Design of a force control grasper through stiffness modulation for endosurgery: theory and experiments

In endosurgery, tissue manipulation is performed by long graspers which hav e a poor force-reflection property, i.e. they do not reflect the grasping f orce to the hand of the surgeon. In this paper, a novel design of an electr o-mechanical system is considered which can enhance the force-reflecting ca pability of endosurgical graspers. The type of synthesis of such a haptic i nterface leads to the application of a tunable spring. The design of a tuna ble spring is optimized based on the haptic and surgical requirements. More over, by using suitable control laws, it is shown that the primary requirem ents of the design application can be met. Simulation and experimental resu lts are presented using a prototype model of such a haptic interface to dem onstrate the practicality of such a design concept. (C) 2000 Elsevier Scien ce Ltd. All rights reserved.