Multi-Point Temporal Interference Stimulation by Using Each Electrode to Carry Different Frequency Currents

Recently, a novel technology for noninvasive deep brain stimulation (NDBS) with temporally interfering electric fields was developed. This noninvasive technology is able to perform one-point temporal interference (TI) stimulation and stimulates the hippocampus without affecting the overlying cortex in mice. In this study, we introduce the concept of multi-point temporal interference (MTI) stimulation, which can simultaneously stimulate multiple nodes in the brain network to modulate its function. For the sake of realizing MTI stimulation, we proposed the scheme with each electrode carrying different frequency currents, which has higher usability with respect to the scheme by adding more electrode pairs. Additionally, to optimize the MTI stimulation, we selected the proper current frequencies and amplitudes, which were verified by geometrical model, magnetic resonance imaging (MRI) human head model, and tissue phantom. Finally, we tested the independence between the two stimulation points in MTI stimulation. The MTI stimulation can be generated by our method with proper parameters in geometrical model, MRI human head model, and tissue phantom. The stimulation points in MTI stimulation are all steerable, and furthermore can be controlled independently. Our results suggest that MTI stimulation can be used to simultaneously stimulate multiple target nodes of the brain network in deep brain areas noninvasively, which paves the way for the modulation of the brain in research and clinical neurobiology.