Adaptive control of the machining process in orthopedic surgery will increase not only productivity but also the safety issues of tool usage. The authors have developed a technology for an adaptive control system. The system has two modes, the "predictive mode" and the "adaptive mode." The predictive mode is used to shorten the air cutting time. In the adaptive mode, the system monitors the cutting force and the cutting temperature, and controls the feed override according to the difference between the real and the desired cutting force. The software is implemented on the robot controller and its effectiveness is evaluated with a urethane bone.

Toolpath generation and optimization is considered as a challenging problem in the minimally invasive orthopedic surgery with a milling robot. The objective of this paper is to minimize the collision of the cutting tool with the soft tissues. A novel approach of toolpath generation and optimization is proposed. A redundant axis is implemented to avoid the collision in the robot. Some important components are modeled based on the physical requirements. A geometric optimization approach based on the model is proposed to improve the toolpath. Case studies show the validity of this approach. Software is developed for this application and the effectiveness is evaluated with a cadaveric bone.