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Not yet recruiting NCT07526402

Different Frequency Applications of Transcutaneous Auricular Vagus Nerve Stimulation in Healthy Individuals

No phase Interventional Healthy Volunteers

For patients and families

In plain language

An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.

What is being studied
The protocol lists: Sham taVNS, taVNS 10 Hz, taVNS 25 Hz, taVNS 50 Hz.
Who it may be relevant to
Registry conditions: Healthy Volunteers. Basic parameters: 18 years — 40 years · All.
What needs checking
Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
Where it takes place
Turkey (Türkiye)
Next step
Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →

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Official title

Investigation of the Acute Effects of Different Frequency Applications of Transcutaneous Auricular Vagus Nerve Stimulation on Autonomic Physiological Responses in Healthy Individuals

Overview

This randomized, participant-blinded, sham-controlled crossover study aims to investigate the acute effects of different frequency applications of transcutaneous auricular vagus nerve stimulation (taVNS) on autonomic physiological responses in healthy adults. Participants will receive sham (0 Hz), 10 Hz, 25 Hz, 50 Hz, and 100 Hz taVNS in separate sessions with washout periods between visits. Heart rate variability, blood pressure, pulse rate, respiratory rate, and subjective discomfort will be assessed before and after each intervention session.

Detailed description

The vagus nerve is a major regulator of the parasympathetic branch of the autonomic nervous system. Transcutaneous auricular vagus nerve stimulation (taVNS) is a non-invasive neuromodulation technique applied to auricular regions innervated by the auricular branch of the vagus nerve. Although taVNS has been reported to modulate autonomic function, the acute physiological effects of different stimulation frequencies remain insufficiently characterized.

This study is designed as a randomized, participant-blinded, sham-controlled crossover trial in healthy adults aged 18 to 40 years. Each participant will undergo five intervention conditions in randomized order: sham (0 Hz), 10 Hz, 25 Hz, 50 Hz, and 100 Hz taVNS. Sessions will be separated by 48 to 72 hours to minimize carryover effects. Each stimulation session will last 10 minutes.

Primary autonomic outcomes will be derived from heart rate variability parameters obtained using a Polar H10 chest strap and analyzed with Kubios HRV software. Secondary physiological outcomes will include systolic and diastolic blood pressure, pulse rate, respiratory rate, and subjective discomfort measured using a visual analog scale. The study aims to identify frequency-specific autonomic response profiles and to evaluate whether respiratory rate influences heart rate variability changes associated with taVNS.

Interventions

  • Device Sham taVNS
    Sham stimulation is delivered under conditions similar to active taVNS without meaningful vagal stimulation.
  • Device taVNS 10 Hz
    Active transcutaneous auricular vagus nerve stimulation applied for 10 minutes at 10 Hz.
  • Device taVNS 25 Hz
    Active transcutaneous auricular vagus nerve stimulation applied for 10 minutes at 25 Hz.
  • Device taVNS 50 Hz
    Active transcutaneous auricular vagus nerve stimulation applied for 10 minutes at 50 Hz.
  • Device taVNS 100 Hz
    Active transcutaneous auricular vagus nerve stimulation applied for 10 minutes at 100 Hz.

Primary outcome measures

  • Change in Root Mean Square of Successive Differences (RMSSD) [Time frame: Immediately before and immediately after each 10-minute intervention session]
  • Change in High-Frequency Heart Rate Variability (HF-HRV) [Time frame: Immediately before and immediately after each 10-minute intervention session]
Secondary outcome measures (8)
  • Change in Standard Deviation of Normal-to-Normal RR Intervals (SDNN) [Time frame: Immediately before and immediately after each 10-minute intervention session]
  • Change in Low-Frequency (LF) Power [Time frame: Immediately before and immediately after each 10-minute intervention session]
  • Change in LF/HF Ratio [Time frame: Immediately before and immediately after each 10-minute intervention session]
  • Change in Systolic Blood Pressure [Time frame: Immediately before and immediately after each 10-minute intervention session]
  • Change in Diastolic Blood Pressure [Time frame: Immediately before and immediately after each 10-minute intervention session]
  • Change in Pulse Rate [Time frame: Immediately before and immediately after each 10-minute intervention session]
  • Change in Respiratory Rate [Time frame: Immediately before and immediately after each 10-minute intervention session]
  • Change in Subjective Discomfort Assessed by Visual Analog Scale (VAS) [Time frame: Immediately before and immediately after each 10-minute intervention session]

Eligibility criteria

Inclusion criteria

  • Healthy adults aged 18 to 40 years
  • No known neurological, cardiovascular, respiratory, or metabolic disease
  • Able to understand study procedures and provide written informed consent
  • No active infection, open wound, or dermatological lesion in the ear region that would interfere with taVNS application
  • Willing and able to attend all study visits

Exclusion criteria

  • History of cardiac arrhythmia, pacemaker, or any implanted electronic medical device History of hypertension, diabetes, chronic pulmonary disease, epilepsy, or systemic disease affecting autonomic nervous system function
  • Regular use of medications that may affect autonomic function (e.g., beta-blockers, antidepressants, antiarrhythmics)
  • Intense physical exercise within the previous 24 hours
  • High caffeine or alcohol intake within 12 hours prior to assessment
  • Active smoking on the assessment day
  • Pregnancy or suspected pregnancy
  • Severe discomfort during stimulation (VAS >= 7), dizziness, nausea, or unwillingness to continue
  • Any condition judged by the investigators to make participation unsuitable'

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Allocation
Randomized
Model
Crossover
Masking
Single blind
Primary purpose
Basic science

Study locations

Turkey (Türkiye) · 1 center
  • Artvin Coruh University, Artvin Vocational School, Disabled Care and Rehabilitation Labora — Artvin

Publications

  • Shaffer F, Ginsberg JP. An Overview of Heart Rate Variability Metrics and Norms. Front Public Health. 2017 Sep 28;5:258. doi: 10.3389/fpubh.2017.00258. eCollection 2017. PMID 29034226
  • Yakunina N, Kim SS, Nam EC. Optimization of Transcutaneous Vagus Nerve Stimulation Using Functional MRI. Neuromodulation. 2017 Apr;20(3):290-300. doi: 10.1111/ner.12541. Epub 2016 Nov 29. PMID 27898202
  • Peuker ET, Filler TJ. The nerve supply of the human auricle. Clin Anat. 2002 Jan;15(1):35-7. doi: 10.1002/ca.1089. PMID 11835542
  • Frangos E, Ellrich J, Komisaruk BR. Non-invasive Access to the Vagus Nerve Central Projections via Electrical Stimulation of the External Ear: fMRI Evidence in Humans. Brain Stimul. 2015 May-Jun;8(3):624-36. doi: 10.1016/j.brs.2014.11.018. Epub 2014 Dec 6. PMID 25573069

Identifiers

NCT: NCT07526402 · TAVNS4

Primary sources (government registries)

View this study on ClinicalTrials.gov ↗