Robot-Assisted Ultrasound Probe Force Control Under Respiration-Induced Motion

A robot-assisted force control system for stable ultrasound imaging has been developed for abdomen intervention. The system aims to integrate $\mathbf{6 - D o F}$ robot arm, 6 -axis force/torque sensor, and ultrasound probe, featuring automatic stabilization during intervention and real-time compensation for respiratory disturbance. Following the procedural workflow, the system has two operational modes. The first, rooted in admittance control, swiftly positions the robotic-held ultrasound for efficient registration. The second mode, employing the proposed adaptive control, ensures stable contact despite respiratory motion influences, enhancing procedural resilience and effectiveness. The adaptive controller predicts and eliminates disturbances more effectively than the baseline admittance controller, thanks to its utilization of the pseudo-periodic nature of respiration. The efficacy of the adaptive controller has been verified through experiments with a sponge abdomen phantom, demonstrating significant improvements in force regulation.