Design and Implementation of a Dual-Transmit/ Receive-Mode Therapeutic Ultrasound Phased Array System for Brain Therapy

Focused ultrasound phased array systems have attracted increased attention for brain therapy applications. However, such systems currently lack a direct and real-time method to intraoperatively monitor ultrasound pressure distribution for securing treatment. This study proposes a dual-mode 256-channel ultrasound phased array system design to support transmit/receive operations for concurrent ultrasound exposure and backscattered focal-beam reconstruction through a spherically focused ultrasound array. A total 256-channel ultrasound transmission system was used to transmit focused ultrasonic energy, with an extended implementation of multiple-channel receiving function (up to 64 channels) using the same 256-channel ultrasound array. Our results showed that PSF and focal beam can be successfully reconstructed and visualized in free-field conditions, and can also be transcranially reconstructed following skull-induced aberration correction. In-vivo experiments were conducted to demonstrate its capability to pre-operatively and semi-quantitatively map a focal beam to guide blood-brain barrier (BBB)-opening. The proposed system may have potential for real-time guidance of ultrasound brain intervention, and may facilitate the design of a dual-mode ultrasound phased array for brain therapeutic applications.