Automatic Tracking Motion Based on Flexible Forbidden Virtual Fixtures Design in Robot Assisted Nasal Surgery

摘要

Traditional nasal surgery with minimal invasiveness requires doctor to hold the endoscope with left hand while the right hand to operate the surgical instruments, which may cause unstable endoscope images and potential danger. Before designed robots lack of dynamic endoscope tracking mechanism and effective safety protection device such as virtual fixtures for the narrow nasal space. This paper describes an innovative robot safety control method of surgical instruments dynamic tracking endoscope based on spatial dynamics flexible virtual fixtures. By designing a dual-layer hyperboloid model generated by a serial of spatial points and hyperboloid parameters to build the virtual fixtures, while setting the safety tracking control strategy after calibrating the navigation system and motion filtering. Finally, several experiments show that the hyperboloid virtual fixtures have a great constraint of the speed of robot at different robot states and robot can automatic track the surgeon's hand with high precision. The proposed safety protection method can easily be applied to any patients with different nose shapes and realize the innovative following mechanism with human-machine interactive safety control.