Research on the Modulation Method of Transcranial Focused Ultrasound based on Multi-array Transducer

Transcranial focused ultrasound (tFUS) has become one of the powerful tools for neuromodulation with its advantages of non-invasive, non-toxic side effects and rapid treatment. However, inappropriate array excitation parameters can lead to problems such as cranial scalding, focal energy deficiency and focal area scattering, and even treatment failure. In this study, a numerical simulation model of tFUS is established based on a multi-array transducer and volunteer cranial data. Then a new modulation method is proposed for the phase and amplitude of the excitation signal of each array, and a compensation algorithm is proposed for the structural differences of the cranium. Compared with the self-focusing method that relies only on the geometric structure and the currently used phase and amplitude modulation methods, the method proposed in this study resulted in 27% and 6% reduction in sound pressure at the skull, 73% and 10% increase in focal acoustic pressure, 85% and 29% reduction in focal area, and 99% and 87% reduction in parafocal, respectively. The method proposed in this study can achieve a substantial increase in focal acoustic pressure while reducing energy at the skull, which will help to enhance the safety and effectiveness of tFUS and further enhance its application in neuromodulation and therapy.