基于Kinect的机器人辅助超声扫描系统研究

提出一种采用Kinect传感器作为视觉伺服的机器人辅助超声扫描系统,来规划引导机器人的扫描路线,以实现机器人辅助的超声扫描操作。系统由Kinect传感器、机器人和超声探头组成。采用Kinect实时获取超声探头的RGB图像和深度图像,并计算探头当前位姿,结合坐标系配准结果,得到机器人的位姿信息,再根据术前的机器人轨迹规划,引导机器人的超声扫描路径。开展腿部模型实验验证本系统的可行性,通过对Kinect传感器的相机标定实验,计算得到了RGB相机和深度相机的内外参数,通过对探头上标识物的定位,进而计算出探头当前位姿,结合Kinect与机器人坐标系的配准结果,得到了两者的转换矩阵,并对机器人的位置给出指令,引导机械臂夹持探头到达指定扫描位置。在机器人夹持超声探头扫描过程中,实时计算探头与腿部之间的距离,以保证所采集超声图像的质量及扫描操作的安全性。实验结果表明,在Kinect视觉系统的导航引导下,机器人可以夹持超声探头实现自主超声扫描,以减少超声医师的扫描时间,降低医师的劳动强度。

Robot assisted ultrasound scanning system based on Kinect

We propose a novel Kinect based robot assisted ultrasound scanning system. The system is composed of a robotic arm, a linear ultrasound probe with marker, and a Kinect as a vision servo. The robot follows the navigation of the Kinect sensors and scans the legs automatically. A Kinect is chosen here to obtain the 3D images of legs and the probe. The probe and legs are segmented in RGB images and depth images in real time. The probe’s position and orientation are registered according to the registration. Then the pose of the robot can be calculated according to the calibration result of Kinect coordinate system and robot coordinate system. The robot holds the probe to scan the legs according to the planned path and current pose. Both phantom and human leg platforms with robot and ultrasound probe and Kinect are built up and scan experiments are carried out. The transformation matrixes between two legs, depth imaging, Kinect and ultrasound probe coordinate systems, are obtained. The distance between the probe and the scanned leg is calculated frame by frame to guarantee safe scanning without force sensors. Results from the initial experiments indicate that the idea is feasible and promising for its improved inspection efficiency. Clinically, the method can be implemented for pre operative procedures and this may improve the ultrasound scanning effiency.