A remote controlled haptic drilling robot for oral and maxillofacial surgery

Background: Surgeons are required advanced techniques and experiences to handle drilling devices correctly. The lack of these may bring on overcuts and damages to the surrounding tissue. This situation has risks of causing the subsequent complications or life-threatening accidents by heavy bleeding and nerve damage. Objectives: In order to solve this problem for any surgeons, we developed a remote controlled haptic drilling robot. Methods: The system consists of a master robot and a slave robot. The master robot is a robot that surgeons operate, and the slave robot is a robot that interacts with the cutting material. The force and position of robots are transmitted in both directions by bilateral remote control. Pine and Balsa wood were used as phantoms. They have same hardness of porous cortical bone and dense trabecular bone as mentioned in Misch's bone density classification. They were drilled continuously and the value of the force scaling function was calculated from the maximum motor torque and the cutting force. Findings and Conclusion: We succeeded to send haptic sense from 15 km remote site. Although the force of master robot was increased, the force scaling function decreased the force of slave robot. It made slave robot stop around the position limitation and the error was in 60 μm. It was only 2.5% of 2 mm margin. The validity of the proposal was confirmed using phantoms individually. The drill could successfully stop within safe position from the position limitation. Higher accuracy was expected by fine adjustment in force scaling.