Schlieren visualization of focused ultrasound beam steering for spatially specific stimulation of the vagus nerve

Abstract

such an invasive technique can be safely used for human vagus nerve stimulation in the long run.

PMUT and CMUT Devices for Biomedical Applications: A Review

“…Ultrasound neurostimulation is used non-invasively [110] for stimulating the brain, peripheral nervous system [117]- [119], [129], and retina [130]. Administering ultrasound via implantable devices is also being investigated as a means to increase the spatial selectivity in peripheral nerve neuromodulation [114], [115], [131]. On the other hand, HIFU can be administered externally or with minimal invasion, such as through body orifices, endoscopic incisions, or intravascularly via catheters [125].…”

“…In [114] and [115] a flexible CMUT array has been curved to 1 mm radius to wrap around the vagus nerve and deliver spatially specific stimulation. The CMUT array operated at 15 MHz and had a focal spot of 110 µm and 550 µm, which is only 2.1% of the cross section of the nerve [114].…”

“…The CMUT array operated at 15 MHz and had a focal spot of 110 µm and 550 µm, which is only 2.1% of the cross section of the nerve [114]. Peak negative acoustic pressures of 1.7 MPa were demonstrated while beam-steering moved the focal spot to arbitrary locations within the focal plane of the transducer array [115]. An analogous work with PZTs showed higher transmit sensitivity (S tx = 160 kPa/V) at the expense of ease of integration [131].…”