Noninvasive vagal nerve stimulation (n-VNS) devices have the potential for widespread applicability in improving the well-being of patients with stress-related psychiatric disorders. n-VNS devices are known to affect physiological signals and, recently, they have been employed in various protocols involving both acute and longitudinal applications. However, questions regarding response time, “dosage,” or optimal treatment paradigms remain open. Prior work evaluated noninvasively obtained biomarkers that quantify the stimulation efficacy based on the changes in autonomic tone in a randomized double-blind study. In this work, we extend the state-of-the-art by investigating the onset of action for n-VNS in these same physiological biomarkers through a three-day clinical trial, including 233 administrations on 24 human participants, with and without immediately preceding acute traumatic stress. Determining n-VNS latency serves as a substantial step toward optimizing stimulation delivery with higher temporal resolution for personalized neuromodulation.

Learning Objective: After participating in this session, the learner should be better able to:
- Understand the current issues related to clinical study design using implanted and noninvasive vagal nerve stimulation devices, including difficulties in optimized delivery, “dosage” recommendations, and patient adherence, and should be able to discuss 1) how stimulation timing affects the outcomes 2) the stimulation timing should be tailored according to the protocol.
- Learn that multiple sensing modalities are required to determine the autonomic effects of neuromodulation.
- Analyze these real-time sensing modalities for the quantification of stimulation effects and evaluate the variations observed in these signals.
- Adopt approaches to use wearable sensing modalities for studies in which noninvasive vagal nerve stimulation devices are used for protocols that study mental stress or stress-related psychiatric disorders.


Nil Gurel (Presenter)
Georgia Institute of Technology

Asim Gazi, Georgia Institute of Technology
Kristine Scott, Georgia Institute of Technology
Matthew Wittbrodt, Emory University School of Medicine
Amit Shah, Rollins School of Public Health, Emory University
Viola Vaccarino, Rollins School of Public Health, Emory University
Douglas Bremner, Emory University School of Medicine
Omer Inan, Georgia Institute of Technology

Presentation Materials: