In pharyngeal cancer surgery, an arc-shaped forceps is used for operations in the curved narrow working space of the throat. A flexible endoscope is also used because the affected portion is not visible directly. Due to the difference between the direction of the endoscopic view and that of the forceps handle, control of the forceps is not intuitive and the surgeons are required of high manipulation skills. In this paper, we propose a 3-DOF mechanical motion converter, which converts the

more »

... d and forward input motion to the rotating motion about the arc center of the forceps in order to prevent collision between the forceps and the organs during insertion. In addition, up and down, and right and left input motions are transmitted to the arc-shaped forceps. These motion conversion and transmission allow intuitive manipulation as if the surgeon manipulated a linear forceps. The proposed mechanism performs the motion conversion and transmission only through mechanical links without any actuators. Thus, it is safe and inexpensive, and its early introduction to practice can be expected. The experimental results demonstrate that the proposed mechanism can convert and transmit the input motions, and the front end of the arc-shaped forceps can move inside a pharynx mockup as expected. 1 CNT RCM L J J − Base J 1 CNT J 4 ) ( 5 2 CNT PLM L J J − Fig. 13 Linkage mechanism that connects the controller to L C−RCM 1 and L C−PLM 1 to transmit the three motions independently. 2·4 14 J L−RCM 1 J L−RCM 4 J L−RCM 2 J L−RCM 3 3 J L−RCM 1 J L−RCM 4 T J L−RCM