# Acoustic Sampling Map (AsMap)

UltraWorld presents a self-distillation recipe that first adapts clinical ultrasound videos into a generator conditioned on reference images and anatomical masks, then synthesizes action-video pairs by sampling masks along programmable trajectories through 3D anatomy, distilling the generator into a world model that predicts future observations from local observations and actions alone, and introduces the Acoustic Sampling Map representing probe poses and imaging settings as pixel-wise 3D sampling positions, beam directions, and depths; experiments show improved prediction fidelity and action following, with mean terminal distance and orientation error reduced by 29% and 38% versus visual servoing across nine simulated closed-loop local planning episodes.

UltraWorld presents a self-distillation recipe that first adapts clinical ultrasound videos into a generator conditioned on reference images and anatomical masks, then synthesizes action-video pairs by sampling masks along programmable trajectories through 3D anatomy, distilling the generator into a world model that predicts future observations from local observations and actions alone, and introduces the Acoustic Sampling Map representing probe poses and imaging settings as pixel-wise 3D sampling positions, beam directions, and depths; experiments show improved prediction fidelity and action following, with mean terminal distance and orientation error reduced by 29% and 38% versus visual servoing across nine simulated closed-loop local planning episodes.