TY - GEN
T1 - Estimation of Viscoelastic Properties of Tissue with Arbitrary Power-Law Attenuation
AU - Tripathi, Bharat B.
AU - Espíndola, David
AU - Pinton, Gianmarco F.
N1 - Publisher Copyright:
© 2018 IEEE.
PY - 2018
Y1 - 2018
N2 - Attenuation in soft solids are governed by power laws with non-integral exponents. Attenuation is a critical component for correctly modeling the wave propagation physics. For nonlinear waves, in particular nonlinear shear waves, it important to model the two competing effects accurately i.e. the generation of higher harmonics due to nonlinearity and its decay due to attenuation. Current numerical methods can model a linear attenuation power law using a single Kelvin or Maxwell body. In this work a collection of Maxwell bodies is used to model power laws with non-integral exponents, which is more general. Also, the nonlinear propagation of shear waves modeled using a system of hyperbolic PDEs together with the relaxation mechanisms is simulated using a custom high order finite volume method: piecewise parabolic method. The numerical method is validated using a set of power laws with different non-integral exponents, and also the dispersion incurred due to causality is validated. Further, attenuation law obtained from linear experiments of shear wave propagation in fresh porcine brain were used to validate the method. This method can be used to accurately determine the other unknown parameters like nonlinearity of soft tissues in brain, liver etc.
AB - Attenuation in soft solids are governed by power laws with non-integral exponents. Attenuation is a critical component for correctly modeling the wave propagation physics. For nonlinear waves, in particular nonlinear shear waves, it important to model the two competing effects accurately i.e. the generation of higher harmonics due to nonlinearity and its decay due to attenuation. Current numerical methods can model a linear attenuation power law using a single Kelvin or Maxwell body. In this work a collection of Maxwell bodies is used to model power laws with non-integral exponents, which is more general. Also, the nonlinear propagation of shear waves modeled using a system of hyperbolic PDEs together with the relaxation mechanisms is simulated using a custom high order finite volume method: piecewise parabolic method. The numerical method is validated using a set of power laws with different non-integral exponents, and also the dispersion incurred due to causality is validated. Further, attenuation law obtained from linear experiments of shear wave propagation in fresh porcine brain were used to validate the method. This method can be used to accurately determine the other unknown parameters like nonlinearity of soft tissues in brain, liver etc.
KW - generalized Maxwell body
KW - Kramers-Kronig dispersion relation
KW - piecewise parabolic method
KW - relaxation mechanisms
KW - tissue characterization
KW - viscoelastic
UR - https://www.scopus.com/pages/publications/85062496601
U2 - 10.1109/ULTSYM.2018.8579880
DO - 10.1109/ULTSYM.2018.8579880
M3 - Conference Publication
AN - SCOPUS:85062496601
VL - 2018-January
T3 - IEEE International Ultrasonics Symposium, IUS
BT - Estimation of Viscoelastic Properties of Tissue with Arbitrary Power-Law Attenuation
T2 - 2018 IEEE International Ultrasonics Symposium, IUS 2018
Y2 - 22 October 2018 through 25 October 2018
ER -