Recently, a noninvasive form of VNS known as transcutaneous auricular vagus nerve stimulation (taVNS) has emerged (George 2000). Unlike surgically-implanted VNS, taVNS is an inexpensive, low-risk, easy to administer, and portable option to modulate the vagus system. taVNS is appealing as it allows for rapid translation of basic VNS research in exploring potential treatments of central and peripheral disease.
Vagus nerve stimulation (VNS) involves surgical implantation of electrodes onto the cervical branch of the vagus nerve. Electrical pulses are delivered to the vagus nerve via an implanted pulse generator (IPG) surgically implanted in the chest. VNS is currently FDA-approved for epilepsy, refractory depression, and chronic obesity and long-term safety of VNS is well established.
The optimal stimulation targets are still being explored (Badran et al 2018), however, the two most common placements are the anterior wall of the outer ear canal (tragus) and the cymba conchae. Sham stimulation may be conducted by stimulating the earlobe of the ear, an area believed to have minimal ABVN innervation. Alternatively, sham may be delivered via a passive control method in which electrodes are attached to active sites, but no stimulation is delivered. Stimulation parameters used have varied between groups, however according to the literature, stimulation is delivered in a pulsatile fashion (pulse width: 250–500 μs, frequency: 10–25 Hz) and delivered at an individualized constant current (< 5 mA).
Based on the revolutionary mini-CT platform, Soterix Medical introduces the first transcutaneous auricular vagus nerve stimulator (taVNS) specially developed for clinical (human) brain stimulation research. The system provides the necessary pulse parameter settings (frequency, train duration, inter-train interval, session duration) that allow testing commonly used protocols. With option to unlock device in as many as three different ways (code-based , time-based, ElectraRx web-based), the system provides researchers with flexibility to plan taVNS trials as they wish.
The Soterix Medical taVNS ear stimulation electrode is the first and only electrode optimized specifically for rigorous human trials. It is simple, easy-to-use, and ensures reliable stimulation. The optimal spring mechanism has been tested to ensure a comfortable and robust fit whether targeting the auditory canal (tragus), the cymba concha or any other desired electrode site.