A laparoscopic grasper with force perception

In laparoscopic surgery, grasping instruments are the only source of force feedback to the surgeon. Therefore, the force transmission characteristics of these instruments are important features. For mechanical graspers to allow force feedback, the force transmission function should ideally be constant throughout its range of motion and be free of hysteresis. In this paper, the design of a laparoscopic grasping instrument with outstanding force transmission characteristics is presented, which satisfies these demands to a large extent. The mechanical efficiency of the prototype amounts to 96% whereas the nonconstancy is only 3% approximately. With these forceps, several physiological properties, such as stiffness of tissue and the pulse of arteries, can be clearly perceived.