation of the stump-socket interaction. The inverse approach has been chosen to eliminate the need for expensive contact formulation. This fact leads to rapid calculations, and consequently, allows to provide real-time numerical feedback during the designing process. The validation was done by comparing the results of our system with the output of FE simulations. The system has been implemented with a user-friendly graphical interface and virtually tested and numerically validated. This system reduces the limitations of the current practices. However, a lot of works is still ahead to refine and develop the system and validate it with clinical experiments
Fan, Ang-Xiao. "Geometric and numerical modeling of facial mimics derived from Magnetic Resonance Imaging (MRI) using Finite Element Method (FEM)." Thesis, Compiègne, 2016. http://www.theses.fr/2016COMP2307.
Human face plays an important role interpersonal communication. Facial dysfunction or disfigurement due to trauma or pathologies may impede normal social activities. Surgical treatment is often necessary. Nowadays, treatment outcome and rehabilitation condition are estimated only by qualitative methods, such as visual observation and palpation. In expectation of providing quantitative criteria, this thesis proposes to model facial mimics using FEM (Finite Element Method) on the basis of MRI (Magnetic Resonance Imaging) data. A subject-specific face model was reconstructed based on segmentation of MRI data; it contains bony parts, mimic muscles (e.g. zygomaticus major muscle), subcutaneous soft tissues and skin. Identification of biological soft tissues was conducted through bi-axial tension tests and numerical modeling. Then the geometric model was meshed to conduct FE calculations simulating three facial mimic movements (smile, pronunciation of sound “Pou” and “O”). Muscle was modeled as quasi-incompressible, transversely-isotropic, hyperelastic material, with activation ability. Relevant information (e.g. contraction amplitude of muscle) used in simulation was extracted from measurement of MRI data. It is to be noted that the same experimental MRI data as used in modeling was taken as validation reference for simulation results. This study can be applied clinically in evaluation of facial treatment andpostoperative recovery
Spingarn, Camille. "Contribution à la biomécanique de la régénération osseuse : modélisation, simulation et applications." Thesis, Strasbourg, 2019. http://www.theses.fr/2019STRAD010/document.
This work deals with modelization of bane remodeling. We present first a madel thal accounts for the cellular res panse to a mechanical stimulus in a general case at a continuous scale. This madel is applied to 2D and 3D geometries at macroscopic scale to mimic real cases, as weil as 2D trabecular-type geometries at mesoscopic scale. However, the complexity of bane remodeling does not allow a unique approach. Th us, the thesis work is focused on the particular case of orthodontie bane re mode ling. A new specifie madel is developed accounting for the influence of the periodontal ligament on orthodontie bane remodeling by integrating the oxygen concentration effect controling the evolutions of cellular densities. The cellular experimental data in vitro are extracted from the literature, and serve as input data of the developed madel in arder to ablain the evolution of bane density around the root of a 3D cylindrical tooth
Goda, Ibrahim. "Micromechanical models of network materials presenting internal length scales : applications to trabecular bone under stable and evolutive conditions." Thesis, Université de Lorraine, 2015. http://www.theses.fr/2015LORR0055/document.
A methodology based on micromechanics has been developed to determine the effective behavior of network materials endowed with a discrete architecture at the microscopic level. It relies on the discrete homogenization method, which has been applied to textile monolayers and trabecular bones. The initially discrete topology of the considered network materials results after homogenization at the mesoscopic level in anisotropic micropolar effective continuum, which proves able to capture the observed internal scale effects. Such micromechanical methods are useful to remedy the difficulty to measure the effective mechanical properties at the intermediate mesoscopic level scale. The bending and torsion responses of vertebral trabecular bone beam specimens are formulated in both static and dynamic situations, based on the Cosserat theory. 3D models have been developed for describing the multiaxial yield and brittle fracture behavior of trabecular bone, including the analysis of size-dependent non-classical plastic yield. We have constructed by FE analyses a homogeneous, orthotropic couple-stress continuum model as a substitute of the 3D periodic heterogeneous cellular solid model of vertebral trabecular bone, based on the equivalent strain energy approach. Bone tissues are able to adapt their local density and load bearing capacities as well as their size and shape to mechanical stimuli. We have developed models for combined internal and external bone remodeling in the framework of the thermodynamics of irreversible processes, at both the cellular and macroscopic levels. We lastly combined anisotropic internal remodeling with fatigue continuum damage