Abstract: With many advantages such as non-invasive, safe and quick effect, focused ultrasound lipolysis stands out among many fat-removing methods. However, during the whole process, the doctor needs to hold the ultrasound transducer and press it on the patient’s skin with a large pressure for a long time; thus the probability of muscle and bone damage for doctors is greatly increased. To reduce the occurrence of doctors’ occupational diseases, a depth camera-based ultrasonic lipolysis robot system is proposed to realize robot-assisted automatic ultrasonic lipolysis operation. The system is composed of RealSense depth camera, KUKA LBR Med seven-axis robotic arm, PC host, and ultrasonic lipolysis instrument. The whole operation includes two parts: preoperative planning and intraoperative operation. In preoperative planning, the treatment area is selected in the camera image by the doctor; then the system automatically plans uniformly distributed treatment points in the treatment area. At the same time, the skin normal vector is calculated to determine the end posture of the robot, so that the ultrasound transducer can be pressed down in the normal direction of skin. During the intraoperative operation, the robot is controlled to arrive at the treatment point in turn. Meanwhile, the patient’s movement can be detected by the depth camera, and the path of robot is adjusted in real time so that the robot can track the movement of patient, thereby ensuring the accuracy of the ultrasonic lipolysis operation. Finally, the human body model experiment is conducted. The results show that the maximum error of the robot operation is within 5mm, average error is 3.1mm, and the treatment points of the robot operation are more uniform than those of manual operation. Therefore, the system can replace the doctor and achieve autonomous ultrasonic lipolysis to reduce the doctor’s labor intensity.

Key words: robot, depth camera, ultrasonic lipolysis