Circular path planning and adaptive force control for breast ultrasound autonomous scanning

Ultrasound is widely used in breast cancer diagnosis, requiring a comprehensive scan of the breast and stable probe-breast interaction for high-quality imaging. This paper introduces a novel autonomous ultrasound scanning solution by integrating breast morphology reconstruction, circular path planning, and adaptive contact force control. First, the 3D shape of the breast surface is acquired via multi-view point cloud image acquisition. Second, an 3D equidistant searching algorithm was employed to select the proper waypoints for planning a circular path around the breast. This scanning policy effectively reduces the nonuniform compression depth along the scanning path when comparing with parallel-line scanning. Then, we propose a novel nonlinear force-velocity control framework and establish an adaptive contact force control method based on the particle swarm optimization algorithm. According to the magnitude of the contact force, this method can adjust its parameters automatically for ensuring stable and complete contact between the ultrasound probe and the breast, even with complex path fluctuations.