Non-invasive measurement of biomechanical properties of in vivo soft tissues

Abstract

Quantitative descriptions of in vivo biomechanical properties of soft tissues are necessary for tissue evaluation and a meaningful surgical simulation. A hand-held ultrasound indentation system that can acquire force-displacement response in vivo has been developed. Using this system, non-invasive measurements of in vivo biomechanical properties of tissues are described in this paper. First, a linear elastic model was used to describe a porcine phantom material. Its Young’s modulus was estimated via a mathematical solution from force-displacement curves. The estimated value of Young’s modulus was in good comparison with those from a material test machine and 2D and 3D finite element simulations. Secondly, a finite element-based inverse scheme was used to reconstruct Young’s modulus distribution of a three-layer phantom based on the displacement field measured from 2D continuous ultrasound images. Finally, in our primary study a pseudo-elasticity model was used to fit the experimental data of in vivo breast tissue.