Localization of ultrasound waveform for low intensity ultrasound-induced neuromodulation in a mouse model.

A collimator design was investigated to localize ultrasound stimulation using a flat ultrasound transducer for ultrasound-induced neuromodulation in a mouse model. In brain stimulation, the specific location of stimulation must be specified, as the region responsible for motor or sensory function is clustered in a narrow brain area. To localize ultrasound stimulation, three types of collimator design were simulated to determine the optimal collimator design. The performance of the simulated optimal collimator was compared to that of an unmounted collimator in a transducer in both in vivo and in vitro experiments. Throughout the experiments, the localized ultrasound waveform was shaped using the optimized collimator, which elicited neural spike activity in the targeted motor cortex. The optimized collimator shows potential for controlling a localized ultrasound waveform for ultrasound-induced neuromodulation in a small animal model.