Modeling, design and control of an endoscope manipulator for FESS

This paper presents the development of an endoscope manipulator with passive and active structures for functional endoscopic sinus surgery (FESS). The 5-DoF passive structure has three translations and two rotations (T3R2) that allows the surgeon to manually place the endoscope near to the entry point during. The 4-DoF motorized structure (T2R2) actively controls the endoscope´s position based on the surgeon´s input commands. We analyze the reciprocal screw of the passive and active structures. The motion control system is based on a real-time Linux kernel that processes the commands from the surgeon and controls the manipulator´s active joints. A user control interface based on an IMU fastened on the surgeon´s foot is developed; this interface measures the foot´s posture and through a series of gestures, it provides the desired pan/tilt/zoom motions of the camera. The developed endoscope manipulator allows the surgeon to conduct `two-hand´ operations while retaining direct control of the camera. We present an experimental study to validate the performance of the robotic prototype.