International Journal for Numerical Methods in Biomedical Engineering

Cover image for Vol. 30 Issue 2

February 2014

Volume 30, Issue 2

Pages 143–295

  1. Research Articles

    1. Top of page
    2. Research Articles
    3. Special Issue Paper - Numerical Methods and Applications of Multi-Physics in Biomechanical Modeling
    4. Research Articles
    5. Special Issue Paper - Numerical Methods and Applications of Multi-Physics in Biomechanical Modeling
    6. Research Articles
    1. Numerical simulation of the fluid structure interactions in a compliant patient-specific arteriovenous fistula (pages 143–159)

      Iolanda Decorato, Zaher Kharboutly, Tommaso Vassallo, Justin Penrose, Cécile Legallais and Anne-Virginie Salsac

      Version of Record online: 5 NOV 2013 | DOI: 10.1002/cnm.2595

      Thumbnail image of graphical abstract

      We study numerically the fluid-structure interactions in a patient-specific arteriovenous fistula taking into account the different mechanical properties of the artery and vein, the non-Newtonian behavior of blood, and the compliance of downstream vessels. We show that, compared to uncoupled fluid and structure simulations, the fluid-structure interactions simulation has the advantage to provide the time-evolution of the stresses acting in and on the vascular wall, but it requires longer computational times.

    2. Inverse problems in 1D hemodynamics on systemic networks: A sequential approach (pages 160–179)

      D. Lombardi

      Version of Record online: 9 SEP 2013 | DOI: 10.1002/cnm.2596

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      In this work, a sequential approach is applied to solve some inverse problems in 1D hemodynamics on the network of the main 55 arteries of the body. For instance, the arterial stiffness is estimated by means of an unscented Kalman filtering approach, by exploiting section and mean speed observations in several locations of the body. Several random configurations were tested in order to take parametric uncertainty into account. The results on the estimation of aorta stiffness are compared with those ones obtained by estimating the pulse wave velocity and by inverting the algebraic Moens-Korteweg law. In the last section, a perspective concerning the identification of the terminal models parameters (Windkessel type of models) is presented.

  2. Special Issue Paper - Numerical Methods and Applications of Multi-Physics in Biomechanical Modeling

    1. Top of page
    2. Research Articles
    3. Special Issue Paper - Numerical Methods and Applications of Multi-Physics in Biomechanical Modeling
    4. Research Articles
    5. Special Issue Paper - Numerical Methods and Applications of Multi-Physics in Biomechanical Modeling
    6. Research Articles
    1. Stabilized second-order convex splitting schemes for Cahn–Hilliard models with application to diffuse-interface tumor-growth models (pages 180–203)

      X. Wu, G. J. van Zwieten and K. G. van der Zee

      Version of Record online: 10 SEP 2013 | DOI: 10.1002/cnm.2597

      Thumbnail image of graphical abstract

      New second-order time-accurate, unconditionally energy-stable schemes for diffuse-interface (phase- field) models are presented. The schemes employ a splitting of the free energy, artificial stabilization, and extrapolation. Numerical results are presented for the Cahn–Hilliard equation and a diffuse-interface tumor-growth model.

    2. You have full text access to this OnlineOpen article
      A systematic comparison between 1-D and 3-D hemodynamics in compliant arterial models (pages 204–231)

      Nan Xiao, Jordi Alastruey and C. Alberto Figueroa

      Version of Record online: 24 SEP 2013 | DOI: 10.1002/cnm.2598

      Thumbnail image of graphical abstract

      We present a systematic comparison of computational hemodynamics in a one-dimensional and a three-dimensional formulation with deformable vessel walls. The formulations share identical inflow and outflow boundary conditions and have compatible material laws. The results show good agreement between the two formulations, especially during the diastolic phase of the cycle.

  3. Research Articles

    1. Top of page
    2. Research Articles
    3. Special Issue Paper - Numerical Methods and Applications of Multi-Physics in Biomechanical Modeling
    4. Research Articles
    5. Special Issue Paper - Numerical Methods and Applications of Multi-Physics in Biomechanical Modeling
    6. Research Articles
    1. You have full text access to this OnlineOpen article
      Segmentation of biomedical images using active contour model with robust image feature and shape prior (pages 232–248)

      Si Yong Yeo, Xianghua Xie, Igor Sazonov and Perumal Nithiarasu

      Version of Record online: 28 OCT 2013 | DOI: 10.1002/cnm.2600

      Thumbnail image of graphical abstract

      In this article, a new level set model is proposed for the segmentation of biomedical images. The image energy of the proposed model is derived from a robust image gradient feature, which gives the active contour a global representation of the geometric configuration, making it more robust in dealing with image noise, weak edges, and initial configurations. Statistical shape information is incorporated using nonparametric shape density distribution, which allows the shape model to handle relatively large shape variations. The segmentation of various shapes from both synthetic and real images depicts the robustness and efficiency of the proposed method.

  4. Special Issue Paper - Numerical Methods and Applications of Multi-Physics in Biomechanical Modeling

    1. Top of page
    2. Research Articles
    3. Special Issue Paper - Numerical Methods and Applications of Multi-Physics in Biomechanical Modeling
    4. Research Articles
    5. Special Issue Paper - Numerical Methods and Applications of Multi-Physics in Biomechanical Modeling
    6. Research Articles
    1. You have full text access to this OnlineOpen article
      Novel wave intensity analysis of arterial pulse wave propagation accounting for peripheral reflections (pages 249–279)

      Jordi Alastruey, Anthony A. E. Hunt and Peter D. Weinberg

      Version of Record online: 16 OCT 2013 | DOI: 10.1002/cnm.2602

      Thumbnail image of graphical abstract

      Using both in vivo and numerical data, we show that wave intensity analysis fails to identify the important role of peripheral wave reflections in shaping the arterial pressure waveform (P). Ignoring peripheral reflections leads to an erroneous indication of a reflection free period in early systole. We provide novel tools for the analysis of arterial pulse wave propagation that combine traditional wave intensity analysis with identification of Windkessel pressures (p w) to account for peripheral reflections and quantify their effect on P.

  5. Research Articles

    1. Top of page
    2. Research Articles
    3. Special Issue Paper - Numerical Methods and Applications of Multi-Physics in Biomechanical Modeling
    4. Research Articles
    5. Special Issue Paper - Numerical Methods and Applications of Multi-Physics in Biomechanical Modeling
    6. Research Articles
    1. Effect of exercise on patient specific abdominal aortic aneurysm flow topology and mixing (pages 280–295)

      Amirhossein Arzani, Andrea S. Les, Ronald L. Dalman and Shawn C. Shadden

      Version of Record online: 28 OCT 2013 | DOI: 10.1002/cnm.2601

      Thumbnail image of graphical abstract

      Image-based computational fluid dynamics was used to simulate blood flow inside five small patient-specific abdominal aortic aneurysms. The computation of LCS was used to investigate topological changes between rest and exercise hemodynamics in the aneurysms, and mixing was quantified via mix-norm and mix-variance measures. Exercise resulted in higher, more uniform mixing in all patients. In some patients, exercise reduced or eliminated major recirculation regions existing during rest, and in other patients, such regions persisted from rest to exercise.

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