Design of an expandable multi-chamber suction gripper for minimally invasive surgery

A-traumatically gripping slippery and delicate tissues during Minimally Invasive Surgery (MIS) presents a frequent challenge. Current grippers during MIS usually consist of two hinged jaws, that are used to apply a pinch force on the tissue, attached to a rigid shaft and handle. To compensate for the low friction coefficient between the jaws of MIS grippers and the tissue surface, serrated surfaces in combination with high pinch forces are often applied, which can lead to undesired tissue trauma. Furthermore, with the added challenge of limited force feedback when using these grippers, the risk of excessive force application during surgery increases. To prevent unwanted tissue damage in future, it is a necessity to rethink how tissues are gripped during MIS. Instead of using serrated surfaces and pinch forces, we propose to use an expandable suction gripper design for tissue grasping. Suction grippers exert pull forces directly in line with the instrument shaft, eliminating the need to enclose the tissue to apply pinch forces for sufficient grip. A major downside for these types of grippers is, however, that the gripping force is limited by the cross-sectional area of the cup, which in turn is constrained by the incision size. Furthermore, if leakage occurs at the edge of the cup, the gripping force is rapidly decreased. Therefore, in this study, we developed an expandable suction gripper for use during MIS containing multiple suction discs.