International Journal for Numerical Methods in Biomedical Engineering

Cover image for Vol. 28 Issue 1

January 2012

Volume 28, Issue 1

Pages 1–185

  1. Editorials

    1. Top of page
    2. Editorials
    3. Special Issue Papers
    1. You have free access to this content
  2. Special Issue Papers

    1. Top of page
    2. Editorials
    3. Special Issue Papers
    1. Numerical simulation of a thermodynamically consistent four-species tumor growth model (pages 3–24)

      Andrea Hawkins-Daarud, Kristoffer G. van der Zee and J. Tinsley Oden

      Version of Record online: 17 OCT 2011 | DOI: 10.1002/cnm.1467

      Thumbnail image of graphical abstract

      In this paper, we develop a thermodynamically consistent four-species model of tumor growth on the basis of the continuum theory of mixtures. Unique to this model is the incorporation of nutrient within the mixture as opposed to being modeled with an auxiliary reaction-diffusion equation. The formulation involves systems of highly nonlinear partial differential equations of surface effects through diffuse-interface models. A mixed finite element spatial discretization is developed and implemented to provide numerical results demonstrating the range of solutions this model can produce.

    2. Quantum dynamics in continuum for proton transport II: Variational solvent–solute interface (pages 25–51)

      Duan Chen, Zhan Chen and Guo-Wei Wei

      Version of Record online: 9 AUG 2011 | DOI: 10.1002/cnm.1458

      Thumbnail image of graphical abstract

      The present work proposes a multiscale/multiphysics model for the understanding of the molecular mechanism of proton transport in transmembrane proteins involving continuum, atomic, and quantum descriptions, assisted with the evolution, formation, and visualization of membrane channel surfaces. We describe proton dynamics quantum mechanically via a new density functional theory based on the Boltzmann statistics, while implicitly model numerous solvent molecules as a dielectric continuum to reduce the number of degrees of freedom.

    3. An active strain electromechanical model for cardiac tissue (pages 52–71)

      F. Nobile, A. Quarteroni and R. Ruiz-Baier

      Version of Record online: 3 OCT 2011 | DOI: 10.1002/cnm.1468

      Thumbnail image of graphical abstract

      We propose a finite element approximation to solve the coupling between the propagation of electrical potential and large deformations of the cardiac tissue, based on the active strain assumption. A new phenomenological model for the mechanical activation is introduced and various numerical tests performed with a parallel finite element code illustrate that the proposed method can capture some important features of the excitation-contraction mechanism.

    4. Coupled electromechanical model of the heart: Parallel finite element formulation (pages 72–86)

      Pierre Lafortune, Ruth Arís, Mariano Vázquez and Guillaume Houzeaux

      Version of Record online: 17 JAN 2012 | DOI: 10.1002/cnm.1494

      Thumbnail image of graphical abstract

      In this paper, a parallel-coupled electromechanical model of the heart is presented and assessed. The parallel-coupled model is thoroughly discussed, with scalability proven up to hundreds of cores. This work focuses on the mechanical part including the constitutive model, the numerical scheme and the coupling strategy.

    5. A continuum description of the damage process in the arterial wall of abdominal aortic aneurysms (pages 87–99)

      Giacomo Marini, Andreas Maier, Christian Reeps, Hans-Henning Eckstein, Wolfgang A. Wall and Michael W. Gee

      Version of Record online: 15 SEP 2011 | DOI: 10.1002/cnm.1472

      Thumbnail image of graphical abstract

      In the present work, we develop a three-dimensional isotropic finite-strain damage model for abdominal aortic aneurysm (AAA) wall that considers both the characteristic softening of the material caused by damage and the spatial variation of the material properties. A strain energy function is formulated that accounts for a hyperelastic, slightly compressible, isotropic material behavior during the elastic phase, whereas the damage process only contributes to the material response when the elastic limit of the AAA wall is exceeded. Material and damage parameters are obtained by fitting the strain energy function to the experimental data obtained by uniaxial tensile tests of freshly harvested AAA wall samples.

    6. Dynamics of the aortic arch submitted to a shock loading: Parametric study with fluid-structure models (pages 100–110)

      A. El Baroudi, F. Razafimahery and L. Rakotomanana

      Version of Record online: 22 DEC 2011 | DOI: 10.1002/cnm.1483

      Thumbnail image of graphical abstract

      We analyse the influence of blood viscosity and stenosis on the aorta loadings during shock.

    7. Computational model of soft tissues in the human upper airway (pages 111–132)

      J-P. V. Pelteret and B. D. Reddy

      Version of Record online: 17 JAN 2012 | DOI: 10.1002/cnm.1487

      Thumbnail image of graphical abstract

      This paper presents an anatomically realistic three-dimensional finite element model of the tongue and surrounding soft tissues with potential application to the study of sleep apnoea. An active Hill three-element muscle model was used to represent the muscular tissue of the tongue, and a genetic algorithm-based neural control model is developed to control movement. It is demonstrated that the neural model is able to control the position of the tongue and produce a physiologically realistic response for the genioglossus under breathing-induced loading conditions.

    8. Semi-automatic surface and volume mesh generation for subject-specific biomedical geometries (pages 133–157)

      Igor Sazonov and Perumal Nithiarasu

      Version of Record online: 2 NOV 2011 | DOI: 10.1002/cnm.1470

      Thumbnail image of graphical abstract

      An overview of surface and volume mesh generation techniques for creating valid meshes to carry out biomedical flows is provided. The methods presented are designed for robust numerical modelling of biofluid flow through subject-specific geometries. The applications of interest are haemodynamics in blood vessels and air flow in upper human respiratory tract. The methods described are designed to minimize distortion to a given domain boundary. They are also designed to generate a triangular surface mesh first and then volume mesh (tetrahedrons) with high quality surface and volume elements.

    9. Automated extraction of the femoral anatomical axis for determining the intramedullary rod parameters in total knee arthroplasty (pages 158–169)

      S. Van Cauter, M. De Beule, A. Van Haver, P. Verdonk and B. Verhegghe

      Version of Record online: 14 NOV 2011 | DOI: 10.1002/cnm.1478

      Thumbnail image of graphical abstract

      The anatomical axis of the femur (FAA) can be automatically extracted from a 3D image by fitting hyperboloids to the diaphysis. The orientation and entry point of a 200-mm long intramedullary rod (FIR), which is used for prosthesis positioning during total knee arthroplasty, can then be computed by fitting a line to the FAA. Precise results are obtained from images that are reduced to 60% of the length, meaning that partial scans can be used for preoperative planning.

    10. Human skull shape and masticatory induced stress: Objective comparison through the use of non-rigid registration (pages 170–185)

      Gerhardus J. Jansen van Rensburg, Daniel N. Wilke and Schalk Kok

      Version of Record online: 17 JAN 2012 | DOI: 10.1002/cnm.1493

      Thumbnail image of graphical abstract

      Non-rigid registration is used to represent variations in human skull shape. Subsequent finite element analyses quantify stresses caused by mastication, and differences in stresses caused by skull shape variation. The effect of mapping uncertainty on these stress differences is also quantified.