Learning-Based Efficient Phase-Amplitude Modulation and Hybrid Control for MRI-Guided Focused Ultrasound Treatment

Magnetic resonance-guided focused ultrasound (MRg-FUS) has become attractive, accredited to its non-invasive nature. However, ultrasound beams focusing and steering is still challenging owing to aberrations induced by soft tissue heterogeneity. In particular for beam motion control to ensure real-time and precise tracking in the deep-seated region over abdominal organs, while considering full-wave propagation. To this end, we proposed a closed-loop hybrid control scheme and a learning-based modulation model for robot-assisted MRg-FUS treatments. By introducing a rapid phase estimator to provide an efficient (<3 ms) solution, the robust H∞ controller enables real-time and accurate tracking (0.30 mm) without prior knowledge of heterogeneous media, even under unknown disturbances. Our model enables rapid (2.65 ms) phase- amplitude modulation and precise targeting (mean 0.35 mm, max. 0.65 mm), meeting clinical standard. Focal obliquity is significantly “aligned” to only 2.7 ̊. Results from sensitivity analysis and transducer design also support the model’s clinical feasibility and potential in widespread MRg-FUS treatments.