Non-Invasive Transcutaneous Auricular Vagus Nerve Stimulation Applied at Different Durations in Healthy Adults

NCT07532005 | Not Yet Recruiting

• 1 other identifier: TAVNS5
• Study Type: interventional
• Target: 44
• Locations: 1 country
• Sites: 1

Brief Summary

This randomized, participant-blinded, sham-controlled interventional study aims to compare the acute effects of non-invasive transcutaneous auricular vagus nerve stimulation (taVNS) applied at different durations on autonomic nervous system responses in healthy adults. Participants will be assigned to either an active taVNS group or a sham stimulation group. Within each group, participants will complete three separate study visits in which stimulation will be applied for 5, 10, and 15 minutes in randomized order, with 48- to 72-hour washout intervals between visits. Heart rate variability, heart rate, blood pressure, respiratory rate, and subjective discomfort will be assessed immediately before and after each intervention session. The study is designed to determine whether the acute autonomic effects of taVNS vary according to stimulation duration and whether a duration-related response pattern can be identified.

Conditions

Healthy Volunteers

Keywords

Transcutaneous Auricular Vagus Nerve Stimulation; Sham Stimulation; Autonomic Nervous System

Outcome Measures

Primary Outcomes (2)

• Change in RMSSD

  Change in the root mean square of successive differences (RMSSD), derived from RR interval recordings, from pre-intervention (T0) to post-intervention (T1) after active taVNS or sham stimulation at 5, 10, and 15 minutes.

  [Time Frame: Baseline (pre-intervention) and immediately after intervention, at each study visit (5, 10, and 15 minutes)]

• Change in high-frequency heart rate variability (HF-HRV)

  Change in high-frequency heart rate variability (HF-HRV) from pre-intervention (T0) to post-intervention (T1) after active taVNS or sham stimulation at 5, 10, and 15 minutes.

  [Time Frame: Baseline (pre-intervention) and immediately after intervention, at each study visit (5, 10, and 15 minutes)]

Secondary Outcomes (7)

• Change in heart rate

  [Time Frame: Baseline (pre-intervention) and immediately after intervention, at each study visit (5, 10, and 15 minutes)]

• Change in systolic blood pressure

  [Time Frame: Baseline (pre-intervention) and immediately after intervention, at each study visit (5, 10, and 15 minutes)]

• Change in diastolic blood pressure

  [Time Frame: Baseline (pre-intervention) and immediately after intervention, at each study visit (5, 10, and 15 minutes)]

• Change in respiratory rate

  [Time Frame: Baseline (pre-intervention) and immediately after intervention, at each study visit (5, 10, and 15 minutes)]

• Change in subjective discomfort assessed by visual analog scale (VAS)

  [Time Frame: Baseline (pre-intervention) and immediately after intervention, at each study visit (5, 10, and 15 minutes)]

Study Arms (2)

Active taVNS

EXPERIMENTAL

Participants assigned to this arm will receive active transcutaneous auricular vagus nerve stimulation during three separate study visits. Stimulation will be applied for 5, 10, and 15 minutes in randomized order, with 48- to 72-hour washout intervals between visits.

Device: Active taVNS

Sham stimulation

SHAM COMPARATOR

Participants assigned to this arm will receive sham stimulation during three separate study visits. Sham stimulation will be applied for 5, 10, and 15 minutes in randomized order, with 48- to 72-hour washout intervals between visits.

Device: Sham stimulation

Interventions

Active taVNS DEVICE

Active transcutaneous auricular vagus nerve stimulation will be applied bilaterally to the cymba conchae region. Stimulation frequency will be 25 Hz, pulse width 200 to 300 microseconds, and intensity will be individually adjusted to a clearly perceptible but comfortable level. Depending on the study visit, stimulation will be delivered for 5, 10, or 15 minutes.

Active taVNS

Sham stimulation DEVICE

Sham stimulation will be delivered using the same device under visually similar conditions. The sham procedure will be applied at a non-vagal auricular site or with minimal non-therapeutic stimulation, depending on the study protocol, for 5, 10, or 15 minutes according to the study visit.

Sham stimulation

Eligibility Criteria

• Age: 18 Years - 40 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Healthy adults aged 18 to 40 years No known chronic systemic disease Non-smoker No regular medication use, including medications that may affect autonomic or cardiovascular function Able to understand the study procedures and provide written informed consent Willing to comply with study instructions and restrictions related to caffeine, alcohol, and strenuous exercise

You may not qualify if:

• Any known chronic systemic disease Current smoker Regular medication use, including medications that may affect autonomic or cardiovascular function Inability to understand the study procedures or provide written informed consent Unwillingness or inability to comply with study instructions and restrictions related to caffeine, alcohol, and strenuous exercise

Sponsors & Collaborators

• Sinop University: lead

Study Sites (1)

Artvin Coruh University, Artvin Vocational School, Disabled Care and Rehabilitation Laboratory

Artvin, Turkey (Türkiye)

Location

Related Publications (3)

• Frangos E, Ellrich J, Komisaruk BR. Non-invasive access to the vagus nerve central projections via electrical stimulation of the external ear. Brain Stimulation. 2015;8(3):624-636. doi:10.1016/j.brs.2014.11.018

  BACKGROUND

• Farmer AD, Strzelczyk A, Finisguerra A, et al. International consensus based review and recommendations for minimum reporting standards in transcutaneous vagus nerve stimulation research. Front Hum Neurosci. 2021;14:568051. doi:10.3389/fnhum.2020.568051

  BACKGROUND

• Clancy JA, Mary DASG, Witte KKA, Greenwood JP, Deuchars SA, Deuchars J. Non-invasive vagus nerve stimulation in healthy humans reduces sympathetic nerve activity. Brain Stimulation. 2014;7(6):871-877. doi:10.1016/j.brs.2014.07.031

  BACKGROUND

Central Study Contacts

Sefa Haktan Hatık Assistant professor, PhD

CONTACT

+90 368 271 55 28; haktanhtk@gmail.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Masking Details: Participants will be blinded to whether they are assigned to active taVNS or sham stimulation. Investigators and care providers cannot be blinded because of the technical requirements of device setup and application.
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Assistant Professor

Model Details: Participants will be randomized to either an active taVNS group or a sham stimulation group and will remain in their assigned group throughout the study. Within each group, participants will complete three separate visits with stimulation durations of 5, 10, and 15 minutes in randomized order, with 48- to 72-hour washout intervals between visits.

Study Record Dates

• First Submitted: April 6, 2026
• First Posted: April 15, 2026
• Study Start: May 1, 2026
• Primary Completion (Estimated): August 31, 2026
• Study Completion (Estimated): September 15, 2026
• Last Updated: April 15, 2026

Record last verified: 2026-04

Data Sharing

• IPD Sharing: Will not share

Locations

TU (1)