Commenced in January 2007
Paper Count: 31105
Constitutive Equations for Human Saphenous Vein Coronary Artery Bypass Graft
Abstract:Coronary artery bypass grafts (CABG) are widely studied with respect to hemodynamic conditions which play important role in presence of a restenosis. However, papers which concern with constitutive modeling of CABG are lacking in the literature. The purpose of this study is to find a constitutive model for CABG tissue. A sample of the CABG obtained within an autopsy underwent an inflation–extension test. Displacements were recoredered by CCD cameras and subsequently evaluated by digital image correlation. Pressure – radius and axial force – elongation data were used to fit material model. The tissue was modeled as onelayered composite reinforced by two families of helical fibers. The material is assumed to be locally orthotropic, nonlinear, incompressible and hyperelastic. Material parameters are estimated for two strain energy functions (SEF). The first is classical exponential. The second SEF is logarithmic which allows interpretation by means of limiting (finite) strain extensibility. Presented material parameters are estimated by optimization based on radial and axial equilibrium equation in a thick-walled tube. Both material models fit experimental data successfully. The exponential model fits significantly better relationship between axial force and axial strain than logarithmic one.
Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1061338Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1360
 R. L. Leask, J. Butany, K. W. Johnston, C. R. Ethier, M. Ojha, "Human saphenous vein coronary artery bypass graft morphology, geometry and hemodynamics," Ann. Biomed. Eng., vol. 33, no. 3, pp. 301-309, March 2005.
 R. Tran-Son-Tay, et al., "An experiment-based model of vein graft remodeling induced by shear stress," Ann. Biomed. Eng., vol. 36, no. 7, pp. 1083-1091, July 2008.
 C. M. Fernandez, et al., "Impact of shear stress on early vein graft remodeling: A biomechanical analysis," Ann. Biomed. Eng., vol. 32, no. 11, pp. 1484-1493, November 2004.
 F. Cacho, M. Doblaré and G. A. Holzapfel, ÔÇ×A procedure to simulate coronary artery bypass graft surgery," Med. Bio. Eng. Cmput., vol. 45, pp. 819-827, August 2007.
 C. Herbst, K. Splitthof, "Q-400 Basics of 3D digital image correlation,"
[online]. Available on http://www.dantecdynamics.com/Default.aspx?ID=855.
 D. Zhang, C. D. Eggleton and D. D. Arola, "Evaluationg the mechanical behavior of arterial tissue using digital image correlation," Exp. Mech., vol. 42, no. 4, pp. 409 - 416, December 2002.
 G. A. Holzapfel, T. C. Gasser, and R. W. Ogden, "A new constitutive framework for arterial wall mechanics and a comparative study of material models," J. Elast., vol. 61, no. 1-3, pp. 1-48, July 2000.
 J. Stalhand, "Determination of human arterial wall parameters from clinical data," Biomechan. Model. Mechanobiol., (Accepted for publication).
 G. A. Holzapfel, G. Sommer, C. T. Gasser and P. Regitnig, "Determination of layer-specific mechanical properties of human coronary arteries with nonatherosclerotic intimal thickening and related constitutive modeling," Am. J. Physiol. Heart Circ. Physiol., vol. 289, no. 5, pp. H2048-H2058, November 2005.
 C. O. Horgan, and G. Saccomandi, "A description of arterial wall mechanics using limiting chain extensibility constitutive models," Biomechan. Model. Mechanobiol., vol. 1, no. 4, pp. 251-266, Aprile 2003.
 C. O. Horgan, and G. Saccomandi, "A new constitutive theory for fiber- reinforced incompressible nonlinear elastic solids," J. Mech. Phys. Solids, vol. 53, no. 9, pp. 1985-2015, September 2005.
 A. N. Gent, "New constitutive relation for rubber," Rub. Chem. Technol., vol. 69, no. 1, pp. 59-61, Mach-April 1996.
 L. Horny, R. Zitny, and H. Chlup, "Strain energy function for arterial walls based on limiting fiber extensibility," Proceedings of 4th European Congress for Medical and Biomedical Engineering 2008, 23-27 Nov 2008 Antwerp, Belgium, IFBME (Accepted for publication).
 G. A. Holzapfel, Nonlinear solid mechanics - A continuum approach for engineering. Chichester: John Wiley & Sons, 2000, ch. 6.