Abstract
Stress analyses of patient-specific vascular structures commonly assume that the reconstructed in vivo configuration is stress free although it is in a pre-deformed state. We submit that this assumption can be obviated using an inverse approach, thus increasing accuracy of stress estimates. In this paper, we introduce an inverse approach of stress analysis for cerebral aneurysms modeled as nonlinear thin shell structures, and demonstrate the method using a patient-specific aneurysm. A lesion surface derived from medical images, which corresponds to the deformed configuration under the arterial pressure, is taken as the input. The wall stress in the given deformed configuration, together with the unstressed initial configuration, are predicted by solving the equilibrium equations as opposed to traditional approach where the deformed geometry is assumed stress free. This inverse approach also possesses a unique advantage, that is, for some lesions it enables us to predict the wall stress without accurate knowledge of the wall elastic property. In this study, we also investigate the sensitivity of the wall stress to material parameters. It is found that the in-plane component of the wall stress is indeed insensitive to the material model.
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References
Brisman, J. L., J. K. Song, and D. W. Newell. Cerebral aneurysms. N. Engl. J. Med. 355:928–939, 2006.
David, G., and J. D. Humphrey. Further evidence for the dynamic stability of intracranial saccular aneurysms. J. Biomech. 36:1143–1150, 2003.
Elger, D. F., D. M. Blackketter, R. S. Budwig, and K. H. Johansen. The influence of shape on the stresses in model abdominal aortic aneurysms. J. Biomech. Eng. Trans. ASME 118:326–332, 1996.
Humphrey, J. D., and P. B. Canham. Structure, mechanical properties, and mechanics of intracranial saccular aneurysms. J. Elast. 61:49–81, 2000.
Humphrey, J. D., and S. K. Kyriacou. The use of laplace’s equation in aneurysms mechanics. Neurol. Res. 18:204–208, 1996.
Humphrey, J. D., R. K. Strumpf, and F. C. P. Yin. Determination of a constitutive relation for passive myocardium. I. A new functional form. ASME J. Biomech. Eng. 112(3):333–339, 1990.
Humphrey, J. D., R. K. Strumpf, and F. C. P. Yin. Determination of a constitutive relation for passive myocardium. II. Parameter-estimation. ASME J. Biomech. Eng. 112(3):340–346, 1990.
Lu, J., and X. Zhao. Pointwise identification of elastic properties in nonlinear hyperelastic membranes. Part I: theoretical and computational developments. J. Appl. Mech. 76:061013/1–061013/10, 2009.
Kim, H., K. B. Chandran, M. S. Sacks, and J. Lu. An experimentally derived stress resultant shell model for heart valve dynamic simulations. Ann. Biomed. Eng. 35(1):30–44, 2007.
Kim, H., J. Lu, M. S. Sacks, and K. B. Chandran. Dynamic simulation of bioprosthetic heart valves using a stress resultant shell model. Ann. Biomed. Eng. 36:262–275, 2008.
Kyriacou, S. K., and J. D. Humphrey. Influence of size, shape and properties on the mechanics of axisymmetric saccular aneurysms. J. Biomech. 29:1015–1022, 1996.
Lu, J., X. Zhou, and M. L. Raghavan. Computational method of inverse elastostatics for anisotropic hyperelastic solids. Int. J. Numer. Methods Eng. 69:1239–1261, 2007.
Lu, J., X. Zhou, and M. L. Raghavan. Inverse elastostatic stress analysis in pre-deformed biological structures: demonstration using abdominal aortic aneurysm. J. Biomech. 40:693–696, 2007.
Lu, J., X. Zhou, and M. L. Raghavan. Inverse method of stress analysis for cerebral aneurysms. Biomech. Model. Mechanobiol. 7:477–486, 2008.
Ma, B., R. E. Harbaugh, and M. L. Raghavan. Three-dimensional geometrical characterization of cerebral aneurysms. Ann. Biomed. Eng. 32:264–273, 2004.
Ma, B., J. Lu, R. E. Harbaugh, and M. L. Raghavan. Nonlinear anisotropic stress analysis of anatomically realistic cerebral aneurysms. ASME J. Biomed. Eng. 129:88–99, 2007.
Mirnajafi, A., J. Raymer, M. J. Scott, and M. S. Sacks. The effects of collagen fiber orientation on the flexural properties of pericardial heterograft biometerials. Biometerials 26:795–804, 2005.
Naghdi, P. M. The theory of plates and shells. In: Handbuch der Physik, vol. VIa/2, edited by C. Truesdell. Berlin: Springer-Verlag, 1972, pp. 425–640.
Sacks, M. S. Biaxial mechanical evaluation of planar biological materials. J. Elast. 61:199–246, 2000.
Schieck, B., W. Pietraszkiewicz, and H. Stumpf. Theory and numerical analysis of shells undergoing large elastic strains. Int. J. Solids Struct. 29:689–709, 1992.
Seshaiyer, P., and J. D. Humphrey. A sub-domain inverse finite element characterization of hyperelastic membranes including soft tissues. J. Biomech. Eng. Trans. ASME 125:363–371, 2003.
Seshaiyer, P., F. P. K. Hsu, A. D. Shah, S. K. Kyriacou, and J. D. Humphrey. Multiaxial mechanical behavior of human saccular aneurysms. Comput. Methods Biomed. Eng. 4:281–289, 2001.
Shah, A. D., and J. D. Humphrey. Finite strain elastodynamics of intracranial saccular aneurysms. J. Biomech. 32:593–599, 1999.
Shah, A. D., J. L. Harris, S. K. Kyriacou, and J. D. Humphrey. Further roles of geometry and properties in the mechanics of saccular aneurysms. Comput. Methods Biomech. Biomed. Eng. 1:109–121, 1998.
Simmonds, J. G. The strain energy density of rubber-like shells. Int. J. Solids Struct. 21:67–77, 1985.
Simo, J. C. On a stress resultant geometrically exact shell model. Part VII: shell intersections with 5/6-dof finite element formulations. Comput. Methods Appl. Mech. Eng. 108:319–339, 1993.
Simo, J. C., and D. D. Fox. On a stress resultant geometrically exact shell model. Part I. Formulation and optimal parametrization. Comput. Methods Appl. Mech. Eng. 72(3):267–304, 1989.
Simo, J. C., and D. D. Fox. On a stress resultant geometrically exact shell model. Part II: the linear theory; computational aspects. Comput. Methods Appl. Mech. Eng. 73:53–92, 1989.
Simo, J. C., D. D. Fox, and M. S. Rifai. On a stress resultant geometrically exact shell model. Part III: computational aspects of the nonlinear-theory. Comput. Methods Appl. Mech. Eng. 79:21–70, 1990.
Taylor, R. L. FEAP User Manual: v7.5. Technical Report. Berkeley: Department of Civil and Environmental Engineering, University of California, 2003.
Zhao, X., X. Chen, and J. Lu. Pointwise identification of elastic properties in nonlinear hyperelastic membranes. Part II: experimental validation. J. Appl. Mech. 76:061014/1–061014/8, 2009.
Zhou, X., and J. Lu. Inverse formulation for geometrically exact stress resultant shells. Int. J. Numer. Methods Eng. 74:1278–1302, 2008.
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The work was funded by the National Science Foundation Grant CMS 03-48194 and the NIH(NHLBI) Grant 1R01HL083475-01A2. The supports are gratefully acknowledged.
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Zhou, X., Raghavan, M.L., Harbaugh, R.E. et al. Patient-Specific Wall Stress Analysis in Cerebral Aneurysms Using Inverse Shell Model. Ann Biomed Eng 38, 478–489 (2010). https://doi.org/10.1007/s10439-009-9839-2
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DOI: https://doi.org/10.1007/s10439-009-9839-2