Acoustic Holography in the Megahertz Range with Optimal Lens Topologies

Overview

Acoustic holograms offer a compact, cost-effective alternative to phased arrays for shaping ultrasound fields through the skull. This work addresses the challenge of designing optimal hologram lens topologies that account for nonlinear wave propagation and skull heterogeneity at therapeutic megahertz frequencies.

Key Contributions

• Formulated an optimization framework for hologram surface topology that incorporates nonlinear acoustic feedback, improving focal accuracy over linear-only designs.
• Demonstrated that optimized holograms achieve improved spatial targeting through heterogeneous skull bone compared to conventional hologram designs.
• Validated results experimentally using hydrophone measurements in skull phantoms and ex vivo human skull specimens.

Methods & Tools

• Heterogeneous Angular Spectrum Approach (HASA) for transcranial wave propagation
• Topology optimization with adjoint-based gradient computation
• Experimental validation with Verasonics multi-channel ultrasound platform
• MATLAB and Python for simulation and data analysis

Related Patent

Arvanitis, C. and Dash, P. P., Georgia Tech Research Corp, 2024. Trans-Skull Focused Ultrasound Using Acoustic Hologram and Heterogeneous Angular Spectrum Approach, and Hologram Registration. USPTO 18/638,465.

Citation

Dash, P. P., & Arvanitis, C. D. (2025). Acoustic Holography in the Megahertz Frequency Range with Optimal Lens Topologies and Nonlinear Acoustic Feedback. arXiv:2508.07103 (Under Revision).