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Comparative study of viscoelastic arterial wall models in nonlinear one-dimensional finite element simulations of blood flow.
J Biomech Eng 2011; 133(8):081003JB

Abstract

It is well known that blood vessels exhibit viscoelastic properties, which are modeled in the literature with different mathematical forms and experimental bases. The wide range of existing viscoelastic wall models may produce significantly different blood flow, pressure, and vessel deformation solutions in cardiovascular simulations. In this paper, we present a novel comparative study of two different viscoelastic wall models in nonlinear one-dimensional (1D) simulations of blood flow. The viscoelastic models are from papers by Holenstein et al. in 1980 (model V1) and Valdez-Jasso et al. in 2009 (model V2). The static elastic or zero-frequency responses of both models are chosen to be identical. The nonlinear 1D blood flow equations incorporating wall viscoelasticity are solved using a space-time finite element method and the implementation is verified with the Method of Manufactured Solutions. Simulation results using models V1, V2 and the common static elastic model are compared in three application examples: (i) wave propagation study in an idealized vessel with reflection-free outflow boundary condition; (ii) carotid artery model with nonperiodic boundary conditions; and (iii) subject-specific abdominal aorta model under rest and simulated lower limb exercise conditions. In the wave propagation study the damping and wave speed were largest for model V2 and lowest for the elastic model. In the carotid and abdominal aorta studies the most significant differences between wall models were observed in the hysteresis (pressure-area) loops, which were larger for V2 than V1, indicating that V2 is a more dissipative model. The cross-sectional area oscillations over the cardiac cycle were smaller for the viscoelastic models compared to the elastic model. In the abdominal aorta study, differences between constitutive models were more pronounced under exercise conditions than at rest. Inlet pressure pulse for model V1 was larger than the pulse for V2 and the elastic model in the exercise case. In this paper, we have successfully implemented and verified two viscoelastic wall models in a nonlinear 1D finite element blood flow solver and analyzed differences between these models in various idealized and physiological simulations, including exercise. The computational model of blood flow presented here can be utilized in further studies of the cardiovascular system incorporating viscoelastic wall properties.

Authors+Show Affiliations

Department of Mechanical Engineering, James H. Clark Center, Stanford University, Stanford, CA 94305, USA. raghu21@stanford.eduNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Comparative Study
Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

21950896

Citation

Raghu, Rashmi, et al. "Comparative Study of Viscoelastic Arterial Wall Models in Nonlinear One-dimensional Finite Element Simulations of Blood Flow." Journal of Biomechanical Engineering, vol. 133, no. 8, 2011, p. 081003.
Raghu R, Vignon-Clementel IE, Figueroa CA, et al. Comparative study of viscoelastic arterial wall models in nonlinear one-dimensional finite element simulations of blood flow. J Biomech Eng. 2011;133(8):081003.
Raghu, R., Vignon-Clementel, I. E., Figueroa, C. A., & Taylor, C. A. (2011). Comparative study of viscoelastic arterial wall models in nonlinear one-dimensional finite element simulations of blood flow. Journal of Biomechanical Engineering, 133(8), p. 081003. doi:10.1115/1.4004532.
Raghu R, et al. Comparative Study of Viscoelastic Arterial Wall Models in Nonlinear One-dimensional Finite Element Simulations of Blood Flow. J Biomech Eng. 2011;133(8):081003. PubMed PMID: 21950896.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Comparative study of viscoelastic arterial wall models in nonlinear one-dimensional finite element simulations of blood flow. AU - Raghu,Rashmi, AU - Vignon-Clementel,Irene E, AU - Figueroa,C Alberto, AU - Taylor,Charles A, PY - 2011/9/29/entrez PY - 2011/9/29/pubmed PY - 2012/4/27/medline SP - 081003 EP - 081003 JF - Journal of biomechanical engineering JO - J Biomech Eng VL - 133 IS - 8 N2 - It is well known that blood vessels exhibit viscoelastic properties, which are modeled in the literature with different mathematical forms and experimental bases. The wide range of existing viscoelastic wall models may produce significantly different blood flow, pressure, and vessel deformation solutions in cardiovascular simulations. In this paper, we present a novel comparative study of two different viscoelastic wall models in nonlinear one-dimensional (1D) simulations of blood flow. The viscoelastic models are from papers by Holenstein et al. in 1980 (model V1) and Valdez-Jasso et al. in 2009 (model V2). The static elastic or zero-frequency responses of both models are chosen to be identical. The nonlinear 1D blood flow equations incorporating wall viscoelasticity are solved using a space-time finite element method and the implementation is verified with the Method of Manufactured Solutions. Simulation results using models V1, V2 and the common static elastic model are compared in three application examples: (i) wave propagation study in an idealized vessel with reflection-free outflow boundary condition; (ii) carotid artery model with nonperiodic boundary conditions; and (iii) subject-specific abdominal aorta model under rest and simulated lower limb exercise conditions. In the wave propagation study the damping and wave speed were largest for model V2 and lowest for the elastic model. In the carotid and abdominal aorta studies the most significant differences between wall models were observed in the hysteresis (pressure-area) loops, which were larger for V2 than V1, indicating that V2 is a more dissipative model. The cross-sectional area oscillations over the cardiac cycle were smaller for the viscoelastic models compared to the elastic model. In the abdominal aorta study, differences between constitutive models were more pronounced under exercise conditions than at rest. Inlet pressure pulse for model V1 was larger than the pulse for V2 and the elastic model in the exercise case. In this paper, we have successfully implemented and verified two viscoelastic wall models in a nonlinear 1D finite element blood flow solver and analyzed differences between these models in various idealized and physiological simulations, including exercise. The computational model of blood flow presented here can be utilized in further studies of the cardiovascular system incorporating viscoelastic wall properties. SN - 1528-8951 UR - https://www.unboundmedicine.com/medline/citation/21950896/Comparative_study_of_viscoelastic_arterial_wall_models_in_nonlinear_one_dimensional_finite_element_simulations_of_blood_flow_ L2 - http://biomechanical.asmedigitalcollection.asme.org/article.aspx?doi=10.1115/1.4004532 DB - PRIME DP - Unbound Medicine ER -