2020 Volume 22 Issue 1 Pages 14-20
We are developing a CT-guided needle insertion robot for the purpose of reducing physician exposure dose. Automatic needle insertion will help a physician because it is a little difficult for unskilled operators to control the robot manually. In this paper, we propose a control law to realize full automatic needle insertion for a CT-guided needle insertion robot. In the control law, speed to insert a needle is given based on the result of our observation on the animal experiment. We found that the number of corrections increases as the needle approaches the target in a robotic needle insertion controlled by a physician. We propose the idea that needle insertion velocity decreases exponentially. The effectiveness of the control law is verified by a simulation experiment in which the needle start at having offset to the target trajectory. As a result, the robot in the simulation environment achieves to reach the target point by decreasing its puncture speed as the needle approaches the target.