A robotic indenter for minimally invasive characterization of soft tissues

Abstract

We have developed a robotic indenter for minimally invasive measurement of tissue properties during a laparoscopic surgery. Using the indenter, we conducted animal experiments in situ and successfully measured the force versus displacement response of pig liver under static and dynamic loading conditions. Using the small deformation assumption, we estimated the effective Young's modulus of pig liver around 15 kPa from the force-displacement data of static indentations. We also obtained the relaxation function, describing the variation of force response with respect to time, from the data of stress relaxation experiments. We observed that pig liver shows linear viscoelastic behavior.