Vagus nerve stimulation (VNS) has been increasingly used in the treatment of several health conditions. These include treatment-resistant epilepsy, obesity, pain, and incontinence. One of the main obstacles in VNS is the lack of stimulation selectivity when it comes to only activating vagus nerve fibres that produce a desired effect while avoiding activation of non-targeted fibres, the latter of which could lead to serious side effects. Moreover, fibre type-selectivity alone cannot always provide adequate control of VNS effects. In this case, spatially selective VNS would need to be deployed. Focused ultrasound stimulation (FUS) is promising for this application, because of its potential to target neuronal structures non-invasively with millimeter resolution and with fibre-type specificity.  The inherent focusing ability of ultrasound also simplifies the stimulator design compared to electrical stimulation. 

The goal of this PhD research is to design a FUS system for spatially selective activation of the vagus nerve.  This PhD project includes fundamental and applied research including simulations of FUS biophysics and validation in experimental in-vitro/in-vivo setups, aiming to improve our understanding of the underlying mechanisms of FUS for VNS.