title: Generalized response of a sphere embedded in a viscoelastic medium excited by an ultrasonic radiation force.
abstract: The response of an embedded sphere in a viscoelastic medium excited by acoustic radiation force has been studied in both the time- and frequency-domains. This model is important because it can be used to characterize the viscoelastic properties of the medium by fitting the response to the theoretical model. The Kelvin-Voigt model has been used exclusively in these models. An extension to the previously reported models is described so that any viscoelastic rheological model can be used. This theoretical development describes the generalized embedded sphere response both in the time and frequency domains. Comparing the results from derivations in both domains showed very good agreement with a median absolute error (MAE) ranging from 0.0044 to 0.0072. Good agreement is demonstrated with finite element model simulations and the theory with a MAE of 0.006. Lastly, results for characterization of gelatin and rubber materials with the new theory are shown where the MAE values were used to determine which rheological model best describes the measured responses.
authors: Department of Physiology and Biomedical Engineering, Mayo Clinic College of Medicine, 200 First Street Southwest, Rochester, Minnesota 55905, USA. urban.matthew@mayo.edu
authors: Matthew W
authors: MW
authors: Urban
authors: Ivan Z
authors: IZ
authors: Nenadic
authors: Scott A
authors: SA
authors: Mitchell
authors: Shigao
authors: S
authors: Chen
authors: James F
authors: JF
authors: Greenleaf
mesh_terms: D003198:Computer Simulation; D004548:Elasticity; D004867:Equipment Design; D020342:Finite Element Analysis; D005583:Fourier Analysis; D005780:Gelatin; D008962:Models, Theoretical; D009038:Motion; D009716:Numerical Analysis, Computer-Assisted; D019047:Phantoms, Imaging; D012212:Rheology; D012408:Rubber; D013016:Sound; D013997:Time Factors; D014465:Ultrasonics / Q000295:instrumentation*; D014732:Vibration; D014783:Viscosity
chemical_list: D005780:Gelatin; D012408:Rubber