Investigating Relationship Between Lateral Time-To-Peak (TTP) Displacement Curves and Stiffness of Viscoelastic Agar-Gelatin Phantoms

Shear wave speed is a metric for the tissue elastic properties and its pathologic changes. This is due to the implicit relationship between the speed of the propagating shear wave within tissue and both its elastic properties and pathologic changes. Wave propagation is a result of a force applied transiently to the tissue model. In this paper, the relationship between lateral TTP displacement curves and stiffness of different Young's moduli phantoms is investigated. Five different elastic moduli Finite Element Models (FEMs) are used; 5.2KPa, 9.8KPa, 23.9KPa, 44.2KPa and 67.3KPa. Agar-gelatin model is used as a general model for mimicking soft tissue. Displacements are tracked with respect to the simulation time to create the displacement magnitude profile for the central node for each phantom. Results have shown that the second highest peak happens after 0.05 seconds in case of low elastic moduli FEMs. This time stamp can be used as a yardstick to differentiate between low and high elastic moduli without considering estimating the shear wave speed for many lateral nodes.