Experimental study of soft tissue recovery using optical fiber probe

This paper proposes a novel experimental study of the recovery of soft tissue after the removal of an external load. An optical fiber probe has been developed to measure the tissue recovery precisely through a static indentation method. Ex-vivo soft tissue recovery tests have been conducted on porcine liver. A robotic manipulator is used to control the motion of the probe and the force sensor is used to record the interaction force at the tip of the probe. An empirical mathematical model which describes the relationship of the liver recovery behavior and the holding time during which the probe keeps the tissue statically indented has been developed. The error analysis shows this model is able to predict liver recovery reasonably well. The experimental study shows that the recovery behavior of soft tissue depends on the holding time of the probe. In addition, the formula of the recovering force of the liver, which was deduced from the rate of liver recovery, is proposed.