In-Vivo and Postmortem Compressive Properties of Porcine Abdominal Organs

In order to provide realistic haptic feedback, simulators must incorporate accurate computational models of the in-vivo mechanical behavior of soft tissues. Surgical simulation technology has progressed rapidly but lacks a comprehensive database of soft tissue mechanical properties with which to incorporate. Simulators are often designed purely based on what "feels about right;" quantitative empirical data are lacking. It is important to test tissues in-vivo and apply surgically relevant ranges of force, deformation, and duration. A motorized endoscopic grasper was used to test seven porcine abdominal organs invivo, in-situ, and ex-corpus with cyclic and static compressive loadings. Elastic and stress relaxation characteristics were examined. Results from liver are presented here. Notable differences were found between successive squeezes and between conditions for elastic and relaxation behaviors.