scholarly journals Elastic Deformation of Soft Tissue-Mimicking Materials Using a Single Microbubble and Acoustic Radiation Force

2020 ◽  
Vol 46 (12) ◽  
pp. 3327-3338
Author(s):  
James H. Bezer ◽  
Hasan Koruk ◽  
Christopher J. Rowlands ◽  
James J. Choi
2015 ◽  
Vol 137 (4) ◽  
pp. 2313-2313
Author(s):  
Benjamin C. Treweek ◽  
Yurii A. Ilinskii ◽  
Evgenia A. Zabolotskaya ◽  
Mark F. Hamilton

Author(s):  
Megan L. Kogit ◽  
Baoxiang Shan ◽  
Assimina A. Pelegri

We have developed a solid mechanics model of nearly incompressible, viscoelastic soft tissue for finite element analysis (FEA) in MATLAB 7.2. Newmark’s method was used to solve the finite element equations of motion for our model. The solution to our dynamic problem was validated with a transient dynamic analysis in ANSYS 10.0. We further demonstrated that our MATLAB FEA qualitatively agrees with those results observed with acoustic radiation force methods on soft tissues and tissue-mimicking materials. We showed that changes in Young’s modulus and the damping coefficient affect the displacement amplitude and phase shift of the response data in the same manner: An increase in Young’s modulus or damping coefficient decreases both the displacement amplitude and response lag. Future work on this project will involve frequency analysis on response data and studying the initial transient region to help uncouple the effects of Young’s modulus and damping coefficient on response characteristics. This will get us one step closer to being able to explicitly determine Young’s modulus and the damping coefficient from the temporal response data of acoustic radiation force methods, which is the ultimate goal of our project.


2015 ◽  
Author(s):  
Benjamin C. Treweek ◽  
Yurii A. Ilinskii ◽  
Evgenia A. Zabolotskaya ◽  
Mark F. Hamilton

2016 ◽  
Vol 140 (4) ◽  
pp. 3310-3310
Author(s):  
Benjamin C. Treweek ◽  
Yurii A. Ilinskii ◽  
Evgenia A. Zabolotskaya ◽  
Mark F. Hamilton

Author(s):  
Xiaodong Zhao ◽  
Assimina A. Pelegri

The responses of soft tissue under acoustic radiation force excitations are used to image tissue mechanical properties for soft tissue discrimination and detection of breast tumors. The soft tissue viscoelasticy has been interrogated by step acoustic radiation force excitations. The corresponding induced time-dependent creep displacement is used to reconstruct soft tissue viscoelasticity or to estimate viscosity and elasticity contrast of the inclusion to background. The acoustic radiation force is highly localized in a small excitation region; and, one degree-of-freedom and homogenous assumptions are generally made to the analysis. However, these simplifying assumptions limit the accuracy of these methods. In this paper, a finite element model was built to demonstrate the effect of the dynamic response of viscoelastic heterogeneous soft tissue to step acoustic radiation force. Factors affecting the dynamic response of soft tissue were first investigated with the homogenous model, and the corresponding estimation quality based on the one degree-of-freedom model was evaluated. Then, the dynamic response of soft tissue with inclusion and different elasticity and viscocity for the tissue and the inclusion was studied. The results suggest that in order to improve the estimate of soft tissue viscoelasticity the heterogenenous nature of the tissue and its three dimensional geometry should be accounted in the model.


2014 ◽  
Vol 136 (9) ◽  
Author(s):  
Xiaodong Zhao ◽  
Assimina A. Pelegri

Acoustic radiation force (ARF) creep imaging applies step ARF excitation to induce creep displacement of soft tissue, and the corresponding time-dependent responses are used to estimate soft tissue viscoelasticity or its contrast. Single degree of freedom (SDF) and homogeneous analytical models have been used to characterize soft tissue viscoelasticity in ARF creep imaging. The purpose of this study is to investigate the fundamental limitations of the commonly used SDF and homogeneous assumptions in ARF creep imaging. In this paper, finite element (FE) models are developed to simulate the dynamic behavior of viscoelastic soft tissue subjected to step ARF. Both homogeneous and heterogeneous models are studied with different soft tissue viscoelasticity and ARF configurations. The results indicate that the SDF model can provide good estimations for homogeneous soft tissue with high viscosity, but exhibits poor performance for low viscosity soft tissue. In addition, a smaller focal region of the ARF is desirable to reduce the estimation error with the SDF models. For heterogeneous media, the responses of the focal region are highly affected by the local heterogeneity, which results in deterioration of the effectiveness of the SDF and homogeneous simplifications.


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