14,911 research outputs found
Numerical simulation of the stress-strain state of the dental system
We present mathematical models, computational algorithms and software, which
can be used for prediction of results of prosthetic treatment. More interest
issue is biomechanics of the periodontal complex because any prosthesis is
accompanied by a risk of overloading the supporting elements. Such risk can be
avoided by the proper load distribution and prediction of stresses that occur
during the use of dentures. We developed the mathematical model of the
periodontal complex and its software implementation. This model is based on
linear elasticity theory and allows to calculate the stress and strain fields
in periodontal ligament and jawbone. The input parameters for the developed
model can be divided into two groups. The first group of parameters describes
the mechanical properties of periodontal ligament, teeth and jawbone (for
example, elasticity of periodontal ligament etc.). The second group
characterized the geometric properties of objects: the size of the teeth, their
spatial coordinates, the size of periodontal ligament etc. The mechanical
properties are the same for almost all, but the input of geometrical data is
complicated because of their individual characteristics. In this connection, we
develop algorithms and software for processing of images obtained by computed
tomography (CT) scanner and for constructing individual digital model of the
tooth-periodontal ligament-jawbone system of the patient. Integration of models
and algorithms described allows to carry out biomechanical analysis on
three-dimensional digital model and to select prosthesis design.Comment: 19 pages, 9 figure
Modeling multi-cellular systems using sub-cellular elements
We introduce a model for describing the dynamics of large numbers of
interacting cells. The fundamental dynamical variables in the model are
sub-cellular elements, which interact with each other through phenomenological
intra- and inter-cellular potentials. Advantages of the model include i)
adaptive cell-shape dynamics, ii) flexible accommodation of additional
intra-cellular biology, and iii) the absence of an underlying grid. We present
here a detailed description of the model, and use successive mean-field
approximations to connect it to more coarse-grained approaches, such as
discrete cell-based algorithms and coupled partial differential equations. We
also discuss efficient algorithms for encoding the model, and give an example
of a simulation of an epithelial sheet. Given the biological flexibility of the
model, we propose that it can be used effectively for modeling a range of
multi-cellular processes, such as tumor dynamics and embryogenesis.Comment: 20 pages, 4 figure
Modelling mitral valvular dynamics–current trend and future directions
Dysfunction of mitral valve causes morbidity and premature mortality and remains a leading medical problem worldwide. Computational modelling aims to understand the biomechanics of human mitral valve and could lead to the development of new treatment, prevention and diagnosis of mitral valve diseases. Compared with the aortic valve, the mitral valve has been much less studied owing to its highly complex structure and strong interaction with the blood flow and the ventricles. However, the interest in mitral valve modelling is growing, and the sophistication level is increasing with the advanced development of computational technology and imaging tools. This review summarises the state-of-the-art modelling of the mitral valve, including static and dynamics models, models with fluid-structure interaction, and models with the left ventricle interaction. Challenges and future directions are also discussed
Finite Element Modeling and Analysis Applications in Osteogenesis Imperfecta
Understanding the biomechanics of bones in persons with osteogenesis imperfecta (OI) is a key component to further understanding the disease, optimizing treatment and quality of life, as well as injury prevention. However, it is not feasible to study bone biomechanics in vivo. Thus, modeling may play a key role in understanding how OI bones respond to the loading experienced during various activities, especially ambulation. Biomechanical modeling can provide insight into bone fracture risks, such as type and location, from single applied loads or repetitive loading. One method for obtaining this information is via a finite element analysis (FEA). FEA is a general technique for mathematically approximating solutions to boundary-value problems.1 It is a powerful computational tool with numerous applications. These numerical methods are used to obtain an output from a system of differential equations in response to boundary condition inputs in many scenarios. FEA allows for the discretization of a structure into numerous subparts (elements) for analysis. Elements represent regular strait-side geometric 2-D or 3-D shapes that enclose a finite area or volume.2 Field output variables (stress, strain, etc.) are explicitly calculated at each vertex (node) of every element.3 These outputs provide information that corresponds to bone strength and, therefore, location and risk for potential fractures
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