Enhancing Safety and Efficacy in Temporal Interference Brain Stimulation Through Ramp Parameter Optimization and Custom Current Stimulator Development

Temporal Interference Brain Stimulation (TIBS) is a promising noninvasive technique for deep brain stimulation. This study focuses on developing a custom-designed TIBS current stimulator and investigates the impact of ramp parameters on stimulation efficacy and neural responses. A finite element model (FEM) was utilized to refine electrode placement, ensuring precise targeting of the CA2 region. The spatial precision of TIBS was validated through immunohistochemical analysis of c-fos expression. Furthermore, we systematically analyzed the effects of ramp time on neural activation using Fiber Photometry in transgenic mice expressing GCaMP-6s. The results indicate that insufficient ramp time leads to excessive neural excitation due to the low-frequency components of the ramp waveform within the enveloped wave, inducing unintended autonomic responses. A comparison of smooth and steep ramp profiles shows that a smooth ramp facilitates gradual adaptation, reducing unwanted neural activation and enhancing stimulation tolerance. These findings provide crucial insights into optimizing ramp parameters for improving the safety and efficacy of TIBS, contributing to its potential for clinical applications.Clinical Relevance-This study provides insights into optimizing ramp time in temporal interference brain stimulation, which is crucial for minimizing unintended neural activation and improving stimulation safety in noninvasive neuromodulation therapies.