Combining Imaging Modalities in the Modeling of Multiparameter Devices

2013 ◽  
Vol 7 (4) ◽  
Author(s):  
Jens Vinge Nygaard

Modeling and simulation of medical devices are typically established to identify parameter dependencies within the system of interest. Most devices are multiphysics problems considering solid and fluid mechanics, and electromagnetic mechanisms bridging time and length scales. Typically, the geometries of interest are described by complex morphologies of biological components. These factors all contribute to significant complexity of the developed numerical models. Access to imaging modalities capable of providing the geometrical information of relevance is central in the establishment and verification of numerical analysis. Here, data from image-based models obtained with MRI and μCT to risk access patients prone to realizing stroke, and to evaluate drug eluding scaffolds is presented.

Author(s):  
Jens Vinge Nygaard

Modeling and simulation of medical devices are typically established in order to identify parameter dependencies within the system of interest. Most devices are multiphysics problems in the sense that coupling can occur between for instance flow, structure, and temperature. In many systems individual and dependent mechanisms are present bridging length scales from nanometer to millimeter. Typically, the geometries of interest are described by the complex morphology of the components in biological tissues. These factors all contribute to significant complexity of the numerical models being developed. Access to imaging modalities capable of providing the geometrical information of relevance to the problems is central in the establishment and verification of numerical analysis. This abstract present how we used image based models obtained from MRI and CT datasets to risk access patients prone to realizing stroke, and how a scaffold technology for tissue engineering is analyzed both in vitro and in vivo to access its drug delivery capability and biocompatibility.


Author(s):  
Hortência Magalhães ◽  
Danielle de Lima Vieira ◽  
Guilherme Luiz de Oliveira Neto ◽  
Tony Herbert Freire de Andrade ◽  
Severino Rodrigues de Farias Neto ◽  
...  

2015 ◽  
Vol 22 (5) ◽  
pp. 585-596 ◽  
Author(s):  
Damian BEBEN ◽  
Adam STRYCZEK

The paper presents a numerical analysis of corrugated steel plate (CSP) bridge with reinforced concrete (RC) relieving slab under static loads. Calculations were made based on the finite element method using Abaqus software. Two computation models were used; in the first one, RC slab was used, and the other was without it. The effect of RC slab to deformations of CSP shell was determined. Comparing the computational results from two numerical models, it can be concluded that when the relieving slab is applied, substantial reductions in displacements, stresses, bending mo­ments and axial thrusts are achieved. Relative reductions of displacements were in the range of 53–66%, and stresses of 73–82%. Maximum displacements and bending moments were obtained at the shell crown, and maximum stresses and axial thrusts at the quarter points. The calculation results were also compared to the values from experimental tests. The course of computed displacements and stresses is similar to those obtained from experimental tests, although the absolute values were generally higher than the measured ones. Results of numerical analyses can be useful for bridge engineering, with particular regard to bridges and culverts made from corrugated steel plates for the range of necessity of using additional relieving elements.


2010 ◽  
Vol 3 (3) ◽  
pp. 346-356 ◽  
Author(s):  
G. Savaris ◽  
P. H. Hallak ◽  
P. C. A. Maia

The objective of this article is to present the results obtained in a study on the interaction between the behavior of the structure and the foundation settlements and verify the influence of normal load distribution on the columns. In this mechanism, known as structure soil interaction (SSI), as the building is constructed, a transfer of loads occurs from the columns which tend to settle more to those that tend to settle less. The study was conducted in a building which had its settlements monitored from the beginning of construction. For this purpose, a linear tridimensional numerical model was constructed and numerical analysis was performed, using the finite elements method. In these analyses, numerical models corre- sponding to the execution of each floor were used, considering the settlements measured in each stage of the construction. The results of analy- ses showed that the effect of SSI are significant for calculating the normal efforts on the columns, particularly on those located in the first floors.


Acta Numerica ◽  
2000 ◽  
Vol 9 ◽  
pp. 39-131 ◽  
Author(s):  
K. A. Cliffe ◽  
A. Spence ◽  
S. J. Tavener

In this review we discuss bifurcation theory in a Banach space setting using the singularity theory developed by Golubitsky and Schaeffer to classify bifurcation points. The numerical analysis of bifurcation problems is discussed and the convergence theory for several important bifurcations is described for both projection and finite difference methods. These results are used to provide a convergence theory for the mixed finite element method applied to the steady incompressible Navier–Stokes equations. Numerical methods for the calculation of several common bifurcations are described and the performance of these methods is illustrated by application to several problems in fluid mechanics. A detailed description of the Taylor–Couette problem is given, and extensive numerical and experimental results are provided for comparison and discussion.


2019 ◽  
Vol 9 (18) ◽  
pp. 3674 ◽  
Author(s):  
Jose A. Sanz-Herrera ◽  
Esther Reina-Romo

Bone tissue engineering is currently a mature methodology from a research perspective. Moreover, modeling and simulation of involved processes and phenomena in BTE have been proved in a number of papers to be an excellent assessment tool in the stages of design and proof of concept through in-vivo or in-vitro experimentation. In this paper, a review of the most relevant contributions in modeling and simulation, in silico, in BTE applications is conducted. The most popular in silico simulations in BTE are classified into: (i) Mechanics modeling and scaffold design, (ii) transport and flow modeling, and (iii) modeling of physical phenomena. The paper is restricted to the review of the numerical implementation and simulation of continuum theories applied to different processes in BTE, such that molecular dynamics or discrete approaches are out of the scope of the paper. Two main conclusions are drawn at the end of the paper: First, the great potential and advantages that in silico simulation offers in BTE, and second, the need for interdisciplinary collaboration to further validate numerical models developed in BTE.


2018 ◽  
Vol 18 (2) ◽  
pp. 121-129 ◽  
Author(s):  
Jerry Ochola ◽  
Benny Malengier ◽  
Lode Daelemans ◽  
John Githaiga ◽  
Lieva Van Langenhove

AbstractThis paper presents the experimental and numerical analysis of the potential of a braided fabric for flexor tendon repair. Numerical models of tubular braided fabrics were generated using a python script interface and imported into ABAQUS®while Flexor tendon models were represented as silicone rubber rods. Experimental tests and Finite Element Modelling (FEM) of the flexor tendon repair was undertaken by deploying two tendon ends from opposite sides of a tubular braided fabric. This was done such that the tendon ends meet at the midpoint within the fabric. The tendons were tightly held to emulate a realistic repaired tendon. A displacement driven uniaxial loading was induced on the tendon-fabric assembly sufficient to cause a 2mm gap between the tendon ends. Numerical analysis of the repair potential of a braided fabric in tendon repair was done by analyzing selected fabric parameters that were crucial in tendon repair applications. The results show that changing the parameters of the braided fabrics significantly affected the potential of the fabrics during tendon repair.


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