Design and development of a Stewart platform assisted and navigated transsphenoidal surgery

Abstract

In this study, technical details of a Stewart platform (SP) based robotic system as an endoscope positionerand holder for endoscopic transsphenoidal surgery are presented. Inverse and forward kinematics, full dynamics, and theJacobian matrix of the robotic system are derived and simulated in MATLAB/Simulink. The required control structurefor the trajectory and position control of the SP is developed and verified by several experiments. The robotic systemcan be navigated using a six degrees of freedom (DOF) joystick and a haptic device with force feedback. Positionand trajectory control of the SP in the joint space is achieved using a new model-free intelligent PI (iPI) controllerand it is compared with the classical PID (proportional-integral-derivative) controller. Trajectory tracking experimentalresults showed that the tracking performance of iPI is better than that of PID and the total RMSE of the trajectorytracking is decreased by 17.64% using the iPI controller. The validity of the robotic system is proven in the endoscopictranssphenoidal surgery performed on a realistic head model in the laboratory and on a cadaver in the Institute of ForensicMedicine. The key feature of the system developed here is to operate the endoscope via the joystick or haptic devicewith force feedback under iPI control. Usage of this system helps surgeons in long, fatiguing, and complex operations.This system can generate new possibilities for transsphenoidal surgery such as fully automated robotic surgery systems.