Dissertations and Theses

Date of Award

2024

Document Type

Thesis

Department

Biomedical Engineering

First Advisor

Jacek P. Dmochowski

Keywords

Transcranial Focused Ultrasound, Neuromodulation, BOLD fMRI, Neuro-navigation, Acoustic Pressure Calibration, sgACC Stimulation

Abstract

This thesis presents the development, calibration, and initial implementation of transcranial focused ultrasound (tFUS) for neuromodulation in a human study. The primary objectives were to design a system capable of delivering precise and safe ultrasound stimulation to targeted brain regions and to conduct preliminary trials to assess its effects on brain activity. A custom calibration device was developed to ensure accurate measurement of acoustic pressure, addressing challenges such as voltage alterations caused by changes in system impedance. Additionally, a neuro-navigation tool was created to facilitate precise targeting of the right subgenual anterior cingulate cortex (right sgACC), enabling accurate placement of the ultrasound transducer based on individual anatomical data. Preliminary human trials were conducted with parameters chosen to balance efficacy and safety, adhering to established guidelines. The results demonstrated that tFUS could modulate brain activity, as indicated by changes in BOLD fMRI signals during and after stimulation. While the study's sample size and focus on a single brain region limit the generalizability of the findings, the research establishes a strong foundation for future studies. These should explore the long-term effects of tFUS, its application to different brain regions, and its integration with other neuromodulation techniques.

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