Strain estimation of moving tissue based on automatic motion compensation by ultrasound visual servoing

This paper presents a robot-assisted system to obtain elastic information of a moving tissue using a 2-D ultrasound probe actuated by a 6 degrees of freedom robotic arm. The proposed method combines ultrasound image-based visual servoing, force control and non-rigid motion estimation. We present how the motion estimation, while the force control and visual sevoing are enabled, is useful to compute the strain map of the tissue. Ex-vivo experiments performed on a moving abdominal phantom demonstrate the efficiency and robustness of this methodology to compute the strain information of a tissue in motion.