Blinding and Adverse Effects of Ultrasonic Vagus Nerve Stimulation (U-VNS)

Ultrasound stimulation of the auricular branch of the vagus nerve using the ZenBud device manufactured by NeurGear (Rochester, New York, USA), a CE-compliant over-the-ear headset. It delivers low-intensity focused ultrasound to the auricular branch of the vagus nerve through several layers of skin (centre frequency 5.3 MHz, pulse repetition rate 41 hertz, 50% duty cycle, average intensity of 1.03 MPa).

Sham device, also produced by NeurGear, which is identical in appearance to the true ZenBud device, emits the same sound and warms up slightly where the transducer sits on the skin.