A New Versatile System for 3D Steered LIFU Based on 2D Matrix Arrays.

Area of Science:

• Neuroscience
• Biomedical Engineering
• Medical Devices

Background:

• Noninvasive brain stimulation is advancing with ultrasound technologies.
• Low-intensity focused ultrasound (LIFU) offers precise deep brain targeting.
• Clinical application requires systems with 3D steering, flexible temporal patterns, and skull aberration correction.

Purpose of the Study:

• To design, fabricate, and characterize a versatile 3D steered LIFU system for clinical applications.
• To validate a phase aberration correction (PAC) algorithm for skull compensation.
• To assess system compliance with medical device standards and perform initial MRI phantom studies.

Main Methods:

• Development of a 2D matrix array LIFU system for 3D beam steering and focusing.
• Implementation and validation of a custom PAC algorithm using an ex vivo skull.
• Testing for medical device standard compliance and conducting MRI phantom studies with magnetic resonance acoustic radiation force imaging.

Main Results:

• Achieved 3D beam steering and focusing with lateral focus sizes down to 4 mm for precise targeting.
• Demonstrated generation of arbitrary temporal signal patterns (waveforms, pulse length, duty cycle, ramping).
• Validated PAC algorithm for skull bone compensation and confirmed absence of transducer artifacts in MRI studies.

Conclusions:

• The developed LIFU system provides a flexible platform for ultrasound neuromodulation, balancing conformal and single-element setups.
• The system meets practical, technical, safety, and regulatory requirements for clinical translation.
• This versatile system facilitates research and aids in understanding LIFU effects for neurostimulation.