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.