Mapping and modeling ultrasound propagation for tailored brain therapies

• Author(s): Carvalho, Óscar Samuel Novais
• Date: 2025
• Persistent ID: https://hdl.handle.net/1822/94392
• Origin: RepositóriUM - Universidade do Minho
• Subject(s): Ultrasound stimulation; Brain; Customized therapy; Acoustic
• Document Type: Other
• Language: English
• Contributor(s): Universidade do Minho

Description

The work presented here is dedicated to the mapping and modeling of the transmission profiles of optical and mechanical stimuli in the brain, with the ultimate goal of optimizing transcranial stimulation techniques for the treatment of neurological and psychiatric disorders. The presentation highlights the methodology used for acoustic transmission studies in brain tissues. A specialized device was developed for these studies, designed to fit the head, consisting of acoustic actuators and a receiver. Both the actuators and the receiver are made from a piezoelectric material, which can convert mechanical deformation into electrical signals and vice versa. This material enables the emission and reception of sound frequencies within a defined range. The receiver, a hydrophone, mounted on a metallic rod and piezoelectric material results in a sensor that converts acoustic signals into measurable data. The device is adaptable to both cadaveric and phantom head models, ensuring flexibility in testing environments. Additionally, an electronic system was developed to control the emission and reception of acoustic signals gathered by the hydrophone. This system operates within a therapeutic window defined by clinical data, enhancing its practical application. The hydrophone development process began with virtual testing using simulations in COMSOL software, optimizing the design to ensure effective signal transmission through brain tissues. Afterward, a physical model was constructed and tested on phantom models, followed by tests using animal tissues. The conception of the set-up for the transmission and mapping studies further involved creating a complete system that includes the actuator, receiver, and electronic control unit, which was previously tested and validated across animal and calibrated phantom, aiming at ultimately enabling precise measurements in human cadaveric models. Parallel to this, a similar approach was applied to optical stimulus studies, reflecting the significance of integrating both optical and ultrasonic stimuli in this research.