Force control and breakthrough detection of a bone-drilling system

Because neurosurgery and orthopedic surgery often require the drilling of bones, this paper attempts to solve the problem of bone drilling. The goal is to realize a control system that drills with a contact drilling force and can automatically stop drilling at the moment of breaking through. In particular, both the dc drilling motor control and the feed rate control are driven by force control in order to accommodate the system impedance. Moreover, breakthrough detection conies from to the threshold information of the thrust force as well as the trend of both the drilling torque and the feed rate. The proposed technique was experimentally verified through the drilling of pig bones, and the results are in accordance with the theoretical model both in the bone-drilling process and at the point of breakthrough.