Investigation on Friction Trauma of Small Intestine In Vivo Under Reciprocal Sliding Conditions

In the process of surgery, operation equipments or materials inevitably rub against the internal organs or tissues of patient, which often causes a series of frictional trauma problems. However, research work on the tribological factors at the interface and subsequent friction trauma is still very limited. In this paper, the friction trauma mechanism of small intestine caused by the surgeon's fingers in the process of grasping and pulling operation was investigated in vivo by means of reciprocal sliding friction testing. The rabbit small intestine was used to simulate human small intestine. An UMT-II tribometer was used to measure tribological parameters of the rabbit small intestine under different normal force of 1.0, 2.0 and 3.0 N to simulate the grip strength of surgeon's hands. Histological analysis was used to evaluate the degree of tissue damage. Results showed that the ratio of tangential force to normal force of rabbit small intestine decreased with the normal force increasing. The frictional behavior under the three normal forces was all in the tissue damage range of intermediate regime from sticking to relative sliding. With the normal force and friction time increasing, the total friction energy dissipation on the small intestine increased, which induced the damage degree of the small intestine aggravation. The damage of rabbit small intestine extended gradually from outside to inside: serosa layer tearing and falling, muscularis bleeding, longitudinal muscularis and circular muscularis division and mucosal bleeding and necrosis.