A Study of Scanning the Ultrasound Probe on Body Surface and Construction of Visual Servo System Based on Echogram

We have developed a scanning method of the ultrasound probe on body surface to construct visual servo system based on acquired echogram by the standalone medical robot, which is developed in our laboratory to move the ultrasound probe on patient abdomen in three-dimension. The visual servo system detects local change of brightness in time series echogram, which is stabilized the position of the probe by conventional force servo system in the robot, to compensate not only periodical respiration motion but also body motion. Then we integrated control method of the visual servo with the force servo as a hybrid control in both of position and force. To confirm the feasibility of application, we experimented tracking the gallbladder in echogram by minimizing abdominal response variations.